Water quality

Melbourne has some of the world’s best drinking water, which we test regularly to ensure it meets strict water quality requirements — as well as checking aesthetics like colour, taste and smell.

What we test water for:

  • clarity (turbidity)
  • minerals and natural substances like iron and manganese
  • colour
  • pH
  • bacteria, such as E. coli
  • chlorine and fluoride levels
  • contaminants like fuel and pesticides

Standards for water quality

All the water we supply, no matter where it comes from, must meet strict water quality requirements. We follow several laws and guidelines:

  • Safe Drinking Water Act 2003 and Safe Drinking Water Regulations 2005, set and administered by the Department of Health and Human Services
  • Australian Drinking Water Guidelines 2011, developed by the National Health and Medical Research Council
  • water quality standards set in our bulk water supply agreements with the retail water companies

We use independently-certified systems to manage water quality, including ISO 9001 and the HACCP (Hazard Analysis and Critical Control Point) system. Both are used in food and pharmaceutical industries worldwide.

We are audited regularly under the Safe Drinking Water Act 2003, and report all drinking water quality issues to the Department of Health each year.

Compliance reports — water quality annual report

Why water varies

The colour, taste and smell of your water can change throughout the year. This is very normal and usually depends on the following factors:

  • source of water — your water can come from a number of reservoirs, each with natural differences in colour and mineral content
  • demand — people tend to use more water in summer, which causes it to travel faster through the pipes
  • temperature — temperature changes its taste (cooler water generally tastes better), and depends on the time of year

Monitoring water quality

We regularly test water being transferred to homes and businesses, as a final check that it meets quality requirements.

Each year we test about 50,000 samples from over 160 sites, including:

  • storage reservoirs
  • service reservoirs
  • aqueducts
  • transfer mains
  • points of supply to our retail water customers

Monitoring also helps us to:

  • fine-tune our water treatment processes, so we can add chemicals in the precise amounts needed
  • identify potential issues like algal blooms in advance
  • decide where to transfer water, such as avoiding reservoirs with water quality issues

The retail water companies monitor water quality at selected taps — contact them to find out about water quality in your area.

Last updated:
11 December 2019