Phase 1 Study for a Change of Use from Retail Premises to Residential

We undertook an EnviroSmart Report to support a planning application to redevelop a retail premises into residential development.

Potential risks to controlled waters and future users of the site were identified from off-site sources and qualified through the formation of the Phase 1 Preliminary Risk Assessment.

Consultation with the Local Authority proved important to the risk assessment as they held both additional formal information regarding known contamination and remediation of the land surrounding the Site.

A phase 1 desk study was conducted to assess the land quality risks for a retail premises which was proposed to be redeveloped to a residential development. As part of the desk study a review of historical maps and environmental data sets is conducted to establish the background information for both the Site and the surrounding area. Both historical and current industrial land uses within 250 m of the Site are reviewed, landfill and waste sites within 500m, pollution incidents, geohazards, controlled waters, water abstractions and geology. By reviewing all the data a conceptual site model is developed which culminates in the production of the preliminary risk assessment for the Site.

Although the risk from the Site itself was relatively modest given its residential and retail former use, following consultation with the local authority it was revealed the surrounding land is known to be contaminated. The land adjacent to the west of the Site was formerly occupied by a bus depot with known bulk fuel tanks. The land to the south of the Site was previously occupied by a fuel filling station. Both of these locations are classified as contaminated land under part 2A of the environmental protection act. The local authority stated the Sites had recently undergone remediation action which involved the removal of subsurface soils to a depth of 9 metres below ground level.

The environmental data for the Site indicated that the underlying geology for the Site is Hythe Formation (sandstone), which is classified as a Principal aquifer. Given the sensitivity of the local groundwater and the proximity of local water abstractions it was considered likely that there was a risk to the aquifer from local contamination.

Based on available information it was considered possible that some form of contamination may be present on-Site relating to current and historical off-Site land uses. The extensive levels of remediation work completed in the immediate vicinity indicate that contamination may have migrated to the Site.
We were able to provide a clear risk rating and appropriate guidance for further work that was in line with the recommendations provided by the local authority.