Grahame Park Stage B (Plots 10, 11 and 12) EIA Volume 3 ... Park NTS … · Grahame Park Stage B...

Grahame Park Stage B (Plots 10, 11 and 12) EIA Volume 3: Non-Technical Summary

Non-Technical Summary 1-1

Contents

1.0 Introduction ............................................................................................................................. 1-3

2.0 Environmental Impact Assessment and methodology ................................................................... 2-5

2.1 Scope of the ES .................................................................................................................... 2-5 2.2 Assessment of Significance .................................................................................................... 2-5

3.0 The Site Context and Description ................................................................................................ 3-6

4.0 Alternatives and Proposed Development Evolution ....................................................................... 4-8

4.1 Grahame Park Design Alternatives ......................................................................................... 4-8 4.2 Consideration of Alternative Development Options .................................................................. 4-8 4.3 Key Aspects of the Proposed Development Evolution ............................................................... 4-9

5.0 Proposed Development .............................................................................................................. 5-10

5.1 Planning Approach ................................................................................................................ 5-10 5.2 Land Use and Quantum of Development ................................................................................. 5-10 5.3 Building Heights and Typologies ............................................................................................ 5-11 5.4 Characteristics and Materials ................................................................................................. 5-11 5.5 Access and Movement .......................................................................................................... 5-11 5.6 Open Space and landscape.................................................................................................... 5-12 5.7 Energy Centre ...................................................................................................................... 5-12 5.8 Provision of utilities and services ............................................................................................ 5-12 5.9 Construction Programme and Methodology ............................................................................. 5-12

6.0 Likely Environmental Impacts and mitigation measures ................................................................ 6-15

6.1 Ground Conditions and Contamination .................................................................................... 6-15 6.2 Noise and Vibration .............................................................................................................. 6-17 6.3 Air Quality ........................................................................................................................... 6-19 6.4 Traffic and Transportation ..................................................................................................... 6-20 6.5 Cumulative and In-Combination Effects .................................................................................. 6-21

7.0 What Will Happen Next? ............................................................................................................ 7-24

Figures

Figure NTS 1 Site location

Figure NTS 2 Planning application boundary

Figure NTS 3 Key features adjacent to the Site

Figure NTS 4 Key features with wider Site context

Figure NTS 5 2004 Masterplan

Figure NTS 6 Masterplan

Figure NTS 7 Building Plots and Sub-Plots

Figure NTS 8 Building Heights

Figure NTS 9 Building Typologies

Figure NTS 10 Street Hierarchy



Tables

Table NTS1: Land use class and maximum Gross Internal Area (GIA)

Table NTS2: Unit tenure and mix summary

Table NTS3: Indicative demolition and construction programme

Table NTS4: Cumulative Assessment Sites

Table NTS5: Summary of predicted significant effects for the individual sites



1.0 INTRODUCTION

1.1.1 This Environmental Statement (ES) has been prepared on behalf of Choices for Grahame Park / Genesis Housing Association (‘the Applicant’) to accompany a planning application submitted to the London Borough of Barnet (LBB), as Local Planning Authority, for the regeneration of part of the Grahame Park Estate in the London Borough of Barnet, London (the ‘Proposed Development’).

1.1.2 The Proposed Development seeks outline planning permission with some matters reserved for a primarily residential development on land at the Grahame Park Estate (the ‘Site’) including:

Demolition of 630 existing residential units, Everglade GP Practice, Community Hall, Library and retail units

Construction in three phases (Plots 10, 11 and 12) of 1,083 residential dwellings (use class C3)

Community Hub of approximately 3,953 sqm (GIA) comprising a community hall and workshop rooms, a day care nursery, a GP Health centre, community health facilities and ancillary office accommodation (all use class D1) along with a 122 sqm (GIA) of café (use class A3)

Retail space of approximately 320 sqm (GIA) (predominantly use class A1, along with A2, A3, and A4 )

Flexible ground floor space of approximately 56.5 sqm (GIA) (use class A1 or use class B1) within Block 10B

New energy centre to provide district heating

Associated car parking, open space, landscaping and access arrangements

1.1.3 The location of the Site and the planning application boundary are shown in Figures NTS 1 and NTS 2.

1.1.4 The Applicant has prepared this Environmental Statement (ES) under the Town and Country Planning (Environmental Impact Assessment) Regulations 2011 (the EIA Regulations) (as amended).

1.1.5 The ES:

Describes the proposals and the area surrounding the Proposed Development

Describes the existing environmental conditions in the area of the Proposed Development

Draws conclusions about the significant effects that the Proposed Development is likely have on the environment

Explains the measures that the Applicant has adopted or intends to adopt in order to mitigate any significant identified adverse effects.



1.1.6 Schedule 4 of the EIA Regulations requires that a summary of the ES is provided in non-technical language. This non-technical summary (NTS) provides a précis of the information contained in this ES.

1.1.7 The planning application comprises a suite of other key documents including:

Full drawings package

Planning Statement

Design and Access Statement

Statement of Community Involvement

Flood Risk Assessment

Biodiversity and Arboriculture reports

Historic Environment Desk-Based Assessment

1.1.8 These documents cover the need for the Proposed Development, the detailed planning proposals, the design of the Proposed Development, consultation that has taken place during the development of the design for the Proposed Development, and a policy appraisal.



2.0 ENVIRONMENTAL IMPACT ASSESSMENT AND METHODOLOGY

2.1 Scope of the ES

2.1.1 In response to a Request for a Screening Opinion LBB on the 18th April 2016. LBB confirmed that the Proposed Development required an EIA.

