Advisory

  • The opportunity to reach jobs, services, housing, recreation, shopping, and entertainment within a reasonable time frame, and without being impeded by physical, social, or economic barriers. Enhancing mobility is one way of providing improved access.
  • The opportunity to reach jobs, services, housing, recreation, shopping, and entertainment within a reasonable time frame, and without being impeded by physical, social, or economic barriers. Enhancing mobility options is one way of providing improved access. 
  • Tiny solid or liquid particles dispersed within a gas. Often used synonymously with particulate matter (PM) and may or may not be visible to the naked eye.
  • The Air Pollution Control Division (APCD) is a branch of the Colorado Department of Public Health and Environment that improves the quality of the air by enforcing pollution laws, reviewing permits, performing compliance inspections, monitoring outdoor air, and overseeing the automobile(...)
  • An air pollution emissions budget sets the maximum quantity of emissions permitted from all sources of air pollution during a specific time period.
  • Established in 1973 under section 25-7-109 of the Colorado Air Quality Control Act, the AQCC is an eight-membered appointed commission with authority to adopt, modify or repeal emission control regulations which require the use of effective practical air pollution controls.
  • The U.S. AQI is the Environmental Protection Agency's (EPA) index for reporting air quality for five major air pollutants regulated by the Clean Air Act. Each of these pollutants has a National Ambient Air Quality Standard set by EPA to protect public health: ground-level ozone, particle(...)
  • Air quality models use mathematical and numerical techniques to simulate the physical and chemical processes that affect air pollutants as they disperse and react in the atmosphere.
  • The Air Quality System (AQS) collects reported air quality data from over thousands of state, local, and tribal air monitors and makes it available for the public to review.
  • The gasoline-only no diesel vehicle emissions testing program for Colorado. See www.aircarecolorado.com for more details.
  • Any motor fuel other than ordinary gasoline, especially those that result in lower levels of air pollutants (e.g., reformulated gasoline, natural gas and biodiesels).
  • Ammonia is most commonly emitted from agricultural activities, landfill sites, sewage facilities and composting of organic materials. Health effects from high levels of exposure to ammonia can cause irritation of the throat, lungs and eyes.  Ammonia is a colorless gas with a pungent odor,(...)
  • Acronym for Air Pollution Control Division (APCD) which is a branch of the Colorado Department of Public Health and Environment that improves the quality of the air by enforcing pollution laws, reviewing permits, performing compliance inspections, monitoring outdoor air, and overseeing the(...)
  • Established in 1973 under section 25-7-109 of the Colorado Air Quality Control Act, the Air Quality Control Commission (AQCC) is an eight-membered appointed commission with authority to adopt, modify or repeal emission control regulations which require the use of effective practical air(...)
  • The U.S. Air Quality Index (AQI) is the Environmental Protection Agency's (EPA) index for reporting air quality for five major air pollutants regulated by the Clean Air Act. Each of these pollutants has a National Ambient Air Quality Standard set by EPA to protect public health: ground-level(...)
  • Acronym for Air Quality System which collects reported air quality data from over thousands of state, local, and tribal air monitors and makes it available for the public to know.
  • Across the U.S. and in Colorado, an emission source that is inventoried on a county basis rather than as a geolocated point source.  Area sources are not required to hold a permit from the Air Pollution Control Division permit nor report emissions to the Air Pollution Emission Notice (APEN)(...)
  • An area with air quality that meets the U.S. Environmental Protection Agency (EPA) health standards periodically reviewed, and revisions promulgated by EPA as required in the Clean Air Act. Nonattainment areas are those that have not met the standards for designated pollutants. An area may be(...)
  • Acronym for best available control technology to control air pollutants from a particular source or sources. BACT is a term used in the U.S. Clean Air Act to refer to the maximum degree of reduction of each pollutant achievable for a major emitting facility through application of production(...)
  • The best available technology to control air pollutants from a particular source or sources. BACT is a term used in the U.S. Clean Air Act to refer to the maximum degree of reduction of each pollutant achievable for a major emitting facility through application of production processes and(...)
  • The Brown Cloud, a pollutant-related visibility problem, is caused by an accumulation of tiny carbon-containing particles smaller than 10 microns in size, and the chemical reactions of certain gases, including NOx, NH3, and SO2. The collective pollutants block light, causing the distinctive(...)
  • Conformity requirement that Metropolitan Planning Organizations (MPO) must show that "building" or implementing a long-range construction plan for roads and related infrastructure or Transportation Improvement Plan (TIP) will provide more emissions reductions than "not building" or(...)
  • The Clean Air Act (CAA) is a comprehensive federal law of the United States that regulates air emissions from stationary, mobile, and other air pollution sources, including greenhouse gases. Among many required statutory elements, it authorizes the Environmental Protection Agency (EPA) to(...)
  • Clean Air Auto Repair program (CAAR) is a RAQC program designed as an ongoing effort to combat air pollution and reduce harmful emissions. CAAR identifies high-emitting vehicles and works to repair and mitigate poor emitting vehicles. CAAR utilizes advanced technologies and regular inspections(...)
  • A colorless, odorless, tasteless gas that deprives the blood of oxygen. CO is mostly formed from incomplete combustion of fuels. For more on CO visit this link which lays out Colorado's history of attainment for carbon monoxide.
  • Colorado Department of Transportation: A state agency that exists to ensure that Colorado has a safe and efficient highway system by building and maintaining interstates, U.S. highways, and state highways. To accomplish this goal, CDOT conducts three primary services: snow and ice operations,(...)
