National Wind Watch: Wind Energy News » State calls for investigation of Sheffield Wind noise

The state’s ratepayer advocates are asking regulators to investigate whether a wind developer in the Northeast Kingdom violated the noise provisions in the permit the company received nearly 10 years ago.

The Public Service Department has filed documents asking the utility-regulating Public Service Board to investigate the noise concerns of a man who lives near wind turbines in Sheffield that were built in 2011, at a time when industrial-scale wind projects were popping up in the Northeast Kingdom.

The department hired an independent consultant to investigate the noise levels on the Sheffield Wind project following years of complaints from Paul Brouha. He has alleged that Vermont Wind LLC, the subsidiary of Sun Edison that owns the Sheffield project, had not used proper procedures to determine how much noise comes off the wind turbines.

The department then filed documents Oct. 14 saying that the department “recommends that the board initiate an investigation in response” to Brouha’s concerns, and that the department is “unable to enforce the project noise conditions as currently written with sufficient certainty to make objective determinations of CPG compliance.”

Vermont Public Radio first reported the Oct. 14 comments Wednesday. The issue comes down to two things: a years-long dispute over how the methodology of several different studies since 2006 determine how loud the Sheffield turbines are; and how the sound that people can and cannot hear affects the health of Vermonters who live near turbines.

The Sheffield Wind owners are supposed to make sure noise levels measure at 30 A-weighted decibels, abbreviated dBA, or below – a sound level that the U.S. Occupational Health and Safety Administration compares to hearing someone whisper from six feet away. In contrast, the sound of a vacuum cleaner 10 feet away would measure around 75 dBA, and a jet taking off 300 feet away would have a sound level around 130 dBA, according to OSHA.

Vermont Wind hired a company called Hessler Associates, Inc. to take quarterly measurements of the noise vibrations starting in 2012. The firm determined that the outside noise level from the Sheffield turbines was 33 dBA, and estimated that the inside noise level was about 20 dBA, meaning that the wind farm wasn’t violating indoor noise standards.

In 2013, Brouha filed documents with the Public Service Board saying that the Vermont Wind contractor’s methodology was flawed; he said the data “clearly” represented the sound a resident would hear with the windows closed “and no disclosure is made of noise level reductions with the windows open as ordered by the board.”

Vermont Wind responded that it was “extremely cold and windy” while the contractor was taking the estimates. However, a report prepared for the department in 2006 while the Sheffield project was being considered says summertime is when the data collected would represent a “worst-case scenario” situation because people sleep with their windows open when it’s hot.

In 2014, Brouha asked the Public Service Board for relief from the situation. He included a study prepared for him by the Noise Pollution Clearinghouse essentially saying that it is only 1 dBA quieter inside his bedroom than outside. That stands in stark contrast to the 13 dBA difference cited in Vermont Wind’s report.

The department commissioned its own report, received a final version in September, and attached it to the Oct. 14 comments asking the Public Service Board to open an investigation into whether the Sheffield Wind project is exceeding the 30 dBA noise limit imposed back in 2007.

That report says that the amount of noise reduction from being inside instead of outside could be between 2 dBA and 4 dBA. The report finds methodology problems with the study that Brouha commissioned but finds a number much lower than 13 dBA.

“The results indicate project-only sound levels that at a few times did exceed an outdoor criterion … and with the bedroom windows open, at times did exceed the indoor criterion that applies to this facility,” the study said. “The results also indicate that project-only sound levels did not exceed the indoor criterion at any time with the bedroom windows fully closed.”

Aaron Kisicki, a lawyer for the Public Service Department, said in an interview that monitoring noise levels are an important part of the department’s duty to “ensure adequate protection of the public health and safety.”

Some people who live near wind turbines say that wind turbines change the acoustical quality of their neighborhoods, making them feel seasick or have trouble sleeping. Developers contest that so-called “wind turbine syndrome” is not a real medical condition.

“We investigated that complaint (from Brouha) and found that further investigation into his complaint may be warranted, and we’re looking for some additional guidance from the board and other parties on how to proceed at this point,” Kisicki said.

John Lamontagne, a spokesperson for Sun Edison, the Boston-based company that has owned Sheffield Wind since early this year, said the company is reviewing how to respond to the department’s filing and will file something new with the Public Service Board “in a timely manner.”

A statement from the company said the following: “The Sheffield project has been in compliance with those standards as established by the (Public Service Department). Scientific studies conducted by independent third parties confirm this. We will continue to cooperate with the (Public Service Board) as they determine next steps in this matter.”