Inert Infill & Preservation of SSSI at Horton Landfill. Environmental Statement Non-Technical Summary. July Prepared for: Viridor

Transcription

1 Inert Infill & Preservation of SSSI at Horton Landfill Environmental Statement Non-Technical Summary Prepared for: Viridor UNITED KINGDOM & IRELAND

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3 REVISION SCHEDULE Rev Date Details Prepared by Reviewed by Approved by 1 Submission Sarah Martin Planning Consultant Chris Nicoll Principal Planner (Minerals and Waste) Ian Campbell EIA Consultant Imogen Scotney Consultant Barry Gore Director URS Infrastructure & Environment UK Limited Royal Court Basil Close Chesterfield Derbyshire S41 7SL Viridor Ardley Fields Farm Ardley Oxfordshire OX27 7PH iii

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5 Copyright This Report is the copyright of URS Infrastructure & Environment UK Limited. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited. iv

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7 TABLE OF CONTENTS 1 INTRODUCTION Preamble Background The Environmental Statement Purpose Screening and Scoping THE SITE AND ITS SETTING The Site and its Surroundings Statutory and Non Statutory Land Designations Landscape Historic Environment Ecology Geological Water Environment Air Quality Green Belt THE PROPOSED DEVELOPMENT (THE SCHEME) Scheme Outline ENVIRONMENTAL EFEFCTS Landscape and Visual Natural Heritage (Ecology) Transport Noise and Vibration Air Quality Flood Risk Assessment/Hydrology Natural Heritage (Geology) Other Matters CONCLUSION PLANS AND FIGURES v

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9 PLANS AND FIGURES Title Reference Scale and Size Revision Site Location Plan NTS.001 1:50,000 (A4) Site Area Plan NTS.002 1:10,000 (A3) Planning Application Area and Land Ownership NTS.003 1:2,500 (A2) Land Designations NTS.004 1:10,000 (A3) Existing Layout NTS.005 1:1,250 (A3) Infill Proposal NTS.006 1:1,250 (A4) Restoration NTS.008 1:1,250 (A3) vi

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11 LIST OF ABBREVIATIONS AOD Above Ordnance Datum AQMA Air Quality Management Area ES Environmental Statement EIA Environmental Impact Assessment Ha Hectare HGV Heavy Goods Vehicle NPPF National Planning Policy Framework NTS Non-Technical Summary PRoW Public Right of Way SS Supporting Statement SSSI Site of Special Scientific Interest TPA Tonnes per Annum WSCC West Sussex County Council REFERENCING The following definitions have been adopted in this NTS: the Site comprises the 3.5 ha planning application area outlined in red on figure NTS.003. the Infill Area comprises the 1.8 ha void containing the Horton Clay Pit geological Site of Special Scientific Interest shown on figure NTS.003. Horton Landfill Site is the total extent of the 32 ha landfill site. It closed for the reception of waste in 2012, restoration has recently been completed and the land in aftercare. Offices and Admin comprise the administration office, landfill gas compound and leachate treatment plant as indicated on figure NTS.003. the SSSI is the 0.38 ha area and geological exposures of the Horton Clay Pit geological Site of Special Scientific Interest. vii

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13 1 INTRODUCTION 1.1 Preamble 1.2 Background This document is a non-technical summary of the Environmental Statement (ES) which accompanies an application for planning permission submitted to West Sussex County Council (WSCC) by Viridor Waste Management Limited (Viridor) which relates to proposed development at Horton Landfill Site. Horton Landfill Site is located to the south of the village of Small Dole, approximately 6km north of Shoreham-by-Sea as identified on figure NTS.001 and lying at NGR TQ The area around the Site is illustrated on Plan NTS.002. The restored landfill site is located in a former clay pit that closed for the reception of wastes in The landfill planning permission required Viridor not to infill the north east corner of the clay pit where a geological exposure of Gault clay is safeguarded by Natural England as the Horton Clay Pit geological Site of Special Scientific Interest (SSSI). The landfill was thus designed and completed with the exposure retained within a void of some 15-20m depth. The SSSI designation covers approximately 0.38ha of the 32ha landfill site area. A photograph of the SSSI from the restored landfill site is provided below. Small Dole village Horton Clay Pit geological SSSI Restored Horton Landfill Photograph 1 the Infill Area and Horton Clay Pit SSSI view east from the restored Horton Landfill Site (URS 2013) Over many years the open exposure of Gault clay has suffered from serious weather erosion, surface cracking and rainwater penetration that have caused repeated local slope failures which are undermining the integrity of the SSSI. Natural England (legal overseers of the SSSI) now considers the SSSI has degenerated to a condition they class as unfavourable decline. Technical assessments conclude that because of the low natural strength of Gault clay and the steep slope angle to which it was excavated, slope failures will continue unless there is direct intervention. Viridor has reached agreement with Natural England to protect and preserve the long term future of the SSSI by infilling the void with inert materials with restoration of the 1

