Residential Redevelopment of Former Garage
A human health risk assessment at a proposed residential development site in North Devon was undertaken as part of a wider scope of works comprising a Phase 1 and Phase 2 contamination assessment, followed by the production of a remediation strategy and subsequent validation testing.
The Phase 1 assessment indicated that the site was a former garage, part of a larger historical coach depot.
The Phase 2 contamination investigation, which comprised windowless sample boreholes and contamination laboratory testing, recorded elevated levels of total petroleum hydrocarbons (TPH)and lead within both made ground and underlying natural soils, associated with a remnant underground storage tank (UST), fuel lines and an off-site tank, within the confines of the former coachworks.
The contamination risk assessment indicated the recorded levels of contamination to potentially be harmful to human health, given the proposed residential land use.
To protect end users, Ruddlesden recommended that all of the tanks and associated fuel lines be remove, and that all proposed garden/ soft-landscaped areas be capped with a minimum thickness of 600mm topsoil and subsoil underlain by a geotextile membrane.
All of Ruddlesden’s reports were approved by the local authority’s environmental health officer and the contaminated land planning condition was satisfied.