An international firm (headquartered in Houston, Texas, USA) providing engineering, and technological services for analyzing and managing hazards, risk, and safety as well as minimizing environmental impacts. Their air dispersion models, offered from their office in Bethesda, Maryland are for routine and accidental airborne releases. Versions available are: quick-running plume model, urban dispersion model and inside building model.

A nation-wide consultant firm (headquartered in San Francisco, California, USA) specializing in process safety and risk management services, training, and software. AcuTech makes use of these dispersion modeling programs: ALOHA, ARCHIE, DEGADIS, HGSYSTEM, SLAB, TSCREEN, and PHAST.

Located in Richmond, Virginia, USA, the Aegis Environmental firm offers environmental consulting services including air dispersion modeling, offsite consequence analyses, air permitting and regulatory compliance strategies.

Environmental consultants based in Canal Fulton, Ohio, USA, whose air services include dispersion modeling.

An air quality and acoustic consulting firm (based in Plaistow, New Hampshire, USA) whose services include air dispersion modeling.

Environmental engineering consultants located in Houston, Texas, USA whose services include air permitting, air pollution control, Clean Air Act compliance, and air dispersion modeling.

Environmental consultancy based in Brisbane, Australia specializing in stack emission testing and air dispersion modeling using AUSPLUME, CAL/AUSPUFF, ISC3, TAPM and AERMOD with particular emphasis on air dispersion from tunnels.

Based in Evansville, Indiana, USA, with additional offices in the states of Tennessee and Florida, the Air Quality Services firm offers consulting services including air dispersion modeling, ambient air monitoring, air permitting and emission inventories.

Located in Ft. Collins, Colorado, USA, this firm provides comprehensive air modeling, permitting, and compliance support to industrial, commercial, and government clients.

A consulting firm in Lakewood, Colorado, USA offering services in the air quality aspects of environmental impact studies, air quality and meteorological monitoring, dispersion modeling, visibility degradation analysis, and permitting of industrial facilities. The models utilized include SCREEN3, ISCST3, CALPUFF, VISCREEN, PLUVUE, and IWAQM.

Services include stack testing, stationary source isokinetic sampling, continuous emission monitoring, compliance permitting, air toxics pollution emission sampling, ambient air quality dispersion modeling. Located in Pennsauken, New Jersey, USA.

A consulting firm located in Westminster, Colorado, USA that offers atmospheric dispersion modeling including dense gases, hazardous releases and complex terrain.

An environmental consulting firm, with multiple offices throughout Western, Canada, whose services include air pollution dispersion modeling.

Located in Starke, Florida, USA, this firm's services include: air dispersion modeling; stack design and building downwash evaluations; toxic air pollution studies, model validation studies; and air quality impact analyses.

Engineering and design company headquartered in Bellingham, Washington, USA with other offices in the states of Washington, Montana and Alaska. Services include air dispersion modeling in support of air permitting, BACT and T-BACT analyses, and compliance studies.

Consultants located in Tempe, Arizona, USA who provide air dispersion modeling in support of air quality permitting and impact analyses as well as air quality regulatory compliance.

Consultants (in Woodland Hills, California, USA) who offer services in: dispersion modeling (using ISCST3 model); regional air quality modeling (for ozone and for particulate matter); urban airshed modeling; and accidental release modeling (using ALOHA, CAMEO, SLAB, DEGADIS and SCREEN models).

An environmental engineering and consulting firm headquartered in Houston, Texas, USA and offering services in air dispersion modeling, air permitting and compliance, and risk management plans.

Air quality consultants located in Milan, Italy whose services include applied meteorology and air pollution dispersion modeling.

An odour control/abatement/design consultancy located in Singapore whose services include air dispersion modeling.

A worldwide engineering firm (with home office in London, England) whose environmental services include air dispersion studies using the AERMOD and UK-ADMS models.

An environmental consulting company based in Agoura Hills, California, USA whose services include air dispersion modeling and air quality impact assessments, air permitting, air toxics studies, and risk assessments.

