Greenpark Energy Ltd April 2010 8. Hydrogeology and Land Contamination 8.1 Summary This chapter assessed the hydrogeological context of the proposed development together with possible impacts resulting from the development and considered the following key issues: The impact of the development on aquifers and groundwater located beneath the site; The impact of the development on nearby groundwater abstractions; Mitigation measures to be undertaken during site preparation, drilling and production and restoration of the site to prevent potential adverse impacts. This chapter also considered the current contamination status of the site and the potential for land contamination resulting from the proposed development and considers the following key issues: Potential contamination of land resulting from the proposed development; Mitigation measures to be undertaken during site preparation, drilling and production and restoration of the site to prevent potential adverse impacts. The site has variable shallow drift geology including glacial sand and gravel and glacial till to depths of between 0.9 and 2.6m below ground level. The solid geology below the site comprises strata of the Mercia Mudstone Group. The Mercia Mudstones overlie strata of the Triassic Sherwood Sandstone Group which comprises thick sandstones and is classified as a Major Aquifer by the Environment Agency; these strata extend up to approximately 300m in thickness in the area and are locally abstracted by Severn Trent Water for public potable supply. The Sherwood Sandstones lie unconformably above Upper Carboniferous Strata which include the Coal Measures Strata which are the target strata for the CBM gas development. The Coal Measures Strata are separated from the overlying Sherwood Sandstone by the Carboniferous Barren Measures Strata which are classified as a Minor Aquifer. The Coal Measures Strata containing the targeted coal seams generally comprise predominantly argillaceous rocks of low permeability and are considered a Minor Aquifer. Mitigation measures suggested therefore include: best practice in the storage or fuels, permanent double steel casing of the boreholes that would last for at least 20 years, using standard water well drilling practices and, at the end of the project, ensuring that capping of the boreholes follow the safety standards required by the Department of Energy and Climate Change and the Health and Safety Executive. By undertaking appropriate mitigation measures, the impacts upon the hydrogeology of the area are assessed as being of no significance. 8.2 Introduction The proposed CBM gas development has the potential to impact upon the underlying hydrogeology. In order to ensure the environmentally sound development of the extraction site, this chapter details the existing baseline conditions at the site and assesses the potential for these to be adversely impacted by the development. This enables any appropriate mitigation measures to be identified, as necessary. This chapter assesses the potential impacts associated with the proposed CBM gas Swynnerton Environmental Statement 8-1 FINAL Greenpark Energy Ltd April 2010 extraction development on the surrounding hydrogeological conditions, for both shallow drift and deep bedrock groundwater reserves. This chapter does not make any assessment of the reverse scenario, i.e. impacts upon the proposed development by hydrogeological conditions at the site. During site preparation, drilling, production and restoration of the site there would be potential for impacts to land quality resulting from development activities and use and storage of various materials on the site. This chapter therefore qualitatively assessed the current baseline condition of soils, the contamination status of the site, potential impacts resulting from the development, and recommends mitigation measures that may be required. 8.3 Relevant Legislation, Policies and Guidelines The hydrogeological and contamination assessment will be conducted in accordance with the following legislation, policies and guidelines: The Water Framework Directive (2000/60/EC) (WFD), and Controlled Waters (Water Framework Directive) (England and Wales) Regulations 2003; Part IIA of the Environmental Protection Act 1990 (the 1990 Act) as inserted by section 57 of the Environment Act 1995; The Contaminated Land (England) Regulations, 2006 (SI 1380/2006), The Stationary Office Limited; Planning Policy Statement 23 (PPS23). Planning and Pollution Control. PPS23 is intended to complement the pollution control framework under the Pollution Prevention and Control Act 1999 and the PPC Regulations 2000; Pollution Prevention Guidelines PPG21: Incident Response Planning, Environment Agency, March 2009, 19pp. Planning