Clean water is one of the pillars of modern society; without it we’d be either sick or dead. Therefore any problem with the water supply can have major consequences for an entire community, and the quality of our water supply is extremely important. As plumbing is predominantly about water, there are several things you should know about your water supply.
What is potable water?
Put simply, 'potable' water is drinking quality water intended for human consumption, either directly as supplied from the tap, or indirectly, in beverages or foods prepared with water.
For water to be considered potable, it must be free from no harmful concentrations of chemicals or pathogenic microorganisms. It should also (ideally) look, taste and smell good.
(Source: Australian Drinking Water Guidelines, National Health and Medical Research Council (2003))
Where does potable water come from?
Potable water is supplied from both surface water and groundwater. Surface water is rainfall and its runoff into streams and rivers, and can come from a river, lake or artificial dam. Groundwater, on the other hand, is that which has been collected from stores or aquifers and is accessed by a bore.
These water supplies are centrally treated and distributed via the water mains to your home. In recent times, many Australian households have been collecting their own rainwater too - particularly in areas like Melbourne where water restrictions apply throughout the year. Rainwater collected in tanks from roofs is not legally drinkable unless it has been treated to potable quality.
The water that is used in most Australian homes and gardens (supplied by the relevant water authorities) is of drinking water quality. This means that it has been carefully managed and treated to make it safe to drink.
An interesting fact, though, is that only around 1% of drinking water supplied in Australia is actually used for drinking. Considerably more is used for activities like cooking, washing clothes, showering and flushing the toilet. Gardens takes the most drinking water, typically accounting for around 35% of our overall consumption, although in hot, dry summers, this figure can be as high as 90% in some parts of Australia.
Maintaining water quality
It is important that your potable water be free of any chemicals or pollutants, and it's up to your water supplier to ensure this is the case. While things like cryptosporidium and giardia are common elsewhere and have been a problem in Australia in the past (notably in the 1998 Sydney water crisis), they're fairly rare these days. Since the 1930s and 1940s water supplies in Australia have been subjected to widespread disinfection.
For the most part the quality of your water is the responsibility of your water provider, but one source of chemicals in your water may also be household plumbing that contains copper or lead. Copper and lead can leach into drinking water on its way to the tap. If you think this is a concern, contact your plumber or local authority.
Water filtration
With few exceptions, drinking water from the tap at home is usually pretty clean and has been treated by your water authority. If you feel you need cleaner water, a water filter can help to improve taste or odour and to protect against microorganisms. Different types of filters and methods are designed to remove different contaminants, so it is important to select the correct type of filter for the right purpose. Many are ‘point-of use’ devices that treat water at point of use, such as at the kitchen sink or bathroom basin. The advantage of this approach is that only water used for drinking or cooking is treated, so it is much cheaper than treating the entire water supply to the home with a point-of-entry device.
Like any treatment device, it needs to be maintained properly as bacteria can grow. Check the manufacturer’s guidelines for proper maintenance instructions.