DALTON — The proposed new Wahconah Regional High School going to voters in April will not include a heat source that can reduce use of fossil fuels, but at a price.

A month after voting to deploy ground source heat pumps in a new school, the committee planning the project reversed course Thursday. Members said they didn't want to risk alienating voters by adding a $1.7 million to $2 million expense that would take decades to recoup in energy savings, despite its advantages.

After hearing pleas pro and con from a dozen community members, and then debating the merits of the geothermal energy source, the Wahconah Building Committee voted 16-5 to drop use of the technology.

Panel members backed a motion by Tom Callahan, a former Wahconah principal who co-chairs the committee, to drop the use of heat pumps they approved 18-1, with two abstentions, at a December meeting. Heat pumps use moderate subsurface temperatures drawn from wells both to heat and cool interior spaces.

The committee scheduled Thursday's reconsideration after the Dalton Select Board raised questions about the added cost last week. As the largest community in the seven-town Central Berkshire Regional School District, Dalton will shoulder roughly two-thirds of a new school's cost.

The district will receive state aid for the project, whose cost is expected to range from $70.8 to $74 million before that backing. The cost to the district is estimated in the mid-$40 million range.

"If we could afford all this, we would buy everything," Callahan said. "We can't get it all. I'm not willing to take a chance and lose this project over geothermal. I think it's time to put before the voters the basic design, which seems to have reasonable support among voters."

The vote followed heartfelt pitches for use of geothermal energy from community residents and from several members of the panel.

Anna Duquette, the committee's student representative, voted against changing course and told fellow members she's concerned about reliance on fossil fuels associated with global warming.

"We also need to think about the world in which our children will have to live," Duquette said.

Committee member Michael Hinkley of Dalton said he did not look forward to the day when Wahconah students would have to be told the district had the chance to build a school with all environmental advances available, but failed to do so.

"I think we're sending the wrong message," said Jan Paxton of Washington, who also supported alternatives to the use of natural gas, a fossil fuel, for heating. "I don't want to gamble our environment."

Earlier, Cheryl and Henry Rose of Dalton and others urged the committee to stick to its guns and embrace geothermal energy in a new school.

Henry Rose said he had no trouble finding people in support of geothermal energy when he began a petition drive backing the technology. He said three out of four people he approached expressed support. "We had no trouble. This was one of the easiest gets from people," Rose said.

Cheryl Rose said a new Wahconah's environmental qualities will make a statement to young people about what adults value. That ought to include a message, she said, discouraging use of fossil fuels to heat the building. "And that's good for our kids," she said.

Stu Besnoff of Windsor urged committee members to consider the efficiency of the geothermal heating source and said there is time to educate voters about the wisdom of creating the most environmentally advanced building possible.

"It is not an experimental or new technology," Besnoff said.

But others had argued for the position the committee took in dropping geothermal energy, mainly because of its upfront cost and the fear that the dollar figures would anger voters whose support will be needed at town votes April 6.

Jared Shannon, the school's athletic director and a member of Families for a New Wahconah, expressed sympathy for the political considerations before the board.

But he argued that the increased cost risked turning voters against the project. "The education of our children has to come first," Shannon said.

Joe Diver of Dalton said that he believes the committee could have done more to explain the merits of heat pumps. Lacking that, he said the question about added costs needed to be removed.

"You're adding risk to the vote," Diver said.

Sarah DiFazio of Dalton, an elementary school teacher and parent, said she has encountered pushback from residents about the added expense. Overcoming that resistance is paramount, she said.

"You are putting a new school in jeopardy," she told the panel. "I think that trumps geothermal."

Committee member Bill Mulholland, representing Becket, agreed with DiFazio's position when he offered his own stance later.

"We would lose the new school and be looking down the barrel of doing things on our own," Mulholland said, referring to the expected loss of tens of millions of dollars in state aid.

John Bartels Jr., chairman of the Dalton Select Board, cautioned that in his community, the project's cost looms large, at a time when the town is digesting other big-ticket expenses, including demolition of the former Dalton High School now underway at a cost of over $1 million.

"I really want to see this school," Bartels said. "I don't want to jeopardize it by adding to it."

Committee member Richard Peters of Hinsdale said that if geothermal had been a given from the start of the planning process, it would not have been flagged as a problem. He urged the architects to keep that in mind with their future projects.

Shawn Armacost, the committee's co-chairman, abstained from the vote, as is his custom because he also sits on the School Committee.

"It's unfortunate this whole school project has come down to geothermal," he said. But he said he agreed with others who felt the feature, in spite of its merits, could derail a vote.

"I'd rather see this building built," Armacost said.

The building panel and district committee will vote Feb. 14 whether to advance the project to replace the 58-year-old school.

The district won financial backing last fall from the Massachusetts School Building Authority, after showing that Wahconah is beset with physical problems and that its educational facilities are substandard. A new school would be built on the same site on Old Windsor Road in Dalton.

The district's member towns are Becket, Cummington, Dalton, Hinsdale, Peru, Washington and Windsor.

Larry Parnass can be reached at lparnass@berkshireeagle.com, at @larryparnass on Twitter and 413-496-6214.