The practical use of short rotation coppice in land restorationMark Paulson Paul Bardos Joop Harmsen Julian Wilczek Malcolm Barton and David Edwards
AbstractA potential for synergy exists between organic waste recycling biomass production and long-term risk management for contaminated land particularly where the immediate economic case for reuse of the land is marginal The possibility of income generation from waste management activities and biomass production offers scope for the regen-eration of useful and sustainable economic activity on such marginal land It also offers an alternative economic use to lsquohardrsquo redevelopment as well as a means of facilitating such redevelopment where the topography or extent of surrounding brownfield land inhibits the case for inward investment for a key site where conditions are otherwise favourable The presence of plant roots organic matter and associated biological activ-ity may play a significant role in the degradation or stabilisation of contaminants and the presence of the plant cover may also contribute to the stabilisation of the site and increase its amenity value
Key words composting containment and stabilisation land restoration Markham Willows Oostwaardhoeve recycling risk management sediment treatment short rotation coppice social and economic context waste management
INTRODUCTION
Biomass production on land is seen as an opportunity to provide non-fossil fuel energy feedstock In 2002 the UK produced 3 of its energy from renewable sources including biomass the government intends this to increase to 10 by 2010 and aspires to double this to
20 by 2020 (DTI 2003) The Netherlands aims to achieve 10 sustainable energy in 2020 (385 peta-joule) 25 petajoule has to come from biomass produc-tion (Novem 2002) Biomass production has been extensively studied (DTI 1998) and is taking place at a number of sites in the UK and elsewhere Short rotation coppice (SRC) is a development of the traditional method of woodland management and provides a con-venient and renewable source of biomass
Fast growing species of willow and poplar are grown and harvested (by coppicing) on a regular cycle to produce useable wood biomass for a range of appli-cations including bioenergy The tree is cut back to just above ground level after the first year of growth caus-ing many new shoots to develop Harvesting involves the cutting and removal of these shoots at regular (nor-mally 2ndash5 year) intervals
A limited amount of biomass production is already taking place on derelict land in the UK Frequently the materials at the surface of the sites where the biomass crops are to be planted offer poor conditions for sus-tained growth such surface materials tend to have a poor ability to provide adequate levels of plant nutri-ents poor physical properties and low pH Typically sewage sludge is used as a soil-forming material prior to planting and liquid sludge may be added as a source
Received March 2003 accepted June 2003
AuthorsMark Paulson Coppice Resources Ltd 19 Long Meadows Everton Doncaster DN10 5BL Tel 01777 818858 Email infocoppiceresourcescouk wwwcoppiceresourcescoukPaul Bardos r3 environmental technology Ltd 4 Watton Road Ware SG12 0AA UK Email paulr3envoronmental couk wwwr3environmentalcomJoop Harmsen Alterra Wageningen University and Research Centre PO Box 47 6700AA Wageningen The Netherlands Tel 31-317-474360 Fax 31-317-419000 Email joop harmsenwurnlJulian Wilczek Future Energy Solutions Harwell Didcot OX11 0QJ UK Email julianwilczekaeatcouk wwwfuture-energy-solutionscoukMalcolm Barton IBIS Consulting lsquoWindhoverrsquo Buildwas Lane Little Wenlock TF6 5AZ UK Email bartonwenlocku-netcomDavid Edwards Exsite Research Ltd Hillcrest Main Street Hillam Leeds LS25 5HG UK E-mail Exsitebtinternetcom
324
Land Contamination amp Reclamation Volume 11 Number 3 2003
of water and nutrients during cultivation1 Initial hopes of a contaminated land risk management benefit from biomass production on contaminated sites were centred on the accumulation of contaminants within biomass with removal of contaminants taking place at harvest However it is by no means certain that any such metal removal would be complete nor how long such removal might take It is also possible that the environ-mental lsquocostsrsquo of using metal loaded biomass (eg as a fuel) outweigh the environmental advantages of the partial removal of metals from the contaminated site (Bardos et al 2001)
The greatest potential risk management benefit of biomass production on large contaminated sites is likely to be the containment of contaminant spread and the longer term phyto-stabilisation of both organic and inorganic contaminants (ie pathway interruption) Therefore biomass crops should be selected that exclude rather than accumulate contaminants to avoid the spread of contamination and facilitate the unhin-dered use of harvested biomass materials
In many areas in Europe large areas of land around former centres of the mining industry have been left essentially undeveloped following the demise of that industry in each particular area Efforts have been made to facilitate regeneration of economic activity and also to provide some improvement of the landscape In the UK many areas of mining dereliction (former mining areas) have received limited landscaping works and have been grassed over Responsibility for long-term maintenance of such sites tends to fall on the local authorities and poses an economic burden in areas where incomes are already low However the use of biomass production as a remediation technique partic-ularly in tandem with green waste recycling has the potential to provide a more sustainable land manage-ment approach in economic terms provide a greater impetus to local communities and support a long-term solution to the environmental problems posed by the former use of the land and also local organic waste management Social and economic benefits in a well managed project of this nature can include
bull engendering wider community involvement and ownership from planning through to implementa-tion leading to greater sustainability of the site
bull developing local training and job creation opportu-nities in new lsquogreen-collarrsquo industries
bull supporting inward investment of environmental technology businesses
bull encouraging wider academic involvement that will monitor the site and assess the success of its various
elements thus validating the results and providing wider dissemination as well as providing an excel-lent learning opportunity for a wide range of stu-dents from biochemists to social scientists
bull developing sites for local amenity use and lsquogreen tourismrsquo potential
bull developing a programme of actions that seeks to protect any important existing site ecology and widen the biodiversity of the site by encouraging the development of habitats that are suitable for the introduction or attraction of rare flora and fauna
This paper reviews the use of biomass on marginal land and introduces a major UK initiative Markham Willows which is perhaps the first project that is spe-cifically being planned to maximise the social and eco-nomic as well as the environmental benefits of biomass production on marginal land along with a case study of SRC use for sediment treatment
Biomass production on marginal land offers a sys-tem by which income is generated from contaminated land without the need for a restoration period where the land is not in use This has a beneficial effect on the economics and in particular cash flow thus making the economics of both the restoration and the development of a commercial crop highly favourable In the Nether-lands SRC is also seen as an opportunity for the reuse and remediation of sediments which are a major lsquowastersquo arising by volume there In the Netherlands large amounts of sediments are collected from dredg-ing inland waterways and harbours Often these sedi-ments are polluted and remediation approaches such as land-farming can be very time consuming (Harmsen et al 1997) Long treatment times imply a requirement for large treatment areas over a long period (Harmsen 2001 Sims and Harmsen 2001) These treatment areas can be put to productive use if SRC is included in the sediment management regime (Breteler et al 2001)
THE USE OF SHORT ROTATION COPPICE IN CONTAMINATED LAND RISK MANAGEMENT
Risk assessment provides an objective technical evalu-ation of the likelihood of unacceptable impacts to human health and the environment Considerations of risk are also used to decide which problems need to be dealt with most urgently This process of decision mak-ing and its consequent actions are called risk manage-ment and form the basis of contaminated land policy in most countries (Ferguson et al 1998 Ferguson and Kasamas 1999)
Phytoremediation is the direct use of living green plants for in situ risk management of contaminated soil
1 Unpublished findings by Coppice Resources Limited and Severn Trent Water 1997
325
The practical use of short rotation coppice in land restoration
sludges sediments and groundwater through contami-nant removal degradation or containment An added advantage of phytoremediation is that it re-establishes a vegetative cover at sites where natural vegetation is lacking due to high metal concentrations in surface soils or physical disturbances in superficial materials Metal-tolerant species can be used to restore vegetation to sites thereby decreasing the potential migration of contamination through wind erosion transport of exposed surface soils and leaching of soil contamina-tion to groundwater (US EPA 1999 2000)
Plants may affect or effect remediation in a number of ways including
bull encouraging degradation activity by commensal organisms (eg pseudomonads) and symbiotic organisms (eg mycorrhizal fungi rhizobia) encouraging activity of parasiticpathogenic organ-isms (eg rot fungi) or by directly affecting the soil environment for microorganisms in their immediate vicinity (eg changing pH redox pCO2 nutrient availability)
bull maintaining a good and improving aerobic struc-ture necessary for biodegradation of organic con-taminants
bull the sorption andor possible translocation of con-taminants (eg accumulation of metals or for organic compounds their metabolism or release to the atmosphere)
bull the mobilisationimmobilisation of contaminants (eg via production of organic ligands for heavy metals changing pH redox potential etc at soil surfaces)
ndash by containing contamination by breaking pathways for example preventing the ingress of water and preventing direct contact partic-ularly as soil horizons develop
ndash evapo-transpiration reducing or even prevent-ing leaching of water
There are several possibilities for positive effects on in situ biodegradation by plants (Anderson and Coats 1994)
bull optimising conditions for bio-degradation by indig-enous soil microorganisms
bull providing stable habitats for introduced organisms or consortia with specific decontamination activi-ties where they may be preserved from competition with or predation by indigenous organisms pro-tected from deleterious environmental factors and supplied with nutrients water and oxygen
Plants may accumulate heavy metals from soils and water The extent of this accumulation depends on the
plant species and soil and contaminant type For many plant species this accumulation process is passive The removal of heavy metals from soils in agricultural crops will gradually reduce soil heavy metal levels in the absence of fresh inputs However for some plants accumulation of metals appears to be an active process possibly related to a tolerance mechanism for their sur-vival on contaminated sites and these plants are referred to as lsquohyper accumulatorsrsquo to distinguish the nature of their metal accumulation from the passive accumulation that is general for plants and typically does not lead to such high leaf concentrations of metals (Baker et al 1994 Baker and Brooks 1989 Japenga 1999) SRC species are typically not hyper accumula-tors although some clones may have higher metal uptakes than others There has been much recent research into the ability of SRC species to take up heavy metals and thus decontaminate land affected by elevated concentrations of these contaminants (eg Riddell-Black 1994 Riddell-Black et al 1997 Pun-shon and Dickinson 1997) Most has focused on vari-ous clones of Salix spp (willow) It is clear that there is considerable variation in the ability of these clones to take up metals and in the metal species which exhibit most movement into the plant For example cadmium and zinc seem to be taken up more than lead nickel and chromium (Labreque et al 1994 Riddell-Black 1994 Oumlstmann 1994 Riddell-Black et al 1997) In addition different metals show different behaviours with respect to their zones of accumulation whether in roots or shoots In practice while some attempts have been made to demonstrate the use of SRC for heavy metal removal from contaminated ground the approach is in reality an emerging concept so far as technical imple-mentation is concerned (Bardos et al 2001) and the technique is open to question on sustainability and risk management grounds as well as practicability
Risk management would need to consider both the effects of the remedial process and the long-term man-agement of risks posed by the condition of the site eg
bull preparation of the site for its conversion to SRCbull working on site in the SRC plantationbull uptake of contaminants into the wood product and
their eventual destinationbull contaminants in the ground the fibrous and shallow
rooting habit of SRC limits its ability to remediate by accumulation
bull use of the site for amenity considering the effects of risks to children who are more vulnerable than adults have a lower awareness of hazards and are higher risk-takers
Regulators are likely to have practical concerns such as which contaminants are likely to be mobilised
326
Land Contamination amp Reclamation Volume 11 Number 3 2003
by the short rotation coppice and what would be their fate The presence of some heavy metals in the biomass may reduce the range of its available end-uses For example the presence of volatile mercury or cadmium would require strict emissions control for combustion processes to avoid potential atmospheric pollution by contaminated particulate matter In addition the fly ash (ash collected from the flue gases) may be contami-nated and would be subject to controls on its disposal Additional controls or restrictions may be required to protect the environment from contamination by incin-erator ash (ash collected in the combustion unit also known as bottom ash) with a high non-volatile metal content (handling and disposal controls required) or dispersal of fly ash (controls on emissions to the atmos-phere required) It could be argued that if the incinera-tor ash is recycled to the SRC site as potash there is no net change in the sitersquos heavy metal content so that the site is stabilised rather than remediated ndash under this scenario there would be no concerns over off-site dis-posal to licensed landfill However this does not com-ply with best practice in contaminated site management since deposition of ash containing heavy metals does not remove identified risk nor does it have an environ-mental benefit In addition it could be viewed as a redeposition of waste by the regulatory bodies It is unlikely that this would be considered best practice by the regulator and may cause the site to come under landfill controls
Plants may accumulate organic compounds through the root system or via foliar uptake (Ryan et al 1988 Paterson et al 1990) This accumulation varies greatly depending on plant species and contaminant and soil type In general the more hydrophobic a contaminant the more likely it is to remain sorbed to roots (bound to cellular lipids) or soil organic matter More soluble compounds may be translocated to the leaves and in some cases these compounds may be degraded by the plant or lost from the leaves by volatilisation The abil-ity of SRC species to stabilise land affected by organic contaminants is being researched The greatest success has been with hybrid poplars which demonstrate uptake and degradation of organic pollutants such as trichloroethylene (TCE) or dioxane from contaminated sites (Schnoor et al 1995 Aitchison et al 1997 Sytsma et al 1997)
Phytostabilisation is the use of certain plant species to immobilise contaminants in the soil and groundwa-ter through absorption and accumulation by roots adsorption onto roots or precipitation within the root zone It also can describe a broader approach to using the growth of plants to break pollutant linkages for example by plant effects on soil water management or prevention of dust blows These processes reduce the
mobility of contamination and prevent migration to the groundwater or air and reduce contaminant availability to the food chain It has been known for many years that organic material in soils can complex heavy met-als reducing their availability to plants and other organisms (see section 6 below)
The revegetation of contaminated sites for example for biomass production may have further beneficial effects in limiting the migration of contaminants from the contaminated area and limiting their availability through immobilisation in roots systems and added or newly generated soil organic matter Successful reveg-etation may also enhance soil microbial activity in turn enhancing processes of in situ biodegradation for some contaminants The addition of organic matter such as waste derived compost to soils may also promote both microbial biodegradation of contaminants and the fixa-tion of some contaminants such as PAHs into humic materials (Kraatz et al 1993 Lotter et al 1993 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promoting abiotic processes of contam-inant degradation for some organic compounds and in co-metabolic degradations of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989)
