Navigating the TMDL Process: Evaluation – A WERF Project Update

Navigating the TMDL Process: Evaluation and Design is a WERF-funded research effort begun in late 2000 directed toward improving the TMDL process. The research is expected to be completed in December 2002, with publication of the final report in Spring 2003. The objective of the Evaluation and Design study is to investigate issues and concerns with the TMDL program, and to develop and identify ways to improve the TMDL process.A detailed survey of eight state TMDL programs from four different areas of the country was developed to further investigate each issue. Additionally, the researchers conducted a broad review of the characteristics of nearly 200 approved TMDLs, and detailed reviews of several TMDLs are used as case studies.Preliminary findings of this investigation will be presented with specific emphasis on several issues identified for further study. These issues were highlighted as areas in need of improved approaches in the TMDL program, and the final WERF report will describe improved methodologies and provide examples for each of the following ten issues:Improved Methods for Calculating the TMDL Margin of SafetyIncorporating Urban Wet Weather Point Sources in the TMDL ProgramGuidance for Modeling Approach in a TMDL ProcessEstimating Background Pollutant LoadsLinking Best Management Practices to Load ReductionsQuantifying Existing and Future Nonpoint Source LoadsInterrelationships Among Multiple Loads and Critical ConditionsApproaches for the Allocation of Loads in TMDLsImplementation Planning, Tracking, and AdjustmentsAdaptive Watershed Management in the TMDL ProcessThis paper reports on the evaluation portion of the WERF TMDL research project. A more complete review will be provided at the November 2002 TMDL Sciences Conference in Phoenix AZ.