Bothell West Water Hardness & Quality Report (2026)

The City of Bothell Water utility serves Bothell West and surrounding areas in King and Snohomish Counties, Washington, providing drinking water to over 48,000 residents including 15,423 in the core district. Water is sourced primarily as purchased surface water from regional suppliers, likely involving the South Fork Sammamish River and Cedar River systems managed by Seattle Public Utilities. Treatment occurs at regional facilities with distribution from the utility at 18415 101st Avenue NE, Bothell, WA 98011.

The Sammamish-Cedar watershed spans the western Cascade foothills, where Pleistocene glacial deposits form surficial aquifers and riverine sources. Geology features Vashon Till and recessional outwash sands over pre-Tertiary bedrock, imparting a moderately mineralised character through gradual mineral dissolution from volcanic and metamorphic sources. This lowlands setting yields water shaped by Cascade geology without the intense hardness of limestone-dominated basins, with dissolved bicarbonates accumulating from limestone fragments and alluvial soils.

Moderately hard water promotes moderate limescale in kettles, dishwashers, and water heaters, with occasional spotting on glassware and reduced soap efficiency. Laundry may feel less soft, and minor pipe scaling can occur over decades. Routine vinegar descaling and magnetic treatments help; a water softener is recommended for optimal appliance life in larger households. Water meets EPA legal standards with pH typically neutral-alkaline; lead and copper rule compliance achieved. Notable contaminants exceeding health guidelines include TTHMs, chromium-6, chloroform, haloacetic acids, 1,1-dichloroethylene, cobalt, and uranium, though below MCLs.