Developing an Odour Policy Framework
In 2005, the Ministry of the Environment (MOE) announced that it would be developing an Odour Policy Framework, which would clarify requirements when industry applies to obtain an air approval certificate and ensure the selection of appropriate odour abatement options. It would also help MOE deal with odour complaints.
Although MOE is still developing the framework, some of the technical aspects have been settled, including the method for establishing odour-based air quality standards for compounds and the time period over which an odour must be perceived in order for the odour-based standard to apply. In addition, it has been decided that the new odour-based standards will apply only to locations “where human activities regularly occur at a time when those activities regularly occur”; this is a new factor in applying a point of impingement (POI) air standard.
In August 2007, the Ontario government amended O. Reg. 419/05, Air Pollution – Local Air Quality, under the Environmental Protection Act (EPA), to include new odour-based standards for three compounds using the new POI criteria for odours. (For the complete text of this review, please refer to 2007 Review of decision on odour policy framework.)
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Regulation of air quality
From the 1970s, the EPA, the General – Air Pollution regulation (R.R.O. 1990, Regulation 346) under the Act, and related policies have been used to manage air quality in Ontario. Air quality standards, guidelines and ambient air quality criteria (AAQC) were based on health and environmental considerations, but were sometimes relaxed due to socio-economic and technical considerations. In 2005, O. Reg. 419/05 was passed, replacing and enhancing parts of Reg. 346 and introducing effects-based air quality limits based on health and environmental impacts alone.
MOE decided to carry forward the odour-based standards from Reg. 346 while it develops an Odour Policy Framework. The first position paper on the Odour Policy Framework was released in April 2005, and the second position paper was released in June 2006 for public consultation. For the ECO’s review of O. Reg. 419/05, refer to our 2005-2006 Annual Report, pages 89-96.
Managing odour is challenging
Due to great variability in individual odour perception and preferences, as well as technical difficulties in attempting to quantify odour levels, it is challenging to set enforceable standards. One person’s perception of odour can be quite different from another person’s and can vary over time. Some people can become less sensitive after repeated exposures to an odour, while others become more sensitive and less tolerant. In addition, some people may enjoy a particular odour ( e.g., the smell of roasting coffee or deep-fried chicken), while others may find the same odour annoying or sickening and complain of a wide variety of health effects. The courts have ruled that medical evidence, such as doctors’ notes, provides strong support for claims of human health effects when an adverse effect is subjective in nature.
Further complicating the assessment and control of odour problems, one odour may mask another odour, weather and wind patterns can affect dispersion, and the time of day and season of the year can influence whether or not anyone complains about an odour. Odours emitted on a winter’s night in a relatively unpopulated area are unlikely to result in complaints, while strong odours wafting through a residential neighbourhood on a warm summer afternoon will surely engender dozens of complaints.
In general, MOE staff do not respond to odour complaints. MOE has advised the ECO that it places more emphasis on repeated complaints from a source and refers some odour complaints, such as odours from a residence (e.g., roof tarring) or a farm, for follow-up (municipalities, OMAFRA, etc.). MOE also advised that it does “follow up on complaints, and documents complaints and abatement strategies in a ministry database.”
Summary of the two Position Papers and Public Consultation
The first position paper (PA05E0007) on the Odour Policy Framework was posted on the Registry for a 60-day comment period and the second position paper (RA06E0006) was posted for a 102-day comment period. In the two position papers, MOE outlined the components of a proposed Odour Policy Framework and explained that the impact of an odour event can be influenced by five factors – the frequency (F), intensity (I), duration (D), offensiveness (O) and location (L) of the event. All of the FIDOL factors can be measured quantitatively, except offensiveness, which is described using subjective terms, such as fishy, oily, sewage, garlic, rotten eggs, bakery, etc. Many commenters were very concerned that the subjective nature of odour would pose some significant management challenges and suggested that odour should not be regulated. In contrast, a member of the public advised that “air free from offensive and sickening odours” is a right, not a privilege.
