Air Quality Program

Air quality is important simply because we can’t avoid breathing in the air around us. Air pollutants can cause a variety of health problems - including breathing problems; asthma; reduced lung function; lung damage; bronchitis; cancer; and brain and nervous system damage. Air pollution also causes haze and smog (as in Denver’s "Brown Cloud"), reduces visibility, dirties and damages buildings and other landmarks, and harms trees, lakes and animals. It is also responsible for thinning the protective ozone layer in the upper atmosphere that protects us from harmful ultraviolet radiation from the sun, and may be contributing to the phenomenon known as global warming- the steady increase in average temperature of the global climate.

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The Environmental Quality Division (EQD) is responsible for conducting compliance inspections of air emissions sources, monitoring pollutant levels, issuing permits and constructing models of air pollutant levels in Denver. Following are brief descriptions of each of the EQD’s program areas:

Air Dispersion Modeling: The division has been using computer models to predict ambient concentrations of hazardous air pollutants. Emissions from stationary, mobile, and area-wide sources have been included in the modeling. The model predictions have been compared with actual observed concentrations where data is available to help evaluate the model and/or the emissions inventory.

Asbestos: The division responds to complaints about asbestos contamination, inspects facilities undergoing remodeling or demolition that contain asbestos, and reviews permits.

Compliance Inspections: The division inspects large and small industrial, manufacturing and commercial air pollution sources located in the City and County of Denver for compliance with state and federal laws, state air pollution permits and local city ordinances. This includes inspections of facilities that emit criteria and hazardous air pollutants, as well as air conditioning sources that emit chloro-fluoro carbons (CFC’s), which harm the earth’s protective ozone layer.

Fugitive Particulates: The EPD responds to complaints received about fugitive dust, and inspects industrial and construction sources of fugitive dust.

Mobile Sources: The division enforces the city’s smoking and idling vehicle ordinances, and promotes the use of alternative fuels and alternative transportation.

Odors: Odors are regulated in the City and County of Denver, and the entire State of Colorado, as a nuisance issue, as opposed to a health issue. One of the difficulties faced by this and other environmental health departments is that odors, like other pollutants, do not abide by jurisdictional boundaries. Denver citizens are impacted by many sources of odors that are located outside of the City and County of Denver.

Open Burning/Wood Burning:The division enforces Denver’s ban on open burning, issues permits for variances to the ordinance, and responds to complaints. The division is also responsible for enforcing Denver’s ban on wood burning on “red” pollution days, reviewing permits for variances to the wood burning ordinance, and responding to complaints. The use of chimneys, fire pits, patio or outdoor “fireplace” devices or structures are all restricted under either the open burning or wood burning ordinances.
While lawmakers and regulators play a big role in legislating and enforcing air quality standards in the Denver area, citizens and business owners can make a large impact by the choices they make every day.

Alternative Transportation: Because mobile sources of pollution such as cars and trucks make up such a large percentage of air pollution, citizens can make the biggest impact in this area. Using alternative transportation such as the bus or lightrail, carpooling, bicycling or walking can reduce the load of pollutants emitted from cars and trucks. Businesses can also help by encouraging employees to use alternative transportation or carpool.

Telecommuting/Flex-schedule: Business owners can also help by allowing employees to telecommute or flex-schedule which can reduce the number of vehicle miles traveled, and therefore vehicular air pollution. This idea has been gaining in popularity over the last decade, and should continue to be encouraged by employers.

Energy Use:
 Energy used to light and heat our homes, run our appliances, and power our cars and trucks all comes at an environmental cost. The more energy we use, the more pollution we cause. Cutting down on our consumption of energy will go a long way toward reducing air pollution. More fuel-efficient vehicles, better insulation, and energy efficient windows and lighting are just a few of the ways to reduce energy use.

Wood Burning/Open Burning: Complying with Denver’s laws regulating wood burning and open burning will continue to keep this source of air pollution in check.

Special Note For New businesses: Specific types of new businesses in Denver including manufacturing, processing or fabrication facilities, automobile recycling facilities, incinerators/ crematoriums, some types of painting operations, print shops, chrome plating operations, food manufacturing, and asphalt/concrete plants must go through the Environmental Review process. In this process, the Environmental Review Committee evaluates the new business’ plan for environmental effects. New businesses should contact the Zoning Department to start the permit process.
Fugitive Particluates: Fugitive particulates are solid airborne particulate matter emissions, which cannot be reasonably collected and are passed through a stack, chimney, vent or equivalent opening. Fugitive particulates are regulated by the Denver Revised Municipal Code, Chapter 4, Section 4-10 (b), and Colorado Air Quality Control Commission Regulation 1., III., D. State of Colorado regulation of fugitive particulates. State of Colorado Regulation of Fugitive Particulates. To report fugitive particulates call 3-1-1.

