Estimated duration of incident: Isolated incident
Location of incident: Barmah
Nature of incident: E.coli detection of 1 org/100mL in a routine weekly sample of reticulation system
Drinking water supplies potentially effected: Barmah
Action taken in response: Chlorine residual levels recorded at the time of sampling were, clear water storage -0.6ppm, reticulation-0.5ppm; Detection discussed with district operational staff. Investigation into incident revealed that there had been no water treatment process issues over the past few days, no CCP breaches had occurred. Storage checked for signs of ingress points none found. Response sampling of clear water storage and reticulation system instigated. All samples were clear of E. coli. No further detections since.
Communication with customers: nil
DH notification: A section 22 notification was sent to the Department of Health on 14/12/2012.
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
Barmah (Victoria) – Chloroacetic Acids
2010/11: Barmah 0.110mg/L Dichloroacetic Acid
2010/11: Barmah 0.150mg/L Trichloroacetic Acid
Australian Guidelines; Dichloroacetic Acid 0.1mg/L, Trichloroacetic Acid 0.1mg/L
“Chloroacetic acids are produced in drinking water as by-products of the reaction between chlorine and naturally occurring humic and fulvic acids. Concentrations reported overseas range up to 0.16mg/L and are typically about half the chloroform concentration. The chloroacetic acids are used commercially as reagents or intermediates in the preparation of a wide variety of chemicals. Monochloroacetic acid can be used as a pre-emergent herbicide, dichloroacetic acid as an ingredient in some pharmaceutical products, and trichloroacetic acid as a herbicide, soil sterilant and antiseptic.” Australian Drinking Water Guidelines – National Health and Medical Research Council…
There are no epidemiological studies of TCA carcinogenicity in humans. Most of the human health data for chlorinated acetic acids concern components of complex mixtures of water disinfectant by-products. These complex mixtures of disinfectant by-products have been associated with increased potential for bladder, rectal, and colon cancer in humans [reviewed by Boorman et al. (1999); Mills et al. (1998)].” Ref: tmp/Trichloroacetic acid (TCA) CASRN 76-03-9 IRIS US EPA.htm
Barmah (Victoria) – Chloral Hydrate
2010/11: Barmah 0.025mg/L Goulburn Valley Water Chloral Hydrate
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.”
2018/19 – Barmah Victoria (Pesticide – Soil Fumigant, Nematocide)
“Single detection of 1,2-dibromo-3-chloropropane in the raw water. At the time of the detection powdered activated carbon was operational in the treatment plant. The risk of WTP breakthrough was low, and all subsequent samples were below the limit of reporting. DBCP Is not listed in the ADWG but the WHO standard was used instead.” https://www.gvwater.vic.gov.au/Portals/0/GV-Water/Documents/Reports/Water%20Quality%20Annual%20Report%20201819%20Goulburn%20Valley%20Water%20-%20Final%20PDF.pdf?ver=2019-10-30-085222-843
1,2-Dibromo-3-chloropropane (DBCP) was used in the past as a soil fumigant and nematocide on crops; it is no longer used except as an intermediate in chemical synthesis. Acute (short-term) exposure to DBCP in humans results in moderate depression of the central nervous system (CNS) and pulmonary congestion from inhalation, and gastrointestinal distress and pulmonary edema from oral exposure. Chronic (long-term) exposure to DBCP in humans causes male reproductive effects, such as decreased sperm counts. Testicular effects and decreased sperm counts were observed in animals chronically exposed to DBCP by inhalation. Available human data on DBCP and cancer are inadequate. High incidences of tumors of the nasal tract, tongue, adrenal cortex, and lungs of rodents were reported in a National Toxicology Program (NTP) inhalation study. EPA has classified DBCP as a Group B2, probable human carcinogen.
Barmah (Victoria) Iron
2018/19: Barmah (Victoria) – Iron 0.4mg/L (max)
Based on aesthetic considerations (precipitation of iron from solution and taste),
the concentration of iron in drinking water should not exceed 0.3 mg/L.
No health-based guideline value has been set for iron.
Iron has a taste threshold of about 0.3 mg/L in water, and becomes objectionable above 3 mg/L. High iron concentrations give water an undesirable rust-brown appearance and can cause staining of laundry and plumbing fittings, fouling of ion-exchange softeners, and blockages in irrigation systems. Growths of iron bacteria, which concentrate iron, may cause taste and odour problems and lead to pipe restrictions, blockages and corrosion. ADWG 2011