## GLOSSARYGlossary

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### GLOSSARY AAQS (Ambient Air Quality Standards): Hea lth and welfare based standards for clean outdoor air that identify the maximum accep table average concentrations of air pollutants during a specified period of time. (See NAAQS)

Acute Health Effect: An adverse health eff ect that occurs over a relatively short period of time (e.g., minutes or hours). Aerosol: Particles of solid or liquid matter that can remain suspended in air for long periods of time because of extrem ely small size and light weight. Air Pollutants: Amounts of foreign and/ or natural substances occurring in the atmosphere that may result in adverse effe cts on humans, animals, vegetation, and/or materials. Air Quality Simulation Model: A computer program that simulates the transport, dispersion, and transformati on of compounds emitted into th e air and can project the relationship between emissions and air quality. Air Toxics: A generic term re ferring to a harmful chemical or group of chemicals in the air. Typically, substances that are especi ally harmful to hea lth, such as those considered under EPA's hazardous air pollu tant program or California's AB 1807 toxic air contaminant program, are consider ed to be air toxics. Technically, any compound that is in the air and has the poten tial to produce adverse health effects is an air toxic. Airborne Toxic Control Measure (ATCM): A type of control meas ure, adopted by the ARB (Health and Safety Code Section 39666 et seq.), which reduces emissions of toxic air contaminants from nonvehicular sources.

Alternative Fuels: Fuels such as methanol , ethanol, natural gas, and liquid propane gas that are cleaner burning and help to meet ARB's mobile and stationary emission standards. Ambient Air: The air occurring at a partic ular time and place outside of structures. Often used interchangeably with "outdoor" air. APCD (Air Pollution Control District): A county agency with authority to regulate stationary, indirect, and area sources of air pollution (e.g., power plants, highway construction, and hous ing developments) within a gi ven county, and governed by a district air pollution control board compos ed of the elected county supervisors. (Compare AQMD.) AQMD (Air Quality Management District): A group or portions of counties, or an individual county specified in law with authority to regulate stationary, indirect, and area sources of air pollution within th e region and governedby a regional airFinal 2003 AQMP

G - 2 pollution control board comprised mostly of elected officials from within the region. (Compare APCD.) AQMP (Air Quality Management Plan): A Plan prepared by an APCD/AQMD, for a county or region designated as a nonattainment area, for the purpose of bringing the area into compliance with the requirements of the national and/or California Ambient Air Quality Standards. AQMPs are incorporated into the State Implementation Plan (SIP). ARB (California Air Resources Board): The State's lead air quality agency, consisting of a nine-member Governor-appointed board. It is responsible for attainment and maintenance of the State and federal air qua lity standards, and is fully responsible for motor vehicle pollution control. It oversees county and regional air pollution management programs. Area-wide Sources (also known as "area" sources): Stationarysources of pollution (e.g., water heaters, gas furnaces, fireplaces, and wood stoves) that are typically associated with homes and non-industrial sources. The CCAA requires districts to include area sources in the development and implementation of the AQMPs. Atmosphere: The gaseous mass or envelope surrounding the earth. Attainment Area: A geographic area which is in compliance with the National and/or California Ambient Air Quality Standards (NAAQS OR CAAQS). Attainment Plan: In general, a plan that details the emission reducing control measures and their implementation schedule necessary to attain air quality standards. In particular, the federal Clean Air Act re quires attainment plans for nonattainment areas; these plans must meet several requi rements, including requirements related to enforceability and adoption deadlines. BACT (Best Available Control Technology): The most up-to-date methods, systems, techniques, and production processes availa ble to achieve the greatest feasible emission reductions for given regulated air pollutants and processes. BACT is a requirement of NSR (New Source Review ) and PSD (Prevention of Significant Deterioration). BACT as used in federa l law under PSD is defined as an emission limitation based on the maximum degree of emissions reductions allowable taking into account energy, environmental & ec onomic impacts and other costs. [(CAA Section 169(3)]. The term BACT as usedin state law means an emission limitation that will achieve the lowest achievable emission rates, which means the most stringent of either the most stringent em ission limits contained in the SIP for the class or category of source, (unless it is demonstrated that one limitation is not achievable) or the most stringent emission limit achieved in practice by that class in category of source. “BACT” under state law is more stringent than federal BACT and is equivalent to fede ral LAER (lowest achievable emission rate) which applies to NSR permit actions.Glossary

