The Drinking Water quality in each city, town and suburb can vary quite a lot depending upon the water source or storage and the treatment process used to filter the water for drinking and use by consumers. All potable drinking water in Australia must meet the Australian Drinking Water Guidelines (ADWG) developed by the National Medical Research Council (NHMRC). While drinking water quality does sometimes fall outside the guidelines most generally exceed the guidelines however this is not to say that it is safe or of a quality that all consumers are happy with.
Over 95% of town water is also used for washing, cleaning, flushing toilets and other uses with only a small percentage actually used for drinking. It is therefore difficult, expensive and not necessary to treat all of the water used to the highest possible standard when such a small percentage is actually used for drinking.
The following water quality analysis have been obtained from local water supply authorities i.e. Sydney Water, ACTEWAGL, Melbourne Water, Brisbane City Council, etc., based on actual water testing carried out over the previous decade.
The Brisbane drinking water supply is drawn from various water storages located around Brisbane and the Gold Coast. The water for the city is treated by 3 water treatment plants; North Pine, Mt Crosby Eastbank and Mt Cosby Westbank before being distributed throughout the city and surrounds.
Aluminium Sulphate (alum) is still used to help flocculate and remove suspended material before treatment with chlorine, chloramine. Fluoride is added during the final stages of treatment.
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The Canberra drinking water supply is drawn from 2 main water storages before being treated by 1 of 2 Water Treatment Plants. The Mount Stromlo and Googong Water Treatment Plants supply water around the city and surrounding districts through a 3034 km network of water mains with 23 pumping stations and 45 service reservoirs.
Aluminium Sulphate (alum is still used at both treatment plants as a coagulant to remove unwanted colour and turbidity from the raw water entering the treatment plants. The water is then filtered, UV treated, pH adjusted and stabilized with lime or carbon dioxide before being chlorinated and fluoride (sodium silico fluoride) added.
The average daily water consumption is 318 litres per person per day.
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The Melbourne water supply originates from a number of water storage dams/reservoirs located up to 120 km from Melbourne. The 3 main storages are Silvan Resevoir (near Mount Dandenong). Sugarloaf Reservoir (near Yarra Glen) and Greenvalve Reservoir near Somerton. Others include the Thomson Reservoir, Maroondah Reservoir and Yarra River.
Water from various storages is fed to 5 Water Treatment Plants: Winneke, The Yan Yean, Tarago, Silvan and Greenvalve. These water treatment plants then use aluminium sulphate (Winneke plant) or a similar coagulant to remove suspended material and colour before filtration, chlorination and pH adjustment with lime. Some plants also have Ultraviolet (UV) Treatment Systems. The water has fluoride added before being pumped into thousands of kilometres of distribution mains and service reservoirs.
The water treat process is undertaken by “Melbourne Water” with bulk water then supplied to separate retail companies owned by the Victorian Government who then distribute the water to consumers. These retail companies include; City West Water, South East Water and Yarra Valley Water with water also supplied to Western Water, Gippsland Water and Southern Rural Water.
The average daily water consumption is 174 litres per person per day.
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Sydney’s drinking water supply originates from a number of storage dams located some distance from the city. The water from these storages is fed to 9 Water Treatment Plants: Cascade, Illawarra, Macarthur, Nepean, North Richmond, Orchard Hills, Prospect, Warragamba and Woronora. These plants treat and filter the water before adding chlorine or chloramine and fluoride. Chlorine is used to treat the water at Cascade, Illawarra, Nepean, North Richmond, Orchard Hills and Warragamba, the remaining plants use chloramination. The vast majority of Sydney Water is therefore treated with chloramine. 21,000 kilometres of pipelines link 152 pumping stations and 255 water service reservoirs to service the 13 water distribution systems covering the city and surrounding town and suburbs.
Four of these treatment plants; Prospect, Macarthur, Illawarra and Woronora were built and are owned and operated by private sector corporations. These 4 plants supply over 90% of Sydney’s Water with the remaining plants owned and operated by Sydney Water.
View the results for Sydney:
Sydney - Table 1
Sydney - Table 2