Four Corners Air Quality Task Force
Report of Mitigation Options
DRAFT: Version 6
April 25, 2007
The draft report is a compilation of mitigation options drafted by members of the Four Corners Air Quality Task Force. This is not a document to be endorsed by the agencies involved, but rather, a compendium of options for consideration following completion of the Task Force in December 2007.
Four Corners Air Quality Task Force Members List Task Force members were those individuals who regularly attended quarterly meetings, participated in
one or more work groups, and who assisted in drafting and providing comments on the mitigation option
papers and other sections of the Task Force Report.
Erik Aaboe New Mexico Environment Department Santa Fe, NM Zachariah Adelman Carolina Environmental Program Chapel Hill, NC Cindy Allen Colorado Dept. of Public Health and Environment Denver, CO Scott Archer USDI-Bureau of Land Management Denver, Colorado Roger Armstrong Twin Stars Ltd. Farmington, NM
Mary Lou Asbury LWV / Cortez / Montezuma Cortez, CO
Cindy Beeler US Environmental Protection Agency, Region 8 Denver, CO Brittany Benko BP America Durango, CO
Andy Berger New Mexico Environment Department Santa Fe, NM Bruce Beynon Chevron Houston, TX
Michael Brand Cummins Columbus, Indiana
Kevin Briggs Colorado Dept. of Public Health and Environment Denver, CO David Brown BP America Denver, CO
Marilyn Brown League of Women Voters of La Plata Co Durango, CO Walt Brown US Forest Service/BLM, Durango Durango, CO
Fran King Brown AKA Energy Group, LLC (SUIT) Durango, CO Greg Crabtree Envirotech, Inc. Farmington, NM
Jim Cue Caterpillar, Inc. Houston, TX
Mark Dalton Samson Resources Co. Tulsa, OK
Carl Daly US Environmental Protection Agency, Reg. 8 (EPA) Denver, CO Chris Dann Colorado Dept. of Public Health & Environment Denver, CO Joseph Delwiche EPA Region 8 Denver, CO
Kris Dixon Concerned Citizen Farmington, NM
Ryan Dupnick Compliance Controls, LLC Houston, TX
Mike Eisenfeld Tetra Tech Inc./ San Juan Citizens Alliance Farmington, NM Mike Farley PNM Albuquerque, NM
Joel Farrell BLM, Farmington Farmington, NM
Kerri Fieldler Environmental Protection Agency Denver, CO Patrick Flynn Resolute Natural Resources Company Denver, CO Erich Fowler Denver University Student Denver, CO
Bruce Gantner ConocoPhillips Farmington, NM
Mike George National Park Service Austin, TX
Richard (Rich) Goebel Archuleta County Pagosa Springs, CO Kevin Golden US Environmental Protection Agency, Region 8 Denver, CO Bob Gonzalez Caterpillar, inc. Houston, TX
Christi Gordon USDA Forest Service, Southwestern Region 3 Albuquerque, NM Richard Grimes AZ Public Service Co. Fruitland, NM
Terry Hertel New Mexico Environment Department Santa Fe, NM Cheryl Heying Utah Division of Air Quality Salt Lake City, Utah Katherine Holt La Plata Vision 2030 - Environmental Stewardship Durango, CO Eric Janes Retired Federal Employee, USDI Mancos, CO
Susan Johnson National Park Service Denver, CO
Mark Jones New Mexico Environment Department Farmington, NM Bob Jorgenson Colorado Dept. of Public Health & Environment Denver, CO Josh Joswick San Juan Citizens Alliance Durango, Colorado Kyle Kerr Envirotech, Inc. Farmington, NM
Chad King Giant Bloomfield Refinery Bloomfield, NM
Myke Lane Williams Aztec, NM
Doug Latimer US Environmental Protection Agency Region 8 Denver, CO Wilson Laughter Navajo Environmental Protection Agency Fort Defiance, AZ Draft Report of Mitigation Options 2
