Phase 4: verification inspection & report
A Phase 4 report or remediation verification inspection is required to check that the remediation plan has been implemented fully and correctly.
It may be in a report or letter, but should contain the following:
- Clear address or plot number;
- Description of remediation methods;
- Evidence of correct implementation:
- Clean cover system;
- Trial pits or depth probes;
- Measurements of depths.
- Certificate of source material;
- Vapour barrier test/certificate.
At this point, we check that the remediation was successfully completed and the site no longer poses a risk. If yes, the site is now suitable for use. If no, the risk remains, further remediation required or further assessment.
Why is this step important? Case study: St Donats Estate, Cardiff
In 2004, the council discovered that the site was contaminated with chemical slurry, and were required to spend more than £1.3m on remediation. As part of the remediation process, new top soil was imported into the site of the 46 houses where contamination was identified.
It was later discovered that the top soil of 10 of the homes was also contaminated with arsenic and benzo(a)pyrene, cancer causing chemicals. As such, these gardens had to be ripped up, and the process started again.
The moral of the story? Test the imported soil before placing in-situ!