Principally, there are four phases to a Contaminated Land Assessment:
Phase 1 Desk Study
Phase 2 Site Investigation
Phase 3 Remediation & Validation
Phase 4 Post-remediation monitoring (i.e. groundwater condition).
It should be noted that if the risks are found to be low enough, it is possible that the condition could be discharged following completion of the Phase 1 Desk Study, subject to a basic non-technical watching brief during construction. If recommendations are made for a Phase 2 Site Investigation, it may be that the scope will be driven principally by the need for a Geotechnical Investigation, with chemical testing bolted on to verify the condition of shallow soils and suitability for use. More complex brownfield sites may need formal Phase 3 Remediation and Validation works, especially if they have had a long history of industrial and contaminative use.
Another common condition relates to managing for any unforeseen or unexpected contamination, an example of which is provided below:
In the event that unexpected contamination is found at the site during the construction of the extension hereby approved, work shall stop immediately, a site investigation/ inspection carried out by a competent person and a report shall be submitted in writing to the Local Planning Authority for Approval. No further works shall be undertaken unless otherwise approved in writing by the Local Planning Authority.