Skip to main content

PRIORITY NEEDS FOR THE TMDL PROGRAM

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

TMDLs, or Total Maximum Daily Loads, are a legislated requirement first stipulated in the 1972 Clean Water Act, but 30 years later we are just now trying to implement and make this program work. Progress in the TMDL program and the quality of the work has come under considerable inquiry and diverse criticism. Many have argued that the schedules are too aggressive, leading to poorly developed TMDLs based on insufficient data, poor science, and overly restrictive assumptions. Others argue that progress is too slow and we have enough information to act.

In response to criticisms, there have been several recent efforts to identify issues and recommend improvements related to the TMDL program. In 2001, US EPA contracted with the National Research Council (NRC) to review how scientific data and information should be used in the TMDL program (NRC/NAS, 2001). The Water Environment Research Foundation (WERF) funded three research projects in 2000–2002 that addressed technical tools used in the development of TMDLs (Limno-Tech, et al., 2002a), the listing and delisting process (FTN, et al., 2002), and narrative criteria (Limno-Tech, et al., 2002b). US EPA also recently issued a report on research needs to improve the TMDL Process called “The Twenty Needs Report: How Research Can Improve the TMDL Program (US EPA, 2002b). This paper explores the shortcomings of the TMDL program that have been identified through these and other recent activities, and highlights improvements the authors see that are needed to improve its effectiveness.

In concept the TMDL program is simple: first, identify waters not meeting water quality standards; second, quantify the pollutant source and stressor; then third, allocate load reductions, and then implement them. Unfortunately, problems exist in all areas and improvements are needed. In regards to the first step, establishing standards is a fundamental problem. Standards and related criteria are often mismatched to urban waterways and nearly half of the listed impaired waters involve narrative standards without clear quantitative measures. Improvements are needed for both as well as general methods on how to compare limited data sets to standards. In the second step, quantifying loads and causes, we have major shortcomings in the availability of data and the utility of models to quantify nonpoint sources. Recommendations for a national database and model improvements are provided in these areas. In the third step, establishing necessary load reductions, we have major challenges in selecting and applying appropriate models, and linking them to actual biological impacts. We also have very little experience determining uncertainty and properly incorporating this into the required margin of safety. Various recommendations have been made in each area. Last, in implementing to achieve results we see major shortcomings in using effective regulatory and programmatic tools to control nonpoint sources and often find little progress in implementation as stakeholders debate the analysis and efficacy of the proposed TMDLs.

In response to the above concerns, this paper highlights a series of research guidance and policy needs ranging from research on model uncertainty, to use of adaptive management.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: 2003-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more