14 final landform. Inert materials comprise uncontaminated non-putrescible stones and rock, rubble, soils, typically arising from excavations and construction projects. The Scheme will firstly clean up the geological site (to allow inspection by Natural England) then protect and preserve the SSSI by a controlled infill operation. Should access be required in the future the location of the preserved SSSI exposure will be marked out at the new finished ground level. Finished ground levels will merge with those of the adjacent restored landfill site. The planning application submitted by Viridor therefore requests temporary planning permission to preserve the SSSI by importing about 92,000m 3 of inert infill material over an infill period of 12 months across a 5 day working week, followed by restoration to grassland, trees and open habitat attractive to invertebrates and reptiles. 1.3 The Environmental Statement Purpose The Environmental Statement (ES) presents the findings from the Environmental Impact Assessment (EIA) of the proposed development, hereafter called the Scheme. The ES has been prepared in accordance with the Town and Country Planning (Environmental Impact Assessment) (England) Regulations 2011 (the EIA Regulations). The purpose of the ES is to ensure that: relevant environmental issues are assessed appropriately; potential environmental impacts associated with the operational and aftercare phases of the proposed Scheme are identified, together with appropriate mitigation measures (if necessary); and interested parties are given the opportunity to address any relevant issues. The ES seeks to present the Scheme proposals and the results of specialist assessments in a clear and unbiased manner and has been produced to accompany the planning application referred to above Screening and Scoping Preliminary details of the application and ES have been the subject of an EIA Screening decision and EIA Scoping Opinion issued by WSCC (see Section 2.2 for details). The specific topics assessed by the EIA are: landscape and visual; natural heritage (ecology); transport; noise (and vibration); air quality; flood risk assessment/hydrology; natural heritage (geodiversity); and other matters, e.g. Public Rights of Way. A short summary description of these environmental factors and their relevance within the Scheme is provided in Section 4 below. 2

15 2 THE SITE AND ITS SETTING 2.1 The Site and its Surroundings The Infill Area is located in the north-east corner of Horton Landfill Site entirely within its fenced site boundary. The Infill area is substantially screened from close by external views (outside Horton Landfill Site) by boundary trees and other vegetation. Natural ground level around the Infill Area lies at about 20m AOD, the base of the void has a lowest point of 5m AOD. The local area comprises low lying gently rolling agricultural land falling towards the River Adur to the west. Higher land (up to 200m AOD) of the north facing chalk escarpment of the South Downs lies about 2km to the south. The highest point of the restored landfill is presently at about 32m AOD. The area around Horton Landfill Site is predominantly rural and in agricultural use lying on the east edge of the valley and floodplain of the River Adur. Adjacent land uses include: to the north of the Site is a small collection of out buildings associated with Oxcroft farm use; immediately east of the Site is Henfield Road (A2037) and beyond this is the Mackley Industrial Estate comprising approximately 30 businesses; to the north-east of the Site are a small number of residential properties on Henfield Road and approximately 300 m north of the Site is the built up area of Small Dole; the closest residential property to the Infill Area is Woodside about 50m to the north-east and on the east side of the A2037 adjoining the Mackley s Industrial Estate; slightly further away to the east is the entrance to the Hillside Scout Camp; to the north, west and south the land surrounding the landfill is predominantly in agricultural use with small woods and occasional isolated residential properties. 2.2 Statutory and Non Statutory Land Designations Landscape The Horsham District Council Landscape Character Assessment (2003) identifies Horton Landfill as falling within landscape character areas D2 Henfield and Small Dole Farmlands and O3 Steyning and Henfield Brooks. The Site falls within area D2. Area D2 is described as an undulating landscape of low ridges and narrow valleys with small streams Historic Environment Ecology The nearest listed building to the Site (Nightingales) is located approximately 540m to the south of the Infill Area and 75m south of the main site access road. There is one scheduled monument within a 2km search area from the Site, the Cross Dyke on Tottington located approximately 1.5km to the south-east. There are no designated habitats afforded protection within the Infill Area or the Horton Landfill Site. Approximately 350m to the north-west of the Infill Area and within 100m of the access haul road is Horton Wood, an ancient and semi natural woodland; 280m to the east of the Site is Tottington Wood which is an ancient woodland and local nature reserve; and 3