G - 3 BAR (Bureau of Automotive Repair): An agency of the California Department of Consumer Affairs that manages the implem entation of the motor vehicle Inspection and Maintenance Program. CAA (Federal Clean Air Act): A federa l law passed in 1970 and amended in 1977 and 1990 which forms the basis for the nationa l air pollution control effort. Basic elements of the act include national am bient air quality standards for major air pollutants, air toxics standards, acid rain control measures, and enforcement provisions. CAAQS (California Ambient Air Quality Standards): Standards set by the State of California for the maximum levels of air pollutants which can exist in the outdoor air without unacceptable effects on human hea lth or the public welfare. These are more stringent than NAAQS. CCAA (California Clean Air Act): A Calif ornia law passed in 1988 which provides the basis for air quality planning and regulation inde pendent of federal regulations. A major element of the Act is the requireme nt that local APCDs/AQMDs in violation of state ambient air quality standards mustprepare attainment plans which identify air quality problems, causes, tr ends, and actions to be take n to attain and maintain California's air quality standards by the earliest practicable date. CEQA (California Environmental Quality Act) : A California law which sets forth a process for public agencies to make info rmed decisions on discretionary project approvals. The process aids decisi on makers to determine whether any environmental impacts are associated w ith a proposed project. It requires environmental impacts associated with a propos ed project to be identified, disclosed, and mitigated to the maxi mum extent feasible. CFCs (Chlorofluorocarbons): Any of a number of substanc es consisting of chlorine, fluorine, and carbon. CFCs ar e used for refrigeration, foam packaging, solvents, and propellants. They have been found to cause depletion of the atmosphere's ozone layer.

Chronic Health Effect: An adverse healtheffect which occurs over a relatively long period of time (e.g., months or years). CMB (Chemical Mass Balance): This re ceptor model is used for PM10 source apportionment, matching the measured ch emical components of the PM10 samples with known chemical profiles, or signatures, of individual sources of PM10 particles. The 1995 PTEP enhanced PM m onitoring program results have been used to update the 1986 analysis used in previous AQMPs. CO (Carbon Monoxide): A colorless, odor less gas resulting from the incomplete combustion of fossil fuels. Over 80% of the CO emitted inurban areas is contributed by motor vehicles. CO inte rferes with the blood's ability to carry oxygen to the body's tissues and re sults in numerous adverse health effects. CO is a criteria air pollutant.Final 2003 AQMP

G - 4 Conformity: Conformity is a process mandate d in the federal Clean Air Act to insure that federal actions do not impede attainme nt of the federal health standards. General conformity sets out a process that requires federal agencies to demonstrate that their actions are air quality neutral or beneficial. Transportation conformity sets out a process that requires transportati on projects that receive federal funding, approvals or permits to de monstrate that their actions are air quality neutral or beneficial. Congestion Management Progr am: A state mandated program (Government Code Section 65089a) that requires each county to prepare a plan to relieve congestion and reduce air pollution.

Consumer Products: Products such as dete rgents, cleaning compounds, polishes, lawn and garden products, personal care produc ts, and automotive specialty products which are part of our everyday lives and, through consumer use, may produce air emissions which contribute to air pollution. Contingency Measure: Conti ngency measures are statut e-required back-up control measures to be implemented in the event of specific conditions. These conditions can include failure to meet interim milestone emission reduction targets or failure to attain the standard by the statutory attainme nt date. Both state and federal Clean Air Acts require that District plan s include contingency measures.

Electric Motor Vehicle: A moto r vehicle which uses a battery-powered electric motor as the basis of its operation. Such vehicles emit virtually no air pollutants. Hybrid electric motor vehicles may operate us ing both electric and gasoline powered motors. Emissions from hybrid electric moto r vehicles are also substantially lower than conventionally powered motor vehicles.

EMFAC: The EMission FACtor model usedby ARB to calculate on-road mobile vehicle emissions. This model is partof ARB’s overall on-road mobile source Mobile Vehicle Emission Inventory (M VEI) model. The 1997 AQMP is based on the latest version of EMFA C and MVEI, which is 7G. (The 1994 AQMP was based on the previous version, EMFAC7F.) Emission Inventory: An estimate of the amount of pollutants em itted from mobile and stationary sources into the atmosphere over a specific period such as a day or a year. Emission Offset (also known as an emission tr ade-off): A rule-mak ing concept whereby approval of a new or modified stationary source of air pollution is conditional on the reduction of emissions from othe r existing stationary sources of air pollution. These reductions are required in additi on to reductions required by BACT.

