Cognition remediated an agricultural machinery yard in Crowmarsh, Oxfordshire which is to be redeveloped for residential housing. Large areas of the yard was built over foundry sand and clinker deposited on the site to raise the land and protect it from flooding. More than 13,000m3 was processed to remove contaminated waste. More than 60% of the material met the remediation targets and was re-used on site achieving significant cost savings on disposal and import of new materials Backfilling required careful re-profiling of the site to meet flood risk requirements including the creation of landscaped flood compensation areas bordering the River Thames. Cognition was also able to blend site won sand to create topsoil to cover a third of the 1.5 hectare site.
The key elements of these works included:
Cognition successfully demolished the buildings, cleared knotweed and bioremediated hydrocarbon contaminated soils. The clinker and foundry waste was screened and picked for disposal and site soils reused under MMP. The site was reprofiled and stabilised to produce construction platforms for the new residential development. Significant archaeological works were carried out over more than half of the site but works were carefully planned to ensure the construction programme was not adversely impacted. Cognition also worked with soil manufacturers to blend clean site won subsoil with nutrients and organic material to produce a topsoil for re-use within the new development.