12 GEOLOGY AND SOILS Executive summary

Transcription

1 12 GEOLOGY AND SOILS 12.1 Executive summary The assessment has investigated the impacts of the Proposed Scheme on statutory and non-statutory geological sites, evaluated the risks associated with existing areas of contamination and assessed existing ground conditions to determine the suitability of soils to be re-used within the works The assessment has concluded that the Proposed Scheme would not impact on any areas designated for the protection of geological interest. Several sites have been identified where the ground is known to be contaminated, mostly in brownfield areas around Strabane. Background testing has identified areas of elevated levels of contaminates where soils cannot be incorporated into the works. Additionally, the contractors would undertake sampling and testing of soils in these areas and prepare detailed plans for avoiding handling, removal and disposal to ensure that site staff and the public would not be exposed to any potential hazard. Where soils have been found to be acceptable, it would be reused in the works Scope of the assessments The assessments and studies relating to geology and soils have been focused on: consideration of potential impacts specific to statutory and non-statutory sites designated for their geological value; a review of geological, geotechnical and soils information prepared by the geotechnical and contaminated land team to identify potential impacts on geological resources; evaluation of contaminated areas and sites relative to potential impacts / risks on environmental receptors in the vicinity of the Proposed Scheme; and an assessment of the background greenfield conditions to determine whether or not soils would be suitable for re-use within the works Statutory designated sites which have been considered include Areas of Special Scientific Interest (ASSIs) where geological value is integral to the designation. Nonstatutorily designated sites include Earth Science Conservation Review Sites (ESCRS). These are sites identified as having national or international importance for earth science conservation by virtue of their geology, palaeontology, mineralogy or geomorphology In relation to contaminated sites, the assessment identified sites where construction is likely to involve disturbance which could result in the release of contaminants into the environment and could result in impacts on sensitive environmental receptors including people, nature conservation resources and aquatic resources. Potential impacts related to human health are described in this chapter. Impacts on the aquatic environment and Mouchel

2 nature conservation resources, are described in Chapter 11 (Ecology and Nature Conservation) and Chapter 16 (Road Drainage and the Water Environment) Contaminated sites include brownfield sites which are defined as previously developed sites with a range of former industrial uses which have been or are associated with industrial or other potentially contaminative activities. Former and active landfills have also been considered The study area for the assessment includes designated and contaminated sites either under or directly adjacent to the Proposed Scheme and new or modified side roads More distant sites which may also be impacted by the road construction, such as large landfills, have also been considered Statutory and planning context Reference has been made to the following statutes, policies and plans. The Nature Conservation and Amenity Lands (Northern Ireland) Order 1985 (as amended) The main provisions include powers for the Department of the Environment Northern Ireland (DOE) to designate National Parks, and to declare statutory Nature Reserves or Marine Nature Reserves. The Environment (Northern Ireland) Order This legislation requires Northern Ireland Environment Agency (NIEA) to identify and designate ASSIs. ASSIs are nationally important sites which are designated for their important flora, fauna or geological features. Planning Policy Statement 2 (PPS 2) Planning and Nature Conservation PPS 2 details DOE policies relative to nature conservation as part of the Department s responsibility for securing orderly, consistent and sustainable development. Geological features and landforms are included as important components which form the focus of the conservation policies within the document. The Waste and Contaminated Land (Amendment) Act (Northern Ireland) The Waste and Contaminated Land Order was made in November It came into operation in March 1998 (with amendments to Part 2 & Part 3 of the order completed in 2011) and implements the European Commission (EC) Framework on Waste in Northern Ireland. The Order makes a number of provisions such as: transfer of responsibility for waste regulation from the district councils to the Department of Environment (DOE), focused within the Northern Ireland Environment Agency (NIEA); introduction of measures designed to increase control over the processing and handling of waste including Waste Management Licensing, Controlled Waste and Mouchel

