Envirotreat has been commissioned by Speller Metcalfe (PC for West Mercia Police and Hereford & Worcester Fire Service), to undertake supplementary site investigation, remediation options appraisal, treatability trials, and remediation works in readiness for a new Fire & Police Combined Hub on a vacant Brownfield site adjoining the existing fire station.
The development site had complex contamination issues, partly that the site was a former (pre WWII) landfill, previous site investigations had shown waste (spent oxides) from the former town gas works had been deposited there, together with a range of contamination, predominately heavy metals. However more importantly was the presence of PFAS chemicals in both the soils and groundwater (1,000ng/l based on an EQS of 0.65ng/l) on the site and existing fire station (part of which fell into the new development area).
The PFAS remediation strategy placed in front of both Worcester Regulatory Services (on behalf of Worcestershire Council) and LQM (on behalf of West Mercia Police and Hereford & Worcester Fire Service) was approved.
Remediation works commenced 6th March and were completed by the 21st April. The works consisted of design and installation of a E-Clay Permeable Reactive Barrier (circa 180m) and PFASorb treatment of soils (and associated groundwater) with identified elevated PFAS concentrations, following delineation.
PFASorb is a modified E-Clay specifically for the stabilisation of PFAS chemicals.
In total circa 4,500m3 of soils were treated in-situ.
Following completion of the works, Envirotreat have been onsite are part of the ongoing watching brief during the earthworks, together with providing water treatment capability for deep excavations (designed and installated by Oracle Environmental), soil classification and disposal as part of the cut and fill and continued groundwater monitoring.