RBWM Borough Local Plan

RBWM Borough Local Plan: Air Quality Assessment of Chilterns Beechwoods SAC Information to Inform an Appropriate Assessment (Habitats Regulations Assessment (HRA) Stage 2) ______Report for: Royal Borough of Windsor and Maidenhead ED11104103

ED 11104103 | Issue Number 4 | Date 25/02/2019

Ricardo Energy & Environment RBWM Borough Local Plan: Air Quality Assessment of Chilterns Beechwoods SAC | i

Customer: Contact: Royal Borough of Windsor and Maidenhead Mark Broomfield, Gemini Building, Fermi Avenue, Harwell, Didcot, OX11 0QR, UK.

t: +44 (0)1235 75 3493 e: [email protected] Confidentiality, copyright & reproduction: This report is submitted by Ricardo Energy & Ricardo-AEA Ltd is certificated to ISO9001 and Environment under contract to the Royal Borough ISO14001 of Windsor and Maidenhead. It may not be used for any other purposes without the specific Author: permission in writing of the Commercial Manager, Ben Jones and Ken Lipscomb Ricardo Energy & Environment.

Approved By:

Mark Broomfield and Richard Andrews

Date: 25 February 2019

Ricardo Energy & Environment reference: Ref: ED11104103- Issue Number 4

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Table of contents

1 Introduction ...... 1 1.1 The overall Plan...... 1 1.2 Purpose of this report ...... 1 1.3 Legislation summary ...... 2 2 Methodology ...... 3 2.1 Sources of guidance ...... 3 2.2 Stages of HRA ...... 3 2.3 Responsibility for undertaking HRA ...... 3 2.4 Approach to informing the Appropriate Assessment (HRA Stage 2) ...... 3 2.4.1 Consultation ...... 3 2.4.2 Impact assessment ...... 4 2.4.3 Incorporated mitigation measures ...... 4 2.4.4 In-combination assessment...... 5 2.4.5 Conservation objectives ...... 5 2.4.6 Additional mitigation measures ...... 6 2.4.7 Integrity test ...... 6 2.5 Limitations ...... 7 3 Summary of Stage 1 Screening Conclusions ...... 8 3.1 Background ...... 8 3.2 Air quality Stage 1 Screening assessment of RBWM BLP ...... 8 4 Stage 2 Appropriate Assessment of Air Quality Effects ...... 13 4.1 Local Plan development allocations ...... 13 4.2 Air quality changes at Chilterns Beechwoods SAC...... 13 4.3 National Vegetation Classification (NVC) survey ...... 15 4.4 Consultation ...... 15 4.5 Appropriate Assessment results ...... 16 5 In-combination Effects ...... 19 6 Summary of Adverse Effects on Conservation Objectives ...... 20 7 The Integrity Test ...... 20

Appendices Appendix 1: Relevant Consultation with Natural England

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1 Introduction 1.1 The overall Plan

Approximately 150,000 people live in the Royal Borough of Windsor and Maidenhead (RBWM). With an area of 198 km2, the borough is predominantly rural, with the main population centres in Maidenhead, Windsor and Ascot. The borough is located in the south-east of England and is subject to the pressures resulting from this location, including relatively high background levels of air pollution and the presence of major roads running through and close to the borough.

The Borough Local Plan (BLP) sets the framework for future development in the Royal Borough of Windsor and Maidenhead. The plan envisages significant new residential development, together with associated infrastructure. The BLP confirms that the Council is seeking to deliver its full Objectively Assessed Housing Need. As set out in the original Invitation to Quote (ITQ), the BLP provides for at least 14,240 new dwellings, 11,200 net new jobs, new open spaces, schools, and leisure facilities. This represents a significant increase in population in the borough, which will have the potential for significant effects on the environment both within the borough and in surrounding areas. At the same time, similar steps being taken in neighbouring boroughs could potentially have effects on people and the natural environment within Windsor and Maidenhead.

In view of the potential significance of air quality impacts on protected nature conservation sites, RBWM has carried out assessments of the potential impacts of the BLP on air quality and protected sites within the borough. The Council has specific obligations in relation to European sites (also referred to as “Natura 2000” sites and defined as Special Areas of Conservation (SACs) and Special Protection Areas (SPAs), plus Ramsar Sites which are accorded equivalent status, despite being an international rather than a European designation).

The European sites located in RBWM and neighbouring boroughs are shown in Figure 3.1.

The assessment carried out in relation to the impact of air quality on nature conservation sites within the borough concluded that such impacts were likely1. As such, an Appropriate Assessment of the potential air quality effects of the development envisaged in the BLP on the Natura 2000 sites was required. This requirement was confirmed during examination hearings on the BLP held in June 2018. During these hearings it was agreed between RBWM and the inspector that the whole BLP HRA would be updated to ensure that it was fully robust and, in particular, consistent with the recent European Union (CJEU) ruling in the matter of People Over Wind and Sweetman v Coillte Teoranta (C-323/17), which ruled that mitigation cannot be considered during Stage 1 Screening.

1.2 Purpose of this report

This assessment is carried out in order to fulfil the requirements of Section 21 of The Conservation of Habitats and Species Regulations (2017 No. 1012) and is known as a Habitats Regulations Assessment (HRA). This report will provide the necessary information to allow the Competent Authority to determine if the proposals within this Plan will have a significant adverse effect on the integrity of Chilterns Beechwoods SAC only (the only designated site where a potential significant air quality impact as a result of the Borough Local Plan was identified)2.

A separate detailed consideration of the Borough Local Plan will be made in the updated Stage 1 Screening report and resultant Appropriate Assessment/s (to be produced in December 2018) This Appropriate Assessment is focussed on air quality impacts to Chilterns Beechwoods SAC only.

A summary of the HRA process that informs this purpose is provided in Section 2.

1 Habitats Regulation and Air Quality Assessment update. Report for Royal Borough of Windsor and Maidenhead. Ricardo 2018. 2 Habitats Regulation and Air Quality Assessment update. Report for Royal Borough of Windsor and Maidenhead. Ricardo 2018.

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1.3 Legislation summary

Under the Conservation of Habitats and Species Regulations 2017, (the ‘Habitats Regulations’), any plan or project which is likely to have a significant effect on a European site (either alone or in combination with other plans or projects) and is not directly connected with or necessary for the management of the site, must be subject to an Appropriate Assessment to determine the implications for the site in view of the site’s conservation objectives.

The objective of an Appropriate Assessment is to determine if there will be a significant adverse effect on site integrity, and is dependent on site-specifics, including condition, status and conservation objectives. As described by the HRA Handbook3 “A significant effect is any effect that would undermine the conservation objectives for a European site. There must be a causal connection or link between the subject plan or project and the qualifying features of the site which could result in possible significant effects on the site.”

Habitats Regulations Assessment (HRA) refers to the assessment of the potential effects of a development project on one or more European sites, including SPAs and SACs. The Government also expects potential SPAs (pSPAs), candidate SACs (cSACs), and any confirmed HRA compensatory habitat to be considered in the same way.

