Water Quality in Washington: Complete Guide
Everything homeowners need to know about Washington tap water - hardness, contaminants, treatment options, and costs.
Quick summary: Washington has an average water hardness of 33 PPM across 26 cities. 0% of cities have hard water above 120 PPM. PFAS contamination is detected above EPA limits in at least one city. Most households do not need water softening equipment.
Water Hardness Across Washington
Washington's water hardness ranges from 12 PPM in Kirkland to 104 PPM in Spokane, with a statewide average of 33 PPM. This makes Washington one of the softer-water states. The national average is approximately 120 PPM.
Most Washington cities use surface water (rivers, lakes, reservoirs), which generally has lower mineral content than groundwater.
Contaminants of Concern in Washington
PFAS: The average PFAS level across Washington cities is 12.4 ppt. Richland has the highest detected PFAS at 63.55 ppt, above the EPA maximum contaminant level of 4 ppt. Residents should consider a reverse osmosis or NSF P473-certified filter for drinking water.
Lead: Lead contamination comes from plumbing infrastructure, not the water source. Washington homes built before 1986 are at higher risk due to lead solder. 2 cities show lead levels above 5 ppb.
Do You Need a Water Softener in Washington?
For most Washington residents, no. Only 0% of cities have hard water above 120 PPM. However, individual situations vary - check your city page for specific data.
Impact of Hard Water in Washington
With an average hardness of 33 PPM, most Washington households do not face significant hard water impact. However, homes with hardness above 120 PPM should evaluate treatment options.