Recently H Fraser Consulting were appointed to work at a former workshop site. The Site was granted planning permission for conversion to residential use. Works involved a Phase 2 intrusive site investigation as a condition of planning. The prior Phase 1 desk study had identified potential contamination risks associated with historic land use, including the presence of oil storage tanks, necessitating further assessment.
Scope of Works
H Fraser Consulting was appointed to deliver a cost-effective yet robust investigation ensuring timely reporting to meet planning deadlines and prevent project delays. Collaboration with the client helped streamline the process – most notably, the client provided a mini digger and operator, reducing overall costs.
The Phase 2 investigation comprised:
- Breaking of existing concrete slab
- Test pitting at nine locations across the site
- Collection of soil samples for laboratory analysis
- Leachability testing to assess potential impact on controlled waters
- Generic Quantitative Risk Assessment (GQRA)
Key findings
- Soil contamination:
Laboratory results were compared to residential-use Generic Assessment Criteria (GACs). The majority of contaminants were below laboratory limits of detection (LOD), indicating negligible risk to future site users. - Controlled waters:
Groundwater was not encountered in any of the test pits. Leachability tests were performed, and concentrations in the leachate were predominantly below LOD. Where detectable, levels were below indicative screening values. Some metals were marginally above Environmental Quality Standards (EQS), but based on site geology and groundwater depth, risks to controlled waters were assessed as low. - Hydrocarbons:
Minor visual and olfactory evidence of hydrocarbon impact was observed in the northern area, where heating oil and waste oil tanks were previously located. However, analytical results did not indicate concentrations above screening thresholds.
Recommendations & outcome
While contamination risks were assessed as low, H Fraser Consulting recommended precautionary measures such as avoiding water supply pipe installation in the hydrocarbon-impacted area or ensuring proper lining and protection.
No site remediation was deemed necessary. The updated conceptual site model confirmed the site was suitable for residential development. The planning authority accepted the findings, and the Client proceeded with the conversion works without further delay.
H Fraser Consulting offer expert support for planning-related contaminated land investigations, guiding clients from initial risk identification through to regulatory approval. With a practical, cost-conscious approach, we deliver robust Phase 1 and Phase 2 assessments. These include intrusive site investigations, laboratory analysis, and risk assessments tailored to proposed site use. By working closely with clients and planning authorities, we ensure timely, clear reporting that meets regulatory requirements – minimising delays and helping to move projects forward with confidence.