• Special Areas of Conservation (SACs) are designated under the Habitats Directive (92/43/EEC) and target particular habitats (Annex 1) and/or species (Annex II) identified as being of European importance.

• Special Protection Areas (SPAs) are classified under the European Council Directive ‘on the conservation of wild birds’ (2009/147/EC) (the ‘Wild Birds Directive’) for the protection of wild birds and their habitats (including particularly rare and vulnerable species listed in Annex 1 of the Directive, and migratory species).

The UK Government has also advised that Ramsar sites should be considered and included within the assessment4: • Ramsar sites support internationally important wetland habitats and are listed under the Convention on Wetlands of International Importance especially as Waterfowl Habitat (Ramsar Convention, 1971).

For ease of reference during HRA, these three designations are collectively referred to as ‘European sites’, despite Ramsar designations being at the wider international level, and are also known as ‘Natura 2000’ sites.

3 Tyldesley, D. and Chapman C. The Habitats Regulations Assessment Handbook. Published and updated online by DTA Publications Limited: http://www.dtapublications.co.uk/handbooks. 4 Department for Communities and Local Government (2012) National Planning Policy Framework.

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2 Methodology 2.1 Sources of guidance

The approach to informing the Appropriate Assessment has been developed from the legislation described in Section 1.3 above and informed by the latest guidance for HRA in the UK, namely:

• Tyldesley, D. and Chapman C. The Habitats Regulations Assessment Handbook. Published and updated online by DTA Publications Limited: http://www.dtapublications.co.uk/handbooks. The Handbook is informed and regularly updated with amendments to the Regulations, the latest Government guidance and case law. • DEFRA (2012) The Habitats and Wild Birds Directives in England and its seas - Core guidance for developers, regulators & land/marine managers (draft for public consultation) 2.2 Stages of HRA

Stage 1 in HRA is a Screening stage to determine whether any part of the proposed Project or Plan is likely to have a significant effect on any European site, and thus if a full Appropriate Assessment of the project is required.

Stage 2 is the Appropriate Assessment stage (if required) that has to conclude whether or not the Project or Plan will adversely affect the integrity of the European site in question. This is judged in terms of the likely impact on a site’s conservation objectives. The conservation objectives specify the overall target for a site’s ‘qualifying features’ (i.e. those Annex I habitats, Annex II species, and Annex I bird populations for which it has been designated) in order for it to contribute to maintaining or reaching favourable conservation status. Significantly, HRA is based on a rigorous application of the precautionary principle.

If significant adverse effects are identified at the Appropriate Assessment stage, feasible alternative options would be examined to avoid or reduce any potential significant effects on the integrity of the European site as Stage 3 of the HRA if it is deemed that the option should proceed under Imperative Reasons of Overriding Public Interest (IROPI). The selection of such alternatives is limited to those which would meet the objectives of the current Project/Plan.

Stage 4 comprises an assessment of compensatory measures where the Project/Plan should proceed under Imperative Reasons of Overriding Public Interest (IROPI). 2.3 Responsibility for undertaking HRA

The responsibility for undertaking HRA lies with the competent authority, i.e. the authority (or authorities) responsible for granting a licence or consent for the Plan. Under the Habitats Regulations, the applicant has an obligation to provide the competent authorities with such information as the authority may reasonably require for the purposes of the assessment, or to enable them to determine whether an Appropriate Assessment is required.

2.4 Approach to informing the Appropriate Assessment (HRA Stage 2)

2.4.1 Consultation

Consultation, via telephone calls and correspondence, has been undertaken with Natural England. This included liaising with the local team responsible for Bisham Woods SSSI, an underlying designation of Chilterns Beechwoods SAC with which the potential air quality impacts are assessed in Section 4 of this report. This consultation was undertaken during the Stage 1 Screening of this HRA and has helped

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This assessment considers the potentially damaging aspects of the proposed BLP with potential effects on a European site’s qualifying features and likely achievement of its conservation objectives.

The potential for adverse effect on the integrity of the site depends on the scale and magnitude of the action and its predicted impacts, taking into account the distribution of the designated features across the site in relation to the predicted impact and the location, timing and duration of the proposed activity and the level of understanding of the effect, such as whether it has been recorded before and, based on current ecological knowledge, whether it can be expected to operate at the site in question.

Where qualitative and/or quantitative information is available, this has been used to inform the assessment. Where this information is not available, professional judgement has been used. In some cases, the ecological functioning of the site and the likely effects are well understood and documented elsewhere, for instance in studies commissioned to inform the Habitats Directive Review of Consents. In these cases, the assessment may simply comprise a review of this information. Where there is not sufficient information to undertake the assessment, this is recorded in this report.

This report aims to set out, in sufficient detail for it to be transparent and understandable, what the effects of the proposed BLP (alone and in combination) are likely to be on each internationally- designated site’s qualifying feature, referring to relevant background documents and other information on which these judgements, which are essentially ecological judgements, rely. Guidance states that the size or complexity of the HRA Stage 2 report to inform the Appropriate Assessment will not necessarily reflect the scale of the proposed Plan, but rather the complexity of potential effects. The length of the report may not reflect the complexity of ecological judgements made to arrive at the necessary conclusions. Very complex ecological analysis and judgements may be expressed succinctly, with detailed supporting analyses contained in appendices or clearly referenced separate documents. 2.4.3 Incorporated mitigation measures

The HRA Stage 2 Appropriate Assessment takes into account any mitigation measures that may already form part of the proposed Plan specification (i.e. that are ‘incorporated’), to determine whether they will most likely reduce the likelihood, magnitude, scale, and/or duration of the effect to a lower level. These measures can include both avoidance and reduction measures, with the former being the preferred option.

A consideration of whether components of the plan could be considered as incorporated mitigation or essential features was undertaken using the following guidance as summarised from the HRA handbook5.

Essential features of a Plan: those that are essential and inseparable, even though they may incidentally have benefits of avoiding or reducing effects on European Sites. These are not considered to be mitigation measures.

Mitigation measures, which are identifiable as: • An added extra to the Plan • Their sole purpose is to avoid or reduce effects on European Sites • The plan and proposals could be lawfully and practically implemented without them if it weren’t for the effect they have on the European Site making them necessary • They could be removed (if their benefit to the European Site were no longer required) without changing the other aims and proposals of the plan.

5 Tyldesley, D. and Chapman C. The Habitats Regulations Assessment Handbook. Published and updated online by DTA Publications Limited: http://www.dtapublications.co.uk/handbooks.

