Air Quality | Learning



AACOG	The Alamo Area Council of Governments (AACOG) is a voluntary association of local governments and organizations that serves its members through planning, information and coordination activities. The 12 county members are Atascosa, Bandera, Bexar, Comal, Frio, Gillespie, Guadalupe, Karnes, Kendall, Kerr, Medina, and Wilson. Click here for more information.
Additives	Chemicals added to fuel in very small quantities to improve and maintain fuel quality. Detergents and corrosion inhibitors are examples of gasoline additives. Source: Alternative Fuel Vehicle Group.
Advanced Technology Vehicle (ATV)	A vehicle that combines new engine/power/drive train systems to significantly improve fuel economy. This includes hybrid power systems and fuel cells, as well as some specialized electric vehicles. Source: Alternative Fuel Vehicle Group.
AIR Committee	The Air Improvement Resources Committee of the Alamo Area Council of Governments consists of elected officials representing the counties (Bexar, Comal, Guadalupe and Wilson) and the major cities (San Antonio, New Braunfels, Seguin, and Floresville) of the Metropolitan Statistical Area designated by the EPA based on Census data from 1990. The AIR Committee is responsible for regional air quality planning and action. The AIR Executive Committee, just the elected officials, is supported by the AIR Advisory Committee, a group of interested local business and civic leaders. The AIR Executive and Advisory committees are, in turn, supported by the AIR Technical Committee , which studies the technical and scientific aspects of local air quality problems, and the AIR Public Education Committee, which works with the media and other regional groups to educate the public on regional air quality issues.
Air Pollution	Dirty air that could injure human health or property, plant or animal life, and/or prevent normal use and enjoyment of property. Source: TCEQ.
AIR Public Education Committee	A sub-committee of the Air Improvement Resources Committee of the Alamo Area Council of Governments whose mission is to educate the public about local air quality problems and issues. The Public Education committee makes recommendations to the AIR Executive and Advisory committees on ways to increase media coverage of air quality issues and the spreading of air quality information to the general public. The AIR Public Education committee is also responsible for annual events, such as the Ozone Season Kickoff, and provides many other public-education and air quality services. Click here for more information.
Air Quality Standard	The allowable amount of an air contaminant in outside air. Source: TCEQ.
AIR Technical Committee	A sub-committee of the Air Improvement Resources Committee of the Alamo Area Council of Governments whose mission is to study the technical and scientific aspects of local air quality problems. This committee is led by AACOG staff and consists of local air quality experts. The AIR Technical committee works closely with the Texas Commission on Environmental Quality and the Environmental Protection Agency to provide the technical expertise necessary to assist the AIR Executive Committee in making air quality planning and policy choices.
Air Toxics	Toxic air pollutants defined under Title II of the Clean Air Act (CAA), including benzene, formaldehyde, acetaldehyde, 1-3 butadiene and polycyclic organic matter POM). Benzene is a constituent of motor vehicle exhaust, evaporative and refueling emissions. The other compounds are exhaust pollutants. Source: Alternative Fuel Vehicle Group.
ALA	American Lung Association® (ALA) is the oldest voluntary health organization in the United States. Founded in 1904 to fight tuberculosis, ALA today fights lung disease in all its forms, with special emphasis on asthma, tobacco control, and environmental health. Click here for more information: http://www.lungusa.org/
Alcohols	Organic compounds that are distinguished from hydrocarbons by the inclusion of a hydroxyl group. The two simplest alcohols are methanol and ethanol. Source: Alternative Fuel Vehicle Group.
Alternative Fuel	As defined by the National Energy Policy Act (EPAct) the fuels are methanol, denatured alcohol and other alcohols, separately or in mixtures of 85 percent by volume or more (or other percentage not less than 70 percent as determined by U.S. Department of Energy rule) with gasoline or other fuels; Compressed Natural Gas (CNG); Liquefied Natural Gas (LNG); Liquefied Petroleum Gas (LPG); hydrogen; “coal-derived liquid fuels;” fuels “other than alcohols” derived from “biological materials;” electricity , or any other fuel determined to be “substantial energy security benefits and substantial environment benefits.” Source: Alternative Fuel Vehicle Group.
