Regulating air quality through the use of total daily maximum load standards for designated airsheds: A conceptual outline and analysis of meteorological constraints

Congress enacted the Clean Air Act Amendments of 1990 in response to concerns that there was widespread noncompliance with air pollution control requirements. In seeking to address noncompliance, Congress turned to the successful National Pollutant Discharge Elimination System (NPDES) permitting program enacted under the Clean Water Act as a model for a federally-mandated operating permit program. Congress` decision to turn to the Clean Water Act to resolve intractable problems in air quality permitting and enforcement suggests that Congress may turn to other Clean Water Act programs, such as the concept of regulating total maximum daily load (TMDL)--the maximum amount of pollutant that can be added to a given stream segment from all sources without violating water quality standards, to address continued nonattainment of the Clean Air Act`s national ambient air quality standards. This paper investigates the applying the TMDL model to airsheds, sets forth a conceptual outline for such a regulatory approach, and analyzes the meteorological and modeling constraints on successful implementation.