January 15, 2015
Michigan

Night study on turbine noise done

By Kelly Krager, Editor | Huron County View | 2015-01-15 | huroncountyview.mihomepaper.com

HURON COUNTY – The Huron County Board of Commissioners has received the results of a night study of turbine noise conducted by Acoustics by Design, which found turbine noise slightly exceeded levels allowed by the county’s noise ordinance, but traffic noise was the most prominent noise source detected.

The nighttime study, which cost the county $9,650, was commissioned to help the county revise its zoning ordinance as it relates to turbine noise. ABD will use the data in its review of the county’s noise ordinance, which the county’s wind energy subcommittee will use to draft proposed changes in the way the county measures turbine noise.

According to the report submitted by ABD, the measurements were completed between 11 p.m. on Nov. 13 and 6 a.m. Nov. 14 at the following locations:

Additionally, an ambient noise measurement was completed at a location that is not close to turbines, 2685 W. Atwater Road in Ubly, from approximately 2:53 a.m. to 3:05 a.m. on Nov. 14.

The county’s ordinance requires that turbine noise does not exceed 45 weighted decibels for more than 10 percent of any hour. The study found the limit was exceeded at three locations: 47 dBA on Stambaugh Road, 49 dBA on Sebewaing Road and 46 dBA on Sebewaing Road. A level of 42 dBA was measured on McAllister Road.

Graphs showing the noise level at each location contain spikes ABD attributes to traffic on nearby roads.

ABD concluded that a measurement of noise present during 90 percent of any hour might be a better indicator of a turbine’s effect at any location.

ABD was hired in August following the wind energy subcommittee’s recommendation to enlist the help of noise experts as the county works to revise its noise ordinance as it applies to commercial wind turbine noise.

The firm, an independent acoustical consulting firms headquartered in Grand Rapids, will be paid $10,500, plus expenses, to review the county’s ordinance and suggest changes so that it better protects residents from the potentially negative effects of living near a wind farm.

At ABD’s suggestion, commissioners contracted the night study to give the firm better information as it drafts its opinion.