  • Colorado Department of Public Health and Environmental: A state agency that seeks to advance Colorado’s health and protect the places where we live, learn, work, and play. Among other responsibilities, this includes the implementation of air quality programs, the monitoring of daily ambient(...)
  • The Colorado Energy Office (CEO) seeks to deliver cost-effective energy services and advance innovative energy solutions for Colorado. They offer funding, financing and technical assistance to support electric vehicle adoption, building energy efficiency, industrial processes, and renewable(...)
  • The Clean Air Act (CAA) is a comprehensive federal law of the United States that regulates air emissions from stationary, mobile, and other air pollution sources, including greenhouse gases. Among many required statutory elements, it authorizes the Environmental Protection Agency (EPA) to(...)
  • Clean Air Auto Repair program (CAAR) is a RAQC program designed as an ongoing effort to combat air pollution and reduce harmful emissions. CAAR identifies high-emitting vehicles and works to repair and mitigate poor emitting vehicles. CAAR utilizes advanced technologies and regular inspections(...)
  • The Congestion Mitigation and Air Quality Improvement Program (CMAQ) provides funds to states for transportation projects designed to reduce traffic congestion and improve air quality particularly in the areas that do not attain the National Ambient Air Quality Standards (NAAQS). The program(...)
  • Carbon Monoxide. A colorless, odorless, tasteless gas that deprives the blood of oxygen. CO is mostly formed from incomplete combustion of fuels. For more on CO visit this link which lays out Colorado's history of attainment for carbon monoxide.
  • A state agency that seeks to advance Colorado’s health and protect the places where we live, learn, work, and play. Among other responsibilities, this includes the implementation of air quality programs, the monitoring of daily ambient pollutant levels, and the compliance of air pollution(...)
  • A state agency that exists to ensure that Colorado has a safe and efficient highway system by building and maintaining interstates, U.S. highways, and state highways. To accomplish this goal, CDOT conducts three primary services: snow and ice operations, roadway maintenance, and preservation,(...)
  • The Colorado Energy Office seeks to deliver cost-effective energy services and advance innovative energy solutions for Colorado. They offer funding, financing and technical assistance to support electric vehicle adoption, building energy efficiency, industrial processes, and renewable energy(...)
  • Conformity refers to the Clean Air Act requirements for federal actions to comply with the National Ambient Air Quality Standards. The general Conformity rule ensures that every action that a federal agency undertakes, approves, permits or supports will conform to the appropriate State(...)
  • The Congestion Mitigation and Air Quality Improvement Program provides funds to states for transportation projects designed to reduce traffic congestion and improve air quality particularly in the areas that do not attain National Ambient Air Quality Standards (NAAQS). The program supports(...)
  • Demand Site Energy Management refers to the modification of consumers' demand for energy through various methods such as financial incentives and behavioral change through education.
  • An international airport in Denver, Colorado, United States. As of 2023 the airport served 77.8 million passengers and is the 6th busiest airport in the world.
  • The Denver Metro/North Front Range air quality planning region for the Ozone NAAQS that includes 9 counties: Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer and Weld.
  • Established in 1955, DRCOG is a metropolitan planning organization that serves 10 counties including: Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver, Douglas, Gilpin, Jefferson and the southwest portion of Weld County. Local governments collaborate on policies, guidelines and the(...)
  • The Department of Energy is a cabinet-level department of the United States Government concerned with the United States' policies regarding energy and safety in handling nuclear material.
  • The Diesel Emissions Reduction Act (DERA) funds rebates and grants to protect human health and improve air quality through the reduction of diesel emissions.
  • The design value is a statistic that describes monitored the air quality status of a given site location relative to the level, averaging time, and compliance form of the National Ambient Air Quality Standards (NAAQS). It is used in determining monitored NAAQS compliance for nonattainment(...)
  • The Denver Internation Airport is an international airport in Denver, Colorado, United States. As of 2023 the airport served 77.8 million passengers in is the 6th busiest airport in the world.
  • This act funds rebates and grants to protect human health and improve air quality through the reduction of diesel emissions.
  • Acronym for Denver Metro/North Front Range air quality planning region for the Ozone NAAQS that includes 9 counties: Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer and Weld.
  • The Department of Energy (DOE) is a cabinet-level department of the United States Government concerned with the United States' policies regarding energy and safety in handling nuclear material.
  • Established in 1955, the Denver Regional Council of Governments (DRCOG) is a metropolitan planning organization that serves 10 counties including: Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver, Douglas, Gilpin, Jefferson and the southwest portion of Weld County. Local governments(...)
  • Demand Site Energy Mangement (DSM) refers to the modification of consumers' demand for energy through various methods such as financial incentives and behavioral change through education.
  • The design value (DV) is a statistic that describes monitored the air quality status of a given site location relative to the level, averaging time, and compliance form of the National Ambient Air Quality Standards (NAAQS). It is used in determining monitored NAAQS compliance for nonattainment(...)
  • The Early Action Compact (EAC) is an agreement with the U.S. Environmental Protection Agency made in December 2002 that lays out a process for the state of Colorado to achieve attainment with EPA's 1997 8-hour ozone standard in an expeditious manner. The agreement allows areas the flexibility(...)
  • The Early Action Compact is an agreement with the U.S. Environmental Protection Agency made in December 2002 that lays out a process for the state of Colorado to achieve attainment with EPA's 1997 8-hour ozone standard in an expeditious manner. The agreement allows areas the flexibility to(...)
  • Electric Generating Units (EGU) refer to any combination of physically connected generators, reactors, boilers, combustion turbines, or other prime movers operated together to produce electric power. EGUs are often sources of air emissions.
