Search by Keyword
Australia has produced its own drinking water guidelines since 1972. The current Australian Drinking Water Guidelines (ADWG) were developed by the National Health and Medical Research Council (NHMRC) in conjunction with the Natural Resource Management Ministerial Council (NRMMC). The guidelines apply to any water intended for drinking, wherever it comes from and wherever it is used, apart from bottled or packaged water. Bottled water is the responsibility of Food Standards Australia New Zealand (FSANZ). The Australian Drinking Water Guidelines are not legally enforceable; instead they provide recommended guideline values for constituents that affect water quality and safety, which state and territory governments use to set regulatory standards. The State government bodies establish the level of impurities that are acceptable for a given water system. The water authority must ensure that its processes prevent these levels being exceeded.
Chemicals in Drinking Water
The chemicals of interest for drinking water include naturally occurring chemicals (such as nitrate, selenium and uranium); agricultural chemicals (such as pesticides and fertilisers), the water treatment chemicals themselves and the disinfection byproducts (DBP) formed when water is treated with a disinfectant (such as trihalomethanes otherwise referred to as THMs).
There are more than 30 chemicals approved for use in treating water (see Approved Chemicals). The purpose of these chemicals is to ensure that your water is safe to drink; however their use introduces other risk factors.
Chlorine - This is the most widely used disinfectant. The problem with it (other than the odour) is that chlorine generates a number of different byproducts, including trihalomethanes (THMs) formed when the chlorine comes into contact with organic matter. It has been suggested that THMs increase the risk of cancer, but scientific opinion is still divided on this issue.
Chlorine dioxide - This produces lower levels of THMs than chlorine but is a weaker disinfectant and, in its turn, produces other potentially harmful byproducts such as chlorate and chlorite.
Chloramine - A long lasting chemical which is good for maintaining a disinfectant residual thus helping to ensure that microorganisms do not multiply in the water in the distribution system. It produces lower THM concentrations than chlorination, but does produce other byproducts such as cyanogen chloride.
Ozone - While it can be very effective, ozone also generates byproducts (eg bromates and aldehydes). As ozone is short lived, it can only be used in combination with another disinfectant.
UV radiation - Using ultraviolet radiation is only effective when the water is relatively free of suspended and dissolved particles. It does not provide residual disinfection; therefore, a small dose of a persistent disinfectant such as chloramine might be added to act as a preservative during distribution.
Where residual disinfectants are used, they have served their purpose once the water has reached the tap. Consuming even small quantities of these substances (not to mention their by-products) does not do anything to improve your health. It also raises the question as to the effect they have on your intestinal bacteria...
Despite the use of all these chemicals, it is still possible for water to be contaminated and in those situations the water authority may issue a "Boil Water Alert" (see Water Alerts). The challenge is getting the alert out early enough. There are tests that can determine whether water has been contaminated but many of these tests take days or weeks to produce a result and in the meantime the community has been exposed to it. Monitoring of water quality relies, instead on the use of 'indicator organisms'. These are organisms that can be tested for quickly and easily and a re generally found when harmful micro-organisms are present. Even with indicator organisms there is still a delay between contamination and a positive test result; thus there remains the possibility of the community being exposed to the contaminant.
Why Purchase a Water Purifier?
There are many reasons but the two main ones would be: (1) for health reasons to protect against micro-organisms and other contaminants; and (2) to improve the taste and odour of the water. This can be especially important with very young children whose immune systems are still developing, and the elderly whose immune systems may be weakened.
The water can be purified at the point where it enters the house (Point of Entry - POE), or at the point of use (POU). Point of Entry systems tend to be more expensive and in some respects may not be necessary unless a person has particularly sensitive skin or other conditions. POU systems are generally more economical while providing the user with the convenience of have pure, crystal clear water on tap for drinking, ice cubes, tea, coffee, soup, stews, etc.
Australian Dollars (AUD)