Biological Bases for Water Quality Standards
C. H. WARD, Professor
Departments of Biology and Environmental
Science and Engineering
Rice University
Houston, Texas
E. M. DAVIS, Assistant Professor
School of Public Health
The University of Texas
Houston, Texas
INTRODUCTION
"Public policy relating to water pollution by the very nature of the processes through
which it develops, is frequently inconsistent with the state of scientific and technological
knowledge. This may render policies ineffective in accomplishing public objectives.
Biologists must be informed on public policy and relevant biological knowledge, for it is
their responsibility to call to the attention of authorities and also the public any
inconsistencies that exist." This statement was made by Warren (1) in his excellent book on
Biology and Water Pollution Control but we believe that it is also the duty of every
pollution control engineer to question the veracity and appropriateness of the data and
procedures used to arrive at water quality standards. Most papers at this conference
concern treatment of industrial waste waters to reduce contaminants, prevent pollution,
and meet water quality standards. Yet little attention has been devoted to discussions of the
basis for the standards which provide the focal point for and by which we judge our efforts.
The purpose of this paper is to review and discuss the basis for and techniques used in
establishing water quality standards. We hope to provide, with minimum detail, the essence
of the process and place it in perspective for rotational analysis. Our conclusion will be, in
part, that the standards setting process, as currently practiced, far exceeds the technical
foundations on which it is based, stifles research to establish valid criteria, and often leads to
irrational behavior of regulatory bodies, e.g., the mercury thing.
SETTING STANDARDS
Water quality standards may be and are set with different objectives in mind.
Standards may be predicated on limited use, but most high quality waters can be used for
primary contact, public and industrial water supplies, and for food processing. Waters of
sufficient quality to meet these objectives are generally excellent habitats for diverse,
desirable aquatic forms that can support both sport and commercial fisheries. In fact,
maintenance of aquatic life generally requires higher quality water than the other uses
because water can be treated or processed before public or industrial consumption. As a
consequence, water quality criteria are generally set with aquatic life foremost in mind.
777i? Bioassay and its Application
How does one seta water quality standard to protect aquatic life? First, using accepted
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