Adventure Bay (Tasmania) – E.coli
8/12/17: “Weekly sample detected E. coli of 1 MPN/100mL at ABSTE288. An incident was declared and DoH was immediately notified. Customers were notified (direct and water carters) and bottled water was provided. A dispatch crew was sent to perform resampling and isolate and inspect the system. Subsequent sampling showed ABSTE288 was clear of E. coli; however the tank sampled detected E. coli of 2 MPN/100mL. Water carters advised to utilise Electrona Fill Station until a new chlorinator installed, commissioned and system back online.” Tas Water Annual Drinking Water Quality Report 2017/18 Section B
Escherichia coli should not be detected in any 100 mL sample of drinking water. If detected
in drinking water, immediate action should be taken including investigation of potential
sources of faecal contamination.
“Coliforms are Gram-negative, non-spore-forming, rod-shaped bacteria that are capable of aerobic and facultative anaerobic growth in the presence of bile salts or other surface active agents with similar growth-inhibiting properties. They are found in large numbers in the faeces of humans and other warm-blooded animals, but many species also occur in the environment.
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 2011