CASE STUDY: USING IMMUNOASSAY TECHNOLOGY AND A DYNAMIC WORK PLAN TO COST EFFECTIVELY ACHIEVE SITE CLEANUP AND STATISTICAL CERTAINTY IN CLOSURE

摘要

On site immunoassay screening for organochlorine pesticides was successfully used at the WTFREC test plot remediation to expedite the soil characterization. The USACE design team selected a characterization approach using on site, near real time chemical analyses supplemented with a limited amount of off site fixed laboratory chemical analyses. The on site analysis was designed to support in field decisions regarding further characterization, removal, waste segregation, and waste disposal. Using fixed laboratory results to correlate the immunoassay results, the action levels for the field analyses were continually updated and adapted to site conditions encountered. The level of effort for the relatively expensive fixed-laboratory analyses was optimized through this approach. The amount of contaminated materials sent for incineration was also minimized. Following the remedial action, the site was successfully closed with the Washington Department of Ecology. Characterization, cleanup, and closure was accomplished within a single 4-month field mobilization, and the entire project cost ($589K) was about half the cost ($1.2 million) estimated according to a more traditional site characterization and remediation scenario relying on multiple rounds of field mobilization, sampling, sample shipment, laboratory analysis, and data assessment. The "surgical" removal of contaminated materials (possible because of the field analyses) ensured that closure testing would demonstrate regulatory compliance to a high degree of certainty, while making field activities such as sample collection, sample analysis, soil removal, soil segregation, and the final disposal of soil and wastewater highly efficient and effective.