3 Duty of Care, Registration of Carriers, Special Waste and Producer Responsibility; and introduction of measures relating to the identification of contaminated land, designation of special sites, duties of enforcing authorities to require remediation, determination of appropriate persons to bear responsibility for remediation, liability of contaminating substances which escape to other land and contaminated land registers Some parts of the order with respect to waste management have yet to be implemented, for example, waste licensing is operating under the provisions of the Pollution Control and Local Government (Northern Ireland) Order 1978 until regulations for the transfer of responsibility to the DOE can be introduced Methods of assessment The assessments have been informed by the guidance detailed in the DMRB, Volume 11, Section 3, Part 11 Geology and Soils They have involved the following tasks: establishment of the baseline environment relative to the location, form and status of designated sites and contaminated sites and the key geological characteristics associated with the Proposed Scheme corridor and its wider setting; evaluation of the form and magnitude of impacts on designated sites and the potential for impacts associated with contaminated sites which would be, or are, likely to be disturbed during construction of the Proposed Scheme; identification of appropriate mitigation where impacts on designated or other important geological features or contaminated sites have been identified; and description of the predicted residual impacts and their effects. Establishment of baseline environment Identification of areas designated for their geological value, contaminated sites and the geological characteristics of the Proposed Scheme corridor has involved reference to the following documents and data sources (see Appendix 12A for further detail): current and historical, geological and hydrogeological mapping; walkover surveys; aerial photography; datasets held by the Geological Survey of Northern Ireland and the Geological Survey of Ireland; datasets held by the Northern Ireland Environment Agency (NIEA); datasets held by the Northern Ireland Executive and Local Authorities; Mouchel

4 datasets held by the Public Records Office; A5 Western Transport Corridor, Environmental Statement, Mouchel, November 2010; A5 Western Transport Corridor Section 1 Preliminary Sources Study, Mouchel, June 2009; A5 Western Transport Corridor Section 2 Preliminary Sources Study, Mouchel, June 2009; A5 Western Transport Corridor Section 3 Preliminary Sources Study, Mouchel, June 2009; A5 Western Transport Corridor Section 1 Factual report on Ground Investigation, Phases 1-4, Glover Site Investigation Ltd, 2010; A5 Western Transport Corridor Section 2 Factual report on Ground Investigation, Phases 1-4, Soil Mechanics Ltd, 2010; A5 Western Transport Corridor Section 3 Factual report on Ground Investigation, Phases 1-4, Soil Mechanics Ltd, 2010; A5 Western Transport Corridor Section 1 Ground Investigation Report, Phases 1-4, Volumes 1-13, Mouchel, June 2012; A5 Western Transport Corridor Section 2 Ground Investigation Report, Phases 1-4, Volumes 1-10, Mouchel, June 2012; A5 Western Transport Corridor Section 3 Ground Investigation Report, Phases 1-4, Volumes 1-11, Mouchel, June 2012; A5 Western Transport Corridor Section 1 Ground Investigation Report Supplement, Phase 5, Arup Atkins, November 2013; and A5 Western Transport Corridor Section 3 Ground Investigation Report Supplement, Phase 5, Volumes 1-13, URS Halcrow, January The principal sources of information specific to geological characteristics, contaminated sites and contaminated land have been the Geotechnical Preliminary Sources Study Reports prepared by Mouchel in 2009 and Ground Investigation Reports prepared by Glovers Site Investigation Limited and Soil Mechanics in A review of ground based information and chemical data prepared by Arup Atkins in 2013 and URS Halcrow in 2014 has also been undertaken, the assessment of which is presented as Addenda to the Ground Investigation Reports. The assessment of chemical data collated as part of the additional works has been included as part of this ES The three reports referred to in paragraph describe the data sources referred to by the geotechnical and contaminated land team, visual surveys which have been undertaken to verify information from the desk-based data sources and the site Mouchel

5 investigations which have been undertaken to establish more detailed knowledge specific to the areas which would be required for construction of the Proposed Scheme. Identification of impacts and risk The evaluation of impacts on geological sites has involved consideration of the sensitivity of the specific site or area and the magnitude of impact taking into account direct impacts on designated features The identification of risk specific to the contaminated sites considered during the assessment has been based on a combination of established experience of the potential type and extent of contaminants which might typically be associated with each type of site and information derived from the ground investigation reports scheduled in above. The assumption has been that all sites would be subject to disturbance. Where this would be the case, an assessment of the potential for impact on human health or consequent impacts on other environmental receptors has been undertaken as described in Baseline environment Designated sites There are three statutorily designated sites located in close proximity to areas required for construction of the Proposed Scheme. McKean s Moss ASSI and McKean s Moss Part 2 (Figure 12.2) are located to the south west of Cloghcor. Tully Bog SAC/ASSI (Figure 12.4), is located some 8kms to the north west of Omagh. All are lowland raised bogs designated for their physiographical and biological value. Non designated geologically / geomorphologically important sites There are three areas of deglacial complexes included in the current schedule of ESCRS which are associated with the Proposed Scheme corridor The Artigarvan Moraines and Outwash deposits (Figure 12.2) and the Deer Park and Strule / Mourne Valley Moraines (Figure 12.3) form part of the Foyle Valley Glacial Complexes. The complexes consist of formations related to ice-margin retreat and comprise a variety of ice marginal and subglacial landforms including moraines, flat topped terraces and eskers of hummocky and ridged ice-contact morphology The Clogher Valley Complex, Kilgreen (Figure 12.5 and 12.6) is characterised by sand and gravel deposited by a temporary realignment of the hydraulic gradient from the retreating ice sheet. This has resulted in a number of north-east tosouth-west trending esker-like ridges, and also ice marginal moraines. Geology and soils Solid geology The relationship of the underlying solid geology to the Proposed Scheme corridor is shown in the geological long section illustrated in Figure This shows that there are Mouchel