16 2.2.4 Geological 2.5km to the south-east of the Site is the South Downs Environmentally Sensitive Area and the Beeding Hill to New Timber Hill SSSI. The boundary of the extensive River Adur water meadows and Wycham Wood Site of Nature Conservation Interest is located close to the south-west corner of the landfill. The Horton Clay Pit SSSI is located within the Infill Area. The SSSI was designated in 1991 relating to the exposure of the Lower Gault Formation that was excavated during development of the clay pit. The Gault clay includes an important sequence of sedimentary stratigraphy and marine fossil assemblages through a vertical section Water Environment Air Quality Green Belt The Environment Agency online mapping identifies that almost all the Site falls within Flood Zone 1, which has the lowest risk of flooding. One small corner is mapped of the landfill main access road is considered to be at risk from flooding which is believed to be a historical reference to previous ground levels. The access road lies level and is not known by Viridor to have experienced flooding. The base of the Infill Area is a receptor for rainwater that is pumped out on a regular basis and periodically dries out. The Site is not located within a ground water source protection zone or aquifer. The Site does not fall within an existing or proposed Air Quality Management Area (AQMA). Horsham District Council does not have any areas of designated Green Belt. 4

17 3 THE PROPOSED DEVELOPMENT (THE SCHEME) 3.1 Scheme Outline The Scheme comprises the following main proposals: Insitu preservation of the SSSI by the import and placement of approximately 92,000m 3 of inert material within the Infill Area; a temporary development period in which infilling will take place over the course of twelve months; access to the Site via the existing landfill site access only; a voluntary routeing undertaking offered by Viridor so HGVs avoid Small Dole village; development of a temporary haul road constructed across the former landfill area; management controls to minimise noise and dust; restoration to surrounding ground levels as indicated on plan NTS.008; surface marking of the position of the buried geological exposure for future identification; restoration of the new land profile to grassland, woodland and open spaces to provide local biodiversity for reptiles and invertebrates, and a surface ditch to provide drainage to prevent flooding; daytime working Monday to Friday only; and a 5 year programme of site aftercare. 5

