Santa Ana Water Hardness & Quality Report (2026)

The City of Santa Ana Water Department serves Orange County, California, providing approximately 11 billion gallons of water annually. The utility operates 21 city-owned wells tapping the Orange County Groundwater Basin and purchases imported water from the Metropolitan Water District of Southern California (MWD). MWD supplies 23% of Santa Ana's water from two sources: the Colorado River (conveyed 242 miles via the Colorado River Aqueduct from Lake Havasu) and Northern California's Sacramento–San Joaquin River system (transported 444 miles through the State Water Project's California Aqueduct). Groundwater comprises 77% of the supply.

The Orange County Groundwater Basin spans approximately 270 square miles with usable storage of around 500,000 acre-feet. Aquifers extend over 2,000 feet deep through Tertiary and Quaternary alluvial and sedimentary deposits, where natural filtration occurs as water percolates through sediment layers. Imported surface water from the Colorado River and Northern California's river systems flows through mineral-rich watersheds, contributing dissolved calcium and magnesium. This combination of deep groundwater dissolution and mineral-laden imported surface water creates a hard water supply.

At hard hardness levels, calcium and magnesium deposits accumulate on dishes, glassware, and fixtures, requiring frequent cleaning. Water heaters, dishwashers, and washing machines suffer reduced efficiency and shortened lifespan due to scale buildup inside pipes and heating elements. Soap and shampoo form less lather, and skin and hair may feel dry or sticky after bathing. A water softener is recommended for households seeking to reduce these effects and extend appliance life, though hard water is safe to drink and poses no direct health risk. Arsenic has been detected above health guidelines in the supply; regular monitoring and compliance with Safe Drinking Water Act standards are maintained through published Consumer Confidence Reports.