Stonington — The town could begin removing contaminated debris from the demolished Connecticut Casting Mill late next week.

First Selectman Rob Simmons said late Thursday afternoon that after what he described as “heated” discussions with the Boston office of the Environmental Protection Agency earlier in the day, he had instructed town officials to begin finalizing a contract with a firm to remove the debris from the site. He said he hopes to sign the contract next Tuesday and the contractor should be able to begin work immediately.

The dilapidated mill on Stillman Avenue began to collapse into the Pawcatuck River last month after a lightning strike and heavy rain on April 15. That forced the town to quickly hire a firm to tear down the mill before more of it could tumble into the river, which could have created a flooding threat and sent contaminated dust into nearby neighborhoods in Pawcatuck and across the Pawcatuck River in Westerly.

Residents in both Pawcatuck and Westerly had become increasingly concerned about the resulting pile of debris, worrying it would get in the water and air, even though air sampling had shown there was no threat. The Pawcatuck fire department has been spraying water on the pile to keep the dust from spreading since the building was demolished on April 15.

Asked about the delay in removing the debris at Wednesday’s selectmen’s meeting, Simmons said the EPA wanted the town to reconstruct information about PCBs on the site because the EPA’s documents had been destroyed. Simmons said the town submitted an 86-page report to the EPA last week and was awaiting a decision.

Having to remove PCBs, which Simmons said are buried 8 to 10 feet underground, would dramatically increase the cost of removing the debris. But he said there are not plans to excavate the site. He has said the cost to remove the debris, which does contain asbestos, will be less than the $600,000 authorized by the Board of Finance to demolish the building and remove the debris.

Simmons said that based on the feedback he received from the EPA on Thursday, he was proceeding with finalizing the contract.

He said the town has placed $147,000 in liens on the property and will add the cost of the demolition and cleanup to that. The owners of the property have not responded to the town’s phone calls since a section of the building began to fall into the river last month and have essentially abandoned the building, according to the town.

Simmons said the town also will look for reimbursement from its insurance company, as well as state and federal grants, to offset the cost.

j.wojtas@theday.com