Orion teamed with IESI of Braintree, Massachusetts, to design and implement an enhanced anaerobic dechlorination (EAD) system to provide in-situ biological treatment of approximately 4 million gallons of groundwater at a former manufacturing facility in Southern California.
The EAD system consists of a network of extraction and injection wells that recirculate approximately 1 million gallons of groundwater in the targeted treatment area every month. Orion staff perform weekly injections of a blend of ethanol, methanol, and n-propyl alcohol to create an anerobic environment in groundwater. This promotes the growth of bacteria such as dehalococcoides (DHE) that naturally consume and break down chlorinated solvents in groundwater. DHE is important to cultivate because it is a species of bacteria capable of completely reducing PCE or TCE to harmless byproducts such as ethene. Other bacteria species can only reduce PCE or TCE to contaminant daughter products including