Wood Burning:
High pollution days are that period of time in which the Colorado Department of Public Health and Environment anticipates levels of carbon monoxide or particulates (i.e. wood smoke) exceeding federal ambient air quality standards or when air pollution standards are exceeded for particulates, carbon monoxide, or visibility. Each day during high pollution season will be given in a “RED DAY” or “BLUE DAY” status. On “RED DAYS”, non-phase II solid-fuel-fired devices (i.e. fireplaces and non-phase II stoves) are not allowed to be operated. Chimineas cannot be used to burn wood or solid fuel in the City and County of Denver, and only Pellet Stoves approved by the Colorado Department of Public Health can be used on blue days. Learn more about Residential Burning rules here.

Idling Vehicles: Engines Off! Denver is a City & County of Denver program working to improve air quality by reducing vehicle idling, a significant source of air pollution. “Idling” is leaving your engine running while your vehicle is parked or not in use. While some vehicle idling is unavoidable, such as in traffic congestion or at a stoplight, most drivers end up voluntarily idling their vehicles at various times—in drive-through lines, waiting to pick-up passengers, while stopped to talk on the phone, and at train crossings, for example. As little as 5-10 minutes of idling each day can result in wasting one to two tanks of fuel per year due to idling. If that doesn’t get your attention, then how about this: 1 minute of idling produces more carbon monoxide than the smoke from 3 packs of cigarettes! Learn more about Idling Laws Here

Odors: "Odors shall be deemed an unlawful nuisance if one (1) or more odorous air contaminants leave the premises upon which it originated for a period exceeding thirty (30) minutes duration and interferes with the reasonable and comfortable use and enjoyment of property." Odors are regulated in the City and County of Denver, and the entire State of Colorado, as a nuisance issue, as opposed to a health issue. One of the difficulties faced by this and other environmental health departments is that odors, like other pollutants, do not abide by jurisdictional boundaries. Denver citizens are impacted by many sources of odors that are located outside of the City and County of Denver. Call 3-1-1 for more info or to report an odor. Learn more about Odor Regulation Here

It shall be unlawful for any person to engage in or allow open burning within the city except when a written permit has been issued by the Denver Department of Environmental Health.

Open burning of yard trash (leaves, branches, twigs, grass cuttings, household trash, paper/cardboard, etc.), materials from residential/commercial demolition and land clearing debris is not allowed in Denver. This restriction may also be applied statewide. For statewide regulations visit: Colorado Department of Public Health and Environment Regulation Number 9

Definition of Open Burning: Open burning is any fire or smoldering (burning and producing smoke without flame) where any material is burned in the outdoor air, or in a receptacle other than a furnace or other equipment connected to a stack or chimney. Examples include campfires and bonfires.


For several years the Denver Metro area has often had bad air days, which violate Federal and/or state air quality standards. The metro area was designated as a “non-attainment” area for particulate matter. In order to maintain good air quality and good visibility and to remain an “attainment” area, it is necessary to limit open burning.

Barbeques: The non-commercial cooking of food (back yard barbecue) is exempt from the ordinance.

Open Burning Permits: Open burning permits are rarely issued to individuals. Open burning permits are issued for fires used in Fireman ship training and fire extinguisher training. Denver Department of Environmental Health, Environmental Protection Division, will review applications, which will protect the ambient air to the greatest extent, the purpose and use of the fire and the availability of reasonable alternatives.

Obtaining An Open Burning Permit: To apply for a permit, call 3-1-1.
Mobile Sources Program Mission Statement: The mobile sources program exists to protect public health by reducing air pollution caused by transportation.

Background and History: In 1972, the number of days that exceeded the federal criteria pollutant levels for carbon monoxide had topped out at 125. Due to the growing concern about pollution generated within the city by cars and trucks (mobile sources), serious efforts began to decrease the visible, physical, health, and environmental effects of transportation. One of the first efforts at decreasing vehicular air pollution began in 1979, when city council passed the smoking vehicle ordinance making it against the law to operate a vehicle with visible tailpipe emissions within Denver boundaries.

Throughout the 1980's, stricter federal emission guidelines for vehicles led to several technological advancements in engine design including catalytic converters, fuel injection, and oxygen sensors. Although these advances significantly contributed to reducing the days Denver exceeded the federal standards--by 1990 only three exceedences were reported--Denver was still classified as non-attainment for carbon monoxide by the EPA.

The non-attainment status provided the impetus to pass additional legislation during the 1990's to further reduce mobile source pollution. The idling vehicle ordinance was passed in 1990 prohibiting vehicles within the city limits to idle more than 10 minutes in any one-hour period of time.