WindAction | Mass DEP on turbine sound survey methodology

Mass DEP on turbine sound survey methodology

Massachusetts Department of Environmental Protection - June 30, 2011

This letter, prepared by the Massachusetts Department of Environmental Protection, details guidelines to the Town of Falmouth on conducting background noise levels. The Mass DEP explains its preference for sound surveys to be attended by trained personnel who can ensure the readings recorded by the equipment are not contaminated by transient noise sources.

Excerpt:

It is important to note that in most cases, MassDEP relies on attended sound observation studies so that sound observations/decibel readings can be attributed to particular sound sources and so the Lmax used for comparison to L90 background is from the sound source in question and not some other sound source. A limitation of attended studies is that they are short-term and provide only small amounts of data for impact evaluation and compliance decisions-making. Long-term unattended studies, like the one performed by HMMH, can provide substantially more data so impact evaluations can include different sound source operating conditions and more times of day, but can leave questions unanswered regarding Lmax data observations and data capture related to the specific sound source in question.