DRAYTON GARDEN VILLAGE

Transcription

1 DRAYTON GARDEN VILLAGE Environmental Statement Non Technical Summary

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3 1 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT Contents > 01 Introduction > 02 Description of Site and Surroundings > 03 The Proposed Development Construction and Phasing > 04 Planning Framework > 05 Socio-Economic > 06 Transport, Accessibility and Movement > 07 Ground Conditions and Hydrogeology > 08 Flood Risk and Water Resources > 09 Noise and Vibration > 10 Air Quality > 11 Biodiversity > 12 Archaeology and Cultural Heritage > 13 Townscape and Visual Analysis > 14 Conclusion

4 2 01 Introduction This document provides a Non-Technical Summary of the Environmental Statement (ES) which accompanies the outline planning application for the redevelopment of the former National Air Traffic Services headquarters (NATS) in West Drayton (now referred to as Drayton Garden Village). The outline planning application relates to a hectare site located in West Drayton, to the west of central London. Locally, the Site lies west of the town centre, 2.4km north of Heathrow Airport, 1km west of Stockley Business Park. The planning application is for 775 dwellings together with a range of commercial facilities. The application is submitted by Inland Homes Limited. The Environmental Impact Assessment Regulations 1999 require that this development proposal is accompanied by an ES. The primary purpose of an ES is to inform the decision making process by reporting the results of an Environmental Impact Assessment (EIA). This is a recognised process for identifying the significant environmental effects of a project and is a formal part of the UK planning regime. The ES considers the environmental effects of the Proposed Development, during construction and completion, and proposes ways to prevent or reduce and where possible offset any significant adverse effects on the environment, known as mitigation measures. These measures are described in Chapters The Non-Technical Summary provides the background to the planning application and describes the Proposed Development. The bulk of the Non-Technical summary sets out the findings of the ES (in non-technical language). Nevertheless, it contains formal definitions that are an essential language of the ES which may be unfamiliar to some readers. A Glossary of Terms is provided in Volume 1 of the ES. Background to the Environmental Statement As part of the formal EIA process a formal screening request was submitted to the London Borough of Hillingdon (LBH) on the 29 May 2009 and a request was made to the Government Office for London (GOL) on 4 July It was considered by GOL that the redevelopment proposals fell within the classification of an urban development project for a site where the development area exceeds 0.5 Hectares (Ha) and that the scale and intensity of the Proposed Development could have a significant impact upon a number of areas. GOL therefore advised the planning application should be subject to an EIA. A copy of the adopted Screening Opinion can be found in Appendix 1.1 of the ES. Following the initial screening of the proposals, a formal Scoping Request was submitted to LBH for determination on 17 August The Scoping Report is an important part of the EIA process. It involves scoping the issues of potential significance, which may arise from the Proposed Development. The Scoping Report sets out the key environmental issues that may result in the implementation of the Proposed Development.

5 3 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT A Scoping Opinion was adopted by LBH on 5 October in response to the Scoping Request. The Scoping Opinion contained specific details and recommendations relevant to each of the topics covered in the ES and also included the following response: Need to include and describe receptors in the methodology; Need to elaborate on public consultation undertaken; Statements should be verifiable and supported by evidence; Acceptance that chapters for Townscape and Visual analysis and Archaeology only require brief treatment; Agreement that waste and daylight/sunlight issues do not need to be assessed as part of the Environmental Statement. A copy of the Council s Scoping Opinion is contained at Appendix 1.2 of the ES. Consultation Inland Homes has carried out an extensive exercise in community consultation on the future of the NATS site. The main stages of consultation were: A number of leaflets outlining the potential development of the Site, information of public consultation events and details of the planning application were circulated during different phases of the schemes evolution. These leaflets were sent to 6,300 homes and businesses over a wide area of West Drayton and Yiewsley; 2 public exhibitions were held showcasing ideas for residential - led regeneration of the Site and invited peoples views and feedback; Continuous liaison and pre-application discussions with the relevant statutory consultees and Officers at LBH. Overall Approach to the Environmental Statement This ES has been prepared by an appointed consultant team in accordance with the requirements set out in the Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999 and DCLG Circular 02/99: EIA. It follows the format and assessment methodologies set out in the Department for Communities and Local Government document Environmental Impact Assessment: A Guide to Procedures (2000). A list of the Consultant Team can be found in paragraph 2.3 of Chapter 2 of the ES Document. The ES identifies and records the results of the EIA undertaken to examine the impacts of the Proposed Development. The assessment relates to the demolition, construction works and the completed development and the EIA considers the environmental impact/s the development will have on a range of topics. These topics were formally agreed with LBH as part of a scoping process. The ES suggests a range of measures to mitigate the identified effects and, where opportunities exist, to introduce improvement measures. Where possible these improvements have been incorporated in the outline planning application and will inform future

