Lomita Water Hardness & Quality Report (2026)

Lomita, California, in Los Angeles County — a small South Bay Los Angeles city adjacent to Torrance and Harbor City in the Los Angeles Harbor corridor, surrounded by the larger South Bay communities — receives its municipal water from California Water Service (Cal Water) or the Los Angeles Department of Water and Power (LADWP), which draws from Metropolitan Water District (MWD) import through the South Bay distribution system. The South Bay region receives MWD's blended Colorado River Aqueduct and State Water Project supply.

The moderately hard 119 mg/L hardness and TDS of 313.5 mg/L reflect the South Bay MWD blended supply's characteristic profile — typical for the Los Angeles Harbor and South Bay region receiving MWD import. MWD's blended supply mixes the harder Colorado River Aqueduct water (Colorado Plateau origin, 200-300 mg/L hardness) with the softer State Water Project (Sierra Nevada snowmelt, ~30-70 mg/L hardness), producing a moderately hard finished supply in the 100-150 mg/L range throughout much of Los Angeles. Lomita's supply reflects a typical South Bay MWD blend proportion.

At 119 mg/L, Lomita's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 5.3 ppt warrants a certified drinking water filter — the Los Angeles Harbor military complex (Naval Base San Pedro, Terminal Island federal facilities), the Port of Los Angeles industrial corridor, and the greater South Bay aerospace and defense manufacturing complex (Northrop Grumman, Raytheon South Bay operations) contribute to Lomita's PFAS background.