Narrative water quality criteria are an integral component of States water quality standards but they pose special problems when incorporated into the TMDL process. The TMDL process is typically a quantitative activity, defining numeric allowable loads necessary to meet a numeric water quality objective. Narrative criteria confound development of quantitative TMDLs, due to the absence of these numeric criteria. The objective of this research was to improve the methods for addressing narrative water quality criteria in the TMDL process. The problems associated with narrative criteria in the TMDL process are known in general terms but, prior to this research, there has not been a thorough review of the use of narrative criteria in TMDLs nor broad guidance on how to address narrative criteria in the TMDL process. The approach taken for this research was to define the range of problems associated with all types of narrative criteria by means of a comprehensive review of 120 narrative TMDLs, and provide guiding principles to help address these problems.

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.

Watershed management is an integrated approach that evaluates system-wide implications of natural resource problems. It has received considerable attention among communities and resource managers as an appropriate approach to deal with complex problems. Problem-solving is an important aspect of watersheds that involves diagnosis, assessment, solution, and implementation issues that often mean processing an enormous amount of information. A typical problem requires compilation of information from a variety of sources and is time consuming. This book will use a problem-based approach to present information on each problem facing watersheds. The subject area derives from a variety of disciplines and experiences and is presented clear and systematically throughout for easy reading and understanding. The problems covered in the book are major ones facing watersheds through the globe. The first chapter introduces principles of watershed management and is followed by chapters that are problem specific. Each problem is dealt with systematically with introduction, analysis, strategies, and further references. Watershed Management provides a valuable reference to professionals, students, scientists, and common citizens who are interested in learning about the variety of problems and approaches in watershed management.