6 4 01 Introduction detailed reserved matters submissions. The content and extent of coverage of the ES is based on the following: Review of the current situation through existing information, data and reports; Desk-top studies; Site surveys; Modelling; Consideration of relevant planning policies (national, regional and local); Identification of likely environmental impacts and an evaluation of their likely duration, magnitude and significance; Consideration of potentially sensitive receptors; Expert opinion; Use of technical guidance and best practice. The following topics (as agreed with LBH) are considered in the ES: The Planning Framework Socio-Economic Transport, Accessibility and Movement Ground Conditions and Hydrogeology Flood Risk and Water Resources Noise and Vibration Air Quality Biodiversity Archaeology and Cultural Heritage Townscape and Visual Analysis The findings of the assessments undertaken on each of these topics is set out in sections 4-13 of this document

7 5 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT 02 Description of Site and Surroundings The Site The former National Air Traffic Services headquarters (NATS) site is located to the east of West Drayton town centre, and to the west of central London. It is only 2.4km north of Heathrow Airport and 1km west of Stockley Business park. Key transport routes that surround the Site include West Drayton railway and bus stations which are approximately 1km walk to the north west of the Site. In addition, there is a bus stop immediately outside the Site on Porters Way which provides links to the local area including Uxbridge Underground Station, Hayes and Harlington mainline railway station and Hounslow. The Site is bounded by the main London Reading railway line to the north, Porters Way to the south, and residential curtilages abut the eastern and western boundaries. The main vehicular access to the Site is from Porters Way which is located to the south of the Site. Porters Way provides good accessibility to the local road network and motorway network beyond (namely, M25, M40 and M3). Heathrow Airport is also in close proximity to the Site via Junction 4 of the M4 motorway (approx 1 mile). Pedestrians and cyclists will also access the Site from Porters Way. In total the Site comprises hectares of large industrial style sheds, power generation buildings, hard-surfaced car parking areas (with up to 1,300 car parking spaces) and large interconnecting office blocks (up to 7 storeys). It provides one of the largest regeneration opportunities within the West Drayton Area. The main office buildings dominate the central and southern boundary areas of the Site fronting Porters Way. There are a number of mature trees on the southern, eastern and north eastern boundaries and the entire Site is located on a major aquifer consisting of Taplow Gravels, which is found at depths of up to 5m below ground level. Site Considerations and Constraints Over the development design period, which began early 2009, a range of considerations and constraints were identified which have influenced the layout and the design of the scheme. These are set out in Table 1 below. These factors are primarily a result of the location of the Site, infrastructure and transport conditions, consultation and the nature of the surrounding built environment. Consequently, the proposals have evolved to respond to these key factors. Issue Urban Design Layout Natural Environmental Conditions Physical Conditions Social Utilities Table 1: Site Considerations and Constraints Considerations and Constraints Regularity of existing urban grain, variety of building heights (particularly Parkwest), massing and scale, long and short distance views of the Site. Creation of Home Zones and clear framework of streets, open areas and public spaces, prioritise sustainable modes of transport. Sunlight orientation, prevailing winds. Proximity to railway line, layout to enable provision of CHP/Energy Centre. Relationship to surrounding buildings. Integration with the community and provision of facilities, provision of affordable housing, provision of elderly accommodation. Existing layout of utilities on-site.