6 two distinct provinces north and south of the Omagh Thrust Fault (OTF), a sub-horizontal thrust fault located to the south of Omagh North of the OTF the corridor is generally underlain by Precambrian strata which are Dalradian in age and which have been thrust southwards over younger, Devonian and Carboniferous rocks by the OTF, to form a large overturned fold known as the Sperrin Nappe The Devonian and Carboniferous rock south of the OTF largely comprise sandstones and limestones This sequence is disturbed by a number of major north-east to south-west trending faults which divide the strata of this area into 3 distinct fault blocks defined by 2 major faults groups; The Tempo Sixmilecross Fault and Killadeas Seskinore Fault to the north and the Clogher Valley Fault to the south. These form a central up-thrust block known as the Slievemore Ridge A stratigraphic column of the solid geology to the north and south of the OTF is provided in Tables 12A.1 and 12A.2 in Appendix 12B. Drift geology Drift deposits associated with the Proposed Scheme corridor are primarily glacial in origin. They comprise glacial till, glacial sands and gravels and glacio-fluvial sands and gravels interspersed with alluvium, lake alluvium and peat. The extent of the various deposits travelling north to south is shown in Figures 12.8 to Appendix 12C provides a summary of stratigraphy encountered in the main ground investigation. New Buildings to South of Strabane Glacial tills make up the principal deposits between New Buildings and the northern margins of the Burn Dennet Valley, other than at Gortmonly Hill and in the vicinity of Bready, where the bedrock is at or close to the surface Between the Burn Dennet Valley and Strabane there are extensive areas of alluvium associated with the wide floodplain of the River Foyle and narrow margins of alluvium associated with the Burn Dennet and a second east-west flowing tributary of the River Foyle, the Glenmornan River. There are extensive areas of glacio-fluvial sands and gravels which border the alluvium along the two tributaries and form a narrow margin between the alluvium and the north western foothills to the Sperrins. This extends south of Ballymagorry as far as the River Mourne in Strabane Located within the wide floodplain of the River Foyle, there are two areas of lowland raised peat bog west of Leckpatrick and Cloghcor. McKean s Moss is the largest of these. There are also islands of glacial till west of Ballymagorry which define localised gently elevated areas within the floodplain. Mouchel

7 Where the Proposed Scheme passes to the west of Strabane, the floodplain and its associated alluvium is narrow along the banks of the Finn River and there is a band of hummocky glacial moraine which marks a transition from alluvium to glacial till. Strabane to South of Omagh Glacial tills constitute the principal deposits between Strabane and the northern margins of the Derg River. There are localised deposits of lake alluvium and raised peat bog. There are also hummocky glacial moraines along the Liscreevaghan Burn west of Victoria Bridge and on the northern margins of the Derg Valley As the route crosses the Derg Valley areas of glacio-fluvial sands and gravels frame a narrow margin of alluvium associated with the banks and channel of the river Beyond the Derg Valley, and as far as the contained Strule Valley as it emerges south of Bessy Bell, deposits of hummocky glacial moraine are virtually continuous. The moraines at Deer Park, west of Newtownstewart, form part of the Foyle Valley Glacial Complexes. There are narrow bands of alluvium associated with the Coolaghy Burn and of glacial till associated with small watercourses descending the western slopes of Bessy Bell. These form brief breaks in the moraines Within the drumlin landscape between Bessy Bell and Omagh an initial expanse of glacial till gives way to a complex mosaic of deposits south of Mountjoy. These include: the designated Tully Bog ASSI and pockets of fen type peat in inter-drumlin areas; glacio-fluvial sands and gravels associated with the Fairy Water and the River Strule; glacial stony clay tills forming drumlin hills; areas of alluvium associated with the confluence of the River Strule and the Fairy Water at Poe Bridge; and lake alluvium to the south of Mountjoy There are also a number of areas of shallow cover where bedrock is close to the surface. South of Omagh to Aughnacloy As the Proposed Scheme corridor curves west and south of Omagh towards Doogary, the principal drift deposits comprise glacial till in the form of drumlins of stoney clay other than for an area where the rock is close to the surface to the south west of Omagh and alluvium defines the banks and channel of the Drumragh River Extensive areas of lowland raised peat bog in the vicinity of Doogary give way to a sequence of glacial till and areas where rock is close to the surface. This extends to Gortaclare / Moylagh, where the rock remains generally close to the surface as far as the crest of the Brougher (Slievemore) ridgeline. There are areas of alluvium associated with the Routing Burn and local watercourses and a locally large pocket of peat located south of Newtownsaville. Mouchel

