GROTON — In a last, brief meeting held one day before the end of the year, selectmen on Wednesday were forced, due to a misunderstanding, to revisit an issue they had considered settled.

At a meeting Monday, the board voted to enter a lease agreement with Groton Landfill Solar, LLC, allowing the private company to construct a solar farm at the town’s landfill covering an area of about 10 acres.

A second vote included the involvement of the Groton Electric Light Department, which would buy energy generated from the array and pay the town up to $40,000 a year in new revenue.

A third vote covered a memorandum of agreement that included payments of $15,000 a year by GELD to lease the landfill property.

However, a subsequent meeting of the Electric Light Commission revealed that a mistake had been made in the board’s first vote. Instead of $40,000 a year, the annual payment would be $1,000 a year for the life of the lease or $25,000 total.

So selectmen on Wednesday rescinded their earlier decision, and a new vote approved the correct numbers. A second vote dealt with liability issues.

With the solar array being located atop the landfill, there had been questions on how much risk the town might be exposed to should the ground sink or collapse beneath the apparatus or if some future legislation requires more remediation at the former dump.

With other towns going ahead with the same kind of solar farms, the risk seemed to be judged as low by other municipalities, and with potential revenue for the town generated by the array, selectmen eventually agreed to approve the plan in a memorandum of agreement.

Wednesday’s vote clarified the memorandum by stating that the annual payment by GELD could be placed on hiatus should the lease be suspended and the solar array forced to shut down until whatever situation prevailed at the landfill could be rectified.

Also on Wednesday, selectmen voted to accept a donation of 13 acres of open land located along the Westford town line in East Groton. The land was donated to the town by Oregon resident Clifford Robinson in the name of his mother, Viola Day Robinson.

According to Conservation Commission member Bruce Easom, the area is “landlocked” and adjacent to another parcel owned by the town.

“It’s a generous gift,” Selectman Joshua Degen said. “It’s a beautiful upland forest.”

Town Manager Mark Haddad said the cost to the town for accepting the land would be a $75 deed registration fee to be paid out of the Conservation Fund. In addition, the town would lose about $500 in annual taxes on the land.

Selectmen Chairman Jack Petropoulos, considering all options before a final vote, wondered if the town could ever sell the land if it chose to, but Easom said that’s easier said than done, with a majority vote of the Conservation Commission and the state Legislature needing to be in favor of it.

But the sale of donated land would not be a good idea in the long run, Easom said, as it would likely discourage other landowners from doing the same.

Voting in favor of accepting the donation were Degen, Petropoulos and Peter Cunningham. Selectmen Stuart Schulman and Anna Eliot were absent.

The Conservation Commission had already voted to accept the donation before the selectmen’s decision.