Estimated duration of incident: Isolated incident
Location of incident: Girgarre
Nature of incident: Detection of 4 org/100mL of E.coli in the reticulation at Girgarre. The cause is unknown but a sampling error is suspected due to rain at time of sampling. There was no E.coli detected in the Water Tower.
Drinking water supplies potentially affected: Girgarre.
Action taken in response: Resampling of the Water Tower and reticulation in Girgarre. No further detections found. Checked for evidence of ingress at the storages – none found.
Communication with customers: Nil
DH notification: A Section 22 notification was sent to the Department of Health on 7/04/2014
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
2010: Girgarre (Victoria) – Chlorophenols
16/09/2010: Girgarre WTP 2,4-Dichlorophenol = 1 µg/L
ADWG Guidelines: Health: 2-chlorophenol 300 µg/L Aesthetic: 0.1 µg/L
No Guideline exists for 2,4,5-Trichlorophenol
Included with the Freedom of Information request from Goulburn Valley Water were detections for 2,4,5 Trichlorophenol (8 detections) (highest level: 460 µg/L 18/10/11 Strathbogie) and 2,4-6 Trichlorophenol (96 detections) (highest level 5.2µg/L: Strathbogie 16/11/15).
According to the Australian Drinking Water Guidelines
“ Chlorophenols may be present in drinking water as a result of chlorination of water that contains phenol or lower chlorophenols, or from contamination of water sources. Chlorination of water containing natural organic compounds can produce very low concentrations of chlorophenols. Degradation of phenoxy herbicides such as 2,4,5 – T and 2,4 – D also generates chlorophenols…
Chlorophenols are used commercially as preservatives, moth – proofing agents, germicides and anti – mildew agents…. No data are available on concentrations of chlorophenols in Australian drinking waters. If present at all, it is likely that concentrations would be extremely low.”
2,4,6 Trichlorophenol is listed under the 2002-3 Goulburn Valley Water – Water Quality Annual Report as “Health – Related Organics – Organic chemicals that can impact on the health of consumers are rarely present in drinking water supplies, but could potentially be present in raw water sources as a result of accidental spills or misuse.”
Due to the unknown source of the Trichlorophenols, these detections were not included in the final pesticide data in this report, but are assumed to be a byproduct of disinfection. Average level of 2,4,6 Trichlorophenol detected 2008-16 in 33 locations: 0.93µg/L. Average level 2,4,5-Trichlorophenol detected 2011-15 in 4 locations: 72.87µg/L.
2,4-D detections in Girgarre channel supply for approximately 4 months in 2010. The average detected levels over the four month period were 1.94µg/L (6.6% of the Australian Drinking Water Guideline for 2,4-D). It is also unclear what percentage of the 2,4-D was removed by the treatment process used at Girgarre. It appears that activated carbon was not used. It is also unclear the level of dioxins contained in the 2,4-D that came down the channel. Dioxins, some of the most toxic substances known, can be created during the 2,4-D manufacturing process. “ An urgent review is underway after a Four Corners investigation found elevated levels of dangerous dioxins in a generic version of 2,4 – D, one of Australia’s most widely used herbicides. Dioxins are one of the most deadly chemical compounds in the world, but Australi an authorities do not routinely test for them. One scientist said the product tested by Four Corners, which was imported from China, had one of the highest dioxin readings for 2,4 – D in the last 10 to 20 years, and could pose potential health risks…” http://www.abc.net.au/news/2013-07-22/four-corners-dangerous-dioxins/4833848
“Under the Radar” Pesticide Detections Victorian Water Supplies 2007-2016 – Anthony Amis – Friends of the Earth Melbourne October 2017
Highest Detections only 2009/11
Girgarre 33ug/L Chloral Hydrate 2010/11
Girgarre 22ug/L Chloral Hydrate 2009/10
2004 Australian Drinking Water Guideline: Trichloroacetaldehyde (chloral hydrate): 0.02mg/L
2011 Australian Drinking Water Guideline: Trichloroacetaldehyde (chloral hydrate): 0.1mg/L
“Chloral hydrate is a disinfection by-product, arising from chlorination of water containing naturally occurring organic material (NOM). Chloral hydrate has only been detected by Goulburn Valley Water since changing to a new contract testing laboratory in November 2007. The Department of Health is currently conducting a study into the detection of chloral hydrate across Victoria.”