A group of legislators who represent the region around Hanscom Field are calling on the state’s emergency and environmental affairs office to reject a report filed in support of expanding the airfield to include 17 new private jet hangars.

In their letter, Reps. Simon Cataldo, Michelle Ciccolo, Carmine Gentile, Ken Gordon and Alice Peisch said the draft environmental impact report was “strikingly cavalier in its omissions” and has “bold unsupported statements.” They specifically questioned how the project proponents’ determined unmet demand for private jet hangars at Hanscom and the expansion’s potential impact on Massachusetts’ environmental goals.

The legislators want the Massachusetts Environmental Policy Act Office, under the Executive Office of Energy and Environmental Affairs, to require the project proponents to submit a revised report that addresses their outstanding questions.

Laurence G. Hanscom Field, located in Bedford and operated by MassPort, is New England’s largest general aviation airport and the region’s largest private jet port. A report issued by the Institute for Policy Studies in 2023 estimates that at least half of all flights through the airfield were recreational and luxury flights. MassPort has previously said the expansion is a response to existing demand.

Legislators are concerned that without additional information, the communities bordering the airport — Lexington, Bedford, Concord and Lincoln — could suffer negative environmental impacts. Private jets emit at least 10 times more pollutants per passenger than commercial planes, according to the Institute for Policy Studies.

In the letter, the legislators say the report has several problems, including “glossing over the carbon emission consequences of private jet use,” questionable alternative fuel strategies, incomplete information about carbon sequestration and the removal of 20 acres of old growth trees. They also disagreed with the report’s claim that expansion could potentially reduce annual “ferry flights,” which involve flying an aircraft from one location to another without any passengers or cargo.

Legislators wrote that a revised report should include factors like existing runway capacity, acknowledgment of the current lack of carbon-free alternatives to jet fuel, and an explanation for how the proposal aligns with the aviation industry and commonwealth’s greenhouse gas reduction goals without using fuel alternatives.

“Nothing could be more antagonistic to the commonwealth’s climate goals and accepting without proper diligence a proposal that threatens to set us back immeasurably from our pursuit of greenhouse gas reduction objectives,” said Cataldo.

Legislators said they can’t have a “principled debate” without analysis on whether the hangars will lead to more or less private jet flights, and by how much.

Cataldo said the logical conclusion is that more hangars at Hanscom means more flights will be flying in and out, and increase ferrying from other nearby airports, and would increase private jet traffic from Logan Airport to Hanscom.

“They declared we’re going to double the hangar capacity for private jets at the airport, but no flights are going to increase. That’s the claim they’re making in this,” said Neil Rasmussen, president of Save Our Heritage, an organization working within the Stop Private Jet Expansion coalition of over 80 groups.

Rasmussen said the issue is two-fold: One is that private jets are an “exclusive club” thats highly subsidized by the government. Second is the greenhouse gas consequences being so large they overwhelm the efforts of many local communities to reduce greenhouse gases.

“It’s overwhelmingly clear they’ve misled the public about those impacts. And they’re going to have to go back to the drawing board and try to do it again,” said Rasmussen.

The draft report is currently before the Massachusetts Environmental Policy Act Office. A spokesperson said the office is “carefully reviewing the environmental impacts of this proposal and will consider all public comments and studies” related to it.

The MEPA office can accept, deny or ask for revisions to the draft proposal, but it doesn’t have the authority to unilaterally approve or deny the project. If the office accepts the draft, the Hanscom expansion plan would then have to get additional approvals, including local government and the Federal Aviation Administration.