The ongoing cleanup of a Superfund Site in southern New Hampshire leverages the best available technology and sustainability practices to protect the health and safety of the community while enhancing wildlife habitat and conservation efforts. The award-winning project work is guided by the team’s commitment to being good neighbors and delivering measurable benefits to the town.
For decades, thousands of New Hampshire residents and businesses across New England sent waste oil to the 41-acre state-licensed recycling and disposal facility. The state of New Hampshire ordered the site’s closure in 1994 and, as a result of soil and groundwater contamination, the United States Environmental Protection Agency (EPA) declared the facility a “Superfund Site” in 1996. The Beede Site Group, a consortium of unaffiliated companies who were customers of the former licensed waste oil facility, hired Woodard & Curran in 2006 as supervising contractor to design, implement, and operate the site’s remediation program.
The Superfund Site abuts Kelly Brook, which is part of a critical wildlife corridor in southern New Hampshire. The ongoing remedial work plays a part in restoring the natural habitat so native species can thrive.
Groundwater Treated
VOC Mass Removed
The site abuts Kelly Brook and several private residences reliant on wells for drinking water. As such, treating contaminated groundwater was the top priority for the Beede Site Group. Our remediation experts designed a groundwater treatment system that extracts groundwater from several near-source and near-receptor wells, treats the influent to drinking water standards, and discharges the effluent to a rapid infiltration basin (RIB) or injection well gallery (IWG). The new facility constructed onsite is designed to operate 24/7 with an average influent flow rate of 130 gallons per minute (gpm). The treatment process addresses naturally occurring metals with microfiltration and volatile organic compounds (VOCs) and 1,4-dioxane with advanced oxidation. The system was designed with sustainable features, such as using extracted groundwater for geothermal heating of the building and the overall focus on water conservation and restoration of the aquifer.
While the groundwater treatment system is integral to the site cleanup plan, the project team also needed to address soil impacted by residual oil to eliminate further groundwater impacts. In partnership with TerraTherm, the project team installed an in-situ thermal remediation treatment via steam-enhanced extraction (SEE) system to address two source areas. This highly effective technology injects steam into the ground to raise the soil temperature to the boiling point of water, allowing for contaminant removal in liquid and vapor form. After the oil and water separates, groundwater and soil vapor are treated above ground. The process used effluent from the groundwater treatment plant to generate steam, which eliminated the need to truck water to the site in absence of a public water source. This remedial approach resulted in the removal of more than 500,000 pounds of VOC mass, including over 70,000 gallons of oil.
The groundwater treatment and SEE systems address most of the groundwater impacts on site. However, one saturated area remains near Kelly Brook. Excavation of this impacted material is scheduled. Once the soil and sediment work along the brook is complete, the final design and construction component for the site will address the remaining shallow soil impacted primarily by polychlorinated biphenyls (PCBs) due to poor waste handling in the past.
It is wonderful to have our team recognized [with the 2021 National Ground Water Association Outstanding Large-Scale Groundwater Remediation Award] not only for achieving the remedial goals of the Beede site, but also for applying sustainable design principles during project delivery that have resulted in measurable positive impact to the surrounding environment.
Sustainable Actions Implemented
Central to the remedial effort is our focus on sustainability. Our team integrates the five core elements of EPA’s Greener Cleanup program in each aspect of the project and focuses on the community impact through outreach and learning. To date, we have implemented more than 172 sustainable actions and 42 ASTM Best Management Practices for Greener Cleanups. For example, the groundwater treatment building is heated by a geothermal system using extracted groundwater and treated groundwater is used for dust suppression during construction. Reuse of water during thermal operations for steam generation reduced greenhouse gas emissions by approximately 65.4 metric tons. As much as possible, materials are reused across the site and sometimes repurposed for habitat enhancement. Remote technology reduces the number of site visits and solar panels power remote monitoring stations, further mitigating greenhouse gas emissions.
During our time onsite, the project team encountered various wildlife species around the property. The Beede Site Wildlife Management Team was formed in 2014 to promote wildlife habitat elements alongside efforts to clean and restore natural attributes, resulting in the site’s conservation certification by the Wildlife Habitat Council in 2015. Collective efforts have included the addition of duck boxes along Kelly Brook, installation of insect hives designed for native pollinators, expansion of the turtle observation program, development of an invasive vegetative species identification and removal program, and the addition of game cameras. Shortly after three game cameras were installed, each began capturing footage of deer, bobcat, coyote, turkeys, and many other native wildlife, helping demonstrate the land’s value for wildlife habitat.
Since residents of Plaistow rely on private drinking water wells, restoring the land and aquifers is extremely important to the community. The Beede Site Group, with the support of our project team, maintains a public website and Facebook page to keep neighbors up to date on the remediation progress. The project team hosts an annual open house, with supplemental virtual lunch and learn sessions during the pandemic. The community is involved in an annual bat count and a local high school STEM program has engaged with some habitat restoration work. Future engineers and scientists studying at the University of New Hampshire have toured the groundwater treatment plant. The project team also prioritizes local businesses to subcontract work to when possible. This has garnered mutual support from town officials and residents as cleanup work continues for at least the next decade.
