HARPSWELL — Demolition of the deteriorating pier at Mitchell Field will cost nearly $5 million, and take about a year.

“The pier in its current condition is a safety hazard and an impediment to further development of the site,” engineer Barney Baker told the Board of Selectmen at a workshop Feb. 10.

If the pier collapses on its own, Baker added, the cost of removing it from the seabed would exceed the cost of proactive demolition.

Voters will be asked to authorize borrowing to pay for the removal at next month’s Town Meeting. The the town voted to demolish the pier last March.

Baker told selectmen that a plan to create an artificial reef out of the pier’s reclaimed material – saving transportation costs – has been tabled because of permitting obstacles.

Instead, Baker said he is “pushing, promoting and recommending” the town use the open space at Mitchell Field as the demolition site.

The alternative, he said, would be loading the deconstructed pier on a barge and shipping it elsewhere – most likely Rockland, he said.

While that option would mitigate construction activity at Mitchell Field – and reduce dust and noise at the popular waterfront and at neighboring properties –Baker said it would add approximately $2 million to the total cost.

Either way, he called the project “an exercise is materials handling” that will take about a year, “or two winters.”

He walked selectmen through the intricate process of stripping away the old U.S. Navy holdover’s component parts.

First, divers will remove steel from the pier’s submerged foundations – a laborious task that crawls at a rate of 12 feet of cutting a day, and costs $6,000 for every day of diving.

“It’s mind-boggling,” Baker said of the divers, who are limited to working underwater for 70 minutes at a time.

Once the steel is removed from the pier’s concrete and gravel foundations, workers will trim and truck it to a recycling center. Most of the salvaged rock and concrete material should have reuse value, Baker said, and interest from nearby construction companies could offset some of the transportation and disposal costs.

Among amounts for overhead like insurance and permitting, Baker also budgeted for a temporary on-site road leading inland to a construction area. He pitched the road as a potential investment in an area of the site already zoned for marine-related businesses.

In November, a company expressed interest in bringing an indoor salmon farm to the zone – although Town Administrator Kristi Eiane said Feb. 10 that negotiations with the company, Whole Oceans LLC, have stalled.

“Not much is going on there,” she said, adding she didn’t think the pier demolition plans would interfere with immediate development in the area.

However, the time-line could affect residents’ ability to use the recreational and waterfront amenities at Mitchell Field, which includes a beach and gazebo that hosts a summer concert series.

Selectmen discussed pausing construction for the summer, but that could cost an additional $300,000 to mobilize and demobilize construction equipment.

“I want to go back and refine these figures,” Baker said as he finished his presentation.

He noted that a similar project  in Cutler had served as a guide in devising plans and cost estimates.

The board was impressed with Baker’s thoroughness and recommendation.

“(It) sounds like the only logical option,” Selectman Kevin Johnson said.

If residents authorize the bond next month, town Treasurer Marguerite Kelly said it would be the most money the town has ever borrowed at once; to her recollection, the largest bond the town has ever issued was around $1 million.

At a meeting following the workshop, Jane Covey, chairwoman of the Mitchell Field committee, recommended the town replace the pier with a seasonal float and ramp system, which will support recreational and light commercial activities.

Callie Ferguson can be reached at 781-3661, ext. 100, or cferguson@theforecaster.net. Follow Callie on Twitter: @calliecferguson.

The pier at Mitchell Field in Harpswell, built in the 1950s to pipe fuel to Brunswick Naval Air Station, is rapidly deteriorating and on the brink of collapse.

Mitchell Field Committee Chairwoman Jane Covey recommended a plan to selectmen Feb. 10 to build a seasonal float and ramp system at Harpswell’s popular waterfront recreational area. Earlier in the day, the board discussed a $5 million plan to demolish the pier, which is deteriorating and presents a safety hazard.