ESxr EDITORIAL Water quality Quality has many meanings, the principal ones being “peculiar and essential character” and “degree of excellence.” With regard to water the first meaning relates to objective reality, such as temperature, density, molecules and ions dissolved in it, particles suspended in it, and plants and animals living in it. In this regard the methods of science are appropriate tools for investigation. The second meaning involves value judgments a b u t the use of water. Here the methods of science are insufficient. Scientists and engineers commonly use the first meaning, but not always. (Keep track of the distinction in the next water quality meeting you attend.) The public, by contrast, almost always focuses on the second meaning. If scientists intend to investigate some aspect of water quality (meaning 1) and the public perceives this as supporting work to improve water quality (meaning 2), then there is risk of unintentional misleading of the public. The two meanings of quality are obviously related because the characteristics of water dictate its value for various uses. Science can serve society by defining the peculiar and essential characters that describe degrees of excellence for uses defined by society. Furthermore, science can predict the impact of effluent insults on water resources as they affect human uses. We use several water-related environmental crises to illustrate how science and technology were or were not involved in their solution. First, the widespread use of DDT caused an insidious crisis. Science neither predicted the seriousness of the problem nor provided for its management or control. In retrospect, we learned that the insecticide selected for resistant genotypes of the target organisms, and thus the effectiveness of the pesticide was comprom i d . Insecticide concentrations in the environment were m n high enough to cause unintentional damage. There was little or no detection and no awareness before vertebrates bemn to die, and the underlying processes leading to their deaths were not appreciated: The second example is lake eutrophication. Once the problem was realized, science provided help. Nevertheless, problems resulting from man-caused nutrient enrichment of lakes reached crisis proportions in the 1960s, before adequate awareness was translated into action. Throughout the 1970s and 1980s, the phenomenon of hyperacidic precipitation has been connected to problems in prly’buffered surface waters of the northeast0013936w87/0921~7501.5010 @ 1987 American Chemical Society
ern United States and of northern Europe. In the arid western United States, a wide array of water quality problems (e&, increased salinity) is related to irrigation of arable lands. Perhaps the most publicized of these problems is the selenium enrichment of Kesterson Reservoir by irrigation drainage in California, where reduced hatchling survival and developmental defects in migratory water fowl have caught public attention. There is a gap between knowing that something is wrong (meaning 2) and knowing what is wrong (meaning 1) and how to correct it. The knowledge gap usually involves insufficient understanding of processes that mediate water quality well enough to predict the outcome or to control events. Furthermore, treatment is becoming more expensive and less feasible as the number and sources of contaminants in water continues to increase. Although our abilities in the analytical laboratory to measure the quality of water are in continual need of improvement, they far outstrip our abilities to interpret the resulting data or understand the controlling processes. Accordingly, we should expend at least as much energy toward understanding the controlling processes as we do toward enhancing analytical capabilities and establishing water quality standards.
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Robert C. Avena is a hydrologisf with fhe U.S. GeologicalSurvey (Resfon,Va.). specializing rivers. in w f e rqualifyof lakes and
a.Q+ k6d G. RicM M o n d f is a professor of biology at Kansas SfafeUniversiry His recenf srudenrs have invesfigared zooplankton nurrifionin furbid reservoirs and have sfudied the dynamics of dissolved organic carbon and nifmfe-Nin prairie sfream.
Note: During 1985-86, Marzo!f W(LF a visiling research h y drologisf with the U.S. Geological Survey in Denver: He and Averen have discussed wafer qualifyat length; this editorial is the oufcomeof those conversations. Envlmn. sci. Technol.. Vol. 21. No. 9. lW7 827
