HARPSWELL — Immediate action needs to be taken on an empty, unused water tower at Mitchell Field to prevent further deterioration and possible collapse, according to an engineer hired by the town to evaluate the structure.

Fully restoring the 100,000-gallon steel tank to its full capacity as a drinking water storage facility, however, could cost more than $430,000.

Selectman Elinor Multer on Wednesday said the Board of Selectmen is gathering information on the options for the tower before proceeding with a recommendation, which will likely go to voters at Town Meeting.

“There are people in the town who feel sure there is some ultimate use for it and we shouldn’t take it down,” she said. “But there are clear implications that to keep it for any use will cost significant money.”

The tower provided drinking water to the U.S. Navy fuel depot at Mitchell Field, which was closed in 1992 and transferred to the town in 2001.

In a report submitted to the town in September, Scott Kelley, of Atlanta-based Utility Service Group, said that while the 100-foot tall tower is in good structural condition, its interior and exterior coating is worn in many places.

That wear exposes the steel tower to degradation, which will only get worse if not addressed by re-coating the structure and fixing other problems with its ladder, security, and sanitation system.

But a more immediate concern is that the tower does not have any water in it and has not for years.

Because the structure was designed to hold water, leaving it empty could allow it to fall over during severe weather, Kelley said in a follow-up email to Town Administrator Kristi Eiane.

“This steel structure was designed to have water in it,” he said. “Without water it is a liability.”

In an interview Wednesday, Kelley repeated that the tower could remain an asset for the town, but only if it is maintained.

“If nothing is done, it’s going to get worse,” he said , adding that his firm finds similar problems in half the tanks it inspects.

“We have cases all over the country where tanks have been neglected, and have gone to failure and they’ve become a catastrophe,” he said.

At this point, the town’s options are to fix the tank or take it down, Kelley said.

But the high cost of bringing the tank up to the “best” standard as a drinking water container has town officials questioning whether keeping the tower is a viable option.

According to Kelley, exterior renovation will cost $260,000 and interior coating will coast $130,000. Additional repairs could run to $42,500.

The costs could be spread out over several years and could be reduced depending on how the town intends to use the structure, he said.

While it is unlikely that the tower will be used as a drinking water facility, Selectman Kevin Johnson said there might be other ways to use it.

Other towns have allowed cellular phone providers to use such structures to help pay for their upkeep, Johnson noted.

“My personal feeling is that if we can find a use for it than I’m fine with keeping it,” he said. “But if there is no purposeful use, than I don’t see how we can afford it.”

Peter L. McGuire can be reached at 781-3661 ext. 100 or pmcguire@theforecaster.net. Follow him on Twitter @mcguiremidcoast.