Alternative Fuel Provider	A fuel provider (or any affiliate or business unit under its control) is an alternative fuel provider if its principal business is producing, storing, refining, processing, transporting, distributing, importing or selling (at wholesale or retail) any alternative fuel (other than electricity); or generating, transmitting, importing, or selling (at wholesale and retail) electricity; or if that fuel provider produces, imports, or produces and imports (in combination), an average of 50,000 barrels per day of petroleum and 30% (a substantial portion) or more of its gross annual revenues are derived from producing alternative fuels. Source: Alternative Fuel Vehicle Group.
Alternative Fuel Vehicle (AFV)	A vehicle that uses a non-typical form of energy for operation - electricity, E85, propane, natural gas, and other. Source: Alternative Fuel Vehicle Group.
Alternative Fuels Data Center (AFDC)	A program sponsored by the Department of Energy (DOE) and managed by the National Renewable Energy Laboratory (NREL) to collect emissions, operational, and maintenance data on all types of alternative fuel vehicles across the country. Source: Alternative Fuel Vehicle Group.
Alternative Fuels Utilization Program (AFUP)	A program managed by the Department of Energy (DOE) with the goals of improving national energy security by displacing imported oil and improving air quality through the development and widespread use of alternative fuels for transportation and increasing the production of alternative fuel vehicles. Source: Alternative Fuel Vehicle Group.
Alternative Motor Fuels Act of 1988 (AMFA)	Encourages the development, production and demonstration of alternative motor fuels and AFVs. Source: Alternative Fuel Vehicle Group.
Ambient Air	According to the EPA, ambient air is the air surrounding us, the air we breathe.
AQHA	An Air Quality Health Alert (formerly Ozone Action Day) is announced when forecasters expect ozone pollution to rise to unhealthy levels in our area. The forecast is sent to the media and public for the following day so that people can take steps to protect health and reduce the emissions that eventually become ozone.
AQI	The Air Quality Index reports how clean or polluted your air is, and what associated health concerns you should be aware of. The AQI focuses on health effects that can happen within a few hours or days after breathing polluted air. EPA uses the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. You can think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health danger.
Area Sources	When discussing the formation of ground-level ozone, the term “area sources” refers to those sources of ozone precursors which are calculated on a category basis, rather than counting individual smokestacks, as one would with point sources. Area source pollution is accounted for in an emissions inventory based on county population numbers and emissions factors established by the EPA . Some examples of area sources are: stationary source fuel combustion such as residential fuel combustion, solvent use, gasoline storage and transport distribution, agriculture (e.g., feedlots, crop burning), waste management (e.g., landfills), and miscellaneous area sources (e.g., forest fires, wind erosion, unpaved roads).
Aromatics	Hydrocarbons based on the ringed six-carbon benzene series of related organic groups. Benzene, Toluene and Xylene are the principal aromatics, commonly referred to as the BTX group. They represent one of heaviest fractions of gasoline. Source: Alternative Fuel Vehicle Group.
ASM Procedures	Acceleration Simulation Mode testing is a type of vehicle exhaust emissions inspection. This inspection is often called a “treadmill test” because the vehicle being tested is run on a dynamometer (an instrument measuring mechanical power), such that emissions can be inspected while the engine is under load. ASM testing is currently mandatory during the annual vehicle inspections performed in Texas’ non-attainment areas (i.e. Dallas, Houston) for all cars with model years 1978-1995. Click here for more information mandatory emissions inspections: http://www.airchecktexas.com/
Attainment	Those areas in "attainment" of the one-hour standard are required to meet the eight-hour standard of a three-year average of the fourth-highest daily maximum eight-hour concentration measured at each site not to be at or exceed 85 ppb.
Attainment Area	A geographic site that meets air quality standards set by the United States Environmental Protection Agency. Source: TCEQ.
Automatic Switchover	A device that automatically switches the engine from CNG or LPG to gasoline when the alternative fuel tank is nearly empty. Source: Alternative Fuel Vehicle Group.

