San Pedro Water Hardness & Quality Report (2026)

San Pedro, California — the Los Angeles harbor neighborhood at the southern tip of the City of Los Angeles (adjacent to the Port of Los Angeles) in San Pedro Bay — receives its municipal water supply from the Los Angeles Department of Water and Power (LADWP), drawing from the standard LADWP regional blend of Los Angeles Aqueduct (Owens Valley and Mono Basin) and State Water Project (SWP) imports, distributed through the south Los Angeles and harbor area distribution network. Water hardness in San Pedro measures 52.5 mg/L — classified as moderately soft.

San Pedro's moderately soft supply reflects the LADWP south harbor distribution zone's supply blend. The southern LADWP distribution area near the Port of Los Angeles–San Pedro waterfront receives a higher proportion of Owens Valley Aqueduct water and State Water Project water — both very soft sources — with relatively limited local groundwater blending compared to some inland LADWP zones. The soft nature of both source streams (Owens Valley/Sierra Nevada granite — very soft; Sacramento–Feather River SWP — moderately soft) produces the consistently soft supply in San Pedro and the South Bay LADWP distribution zone. The 52.5 mg/L reading is consistent with LADWP south district delivery.

With hardness at 52.5 mg/L, San Pedro residents experience minimal to moderate scale challenges. Soap and shampoo lather well. Faucet aerators and showerheads develop deposits slowly — bi-monthly cleaning with citric acid solution is sufficient. LADWP consistently delivers water meeting all California SWRCB and EPA Safe Drinking Water Act requirements.