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Following this guidance, no incorporated mitigation measures of the BLP of relevance to the air quality assessment of Chilterns Beechwoods SAC were identified for inclusion within this assessment. 2.4.4 In-combination assessment

In accordance with the legislation, an in-combination assessment with other relevant plans and projects should be undertaken for the Plan in question. The approach to this is described as a series of steps below: • STEP 1 – Does the Plan have no discernible effect, whatsoever, on the European site? If not, then there is no need for in-combination assessment, as it cannot have in- combination effects. • STEP 2 - Does the Plan, alone, have an adverse effect on the European site? If so, then there is no need for in-combination assessment as consent cannot be given unless the HRA Stages 3 and 4 derogation tests are met, in which case all residual effects of the Plan acting alone will be compensated for. • STEP 3 – Does this Plan have a discernible effect, but one which is not adverse (i.e. ’significant’) to site integrity alone? If so, then an in-combination assessment is required. In this case, go the Step 4. • STEP 4 – Identify the other Plans/Projects that also have discernible effects that (1) aren’t an adverse effect alone but (2) might act in combination with effects of the Plan. It is normal practice to agree this list of potential in-combination Plans/Projects with the Competent Authority before doing the assessment. • STEP 5 – Assess these other Plans/Projects in combination with this Plan.

The above steps recognise that effects acting alone are already dealt with for that Plan/Project and should not form part of an in-combination assessment. It is only where effects that may become adverse when acting in combination that require an in-combination assessment. An in-combination assessment should only consider the potential for impacts to the same qualifying feature/s of the same European site (rather than assessing potential impacts to different European sites or different qualifying features).

Equally, in accordance with best-practice guidance, any projects or plans which have been completed, consented and implemented are considered to be part of the baseline (and should have been subject to their own HRA before being consented and implemented). Therefore, these will not be included as part of any in-combination assessment, but any ongoing operational effects will be noted as part of the baseline environment. 2.4.5 Conservation objectives

The Habitats Regulations require that the Appropriate Assessment is of “the implications for the site in view of that site’s conservation objectives.” The development of conservation objectives is required by the 1992 ‘Habitats’ Directive (92/43/EEC). In accordance with the Habitats Directive, the objectives aim to achieve the ‘favourable conservation status’ of the habitat and species features for which a European site is designated (see Figure 2.1).

Site-specific conservation objectives for SACs (and SPAs) have been developed by Natural England and provide a description of what is considered to be the favourable conservation status of the feature within the whole plan area.

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Figure 2.1 Favourable conservation status as defined in Articles 1(e) and 1(i) of the Habitats Directive

“The conservation status of a natural habitat is the sum of the influences acting on it and its typical species that may affect its long-term natural distribution, structure and functions as well as the long term survival of its typical species. The conservation status of a natural habitat will be taken as favourable when:

• Its natural range and areas it covers within that range are stable or increasing, and • The specific structure and functions which are necessary for its long -term maintenance exist and are likely to continue to exist for the foreseeable future , and • The conservation status of its typical species is favourable.

The conservation status of a species is the sum of the influences acting on the species that may affect the long-term distribution and abundance of its populations. The conservation status will be taken as ‘favourable’ when:

• Population dynamics data on the species indicate that it is maintaining itself on a long -term basis as a viable component of its natural habitats, and • The natural range of the species is neither being reduced nor is likely to be reduced for the foreseeable future, and • There is, and will probably continue to be, a sufficiently large habitat to maintain its populations on a long-term basis.”

The generic conservation objectives coving the European site assessed in this report (Chilterns Beechwoods SAC) are:

Ensure that the integrity of the site is maintained or restored as appropriate, and ensure that the site contributes to achieving the Favourable Conservation Status of its Qualifying Features, by maintaining or restoring:

• The extent and distribution of qualifying natural habitats and habitats of qualifying species; • The structure and function (including typical species) of qualifying natural habitats; • The structure and function of the habitats of qualifying species; • The supporting processes on which qualifying natural habitats and the habitats of qualifying species rely; • The populations of qualifying species; and • The distribution of qualifying species within the site.

2.4.6 Additional mitigation measures

If the Plan has been assessed as having an adverse effect by undermining the site’s conservation objectives, additional mitigation may be necessary to satisfy the integrity test (Section 2.4.7). Such mitigation is that which is in addition to the incorporated measures described in Section 2.4.3 above, and which is usually imposed by a Competent Authority through enforceable conditions or restrictions. 2.4.7 Integrity test

The integrity test is the conclusion of the Appropriate Assessment and requires the competent authority to ascertain whether the proposed Plan (either alone or in combination with other plans or projects), will not have an adverse effect on site integrity. The following definition of site integrity is provided by Defra. The integrity of the site is:

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“the coherence of its ecological structure and function, across its whole area, that enables it to sustain the habitat, complex of habitats and/or the level of populations of the species for which it was classified”

This report will conclude with a professional opinion on whether such a test can be met, but it is for the Competent Authority to make that decision in light of the information presented.

2.5 Limitations

Information provided by third parties, including publicly available information and databases, is considered correct at the time of publication. Due to the dynamic nature of the environment, conditions may change in the period between the preparation of this report, and the construction and operation of the proposed Plan.

The HRA has been undertaken in as detailed a way as possible, using all available data sources where they exist. However, the conclusions drawn from this is necessarily limited by the age, type, coverage and availability of data.

Any uncertainties and the limitations of the assessment process are acknowledged and highlighted. Any recommendations for avoidance and mitigation measures to address the potential adverse effects on European Site integrity identified by this report are also based on the information available at the time of the assessment.

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3 Summary of Stage 1 Screening Conclusions 3.1 Background

An initial Stage 1 Screening assessment6 of the Borough Local Plan was prepared by the Royal Borough of Windsor and Maidenhead Council in June 2017 and suggested that the proposed development plan will not have significant effects on the European sites in and near the borough. However, established guidance indicates that road traffic impacts can be relevant where a European site is within 200 metres of a road on which the Project/Plan would give rise to an increase in traffic flows. RBWM’s initial assessment concluded that a full Appropriate Assessment of the BLP was not required; however, this assessment was subsequently questioned (in part due to the CJEU People over Wind7 ruling and the outcome of the BLP hearings). It was determined that more detailed air quality modelling across the borough was in fact required to evaluate the potential effects of the development envisaged in the BLP on air quality within the Natura 2000 sites shown in Figure 3.1. Subsequent modelling of traffic flows carried out for RBWM8 demonstrated that the BLP would give rise to increased traffic flows on numerous roads within 200 metres of European sites in and near the borough.

3.2 Air quality Stage 1 Screening assessment of RBWM BLP

A summary of the air quality Stage 1 Screening assessment is provided in Table 3.1 below. A separate consideration of all potential effects of the Borough Local Plan will be made in the updated Stage 1 Screening report and resultant Appropriate Assessment/s (to be produced in December 2018).

All roads and all potentially relevant designated sites were included, whether or not the roads were located within 200 metres of the European sites. This ensured a robust assessment without relying on a distance-based screening criterion. This approach had the advantage of not relying on any specific screening thresholds, but instead provided a more detailed assessment for each relevant habitat site.

