Ontario Noise Regulations – pre GEA

Ontario, like most other governments in the world, recognizes the problems of noise in our environment and has a set of rules and regulations in place to minimize health and annoyance problems. And surely, you would think, these rules would protect nearby residents from excessive noise from a wind farm. Sadly, experience so far shows you would be wrong, even assuming the rules were actually being followed, which in some cases they are not. Like most non-local governments, Ontario uses dBA-related rules, which I discuss below, along with some minimum setbacks.

This page relates my understanding of the noise regulations that wind farms have to meet, and any corrections would be appreciated. It all starts with NPC-232, which covers noise from stationary sources in rural environments. For certain types of noise (which certainly includes the noise that wind farms produce) there’s some additional requirements in NPC-104. And finally there’s the MOE Interpretation for applying the rules in NPC-232 and NPC-104 specifically for wind farms.

There’s some additional rules that are not so important or do not apply to rural areas.
These include NPC-101 (Definitions of Terms), NPC-102 (Instrumentation), NPC-103 (Procedures) and NPC-205 (Urban Areas). Links to all of these are below.

NPC-232 starts very aggressively, with the sound level limit at a point of reception [defined as 30m from, for example, a house] must be established based on the principle of “predictable worst case” noise impact. In general, the limit is given by the background sound level at the point of reception. In other words, in the “predictable worst case”, you can’t make any noise above the normal background level. What constitutes “predictable worst case” has been, predictably, interpreted differently depending on one’s interests. But later on, there’s an exclusion if the noise you produce is below certain absolute limits.

TABLE 232-1 – One Hour Leq by Time of Day

Time of Day One Hour Leq (dBA)
0700 – 1900 45
1900 – 2300 40
2300 – 0700 40

Recall our earlier discussion on Leq, where louder noises are weighted much higher than softer ones. Plus, as we shall see, there’s additional restrictions on certain types of noise. Still, using an average lessens the protection by quite a bit.

NPC-232 allows that the noise shall be obtained by measurement or prediction. It does not mention what “prediction” consists of. It does not require the noise to be measured, except in response to a complaint. In the case of a wind turbine, it would pretty difficult to measure anything until the turbine was built and put into operation, along with all its neighbors.

Next, NPC-104 specifies adjustments that must be made for certain types of noise that are more intrusive than background-type noises. One of these types, cyclic, certainly applies to wind turbines: If a sound has an audible cyclic variation in sound level such as beating or other amplitude modulation then the observed value shall be increased by 5. There are no stated exceptions to this penalty. So in essence the 40 bBA limit now becomes 35 dBA. So far, so good – even better!

Finally we get to the MOE Interpretation, which has been developed in order to provide consistency in the submissions and to streamline the review and approval process.
Unfortunately, it does more than “provide consistency”, it also loosens up the rules as lobbied for by the wind industry. First, it clarifies “point of reception” so that it seems to include any of the following existing or zoned for future use premises: permanent or seasonal residences,[…] Unfortunately, on Wolfe Island, as an example, the plans consider only existing residences, so I’m not sure what happens if turbine noise is over the limits on a empty parcel, which then might well become unbuildable. There’s also the problem that the limit is applied at an existing residence. What about the rest of the neighbor’s property? Does this then restrict severances, or additional buildings? So far, the answer seems to be that it does. Next, it undoes NPC-104’s 5 dBA penalty with no justification or explanation at all. John Harrison has been arguing this point with anyone who will listen, and this letter contains a concise explanation of the NPC-104 issue.

There used to be a “masking” allowance, where higher noise limits were permitted in windier conditions, the theory being the noise from the wind itself would mask the noise from the turbines. Van den Berg’s first contribution to the discussion was to debunk this theory, and finally, with the GEA, Ontario sort of undoes the masking allowance, but in a complicated fashion that almost certainly was due to wind industry influence. John Harrison has written a fine commentary that explains what Ontario has done, and I’ve taken his work and dumbed it down for the rest of us.

UPDATE, June 2009. Ontario has passed the Green Energy Act, which promises to remake a large part of these rules. I’ve heard (1)preening from the government about how they are protecting the neighbors, (2)hype from the adoring media, and (3)whining and wailing from the industry. But for the largest (and most problematical) projects, nothing much has changed at all. The GEA is analyzed here. I have submitted this letter to the MOE regarding their proposed regulations. John Harrison has submitted this letter about the proposed noise regulations. Bill Palmer has submitted this letter with pages 2-8 detailing his objections to the proposed noise regulations.

Graph of Ontario’s Wind Turbine Noise Limits

This chart shows a summary of the limits that all Ontario wind farms must adhere to. For rural areas (the pink dots) the limit is 40 dBA up to wind speeds of 6 m/sec, increasing to 53dBA at 11 m/sec. Updated in October 2008, now only allows 51 dB.


Below are copies of the significant Ontario Noise Regulations.

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