Science · Core 7
Water
Safe at the meter. Worth checking at the tap.
Australian mains water is treated and monitored against national guidelines. Most problems we see start inside the property: fittings, pipes, tanks and poorly maintained filters.
Why it matters
Water utilities in Australia manage drinking water against the Australian Drinking Water Guidelines, which set health-based values for microbial, chemical and physical characteristics, including lead and PFAS 1. Their responsibility largely ends at the property boundary. What happens between the meter and the glass depends on the building: pipe materials, tap fittings, hot water systems, rainwater tanks and any filters installed.
What the research shows
Tap fittings can add metals. A study of 212 first-draw samples from kitchen taps in New South Wales homes detected lead in 56 per cent of samples and found lead above the guideline value in 8 per cent, and copper above its guideline in 5 per cent. Brass tap fittings and connecting pipework were identified as a main source 2. The Australian guideline value for lead in drinking water is 0.01 mg/L 1.
Private supplies are the owner's responsibility. Rainwater tanks and bores are not treated by a utility, so their quality depends on design, maintenance and testing.
What can be done
Where water has sat in the pipes for hours, running the cold tap briefly before drinking reduces water that has been standing in fittings. When replacing taps and fittings, choose products certified as low-lead. Choose filtration to match what testing actually shows, and maintain it, because neglected filters can make water worse. Rainwater tanks need screening, first-flush diversion and regular cleaning.
How we assess it
We review the supply, plumbing age and materials, tap fittings, hot water system and any tanks or filters. Where warranted, we arrange laboratory testing through a NATA-accredited laboratory, including first-draw and flushed samples so the source of any problem can be identified.
Evidence at a glance
- Well supported
Some tap fittings and plumbing can leach lead and copper into household water. 2
- Reasonable
Point-of-use filtration, when testing shows a specific problem it is designed to remove.
General information only, not medical advice. How we grade evidence.
References
- National Health and Medical Research Council, Natural Resource Management Ministerial Council. Australian Drinking Water Guidelines 6 (2011), version 3.7. Canberra: NHMRC; updated 2022. www.nhmrc.gov.au/about-us/publications/australian-drinking-water-guidelines
- Harvey PJ, Handley HK, Taylor MP. Widespread copper and lead contamination of household drinking water, New South Wales, Australia. Environ Res. 2016;151:275-285. doi.org/10.1016/j.envres.2016.07.041 · PubMed 27512893