Arboricultural Report...within BS5837. These areas are shown as a dashed red line at the appropriate...

Arboricultural Report

Tree Survey Arboricultural Impact Assessment & Tree Protection Plan

St Leonards Academy Filsham Valley School Edinburgh Road St Leonards-on-Sea TN38 8HH Grid Ref: TQ 7845 0945

Prepared by:

The Mayhew Consultancy

30 Fair Lane Robertsbridge East Sussex TN32 5AS Tel: 07711 673138 www.cmarb.co.uk

AR/11411 October 2011

AR/11411 – St Leonards Academy, Filsham Valley School, Edinburgh Road, St Leonards-on-Sea. TN38 8HH

The Mayhew Consultancy Page 2 of 11 October 2011

Contents

Section

Title

Page

1.0 Details of survey 3

2.0 Instructions 3

3.0 Summary 4

4.0 Documents supplied 5

5.0 Site details 5

6.0 Planning history 5

7.0 The proposal 5

8.0 Existing trees 6

9.0 Arboricultural Impact Assessment 7

10.0 Tree Protection Measures 8

11.0 Tree works 11

12.0 Sequence of works 11

13.0 Recommendations 11

14.0 Conclusion 11

Appendix A General site plan and Location A

Appendix B Location B – Existing

Appendix C Location B – Proposed

Appendix D Location C – Existing and Proposed

Appendix E Tree survey

Appendix F Tree survey key

Appendix G BS 5837 Table 1 – Cascade chart for tree quality assessment.

Appendix H BS 5837 Figure 2 - Tree protection fencing

Appendix I BS5837 Figure 3 – Ground protection in Root Projection Areas

Appendix J Sample tree protection warning sign

Appendix K Sample specification for no-dig cellular confinement systems

Appendix L 1) Scope of this report 2) Survey method



1.0 Details of survey The Site: St Leonards Academy, Filsham Valley School,

Edinburgh Road, St Leonards-on-Sea. TN38 8HH

Grid Ref: TQ 7845 0945

Mayhew Consultancy Ref: AR/11411

Local authority: Hastings Borough Council

Survey date: 4th October 2011

Report date: 8th October 2011

Surveyed by: Clive Mayhew BA (Hons), MICFor, M.Arbor.A., CEnv

2.0 Instructions 2.1 I am instructed to:

1) Survey the trees potentially affected by the proposal. 2) Produce an arboricultural report which is compliant with the

recommendations contained within ‘BS5837 Trees in Relation to Construction’ 2005

2.2 My name is Clive Mayhew and I am the author this report. I have over 20

years experience in tree, landscape and ecology management in both the public and private sectors. I am a Chartered Arboriculturist within the Institute of Chartered Foresters, a Chartered Environmentalist, and a Professional Member of the Arboricultural Association.



3.0

Summary

3.1 Site summary:

The subject site is at St Leonards Academy, Filsham Valley School, Edinburgh Road, St Leonards-on-Sea. TN38 8HH

3.2 Proposal summary: The proposal is to undertake a range of building works across the school site, of which works in three locations are in close proximity to existing trees.

3.3 Existing trees (Section 8 refers): I surveyed 4 individual trees and two groups of trees.

3.4 Consequences of development on trees (Section 9 refers): Location A - All existing trees will be removed. Location B - No existing trees will be removed. Location C – A strip of young trees will be removed.

3.5 Tree Protection (Section 10 refers): In order to protect the root systems of retained trees the following tree protection measures would be required: Location A – No specific measures. Locations B and C -

1. The installation of protective fencing during the construction period.

2. The adoption of appropriately robust ground protection measures –

particularly in location B - for the duration of the development period.

3.6 Conclusion:

If the advocated tree protection measures are specified, installed and adequately supervised, I consider that the proposal can be successfully implemented while protecting the retained trees to a level which complies with current arboricultural standards.



4.0

Documents supplied

1) An annotated drawing by EDCO Design London. Drawing number: C460 - D003 Dated: May 2011

5.0 Site details

5.1 The subject site is a school located off Edinburgh Road, St Leonards-on-Sea, which is a public highway. The general landscape character of the area is suburban.