Air dispersion models to predict pollution identified a forecast increase in nitrogen deposition from future proposed development as part of the local plan. This contribution was compared to the critical levels for various pollutants listed on the Air Pollution Information System (APIS) website (http://www.apis.ac.uk/). Where the contribution from the local plan exceeded 1% of the critical level of that pollutant, then it was considered that likely significant effects as a result of air quality impacts could not be ruled out on the designated site.

The traffic data used in the air quality assessment took account of ‘essential features’9 integral to the BLP, such as road junction improvements designed to reduce congestion. These measures would be needed in order to make the BLP deliverable from other perspectives, such as road safety considerations, and could therefore be relied on for the assessment.

To further inform the assessment of likely significant effects of the BLP, the habitat areas where impacts were forecast to exceed the Critical Levels by 1% or more were investigated to identify whether their qualifying features were present. The investigation comprised a review of aerial photography, OS mapping and SSSI citations, field survey and consultation with Natural England officers and site owners.

The air quality Stage 1 HRA Screening assessment identified the following European sites as being potentially affected by the BLP in terms of air quality:

• Burnham Beeches SAC • Chilterns Beechwoods SAC

6 Borough Local Plan Regulation 19 Consultation. Draft Habitat Regulations Screening Report. Royal Borough of Windsor and Maidenhead 2017. 7 European Union (CJEU) ruling in the matter of People Over Wind and Sweetman v Coillte Teoranta (C-323/17) 8 Habitats Regulation and Air Quality Assessment update. Report for Royal Borough of Windsor and Maidenhead. Ricardo 2018. 9 Tyldesley, D. and Chapman C. The Habitats Regulations Assessment Handbook. Published and updated online by DTA Publications Limited: http://www.dtapublications.co.uk/handbooks.

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• South West London Waterbodies SPA/Ramsar • Thames Basin Heaths SPA • Thursley, Ash, Pirbright and Chobham SAC • Windsor Forest Great Park SAC

These sites are shown in Figure 3.1 and the conclusions of the air quality HRA Stage 1 Screening10 for each site are provided in Table 3.1 below.

Table 3.1: Conclusions of air quality assessment for each designated site identified through Stage 1 Screening for the BLP Conclusion of Air Quality Site Qualifying Features Assessment The increase in nitrogen deposition was identified to be below 1% of the minimum Critical Load and as such no likely significant effects due to 9120 Atlantic acidophilous beech forests the BLP alone were concluded. with Ilex and sometimes also Taxus in the

Burnham Beeches SAC shrub layer (Quercion robori-petraeae or Ilici-Fagenion) A possible in-combination effect with Slough Borough Council and/or South Buckinghamshire Council Local Plan are likely to be limited but cannot be ruled out at this stage. 9130 Asperulo-Fagetum beech forests The increase in nitrogen deposition was identified to be above 1% of the

minimum Critical Load in a small 6210 Semi-natural dry grasslands and part of the site close to the junction Chilterns Beechwoods scrubland facies on calcareous substrates of the A404. SAC (Festuco-Brometalia) (* important orchid

sites) In-combination effects could

potentially be significant within 65 1083 Stag beetle Lucanus cervus metres of the A404. Gadwall Anas strepera, 786 individuals representing at least 2.6% of the wintering This site was excluded from the Northwestern Europe population (5 year study as the site had no sensitivity peak mean 1991/2 - 1995/6) to air quality impacts, this included South West London any potential off-site functional

waterbodies SPA/Ramsar linked habitat for the site. Shoveler Anas clypeata, 1,075 individuals Therefore, no likely significant representing at least 2.7% of the wintering effect is predicted. Northwestern/Central Europe population (5 year peak mean 1991/2 - 1995/6)

Dartford Warbler Sylvia undata, 445 pairs The increase in nitrogen and acid representing at least 27.8% of the breeding deposition was identified to be population in Great Britain (Count as at above 1% of the minimum Critical 1999) Load in a small part of the site within 50 metres of the M3. The area in question was identified though the Nightjar Caprimulgus europaeus, 264 pairs Habitats Regulations Assessment representing at least 7.8% of the breeding prepared for Runnymede Borough Thames Basin Heaths SPA population in Great Britain (Count mean Council, which stated the area of (1998-99)) the SPA “either side of the M3 is closely mown as a firebreak up to a distance of c. 50-75m from the Woodlark Lullula arborea, 149 pairs roadside, which essentially representing at least 9.9% of the breeding removes the ability of that zone to population in Great Britain (Count as at support SPA birds or to function as 1997) heathland.”

10 Habitats Regulation and Air Quality Assessment update. Report for Royal Borough of Windsor and Maidenhead. Ricardo 2018.

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It was therefore concluded that this small increase in nitrogen and acid deposition would not have likely significant effects on this European site as a result of the BLP alone.

In-combination effects could potentially be significant up to 200 metres from B311. The increase in airborne NOx concentrations was identified to be 4010 Northern Atlantic wet heaths with above 1% of the Critical Level in Erica tetralix some parts of this SAC. However, it was concluded that total

Thursley, Ash, Pirbright concentrations would remain well 4030 European dry heaths and Chobham SAC below the Critical Level throughout the SAC. 7150 Depressions on peat substrates of the Rhynchosporion In-combination effects could potentially be significant up to 200 metres from A3. The increase in nitrogen deposition was identified to be above 1% of the minimum Critical Load in a small part of the site close to the junction of the A332 and B383. Because there were no relevant interest features in the area with a forecast 9190 Old acidophilous oak woods with increase above 1% of the minimum Quercus robur on sandy plains Critical Load, it was concluded that there would be no likely significant effects at this European site. 9120 Atlantic acidophilous beech forests Windsor Forest Great Park with Ilex and sometimes also Taxus in the SAC shrublayer (Quercion robori-petraeae or The increase in airborne NOx Ilici-Fagenion) concentrations is above 1% of the Critical Level in some parts of this SAC. However, total 1079 Violet click beetle Limoniscus concentrations would remain well violaceus below the Critical Level throughout the SAC.

A possible in combination effect with Bracknell Forest Local Plan is likely to be limited, but cannot be ruled out at this stage.

The assessment was carried out with regard to guidance published by the Institute for Air Quality Management on assessment of habitat impacts.11 This guidance quotes the Environment Agency as stating: “‘For installations other than intensive pig and poultry farms, AQTAG is confident that a process contribution <1% of the relevant critical level or load can be considered inconsequential and does not need to be included in an in-combination assessment.”. It goes on to state that: “This statement reinforces the logic behind the development of the 1% threshold, which was originally set at a level that was considered to be so low as to be unequivocally in the ‘inconsequential’ category. In other words, this can be reasonably taken to mean that an impact of this magnitude will have an insignificant effect. This would be determined as part of the HRA screening stage. Such a conclusion would eliminate the requirement to proceed to ‘Appropriate Assessment.’”

