Atlantic Wind brings new sound engineer to testify on turbine noise level modeling 

Atlantic Wind attorney Edward Greene called on sound modeling expert Robert O’Neal to refute the testimony of opposition witness Robert W. Rand before the Penn Forest Zoning Hearing Board.

O’Neal, a managing principal at Epsilon Associates of Maynard, Massachusetts, has experience in areas of noise assessment, meteorological data collection and analysis.

O’Neal testified that he did not personally do any noise modeling for the permit that is being sought for the wind farm in Penn Forest Township, but that he had reviewed the reports and testimony of Mark Bastasch, noise control engineer for Atlantic Wind and Rand, the expert who testified on noise impact for the residents in opposition to the permit.

O’Neal confirmed Bastasch’s testimony and explained that modeling is done before the actual source of the noise is built and is mainly based on manufacturer’s supplied performance specifications.

Sound levels

O’Neal did not testify to any sound studies performed after a wind turbine farm is built.

When pushed by opposition attorney Bruce Anders, O’Neal said that the maximum noise specified could exceed the level in the model due to “ice accumulation” or other occurrences, such as a damaged blade.

O’Neal said the noise level mentioned for turbines is 45 decibels. That is for the turbine only and not the maximum level of noise found in any location, at any time.

Board alternate Shawn Kresge asked O’Neal what the impact of the Pennsylvania Turnpike noise would be and would the noise in the area of the turbine exceed the 45 decibels.

O’Neal said noise levels would “absolutely increase.”

Chairwoman Audrey Wargo asked O’Neal if he could determine what the noise level in the meeting room was if everyone were quiet.

The room went silent, except for the humming of the fluorescent lights and other background noises. O’Neal closed his eyes and concentrated for a few seconds, then said, “It’s about 45 db.”

Continuous sound

O’Neil also testified about an LEQ measurement versus an Lmax.

O’Neal said that Bastasch used LEQ measurements in his modeling, or what is described as an Equivalent Continuous Sound Level.

A search found that LEQ is defined as a method to describe sound levels that vary over time, he said. The LEQ is a single decibel level that takes into account the total sound energy over a period of time.

Lmax is the maximum sound level recorded during a period of time over which the sound is being measured.

O’Neal wavered in his testimony between stating the Lmax is “difficult to measure” to Lmax is “impossible to measure.”

“I am surprised as to how your testimony has changed,” said Thomas Nanovic, attorney for Penn Forest Township. “An hour ago it was difficult, now it’s impossible.”

Another area where O’Neal wavered was in the amount of time used in the Bastasch model. On cross-examination O’Neal admitted that he assumed 5 minutes because of a study Bastasch referenced in his report, but that the actual time was not included in the report.

“You really cannot explain LEQ so that the people in this room can understand it?” Nanovic asked. “We all understand Lmax. So why can’t you use Lmax?”

The wind industry frequently uses the LEQ standard.

O’Neal said the operators at a central monitoring station would be able to control noise output of the turbines by adjusting the turbines or taking them out of operation if damage would increase the noise being produced by the turbine.

“Do the operators monitor specifically for noise?” Nanovic asked.

“No,” was O’Neal’s response.

He then clarified that the operator could notice a number of changes or weather conditions that “might” affect the noise level and adjust the operation to take those issues into consideration.

“A lot of operations get monitored. Some affect sound, many do not,” O’Neal said. “But some are indirect indicators of sound.”

The next hearing has been scheduled for Oct. 30 at 6 p.m. at the Penn Forest No. 1 fire hall.