Rosemont Water Hardness & Quality Report (2026)

Rosemont, California, in Sacramento County in the southeast Sacramento metropolitan area near Elk Grove and Rancho Cordova — a large unincorporated Sacramento County community along the Folsom Boulevard corridor at the eastern edge of the Sacramento urban area — receives its municipal water from California American Water (CalAm) or the Sacramento County Water Agency, which draws from the Sacramento River at surface intakes and from Sacramento Basin groundwater wells in the Central Valley alluvial aquifer. Sacramento County's water supply infrastructure blends multiple sources from the Sacramento Valley.

The moderately hard 144.5 mg/L hardness and TDS of 411.8 mg/L reflect the Sacramento Valley blended supply character. The Sacramento River drains the Sierra Nevada — crystalline granite and metamorphic terrain with inherently soft character (~40–80 mg/L) — but gains additional dissolved minerals as it crosses the Sacramento Valley floor alluvial deposits (Quaternary gravel, sand, and silts) en route to the Sacramento area intakes. Sacramento Basin groundwater from the Central Valley alluvial aquifer adds higher-TDS water from prolonged soil and aquifer contact, blending with the river supply to produce a moderately hard finished product at Rosemont.

At 144.5 mg/L, Rosemont's water is moderately hard — manageable for everyday household use. 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 6.2 ppt warrants a certified drinking water filter — the Sacramento Valley agricultural corridor, the Folsom-Rancho Cordova industrial parks, and the regional military installations (McClellan Air Force Base, now closed but still a Superfund site) contribute to the Sacramento metro PFAS baseline.