While the fibrous and shallow rooting habit of SRC limits its ability to remediate by accumulation it is potentially an enormous asset for remediation of con-taminated land by containment and stabilisation The Markham Willows project in the UK (described below) is examining an approach of combining SRC cultiva-tion with organic matter applications to generate a new soil horizon over mine spoil Its working premise for risk management is that the expanding soil horizon would gradually move the rooting zone away from the old mine spoil and the organic matter content of the lower layers of the new soil would help stabilise pH and eH as well as sorb any upwardly migrating con-tamination In this scenario risk management is effected by interrupting pathways rather than removing the source term The SRC would also quickly prevent direct contact on site or from dust blow and also pro-vide physical stabilisation for the site
SRC FOR LAND REMEDIATION
Types of SRC speciesThere is a range of tree species and clones suitable for SRC production Extensive research has been carried out to screen species and clones for different site condi-tions such as nutrient and water availability and other environmental factors such as disease suppression The selection of clones to plant on a contaminated site
327
The practical use of short rotation coppice in land restoration
should take account of the following factors
bull Site characteristics ndash A comprehensive site investi-gation should always be undertaken to reveal the nature of the substrate ie soil chemistry nutrient content hydrology of the area the type and extent of metal loading Clonal selection should always be based on suitability for site conditions
bull Yield ndash It is commercially important to plant clones that will maximise yields (Tabbush and Parfitt 1999) to maximise the potential for income genera-tion and hence resources for site management
bull Mixing clones ndash The planting of monoclonal plots of SRC is considered unwise owing to the possible spread of certain species-specific diseases such as rust By planting a genetically diverse mix the risk of the spread of disease in a large scale coppice is minimised (Tabbush and Parfitt 1999)
bull Metal uptake ndash Different clones take up different metals at different rates from the substrate Some clones accumulate metals with considerable detri-ment to their yield whereas other clones are more tolerant of contamination (Riddell-Black et al1997)
bull Harvesting ndash Mechanical harvesting must be possi-ble which limits the shape of the clone
The yield of biomass from SRC depends on envi-ronmental and climatic conditions throughout the growing season When biomass is grown on contami-nated or restored land the situation is complex so yield calculations can vary widely Careful management based on a sound site appraisal can produce commer-cially viable yields For example SRC on ex-agricul-tural land can produce as much as 17 odt per ha1 Even a crop on a well reclaimed site can produce 10 odt per ha or more (Birse British Biogen personal communi-cation) if well managed On contaminated sites yields can be limited by contamination such as heavy metals pyrites or organic compounds however treatment by the addition of organic matter and selection of clones tolerant to the type of contamination present may over-come problems arising from contamination
Site preparationSite preparation begins with site investigation work both to assess the risk management needs of the site (Armstrong 1999) and the cultivation requirements of the SRC crop Site preparation is the single most important factor in establishing a good SRC crop (Anon 1996) Levels of preparation will vary consider-ably depending on the nature and condition of the site
so that some sites (for example a site with a compacted soil or with very low pH soil) will require more inten-sive preparation methods than others
Topographysite conditionLandforming ie altering the sub-surface structure and shape of the land should be considered ndash not only to allow minimum standards for vegetation growth but also from safety and landscaping aspects (Forestry Commission 1995) For example if the site has been used for mineral extraction then radical re-shaping of the site will usually be required to ensure that any phys-ical dangers are removed so that it is suitable for SRC growing and to improve the visual appearance of the site Restoration conditions may be attached to plan-ning permission for change of use to ensure that this happens If the site is being landformed by the mineral operator then the operator will be responsible for fund-ing the restoration ndash early consultation with the opera-tor is advised to ensure that the site is returned to a landform suitable for SRC production Flatter ground is preferable for harvesting operations but some slope is acceptable so long as it does not exceed safe working limits for farm machinery or cause excessive pooling in wetter conditions Adequate planning of topography is also essential particularly when slopes are an issue and so there exists potential for physical soil erosion The roots of SRC can bind unstable soils together which can be advantageous for the management of slopes
Soil conditioningPhysical improvement to reduce compaction and the incorporation of organic matter into the site where required are important factors in achieving a commer-cially adequate yield A typical SRC crop will remain in production for 16ndash25 years and good soil condition is critical to the establishment and continued productiv-ity of the crop during this period Minimum soil requirements for planting trees on restored land and ideal conditions for SRC establishment are well-docu-mented (Moffat and McNeill 1994 Armstrong 1999) Key criteria are summarised in Table 1
The ideal conditions required for SRC are medium textured soils 100 cm depth (except perhaps in the wet-ter west of the UK where 50 cm may be acceptable) Sites should not be permanently waterlogged as har-
1 odt = oven dried tonnes This is the usual measurement of SRC yield
328
Land Contamination amp Reclamation Volume 11 Number 3 2003
vesting operations are usually carried out in winter and waterlogged sites will make plant movement difficult as well as damaging the soil
Rootable depthThirty centimetres of rootable material is usually suffi-cient for horizontal root development for willow SRC although research has shown that mature SRC planta-tions can root down to 100 cm depth If the tillable depth does not already meet these conditions then culti-vation using a 360 degree excavator should be consid-ered not only to allow sufficient root penetration but also to facilitate stone removal and allow the incorpo-ration of organic matter
AcidityIdeal conditions for SRC growth are pHs in the range 55ndash75 although 35ndash85 should be regarded as the maximum tolerable limits (Armstrong 1999) Pyrites can be problem on sites such as colliery spoil tips Oxi-dation of pyrites causes an increase in acidity which can be toxic to vegetation The recommended maxi-mum tolerable level of pyrite in soil is 05 (Moffat and McNeill 1994) Lime may be added to neutralise acidity but this is expensive and difficult to apply the precise quantities of lime used must be calculated care-fully to avoid imbalances of other essential minerals in the spoil which might restrict tree growth For example for each 1 of pyrite in a thickness of 15 cm of spoil 40 tonnes of limestone per hectare are required to neu-tralise the potential acidity (Costigan et al 1981) If the trees are expected to root to a depth of 100 cm this
means applying over 250 tonnes per hectare for each 1 of pyrite
Nutrient statusSRC requires water and light to survive In all cases one of these major factors is the limit on either presence or rate of growth Table 2 below summaries removal rates of a range of nutrients by SRC These will be drawn from lsquosoil reservesrsquo or from additions of materi-als that contain these substances
If the fertiliser input to the soil is less than the rate of removal then the soil will become drained of reserves and vice versa Sub optimal nutrient levels can be com-pensated for by the plant in the early stages of its life cycle but in general after first true harvest (typically after four years) if no additional nutrient input is made then the SRC crop will show reduced growth rates and eventually fail Table 2 also highlights the value of applying the nutrient in organic form
LayoutSRC planning needs to reflect the cultivation planting management and harvesting requirements of the crop In essence machinery is at its most vulnerable when turning across slopes and so wherever possible the safest operation is by travelling directly up and down the slope thus avoiding potential slippage and over-turning From a commercial harvesting point of view there need to be suitable breaks in the crop to allow full trailers to exit and empty ones to join without the need to travel along the rows for a great distance (thus creat-ing compaction) or having to drive across harvested
Table 1 Criteria for the use of soil-forming materials as a tree rooting substrate (from Moffat and McNeill 1994)
Soil property RequirementsBulk density lt 15 g cmndash3 to at least 50 cm depth
lt 17 g cmndash3 to 100 cm depthStoniness lt40 by volume few stones greater than 100 mmpH 35 to 85Electrical conductivity lt2000 microS cmndash1 (11 volvol soilwater suspension)Iron pyrite content lt05Heavy metal concentration As set out in site risk management plansOrganic contaminants As set out in site risk management plans
Table 2 Rates of nutrient removal by willow SRC
Tree species Age(yrs)
Stem amp branch
productiont DM handash1 yrndash1
Nutrient content in stems and brancheskg t DMndash1 kg handash1 yrndash1
The practical use of short rotation coppice in land restoration
stools (causing splitting and potential diseasefungal insertion)
CultivationCultivation is required to create a suitable medium for the SRC crop to establish and grow For the crop to reach full potential it requires an open deep tilled soil structure This is achieved by operating under dry soilland conditions This may conflict in the short term with the requirement to stabilise unstable slopes Then it is preferable to carry out the operation but to do so immediately prior to planting in order to minimise the time during which the soil is unsupported and thus at risk of erosion or slippage Seedbed preparation also offers an opportunity to apply and incorporate any additional materials such as green wastecompost and biosolids By incorporating these materials to a depth of around 200 mm a suitable growing medium can be created This technique has been demonstrated suc-cessfully in restoring sand and gravel quarries and on colliery shale where the base soil is inherently deficient in nutrient and water holding capacity
Planting of SRC is a mechanical operation A mod-ern lsquosteprsquo type planter is capable of planting 6ndash8 ha per day This requires a weed and debris free seedbed with at least 200 vertical millimetres of passable material in order to vertically plant the cutting Further additions of organic matter are possible during early crop growth and immediately after harvesting allowing more organic material to be recycled and helping build the topsoil layer
SRC harvestingHarvesting requires the use of large agricultural machinery (see Figures 3 and 4) Slope and stability are the major factors on sites such as colliery spoil while on sand and gravel quarries the emphasis is on the soilrsquos ability to support machinery (aided by the root network) and the drainage of surface waters Commer-cial machinery for harvesting has to have the ability to cut and chip lsquotreesrsquo that are 9 m tall with a stem base of 50 mm at a rate of some 60 tonnes per hour On wet sites the best way of ensuring that the crop is harvested in conditions that do not detrimentally affect the root structure (and so future growth) is to harvest during the summer months when the sites are at their driest
In general there will need to be an area for crop storage on site It is essential that this area is dry level and of hard base material to allow access for vehicles to
FIGURE 1 SRC PLANTING USING A lsquoSTEPrsquo PLANTER
FIGURE 2 A PLANTED WILLOW CUTTING AND ITS DIMENSIONS
200 mm
Ground level
20 mm
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
324
Land Contamination amp Reclamation Volume 11 Number 3 2003
of water and nutrients during cultivation1 Initial hopes of a contaminated land risk management benefit from biomass production on contaminated sites were centred on the accumulation of contaminants within biomass with removal of contaminants taking place at harvest However it is by no means certain that any such metal removal would be complete nor how long such removal might take It is also possible that the environ-mental lsquocostsrsquo of using metal loaded biomass (eg as a fuel) outweigh the environmental advantages of the partial removal of metals from the contaminated site (Bardos et al 2001)
The greatest potential risk management benefit of biomass production on large contaminated sites is likely to be the containment of contaminant spread and the longer term phyto-stabilisation of both organic and inorganic contaminants (ie pathway interruption) Therefore biomass crops should be selected that exclude rather than accumulate contaminants to avoid the spread of contamination and facilitate the unhin-dered use of harvested biomass materials
In many areas in Europe large areas of land around former centres of the mining industry have been left essentially undeveloped following the demise of that industry in each particular area Efforts have been made to facilitate regeneration of economic activity and also to provide some improvement of the landscape In the UK many areas of mining dereliction (former mining areas) have received limited landscaping works and have been grassed over Responsibility for long-term maintenance of such sites tends to fall on the local authorities and poses an economic burden in areas where incomes are already low However the use of biomass production as a remediation technique partic-ularly in tandem with green waste recycling has the potential to provide a more sustainable land manage-ment approach in economic terms provide a greater impetus to local communities and support a long-term solution to the environmental problems posed by the former use of the land and also local organic waste management Social and economic benefits in a well managed project of this nature can include
bull engendering wider community involvement and ownership from planning through to implementa-tion leading to greater sustainability of the site
bull developing local training and job creation opportu-nities in new lsquogreen-collarrsquo industries
bull supporting inward investment of environmental technology businesses
bull encouraging wider academic involvement that will monitor the site and assess the success of its various
elements thus validating the results and providing wider dissemination as well as providing an excel-lent learning opportunity for a wide range of stu-dents from biochemists to social scientists
bull developing sites for local amenity use and lsquogreen tourismrsquo potential
bull developing a programme of actions that seeks to protect any important existing site ecology and widen the biodiversity of the site by encouraging the development of habitats that are suitable for the introduction or attraction of rare flora and fauna
This paper reviews the use of biomass on marginal land and introduces a major UK initiative Markham Willows which is perhaps the first project that is spe-cifically being planned to maximise the social and eco-nomic as well as the environmental benefits of biomass production on marginal land along with a case study of SRC use for sediment treatment
Biomass production on marginal land offers a sys-tem by which income is generated from contaminated land without the need for a restoration period where the land is not in use This has a beneficial effect on the economics and in particular cash flow thus making the economics of both the restoration and the development of a commercial crop highly favourable In the Nether-lands SRC is also seen as an opportunity for the reuse and remediation of sediments which are a major lsquowastersquo arising by volume there In the Netherlands large amounts of sediments are collected from dredg-ing inland waterways and harbours Often these sedi-ments are polluted and remediation approaches such as land-farming can be very time consuming (Harmsen et al 1997) Long treatment times imply a requirement for large treatment areas over a long period (Harmsen 2001 Sims and Harmsen 2001) These treatment areas can be put to productive use if SRC is included in the sediment management regime (Breteler et al 2001)
THE USE OF SHORT ROTATION COPPICE IN CONTAMINATED LAND RISK MANAGEMENT
Risk assessment provides an objective technical evalu-ation of the likelihood of unacceptable impacts to human health and the environment Considerations of risk are also used to decide which problems need to be dealt with most urgently This process of decision mak-ing and its consequent actions are called risk manage-ment and form the basis of contaminated land policy in most countries (Ferguson et al 1998 Ferguson and Kasamas 1999)
Phytoremediation is the direct use of living green plants for in situ risk management of contaminated soil
1 Unpublished findings by Coppice Resources Limited and Severn Trent Water 1997
325
The practical use of short rotation coppice in land restoration
sludges sediments and groundwater through contami-nant removal degradation or containment An added advantage of phytoremediation is that it re-establishes a vegetative cover at sites where natural vegetation is lacking due to high metal concentrations in surface soils or physical disturbances in superficial materials Metal-tolerant species can be used to restore vegetation to sites thereby decreasing the potential migration of contamination through wind erosion transport of exposed surface soils and leaching of soil contamina-tion to groundwater (US EPA 1999 2000)
Plants may affect or effect remediation in a number of ways including
bull encouraging degradation activity by commensal organisms (eg pseudomonads) and symbiotic organisms (eg mycorrhizal fungi rhizobia) encouraging activity of parasiticpathogenic organ-isms (eg rot fungi) or by directly affecting the soil environment for microorganisms in their immediate vicinity (eg changing pH redox pCO2 nutrient availability)
