Location: Somerset, Southwest England, UK
Services: Strategic Advice on Brownfield Development, Site Investigation, Risk Assessment
Summary: ESI was able to identify options for managing land contamination to maximise the value of site divestment, based on high quality site investigation and risk assessment
ESI was commissioned to conduct a Phase 2 site investigation of a food manufacturing facility (the site) in Somerset. At the time the sit was being progressively decommissioned with the intention of being redeveloped for residential use following closure.
The purpose of the Phase 2 ground investigation was to acquire sufficient geo-environmental information to support the sale of the site and a planning application for the redevelopment.
Site investigations included: drilling of 35 boreholes, in situ geotechnical testing, collection and analysis of soil and groundwater samples; and installation of temporary piezometers for ongoing soil gas and groundwater monitoring.
The site investigation proved that Made Ground was present across the entire site and was underlain by superficial deposits and mudstone bedrock of the Mercia Mudstone Group. The Made Ground included general construction waste (including some asbestos material) and in some areas glass fragments. Ash waste was found and a black viscous liquid (confirmed by laboratory analysis to contain hydrocarbons) was identified in a few locations.
Laboratory analysis of soil samples found that metals including arsenic, copper, lead, nickel selenium and zinc were present within shallow soils across the site. Hydrocarbons were generally found to be widespread at low to moderate concentrations across the site, although significant concentrations were found in some localised areas. The quality of shallow groundwater was of lower quality compared to the deep groundwater and contained elevated metals (lead and arsenic) and higher concentrations of chloride and ammoniacal nitrogen.
Information from the site investigation identified a number of potential pollutant linkages from areas of soil and groundwater contamination to receptors at the site, including future residents and local controlled waters. The impact on these receptors was assessed in accordance with UK best practice.
Options to manage the areas potentially affected by contamination were identified, in consultation with our client and their advisors. Options included: further assessment to reduce remediation requirements; remediation prior to sale of the site to maximise site value; and divestment of the site with adequate contractual protection to ensure that potential future environmental liabilities were passed on to the purchaser.