An environmental engineering firm based in Gujarat, India, whose consulting services include air pollutant dispersal modeling.

An environmental engineering and sciences company, based in Sandwich, Massachusetts, USA, whose air quality services include dispersion modeling.

Environmental and meteorological consultants located in Boulder, Colorado, USA whose services include air pollution dispersion modeling, emergency response modeling, long range transport, and applied atmospheric research.

A nation-wide consultant firm, headquartered in Cambridge, Massachusetts, USA, whose air quality modeling services include model development, applications, customization and testing. Models developed and used by AER encompass such air quality issues as photochemical smog formation, particulate matter levels, atmospheric visibility degradation and acid deposition.

An environmental engineering firm headquartered in Helena, Montana, USA, whose services include: air dispersion modeling; air emission inventories, air permit applications, and risk management plans (RMPs).

Consultants (in Cambridge, Massachusetts, USA) with expertise in: air dispersion modeling, off-site consequence analysis, fire and explosion, and other safety problems. For dispersion modeling, the firm uses ADORA (Atmospheric Dispersion of Reacting Agents) ... a model with complex thermodynamics and chemical reactions.

An environmental engineering and consulting firm based in Aachen, Germany whose services include air dispersion modeling.

A group of environmental consultants headquartered in Cambridge, Massachusetts, USA. Their services include the use of air dispersion modeling in support of health risk assessments.

Scientific consultants in the field of atmospheric dispersion located in Cambridge, England.. They offer a range of air dispersion models including: ADMS 3 for dispersion of industrial emissions; ADMS-SCREEN for initial screening studies of emission dispersion; and GASTAR for dispersion of accidental dense gas releases.

A research/development/consultancy facility located in Sheffield, England that uses the ADMS-2 dispersion model to offer air pollution dispersion modeling services to the castings production industry.

A wind engineering consulting firm (located in Fort Collins, Colorado, USA) that offers wind tunnel modeling of pollutant transport and dispersion involving complex building and terrain situations.

An environmental engineering firm based in Toronto, Ontario, Canada whose services include air dispersion modeling. The dispersion models used include the Ontario Ministry of Environment Regulation 346 model as well as the USA EPA models ISC3 and AERMOD.

An environmental consulting firm headquartered in Littleton, Colorado, USA (with other offices in Oklahoma and Wyoming) whose services include permitting, dispersion modeling, and developing and implementing compliance programs for the natural gas industry.

An engineering, construction and environmental consulting firm based in Nottingham, England with 40 offices in Europe and North America. Their services include air pollution dispersion modeling in support of environmental impact studies as well as response planning for accidental releases.

A firm based in Hungary that provides atmospheric environmental impact assessments for Central Europe based on local meteorological data and relevant models.

A consulting group (located in North Clayton, Victoria, Australia) who provide: air pollution dispersion and consequence modeling services; complex terrain modeling; meteorological services; and training in dispersion modeling. The models used include AUSPLUME, AUSTOX, TAPAS, TAPM, AUSPUFF/CALPUFF, ISC3.

A firm of environmental, health and safety consultants based in Norcross, Georgia, USA whose services include air dispersion modeling, air permitting and compliance, and air toxics assessments.

The Center for Toxicology and Environmental Health is a consulting firm based in Little Rock, Arkansas, USA whose environamental services in include air dispersion modeling using the SAFER dispersion model.

D&E Technical is an environmental engineering and software development company located in Champaign, Illinois, USA. Their services include air dispersion modeling and hazard analysis.

Engineering consultants and designers based in Genoa, Italy whose services include risk assessment studies and industrial air pollution dispersion modeling.

A firm of engineering and environmental consultants based in Greenwood, South Carolina, USA whose services include air dispersion modeling for: air permitting, evaluating toxic air emission impacts, evaluating compliance with air quality standards, and risk assessments.

A firm of engineering and construction consultants, headquartered in Montreal, Canada, whose air quality services include air dispersion modeling.