bull maintaining a good and improving aerobic struc-ture necessary for biodegradation of organic con-taminants
bull the sorption andor possible translocation of con-taminants (eg accumulation of metals or for organic compounds their metabolism or release to the atmosphere)
bull the mobilisationimmobilisation of contaminants (eg via production of organic ligands for heavy metals changing pH redox potential etc at soil surfaces)
ndash by containing contamination by breaking pathways for example preventing the ingress of water and preventing direct contact partic-ularly as soil horizons develop
ndash evapo-transpiration reducing or even prevent-ing leaching of water
There are several possibilities for positive effects on in situ biodegradation by plants (Anderson and Coats 1994)
bull optimising conditions for bio-degradation by indig-enous soil microorganisms
bull providing stable habitats for introduced organisms or consortia with specific decontamination activi-ties where they may be preserved from competition with or predation by indigenous organisms pro-tected from deleterious environmental factors and supplied with nutrients water and oxygen
Plants may accumulate heavy metals from soils and water The extent of this accumulation depends on the
plant species and soil and contaminant type For many plant species this accumulation process is passive The removal of heavy metals from soils in agricultural crops will gradually reduce soil heavy metal levels in the absence of fresh inputs However for some plants accumulation of metals appears to be an active process possibly related to a tolerance mechanism for their sur-vival on contaminated sites and these plants are referred to as lsquohyper accumulatorsrsquo to distinguish the nature of their metal accumulation from the passive accumulation that is general for plants and typically does not lead to such high leaf concentrations of metals (Baker et al 1994 Baker and Brooks 1989 Japenga 1999) SRC species are typically not hyper accumula-tors although some clones may have higher metal uptakes than others There has been much recent research into the ability of SRC species to take up heavy metals and thus decontaminate land affected by elevated concentrations of these contaminants (eg Riddell-Black 1994 Riddell-Black et al 1997 Pun-shon and Dickinson 1997) Most has focused on vari-ous clones of Salix spp (willow) It is clear that there is considerable variation in the ability of these clones to take up metals and in the metal species which exhibit most movement into the plant For example cadmium and zinc seem to be taken up more than lead nickel and chromium (Labreque et al 1994 Riddell-Black 1994 Oumlstmann 1994 Riddell-Black et al 1997) In addition different metals show different behaviours with respect to their zones of accumulation whether in roots or shoots In practice while some attempts have been made to demonstrate the use of SRC for heavy metal removal from contaminated ground the approach is in reality an emerging concept so far as technical imple-mentation is concerned (Bardos et al 2001) and the technique is open to question on sustainability and risk management grounds as well as practicability
Risk management would need to consider both the effects of the remedial process and the long-term man-agement of risks posed by the condition of the site eg
bull preparation of the site for its conversion to SRCbull working on site in the SRC plantationbull uptake of contaminants into the wood product and
their eventual destinationbull contaminants in the ground the fibrous and shallow
rooting habit of SRC limits its ability to remediate by accumulation
bull use of the site for amenity considering the effects of risks to children who are more vulnerable than adults have a lower awareness of hazards and are higher risk-takers
Regulators are likely to have practical concerns such as which contaminants are likely to be mobilised
326
Land Contamination amp Reclamation Volume 11 Number 3 2003
by the short rotation coppice and what would be their fate The presence of some heavy metals in the biomass may reduce the range of its available end-uses For example the presence of volatile mercury or cadmium would require strict emissions control for combustion processes to avoid potential atmospheric pollution by contaminated particulate matter In addition the fly ash (ash collected from the flue gases) may be contami-nated and would be subject to controls on its disposal Additional controls or restrictions may be required to protect the environment from contamination by incin-erator ash (ash collected in the combustion unit also known as bottom ash) with a high non-volatile metal content (handling and disposal controls required) or dispersal of fly ash (controls on emissions to the atmos-phere required) It could be argued that if the incinera-tor ash is recycled to the SRC site as potash there is no net change in the sitersquos heavy metal content so that the site is stabilised rather than remediated ndash under this scenario there would be no concerns over off-site dis-posal to licensed landfill However this does not com-ply with best practice in contaminated site management since deposition of ash containing heavy metals does not remove identified risk nor does it have an environ-mental benefit In addition it could be viewed as a redeposition of waste by the regulatory bodies It is unlikely that this would be considered best practice by the regulator and may cause the site to come under landfill controls
Plants may accumulate organic compounds through the root system or via foliar uptake (Ryan et al 1988 Paterson et al 1990) This accumulation varies greatly depending on plant species and contaminant and soil type In general the more hydrophobic a contaminant the more likely it is to remain sorbed to roots (bound to cellular lipids) or soil organic matter More soluble compounds may be translocated to the leaves and in some cases these compounds may be degraded by the plant or lost from the leaves by volatilisation The abil-ity of SRC species to stabilise land affected by organic contaminants is being researched The greatest success has been with hybrid poplars which demonstrate uptake and degradation of organic pollutants such as trichloroethylene (TCE) or dioxane from contaminated sites (Schnoor et al 1995 Aitchison et al 1997 Sytsma et al 1997)
Phytostabilisation is the use of certain plant species to immobilise contaminants in the soil and groundwa-ter through absorption and accumulation by roots adsorption onto roots or precipitation within the root zone It also can describe a broader approach to using the growth of plants to break pollutant linkages for example by plant effects on soil water management or prevention of dust blows These processes reduce the
mobility of contamination and prevent migration to the groundwater or air and reduce contaminant availability to the food chain It has been known for many years that organic material in soils can complex heavy met-als reducing their availability to plants and other organisms (see section 6 below)
The revegetation of contaminated sites for example for biomass production may have further beneficial effects in limiting the migration of contaminants from the contaminated area and limiting their availability through immobilisation in roots systems and added or newly generated soil organic matter Successful reveg-etation may also enhance soil microbial activity in turn enhancing processes of in situ biodegradation for some contaminants The addition of organic matter such as waste derived compost to soils may also promote both microbial biodegradation of contaminants and the fixa-tion of some contaminants such as PAHs into humic materials (Kraatz et al 1993 Lotter et al 1993 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promoting abiotic processes of contam-inant degradation for some organic compounds and in co-metabolic degradations of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989)
While the fibrous and shallow rooting habit of SRC limits its ability to remediate by accumulation it is potentially an enormous asset for remediation of con-taminated land by containment and stabilisation The Markham Willows project in the UK (described below) is examining an approach of combining SRC cultiva-tion with organic matter applications to generate a new soil horizon over mine spoil Its working premise for risk management is that the expanding soil horizon would gradually move the rooting zone away from the old mine spoil and the organic matter content of the lower layers of the new soil would help stabilise pH and eH as well as sorb any upwardly migrating con-tamination In this scenario risk management is effected by interrupting pathways rather than removing the source term The SRC would also quickly prevent direct contact on site or from dust blow and also pro-vide physical stabilisation for the site
SRC FOR LAND REMEDIATION
Types of SRC speciesThere is a range of tree species and clones suitable for SRC production Extensive research has been carried out to screen species and clones for different site condi-tions such as nutrient and water availability and other environmental factors such as disease suppression The selection of clones to plant on a contaminated site
327
The practical use of short rotation coppice in land restoration
should take account of the following factors
bull Site characteristics ndash A comprehensive site investi-gation should always be undertaken to reveal the nature of the substrate ie soil chemistry nutrient content hydrology of the area the type and extent of metal loading Clonal selection should always be based on suitability for site conditions
bull Yield ndash It is commercially important to plant clones that will maximise yields (Tabbush and Parfitt 1999) to maximise the potential for income genera-tion and hence resources for site management
bull Mixing clones ndash The planting of monoclonal plots of SRC is considered unwise owing to the possible spread of certain species-specific diseases such as rust By planting a genetically diverse mix the risk of the spread of disease in a large scale coppice is minimised (Tabbush and Parfitt 1999)
bull Metal uptake ndash Different clones take up different metals at different rates from the substrate Some clones accumulate metals with considerable detri-ment to their yield whereas other clones are more tolerant of contamination (Riddell-Black et al1997)
bull Harvesting ndash Mechanical harvesting must be possi-ble which limits the shape of the clone
The yield of biomass from SRC depends on envi-ronmental and climatic conditions throughout the growing season When biomass is grown on contami-nated or restored land the situation is complex so yield calculations can vary widely Careful management based on a sound site appraisal can produce commer-cially viable yields For example SRC on ex-agricul-tural land can produce as much as 17 odt per ha1 Even a crop on a well reclaimed site can produce 10 odt per ha or more (Birse British Biogen personal communi-cation) if well managed On contaminated sites yields can be limited by contamination such as heavy metals pyrites or organic compounds however treatment by the addition of organic matter and selection of clones tolerant to the type of contamination present may over-come problems arising from contamination
Site preparationSite preparation begins with site investigation work both to assess the risk management needs of the site (Armstrong 1999) and the cultivation requirements of the SRC crop Site preparation is the single most important factor in establishing a good SRC crop (Anon 1996) Levels of preparation will vary consider-ably depending on the nature and condition of the site
so that some sites (for example a site with a compacted soil or with very low pH soil) will require more inten-sive preparation methods than others
Topographysite conditionLandforming ie altering the sub-surface structure and shape of the land should be considered ndash not only to allow minimum standards for vegetation growth but also from safety and landscaping aspects (Forestry Commission 1995) For example if the site has been used for mineral extraction then radical re-shaping of the site will usually be required to ensure that any phys-ical dangers are removed so that it is suitable for SRC growing and to improve the visual appearance of the site Restoration conditions may be attached to plan-ning permission for change of use to ensure that this happens If the site is being landformed by the mineral operator then the operator will be responsible for fund-ing the restoration ndash early consultation with the opera-tor is advised to ensure that the site is returned to a landform suitable for SRC production Flatter ground is preferable for harvesting operations but some slope is acceptable so long as it does not exceed safe working limits for farm machinery or cause excessive pooling in wetter conditions Adequate planning of topography is also essential particularly when slopes are an issue and so there exists potential for physical soil erosion The roots of SRC can bind unstable soils together which can be advantageous for the management of slopes
Soil conditioningPhysical improvement to reduce compaction and the incorporation of organic matter into the site where required are important factors in achieving a commer-cially adequate yield A typical SRC crop will remain in production for 16ndash25 years and good soil condition is critical to the establishment and continued productiv-ity of the crop during this period Minimum soil requirements for planting trees on restored land and ideal conditions for SRC establishment are well-docu-mented (Moffat and McNeill 1994 Armstrong 1999) Key criteria are summarised in Table 1
The ideal conditions required for SRC are medium textured soils 100 cm depth (except perhaps in the wet-ter west of the UK where 50 cm may be acceptable) Sites should not be permanently waterlogged as har-
1 odt = oven dried tonnes This is the usual measurement of SRC yield
328
Land Contamination amp Reclamation Volume 11 Number 3 2003
vesting operations are usually carried out in winter and waterlogged sites will make plant movement difficult as well as damaging the soil
Rootable depthThirty centimetres of rootable material is usually suffi-cient for horizontal root development for willow SRC although research has shown that mature SRC planta-tions can root down to 100 cm depth If the tillable depth does not already meet these conditions then culti-vation using a 360 degree excavator should be consid-ered not only to allow sufficient root penetration but also to facilitate stone removal and allow the incorpo-ration of organic matter
AcidityIdeal conditions for SRC growth are pHs in the range 55ndash75 although 35ndash85 should be regarded as the maximum tolerable limits (Armstrong 1999) Pyrites can be problem on sites such as colliery spoil tips Oxi-dation of pyrites causes an increase in acidity which can be toxic to vegetation The recommended maxi-mum tolerable level of pyrite in soil is 05 (Moffat and McNeill 1994) Lime may be added to neutralise acidity but this is expensive and difficult to apply the precise quantities of lime used must be calculated care-fully to avoid imbalances of other essential minerals in the spoil which might restrict tree growth For example for each 1 of pyrite in a thickness of 15 cm of spoil 40 tonnes of limestone per hectare are required to neu-tralise the potential acidity (Costigan et al 1981) If the trees are expected to root to a depth of 100 cm this
means applying over 250 tonnes per hectare for each 1 of pyrite
Nutrient statusSRC requires water and light to survive In all cases one of these major factors is the limit on either presence or rate of growth Table 2 below summaries removal rates of a range of nutrients by SRC These will be drawn from lsquosoil reservesrsquo or from additions of materi-als that contain these substances
If the fertiliser input to the soil is less than the rate of removal then the soil will become drained of reserves and vice versa Sub optimal nutrient levels can be com-pensated for by the plant in the early stages of its life cycle but in general after first true harvest (typically after four years) if no additional nutrient input is made then the SRC crop will show reduced growth rates and eventually fail Table 2 also highlights the value of applying the nutrient in organic form
LayoutSRC planning needs to reflect the cultivation planting management and harvesting requirements of the crop In essence machinery is at its most vulnerable when turning across slopes and so wherever possible the safest operation is by travelling directly up and down the slope thus avoiding potential slippage and over-turning From a commercial harvesting point of view there need to be suitable breaks in the crop to allow full trailers to exit and empty ones to join without the need to travel along the rows for a great distance (thus creat-ing compaction) or having to drive across harvested
Table 1 Criteria for the use of soil-forming materials as a tree rooting substrate (from Moffat and McNeill 1994)
Soil property RequirementsBulk density lt 15 g cmndash3 to at least 50 cm depth
lt 17 g cmndash3 to 100 cm depthStoniness lt40 by volume few stones greater than 100 mmpH 35 to 85Electrical conductivity lt2000 microS cmndash1 (11 volvol soilwater suspension)Iron pyrite content lt05Heavy metal concentration As set out in site risk management plansOrganic contaminants As set out in site risk management plans
Table 2 Rates of nutrient removal by willow SRC
Tree species Age(yrs)
Stem amp branch
productiont DM handash1 yrndash1
Nutrient content in stems and brancheskg t DMndash1 kg handash1 yrndash1
The practical use of short rotation coppice in land restoration
stools (causing splitting and potential diseasefungal insertion)