11 Institute for Air Quality Management, “Position Statement: Effect of Air Quality Impacts on Sensitive Habitats,” February 2017

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In view of the guidance outlined above, it was concluded that the implementation of the BLP may have significant impacts due to emissions to air from road traffic at a small part of Chilterns Beechwoods SAC. The air quality modelling study identified that the BLP was forecast to result in an increase of 1% or more of the Critical Level at Chilterns Beechwood SAC (and baseline levels are already above the Critical Level in this area). Whilst this did not necessarily mean that the BLP would result in an adverse effect on the integrity of the SAC, it did highlight the need for Appropriate Assessment of potential effects.

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Figure 3.1 Borough extent, location and position of applicable European designated sites

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4 Stage 2 Appropriate Assessment of Air Quality Effects 4.1 Local Plan development allocations

Of the 76 different allocations within the Borough Local Plan12 (each of which can be regarded as a component of the plan) 30 of these lie within 5km of Chilterns Beechwoods SAC (the focus of this Appropriate Assessment). This equates to a total of 4761 dwellings and a leisure centre being constructed within that 5km radius, with potential for associated increase in vehicular traffic and air pollution. However, just four BLP allocations exist within 3km of Chilterns Beechwoods SAC. This reduces to only 240 new dwellings proposed within 2km of the site. As such, the potential air pollution impacts arising from the BLP are not expected to be as severe than if there were greater allocations within close proximity to Chilterns Beechwood SAC. 4.2 Air quality changes at Chilterns Beechwoods SAC

An area of 1350m2 (0.14ha) of Bisham Woods, an underlying SSSI within the Chilterns Beechwoods SAC, was identified as likely to be subject to increased airborne NOx (nitric oxide and nitrogen dioxide). During a brief site visit on 18 June 2018, this area was identified as probably constituting beech woodland which could therefore comprise the qualifying habitat, Asperulo-Fagetum beech forests. It was concluded that further investigation of potential air quality impacts was needed with respect to a small area of the site, close to the junction of the A404 and the A308 (Figures 4.1 and 4.2).

APIS indicated that the critical level for nutrient nitrogen in the Chilterns Beechwoods SAC is 10-20 kg N / ha-year. 1% of the lowest value (10 kgN/ha-year) was used as the screening threshold; the potential for likely significant effects as a result of air quality cannot be ruled out at any location within the SAC where this screening threshold is exceeded. The maximum modelled increase in nitrogen deposition at Chilterns Beechwoods SAC due to the BLP in 2032 is 0.16 kgN/ha-year. This is 1.6% of the minimum critical load (10 – 25 kgN/ha-year)

Modelling indicated that, for a small area of Bisham Woods SSSI (also part of the Chilterns Beechwoods SAC), likely significant effects from nitrogen deposition were predicted. The modelling indicated that there were no likely significant effects for the rest of the woodland or indeed the rest of Chilterns Beechwoods SAC.

This predicted increase has the potential to negatively impact the flora in Bisham Woods SSSI and the qualifying feature criteria of Chilterns Beechwoods SAC.

12 Borough Local Plan Regulation 19 Consultation. Draft Habitat Regulations Screening Report. Royal Borough of Windsor and Maidenhead 2017.

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Figure 4.1: The area of Chilterns Beechwoods SAC where the modelled deposition of nitrogen exceeded 1% of the Critical Levels threshold (blue triangle).

Figure 4.2: Modelled contribution from BLP to nitrogen deposition at Chilterns Beechwoods SAC (2032)

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4.3 National Vegetation Classification (NVC) survey

A detailed NVC survey of the 1350m2 area of Bisham Woods (within Chilterns Beechwoods SAC) identified as potentially subject to increased levels of nitrogen deposition was conducted on 25 August 201813. The results of this survey suggested the woodland broadly fitted the W12a Fagus sylvatica - Mercurialis perennis woodland - Mercurialis perennis sub-community. The woodland area surveyed was considered to be a gap in the overall beech dominated woodland where ash and sycamore have colonised the stand, possibly as a result of mature beech trees falling down and leaving space and light for other species.

The surveyed area falls within the boundary of the SAC and has been assessed as a sub-community type of the W12 woodland. Therefore, it comprises the Annex 1 qualifying feature habitat Asperulo- Fagetum beech forests for which Chilterns Beechwoods SAC is (in part) designated and it is predicted to receive increased levels of atmospheric nitrogen above the critical load. Only 0.14ha of woodland is forecast to receive an increase of more than 0.1Kg/ N/Ha-year. This amounts to only 0.01% of the Chilterns Beechwoods SAC.

Therefore, due to the small size of the area and the absence of any apparent health issues with the woodland, the predicted impacts on the SAC were not considered likely to adversely affect the integrity of this European protected site or its ability to achieve its conservation objectives. However, further consultation with Natural England (and an Appropriate Assessment if required) was advocated to fully confirm this, so as to ensure this position is based on best available scientific evidence in order to comply with the Habitats Regulations14. 4.4 Consultation

The Natural England representatives responsible for the management of Bisham Woods SSSI (part of the Chilterns Beechwoods SAC) were consulted (by telephone and e-mail) to determine what evidence existed in relation to air quality impacts on the health of the woodland and evaluate whether mitigation of impacts was required. This consultation between RBWM/Natural England and Ricardo took place on 28/08/18, 12/09/18, 14/09/18, 17/09/18, 20/12/18 and was concluded on 02/01/19. The e-mails regarding this consultation with Natural England are contained in Appendix 1 for record.

In summary, the advice from Natural England was: • Even if Critical Levels exceed the threshold value, or are predicted to, this should be treated as a trigger for further consideration, not necessarily a full Appropriate Assessment and consideration of mitigation. • In the case of Bisham Woods SAC, the beech woodland habitat feature is currently assessed by Natural England as being in a favourable condition and there is no clear evidence of adverse impacts which could be attributed to aerial pollution. • Natural England has not identified aerial pollution as an immediate threat to the condition of the beech woodland feature and has not considered it necessary to identify measures which may be necessary to address the issue. • The monitoring that has taken place is standard SSSI site condition monitoring. This does not specifically look at air pollution but should pick up chronic health issues of vegetation. • It is very difficult to separate climate change and air pollution impacts, and at most there could be climatic effects perhaps exacerbated by air pollution. • The timescale over which Natural England would consider air pollution to become problematic is very much site specific and relates to a wide range of complex variables such as slope, aspect, soil chemistry etc. Essentially, Natural England need clear evidence of a long-term trend/clear impact/stress of tree canopies/crown die back/chlorosis etc. At the moment, this is not the case and there is no cause for concern. Another way of assessing this is by looking at changes in ground flora species and composition. There is no evidence to suggest such changes are occurring. An example of this type of nitrogen induced change would be transition from woodland to grassland ground flora.

13 Bisham Woods SSSI National Vegetation Classification Report, Report for Royal Borough of Windsor and Maidenhead. Ricardo 2018. 14 The Conservation of Habitats and Species Regulations 2017.

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Natural England advocated that a ‘light touch’ Appropriate Assessment (i.e. proportionate to the level of perceived risk outlined above) was a correct approach to support RBWM’s BLP (via an e-mail to RBWM dated 14/09/18 – Appendix 1).

