Loureiro Environmental and Bioremediation Consulting, Inc. (acquired by Loureiro Environmental in 2013) was contracted by Nobis Engineering, Inc. to evaluate the potential for anaerobic in situ bioremediation to treat a recalcitrant PCE hotspot in fractured bedrock at the Eastern Surplus Superfund Site in Meddybemps ME. The ultimate goal being to avoid restarting a previously installed pump and treat containment system at the site. Treatability testing was performed by Loureiro Environmental to determine:
- Reagent requirements to achieve complete enhanced reductive dechlorination (ERD) of the PCE
- Evaluating the potential for creating metals mobility as a result of the ERD
- Developing remedial design parameters
Result: The microcosm experiment demonstrated:
- Site groundwater required the addition of organic and mineral amendments and inoculation with dechlorinating culture to effective treat the PCE to ethane in a timely and cost-effective manner.
- There was minimal potential for metals mobility and site-specific metals of concern aluminum, arsenic and lead were extensively removed by precipitation, consistent with the literature.
The treatability testing results were used in the design of the pilot / full-scale application at the site by Loureiro Environmental. The field implementation was successful and lead to the Maine Department of Environmental Protection being able to keep from re-activating the pump and treat containment system.