A consulting firm headquartered in Sillery, Quebec, Canada, that offers service in air pollution dispersion modeling as well as other unrelated fields.

An environmental consulting firm (located in Holladay, Utah, USA) whose services include air quality regulatory work, dispersion modeling, and emission inventories.

Cosulting environmental engineers located in Holladay, Utah, USA whose air quality services include air dispersion modeling.

Det Norske Veritas (DNV), headquartered in Oslo, Norway, is an international consulting firm with numerous offices worldwide. Their primary focus is on safety, environmental, risk management, and consequence analyses using their own PHAST dispersion modeling software.

A software development company in Toronto, Canada that also provides a full range of risk management consulting services. They offer software for Risk Analysis, Process Hazard Analysis (PHA), HAZOP, Failure Modes and Effects Analysis (FMEA), and Risk Management Plans (RMP).

Environment and Ecology, Inc. is an environmental consulting and engineering company headquartered in Lancaster, NY with other offices nation-wide in the USA. Their services include air permitting, compliance studies, impact assessments and air dispersion modeling.

A consulting firm, headquartered in Stoughton, Massachusetts, USA with other offices in the states of North Carolina and Washington, that utilizes air dispersion modeling as part of their services in odor abatement.

A worldwide environmental consultant firm, headquartered in Long Beach, California, USA, whose modeling group are recognized experts in air dispersion modeling. They have developed or enhanced many models (CALPUFF, CALMET, CALGRID, BLP, ISC3, CTDMPLUS, OCD, and KSP), several of which are now U.S. EPA 'Guideline' models.

An environmental consulting firm (based in Richmond Hill, Ontario, Canada) that develops, supports and implements environmental monitoring, management and reporting software systems including their sophMOD program.

Earthguard Environmental is a consulting firm (based in Richmond Hill, Ontario, Canada) that provides services for development, evaluation and application of air dispersion models using EPA and other regulatory models as well as specialized models designed for specific applications.

A consulting and design firm (located in Salt Lake City, Utah, USA) whose services include air dispersion modeling.

A firm of air quality consultants, based in Reading, England, whose services include atmospheric dispersion modelling.

A firm headquartered in Lahaina, Hawaii, USA and offering air dispersion modeling software focused primarily upon the regulatory requirements of Germany.

A consulting firm based in Brampton, Ontario, Canada (with an office in Dhaka, Bangladesh) whose services include air dispersion modeling.

Environmental engineering consultants based in Little Rock, Arkansas, USA who utilize air dispersion modling in their air permitting services, compliance studies and air toxics studies.

Consulting engineers and scientists based in Springfield, Virginia and Melbourne, Florida with other nationwide offices on the USA. Atmospheric science services include air pollution dispersion modeling and developing customized dispersion models.

A worldwide environmental service company (headquartered in Westford, Massachusetts, USA) that has developed: dispersion models that accommodate complex terrain and aerodynamic downwash; visibility models; hazardous air pollutant dispersion models; and others for facilities located in dispersion environments where standard models are inaccurate.

Environmental consultants, headquartered in Cambridge, England, whose services include numerical air dispersion modeling as well as wind tunnel modeling

A consulting firm based in Westboro, Massachusetts, USA who provide technical support and computer software to the nuclear power industry in the areas of radiological engineering, and atmospheric dispersion of radioactive effluents.

Located in Wolfville, Nova Scotia, Canada, the EnviroChem Engineering Consultants firm offers chemical engineering services as well as environmental engineering services. Their environmental services include ambient air monitoring, stack sampling and air dispersion modeling using models such as ISC3, AFTOX, SLAB, CALINE3 and SCREEN3.

EnviroComp Consulting (based in Fremont, California, USA) develops and applies computational techniques to study environmental problems and, in particular, air pollution by using data analysis, simulation modeling, statistical methods, and advanced visualization.

An air quality consulting firm located in Cherry Hill, New Jersey, USA, whose services include air permitting, air dispersion modeling, emissions estimation, site evaluations, regulatory analysis, and human health and ecological risk assessments.

