Mortdale Water Hardness & Quality Report (2026)
Water Hardness
Source
reservoir
pH Level
7.2
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
74.2 mg/L
Est. Daily Cost
A$0.14
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 Mortdale, your appliances are currently losing 6% efficiency due to mineral buildup.
| Appliance | In Mortdale | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 8.2 yrs | 8.5 yrs | -4% |
| Washing Machine | 12 yrs | 12 yrs | — |
| Water Heater | 13.9 yrs | 15 yrs | -7% |
Regional Water Comparison
How Mortdale compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Mortdale, New South Wales | 43.5 mg/L | 🟢 Soft | reservoir |
| Oatley, New South Wales | 62.5 mg/L | 🟡 Moderately Hard | reservoir |
| Penshurst, New South Wales | 167 mg/L | 🟠 Hard | reservoir |
| Peakhurst, New South Wales | 52.5 mg/L | 🟢 Soft | reservoir |
| Beverly Hills, New South Wales | 145 mg/L | 🟠 Hard | reservoir |
National Benchmark
How Mortdale compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Mortdale | 43.5 mg/L | 🟢 None |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Mortdale's Water Unique?
Local geology and source profile
Mortdale's drinking water is supplied by Sydney Water, treated at the Prospect Water Filtration Plant drawing predominantly from Warragamba Dam (Nepean River system) for the Georges River LGA inner southern Sydney distribution in New South Wales. Water hardness in Mortdale is measured at 43.5 mg/L — classified as soft — well below the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Mortdale — a residential suburb in the Georges River LGA adjacent to Peakhurst and Oatley on the Como Creek corridor, known for the Mortdale station on the Illawarra Line, the Mortdale Village shops, the Mortdale Park and Salt Pan Creek Regional Park bushland, and the established southern Sydney residential community of the Hurstville–Peakhurst district — receives soft supply consistent with the predominantly soft character of the inner southern Georges River LGA Sydney Water sub-zones.
Mortdale's soft supply reflects a predominantly Warragamba Dam contribution with minimal Hawkesbury-Nepean blending at the inner southern Georges River Prospect distribution sub-zone. Warragamba Dam collects rainfall from the Blue Mountains sandstone plateau and Kanangra–Boyd granite uplands — chemically resistant terrain contributing negligible dissolved minerals. At 43.5 mg/L and TDS 74.2 mg/L, Mortdale is one of the softest of the Georges River LGA sub-zones, consistent with the adjacent soft Peakhurst (52.5 mg/L), Oatley (62.5 mg/L), and Sans Souci (52 mg/L) sub-zones — all dramatically softer than the very hard Carlton sub-zone (198 mg/L) in the same Georges River LGA.
Mortdale residents enjoy very low limescale accumulation on taps and in kettles — descaling every two to three months is typically more than adequate. Hot water systems accumulate minimal scale. The very low lead reading (0.002 mg/L) is excellent. Sydney Water provides water quality information at sydneywater.com.au, with all ADWG health standards consistently met. Mortdale's inner southern Sydney residential community benefits from this soft supply meeting all ADWG standards.
Geology & Source: Supplied by Sydney Water via the Prospect Water Filtration Plant drawing predominantly from Warragamba Dam — the Mortdale Georges River inner southern Sydney supply carries soft water at 43.5 mg/L with very low TDS of 74.2 mg/L, reflecting the predominantly Warragamba-dominant supply at the inner southern Georges River LGA Mortdale sub-zone, consistent with the soft character of the surrounding Oatley, Peakhurst, and Sans Souci Georges River sub-zones.