Robert W. Rand, INCE RAND ACOUSTICS 65 Mere Point Road Brunswick, Maine 04011
E-mail: rrand@randacoustics.com Fax: 206.339.3441 Tel: 207-632-1215
November 8, 2012 G.F. (Junior) Croes GFC Holding N.V. Subject:
Background Sound Levels Urirama Wind Project
Dear Junior, The KEMA report of June 2012 indicates that background sound levels near the proposed project are in the range of 43-50 dBA (see KEMA data in figure below). However, review of the KEMA instruments indicates the data probably contained wind noise on the microphone element, which does not represent the background sound levels. The windscreen KEMA used was a RION WS10 which allows the wind to strike the microphone element at wind speeds above 3-4m/s, producing wind "self-noise" that is not the sound level. The KEMA reported background levels are shown below with the self-noise specification from RION for the WS-10.
I acquired a preliminary set of background sound levels on October 25 and November 1, 2012 in the nearby residential area, using a calibrated Type 1 meter (Larson Davis 824 w/GRAS 40AN microphone) and an ACO WS-7 untreated 7-inch (18 cm) wind screen. While winds were
-1-
Advisory Letter: G.F.Croes – Urirama background sound levels
November 8, 2012
present during the two test periods, at times the winds dropped away briefly at the meter. I stood with the meter for some time and observed background noise levels when there was no wind directly on the meter (shown as RA Background Levels). The results were lower than the "selfnoise" for the WS-7 because there was no wind noise on the microphone: 24 dBA at 2-4m/s and 31 dBA at 7-8m/s. These are much lower than the 43-50 dBA levels asserted by KEMA. Why is it important to measure the background sound levels? People respond negatively to increases in sound level due to a new intrusive sound over the background. Industrial facilities should be, and are, designed to produce no reaction. As the ISO has documented, widespread community complaints emerge when new intrusive noise is 5-10 dBA over the normally occurring quiet background sound levels. As a preliminary determination: with background sound levels at 31 dBA or lower, it would be correct to design for "no reaction" by limiting Urirama Wind Project noise levels to existing background sound levels at nearby homes using the available noise control option, distance. However if the project were to use the 50 dBA levels asserted by KEMA, and intrusive wind turbine noise levels exceed background sound levels by several dB or more, a negative community reaction is likely, because the KEMA levels do not represent the community setting. Please feel free to contact me if you have questions or need additional discussion. Respectfully Submitted,
_______________________ Robert W. Rand, Member INCE Measurement locations and levels:
-2-
Advisory Letter: G.F.Croes – Urirama background sound levels
November 8, 2012
Qualifications Robert Rand is a professional consultant in acoustics with community noise reaction and industrial noise assessment experience dating back to 1980. His experience includes ten years as project engineer and principal noise consultant for Stone & Webster Engineering Corporation in Boston. Mr. Rand is a Member of the Institute of Noise Control Engineering (INCE) and committed to the INCE Canon of Ethics which reads, "Hold paramount the safety health and welfare of the public." Mr. Rand has investigated IWT noise since early 2009 and has a clear understanding of why neighbors are complaining about IWT noise when IWTs are built too close to homes. He has experienced the same negative health impacts (dizziness, nausea, cloudy thinking, inability to concentrate) reported by neighbors near wind turbines, while assessing wind turbine noise in Falmouth, Massachusetts in April, 2011. He also experienced headache and dizziness while assessing operating wind turbine facilities in New York and Aruba in 2012. His investigations include sound level measurements and talks with neighbors made at several operating IWT sites for 100kw, 660kw, 1.5MW, 1.6MW, 1.65MW, and 3MW sizes under a variety of wind speed conditions in Massachusetts, Maine, New York, and Aruba. Mr. Rand provided expert testimony to the Maine Board of Environmental Protection (July 2011) along with other concerned professionals including Dr. Nissenbaum and Stephen E. Ambrose, Member INCE, after which the BEP lowered the maximum noise limits allowed for wind turbines. Mr. Rand made expert testimony to the Environmental Tribunal of Ontario in 2012 regarding his wind turbine noise research in Falmouth, Ma with his colleague Mr. Ambrose. Mr. Rand has published three peer-reviewed professional papers on the effects of wind turbine noise [1,2,3]. His recommendations to communities on wind turbine noise over the last three years are grounded by research documents published by the US Environmental Protection Agency (EPA) and WHO [4,5]. 1 Robert W. Rand, Stephen E. Ambrose, Carmen M. E. Krogh, "Occupational Health and Industrial Wind Turbines: A Case Study", Bulletin of Science Technology Society October 2011 vol. 31 no. 5 359-362. 2 Robert W. Rand, Stephen E. Ambrose, Carmen M. E. Krogh, "Wind Turbine Acoustic Investigation: Infrasound and Low-Frequency Noise—A Case Study", Bulletin of Science Technology Society Published Online before print, August 17, 2012. 3 Stephen E. Ambrose, Robert W. Rand, Carmen M. E. Krogh, "Falmouth, Massachusetts wind turbine infrasound and low frequency noise measurements", Invited Paper, Noise-Con 2012. 4 "Information On Levels Of Environmental Noise Requisite To Protect Public Health And Welfare With An Adequate Margin Of Safety", EPA 550/9-74-004, March 1974. 5 WHO, Night Noise Guidelines For Europe, 2009. ISBN 978 92 890 4173 7, and WHO, Night Noise Guidelines For Europe, Final implementation report, 2007, Grant Agreement 2003309.
-3-