ATTLEBORO -- The U.S. Environmental Protection Agency has decided on a final cleanup plan for the Walton & Lonsbury Superfund site on North Avenue.
The move comes after a hearing on the proposal in July, which was attended by about 25 neighbors of the project.
Nothing will happen immediately.
It will take one to two years for EPA to work out details of the plan and another two to four years to implement it.
The earliest the work will be done is three years and the latest is six years, unless funding is delayed for some reason, officials said in July.
The government has already spent $15 million on the site and surrounding parcels.
Officials estimate the additional cost at $22 million.
Work began in 2010 to remove immediate health threats. That part of the project ended in 2013.
Since then, the EPA has studied the extent of the pollution which includes the highly toxic hexavalent chromium, trichloroethylene (TCE) and lead, and mapped out potential remedies.
The cleanup is detailed in a document called a Record of Decision, which includes the following actions:
• Removal and off-site disposal of remaining Walton & Lonsbury facility features.
• Soil excavation at the former Walton & Lonsbury property and off-site disposal of contaminated soil.
• On-site soil treatment at the former Walton & Lonsbury facility property.
• Extension of the existing permeable reactive barrier along Bliss Brook.
• Mid-plume on-site soil treatment along the west side of North Avenue.
• Soil excavation and off-site disposal of lead-contaminated surface soil at residential yards west of North Avenue.
• Restoration of affected areas.
• Contingency remedy of on-site bedrock groundwater treatment west of North Avenue, if additional investigations to be conducted indicate groundwater contaminants are found to exceed drinking water standards in the down gradient aquifer.
• The overall remedy will also include land use controls to protect the remedy where unrestricted use standards are not achieved, long-term monitoring and maintenance, and periodic five-year reviews to ensure protectiveness of the remedy.
"Today's cleanup decision demonstrates EPA's commitment to making meaningful progress cleaning up Superfund Sites in New England and across the country," EPA New England Regional Administrator Dennis Deziel said in an emailed statement. "Finalizing the cleanup plan for the Walton & Lonsbury Superfund Site is an important milestone. EPA looks forward to working with area residents and officials as we move forward with cleanup activities, which will benefit Attleboro."