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The U.S. Environmental Protection Agency (EPA) announced today a proposed cleanup plan for the Olin Chemical Superfund Site in Wilmington, Mass. The plan intends to provide interim cleanup options to remove ongoing sources of contamination in groundwater and final cleanup options for addressing contaminated soil, sediments, and surface water at the site. They will also solicit public comment on EPA’s preferred alternatives for addressing the contamination.

The Olin Chemical site was placed on the Administrator’s Emphasis List of Superfund sites slated for “immediate, intense attention” by the EPA Administrator and leadership in April 2019 to facilitate cleanup and redevelopment activities.

“The interim action for groundwater is EPA’s first step in the cleanup of the aquifer, while long-term groundwater studies continue to identify a final cleanup plan for groundwater,” says EPA New England Regional Administrator Dennis Deziel.

EPA estimates that the proposed cleanup will cost approximately $48 million.

Some of the cleanup components of the proposal include:

•    Begin cleanup of the aquifer by constructing and operating new groundwater extraction and treatment systems.
•    Capture and treat oily waste and contaminated groundwater that flows into surface water by constructing and operating new multi-phase extraction and treatment systems.
•    Construct and maintain caps and cover systems on areas of soil contamination that pose an unacceptable ecological risk, including an impermeable cap over the feature on the Olin property known as the “Containment Area.”
•    Excavate contaminated wetland soil and sediment, dispose excavated materials off-site at an appropriate approved facility, and restore impacted wetlands and floodplains.
•    Prevent potential exposure to contaminants that pose inhalation risks in future buildings by requiring additional evaluations and/or engineering controls such as vapor barriers or venting systems.
•    Continue studies to further characterize bedrock aquifer and the full extent of groundwater contamination.
•    Conduct long-term groundwater and surface water monitoring and periodic five-year reviews to ensure protectiveness of the remedy.  

Background Info

The site comprises the Olin property, an 50-acre parcel at 51 Eames Street in Wilmington and adjoining areas impacted by contaminant releases from manufacturing and waste disposal activities formerly conducted at the property.

Chemical manufacturing began at the Olin property in 1953. The facility was used to produce blowing agents, stabilizers, antioxidants and other specialized chemicals for the rubber and plastics industry. Prior to 1970, chemicals were discharged into several unlined pits and ponds in the central portion of the property. The wastes percolated into the soil or overflowed into streams. As the liquid materials moved downward through the soil, they reached the groundwater table. Because the liquids were denser than water, they continued to sink downward, pooling in a series of cascading depressions on the bedrock surface.

Ultimately, contaminated groundwater migrated nearly a mile to the north and northwest of the property and resulted in the Town of Wilmington shutting down its municipal drinking water supply wells in the Maple Meadow Brook aquifer due to contamination from the site.

Get Involved

The public is invited to submit written input on the Proposed Plan during a 30-day comment period from August 26 through September 25, 2020. EPA has also established a dedicated voice mailbox at 617-918-1880 to receive oral comments during the comment period. To review the Proposed Plan and learn more about the Olin Chemical Superfund Site, visit

EPA will hold a virtual public informational meeting and question-and-answer session on Tuesday, August 25, from 7:00 – 8:30 p.m. Interested individuals may pre-register for this meeting opportunity. Those who pre-register via the Eventbrite link we be put in a queue to ask questions after the presentation is given.

EPA will also hold a virtual public hearing on Tuesday, September 22, 2020 from 7:00 – 8:30 p.m. The public will be able to provide oral comments at this event. Instructions for how to register for this event will be posted on EPA’s website at A copy of EPA’s presentation will be available on the site webpage prior to the informational meeting. For those without computer access, you may visit EPA’s website before the informational meeting begins to download and print a copy of the presentation materials to view while participating by telephone (call-in number to be listed on EPA’s website prior to the meeting). Closed captioning will be available during the virtual informational meeting and formal hearing.

Written comments may be mailed or e-mailed by Friday, September 25 to:
Melanie Morash
U.S. EPA Region 1 – New England
Mail Code 7-4
5 Post Office Square
Boston, MA 02109-3912