  • Electric Vehicles are battery-powered and use one or more electric motors or traction motors for propulsion. in comparison to a gas vehicle, EVs have no tailpipe emissions.
  • Electric Generating Units refer to any combination of physically connected generators, reactors, boilers, combustion turbines, or other prime movers operated together to produce electric power. EGUs are often sources of air emissions.
  • Engines Off is a multipronged program to reduce harmful emissions from vehicle idling. The RAQC partners with schools to launch education campaigns, local governments to adopt anti-idling ordinances and policies, and small businesses to electrify food trucks and other mobile businesses. Learn(...)
  • Envirotest Systems Corp. is a subsidiary of Environmental Systems Products, Inc (ESP). ESP operates the Air Care Colorado emissions testing centers under contract to the State of Colorado.
  • The Environmental Protection Agency (EPA) leads the nation's environmental science, research, education, and assessment efforts, including in relation to air quality. The mission of the EPA is to protect human health and the environment. Since 1970, EPA has been working for a cleaner,(...)
  • Electric vehicles (EV) are battery-powered and use one or more electric motors or traction motors for propulsion. in comparison to a gas vehicle, EVs have no tailpipe emissions.
  • This federal agency carries out the Federal highway programs in partnership with state and local agencies to meet the nation's transportation needs. FHWA adds values to the delivery of the Federal highway programs by administering and overseeing these programs to ensure that Federal funds are(...)
  • The Federal Implementation Plan is an air quality plan developed by EPA under certain circumstances to help states or tribes attain and/or maintain the NAAQS for common air pollutants. These are made when the State Implementation Plan is proven non-effective.
  • The Federal Register is the official journal for the federal government of the United States that contains daily publications of government agency rules, proposed rules, and public notices,
  • The Federal Test Procedure is a series of tests defined by the U.S. EPA to measure tailpipe emissions and fuel economy of passenger cars (excluding light trucks and heavy-duty trucks).
  • As authorized by the Safe, Accountable, Flexible, Efficient Transportation Act: A Legacy for Users of 2005 (SAFETEA-LU), the FTA supports locally planned and operated public mass transit systems throughout the United States.
  • The Federal Highway Administration (FHWA) carries out the Federal highway programs in partnership with state and local agencies to meet the nation's transportation needs. FHWA adds values to the delivery of the Federal highway programs by administering and overseeing these programs to ensure(...)
  • The Federal Implementation Plan (FIP) is an air quality plan developed by EPA under certain circumstances to help states or tribes attain and/or maintain the NAAQS for common air pollutants. These are made when the State Implementation Plan is proven non-effective.
  • The Federal Register (FR) is the official journal for the federal government of the United States that contains daily publications of government agency rules, proposed rules, and public notices,
  • As authorized by the Safe, Accountable, Flexible, Efficient Transportation Act: A Legacy for Users of 2005 (SAFETEA-LU), the Federal Transit Authority (FTA) supports locally planned and operated public mass transit systems throughout the United States.
  • The Federal Test Procedure (FTP) is a series of tests defined by the U.S. EPA to measure tailpipe emissions and fuel economy of passenger cars (excluding light trucks and heavy-duty trucks).
  • A Geographical Information System is a computer system for capturing, storing, checking, and displaying data related to positions on Earth's Surface.
  • Greenhouse gases (GHGs) are gases in the atmosphere that absorb and emit radiation within the thermal infrared range. They greatly affect the temperature of the Earth; without them, Earth's surface would be on average about 59 degrees Fahrenheit colder than at present. These can be emitted(...)
  • A Geographical Information System (GIS) is a computer system for capturing, storing, checking, and displaying data related to positions on Earth's Surface.
  • Greenhouse gases are gases in the atmosphere that absorb and emit radiation within the thermal infrared range. They greatly affect the temperature of the Earth; without them, Earth's surface would be on average about 59 degrees Fahrenheit colder than at present. These can be emitted through(...)
  • Hazardous Air Pollutants (HAP) (also referred to as "Air Toxics") are those known to cause cancer and other serious health impacts.
  • Hazardous Air Pollutants (also referred to as "Air Toxics") are those known to cause cancer and other serious health impacts.
  • Hydrocarbons (HC) are organic compounds that consist of hydrogen and carbon atoms. They are found in petroleum and natural gas.
  • The Federal Highway Administration's definition of a heavy-duty vehicle is a vehicle weighing more than 26,001 pounds (about 11793.85 kg).
  • A high occupancy vehicle refers to a motor vehicle carrying a required minimum number of passengers--normally two. If you see a sign that says HOV 3+ that would mean the vehicle must be holding a minimum of three passengers. There are HOV lanes on some heavily trafficked roads and often there(...)
  • A high occupancy vehicle (HOV) refers to a motor vehicle carrying a required minimum number of passengers--normally two. If you see a sign that says HOV 3+ that would mean the vehicle must be holding a minimum of three passengers. There are HOV lanes on some heavily trafficked roads and often(...)
  • Hydrocarbons are organic compounds that consist of hydrogen and carbon atoms. They are found in petroleum and natural gas.
  • Vehicle Inspection and Maintenance (I/M) programs help improve air quality by identifying cars and trucks with high emissions that may need repairs. Owners or operators of vehicles with high emissions are notified to make any repairs so that emissions are within legal limits.