Best Available Control Technology (BACT)	Best Available Control Technology to reduce specific air pollutants. Source: TCEQ.
Bi-Fuel Vehicle	A vehicle with two separate fuel systems designed to run on either an alternative fuel, or gasoline or diesel using only one fuel at a time. CAA and EPACT refers to bi-fuel vehicles as also being referred to as dual-fuel vehicles. Source: Alternative Fuel Vehicle Group.
Biochemical Conversion	The use of enzymes and catalysts to change biological substances chemically to produce energy products. For example, the digestion of organic wastes or sewage by microorganisms to produce methane is a biochemical process. Source: Alternative Fuel Vehicle Group.
Biodiesel	A biodegradable transportation fuel for use in diesel engines that is produced through the transesterification of organically derived oils or fats. It may be used either as a replacement for or as a component of diesel fuel. Source: Alternative Fuel Vehicle Group.
Biogenic	When discussing the formation of ground-level ozone, the term “biogenic sources” refers to natural sources of ozone precursors. These natural sources, such as trees and other plants, emit only volatile organic compounds (VOCs), not NOx. In the ozone formation modeling process, emissions of VOCs from vegetation are estimated by taking into account the species of trees and plants present, the density of their foliage, the temperature and solar radiation on the day in which ozone formation is being modeled, and the distribution of vegetation throughout the modeling domain. Among trees the largest emitters of VOCs, according to the Texas Commission on Environmental Quality, are oaks, pines, sweet gums, eucalyptus, and poplars. Some VOCs, such as the fragrances emitted by pine, sycamore, and eucalyptus, are easy to identify by their smell.
Biomass	Renewable organic matter such as agricultural crops, crop-waste residues, wood, animal, and municipal waste, aquatic plants, and fungal growth, etc., used for the production of energy. Source: Alternative Fuel Vehicle Group.
Btu	One BTU (British Thermal Unit) is a measurement of heat. A BTU is the amount of heat needed to raise the temperature of one pound of water one degree Fahrenheit. Anything that produces heat or uses energy can be measured in BTUs. BTUs are produced by the burning of energy resources such as fossil fuels and wood. Here are some examples of the BTUs typically needed to run these common household appliances for one year: Clock 17,065 Garbage disposal 170,650 Electric blanket 682,600 Coffee maker 1,023,900 Computer 1,365,200 Color TV 3,413,000
Butane	A gas, easily liquefied, recovered from natural gas. Used as a low-volatility component of motor gasoline, processed further for a high-octane gasoline component, used in LPG for domestic and industrial applications and used as a raw material for petrochemical synthesis and as a solvent. Source: Alternative Fuel Vehicle Group.
Butyl Alcohol	Alcohol derived from butane that is used in organic synthesis and as a solvent. Source: Alternative Fuel Vehicle Group.

CAMS	Continuous Air Monitoring Stations record information, which can be used to document local air quality and trends, confirm effectiveness of emissions control measures, and provide data to emergency response teams. San Antonio area has four stations that collect and report ozone data.
Carbon Dioxide (CO2)	A product of combustion that has become an environmental concern in recent years. CO2 does not directly impair human health but is a "greenhouse gas" that traps the Earth's heat and contributes to the potential for global warming. Source: Alternative Fuel Vehicle Group
Carbon Monoxide (CO)	A colorless, odorless gas produced by the incomplete combustion of fuels with a limited oxygen supply as in automobile engines. CO is poisonous if inhaled, entering the bloodstream through the lungs and forming carboxyhemoglobin, a compound that inhibits the blood's capacity to carry oxygen to organs and tissues. CO can impair exercise capacity, visual perception, manual dexterity, and learning functions. Source: Alternative Fuel Vehicle Group.
CARE	Certified Auto Ride in an Emergency (CARE) is commuter's insurance. If you commute to work at least three times a week by carpool, bicycle, walking, or on a VIA bus, then for $15 dollars you are eligible to purchase this insurance. CARE offers up to four vouchers which can be redeemed for cab rides whenever an emergency arises. Click here for more information
Clean Air Act	Congress created the Clean Air Act (CAA, 1990) to protect our health and air from further damage, and to begin to reverse some of the damage caused by decades of air pollution. The simple fact is that air pollution can make you sick, damage the environment, damage property, and cause haze that reduces visibility in national parks and interferes with aviation. The Clean Air Act aims to improve air quality in the United States, which is a positive thing for your health, your property, and the environment.