2.1.2 The scope of the assessment was subsequently agreed with LBB to include:

Ground Conditions and Contamination

Noise and Vibration

Air Quality Traffic

Traffic and Transportation

2.1.3 Each of the above topics has been addressed in a dedicated chapter within the ES. The ES text and figures are contained within Volume 1, with the Technical Appendices contained in Volume 2. This document forms the Non-technical Summary (NTS), and is Volume 3.

2.1.4 Within each technical chapter of the ES, a description of the assessment methodology, the baseline conditions within the Site and surrounding area are provided. Assessments of the likely significant impacts of the Proposed Development (both beneficial and adverse) during the construction and occupation / operational phase are assessed and any mitigation measures that should be adopted to reduce or offset any significance adverse impacts identified during the assessment are described. The residual effects that would remain after mitigation measures have been implemented, as well as the likely cumulative and in-combination effects of the Proposed Development are also assessed.

2.1.5 The methodologies used for the assessment of specific issues are described in the relevant topic chapters of this ES, and are summarised in the respective sections of this document. The assessments have been informed by a range of information, including planning policy, desk-top studies, consultation with statutory bodies, surveys and computer modelling.

2.2 Assessment of Significance

2.2.1 The evaluation of effect significance is fundamental to the EIA process. The degree of an effect contributes to determining the resources that should be deployed in avoiding or mitigating an adverse effect, or identifying the actual value of a beneficial effect. As far as possible, standard words have been used to define degrees of effect (i.e. ‘very substantial’, ‘substantial’, ‘moderate’, ‘slight’ and ‘negligible’), but not so rigorously as to stifle flexibility or particular individual requirements. Where a different approach to defining the sensitivity is required, this is explained within the methodology of the respective topic chapter.

2.2.2 The degree of an effect is determined by the interaction of two factors: the magnitude, scale or severity of the effect or change, and the value, importance or sensitivity of the environmental resource being affected. This is then used to determine whether an effect is significant.



3.0 THE SITE CONTEXT AND DESCRIPTION

3.1.1 The Site covers an area of 9.67 hectares (ha) and is located within the Grahame Park Estate, situated within the Colindale Ward of the LBB, NW9 5XL in the north west of Greater London. The Site is an inverted L-shape made up of three plots which are each approximately equal in size; Plots 10, 11 and 12 (with Plot 10 in the north of the Site, Plot 11 in the centre, and Plot 12 in the south of the Site).

3.1.2 Grahame Park is the borough’s largest housing estate, originally comprising 1,777 units of mainly social rented accommodation alongside a small neighbourhood shopping centre and various community facilities. The estate comprises a mixture of flats and houses with buildings of varying heights and set in areas of open space.

3.1.3 The Site is relatively flat with minor slopes observed and is generally bounded to the west by Lanacre Avenue, to the south by Grahame Park Way, to the east by Great Strand and Corner Mead and to the north by Field Mead.

3.1.4 The main area of open space is known as Heybourne Park (formerly known as Grahame Park Open Space) and is located to the west of the Concourse, whilst other areas of informal open space exist between individual buildings.

3.1.5 The immediate surrounding land use of the Site is formed by the existing and redeveloped areas of the Grahame Park Estate, consisting of low rise developments. The wider context of the Site is formed by a mix of open space, educational facilities, the M1 motorway and railway line, and further residential developments.

3.1.6 Colindale Underground Station serves the immediate area and is located to the south west of the Site. The Site is also served by the strategic road network, with good access to the A5 to the west and A41/A1 to the east. The borough boundary with the London Borough of Brent runs along the A5.

3.1.7 Grahame Park Estate and its immediate surroundings were developed in the 1960s on the former Hendon Aerodrome, which was one of the earliest aerodromes and aircraft factories in the country and played a key role in the early development of the British aircraft industry and the Royal Air Force. Some buildings from the aerodrome still remain in the area, including the listed former officers’ mess and watchtower, whilst the RAF Museum ensures that an aeronautical presence is retained in Colindale. The listed buildings are located within the built up area to the south of the Site, with the nearest building being approximately 350m from the southern boundary of the site. There is no visual or physical relationship between the Site and these listed buildings.

3.1.8 The key features adjacent to the Site and within the wider Site context are shown in Figures NTS 3 and NTS 4.

3.1.9 A review of the earliest historical mapping for the Site (1883 - 1897) shows the Site as undeveloped open land, likely to be used for agricultural purposes based on the presence of several ancillary structures in fields in the surrounding areas. By 1910 work had begun to clear trees from the area in preparation for the use of the land for aviation purposes and by 1914 the area was labelled on mapping as the London Aerodrome. The Site remained as open land until at least c.1936. Aerial photography dated c.1948 indicates that by this time several runways



had been constructed at the aerodrome. The north west, north east and south sectors of the Site appear to have remained as open, grassed land; however the runways intersected in the approximate centre of the Site and remained until at least c.1968.

3.1.10 By 1974 the runways had been completely removed and the area redeveloped as the Grahame Park residential estate. Mapping suggests that the north west sector of the Site was predominantly open space with some isolated apartment buildings, with the remainder occupied by numerous apartment buildings (4-6 storeys in height), as well as areas of associated communal soft landscaping, car parking, access roads and garages. More recent mapping and street level photography have also identified several commercial properties, a health centre and a community centre. Further development to the north west sector is apparent between 1974 and 1983, which introduced additional apartment buildings and garages.