This Appropriate Assessment report has therefore been prepared in response to Natural England’s advice.

Prior to being finalised, this Stage 2 Appropriate Assessment report was issued to Natural England for comment and responses to any comments are incorporated in this version. 4.5 Appropriate Assessment results

The results of this Appropriate Assessment are provided in Table 4.1 below.

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Table 4.1: Appropriate Assessment of air quality effects on Chilterns Beechwood SAC

DESIGNATED SITE: Chilterns Beechwood SAC PLAN NAME: Royal Borough of Windsor and Maidenhead, Borough Local Plan REF: UK0012724 Constituent SSSIs: Naphill Common SSSI, Bisham Woods SSSI, Windsor Hill SSSI, Tring Woodlands SSSI, Hollowhill and Pullingshill Woods SSSI, Ellesborough and Kimble Warrens SSSI, Bradenham Woods, Park Wood and The Coppice SSSI, Ashridge Commons and Woods SSSI, Ashton Rowant Woods SSSI. Conservation Status: Site Condition (where relevant to feature): Adverse Potential Effects Effect? (on Qualifying Feature Status of species/habitat in EU and UK: Refer to underpinning SSSI condition where conservation

numbers, distribution, trends, threats etc. relevant. Refer to Site Improvement Plan (SIP) objectives

where relevant. and site integrity) 9130 Asperulo-Fagetum beech Distribution: This habitat is predominantly located The SAC overlaps Bisham Woods SSSI whose Critical Load (Kg/N/Ha/Y) - 10 to 20. These figures relate to the relevant nitrogen critical load class, None forests within south-central and south-western Britain. The qualifying features include W12 - Fagus sylvatica - Fagus woodland as obtained from the nature conservation agencies’ online resource15. habitat is located almost exclusively in England apart Mercurialis perennis woodland and W14 - Fagus from a small distribution within south-east Wales. sylvatica - Rubus fruticosus woodland which relate Sensitivity and Potential Effects of Increased Deposition/Exceeded Thresholds - Changes in This habitat occurs on circumneutral to calcareous to this qualifying feature. ground vegetation, fungal mycorrhiza, nutrient imbalance and changes in soil fauna could occur soils. In the UK it mostly corresponds to NVC type as a result of air pollution arising from the Royal Borough of Windsor and Maidenhead’s Borough W12 Fagus sylvatica – Mercurialis perennis The relevant SSSI unit ID is 1002553 and the most Local Plan. woodland, but more calcareous stands of NVC type recent condition assessment was reported as W14 Fagus sylvatica – Rubus fruticosus woodland Favourable in 2009. The maximum modelled increase in nitrogen deposition at Chilterns Beechwoods SAC due to the may also conform to this habitat type. The two NVC BLP in 2032 is 0.16 kgN/ha-year. This is 1.6% of the minimum critical load (10 – 25 kgN/ha-year) types often occur together on a site SAC Site Improvement Plan proposed When consulted, Natural England were of the view that this level of exceedance would not likely measures relevant to this qualifying feature: constitute a significant issue (Appendix 1). Article 17 status: Unfavourable – bad but improving Secure appropriate woodland management, (Range: favourable, area: unfavourable – inadequate improve deer management, investigate the impacts There is currently no evidence to suggest that this effect is occurring at the part of Chilterns but improving, structure and function: unfavourable – of grey squirrel and address box blight & other Beechwoods SAC where the 1% critical load/critical level threshold is already exceeded. This view bad but improving, future prospects: favourable). diseases. Establish a Site Nitrogen Action Plan has been stated by the Natural England team responsible for Bisham Woods SSSI. The Site (this has yet to be undertaken). Improvement Plan states that (existing) ‘atmospheric nitrogen deposition exceeds the critical loads Main Pressures and threats: Deer browsing, grey for ecosystem protection...but impacts associated with nitrogen deposition are unclear.’ The SIP squirrel (Sciurus carolinensis) and edible dormouse was published in March 2015 and no such evidence of impacts has since been identified by Natural (Glis glis), habitat fragmentation and isolation, England. A study looking at the effects of nitrogen deposition on timber production suggests a time insufficient or inappropriate woodland management lag before effects are measurable of 12-24 months. As such, effects of nitrogen deposition on the and air pollution. health of Bisham Woods SSSI should already be apparent if there were to be any16.

The IAQM guidance17 which identifies the assessment threshold of 1% of critical load/critical level states that: ‘the use of a criterion of 1% of an assessment level in the context of habitats should be used only to screen out impacts that will have an insignificant effect. It should not be used as a threshold above which damage is implied and is therefore used to conclude that a significant effect is likely. It is instead an indication that there may be potential for a significant effect, but this requires evaluation by a qualified ecologist and with full consideration of the habitat’s circumstances.’18

As such, no discernible effects as a result of nitrogen deposition have been identified.

Although still above the Critical Level the predicted future outcome (2033) for the Borough Local Plan is that there will be a reduction in the level of air pollution compared to the current baseline and therefore the risk of impact to this qualifying feature of the SAC is reduced rather than increased by the BLP.

15 www.apis.ac.uk 16 https://ukair.defra.gov.uk/assets/documents/reports/cat10/1511251140_AQ0827_Asessment_of_the_impacts_of_air_pollution_on_Ecosystem_Services_Final_report.pdf 17 Institute for Air Quality Management, “Position Statement: Effect of Air Quality Impacts on Sensitive Habitats,” February 2017 18 Habitats Regulation and Air Quality Assessment update. Report for Royal Borough of Windsor and Maidenhead. Ricardo 2018.

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Table 4.1: Appropriate Assessment of air quality effects on Chilterns Beechwood SAC

numbers, distribution, trends, threats etc. relevant. Refer to Site Improvement Plan (SIP) objectives

where relevant. and site integrity) 6210 Semi-natural dry Distribution: Festuco-Brometalia grasslands are The SAC overlaps Bisham Woods SSSI whose Critical Load (Kg/N/Ha/Y) - 15 to 25. These figures relate to the relevant nitrogen critical load class, None grasslands and scrubland facies found on thin, well-drained, lime-rich soils associated qualifying features include W12 - Fagus sylvatica - Sub-atlantic semi-dry calcareous grassland as obtained from the nature conservation agencies’ on calcareous substrates with chalk and limestone. They occur predominantly Mercurialis perennis woodland and W14 - Fagus online resource19. (Festuco-Brometalia) (*important at low to moderate altitudes in England and Wales, sylvatica - Rubus fruticosus woodland which does orchid sites) extending locally into upland areas in northern not include this qualifying feature. Sensitivity and Potential Effects of Increased Deposition/Exceeded Thresholds - Increase in tall England, Scotland and Northern Ireland. Most of grasses, decline in diversity, increased mineralization, Nitrogen leaching, surface acidification these calcareous grasslands are maintained by SAC Site Improvement Plan proposed could occur as a result of air pollution arising from the Royal Borough of Windsor and grazing. measures relevant to this qualifying feature: Maidenhead’s Borough Local Plan. Establish a Site Nitrogen Action Plan (this has Article 17 status: Unfavourable – bad but improving yet to be undertaken). The air quality modelling has only identified the 1% screening threshold being exceeded in a small (Range: favourable, area: unfavourable - inadequate area of Bisham Woods SSSI where this qualifying feature habitat is absent. Therefore, no air and deteriorating, structure and function: quality impact on this qualifying feature of the SAC as a result of the BLP is anticipated. unfavourable – bad but improving, future prospects: favourable).

