2005/12 + 2017 – Harcourt (Victoria) – E.coli, Formaldehyde, Bromate

Harcourt (Victoria) – E.coli
11/4/07: Harcourt (Victoria) 2org/100mL (sample at customer tap).
No known cause. Operation of the Castlemaine WTP checked and OK (no E.Coli). Re-sampling completed showing no further E.Coli

2009/10 Harcourt E.coli 5orgs/100ml 98.1% samples no e.coli (1 positive)

19/10/11 Harcourt E.coli  1/100mL

9/11/11 Harcourt E.coli  1/100mL

29/2/12 Harcourt E.coli  4/100mL


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

2005/6 – Harcourt (Victoria) – Formaldehyde

2005/6 – Harcourt (Victoria) – Formaldehyde 1mg/L (maximum detection)

Guideline: Based on health considerations, the concentration of formaldehyde in drinking water should not exceed 0.5 mg/L.
Formaldehyde may be present in drinking water through ozonation of naturally occurring humic material, contamination by accidental spills, or deposition from the atmosphere. Typical concentrations in air are probably in the low parts-per-billion range. Overseas, formaldehyde has been detected in ozonated drinking water at concentrations up to 0.03 mg/L.
Formaldehyde is used industrially in the wood, paper and textile industries. It is also used in the production of a number of chemicals and for the preservation of biological material. It is occasionally used as a disinfectant, sometimes to disinfect water filters. Other sources of exposure include cigarette smoke and food. Formaldehyde is present in almost all common foods, and adult dietary intake is estimated at 11 mg/day. Drinking water would contribute less than 10% of total intake.
No data are available on the concentrations of formaldehyde in Australian drinking waters

Harcourt – (Victoria) – Bromate

17/8/17 – Harcourt (Victoria) – Bromate 0.27mg/L (maximum)

A water sample collected from a Harcourt customer tap site had an
elevated level of bromate 0.27mg/L, which exceeded the health based
guideline value for bromate (0.02mg/L) in the ADWG.

Bromate: Regulatory Standard = 0.02mg/L (Also see section of desalination). A suspected carcinogen. Bromate is formed when ozone used to disinfect drinking water reacts with naturally occurring bromide found in source water. Bromate formation in disinfected drinking water is influenced by factors such as bromide ion concentration, pH of the source water, the amount of ozone and the reaction time used to disinfect the water.