8 As the Proposed Scheme crosses the Brougher ridgeline, the Kilgreen deglacial sand and gravel complexes extend between Tullanafoile Hill and Birneys Hill / Tycanny Hill. Descending from the ridge and crossing the Clogher Valley there is a complex arrangement of glacial tills (which are typically formed into tightly packed oval shaped drumlins), alluvium associated with watercourses and areas where bedrock is close to the surface South of Ballygawley the Proposed Scheme corridor crosses a regularly changing sequence of glacial tills associated with drumlins and areas where rock is close to the surface. These are interspersed with deposits of alluvium and sands and gravels in the vicinity of the main watercourses (which include the River Blackwater and the Ballygawley Water) and alluvium deposits and peat accumulations in inter-drumlin areas. Topsoils The principal surface soils comprise: surface water gleys with some brown earths and peat podzols on gravel north of Strabane; brown earths and gleys in the immediate vicinity of Strabane; brown earth and gleys between Strabane and Omagh - gleys are more prevalent in the south; large areas of brown podzolics at Newtownstewart and in the upland areas north of Errigal; gleys south of Omagh; and peat in the Doogary area, south of Newtownsaville and more minor areas in inter drumlin areas, particularly to the south of Mountjoy. Potentially contaminated / brownfield sites Potentially contaminated sites which have been considered during the assessment are shown in Figures 12.1 to 12.6 and are scheduled in Table 12.1 Table 12.1 Potentially Contaminated Sites Ref No. Type Location Figure Reference 1 Petrol Filling Station New Buildings Corn Mills Magheramason Infilled Mill Pond Grange Road Backfilled Quarry Sollus Hill Disused Quarry Sollus Hill Infilled Brick Field Route to Leckpatrick Great Northern Railway Line, Including Mainline New Buildings to South of Omagh 12.1 Mouchel

9 Ref No. 8 Type Two Infilled Refuse Tips Location North Strabane, east of Park Road Figure Reference Infilled Canal and Tow Path North Strabane Disused Railway Station, Sidings and Engine House North Strabane, south of Park Road Area of Waste Deposition Adjacent Urney Road Flooded Limestone Quarry East of Carricklee Hill Petrol Station Lifford Road Backfilled Quarry West of Sion Mills Active Quarries Urbalreagh Active Quarries Deer Park Former Route of Great Northern Railway South of Rash Road 1.5 km to Todds Road Disused Nestle Factory Poe Bridge Back Filled Gravel Pit Moylagh Road Junction Back Filled Gravel Pit and Brick Kiln Greenmount Road Made Ground South of Newtownsaville Back Filled Quarries and Gravel Pits Tullyvar Landfill Clogher Valley and Aughnacloy Clogher Valley and Aughnacloy Reclaimed Landfill Aughnacloy Back Filled Quarries West of Old Chapel Road Clogher Valley Railway Follows Clogher Valley through Aughnacloy 12.6 Human health risk Samples from brownfield sites where they lie beneath the footprint of the Proposed Scheme were analysed in the ground investigation to determine chemical conditions. Very few concentrations of concern were identified. Occasional elevated chemical elements and compounds were found in these brownfield areas, with respect to longterm human health. Long term human health risks associated with ph (acidic), lead, carbazole and total petroleum hydrocarbons (C 12 -C 16 ) where identified in locations positioned between New Buildings and Strabane. ph (acidic & alkaline) exceedances were respectively identified at two locations positioned between Strabane and Omagh. No exceedances with respect to long term human health were identified in locations positioned between Omagh and Aughnacloy Samples were analysed as part of the additional ground investigation works completed by the contractors between New Buildings and Strabane, and Omagh and Aughnacloy. Mouchel

