Iberdrola: Wind Noise Not A Problem

HAMMOND - A sound consultant under contract with Iberdrola Renewables told the Hammond Wind Committee Monday that professional studies show that several health concerns involving noise from wind turbines are not scientifically proven.

Mark Bastasch, P.E., a registered acoustical engineer for CH2M Hill, an Oregon-based consulting firm, told those in attendance at the Hammond Village Community Center about the findings of the International Multidiscipline Sound Advisory Panel, a group of professionals that was assembled to research concerns about the health effects of living in proximity to wind turbines.

Mr. Bastasch said that the research group looked at health concerns including infrasound and low-frequency affects, vibroacoustic disease, and Wind Turbine Syndrome.

The consultant said the panel determined that infrasound and low-frequency sounds were "not perceptible and do not exceed levels produced by natural resources."

He said that vibroacoustic disease was most common in "extremely high occupational exposure over 10 years," at sound levels of "100 dB" or greater," and that wind turbine facilities sound levels are commonly "50 to 60 dB" below this level.

As for Wind Turbine Syndrome, a "phenomenon" made popular by Dr. Nina Pierpont, who is scheduled to speak at an upcoming wind committee meeting, Mr. Bastasch questioned its validity and said it was simply "not plausible."

While several sound experts who previously spoke to the wind committee, including Dr. Paul Carr, Clif Schneider, and Charles Ebbing, have suggested taking a hard look at safety and health concerns, Mr. Bastasch said that sound and noise were "not likely an issue" for people who lease their property to the wind turbine company.

He explained that the majority of the noise emitted from turbines was "aerodynamic" in nature and made "by the trailing edge of the blade," or mechanical in nature, and created by generators and motors rotating the turbine.

The aerodynamic noise he said, is intermittent, while the mechanical noise is steady. Most commonly, he said, noise issues are dependent upon proximity to turbines, wind conditions, an opposition to the project in general, and high wind shear - or occassions when the wind is calm at ground level but high speed at higher elevations - such as at the turbine's hub.

If hired by Iberdrola to conduct wind studies in Hammond, Mr. Bastasch explained that he would measure the existing noise levels at five or six locations throughout the community every 10 minutes for two to three weeks. He said if these studies were done in the summer, they should be repeated in the winter - when foilage and tree cover is minimal.

Mr. Bastasch said it was important for any project to "foster a positive outlook" in the community and "coordinate construction times to avoid conflicts" to "ensure that the local community and land owners understand the benefits" of such a project.

Noise issues "depend primarily on personal characteristics as opposed to the intensity of the sound level," he said. The majority of issues stem from "a small propensity of sensitive persons to low-level sounds."