4.0 ALTERNATIVES AND PROPOSED DEVELOPMENT EVOLUTION

4.1 Grahame Park Design Alternatives

4.1.1 The aim of the Grahame Park Estate Regeneration is to provide and increase in the number of dwellings in the area, along with the provision of a high quality urban realm. To this end, the alternatives considered focus on the provision of housing on the existing Site.

4.2 Consideration of Alternative Development Options

2004 Masterplan

4.2.1 The first attempt to regenerate the Estate looked to dispose of the original design principles to create a more people focussed estate. A more traditional hierarchy of streets was proposed, facilitated by the relocation of Lanacre Avenue. The 2004 Masterplan as shown in Figure NTS 5 introduces “good design” concepts such as homes with access onto streets, greater diversity in the character, typology and materiality of buildings, and providing clearly defined routes into, and through, the Estate. The Masterplan also increased housing density, with a variety of dwelling types.

4.2.2 The 2004 Masterplan sought to deliver in two stages, A, and B. Stage A is currently nearing completion.

Grahame Park Supplementary Planning Document

4.2.3 Greater flexibility was sought within the planning process to deliver Stage B of the regeneration therefore this was done by the way of a Supplementary Planning Document (SPD) which was formally adopted on 26th July 2016.

4.2.4 The SPD evolved the 2004 design by replacing the concept of a discrete estate with three distinct character areas each with localised centres. The core principles remain largely unchanged with a more explicit recognition for the provisions of improved public space with enhanced green space and preserving the use of mature trees within the landscape.

Consultation exercises and design responses

4.2.5 Evolution of the Proposed Development has been informed by a series of consultation exercises post-SPD adoption. As a result of consultations undertaken throughout 2016 sought to ascertain the views and opinions of the key stakeholders, and to incorporate as far as possible these views in the merging design.

Current Masterplan and Proposed Development

4.2.6 The Proposed Development has responded by incorporating the principles of the SPD. Using a combination of the new street hierarchy and character areas, the Proposed Development incorporates mansion blocks, terraces, mews and villas, punctuated by taller “landmark” buildings and a mixed use Community Hub at the centre of the Proposed Development. As part of the desire to deliver a sustainable design, the drainage for the Proposed Development been undertaken using a Sustainable drainage Systems (SuDS) principles which incorporates sub-surface tanks and a network of swales.

4.2.7 The Proposed Development also seeks to retain as may mature trees as possible as part of the new network of open, green spaces.



4.3 Key Aspects of the Proposed Development Evolution

4.3.1 The Grahame Park Estate Regeneration Proposed Development has been subject to a long term design evolution, the key stages of which are outlined below:

Initial Masterplan – 2004

Outline Planning Application – May 2004

Adopted SPD – July 2016

Consultation process – July-November 2016

Current Proposed Development Design – April 2017



5.0 PROPOSED DEVELOPMENT

5.1 Planning Approach

5.1.1 The application is outline planning permission with some matters reserved. Within the outline planning application, full details are submitted for the means of access, layout, scale, appearance and landscaping of Plots 10 and 12 and associated works. Full details of Plot 11 are submitted for the means of access, layout, scale, appearance and landscaping with the exception of Plot 11D, where details of layout and scale are submitted, with means of access, appearance and landscaping reserved.

5.1.2 The Masterplan for the Proposed Development, in Figure NTS 6, shows how the Proposed Development will be implemented taking into account the following details which are listed below and discussed in more detail within each section:

1. Land use and quantum of development

2. Building heights and typologies

3. Characteristics and materials

4. Access and movement

5. Open space and landscape

5.1.3 The Proposed Development comprises the following plots and sub-plots as shown in Figure NTS 7:

Plot 10 – 10A1, 10A2, 10B

Plot 11 – 11A, 11B1, 11B2, 11C1, 11C2, 11D1, 11D2, 11D3

Plot 12 – 12A1, 12A2, 12B1, 12B2

5.2 Land Use and Quantum of Development

5.2.1 The application seeks permission for development land use zones within the Site. The land use zone and the area applied for are listed in Table NTS1.

Table NTS1: Land use class and maximum Gross Internal Area (GIA)

Land Use Land use areas (Gross Internal Area) sqm

Residential (C3) 100,216

Non-residential institutions (D1) 3,953

Restaurants and Cafes (A3) 122

Shops (A1) – including A2, A3 and A4 376.5

5.2.2 The Proposed Development will deliver a total of 1,083 new residential units comprising a mix housing types and tenures. The total size mix of the new homes are:

1 bed – 365 units

2 bed – 429 units

3 bed – 289 units



5.2.3 A mixture of market and affordable housing would be provided which will allow for a wide range of choice and opportunity. Table NTS2 shows the unit and tenure mix.

Table NTS2: Unit and tenure mix summary

1b 2b 3b+

Private Sale 175 245 91

London Living rent and Shared Ownership 158 129 100

London Affordable Rent 34 54 99

5.2.4 Community facilities comprise a Community Hub, a day nursey, a GP heath centre, community health facilities and ancillary office accommodation which replace the Everglade GP Practice, Community Hall and Library.

5.2.5 The Community Hub would serve the new and existing communities and would be accessible by foot and bicycle and served with car parking within the vicinity.

5.3 Building Heights and Typologies

5.3.1 The building heights and typologies proposed across the Site are shown in Figure NTS 8 and NTS 9.

5.3.2 Higher buildings are located around the edges of the Proposed Development, lower buildings are located within the centre and step buildings are located to the north where existing two storey dwellings are located.