8 6 02 Description of Site and Surroundings Site location and proximity to Heathrow Airport

9 7 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT Surrounding Area The site lies within an area that is predominantly in residential use. To the east, are the single and two-storey residential properties in Rutters Close and Mulberry Crescent, and the 3-storey shopping parade/flats at Mulberry Parade. To the west is St George s Parkwest residential development which includes large flatted buildings, between 4 and 7 storeys in height. The southern part of Parkwest is largely complete and construction work continues on the northern blocks comprising mainly affordable housing for Notting Hill Trust. The existing residential area to the south of Porters Way comprises mainly bungalows and 2 and 3-storey terraced and semi-detached housing with a relatively open, suburban character. Committed Developments West Drayton station is identified as a future Crossrail Station with fast trains serving central London 6 times an hour from Following consultation with LB Hillingdon, the following committed developments have been considered within the future baseline assessment: Parkwest; Stockley Park Phase 3; Tesco, Yiewsley; and Honeywell; Beyond the railway to the north is the Grand Union Canal which links London to the Midlands. The MOD s retained Air Cadets facility is located adjacent to the north-east corner of the Site and Rutters Close. There are local retail facilities, including a food store, chemist and post office, at Mulberry Parade which is located immediately adjacent to the south-east corner of the Site fronting Porters Way. Mulberry Parade is a Council-owned building comprising 12 shops at ground floor level and flats at first and second floor levels. Residents parking and a service yard are located at the rear of the building. Stockley recreation ground is located a short distance to the south-east of the Site off Porters Way. Site Context Plan

10 8 03 The Proposed Development This section sets out the main components of the proposed scheme. The planning application is in outline with Access, Siting and Scale fixed for determination. Therefore, details such as the proposed materials/appearance and landscaping are only illustrative at this stage. The Proposed Development will comprise of 775 dwellings (504 flats and 271 houses) providing a number of studio, one, two and three bedroom flats as well as two, three, four and five bedroom houses. The average density will equate to 86 dwellings per hectare (dph). A Nursing Home (up to 3,630m 2 GEA ) for elderly people who need 24hr supervision is also included as part of the redevelopment. The scheme will be residential led with a number of other community/service uses. A Primary Healthcare facility including a room for joint community use (up to 1,085m 2 GEA ) with space for up to 9 GP s. Small scale retail accommodation will be included within the footprint of the medical centre to complement Mulberry Parade (up to 185m 2 GEA depending on the size of the Primary Healthcare building), small scale business units including site management office are proposed (up to 185m 2 GEA ) and an Energy Centre (up to 220m 2 GEA ) comprising a Combined Heat and Power (CHP) facility and Biomass boiler to provide heating of hot water and space heating for the whole site. This will not only enhance the environmental sustainability of the development but will ensure the development can reduce its Carbon Dioxide emission by 20% through the use of renewable energy. In addition the development will include: Access roads The main vehicle and cycle access will be off Porters Way, with a secondary access provided off Rutters Close. The scheme is designed to incorporate Home Zone principles ensuring the safety and comfort of pedestrians and minimising vehicle speeds. Car and cycle parking - A total of 1,122 car parking spaces will be provided within the development, 68 spaces are allocated to commercial uses and the remaining 1,054 spaces will be set out around the scheme relating to building typology. Cycle parking will be provided for every flat at a ratio of 1 space per unit and 2 spaces per unit for the houses. Public open space areas - The scheme provides two principle areas of Public Open Space which are known as Village Greens. The total area of these including surrounding footpaths and access routes is 9,967 sq. m. Contained within these village greens will be one LEAP (Local Equipped Area of Plan) and one LAP (Local Area of Play) for children. Further incidental play areas are incorporated into the pedestrian home zones and the promenade areas. Cycle ways and footpaths This includes a new permanent pedestrian link running from east to west through the Site, providing connections to West Drayton railway station and local shops and will also be used by cyclists, further minimising their journey times.

