In-Situ and Ex-Situ Bioremediation Pilot Test Case Studies for Pesticide Impacted Soils

Two different pilot studies were performed to evaluate the efficacy of different bioremediation protocols on pesticide and VOC impacted soils.  One study is evaluating an ex-situ mycoremediation approach with white rot fungus (WRF) on their ability to degrade DDT, toxaphene, and  VOCs in soils using biopiles.  Concurrently, a separate trial is being conducted using an approach whereby the contaminated, surficial vadose zone is converted to a partially saturated zone. This in-situ strategy, called controlled vadose saturation remediation (CVSR), relies on the biostimulation of anaerobic microbes that can degrade the compounds of concern. 
The pilot tests were devised to simulate full scale systems that are being contemplated at this large site and are actively monitored.  In the WRF study, five 10 yd³ test piles were constructed with the appropriate controls while utilizing lab-prepared, acclimated WRF cultures that were mixed with impacted site soils to achieve degradation.  Various parameters are being manipulated to optimize growth and degradation such as moisture content and oxygen content.  In the CVSR study, sodium lactate-laden water is being used to saturate subsurface vadose soil to create and maintain an anaerobic environment rich inthe electron donor source material that can drive reductive dechlorination.  Multiple in-situ monitoring devices are employed to help regulate the degree of saturation and collect data fto optimize the system.  Both systems have been designed to collect and transmit data in real-time via wireless telemetry.  System control and operation is being performed remotely to ensure immediate response to changes in site conditions and system performance.