Assessing a sites risk from contamination involves following the procedures set out in a number of British Standards, including BS10175 and LCRM
If you’ve been asked by planning for a “Contaminated Land ‘ Risk Assessment,” we’re here to help. Planning may have specified “No development, other than demolition of any buildings or structures, shall commence until an assessment of the risks posed by any contamination shall have been submitted to and approved in writing by the local planning authority.” What they’re asking for, is a Phase 1 Preliminary Risk Assessment (PRA).
Most small developments start with a Phase 1 Preliminary Risk Assessment (PRA). This desk-based report has various names including desk study, preliminary investigation, preliminary risk assessment or contaminated land – risk assessment. They’re all essentially the same thing and form Phase 1 of the ‘Phased Approach to Land Contamination.’ We call it a Phase 1 Desk Study. Cornwall Council’s useful Validation Guide “A Guide to Submitting Planning Applications” contains information on when and why a Phase 1 Report might be required, as well as what they should contain [page 25]. More information can be found in Cornwall Councils “Land Affected by Contamination, Developers Guide.” Our PRAs are carefully structured to ensure they pass through planning without a hitch.
Should the Phase 1 Desk Study identify a risk, it is likely that an intrusive ground investigation will be required; commonly known as a Phase 2 investigation. This physical investigation essentially tests the hypothesis set out in the PH1. I.e., if the Phase 1 PRA identifies an unacceptable risk from Arsenic (as is common in Cornwall), the Phase 2 investigation will involve recovering soils samples and testing them at the laboratory.
If a risk still remains following soil testing, a Phase 3 remediation scheme may be required, followed by a Phase 4 verification report. These four phases are summarised in the flow-chart below.
In Cornwall in particular, Phase 1s often go hand-in hand with an archival mine search. This low-cost report assesses the site’s risk from historic mining, with respect to subsidence as well as contamination causes by mining. GCL offer mine searches in conjunction with PH1 reports, through our local trusted partners. If you would prefer to source a mine search yourself, a list of local companies can be found on the Cornwall Mining Alliance website, here.