Palmdale Water Hardness & Quality Report (2026)

The Palmdale Water District (PWD) serves approximately 120,000 residents in the City of Palmdale and surrounding unincorporated areas of northern Los Angeles County, California. Water supply is a blend of groundwater from local wells in the Antelope Valley Groundwater Basin and surface water imported via the California State Aqueduct and Littlerock Reservoir. PWD operates multiple wellfields and treatment facilities — including advanced oxidation and filtration plants — to blend and treat raw water before distribution through its extensive pipeline network.

Palmdale's supply originates in the Antelope Valley portion of the Mojave Desert watershed. Groundwater comes from the local subbasin, while surface imports arrive from distant Sierra Nevada snowmelt via the California State Aqueduct and from the San Gabriel Mountains foothills via Littlerock Reservoir. The geology features Quaternary alluvial deposits over Tertiary sedimentary layers, including carbonate rocks such as limestone that dissolve to contribute hardness. Evaporative concentration in the arid basin enhances mineralisation, shaping a consistently hard supply from geological rather than anthropogenic sources.

The moderately hard to hard supply produces noticeable scale buildup on faucets, showerheads, and inside pipes, reducing water flow and efficiency. Water heaters, dishwashers, and washing machines suffer reduced lifespan and higher energy costs as mineral deposits insulate heating elements. Maintenance involves regular vinegar descaling of fixtures, installing drain screens, and flushing water heaters biannually. A water softener is recommended to prevent these issues and extend appliance life. pH ranges 6.8–8.4; notable contaminants include arsenic (up to 3 ppb), chromium (up to 20 ppb), nitrates (up to 2 ppm), uranium (up to 4 pCi/L), and TTHMs — all within EPA limits. TDS ranges 150–470 ppm, affecting taste.