Seattle Water Quality Facts and Drinking Water Problems

Before water reaches your tap, it is sourced from a complex system of surface water and groundwater from around Washington that includes lakes, rivers, streams, reservoirs, wells, and more. After water is pumped from these sources, it is purified, cleaned, and tested at a water treatment plant before being distributed throughout the state.

While the quality of Washington’s water varies significantly depending on the region, residents of the Evergreen State often report their water being hard, which contributes to cloudy dishes and glassware, limescale or white scale buildup, and soap scum residue in bathroom areas.

Seattle sources its drinking water from two large regional watersheds – the Cedar and Tolt. Roughly 70% of the city’s drinking water comes from the Cedar River Watershed, while the Tolt River Watershed supplies the other 30%. The water is typically treated at either the Cedar Water Treatment Facility or the Tolt Water Treatment Facility before being distributed throughout the city to homes and businesses in the Seattle metro area.

The most common water quality issues in the Seattle area include:

Lime or White Scale Buildup

• Pesky sediment and scum buildup on bathroom and kitchen appliances
• Under-performing appliances that result in added household costs
• Off-white buildup that causes faucets and showerheads to clog
• Difficult-to-clean surfaces

Soap Scum and Sediment

• Buildup on household appliances and faucets
• Cloudy dishes and glassware
• Uncomfortable film on skin and hair

Spots on Glasses

Whether you wash your dishes by hand at the tap or you let your dishwasher do the work for you, dishes that are washed and rinsed with hard water can appear spotty and streaky after water dries.

Ready for Better Water in Your Home?