Remediation at former gasworksThere are thousands of sites across the UK that have been contaminated to some degree as a result of past uses. Some of these are obvious, such as former gasworks, industrial plants and petrol filling stations, but there are many other less well-known sources of contamination, such as light industrial uses, vehicle maintenance and storage, printing works and furniture makers, along with sites such as farms, schools and hospitals that might include specific and localised sources of contaminants associated with, for example, storage of materials and use of oil-fired heating.

In a small number of situations where certain criteria are met, a site might be determined as ‘contaminated land’ which has a specific legal definition set out in Part IIA of the Environmental Protection Act. However, in most cases, the degree of contamination on a site is such that it will be dealt with through the planning process, with contamination being a ‘material planning consideration’ which means that a planning authority must consider contamination when they prepare development plans or consider individual applications for planning permission.

The necessary scope of ground investigation, along with the requirements for reporting, risk assessment, remediation and validation will need to be approved by the local authority, and where there may be a risk that pollution of ‘controlled waters’ may occur or may have occurred in the past (controlled waters are coastal waters, inland fresh waters and groundwaters) the local authority is likely to require consultation to be carried out with the Environment Agency.

For sites that are being redeveloped by housing, NHBC and similar insurers will require evidence that any contamination has been satisfactorily remediated. As well as the requirements of regulators, site purchasers and their advisers will require an assessment of contamination as part of the due diligence process.

In addition to ground contamination, consideration often needs to be given to the presence of “landfill gas”, either as a result of decomposition of material on site, or as a result of migration from a nearby landfill site. The presence of a landfill will be identified at the desk study stage, allowing a programme of gas monitoring to be incorporated into the ground investigation if required.

GEA has the necessary expertise and experience to deliver investigations and detailed remedial solutions for any contaminated site. As with all of our work, we offer a commonsense and pragmatic approach and avoid unneccessary sampling and analysis. We have a proven track record of obtaining planning consent on contaminated sites without incurring excessive cost and delays for the development.