2005/9 + 2016/22 – Heathcote (Victoria) – Boil Water Alert, Mercury, Manganese, Ammonia, Hardness, Trihalomethanes, Total Dissolved Solids

‘Boil water’ advisory lifted in Heathcote

October 2 2022 https://www.bendigoadvertiser.com.au/story/7925803/coliban-lifts-boil-water-advisory-in-heathcote/

People no longer need to boil tap water, days after a broken main caused havoc across Heathcote.

Coliban Water lifted its suit of warnings on Sunday after consultations with the Department of Health.

“We recommend customers flush their internal taps for two minutes to draw fresh water into their internal plumbing,” it said.

Access to the town’s standpipe is being reinstated.

Residents were told to boil their water until further notice last Thursday evening following a burst in the town’s pipe network.

“This burst has resulted in a supply interruption for some Heathcote customers and very low water pressure for others which may cause ingress into the system and compromise the safety of the drinking water,” Coliban said in an advisory message issued on Thursday.

Contractors spent Friday flushing the network and on Saturday Coliban was awaiting results from water sampling.

The water corporation supplied bottled water to a raft of groups including Heathcote’s hospital, nursing home and childcare centre.

Coliban also supplied bottled water to the Heathcote Food and Wine Festival, which went ahead as planned.

The boil water notice may inadvertently draw further attention to an unrelated but ongoing problem with Heathcote’s supply.

It is not fluoridated.

City of Greater Bendigo councillors voted in July to push state election candidates for promises to help fund the $920,000 bill to reverse that problem.

Coliban Water has recently upgraded a plant in the area, potentially paving the way for change, Cr Margaret O’Rourke said.

“It’s … the second largest population base in Greater Bendigo and it’s quite remarkable that they don’t have fluoridation already,” she said.

The National Health and Medical Research Council says fluoridation is safe when at Australian standards.

2005/06 – Heathcote (Victoria) – Mercury
2005/6 Heathcote (Victoria) – Mercury 0.0023mg/L

Mercury: Australian Drinking Water  Guideline 0.001mg/L

Mercury, if it enters the ecosystem can transform into the more toxic methylmercury where it can bioaccumulate. Methylmercury is highly toxic to human embryos, fetuses, infants and children. Mercury has numerous sources including old gold mines, where mercury was used in gold recovery process. It has been estimated that 950 tonnes of
mercury was deposited into Victorian soil, rivers and streams during the various gold rushes.

Heathcote – Victoria – Manganese

2016/17: Heathcote (Victoria) – Manganese 0.51mg/L (highest level)

Manganese: ADWG Guidelines 0.5mg/L. ADWG Aesthetic Guideline 0.1mg/L
Manganese is found in the natural environment. Manganese in drinking water above 0.1mg/L can give water an unpleasant taste and stain plumbling fixtures and laundry.

Heathcote (Victoria) – Ammonia

2016/17: Heathcote (Victoria)  – Ammonia 0.778mg/L (Highest level only – Ammonia as N)

2019/20: Heathcote (Victoria)  – Ammonia 0.657mg/L max (0.162mg/L av.)

Based on aesthetic considerations (corrosion of copper pipes and fittings), the concentration
of ammonia (measured as ammonia) in drinking water should not exceed 0.5 mg/L.
No health-based guideline value is set for ammonia. (0.41mg/L mg of Ammonia as N)

“…Most uncontaminated source waters have ammonia concentrations below 0.2 mg/L. High concentrations (greater than 10 mg/L) have been reported where water is contaminated with animal waste. Ammonia is unlikely to be detected in chlorinated supplies as it reacts quickly with free chlorine. Ammonia in water can result in the corrosion of copper pipes and fittings, causing copper stains on sanitary ware. It is also a food source for some microorganisms, and can support nuisance growths of bacteria and algae, often with a resultant increase in the nitrite concentration.” ADWG 2011

2005/06 -Heathcote (Victoria) – Hardness

2005/06: Heathcote (Victoria) Hardness 260mg/L (max), 190mg/L (mean)

2006/07: Heathcote (Victoria) Hardness 260mg/L (max)


“To minimise undesirable build‑up of scale in hot water systems, total hardness (as calcium
carbonate) in drinking water should not exceed 200 mg/L.

Hard water requires more soap than soft water to obtain a lather. It can also cause scale to form on hot water pipes and fittings. Hardness is caused primarily by the presence of calcium and magnesium ions, although other cations such as strontium, iron, manganese and barium can also contribute.”

Heathcote (Victoria) – Trihalomethanes

2006/07: Heathcote (Victoria) – Trihalomethanes 310μg/L (maximum), 149μg/L (average)

Trihalomethanes Australian Guideline Level 250μg/L

Why and how are THMs formed?
“When chlorine is added to water with organic material, such as algae, river weeds, and decaying leaves, THMs are formed. Residual chlorine molecules react with this harmless organic material to form a group of chlorinated chemical compounds, THMs. They are tasteless and odourless, but harmful and potentially toxic. The quantity of by-products formed is determined by several factors, such as the amount and type of organic material present in water, temperature, pH, chlorine dosage, contact time available for chlorine, and bromide concentration in the water. The organic matter in water mainly consists of a) humic substance, which is the organic portion of soil that remains after prolonged microbial decomposition formed by the decay of leaves, wood, and other vegetable matter; and b) fulvic acid, which is a water soluble substance of low molecular weight that is derived from humus”. US EPA

Heathcote – Victoria – Total Dissolved Solids

2006/07: Heathcote (Victoria) – Total Dissolved Solids 1300 EC Units


“No specific health guideline value is provided for total dissolved solids (TDS), as there are no
health effects directly attributable to TDS. However for good palatability total dissolved solids
in drinking water should not exceed 600 mg/L.

Total dissolved solids (TDS) consist of inorganic salts and small amounts of organic matter that are dissolved in water. Clay particles, colloidal iron and manganese oxides and silica, fine enough to pass through a 0.45 micron filter membrane can also contribute to total dissolved solids.