  • The Inter-agency Consultation Group (ICG) is a subcommittee of DRCOG that focuses on coordination of the transportation conformity process. This group works to promote coordination among the transportation and air quality agencies for the region
  • To leave a vehicle's internal combustion engine running while the vehicle is parked. Currently the RAQC is running a program called "Engines Off", which is aimed at reducing idling emissions around schools and by food trucks.
  • The International Energy Conservation Code (IECC) established minimum requirements for energy efficient buildings using prescriptive and performance-related provisions.
  • Indirect sources are facilities, structures, buildings, installations, real property, roads or highways that attract or may attract mobile sources of pollution. Activities associated with an indirect source can result in emissions of air pollutants that interfere with the attainment and(...)
  • Vehicle Inspection and Maintenance programs help improve air quality by identifying cars and trucks with high emissions that may need repairs. Owners or operators of vehicles with high emissions are notified to make any repairs so that emissions are within legal limits.
  • The Inter-agency Consultation Group is a subcommittee of DRCOG that focuses on coordination of the transportation conformity process. This group works to promote coordination among the transportation and air quality agencies for the region
  • Intermodal refers to the connections made between modes of transportation (e.g. transfer from train to truck).
  • ISTEA is a United States federal law that posed a major change to transportation planning and policy. It presented an overall intermodal approach to highway and transit funding with collaborative planning requirements, giving significant additional powers to the metropolitan planning(...)
  • The IECC established minimum requirements for energy efficient buildings using prescriptive and performance-related provisions.
  • The Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 is a United States federal law that posed a major change to transportation planning and policy. It presented an overall intermodal approach to highway and transit funding with collaborative planning requirements, giving(...)
  • Refers to the way portions of land or the structures on them are used, e.g., commercial, residential, retail, industrial, etc.
  • The light emitting diode (LED) is a semiconductor device that emits visible light when an electrical voltage is applied. LED lights do not emit harmful gases or chemicals, leading to reduced indoor air pollution and a healthier workplace. In addition, LEDs use 75% less energy and last up to 25(...)
  • The Federal Highway Administration's definition of a light-duty vehicle is a vehicle weighing less than 10,000 pounds (about 4535.92 kg), excluding trucks with two or more axles or with six or more tires.
  • The light emitted diode is a semiconductor device that emits visible light when an electrical voltage is applied. LED lights do not emit harmful gases or chemicals, leading to reduced indoor air pollution and a healthier workspace. In addition, LEDs use 75% less energy and last up to 25 times(...)
  • Refers to the maximum daily 8-hour averaged concentration of a certain pollutant--the averaging period form of the 1997, 2008 and 2015 ozone NAAQS.
  • Refers to the maximum daily 8-hour averaged concentration of a certain pollutant--the averaging period form of the 1997, 2008 and 2015 ozone NAAQS.
  • The Federal Highway Administration's definition of a medium-duty vehicle is a vehicle weighing greater than 14,000 pounds (about 6350.29 kg) but less than or equal to 26,000 pounds (about 11793.39 kg).
  • The Model Emissions of Gases and Aerosols (MEGAN) is a modeling system for estimating the emission of gases and aerosols (also called biogenic emissions) from terrestrial ecosystems into the atmosphere.
  • A megawatt is a unit of power equal to one million watts, often used to quantify the power output of an industrial sized power system.
  • A metropolitan planning organization is a transportation policy-making organization made up of representatives from local government and transportation authorities. In 1962, the United States Congress passed legislation that required the formation of an MPO for any urbanized area (UZA) with a(...)
  • A source of pollution that moves or can be moved from place to place, such as automobiles, planes and trains.
  • The mobile vehicle emissions simulator is a state-of-the-science emission modeling system that estimates emissions for mobile sources at the national, county, and project level for criteria air pollutants, greenhouse gases, and air toxins. Over time, multiple versions of this modeling platform(...)
  • Mode is a form of transportation of people and goods, such as automobile, transit, bicycling, and walking.
  • MEGAN is a modeling system for estimating the emissions of gases and aerosols (also called biogenic emissions) from terrestrial ecosystems into the atmosphere.
  • Model Performance Evaluation is a process through which the validity and accuracy of the results produced by a model are evaluated. MPE is a required part of the Attainment Plan development process for a Nonattainment area and can involve analyzing how well the model is able to replicate(...)
  • The model year of a product is a number used worldwide, with a high level of prominence in North America, to describe approximately when a product was produced.
  • The Motor Vehicle Emissions Budget is a part of the Attainment Plan that identifies allowable emission levels for the regional total of specific pollutants emitted from mobile sources within a Nonattainment area. The emissions levels in the budget are used for meeting emissions reductions(...)
  • The mobile vehicle emissions simulator (MOVES) is a state-of-the-science emissions modeling system that estimates emissions for mobile sources at the national, county, and project level for criteria air pollutants, greenhouse gases, and air toxins. Over time, multiple versions of this modeling(...)
  • The Regional Air Quality Council has launched the Mow Down Pollution – exchange program as part of their efforts to mitigate ground-level ozone and enhance air quality. This initiative offers vouchers to support individuals and organizations who opt to recycle their gas-powered lawn equipment(...)
  • Model Performance Evaluation (MPE) is a process through which the validity and accuracy of the results produced by a model are evaluated. MPE is a required part of the Attainment Plan development process for a Nonattainment area and can involve analyzing how well the model is able to replicate(...)
  • A metropolitan planning organization (MPO) is a transportation policy-making organization made up of representatives from local government and transportation authorities. In 1962, the United States Congress passes legislation that required the formation of an MPO for any urbanized area (UZA)(...)
  • Multimodal refers to the availability of multiple transportation options within a system corridor. 