10 Long term risks associated with ph were identified at a number of locations, in addition to two exceedances of C 12 -C 16. Asbestos was identified within two made ground samples at one location between Omagh and Aughnacloy. No additional sampling was undertaken between Strabane and Omagh Short term human health risks associated with ph (acidic), nickel, cadmium, copper, zinc and arsenic were identified in brownfield sites positioned between New Buildings and Strabane. A single ph (alkaline) exceedance was identified between Strabane and Omagh. A single sulphide exceedance was identified in one location between Omagh and Aughnacloy. All exceedances were identified in brownfield sites Samples were analysed as part of the additional ground investigation works completed by the contractors between New Buildings and Strabane and Omagh and Aughnacloy. Short term risks associated with nickel were identified in made ground and natural ground at several locations between New Building and Strabane and Omagh and Aughnacloy. In addition asbestos identified at one location between Omagh and Aughnacloy. No additional sampling was undertaken between Strabane and Omagh The background sampling of the greenfield sites established the unexpected presence of Polychlorinated biphenyls (PCBs) within natural ground at four locations, between New Buildings and Strabane. They occurred at depths of between 0.4 and 2.3mbgl indicating they cannot be attributed to aerial deposition. They are, however, at concentrations below the applied screening values and are not considered to be a risk to human health Occasional elevated concentrations of arsenic, nickel and boron in addition to ph with respect to short term human health risk, were identified in samples taken from greenfield sites during the site investigations undertaken along the entire route. There is no information available regarding expected background levels of these determinands in Northern Ireland. It has not been possible, therefore, to establish if the identified level is due to background conditions. However the Geological Society of Northern Ireland mapping indicates several mineral veins in the Sperrins Nappe strata and these are commonly associated with naturally enriched arsenic in soils. Environmental Quality Standard aquatic environment A number of samples from brownfield areas distributed throughout the proposed route corridor also exceeded Environmental Quality Standard (EQS) screening values for risk to the aquatic environment. Elevated concentrations of chromium, copper, selenium, zinc, cadmium, nickel, naphthalene, ammonia as N and ph were identified at a number of locations between New Buildings and Strabane. Elevated concentrations of cadmium, copper, zinc, lead, mercury, selenium, ammonia as N, poly aromatic hydrocarbons and aliphatic hydrocarbons where identified in a number of locations between Strabane and Omagh. Elevated concentrations of copper, lead, zinc and selenium were identified at a number of locations between Omagh and Aughnacloy A number of samples from the greenfield areas along the entire proposed route corridor also exceeded EQS screening values for risk to the aquatic environment. Elevated concentrations of chromium, copper, selenium, zinc, cadmium, nickel and ammonia as N in addition to ph were identified at a number of locations positioned between New Mouchel

11 Buildings and Strabane. Elevated concentrations of cadmium, copper, nickel, zinc, lead, mercury, selenium, ammonia as N in addition to ph, where identified in a number of locations positioned between Strabane and Omagh. Elevated concentrations of chromium, copper, lead, zinc mercury, selenium and phosphorus were identified at a number of locations positioned between Omagh and Aughnacloy A number of samples, analysed as part of the of the additional ground investigation works completed by the contractors between New Buildings and Strabane and Omagh and Aughnacloy, exceeded the EQS screening values for risk to the aquatic environment. Occasional elevated concentrations of cadmium, chromium, lead, copper, selenium, zinc, ammoniacal nitrogen, phenols, pyrene, nitrite and mercury were identified in made ground and natural ground at a number of locations. No additional sampling was undertaken between Strabane and Omagh. Phytotoxicity A number of samples from the brownfield areas exceeded the screening applied values for phytotoxicity. With the exception of ph (alkaline) identified at one location between Strabane and Omagh, all remaining exceedances, including arsenic, molybdenum, nickel, zinc, lead, copper cadmium and ph were identified between New Buildings and Strabane. No exceedances were identified between Omagh and Aughnacloy Samples of greenfield sites were also tested to determine the background chemical concentrations with regard to phytotoxicity. Occasional elevated concentrations of boron, nickel in addition to ph (acidic & alkali) were identified at a limited number of locations positioned between New Buildings and Strabane. Occasional elevated concentrations of arsenic, zinc and boron in addition to ph (acidic & alkali) where identified at a limited number of locations positioned between Strabane and Omagh. Occasional elevated concentrations of boron and nickel in addition to ph (acidic) were identified at a limited number of locations positioned between Omagh and Aughnacloy Samples were analysed as part of the of the additional ground investigation works completed by the contractors between New Buildings and Strabane and Omagh and Aughnacloy. Phytotoxic risk associated with ph (acidic) were identified at several locations between New Buildings and Strabane, in addition to a single copper exceedance. No exceedances were identified between Omagh and Aughnacloy. No additional sampling was undertaken between Strabane and Omagh. Other testing Samples primarily related to areas of overlying peat were found to be naturally highly acidic. Samples of peat taken between Strabane and Aughnacloy also contained phytotoxic concentrations of arsenic (two samples), boron and a number of acidic occurrences Levels of ammonia and ammonium within soils sampled throughout the Proposed Scheme corridor were found to be consistent with agriculture regimes with moderate to high fertilizer inputs. Mouchel

