Odor is defined in DEQ's air pollution control rules as "the sensation resulting from stimulation of the human sense of smell." Odor is a sensitive subject because perception of odors is subjective. What smells bad to one person may not offend another. Our sensitivities and reactions to odors are influenced by personal preferences, opinions, experiences, and the varying sensitivities of our olfactory systems.
In an effort to respond to citizen concerns over odors, the Idaho Legislature has enacted laws directing the Idaho State Department of Agriculture (ISDA) and DEQ to take certain actions to minimize the impacts of odors on the environment and public health. Public health districts in Idaho also play a role in addressing odor problems.
Regulation of Odors
Odors are regulated by a number of state laws, rules, and agreements, depending upon the odor's source and potential impact on the environment and public health. Some regulations address odors generated by specific types of operations such as commercial agricultural operations, swine and poultry facilities, dairies, solid waste facilities, and rendering plants and associated processes. Other regulations are broader in scope and may be applied to odors when they are considered to be a nuisance or if they create a public health hazard or cause air or water pollution.
Just as odors are regulated by several regulations, responsibility for enforcement and for resolving odor complaints is shared among several state agencies and local governments. ISDA and DEQ are the two primary state agencies assigned by the Idaho Legislature to oversee certain odors. City and county governments have jurisdiction in some cases.
DEQ's job is to protect public health and Idaho's natural resources from the impacts of pollution. If an odor poses a threat to human health or causes pollution, DEQ takes the lead in resolving the odor problem. Unpleasant odors often result from substances that do not present a health hazard, however. If an odor does not represent a health hazard, DEQ's regulatory authority may be limited.
...if the odor is created by a business or industry regulated by DEQ, in most cases, DEQ will investigate and work to resolve the odor complaint through development, modification, and/or enforcement of an odor management plan. Minimizing odor is often a matter of combining good housekeeping practices with technological improvements. DEQ-regulated sources include facilities with DEQ-issued air quality operating and/or wastewater land application permits.
- Rules for the Control of Air Pollution in Idaho (IDAPA 58.01.01)
- Water Quality Standards (IDAPA 58.01.02)
...if the odor is created by an agricultural operation, it is ISDA's responsibility to address the problem. Pursuant to an agreement between DEQ and ISDA, odor complaints specific to animal feeding operations, including dairies, are handled by ISDA. Responsibility for addressing odor problems at large swine facilities is DEQ's responsibility, however.
- Agriculture Odor Management Act (Idaho Code §25-38)
- Rules Governing Agriculture Odor Management (IDAPA 02.04.16)
- Beef Cattle Environmental Control Act (Idaho Code §22-49)
- Rules of the Department of Agriculture Governing Beef Cattle Animal Feeding Operations (IDAPA 02.04.15)
- Idaho Health and Safety Act (Idaho Code §39-1)
- Rules Regulating Swine Facilities (IDAPA 58.01.09)
...if the odor is created by a solid waste facility, it is the responsibility of the health district in which the source is located to resolve the situation, under an agreement between DEQ and the health districts.
- Solid Waste Management Rules (IDAPA 58.01.06)
- Memorandum of Understanding between DEQ and Public Health Districts
...if the odor is created by pets or the presence of other livestock in residential areas, the complaint is referred to the appropriate city or county authority for regulation under local zoning regulations.
How DEQ Deals with Odor Complaints
DEQ's Procedures for Responding to Odor Complaints is designed to ensure that odor issues are handled in a responsive, timely manner by the appropriate governmental unit. These procedures outline the process DEQ follows to resolve odor complaints and to ensure compliance with odor regulations. Odor complaints are addressed with appropriate and increasing intervention, up to and including filing of civil action in certain circumstances.
Health Impacts of Odors
Odors are a nuisance, but are they a public health hazard? The current state of knowledge suggests that it is possible for certain odorous emissions to have an impact on physical health. The most frequently reported symptoms attributed to odors include headache, nausea, hoarseness, cough, nasal congestion, palpitations, shortness of breath, stress, drowsiness, alterations in mood, and eye, nose, and throat irritation.
Odors are a complex mixture of gases, vapors, and dust. The potential health impact of any odor depends upon the concentration of odorous emissions as well as the frequency and duration of exposure. A variety of methods are available to quantify odorous emissions including olfactometry, gas chromatography, and a device known as an electronic nose. More research and scientific data are necessary to quantify health symptoms from the types of exposures experienced by neighbors downwind of livestock or wastewater operations compared to those who work day in and day out at these kinds of facilities.