Policy Statement 10 (PPS10). Planning for Sustainable Waste Management. PPS10 sets out the Government's policy to be taken into account by waste planning authorities and forms part of the national waste management plan for the UK; DEFRA, 2008, Guidance on the Legal Definition of Contaminated Land; DEFRA, Circular 1/2006, Environmental Protection Act 1990: Part IIA Contaminated Land; DEFRA, 2004 Model Procedures for Management of Land Contamination (CLR11); British Standard, Investigation of potentially contaminated sites – Code of Practice, BS10175:2001; Department for Communities and Local Government, 2006. Environmental Impact Assessment: A guide to good practice and procedures – A Consultation Paper; Department of Transport, 2003. The Water Environment Sub-Objective; Environment Agency 2008, managing all our water needs. Abstracting water, A guide to getting your license; Environment Agency, 2007, water abstraction getting the balance right. Staffordshire and Trent Valley Catchment Abstraction Management Strategy; CIRIA C665, 2007. Assessing risks posed by hazardous ground gases to buildings; and, US Geological Survey (USGS), October 2000. Fact Sheet FS–123–00. Coal- Bed Methane: Potential and Concerns. CIRIA C502 Environmental Good Practice on Site (1999); CIRIA C532 Control of Water Pollution from Construction Sites (2001); CIRIA C552 Contaminated Land Risk Assessment – A Guide To Good Practice (2001); Swynnerton Environmental Statement 8-2 FINAL Greenpark Energy Ltd April 2010 The Borehole Sites and Operations Regulations 1995. Statutory Instrument 1995 No. 2038, HMSO. Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR). And; The Control of Pollution (Oil Storage) (England) Regulations 2001 8.4 Methodology The hydrogeological and land contamination assessment: Obtained qualitative baseline information on the condition of the site and connected hydrogeological systems, through consultation with relevant statutory organisations, site walkover survey observations and desk based review of published information; Assessed potential impacts, both direct and indirect, on the hydrogeological features and soils at the site including identifying critical pathways between contaminant sources and receptors for potential pollutants; Identified mitigation measures and residual impacts; and Evaluated the significance of impacts. Water Companies, the Environment Agency, the British Geological Survey and the relevant Local Authority departments have been consulted to obtain surface and groundwater information and matters related to potential land contamination. A site visit was carried out to verify this information and to gain a good understanding of the shallow hydrogeological conditions on site. This included: Water supplies (whether springs, boreholes or wells) including private water supplies; Surface or groundwater abstractions; Historical land use and the potential of containing contaminated land, including aspects of waste management that may be relevant to the assessment; Borehole records; Rainfall data; and Any existing and/or historical reports relating to the hydrogeology / contamination status of the site. Information about the following was analysed: Local geology (superficial deposits and bedrock) and soils; Aquifer status and resource potential; Topography; Climate; Current and historical land use; and, National, regional and local landscape and character designations. Specific environmental information regarding the history and condition of the site and its catchment area was obtained from Stafford Borough Council’s Environmental Protection Department. Reference was also made to the EA documents Abstracting Water, A guide to getting your license and the Staffordshire Trent Valley Catchment Abstraction Management Strategy (CAMS) report. Swynnerton Environmental Statement 8-3 FINAL Greenpark Energy Ltd April 2010 Lastly, the EA was consulted concerning water features, their attributes and indicators of quality within the site and its catchment area. Assessment of Significance Table 8.1 provides guidance on defining the magnitude criteria for potential impacts, with some examples. The magnitude of the potential impact is completely independent of the value of the attribute affected and therefore gives no indication of significance when considered alone. TABLE 8.1 – CRITERIA FOR DETERMINING IMPACT MAGNITUDE Magnitude Criteria Example Major Results in loss of attribute loss of EC designated Salmonid fishery change in GQA grade of river reach loss of flood storage/increased flood risk pollution of potable source of abstraction Moderate Results in impact on integrity of loss in productivity of a fishery attribute or loss of part of contribution of a significant proportion of