An international firm (headquartered in Novato, California, USA) offering services in: dispersion modeling of emissions from industrial plants and hazardous waste sites; air toxics impact studies; air pollution compliance assistance; emergency release modeling and consequence analysis; regional modeling of photochemical reactive plumes and of particulate matter; and visibility models.

Environmental Engineering Solutions is an environmental engineering consulting firm, based in Westchester, New York, USA, whose services include air dispersion modeling.

An environmental engineering firm (located in Carlsbad, California, USA) whose consulting services include air dispersion modeling studies.

A consulting firm based in Cincinnati, Ohio (with multiple offices across the USA) that provides environmental engineering and air quality services including permitting, compliance studies, NSPS reviews, and air dispersion modeling.

An environmental consulting and engineering firm (located in Bloomfield, Connecticut, USA) whose air quality services include air emissions dispersion modeling, accidental release modeling, and cooling tower impact modeling.

A consulting firm (headquartered in Fairfield, New Jersey, USA) that offers services in air dispersion modeling, air quality and meteorological monitoring, air pollution emissions estimation, permitting and compliance plans, hazard assessments and risk management plans.

An environmental consulting firm based in Brisbane, Australia offering services in Environmental Impact Assessments and Environmental Risk Assessments, including the use of the AUSPLUME air dispersion model.

These consultants, located in Italy, provide a number of air dispersion models. The site includes an online Gaussian dispersion model called Tox-Flam, for releases of inert buoyant pollutants into a mixing layer of a user-specified height.

An environmental engineering company based in Maynard, Massachusetts, USA whose services include air dispersion modeling for: risk management studies, offsite consequence analyses, and air emissions permitting.

A firm of environmental consulting engineers and scientists (based in South Wales, UK) whose services include atmospheric dispersion modelling.

A firm of scientific and engineering consultants, headquartered in Menlo Park, California with multiple offices across the United States, whose services include air dispersion modeling.

Shell Oil and Tel-Tek offer consulting studies involving the EXSIM mathematical model that predicts the overpressure (explosion) generated by the accidental release and ignition of a gas cloud in a congested area of an industrial plant onshore, or offshore on oil drilling platforms. The model was developed by Shell Oil Global Solutions in England and by the Telemark Technological R&D Center (Tel-Tek) in Norway.

FaberMaunsell is an international, multi-disciplinary consultancy (located in St. Albans, Herts, UK) whose environmental services include air dispersion modeling.

Headquartered in Lebanon, New Hampshire, USA with other offices nationwide and worldwide, this firm specializes in computational fluid dynamics (CFD) modeling. Their many services include atmospheric plume dispersion modeling.

Based in Columbia, Maryland, USA (with other offices in Canada, South America, Europe and Asia), General Physics is a firm of scientists, technologists and engineers whose air emissions management services include air dispersion modeling in support of air emissions compliance studies, offsite consequence analyses, and evaluation/selection of emission stack heights.

A consulting group in Norway that uses a CFD program called FLACS to model the dispersion of leaks (on offshore oil drilling platforms) as well as their subsequent ignition and explosion. Far field blast effects (up to two kilometers away) from such explosions can also be modeled. GexCon both sell FLACS and perform consultancy services using FLACS.

Environmental engineering consultants, located in Orlando, Florida, USA, whose services include: industrial air pollution studies, air permitting, emission inventories and air dispersion modeling.

Engineering firm (headquartered in Somerville, New Jersey, USA)that designs, constructs and maintains industrial chimneys and smokestacks. Their engineering services include air dispersion modeling. The firm is part of the Hamon Group (headquartered in Brussels, Belgium) with offices worldwide.

Chemical and environmental consultants based in St. Louis, Missouri, USA whose services include air dispersion modeling used for: air permitting, accidental release modeling, and risk assessments.

A consulting engineering firm (headquartered in Owen Sound, Ontario, Canada) whose environmental services include air pollution dispersion modeling.