CultivationCultivation is required to create a suitable medium for the SRC crop to establish and grow For the crop to reach full potential it requires an open deep tilled soil structure This is achieved by operating under dry soilland conditions This may conflict in the short term with the requirement to stabilise unstable slopes Then it is preferable to carry out the operation but to do so immediately prior to planting in order to minimise the time during which the soil is unsupported and thus at risk of erosion or slippage Seedbed preparation also offers an opportunity to apply and incorporate any additional materials such as green wastecompost and biosolids By incorporating these materials to a depth of around 200 mm a suitable growing medium can be created This technique has been demonstrated suc-cessfully in restoring sand and gravel quarries and on colliery shale where the base soil is inherently deficient in nutrient and water holding capacity
Planting of SRC is a mechanical operation A mod-ern lsquosteprsquo type planter is capable of planting 6ndash8 ha per day This requires a weed and debris free seedbed with at least 200 vertical millimetres of passable material in order to vertically plant the cutting Further additions of organic matter are possible during early crop growth and immediately after harvesting allowing more organic material to be recycled and helping build the topsoil layer
SRC harvestingHarvesting requires the use of large agricultural machinery (see Figures 3 and 4) Slope and stability are the major factors on sites such as colliery spoil while on sand and gravel quarries the emphasis is on the soilrsquos ability to support machinery (aided by the root network) and the drainage of surface waters Commer-cial machinery for harvesting has to have the ability to cut and chip lsquotreesrsquo that are 9 m tall with a stem base of 50 mm at a rate of some 60 tonnes per hour On wet sites the best way of ensuring that the crop is harvested in conditions that do not detrimentally affect the root structure (and so future growth) is to harvest during the summer months when the sites are at their driest
In general there will need to be an area for crop storage on site It is essential that this area is dry level and of hard base material to allow access for vehicles to
FIGURE 1 SRC PLANTING USING A lsquoSTEPrsquo PLANTER
FIGURE 2 A PLANTED WILLOW CUTTING AND ITS DIMENSIONS
200 mm
Ground level
20 mm
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
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Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
325
The practical use of short rotation coppice in land restoration
sludges sediments and groundwater through contami-nant removal degradation or containment An added advantage of phytoremediation is that it re-establishes a vegetative cover at sites where natural vegetation is lacking due to high metal concentrations in surface soils or physical disturbances in superficial materials Metal-tolerant species can be used to restore vegetation to sites thereby decreasing the potential migration of contamination through wind erosion transport of exposed surface soils and leaching of soil contamina-tion to groundwater (US EPA 1999 2000)
Plants may affect or effect remediation in a number of ways including
bull encouraging degradation activity by commensal organisms (eg pseudomonads) and symbiotic organisms (eg mycorrhizal fungi rhizobia) encouraging activity of parasiticpathogenic organ-isms (eg rot fungi) or by directly affecting the soil environment for microorganisms in their immediate vicinity (eg changing pH redox pCO2 nutrient availability)
bull maintaining a good and improving aerobic struc-ture necessary for biodegradation of organic con-taminants
bull the sorption andor possible translocation of con-taminants (eg accumulation of metals or for organic compounds their metabolism or release to the atmosphere)
bull the mobilisationimmobilisation of contaminants (eg via production of organic ligands for heavy metals changing pH redox potential etc at soil surfaces)
ndash by containing contamination by breaking pathways for example preventing the ingress of water and preventing direct contact partic-ularly as soil horizons develop
ndash evapo-transpiration reducing or even prevent-ing leaching of water
There are several possibilities for positive effects on in situ biodegradation by plants (Anderson and Coats 1994)
bull optimising conditions for bio-degradation by indig-enous soil microorganisms
bull providing stable habitats for introduced organisms or consortia with specific decontamination activi-ties where they may be preserved from competition with or predation by indigenous organisms pro-tected from deleterious environmental factors and supplied with nutrients water and oxygen
Plants may accumulate heavy metals from soils and water The extent of this accumulation depends on the
plant species and soil and contaminant type For many plant species this accumulation process is passive The removal of heavy metals from soils in agricultural crops will gradually reduce soil heavy metal levels in the absence of fresh inputs However for some plants accumulation of metals appears to be an active process possibly related to a tolerance mechanism for their sur-vival on contaminated sites and these plants are referred to as lsquohyper accumulatorsrsquo to distinguish the nature of their metal accumulation from the passive accumulation that is general for plants and typically does not lead to such high leaf concentrations of metals (Baker et al 1994 Baker and Brooks 1989 Japenga 1999) SRC species are typically not hyper accumula-tors although some clones may have higher metal uptakes than others There has been much recent research into the ability of SRC species to take up heavy metals and thus decontaminate land affected by elevated concentrations of these contaminants (eg Riddell-Black 1994 Riddell-Black et al 1997 Pun-shon and Dickinson 1997) Most has focused on vari-ous clones of Salix spp (willow) It is clear that there is considerable variation in the ability of these clones to take up metals and in the metal species which exhibit most movement into the plant For example cadmium and zinc seem to be taken up more than lead nickel and chromium (Labreque et al 1994 Riddell-Black 1994 Oumlstmann 1994 Riddell-Black et al 1997) In addition different metals show different behaviours with respect to their zones of accumulation whether in roots or shoots In practice while some attempts have been made to demonstrate the use of SRC for heavy metal removal from contaminated ground the approach is in reality an emerging concept so far as technical imple-mentation is concerned (Bardos et al 2001) and the technique is open to question on sustainability and risk management grounds as well as practicability
Risk management would need to consider both the effects of the remedial process and the long-term man-agement of risks posed by the condition of the site eg
bull preparation of the site for its conversion to SRCbull working on site in the SRC plantationbull uptake of contaminants into the wood product and
their eventual destinationbull contaminants in the ground the fibrous and shallow
rooting habit of SRC limits its ability to remediate by accumulation
bull use of the site for amenity considering the effects of risks to children who are more vulnerable than adults have a lower awareness of hazards and are higher risk-takers
Regulators are likely to have practical concerns such as which contaminants are likely to be mobilised
326
Land Contamination amp Reclamation Volume 11 Number 3 2003
by the short rotation coppice and what would be their fate The presence of some heavy metals in the biomass may reduce the range of its available end-uses For example the presence of volatile mercury or cadmium would require strict emissions control for combustion processes to avoid potential atmospheric pollution by contaminated particulate matter In addition the fly ash (ash collected from the flue gases) may be contami-nated and would be subject to controls on its disposal Additional controls or restrictions may be required to protect the environment from contamination by incin-erator ash (ash collected in the combustion unit also known as bottom ash) with a high non-volatile metal content (handling and disposal controls required) or dispersal of fly ash (controls on emissions to the atmos-phere required) It could be argued that if the incinera-tor ash is recycled to the SRC site as potash there is no net change in the sitersquos heavy metal content so that the site is stabilised rather than remediated ndash under this scenario there would be no concerns over off-site dis-posal to licensed landfill However this does not com-ply with best practice in contaminated site management since deposition of ash containing heavy metals does not remove identified risk nor does it have an environ-mental benefit In addition it could be viewed as a redeposition of waste by the regulatory bodies It is unlikely that this would be considered best practice by the regulator and may cause the site to come under landfill controls
Plants may accumulate organic compounds through the root system or via foliar uptake (Ryan et al 1988 Paterson et al 1990) This accumulation varies greatly depending on plant species and contaminant and soil type In general the more hydrophobic a contaminant the more likely it is to remain sorbed to roots (bound to cellular lipids) or soil organic matter More soluble compounds may be translocated to the leaves and in some cases these compounds may be degraded by the plant or lost from the leaves by volatilisation The abil-ity of SRC species to stabilise land affected by organic contaminants is being researched The greatest success has been with hybrid poplars which demonstrate uptake and degradation of organic pollutants such as trichloroethylene (TCE) or dioxane from contaminated sites (Schnoor et al 1995 Aitchison et al 1997 Sytsma et al 1997)
Phytostabilisation is the use of certain plant species to immobilise contaminants in the soil and groundwa-ter through absorption and accumulation by roots adsorption onto roots or precipitation within the root zone It also can describe a broader approach to using the growth of plants to break pollutant linkages for example by plant effects on soil water management or prevention of dust blows These processes reduce the
mobility of contamination and prevent migration to the groundwater or air and reduce contaminant availability to the food chain It has been known for many years that organic material in soils can complex heavy met-als reducing their availability to plants and other organisms (see section 6 below)
The revegetation of contaminated sites for example for biomass production may have further beneficial effects in limiting the migration of contaminants from the contaminated area and limiting their availability through immobilisation in roots systems and added or newly generated soil organic matter Successful reveg-etation may also enhance soil microbial activity in turn enhancing processes of in situ biodegradation for some contaminants The addition of organic matter such as waste derived compost to soils may also promote both microbial biodegradation of contaminants and the fixa-tion of some contaminants such as PAHs into humic materials (Kraatz et al 1993 Lotter et al 1993 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promoting abiotic processes of contam-inant degradation for some organic compounds and in co-metabolic degradations of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989)
While the fibrous and shallow rooting habit of SRC limits its ability to remediate by accumulation it is potentially an enormous asset for remediation of con-taminated land by containment and stabilisation The Markham Willows project in the UK (described below) is examining an approach of combining SRC cultiva-tion with organic matter applications to generate a new soil horizon over mine spoil Its working premise for risk management is that the expanding soil horizon would gradually move the rooting zone away from the old mine spoil and the organic matter content of the lower layers of the new soil would help stabilise pH and eH as well as sorb any upwardly migrating con-tamination In this scenario risk management is effected by interrupting pathways rather than removing the source term The SRC would also quickly prevent direct contact on site or from dust blow and also pro-vide physical stabilisation for the site
SRC FOR LAND REMEDIATION
Types of SRC speciesThere is a range of tree species and clones suitable for SRC production Extensive research has been carried out to screen species and clones for different site condi-tions such as nutrient and water availability and other environmental factors such as disease suppression The selection of clones to plant on a contaminated site
327
The practical use of short rotation coppice in land restoration
should take account of the following factors
bull Site characteristics ndash A comprehensive site investi-gation should always be undertaken to reveal the nature of the substrate ie soil chemistry nutrient content hydrology of the area the type and extent of metal loading Clonal selection should always be based on suitability for site conditions
bull Yield ndash It is commercially important to plant clones that will maximise yields (Tabbush and Parfitt 1999) to maximise the potential for income genera-tion and hence resources for site management
bull Mixing clones ndash The planting of monoclonal plots of SRC is considered unwise owing to the possible spread of certain species-specific diseases such as rust By planting a genetically diverse mix the risk of the spread of disease in a large scale coppice is minimised (Tabbush and Parfitt 1999)
bull Metal uptake ndash Different clones take up different metals at different rates from the substrate Some clones accumulate metals with considerable detri-ment to their yield whereas other clones are more tolerant of contamination (Riddell-Black et al1997)
bull Harvesting ndash Mechanical harvesting must be possi-ble which limits the shape of the clone
The yield of biomass from SRC depends on envi-ronmental and climatic conditions throughout the growing season When biomass is grown on contami-nated or restored land the situation is complex so yield calculations can vary widely Careful management based on a sound site appraisal can produce commer-cially viable yields For example SRC on ex-agricul-tural land can produce as much as 17 odt per ha1 Even a crop on a well reclaimed site can produce 10 odt per ha or more (Birse British Biogen personal communi-cation) if well managed On contaminated sites yields can be limited by contamination such as heavy metals pyrites or organic compounds however treatment by the addition of organic matter and selection of clones tolerant to the type of contamination present may over-come problems arising from contamination
Site preparationSite preparation begins with site investigation work both to assess the risk management needs of the site (Armstrong 1999) and the cultivation requirements of the SRC crop Site preparation is the single most important factor in establishing a good SRC crop (Anon 1996) Levels of preparation will vary consider-ably depending on the nature and condition of the site
so that some sites (for example a site with a compacted soil or with very low pH soil) will require more inten-sive preparation methods than others
Topographysite conditionLandforming ie altering the sub-surface structure and shape of the land should be considered ndash not only to allow minimum standards for vegetation growth but also from safety and landscaping aspects (Forestry Commission 1995) For example if the site has been used for mineral extraction then radical re-shaping of the site will usually be required to ensure that any phys-ical dangers are removed so that it is suitable for SRC growing and to improve the visual appearance of the site Restoration conditions may be attached to plan-ning permission for change of use to ensure that this happens If the site is being landformed by the mineral operator then the operator will be responsible for fund-ing the restoration ndash early consultation with the opera-tor is advised to ensure that the site is returned to a landform suitable for SRC production Flatter ground is preferable for harvesting operations but some slope is acceptable so long as it does not exceed safe working limits for farm machinery or cause excessive pooling in wetter conditions Adequate planning of topography is also essential particularly when slopes are an issue and so there exists potential for physical soil erosion The roots of SRC can bind unstable soils together which can be advantageous for the management of slopes
Soil conditioningPhysical improvement to reduce compaction and the incorporation of organic matter into the site where required are important factors in achieving a commer-cially adequate yield A typical SRC crop will remain in production for 16ndash25 years and good soil condition is critical to the establishment and continued productiv-ity of the crop during this period Minimum soil requirements for planting trees on restored land and ideal conditions for SRC establishment are well-docu-mented (Moffat and McNeill 1994 Armstrong 1999) Key criteria are summarised in Table 1
The ideal conditions required for SRC are medium textured soils 100 cm depth (except perhaps in the wet-ter west of the UK where 50 cm may be acceptable) Sites should not be permanently waterlogged as har-
1 odt = oven dried tonnes This is the usual measurement of SRC yield
328
Land Contamination amp Reclamation Volume 11 Number 3 2003
vesting operations are usually carried out in winter and waterlogged sites will make plant movement difficult as well as damaging the soil
Rootable depthThirty centimetres of rootable material is usually suffi-cient for horizontal root development for willow SRC although research has shown that mature SRC planta-tions can root down to 100 cm depth If the tillable depth does not already meet these conditions then culti-vation using a 360 degree excavator should be consid-ered not only to allow sufficient root penetration but also to facilitate stone removal and allow the incorpo-ration of organic matter