5.2 Existing structures: The northern part of the site is extensively developed with school buildings, and parking, recreation and sports areas, interspersed with open spaces.

5.3 Existing topography: The site slopes generally – and in some locations quite

steeply – from west to east.

5.4 Existing vegetation: Ground vegetation across the open areas of the site is

predominantly close-mown amenity grass. Scattered individual trees and young groups of trees planted for screening and general landscape amenity are also present.

5.5 Soils: The British Geological Survey website indicates the bedrock soil

geology to be comprised of mudstones from the Wadhurst clay formation. The impression I gained during my site inspection was that much of the soil is made up ground containing a high percentage of subsoil, presumably as a result of previous construction works. The occurrence of clay within the soil means that it could be susceptible to compaction and this characteristic can be highly damaging to tree roots. The tree protection measures recommended in this report recognises this potential.

6.0 Planning history

6.1 I have been given no details regarding the planning history of the site.

7.0 The proposal

7.1 The proposal is to undertake a range of building works across the school site, of which works in three locations are in close proximity to existing trees.



8.0

Existing trees

8.1.1 I surveyed 4 individual trees and two groups of trees in detail. All of these trees are located within the three areas of construction activity illustrated at Appendix A. The tree survey information is appended to this report (Appendix E).

8.1.2 I classed all the trees according to the classifications outlined within BS5837

‘Trees in Relation to Construction’ 2005 (See Appendix G).

8.1.3 I classified 1 individual tree as A grade. BS5837 considers that A grade trees are of high quality and value, and in such a condition as to make a substantial contribution to the general amenity of the area in which they stand. A minimum of 40 years contribution is suggested.

8.1.4 I classified 3 individual trees and one group of trees as B grade. BS5837 considers that B grade trees are of moderate quality and value, and in such a condition as to make a significant contribution to the general amenity of the area in which they stand. A minimum of 20 years contribution is suggested.

8.1.5 I classified 1 individual tree and one group of trees as C grade. BS5837 considers that C grade trees are of low quality and value but in such a condition as to make an adequate contribution to the general amenity of the area in which they stand, either because they are young trees or because they can remain until new planting is established. A minimum of 10 years contribution is suggested.

8.2

Description of trees

8.2.1 A Grade tree: Holm oak T1 is in a prominent position adjacent to the public footpath which runs along the northern boundary of the site.

8.2.2 B Grade trees: T2 oak is slightly smaller and has poorer form than T1 but is in the same prominent position adjacent to the public footpath which runs along the northern boundary of the site. T3 oak is a mature, ex-hedgerow tree located to the south of the main entrance drive. G5 is a linear group of young native trees planted to the south of the main entrance drive. Collectively their impact is significant and warrants a B grade.

8.2.3 C Grade trees: T4 ash is an individual tree within G5 which is larger than the trees immediately surrounding it. G6 is a group of young, predominately native trees, growing at Location A. Individually these trees possess little merit or public amenity.



9.0

Arboricultural Impact Assessment

9.1 The recommendations made here relating to tree retention, removal and planting are informed by current arboricultural, planning and urban design best practice, primarily British Standard 5837: Trees in Relation to Construction 2005, which advocates a pragmatic approach to tree removal and retention, based on sustainability.

9.2 Trees requiring removal irrespective of the proposal:

9.2.1 None of the inspected trees are considered to be in such a poor structural condition as to require removal irrespective of the outcome of this proposal.

9.3 Trees requiring removal as a consequence of the proposal:

9.3.1

Location A – All of the trees will be lost as a consequence of the proposal. Significance: The trees at this location are a landscape native planting mix, along with some additional ornamental cypresses. Collectively these trees form a green mass that contributes to the immediate landscape. I do not believe, however, that the contribution is significant, and most of the general visual amenity from these trees is lost by the fact that the plot lies between two residential housing terraces.