A multi-discipline firm of consulting engineers and scientists (with headquarters in Sydney, Australia) whose services include air dispersion modeling and other aspects of air quality.

A risk management company based in Baton Rouge, Louisiana, USA and offering software and consulting services nationwide. Included in their software offerings is D2-Puff, an air dispersion model developed specifically to predict the path and extent of plume resulting from the accidental release of hazardous chemicals.

Consulting and engineering firm based in Oakland, California , USA whose environmental management services include air dispersion modeling.

A multi-national engineering firm (headquartered in Dartmouth, Nova Scotia, Canada) who offers air dispersion modeling in support of their environmental, geotechnical and risk management services.

A consulting firm located in Dunum, Germany who develop and market air dispersion modeling software, such as: LASAT, a Lagrangian dispersion model; IBJplume, a Gaussian model; IBJXodor; a model specifically for odor dispersion.

A regional consulting firm, headquartered in Sandy, Utah, USA and with other offices in the states of Nevada and Idaho, whose services include: air pollutant dispersion modeling, emission inventories, air permitting, and risk management.

Consultants, based in Dallas, Texas, USA, who offer dispersion modeling services and a proprietary Air Modeling Organizational System (AMOS) designed to create input files and organize all of the ISCST modeling runs for an entire project.

An environmental consulting firm based in Long Beach, California, USA (with branch offices in Las Vegas, Nevada and Chicago, Illinois) whose services include air dispersion modeling.

Consulting firm based in Brisbane, Australia that offers air dispersion modeling services, using these models: AUSPLUME, AUSMET/AUSPUFF, LADM, TAPM, CALMET/CALPUFF, and the U.S. EPA's ISC models.

An environmental consulting firm based in Indianapolis, Indiana, USA whose air quality services include: emission inventories, air permitting, risk management plans, and air pollution dispersion modeling.

A consulting firm based in Toronto, Canada who offers air dispersion modeling in support of their electric power generation services.

Located in Ontario, Canada, this firm provides easy-to-use air dispersion and risk assessment modeling software for Windows. Their air pollution dispersion modeling software includes: ISC-AERMOD View, RMP View, SCREEN View, and SLAB View, all of which are U.S. EPA models adapted for use with Windows. Training and technical support are also provided.

A Canadian consulting firm offering services in air dispersion modeling (including odor dispersion), stack sampling, and environmental permitting. Most of Lehder's modeling work for clients utilizes the U.S. EPA's Industrial Source Complex Short Term Model Version 3 (ISCST3).

A consulting firm based in Dallas, Texas, USA offering air quality permitting and related environmental services including air dispersion modeling.

Headquartered in Alpharetta, GA, USA, with other offices nationwide, Mactec's engineering and consulting services include air pollution dispersion modeling in support of their environmental services.

An air quality consulting firm, headquartered in Englewood, Colorado, USA with other offices in Arizona and Wyoming. Their services include air dispersion modeling for determining: ambient impacts for permitting industrial sources, impacts of cooling tower plumes, impacts of complex terrain on pollutant dispersion, mobile source impacts, and toxic air pollutant exposures.

A consultant firm in Dayton, Texas, USA that provides litigation support and expert witness testimony to environmental lawyers and to insurance companies for either plaintiffs or defendants in court cases that involve air dispersion and air quality modeling.

Air quality consultants (located in Salt Lake City, Utah, USA) who provide a comprehensive range of air dispersion modeling services. The site includes links to the specifics of their various services as well as to a listing of the names, email addresses, and experience of their key people.

Consultants located in Balwyn, Victoria, Australia. Services offered include air pollution plume dispersion modeling using the Australian EPA's latest "AUSPLUME" package as required under the State Environment Protection Policy (SEPP).

An environmental consulting firm providing services in the areas of planning, engineering, safety, industrial hygiene, the earth and environmental sciences, design and regulatory assistance. The firm is located in Clarksburg, West Virginia, USA.

A firm of certified consulting meteorologists (located in Northfield, Illinois) whose environmental services include air dispersion modeling.

