GREAT BARRINGTON -- The old town firehouse on Castle Street soon may be undergoing a potential $4 million conversion into a vocational training school, museum and cafe.

After nearly two years of contract negotiations and more than a dozen negotiation extensions, the Board of Selectmen on Wednesday unanimously approved the $50,000 sale to business group 20 Castle Street. The group, backed by principal owner Tom Borshoff, has expressed interest in refurbishing the 114-year-old building into a multi-use facility.

"This is as good as it gets and there is a huge opportunity with this buyer," Select Board Chairman Sean Stanton said after the meeting.

The town and 20 Castle Street signed a purchase-and-sale agreement on February 2012. The town originally began soliciting bids on the firehouse in December 2010. The town would be obligated to spend $270,000 for environmental cleanup, including removal of on-site asbestos. 20 Castle Street would pay up to $50,000 for remediation, with the town on the hook for remediation if it exceeds $320,000.

Any additional environmental cleanup cost above $270,000 would be subject to town meeting approval, according to the contract.

The sale's finalization has dragged on because of environmental studies and community concerns, which includes objections from Railroad Street merchants. The sale will restrict when and how often large trucks could use an adjacent alleyway, which sits between the firehouse and a parking lot.

Merchants say that alley is critical to getting merchandise and food into their businesses and taking trash and other refuse out.

Town Manager Jennifer Tabakin on Wednesday said she would ensure local businesses aren't negatively impacted.

"I think this is excellent for the town, but I do want ensure a commitment to local business and that is a huge priority for the town," she said.

The comment didn't relieve concerns from Railroad Street merchant Rob Navarino, owner of the Chef Shop.

Navarino said the easement agreement negotiated between the town and 20 Castle Street would require any truck over 25 feet to receive approval from Tabakin, who will enforce the easement.

"We understand the good intents, but [in the contract] there's no legal right of way for these trucks," Navarino said.

Following the meeting Tabakin disagreed with the statement and re-asserted a "reasonable" compromise would be reached.

Stanton, who has been the most vocal publicly about addressing Railroad Street merchant concerns, said the town has amended the original contract to address Railroad Street merchants. He approved the contract, saying it was fair for taxpayers.

"I think when you look at the big picture it makes sense," Stanton said.

The agreement would allow town departments to use 7,500 square feet rent-free for the first year of the sale. In the following year, the town would pay $2,500 a month with the option of subletting the space.

20 Castle Street also is eligible to apply for a Tax Increment Financing Agreement that would reduce its property tax rate.