Non-potable water is water that is not of drinking quality, but may still be used for many other purposes, depending on its quality.
Potable water is water of a quality suitable for drinking, cooking and personal bathing according to Australian guidelines.
The standards that define potable water are described in the Australian Drinking Water Guidelines.
Unless water is known to be of potable quality, for example from a drinking water supply system, it should be regarded as non-potable and used appropriately.
Examples of non-potable water
Some examples of non-potable water use in the workplace include:
- rainwater from tanks used for various workplace uses, for example cooling towers and car washing
- quarry water used for dust suppression and landscape irrigation
- swimming pool backwash water used for toilet flushing
- agricultural waste water used for crop irrigation
- creek, dam, and river water used for dust suppression
- class A recycled water from a sewage treatment plant used for dust suppression, car washing, landscape irrigation or irrigation of sporting ovals.
The person in control of the workplace must manage any risks from the use, handling, storage, and transport of the water at the workplace. To do this, information on health hazards, precautions for use, recommended uses and testing data must be obtained.
Information within a product safety information sheet should contain at a minimum, information on health hazards, precautions for use, recommended uses, and water quality testing data.
For both workers and members of the public, the person in control of the workplace must:
- identify any hazards in the water, for example bacteria, viruses, chemicals, metals
- assess any risks to people from the proposed use of the water, for example are they likely to be saturated with the water?
- control any risks to people from exposure to the water for example accidental drinking of the water, inhaling droplets, becoming drenched in the water
- control any risk from storage of the water causing deterioration of the water
- evaluate the effectiveness of controls by supervising the use of control strategies and testing the water periodically.
You should notify WHSQ of an incident that occurs in relation to the use of non-potable water in the workplace.
What is recycled water?
Recycled water, a form of non-potable water, is any water that has been used at least once and then supplied for reuse, either treated or untreated. Without appropriate treatment, recycled water may contain a range of contaminants.
For example, water used for the final rinse in a commercial laundry is only lightly contaminated and thus may be used again, untreated, for the first wash cycle. On the other hand, sewage must be treated at a sewage treatment plant before it can be recycled for any purpose.
In Queensland, recycled water from sewage treatment plants is put into different classes depending on its microbiological quality. These classes range from Class A+ (the highest) to Class D (the lowest). Recycled water can even be treated at an advanced water treatment plant so that it meets drinking water standards. This is then called 'purified recycled water'.