The Tri-Town Ambulance Service has a new chief, new medics and soon will have a new intermunicipal agreement among the three towns it serves.

Aquinnah, Chilmark and West Tisbury selectmen met on Wednesday to begin discussing changes to the 35-year-old ambulance service agreement and assessment formula.

West Tisbury selectman Richard Knabel, who led the effort to draft a new agreement over the summer, said there were two major issues — governance structure and dividing assessments and revenues among the towns.

The selectmen voted to reorganize and downsize the tri-town committee; the new committee will include one selectman from each town and two ex officio members, the ambulance chief and the director of emergency medicine at the Martha’s Vineyard Hospital. Only the three selectmen will have voting powers.

First-time elected selectmen cannot serve on the committee and the chairmanship will rotate annually. The committee will evaluate the chief, and the chief will evaluate the deputy chief and employees (there is currently no deputy chief).

The current tri-town committee has seven members including selectmen’s appointees, squad members and police chiefs from each town. The reorganization comes with the support of the police chiefs who said their workload already was too much.

Aquinnah selectman Spencer Booker suggested having the fire chiefs serve on the committee and West Tisbury selectman Jeffrey (Skip) Manter said he’d like to see the current committee structure remain the same.

But Aquinnah selectman Jim Newman disagreed, saying the committee needed “to be closer to home.”

“In my experience of the past nine years we rarely heard about tri-town from either the chief of police or fire chief, it’s always the budget,” he said. “I think if the selectmen were involved we would have more of a pulse on what’s happening and I don’t see the selectmen as micromanaging whatsoever, but seeing the policy is in place and followed and the budgetary requirements are being met and everything is equitable.”

Mr. Knabel concurred. “We should respect what police chiefs want with the input of the medical director and the chief. If you’ve got a good chief and you’re confident in the chief, then let him run the day-to-day,” he said.

The new committee structure was approved, with Mr. Booker and Mr. Manter dissenting.

The selectmen also agreed to change the assessment formula, but are still undecided on the details. The current formula divides costs and revenues equally three ways.

The tri-town budget rocketed up to $453,000, a 40 per cent increase, this year due to the state requirement for 24-hour paramedic service.

Aquinnah selectmen say their small town has fewer emergency calls and should not bear the same cost as the other two towns. But West Tisbury and Chilmark say they are the farthest away (the ambulance is housed in Aquinnah).

Mr. Knabel laid out eight different funding options, and there was consensus around a scenario where all three towns paid a fixed cost with the remaining portion based on mileage to each town. The selectmen agreed to ask ambulance chief Paul (Zeke) Wilkins, who was not at the meeting, to prepare fixed operating cost estimates for their next meeting on Oct. 20.

Chilmark selectman Warren Doty said time is of the essence.

“This is something we’re trying to do before the 2013 budget process,” he said. “These are things we have to do this fall to have a formal agreement in place before Dec. 31 so everyone can build their town budgets.”