The Public Service Board held a series of meetings this week on its proposed sound standards for wind turbines.
The board released its draft version of the new rules in March, and the board members held four meetings this week to hear from the public and from wind and sound experts as they get ready to finalize the sound standards.
The proposed rules set a standard of 42 decibels during the day and 35 at night.
They would also establish setback standards of 10 times the turbine height, so a 500-foot turbine, for example, would have to be 5,000 feet from the nearest residence or property line.
Stephen Ambrose, a sound expert who spoke at a PSB technical workshop in Montpelier, said the proposed standards surprised a lot of people when they were released.
"I've been working at this almost six years, all across the country," Ambrose said. "And Vermont was the last state that I thought would be the first to do this."
If the new rules move forward as written, Vermont would have the lowest noise standards in the country for wind turbines.
Ambrose said Vermont's proposed sound rules would go a long way to protect human health, and he spent about 30 minutes tearing apart how other sound studies measure decibel levels.
Ambrose was there to support Vermonters for a Clean Environment, a group that opposes industrial wind development.
The group's director, Annette Smith, said that while Vermont has been moving aggressively on supporting renewable energy, the state has not taken the time to really understand how turbine noise impacts people who live nearby.
"We are strong supporters of renewable energy, and want to see the renewable energy business succeed," said Smith. "We believe that what has happened in recent years has actually caused more opposition because we have not addressed the noise issues in an effective way."
The board is writing the new rules following a 2016 law that was passed to set consistent sound standards for wind development, as the state tries to reach its goal of achieving 90 percent of its power from renewable energy by 2050.
But Sarah Wolfe, who works for VPIRG, says these rules would make it much harder for developers to find suitable sites.
"Taking a critical renewable energy source off the table right now — which, to be clear, we think this decibel will do — means that we're inherently encouraging new fossil fuel generation," Wolfe said.
The new rules would set up setback limits that Wolfe said would effectively stop industrial wind developments.
And while she acknowledged that some people who live nearby wind turbines notice low-level sound waves, Wolfe says there are no studies that show that turbine noise, at the proposed standards, impact public health.
"So what we're talking about is more of an aesthetic- or annoyance-based decision," she said. "It's clear that there is some level of annoyance from wind turbine sound. But the number of respondents who said that they were annoyed was a small minority of the respondents, and by the same token it couldn't be characterized as a substantial interference with a normal person's enjoyment of their property ."
The Public Service Board also held meetings in Bennington, Lowell and Montpelier to hear from the public.
Aaron Kisicki is a staff attorney with the Public Service Department, which represents all Vermonters in the rulemaking proceedings. He says the department does have some questions about how the board developed its proposed standards.
"We want to insure that ultimately that the sound rule creates sound limits that are responsible, and that are appropriate for Vermont," Kisicki said. "A lot of new issues are being raised as part of this workshop, and that will help inform our ultimate position with respect to the rule. And we'll certainly take these issues into account as we prepare our final comments for the board's consideration."
The Public Service Board expects to take the input from these meetings and file its final rules with the Secretary of State and the Legislature on May 16.