Glenrowan (Victoria)
11 Feb 2014 E.coli 1org/100mL. E. coli was detected at the Glenrowan entry point through routine monitoring. At the time of detection a free chlorine residual of 1.2 mg/L and a turbidity of 0.1 NTU was recorded. North East Water immediately investigated the suspected contamination with no cause found. An Operator visually inspected the tank at the entry point and found no signs of damage, open hatches or ingress. A free chlorine residual of 1.3 mg/L was also recorded. The contracting laboratory resampled the entry point and next nearest clear water storage on the main to Glenrowan and found good chlorine residuals and no E. coli. This incident is attributed as a sampling or analysis anomaly.
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
2009/10 – Glenrowan (Victoria) – Turbidity
2009/10: Glenrowan Turbidity 6.5NTU
Chlorine-resistant pathogen reduction: Where filtration alone is used as the water treatment
process to address identified risks from Cryptosporidium and Giardia, it is essential
that filtration is optimised and consequently the target for the turbidity of water leaving
individual filters should be less than 0.2 NTU, and should not exceed 0.5 NTU at any time
Disinfection: A turbidity of less than 1 NTU is desirable at the time of disinfection with
chlorine unless a higher value can be validated in a specific context.
Aesthetic: Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the
consumer’s tap