AcidityIdeal conditions for SRC growth are pHs in the range 55ndash75 although 35ndash85 should be regarded as the maximum tolerable limits (Armstrong 1999) Pyrites can be problem on sites such as colliery spoil tips Oxi-dation of pyrites causes an increase in acidity which can be toxic to vegetation The recommended maxi-mum tolerable level of pyrite in soil is 05 (Moffat and McNeill 1994) Lime may be added to neutralise acidity but this is expensive and difficult to apply the precise quantities of lime used must be calculated care-fully to avoid imbalances of other essential minerals in the spoil which might restrict tree growth For example for each 1 of pyrite in a thickness of 15 cm of spoil 40 tonnes of limestone per hectare are required to neu-tralise the potential acidity (Costigan et al 1981) If the trees are expected to root to a depth of 100 cm this
means applying over 250 tonnes per hectare for each 1 of pyrite
Nutrient statusSRC requires water and light to survive In all cases one of these major factors is the limit on either presence or rate of growth Table 2 below summaries removal rates of a range of nutrients by SRC These will be drawn from lsquosoil reservesrsquo or from additions of materi-als that contain these substances
If the fertiliser input to the soil is less than the rate of removal then the soil will become drained of reserves and vice versa Sub optimal nutrient levels can be com-pensated for by the plant in the early stages of its life cycle but in general after first true harvest (typically after four years) if no additional nutrient input is made then the SRC crop will show reduced growth rates and eventually fail Table 2 also highlights the value of applying the nutrient in organic form
LayoutSRC planning needs to reflect the cultivation planting management and harvesting requirements of the crop In essence machinery is at its most vulnerable when turning across slopes and so wherever possible the safest operation is by travelling directly up and down the slope thus avoiding potential slippage and over-turning From a commercial harvesting point of view there need to be suitable breaks in the crop to allow full trailers to exit and empty ones to join without the need to travel along the rows for a great distance (thus creat-ing compaction) or having to drive across harvested
Table 1 Criteria for the use of soil-forming materials as a tree rooting substrate (from Moffat and McNeill 1994)
Soil property RequirementsBulk density lt 15 g cmndash3 to at least 50 cm depth
lt 17 g cmndash3 to 100 cm depthStoniness lt40 by volume few stones greater than 100 mmpH 35 to 85Electrical conductivity lt2000 microS cmndash1 (11 volvol soilwater suspension)Iron pyrite content lt05Heavy metal concentration As set out in site risk management plansOrganic contaminants As set out in site risk management plans
Table 2 Rates of nutrient removal by willow SRC
Tree species Age(yrs)
Stem amp branch
productiont DM handash1 yrndash1
Nutrient content in stems and brancheskg t DMndash1 kg handash1 yrndash1
The practical use of short rotation coppice in land restoration
stools (causing splitting and potential diseasefungal insertion)
CultivationCultivation is required to create a suitable medium for the SRC crop to establish and grow For the crop to reach full potential it requires an open deep tilled soil structure This is achieved by operating under dry soilland conditions This may conflict in the short term with the requirement to stabilise unstable slopes Then it is preferable to carry out the operation but to do so immediately prior to planting in order to minimise the time during which the soil is unsupported and thus at risk of erosion or slippage Seedbed preparation also offers an opportunity to apply and incorporate any additional materials such as green wastecompost and biosolids By incorporating these materials to a depth of around 200 mm a suitable growing medium can be created This technique has been demonstrated suc-cessfully in restoring sand and gravel quarries and on colliery shale where the base soil is inherently deficient in nutrient and water holding capacity
Planting of SRC is a mechanical operation A mod-ern lsquosteprsquo type planter is capable of planting 6ndash8 ha per day This requires a weed and debris free seedbed with at least 200 vertical millimetres of passable material in order to vertically plant the cutting Further additions of organic matter are possible during early crop growth and immediately after harvesting allowing more organic material to be recycled and helping build the topsoil layer
SRC harvestingHarvesting requires the use of large agricultural machinery (see Figures 3 and 4) Slope and stability are the major factors on sites such as colliery spoil while on sand and gravel quarries the emphasis is on the soilrsquos ability to support machinery (aided by the root network) and the drainage of surface waters Commer-cial machinery for harvesting has to have the ability to cut and chip lsquotreesrsquo that are 9 m tall with a stem base of 50 mm at a rate of some 60 tonnes per hour On wet sites the best way of ensuring that the crop is harvested in conditions that do not detrimentally affect the root structure (and so future growth) is to harvest during the summer months when the sites are at their driest
In general there will need to be an area for crop storage on site It is essential that this area is dry level and of hard base material to allow access for vehicles to
FIGURE 1 SRC PLANTING USING A lsquoSTEPrsquo PLANTER
FIGURE 2 A PLANTED WILLOW CUTTING AND ITS DIMENSIONS
200 mm
Ground level
20 mm
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
326
Land Contamination amp Reclamation Volume 11 Number 3 2003
by the short rotation coppice and what would be their fate The presence of some heavy metals in the biomass may reduce the range of its available end-uses For example the presence of volatile mercury or cadmium would require strict emissions control for combustion processes to avoid potential atmospheric pollution by contaminated particulate matter In addition the fly ash (ash collected from the flue gases) may be contami-nated and would be subject to controls on its disposal Additional controls or restrictions may be required to protect the environment from contamination by incin-erator ash (ash collected in the combustion unit also known as bottom ash) with a high non-volatile metal content (handling and disposal controls required) or dispersal of fly ash (controls on emissions to the atmos-phere required) It could be argued that if the incinera-tor ash is recycled to the SRC site as potash there is no net change in the sitersquos heavy metal content so that the site is stabilised rather than remediated ndash under this scenario there would be no concerns over off-site dis-posal to licensed landfill However this does not com-ply with best practice in contaminated site management since deposition of ash containing heavy metals does not remove identified risk nor does it have an environ-mental benefit In addition it could be viewed as a redeposition of waste by the regulatory bodies It is unlikely that this would be considered best practice by the regulator and may cause the site to come under landfill controls
Plants may accumulate organic compounds through the root system or via foliar uptake (Ryan et al 1988 Paterson et al 1990) This accumulation varies greatly depending on plant species and contaminant and soil type In general the more hydrophobic a contaminant the more likely it is to remain sorbed to roots (bound to cellular lipids) or soil organic matter More soluble compounds may be translocated to the leaves and in some cases these compounds may be degraded by the plant or lost from the leaves by volatilisation The abil-ity of SRC species to stabilise land affected by organic contaminants is being researched The greatest success has been with hybrid poplars which demonstrate uptake and degradation of organic pollutants such as trichloroethylene (TCE) or dioxane from contaminated sites (Schnoor et al 1995 Aitchison et al 1997 Sytsma et al 1997)
Phytostabilisation is the use of certain plant species to immobilise contaminants in the soil and groundwa-ter through absorption and accumulation by roots adsorption onto roots or precipitation within the root zone It also can describe a broader approach to using the growth of plants to break pollutant linkages for example by plant effects on soil water management or prevention of dust blows These processes reduce the
mobility of contamination and prevent migration to the groundwater or air and reduce contaminant availability to the food chain It has been known for many years that organic material in soils can complex heavy met-als reducing their availability to plants and other organisms (see section 6 below)
The revegetation of contaminated sites for example for biomass production may have further beneficial effects in limiting the migration of contaminants from the contaminated area and limiting their availability through immobilisation in roots systems and added or newly generated soil organic matter Successful reveg-etation may also enhance soil microbial activity in turn enhancing processes of in situ biodegradation for some contaminants The addition of organic matter such as waste derived compost to soils may also promote both microbial biodegradation of contaminants and the fixa-tion of some contaminants such as PAHs into humic materials (Kraatz et al 1993 Lotter et al 1993 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promoting abiotic processes of contam-inant degradation for some organic compounds and in co-metabolic degradations of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989)
While the fibrous and shallow rooting habit of SRC limits its ability to remediate by accumulation it is potentially an enormous asset for remediation of con-taminated land by containment and stabilisation The Markham Willows project in the UK (described below) is examining an approach of combining SRC cultiva-tion with organic matter applications to generate a new soil horizon over mine spoil Its working premise for risk management is that the expanding soil horizon would gradually move the rooting zone away from the old mine spoil and the organic matter content of the lower layers of the new soil would help stabilise pH and eH as well as sorb any upwardly migrating con-tamination In this scenario risk management is effected by interrupting pathways rather than removing the source term The SRC would also quickly prevent direct contact on site or from dust blow and also pro-vide physical stabilisation for the site
SRC FOR LAND REMEDIATION
Types of SRC speciesThere is a range of tree species and clones suitable for SRC production Extensive research has been carried out to screen species and clones for different site condi-tions such as nutrient and water availability and other environmental factors such as disease suppression The selection of clones to plant on a contaminated site
327
The practical use of short rotation coppice in land restoration
should take account of the following factors
bull Site characteristics ndash A comprehensive site investi-gation should always be undertaken to reveal the nature of the substrate ie soil chemistry nutrient content hydrology of the area the type and extent of metal loading Clonal selection should always be based on suitability for site conditions
bull Yield ndash It is commercially important to plant clones that will maximise yields (Tabbush and Parfitt 1999) to maximise the potential for income genera-tion and hence resources for site management
bull Mixing clones ndash The planting of monoclonal plots of SRC is considered unwise owing to the possible spread of certain species-specific diseases such as rust By planting a genetically diverse mix the risk of the spread of disease in a large scale coppice is minimised (Tabbush and Parfitt 1999)
bull Metal uptake ndash Different clones take up different metals at different rates from the substrate Some clones accumulate metals with considerable detri-ment to their yield whereas other clones are more tolerant of contamination (Riddell-Black et al1997)
bull Harvesting ndash Mechanical harvesting must be possi-ble which limits the shape of the clone
The yield of biomass from SRC depends on envi-ronmental and climatic conditions throughout the growing season When biomass is grown on contami-nated or restored land the situation is complex so yield calculations can vary widely Careful management based on a sound site appraisal can produce commer-cially viable yields For example SRC on ex-agricul-tural land can produce as much as 17 odt per ha1 Even a crop on a well reclaimed site can produce 10 odt per ha or more (Birse British Biogen personal communi-cation) if well managed On contaminated sites yields can be limited by contamination such as heavy metals pyrites or organic compounds however treatment by the addition of organic matter and selection of clones tolerant to the type of contamination present may over-come problems arising from contamination
Site preparationSite preparation begins with site investigation work both to assess the risk management needs of the site (Armstrong 1999) and the cultivation requirements of the SRC crop Site preparation is the single most important factor in establishing a good SRC crop (Anon 1996) Levels of preparation will vary consider-ably depending on the nature and condition of the site
so that some sites (for example a site with a compacted soil or with very low pH soil) will require more inten-sive preparation methods than others
Topographysite conditionLandforming ie altering the sub-surface structure and shape of the land should be considered ndash not only to allow minimum standards for vegetation growth but also from safety and landscaping aspects (Forestry Commission 1995) For example if the site has been used for mineral extraction then radical re-shaping of the site will usually be required to ensure that any phys-ical dangers are removed so that it is suitable for SRC growing and to improve the visual appearance of the site Restoration conditions may be attached to plan-ning permission for change of use to ensure that this happens If the site is being landformed by the mineral operator then the operator will be responsible for fund-ing the restoration ndash early consultation with the opera-tor is advised to ensure that the site is returned to a landform suitable for SRC production Flatter ground is preferable for harvesting operations but some slope is acceptable so long as it does not exceed safe working limits for farm machinery or cause excessive pooling in wetter conditions Adequate planning of topography is also essential particularly when slopes are an issue and so there exists potential for physical soil erosion The roots of SRC can bind unstable soils together which can be advantageous for the management of slopes
Soil conditioningPhysical improvement to reduce compaction and the incorporation of organic matter into the site where required are important factors in achieving a commer-cially adequate yield A typical SRC crop will remain in production for 16ndash25 years and good soil condition is critical to the establishment and continued productiv-ity of the crop during this period Minimum soil requirements for planting trees on restored land and ideal conditions for SRC establishment are well-docu-mented (Moffat and McNeill 1994 Armstrong 1999) Key criteria are summarised in Table 1
The ideal conditions required for SRC are medium textured soils 100 cm depth (except perhaps in the wet-ter west of the UK where 50 cm may be acceptable) Sites should not be permanently waterlogged as har-
1 odt = oven dried tonnes This is the usual measurement of SRC yield
328
Land Contamination amp Reclamation Volume 11 Number 3 2003
vesting operations are usually carried out in winter and waterlogged sites will make plant movement difficult as well as damaging the soil
Rootable depthThirty centimetres of rootable material is usually suffi-cient for horizontal root development for willow SRC although research has shown that mature SRC planta-tions can root down to 100 cm depth If the tillable depth does not already meet these conditions then culti-vation using a 360 degree excavator should be consid-ered not only to allow sufficient root penetration but also to facilitate stone removal and allow the incorpo-ration of organic matter
AcidityIdeal conditions for SRC growth are pHs in the range 55ndash75 although 35ndash85 should be regarded as the maximum tolerable limits (Armstrong 1999) Pyrites can be problem on sites such as colliery spoil tips Oxi-dation of pyrites causes an increase in acidity which can be toxic to vegetation The recommended maxi-mum tolerable level of pyrite in soil is 05 (Moffat and McNeill 1994) Lime may be added to neutralise acidity but this is expensive and difficult to apply the precise quantities of lime used must be calculated care-fully to avoid imbalances of other essential minerals in the spoil which might restrict tree growth For example for each 1 of pyrite in a thickness of 15 cm of spoil 40 tonnes of limestone per hectare are required to neu-tralise the potential acidity (Costigan et al 1981) If the trees are expected to root to a depth of 100 cm this
means applying over 250 tonnes per hectare for each 1 of pyrite
Nutrient statusSRC requires water and light to survive In all cases one of these major factors is the limit on either presence or rate of growth Table 2 below summaries removal rates of a range of nutrients by SRC These will be drawn from lsquosoil reservesrsquo or from additions of materi-als that contain these substances
If the fertiliser input to the soil is less than the rate of removal then the soil will become drained of reserves and vice versa Sub optimal nutrient levels can be com-pensated for by the plant in the early stages of its life cycle but in general after first true harvest (typically after four years) if no additional nutrient input is made then the SRC crop will show reduced growth rates and eventually fail Table 2 also highlights the value of applying the nutrient in organic form
