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Drinking Water Quality Across Australia

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Key Characteristics & Concerns for Your State

If you’ve ever been on an interstate holiday and tried some of the local water, you’ll know that not all taps in Australia are created equal. With the lowest rainfall of any inhabited continent and a population largely scattered around the edges of a vast, dry landmass, we’ve had to get creative in our efforts to secure regular access to clean water.

Where Does Our Water Come From?

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–   Surface Water

Rivers, streams and constructed reservoirs are significant sources of drinking water for most states. The Murray-Darling River basin, the largest river system in Australia, accounts for roughly half of the country’s total water usage all by itself.

Surface water is the most easily accessible, but it’s also the most susceptible to environmental factors like decreased rainfall and bacterial contamination. It is also the most directly impacted by human factors like industrial and agricultural run-off. To avoid depleting these reservoirs, Australia has invested in more sustainable water sources.

–   Seawater

It’s right there in our national anthem: we are positively girt by sea. With most of our population living on or near the coast, seawater is an abundant and readily available resource. Despite containing high levels of salt and bacteria, the ocean is one of Australia’s more reliable sources of drinking water thanks to desalination technology.

Desalination (desal) is the process of removing the salt from seawater and turning it into fresh, drinkable water. There are several large desalination plants around the country, particularly in drier states with less reliable access to surface water. Processed seawater is largely unaffected by rainfall levels, making it a sustainable alternative to freshwater sources.

Desal isn’t a magic solution, though. The process of purifying seawater requires a lot of power, and most desalination plants around the world run on fossil fuels. The water treatment also creates disinfection by-products and pumps brine (water with above-average salt levels) back into the ocean, impacting marine life.

–   Groundwater

Rainwater gradually seeps into the earth and accumulates thousands of metres below ground in porous soils and rocks. This accumulated water moves slowly through underground aquifers, feeding into streams and being collected by the roots of trees.

These aquifers can be enormous, with the Great Artesian Basin (our biggest groundwater source) covering a whopping 22% of Australia. Groundwater is often very hard, as it picks up higher concentrations of minerals when it travels through soil. It is also still vulnerable to contamination from the surface, particularly from PFAS and run-off chemicals.

Groundwater is a finite resource that recharges slowly and feeds into the Australian ecosystem, so use must be carefully controlled to avoid depleting our natural aquifers.

–   Wastewater

Water from sewage, industrial areas and greywater can sometimes be cleaned and repurposed for further use. While it is typically saved for non-drinking purposes like power generation and irrigation, recycled wastewater can also be used to recharge other water sources in times of need.

Recycled water, sometimes referred to as “groundwater recharge”, undergoes several layers of filtration and disinfection to remove contaminants and bacteria. While this kind of water requires the most extensive treatment, it is also climate-neutral and resistant to environmental factors, making it another good backup for cleaner but less reliable sources.

However, like desal, this treatment process is significantly more power-hungry than others and creates concentrated waste products. It is also very difficult to filter out 100% of the potential contaminants, so recycled water is not currently a suitable primary water source.

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The State of Your Water

Each state faces its own unique challenges in acquiring and treating drinking water. The sheer size of Australia means that water often needs to travel long distances between the source and the consumer, making it more susceptible to environmental influences and potential contaminants.

Much of Australia’s drinking water comes from rivers, streams, reservoirs and underground aquifers, and the contents and characteristics of the land surrounding these sources have a significant impact on the hardness and quality of the water.

Since it would be absurdly difficult for a single, Australia-wide system to account for this spectrum of environmental influences, the states are each responsible for coordinating the treatment and supply of their own water. Between the unique environmental factors and different treatment techniques, the water that ends up in our homes varies quite a lot across the country.

The Australian Drinking Water Guidelines (ADWG) set standards for drinking water across the country, including safe limits for certain chemicals and proper methods of disinfection and treatment. The guidelines’ stance on chemicals and disinfection by-products, however, is that it is better to allow trace amounts of them to remain in the water than to risk compromising the disinfection process.

Western Australia

As the largest state in terms of land mass, WA has to contend with a diverse range of environmental factors. Managed by the Water Corporation (WA’s Government-owned water provider and one of the largest suppliers in the country), WA’s water system draws from two major desalination plants, 40 surface water sources, 88 groundwater sources and one groundwater replenishment scheme (recycled water).

