LEWISTON – A group of residents and Central Maine Power Co. will continue tweaking a plan to reduce some of the impacts a huge power line upgrade would have on their homes.

A possible solution could see the city giving the utility a tax-increment financing incentive to reduce their costs. Councilors on Tuesday said they liked the idea, but wanted to be sure the costs were as low as possible.

“If the numbers start to climb up too high, I want you to know that you’ll get nothing,” Councilor Nelson Peters told neighbors. “The rest of the city is going to have to pay to help you. I think they’d agree they want to do it, but it has to be at the bottom dollar.”

Potential changes to CMP’s power reliability upgrade would cost the utility between $4.4 and $6.5 million. Resident Elaine DuMais, speaking on behalf of a group of residents, said they developed a new plan Monday that should be cheaper.

Company officials said they needed a few days to look at the group’s plan to determine costs. Attorney Tom Welch, representing CMP, said the company would try to report back by the council’s June 16 meeting.

Called the Maine Power Reliability Program, CMP’s proposal calls for upgrading a nearly 40-year-old swath of power lines. The lines start south in Eliot and pass through central Maine in Litchfield, Monmouth, Leeds, Greene, Lewiston and a corner of Auburn at the Durham line. They stop in Orrington, where they connect to lines from Canada.

In some places, lines would be rebuilt or replaced. In other places, lines would be added, including 115-kilovolt and 345-kilovolt lines. The 345-kilovolt poles, not common in Maine, are wider than traditional power-line towers, and depending on location, are about 20 to 25 feet taller than the lower-voltage poles.

The project would affect about 4,000 property abutters statewide. If approved, it could take three to five years to complete. Opponents say the 345-kilovolt lines buzz and emit an electromagnetic field they fear could cause cancer. Abutters say the new lines will lower their property values.

A group of Lewiston residents have been meeting since January trying to come up with alternatives. DuMais, of 228 Dyer Road, said CMP’s first alternative would have put the lines atop much taller H-frame towers throughout Lewiston.

“That came to us as costing $6.5 million, and we knew that was too much,” she said. Subsequent plans used different kinds of towers to move the lines away from homes.

“But nothing that uses one kind of tower works for every property that’s being affected in Lewiston,” she said. “Our latest proposal uses towers from each of the other proposals – whatever works for each neighborhood.”

CMP is expected to pay the city an additional $1.5 million in property taxes once the upgrade is complete. Some of that money could be returned to the company in the form of a TIF to pay for the changes. City Administrator Jim Bennett said once his staff has an idea how much the proposed changes would cost, they can figure how how the TIF district would be set up.

Councilors could vote on the plan sometime in July.