AMI Environmental

Mr. Tran is President of AMI since its establishment in 1980. He has over 30 years of experience in project management, meteorological modeling, air quality modeling, emission inventory and data base management. For the last  25 years, he successfully managed over 75 air quality studies conducted by AMI on behalf of government agencies as well as Fortune 500 companies. Some of these controversial projects involved large budgets  and were going simultaneously under tight deadlines, yet AMI was able to complete them on time and within budget.

In addition to his demonstrated management skills, Mr. Tran has extensive experience in the development, evaluation and application of air quality simulation models, from simple Gaussian dispersion models (AERMOD, CALPUFF) to complex photochemical grid models (CAMx, CMAQ,  UAM).  He had applied these photochemical grid models to the development of ozone air quality attainment plans (AQAP) for Santa Barbara County, San Diego County and Kern County in California, and the Phoenix metropolitan area of Arizona. He conducted a comparative study of running regional air quality models on various UNIX workstations and IBM-compatible PCs. He adapted the advanced mesoscale model MM5 for use in photochemical modeling and applied these models to assess the effectiveness of large-scale albedo changes in the Los Angeles air basin. He conducted photochemical modeling for several power plants being proposed in Arizona and California. He has recently used the PC-based versions of the MM5 and WRF models to provide Web-based real-time weather forecasts for wind energy plants in California and Texas as well as tropical storms in Southeast Asia.

Mr. Tran has recently completed reviews of the air quality and visibility impact analyses submitted as part of PSD Permit Applications for several proposed coal-fired power plants  throughout the US, including Georgia (Longleaf and Plant Washington), Kentucky (Kentucky Syngas and Trimble), Michigan (Consumers Energy and Wolverine), Nevada (Ely), Montana (Highwood), New Mexico (Desert Rock), Ohio (AMP), South Dakota (Hyperion),   Virginia (Dominion) and Wyoming (Dry Fork and Medicine Bow Fuels). For these facilities, he performed dispersion modeling with AERMOD and ISCST3 for NAAQS compliance and PSD increment analyses in PSD Class II areas, and CALPUFF modeling for long-range transport to the nearest PSD Class I areas. He also performed visibility impact analysis based on the FLAG and BART procedures recommended by the US EPA and Federal Land Managers. In addition, he was deposed and performed expert testimony in legal challenges to the PSD permits of proposed coal-fired power plants (AMP, Dry Fork, Highwood and Longleaf).

Mr. Tran is the leading expert on health risk assessment for air toxics. He developed the multipathway risk assessment model ACE2588 that has become the most widely used model. It has been applied by AMI and others in over 1000 facilities under California's AB 2588 and Proposition 65. The ACE2588 model has also been used in other states and foreign countries. He improved the ACE2588 model to include a Monte Carlo uncertainty analysis to provide more realistic risk estimates. He recently developed the ACEHWCF model that implements the U.S. EPA health risk assessment guidelines for hazardous waste combustion facilities. He was in charge of prioritizing over 800 air toxics facilities in the Los Angeles air basin, reviewing and modifying their risk assessments submitted under AB 2588. He completed the development of a comprehensive emission inventory of over 10,000 point sources for regional exposure modeling of air toxics in the Los Angeles area. He has also used several dispersion models ranging from simple Gaussian puff to multiphase, dense gas models (e.g., DEGADIS and SLAB) to simulate accidental releases of hazardous chemicals.  

Mr. Tran is a former member of the National Committee on Meteorological Aspects of Air Pollution of the American Meteorological Society. He received his B.S. (1973) and M.S. (1974) degrees in Mechanical Engineering from the University of California, Santa Barbara. He completed graduate courses in Atmospheric Sciences, Computer Sciences and Environmental Fluid Dynamics and developed in 1980 a predictive atmospheric modeling system for real-time emergencies as his Doctoral research at UCLA. 

Selected Recent Publications

Development of A Comprehensive Health Risk Assessment Model for Air Toxics, 84th Annual Meeting, Air & Waste Management Association, 1991. Khanh T. Tran and Robert Sears (Santa Barbara County Air Pollution Control District).

Evaluation of a Nested Photochemical Grid Model for the Los Angeles Air Basin, 10th Symposium on Turbulence and Diffusion, American Meteorological Society, 1992. Khanh T. Tran and Vincent A. Mirabella (Southern California Edison).

Comparison of Modeling Techniques for Generating 3-D Wind Fields Used in Photochemical GridModeling, 6th Symposium on Mountain Meteorology, American Meteorological Society, 1992. Khanh T. Tran and Vincent A. Mirabella (Southern California Edison).

Wind Field and Photochemical Modeling in the Santa Barbara Channel, 86th Annual Meeting, Air & Waste Management Association, 1993. Khanh T. Tran and Thomas M. Murphy (Santa Barbara County Air Pollution Control District).

Assessing Air Toxics Health Risk from Industrial Facilities - the California Experience, 1995 Pacific Rim Environmental Conference, Air & Waste Management Association, 1995. Khanh T. Tran.

Development of a PC-based System for Regional Air Quality Modeling, 9th Joint Conference on Applications of Air Pollution Meteorology, American Meteorological Society, 1996. Khanh T. Tran and Fabrice Cuq.

An Integrated System for Air Toxics Inventory and Risk Assessment, 9th Joint Conference on Applications of Air Pollution Meteorology, American Meteorological Society, 1996. Khanh T. Tran, Garen Moradkhanian and Frank Wang.

Testing of a PC-Based Regional Air Quality Modeling System. A&WMA 91st  Annual Meeting, San Diego, June 1998.

NOx Sensitivity of Phoenix, AZ Ozone. A&WMA 91st  Annual Meeting, San Diego, June 1998.

ACEHWCF – A Comprehensive Risk Assessment Model for Hazardous Waste Combustion Facilities. A&WMA Hazardous Waste Combustors Specialty Conference, Kansas City, March 2001.

Comparative Use of ISCST3, ISC-PRIME and AERMOD in Air Toxics Risk Assessment. A&WMA Guideline Models Specialty Conference, Newport. RI, April 2001.

Last Updated July 1, 2001 by webmaster