WA was the first state to invest in desalination as its primary source of drinking water. With a particularly dry climate across most of the state, WA’s surface water sources are quite limited (and have above-average salinity levels already), making seawater a much more reliable and sustainable option.

In Perth, 45% of our drinking water is desalinated seawater, with another 40% drawn from groundwater. Our water is significantly harder than average, with mineral levels typically ranging from 121 to 180 mg/L. Elevated levels of magnesium, calcium and sodium lead to stains and scale-build up around taps and strain/wear on fixtures and appliances.

Since the water often has to travel long distances in warm temperatures, the Water Corporation adds chlorine to all its water supply schemes to combat the bacteria that grows in the pipes along the way. Chlorine is an effective disinfectant, but it produces several by-products like trihalomethanes, chloral hydrate and chloroacetic acids that remain in the water. It also has a noticeable impact on the taste and smell of our water.

Fluoride is also added to certain water supply schemes as directed by the WA Department of Health. Fluoride levels will depend on which scheme your house is connected to, with details available on the Water Corporation website.

Fluoride doesn’t have nearly as much of an aesthetic impact on water as chlorine, but it is also harder to remove and will slip through most filtered taps and jugs. Anyone looking to remove the fluoride from their water will need a reverse osmosis filtration system.


New South Wales

While WA needs to lean on desalination to make up for dwindling surface water reserves, New South Wales draws most of its drinking water from five major surface water catchments: Warragamba, Shoalhaven, Upper Nepean, Woronora and the Blue Mountains.

These catchments flow into dams and reservoirs that supply households and businesses throughout the state via roughly 21,000 kilometres of pipes. Roughly two thirds of NSW’s water is supplied by WaterNSW, a State-owned corporation that operates, monitors and supports most of the state’s water supply systems.

NSW’s water is relatively soft, with average hardness levels of around 50mg/L. The state’s relatively low reliance on groundwater (only about 15%) means that the mineral content of drinking water typically remains below the national average.

WaterNSW adds chlorine and fluoride to drinking water for the same health reasons as WA, with household levels usually measured around 1mg/L of each. NSW also adds ammonia to its drinking water to form chloramine, a more persistent disinfectant that will stay in the water longer as it travels out to regional areas. You can read more about the benefits and potential concerns of using chloramine in drinking water here.

If you’re curious about exactly what is in your house’s water, WaterNSW provides a useful digital tool that shows water data for any given NSW address. You can see chlorine and fluoride levels, average pH and temperature, water hardness and more, all based on data from the largest surface and groundwater monitoring network in the Southern Hemisphere (with samples collected from rivers/reservoirs, treatment plants and homes/businesses).

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While the majority of Queensland’s drinking water comes from surface reservoirs, it also uses groundwater to supply many regional and inland towns. Much of this groundwater comes from the Great Artesian Basin, one of the largest and deepest groundwater basins in the world and the biggest water reserve in Australia.

The coordination of water supply in Queensland is largely divided between two Government-owned bodies: Seqwater in Brisbane and Southeast Queensland, and Sunwater for the rest of the state. To account for the different needs of agricultural, urban and regional customers, the state is divided into 22 water plan areas (with a 23rd to manage the Great Artesian Basin and other local aquifers).

Queensland’s water has been quite turbid lately, with a more earthy, muddied quality than is found in other states. To combat the naturally more turbid water, QLD water treatment facilities use coagulants like aluminium sulphate to collect sediment and other particles in thickened clumps (“floc” particles) that are easier to remove during filtration.

As QLD’s surface water stores are more susceptible to drought and other environmental factors, Seqwater uses recycled wastewater as a backup supply. The Western Corridor Recycled Water Scheme, a wastewater purification system designed to be a climate-resilient source of water in times of need, can produce enough filtered water to meet roughly 20% of current demand. This backup system is triggered if dam levels fall below 40%, with the recycled water otherwise being used for power generation.

Brisbane uses chloramine as its primary disinfectant, adding ammonia  alongside chlorine to treat bacteria across long distances. This means that chlorine levels in QLD drinking water are typically higher, as the disinfectants take longer to dissipate.

Residents of Southeast Queensland can see a breakdown of their region’s water content using Seqwater’s Water Reporting Zones tool to review chemical and metal levels in their drinking water.