11 9 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT Master Plan

12 10 03 The Proposed Development Landscaping works The landscaping details at this stage are indicative, however the scheme proposes two new village greens, new ecology areas located on the northern, and eastern boundaries, rear gardens for the houses, private amenity courtyards, balcony spaces for the flats and hard and soft landscaping. The outline planning application provides indicative detail for materials. It is intended that traditional materials will be used, such as combinations of brick, render, rainscreen cladding and timber boarding with either tiled or flat roofs dependant upon location and urban design characteristics. Construction and Phasing The current expectation is that the construction would take approximately 7 years (84 months/364 weeks) to complete in full, with defined development stages shown below: Enabling works - The enabling works and site preparation will be ongoing as difference phases in the demolition and construction commence. Hoardings would be erected around the Site perimeter (in accordance with the Health and Safety Executive and LBH requirements) It is anticipated the enabling stage will include: Preparation of services and diversion of public surface water sewer Further intrusive investigations for soils and groundwater, to be undertaken prior to soil and groundwater remediation. Completion of a geotechnical assessment of the ground conditions. Demolition - Demolition phase 1 commenced on site on 7 September 2009 and is expected to occur in 7 phases as set out in detail in Figure 5.1 of the ES, Chapter 5. The demolition works will take approximately 36 weeks in total to complete and will be phased over a year. The demolition phasing plan indicates that Phase 1 to 6 of demolition and excavation is scheduled to take 16 weeks with phase 7 anticipated to take 20 weeks, however the time period will depend largely upon asbestos removal, oil cleaning, and remediation. A Discovery Strategy (Appendix 5.2 of the ES) is being implemented during demolition and construction phases to ensure that in the event that any unidentified areas of contamination are identified they are managed appropriately. A Dust Monitoring and Management system (Appendix 5.2 of the ES) is also being implemented to reduce dust during demolition. Reuse and recycling of materials obtained from the existing buildings and concrete ground slabs would be undertaken wherever possible on-site (e.g. the use of some crushed material of a suitable grade for fill material or using sub-base for roads and hard cover). A Site Waste Management Plan (SWMP) (submitted with the planning application) is in place to ensure the reduction, reuse, recycling and appropriate disposal of waste as well as the appropriate storage of waste on-site, prior to disposal Approximately 9,000m 3 of materials would be removed from the Site during the demolition process. This would equate to approximately 300 HGV movements during the demolition and excavation stages of the development

13 11 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT Aerial view looking west across site

14 12 03 The Proposed Development Temporary provisions These will be delivered as required to resolve infrastructure requirements and will be ongoing for duration of the construction and demolition programme. The temporary works are timetabled to commence in March 2010 and be competed in There are four components to the temporary works: The preservation of a safe and secure access across the Site for the ATC who retain the right to a route from Porters Way to their premises; Definition and control of each phase to ensure that occupants and tenants can live and access a safe environment; The remediation strategy and external works requirements, including the use of demolition material which will require stockpiling, movement of levels and preparation of construction access and compounds. Site remediation - In accordance with the remediation strategy it is anticipated that remediation works will commence towards the end of 2009 and will take approximately 2 years to complete and will be carried out in 3 phases. It is the intention that almost all of the soil arisings produced during remediation will be reused on-site as soft cover or below hard cover. The reuse of soil will be undertaken in line with current policies on the definition of waste, so that once emplaced the material is expected to no longer be classed as waste. Ground works this will include preparation of new site ground levels, includes preparation of foundations and forms part of the overall landscaping strategy. The construction of groundworks will be ongoing for the duration of the construction programme and is expected to commence in May 2010 and be completed by Construction - The application is outline and therefore at this stage a full detailed construction specification is yet to be agreed and will be developed over 7 years from A Construction Management Plan (CMP) has been prepared and will be agreed with LBH. The CMP will provide details on-site planning, construction traffic, noise and dust associated with the demolition works and construction activities. The prescribed hours of work would be agreed with LBH. However, due to the proximity of residential dwellings and commercial activities to the Site it is likely that the standard hours of work would be restricted by condition to the following times: 08:00 to 18:00 hours Monday to Friday; 08:00 to 13:00 hours Saturday; and No working on Sundays or Bank Holidays. All noise generated during such works should be controlled in compliance with BS5228 and use best practice means as defined in Section 72 of the Control of Pollution Act 1974.