Main Pressures and threats: Grazing, air pollution, biocenotic evolution, modification of cultivation practices, fertilisation, artificial planting, abandonment of pastoral systems, fragmentation, lack of remedial management (includes scrub control), invasive species and climate change.

1083 Stag beetle Lucanus Distribution: In the UK Lucanus cervus is largely The SAC overlaps Bisham Woods SSSI whose No specific sensitivities for the species is given by APIS. Therefore, qualifying feature habitat None cervus restricted to south and south-east England, occurring qualifying features include W12 - Fagus sylvatica - sensitivities are used as a proxy and are considered broadly similar to those set out for the in a broad area south-east of a line extending from Mercurialis perennis woodland and W14 - Fagus primary habitats within the designated site. southern Suffolk, through Hertfordshire, sylvatica - Rubus fruticosus woodland which Buckinghamshire, Oxfordshire and Hampshire to supports this qualifying feature through the No potential impact of air pollution on stag beetle (or its habitat) has been identified. If there were Dorset, with a particular concentration around the abundance of fallen and standing deadwood as an impact on stag beetle habitat this would take the form of (worst case) the premature death of London Basin, and with outlying populations in the reported in the most recent condition assessment. certain trees within the woodland, which in turn would lead to an increase in the abundance of West Country, south Wales, and standing and fallen deadwood within the woodland upon which this species relies to complete its Worcestershire/Gloucestershire border area. The relevant SSSI unit ID is 1002553 and the lifecycle. Although it is relatively common in some of the areas, most recent condition assessment was reported it is listed as Nationally Scarce Category B (Hyman & as Favourable in 2009. Parsons 1992), which means that it is likely to occur in 100 or fewer 10x10 km national grid squares. In SAC Site Improvement Plan proposed midland and northern England and Wales the stag measures relevant to this qualifying feature: beetle is rare or extinct. Monitor stag beetle population and reduce visitor impact on dead wood. Article 17 status: Favourable (Range: favourable, population: favourable, habitat: unknown, future prospects: favourable).

Main Pressures and threats: Removal of dead and dying trees.

19 Ibid Table 3.1.

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5 In-combination Effects

As part of the Appropriate Assessment process, the Borough Local Plan should be assessed against other known plans and projects that could have in-combination effects, as agreed with the competent authority. The approach of the in-combination assessment follows that set out in Section 2.4.4 of this report.

In-combination effects on Chilterns Beechwoods SAC as a result of air quality impacts arising from RBWM’s Borough Local Plan are not considered possible. This is because there is a lack of evidence, as stated by Natural England, of any air quality impacts within the small portion of Bisham Woods SSSI where there was a modelled increase in nitrogen deposition of >1% of the Critical Load.

This is not because the Critical Level has yet to be exceeded, as the existing baseline already exceeds the minimum Critical Level; rather that this exceedance is not resulting in any identifiable or measurable health impact to the qualifying feature beech woodland. As such, there is no definitive ‘discernible’ air quality impact which could operate in combination with other plans and projects to lead to an adverse effect on site integrity or compromise the ability of the site to achieve its conservation objectives. It is also important to consider that by the time the Borough Local Plan as a whole is realised there is forecast to be a reduction in the level of air pollution experienced compared to the existing baseline.

The area where the exceedance of the 1% threshold for nitrogen deposition was recorded is approximately 0.14ha in size. This represents just 0.17% of the 83.67ha Bisham Woods SSSI and just 0.01% of the whole of Chilterns Beechwoods SAC (1285.86ha). This is considered to be such a small proportion of the overall SAC that any impact here would be so minor as to not affect site integrity (or the ability of the site to achieve its conservation objectives) even in combination with other plans and projects that were deemed not to have a significant effect alone. However, no such ‘discernible’ impact has been identified.

Similarly, although RBWM’s 2017 Stage 1 Screening report20 of the BLP highlights the potential for in- combination effects from increased recreational pressure on the SAC (which could act in combination with air quality impacts on the same site and the same qualifying feature/s) this too is discounted for the following reasons: • No definitive air quality impact has been identified and any such impact would be so negligible as to not be able to act in-combination to adversely affect site integrity. • The qualifying feature within the area where the nitrogen deposition exceedance was identified (Asperulo-Fagetum beech woodland) is regarded as being relatively tolerant of recreational disturbance. Recreational disturbance is listed within the Site Improvement Plan but specifically relates to the impact of visitor pressure on dead wood for stag beetles. Stag beetles and their dead wood habitats are not sensitive to air quality impacts so these impacts cannot operate in combination. • The Borough Local Plan seeks to address recreational pressure through its integral IF4 Open Space policy21 and air quality through its integral EP2 Air Pollution22 and IF2 Sustainable Transport policies23. Designated sites are addressed through their integral NR3 Nature Conservation policy24. All of these policies comprise ‘essential features’25 (see Section 2.4.3 for additional information) of the BLP rather than mitigation measures targeted at European sites.

20 Borough Local Plan Regulation 19 Consultation. Draft Habitat Regulations Screening Report. Royal Borough of Windsor and Maidenhead 2017. 21 http://consult.rbwm.gov.uk/portal/blp/blpr19/blpr19?pointId=ID-4407973-POLICY-IF-4 22 http://consult.rbwm.gov.uk/portal/blp/blpr19/blpr19?pointId=s1486464474630 23 http://consult.rbwm.gov.uk/portal/blp/blpr19/blpr19?pointId=s1495538737852 24 http://consult.rbwm.gov.uk/portal/blp/blpr19/blpr19?pointId=s1495537727387 25 Tyldesley, D. and Chapman C. The Habitats Regulations Assessment Handbook. Published and updated online by DTA Publications Limited: http://www.dtapublications.co.uk/handbooks.

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6 Summary of Adverse Effects on Conservation Objectives

The assessment reported in Sections 4 and 5, has concluded that there will be no effects as a result of air quality impacts that will undermine Chilterns Beechwoods SAC’s conservation objectives.

7 The Integrity Test

It can be reasonably concluded that the Royal Borough of Windsor and Maidenhead’s Borough Local Plan will not have an adverse effect (either alone or in combination) on the integrity of the Chilterns Beechwoods SAC as a result of changes to air quality.

Ref: Ricardo/ED11104103/Issue Number 4

Appendices

Ref: Ricardo/ED11104103/Issue Number 4

Appendix 1 – Relevant consultation with Natural England

Sent: 28 August 2018 13:59

Subject: RE: Bisham Woods SAC

Further to our conversation, I have spoken with (redacted) and checked the information we hold on the site in relation to its current condition.

