Under the current version of the OAC 1301:7-9-13, all UST closure assessment samples must be compared to the strictest action level unless you can prove through a geotechnical analysis that a different soil type applies. Flynn recently completed a UST closure assessment at an active station. The closure results slightly exceeded the strict sand/gravel soil class 1 action levels. Instead of submitting a “dirty” closure report that would require additional corrective actions, Flynn conducted a geotechnical analysis on soil samples and proved that the soil at the site should be classified as soil class 2 (silty/clayey sands).
Using the higher soil class 2 action levels, the remaining chemical of concern concentrations in the soil were within acceptable limits. The site received No Further Action status a month later.
- UST Closure
- Geotechnical Analysis