Processing Your Payment

Please do not leave this page until complete. This can take a few moments.

October 18, 2023

EPA selects cleanup plan for Keddy Mill Superfund site in Windham

old photo of mill buildings COURTESY / WINDHAM HISTORIC SOCIETY, EPA Windham's Keddy Mill building is shown in 1875.

A $17 million plan has been selected to clean up contaminated soil, sediment and groundwater at the former Keddy Mill in Windham, a federal Superfund pollution site.

The site include a dilapidated, two-story concrete industrial structure that has elevated levels of polychlorinated biphenyls, asbestos and other contaminants known to endanger human health and the environment.

The U.S. Environmental Protection Agency said this week the plan for the seven-acre property, at 7 Depot St. in the Little Falls portion of Windham, is based on its remedial investigation report, human health and ecological risk assessments, a feasibility study and comments received on a proposal issued this past summer.

“EPA’s cleanup plan for the Keddy Mill Superfund Site is a strong effort to ensure the health and safety of community members, protecting them for generations to come.” said David Cash, the agency's New England regional administrator. “Cleaning up Superfund sites helps us ensure that no community, no family and no child has to face exposure to chemicals and other dangerous substances in their day to day lives.”  

aerial of buildings with color dots
PCB concentrations are depicted on the first floor of the former mill.

The plan comes nearly a decade after federal regulators launched an environmental review of the site.

Keddy Mill was listed on the National Priorities List of Superfund sites in 2014.

Superfund is a federal program that investigates and cleans up complex, uncontrolled or abandoned hazardous waste sites. 

ITT LLC is the “potentially responsible party” for the site and has agreed to building demolition and removal of contaminated materials.

EPA’s plan is expected to take two to four years to design and execute and will take place after most of the mill complex and associated structures are demolished.

The plan, which the EPA estimates will cost around $17 million to implement fully, includes the following components: 

  • Excavation and off-site disposal of contaminated soil and debris from the property; 
  • Targeted treatment of soil within the footprint of the excavation, with amendments in support of groundwater cleanup; 
  • In situ treatment of groundwater contaminants; 
  • Excavation and off-site disposal of contaminated sediments from the Presumpscot River; 
  • Treatment of water generated from soil and sediment dewatering and removed from excavations based on applicable water discharge standards, as required; 
  • Restoration of the portions of the Presumpscot River altered by the remedial action; 
  • Land use restrictions to prevent exposure to site-related contaminants in groundwater and fish tissue until cleanup levels are met,  
  • Inspections and operation and maintenance; 
  • Monitoring of groundwater and fish tissue to evaluate the achievement of cleanup levels; and
  • Five-year reviews to assess the protectiveness of the remedy. 

“This plan protects the human health or welfare of residents, the environment from actual or threatened releases of hazardous substances, pollutants, or contaminants into the environment.” said Windham Town Manager Barry Tibbetts.

Maine Department of Environmental Protection Commissioner Melanie Loyzim said the plan is expected to return the property “to a productive future.”

The Keddy Mill site has a history of operations dating to the late 1700s and ending in 1997. The building that will be demolished and removed was used as a grist and carding mill, pulp mill, box-board manufacturing facility and as a steel mill. Throughout the industrial history, several buildings have been demolished and others added to the complex.

Sign up for Enews

Related Content


Order a PDF