Westpark Water Hardness & Quality Report (2026)

Westpark, California, in Orange County in the City of Irvine — a planned residential neighborhood within Irvine's master-planned community framework near Woodbridge and Northwood — receives its municipal water from the Irvine Ranch Water District (IRWD), which draws from two main sources: Metropolitan Water District of Southern California (MWD) import (Colorado River Aqueduct and State Water Project) and the Orange County Water District (OCWD) purified local groundwater from the Santa Ana River basin alluvial aquifer. IRWD blends both sources to manage supply reliability across Irvine's substantial residential and commercial service area.

The moderately hard 145 mg/L hardness and TDS of 409.1 mg/L reflect the Orange County blended supply character. The Colorado River Aqueduct component brings hard water (~200–260 mg/L) from the highly calcareous Colorado Plateau — having traversed Permian Kaibab Limestone and desert evaporite terrain — while the State Water Project Sierra Nevada component contributes softer water (~50–80 mg/L). OCWD's purified local groundwater from the Santa Ana River alluvial basin (Pleistocene gravel and sand aquifer) adds a moderate-hardness component. The finished IRWD blend produces consistently moderately hard water across Irvine's planned neighborhoods.

At 145 mg/L, Westpark residents experience moderately hard water typical of the Irvine water system. Scale builds in kettles and coffee machines over months, the dishwasher benefits from rinse aid, and bathroom fixtures develop calcium deposits. Quarterly descaling of heating appliances is the standard schedule. The PFAS level of 6.1 ppt warrants a certified drinking water filter — while Orange County's water treatment through OCWD's advanced purification systems provides comprehensive filtration, the Colorado River Aqueduct's long-distance supply from the broader Southwest introduces some PFAS to the regional supply.