LayoutSRC planning needs to reflect the cultivation planting management and harvesting requirements of the crop In essence machinery is at its most vulnerable when turning across slopes and so wherever possible the safest operation is by travelling directly up and down the slope thus avoiding potential slippage and over-turning From a commercial harvesting point of view there need to be suitable breaks in the crop to allow full trailers to exit and empty ones to join without the need to travel along the rows for a great distance (thus creat-ing compaction) or having to drive across harvested
Table 1 Criteria for the use of soil-forming materials as a tree rooting substrate (from Moffat and McNeill 1994)
Soil property RequirementsBulk density lt 15 g cmndash3 to at least 50 cm depth
lt 17 g cmndash3 to 100 cm depthStoniness lt40 by volume few stones greater than 100 mmpH 35 to 85Electrical conductivity lt2000 microS cmndash1 (11 volvol soilwater suspension)Iron pyrite content lt05Heavy metal concentration As set out in site risk management plansOrganic contaminants As set out in site risk management plans
Table 2 Rates of nutrient removal by willow SRC
Tree species Age(yrs)
Stem amp branch
productiont DM handash1 yrndash1
Nutrient content in stems and brancheskg t DMndash1 kg handash1 yrndash1
The practical use of short rotation coppice in land restoration
stools (causing splitting and potential diseasefungal insertion)
CultivationCultivation is required to create a suitable medium for the SRC crop to establish and grow For the crop to reach full potential it requires an open deep tilled soil structure This is achieved by operating under dry soilland conditions This may conflict in the short term with the requirement to stabilise unstable slopes Then it is preferable to carry out the operation but to do so immediately prior to planting in order to minimise the time during which the soil is unsupported and thus at risk of erosion or slippage Seedbed preparation also offers an opportunity to apply and incorporate any additional materials such as green wastecompost and biosolids By incorporating these materials to a depth of around 200 mm a suitable growing medium can be created This technique has been demonstrated suc-cessfully in restoring sand and gravel quarries and on colliery shale where the base soil is inherently deficient in nutrient and water holding capacity
Planting of SRC is a mechanical operation A mod-ern lsquosteprsquo type planter is capable of planting 6ndash8 ha per day This requires a weed and debris free seedbed with at least 200 vertical millimetres of passable material in order to vertically plant the cutting Further additions of organic matter are possible during early crop growth and immediately after harvesting allowing more organic material to be recycled and helping build the topsoil layer
SRC harvestingHarvesting requires the use of large agricultural machinery (see Figures 3 and 4) Slope and stability are the major factors on sites such as colliery spoil while on sand and gravel quarries the emphasis is on the soilrsquos ability to support machinery (aided by the root network) and the drainage of surface waters Commer-cial machinery for harvesting has to have the ability to cut and chip lsquotreesrsquo that are 9 m tall with a stem base of 50 mm at a rate of some 60 tonnes per hour On wet sites the best way of ensuring that the crop is harvested in conditions that do not detrimentally affect the root structure (and so future growth) is to harvest during the summer months when the sites are at their driest
In general there will need to be an area for crop storage on site It is essential that this area is dry level and of hard base material to allow access for vehicles to
FIGURE 1 SRC PLANTING USING A lsquoSTEPrsquo PLANTER
FIGURE 2 A PLANTED WILLOW CUTTING AND ITS DIMENSIONS
200 mm
Ground level
20 mm
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
327
The practical use of short rotation coppice in land restoration
should take account of the following factors
bull Site characteristics ndash A comprehensive site investi-gation should always be undertaken to reveal the nature of the substrate ie soil chemistry nutrient content hydrology of the area the type and extent of metal loading Clonal selection should always be based on suitability for site conditions
bull Yield ndash It is commercially important to plant clones that will maximise yields (Tabbush and Parfitt 1999) to maximise the potential for income genera-tion and hence resources for site management
bull Mixing clones ndash The planting of monoclonal plots of SRC is considered unwise owing to the possible spread of certain species-specific diseases such as rust By planting a genetically diverse mix the risk of the spread of disease in a large scale coppice is minimised (Tabbush and Parfitt 1999)
bull Metal uptake ndash Different clones take up different metals at different rates from the substrate Some clones accumulate metals with considerable detri-ment to their yield whereas other clones are more tolerant of contamination (Riddell-Black et al1997)
bull Harvesting ndash Mechanical harvesting must be possi-ble which limits the shape of the clone
The yield of biomass from SRC depends on envi-ronmental and climatic conditions throughout the growing season When biomass is grown on contami-nated or restored land the situation is complex so yield calculations can vary widely Careful management based on a sound site appraisal can produce commer-cially viable yields For example SRC on ex-agricul-tural land can produce as much as 17 odt per ha1 Even a crop on a well reclaimed site can produce 10 odt per ha or more (Birse British Biogen personal communi-cation) if well managed On contaminated sites yields can be limited by contamination such as heavy metals pyrites or organic compounds however treatment by the addition of organic matter and selection of clones tolerant to the type of contamination present may over-come problems arising from contamination
Site preparationSite preparation begins with site investigation work both to assess the risk management needs of the site (Armstrong 1999) and the cultivation requirements of the SRC crop Site preparation is the single most important factor in establishing a good SRC crop (Anon 1996) Levels of preparation will vary consider-ably depending on the nature and condition of the site
so that some sites (for example a site with a compacted soil or with very low pH soil) will require more inten-sive preparation methods than others
Topographysite conditionLandforming ie altering the sub-surface structure and shape of the land should be considered ndash not only to allow minimum standards for vegetation growth but also from safety and landscaping aspects (Forestry Commission 1995) For example if the site has been used for mineral extraction then radical re-shaping of the site will usually be required to ensure that any phys-ical dangers are removed so that it is suitable for SRC growing and to improve the visual appearance of the site Restoration conditions may be attached to plan-ning permission for change of use to ensure that this happens If the site is being landformed by the mineral operator then the operator will be responsible for fund-ing the restoration ndash early consultation with the opera-tor is advised to ensure that the site is returned to a landform suitable for SRC production Flatter ground is preferable for harvesting operations but some slope is acceptable so long as it does not exceed safe working limits for farm machinery or cause excessive pooling in wetter conditions Adequate planning of topography is also essential particularly when slopes are an issue and so there exists potential for physical soil erosion The roots of SRC can bind unstable soils together which can be advantageous for the management of slopes
Soil conditioningPhysical improvement to reduce compaction and the incorporation of organic matter into the site where required are important factors in achieving a commer-cially adequate yield A typical SRC crop will remain in production for 16ndash25 years and good soil condition is critical to the establishment and continued productiv-ity of the crop during this period Minimum soil requirements for planting trees on restored land and ideal conditions for SRC establishment are well-docu-mented (Moffat and McNeill 1994 Armstrong 1999) Key criteria are summarised in Table 1
The ideal conditions required for SRC are medium textured soils 100 cm depth (except perhaps in the wet-ter west of the UK where 50 cm may be acceptable) Sites should not be permanently waterlogged as har-
1 odt = oven dried tonnes This is the usual measurement of SRC yield
328
Land Contamination amp Reclamation Volume 11 Number 3 2003
vesting operations are usually carried out in winter and waterlogged sites will make plant movement difficult as well as damaging the soil
Rootable depthThirty centimetres of rootable material is usually suffi-cient for horizontal root development for willow SRC although research has shown that mature SRC planta-tions can root down to 100 cm depth If the tillable depth does not already meet these conditions then culti-vation using a 360 degree excavator should be consid-ered not only to allow sufficient root penetration but also to facilitate stone removal and allow the incorpo-ration of organic matter
AcidityIdeal conditions for SRC growth are pHs in the range 55ndash75 although 35ndash85 should be regarded as the maximum tolerable limits (Armstrong 1999) Pyrites can be problem on sites such as colliery spoil tips Oxi-dation of pyrites causes an increase in acidity which can be toxic to vegetation The recommended maxi-mum tolerable level of pyrite in soil is 05 (Moffat and McNeill 1994) Lime may be added to neutralise acidity but this is expensive and difficult to apply the precise quantities of lime used must be calculated care-fully to avoid imbalances of other essential minerals in the spoil which might restrict tree growth For example for each 1 of pyrite in a thickness of 15 cm of spoil 40 tonnes of limestone per hectare are required to neu-tralise the potential acidity (Costigan et al 1981) If the trees are expected to root to a depth of 100 cm this
means applying over 250 tonnes per hectare for each 1 of pyrite
Nutrient statusSRC requires water and light to survive In all cases one of these major factors is the limit on either presence or rate of growth Table 2 below summaries removal rates of a range of nutrients by SRC These will be drawn from lsquosoil reservesrsquo or from additions of materi-als that contain these substances
If the fertiliser input to the soil is less than the rate of removal then the soil will become drained of reserves and vice versa Sub optimal nutrient levels can be com-pensated for by the plant in the early stages of its life cycle but in general after first true harvest (typically after four years) if no additional nutrient input is made then the SRC crop will show reduced growth rates and eventually fail Table 2 also highlights the value of applying the nutrient in organic form
LayoutSRC planning needs to reflect the cultivation planting management and harvesting requirements of the crop In essence machinery is at its most vulnerable when turning across slopes and so wherever possible the safest operation is by travelling directly up and down the slope thus avoiding potential slippage and over-turning From a commercial harvesting point of view there need to be suitable breaks in the crop to allow full trailers to exit and empty ones to join without the need to travel along the rows for a great distance (thus creat-ing compaction) or having to drive across harvested
Table 1 Criteria for the use of soil-forming materials as a tree rooting substrate (from Moffat and McNeill 1994)
Soil property RequirementsBulk density lt 15 g cmndash3 to at least 50 cm depth
lt 17 g cmndash3 to 100 cm depthStoniness lt40 by volume few stones greater than 100 mmpH 35 to 85Electrical conductivity lt2000 microS cmndash1 (11 volvol soilwater suspension)Iron pyrite content lt05Heavy metal concentration As set out in site risk management plansOrganic contaminants As set out in site risk management plans
Table 2 Rates of nutrient removal by willow SRC
Tree species Age(yrs)
Stem amp branch
productiont DM handash1 yrndash1
Nutrient content in stems and brancheskg t DMndash1 kg handash1 yrndash1
The practical use of short rotation coppice in land restoration
stools (causing splitting and potential diseasefungal insertion)
CultivationCultivation is required to create a suitable medium for the SRC crop to establish and grow For the crop to reach full potential it requires an open deep tilled soil structure This is achieved by operating under dry soilland conditions This may conflict in the short term with the requirement to stabilise unstable slopes Then it is preferable to carry out the operation but to do so immediately prior to planting in order to minimise the time during which the soil is unsupported and thus at risk of erosion or slippage Seedbed preparation also offers an opportunity to apply and incorporate any additional materials such as green wastecompost and biosolids By incorporating these materials to a depth of around 200 mm a suitable growing medium can be created This technique has been demonstrated suc-cessfully in restoring sand and gravel quarries and on colliery shale where the base soil is inherently deficient in nutrient and water holding capacity
Planting of SRC is a mechanical operation A mod-ern lsquosteprsquo type planter is capable of planting 6ndash8 ha per day This requires a weed and debris free seedbed with at least 200 vertical millimetres of passable material in order to vertically plant the cutting Further additions of organic matter are possible during early crop growth and immediately after harvesting allowing more organic material to be recycled and helping build the topsoil layer
SRC harvestingHarvesting requires the use of large agricultural machinery (see Figures 3 and 4) Slope and stability are the major factors on sites such as colliery spoil while on sand and gravel quarries the emphasis is on the soilrsquos ability to support machinery (aided by the root network) and the drainage of surface waters Commer-cial machinery for harvesting has to have the ability to cut and chip lsquotreesrsquo that are 9 m tall with a stem base of 50 mm at a rate of some 60 tonnes per hour On wet sites the best way of ensuring that the crop is harvested in conditions that do not detrimentally affect the root structure (and so future growth) is to harvest during the summer months when the sites are at their driest
In general there will need to be an area for crop storage on site It is essential that this area is dry level and of hard base material to allow access for vehicles to
FIGURE 1 SRC PLANTING USING A lsquoSTEPrsquo PLANTER
FIGURE 2 A PLANTED WILLOW CUTTING AND ITS DIMENSIONS
200 mm
Ground level
20 mm
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
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Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
328
Land Contamination amp Reclamation Volume 11 Number 3 2003
vesting operations are usually carried out in winter and waterlogged sites will make plant movement difficult as well as damaging the soil
Rootable depthThirty centimetres of rootable material is usually suffi-cient for horizontal root development for willow SRC although research has shown that mature SRC planta-tions can root down to 100 cm depth If the tillable depth does not already meet these conditions then culti-vation using a 360 degree excavator should be consid-ered not only to allow sufficient root penetration but also to facilitate stone removal and allow the incorpo-ration of organic matter
AcidityIdeal conditions for SRC growth are pHs in the range 55ndash75 although 35ndash85 should be regarded as the maximum tolerable limits (Armstrong 1999) Pyrites can be problem on sites such as colliery spoil tips Oxi-dation of pyrites causes an increase in acidity which can be toxic to vegetation The recommended maxi-mum tolerable level of pyrite in soil is 05 (Moffat and McNeill 1994) Lime may be added to neutralise acidity but this is expensive and difficult to apply the precise quantities of lime used must be calculated care-fully to avoid imbalances of other essential minerals in the spoil which might restrict tree growth For example for each 1 of pyrite in a thickness of 15 cm of spoil 40 tonnes of limestone per hectare are required to neu-tralise the potential acidity (Costigan et al 1981) If the trees are expected to root to a depth of 100 cm this
means applying over 250 tonnes per hectare for each 1 of pyrite
Nutrient statusSRC requires water and light to survive In all cases one of these major factors is the limit on either presence or rate of growth Table 2 below summaries removal rates of a range of nutrients by SRC These will be drawn from lsquosoil reservesrsquo or from additions of materi-als that contain these substances
If the fertiliser input to the soil is less than the rate of removal then the soil will become drained of reserves and vice versa Sub optimal nutrient levels can be com-pensated for by the plant in the early stages of its life cycle but in general after first true harvest (typically after four years) if no additional nutrient input is made then the SRC crop will show reduced growth rates and eventually fail Table 2 also highlights the value of applying the nutrient in organic form
LayoutSRC planning needs to reflect the cultivation planting management and harvesting requirements of the crop In essence machinery is at its most vulnerable when turning across slopes and so wherever possible the safest operation is by travelling directly up and down the slope thus avoiding potential slippage and over-turning From a commercial harvesting point of view there need to be suitable breaks in the crop to allow full trailers to exit and empty ones to join without the need to travel along the rows for a great distance (thus creat-ing compaction) or having to drive across harvested
Table 1 Criteria for the use of soil-forming materials as a tree rooting substrate (from Moffat and McNeill 1994)
Soil property RequirementsBulk density lt 15 g cmndash3 to at least 50 cm depth
lt 17 g cmndash3 to 100 cm depthStoniness lt40 by volume few stones greater than 100 mmpH 35 to 85Electrical conductivity lt2000 microS cmndash1 (11 volvol soilwater suspension)Iron pyrite content lt05Heavy metal concentration As set out in site risk management plansOrganic contaminants As set out in site risk management plans
