Entry by JoeDerhake
Vapor barriers are great for buildings above contamination, but what if the contamination happens on top of the barrier? I recently did a Phase I on a strip shopping center that has had a vapor barrier and passive venting system in place for 12 years. The vapor barrier was originally installed to mitigate the effects of naturally occurring methane. One of the tenants is a dry cleaner that uses PCE. Clearly, the potential for releases from a 12-year dry cleaner is sufficient to justify a Phase II, but does the presence of the vapor barrier change things?
Doing a traditional Phase II with soil borings would be infeasible as borings would penetrate the vapor barrier. Also, the vapor barrier would likely prevent PCE from getting into the native soil; thus, greatly reducing the threat of groundwater contamination. Does this eliminate the REC? What do you think?