How common is E. coli bacteria found in the drinking water systems that are regulated by Environmental Health?
A. In the 2005-06 Fiscal Year (FY), the EHD Drinking Water Protection Program sampled 943 Local and State Small Water Systems (670 Local Smalls and 273 State Smalls). Out of these systems, only 21 (2.23%) tested positive for E. coli (19 Local Smalls and two State Smalls). In 2005, a total of ten E. coli positives were detected in water systems that collect their own samples, or have a licensed operator collect the system’s samples. Six of these samples were found in CWS (which are tested monthly), three were found in NTNC water systems (which are tested monthly) and the remaining one was detected in a TNC water system (which are tested quarterly). In short, the occurrences of E. coli positives in the water systems regulated by Environmental Health are very infrequent. Out of the thousands of bacteriological lab results received by the Environmental Health Drinking Water Protection Program each year, less than 1% show a positive for E. coli.
