Water Pump and Treat

Groundwater and Surface Water Pump and Treat

Groundwater and surface water remediation for proposed wetland in Kent

Sevenoaks Environmental Consultancy worked with a Wildlife and Conservation charity and provided a contaminated land solution to remediate a long term fuel leak that had occured at a remote agricultural site for the creation of a wildlife wetland. The site occupied an area of low lying land which had previously been kept dry during its former agricultural usage by a network of ditches, dykes and pump houses which de-watered drainage channels during periods of heavy rainfall. The site was situated in a remote location with poor access and had suffered hydrocarbon contamination from a fuel tank associated with a pump house which had leaked into the ground for years and runoff into into a section of the adjacent ditch.

Following some initial site investigation SEC were employed to design and implement remedial work to clean up soil, surface water and groundwater hydrocarbon contamination. This involved the conduct of deep boreholes to facilitate groundwater monitoring, clearance of the former pump house structure and decommissioning the fuel tank, installation of a sheet pile cut off wall to facilitate remedial excavation and groundwater remediation adjacent to the ditch and remediation of the ditch itself. Heavy plant including long reach excavators and tippers with flotation tyres were used to facilitate the remedial work and establish the surface water / groundwater pump and treat system.

The impacted stretch of the drainage ditch was determined and isolated by a dam. The surface water within the ditch was pumped through the treatment system together with the impacted groundwater recovered from the remedial excavation, in order to remove hydrocarbon contamination. Works were undertaken for several months until validation analysis of the ditch and groundwater confirmed that hydrocarbon impact had been reduced below remedial target values. A period of post remediation groundwater monitoring was completed to confirm an absence of hydrocarbon rebound and to meet with Regulatory requirements.

Following completion of the remedial works a Validation Report was produced to document the remedial measures implemented and final reinstatement work was completed to form the wetland and meet with the Client's brief.