Based in Singapore, NatSteel Enviro Tech comprises four divisions: steel mill services, industrial wastes, wastewater treatment, and air quality. The air quality division offers air pollution dispersion modeling services.

Meteorological consultants (located in Salt Lake City, Utah, USA) who offer extensive experience in performing dispersion modeling for: simple, complex or intermediate terrain; single or multiple emission points; and buoyant or dense gas releases.

NEMS offers environmental, health and safety consulting services and their dispersion modeling expertise ranges from single stacks to multiple sources, spills and traffic pollution. NEMS is located in Darlington, England and uses the UK Atmospheric Dispersion Modeling System (ADMS). Their modeling has included: power plant emissions; cooling tower plume visibility; explosion risk assessments; and odor abatement.

Consulting environmental engineering firm located in St. Louis, Missouri, USA. Services include air dispersion modeling, air emission inventories, air permitting and compliance programs.

A nuclear research, engineering and consultancy group with offices in Petten and Arnheim in the Netherlands. Their services include environmental and dose assessments of radionuclides using dispersion modeling in air, water and soil.

A firm of environmental consultants and engineers with corporate headquarters in Syracuse, New York and other offices nation-wide in the USA as well as Canada and the UK. Their services include air permitting, air regulation assistance and air dispersion modeling.

An engineering and consulting company headquartered in Calgary, Alberta, Canada (with multiple offices across Canada) whose air quality services include air dispersion modeling.

A firm of odor-related consultants (located in Montreal, Canada) whose services include air pollution dispersion modeling.

Odour abatement specialists located in Trim, County Meath, Ireland whose services include air and odour dispersion modelling using ISCST3, AERMOD, ADMS3.1 and Calpuff.

An environmental consulting firm based in Research Triangle Park, North Carolina, USA whose air quality services include air permitting, compliance studies and air dispersion modeling.

A chemical engineering and environmental management consultancy located in Stockton-on-Tees, England. They have developed a basic Gaussian dispersion model implemented with Microsoft's Excel spreadsheet program.

A consultant group, headquartered in Brisbane, Australia with satellite offices in Melbourne and Sydney, who offer air quality modeling and emissions estimation services. The air dispersion models used include models developed in Australia (AUSPLUME, AUSPUFF and TAPM) as well as models developed in the USA (ISC3, AERMOD, CALPUFF and CALINE4).

Nationwide company headquartered in Herndon, Virginia, USA. The PES modeling section specializes in developing, evaluating, and applying air pollution dispersion models. PES was involved in developing the U.S. EPA's dispersion models, such as ISC3, SCREEN3, and SCREEN. PES has also been involved in developing the new AERMIC Model (AERMOD), to be proposed by EPA as a regulatory model.

An environmental consulting firm (headquartered in Madison, Connecticut, USA) whose services include air permitting, emission inventories, dispersion modeling studies, and health risk assessments.

An environmental consulting firm based in Southern California, USA, whose services include air dispersion modeling, stationary source permitting, and emission inventories, allotments, and mitigations.

A consultant group based in Mississauga, Ontario, Canada (with multiple offices in Canada) who offer air dispersion modeling services. The dispersion models utilized include Ontario Regulation 346 as well as these U.S. EPA models: Screen3, ISCST3, AERMOD and PRIME.

An acoustical and environmental engineering consulting firm based in Sydney, Australia that provides a range of services which includes air dispersion modeling.

The engineering and scientific center of PowerGen UK plc. They use various models to simulate gas and dust dispersion from: industrial chimneys, stockpiles, fugitive sources, accidental releases, and cooling tower plumes. The models include: ADMS (Atmospheric Dispersion Modeling System), VISPACT (an in-house cooling tower model), MATADOR (UK acid rain model), MODELS-3 and U.S. EPA models.

Environmental consultants based in the south and southeastern United States (Louisiana, Alabama, Mississippi and Florida) whose services include air dispersion modeling, air permitting, risk management plans, and emission inventories.

