This is very interesting, though may get blown out of proportion: in April 2010 a District Environmental Officer submitted a memo to his Ontario Ministry of Environment superiors that offered detailed comments about the field realities he observed, in relation to the proposed Provincial wind farm siting regulations. These regulations currently guide Ontario siting, and call for at least a 550m setback, and sound levels at nearby residences of 40dB or less; the memo cites observations on the ground to recommend limits of under 35dB, and perhaps as low as 30dB.

What’s striking about Cameron Hall’s comments is that his concerns about the 40dB limit are largely similar to those of an increasing number of acousticians who have also been coming to a consensus that lower sound limits may be necessary in many rural locations. In particular, Hall noted that the regulatory 40dB limit should be adjusted downward 5dB due to the pulsing swish of turbine noise, and that it may be necessary to also factor in the acknowledged 3-5dB of error that can occur in sound modeling and the slightly variable sound output of the turbines. Combining these, Hall writes that “it appears reasonable to suggest the setback distances should be calculated using a sound level limit of 30 to 32 dBA at the receptor, instead of the 40dBA sound level limit.”

In addition, Hall stresses another factor often brought up by those trying to understand why 40-45dB turbine noise is stirring up so many complaints: the fact that rural soundscapes in his district are often as quiet at 20-25dB, and noise intrusions should be kept to less than 10dB over that; this leads Hall to similarly suggest that “An intrusion of 7 to 10 dBA above background in our case would result in sound level limits at the receptors in the range of 30 to 33 dBA. As noted earlier, observations by several Provincial Officers indicate sound levels at the receptor in the range of 30 to 32 dBA would not cause or be likely to cause adverse effects in the opinion of the Provincial Officers.”  You can download Hall’s memo here.

It’s great to know that some on-the-ground Environmental Officers are noting the same shortcomings in current noise standards as those being explored by acousticians working to understand the excessive complaints coming from noise levels that would in most circumstances be considered moderate. The existence of this memo doesn’t necessarily imply any particularly nefarious government conspiracy, though. It’s not surprising that, among Ministry of Environment staff, there was a range of opinions about the best approach to wind farm regulation, and there’s no indication at this time whether this memo was even passed further up the “chain of command” from the Guelph District Office.

The memo was obtained via FOIA by the active anti-wind group Wind Concerns Ontario, and is the lead document in their new “WindyLeaks” project; their commentary calls the memo “incriminating,” and is headlined “McGuinty Liberal Ministers Hide Wind Turbine Truth.”  While I am all in favor of tighter noise standards around wind farms, and agree with Hall that 40dB is not protective of rural quality of life, I don’t necessarily think that the fact that government policy didn’t align with the most cautionary stance means that those involved are hiding the fact that some staffers disagreed with the final policy.  As Jonathan Rose, a spokesman for Environment Minister John Wilkinson, said “All this information was already examined by the Environmental Review Tribunal, an independent, quasi-judicial body which ruled that wind farm projects in Ontario are safe.” He added, “We have struck the right balance.” (Ed. note: in fact, the tribunal, while denying a specific appeal, urged further study of indirect health impacts, of which it said, “It is obvious that new ground is being broken and that important questions are being raised.” The tribunal stressed the evidence shows there are risks and uncertainties in wind farm siting, and hoped that “further debate focuses on the most appropriate standards rather than ‘yes or no’ arguments about whether turbines can cause harm.” For AEI’s full assessment of the tribunal decision, see this earlier post.)

In Ontario, the anti-wind movement is often aligned with conservative political resistance to renewable energy in general, and government renewable energy standards in particular (as reflected in the partisan headline of the WCO commentary). This creates a wind debate that is far more complex than the simpler question of what the proper noise standards should be. I don’t really want to wade into the full scope of Wind Concern Ontario’s objections to wind development, and I recognize the valuable role that vocal advocates and gadflies always play in keeping the public dialogue moving forward.  I certainly am glad to see this memo, which affirms that the concerns of acousticians I’ve been following in recent months are shared by some in government agencies as well.  I just see the memo as more illuminating than incriminating.

For more of AEI’s perspective on community responses to wind farm noise, including our more recent 50-page report Wind Farm Noise 2011, see:
http://www.acousticecology.org/wind/

(note: I have been unable to confirm whether Cameron Hall is male or female.  I went with a press report that used “he”, but have seen no clear indication whether this is true.  If Cameron is female, I apologize…)