Record Display for the EPA National Library Catalog


Main Title Effects of Streamflow Variation on Critical Water Quality for Multiple Discharges of Decaying Pollutants.
Author Eheart, J. W. ;
CORP Author Illinois Univ. at Urbana-Champaign. Dept. of Civil Engineering.;Environmental Protection Agency, Cincinnati, OH. Risk Reduction Engineering Lab.
Publisher c1988
Year Published 1988
Report Number EPA/600/J-88/396;
Stock Number PB90-100587
Additional Subjects Water quality management ; Streams ; Water flow ; Decay ; Unloading ; Numerical analysis ; Concentration(Composition) ; Oxygen ; Biochemical oxygen demand ; Water pollution sampling ; Nonpoint sources ; Point sources
Library Call Number Additional Info Location Last
NTIS  PB90-100587 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
The assumption that the worst water quality occurs at the lowest streamflow may not always hold in instances involving multiple discharges and nonconservative pollutants. The additional dilution resulting from increased streamflow may be offset by adverse changes in the parameters that govern water quality and in decreased residence time, which allows the stream less time to recover from the effect of one discharge before receiving another. The paper addresses the question of whether, with multiple sources of decaying pollutants, water quality might worsen with increasing streamflow. For an isothermal uniform stream it is shown that the pattern of discharge that maximizes the derivative with respect to streamflow of critical dissolved oxygen deficit or the concentration of a substance exhibiting a first-order decay is an infinite uniform distributed load. Theoretical results presented here indicate that for most natural streams the traditional assumption, that the lowest streamflow is the worst from a water quality perspective, will usually be valid for first-order pollutants. Nevertheless, they also lead to the expectation that increases in impacts with increasing streamflow might occur for dissolved oxygen, especially in highly polluted and regulated streams. (Copyright (c) 1988 The American Geophysical Union.)