Project

Demolition of former dairy buildings on a proposed housing development site had resulted in release of ground heating oil into the ground and groundwater and contamination of crushed concrete with PCB’s resulting in a prosecution by the Environmental Agency. Site was bounded by a river and had a ‘leat’ or ‘mill race’ running through the middle of the site that required filling. All this resulted in very close scrutiny from the Environment Agency and Local EHO.

Contaminant

Polychlorinatedbiphenols (PCB's) and heating oil (hydrocarbons)

Challenges

Site was restricted in size with different contaminants being treated in close proximity. Validation was critical in removing the Section 106 agreements on a site that had been held up for almost two years by legal issues.

Churngold Solution

Churngold proposed dry screening of the PCB, contaminated crushed concrete to remove the fine fraction that contained the PCB’s. This recovered fraction was then taken to landfill. This was successfully undertaken under a mobile plant license. Hyrdrocarbon impacted soils under went ex-situ bioremediation in bio-piles under the same mobile plant license.

The exposed groundwater underwent product skimming using peristaltic pumps to remove floating free product. Civil engineering works completed the diversion of the stream and allowed the mill race to be infilled. All recovered and crushed concrete was used on site to raise site levels above the new flood levels.

Technologies employed

• Mobile Plant License
• Dry screening
• Dig & Dump
• Bioremediation
• Product skimming
• Stream diversion