A hearing has been set for Dec. 4 in Ludington at which Consumers Energy will appeal the Mason County Zoning Board’s decision that a few of the Lake Winds Energy Park turbines are slightly over the allowed decibel level for noise.
Mary Reilly, Mason County zoning and building director, said the planning commission has asked Consumers Energy to provide a mitigation plan that would bring the turbines into compliance. Instead, the utility has filed an appeal with the county Zoning Board of Appeals.
Consumers Energy isn’t commenting on the matter because it is also being sued by owners of 10 adjacent homes who claim the spinning 160-foot blades on the turbines cause shadow flicker and noise that amounts to “significant and material intrusions upon their properties and inside their homes.” The suit was filed by Craig W. Horn and David L. Puskar of Braun Kendrick Finkbeiner in Saginaw and asks for damages in excess of $25,000.
Reilly said the sound measurements, taken in April and May by HGC Engineering, a Toronto-based acoustical consulting firm, indicated that “several of the sites (at Lake Winds) were found to be out of compliance but in a relatively small range.” She said that range was from 0.3 to 1.2 decibels above the 45-decibel maximum wind turbine noise at the property line for those property owners who did not sign an easement agreement with Consumers Energy.
However, Reilly said the acoustic tests were independent of that lawsuit and not in response to noise complaints the zoning department had received from some of the adjacent homeowners — although some had, in fact, filed complaints.
Reilly said the zoning ordinance covering the 56-turbine wind farm, spread over parts of two Mason County townships, grants Consumers Energy a special use permit. The ordinance also requires noise testing be done there within one year of the wind farm beginning operation. That was a year ago, in November 2012.
Reilly said some of the specific sites tested, however, were “partially in response to complaints and partially in response to the modeling that was submitted by Consumers Energy.”
Results of the tests were discussed at meetings the zoning board held in August and September, with Consumers Energy in attendance.
She said eight sites were tested for noise. Two of the sites were more than one decibel above the maximum allowed, and both had two turbines nearby. The tests were done at the property lines and were about 1,000 feet from the turbines, according to Reilly.
Reilly said she would emphasize that “each site is unique,” with the direction of the wind during testing a determining factor. Low winds on the ground and high winds at turbine hub height — 312 feet above the ground — also impact the audibility of the turbine noise. Higher ground wind levels tend to mask the sound of the turbine blades moving through the air. Other factors impacting the noise level of the turbines are nearby traffic, birds and trees.
“Frogs were an issue at that time,” she said. “The spring peepers were starting to emerge. We had to kind of pick sites away from those frogs.”
Spring peepers are “louder than the turbines, when they really get going,” she added.