  • The Motor Vehicle Emissions Budget (MVEB) is a part of the Attainment Plan that identifies allowable emission levels for the regional total of specific pollutants emitted from mobile sources within a Nonattainment area. The emissions levels in the budget are used for meeting emissions(...)
  • A megawatt (MW) is a unit of power equal to one million watts, often used to quantify the power output of an industrial sized power system.
  • The model year (MY) of a product is a number used worldwide--with a high level of prominence in North America, to describe approximately when a product was used.
  • A nonattainment area (NAA) is an area considered to have air quality worse than the National Ambient Air Quality Standards as defined by the Clean Air Act Amendments of 1970--it is not attaining one or more standards.
  • The National Ambient Air Quality Standards (NAAQS) are federal standards that set allowable concentrations in ambient air for indicator pollutants. Pollutants regulated under the NAAQS include ozone, particulate matter, lead, carbon monoxide, sulfur oxides, and nitrogen oxides.
  • Federal standards that set allowable concentrations in ambient air for indicator pollutants. Pollutants regulated under the NAAQS include ozone, particulate matter, lead, carbon monoxide, sulfur oxides, and nitrogen oxides.
  • The NESHAP are stationary source standards for hazardous pollutants. NESHAPs are allowable emission rates for HAPs.
  • The National Emissions Inventory is a comprehensive and detailed estimate of area emissions of both criteria and hazardous pollutants from all air emissions sources. The NEI is prepared with inputs from state air pollution control agencies and EPA and is compiled every three years by the U.S. EPA.
  • The National Environmental Policy Act was signed in 1970 and requires federal agencies to assess the environmental effects of their proposed actions prior to making decisions.
  • The National Oceanic and Atmospheric Administration is an American scientific agency within the United States Department of Commerce that focuses on the conditions of the oceans and the atmosphere.
  • The National Park Service is an agency in the Department of the Interior of the United States' federal government that manages all national parks, many national monuments, and other conservation and historical properties with various title designations.
  • The National Renewable Energy Laboratory, located in Golden, CO, is the Unites States' primary laboratory for renewable energy and energy efficient research and development.
  • The National Emissions Inventory (NEI) is a comprehensive and detailed estimate of area emissions of both criteria and hazardous pollutants from all air emissions sources. The NEI is prepared with inputs from state air pollution control agencies and EPA and is compiled every three years by the(...)
  • The National Environmental Policy Act (NEPA) was signed in 1970 and requires federal agencies to assess the environmental effects of their proposed actions prior to making decisions.
  • The National Emission Standards for Hazardous Air Pollutants (NESHAPs) are stationary source standards for hazardous air pollutants. NESHAPS are allowable emission rates for HAPs.
  • The New Source Performance Standards are pollution control standards issues by EPA that apply minimum requirements to new, modified, and reconstructed affected facilities.
  • The New Source Review is a Clean Air Act program that safeguards communities from increases in pollution through permitting requirements when a new facility is built, or an existing facility is modified. Most NSR permits are issued by state or local air pollution control agencies, although EPA(...)
  • The Northern Front Range Metropolitan Planning Organization (NFRMPO) is an association of 15 local governments working together to improve regional transportation and air quality (Berthoud, Eaton, Evens, Fort Collins, Garden City, Greeley, Johnstown, LaSalle, Loveland Milliken, Severance,(...)
  • Ammonia Gas. Ammonia is most commonly emitted from agricultural activities, landfill sites, sewage facilities and composting of organic materials. Health effects from high levels of exposure to ammonia can cause irritation of the throat, lungs and eyes.  Ammonia is a colorless gas with a(...)
  • The sum of nitric oxide (NO) and nitrogen dioxide (NO2). The primary nitrogen pollutants emitted from the combustion process.
  • The National Oceanic and Atmospheric Administration (NOAA) is an American scientific agency within the United States Department of Commerce that focuses on the conditions of the oceans and the atmosphere.
  • EPA issues Notices of Data Availability (NODAs) to inform stakeholders that new data related to air quality is available.
  • A nonattainment area is an area considered to have air quality worse than the National Ambient Air Quality Standards as defined in the Clean Air Act Amendments of 1970--it is not attaining one or more standards.
  • The NFRMPO is an association of 15 local governments working together to improve regional transportation and air quality (Berthoud, Eaton, Evens, Fort Collins, Garden City, Greeley, Johnstown, LaSalle, Loveland Milliken, Severance, Timnath, Windsor and the urban portions of Weld and Larimer(...)
  • EPA issues NODAs, published in the Federal Register, to inform stakeholders that new data related to air quality and emissions are available.
  • Nitrogen Oxide (NOx) is the sum of nitric oxide (NO) and nitrogen dioxide (NO2). The primary nitrogen pollutants emissions emitted from the combustion process.
  • The National Park Service (NPS) is an agency in the Department of the Interior of the United States federal government that manages all national parks, many national monuments, and other conservation and historical properties with various title designations.
  • The National Renewable Energy Laboratory (NREL), located in Golden, CO, is the United States' primary laboratory for renewable energy and energy efficiency research and development.
  • The New Source Performance Standards (NSPS) are pollution control standards issued by EPA that apply minimum requirements to new, modified, and reconstructed affected facilities.
  • The New Source Review (NSR) is a Clean Air Act program that safeguards communities from increases in pollution through permitting requirements when a new facility is built, or an existing facility is modified. Most NSR permits are issued by state or local air pollution control agencies,(...)
  • The Ozone Transportation Commission (OTC) is a multi-state organization founded in 1991 and required under the 1990 Clean Air Act amendments. They are responsible for advising EPA on air pollution transport issues and for developing and implementing regional solutions to the ground-level ozone(...)