Clean Air Plan	Local solutions to the clean air challenge in the San Antonio region. Visit www.aacog.com/cap for more information.
Clean Cities Program	A voluntary program established and administered by the Department of Energy (DOE) to increase AFV market penetration, particularly in more polluted urban areas. Clean Cities chapters are recognized by DOE has having successfully established a self-sustaining environment for AFVs. Specific chapters may include federal, state, and local government agencies, vehicle manufacturers and suppliers, fleet managers, utilities, local distribution companies, and other stakeholders. The first international entities joined the program in 1995. Source: Alternative Fuel Vehicle Group.
Clean Diesel	An evolving definition of diesel fuel with lower emission specifications, which strictly limit sulfur content to 0.05% weight%; in California, aromatics content is further limited to 10 volume % (for large refiners).
Clean Fuel	Any fuel or power source that is used to certify a vehicle to the LEV, ILEV, ULEV, SULEV, or ZEV standard. Source: Alternative Fuel Vehicle Group.
Clean Fuel Fleet (CFF)	The Clean Fuel Fleet Program was initiated by the Clean Air Act Amendments of 1990. The CAAA requires the established of clean-fuel vehicle programs, one of which is the CFF program, mandating designated fleets to allocate certain percentages of new vehicle purchases that meet clean-vehicle (CFV) emission standards. Source: Alternative Fuel Vehicle Group.
Clean Fuel Vehicle (CFV)	Any vehicle certified by the EPA as meeting certain federal emissions standards. The five categories of Federal CFVs, from least to most stringent, are TLEV, LEV, ULEV, ILEV, and ZEV. CRVs are eligible for two Federal programs: The California Pilot Program and the Clean-Fuel Fleet Program. CFV exhaust emissions standards for light-duty vehicles and light duty trucks are numerically identifiable to those of CARB’s Low Emission Vehicle Program. Source: Alternative Fuel Vehicle Group.
Code of Federal Regulations (CFR)	Publication containing federal regulations. EPA regulations are in Title 40 (40 CFR). These can be found at law libraries and some public libraries. Call before you go. Source: TCEQ
Compliance	Observing and accepting all the TCEQ and federal environmental rules and regulations. Source: TCEQ.
Compressed Natural Gas (CNG)	Natural gas that has been condensed under high pressures, typically between 2,000 and 3,600 pounds per square inch, held in a container. The gas expands when released for use as a fuel. Source: Alternative Fuel Vehicle Group.
Compression Ignition	The form of ignition that initiates combustion in a diesel engine. The rapid compression of air within the cylinders generators requires heat to ignite the fuel. Source: Alternative Fuel Vehicle Group.
Contaminant	An element that soils the air. Source: TCEQ.
Converted Vehicle	A vehicle originally designed to operate on gasoline or diesel that has been modified or altered to run on an alternative fuel. Source: Alternative Fuel Vehicle Group.
Corporate Average Fuel Economy (CAFÉ)	Law passed in 1975 that set federal fuel economy standards. The CAFÉ values are an average of city and highway fuel economy test results weighted by a manufacturer for either its car or truck fleet. A program created to determine whether vehicle manufacturers are complying with the gas mileage, or gruel economy, standards set by the federal government. The CAFÉ values are obtained by combining the city and highway fuel economy test results and computing and average that is weighted by vehicle sales. Source: Alternative Fuel Vehicle Group.

Dedicated Natural Gas Vehicle	A vehicle that operates only on natural gas. Such a vehicle is incapable of running on any other fuel. Source: Alternative Fuel Vehicle Group.
Dedicated Vehicle	A vehicle that operates only on one fuel. Generally, dedicated vehicles have superior emissions and performance results because their design has been optimized for operation on a single fuel. Source: Alternative Fuel Vehicle Group.