5.3.3 The Proposed Development will provide a ‘pattern block’ approach using a mix of mansion blocks, terraces, mews and villas to maintain two distinct character areas which are the Central and Southern Character Areas.

5.4 Characteristics and Materials

5.4.1 There are two distinct character areas within the Proposed Development, the Southern Character Area and the Central Character Area. Character has been reinforced within the design of the Proposed Development through landscape and materials.

5.4.2 The Southern Character Area has been designed using lighter brick colours, graduating to darker red brick colours in the Central Character Area where the buildings relate more closely to the existing estate.

5.5 Access and Movement

5.5.1 The Proposed Development will provide a permeable network of streets that allows pedestrian, cyclists and vehicles to move through the Site and improve connectivity to those parts of the Estate that are likely to remain as they are, as well as accommodating future connections in later phases of the development. There are various routes for cyclists including a quick route via Bristol Avenue or a more leisurely route through Woodland Walk with secure cycle parking throughout the Site. The hierarchy of streets within the Proposed Development is shown in Figure NTS 10.



5.6 Open Space and landscape

5.6.1 The approach to open space is to create a clear definition between what is private, what is shared and what is public. This is achieved through the creation of perimeter blocks for the majority of the development that enclose internal parking at grade with a podium level courtyard above providing amenity space to the residents of each block.

5.6.2 Private amenity areas are provided in the form of small gardens bordering the podium courtyards for maisonettes, and terraces and balconies for the other units.

5.6.3 Public spaces are created within Woodland Walk and the hard landscaped spaces within Plot 11 and adjacent to the Community Hub.

5.6.4 Doorstep play space for young children will be provided within the podium courtyards, with play for older children principally located within Woodland Walk. The off-site provision for older children is expected to be provided within Heybourne Park.

5.6.5 The presence of many existing mature trees is a dominant factor in the landscape design, influencing layout and levels of the new spaces. These trees provide a mass of screening foliage and bring a sense of ‘ready-made’ established landscape. The retention of as many trees as possible is recognised as being the starting position and a basis from which to consider new tree planting. Of the 395 tree features, 174 will require removal in order to facilitate the Proposed Development.

5.6.6 Proposals for tree planting have been carefully considered, taking into account of height, spread, shade and rooting area. Each species provides a particular contribution in the form of canopy shape, foliage, colour, fruit, flower and bar to the collective tree-scape composition. The proposals include the planting of new trees selected to complement the existing tree stock and to enhance biodiversity.

5.7 Energy Centre

5.7.1 A new district heating comprising a single energy centre housing two combined heat and power (CHP) gas engines and commercial gas boilers is to be located in Plot 10B which will serve the Proposed Development and will provide heat to the district heating network.

5.8 Provision of utilities and services

5.8.1 An integrated drainage system will be used within the Proposed Development to provide an efficient and sustainable drainage solution, following the Sustainable Drainage Systems (SuDS) management train. Swales and detention basins will be used to attenuate surface water runoff from the adopted road before discharging into the Thames Water surface water sewers. Plot drainage will run directly into the Thames sewerage network.

5.9 Construction Programme and Methodology

5.9.1 It is assumed that the Proposed Development will be demolished and constructed over five phases. The indicative timescales for each phase of development are listed in Table NTS3. Completion of the Proposed Development is envisaged to be in 2026.

5.9.2 This information has been obtained from the Outline Construction Management Plan and Indicative Construction Programme which has been submitted in support of the planning application.



Table NTS3: Indicative demolition and construction programme

Phase of Proposed

Development

Demolition Construction

Description Duration (months) Description Duration

Phase i Noel Nisbet Nimrod Nicolson Nighthawk Napier Nardini

April 2018 – July 2018 (5 months)

10A-1 10A-2 10B

August 2018 – December 2020 (29 months)

Phase ii Moorhouse Moineau Mitchell Library Mercury Merlin Martynside Welfare Centre March Kemp Health Centre Community Centre Hudson Energy Centre

September 2020 – January 2021 (5 months)

11A-1 11B-1 11C-1 11B-2 11C-2

March 2021 – June 2024 (40 months)

Phase iii N/A 11B-2 11C-2 11D-1 11D-2

May 2023 – April 2024

Phase iv Heracles Hector Gauntlet

12A-1 12A-2

October 2023 – November 2025 (25 months)

Phase v Galy Folland

12B-1 12B-2

August 2024 – December 2025

5.9.3 A contractor has not yet been appointed; therefore as a result the the detailed construction practices are yet to be established. It is however expected that the construction of the Proposed Development will entail the following, the likely significant environmental effects of which have been considered in this ES::

Establishing the construction compounds

Enabling works and site preparation

Construction of site access



Vegetation clearance

Drainage works, including SuDS

Installation of utilities

Construction of residential units, community hub and open space

5.9.4 Construction traffic and type of delivery will vary, however there will be increases in vehicle movements along the local road network especially along Lanacre Avenue, Aerodrome Road and Bristol Avenue (when this has been constructed).

5.9.5 Working hours on Site will be agreed with LBB prior to the commencement of construction works. Night time working will be restricted to exceptional circumstances.

5.9.6 Lighting may be required during the winter months; however it will be directed towards less sensitive receptors to reduce any impacts.

5.9.7 During the construction phase, environmental controls (mitigation measures) have been identified to reduce or offset the likely significant adverse impacts on the environment and are detailed below:

Preparation of a Construction Environmental Management Plan (CEMP). This provides the management framework required for the planning and implementation of construction activities in accordance with the environmental commitments identified within this ES. It will also address the requirements of any subsequent planning conditions imposed by Barnet Council. Its purpose is to minimise the risks of adverse impacts on environmental resources, local residents and businesses and it will be approved before the start of construction works.

