Clostridium perfringens as a point source indicator in non-point polluted streams

Abstract

Clostridium perfringens spores were evaluated as an indicator of point source pollution in small streams whose bacteriological water quality was influenced by both point and non-point sources. Samples were collected from small streams (the Rio San Jose, New Mexico and Worm Creek, Idaho/Utah); the Grants, New Mexico; Preston, Idaho; Hyrum, Utah; and San Jose/Santa Clara, California; sewage treatment plant effluents; and the Franklin, Idaho; Logan, Utah; and Wellsville, Utah: facultative sewage lagoons. In both of the small streams, C. perfringens spores could be detected, in decreasing concentrations, for more than 10 km downstream from municipal wastewater treatment plant effluents. Coliform and fecal streptococci concentrations varied widely along the streams in apparent response to non-point sources. Samples of cow, horse and sheep feces; farmlot runoff; oxbow lakes that receive fecal material from animal feeding facilities; and from animal grazing area soil were low in C. perfringens spores, but contained high concentrations of other fecal indictor bacteria. C. perfringens spores appear to be a sensitive indicator for microorganisms entering streams with municipal wastewater, even when agricultural non-point sources of fecal indicator bacteria are important in the receiving stream. Samples of effluents taken from sewage treatment plants with sand filtration processes, and from facultative sewage lagoons, indicate that C. perfringens spores concentrations may be low in these effluents.