Pilot project will use new technologies to deal with problem nutrients
Fieldwork has begun in the Massachusetts communities of Barnstable, Dennis, Falmouth, Mashpee and Orleans on a project that may help reduce harmful levels of nitrogen and other nutrients from flowing into Cape Cod waters. Lessons learned from this pilot project can be applied to other locations throughout the Southeast New England region to determine the most effective means to capture nutrients before they negatively impact bays, ponds, streams or coastal estuaries.
With funding from the U.S. Environmental Protection Agency’s Southeast New England Program (SNEP) for coastal watershed restoration, EPA is investigating treatment technologies to help control the discharge of nitrogen from groundwater to Cape Cod waters. One of these technologies is called a Permeable Reactive Barrier (PRB), a technology that may be able to intercept and mitigate nitrogen reaching Cape Cod water bodies. EPA chose sites in the five Cape communities for preliminary investigation to explore their potential as suitable sites for PRB installations.
“EPA is eager to see if this promising, low-cost technology can be applied more widely on the Cape and elsewhere to help solve the problem of nutrient pollution impacting local waters,” said Curt Spalding, regional administrator of EPA’s New England office. “We have experience with PRBs to remediate contaminated groundwater plumes, so we are hopeful that this technique can also help diffuse nutrient pollution.”
“Cape Cod is at the heart of this problem in New England,” said U.S. Representative Bill Keating, a longtime champion of SNEP funding in Congress. “I am very proud to join the EPA in announcing the release of funding from SNEP for these deserving projects on the Cape, which seek to combat contamination and purify our water bodies. These five projects are the realization of the SNEP’s goals—utilizing innovative technologies to mitigate and reduce nitrogen levels in our region’s groundwater.”
A PRB is located below the ground surface in order to intercept groundwater plumes and uses a variety of substrates, such as vegetable oil or wood chips, to intercept nitrogen as it flows towards surface water. PRBs are usually sited perpendicular to the direction that groundwater is flowing towards the water body and can be built as a trench-like design or through a series of injection points. Each site has specific factors that will help EPA and its partners best determine the type of PRB technology to propose.
The sites undergoing preliminary characterization include Prince Cove Marina, Barnstable; Vinland Road, Kelley’s Bay, Dennis; Mashpee River Road, Mashpee; Sailfish Drive, Bourne’s Pond, Falmouth; Shorewood Drive, Great Pond, Falmouth; and Lonnie’s Pond, Orleans. The site characterization work should be completed during the spring of 2016.
Following the initial site investigation, EPA will choose one or more of the most promising sites for more detailed characterization to determine if it can fully support a PRB design. This full site characterization will yield additional data needed to determine the size, depth, type and placement of a potential PRB. While a PRB will not be installed through this project, a full design will be made available to the towns. The process will help Cape Cod communities decide if a PRB is a suitable solution for future sites and how to design it effectively.
For this project, EPA is collaborating with the U.S. Geologic Survey, the Cape Cod Commission (CCC) and each municipality. This collaboration also aligns with and is in support of the objectives of the Massachusetts Department of Environmental Protection’s Total Maximum Daily Load for Cape Cod and the CCC’s Clean Water Act Section 208 Plan Update. Both of these documents were developed to help address excess nutrient pollution, and PRBs are one method that may be both cost-effective and efficient in mitigating the discharge of nitrogen into Cape Cod waters.