Client: Mole Valley District Council
Location: Mole Valley, UK
Services: Statistical Assessment, Site Investigation Design, Human Health Risk Assessment
Summary: ESI provided site investigation design based on statistical assessment of existing data sets.
Client Comments: The statistical techniques and tools developed by ESI have greatly increased our certainty in making justifiable decisions about investigations and also determination of our contaminated sites. We're convinced that statistical approaches save money and produce better organised, more scalable investigations
Mole Valley District Council (MVDC) appointed ESI to give advice on the development of site-specific screening values for total Polycyclic Aromatic Hydrocarbons (PAH) and Total Petroleum Hydrocarbons (TPH), and develop a statistically based sampling strategy at a former Brickworks site, now a housing estate. The work was carried out to fulfill the council’s duty to inspect their area under Part 2A of the Environmental Protection Act (1990).
Under Part 2A legislation, Mole Valley District Council (MVDC) carried out a preliminary inspection of the site. To this purpose, the total area was divided into zones from 1 to 4. The investigation and subsequent chemical analysis identified TPH and PAH as contaminants of concern.
ESI provided MVDC with the following:
- Generic Soil Screening Values (GSSV) for aggregated TPH and total PAH;
- a statistical analysis tool to aid decisions regarding the number of samples required when designing site investigations, and to assess whether sufficient samples have been taken for existing data sets;
- A statistically based sampling strategy including advice on the appropriate number of samples and sample locations;
- A sampling and assessment strategy to deal with isolated PAH hotspots.