ASABE Technical Library - Abstract
Member and Access Notice
Findings of the National Research Council’s Committee on Assessing the TMDL Approach to Water Quality Management
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org
Citation: Pp. 307-311 in Total Maximum Daily Load (TMDL) Environmental Regulations: Proceedings of the March 11-13, 2002 Conference, (Fort Worth, Texas, USA) 701P0102.(doi:10.13031/2013.7574)Authors: J. Mandrup-Poulsen
Keywords: TMDL Program, National Research Council, Scientific Basis
Recently, the TMDL program has become one of the most discussed and debated environmental
programs in the nation, primarily because of EPAs drafting of final rules for the program. These
rules follow several years of intense activity, including the formation of a Federal Advisory
Committee devoted to this topic. In October 2000, Congress suspended EPAs implementation of
these rules until further information could be gathered on several aspects of the program. In
particular, Congress requested that the National Research Council (NRC) form a committee to
examine the scientific basis of the TMDL program. This committee found that substantial
improvements could be made in a number of areas to strengthen the scientific basis of the TMDL
program. The committee also identified several policy issues that are restricting the use of the
best science in the TMDL program.
Using the information gathered during the study and the NRC committees collective experience,
it was felt that the data and science have progressed sufficiently over the past 35 years to support
the nations return to ambient-based water quality management. In addition, the need for this
approach is made apparent by the inability of a large percentage of the nations water to meet
water quality standards using point source controls alone. Given reasonable expectations for
data availability and inevitable limits on our conceptual understanding of complex systems,
statements about the science behind water quality management must be made with
acknowledgment of uncertainties. The committee also concluded that there are creative ways to
accommodate this uncertainty while moving forward in addressing the nations water quality
challenges. These broad conclusions will be elaborated upon throughout this presentation.