Over the last 30 years, water quality management in the United States has been driven by the control of point sources of pollution and the use of effluent-based water quality standards. Under this paradigm, the quality of the nation's lakes, rivers, reservoirs, groundwater, and coastal waters has generally improved as wastewater treatment plants and industrial dischargers (point sources) have responded to regulations promulgated under authority of the 1972 Clean Water Act. These regulations have required dischargers to comply with effluent-based standards for criteria pollutants, as specified in National Pollutant Discharge Elimination System (NPDES) permits issued by the states and approved by the U.S. Environmental Protection Agency (EPA). Although successful, the NPDES program has not achieved the nation's water quality goals of "fishable and swimmable" waters largely because discharges from other unregulated nonpoint sources of pollution have not been as successfully controlled. Today, pollutants such as nutrients and sediment, which are often associated with nonpoint sources and were not considered criteria pollutants in the Clean Water Act, are jeopardizing water quality, as are habitat destruction, changes in flow regimes, and introduction of exotic species. This array of challenges has shifted the focus of water quality management from effluent-based to ambient- based water quality standards.
Given the most recent lists of impaired waters submitted to EPA, there are about 21,000 polluted river segments, lakes, and estuaries making up over 300,000 river and shore miles and 5 million lake acres. The number of TMDLs required for these impaired waters is greater than 40,000. Under the 1992 EPA guidance or the terms of lawsuit settlements, most states are required to meet an 8- to 13-year deadline for completion of TMDLs. Budget requirements for the program are staggering as well, with most states claiming that they do not have the personnel and financial resources necessary to assess the condition of their waters, to list waters on 303d, and to develop TMDLs. A March 2000 report of the General Accounting Office (GAO) highlighted the pervasive lack of data at the state level available to set water quality standards, to determine what waters are impaired, and to develop TMDLs.
This report represents the consensus opinion of the eight-member NRC committee assembled to complete this task. The committee met three times during a three-month period and heard the testimony of over 40 interested organizations and stakeholder groups. The NRC committee feels that the data and science have progressed sufficiently over the past 35 years to support the nation's return to ambient-based water quality management. Given reasonable expectations for data availability and the inevitable limits on our conceptual understanding of complex systems, statements about the science behind water quality management must be made with acknowledgment of uncertainties. This report explains that there are creative ways to accommodate this uncertainty while moving forward in addressing the nation's water quality challenges.
Table of Contents
|2 Conceptual Foundations for Water Quality Management||22-31|
|3 Waterbody Assessment: Listing and Delisting||32-67|
|4 Modeling to Support the TMDL Process||68-88|
|5 Adaptive Implementation for Impaired waters||89-102|
|Appendix A: List of Guest Presentations at the First Committee Meeting||103-104|
|Appendix B: Biographies of the Committee Members and NRC Staff||105-109|
Find relevant information like your own rough draft from among the thousands of reports available for free at NAP.edu. Copy and paste up to 8 pages of content—whether from your own draft or an outside article—and Reference Finder will recommend NAP publications related to your text.
View Reference Finder
The National Academies Press (NAP) has partnered with Copyright Clearance Center's Rightslink service to offer you a variety of options for reusing NAP content. Through Rightslink, you may request permission to reprint NAP content in another publication, course pack, secure website, or other media. Rightslink allows you to instantly obtain permission, pay related fees, and print a license directly from the NAP website. The complete terms and conditions of your reuse license can be found in the license agreement that will be made available to you during the online order process. To request permission through Rightslink you are required to create an account by filling out a simple online form. The following list describes license reuses offered by the National Academies Press (NAP) through Rightslink:
Click here to obtain permission for the above reuses. If you have questions or comments concerning the Rightslink service, please contact:
Rightslink Customer Care
Tel (toll free): 877/622-5543
To request permission to distribute a PDF, please contact our Customer Service Department at 800-624-6242 for pricing.
To request permission to translate a book published by the National Academies Press or its imprint, the Joseph Henry Press, please click here to view more information.
Loading stats for Assessing the TMDL Approach to Water Quality Management...