Paramount Water Hardness & Quality Report (2026)

Paramount, California, in southeast Los Angeles County adjacent to Compton and Lynwood — a densely populated southeast LA County industrial and residential community with a large Latino population, known for its dairy industry roots and the Paramount Boulevard commercial corridor — draws its municipal water supply from the Central Basin Municipal Water District (combining Metropolitan Water District import and local groundwater) via the City of Paramount Public Works Water Division. Water hardness in Paramount measures 147 mg/L — classified as moderately hard.

Paramount's moderate hardness reflects the Central Basin's blended MWD import and local Los Angeles County groundwater. The Central Basin (southeast Los Angeles County's primary groundwater basin — Quaternary alluvial deposits recharging from the San Gabriel Mountains and the Los Angeles River system) receives blended recharge from: MWD-imported Colorado River water (moderately hard, approximately 270–310 mg/L) and State Water Project Bay-Delta water (soft, approximately 50–100 mg/L) percolated through spreading grounds; and local Los Angeles River recharge from the San Gabriel Mountains (Transverse Ranges granitic and calcareous terrain). The Central Basin blend at Paramount produces the moderate 147 mg/L — a characteristic mid-range hardness for the southeast LA County water table zone.

At 147 mg/L, Paramount residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. City of Paramount Public Works Water Division consistently delivers water meeting all California SWRCB and EPA Safe Drinking Water Act requirements.