2017 – Mitchelton (Queensland) – E.coli

Mitchelton (Queensland): E.coli
1/2/17 E. coli Mitchelton The non-compliance was a detection of E. coli from a routine sample taken on 1/2/17 at SP231. 1MPN E. coli organisms per 100mL was detected. Follow up samples indicated no continued presence of E. coli. Mitchelton reservoir was flood tested to identify rainwater ingress points. Ingress points have been sealed and additional precautionary
works conducted. Continuous online monitoring has been installed on the reservoir outlet. Further network improvements will be investigated.

“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