Artesia Water Hardness & Quality Report (2026)

Golden State Water Company (GSWC) operates the Artesia Water System (PWS ID CA1910004), serving approximately 16,000 residents across a 4.5 square mile area in southeastern Los Angeles County, California. The utility sources 100% of its supply from local groundwater wells tapping the Central Basin aquifer system, managed by the Water Replenishment District of Southern California. Treatment occurs at wellhead facilities with chlorination, fluoridation, and blending before distribution; no surface water reservoirs or rivers are directly involved in the supply.

The watershed encompasses the Los Angeles Basin groundwater basin, specifically the Alamitos Forebay subarea formed by ancient river sediments. Key geological features include thick sequences of Quaternary alluvial deposits overlying the deeper Silverado and Fernando Formations, containing interbedded sandstones and limestones from the Pliocene-Pleistocene epochs. This geology imparts a hard character through natural leaching of alkaline earth metals from carbonate-bearing rocks; replenishment is supplemented by imported surface water from the Colorado River Aqueduct and State Water Project to maintain basin levels.

Mineral scaling significantly shortens the lifespan of water heaters, dishwashers, and washing machines by 30–50%, increases energy costs by up to 20%, and leaves spots on glassware while reducing soap lathering. Laundry fabrics stiffen and bathroom fixtures develop bathtub rings. Monthly vinegar descaling of faucets and showerheads, annual heater flushing, and scale-inhibiting filters are recommended; a whole-house water softener is strongly advised. GSWC water meets all federal and state standards, with pH typically 7.5–8.5; corrosion control via pH adjustment and orthophosphate addition keeps copper below 1.3 mg/L; notable detections include arsenic (2–5 ppb, below MCL) and nitrate (3–7 mg/L); treatment includes chlorine disinfection and fluoridation to 0.7 mg/L.