  • The oxidation catalyst is the second stage in the catalytic converter. It reduces hydrocarbons and carbon monoxide from vehicle exhaust by oxidizing (burning) them over a platinum and palladium catalyst.
  • Oxygenates are fuel additives containing oxygen, usually alcohol or ether, that enhance fuel combustion and reduce exhaust emissions.
  • Ozone is a colorless and odorless gas. Ozone is a secondary pollutant, rather than one directly emitted, formed when hydrocarbons (commonly known as VOCs) and nitrogen oxides combine in the presence of sunlight. High concentrations of tropospheric ozone are the result of smog or haze(...)
  • The Ozone Transport Commission is a multi-state organization founded in 1991 and required under the 1990 Clean Air Act amendments. They are responsible for advising EPA on air pollution transport issues and for developing and implementing regional solutions to the ground-level ozone problem in(...)
  • Any material that exists as a solid or liquid in the atmosphere. Particulate matter may be in the form of fly ash, soot, dust, fog, fumes, etc.
  • A unit of concentration used to measure pollutant levels. For example, the 2015 ground level ozone standard is 0.070 ppm and is usually discussed as 70 ppb. For comparison 1 ppb is equivalent to one drop of water in a municipal-sized (10,000 gallons) swimming pool. 
  • A unit of concentration used to measure pollutant levels. For example, the 2015 ground level ozone standard is 0.070 ppm. For comparison, 1 ppm is equivalent to a drop of water in a 10-gallon bathtub. 
  • A plug-in hybrid electric vehicle (PHEV) is a hybrid electric vehicle that uses rechargeable batteries or another energy storage device and can be recharged by plugging it into an external source of electric power.
  • A large-scale air quality modeling technique that simulates the changes of pollutant concentrations in the atmosphere using a set of mathematical equations within virtual 3-dimensional gird cells accounting for emissions and meteorology to characterize chemical and physical processes in the(...)
  • A plug-in hybrid electric vehicle is a hybrid electric vehicle that uses rechargeable batteries or another energy storage device and can be recharged by plugging it into an external source of electric power.
  • Particulate Matter: Any material that exists as a solid or liquid in the atmosphere. Particulate matter may be in the form of fly ash, soot, dust, fog, fumes, etc.
  • PM2.5 is a smaller particulate matter which is less than 2.5 microns in size and when breathed is trapped deep in the lungs, making it the biggest health concern regarding PM.
  • PM10 is small particulate matter that is less than 10 microns in size - about one-eight the diameter of a human hair - and is too small to be filtered by the nose and lungs.
  • A unit of concentration used to measure pollutant levels. For example, the 2015 ground level ozone standard is 0.070 ppm and is usually discussed as 70 ppb. For comparison 1 ppb is equivalent to one drop of water in a municipal-sized (10,000 gallons) swimming pool. 
  • A unit of concentration used to measure pollutant levels. For example, the 2015 ground level ozone standard is 0.070 ppm. For comparison, 1 ppm is equivalent to a drop of water in a 10-gallon bathtub. 
  • Pollutant gases or particles directly emitted from a pollutant source, such as nitrogen oxides (NOx) and Volatile Organic Compounds (VOCs).
  • A process for determining the accuracy of emissions information. Examples of activities include checking with specific industrial firms concerning the information reported on the Air Pollution Emissions Notifications and reviewing the body of literature regarding the best methods for(...)
  • RACM are reasonably available control measures designed to bring an area back into attainment. According to the Clean Air Act, one of the processes in implementing emission controls to attain the 8-hour ozone standards is to complete a RACM analysis that typically focuses on area, mobile and(...)
  • According to the EPA, Reasonably Available Control Technologies (RACT) are any technologies that are reasonably available, considering technological and economic feasibility, to control and reduce different pollutants from a source or sources.
  • The Regional Air Quality Council is the Denver Metro/North Front Range area's lead air quality planning agency.
  • A Rate of Progress Plan, which can be included in a State Implementation Plan, documents the control strategies that a state is implementing to reduce emissions of ozone precursors.
  • The Resource Conservation and Recovery Act (RCRA) gives EPA the authority to control hazardous and solid waste from "cradle-to-grave." This includes the generation, transportation, treatment, storage, and disposal of hazardous and solid waste.
  • Particulate emissions that are kicked up from the movement of vehicles on paved roadway surfaces.
  • Reporting of periodic incremental reductions in air pollutant emissions as required by the CAA and reflected in an Attainment Plan.  
  • RACM are readily available control measures designed to bring an area back into attainment. According to the Clean Air Act, one of the processes in implementing emission controls to attain the 8-hour ozone standards is to complete a RACM analysis that typically focuses on area, mobile and(...)
  • According to the EPA, any technology that is reasonably available, considering technological and economic feasibility, to control and reduce different pollutants from a source or sources.
  • Also known as piston engines, RICE engines are heat engines that use one or more reciprocating pistons to convert pressure into a rotary motion.
  • Gasoline that is refined and blended to burn more efficiently and cleanly in motor vehicles, reducing smog-forming and toxic pollutants in the air. It is mandated by the 1990 Clean Air Act amendments in ozone nonattainment areas that are classified as Severe and higher on the CAA(...)
  • The Denver Metro/North Front Range area's leading air quality planning agency.
  • Regional Transportation District is a bus and rail transit system in the Denver, Colorado, metropolitan area.