Design Value	A design value is another tool that can be used to understand pollution levels in a specific location. A design value may be set for any pollutant. The U.S. EPA's official definition: "a design value is the mathematically determined pollutant concentration at a particular site that must be reduced to, or maintained at or below the National Ambient Air Quality Standard to assume attainment." In other words, the number can tell us how we're doing in terms of controlling air pollution - i.e., whether a location is below the standard level or above it.
Diesel Fuel	Petroleum products normally used as fuel for diesel engines are components of crude oil having heavy hydrocarbons containing at least 16 to 123 carbon atoms per molecule. These heavier fractions are taken from crude oil after the more volatile portions used in gasoline are removed. Source: Alternative Fuel Vehicle Group.
Dimethyl Ether (DME)	A synthetic diesel fuel derived from natural gas, an excellent candidate for direct-injection engines. DME contains no sulfur and burns more cleanly than conventional diesel fuel, so it produces fewer particulates. It behaves much like propane. Source: Alternative Fuel Vehicle Group.
Domestic Fuel	As defined by the Energy Policy Act, Section 301, domestic fuel is derived from resources within the United States, its possessions and commonwealths, and Canada and Mexico (the two nations in a free-trade agreement with the U.S.). Source: Alternative Fuel Vehicle Group.
Dual-Fuel Vehicle	EPAct Definition: Vehicle designed to operate on a combination of an alternative fuel and a conventional fuel. This includes: a) vehicles using a mixture of gasoline or diesel and an alternative fuel in one fuel tank, commonly called flexible-fueled vehicles; and b) vehicles capable of operating either on an alternative fuel, a conventional fuel, or both, simultaneously using two fuel systems, commonly called bi-fuel vehicles. Source: Alternative Fuel Vehicle Group.

EAC	The Early Action Compact (EAC) was written as an agreement between local governments, the TCEQ, and the EPA designed to develop and implement control strategies, account for growth, and achieve and maintain the 8-hour ozone standard. The EAC will offer a more efficient time line for achieving emission reductions than the EPA's expected 8-hour implementation rule making, while providing "fail-safe" provisions for the area to revert to the traditional State Implementation Plan (SIP) process if specific milestones are not met. The EAC has been integrated into our area’s Clean Air Plan.
EEMs	Energy Efficient Mortgages allow larger mortgages for homes meeting certain energy efficiency standards. Since highly efficient structures will use less energy, utility bills are lower and more income is available to pay the mortgage. This program promotes the construction of new energy efficient homes, qualifies buyers for a larger loan if the home meets certain energy-efficient criteria, and allows buyers to roll the cost of energy improvements into their mortgages.
Eight-Hour Average Ozone Standard	The eight-hour average ozone standard is one of the National Ambient Air Quality Standards, designed by the U.S. Environmental Protection Agency to keep pollution levels in the ambient air within healthy limits. This standard is set at 85 parts per billion, that is, there should only be 85 molecules (or less) of ozone per billion molecules of air in the air we breathe, averaging over an eight hour period. In judging whether an area’s air quality has become unhealthy because of ozone pollution, and thus whether the area should be designated “non-attainment ” of the standard, the EPA examines ozone pollution averages over three years. For any three year period, the EPA will look at the four highest 8-hour average ozone pollution levels in each year, then drop the three highest levels from each year. They then average the fourth-highest 8-hour averages from the three years to get the three-year 8-hour average. If this average is higher than 85 ppb, they may designate the area in question to be in “non-attainment.” Example Calculation: For three successive years, A, B, and C, the EPA will look at the four days within those years that had the highest 8-hour ozone levels, days 1, 2, 3, and 4. Note that only the fourth-highest values for each year count. Thus, the three-year ozone average is calculated by averaging 89, 84, and 90. The three year average 8-hour ozone value for this hypothetical case would be 87.6 ppb, and, hence, this hypothetical area would be in violation of the 8-hour ozone standard. To see where our region stands in terms of its compliance with the 8-hour ozone standard, email: pbella@aacog.com.