Rather than having one or two major water suppliers, Victorians receive their drinking water from one of over 20 different supplying companies. These companies each have their own water treatment processes and draw from different sources (primarily surface water and desalination).

Secondary water treatment in Melbourne (overseen by Greater Western Water) involves chlorine, chloramine and, for some areas, fluoride. Other suppliers may use a combination of these chemicals and other treatments like chlorine dioxide and ultraviolet disinfection.

Victoria has some of the softest water in the country, with average hardness levels reading around 20-30mg/L. Exact levels vary depending on the supplier, but the Victorian Department of Health provides a convenient table showing which company supplies each suburb/town and water sampling locality.


South Australia

South Australia draws its drinking water from a series of surface reservoirs, with roughly half of them filled directly or indirectly from the River Murray. Desalination, groundwater and recycled water are also major facets of the water system, particularly in areas without reliable access to surface water.

Adelaide’s tap water has an unfortunate reputation for being some of the worst-tasting water of any capital city in Australia. In the 1970s, South Australians regularly resorted to adding cordial to disguise the taste – or abandoning the taps altogether and drinking from rainwater tanks.

The quality has definitely gone up, but Adelaide still faces the unique challenge of being at the end of the River Murray, filling its reservoirs with water that has travelled long distances and picked up all sorts of contaminants (and therefore needs higher chlorine levels). Regional areas often also have more turbid water, putting South Australia up there with WA in terms of having some of the hardest water in the country.

SA Water is the central body coordinating water supply and infrastructure for the state. With over 80 different water supply systems, SA Water uses a number of different filtration and disinfection treatment methods to combat the challenges of South Australian water sources.

South Australian water contains higher levels of disinfectant than other states, with chloramine being preferable to chlorine because of its less prominent taste and odour. SA Water provides a robust and convenient water profile tool that allows you to look up detailed breakdowns of the different chemicals and contaminants in the drinking water of a given postcode.

This tool is also useful for seeing which areas will have fluoride in their water, as SA Water only adds this chemical to certain supply systems.

SA Desal


While Complete Home Filtration has yet to establish a team in these three areas, we know that each faces its own set of challenges in providing clean water.

The Northern Territory draws 90% of its drinking water from groundwater. While Darwin has access to the soft surface water of Darwin River Dam, more central town like Alice Springs rely on water from aquifers that regularly exceeds the 200mg/L hardness limit recommended by the Australian Drinking Water Guidelines.

While these aquifers are recharged during the wet season, rainfall in the NT is very low for the rest of the year. Water use needs to be carefully managed by towns in central Australia to avoid depleting groundwater sources.

Tasmania, on the other hand, famously has the softest water in Australia (average hardness below 10mg/L). Managed by TasWater, most of Tasmania’s drinking water comes from surface water supplies (Bryn Estyn Water Treatment Plant, Lake Fenton and the Ridgeway Dam). Tasmania also benefits from high rainfall – although droughts in recent years have led to more careful management of water use.

Chlorine and fluoride are both used in Tasmania’s water, but the chlorinated flavour is less prominent than in cities like Perth and Adelaide. TasWater customers can use the Your Drinking Water tool to view a detailed summary of their water quality.

The Australian Capital Territory has its water managed by Icon Water, with average hardness (around 40mg/L) and comparatively low chlorine levels. Canberra gets most of its water from surface rivers and groundwater, with occasional influxes in turbidity from storm run-off and naturally occurring compounds.


Clean Water Everywhere

Soft or hard, turbid or clear, groundwater aquifer or straight from the pond; whatever your water looks or tastes like, it’s important to make sure you know what you’re putting in your body. Chlorine and disinfectants play an important role in the disinfection process, but there’s no need to leave them in your water after it has arrived at your home.

A Complete Home Filtration system is the easiest way to make sure your water is clean, healthy and delicious no matter which state you live in. Our filters are custom-built for each individual customer so that we can adapt to the unique characteristics of your water.

We have teams and installers across Australia, with systems that can be set up by any local plumber or simply screwed in under your kitchen sink. A Complete Home Filtration system can remove particles from 1 micron all the way down to 0.0005 microns, making it a perfect safeguard for your taps, showers and water-using appliances.

Say goodbye to murky water and chlorine cocktails and start feeling the benefits of clean, healthy water. Begin your better water journey today by sending us a message below or filling out our quick web survey.