Fecal streptococcal indicators
The total coliform and fecal coliform tests have been paramount in the bacteriological monitoring of water quality. They have been the chosen principle indicators in all fifty states and territories, and have been recommended by the committee on Water Quality Criteria for this purpose. However, although coliforms occur in human feces in larger numbers than fecal streptococci, the latter occur in animal feces in larger numbers than the fecal coliforms. The daily output of animal feces in the U.S. is roughly equivalent to that of 1.9 billion human beings! Thus, the fecal coliform and total coliform tests may not be totally reliable as all-inclusive measures of fecal contamination in water. According to Shuval, There is a need for a more questioning attitude toward many standard, and efforts should be made to reevaluate even the most accepted ones in terms of the more rigorous scientific techniques in use today.... This chapter presents data and arguments in support of using fecal streptococci as indicators of fecal pollution of waters. The effect of water toxicity on the persistence of fecal streptococci in various waters in different areas of the United States will be documented along with the effect of water toxicity on the survival of Escherichia coli, Enterobacter aerogenes, and certain selected pathogens in water.