9.3.2 Location B – No trees will be lost at this location.

9.3.3 Location C – A strip of young trees parallel with the existing roadway will be lost as a consequence of the proposal. Significance: The removal of the strip of trees is necessary to allow new parking bays to be accommodated. The trees are growing in a dense group which has established well. I consider that the removal of a strip of trees from the outer edge would have little impact on the general visual amenity of the area, or degrade the screening effect they have on neighbouring properties.

9.4 Impact of the proposal on retained trees

9.4.1 The proposal has the potential to impact on retained trees and as a consequence tree protection measures are recommended below.



10.0

Tree Protection Measures

10.1 Root Protection Areas (RPAs)

The identification of Root Protection Areas is the primary means by which retained trees are protected on construction sites. No unspecified activity should occur within any prescribed Root Protection Area, access should only be permitted with prior approval of the Local Planning Authority, and encroachment should normally only take place if the ground beneath is suitably protected.

10.1.2 BS5837 provides arboriculturists with a method to determine the extent to which excavations associated with construction works might have a damaging effect on the roots of adjacent trees. The Standard enables a Root Protection Area to be calculated for each retained tree, and this is usually described as a circle with a radius at the prescribed distance from the tree. The size of each Root Protection Area is calculated from the tree’s diameter.

10.1.3 I have calculated the Root Protection Areas of the existing trees as prescribed within BS5837. These areas are shown as a dashed red line at the appropriate appendices attached to this report, and each figure is included within the survey schedule at Appendix E.

10.1.4 BS5837 gives general guidance for the calculation of RPA’s, but it also recognises that in appropriate circumstances it is possible to off-set the RPAs of individual open grown trees by up to 20% - so long as this adjustment can be reflected in a corresponding increase in a different area of the same RPA. I have not applied this off-set provision to any of the surveyed trees.

10.2 RPAs and the subject site:

10.2.1 I have calculated the Root Protection Areas of the existing trees as prescribed within BS5837 - shown as a dashed red line at the appropriate appendices attached to this report.

10.2.2 Location A – RPA information is not relevant to this location as all the trees will be removed.

10.2.3 Location B – It is proposed to install a temporary haul road in Location B which will also necessitate the diversion of the DPROW adjacent to T1 – see Appendix B and C. Both of these proposals will result in activity occurring within the RPAs of adjacent trees and the following tree protection measures are recommended as a result: The haul road: The haul road is routed through the RPAs of T1 and T2. No excavation works are anticipated but the ground in these locations will need to be protected in order to prevent soil compaction. Compaction can render clay soils aerobic and consequently any roots which might be present within them can die. Any ground protection within this area will need to be sufficiently robust to prevent the weight of passing vehicles from compacting the soil beneath. The final specification of the protection adopted will need to be agreed with the Local Authority’s tree officer, but I would recommend that a double layer artificial track way is laid on a 100mm bed of wood mulch within the RPAs of the retained trees – the much can be left in situ at the end of the construction period because it will be quickly absorbed into the ground where it will act as a soil conditioner.



The footpath diversion: The proposed temporary footpath diversion will extend to the north of T1 and along the school boundary fence. My recommendation is that the temporary footpath is constructed off a ‘no-dig’ cellular confinement system as this will provide protection against soil compaction and can then be removed on completion of the construction phase. Additional protection for roots can be achieved by the specification of a cell infill material which allows for moisture infiltration and gaseous diffusion; washed gravel with a low fines content for example. Paragraphs 11.8 – 11.9 of BS 5837 provide detailed guidance for this type of specification. Appendix K details a generic specification for the installation of ‘no-dig’ surfaces. Particular care needs to be taken to ensure that the edges of such confinement systems are retained by predominantly above ground methods such as pegging, rather than kerbs within excavated trenches which would be highly damaging to tree roots. I also noted during my site inspection that an existing flight of concrete steps remains in-situ, though overgrown, at this location. I would suggest that these steps are utilised within the temporary footpath, thus avoiding the need for potentially damaging excavation works to occur within the RPA of T1.

