Safe drinking water

Your water's journey from source to tap

The water you use every day is water you can trust – and we can prove it. We rigorously test and monitor the water we source as it makes its way to you from rivers, lakes and dams to our reservoirs and filtration plants, all the way to your tap. The result is some of the best drinking water in the world.

Where your water comes from

Most fresh water supplied to Sydney, the Blue Mountains and the Illawarra as drinking water comes from rain stored in lakes surrounded by unspoilt native bushland in the Blue Mountains and the Southern Highlands. Of the water we supply, 80% comes from Lake Burragorang at Warragamba Dam – WaterNSW manages and protects the area around Lake Burragorang.

WaterNSW supplies us with rainwater from local lakes and rivers. It monitors these sources so it can choose the best water for us to filter. We also source water from the ocean using the Sydney Desalination Plant. Desalinated water is especially valuable during droughts, when water from lakes and rivers is scarce.

We measure the quality of this source water. We look at the suspended particles in the water (turbidity) and other things, like the amount of natural matter.

Lake Burragorang, Warragamba Dam

How your water is filtered

Our 9 filtration plants are run by teams of dedicated, experienced people committed to ensuring that everyone across Sydney, the Blue Mountains and the Illawarra region has safe, filtered water every day of the year. We filter 100% of your water to ensure it’s safe to drink straight from the tap.

  • First, the water flows through fine screens to remove debris like twigs and leaves.
  • Then we add a solution (a coagulant) to make smaller particles stick together (or floc) so they can be filtered out more easily. 
  • Last, we filter the water through tightly packed beds of sand and anthracite. This removes any remaining particles, including Cryptosporidium and Giardia. 

When you see 'Filtration Successful' in our daily drinking water quality report, you know that turbidity levels are lower than our limit of 0.5 units.

How we get clean water to you

From our filtration plants, we send your water to secure covered reservoirs in your area. Our pipes connect the reservoirs to the taps in your home. We monitor them for leaks and breaks, and make sure water is not wasted.

To ensure your water’s safety all the way to your tap, we add small amounts of chlorine to our reservoirs. Our daily drinking water quality report confirms how chlorine levels at your tap compare with our limit of 5 milligrams per litre. We balance your water’s pH levels to boost its effectiveness.

Cecil Park Reservoir

The bonus of stronger teeth
NSW Health recommends adding small amounts of fluoride to drinking water to help prevent tooth decay. Check out our daily drinking water quality report to see how your water’s fluoride levels compare with our limit of 1.5 milligrams per litre.

How we monitor quality

Sydney Water Monitoring Services is Australia's largest and oldest dedicated water, trade wastewater and environmental sampling and testing facility. We collect and test samples taken from our entire network, doing up to 70 different tests to make sure your drinking water meets the Australian Drinking Water Guidelines. Australia’s National Association of Testing Authorities accredits our state-of-the-art laboratory and field sampling teams.

Regional councils and other authorities around NSW rely on our services. Our lab can provide field sampling, laboratory analysis, hydrometric services, sample design, data analysis and reporting for drinking water and our raw water catchments, beaches and groundwater.

What to do if your water looks, smells or tastes unusual

Most of the time, it's easy to explain and there’s nothing you need to worry about. If you think something else is going on, contact us.

You might notice the colour of your tap water changes from time to time. It’s normally still safe to drink. Try running the cold tap to see if it goes clear again. There are a few reasons water may change colour.

  • The pipes on your property may be old or need to be repaired. Call a plumber to check their condition.
  • If discoloured water only comes from your hot water taps, maybe your hot water service needs to be repaired or replaced. It’s another job for a plumber.
  • We could be working on the water pipes in your area. Find out at water supply and service updates.

If you’re sensitive to taste and smell, you might notice metallic or chlorine tastes and odours. These may be due to tiny amounts of chlorine we need to add to drinking water to kill germs and keep it safe. It’s totally harmless. The smell and taste of chlorine should disappear if you let your water stand in a jug for about an hour - or keep it in the fridge.

Sometimes tap water appears cloudy, especially when the weather is warmer. The cloudiness is caused by tiny air bubbles that form when water of different temperatures enters our system. When you fill a glass, you may notice the water clears from the bottom up. It should be completely clear in 30 seconds or less. 

Black specks in tap water are normally caused when the rubber from tap washers or O-rings wears out or perishes, often in taps that aren't used very much. It could be a job for a plumber. If you’re feeling handy, find out how to change a tap washer yourself.