Risk Assessment (GQRA/DQRA)

 

Previous Stage- Phase 2

A risk assessment forms the principal element of the site investigation process, and is the way that suitability of a site for it’s intended use is established. A good quality, effective and appropriately tailored risk assessment can save on costly remediation, and will allow swift planning consent to be obtained.

Where contamination has been identified, it is vital to understand what impact it may have on human health or controlled waters. Whilst risk assessment is integrated into every level of investigation, the nature of the assessment is tailored to the type, location and severity of contamination.

The iterative investigation process set out in EA CLR11 ensures that initial phases of assessment are less data intensive, and therefore present limited costs to the developer/client. This allows exclusion of low risk sites early in the process, and with limited expenditure. These assessments are referred to qualitative risk assessments, and usually undertaken as part of a Phase 1 Desk Study.

Should a potential risk be identified, it will likely be necessary to undertake intrusive investigations (using trial pits, boreholes etc) in order to get site specific data on ground conditions and chemical quality. The results of chemical analysis are then usually compared against a series of published criteria in a process referred to a ‘Generic Quantitative Analysis’ (GQRA).

Phoenix Environmental ensure that the methods used to support the assessment are current, and accepted by regulators and planning authorities.

Should this phase of assessment confirm the presence of contaminative risk, it may be possible to move on to remedial works, or, it may be appropriate to produce a model of the site and contaminants. This is termed a ‘Detailed Quantitative Risk Assessment’ (DQRA).

Using this process it is possible to predict the mechanism of dispersal and degradation, and to develop site specific assessment criteria or remedial targets which will be protective of both human health and controlled water receptors.

Phoenix Environmental are able to deploy a number of environmental modelling packages including CLEA (human health), P20 assessments, and CONSIM (Controlled Waters).

Next Stage- Remediation