Table 2 Rates of nutrient removal by willow SRC
Tree species Age(yrs)
Stem amp branch
productiont DM handash1 yrndash1
Nutrient content in stems and brancheskg t DMndash1 kg handash1 yrndash1
The practical use of short rotation coppice in land restoration
stools (causing splitting and potential diseasefungal insertion)
CultivationCultivation is required to create a suitable medium for the SRC crop to establish and grow For the crop to reach full potential it requires an open deep tilled soil structure This is achieved by operating under dry soilland conditions This may conflict in the short term with the requirement to stabilise unstable slopes Then it is preferable to carry out the operation but to do so immediately prior to planting in order to minimise the time during which the soil is unsupported and thus at risk of erosion or slippage Seedbed preparation also offers an opportunity to apply and incorporate any additional materials such as green wastecompost and biosolids By incorporating these materials to a depth of around 200 mm a suitable growing medium can be created This technique has been demonstrated suc-cessfully in restoring sand and gravel quarries and on colliery shale where the base soil is inherently deficient in nutrient and water holding capacity
Planting of SRC is a mechanical operation A mod-ern lsquosteprsquo type planter is capable of planting 6ndash8 ha per day This requires a weed and debris free seedbed with at least 200 vertical millimetres of passable material in order to vertically plant the cutting Further additions of organic matter are possible during early crop growth and immediately after harvesting allowing more organic material to be recycled and helping build the topsoil layer
SRC harvestingHarvesting requires the use of large agricultural machinery (see Figures 3 and 4) Slope and stability are the major factors on sites such as colliery spoil while on sand and gravel quarries the emphasis is on the soilrsquos ability to support machinery (aided by the root network) and the drainage of surface waters Commer-cial machinery for harvesting has to have the ability to cut and chip lsquotreesrsquo that are 9 m tall with a stem base of 50 mm at a rate of some 60 tonnes per hour On wet sites the best way of ensuring that the crop is harvested in conditions that do not detrimentally affect the root structure (and so future growth) is to harvest during the summer months when the sites are at their driest
In general there will need to be an area for crop storage on site It is essential that this area is dry level and of hard base material to allow access for vehicles to
FIGURE 1 SRC PLANTING USING A lsquoSTEPrsquo PLANTER
FIGURE 2 A PLANTED WILLOW CUTTING AND ITS DIMENSIONS
200 mm
Ground level
20 mm
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
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Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
329
The practical use of short rotation coppice in land restoration
stools (causing splitting and potential diseasefungal insertion)
CultivationCultivation is required to create a suitable medium for the SRC crop to establish and grow For the crop to reach full potential it requires an open deep tilled soil structure This is achieved by operating under dry soilland conditions This may conflict in the short term with the requirement to stabilise unstable slopes Then it is preferable to carry out the operation but to do so immediately prior to planting in order to minimise the time during which the soil is unsupported and thus at risk of erosion or slippage Seedbed preparation also offers an opportunity to apply and incorporate any additional materials such as green wastecompost and biosolids By incorporating these materials to a depth of around 200 mm a suitable growing medium can be created This technique has been demonstrated suc-cessfully in restoring sand and gravel quarries and on colliery shale where the base soil is inherently deficient in nutrient and water holding capacity
Planting of SRC is a mechanical operation A mod-ern lsquosteprsquo type planter is capable of planting 6ndash8 ha per day This requires a weed and debris free seedbed with at least 200 vertical millimetres of passable material in order to vertically plant the cutting Further additions of organic matter are possible during early crop growth and immediately after harvesting allowing more organic material to be recycled and helping build the topsoil layer
SRC harvestingHarvesting requires the use of large agricultural machinery (see Figures 3 and 4) Slope and stability are the major factors on sites such as colliery spoil while on sand and gravel quarries the emphasis is on the soilrsquos ability to support machinery (aided by the root network) and the drainage of surface waters Commer-cial machinery for harvesting has to have the ability to cut and chip lsquotreesrsquo that are 9 m tall with a stem base of 50 mm at a rate of some 60 tonnes per hour On wet sites the best way of ensuring that the crop is harvested in conditions that do not detrimentally affect the root structure (and so future growth) is to harvest during the summer months when the sites are at their driest
In general there will need to be an area for crop storage on site It is essential that this area is dry level and of hard base material to allow access for vehicles to
FIGURE 1 SRC PLANTING USING A lsquoSTEPrsquo PLANTER
FIGURE 2 A PLANTED WILLOW CUTTING AND ITS DIMENSIONS
200 mm
Ground level
20 mm
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
330
Land Contamination amp Reclamation Volume 11 Number 3 2003
collect the fuel Figure 4 shows chips stored on a mound of reclaimed pulverised fly ash covered by short grasses Harvested fuel can be stored for over six months in outdoor clamps such as that shown in Figure 4
SRC useThe wood crop produced from the SRC is normally air dried or if necessary mechanically dried The wood is chipped to make it convenient for transport and han-dling The value of the fuel is quite low perhaps about pound25 per tonne (dry weight) and it is bulky so it makes
economic sense to minimise the distance that is trans-ported Using the fuel locally to the SRC production area in clusters of boilers enables fuel to be supplied economically and boilers to be bulk purchased and managed
For example the fuel produced may be used in com-munity or local authority based schemes using small-scale energy clusters or in purpose built energy parks These will create the greatest additional benefit in social terms and can be targeted at areas that are in need of regeneration following the closure of traditional
FIGURE 3 SRC HARVESTING USING A CRL DESIGNED CUTTING HEAD MOUNTED ON A CLAAS FORAGE HARVESTER
FIGURE 4 HARVESTED SRC CHIP STORED IN OUTDOOR CLAMPS FOR DRYING
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
331
The practical use of short rotation coppice in land restoration
mining and heavy industrial processes that probably created the need for remediation in the first place
Another potential market is co-firing with coal in large power stations The wood chips can be pelletised which improves material handling characteristics and bulk density so reducing transport costs However pel-letisation requires significant production energy and so raises the fuel cost There are also the higher technol-ogy systems of gasification and pyrolysis that may offer future opportunities for electrical and heat based energy generation
SRC IN A SOCIAL CONTEXT
SRC fits conveniently into that category of subjects that can be generically termed lsquoenvironmentalrsquo This is very useful because it provides an automatic link to the subliminal almost visceral relationship that people have with nature
Local communities who have found that the land-scapes on their doorsteps can be places in which to play take exercise or simply enjoy nature have quietly sequestrated many a tract of abandoned post-industrial land It should be quite possible to harness this commu-nity affinity for green spaces with projects such as those involving SRC
Environmental projects can provide society with more than just facilities for leisure and recreation There are many positive socio-economic benefits to be found in this area In most modern societies employ-ment is cyclical The change between phases presents different challenges When the level of unemployment is low environmental projects can be a useful means of targeting the disadvantaged and long-term unem-ployed When unemployment is high and the lsquomarketrsquo is unable to deal with the redundant labour resource then socio-environmental projects can help to take up some of the slack providing hope and some form of income for those vulnerable members of society who are less well able to compete for scarce jobs
Today the larger problem of unemployment has for the time being been resolved What we now need to concentrate on are those members of society who are lodged in circumstances that reduce their employabil-ity The people in need of most help often live in areas suffering high rates of depravation They are trapped in circumstances that disrupt their education which fur-ther reduces their chances of employment Locked in to a poverty and educational trap they become disillu-sioned and disaffected It is at this point that special assistance is required and the use of socially orientated ventures can be of use in this endeavour The value of these schemes is that they provide controlled surround-
ings within which people can be helped back into long-term employment Intermediate labour market (ILM) social enterprise or transitional employment schemes can tap in to the rich resource offered by the environ-ment Basing an ILM scheme on the use of SRC is par-ticularly interesting because it offers significant additional benefits beyond helping people back into work
The first strength to recognise about a social enter-prise is that it is locally based This means that there is a high degree of ownership by local partnerships and communities
There is a natural symbiosis between post-industrial land and people Simply speaking the resources occur-ring at a particular location led to the development of industry and populations grew as a result of the availa-ble work Global trends and a change in the economic uses of land have often left large amounts contaminated land in close proximity to people In many instances for complex related reasons (Barton 2000) these areas are also those that suffer the highest rates of social and environmental damage and depravation This provides an excellent opportunity for an SRC-based ILM to strike at many problems simultaneously
An ILM based on SRC offers many associated bene-fits Not all are directly related to helping people into full-time employment Some would help to deliver sus-tainable outcomes and outputs The recycling of green wastes as a source of nutrients the recycling of con-taminated land and the provision of renewable energy are all examples of how to support the delivering of inter-generational equity through SRC However the need for these projects to maintain their benefits into the future is also important This is especially true of schemes that involve producing changes to the land-scape ndash changes that are likely to develop and mature over decades
The effort to clear away post-industrial dereliction has led to many projects where the outcome was an area of green space All too often these schemes have been attended by poorly structured funding for their long-term maintenance Finding revenue funding for this aspect of stewardship can pose a substantial prob-lem SRC embedded in a social enterprise may offer a solution The idea would be to develop a scheme employing local people which would generate income from an SRC to support the entire project in the long-term The outcomes would cover a wide spectrum of social economic and environments benefits including
bull providing employmentbull assisting neighbourhood renewalbull promoting community healthbull providing a recreationalleisure resource
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
332
Land Contamination amp Reclamation Volume 11 Number 3 2003
bull assisting with the mitigation of storm water run-offbull dealing with post-industrial landbull aiding biodiversity and nature conservationbull promoting sustainabilitybull improving visual amenitybull playing a part in the reduction of airborne pollutionbull providing an educational resource
In short this type of development could contribute to an integrated functional green infrastructure that transforms derelict contaminated post-industrial land and provides a legacy for future maintenance
RECYCLING ORGANIC MATTER
Soil organic matter underpins the key functions of soil for agricultural production
bull sustaining plant growth and an active soil flora and fauna
bull allowing the flow of water from the soil surface into the soil
bull allowing gaseous exchange between the soil layers and the atmosphere
If surface materials are low in organic matter it is unlikely that these soil functions will be adequately provided or if they do occur in the short term that they will be sustained
The simple mixture of low density organic material with the mineral fraction lowers the soilrsquos bulk density but the significant effects are on the formation and sta-bility of soil aggregates and the associated pore related properties such as aeration and water flow through soil The retention and release of water and the ability to provide charged surfaces (variable with pH) where cations may be retained in a form available to plants are vitally important for the production of a good fertile soil
Enhancing soil organic matter content may also confer a risk management benefit Additions to soil of composted organic materials have been found to pro-duce significant decreases in amounts of bioavailable lead in contaminated soils (Jones and Jarvis 1981) It has been known for many years that organic material in soils can complex heavy metals reducing their availa-bility to plants and other organisms The bioavailabil-ity of inorganic contaminants is thought to decrease over time (Hatzinger and Alexander 1995) Recent work reported by the US EPA based on this ability of organic matter to complex heavy metals has shown that additions to soil of composted organic materials produced significant decreases in the amount of bioa-vailable lead in contaminated soils (the stabilisation of
contaminant metals) (Jones and Jarvis 1981) Soil organic matter is also a sink for many organic contami-nants in particular pesticides and PAHs (Lamar et al 1990) PAHs may bind irreversibly to soil humus (Stegmann et al 1991 Mahro and Kaestner 1993) Soil organic matter also appears to be important in promot-ing abiotic processes of contaminant degradation for some organic compounds and in co-metabolic degrada-tions of organic compounds (Dragun 1988 West 1994) and also strongly sorbs heavy metals (Sposito 1989) In an active soil system additions of residues of vegetation and stabilised organic matter are very important to its function and potentially also because organic contaminants are extra strongly adsorbed in this material (Weber et al 1992 Xing et al 1996)
Improvement in soil organic matter content is often initiated by the addition of organic materials imported onto site These materials might include sewage sludge and derived materials composted wastes including green wastes food wastes and other materials includ-ing
bull composted food wastebull green waste compostbull municipal solid waste compost (mixed and source
separated)bull paper waste compostbull other composted industrial wastes
The major additions through these materials are car-bon and nitrogen but the amounts added vary consider-ably depending on the nature of the waste Table 3 shows CN ratios for a range of wastes applied to soil
Incorporating wastes with a high CN ratio will cause nitrogen to be stored in soil biomass As a rule of thumb where the N content is more than 1 there will be mineralisation and release of added N where the N content is less than 1 it is likely soil N will be immo-bilised Therefore adjusting the CN ratio can help to reduce nitrogen losses resulting from the addition of nitrogen-rich amendments There are however major differences between organic and inorganic sources of
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
333
The practical use of short rotation coppice in land restoration
nutrients In particular organic sources of nutrients often consist of a substantial pool of relatively slow release materials
For SRC cultivation on marginal land it may be use-ful to add more organic matter than is strictly necessary to support SRC cultivation to
bull enhance any risk management benefit from added organic matter and
bull maximise income from any on-site green waste composting operations
Problems of compost quality for soil improvement include the possible presence of plant andor animal pathogens the possibility of their containing toxic sub-stances andor litter and their content of propagules for weeds The quality of the organic compost additions must be controlled to ensure that the addition of these materials does not have a contaminating effect on the site
Typically control of pathogens is attempted by using some form of processing to treat the organic mat-ter for example digestion or composting Where com-posting is effective acute problems due to pathogens are unlikely indeed some benefits of suppression of soil borne pathogens may occur (Bardos and Lopez-Real 1989) Dust can be a problem when composted or other stored organic wastes are moved in particular the possibility of the dust containing allergens (Lacey et al 1990)
Contaminating materials and substances can be a particular concern While toxic organic substances are unlikely to be a concern for composts from municipal waste and sewage sources Vogtmann and Fricke 1992) litter1 and toxic metals may be present at unacceptable levels
