Richland Water Hardness & Quality Report (2026)

Richland, Washington, in Benton County at the confluence of the Yakima and Columbia Rivers — one of the three cities of the Tri-Cities area (with Kennewick and Pasco), historically defined by the Hanford Site (where plutonium for the Trinity test and Fat Man atomic bomb was produced), and now a major Pacific Northwest energy research hub (Pacific Northwest National Laboratory) — draws its municipal water supply from the Columbia River via the City of Richland Utilities Water Division. Water hardness in Richland measures 31.5 mg/L — classified as very soft.

Richland's very soft supply reflects the Columbia River's dominance of the Richland water system. The Columbia River at the Tri-Cities receives the vast majority of its flow from: the Rocky Mountains and Selkirk Range (British Columbia and Idaho — granite and metamorphic crystalline terrain, calcium-poor); the Cascade Range (Quaternary basalt and andesite volcanic terrain — calcium-poor mafic volcanic rock); the Columbia River Basalt Group (flows in the Columbia Basin, but the river carries the soft mountain snowmelt from upstream). Despite the Columbia River flowing through the highly calcareous Columbia Basin basalt plateau, the enormous snowmelt volume from the soft Rocky Mountain and Cascade headwaters dominates, producing the very soft 31.5 mg/L at Richland.

With hardness at 31.5 mg/L, Richland residents enjoy very soft water with essentially no scale challenges. City of Richland Utilities Water Division consistently delivers water meeting all Washington DOE and EPA Safe Drinking Water Act requirements.