15 13 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT 04 Planning Framework 04 Planning Framework Chapter 7 of the Environment Statement examines the planning policy framework within which these redevelopment proposals for the NATS site must be considered. This planning framework is provided by the following range of documents: Government planning policy and guidance set out in national planning policy statements (PPSs) and planning policy guidance notes (PPGs); The GLA s London-wide policies set out principally in the London Plan (2008) and associated policy statements; and Local planning policies comprising the saved policies from the 1998 Hillingdon Unitary Development Plan, the Council s adopted Supplementary Planning Guidance (SPG) and Supplementary Planning Documents (SPD), including the Former NATS site, Porters Way, West Drayton SPD adopted in September The London Borough of Hillingdon Sustainable Community Strategy which sets out the aims and ambitions of the Hillingdon Local Strategic Partnership members for the next 10 years. LBH is in the process of formulating the new Local Development Framework for Hillingdon Borough and intends to publish the Core Strategy Development Plan Document (DPD) for public consultation before the end of This DPD is still at an early stage of preparation and consequently is not yet a material consideration for development control purposes. The proposed redevelopment of the Site accords with the main objectives of national, London-wide, and LBH planning policies in the following ways: It makes effective and efficient use of a vacant, previously developed site within a predominantly residential area; It will provide a high quality and sustainable residential-led, mixed-use development which will integrate well with its surroundings and provide improved pedestrian and cycle links to West Drayton and Yiewsley town centres and railway station; It will provide new community facilities (primary healthcare centre, care-home, and community meeting room), built to DDAcompliant standards, which will be of benefit to existing and new residents in this part of the Borough; It will provide a range of accessible dwelling types, sizes and tenures to meet the housing needs and demands of the West London subregional area. All dwellings will be built to Lifetime Homes standards and 10% will be wheelchair adaptable; It will provide additional small-scale convenience shopping facilities to complement and reinforce the existing shops in Mulberry Parade, for the benefit of existing and new residents in this part of the Borough; It will provide small-scale business accommodation (Class B1) in an attractive landscaped setting within walking and/or cycling distance of bus and train services;

16 14 04 Planning Framework The proposed greening of the Site will enhance its nature conservation and biodiversity value, and provide new open space and recreation facilities for the local area, including childrens play spaces, cycle and pedestrian routes and high quality landscaped amenity areas; It will result in a significant environmental enhancement for the local area by removing the unsightly large buildings and hostile boundary fencing, and opening up the Site both functionally and visually to the whole community. The potential environmental impacts of the development are examined in detail in the other chapters of this Environmental Statement. Where appropriate, mitigation measures are proposed to ensure that the development does not result in any significant harm to the local environment in this part of West London. For all the above reasons, it is considered that the Proposed Development is in accordance with all relevant national, London-wide and local planning guidance and policies. This proposed mixed-use redevelopment scheme makes efficient and effective use of this large previously-developed site in accordance with sustainable development principles. The scheme is designed to a high standard and integrates well with its surroundings. It will provide a range of housing types, sizes and tenures that is appropriate for the local area. The principle of a residential-led redevelopment scheme is accepted by LBH. Implementation of the scheme will assist LBH in meeting its strategic housing targets and other Community Strategy objectives over the next 5 10 year period.

17 15 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT 05 Socio-Economic In considering the socio economic impacts of the development, regard has been had to the baseline data established in chapter 8 of the ES. The Borough has high rates of economic activity and a successful local economy relating mainly to knowledge industries, which make up 41.5% of the total. About two thirds of jobs are filled by people commuting into Hillingdon, rather than by residents themselves reflecting some of the levels of low skills in the area. West Drayton has higher percentage proportion of households with 3 or more people and a high number of owner occupied residential accommodation. Despite this there are pockets of deprivation in proximity to the site. Development proposals will contribute to improving the socio economic characteristics of West Drayton ward and the wider area. The main benefit for local people will be the delivery of a range of housing types as well as other community facilities provision. The benefits of this development will impact directly and positively upon the lives of local people. a result of improved connectivity of the Site, providing higher levels of natural surveillance over the Site than currently exists and creating an attractive pubic realm. The development will provide 775 new dwellings providing a range of housing types and tenure which will help to meet local housing need and alleviate some of the pressure to provide new housing in LBH. The Healthcare facility and other commercial facilities will offer good secure employment opportunities, in addition to construction opportunities. The new medical facilities will have a positive affect on the population s health. In addition, the provision of a care home on the Site will represent a significant improvement to the care for elderly people, and will help to ensure that some of the elderly population can be housed in the local area. In the longer term, once all units are occupied and any off-site improvements are made, the development has the potential to act as a catalyst to enhance local lifestyles. During the construction phase, the development will generate a number of job opportunities that will match local skill levels and provide opportunity for local training. It is predicated that the construction phase will have a negligible impact on the local health conditions, due to the possible increase in dust particles and air pollution, particularly during the site clearance phase. Once complete, the socio-economic impact of the development is likely to be positive. The area will be accessible to all members of the community more as

