West Pennant Hills Water Hardness & Quality Report (2026)
Water Hardness
Source
reservoir
pH Level
7.4
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
129.7 mg/L
Est. Daily Cost
A$0.22
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 West Pennant Hills, your appliances are currently losing 9% efficiency due to mineral buildup.
| Appliance | In West Pennant Hills | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 7.3 yrs | 8.5 yrs | -14% |
| Washing Machine | 11 yrs | 12 yrs | -8% |
| Water Heater | 12.8 yrs | 15 yrs | -15% |
Regional Water Comparison
How West Pennant Hills compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ West Pennant Hills, New South Wales | 71 mg/L | 🟡 Moderately Hard | reservoir |
| Cherrybrook, New South Wales | 105.5 mg/L | 🟡 Moderately Hard | reservoir |
| Carlingford, New South Wales | 41 mg/L | 🟢 Soft | reservoir |
| Epping, New South Wales | 51 mg/L | 🟢 Soft | reservoir |
| Castle Hill, New South Wales | 28 mg/L | 🟢 Soft | reservoir |
National Benchmark
How West Pennant Hills compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ West Pennant Hills | 71 mg/L | 🟡 Low |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes West Pennant Hills's Water Unique?
Local geology and source profile
West Pennant Hills' drinking water is supplied by Sydney Water, treated at the Prospect Water Filtration Plant blending Warragamba Dam with a moderate Hawkesbury-Nepean component for the The Hills Shire LGA distribution in New South Wales. Water hardness in West Pennant Hills is measured at 71 mg/L — classified as slightly hard — within the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. West Pennant Hills — a leafy prestige suburb on the northern Hills District escarpment, known for its bushland reserves, the Pennant Hills Park, and quality residential estates adjacent to the Beecroft-Cheltenham corridor — receives supply with a moderate Hawkesbury-Nepean contribution, consistent with the Hills District supply pattern intermediate between the softer standard Sydney zones and the harder outer Hills corridor sub-zones.
West Pennant Hills' slightly elevated hardness reflects the moderate Hawkesbury-Nepean component in the Hills District North Shore Prospect distribution blend. The Hawkesbury-Nepean system traverses Triassic Hawkesbury Sandstone and Cumberland Plain carbonate-cemented terrain — dissolving moderate calcium bicarbonate before Prospect treatment. The West Pennant Hills Hills District distribution sub-zone at 71 mg/L and TDS 129.7 mg/L receives an intermediate Hawkesbury-Nepean fraction, positioned between the softer standard inner Sydney zones and the harder outer Hills and upper North Shore sub-zones such as Cherrybrook (105.5 mg/L) and Saint Ives (152 mg/L).
West Pennant Hills residents can expect occasional moderate limescale on taps and in kettles — descaling every two to three months is typically adequate. Hot water systems benefit from periodic inspection. The low lead reading (0.002 mg/L) is reassuring. Sydney Water provides water quality information at sydneywater.com.au, with all ADWG health standards consistently met. The slightly hard supply is well within comfortable household use ranges for West Pennant Hills' prestigious bushland residential community in the northern Hills District.
Geology & Source: Supplied by Sydney Water via the Prospect Water Filtration Plant blending Warragamba Dam with a moderate Hawkesbury-Nepean component — the West Pennant Hills The Hills LGA supply carries slightly hard water at 71 mg/L, consistent with the moderate Hawkesbury-Nepean proportion at the Hills District North Shore distribution corridor.