Oakfield Wind: Might The Model Be Low?

Sound level versus distance on semi-log paper has been for many years one of the best ways to review noise emissions and potential impacts from a power generation facility. Recently a comparison was developed from the Oakfield Wind Facility predictions at nearby residences and the existing Mars Hill data compiled for the Maine DEP. The resulting chart is shown below. It raised several points right away.

– Both sites use the same wind turbine, the GE 1.5MW. Is it appropriate to compare the Oakfield prediction to actual noise emissions documented at Mars Hill?

– Are the predicted noise levels at nearby residences in the ranges associated with sleep disturbance as well as adverse health impacts for risk groups (children, elderly, those with pre-existing conditions or disease), according to peer-reviewed medical evidence compiled and published by the World Health Organization in their Night Noise Guideline (NNG) of October 2009?

– Is the existing Maine DEP night noise limit of 45 dBA adequate to protect the public health in the area?

– Does the data comparison to WHO health thresholds suggest that a setback distance of over two miles would be needed to minimize sleep disturbance and prevent adverse health impacts for risk groups?