12 12.6 Predicted impacts Statutory and non-statutory designated sites There would be no direct impact on McKean s Moss (1 & 2) ASSIs. The designated site is located 125m to the west of the Proposed Scheme, which would be aligned some 5m above the existing level of the moss. The road would be located on sands and gravels outside of the peat deposits or the river alluvium surrounding the moss such that there would be negligible risk of the construction of the road having an effect on the soils of, or the hydrological regime that currently supports the designated site There would be no direct impact on Tully Bog SAC/ASSI. The designated site is located a minimum of 110m to the west of the Proposed Scheme, which would be aligned a minimum of 4m above the existing level of the bog. The road would not cross any outliers of the peat associated with the bog. In this instance the bog is primarily supported by rainwater The Proposed Scheme is aligned across or on the fringe of the following areas of deglacial deposits included in the national schedule of ESCRS: the Foyle Valley Complex at Artigarven, near the Derg River, at Deer Park near Newtownstewart and in the Strule Valley south of Newtownstewart; and the Clogher Valley Complex south of Newtownsaville Where this occurs, there would be a direct impact on the integrity of the geological formation, by virtue of the earthworks required to form the road. In all instances, the affected areas are small in the context of the defined area of interest. There may however be the opportunity for geological logging in these locations subject to the nature of the deposits and construction methodology Taking into account the extent of the impact, the effect on the integrity of the areas would be low. Potentially contaminated sites The assessment has demonstrated that construction of the Proposed Scheme is likely to involve the disturbance of some 26 potentially contaminated sites. Results to date suggest that elevated concentrations of contaminants are concentrated in the known brownfield areas around Strabane. Disturbance of these could potentially pose a risk to human health if the appropriate mitigation is not undertaken. Potential consequential impacts related to sensitive water related and nature conservation receptors are addressed in Chapter 11 (Ecology & Nature Conservation) and Chapter 16 (Road Drainage and the Water Environment). The contaminated land results are discussed in Appendix 12D Background testing in the greenfield areas has indicated there are occasional random naturally elevated concentrations of arsenic, nickel and boron in addition to ph which Mouchel

13 could be a potential short term human health risk to construction staff. In addition asbestos was identified at one location between Omagh and Aughnacloy Where there are elevated levels of ammonia and ammonium, potential risks to nearby aquatic environments or sensitive terrestrial habitats are described in Chapter 11 and Chapter In relation to the potential for soils to support proposed planting, there would be a low risk to plant growth associated with areas of high acidity, elevated ammonium levels and/or phytotoxic determinands (copper, boron, nickel, zinc) Proposed mitigation In relation to the identified brownfield sites adjacent to and underlying the Proposed Scheme, more detailed investigations and sampling would be undertaken by the contractor in advance of construction commencing. This would enable the nature and extent of contaminants to be determined. A qualitative risk assessment would be undertaken to determine whether the associated risk is acceptable and no further remedial action is required. However, if treatment is necessary, then further testing and quantitative risk assessment would allow method statements to be prepared detailing handling, removal and disposal measures to ensure that site staff and the public are not exposed to risk. Where this involves removal of materials, the resultant material would be disposed of to a suitably licensed facility in accordance with the Duty of Care provisions under the Waste & Contaminated Land Order Where there are high levels of background acidity and phytotoxic determinands in the soils, adoption of seed mixes and species that have developed natural tolerance to these chemicals would ensure that adverse effects on planting are mitigated Conclusions and effects The assessment has demonstrated that there would be no significant impacts on geology and soils. It has highlighted the presence of a small number of contaminated sites and land and identified an appropriate process for further investigation and the development of appropriate method statements to ensure the handling, removal and disposal of such material would not pose a risk to site staff or members of the public. Mouchel