Remediation of Chlorinated Solvents

Project Location: SW Florida
Client: DoE
Contamination: TCE, PCE, Vinyl Chloride, Toluene
Site Size: 4+ Acres
Remediation of Chlorinated Solvents Project Description: Over the previous 13 years, the incumbent remediation contractor had attempted to removed a large chlorinated solvent plume, extending 20+ feet below grade covering a footprint of approx. 4+ acres, with an elaborate vertical well pump-and-treat system. The cost expended by the client to date exceeded $13 million. We knew we could do far better, and we did.

Based upon a review of past documents, we determined that the incumbent contractor was removing less than 30 pounds of contaminants per year from the site, indicating that the site would never clean up. The client was desperate to complete remediation, so the site could be turned over to the community for a park.

Our approach was to employ concurrent in situ co-metabolic bioremediation and in situ air stripping to remediate the site using horizontal well biosparge systems. Since the plume contained not only chlorinated solvents and daughter products (TCE, DCE and vinyl chloride) as well as toluene, we were confident that co-metabolic bioremediation would work quite well.

Using our proprietary FEA CFD design and analysis software SPARGE™ and DISPERSION™, we were able to model the horizontal well systems perfectly, so that their 3-D placement underground was precisely known. IN SITU STRIPPER™ modeled the fate of each compound as it stripped from the formation.

We used SYSTEM DESIGN’R™ to design and specify the motive equipment. In all, we designed and installed three horizontal well biosparge systems to remediate the 4.5 acre site.

Our analyses indicated that the site would remediate very quickly, on the order of several months, and we were right. Within 6 months of system start-up, none of the previously found contaminants were identified in any monitor well sample. Several rounds of sampling were directed by the client over a period of several more months, all similarly indicated “non-detect” for each of the contaminant species.

In all, the client spent more than one decade and millions of dollars pursuing cleanup with a technology that could not possibly work. We completed site clean up in less than 6 months at a small fraction of this cost.