10.2.4 Location C: It is proposed to install a row of parking places and an associated access path along the western edge of the existing main accesses drive. This will necessitate the removal of some trees and the encroachment into the RPAs of others: T3 Oak – The proposed parking spaces stop short of T3 in order to preserve the integrity of its RPA. The final spaces on either side of the tree encroach slightly into the RPA but not to a significant degree. Care will need to be taken, however, to protect the ground adjacent to these spaces. BS5837 recommends a method of protecting the ground against soil compaction in such circumstances and a sample specification for this is illustrated at Appendix I. New path - A new connecting path runs parallel to the existing driveway behind the kerb line. This path is situated within the RPA of T1 and normally a requirement to install ‘no-dig’ surfacing would be specified. In this particular location however I consider that previous construction works have already compromised the RPA in this location by removing any original soil that may have been present and replacing it with made up clay subsoil. There is topographical evidence for this on site where it can be seen that the original hedgerow bank on which T1 stands has been removed adjacent to the driveway and replaced with machine graded soil. I therefore consider that it would be superfluous to specify ‘no-dig’ surfacing in this area, but I would still specify that the ground between the back of the path and the tree be protected as illustrated at Appendix D.

10.3

Protective fencing

10.3.1 BS5837 recommends that the RPAs of the subject trees should be protected by the erection of Tree Protection Barriers, the preferred form of which consists of steel mesh ‘Heras’ type panels 1.8 metres high, mounted on a scaffolding frame as detailed in Figure 2 of BS5837. (See Appendix H). The barriers should carry laminated signs stating: “Construction exclusion zone – Keep out.” (See Appendix J).



10.3.2 The subject site:

Location A – No Tree Protection Barriers are required at this location. Location B – A single Tree Protection Barrier illustrated with a purple dashed line at Appendix C is recommended to: a) Prevent encroachment from the haul road into the RPAs of T1 and T2, and b) Separate the RPA of T1 from the temporary footpath. Location C – A single Tree Protection barrier is recommended to separate the construction activity and the retained trees T3, T4 and G5; this is illustrated with a purple dashed line at Appendix D.

10.4 Construction Exclusion Zones 10.4.1 In some instances discrete portions of a site can be identified from which all

construction activity can be excluded.

10.4.2 The subject site: No specific construction exclusion zones have been identified within this scheme.

10.5 Ground protection 10.5.1 Where works are occurring within the Root Protection Areas of trees, in order

to facilitate development, the ground should be protected against potential root damage, particularly as a result of soil compaction.

10.5.2 The subject site: Details of required ground protection are given in Section

10.2.3 and 10.2.4 above.

10.6

Demolition

10.6.1 There are no demolition works identified within this proposal.

10.7 Other general activities 10.7.1 Many of the activities which occur on construction sites are potentially

damaging to trees. These include the location of site huts, parking arrangements, the storage of materials, the storage of rubbish, and the movement and operation of plant. It is important to understand the range of potentially damaging activities that might occur on a particular site, and ensure at an early stage that these possible conflicts are recognised and avoided. Therefore areas designated for site huts, parking and storage of materials should be identified prior to the commencement of works and agreed with the LPA.

10.7.2 The subject site: This is a large site and there is ample room for storage areas to be safely situated away from trees. The site is also effectively divided by an internal security fence. All construction works will occur to the north of this fence which, in this context, will act as an effective Tree Protection Barrier for the trees located to the south.



11.0 Tree works 11.1 Location A – Works will be required to remove all of the trees at Location A.

Location B – Works will be required to lift the crown of T1 to allow access along the haul road and for clearance above the temporary footpath. Any works that might be required should comply with BS3998:2010 ‘Tree work,’ and be within the confines of currently accepted arboricultural good practice. Location C – Works will be required to remove the strip of trees along the edge of G5.

12.0 Sequence of works

12.1 The sequence of works should be as follows:

1. Erection of protective fencing.

2. Installation of ground protection measures.

3. Construction phase.

4. Removal of ground protection measures.

5. Removal of protective fencing.

13.0 Recommendations 13.1 It is recommended that the tree protection measures advocated in this report

should be followed at all times. Any deviation should only occur following consultation with the local authority’s arboricultural officer, and only then with their specific approval.

