La Crescenta-Montrose Water Hardness & Quality Report (2026)

La Crescenta-Montrose, California, in Los Angeles County — an unincorporated Los Angeles County community in the Crescenta Valley between Glendale and Sunland-Tujunga, nestled in the foothills of the Verdugo Mountains and the San Gabriel Mountains — receives its municipal water from the Crescenta Valley Water District (CVWD), which draws from MWD import (Metropolitan Water District State Water Project-Colorado River blend) and local Verdugo Hills groundwater wells.

The moderately hard 109.5 mg/L hardness and TDS of 280.8 mg/L reflect the Crescenta Valley's blended MWD import and local groundwater character. CVWD blends the soft MWD import (SWP-dominated: ~50-90 mg/L) with local Verdugo Hills groundwater from wells in the Crescenta Valley alluvium and weathered Mesozoic granodiorite bedrock of the Verdugo Mountains. The local groundwater is moderately harder than the MWD import, and the blend produces the moderately hard 109.5 mg/L reading — between the soft pure MWD and harder San Gabriel Valley groundwater supplies.

At 109.5 mg/L, La Crescenta-Montrose'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 5.1 ppt warrants a certified drinking water filter — the Verdugo Hills defense-aerospace corridor (Lockheed Air Terminal at Burbank, JPL Pasadena), the San Fernando Valley PFAS groundwater plume (one of the most PFAS-contaminated aquifer systems in California), and the LA aerospace-defense industrial complex contribute to La Crescenta-Montrose's readings.