Hermosa Beach Water Hardness & Quality Report (2026)

California Water Service Company operates the Hermosa-Redondo system, serving Hermosa Beach and Redondo Beach in Los Angeles County, California, with a population of approximately 95,985. Water is purchased as treated surface water from the Metropolitan Water District of Southern California via the Colorado River Aqueduct, with Lake Havasu on the Colorado River as the key source. Treatment occurs at regional facilities including the Jensen and Skinner plants before distribution; local infrastructure includes blending and disinfection at the utility's facilities in Redondo Beach at 415 Diamond Street.

The supply originates in the expansive Colorado River Watershed, spanning seven U.S. states and Mexico with headwaters in the Rocky Mountains. Water travels through the river channel, picking up minerals from Paleozoic carbonate rock formations including the Kaibab Limestone and Supai Group, as well as Quaternary alluvium in the lower basin. No local aquifers are used; the hard character reflects the river's transit through limestone-dominated terrain in an arid climate, with elevated dissolved calcium and magnesium from geological dissolution and minimal dilution from soft precipitation.

Hard water causes moderate scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan, with impaired soap lathering requiring more detergent. Maintenance includes periodic flushing of water heaters, installing scale-inhibiting filters, and vinegar descaling for appliances. A water softener may be considered to improve lathering and reduce spotting on fixtures, though it adds sodium — check local regulations before installing. The system meets all primary drinking water standards per the 2023 and 2024 Consumer Confidence Reports; chloramine is used for disinfection, with turbidity below 0.3 NTU in 95% of monthly samples. Lead and copper compliance is achieved at the 90th percentile tap levels.