The Landfill Directive & its implications for Remediation
Jan GronowScience Manager - Waste & Remediation
Contents▪ Requirements & implications of LFD▪ Classification of LF sites▪ Treatment & sorting▪ WAC development▪ The testing hierarchy ▪ Sampling▪ Characterisation▪ Compliance testing▪ Monolithic wastes
Acknowledgements
▪ Remediation in the context of the LFD Steve Gibbs & colleagues at Atkins Design, Environment Engineering
▪ Sampling & Testing:Kathy Lewin, Jane Turrell & Julian Ellis at WRc
▪ WACs David Hall & colleagues at Golder Associates (UK) f
The Landfill Directive
▪ The Landfill Directive & its associated decision document has a significant impact in those parts of Europe that do not have a waste management infrastructure based on incineration.
▪ Planning for the required changes gives an opportunity to review:▪ the cost; & ▪ the sustainability of the measures put in place.
The requirements that most affect remediation
▪ the classification of LFs and the end of the co-disposal of haz with non-haz wastes;
▪ prohibition of certain waste types from LF;▪ pre-treatment of wastes before LF; ▪ the general characterisation and testing of waste to
be landfilled ▪ the setting of waste acceptance criteria for the
deposit of waste in inert sites and the landfilling of hazardous waste.
Waste Acceptance Criteria▪ most waste to be treated prior to Landfillng▪ inert waste sites -limit values define inert waste▪ non-haz sites - demonstrate waste is not haz▪ limit values apply only to SNRHW & wastes co-
disposed with them ▪ they define SNRHW & ∴treatment objectives for haz
waste going to non-haz sites▪ others set by permit
▪ haz waste sites - defined by EWC & HWD▪ limit values set upper limits for the landfilling of Haz
waste
Hazardous Waste Sites▪ Haz waste defined by new EWC & HWD - not by
WACs
▪ Ban on co-deposit of haz & non-haz wastes,▪ Requirement to treat wastes prior to disposal.▪ Stringent nature of WAC for haz waste sites (TOC
6% or 10% LOI)
▪ even more stringent criteria for the placement of SNRHW (TOC 5%)
New categories for soil wereestablished by the revised EWC.17 05 soil (including excavated soil from
contaminated sites), stones & dredging spoil
17 05 03* soil and stones containing dangerous substances
17 05 04 soils and stones other than those mentioned in 17 05 03
17 05 05* dredging spoil containing dangerous substances
17 05 06 dredging spoil other than those mentioned in 17 05 05.
to landfill a contaminated soil
▪ it must have been treated;▪ the resultant product must not be a prohibited
waste;
▪ the product must be characterised ▪ it must be assessed as to whether it is haz or non-
haz;
▪ the product must comply with the WAC for the most appropriate class of landfill.
What is Treatment?A physical, thermal, chemical, or biological process (including sorting) that changes the characteristics of waste in order to:▪ reduce its quantity;▪ reduce its hazardous nature; ▪ facilitate its handling (in the LF); or ▪ enhance recovery. Dilution via mixing with uncontaminated media to meet WACs is not acceptable; nor is:▪ bagging▪ wetting▪ compaction
Sorting
▪ This appears to have potential in the short term for remediation of soils.
▪ The segregation of haz soils from non-haz is required & is likely to have economic benefits.
▪ If sorting is to be regarded as a treatment, not all of the resulting fractions can be landfilled - one fraction at least must be diverted from landfill.
WAC Development
▪ A procedure based on GW modelling to establish a relationship between: ▪ the behaviour of inorganic contaminants released by
leaching from waste in a LF; & ▪ the risk these contaminants pose to GW.
▪ Used back-calculation: ▪ from GW quality criteria at specific compliance points
downstream of the LF;▪ to corresponding limit values for the results of leaching
tests on the waste ▪ assessed sensitivity to assumptions made & to account for
this when limit values were set.
A Scenario for mobile contaminants
POC1 POC2
GWF
B Concentration at points of compliance
Waste
GWL
C C
Time Time
Percolation test data
1
10
100
1000
10000
0.1 1 10L/S (l/kg)
Con
cent
ratio
n (m
g/l)
Time(y)10 100 1000
100
1000
10000
0.1 1 10L/S (l/kg)Cum
ulat
ive
leac
hed
amt (
mg/
kg)
Wash-out
Time(y)10 100 1000
POC1
GWQPOC2
C
Scenario for retarded contaminantsA
POC1 POC2
GWF
Waste
GWL
B Concentration at targets
C
Time
Percolation test data
POC1
C
0.001
0.01
0.1
1
10
0.1 1 10L/S (l/kg)
Cum
ulat
ive
leac
hed
amou
nt(m
g/kg
)
Time(y)10 100 1000
0.001
0.01
0.1
1
10
0.1 1 10L/S (l/kg)
Con
cent
ratio
n (m
g/l)
Time(y)10 100 10
GWQ
Three Tier Hierarchy of Testing
▪ Level 1 - Characterisation- the responsibility of the person sending the
waste to landfill
▪ Level 2 - Compliance Checking- the responsibility of the operator
▪ Level 3 - on-site verification of every load- the responsibility of the operator
Sampling
▪ There is absolutely no point in doing any testing unless the sample has been chosen correctly
▪ For the sampling of waste, a sampling plan shall be developed according to part 1 of the standard (prEN 14899:2004)
▪ The plan should include everything from the sampling objectives to the toolbox of appropriate methods for the site specific situation.