  • A Regional Transportation Plan is a long-term blueprint of a region's transportation system. Usually conducted every five years, RTPs are developed to prioritize and manage a transport system so that it effectively supports regional communities, growth and productivity.
  • A measure which indicates how volatile a fuel is (how easily is evaporates).
  • The RRF is a factor to estimate future ozone and/or PM2.5 design values at existing monitoring sites by multiplying the modeled relative response factor for each monitor by the monitor-specific base year design value.  See Section 3 of: Modeling Guidance for Demonstrating Attainment of Air(...)
  • Renewable energy sources (RES) are biomass, hydropower, geothermal, wind, solar and are a growing source of energy used in the United States and around the world.
  • Renewable energy sources are biomass, hydropower, geothermal, wind, and solar and are a growing source of energy used in the United States and around the world.
  • The Resource Conservation and Recovery Act gives EPA the authority to control hazardous and solid waste from "cradle-to-grave." This includes the generation, transportation, treatment, storage and disposal of hazardous and solid waste.
  • Reformulated Gasoline (RFG) is gasoline that is refined and blended to burn more efficiently and cleanly in motor vehicles, reducing smog-forming and toxic pollutants in the air. It is mandated by the 1990 Clean Air Act amendments in ozone nonattainment areas that are classified as Severe and(...)
  • Reasonable Further Progress (RFP) is a reporting of periodic incremental reductions in air pollutant emissions as required by the CAA and reflected in an Attainment Plan.  
  • Also known as piston engines, reciprocating internal combustion engines (RICE) are heat engines that use one of more reciprocating pistons to convert pressure into a rotary motion.
  • A Rate of Progress (ROP) plan, which can be included in a State Implementation Plan, documents the control strategies that a state is implementing to reduce emissions of ozone precursors.
  • The Relative Response Factor (RRF) is a factor to estimate future ozone and/or PM2.5 design values at existing monitoring sites by multiplying the modeled relative response factor for each monitor by the monitor-specific base year design value.  See Section 3 of: Modeling Guidance for(...)
  • Regional Transportation District (RTD) is a bus and rail transit system in the Denver, Colorado, metropolitan area.
  • A Regional Transportation Plan (RTP) is a long-term blueprint of a region's transportation system. Usually conducted every five years, RTPs are developed to prioritize and manage a transport system so that it effectively supports regional communities, growth and productivity.
  • Reid Vapor Pressure (RVP) is a measurement that indicates how volatile a fuel is (how easily it evaporates).
  • A pollutant such as ozone or ammonium sulfate, formed in the atmosphere through the chemical or physical interactions between primary pollutants.
  • Supplemental Environmental Projects (SEP) are a means by which penalties for environmental violations may be mitigated by directing funds towards environmentally beneficial projects.
  • Simple Steps. Better Air. (SSBA) is the RAQC's outreach, awareness, and education program. It provides information for the general public regarding the Front Range region’s current ozone challenges, and how individuals can take simple steps for better air. SSBA also runs the RAQC’s summer(...)
  • A single-occupant vehicle refers to an automobile that is used to get just one person to a destination.
  • The State Implementation Plan (SIP) is a collection of required air quality planning documents prepared by states, territories, or local air districts to implement, maintain, and enforce the National Ambient Air Quality Standards and fulfill numerous other requirements of the Clean Air Act.(...)
  • A pipe or funnel through which smoke and gases are discharged.
  • Sulfur Dioxide. The main sources of sulfur dioxide emissions are fossil fuel combustion and natural volcanic activity. Prolonged exposure to this chemical can lead to throat and lung irritation and difficulty breathing.
  • A single-occupant vehicle (SOV) refers to an automobile that is used to get just one person to a destination.
  • Sparse Matrix Operator Kernal Emissions is primarily an emissions processing system designed to create gridded, speciated, hourly emissions for input into a variety of air quality models.
  • Simple Steps. Better Air. (SSBA) is the RAQC's outreach, awareness, and education program. It provides information for the general public regarding the Front Range region’s current ozone challenges, and how individuals can take simple steps for better air. SSBA also runs the RAQC’s summer(...)
  • These are mechanisms on gasoline pumps designed to control and capture vapors during vehicle fueling by recycling the vapors back into fuel storage tanks, preventing them from polluting the air.
  • Required air quality planning documents prepared by states, territories, or local air districts to implement, maintain, and enforce the National Ambient Air Quality Standards in areas violating the NAAQS, and to fulfill numerous other requirements of the Clean Air Act. They are submitted to(...)
  • A stationary source of air pollution is any fixed emitter of air pollutants. Examples include fossil fuel burning power plants, petrochemical plants, food processing plants, and other heavy industrial sources.
  • Storage tank emissions management (STEM) requires emission reductions from storage tanks at exploration and production operations, including well production facilities, compressor stations, and processing plants.
  • Storage tank emissions management requires emissions reductions from storage tanks at exploration and production operations, including well production facilities, compressor stations and processing plants.
  • The main sources of sulfur dioxide emissions are fossil fuel combustion and natural volcanic activity. Prolonged exposure to this chemical can lead to throat and lung irritation and difficulty breathing.
  • Supplemental Environmental Projects are a means by which penalties for environmental violations may be mitigated by directing funds toward environmentally beneficial projects.
  • A receptacle (typically a large one) for holding, transporting or storing liquids such as water or fuel.
  • Transportation Analysis Zones (TAZ) are the unites of geography most commonly used in conventional transportation planning models, usually made up of one or more census blocks, groups, or tracts.