Emission Standard: The maximum amount of a pollutant that is allowed to be discharged from a polluting source such as an automobile or smoke stack. EPA (Environmental Protection Agency): The United States agency charged with setting policy and guidelines, and carrying out legal mandates for the protection of national interests in environmental resources.Glossary

G - 5 FIP (Federal Implementation Plan): In the absence of an approve d State Implementation Plan (SIP), a plan prepared by the EPA wh ich provides measures that nonattainment areas must take to meet the requirements of the Federal Clean Air Act. Fugitive Dust: Dust particles which are in troduced into the air through certain activities such as soil cultivation, off-ro ad vehicles, or any vehicles operating on open fields or dirt roadways. Growth Management Plan: A plan fo r a given geographica l region containing demographic projections (i .e., housing units, employmen t, and population) through some specified point in time, and wh ich provides recommendations for local governments to better manage growth and reduce projected environmental impacts. Hydrocarbon: Any of a large number of co mpounds containing various combinations of hydrogen and carbon atoms They may be emitte d into the air as a result of fossil fuel combustion, fuel volatiliz ation, and solvent use, and are a major contributor to smog. (Also see VOC.) Indirect Source: Any facility, building, struct ure, or installation, or combination thereof, which generates or attracts mobile source ac tivity that results in emissions of any pollutant (or precursor) for which there is a state ambient air quality standard. Examples of indirect sources include employment sites, shoppi ng centers, sports facilities, housing developments, airports, commercial and industrial development, and parking lots and garages. Indirect Source Control Program: Rules, regulations, local ordi nances and land use controls, and other regulatory strategies of air pollution control districts or local governments used to control or reduce emi ssions associated with new and existing indirect sources. Inspection and Maintenance Program: A motor vehicle inspection program implemented by the BAR. It is designed to identify vehicles in need of maintenance and to assure the effectiveness of their em ission control systems on a biennial basis. Enacted in 1979 and strengthened in 1990. (Also known as the "Smog Check" program.) LEV (Low Emission Vehicle): A vehicle which is certified to meet the ARB 1994 emission standards for low emission vehicles. Maintenance Plan: In general, a plan that details the actions necessary to maintain air quality standards. In particular, the fe deral Clean Air Act requires maintenance plans for areas that have been redesignated as attainment areas.

Mobile Sources: Sources of ai r pollution such as automobile s, motorcycles, trucks, offroad vehicles, boats and airplanes. (Contrast with stationary sources.) NAAQS (National Ambient Air Quality Standards): Standards set by the federal EPA for the maximum levels of air pollutants which can exist in the outdoor air without unacceptable effects on human health or the public welfare.Final 2003 AQMP

G - 6 Nitrogen Oxides (Oxides of Nitrogen, NO x ): A general term pertaining to compounds of nitric acid (NO), nitrogen dioxide (NO 2 ), and other oxides of nitrogen. Nitrogen oxides are typically created during combusti on processes, and are major contributors to smog formation and acid deposition. NO 2 is a criteria air pollutant, and may result in numerous adverse health effect s; it absorbs blue light, resulting in a brownish-red cast to the atmosphere and reduced visibility. NonAttainment Area: A geographic area identified by the EPA and/or ARB as not meeting either NAAQS or CAAQS st andards for a given pollutant. NSR (New Source Review): A program usedin development of permits for new or modified industrial facilities which are in a nonattainment area, and which emit nonattainment criteria air pollutants. The two major requirements of NSR are Best Available Control Technol ogy and Emission Offset. Ozone: A strong smelling, pale blue, reactiv e toxic chemical gas consisting of three oxygen atoms. It is a product of the photochemical process involving the sun's energy. Ozone exists in the upper atmosphe re ozone layer as well as at the earth's surface. Ozone at the earth's surface causes numerous adverse health effects and is a criteria air pollutant. It is a major component of smog. Ozone Precursors: Chemicals such as hydr ocarbons and oxides of nitrogen, occurring either naturally or as a result of human activities, which contribute to the formation of ozone, a major component of smog. Permit: Written authorization from a gove rnment agency (e.g., an air quality management district) that allows for the construction and/ or operation of an emissions generating facility or its equi pment within certain specified limits. PIC (Particle-in-Cell) Model: An air quality simulation model that is used to apportion sulfate and nitrate PM10 concentrations to their precursor emissions sources. The PIC model uses spatially and tempora lly resolved sources of NOx and SOx emissions, with meteorological, physical, and simplified chemical processes, to calculate the contributions from various emission source categories. PM (Particulate Matter): Solid or liquid particles of soot, dust, smoke, fumes, and aerosols. PM10 (Particulate Matter less than 10 microns): A major air pollutant consisting of tiny solid or liquid particles of soot, dust, sm oke, fumes, and aerosols. The size of the particles (10 microns or sma ller, about 0.0004 inches or less) allows them to easily enter the air sacs in the lungs where th ey may be deposited, resulting in adverse health effects. PM10 also causes visib ility reduction and is a criteria air pollutant. PM2.5 (Particulate Matter less than 2.5 microns ): A major air pollutant consisting of tiny solid or liquid particles, generally soot and aerosols. The size of the particles (2.5 microns or smaller, about 0.0001 inches or less) allows them to easily enter the air sacs deep in the lungs where they may cause adverse health effects, as noted inGlossary

