The client’s consultant performed an enhanced bio pilot test that appeared to be successful for a TCE source area at a Superfund site. An ESD (Explanation of Significant Difference) to the ROD included enhanced bio as an alternative and a full-scale work plan was completed.
I provided a 3rd party review of the pilot results and full-scale work plan. The resulting tech memo showed the pilot results were not representative of a full-scale application, and due to the presence of DNAPL, bio would not meet the client’s goals of reducing concentrations sufficiently prior to capping the site within a year. This prevented full-scale implementation at a cost-savings in excess of $1,500,000. The $300,000 spent on the pilot also could have been saved if consulted sooner.
NOTE: this evaluation occurred in 1996 when it was still believed that DNAPL could not be treated with bioremediation. Our knowledge has changed in the past 25 years, however, this decision was still correct given the client’s time schedule for capping the site.
