2010 May – Mt Eliza – Gillards Rd (Victoria) – E.coli

Mt.Eliza – Gillards Rd – Victoria – E.coli
The fourteenth event was a detection of E. coli from a routine sample taken on 5 May 2010 at Gillards Road, Mt Eliza, (six E. coli organisms per 100mL) with a free chlorine residual of 0.01 mg/L. This sample point, which is located within the Frankston locality, is supplied directly from Armagh Road Basin. The Armagh Road Basin was immediately isolated and the supply to the area was changed. Resamples at the sample tap and a number of nearby taps were clear of E. coli. The Basin was also sampled over a number of days, each time sampling a number of locations, until we were confident that it was not the source of the E. coli and the Basin was
put back into service.

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