Requirement to comply with the CEMP included as part of the contract conditions for each element of the work.

In respect of necessary departures from the above, procedures for prior notification to LBB and affected parties would be established; and

Establishing a dedicated point of contact and assigning responsibility to deal with construction related issues if they arise. This would be a named representative from the construction team.



6.0 LIKELY ENVIRONMENTAL IMPACTS AND MITIGATION MEASURES

6.1 Ground Conditions and Contamination

6.1.1 The Site is currently a developed area, underlain by London Clay Formation over the Lambeth Group with White Chalk subgroup at depth and localised areas of Made Ground. There are no significant surface watercourses on or adjacent to the Site and the Site is considered to be at low risk of flooding. Historic mapping has confirmed that the Site was undeveloped open land until c.1948 when several runways had been constructed, remaining as an aerodrome until c.1968. By 1974 the runways had been completely removed and the area redeveloped as the present day Grahame Park residential estate.

6.1.2 Potential contamination sources consist of landfills, waster transfer stations, fuel stations, pollution incidents, garages, sub-stations (onsite) and onsite transportation. On the basis of the moderate UXO risk considered for the Site, a more detailed UXO desk study was commissioned for the Site in July 2016 which concluded that the attendance of any intrusive ground works by a UXO clearance engineer was considered pertinent.

6.1.3 Previous ground investigations were undertaken in 2010, 2011 and 2013. To inform this ES, a desktop study, Site walkover survey and contaminated land assessment were undertaken alongside a series of ground investigations in 2016 undertaken to provide specific information on the ground conditions on the Site.

Soil Conditions

6.1.4 A human health risk assessment and soil sampling analysis were undertaken. Typically the soil encountered on Site was limited to Made Ground which contained brick, concrete, clay piping, metal wire and tiles. Visual and olfactory evidence of potential contamination was shown in a number of exploratory locations; with the presence of clinker, ash, plastic, metal, possible asbestos fragments noted; as well as a single occurrence of malodorous odour encountered in the location of one hand dug pit. The presence of asbestos is not considered to be widespread throughout the Made Ground material; however where such material is present the potential for asbestos to be encountered should be considered a presumed risk.

6.1.5 This analysis identified elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPH) to be present as hotspots of potential risk if Made Ground in these areas was to remain within 1m of the ground surface in soft landscaped areas.

Groundwater

6.1.6 Groundwater samples were taken where such water was encountered, and these were analysed against screening criteria designed to be protective of aquatic life in the environment. This identified some minor exceedances; however based on the near surface soils conditions and the presence of approximately 14.0m of highly impermeable London Clay beneath the Site, these exceedances are considered to represent minor impacts to general water quality in the surrounding area, likely due to the historically urbanised location of the Site. No targeted remedial works are considered to be required in relation to controlled waters; however the consideration of the potential for piling works which may penetrate the London Clay strata to have an impact on the underlying aquifers is considered diligent.



Construction Impacts

6.1.7 Construction phase activities have the potential to disturb, expose or mobilise existing contamination. Construction activities can also introduce new potential contamination sources through the temporary storage of chemicals (e.g fuels) and through the importation of soils for earthworks.

6.1.8 In common with the majority of construction projects there is potential for accidental leaks and spills of substances such as fuels and oils.

6.1.9 Measures covering the handling and storage of potentially hazardous liquids on Site will be implemented through the Construction Environment Management Plan (CEMP) which will also include measures to protect construction workers through the construction phase. With the implementation of the CEMP, no significant contamination effects are predicted during the construction phase of the Proposed Development.

6.1.10 Construction impacts on the groundwater beneath the Site are considered to be a minor risk based on the presence of approximately 14.0m of highly impermeable London Clay strata beneath the Site. The results of the groundwater monitoring have shown that groundwater is encountered at depth across the Site. As such, should any incidents such as localised spillages or leaks occur during works, these are unlikely to reach groundwater; hence there would not be a full pollutant linkage. It is however considered pertinent that the potential impacts of any piling which would be to a sufficient depth to penetrate the London Clay be considered.

6.1.11 Redevelopment or maintenance of the Site may involve ground workers coming into contact with the underlying soils and groundwater. Given the likely exposure frequency and duration of these scenarios, the risks posed by the elevated PAH and TPH concentrations identified in soils, as well as potential risks presented by any groundwater present, are considered to be reasonably mitigated by the provision of basic PPE and employment of good site practice.

6.1.12 By virtue of the potential presence of asbestos in the Made Ground present on Site, if the generation of dust during works is not controlled then a complete pollutant linkage may be present. Based on the concentrations of asbestos fibres measured to date the risk associated with this is perceived as being low; however as with all asbestos risk the potential worst case impact is severe. As such appropriate risk assessment and control measures should be undertaken and employed as necessary. Any Contractor employed to undertaken works within this media should have demonstrated suitable experience and proficiency with regards to the roles and responsibilities presented in the Control of Asbestos Regulations 2012. All relevant information relating to the ground conditions should be supplied to any Contractor employed in order for them to produce any risk assessments, method statements and work plans required. On the basis that this risk can be mitigated appropriately, the significance of the risk is considered minor.

