2015/16 – Baralaba (Queensland) – E.coli

Baralaba (Queensland): E.coli
E.coli Detection – Baralaba Reticulation: There was an instance during the reporting period of E.coli detected in a sample collected from the Baralaba Reticulation network. Incident no DWI-7504-00039 (9/1/2015) refers.
E.coli was detected with a count of 9 E.coli per 100ml with a disinfection residual of 0.16mg/L. Investigation identified incorrect sampling procedure as the most likely cause. Instructions regarding correct sampling location and procedure were re-iterated to staff
Incident Description: The second non-compliance was a detection of E. coli from a routine sample taken on 4/01/2016 at Stopford St median, Baralaba. 5 E. coli organisms per 100 mL were detected, with a disinfection residual of 0.07 mg/L. Corrective and Preventative Actions: The target free chlorine residual was increased to 2.0mg/L to achieve a residual free chlorine throughout reticulation of 0.2mg/L. Sampling and testing was performed at all reticulation sampling points to ensure that the residual target was achieved, and the reservoir setpoints were changed to increase the volume of water exchanged. Follow up sampling did not detect any further E. coli
Banana Shire Drinking Water Quality Management Plan 2014-15 + 2015-16

“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