2017/18: Goovigen (Queensland) – E.coli

Incident description, a positive detection of e.coli was found in the Goovigen Town water supply
during routine sampling. As a public safety precaution, a boil water alert was issued. Despite repeated sampling, there were no failures in disinfection or subsequent detections of microorganisms.

Occasionally false positives test results can occur due to the sensitivity of the testing techniques, and the challenge of preserving aseptic conditions during field sampling.

Thermotolerant coliforms are a sub-group of coliforms that are able to grow at 44.5 ± 0.2°C. E. coli is the most common thermotolerant coliform present in faeces and is regarded as the most specific indicator of recent faecal contamination because generally it is not capable of growth in the environment. In contrast, some other thermotolerant coliforms (including strains of Klebsiella, Citrobacter and Enterobacter) are able to grow in the environment and their presence is not necessarily related to faecal contamination. While tests for thermotolerant coliforms can be simpler than for E. coli, E. coli is considered a superior indicator for detecting faecal contamination…” ADWG