Cognition undertook remediation works at the site of a former petrol station and car show room in Cuffley, Hertfordshire that was contaminated with PAHs, TPHs, and lead.
Cognition Land and Water undertook remediation works at a former petrol station and car show room in Cuffley, Hertfordshire. The soil was contaminated with PAHs, TPHs, and lead; perched groundwater beneath the site was also impacted by TPHs. The site was to be redeveloped with the construction of a 4-storey residential block of flats and a commercial unit for local residents.
Cognition carried out demolition works and removed the underground storage tanks, which were considered to be the contamination source. Contaminated soil was excavated and the excavation backfilled with clean material. Contaminated groundwater was pumped to a mobile treatment plant (comprising an oil water separator, sand filter and granular activated carbon vessel) and disposed to the sewer under a consent of discharge. Cognition were required to carry out six months of post-remediation groundwater monitoring to demonstrate that there was no residual risk to groundwater or nearby surface waters.