BREWER – The Maine Department of Environmental Protection and Brewer Fire Department were investigating a spill of an undetermined substance into the Penobscot River on Thursday.

Just before noon, the town office received a call regarding an iridescent sheen on the river near Kustom Steel boatyard at 195 South Main St.

“I can almost guarantee it’s not a petroleum substance,” said Cleve Leckey, an oil and hazardous materials specialist with the Maine DEP. Based on his years of experience with the DEP, Leckey said he believes the white, slimy substance is oil-based paint.

A boat is being painted in the Kustom Steel yard and 5-gallon pails of paint can be found around the area, Brewer Fire Chief Rick Bronson said. He also said the owners of the boatyard have tried to contact the owners of the boat all day, but have not received a return call.

The DEP, Fire Department and members of the Penobscot River Oil Pollution Abatement Committee worked all afternoon to install a containment boom to keep the substance from being swept downriver. With the help of two boats, the boom was in place around 4:30 p.m.

Although some of the substance was taken with the current down the river, Leckey said it was so diluted he was not concerned with health or environmental repercussions.

Anyone found responsible for the spill may be required to pay the cleanup costs, Leckey said.