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Michael Lazaro Argonne National Laboratory Argonne, IL Kim Bruce Livo Colorado Dept. of Public Health and Environment Denver, CO Ran Macdonald Utah Dept. of Environmental Quality Salt Lake City, Utah Jen Mattox Colorado Dept. of Public Health and Environment Denver, CO Mark McMillan Colorado Dept. of Public Health & Environment Denver, CO Shirley McNall Concerned Citizen Aztec, NM
Joe Miller Southern Ute Tribe (Consultant) Arvada, CO
Ray Mohr Colorado Dept. of Public Health & Environment Denver, CO Theodore Mueller Retired Professor, Adams State University Aztec, NM Michael Nelson Conoco Phillips Co. Houston, TX
Craig Nicholls USDI-Bureau of Land Management Denver, CO Jeremy Nichols Rocky Mountain Clean Air Action Denver, CO Koren Nydick Mountain Studies Institute Durango, CO
Ted Orf Orf & Orf Denver, CO
Casey Osborn EMIT Technologies Sheridan, WY
Kelly Palmer USFS / BLM Durango, CO
Bill Papich BLM Farmington, NM
Margie Perkins Colorado Dept. of Public Health and Environment Denver, CO Gordon Pierce Colorado Dept. of Public Health and Environment Denver, CO Debby Potter US Forest Service, Reg. 3 Albuquerque, NM John Prather Devon Energy Corporation Navajo Dam, NM
Dan Randolph San Juan Citizens Alliance Durango, CO
Jan Rees Concerned Citizen Bloomfield, NM
Rebecca Reynolds 4CAQTF Project Manager, RRC Inc. Brighton, CO Roxanne Roberts Williams Tulsa, OK
Bud Rolofson USDA - U.S. Forest Service Golden, Colorado Curtis Rueter Noble Energy, Inc. Denver, CO
Dave Ruger Honeywell Farmington, NM
George San Miguel Mesa Verde National Park Mesa Verde, CO Mark Sather US Environmental Protection Agency, Region 6 Dallas, TX Randy Schmaltz Giant Bloomfield Refinery Bloomfield, NM David Schneck San Miguel Co. Environmental Health Dept. Telluride, CO Ted Schooley New Mexico Environment Department Santa Fe, NM Jack Schuenemeyer Southwest Statistical Consulting, LLC Cortez, CO Brett Sherman La Plata County Government Durango, CO Mike Silverstein Colorado Dept. of Public Health and Environment Denver, CO Stacey Simms American Lung Association / Clean Cities Coalition Greenwood Village, CO
Kellie Skelton Energen Resources Inc. Farmington, NM Reid Smith BP America Houston, TX
Carla Sonntag NMUSA Albuquerque, NM
Jeff Sorkin US Forest Service, Reg. 4 Golden, CO
Lisa Sumi Oil and Gas Accountability Project Durango, CO Zach Tibodeau Beaver Creek Resorts / Vail Associates Avon, CO Ron Truelove Devon Oklahoma, City, Oklahoma
Rita Trujillo New Mexico Environment Department Santa Fe, NM Evan Tullos EPCO, Inc. Farmington, NM
Mary Uhl New Mexico Environment Department Santa Fe, NM Wano Urbonas San Juan Basin Health Department Durango, CO Callie Vanderbilt San Juan College Farmington, NM
Beverly Warburton Citizen Pagosa Springs, CO
Sarah Jane White Dine CARE / Dooda Desert Rock Committee Shiprock, NM. Brady Winkleman Caterpillar, Inc. Lafayette, IN
Dale Wirth Bureau of Land Management, Farmington Farmington, NM
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Four Corners Air Quality Task Force Interested Parties List Interested Parties were those individuals who followed the progress of the Task Force, and who may have
attended one or more quarterly meetings, may have participated in work groups and may have provided
comments on sections of the Task Force Report.