G - 7 several recent studies. PM2.5 also causes visibility reduction, but is not considered a criteria air pollutant at this time. PSD (Prevention of Significant Deterioration): A programused in development of permits for new or modified industrial fa cilities in an area that is already in attainment. The intent is to preven t an attainment area from becoming a nonattainment area. This program, like NSR, can require BACT and, if an AAQS is projected to be exceeded, Emission Offsets. PTEP (PM10 Technical Enhancement Program ): A cooperative study to improve the technical knowledge base for PM10, partic ularly ambient PM measurements (mass and composition), improved emission i nventory estimates, and improved PM modeling tools. Public Workshop: A workshop held by a public agency for the purpos e of informing the public and obtaining its input on the development of a re gulatory action or control measure by that agency. RME (Regional Mobility Element): The Regional Mobility Element (RME) is the principal transportation policy, strategy, and objective statement of the Southern California Association of Governments, proposing a comprehensive strategy for achieving mobility and related air quality mandates. The impacts of RME are included in the AQMP. ROG (Reactive Organic Gas): A reactive chem ical gas, composed of hydrocarbons, that may contribute to the formation of smog. Also sometimes referred to as NonMethane Organic Compounds (NMOCs). (Also see VOC.) SIP (State Implementation Plan): A document prepared by each st ate describing existing air quality conditions and measures which will be taken to attain and maintain national ambient air quality standards (see AQMP). Smog Check Program: (See Inspection and Maintenance Program.) Smog: A combination of smoke, ozone, hydrocarbons, nitrogen oxides, and other chemically reactive compounds which, unde r certain conditions of weather and sunlight, may result in a murky brown haze th at causes adverse health effects. The primary source of smog in California is motor vehicles. Smoke: A form of air pollution consisting primar ily of particulate matter (i.e., particles). Other components of smoke include gase ous air pollutants such as hydrocarbons, oxides of nitrogen, and carbon monoxide. S ources of smoke may include fossil fuel combustion, agricultural burning, and other combustion processes.

SO 2 (Sulfur Dioxide): A strong smelling, colo rless gas that is formed by the combustion of fossil fuels. Power plants , which may use coal or oil high in sulfur content, can be major sources of SO 2 . SO 2 and other sulfur oxides contribute to the problem of acid deposition. SO 2 is a criteria pollutant.Final 2003 AQMP

G - 8 Stationary Sources: Non-mobile sources such as power plants, refineries, and manufacturing facilities which emit air pollutant s. (Contrast with mobile sources.) Toxic Air Contaminant: An air pollutant, identified in regulation by the ARB, which may cause or contribute to an increase in d eaths or in serious illness, or which may pose a present or potential hazard to humanhealth. TACs are considered under a different regulatory process (California Health and Safety Code Section 39650 et seq.) than pollutants subject to CAAQS. H ealth effects due to TACs may occur at extremely low levels, and it is typically di fficult to identify levels of exposure which do not produce adverse health effects. Transportation Control Measure (TCM): Any control measure to reduce vehicle trips, vehicle use, vehicle miles traveled, vehi cle idling, or traffic congestion for the purpose of reducing motor vehicle emissions . TCMs can include encouraging the use of carpools and mass transit. UAM (Urban Airshed Model): The three-di mensional photochemical grid model used to simulate ozone formation. Used to pr oject episodic ozone c oncentrations. (See also air quality simulation model.) UAM/Aero (Urban Airshed Model with Aero sol Chemistry): A three-dimensional photochemical grid model used to simulate PM and ozone formation, based on the UAM. Additional chemical mechanism modul es are used to simulate PM aerosol components. Used to project episodic PM concentrations. UAM/LC (Urban Airshed Model with Line ar Chemistry): A three-dimensional photochemical grid model used to simulate PM formation, particularly particulate sulfates and nitrates. The complex, non- linear chemical mechanism used in UAM and UAM/Aero is replaced by a simplified, linear chemistry that uses empirical relationships to determine particulate nitr ate and sulfate levels. Used to project annual average PM component concentrations. Visibility: The distance that atmospheric c onditions allow a person to see at a given time and location. Visibility reduction from air pollution is often due to the presence of sulfur and nitrogen oxides, as well as particulate matter. VOCs (Volatile Organic Compounds): H ydrocarbon compounds that exist in the ambient air. VOCs contribute to the forma tion of smog and/or may themselves be toxic. VOCs often have anodor, and some examples include gasoline, alcohol, and the solvents used in paints.