Water Quality in Seattle, WA
Detailed water quality data for Seattle, Washington including contaminant levels, EPA comparisons, AquaScore™ grading, and treatment recommendations.
Water utility: Seattle Public Utilities.
Water source: Cedar River Watershed, South Fork Tolt River.
Key Contaminants Found
- Haloacetic acids (HAA5)
- Total trihalomethanes (TTHMs)
- Chloroform
- Lead
- Copper
Seattle has some of the cleanest municipal water in the US, sourced from protected mountain watersheds. However, older buildings with lead solder joints may still contribute to elevated lead at the tap.