(Redacted) advises that, even if Critical Levels exceed the threshold value, or are predicted to, this should be treated as a trigger for further consideration, not necessarily a full Appropriate Assessment and consideration of mitigation.

In the case of Bisham Woods SAC, the beech woodland habitat feature is currently assessed by Natural England as being in a favourable condition and there is no clear evidence of adverse impacts which could be attributed to aerial pollution. Natural England has not identified aerial pollution as an immediate threat to the condition of the beech woodland feature and has not considered it necessary to identify measures which may be necessary to address the issue.

I hope that this information is helpful.

(Redacted) Land Management Advisor Thames Team Natural England (Redacted) We are here to secure a healthy natural environment for people to enjoy, where wildlife is protected and England’s traditional landscapes are safeguarded for future generations

Natural England is accredited to the Cabinet Office Customer Service Excellence Standard www.gov.uk/natural-england

Sent: 12 September 2018 15:55

Subject: FW: Bisham Woods SSSI air quality impacts?

Hello (Redacted)

Please see the e-mail chain below for context.

I have just had a useful conversation with (redacted) in which I asked the following devil’s advocate questions in order for us to better determine whether an Appropriate Assessment is required or whether an alternative approach would be robust. I have included notes on (redacted) responses (underlined) for information. Please feel free to add to/edit these are required.

• Please can you tell us what studies underpin the view that: o a) the beech woodland qualifying feature of the SAC is in a favourable condition?

Ref: Ricardo/ED11104103/Issue Number 4

Standard SSSI site condition monitoring. This does not specifically look at air pollution but should pick up chronic health issues of vegetation. Other than this no particular studies have been undertaken at this site looking at health impacts to beech trees but (redacted) thought that something similar may have been done elsewhere, perhaps in the Chilterns.

o b) there is no clear evidence of adverse impacts which could be attributed to aerial pollution?

As above. There are no specific studies at this site. (Redacted) advised that it is very difficult to separate climate change and air pollution impacts and his view was that at most there could be climatic effects perhaps exacerbated by air pollution.

• How recent are these studies please?

The most recent site condition monitoring study was undertaken in 2009.

• The SIP for Chilterns Beechwoods SAC does identify atmospheric nitrogen deposition as a pressure – please can you tell us how was this determined and why does it differ to the view that aerial pollution does not pose an immediate threat to the condition of the beech woodland feature?

The SIP is likely based on modelled deposition of pollutants which indicates that an issue could occur. That is not the same as saying there will be actual impacts to tree health that would necessarily require mitigation.

• If the threat is not immediate is there a timescale in which NE regard it might become an issue?

This is very much site specific and relates to a wide range of complex variables such as slope, aspect, soil chemistry etc. Essentially we need clear evidence of a long term trend/clear impact/stress of tree canopies/crown die back/chlorosis etc. At the moment this is not the case and there is no cause for concern. Another way of assessing this is by looking at changes in ground flora species and composition. There is no evidence to suggest such changes are occurring. An example of this type of nitrogen induced change would be transition from woodland to grassland ground flora.

• Other than conducting a full AA what further consideration would you consider to be a suitable alternative please?

Essentially it would need to provide an audit trial that shows consideration of risk and impacts. It needs to demonstrate our understanding of the issues and that we have taken them properly in to account.

• What are your thoughts on Natural England signing up to a Statement of Common Ground that an AA is not required in this instance?

This last question is the one (redacted) referred me to you on please (redacted). What are your thoughts on this approach please?

Thank you in advance

(Redacted)

Ref: Ricardo/ED11104103/Issue Number 4

------(Redacted) Senior Consultant Water and Environment Practice ------(Redacted) ------

Sent: 14 September 2018 09:00

Subject: RE: Bisham Woods SSSI air quality impacts?

Hi (redacted),

Thanks for your email, and an interesting question.

In my opinion there are two options to be followed both of which require little or no extra work, but one requires an AA and one doesn’t. Ultimately the level of risk as to what approach to take likes with RBWM.

1) The 1% threshold has been exceeded, NE advice dictates that if this occurs then an Appropriate Assessment is required. That AA can be tremendously light touch, and effectively can use the evidence (redacted) has provided, to show that there won’t be LSE caused by this Local Plan. 2) You acknowledge that although there is a greater than 1% increase, you aren’t going to do an AA, because due to (redacted) comments. It is very unlikely to pollutant is going to get to the qualifying species, or even harm them. However you will still need to put some rhetoric together to explain this, and not call it an AA.

I’m happy to sign up to either approach, but it would seem to me, doing a light touch AA at least stops any challengers from claiming you haven’t. Here is our link to the external guidance if you haven’t already seen it. http://publications.naturalengland.org.uk/publication/4720542048845824

Kind Regards

(Redacted)

(Redacted) – Senior Planning Adviser Thames Team Natural England (Redacted) www.naturalengland.org.uk

------

Sent: 20th December 2018

Hi (redacted),

I have had chance to have a look at this. I am relatively happy with it. One question though, I don’t think it anyway actually shows how much of an exceedance over the 1% there is on Bisham Woods. Is it 1.2% or is 5%? If it is only just over the 1% then that is not a massive issue, and could form part of the justification in the document for screening it out.

Kind Regards

Ref: Ricardo/ED11104103/Issue Number 4

(Redacted)

(Redacted) – Senior Planning Adviser Thames Team Natural England (Redacted)

------

Sent: 21 December 2018 15:00

Subject: RE: Final Stage 2 Appropriate Assessment of Chilterns Beechwoods SAC

(Redacted)

(Redacted) asked about specific levels of pollutants to be generated and I have now got answer to this from Ricardo:

‘The answer to the question raised by (Redacted) is that the maximum modelled increase in nitrogen deposition at Chilterns Beechwoods SAC due to the BLP in 2032 is 0.16 kgN/ha-year. This is 1.6% of the minimum critical load (10 – 25 kgN/ha-year). So “not a massive issue” to use (Redacted’s) phrase. We can add that in as an additional point in the Appropriate Assessment for Chilterns Beechwoods. Are you expecting any more feedback on this report, or should we add that point in and reissue the report for Chilterns Beechwoods SAC?’

I hope this helps and I will reply to (Redacted) on the question at the end.

Kind regards

(Redacted)

Principal Lead Neighbourhood Plans Planning Policy Corporate and Community Services Royal Borough of Windsor & Maidenhead Town Hall, St Ives Road, Maidenhead SL6 1RF (Redacted)

------

Sent: 02 January 2019

Hi (Redacted),

Yes that sounds fine, please make sure that is all included in the report as you have suggested.

Kind Regards

(Redacted)

(Redacted) – Senior Planning Adviser Thames Team

Ref: Ricardo/ED11104103/Issue Number 4

Natural England (Redacted) www.naturalengland.org.uk

Ref: Ricardo/ED11104103/Issue Number 4

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