EPA Research Partner Support Story: Determining extent of contaminant impacts
Partners: Massachusetts Department of Environmental Protection (MassDEP), Massachusetts Development Finance Agency (MassDevelopment)
Challenge: Defining the extent and nature of contaminant impact to groundwater and a recreational lake from a landfill at the Former Fort Devens; providing technical analysis of viable alternatives to stop contaminant impacts to off-site public and private properties
Resource: Applying novel methods for detailed assessment of groundwater and contaminant movement in a complex setting, in collaboration with the U.S. Army
Project Period: 2014 – Present
The former Fort Devens made use of an onsite landfill for solid waste generated during several decades of operations. The landfill was not equipped with a system to prevent release of landfill leachate into the underlying aquifer. The resulting contaminated groundwater has since moved beyond the base property, impacting an adjacent recreational lake (Plow Shop Pond) and the aquifer underlying the Town of Ayer, MA.
“EPA ORD’s involvement has been essential to the ongoing development of a groundwater model that can be used to support a remedy modification. Because of the technical complexity and importance of this project, it is doubtful that the results from the model could be accepted by the state without EPA ORD’s participation.” – MassDEP, Devens Project Manager David Chaffin
EPA ORD, in collaboration with EPA Region 1 (New England) and the U.S. Army, implemented a monitoring program during 2005-2008 to clearly define the location and nature of impact to Plow Shop Pond.
This established that contaminated groundwater entering the lake was caused by leachate migration from the eastern edge of the landfill, causing contamination of lake sediment and water.
The multi-year effort included installation of supplemental monitoring locations and collection of detailed chemistry data to define the source of arsenic contamination observed in the lake. Confirmation that the landfill was the source of contamination led to construction in 2013 of a hydraulic barrier wall to prevent plume discharge to the lake and removal of contaminated sediments. The U.S. Army is conducting an assessment during 2024 to confirm performance of the barrier wall. EPA ORD will conduct a final round of groundwater sampling during Fall 2024 from the supplemental monitoring locations to support the remedy performance assessment. Continued work will evaluate the success of the interim groundwater remedy installed at the northern edge of the landfill and allow stakeholders to select a permanent solution to address contamination impacting groundwater under the Town of Ayer, MA.
More information can be found on the Fort Devens Superfund Site profile.