Coos Bay Water Hardness & Quality Report (2026)

The Coos Bay-North Bend Water Board serves Coos Bay, North Bend, and surrounding areas in Coos County, Oregon, providing drinking water to approximately 15,000 connections. Water is sourced primarily from surface water intakes on the Coos River and Tenmile Creek, supplemented by groundwater wells. The utility operates the C.D. Anderson Treatment Plant for surface water processing and maintains several well stations for groundwater blending. This mixed supply ensures reliable service across the coastal communities, with infrastructure managed under strict EPA and Oregon DEQ oversight.

The Coos Bay watershed encompasses the Coos River basin within the Oregon Coast Range, characterized by forested uplands and sedimentary rock formations like the Tyee Sandstone of Eocene age. Volcanic rocks from the Siletz River Formation underlie parts of the catchment, while alluvial deposits form shallow aquifers near the coast. This geology imparts a soft water character, as rainwater percolates through silica-rich but calcium-poor soils, yielding minimally mineralized supplies with low dissolved solids from the granitic and basaltic influences prevalent in coastal Oregon.

Homeowners in the area can appreciate the benefits of this naturally soft water, which spares appliances like water heaters, dishwashers, and coffee makers from common hard water damage. Soap lathers easily without excess use, and plumbing fixtures resist mineral deposits, reducing maintenance needs. The 2023 Consumer Confidence Report confirms full compliance with EPA primary and secondary standards, including no violations for lead or copper at the action levels, and with water treated via coagulation, filtration, disinfection with chlorine, and fluoridation at the C.D. Anderson plant, residents can trust the quality of their tap water.