Chlorine in drinking water

Chlorine is a widely used disinfectant that helps protect drinking water from harmful micro-organisms. When added to water, it breaks down to form free chlorine, which destroys bacteria, viruses and parasites.

You may notice a slight chlorine smell in your water — some people can detect it at levels as low as 0.2 milligrams per litre (mg/L), although the odour threshold is generally around 0.6 mg/L. To ensure water stays safe all the way to your tap, TasWater may sometimes need to maintain chlorine levels above this threshold.

Water from natural sources like rivers, dams or rainwater tanks can contain micro-organisms that make people sick. Disinfection is a critical step in water treatment, helping to ensure water is safe for drinking. Without it, we couldn’t guarantee safe supply — and may need to issue a boil water alert if risks aren’t managed.

The small amounts of chlorine added to your water are safe to drink and well within national guidelines. In fact, chlorination is recommended by the National Health and Medical Research Council and used by water utilities across Australia.

At TasWater, we typically keep chlorine levels below 1.0 mg/L (that’s less than 0.0001%), which is safe for consumption and effective for disinfection.

Our systems are monitored 24/7 using electronic sensors that send alerts if chlorine levels fall outside the safe range. We also carry out daily manual checks using portable testing devices. All monitoring equipment is calibrated regularly to ensure accuracy. 

TasWater continuously monitors the chemical and microbiological quality of drinking water. Our treatment systems are regulated under Tasmania’s Public Health Act 1997 and follow the Australian Drinking Water Guidelines.

You can check which systems have a fluoridated supply in our Annual Drinking Water report, or use the Water Quality portal.