AWWA JAW65913

The ongoing renegotiation of the Total Coliform Rule will directly affect how water providers detect and respond to contamination. This article summarizes the issues and history surrounding the use of indicator bacteria for detecting microbial contamination of drinking water and provides background to help utilities understand possible rule changes and participate more meaningfully in the renegotiation process. Numerous problems are associated with the use of total coliform bacteria as the indicator of choice for drinking water monitoring in the United States. Escherichia coli has emerged as a viable replacement for total coliforms because of advances in E. coli testing, new understanding about distribution systems biofilms, newly emerged waterborne pathogens, and growing international acceptance of E. coli as an indicator of fecal contamination. Replacing total coliform with E. coli as the indicator of choice would significantly reduce followup efforts now spent on total coliform detections that have little or no public health significance. Includes 51 references.