Ontario health, environment officials agree: on-the-ground sound measurement is needed near wind farmsNews, Wind turbines Add comments
Over the past week or so, two reports from Ontario have spurred a fair amount of notice and comment among those following wind development issues. First, the provincial health office responded to the public’s concerns about health problems reported by some wind farm neighbors, framing its answer carefully and narrowly: “According to the scientific evidence, there isn’t any direct causal link between wind turbine noise and adverse health effects,” said Dr. Arlene King, Ontario’s Chief Medical Officer, as reported by the Vancouver Sun. Since the report’s focus was to asses peer-reviewed science, its authors did not incorporate any reference to the experiences or changes in sleep patterns or health of real-life neighbors of wind farms who have reported negative impacts since the turbines began turning. It is no real surprise that the sound levels near wind farms aren’t loud enough to directly cause physiological damage or effects, though it seems clear that annoyance and sleep disruption may well contribute to health effects in some people; the report acknowledges the likelihood of some annoyance, and notes too that while low-frequency sound is below generally perceptible levels, and generally no louder than naturally-occuring low-frequency sound sources, some people who hear these frequencies better than most may be bothered. While the report itself is brief and lacks the detail of the recent industry-funded AWEA/CanWEA report, which reached similar conclusions in addressing the same narrowly-focused questions, King’s report frames the results with two crucial but under-reported observations:
- By way of introduction, the report explicitly states a simple fact that is rarely acknowledged: “Little information is available on actual measurements of sound levels generated from wind turbines and other environmental sources. Since there is no widely accepted protocol for the measurement of noise from wind turbines, current regulatory requirements are based on modelling.” Indeed, sound models are used to determine what distance a turbine needs to be from nearby homes in order to meet local statutory noise limits (which stand at 40dB in Ontario).
- And in its final words, the report stresses the corollary to this observation: “The review also identified that sound measurements at residential areas around wind turbines and comparisons with sound levels around other rural and urban areas, to assess actual ambient noise levels prevalent in Ontario, is a key data gap that could be addressed. An assessment of noise levels around wind power developments and other residential environments, including monitoring for sound level compliance, is an important prerequisite to making an informed decision on whether epidemiological studies looking at health outcomes will be useful.”
Actual rural ambient noise levels are often very low, so that wind farm noise becomes bothersome at lower levels than industrial or transportation noises prevalent in urban and suburban areas; and, as noted in the body of the report, most of the case studies and other reports of health effects lack any clear information on how loud the turbine sounds are in the homes of those being affected. So while this report is in large part another seemingly definitive, yet stubbornly partial, assessment of the health effects reported near wind farms, it also lays the groundwork for much-needed on the ground assessment of noise patterns around wind farms. (See this more recent post, regarding a section on community health and disruption that was omitted in the final draft of this report. And see this critique of the CMOH report, written by several doctors from Canada, the UK, and the US who have been advocating for closer study of these issues)
On a similar note, Ontario Ministry of Environment officials confirmed this week that they do not have the capability to record or assess the noise near wind farms where noise complaints arise. According to the Windsor Star, “Although hundreds of wind turbines have already been built in Ontario, Michael Parker, district manager for the environment ministry, said staff have not yet been given noise-monitoring equipment. The ministry is responsible for ensuring that wind turbine noise reaching a residence doesn’t exceed 40 decibels, he said. If a complaint about turbine noise is made to the ministry, two environment officers are sent to the area to listen for the noise and contact the turbine owner, Parker said, noting that the ministry could still intercede with turbine owners even without hard data on the noise levels. In some cases, turbine speeds have been scaled back or the turbine shut down completely.” In January, the Ministry of Environment issued two Requests for Proposals seeking advice and technical standards to use in assessing wind farm noise. The RFPs said that “The Ministry requires a consultant to assist in the development of a measurement procedure to assess noise compliance of existing wind farms with the applicable sound level limits,” noting that “Unlike typical industrial noise sources, measurement of audible noise from wind turbines in general raises technical challenges.” At that time, the Ministry acknowledged that its “Noise Guidelines for Wind Farms…do not contain a measurement method for assessing the actual noise impact.”