January 18, 2020
Pennsylvania

Packer windmill farm session hears sound expert

By Seth Isenberg | Times News | Published January 18. 2020 | www.tnonline.com

Opponents of the proposed wind turbine farm atop Broad Mountain in Packer Township brought in an expert on noise measurement and acoustics for the Packer Township Zoning Hearing Board on Thursday.

Over 200 opponents, represented by attorney Bruce Anders, funded expert Robert Rand, who traveled from Brunswick, Maine, to appear.

Anders asked for Rand’s conclusions. Rand prepared a 32-page report, submitted to the board. His summary is that, with the rules of Packer Township stating the turbines’ noise “shall not exceed 50 decibels” at the property line, “noise levels are certain to be exceeded.” He sees the proposed turbines for the Broad Mountain Power project as “too big and too loud.”

Rand looked at Broad Mountain Power’s sound expert Michael Hankard’s report, as presented as testimony in May, and disagreed with those conclusions.

Specifically, he said, Hankard used manufacturer’s numbers about noise without factoring in variables. Plus, Hankard assumed sound reflectivity – that sound would be absorbed by foliage – resulting in lower sound projections than what Rand sees as the reality here.

Rand presented his model in the form of a graph that listed the Hankard report’s 16 measuring spots on the project’s property lines, and at 10 homes within sight of the proposed turbines.

The graph lists the closest turbine to each spot, whether that turbine is a tall or shorter model unit, and then Hankard’s original sound prediction.

To this, Rand added two levels of variable average sound. In this scenario, seven locations on the property lines would experience sound exceeding the 50 dBA limit.

Then by adding two more levels, he showed how the sound could reach Lmax – the loudest noise incidents.

Rand explained that Lmax noise levels of an operating turbine go up and down. His report shows two examples where turbine sound was measured during operations.

In one, the predicted sound level was exceeded by 8 decibels.

In another, measurements showed ebbs and flows of sound with a maximum variation of 10 decibels. He used these examples to explain how wind turbine noise changes as the blades turn, noting that figures developed by a manufacturer’s test are of short duration, “in a very even wind.”

Conditions that would add to noise would be those of wind shear – where wind is blowing faster on top of the turbine than down low, pitting of the blades so they are not as smooth, ice buildup, gusts and certain weather, leading to Lmax. At Lmax, Rand’s chart showed noise in excess of the 50 dBA at all 16 spots along the property line, and at half of the homes.

If World Health Organization standards are applied – 40 dBA in the evening and 35 at night, all sites experience louder than those levels.

Rand said the WHO states: “when long-term averages are over 40, you can expect sleep disturbances.”

Attorney Brian Stahl, representing Broad Mountain Power, offered a string of objections throughout Rand’s testimony – all noted, all overruled to allow the zoning board to hear Rand’s conclusions. Stahl made some headway in chipping away at Rand’s conclusions and his metrics.

Attorney Cindy Yurchak, representing the township, gave a summary in which she repeated the township’s rules that the noise is “not to exceed, at any time, 50 dBA” at the property line.

This meeting drew 55 citizens.

The hearing continues on Jan. 27, again at Packer Township’s Municipal Building on Route 93 in Hudsondale, at 6 p.m. Proposed February dates are the Feb. 6 and 20 at a location to be announced.


URL to article:  https://www.wind-watch.org/news/2020/01/18/packer-windmill-farm-session-hears-sound-expert/