MONTPELIER - Supporters of wind power in Vermont are asking a group of state lawmakers to block regulations that would more strictly limit wind turbine noise.
People who are worried about the health impacts of living near wind turbines say the new rules would be a helpful step.
Advocates and opponents of ridgeline wind projects filled a committee room Thursday at the Vermont Statehouse in Montpelier as lawmakers took more than an hour of testimony.
Utility regulators at the Public Service Board have filed the new restrictions on wind projects. The Legislative Committee on Administrative Rules is the final step in the approval process.
Under the proposed rules, noise from large turbines would be limited to 42 dBA during the day and 39 dBA at night; smaller turbines would be limited to 42 dBA.
Previously approved wind projects were held to a standard of 45 dBA, said John Cotter, a lawyer for the Public Service Board.
"Some people found that sound level to be annoying, and we were encouraged to think about the aesthetic impacts of sound levels from wind facilities," Cotter said.
Developers also would have to build large wind turbines away from local residents by a distance of 10 times the height of the turbine. Residents could sign an agreement to allow closer turbines, and state regulators also could grant a waiver.
Margaret Cheney, a member of the Public Service Board, said the board developed the rules after an unusual set of three public hearings.
"We believe the rule strikes the appropriate balance among the potentially competing concerns of continuing to support the deployment of in-state renewable energy facilities, including wind," Cheney said, "while avoiding undue sound-related aesthetic effects and public-health impacts."
Olivia Campbell Andersen, an advocate for wind power from Renewable Energy Vermont, brought a map that showed just 0.6 percent of Vermont land would be viable for a wind project under the new rules, preventing new projects.
Andersen asked lawmakers to reject the rules.
"None of Vermont’s existing utility- or community-scale wind projects would have been constructed under this rule," Andersen said. "So I believe that clearly addresses the question as to whether future projects could or would be constructed under this rule."
Annette Smith, executive director of Vermonters for a Clean Environment, questioned Andersen's calculations and pointed to several proposed wind projects that were not included on the Renewable Energy Vermont map.
Smith supports the new rules, which she says would help to protect the health of wind-turbine neighbors and encourage developers to reach out to the local community.
"It is not like transportation noise," Smith said. "It is a complex source of feelings, sensations — that’s what people describe. It’s not just the audible noise at all. People describe their heart beating in rhythm with the turbines.
Anderson, the renewable-energy advocate, doubted the stories of health impacts from wind-turbine noise.
"More than 487 gigawatts of wind have been installed around the world," Andersen said. "We have also had significant installment of wind in Vermont. And I think that if we were facing a health crisis, that would be well-documented at this point. It is not, however."
Lawmakers postponed a decision on the wind rules until a future meeting, possibly later in June.