An environmental consulting firm headquartered in Davenport, Iowa, USA, whose services include air pollution dispersion modeling.

A consulting firm based in Columbus, Ohio, USA and with multiple offices in North America. Their services include: process hazard analyses; source term calculations; air dispersion and consequence modeling; and probability modeling. They also market proprietary software for process hazard analysis (PHA) and safety management (PSM).

A consulting firm (based in Baton Rouge, Louisiana, USA and Houston, Texas, USA) whose services include air dispersion modeling, risk management plans and emergency response plans.

Environmental consultancy headquartered in Reading, England (with other offices in the UK) whose services include air dispersion modeling.

A consulting firm based in Madison, Wisconson, USA (with multiple offices in the USA, UK and France) whose environmental services include air dispersion modeling.

An environmental consulting firm (located in Greenville, South Carolina, USA) whose services include air dispersion modeling, air permitting and air toxics evaluations.

RTP has offices nationwide in the USA and has performed modeling studies for: rural and urban locations; single-point sources; complex multi-source industrial sources; flat terrain; complex terrain; and time and spatial scales from short-term to multi-year analyses over distances of several meters to several hundred kilometers.

Rowan Williams Davies and Irwin Inc. (RWDI) are a Canadian firm of consulting engineers and scientists. Their services include wind engineering, air quality studies, microclimate, snow engineering, hazard and risk studies and acoustics.

An environmental consulting firm headquartered in Lafayette, Colorado, USA with other offices in Idaho, New Mexico and Texas. Their services include risk assessments and air pollution dispersion modeling.

An environmental consulting company based in Texas (with offices in Richardson, Austin and Beaumont) who offer services in air dispersion modeling, air permitting and compliance, risk management plans and offsite consequence analyses.

An environmental engineering firm based in Mobile, Alabama, USA that specializes in air permitting and air quality testing. Their air dispersion modeling includes the use of the U.S. EPA's ISC short and long term models, complex terrain modeling, and the Valley model.

An engineering consulting firm headquartered in Redmond, Washington, USA (with other offices nation-wide) whose services include air quality management and regulatory compliance.

An environmental consulting company (based in Vashi, Navi Mumbai, India) whose services include air dispersion modeling.

Environmental management consultants located in Columbus, Missouri, USA. Their services include: air quality monitoring; air permitting; and air dispersion modeling involved in evaluating the offsite consequences of accidental releases and of air toxics emissions.

An applied research institute located in Bratislavia, Slovak Republic whose services include air dispersion modeling using the CFD program called Fluidyn-PANACHE.

An environmental consulting firm, located in Houston, Texas, USA, whose air quality services include: air pollution dispersion modeling, air emission inventories, and air permitting.

Environmental consultants with multiple offices in England. Together with the University of Greenwich, Stanger operates a 24-hour telephone helpline for air dispersion modeling.

An environmental consulting firm based in Coraville, Iowa, USA and a subsidiary of the Stanley Group. Their services include air permitting, risk management plans, emission inventories and air dispersion modeling.

An environmental consulting firm (located in Littleton, Colorado, USA) whose services include air dispersion modeling.

An environmental testing and consulting firm (headquartered in Burlington, Ontario, Canada) whose services include air dispersion modeling.

A consulting firm headquartered in Rolling Hills Estates, California, USA who offer services in air dispersion modeling, toxic chemical exposure evaluations, reconstruction of past environmental exposures, and specialized software.

This firm (located in Alexandria, Virginia, USA) offers services including urban scale air quality assessment, exposure assessment, permit support, air quality modeling, and risk management planning.

Located in Waltham, Massachusetts, USA, TEI provides consulting for air quality and noise issues. Their services include: permit applications; siting and feasibility studies; environmental impact assessments; and technical support tasks such as air dispersion and noise modeling, planning, and monitoring.

Consultants located in Dallas, Texas, USA who offer air permitting and compliance services, air dispersion modeling, and training workshops.

