2001 + 2016/20: Cummins (South Australia) – Trihalomethanes, Hardness

Cummins (South Australia) Trihalomethanes

Breaches to Australian Drinking Water Guidelines Levels Only

16/01/2001 Cummins  Phillip St Edu Min Trihalomethanes – Total 463 ug/L

Trihalomethanes Australian Guideline Level 250μg/L (0.25mg/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”. Source: https://water.epa.gov/drink/contaminants/index.cfm

Cummins (South Australia) – Hardness

November 8 2016: Cummins (South Australia) – Calcium Hardness 208mg/L

2018/19: Cummins (South Australia) Hardness as CaCO3 263mg/L (max), 259mg/L (mean)

2019/20: Cummins (South Australia) Total Hardness as CaCO3 277mg/L (max), 266mg/L av.


“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.”

Australian Drinking Water Guidelines 2011