18 16 06 Transport, Accessibility and Movement The impact of the development on the surrounding local area and transport network has been assessed in terms of transport, access and mobility. A range of computer models have assessed the amount of vehicle movements around the site and calculated the impact of the proposals on the immediate and surrounding road network. In terms of demolition and construction, a certain level of disruption will be expected during these phases with the most disruption forecasted to be during the construction phase of the development. It is expected that all construction traffic will use Stockley Road before turning into Porters Way and entering the Site from there. This disruption will be managed so that it will last for as short a period as possible. The disruption will be managed by the onsite management company so that vehicles arrive at times causing as little disruption on the road network as possible. The number of vehicles expected to the Site during any given hour will have very little impact on the roads surrounding the Site. The construction phase will have little impact on the local community accessibility. It is not anticipated the construction will affect any local routes in terms of the number of vehicles generated and contractors will be required to adopt considerate contractor procedures. Lorry routing will wherever possible avoid residential roads and neighbourhood centres while the existing cycle routes surrounding the Site will be retained. In addition, improvements to the Site frontage on the main vehicular access will improve pedestrian safety with an improved crossing facility and landscaping of the Site access. The operational phase of the development will increase road traffic surrounding the Site. The increases in traffic caused by Drayton Garden Village will have no significant impact on the local road network with the increase in traffic being minimal in comparison to the existing traffic surrounding the Site. Junctions surrounding the Site have been assessed to see how the traffic generated by the development will impact the surrounding junctions. These have been shown to work within capacity with the additional traffic distributed onto the surrounding network. The additional trips that are expected to take place on public transport services as a result of the development will have no negative impact on the local public transport facilities within the vicinity of the Site. In terms of accessibility, the development will not negatively affect accessibility in the area and will be beneficial as the Site will provide a new pedestrian route through the Site improving permeability. The new link will provide a connection through to West Drayton railway station reducing walk and cycle times. New signage is proposed through the Site which will illustrate routes through to the railway station, bus services and local facilities. Sustainable modes of transport (for example walking, cycling and public transport) will be encouraged to reduce the number of car journeys associated with the Proposed Development. To facilitate this, the Proposed Development will provide cycle parking spaces in accordance with

19 17 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT standards set by the London Borough of Hillingdon and Transport for London. In addition to the above, a Travel Plan has been prepared for the Proposed Development. As part of the implementation of this Plan initial travel surveys will be undertaken once the development reaches 75% occupation. The Travel Survey will be undertaken thereafter one, three and five years after the initial survey.

20 18 07 Ground Conditions and Hydrogeology The soils beneath the Site are mainly Taplow Gravels (sand and gravel) and overlying London Clay (firm brown clay). Groundwater is encountered at approximately 2.5m depth that is flowing towards the south-west. Minor contamination was identified in sub-surface soils, mainly in the northern portion of the Site and associated with the former diesel powered generators, engine workshops & vehicle repairs. Prior to any redevelopment, there will be a requirement to remediate this contamination such that the Site will be suitable for residential occupation. This will involve both soil and groundwater remedial treatment, which will extend to any additional areas of contamination that are encountered during the development. All remedial treatment will be conducted on-site, using sustainable technologies where practical. A robust waste strategy will be in place during the redevelopment that will limit the amounts of waste materials exported from the Site. Where possible, materials will be re-used on-site to reduce the amount of materials imported onto the Site. With suitable precautions, the completed development will have a negligible impact on the Site and surrounding area. It is anticipated that there will be minimal imported material brought onto the Site, further reducing the impact on the Site in relation to contaminated land. With suitable precautions, the construction phase will have a minor adverse to negligible impact on the Site and surrounding area. Furthermore, the Operation phase will have a negligible to minor beneficial impact on the Site and surrounding area.

