Drinking water quality data

We test water quality at our major storage reservoirs once it has been through the primary treatment process. Results are used to provide a typical analysis of Melbourne's water quality, which is based on data from the previous five years.

Typical analysis of Melbourne's water

Last update July 2015

Please note:

  • all parameters are measured in milligrams per litre unless otherwise noted
  • values are rounded to the nearest decimal point
  • Tarago figures are based on the previous 4 years, when the Tarago water treatment plant began operating
​Parameter/ source Cardinia Greenvale Silvan Winneke Tarago​ Yan Yean​
pH (units)​ 7.0-7.4 7.0-7.2 7.0-7.6 7.0-7.3​ 7.0-7.3 7.0-7.3
Colour (Pt/Co)​ 4​ 4​ 8​ <2​ <2 <2
Turbidity​ (NTU) 0.6-1.3 0.2-1.6 0.2-1.6 0.2-0.4 0.2-0.4 0.2-0.4
Specific conductance (uS/cm)​ 58-71 63-140 54-65 99-160 160-190 99-170
Iron 0.07​ 0.09​ 0.08​ ​0.01 ​0.01 ​0.01
Manganese ​0.004 ​0.004 ​0.006 ​0.003 0.012 0.002
Fluoride​ 0.85 0.91 0.83 0.85 0.83 0.84
Aluminium - acid soluble​ 0.02​ 0.03 ​0.04 0.3 0.4 0.03
Arsenic​ <0.005​ <0.005​ <0.005​ <0.005​ <0.005​ <0.005​
Boron​ <0.05​ <0.05​ <0.05​ <0.05​ <0.05​ <0.05​
Bromide​ <0.05​ - <0.05​ - - -​
Cadmium​ <0.0005 <0.0005​ <0.0005 <0.0005​ <0.0005 <0.0005
Calcium​ 4.2​ 5.1 4.0 7.8 13.7 10.2​
Chloride​ 7.3​ 10.6 7.4 18.5 22.4​ 23.0​
Chromium <0.005​ <0.005​ <0.005​ <0.005​ <0.005​ <0.005​
Copper​ 0.02​ 0.02​ 0.07​ <0.02​ <0.02 <0.02​
Cyanide​ <0.005​ <0.005​ <0.005​ <0.005​ <0.005​ <0.005​
Haloacetic acids:​ ​ ​ ​ ​ ​ ​
- Chloroacetic acid​ <0.005​ <0.005​ <0.005​ <0.005​ <0.005​ <0.005
- Dichloroacetic acid​ 0.011 0.005 0.018 0.004​ 0.008 0.002
- Trichloroacetic acid 0.012 0.006​ 0.011 0.003 0.007 0.006​
Hardness​ 16​ ​20 ​15 ​29 ​45 ​36
Lead​ <0.002​ <0.002​ <0.002​ <0.002​ <0.002​ <0.002​
Magnesium​ 1.3​ 1.6​ 1.2​ 2.4​ 2.5 2.7​
Mercury​ <0.0001​ ​<0.0001 <0.0001 ​<0.0001 <0.0001 <0.0001
Nickel​ <0.002​ <0.002​ <0.002​ <0.002​ <0.002​ <0.002​
Nitrate​ 0.20 0.15 0.26 0.4​4 0.38 0.47​
Potassium​ 0.7​ 0.9​ 0.7​ 1.4 2.2 1.6​
Selenium​ <0.002​ <0.002​ <0.002​ <0.002​ <0.002​ <0.002​
Silica as SIO2​ 5.5​ 5.8 6.6 4.5 7.9 4.6​
Sodium​ 4.7 6.0 4.4 10.1 12.8 11.5​
Sulphate​ 1.2 2.9 0.9​ 12.7 17.6 17.5​
Total alkalinity as CaCO3​ 11.3 11.9 10.3 11.1 24.3​ 14.0​
Total organic carbon​ 2.0 2.1 2.1 1.6 2.4 1.8​
Total phosphorus​ 0.007​ 0.007 0.004 0.005 0.005​ 0.006
Total dissolved solids​ 39​ 49 36​ 78 108 100​
Total trihalomethanes 0.033 0.019 0.03​3 0.028 0.041 0.045​
Zinc​ <0.01​ <0.01​ <0.01​ 0.01​ <0.01​ <0.01​

Our Water Quality Annual Report (previously Annual Report to the Department of Health) provides a comprehensive account of drinking water quality issues for each financial year. Yearly summaries of water quality data specific to your region are available from your local water retail company.

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