Operational Impacts

6.1.13 The nature of the Proposed Development is such that there are no new potentially significant sources of contamination (e.g. industrial processes) once the Proposed Development is occupied / operational. The current use of the site is considered to be representative of the proposed end use, with end-user receptors of moderate sensitivity currently utilising the soft landscaped areas in a similar manner to those proposed. As such the Proposed Development is considered to represent a change of low magnitude, which corresponds to be of low adverse



significance (unmitigated) which would not be significant for EIA purposes. In effect the Proposed Development works offer an opportunity to provide betterment at the site compared to current site conditions; with the potential risks derived from source-pathway-target linkages involving soils already existing.

6.1.14 Ground gases within the Site have been shown to be sufficient to require basic, passively ventilated gas protection measures. These will be incorporated into the proposed floor slab design and construction.

6.1.15 The surface water drainage strategy for the Site is based around the use of Sustainable Drainage Systems (SuDS). There is potential for any contaminants from surface water run-off from areas of car parking to migrate; however given the presence of a significant thickness of highly impermeable London Clay above the groundwater present, the potential for this to impact groundwater quality is considered to be low.

Mitigation

6.1.16 Mitigation measures will be put in place in order to minimise adverse effects identified by the assessments. The Construction Environmental Management Plan (CEMP) will be produced prior to the start of the works and implemented by the Principal Contractor. Alongside this measures will be out in place to prevent the pollution of soil, groundwater and surface watercourses will be incorporated onsite.

6.2 Noise and Vibration

6.2.1 Particular consideration is given to the effects of noise and vibration during the construction of the Proposed Development at existing nearby sensitive receptors and those receptors constructed in earlier phases of the Proposed Development, and the effects of noise during the operation of the Proposed Development due to changes in road traffic volumes and plant noise from the proposed residential, employment and retail areas.

Noise Measurements

6.2.2 Noise measurements were undertaken at a number of positions across the Site in order to characterise the existing noise climate and noise measurements were carried out in June 2016. . From this a noise model was created and has been used in conjunction with traffic data to predict the impact of noise arising from the Proposed Development on existing and future noise sensitive receptors.

6.2.3 A study area of approximately 300m around the Site has been considered for the noise and vibration assessments. The existing noise and vibration sensitive receptors which have been considered in the assessment are primarily residential dwellings within the study area.

6.2.4 The ambient noise climate across the Site is dominated by transportation noise due to road traffic on the M1 motorway, local roads including Lanacre Avenue and Grahame Park Way and noise due to train movements on the Midland Main Line to the east of the Site.

Construction Noise

6.2.5 Any major development will give rise to some noise disturbance for receptors within the vicinity of the Site during the construction phase. Disruption due to construction is generally a more localised phenomenon than the effects of the Proposed Development after opening, and is temporary and short-term in nature.



6.2.6 The exact construction plant type and detailed construction programme are unknown at this stage of the planning process. Until the exact types and numbers of machinery are known, along with the expected percentage on-time and locations of fixed plant, a detailed Noise Impact Assessment cannot be completed.

6.2.7 Due to the large number of existing noise sensitive receptors in the vicinity of the Site, 10 existing representative receptors around the Proposed Development have been selected for the construction noise assessment. Where appropriate, an additional six receptors from current and future buildings within the Site have also been considered.

6.2.8 All construction effects would comprise of multiple short-term, temporary phases and be of significance at the local level. It should also be noted that people are generally more tolerant of higher noise levels if they know that they are only going to be of a short duration which would reduce the likelihood of complaint. A detailed assessment should be carried out at a later stage once the construction programme and proposed plant items have been determined.

6.2.9 It is unlikely that vibration due to activities such as excavation, hydraulic breaking and auger piling will be perceptible by inhabitants of nearby dwellings, however, as the distances are similar to the distances of receptors from the Proposed Development, vibration from these activities may be perceptible to some residents for short periods of times. It is noted that any vibratory compaction activities would be mobile which would reduce the amount of time any vibration sensitive receptor would be affected by vibration from these activities.

6.2.10 Provided that noise from the temporary plant installations do not exceed the background noise levels at the nearest noise sensitive receptors, there would not be a significant adverse effect due to noise from these items of plant during their operation. As the precise specifications of the temporary plant are unknown, a further assessment should be carried out prior to their installation in order to determine whether mitigation measures or an alternative plant unit would be required.

6.2.11 The Energy Centre is proposed to be located within Plot 10B, however, the precise specifications of any plant to be installed are unknown at this stage. In addition, there may be other items of plant installed across the development associated with retail units, the Community Hub or residential units, the locations and specifications of which are unknown at this stage. For all of the above plant items, the nearest noise sensitive receptors are likely to be residential units within the Proposed Development. Noise from any plant would be subject to a detailed Noise Impact Assessment at an appropriate design stage to ensure that they do not cause an adverse impact on other areas of the Proposed Development. Consequently, this would minimise the likelihood of an adverse impact at existing, off-site noise sensitive receptors.

6.2.12 The preliminary construction noise predictions show that the assumed construction activities which have been assessed have the potential to exceed the significance criteria at the representative receptors around the Site. This assessment has been carried out with limited information on the construction programme and assumptions of the potential construction plant items.

Operational Impacts

6.2.13 The assessment of road traffic noise has shown that noise from traffic generated from the Proposed Development is predicted to have a negligible or minor effect on the majority of existing noise sensitive receptors and road traffic noise levels.



6.2.14 Assuming that, plant installations do not exceed LBB’s plant noise criteria at the nearest noise sensitive receptor, no further mitigation measures would be required. The likely significant residual effects would remain negligible

6.3 Air Quality

Introduction to key pollutants

6.3.1 Concentrations of nitrogen dioxide (NO2), particulate matter of less than 10 micrometres in size (PM10) and particulate matter of less than 2.5 micrometres in size (PM2.5) have been predicted at forty-two (42) locations within, and close to, the Proposed Development.

