The Role of the CCM in the Air Quality Industry

The Clean Air Act is the vehicle through which Congress enabled air quality in the United States to be monitored, evaluated, and improved to protect both human health and the environment. To implement the Clean Air Act, the Environmental Protection Agency, along with various state and local agencies, interacts with industrial sources and citizen groups to ensure that compliance with regulations intended to protect air quality is fulfilled. Meteorologists play a variety of roles in this interaction and work directly with other professionals including engineers and environmental scientists. The roles played by meteorologists in air quality protection include operation of ambient monitoring networks, forecasting high air pollution days, preparation of pollutant display maps for community outreach, development of dispersion models, and use of dispersion models to assess compliance with ambient air quality standards.

One environmental program through which meteorologists can provide specialized expertise is the Prevention of Significant Deterioration (PSD) Program. Through the PSD Program, large emissions sources are required to obtain a permit allowing the project to proceed prior to beginning construction of a new facility or making a major modification to an existing facility. As one part the PSD permit application, an applicant must provide an air quality dispersion modeling analysis to demonstrate compliance with air quality standards. The results of the modeling analysis are affected by atmospheric phenomena, such as turbulence and resulting characteristics of plume dispersion, making this aspect of the analysis particularly suited to the expertise of an experienced meteorologist.

The complexity of the PSD Program means that many companies do not have the in-house expertise to prepare a complete PSD application. Therefore, frequently consultants, including Certified Consulting Meteorologists, are hired to provide specialized expertise in this process. In this paper, the role of the meteorologist in the PSD application and review process will be discussed. Additionally, a case study highlighting aspects of a typical air quality dispersion modeling analysis to support a PSD application will be shown, with particular emphasis on those aspects to which a meteorologist's knowledge of atmospheric phenomena can be especially important. Some of these aspects include selection of the most appropriate atmospheric simulation technique (within regulatory recommendations), determining meteorological representativeness of existing nearby data versus the merits of an onsite data collection effort, evaluating model performance within the context of the meteorological/climatological data sets, and other aspects of the modeling exercise.