18 4 ENVIRONMENTAL EFEFCTS The findings of the environmental factors considered by the EIA procedures and listed in Section 1.2 are provided in brief summary below Landscape and Visual The Site lies within National Character Area (NCA) 125 South Downs. NCA 121 Low Weald also lies within the wider study area used to asses this topic. The former is noted for its natural beauty and importance for access and recreation, the latter is predominantly agricultural with many densely wooded areas. Overall the Site has been heavily influenced by mineral extraction and landfill activity. Due to its relatively unmanaged state, absence of characteristic landscape elements and incongruous landform, the Site is currently assessed as being of low landscape quality and poor condition. Views: The Site is well screened by fencing, mature vegetation and landform, including the landform of the restored Horton Landfill Site, such that there are no direct views of the Infill Area from publicly accessible locations external to the Site. Partial first floor views are potentially obtained from properties on the edge of Small Dole to the north of the Site although these are likely to be limited by intervening vegetation. Distant elevated views towards the Site are obtained from the South Downs ridgeline, incorporating Beeding Hill and Tottington Hill, within the SDNP. Views of the perimeter access road and top of the restored Horton landfill Site are obtained from locations to the west, principally from within the Adur valley. During infilling in landscape terms effects on the Site will be of moderate adverse significance given the low sensitivity and high magnitude of effect and the context of occurring within a former landfill site. Landscape effects within the wider study area will be of minor adverse significance during infilling given the low sensitivity and low magnitude of effect. By year 15 landscape effects on the Horton Landfill Site will be minor beneficial significance, within the wider study area negligible beneficial significance Natural Heritage (Ecology) Habitats within the Site include semi-improved neutral grassland, standing water, scrub, marginal vegetation, bare ground, ephemeral/short perennial and tall ruderal habitats. The Site is bordered to the north by scrub and improved grassland, scrub to the east, and semi-improved neutral grassland (a continuation of the landfill site) to the west and south. No mature trees will be affected. No habitats within the planning application boundary are considered to fall within the Habitat of Principal Importance or Local Biodiversity Action Plan priority habitat definitions and there are no protected sites within the Site. Ecological surveys of the Site and adjacent area has been undertaken, including a Phase 1 habitat mapping survey and Phase 2 field surveys for reptiles and amphibians (including great crested newt) in water bodies around the Site. Other species were not surveyed due to the limited range of habitats available. Great crested newts were not found in the Site or the two closest water bodies, surveys of water bodies in the wider area found a population considered to be of County level importance. Common species of reptiles (grass snake, slow worm and common lizard) were found within the Infill Area. The populations recorded are considered dependent 6

19 4.1.3 Transport on the hedgerows, scrub and grassland which adjoin it, including the more established areas of restored landfill cap to the south east of the Infill Area. The Horton Landfill Site is considered to be of up to the district value level for terrestrial invertebrates with the grizzled skipper seen; (it favours unimproved grassland and recently abandoned industrial sites). The Scheme is not predicted to have any environmental effects on any of the habitat sites with statutory protection. In terms of the effect on local habitat the initial loss of habitat in the Infill Area (e.g. grassland/bare ground) is assessed as a moderate adverse effect on invertebrates that is significant prior to mitigation. The loss of this habitat and the act of infilling is also predicted to have a moderate adverse effect that is significant prior to mitigation on common reptiles (slow worm, grass snake and common lizard) and also on some terrestrial invertebrate species (e.g. grizzled skipper). Habitat compensation to prevent any net loss of biodiversity as a consequence of the Scheme upon completion of infilling will be secured via restoration to provide grassland, woodland and mosaic habitats that mimic the value and function of those currently present within the Infill Area. Including lowland meadow, woodland planting, bare ground for basking reptiles, raised bunds and scrub for terrestrial invertebrates. Once restoration is established the impact on habitat receptors will be mitigated to reduce the local environmental effects from significant to neutral. The existing landfill site access off the A2037 will be utilised for all lorry movements, it has been reviewed by a highways engineer and found to be fit for the intended purpose. The road s accident record nearby is good with substantial spare flow capacity. The quantative assessment concludes that in terms of total traffic, when considered the worst case scenario of 100% of predicted traffic travelling from the north or south (39 deliveries per day), the proposed infill traffic would not generate sufficient trips to have a significant impact on the local road network. The predicted increase in total traffic flows both north and south of the site on the A2037 are less than 2% which is no more than typical day to day variations in traffic flows. The number of lorry movements is considerably less than when the landfill was operating. The above analysis shows that, in terms of total traffic, the proposed works would not generate sufficient trips to create any discernible environmental impacts associated with increases in traffic. The Scheme includes a voluntary routeing agreement to minimise the amount of HGV traffic travelling through Small Dole and nearby country lanes. The agreement is proposed to minimise amenity impacts arising from lorry traffic but is not necessary to satisfy traffic impact requirements Noise and Vibration To determine the existing noise environment at the nearest residential properties, ambient noise monitoring was undertaken at five locations in the area. The surveys result in a good understanding of the existing noise climate at the closest noise sensitive receptor locations. Noise levels have been predicted for the early stage of infilling when operations will be at the lower levels of the Infill Area and at the higher ground level in the latter stages of restoration. In all cases the adjacent existing acoustic fence remains in place. 7