6.3.2 A search of the UK Pollutant Release and Transfer Register has not identified any significant industrial or waste management sources that are likely to affect the Proposed Development in terms of air quality. All background concentrations of NOx, NO2, PM10 and PM2.5 used in the assessment are significantly below their respective objective.


6.3.3 There is the potential for the construction activities to impact upon both existing and new properties. The main pollutants of concern related to construction activities are dust and PM10. A detailed assessment of emissions from construction traffic has been scoped out of the assessment as the total traffic generation during construction will be considerably lower than the total completed development traffic generation which forms the basis of the operational impact assessment. The impacts from construction traffic will therefore be less significant than the operational traffic emission impacts.

6.3.4 Initial screening has identified that the Proposed Development has the potential to lead to dust impacts during construction and as such a detailed construction dust risk assessment has been carried out. This concluded that with the appropriate mitigation, in place, the residual effect will be not significant.

6.3.5 As the current dwellings are part of an existing district heating network, a temporary combustion plant will be required in stages depending on what phase the demolition and construction has reached.

6.3.6 The assessment has demonstrated that the use of temporary combustion plant, installation of the Energy Centre and construction traffic will not cause any exceedances of the air quality objectives.

Operational Impacts

6.3.7 All Development Receptors are significantly below the annual mean objective. All particulate matter concentrations are all significantly below their respective annual mean objectives at all Development Receptors in all years. Therefore, air quality for future residents within the Proposed Development will thus be acceptable.

6.3.8 Mitigation measures will be implemented in order to minimise the impacts upon nearby sensitive receptors, including a Dust Management Plan.



6.4 Traffic and Transportation

6.4.1 Effects are assessed for three development scenarios: Observed Year 2016, Future year 2026 (‘Do nothing’ base which is obtained by applying growth factors) and Future Year 2026 with development (‘Do something’).

6.4.2 The assessment of construction traffic during the construction period 2018-2026 has been assessed on the difference between ‘do-nothing’ baseline Annual Average Daily Traffic (AADT) traffic flows and the ‘with construction’ traffic flows, which include the number of trips to be made to and from the construction area by site construction workers and heavy goods vehicles (HGVs). The assessment of ‘Occupation/Operational Phase traffic has been based on the difference between the 2026 ‘do-nothing’ and the 2026 ‘with development’ (do-something) flows.

6.4.3 The determination of sensitivity of individual receptors is based on a number of factors such as level of activity and vulnerability of users. The baseline traffic conditions were established through a series of classified manual traffic surveys and Automatic Traffic Counts (ATC) undertaken in June 2016.

6.4.4 The Site has and is surrounded by a well-defined pedestrian network with all streets providing footways on one or both sides of the street. The existing network provides easy access to all local facilities, schools and transport nodes. There are no formal cycle lanes or cycle paths within the general area of the Site and the broader Grahame Park Estate. Public transport provision in the vicinity of the Site is relatively good with bus stops provided at regular interval on Lanacre Avenue, Corner Mead and in Quakers Course. In addition, Colindale Underground Station and Mill Hill Broadway Station are located within a short distance of the Site. The operation of the local road network has been assessed using industry standard network modelling software.


6.4.5 The impacts of construction traffic on traffic flows, congestion and delays are considered to be low. Construction traffic will be constrained to defined routes. The effects on pedestrians and cyclists will be temporary and only occur over the duration of the construction phase.


6.4.6 Results from the modelling show that the Proposed Development will not have a major impact on the operation of the local road network. The model has shown that with the new road connection there is some traffic re-routing through the site within the model but that the overall observed traffic distribution was reasonably similar to the existing situation. Therefore the traffic impacts arising from introducing a vehicular connection between Lanacre Avenue and Corner Mead is anticipated to be negligible.

Mitigation

6.4.7 Mitigation measures such as the implementation of a Construction Traffic Management Plan will be prepared in order to minimise any environmental impact during the construction period. Other mitigation measures include encouraging use of sustainable modes of transport in particular walking and cycling, details of which can be found in the TA and the Design and Access Statement.



6.5 Cumulative and In-Combination Effects

6.5.1 An assessment has been undertaken within the ES of the likely significant cumulative effects of the Proposed Development with other committed developments in the area.

6.5.2 The Proposed Development will form the most substantial component of the wider Grahame Park Estate Supplementary Planning Document (SPD). The potential for cumulative effects within the full scope of the Grahame Park SPD has therefore been assessed.

6.5.3 A list of cumulative sites (shown in Table NTS4) was agreed with Barnet Council.

6.5.4 The potential for cumulative effects with other developments that are consented, for which planning permission is being sought, or which are reasonably foreseeable, has also been assessed within this chapter of the ES.

