operations. The main compounds of concern were trichlorethene (TCE), trichlorethane (TCA) carbon tetrachloride (CT) and daughter products.
The groundwater was at a depth to water of approximately 1.75m with a river around 600m to the north. Glacial deposits included variable clay 0-10mbgl with occasional silt and sand seams/lenses, gravel 10-12mbgl and London clay at 12-25m.
Previous remediation undertaken
Free product removal occurred through manual purging (1994-1996) and vacuum extraction (1997-1999). Partial excavation occurred during 2000 due to limited access within the working site. Pump and Treat went on to stabilise the contamination before the HRC technique was employed. HRC to speed up attenuation Consultant Golder worked with Regenesis and Churngold to apply Hydrogen Release Compound (HRC) to accelerate the natural attenuation.