20 4.1.5 Air Quality The predicted worst case noise levels are calculated to be below the NPPF preferred criterion (a maximum of 10 db over the average measured background level plus up to a limit of 55 dbl Aeq ) by at least 3dB at each location. With the adoption of best practice procedures for control and mitigation noise, it is considered the Scheme will result in a negligible environmental impact due to noise. In the absence of large numbers of heavy plant or piling etc. vibration is not considered to have any significant environmental effects. The Site does not fall within an existing or proposed Air Quality Management Area (AQMA) and is in a rural setting therefore it is considered local air quality will be good. The deposit of the inert infill material is not usually itself associated with the generation of fugitive dust because of the heavy and damp nature of the material, however the passage of vehicles on haul roads associated with the operations can create dust without mitigation through best practice. The magnitude and location of dust impacts are highly variable in nature and can be considered as mainly dependent on the prevailing meteorological conditions at the time and the nature of the dust generating activity. Previous dust monitoring at Horton Landfill Site (undertaken in 2011/12) indicates that the site has experienced no significant fugitive dust issues. One exceedance was recorded on the western edge of the site close to a haul road, and was believed to be caused by an isolated event. All other monitoring points recorded concentrations well below the threshold adopted to indicate significant environmental effects are likely. A reactivation of boundary monitoring forms part of the Scheme. The potential for dust impacts on local receptors including local habitat sites has been assessed. Overall with the adoption of the proposed management scheme the impact on air quality arising from the Scheme is considered to be not significant Flood Risk Assessment/Hydrology The Environment Agency (EA) website identifies that the Infill Area Site lies entirely within Flood Zone 1 and is therefore classed as at low risk from fluvial flooding. A formal flood risk assessment has been completed in accordance with the requirements of the NPPF. The base of the Infill Area is a low lying void, a receptor for rainfall which drains down to small sump has to be dewatered by regular pumping. The Scheme will remove the sump allowing for a gravity field drainage ditch to be introduced at restoration. A small part of the main access road lies within a designated zone at higher risk of flooding (although none is known) but no works are proposed by the Scheme to affect the road structure and thus drainage from and to it. The Infill Area falls within the catchment area of Horton Landfill Site, the drainage scheme for which is approved under the landfill planning permission and the discharge regulated by Environmental Permit. No consequential impact on flooding and drainage is therefore predicted Natural Heritage (Geology) The Horton Clay Pit geological SSSI forms part of the environmental baseline and will be directly impacted upon by the Scheme to a significant level in that direct access to it will be denied. However, this consequence is a result of preservation of the exposure by infill and has been agreed in advance with Natural England. Preservation is 8

21 considered a beneficial effect of the Scheme. Within that context the negative effect on the SSSI is considered outweighed by the positive benefits Other Matters Community and Socio Economic/Amenity Considerations: the construction works at the Site will lead to the creation of some employment opportunities in the supervision of the works and the use of contractors to provide the infill materials. Specific baseline conditions relating to landscape and visual amenity, noise and vibration, and air quality are considered in the above sections. No Public Rights of Way will be affected. Cumulative and Combined: Cumulative effects are those that could arise as a result of impacts from several different schemes. In this case URS are not aware of any schemes likely to give rise to significant cumulative effects. There may be some combined effects of the Scheme. For example, noise and air quality impacts may both potentially affect sensitive receptors in close proximity during operations. These have been included in the in the individual assessments as appropriate. Risk of Accidents: the Scheme does not involve materials that could be harmful to the environment (including people) in the event of an accident. There are therefore no such potential environmental effects. 9

22 5 CONCLUSION The ES undertakes a comprehensive assessment of the environmental implications of the construction and operation of the Scheme. It includes detailed assessment of a wide range of environmental issues and considers the effect of mitigation measures proposed. Implementation of the mitigation measures defined therein will mean that residual effects should be minimised to an acceptable degree. In terms of the loss of immediate access to the SSSI, in itself this is considered a significant impact but one that is outweighed by the benefit of long terms preservation and is acceptable within that context. 10

23 6 PLANS AND FIGURES 3 13