Reid Allan Souder, Miller & Associates Farmington, NM Lee Alter Western Governors' Association Denver, CO
Charlene Anderson Creative Geckos Farmington, NM
Donald Anderson Private Citizen, VLUA Bayfield, CO Blair Armstrong TEPPCO - Natural Gas Services Bloomfield, NM Mohan Asthana Navajo Environmental Protection Agency Fort Defiance, AZ Amon Bar-Ilan ENVIRON International Corporation Novato, CA Richard Baughman Southern Ute Department of Energy Ignacio, CO David Bays Williams
Joe Becko Cummins Rocky Mountain Avondale, AZ
Steve Begay Navajo Nation; Dine Power Authority Window Rock, AZ Erickson Bennally Dine Power Authority Window Rock, AZ Carlos Betancourth Farmington MPO Farmington, NM
Gail Binkly Four Corners Free Press
Robin Blanchard SJCA Aztec, NM
Doug Blewitt Representing BP Englewood, CO
Sheila Burns Colorado Dept. of Public Health and Environment Denver, CO James Chivers Citizen
Hugh Church American Lung Association of NM
Roger Clark Grand Canyon Trust Flagstaff, AZ
Cynthia Cody US EPA Region 8 Denver, CO
Leona Conger League of Women Voters Durango, CO
Joe Cotie New Mexico Environment Department Farmington, NM Chris Crabtree Science Applications Int Corp Santa Barbara, CA Orion Crawford Citizen
Nicholas Cullander Concerned Citizen
Pat Cummings Western Governors' Association Bayfield, CO Michele Curtis Caterpillar Denver, CO
Mike D'Antonio PNM Albuquerque, NM
Joseph Delwiche EPA Region 8 Denver, CO
Gus Eghneim Wood Group
Joe Elliott Industrial Maintenance Service Lawndale, CA Bob Estes URS Corporation
Don Fernald Enterprise Products Operating LP Santa Fe, NM Karin Foster Independent Petroleum Association
Erich Fowler Denver University Student Denver, CO
Brett Francois San Juan Basin Health Department Durango, CO Susan Franzheim Citizen Durango, CO
Dan Frazer Sierra Club
Virgil Frazier SUIT GF
Steve Frey US Environmental Protection Agency, Region 9 San Francisco, CA Ron Friesen ENVIRON International Corporation Novato, CA Maureen Gannon Public Service Company of New Mexico Albuquerque, NM Gary Gates Corporate Compliance, Inc. Thornton, CO
Gordon Glass Sierra Club / Democratic Party Farmington, NM Lori Goodman Dine CARE Durango, CO
Art Goodtimes San Miguel County
Bill Green NMED-AQB Santa Fe, NM
Lee Gribovicz Western Governors' Association / WRAP Cheyenne, Wyoming Sherri Grona Northwest New Mexico Council of Governments Farmington, NM Draft Report of Mitigation Options 4
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Dick Grossman Citizen
Bill Hagler NMUSA
Carol Harkins New Mexico Environment Department Farmington, NM Jacob Hegeman Stateside Associates Arlington, VA Daniel Herman WDEQ\Division of Air Quality Cheyenne, WY Robert Heyduck New Mexico State University - Ag Science Center Farmington, NM
Cheryl Heying Utah Division of Air Quality Salt Lake City, UT Ethan Hinkley Southern Ute Indian Tribe Ignacio,CO Jeanne Hoadley USDA Forest Service Santa Fe, NM Bill Hochheiser U.S. Department of Energy Washington DC Suzanne Holland Chevron North America Houston, TX Rima Idzelis Stateside Associates Arlington, VA Sethuraman Jagadeesan Whiting Petroleum Denver, CO Chris Jocks Ft. Lewis College Durango, CO
Keith Johns Sithe Global New York, NY
Keith Johnson San Juan County Commissioner / Bloomfield Mayor Bloomfield, NM
Isabella Johnson Citizen Farmington, NM
Matt KeeFauver City Council Cortez Cortez, CO
Lisa Killion New Mexico Environment Department Santa Fe, NM Aaron Kimple Friends of the Animas River Durango, CO Richard Knox URS Corporation Phoenix, AZ
Brian Larson SJ Basin Health Department Durango, CO Chris Lee Southern Ute EPD
David LeMoine Concerned Citizen Farmington, NM Kandy LeMoine Concerned Citizen Farmington, NM Renee Lewis Oil and Gas Accountability Project Durango, CO Doug Lorimier Sierra Club
Charles Lundstrom New Mexico Environment Department Grants, NM Javier Macias TEPPCO Houston, TX
Chandler Marechal La Plata County Government
Louise Martinez NMEMNRD Santa Fe, NM
Marilyn McCord Private Citizen, VLUA Bayfield, CO Ann McCoy-Harold Representing Senator Allard
Lisa Meerts The Daily Times & Four Corners Business Journal Durango, CO Rachel Misra Navajo Environmental Protection Agency Fort Defiance, AZ Tom Moore Western Governors' Association Bayfield, CO Michelle Morris Navajo Environmental Protection Agency Fort Defiance, AZ Gary Napp Environment, LLC Paoli, PA 19301