Electric Vehicle (EV)	A vehicle powered by electricity, usually provided by batteries, but may also be provided by photovoltaic (solar) cells or a fuel cell. Source: Alternative Fuel Vehicle Group.
Emissions	An emission inventory is an accounting of the amount of air pollutants discharged into the atmosphere. It is generally characterized by the following factors: The chemical or physical identity of the pollutants included; The geographic area covered; The institutional entities covered; The time period over which emissions are estimated; and The types of activities that cause emissions. Emission inventories are developed for a variety of purposes. Inventories of natural and anthropogenic emissions are used by scientists as inputs to air quality models, by policy makers to develop strategies and policies or track progress of standards, and by facilities and regulatory agencies to establish compliance records with allowable emission rates. A well constructed inventory should include enough documentation and other data to allow readers to understand the underlying assumptions and to reconstruct the calculations for each of the estimates included.
Emissions Inventory	A list of air pollutant sources and the amounts emitted into a community's air. Source: TCEQ.
Emission Standard	The great amount of a pollutant that can be discharged from a single source.
Energy Policy Act of 1992 (EPAct)	A broad ranging act signed into law on Oct. 25, 1992. Titles III, IV, V, XV and XIX of EPAct deal with alternative transportation fuels. EPAct accelerates the purchase requirements for AFVs by the federal and state fleets, proposes eliminating the cap on CAFE credits that manufacturers can earn by producing dual- and flexible-fuel vehicles and requires fleets in large urban areas to purchase AFVs. Establishes tax incentives for purchasing AFVs, converting conventional gasoline vehicles to operate on alternative fuels and installation refueling or recharging facilities by the private sector. Source: Alternative Fuel Vehicle Group.
Energy Star	ENERGY STAR offers businesses and consumers energy efficient solutions -- helping to save money while protecting the environment for future generations. ENERGY STAR is the government-backed symbol for energy efficiency. The ENERGY STAR label makes it easy to know which products to buy for the home or office. Click here for more information: http://www.energystar.gov/default.shtml
Environmental Protection Agency	The Environmental Protection Agency (EPA) works with federal agencies, state and local governments, and Indian tribes to develop and enforce regulations under existing environmental laws. The EPA is responsible for researching and setting national standards for many environmental programs and delegates to states and tribes responsibility for issuing permits, and monitoring and enforcing compliance. Where national standards are not met, the EPA can issue sanctions and take steps to assist in reaching the desired levels of environmental quality. Click here for more information: http://www.epa.gov/
Ethanol	Can be produced chemically from ethylene or biologically from the fermentation of various sugars from carbohydrates found in agricultural crops and cellulosic residues from crops or wood. Used in the United States as a gasoline octane enhancer and oxygenate. Ethanol can also be used in higher concentration in alternative-fuel vehicles optimized for its use. Source: Alternative Fuel Vehicle Group.
Exhaust Emissions	Exhaust emissions are the pollutants emitted by the engine through the tailpipe. High exhaust emission leads to smog, poor air quality, and global warming. Source: Alternative Fuel Vehicle Group.

Facility	A specific structure, device, item, equipment, or enclosure that is and/or contains a stationary source. Source: TCEQ.
Flexible Fuel Vehicle	A vehicle that can operate on either alcohol fillers (methanol or ethanol) or regular unleaded gasoline or any combination of the two from the same tank. Source: Alternative Fuel Vehicle Group.
Fuel Cell	An electrochemical engine (no moving parts) that converts the chemical energy of a fuel such as hydrogen, and an oxidant, such as oxygen, directly to electricity. The principal components of a fuel cell are catalytically activated electrodes for the fuel (anode) and the oxidant (cathode) and an electrolyte to conduct ions between the two electrodes. Source: Alternative Fuel Vehicle Group.
Fugitive Dust	PM-10 suspended in the air by wind action and human activities. Source: TCEQ.

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For more information about AACOG's Air Quality Program contact:

Peter Bella, AACOG Natural Resources Director
8700 Tesoro Drive, Suite 700
San Antonio, TX 78217
Phone: (210) 362-5249
Fax: (210) 225-5937
E-Mail: pbella@aacog.com