An environmental consulting firm based in Irvine, California, USA whose range of services includes atmospheric dispersion modeling for: air toxics assessments, air permitting, compliance studies, and consequence analyses of accidental releases.

Consultants based in Carrollton, Texas, USA who offer dispersion modeling services for: air toxic evaluations and risk assessments; demonstrating compliance with air quality standards; evaluation of accidental releases; stack height studies; new facility site selection; visibility studies.

A scientific and regulatory consulting firm, headquartered in Washington,DC, whose services include air dispersion modeling.

Environmental consultants located in Ontario, Canada whose services include physical modeling as well as computer modeling of stack exhaust gas dispersion and dust dispersion.

A multinational company, based in St. Denis, France, offering technology solutions and consulting services in the field of computational fluid dynamics including air dispersion modeling for environmental impact studies, accidental releases, and risk assessments.

Environmental engineers and consultants, based in Windsor, Connecticut, USA with multiple offices nationwide as well as offices in South America. Air dispersion modeling is used for air permitting and for evaluating: impact of accidental releases, compliance with ambient air quality standards, optional air pollution control systems, and impacts of toxic air pollutant emissions.

A consulting firm based in Dallas, Texas, USA whose services include consulting, software, and training in the fields of air quality, dispersion modeling, permitting, compliance, Clean Air Act, environmental management information systems and industrial risk.

An environmental engineering and consulting firm based in Reading, Pennsylvania, USA that offers a range of air dispersion modeling services.

Vector AS is based in Tønsberg, Norway and offers air dispersion modeling using WindSim, which is a flow and dispersion simulator for complex terrain using computational fluid dynamics (CFD).

A company headquartered in Melbourne, Australia whose consulting services include air pollution dispersion modeling using models such as AUSPLUME, CALINE 4, MAXCON, RTDM and AIRPLAN.

Environmental consultants based in Massachusetts and Michigan in the USA. Their services include the use of air dispersion modeling for risk assessments, air permitting, air toxics evaluations, and New Source Reviews.

WebMET is a repository of meteorological data for air dispersion models such as ISCST3, ISC-PRIME and AERMOD, as well as for digital elevation terrain data. The data covers the entire United States and can be downloaded free of charge. The site is sponsored by Lakes Environmental located in Ontario, Canada.

An environmental engineering, science and management firm headquartered in Emeryville, California, USA whose air quality services include air dispersion modeling.

Consulting engineers based in Maple Plains, Minnesota, USA with multiple other offices in Minnesota. Their services include the use of air dispersion modeling for air permitting, regulatory compliance studies, air toxics evaluation, and New Source Reviews.

Located in San Diego, California, the environmental services offered by this firm include air dispersion modeling, offsite consequence analyses, air permitting, toxic emission evaluations and risk assessments. Models used include: ISCST3, CALPUFF, SCREEN3, CALINE4, AERMOD, VISCREEN, PLUVUE, CTSCREEN, SHORTZ, and BPIP.

A firm of consulting engineers (based in Arncliffe, NSW, Australia) whose services include air pollution dispersion studies by physical modeling in a wind tunnel.

A multi-office environmental consulting firm headquartered in Portland, Maine, USA whose services include air dispersion modeling, air permitting and compliance, air toxics studies and risk management plans.

Yamada Science & Art Corporation (YSA), located in Santa Fe, New Mexico, USA, specializes in computer modeling of atmospheric airflows and the dispersion of airborne materials over complex terrain. YSA developed, markets, and provides user support for the three-dimensional atmospheric models HOTMAC and RAPTAD.

An environmental consulting firm, headquartered in Austin, Texas, USA, whose air dispersion modeling services include: simple and complex terrain modeling; line and mobile source modeling; and modeling of accidental dense gas releases. Zephyr utilizes U.S. EPA models such ISCST3 and SCREEN3; and public domain models such as SLAB and RMP-COMP.

Environmental firm (located in Austin, Texas, USA) that provides air dispersion modeling services, air pollution meteorological data analyses, and expert witness testimony.