David Neleigh US EPA Region 6 Dallas, TX
Jan Neleigh Citizen Bayfield, CO
Charlene Nelson Navajo Environmental Protection Agency Fort Defiance, AZ Sylvia Oliva National Park Service Cortez, CO
Dan Olsen Colorado State University Fort Collins, CO Dianna Orf Orf and Orf Denver, CO
Mark Pearson SJ Citizens Alliance
Nathan Plagens Sithe Global Farmington, NM
Roger Polisar New Mexico Environment Department Carlsbad, NM Alison Pollack Environ International Corporation Novato, CA James Powers USDA FS
Patricia Prather San Juan County Resident
Jim Ramakka Bureau of Land Management, Farmington Farmington, NM Brinda Ramanathan Serafina Technical Consulting LLC Liana Reilly National Park Service, Air Resources Division Lakewood, CO Jeff Robinson EPA Region 6 Dallas, TX
Dennis Roundtree Onsite Power Inc. Aurora, CO
Larry Rule Montezuma County Commissioner
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Edward Rumbold BLM
James Russell ENVIRON International Novato, CA Brenda Sakizzie SUIT Air Quality Program Ignacio, CO Ken Salazar U.S. Senator Durango, CO
Robert Samaniego New Mexico Environment Department Santa Fe, NM Martin Schluep Kleinfelder, Inc. Albuquerque, NM Judy Schuenemeyer League of Women Voters, Cortez Cortez, CO Runell Seale Enterprise Products Operations LLC Farmington, NM Pat Senecal Town of Ignacio representative Ignacio, CO George Sharpe City of Farmington Commissioner Farmington, NM Chris Shaver National Park Service Denver, CO
Vic Sheldon Caterpillar Inc - Global Petroleum Group Houston, TX George Sievers Citizen Durango, CO
Elaine Slade Citizen Hesperus, CO
Bob Spillers New Mexico Environment Department Santa Fe, NM Karen Spray Colorado Oil & Gas Conservation Commission Durango, CO Jay Stimmel New Mexico Environment Department Santa Fe, NM Till Stoeckenius Environ Novato, CA
Dirk Straussfeld Sithe Global New York, NY
James Temte Southern Ute Tribe Air Quality Ignacio, CO Paul Tourangeau Colorado APCD Denver, CO
Denise Tuck Halliburton Energy Systems, Inc. Houston, TX Kathy Van Dame Wasatch Clean Air Coalition Salt Lake City, UT Joni Vanderbilt USFS - Manti-La Sal National Forest Hesperus, CO John Volkerding Basin Disposal, Inc. Aztec, NM Lany Weaver New Mexico Environment Department Santa Fe, NM Wally White La Plata County, CO Commissioner Durango, CO John Whitney Representing Congressman John Salazar Lisa Winn XTO Energy - San Juan Division Farmington, NM Leslie Witherspoon Solar Turbines Incorporated San Diego, CA Bill Witt Citizen Brighton, CO
Aaron Worstell URS Corporation - Denver Tech Center Denver, CO Winfield Wright Southwest Hydro-Logic Durango, CO Orion Yazzie Dooda Desert Rock Dine CARE Aztec, NM Jim York Safety/Environmental - Sky Ute Sand & Gravel Farmington, NM Angela Zahniser BLM Washington, DC
Jeanne Zamora Indian Health Service
Christi Zeller La Plata County
Alan Zumwalt Archuleta County Public Works Department Draft Report of Mitigation Options 6
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Acid Deposition: A comprehensive term for the various ways acidic compounds precipitate from the atmosphere and deposit onto surfaces. It can include: 1) wet deposition by means of acid rain, fog, and snow; and 2) dry deposition of acidic particles (aerosols).
Acid Rain: Rain which is especially acidic (pH <5.2). Principal components of acid rain typically include nitric and sulfuric acid. These may be formed by the combination of nitrogen and sulfur oxides with water vapor in the atmosphere.
Add-On Control Device: An air pollution control device such as carbon absorber or incinerator that reduces the pollution in exhaust gas. The control device usually does not affect the process being controlled and thus is "add-on" technology, as opposed to a scheme to control pollution through altering the basic process itself. See also pollution prevention.
Adsorber: An emissions control device that removes volatile organic compounds (VOCs) from a gas stream as a result of the gas attaching (adsorbing) onto a solid matrix such as activated carbon.
Adverse Health Effect: A health effect from exposure to air contaminants that may range from relatively mild temporary conditions, such as eye or throat irritation, shortness of breath, or headaches to permanent and serious conditions, such as birth defects, cancer or damage to lungs, nerves, liver, heart, or other organs.