21 19 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT 08 Flood Risk and Water Resources A Flood Risk Assessment (FRA) has been prepared and accompanies the Planning Application. The FRA has been prepared in response to Government guidance in the form of Planning Policy Statement 25: Development and Flood Risk (PPS25) which requires a FRA for all sites greater than 1 hectare, regardless of their flood status. The Site is located in an area of Low Flood Risk as defined by the Environment Agency. It is a requirement that the Site must be shown not to contribute to any flooding off-site by allowing flows to either pass directly to the adjoining land or to increase any discharge to a piped sewer system which may then cause flooding downstream. It is also a requirement that, if disposal of surface water is direct into the ground (by way of soakaways or similar devices), contaminants are not introduced into the sub-strata. Geotechnical testing of the Site has revealed that the Site in general is underlain by up to 5 metres depth of terrace gravels, a highly permeable material which is suitable for the use of infiltration devices (soakaways or similar) as a means of surface water disposal. The use of SUDS devices results in the elimination of any surface water from the Site flowing into the existing surface water sewer which crosses the Site from north to south. The consequent significant reduction in flow within this sewer would reduce the likelihood of any downstream flooding problems which may arise at times of heavy storms. Any contaminants within the existing ground will be remediated before the installation of any SUDS device thereby removing the risk of contaminants being introduced into the sub-strata. Through consultation with Thames Water a foul discharge point has been agreed together with a discharge limit (the maximum rate of flow allowed to enter the sewer system). The entire Site s foul drainage will gravitate to an on-site pumping station whereupon it will be pumped at the agreed rate to the public foul sewer located to the south-east of the Site on the south side of Porters Way. The entire Site is intended to deal with surface water run-off by the use of infiltration devices. These devices form part of the recommendations for Sustainable Drainage Systems (SUDS). The systems will be designed to allow for a 1 in 100 year storm without any above ground flooding and also includes a climate change factor allowing for a 30% increase in the rate of rainfall.

22 20 09 Noise and Vibration The noise climate of the Site is characterised by road traffic and railway noise. The assessment considers both the potential noise and vibration impacts of these existing sources on the suitability for residential occupation at the Proposed Development and whether the demolition, construction and operation of the development has the potential to increase these levels at the nearest existing residential receptors. The assessment has shown that the proposed properties situated adjacent to the railway line require mitigation measures in the form of enhanced glazing to ensure that suitable internal noise levels are achieved. During the demolition and construction phases the assessment has concluded that there will be a temporary increase in the noise and vibration levels at the nearest existing residential receptors; however these impacts can be kept to a minimum through the use of appropriate site equipment, the use of temporary screens and appropriate operating hours. Finally the assessment has shown that the growth in traffic levels due to the development is sufficiently low so as not to generate noticeable noise effects and noise generated by the fixed plant associated with the commercial areas of the development are below the prevailing background noise levels at the nearest existing residential receptors.

23 21 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT 10 Air Quality The assessment of the possible impacts of the proposed redevelopment of the Site on local air quality has been undertaken. It looked at potential impacts during both the construction and operational phases. A generic assessment of the potential air quality impacts during construction using local wind speed and direction data, climate data (e.g. rainfall etc) and the location of sensitive receptors (e.g. residential dwellings etc.) was undertaken to determine the likely significance of any impacts on areas in and around the Site. This showed that during site construction activities releases of dust and particulate matter (PM10) were likely to occur. However, through good site practice and the implementation of suitable mitigation measures, the impact of dust and PM10 releases will be reduced and excessive releases prevented. The residual effects of the construction phase on air quality are considered to be moderate to minor adverse. anticipated year of the first occupation of the Proposed Development) and 2017 (when the whole of the Proposed Development will be completed and occupied). The results of the dispersion modelling showed that the Proposed Development would cause a small increase in NO2 concentrations at all of the assessment receptors and a small increase or no change at the assessment receptors for PM10. According to the assessment significance criteria the residual effects of the Proposed Development are considered to be negligible for NO2 and negligible to neutral for PM10. For the operational phase of the development (i.e. completed and occupied), a quantitative assessment of the potential impacts was undertaken. A computer model was used to predict concentrations of nitrogen dioxide (NO2) and fine particulate matter (referred to as PM10) at locations (existing and proposed) sensitive to changes in air quality, resulting from changes in traffic flows on the surrounding roads associated with the Proposed Development Predictions were made for a number of years, including 2009 (the current year), 2011 (the

