FOOD AND DRINK Site Closure and Environmental Permit Surrender Food Processing Facility, UK
Project Summary
Site Closure and Environmental Permit Surrender Food Processing Facility, UK
Key Project Elements Intrusive Investigation Collection of Surrender Data Environmental Permit Surrender Site Condition Report Forensics Analysis Contamination Delineation Excavation of Hydrocarbon Impacted Soil Abstraction of Hydrocarbon Impacted Groundwater Abstraction Well Decommissioning
CRA was commissioned to support a client during their site closure process. As the site was operating under an Environmental Permit, this involved the collection of Surrender Data to prove that the condition of the soil and groundwater beneath the site had not deteriorated during operation under the permit. Reference Data (baseline data) for the site had historically been collected as part of a Site Protection and Monitoring Programme (SPMP). Soil samples were collected from borehole locations drilled using a dynamic percussive sampling rig, and groundwater samples were collected from the existing monitoring well network. The soil and groundwater sampling locations, depths and analytical suite were selected to mirror the Reference Data collected several years previously. The results of the soil and groundwater Surrender Data were then compared against the Reference Data. The investigation demonstrated that soil and groundwater beneath the site had not deteriorated significantly except in one area adjacent to petrol and diesel fuel above ground storage tanks. CRA submitted soil and groundwater samples for forensic laboratory analysis to determine the age of the identified petroleum hydrocarbon contaminants to confirm whether the contamination had occurred during the life of the permit. CRA undertook an intrusive investigation to delineate the extent of the impacted soil and groundwater. The investigation comprised the excavation of trial pits, the advancement of additional boreholes, and the installation of groundwater monitoring wells. The results of this investigation identified areas of soil requiring excavation and removal, and impacted groundwater that required abstraction. An area of 750m2 was excavated and 340 tonnes of impacted soils were disposed of off-site. The resulting excavation was backfilled with clean, imported fill material. Verification samples were also collected to ensure that the excavation had been extended sufficiently, both vertically and laterally. During the excavation works, CRA identified an abandoned 85 metre deep groundwater abstraction well. CRA decommissioned this well as per Environment Agency guidance to eliminate the potential contamination migration pathway. A groundwater abstraction system was installed by CRA to extract the impacted groundwater. Groundwater monitoring was undertaken during and after the groundwater abstraction process to assess its effectiveness. The results of the investigations and remedial works provided evidence to the Environment Agency to allow the surrender of the site’s Environmental Permit.
Ref: PS0040a