Total coliform and fecal coliform have been used as measures of water quality for uses ranging from shellfish waters to public water supplies. Because of the weaknesses of the coliform tests, research has continued in the search for indicators of fecal pollution. Coprostanol, or 5 beta-cholestan-3 beta-ol, has shown promise as an indicator of fecal pollution. This sterol is a characteristic fecal organic compound which is found in the feces of higher animals, including man. The gas chromatographic analysis of coprostanol was improved and a method of sample preservation was developed using H2SO4. Field surveys compared coprostanol analyses with total and fecal coliform and confirmed the predicted advantages of a chemical method over a biological method. The gas chromatographic method was used in extensive field surveys, in degradation studies, in treatment plant efficiency studies and as the standard for evaluation of a colorimetric method. The method was capable of determining twenty nanograms per liter, which was estimated to be equivalent to approximately two coliforms per 100 ml. An attempt was made to correlate coprostanol concentration with treatment plant efficiency. There was a reasonably good correlation between coprostanol and BOD, COD and TOC. A colorimetric method has been developed that can be used to determine coprostanol at levels of one microgram g/l in polluted water. The color developer used is dinitrophenylhydrazine. (Modified author abstract)

Report prepared by Florida University, Department of Environmetal Engineering Sciences, Gainsville, Florida. Prepared for Office of Research and Development, U.S. Environmental Protection Agency. "EPA 660/2-74-021." "Project 16020 EVG; Program element 1BA027." Includes bibliographical references (pages 109-112).