Basic Characterisation▪ source & origin of the waste;▪ process producing the waste ▪ appearance; ∗ EWC code; ∗ relevant hazard properties; ▪ whether the waste can be recycled or recovered;▪ waste treatment applied (Reg 10(1)) ∗ composition, other characteristic properties & where relevant,
leaching test values;▪ demonstrate the waste is not prohibited under Reg 9;▪ LF class at which the waste may be accepted;∗ likely behaviour in a LF (& if relevant, leaching behaviour) & any
precautions to be taken at the landfill; ∗ key variables
Characterisation Testing (1)▪ If hazardous - any testing to demonstrate which
hazard etc. ▪ Composition ▪ there are standard methods for:▪ sample preparation▪ sample digestion▪ analysis of digestate
▪ To inform compliance testing▪ key variables▪ variability
Characterisation Testing (2)
▪ total availability EA NEN 7371:2004▪ pH dependence prEN 14997:2004 or
prCEN/TS 14429:2003▪ Leaching characteristics▪ upflow percolation prCEN/TS 14405:2003▪ standard leaching ▪ granular BS EN 12457:2002▪monolithic EA NEN 7375:2004
CEN TC 292 Model
Compliance Testing▪ When waste has been deemed acceptable for LF it
shall be subject to compliance testing.
▪ Compliance testing is to check that the waste complies with the basic characterisation
▪ The parameters to be tested are determined by the basic characterisation.
▪ The compliance tests used shall be one or more of those used in the basic characterisation.
▪ Compliance testing shall be carried out at least once a year at the frequency determined by the basic characterisation.
Regularly Generated Wastesderived from a process with well-defined inputs that generates waste with consistent characteristics & constituents within known boundaries▪ requires infrequent characterisation but more stringent
compliance testing a more inconsistent waste produced regularly as a result of variable inputs &/or a variable ‘recipe’ (e.g. merchant treatment plant, aggregate recovery plant or waste transfer plant). ▪ requires frequent characterisation
Both types require compliance testing
One-off Wastes▪ Compliance testing is required for all wastes
except ‘one-off’ consignments:▪ Q these are characterised immediately before
arriving at site;▪ they are individual wastes that exist & where
all of the waste is available to be sampled for characterisation;
▪ characterisation is representative of the whole consignment which might be several loads delivered over several days.
Monolithic Wastes
Generally non-granular, deliberately produced waste forms
Monolithic WACs produced to provide the same degree of environmental
protection as the granular ones
Characterisation of plant output
▪ Wastes entering waste-forming plant must meet TOC or LOI limits
▪ plant should provide appropriate number of monolithic testing samples at start-up & whenever the feed to the plant or the ‘recipe’ changes
▪ >40mm in any direction ▪ Compressive Strength of 1.5 MPa or greater
depending on site conditions.
Characterisation of wastes for a site risk assessment (1)▪ 8 stage 64 day EA NEN 7375:2004 tank test gives
long term diffusive leaching from the waste product. ▪ Cumulative data should meet full 64 day leaching
limit values for monolithic wastes.▪ If a cementaceous binder is used the waste forms
should cure for 28d, as the test also indicates the longevity of the waste form.
▪ The test is to demonstrate that emissions result from diffusion & not from advection or a solubility controlled mechanism
Characterisation of wastes for a site risk assessment (2)▪ The following tests on the ground monolith are used
for LF site risk assessments to:▪ quantify the source term; and ▪ to predict changes in leachability should the
monolith be overlain by waste of different pH & buffering capacity.
▪ max availability for leaching (EA NEN 7371:2004); ▪ pH dependent leaching (prCEN/TS 14429:2003); and▪ calculation of ANC/BNC
Compliance testing at the LF
▪ A shortened version of the standard 64 day tank test (EA NEN 7375:2004).
▪ Cumulative leaching from the first 4 steps of the test is the benchmark for periodic compliance testing.
▪ Samples must be >40mm in any direction.▪ There is no requirement to cure the sample ▪ WAC for monolithic wastes are ¼ of the values given
for Level 1 characterisation.
▪ No need to determine EC at compliance.
Conclusions
▪ The LFD introduces a raft of measures with considerable implications for the remediation of contaminated soils.
▪ These measures entail: ▪ increased responsibilities for waste holders to
characterise their wastes, ▪ a significant increase in the cost of landfilling ▪ a reduction in the number of landfill sites.
▪ it is time to invest in treatment technologies that reduce reliance on landfilling.