Aerosol: Particles of solid or liquid matter that can remain suspended in air from a few minutes to many months depending on the particle size and weight.
Afterburner: An air pollution abatement device that removes undesirable organic gases through incineration.
Agricultural Burning: The intentional use of fire for vegetation management in areas such as
agricultural fields, orchards, rangelands, and forests.
Air: So called "pure" air is a mixture of gases containing about 78 percent nitrogen; 21 percent oxygen; less than 1 percent of carbon dioxide, argon, and other gases; and varying amounts of water vapor. See also ambient air.
Air Monitoring: Sampling for and measuring of pollutants present in the atmosphere.
Air Pollutants: Amounts of foreign and/or natural substances occurring in the atmosphere that may result in adverse effects to humans, animals, vegetation, and/or materials. (See also air pollution.)
Air Pollution: Degradation of air quality resulting from unwanted chemicals or other materials occurring in the air. (See also air pollutants.)
Air Quality Index (AQI): A numerical index used for reporting severity of air pollution levels to the public. The AQI incorporates five criteria pollutants -- ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide -- into a single index. The new index also incorporates the 8-hour ozone standard and the 24-hour PM standard into the index calculation. AQI levels range from 0 (Good air 2.5
quality) to 500 (Hazardous air quality). The higher the index, the higher the level of pollutants and the greater the likelihood of health effects. The AQI incorporates an additional index category -- unhealthy Draft Report of Mitigation Options 7
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for sensitive groups -- that ranges from 101 to 150. In addition, the AQI comes with more detailed cautions.
Air Quality Model: A mathematical relationship between emissions and air quality which simulates on a computer the transport, dispersion, and transformation of compounds emitted into the air.
Air Quality Standard (AQS): The prescribed level of a pollutant in the outside air that should not be exceeded during a specific time period to protect public health. Established by both federal and state governments. (See also ambient air quality standards.)
Airshed: Denotes a geographical area that shares the same air because of topography, meteorology, and climate.
Air Toxics: A generic term referring to a harmful chemical or group of chemicals in the air. Substances that are especially harmful to health, such as those considered under U.S. EPA's hazardous air pollutant program, are considered to be air toxics. Technically, any compound that is in the air and has the potential to produce adverse health effects is an air toxic.
Alternative Fuels: Fuels such as methanol, ethanol, natural gas, and liquid petroleum gas that are cleaner burning and help to meet ARB's mobile and stationary emission standards. These fuels may be used in place of less clean fuels for powering motor vehicles.
Ambient Air: The air occurring at a particular time and place outside of structures. Often used interchangeably with "outdoor air." (See also air.)
Ambient Air Quality Standards (AAQS): Health- and welfare-based standards for outdoor air which
identify the maximum acceptable average concentrations of air pollutants during a specified period of time. (See also NAAQS and Criteria Air Pollutant.)
American Society for Testing and Materials (ASTM): A nonprofit organization that provides a forum
for producers, consumers, and representatives of government and industry, to write laboratory test standards for materials, products, systems, and services. ASTM publishes standard test methods, specifications, practices, guides, classifications, and terminology.
Ammonia (NH): A pungent colorless gaseous compound of nitrogen and hydrogen that is very soluble 3
in water and can easily be condensed into a liquid by cold and pressure. Ammonia reacts with NOx to form ammonium nitrate -- a major PM component in the Western United States. 2.5
Area Sources: Those sources for which a methodology is used to estimate emissions. This can include area-wide, mobile and natural sources, and also groups of stationary sources (such as dry cleaners and gas stations). Sources which are not reported as individual point sources are included as area sources. The federal air toxics program defines a source that emits less than 10 tons per year of a single hazardous air pollutant (HAP) or 25 tons per year of all HAPs as an area source.
Asthma: A chronic inflammatory disorder of the lungs characterized by wheezing, breathlessness, chest tightness, and cough.
Atmosphere: The gaseous mass or envelope of air surrounding the Earth. From ground-level up, the atmosphere is further subdivided into the troposphere, stratosphere, mesosphere, and the thermosphere.
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Attainment Area: A geographical area identified to have air quality as good as, or better than, the national ambient air quality standards (NAAQS). An area may be an attainment area for one pollutant and a nonattainment area for others.
