DNAPL treatment is already challenging, but imagine your site sitting on top of fractured bedrock as well. When the DNAPL penetrates the overburden, it finds paths to go deeper. Driven by density, DNAL migrates downward along fissures and fractures, before coming to rest once the liquid stops draining, and the NAPL has either been trapped or dissolved. At this point, some of the mass diffuses into the matrix and will become a long-term source of contamination to groundwater.
One remediation approach for this type of issue is thermal conductive heating. If we can get the subsurface temperatures to increase to boiling temperature, we can get the DNAPL to vaporize. Solvents such as TCE and PCE turn into a gas and migrates with the steam produced by boiling groundwater in the fractures and the matrix. This steam must then be extracted and treated.
Attendees of this webinar will:
Several full-scale remedies will be shown, including a 100-ft deep fractured granite site in California treated successfully to very low concentrations.