13.2 It is recommended that a suitably qualified arboriculturist supervises the installation of the tree protection measures and confirms that they comply with BS5837, and if necessary briefs the individual who will be responsible for the maintenance of tree protection measures for the duration of the works.

13.3 An individual should be identified as a point of contact for arboricultural matters for the duration of the works. This individual will need to be familiar with the arboricultural constraints presented by the site, the tree protection measures that have been installed, and the requirement to keep those measures adequately monitored and maintained.

14.0 Conclusion

14.1 I consider that this scheme is acceptable in arboricultural terms and that the

subject trees can be protected according to current standards, providing the recommended mitigation measures are adopted.

Edin

burg

hR

oad

G6

General Site Location PlanNot to scale

Location A

Location C

Location B

Location A - ExistingScale 1:500

The Mayhew Consultancy30 Fair Lane, Robertsbridge

East Sussex TN32 5DA

Tel:01580 881092 Mobile:07711 673138

E-mail: [email protected]

AR/11411 - St Leonards Academy,St Leonards on Sea.

General Site Plan & Location A

October 2011

Do not scale from drawing

N

APPENDIX A



Tel:01580 881092 Mobile:07711 673138



Location B - Existing

October 2011

1:500 @ A4 - Do not scale from drawing

N

T1

T2

APPENDIX B

Key:

A class tree

B class tree

RootProtectionArea



Tel:01580 881092 Mobile:07711 673138



Location B - Proposed

October 2011

1:250 @ A4 - Do not scale from drawing

N

T1

T2

Indic

ative

line

of tem

porary

haul road

Temporaryfootpathdiversion

APPENDIX C

Key:

A class tree

B class tree

RootProtectionArea

TreeProtectionBarrier

Areas of groundprotection

Existingcar park

Existingcar park

G1

T3T4

Existingcar park

Existingcar park G1

T3T4

Existing

Proposed



Tel:01580 881092 Mobile:07711 673138



Location C

October 2011

1: 500 @ A4 - Do not scale from drawing

N

APPENDIX D

Key:

B class tree

C class trees

RootProtectionArea

TreeProtectionBarrier

Area of groundprotection


APPENDIX E

The Mayhew Consultancy October 2011

Tree Survey – 4th October 2011 Tree No

Species Ht. Stem dia.

RPA Rad

RPA Area

Crown spread N – S – E - W

Crown break

Age class

Phy con

Str con

ECR Class Observations & recommendations

T1 Holm oak 10 69 8.3 215 8 7 7 8 3 M G G L A Fine tree.

T2 Oak 7 101ms 10.1 321 8 3 5 5 1.5 M F F M B Crown has been wind pruned from sea.

T3 Oak 10 73 8.8 241 7 5 6 6 1 M G F L B Hedgerow bank tree.

T4 Ash 7 27 3.2 33 3 3 3 3 2 SM G G L C

G5 Species mix including: Goat willow, thorn, ash, field maple

< 7 10 1.2 - - - - - GL Y G G L B Native species ‘landscaping mix.’ Location and collective amenity warrants a B grade

G6 Species mix including: Goat willow, thorn, ash, field maple, oak and cypress

< 8 15 1.8 - - - - GL Y G G M C Native species ‘landscaping mix.’ Less prominent than G5.



