LISBON — The Maine Department of Environmental Protection is set to begin removing mercury from a section of the Sabattus River and taking out the Mill Street Dam, the Town Council was told Tuesday night.

The first phase, which is expected to be completed by the end of September, will be dredging and removing mercury contamination near an old water main and removing the dam, DEP officials said.

The second phase, set to be done next year, will be removing 1 foot of the riverbed for 1,500 square feet to take out pieces of linoleum that are backed with asbestos and PCPs, an organochlorine compound used as a pesticide and a disinfectant. The waste will be deposited in a nearby landfill, which will be capped.

The shoreline will be armored to prevent the landfill material from leaking into the river, which it has been doing for over 50 years, state officials said at the meeting.

Town officials asked DEP representatives to explain the project in detail because some landowners along the river were angered to learn the dam would be removed because water levels are expected to drop.

The project did not need council approval and is not being funded by the town.

Shoreline landowners had seen water levels drop when the dam was breached due to a naturally occurring event, according to the Maine Department of Marine Resources. The removal of the dam stands to further reduce the water levels by an estimated 4 to 5 feet.

“Landowners along the river are not pleased with the drop,” said Councilor Chris Brunelle, who owns property along the river. “People are a little upset that the river is dropping for fish. It’s going to be a stream.”

Officials countered that no one is maintaining the dam and the structure needs to be removed for various reasons. They also stressed the need to improve the environmental condition of the river, which has been a priority for the Departments of Environmental Protection and Marine Resources for many years.

The impetus to begin the work now is, in part, because the water main that prevented dredging earlier has been moved, with only a pipe remaining. Also, the previous business operating at the mill site, Miller Industries, went bankrupt, and the new owner is being proactive in addressing the facility’s ongoing pollution of the river.

“We understand that this is a benefit to our community,” Councilor Norm Albert said, adding, “we understand what the impact will be” on riverfront landowners.

In other business, a public hearing will be held at 6 p.m. Tuesday, Sept. 17, to discuss proposed changes to the policies at the Solid Waste Transfer Station. Fees generally have gone up and other changes are proposed as well.

The council also set Nov. 5 for referendums on a $1.5 million bond to finance road construction and improvements on Pinewoods Road, and a $6 million bond to replace all water department infrastructure along Route 125. A public hearing on the questions will be held Sept. 5.