T.M.D.L. Development: Cheap, Fast, Accurate (Pick Two)

Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.Nationally, regionally and specifically in the State of Georgia, legal requirements are mandating Total Maximum Daily Loads (TMDLs) be developed at an accelerated time scale for impaired waters. In Georgia, 571 impaired waters are listed on the 1998 Georgia 303(d) list (per Section 303(d) under the U.S. Clean Water Act). The total number of pollutants of concern in these waters is approximately 685. Therefore up to 685 TMDLs may be required for these waters and other impaired waters, identified in the future, for each of the pollutants of concern, in the next 6 to 7 years. Developing a TMDL for a water body usually involves developing a mathematical water quality model of the water body to determine the "total maximum daily load" of pollutants from all sources (both point and nonpoint sources) that may be discharged into the waters while still maintaining the water quality standards. The available models range from the fairly simple hand-equation models to the highly complex, data-intensive and time-consuming state-of-the-art computer models. The choice of model and TMDL development method within this range determines whether the analysis is "fast, cheap, or accurate". To meet this accelerated timeline, TMDL development will have to be fast paced and, with limited resources, it will also need to be cheap. Some of the waterbodies that are impaired are environmentally sensitive and may demand a more accurate projection of the pollutant loads necessary to protect the resource; or, if the prospective pollution reduction is very expensive, an accurate loading projection is needed to justify the expenditure. Since TMDL development can be either "fast, cheap or accurate" (any two, but not all three), a practical method is needed to select the best approach. To accomplish this task, a common sense TMDL development approach is being developed. Georgia EPD and EPA Region 4, with the contract help of Tetra Tech, Inc. in Fairfax, Virginia, are in the process of producing a TMDL Technical Procedures Manual: A Technical Roadmap for TMDL DevelopmentSponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202 with partial funding provided by the U.S. Department of Interior, geological Survey, through the Georgia Water Research Insttitute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors