2015 November/2016 April – Julia Creek (Queensland) – E.coli
Incident Description: The first non-compliance was a detection of E. coli from a routine sample taken on the 25th November 2015 at the Airport Residence located Airport Road, Julia Creek. One E. coli organisms per 100 mL was detected. It was noted that the water that serviced the residence was stored in two poly tanks and then pumped into the house.
Corrective and Preventative Actions: The two poly tanks were flushed out and dosed with chlorine immediately after the positive result and continued to be regularly flushed and dosed as preventative action. Boil Water Alert was raised for the township immediately. The first follow up samples were taken on 30th November 2015 and returned a value of 2 org/100mL from the Airport Residence and <1org/100mL form the Airport Building. The second follow
up samples were taken on the 2ndDecember 2015 and both the Airport Residence and Airport Building had a detection of 1 org/100mL. Following these positives, the tanks were flushed out completely and dosed with chlorine. A third follow up sampling was completed on the 8th
December 2015 and both the Airport Residence and Airport Building detected <1 org/100mL. On this same date, a sample was taken at another residence running off the same bore but without poly tanks and returned a value of <1 org/100mL. Another sample was taken on the 15
th December 2015 and was found clear of E.coli.
Incident Description: The second non-compliance was a detection of E.coli from a routine same taken on the 27th April 2016 at the Council Residence located at Airport Road as part of the Julia Creek water supply scheme. 109 org / 100 mL were detected.
Corrective and Preventative Actions: Boil Water Alert was raised for the township immediately.
After an initial chlorine flush of the two poly tanks, the Council staff decommissioned both tanks. The Airport Building and Airport Residence are now sourced directly from the Scour Bore. After decommissioning the tanks, three follow up samples were taken and were shown to
be clear of E.coli. Monthly testing at the Airport will continue despite the removal of the tanks as a preventative action.
“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