Survey sheet key

Tree No Tree reference number as used in the report and survey plan T = Tree G= Group H = Hedge W = Woodland

Ht Tree height in metres

Stem dia. Stem diameter in millimetres Measured at 1.5 metres above ground level, or immediately above the root flare of multi-stemmed trees M = Multi-stemmed tree

Crown sp. N S E W

Crown spread measured in metres from the stem to the four compass points

Crown break Height of crown clearance above adjacent ground level, given in metres

Age class Age class Y = Young: Staked or newly established tree SM = Semi-mature: An established tree at a stage of rapid growth M = Mature: A tree nearing its ultimate canopy size for its situation V = Veteran: A mature tree, often of great historical or ecological importance

P. Con Physiological condition of the tree expressed through an assessment of its general well-being G = Good, F = Fair, P = Poor, D = Dead

S. Con Structural condition of the tree G = Good, F = Fair, P = Poor, D = Dangerous

R.C. Estimated remaining contribution expressed in years D = <10, S = 10-20, M = 20-40, L = >40

BS Cat Tree category graded as per the guidance given within Table 1 of BS 5837 – See Appendix E A - Green = Trees of high quality and value, which are likely to contribute for at least 40+ years B - Blue = Trees of moderate quality and value, which are likely to contribute for another 20 to 40 years C - Grey = Trees of low quality and value, which are likely to contribute for another 10 to 20 years R – Red = Trees in such a condition that their existing value would be lost within 10 years and therefore should be removed

RPA ~ R Root Protection Area radius, as measured in metres from the centre of the tree

RPA ~ A Root Protection Area expressed in square metres

AP

PE

ND

IX F



BS 5837 Table 1 – Cascade chart for tree quality assessment TREES FOR REMOVAL

Category and Definition

Criteria Identification on

plan

Category R Those in such a condition that any existing value would be lost within 10 years and which should, in the current context, be removed for reasons of sound arboricultural management

• Trees that have a serious, irremediable, structural defect, such that their early loss is expected due to collapse, including those that will become unviable after removal of other R category trees (i.e. where, for whatever reason, the loss of companion shelter cannot be mitigated by pruning)

• Trees that are dead or are showing signs of significant, immediate, and irreversible overall decline

• Trees infected with pathogens of significance to the health and/or safety of other trees nearby (e.g. Dutch elm disease), or very low quality trees suppressing adjacent trees of better quality

• NOTE Habitat reinstatement may be appropriate (e.g. R category tree used as a bat roost: installation of bat box in nearby tree).

DARK RED

TREES TO BE CONSIDERED FOR RETENTION

Category and definition

Criteria – Subcategories Identification on plan 1. Mainly arboricultural values

2. Mainly landscape values

3. Mainly cultural values, including conservation

Category A Those of high quality and value: in such a condition as to be able to make a substantial contribution (a minimum of 40 years is suggested)

Trees that are particularly good examples of their species, especially if rare or unusual, or essential components of groups, or of formal or semi-formal arboricultural features (e.g. the dominant and/or principal trees within an avenue)

Trees, groups or woodlands which provide a definite screening or softening effect to the locality in relation to views into or out of the site, or those of particular visual importance (e.g. avenues or other arboricultural features assessed as groups)

Trees, groups or woodlands of significant conservation, historical, commemorative or other value (e.g. veteran trees or wood-pasture) LIGHT GREEN

Category B Those of moderate quality and value: those in such a condition as to make a significant contribution (a minimum of 20 years is suggested)

Trees that might be included in the high category, but are downgraded because of impaired condition (e.g. presence of remediable defects including unsympathetic past management and minor storm damage)

Trees present in numbers, usually as groups or woodlands, such that they form distinct landscape features, thereby attracting a higher collective rating than they might as individuals but which are not, individually, essential components of formal or semi-formal arboricultural features (e.g. trees of moderate quality within an avenue that includes better, A category specimens), or trees situated mainly internally to the site, therefore individually having little visual impact on the wider locality

Trees with clearly identifiable conservation or other cultural benefits

MID BLUE

Category C Those of low quality and value: currently in adequate condition to remain until new planting could be established (a minimum of 10 years is suggested), or young trees with a stem diameter below 150mm

Trees not qualifying in higher categories

Trees present in groups or woodlands, but without this conferring on them significantly greater landscape value, and/or trees offering low or only temporary screening benefit

Trees with very limited conservation or other cultural benefits

GREY

NOTE Whilst Category C trees will usually not be retained where they would impose a significant constraint on development, young

trees with a stem diameter of less than 150 mm should be considered for relocation.