24 22 11 Biodiversity Surveys have been carried out to inform the ES. An Extended Habitat Survey was carried out during the summer of 2009, accompanied by a Tree Survey and a Landscape Assessment which were carried out simultaneously. The Habitat Surveys revealed that the Site is comprised of a series of buildings, hard standing areas, amenity grassland and ornamental planting. The Site boundary hedgerows and the off-site boundary hedgerows are considered to fall within the definition of the UK BAP hedgerows. All the Site s habitats are relatively common and widespread. No notable plant species were recorded during the site visit. The Site s habitats have been identified to support breeding birds and fox. The Tree Survey identified that there are two groups of trees; a group of Horse Chestnuts to the south of the Site adjacent to Porters Way, and four trees in the northeast corner. It has been confirmed that there are no Tree Preservation Orders covering the Site. The Landscape Assessment revealed that the main feature of the Site is the boundary vegetation; there are no other landscape features within these boundaries and that supplementary planting would be required to create boundary features to benefit screening and site biodiversity. The current proposals include the retention of the boundary hedge vegetation and a number of the surveyed trees of value. The proposals also include supplementary planting along the north, east and western boundaries creating wilderness corridors. The supplementary planting will comprise of a mixture of native trees, hedgerows and shrub planting to provide the main visual screening with further enhancement to the biodiversity through careful selection of native herbaceous, wildflower and grass areas. This diversity in vegetation will provide a variety of habitats and feeding grounds for existing and new species. Artificial refugia is to be incorporated along these boundaries to provide instant habitats for insects and invertebrates, with the long term aim that the wilderness corridors will be created and managed to ensure that other, natural refugia, are provided. The tree survey identified a number of Horse Chestnut trees along the Porters Way frontage that are to be retained, as far as practically possible, and enhanced with additional avenue tree, hedge and ornamental planting beds. Whilst the proposed species along this frontage will not all be native in origin they will however provide potential diversity of vegetative habitats and foraging opportunities. Within the development a large proportion of the Site is being landscaped with green connections of the wilderness corridors through boulevard, avenue and strategic hedgerow planting. This will create a network of open spaces, landscaped corridors, soft landscaped front gardens, landscaped streets and car parking areas. The installation of the proposed native and non-native tree, hedgerow, shrub, herbaceous, bulb, wildflower and grass areas will have a large beneficial effect on not only the Site, but also its immediate surroundings.

25 23 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT 12 Archaeology and Cultural Heritage A desktop survey including relevant consultation has established that no known elements of archaeological or cultural heritage resource have been identified within the Site that would be directly or indirectly affected by the proposed scheme. It is considered that overall there is a low potential for the presence of previously unrecorded buried archaeological remains within the Site.

26 24 13 Townscape and Visual Analysis The NATS Site is a large industrial site occupied by a number of vacant large industrial-style sheds, power generation buildings/equipment, and large interconnecting office blocks and is surrounded predominantly by 2/3 storey residential properties. It is considered to be barren, featureless and lacking a coherent landscape and urban design character. A number of urban design and landscape assessments have been carried out which have informed the design proposals and have demonstrated that the development will create a high quality residential community. During the construction stage there will be temporary changes to the character of the townscape resulting from the demolition, construction activity and hoardings. These visual impacts are negligible owing to their temporary nature and limited duration and will be mitigated through the erection of hoardings around the active areas of demolition and construction. Once construction is complete it is considered that the visual impact of the development upon the local area will result in significant improvements.

27 25 DRAYTON GARDEN VILLAGE / ENVIRONMENTAL STATEMENT 14 Conclusion The site is currently occupied by a range of industrial style buildings. A thorough and complete assessment of the Proposed Development has been undertaken and the likely significant environmental effects, in terms of the demolition and construction process and the completed development. Overall, the Proposed Development will result in number of benefits to the Site and surrounding area as well as the wider West Drayton area Whilst negative impacts are identified during the construction phase in respect of noise, air quality and trees, these are limited and generally of a temporary nature. Very few adverse impacts are identified at the completed development and operational phase. These are limited to the impact that the development will have on the surrounding roads of Porters Way and North Road. The traffic surveys have shown that these roads are currently lightly trafficked, thereby accounting for the high impact rating. Both roads have significant existing capacity to accommodate the Proposed Development. The scheme provides a well designed mixed use development that will deliver housing, social and economic benefits. View looking east towards Rutters Close over northern green

28 26 Further Information This document is a Non-Technical Summary of the Environmental Statement in support of the planning application for the redevelopment of the NATS site, Porters Way. The full ES statement is a more detailed study of the environmental effects of the planning application. The full statement can be inspected at: Planning and Community Services Department London Borough of Hillingdon Civic Centre High Street Uxbridge UB8 1UW Or online at