Carlton Water Hardness & Quality Report (2026)

Carlton's (NSW) drinking water is supplied by Sydney Water, treated at the Prospect Water Filtration Plant with a very high Hawkesbury-Nepean component for the Georges River LGA inner southern Sydney distribution in New South Wales. Water hardness in Carlton (NSW) is measured at 198 mg/L — classified as hard, just below the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Carlton (NSW) — a residential suburb in the Georges River LGA adjacent to Kogarah, Allawah, and Penshurst, known for the Carlton residential community on the Kogarah–Allawah train corridor, the Carlton Park and Kogarah Bay foreshore, and the established inner southern Sydney community of the Georges River LGA south of the St George area — receives very hard supply approaching the ADWG aesthetic guideline, consistent with the hard supply character of the southern Sydney Georges River LGA distribution.

Carlton's (NSW) very hard supply reflects a dominant Hawkesbury-Nepean component in the inner southern Georges River Prospect distribution blend at this sub-zone. The Hawkesbury-Nepean system traverses the Cumberland Plain alluvial valley and Triassic carbonate-cemented Hawkesbury Sandstone — contributing very high dissolved calcium and minerals before Prospect treatment. At 198 mg/L and TDS 473.7 mg/L, Carlton's inner southern Georges River supply is one of the hardest inner Sydney sub-zones, comparable to Botany (199 mg/L, Bayside LGA), Hinchinbrook (198.5 mg/L, Liverpool LGA), and Mount Annan (198 mg/L), all driven by the dominant Hawkesbury-Nepean proportion in the Prospect distribution routing.

Carlton (NSW) residents face significant limescale build-up on taps and in kettles — descaling every four to six weeks is typical. Hot water systems benefit from regular annual inspection. The elevated lead reading (0.005 mg/L) warrants always briefly running the cold tap before drinking or cooking. Sydney Water provides water quality information at sydneywater.com.au, with all ADWG health standards consistently met. Carlton's inner southern Sydney residential community benefits from supply meeting all ADWG safe drinking standards.