December 13, 2013
Michigan

Engineer: Lake Winds design left no room for error

BY KEVIN BRACISZESKI DAILY NEWS STAFF writer | December 13, 2013 | shorelinemedia.net

An engineer for the company Mason County hired to study noise levels at the Lake Winds Energy Park in Riverton and Summit townships stated in November that he believed the park was built in a way that excessive noise should have been expected.

Brian Howe of Howe Gastmeier Chapnik (HGC) said the company designed the wind turbine development to produce sound levels equal to 45 decibels – which is the maximum limit for noise levels at the property lines of people who are not receiving payments for siting the project in their neighborhood.

Lake Winds Energy Park was built by Consumers Energy and includes 56 wind turbines to create 100 megawatts of electricity.

The Mason County Planning Commission had set 45 decibels as the maximum level for noise at the property lines of non-pooled properties and HGC found sound levels higher than that near four turbines. The planning commission then ordered Consumers Energy to mitigate the problems so there were no noise levels higher than 45 decibels at unpooled properties.

Consumers Energy then appealed that decision to the Mason County Zoning Board of Appeals and the ZBA held a hearing on that appeal Dec. 5 and may make a decision on Dec. 18.

HGC opinion

In a Nov. 22 letter to the ZBA, Howe stated the sound consultants Consumers Energy had hired before installing the turbines did not include a safety factor in the project’s design and that the company should have expected the sound levels to rise above 45 decibels.

Howe stated, “the Lake Winds Energy Park was designed and constructed by Consumers in a manner that should have been expected to create an exceedance of the 45 dBA standard. The Tech Environmental “Verification Sound Monitoring of Lake Winds Energy Park” report of August 2013 confirms that the June 2011, pre-construction, acoustic study prepared by Tech Environmental indicated that the wind energy park was designed to produce sound levels equal to the 45 dBA standard. However no factor of safety was included by Tech Environmental to address the fact that their sound propagation prediction methodology has a stated accuracy worse than +/- 3 dBA. In short, the wind energy park was designed so as to have expected exceedances of the 45 dBA standard.”

Mason County Zoning Director Mary Reilly said the ZBA members and representatives of Consumers Energy received copies of the HGC opinion eight days before the appeal hearing.

Company’s response

Consumers Energy spokesman Dennis Marvin told the Daily News the company would not comment on the opinion except to refer to the appeal filed with the ZBA.

The company, through its attorney, Adam Smith, is appealing the planning commission’s ruling based on two reasons – it contends it was not given due process prior to the planning commission decision and that only the sound level of the turbines should be considered, not background noise too.

Consumers is also claiming that HGC’s sound measurement data can’t be used because the measurements included non-turbine sounds and that compliance with the ordinance must be limited to sounds of the turbines.

An attorney representing Consumers Energy also said measurements should be made both with the turbines on and with them off so the sound level when they are off can be subtracted from the total noise level to determine what the turbine sound level is.

Reilly has said HGC can separate the sources of sound recorded and determine the level of sound produced by the turbines.

[rest of article available at source]


URL to article:  https://www.wind-watch.org/news/2013/12/13/engineer-lake-winds-design-left-no-room-for-error/