What is in Newcastle and Hunter tap water, and which filter fixes what

Hunter Water publishes more useful numbers than most utilities, plant by plant, and they tell a simple story: soft, chlorinated, fluoridated water that needs very little filtering. Here is the detail and what to buy.

Where the water comes from

Hunter Water supplies more than half a million people in the Lower Hunter from several treatment plants. Newcastle and Lake Macquarie are typically supplied by Grahamstown (fed by Grahamstown Dam and the Tomago sandbeds) and Dungog (Chichester Dam). Maitland, Cessnock and Kurri are typically on Dungog. Port Stephens is on Anna Bay, Nelson Bay, Lemon Tree Passage and Grahamstown. The supply zones can switch, so Hunter Water publishes ranges rather than single figures.

The numbers, plant by plant

All from Hunter Water’s Typical Composition of Supplied Drinking Water, updated August 2025, covering 1 June 2020 to 31 May 2025; figures are 5th percentile, median and 95th percentile.

The chlorine figures are Hunter Water’s plant medians and percentiles as listed; the aesthetic guideline it reports against is 0.6 mg/L and the health guideline 5 mg/L. pH across all plants runs 7.3 to 7.6.

The three things that matter

Chlorine, not chloramine. Hunter Water chlorinates and explains why on its What’s in your water page. Residuals of 1 to 2 mg/L are typical of a utility that keeps a firm residual to the ends of its network, and the Port Stephens plants run a little higher. Any carbon filter in the kitchen and a KDF filter in the shower handle it; no catalytic carbon or vitamin C is needed.

Soft water. Hunter Water’s own hardness fact sheet puts all its sources in the NHMRC “soft” or “good quality” bands and describes them as soft, non-scaling waters at room temperature. Newcastle at a median of 56 mg/L sits a little above Sydney (about 43) and well below Adelaide and Perth. There is no case for a softener.

Fluoride. Just under 1 mg/L at every main plant, added under NSW legislation. It passes through carbon. The fluoride guide covers what removes it.

What to buy in Newcastle and the Hunter

• Chlorine taste: any carbon filter. Owners: the Philips FastFlow, WaterMark-listed and certified for chlorine and PFAS. If lead from the old brass fittings common in Newcastle’s inner suburbs and Maitland’s older housing worries you, choose a filter whose own NSF/ANSI 53 listing names lead. Get the water tested first. Renters: the Philips on-tap or a jug.
• Shower: the Philips KDF filter, the right media for a chlorinated supply. See do shower filters work.
• Fluoride: a WaterMark-listed reverse osmosis system such as the Philips 75 GPD station. The cheapest online kits (Geekpure, iSpring) aren’t on the WaterMark register, so a licensed plumber can’t install them. The worth-it guide puts Newcastle in the “only for fluoride” column.
• Scale: nothing. Hunter Water’s words are “soft non-scaling”.
• Tank water in the Hunter Valley: a different problem, covered in the whole-house guide.
• Your own water: test your own tap water with hardness strips or a TDS meter before you buy. The test kit guide covers what a home kit can and can’t tell you, and when to use a NATA-accredited lab instead.

Setting appliances and finding your zone

Hunter Water’s hardness fact sheet gives each plant’s water in the units a dishwasher manual asks for: Grahamstown at 1.68 to 5.88 German degrees, 3 to 10.5 French degrees and 0.3 to 1.05 mmol/L, Dungog softer at 0.84 to 3.08 German degrees. Set the dishwasher to soft and skip the salt. The same page that holds the composition table links a water supply zones map and the monthly water quality reports, which is how to find which plant feeds your street before you buy anything that depends on the number. Hunter Water also notes that silica should stay under 80 mg/L to limit scale; its plants run at 1 to 15 mg/L, which is another reason scale is not a Hunter problem.

The one trap

Treating the Hunter as one supply. Nelson Bay’s water at a median hardness of 17 mg/L is among the softest in the country; Lemon Tree Passage, twenty minutes away, reads 68 with the highest chlorine median in the table. Hunter Water publishes a supply zones map alongside its composition table. Find your zone before buying anything that depends on the number, and re-check it if the taste changes, because zones can be switched between plants.

Sources: Hunter Water, Typical Composition of Supplied Drinking Water (updated August 2025); Hunter Water, Water Hardness fact sheet (May 2014); Hunter Water, What’s in your water; Australian Drinking Water Guidelines (NHMRC). The city comparison sets these figures beside the other capitals.