Bartlesville Water Hardness & Quality Report (2026)

Bartlesville, Oklahoma, the Washington County seat — a major northeast Oklahoma city with profound historical significance in the American petroleum industry (Bartlesville is where the first commercial oil well in Oklahoma was drilled in 1897 — the Nellie Johnstone No. 1 well, the birthplace of the Oklahoma oil industry; Bartlesville was the original headquarters of Phillips Petroleum Company, founded by Frank Phillips in 1917), home of Frank Lloyd Wright's only skyscraper — Price Tower (the 19-story Price Tower, now a hotel and arts center, was designed by Frank Lloyd Wright and completed in 1956), a mid-size northeast Oklahoma city with a significant energy industry heritage, and a diverse Washington County community — draws its municipal water supply from Hulah Lake (Caney River) via the City of Bartlesville Water Division. Water hardness in Bartlesville measures 341 mg/L — classified as extremely hard.

Bartlesville's extremely hard supply reflects the northeast Oklahoma Carboniferous Platform's highly calcareous limestone and dolomite geology. The Caney River watershed at Hulah Lake drains: the Pennsylvanian Verdigris Limestone, Dewey Limestone, and Coffeyville Formation (highly calcareous marine limestone of the Oklahoma Carboniferous Platform); the Devonian Woodford Shale (calcareous-moderate organic shale); and the Ordovician Arbuckle Group Dolomite (highly calcareous Ordovician dolomite). City of Bartlesville applies limited softening, producing the extreme 341 mg/L.

At 341 mg/L, Bartlesville residents face severe hard water challenges. Water softeners are essentially a necessity. City of Bartlesville Water Division consistently delivers water meeting all Oklahoma DEQ and EPA Safe Drinking Water Act requirements.