The content of weed seeds and viable root fragments can be a problem for many organic wastes used as amendments These propagules can persist through digestion processes (eg tomato seeds in sewage sludge) but are a particular problem for most current green waste composts that are produced by windrow turning Weeds may interfere with biomass establish-ment but their longer term effect is likely to be limited as they are shaded out by the SRC canopy
UK CASE STUDY MARKHAM WILLOWS
In the United Kingdom there are reputedly over one thousand redundant or abandoned coal mine sites Most of these sites share common features They are usually
bull owned by the public sectorbull unsuitable in whole or in part for commercial devel-
opmentbull chemically contaminatedbull physically unstablebull subject to erosionbull unsightlybull an economic burden on their owners potentially for
generations to come
Markham Willows is a large project that will take place on the north spoil tip of the former Markham Col-liery (Figure 5) The former Markham Colliery and its extensive spoil tips span the Bolsover Northeast Der-byshire and Chesterfield District Boundaries The site lies to the East of the M1 Motorway between Junctions 29 and 30
Markham Willows will initially implement 60 ha of short rotation coppicing and regular organic matter addition as a means of managing the land providing beneficial reuse of wastes such as green wastes and sewage sludge and stabilising or containing contami-nants in the former colliery spoil heap The intention is that Markham Willows will generate revenue from sales of heat and composting services to provide for the economically sustainable management of the land into the future Markham Willows also has an important social dimension in the promotion of local regenera-tion community enablement and lsquogreen tourismrsquo
Markham was seen as an opportunity for a holistic approach to biomass-based land management for sev-eral reasons
bull the existing derelict nature of much of the sitebull strong local authority and regional development
agency support and the existence of partners such as Groundwork Creswell who could provide an effec-tive and durable link to local communities
bull the ambitious regeneration proposals for the area including the proposed commercial development initiatives to be served by the nearby M1 Motorway junction 29a and the Markham Employment Growth Zone (MEGZ)
The Markham Willows project not only forms a vital part of the sustainable regeneration of the Markham area but will also provide a new focus and identity for a major part of the North DerbyshireNorth Nottinghamshire coalfields region through its potential
1 Litter refers to particulate contaminants such as glass plas-tic polythene and pieces of metal These contaminant materi-als will have potential negative effects on the use of the compost and have considerable negative aesthetic impacts Where large metal pieces glass and plastics are incorporated in the composted materials they may cause damage to machinery used to apply the compost and subsequently culti-vate the site and be a hazard to humans and animals
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
334
Land Contamination amp Reclamation Volume 11 Number 3 2003
position as an internationally recognised example of environment-led regeneration
The project seeks to integrate organic matter reuse SRC willow growing and phytoremediation works into a coordinated and synergistic range of environmentally focused activities that could in turn promote local com-munity business formation the development of train-ing opportunities and community involvement of a truly fundamental nature
In particular it is considered that the project could provide a wide range of opportunities for social enter-prise formation in a range of activities such as wood-landcoppice management green waste composting materials recycling linked to the proposed business park (that could in turn support the development of a lsquogreen business parkrsquo) and woodland enterprises pos-sibly linked to the green tourism industry
The lsquotechnical corersquo objectives of the Markham Willows project will be the regeneration of despoiled ex-colliery land through the utilisation of biological processes associated with SRC and the concomitant build-up of organic materials to form soils and by so doing contain and lsquofixrsquo contaminants As part of the core objectives the coppice material is to be utilised as a feedstock fuel for a biomass-energy plant that will powerheat the proposed industrial park
The partners in the project are Derbyshire County Council exSite AEA Technology PLC r3 Environ-mental Technology Limited and Groundwork Enviro-sphere has been commissioned by the project partners to work with Groundwork Creswell to support their
activities in the project Funding partners include shanks first fund Derbyshire County Council East Midlands Development Agency and Groundwork
DUTCH CASE STUDY OOSTWAARDHOEVE
Oostwaardhoeve is an experimental farm in the north
FIGURE 5 THE FORMER MARKHAM COLLIERY FROM THE AIR
FIGURE 6 SEDIMENT IN SRC FOR REMEDIATION ONE YEAR AFTER APPLICATION TO AN EXISTING WILLOW CROP
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
335
The practical use of short rotation coppice in land restoration
west of the Netherlands Cultivation of willows as bio-mass for energy production has been studied since 1993 From 1996 this cultivation has been combined with the remediation (landfarming) of polluted sedi-ments During this treatment the quality of the sedi-ment improves due to biodegradation of PAHs and mineral oil At the moment 20 ha are used for the com-bination cultivation of willows and the bioremediation of sediments It is the intention to increase the area used to 100 ha
Work began as a project of the Wageningen research institutes IMAG and Alterra and the contractor De Vries en van de Wiel in Schagen Initial projects were successful and Oostwaardhoeve is now functioning commercially (in co-operation with IMAG and De Vries en van de Wiel) and combines this with further development of the concept The activities of Oost-waardhoeve Co are strictly regulated by Dutch envi-ronmental legislation which requires regular checks on soils sediments and water the very careful transport and application of the polluted sediments and thorough bookkeeping
The proper application of sediments on a hectare scale requires a thorough macro-filtration of the sedi-ment so that objects that may be encountered in the sediments removed from the bottom of waterways such as bicycles safes car wheels etc are removed before the sediment is transported to the landfarm Application of sediment in an even layer on the land requires experience and technical skill to tune the pumping equipment to the acceptable variation of qual-ity and quantity of the applied sediment At this site it appeared easier to apply sediments to an existing wil-low crop than to establish a new crop on a layer of fresh
sediment (Figure 6) On the other hand the existing crop presented a barrier towards the even distribution of sediment On average approximately 10 m of sedi-ment was applied to the land eventually leaving approximately 05 m of matured sediment With this concept 10 to 20 years of landfarming are available to clean the sediments to the extent that the remaining material fulfils the requirements for reuse (Breteler et al 2001)
The crops are harvested in the winter during periods when it is possible to drive on the land (dry or frosty conditions) The harvested willow stems are dried com-pletely in the field as shown in Figure 7 and are not cut Cut willow is easily composted which reduces the ben-efit for energy supply (Gigler 2000)
CONCLUSIONS
Development of polluted sites is often hampered by the presence of contaminants These sites can be rapidly returned to an economic use with SRC
The SRC farming also creates opportunities for the reuse of organic wastes and for managing the risks from derelict or contaminated land in the long term using a process that effectively pays for itself
Furthermore the return of economic activity to the land can be a focus for community regeneration efforts and return a blighted environment to a more appealing condition supporting local employment and commu-nity pride without local authorities incurring large long-term financial commitments
FIGURE 7 WHOLE ROD HARVESTING OF SRC ON OOSTWAARDHOEVE THE STEMS ARE DRIED NATURALLY IN THE FIELD
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
336
Land Contamination amp Reclamation Volume 11 Number 3 2003
REFERENCES
Aitchison EW Schnoor JL Kelley SL and Alvarez PJJ (1997) Phytoremediation of 14-dioxane by Hybrid Poplars Proceedings of the 12th Annual Conference on Haz-ardous Waste Research 20-22 May 1997 Kansas City Mis-souri
Anderson TA and Coats JR (eds) (1994) Bioremediation through Rhizosphere Technology ACS Symposium Series 563 American Chemical Society Washington DC USA ISBN 08412 2942 2
Anon (1996) Short Rotation Coppice for Energy Produc-tion Good Practice Guidelines ETSU for the DTI Now available from British Biogen London
Armstrong AT (1999) Establishment of Short Rotation Coppice Forestry Commission Practice Note 7 Forestry Commission Edinburgh
Baker AJM and Brooks RR (1989) Terrestrial plants which hyper-accumulate metallic elements ndash a review of their distribution ecology and phytochemistry Biorecovery1 81-126
Baker AJM McGrath SP Sidoli RD and Reeves RD (1994) The possibility of in situ heavy metal decontamina-tion of polluted soils using crops of metal-accumulating plants Resources Conservation Recycling 11 41-49
Bardos RP and Lopez-Real JM (1989) The composting process susceptible feedstocks temperature microbiology sanitisation and decomposition pp 179-190 In Proc CEC Workshop on Compost Processes in Waste Management Neresheim Germany 13-15 Sept 1988 (Bidlingmaier W and LHermite P eds) E Guyot SA Belgium CEC ISBN 2872630198
Bardos RP French C Lewis A Moffat A and Nortcliff S (2001) Marginal Land Restoration Scoping Study Infor-mation Review and Feasibility Study exSite Research Project Report 1 ISBN 0953309029 LQM Press (Notting-ham)
Barton MR (2000) Lessons learned the Groundwork approach to delivering a large-scale programme of brown-field land reclamation In Proceedings of the Conference lsquoBeyond Brownfields Towards Equitable and Sustainable Developmentrsquo PICCED New York 2000
Breteler H Duijn R Goedbloed P and Harmsen J (2001) Surface treatment of polluted sediments in an energy plantation In Magar VS von Fahnestock FM and Lee-son A Ex situ Biological Treatment Technologiesthe Sixth International in situ and on-site Bioremediation Symposium pp 59-63 Battelle Press Columbus
Costigan PA Bradshaw AD and Gemmell RP (1981) The reclamation of acidic colliery spoil I Acid production potential Journal of Applied Ecology 18 865-878
Department of Trade and Industry (1998) Energy from Bio-mass Summaries of Biomass Projects Carried Out as part of the Department of Trade and Industryrsquos New and Renewable Energy Programme ETSU BM0400048
Department of Trade and Industry ndash DTI (2003) Our Energy Future ndash Creating a Low Carbon Economy Report to Parlia-ment February 2003 CM 5761 The Stationery Office Nor-wich
Dragun J (1988) The fate of hazardous materials in soils Part 3 Haz Mat Control 1 24-43
Ferguson C and Kasamas H (1999) Risk Assessment for Contaminated Sites in Europe Volume 2 Policy Frame-works Report of CARACAS Project Concerted Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham ISBN 0953 309010
Ferguson C Darmendrail D Freier K Jensen BK Jensen J Kasamas H Urzelai A and Vegter J (1998) Risk Assessment for Contaminated Sites in Europe Volume 1 Scientific Basis Report of the CARACAS Project Con-certed Action on Risk Assessment for Contaminated Sites in the European Union LQM Press Nottingham
Forestry Commission (1995) Short Rotation Coppice in the Landscape Forestry Commission Forestry Practice Advice Note 1 Edinburgh
Gigler J (2000) Drying of Willow Biomass in Supply Chains Phd thesis Wageningen University Wageningen the Netherlands
Harmsen J (2001) Bioremediation of polluted sediment a matter of time or effort In Leeson A Foote EA Banks MK and Magar VS Phytoremediation Wetlands and Sedi-ments The Sixth International in situ and on-site Bioremedi-ation Symposium pp 279-287 Battelle Press Columbus
Harmsen J Wieggers HJJ van de Akker JJH van Dijk-Hooyer OM van den Toorn A and Zweers AJ (1997) Intensive and extensive treatment of dredged sedi-ments on landfarms In Leeson A and Alleman BC eds Fourth International in situ and on-site Bioremediation Sym-posium (New Orleans Louisiana April 28-May 1 1997) Battelle Press Columbus
Hatzinger PB and Alexander M (1995) Effect of ageing chemicals in soil on their biodegradability and extractability Environ Sci Technol 29 537-545
Japenga J (1999) Phytoremediation Ready for Use in the Netherlands Integrated Soil Research Programme Wage-ningen Report 24
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
337
The practical use of short rotation coppice in land restoration
Jones LHP and Jarvis SC (1981) The fate of heavy met-als In The Chemistry of Soil Processes (Greenland DJ and Hayes MB eds) pp 593-620 Wiley Chichester
Kraatz M Yammering C and Schroeder D (1993) Devel-opment of soil microbial activities soil fauna and humic matter during remediation and recultivation of PAH-contam-inated soil In Contaminated Soil 93 pp 947-948 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) Kluwer Acad Pub Dordrecht
Labrecque M Teodorescu TI and Daigle S (1994) Effect of sludge application on early development of two Salix spe-cies productivity and heavy metals in plants and soil solu-tions In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 157-165 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sci-ences Report 50
Lacey J Williamson AM King P and Bardos RP (1990) Airborne Micro-organisms Associated with Domestic Waste Composting LR 808 (MR) Warren Spring Labora-tory Gunnels Wood Road Stevenage SG1 2BX UK ISBN 85624 6662
Lamar RT Glaser JA and Kirk TK (1990) Fate of pen-tachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium mineralisation volatilization and depletion of PCP Soil Biology and Biochemistry 22 433-440
Lotter S Brumm A Bundt J Herrenklage J Paschke A Steinhart H and Stegmann R (1993) Carbon balance of a PAH-contaminated soil during biodegradation as a result of the addition of compost In Contaminated Soil lsquo93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1235-1246 Kluwer Acad Pub Dordrecht
Mahro B and Kaestner M (1993) Mechanisms of micro-bial degradation of polycyclic aromatic hydrocarbons (PAH) in soil-compost mixtures In Contaminated Soil 93 (Arendt F Annokkee GJ Bosman R and van den Brink WJ eds) pp 1249-1256 Kluwer Acad Pub Dordrecht
Moffat AJ and McNeill JD (1994) Reclaiming Disturbed Land for Forestry Forestry Commission Bulletin 110 HMSO London
Novem (2002) Energy from the Rural Area Use of Agricul-tural Residues for Sustainable Energy Novem Utrecht
Oumlstmann G (1994) Cadmium in Salix ndash a study of the capacity of Salix to remove cadmium from arable soils In Willow Vegetation Filters for Municipal Wastewaters and Sludges pp 153-155 (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50
Paterson S Mackay D Tam D and Shiu WY (1990) Uptake of organic chemicals by plants a review of proc-
esses correlations and models Chemosphere 21 (3) 297-331
Punshon T and Dickinson NM (1997) Mobilisation of heavy metals using short-rotation coppice In Biomass and Energy Crops (Bullard MJ Ellis RG Heath MC Knight JD Lainsbury MA and Parker SR eds) Aspects of Applied Biology 49 285-292
Riddell-Black D (1994) Heavy metal uptake by fast grow-ing willow species In Willow Vegetation Filters for Munici-pal Wastewaters and Sludges (Aronsson P and Perttu K eds) Swedish University of Agricultural Sciences Report 50 pp 145-151
Riddell-Black D Pulford ID and Stewart C (1997) Clonal variation in heavy metal uptake by willow Aspects of Applied Biology 49 327-334
Ryan JA Bell RM Davidson JM and OrsquoConnor GA (1988) Plant uptake of non-ionic organic chemicals from soils Chemosphere 17 (12) 2299-2323
Schnoor JL Licht LA McCutcheon SC Wolfe NL and Carreira LH (1995) Phytoremediation of organic and nutrient contaminants Env Sci Tech 29 318A-323A
Sims RC and Harmsen J (2001) Conseptual Description of Landfarming for Sustainable Restoration of Soils World-wide In Magar VS von Fahnestock FM and Leeson A Ex situ Biological Treatment Technologies The Sixth Inter-national in situ and on-site Bioremediation Symposium 1-8 Battelle Press Columbus
Sposito G (1989) The Chemistry of Soils Oxford Univ Press Oxford
Stegmann R Lotter S and Heerenklage J (1991) Biologi-cal treatment of oil contaminated soils in a bioreactor In On-site Bioreclamation Processes for Xenobiotic and Hydrocarbon Treatment (Hinchee RE and Olfenbuttel R eds) pp 188-208 Butterworth-Heinemann
Sytsma L Mulder J Schneider J et al (1997) Uptake and fate of organohalogens from contaminated groundwater in woody plants Proceedings of the 213th National Meeting of the American Chemical Society 13-17 April 1997 American Chemical Society Washington DC
Tabbush P and Parfitt R (1999) Poplar and willow varie-ties for short rotation coppice Forestry Commission Infor-mation Note 17 Forestry Commission Edinburgh
US EPA (1999) Phytoremediation Resource Guide Office of Solid Waste and Emergency Response Document EPA 542-B-99-003 EPA Washington DC 20460
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
338
Land Contamination amp Reclamation Volume 11 Number 3 2003
US EPA (2000) Introduction to Phytoremediation Office of Research and Development EPA 600-R-99-107 httpclu-inorgtechpubshtm
Vogtmann H and Fricke K (1992) Organic chemicals in compost how relevant are they for the use of it In Com-posting and Compost Quality Assurance Criteria Proc ECDGXII Workshop (Angers France Sept 11ndash13 1991) Jack-son DV Merillot J-M and LHermite P eds pp 227-236 CEC Report EUR 14254 EN
Weber WJJr McGinley PM and Katz LE (1992) A dis-tributed reactivity model for sorption by soils and sediments
1 Conceptual basis and equilibrium assessments Environ Sci Technol 16 1955-1962
West CC (1994) Natural organic matter supports reductive dechlorination of PCE EPA Ground Water Currents 10 EPA Pub EPA-542-N-94-009
Xing B Pignatello JJ and Gigliotti B (1996) Competi-tive sorption between atrazine and other organic compounds in soils and model sorbents Environ Sci Technol 30 2432-2440