AP

PE

ND

IX G

AR/11411 – St Leonards Academy, Edinburgh Road, St Leonards-on-Sea. TN38 8HH APPENDIX H


Tree protection fencing

12

34

5

6

7

8 7

1

2

3

4

Standard scaffold poles

Uprights to be driven into the ground

Panels secured to uprights with wire ties and where necessarystandard scaffold clamps

Weldmesh wired to the uprights and horizontals

5

6

7

8

Standard clamps

Wire twisted and secured on inside

face of fencing to avoid easy dismantling

Ground level

Approx. 0.6m driven into the ground

Taken from Figure 2 - BS5837

3.0m

0.6

m

2.3

m

AR/11411 – St Leonards Academy, Edinburgh Road, St Leonards-on-Sea. TN38 8HH APPENDIX I


Ground protection within Root Protection Areas

Edge of RPA

Protective fencing

Toeboard

Platform level at first lift of brickwork

Protective fencing

Protectedarea Ground undisturbed and

protected by geotextile fabric, and side butting scaffold boards on a compressible layer

Ground undisturbed andprotected by geotextilefabric, and side butting

scaffold boards on a compressible layer

Taken from Figure 3 - BS5837

AR/11411 – St Leonards Academy, Edinburgh Road, St Leonards-on-Sea. TN38 8HH APPENDIX J


Tree protection area warning sign

AR/11411 – St Leonards Academy, Edinburgh Road, St Leonards-on-Sea. TN38 8HH APPENDIX K


Installation of ‘No-Dig’ Surfaces in Proximity to Trees This indicative specification is based on adapted advice given in Arboricultural Practice Note 12, and British Standard 5837, and is intended only to illustrate the feasibility of such an approach. Any adopted specification would need to be prepared and approved by an appropriately qualified engineer.

a) Remove surface vegetation either: 1) By hand, ensuring that any soil stripping operations do not exceed 50mm in depth. 2) By the use of an approved herbicide. The chosen chemical should not adversely affect

tree roots, and must be applied by appropriately trained and qualified operatives. Any roots encountered during this process should be pruned so that the final wound is as small as possible and free from ragged ends – See BS3998 ‘Tree Work.’ paragraph 14.3.

b) Remove major obstructions and use sharp sand to in-fill hollows, ensuring that a level and

well graded surface is achieved.

c) Lay a geotextile membrane of appropriate specification over the prepared sub grade area.

d) Install edge restraints to contain the lateral movement of the infill. Care must be taken to ensure that edge restraints are laid along the soil surface and that no excavation occurs. The restraints can be secured either with pegs into the ground, or through the use of tie bars.

e) Expand and lay the perforated cellular confinement system to fit the required area. Suppliers include: Geosynthetics Limited - www.geosyn.co.uk

f) Backfill the cellular confinement system, using a no-fines angular material with a general

particle size of between 30mm and 50mm.

g) Following completion of development: 1) Where permanent access is required; apply a 50mm wearing surface of angular gravel,

OR permeable block paving on an appropriate laying course, as appropriate. The level differential between the top of the confinement system and the surrounding soil can be re-graded using good quality top-soil.

2) If the access is intended to be temporary, all materials should be carefully removed by hand, working off the access surface to avoid soil compaction by machinery. The soil surface should then be lightly forked by hand to a depth of 300mm.

Existing sub-grade soil

Angular gravel wearing course

Cell confinement system containing granular stone infill

Geotextile layer

Permeable bock paving

Indicative diagram of ‘no-dig’ access specification

AR/11411 – St Leonards Academy, Edinburgh Road, St Leonards-on-Sea. TN38 8HH APPENDIX L


i) Scope of this report

i.i I have been commissioned to produce base line survey data for trees, with a view to identifying constraints and opportunities for sustainable tree cover in the context of the development proposal for the site. The survey has been undertaken in accordance with British Standard 5837: 2005 ‘Trees in relation to construction - Recommendations’ and was made in the context of the site’s current usage.

i.ii This report comprises the prerequisite information for the planning process recommended in BS5837:

− The production of a Tree Survey

− The production of a Tree Constraints Plan (TCP)

− A discussion of the relevant planning and development issues in an ArboriculturalImplications Assessment (AIA)

− The production of a Tree Protection Plan (TPP), if required.