Baghouse: An air pollution control device that traps particulates by forcing gas streams through large permeable bags usually made of glass fibers.
Banking: A provision used in emissions trading programs that allows a facility to accumulate credits for reducing emissions beyond regulatory limits (emission reduction credits) and then use or sell those credits at a later date.
Best Available Control Measure (BACM): A term used to describe the "best" measures (according to
U.S. EPA guidance) for controlling small or dispersed sources of particulate matter and other emissions from sources such as roadway dust, woodstoves, and open burning.
Best Available Control Technology (BACT): The most up-to-date methods, systems, techniques, and
production processes available 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).
Best Available Retrofit Technology (BART): An air emission limitation that applies to existing sources
and is based on the maximum degree of reduction achievable, taking into account environmental, energy, and economic impacts by each class or category of source. (See also Best Available Control Technology.)
Biogenic Source: Biological sources such as plants and animals that emit air pollutants such as volatile organic compounds. Examples of biogenic sources include animal management operations, and oak and pine tree forests. (See also natural sources.)
Carbon Dioxide (CO): A colorless, odorless gas that occurs naturally in the Earth's atmosphere. 2
Significant quantities are also emitted into the air by fossil fuel combustion.
Carbon Monoxide (CO): A colorless, odorless gas resulting from the incomplete combustion of
hydrocarbon fuels. CO interferes with the blood's ability to carry oxygen to the body's tissues and results in numerous adverse health effects. CO is a criteria air pollutant.
Carcinogen: A cancer-causing substance. (See also cancer.)
CAS Registry Number: The Chemical Abstracts Service Registry Number (CAS) is a numeric
designation assigned by the American Chemical Society's Chemical Abstract Service and uniquely identifies a specific compound. This entry allows one to conclusively identify a material regardless of the name or naming system used.
Catalyst: A substance that can increase or decrease the rate of a chemical reaction between the other chemical species without being consumed in the process.
Chronic Exposure: Long-term exposure, usually lasting one year to a lifetime.
Chronic Health Effect: A health effect that occurs over a relatively long period of time (e.g., months or years). (See also acute health effect.)
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Cleaner-Burning Gasoline: Gasoline fuel that results in reduced emissions of carbon monoxide,
nitrogen oxides, reactive organic gases, and particulate matter, in addition to toxic substances such as benzene and 1,3-butadiene.
Combustion: The act or instance of burning some type of fuel such as gasoline to produce energy. Combustion is typically the process that powers automobile engines, oil and gas-field engines, and power plant generators.
Continuous Emission Monitor (CEM): A type of air emission monitoring system installed to operate
continuously inside of a smokestack or other emission source.
Continuous Sampling Device: An air analyzer that measures air quality components continuously. (See also Integrated Sampling Device.)
Control Techniques Guidelines (CTG): Guidance documents issued by U.S. EPA that define
reasonably available control technology (RACT) to be applied to existing facilities that emit excessive quantities of air pollutants; they contain information both on the economic and technological feasibility of available techniques.
Cost-Effectiveness: The cost of an emission control measure assessed in terms of dollars-per-pound, or dollars-per-ton, of air emissions reduced.
Criteria Air Pollutant: An air pollutant for which acceptable levels of exposure can be determined and for which an ambient air quality standard has been set. Examples include: ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and PM and PM. The term "criteria air pollutants" derives from the 102.5
requirement that the U.S. EPA must describe the characteristics and potential health and welfare effects of these pollutants. The U.S. EPA periodically reviews new scientific data and may propose revisions to the standards as a result.
Cyclone: An air pollution control device that removes larger particles -- generally greater than one micron -- from an air stream through centrifugal force.
Deciview: A measurement of visibility. One deciview represents the minimal perceptible change in visibility to the human eye.
Diesel Engine: A type of internal combustion engine that uses low-volatility petroleum fuel and fuel injectors and initiates combustion using compression ignition (as opposed to spark ignition that is used with gasoline engines).
Dispersion Model: See air quality model above.
Dose: The amount of a pollutant that is absorbed. A level of exposure which is a function of a pollutant's concentration, the length of time a subject is exposed, and the amount of the pollutant that is absorbed. The concentration of the pollutant and the length of time that the subject is exposed to that pollutant determine dose.
Dose-Response: The relationship between the dose of a pollutant and the response (or effect) it produces on a biological system.
Dust: Solid particulate matter that can become airborne.
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