ABSTRACT
Accurate knowledge of physical and biological relationships in water bodies is an essential prerequisite to the design and operation of optimum waste-disposal systems. The problems presented by excessive algae growth have recently elicited much discussion because, with the expansion of population and economic activity, the amount of plant nutrient entering water courses has increased rapidly in recent years. Degradable pollutants, which do not remain constant in quantity or form and whose effects on the stream are conditioned by a number of variables, are not necessarily the most destructive pollutants. Photosynthetic oxygen production is affected by factors such as cloudiness, time of day, turbidity, and temperature. The significance of photosynthesis in the determination of the oxygen balance of waters is a matter of course related to the plant nutrient question. Furthermore, an efficient means of calculating the effects on receiving water of changes in amounts and types of waste loads, streamflow, temperature, and other relevant variables is necessary.