MOE discussed two options for setting short-term odour-based AAQC for compounds using data from the American Industrial Hygiene Association and ORTECH studies. Under Option 1, the AAQC for each compound would refect the level at which 50 per cent of the general population can detect the odour. Under Option 2, the AAQC determined under Option 1 would be adjusted upwards or downwards based on the level at which 10 per cent of the general population would be expected to complain. Option 2 would result in a more stringent AAQC for a more offensive odour and a less stringent AAQC for a less offensive odour. Option 1 was chosen by MOE as the basis for setting odour limits. The Region of Peel preferred Option 2, noting that many people would still be able to detect an odour under Option 1 conditions and potentially complain. MOE explained that highly offensive and high-intensity odorous compounds, such as total reduced sulphur, would be subject to odour-based standards, which are enforceable; whereas, less offensive and intense compounds, such as toluene, would be subject only to guidelines, which are not generally enforceable.
According to an informal survey done by MOE, people will tolerate an offensive odour for only about 10 minutes before complaining. On this basis, MOE decided to make it an offence to exceed a 10-minute odour-based standard for a compound at points of impingement frequented by humans (including residences, schools and day care centres) more than 13 times per year. In response to some comments, MOE agreed that the POI should only refer to locations where people spend significant amounts of time. It did agree to the suggestion that only exceedances resulting in complaints should be counted and the time of day and year be considered. The Region of Peel, however, thought that the maximum number of allowed exceedances before it is deemed an offence has occurred was too high.
Although the majority of odour complaints are caused by mixtures, which are comprised of multiple compounds that may be interacting with each other, affecting the overall odour properties, MOE decided that more work was required before it could set appropriate limits for mixtures. In two related decisions, MOE amended O. Reg. 419/05 to include 10-minute odour- based standards for three highly odorous substances or classes of substances: total reduced sulphur (TRS), hydrogen sulphide (H2S), and mercaptans. Facilities will be required to comply with the new standards by February 1, 2013 (at the latest) at those POIs “where human activities regularly occur at a time when those activities regularly occur” based on actual measurements. Since many commenters were concerned that the concept of sensitive receptors (locations where human activities occur) would introduce ambiguity into the process, MOE agreed to develop guidelines for identifying POIs “frequented by humans.”
ECO Comment
The ECO commends MOE for taking on this challenging and important initiative. MOE has made some significant decisions that will influence how odour is managed. The benefits may not be immediately apparent, but are likely to accrue long-term. Effective odour management is becoming increasingly important as residential development and other sensitive uses are located closer to odour-producing facilities in order to accommodate growth. Also, odours are not just annoyances – they can have health effects and indicate serious air emissions are occurring. Consideration of the FIDOL factors will enable MOE to set odour-based limits that more closely reflect a contaminant’s odorous nature and should reduce the number of complaints eventually. A stronger regulatory and policy framework will make it easier for MOE to add enforceable odour-based requirements to air approvals and to investigate odour complaints. However, the position papers make no mention of a formal odour complaint management system, which the ECO believes is required, and without which, MOE will not know if it has achieved its objective of reducing the number of odour complaints overall.
The ECO also believes that land-use planning decisions must include greater consideration of odour impacts. Appropriate siting of residential areas and other sensitive uses, and odour-emitting facilities, taking into consideration prevailing winds, land forms, other odour-emitting sources in the area and separation distances, is among the most effective tools available to minimizing or even preventing odour complaints.
When O. Reg. 419/05 was implemented in 2005, the ECO was concerned that MOE may lack the capacity to manage and implement the new air regulation. Completing the odour policy framework and implementing and enforcing odour limits add to MOE’s workload. The ECO will continue to monitor the operating budgets for MOE’s Air Program and enforcement activities, both of which were increased in 2008/2009, and progress on updating air quality standards and odour-based limits.
| This is an article from the 2007/08 Annual Report to the Legislature from the Environmental Commissioner of Ontario. |
Citing This Article:
Environmental Commissioner of Ontario. 2008. "Developing an Odour Policy Framework." Getting to K(No)w, ECO Annual Report, 2007-08. Toronto, ON : Environmental Commissioner of Ontario. 115-118.