− The production of an Arboricultural Method Statement (AMS), if required.

i.iii The tree locations and canopy spreads are plotted on the indicative plans at Appendix A.

i.iv A detailed condition survey or hazard assessment of each tree has not been undertaken within the scope of this report. If a tree was noted as being in such a condition as to require more detailed assessment then that observation is included in the tree survey notes at Appendix B.

i.v The findings within this report have been made on the basis of evidence seen on the day of inspection. It should be understood that some indications of tree hazard, such as leaf appearance and density, fungal fruiting bodies, and specific pests and diseases, are only visible at specific times of the year. Should significant additional information become apparent following the submission of this report I would reserve the right to modify the conclusion made accordingly.

i.vi This report is valid until:

− The re-inspection dates given for any tree in the survey schedule

− An episode of adverse weather conditions - for example winds over land measured at Beaufort scale force 8 or above.

− For two years from the date of inspection. Whenever any of the above occurs first, the trees must be re-inspected and any recommendations carried out. The presence of a hazard, the probability of the risk and the value of the target area all help to determine the frequency of re-inspection.

i.vii Some trees are protected in law. Prior to any works to trees being undertaken a check should be made with the relevant Local Authority to ensure that prior permission is not required with regard to Tree Preservation Orders (TPOs), Conservation Areas (CAs) or planning conditions that may affect the site or its trees.

i.viii Works to trees can also be regulated because of the risk of harming wildlife which may live

on, or around them. Wild birds and bats are protected under the Wildlife and Countryside Act (1981) for example, and it is an offence to knowingly disturb their nests or roosts, whileworks to trees in proximity to badger setts may require a license.

i.ix Any tree works should be undertaken in accordance with British Standard 3998: 1989 ‘Tree work’.

AR/11411 – St Leonards Academy, Edinburgh Road, St Leonards-on-Sea. TN38 8HH APPENDIX L


i.x If hard surfacing needs to be installed close to trees the principles prescribed in BS5837

and modified specification contained within Arboricultural Practice Note 12, ‘Through the Trees to Development,’ should be adopted.

i.xi My expertise is within the field of arboriculture and this report is limited to the arboricultural

aspects of the site only. Any comments made with regard to other matters are from a lay person’s point of view.

ii) Survey method

ii.i Each tree was inspected from ground level, noting only external features and defects. The

Visual Tree Assessment (VTA) method was used to carry out the tree survey; this is an industry standard, best practice method for assessing the health, stability and, to some degree, the amenity of urban trees. A tree may be physiologically healthy, with vigorous growth, but also exhibit mechanical defects and therefore be structurally weak, consequently presenting a risk. VTA involves an assessment of each tree’s physiological and structural condition. It is carried out from ground level, with the aid of binoculars as necessary.

ii.ii No climbing inspection was made of the crown, no excavation was made of the root system, and no specific decay detection equipment was used.

ii.iii The following instruments were available to carry out the inspection:

− Diameter tape – To measure stem diameters

− Nylon headed mallet – To sound trees for audible indications of decay

− Steel probe – To indicate the presence and extent of cavities

− Binoculars – To visually inspect above ground parts of the tree

ii.iv No soil samples were taken and no tissue samples were collected.

ii.v The following publications have been used to inform this survey, and the recommendations which follow from it:

1. British Standard 5837:2005 ‘Trees in relation to construction – Recommendations.’

2. British Standard 3998:1989 ‘ Recommendations for Tree work.’

3. ‘Diagnosis of ill-health in trees’ by R.G. Strouts and T.G. Winter. DoE booklet Research for Amenity Trees No. 2, 1994.

4. ‘The body language of trees - A handbook for failure analysis’ by C. Mattheck and H. Breloer. DoE booklet Research for Amenity Trees No. 4, 1994.

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