Table NTS4: Cumulative Assessment Sites

Site name Planning application reference(s)

Location in relation to the Proposed Development

Plot B1, (Grahame Park Estate Regeneration) Lanacre Avenue, Colindale

H/00308/11 68m south

Plot B6, (Grahame Park Estate Regeneration) Lanacre Avenue, Colindale

14/07210/FUL 36.5m south

Plot A1, (Grahame Park Estate Regeneration) Lanacre Avenue, Colindale

15/04039/FUL 136m south

Plot A9, (Grahame Park Estate Regeneration) Lanacre Avenue, Colindale

H/00310/11 203m south

The Peel Centre – off Colindale Avenue H/04753/14 619m south

Beaufort Park – Former East Camp RAF Hendon, Aerodrome Road

W00198AA/04 450m south east

Station House - Colindale Avenue H/01110/13

526m south west

Colindale Hospital – Colindale Avenue H/00342/09 616m south west

National Blood Service Expansion Site – Colindale Avenue

H/04541/11 670m south west

Former College Plot within Colindale Hospital site H/00093/13 536m south west

Barnet and Southgate College H/03551/14 106m north east

Peel Centre – Aerodrome Road LBB - H/01571/13

616m south east

British Library – Colindale Avenue H/05856/13

634m south west

Colindale Business Centre – Colindale Avenue H/05833/14 690 south west

St Augustine’s Church Site (DoL) N/A 27m north

RAF Museum Site 16/2106/FUL 394m east

Heybourne Park N/A Adjacent to the Site

Pentavia Retail Park 15/01825/FUL 779m north

6.5.5 The assessment of cumulative effects has been based on the assessments undertaken within the EIA for the Proposed Development and, where available, the respective planning application



documentation and Environmental Statements prepared for other developments. Where planning applications have not yet been submitted for other developments, the extent to which their respective effects can be considered is limited by the information that is available.

6.5.6 Where there are no significant residual effects predicted for other developments and no significant predicted residual effects for the Proposed Development, it is concluded that it is unlikely that there will be any significant cumulative effects for that topic area.

6.5.7 The in-combination effects were assessed by reviewing the relationship between the topics assessed within the ES.


6.5.8 A review of the construction impacts of each site was undertaken to address potential impacts.

6.5.9 Construction effects can be minimised through the use of appropriate mitigation measures such as those included within the CEMP and it is anticipated that attitudes towards best construction practices will be undertaken for all of the identified committed developments.

6.5.10 In terms of construction effects, nine of the cumulative assessment sites are complete or to be completed by the end of 2017. As the construction activities associated with the Proposed Development are not expected to commence until 2018, there will therefore be no significant construction cumulative impacts arising from these developments. Taking this into consideration, reference to those developments were scoped out.

6.5.11 In relation to cumulative construction traffic impacts, all of the identified sites can be scoped out as having no significant construction traffic impacts, with the exception of The Peel Centre - Colindale Avenue and Beaufort Park. It has been identified that these developments will continue construction activities through the timeline of the Proposed Development. Movements from these two sites will be strictly east towards the A41 and are not anticipated to use any western routes. Based on available capacities and information, it can be concluded that there will be no significant cumulative construction impacts.

Operational Impacts

6.5.12 Because the scope of the ES is focussed upon traffic generation and the ancillary impacts associated with this, cumulative operational impacts are incorporated into the assessments as presented. These assessments conclude that there are no significant impacts as a result of traffic generation (including noise and air quality issues) taking into account the mitigation measures outlined within the ES. In terms of ground conditions, taking into account the mitigation measures proposed, no significant cumulative operational impacts are expected.

6.5.13 A summary of the predicted significant effects for each of the individual developments is provided within Table NTS5 and is reliant on the information provided within the other planning applications in terms of the predicted impacts of each development on ground conditions, noise and vibration, air quality and traffic and transportation. This assessment also assumes that mitigation measures set out in the assessments for other developments will be implemented. Where EIA was not required, it has been assumed that there would be no significant environmental effects.

Table NTS5: Summary of predicted significant effects for the individual sites



Individual Sites ES undertaken Ground conditions

Noise and vibration

Air quality

Traffic and transportati

on The Proposed Development Y N N N N

Plot A1, Lanacre Avenue N N N N N

Plot A9, Lanacre Avenue N N N N N

The Peel Centre- Colindale Avenue Y N N N N

Beaufort Park –Aerodrome Road U N N N N

Barnet and Southgate College N N N N N

Colindale Business Centre, Colindale Avenue

N N N N N

St Augustine’s Church Site (DoL) N/A U U U U

Heybourne Park N/A U U U U

Pentavia retail Park Y N N N N

Y = Yes

N = No L = Considered likely based on available information and the known scale of development U = Uncertain based on available information N/A = not applicable

6.5.14 On the basis of the above information, it can be concluded that the likelihood of cumulative impacts is unlikely or not significant.

6.5.15 Similarly, the assessment concluded that there would be no significant in-combination impacts.



7.0 WHAT WILL HAPPEN NEXT?

7.1.1 Following the submission of the planning application, there will be an opportunity for any interested parties to view and comment on the Proposed Development.

7.1.2 The ES is available for public viewing on LBB’s website:

www.barnet.gov.uk

7.1.3 A copy of the ES is also available for viewing by the public during normal office hours in the planning department of LBB at the address given below. In addition, should you have any comments on the planning application, these should be forwarded to the LBB planning case officer at the address provided below:

London Borough of Barnet North London Business Park 4 Oakleigh Road London N11 1NP

7.1.4 Copies of the ES (Volume 1 – 3) can be purchased from Tibbalds Planning and Urban Design on request, the costs for which are set out below:

Volume 1: ES Main Text & Figures - £400.00

Volume 2: ES Appendices - £400.00

Volume 3: Non-Technical Summary (NTS) – £15.00

Full copy (Volumes 1-3) of the ES on CD - £25

7.1.5 For copies of any of the above please contact the Applicant at Genesis Housing Association at:

Choices for Grahame Park / Genesis Housing Association Atelier House 64 Pratt Street London NW1 0DL

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