  • Transportation Control Measures (TCMs) are local actions to adjust traffic patterns or reduce vehicle use to reduce air pollutant emissions. These may include High-Occupancy Vehicle lanes, provision of bicycle facilities, ridesharing, working from home, etc.
  • Transportation Demand Management (TDM) is the application of strategies and policies to reduce automobile travel demand, or to redistribute this demand in space or time.
  • A Transportation Improvement Plan (TIP) is a document prepared by states and regional planning commissions (i.e., DRCOG) that shows comprehensive transportation projects. If it is not included in a conforming TIP, a project is ineligible for federal funding.
  • Transportation Management Association (TMA) is a formal organization of businesses and local governments dedicated to solving local transportation concerns.
  • Transportation Management Organization (TMO) is a voluntary association of public and private agencies and firms joined to cooperatively develop transportation-enhancing programs in a given area. TMOs typically manage transportation demand in congested urban and suburban communities. The first(...)
  • Tons Per Day is used as a measurement of the emissions rate of air pollutants from all sources.
  • Tons Per Day (TPD) is used as a measurement of the emission rate of air pollutants from all sources.
  • Colorado is divided into 15 regions for transportation planning purposes. Ten of these are rural transportation planning regions (TPRs) and five are metropolitan planning organizations (MPOs). Both the TPRs and MPOs make regional transportation plans that identify unique needs and priorities(...)
  • The Traffic Signal System Improvement Program is a combination of management and operations strategies designed to time and coordinate traffics signals in the Denver Region.
  • Transportation Analysis Zones are the units of geography most commonly used in conventional transportation planning models, usually made up of one or more census blocks, groups, or tracts.
  • Local actions to adjust traffic patterns or reduce vehicle use to reduce air pollutant emissions. These may include High-Occupancy Vehicle lanes, provision of bicycle facilities, ridesharing, working from home, etc.
  • TDM is the application of strategies and policies to reduce automobile travel demand, or to redistribute this demand in space or time.
  • Activities designed to reduce the need for single occupant vehicle trips within transportation systems. An example of a demand management strategy is telecommuting.
  • A document prepared by states and regional planning commissions (i.e., DRCOG) that shows comprehensive transportation projects. If it is not included in a conforming TIP, a project is ineligible for federal funding.
  • Transportation Management Associations is a formal organization of businesses and local governments dedicated to solving transportation concerns.
  • A voluntary association of public and private agencies and firms joined to cooperatively develop transportation-enhancing programs in a given area. TMOs typically manage transportation demand in congested urban and suburban communities. The first Denver region TMO formed downtown in early 1995.
  • A mathematical and geometric projection of activity and the interactions in the transportation system in an area. This projection must be able to be evaluated according to a given set of criteria, which might include land use, economics, social values, and travel patterns.
  • Colorado is divided into 15 regions for transportation planning purposes. Ten of these are rural transportation planning regions (TPRs) and five are metropolitan planning organizations (MPOs). Both the TPRs and MPOs make regional transportation plans that identify unique needs and priorities(...)
  • The Traffic Signal System Improvement Program (TSSIP) is a combination of management and operations strategies designed to time and coordinate traffics signals in the Denver Region.
  • The EPA leads the nation's environmental science, research, education, and assessment efforts, including in relation to air quality. The mission of the EPA is to protect human health and the environment. Since 1970, EPA has been working for a cleaner, healthier environment for the American(...)
  • A standard areawide measure of travel activity. The most conventional VMT calculation is to multiply the average length of trips by the total number of trips.
  • A visibility standard is a measure of visual air quality. Colorado's visibility standard, as established by the state legislature, requires that not more than 7.6 percent of the light across a path of a kilometer in length of air be extinguished, averaged daily over four daylight hours. The(...)
  • Vehicle Miles Traveled (VMT) is a standard areawide measure of travel activity. The most conventional VMT calculation is to multiply the average length of trips by the total number of trips.
  • Volatile Organic Compounds (VOCs) are natural (organic) emissions from plant material or emissions from industrial and/or combustion processes. These combine in the atmosphere with NOx in the presence of sunlight to form tropospheric ozone.
  • Natural (organic) emissions from plant material or emissions from industrial an/or combustion processes. These combine in the atmosphere with NOx in the presence of sunlight to form tropospheric ozone.
  • Weather Research and Forecasting is a next-generation mesoscale numerical weather prediction system designed for both atmospheric research and operational forecasting needs.
  • The weight of evidence approach is used in Attainment Plans to assess all analyses, data, and information available, including modeled attainment and other supplemental analyses, and provide a more informed and holistic basis for the attainment strategy.  See Section 6.2 of: Modeling Guidance(...)
  • Working from home (WFH) is a work arrangement in which employees enjoy flexibility in work location and hours. Can also be referred to as "Remote Work" or "Hybrid Work Schedule". Both are not standard practices in the workplace.
  • The weight of evidence (WOE) approach is used in Attainment Plans to assess all analyses, data, and information available, including modeled attainment and other supplemental analyses, and provide a more informed and holistic basis for the attainment strategy.  See Section 6.2 of: Modeling(...)
  • This is a work arrangement in which employees enjoy flexibility in work location and hours. Can also be referred to as "Remote Work" or "Hybrid Work Schedule". Both are not standard practices in the workplace.
  • Weather Research and Forecasting (WRF) is a next-generation mesoscale numerical weather prediction system designed for both atmospheric research and operational forecasting needs.
  • Zero Emission Vehicles are vehicles that don't emit any tailpipe pollutants from the on-board source of power.
  • Zero Emission Vehicles (ZEV) are vehicles that don't emit any tailpipe pollutants from the on-board source of power.