Prestons Water Hardness & Quality Report (2026)
Water Hardness
Source
reservoir
pH Level
7.6
neutral = 7.0
Lead
0.003 mg/L
✓ Below action level
TDS
216.3 mg/L
Est. Daily Cost
A$0.34
energy & soap waste
Source: BOM National Performance Report & ADWG · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Prestons, your appliances are currently losing 14% efficiency due to mineral buildup.
| Appliance | In Prestons | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 6 yrs | 8.5 yrs | -29% |
| Washing Machine | 9.6 yrs | 12 yrs | -20% |
| Water Heater | 11.3 yrs | 15 yrs | -25% |
Regional Water Comparison
How Prestons compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Prestons, New South Wales | 108.5 mg/L | 🟡 Moderately Hard | reservoir |
| Hinchinbrook, New South Wales | 198.5 mg/L | 🔴 Very Hard | reservoir |
| Casula, New South Wales | 147.5 mg/L | 🟠 Hard | reservoir |
| Green Valley, New South Wales | 122 mg/L | 🟠 Hard | reservoir |
| Macquarie Fields, New South Wales | 160 mg/L | 🟠 Hard | reservoir |
National Benchmark
How Prestons compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Prestons | 108.5 mg/L | 🟡 Low |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Prestons's Water Unique?
Local geology and source profile
Prestons' drinking water is supplied by Sydney Water, treated at the Prospect Water Filtration Plant blending Warragamba Dam storage with a moderate Hawkesbury-Nepean component for the Liverpool LGA outer south-western Sydney distribution in New South Wales. Water hardness in Prestons is measured at 108.5 mg/L — classified as moderately hard — within the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Prestons — a growing outer south-western Sydney suburb in the Liverpool LGA adjacent to the M7 Westlink motorway and the Prestons industrial estate, with large residential estates attracting western Sydney families — receives supply with a moderate Hawkesbury-Nepean component, softer than the adjacent Casula sub-zone (147.5 mg/L) in the same Liverpool LGA, reflecting sub-zone variation within the outer south-western Liverpool supply network.
Prestons' moderately elevated hardness reflects the Hawkesbury-Nepean component in the Liverpool outer south-west Prospect distribution blend. The Hawkesbury-Nepean system traverses Cumberland Plain alluvial terrain and Triassic carbonate-cemented sedimentary deposits near the Liverpool–Macarthur corridor — dissolving moderate calcium bicarbonate before Prospect treatment. The Prestons outer south-west Liverpool distribution sub-zone at 108.5 mg/L and TDS 216.3 mg/L reflects a somewhat more direct Warragamba supply proportion than the harder Casula sub-zone, confirming the sub-zone blend variation across Liverpool LGA's outer south-western distribution network.
Prestons residents face moderate limescale build-up on taps and in kettles — descaling every two to three months is typically adequate. Hot water systems benefit from periodic inspection. The elevated lead reading (0.003 mg/L) warrants briefly running the cold tap before use in older Prestons properties. Sydney Water provides water quality information at sydneywater.com.au, with all ADWG health standards consistently met. A point-of-use water filter is a practical investment for Prestons' growing outer south-western Sydney residential and industrial community.
Geology & Source: Supplied by Sydney Water via the Prospect Water Filtration Plant blending Warragamba Dam with a moderate Hawkesbury-Nepean component — the Prestons Liverpool LGA outer south-western supply carries moderately hard water at 108.5 mg/L, consistent with the moderate Hawkesbury-Nepean contribution in the Liverpool outer south-western distribution corridor, softer than adjacent Casula (147.5 mg/L) in the same Liverpool LGA.