Home water testing in WA: when you need it

If your tap is on a Water Corporation scheme, the water is already tested through a large official monitoring program. In 2024–25, Water Corporation took almost 70,000 samples from sources, treatment plants and pipe networks, with more than 365,800 analyses by contracted independent laboratories. The Department of Health regulates that work against the Australian Drinking Water Guidelines.

A home lab test is still useful when the water you drink is not that scheme supply, or when you are worried about something the annual report cannot see, such as a rainwater tank, a bore, or plumbing inside the house. ChemCentre, the state's NATA-accredited chemistry laboratory, puts it plainly: its mains-water suite is the most economical option because mains water is also monitored by Water Corporation, so you may not need extra testing.

WaterWatch does not test household samples. We re-analyse the official scheme results, locality by locality, so you can see how your supply compares before you decide whether a lab test is worth doing.

What the water supplier already tests

Scheme drinking water is sampled for health and aesthetic characteristics, including E. coli, Naegleria, fluoride, metals, disinfection by-products, hardness, salts, pH and turbidity. All 28 Perth supply localities met the 2024–25 E. coli and Naegleria requirements in the published tables. Fluoride, where it is added, is checked at least weekly. Aesthetic figures such as hardness are often based on only a handful of samples across the year, taken in the supply network, not at your kitchen tap.

That last point matters. The official report, and the WaterWatch locality page built from it, describe the scheme. They do not describe a tank, a bore, or a tap downstream of old pipes or fittings.

Suburb pages on WaterWatch still show the 2023–24 report. The 2024–25 scheme totals in this guide are from the newer annual report. Either way, a locality page describes the scheme, not the water after it has passed through your own plumbing.

When testing your own water is worth it

The WA Department of Health publishes a Standard Drinking Water Test for people who need to know whether their water is suitable for drinking or food preparation. It is the right starting point for:

• Rainwater collected from a roof
• Bore or dam water used for drinking
• Household plumbing concerns, including possible lead from fittings or pipes
• A taste, colour or odour change that you want a laboratory to measure, rather than guess

HealthyWA says routine testing of a domestic tank is not normal practice and in most cases would not be necessary. If you do test tank water, use the Standard Drinking Water Test and compare the results with the Australian Drinking Water Guidelines. Extra tests may be needed if the catchment has obvious hazards, such as pesticide spray drift, septic systems, fire ash, or lead flashing on a roof.

If you only want to know how hard or salty the scheme water is in your area, start with the suburb lookup and, for the newer Perth ranking, Does Perth have hard water? A paid lab test of mains water can still make sense if you want a reading from your own tap.

How to get a proper test

Use a NATA-accredited laboratory. The Department of Health lists participating labs and accepts their Standard Drinking Water Test results. Contact the lab first and ask for the right bottles and sampling instructions. A sample in the wrong bottle, stored warm, or delivered late can make the result unreliable.

The Standard Test has two parts. The microbiological test looks for total coliforms and thermotolerant coliforms or E. coli. The chemical test covers a set of metals, salts and physical measures. The chemical list is a little longer for bore or groundwater than for roof-collected rainwater.

Participating laboratories listed by the Department of Health, as cited when this guide was written. Check the live Department of Health page before you book, because the list can change.

Microbiological and chemical: ALS in Wangara, (08) 9406 1301. Eurofins ARL in Welshpool, (08) 6253 4444. MPL Laboratories in Canning Vale, (08) 9317 2505. SGS Environmental Services in Newburn, (08) 9373 3500. Agrifood Technology / AWTA in Bibra Lake, (08) 9418 0219.

Microbiological only: Symbio Laboratories in Canning Vale, 1300 703 166. PathWest in Nedlands, (08) 6457 2583. Merieux NutriSciences in Perth, (08) 9227 6499. BVAQ in Canning Vale, (08) 9445 9600.

Chemical only: ChemCentre in Bentley, (08) 9422 9800. Intertek Australia in Maddington, (08) 9251 8100.

ChemCentre offers four household suites: a Domestic Water Suite for mains water (500 mL in a clean plastic bottle); the same suite with microbiological testing, subcontracted to PathWest, in a separate sterile bottle; a Rainwater Suite that follows the Standard Test, using four specialised bottles; and a Bore/Dam Water Suite using six specialised bottles. Bottles are free. Keep the sample cool, not frozen, and deliver it within 24 hours, Monday to Friday, 8:30am to 4:30pm. Allow ten working days for results. Prepayment is required when you submit the sample. Ask for a quote first.

PathWest's Environmental Microbiology Unit is a NATA-accredited specialist water laboratory at J Block, QEII Medical Centre, Nedlands. It tests drinking water, tanks and dams for bacteria and amoebae, including Naegleria fowleri. Containers, coolers and ice bricks are free; you pay the courier if they are sent out. There is no administration or batch fee. Most microbiological samples must reach the lab within 24 hours, by 3pm on weekdays. Do not drop them at a PathWest Collection Centre. Those centres are for pathology only. Ask for a quote. PathWest says quotes expire at the end of each financial year.

The Department of Health Water Unit can help interpret laboratory results and give general advice on making water safe to drink, on (08) 9222 2000. Laboratories can give technical advice about the analysis. They are not in a position to give health advice.

What a test costs, and what "free" usually means

Accredited laboratory tests are paid services. The Department of Health says the cost varies between laboratories and that you should contact them for a quote. ChemCentre and PathWest also ask you to request a quote. Public price lists were not published on those pages when this guide was written, so there is no dollar figure here.

Searches for a free water test in Perth often lead to a company offering an on-site check of pH, total dissolved solids or sediment, sometimes as part of a sales visit. That is not the Department of Health Standard Drinking Water Test, and it is not a substitute for a NATA laboratory report. No official free Standard Test was found from the Department of Health, Water Corporation, ChemCentre or PathWest.

How to read the results

Compare each result with the Australian Drinking Water Guidelines. Health guidelines are about safety over a lifetime of drinking the water. Aesthetic guidelines are about taste, appearance and wear on plumbing. A hardness result, for example, should be read against the 200 mg/L aesthetic guideline and the degrees-of-hardness bands, which we explain in water hardness explained.

If the sample was scheme water, set the lab result beside your WaterWatch locality page. A difference can happen. The official typical reading is a yearly mean from the supply network. Your tap is one point in time, downstream of household pipes. If the sample was tank or bore water, the locality page is useful background only. It is not a substitute for the lab report.