Seattle tap water: lead, PFAS and violations

Supplied by Seattle Public Utilities · EPA ID WA5377050 · 1,161,961 people

By Daryna Klochko · Data checked Oct 13, 2026
Short answer

Seattle tap water comes from Seattle Public Utilities, which serves 1,161,961 people. In 2025 sampling, the lead 90th percentile was 1.6 ppb, against the 15 ppb action level. EPA-required UCMR 5 testing found no PFAS at reporting levels. EPA lists no violations since 2015.

Lead · 90th pct 1.6 ppb Action level 15 ppb · 2025 PFAS · UCMR 5 None detected 29 PFAS tested · Mar 2023 – Dec 2023 Hardness — not reported Not in the utility’s report EPA violations · 10 yrs 0 records 0 health-based · 1 in all since 2015

These numbers describe the water system, not your tap. Lead and copper often come from pipes and fixtures inside a home, so your water can differ. Where a goal (MCLG) is 0, EPA’s goal for that contaminant is zero. Legal limits are set above it.

Is Seattle tap water safe to drink?

In the latest results, every contaminant we list with a single federal limit was below that limit or action level. Lead was 1.6 ppb at the 90th percentile, below the 15 ppb action level. EPA’s goal for lead is zero. EPA lists no violations since 2015. See how US tap water compares nationally.

What’s in Seattle tap water

Latest results from Seattle Public Utilities’ 2025 report and EPA records. One row per contaminant, with the type of limit in the limit column.

ContaminantResultLimitSampledSource
LeadComes mostly from home plumbing, not from the source water. 1.6 ppb 90th percentile reported to EPA; previous round (2024): 3.5 ppb 15 ppbAction level · goal 0Drops to 10 ppb on Nov 1, 2027 (Lead and Copper Rule Improvements). 2025 EPA SDWIS record, WA5377050
PFOA and PFOS (PFAS)Two “forever chemicals” with a federal limit. Not detected 8 samples at 2 entry points; none at or above the reporting level (4 ppt) 4.0 ppt eachLegal limit (MCL) · goal 0Utilities must comply from 2029; EPA proposed 2031 in May 2026. Mar 2023 – Dec 2023 EPA UCMR 5 final occurrence data (Aug 2026 release)
Total trihalomethanesByproducts of disinfection. 34 ppb Highest locational running annual average; range 16–43 80 ppbLegal limit (MCL) 2025 Seattle Public Utilities 2025 Drinking Water Quality Report
Haloacetic acids (HAA5)Byproducts of disinfection. 28 ppb Highest locational running annual average; range 13–41 60 ppbLegal limit (MCL) 2025 Seattle Public Utilities 2025 Drinking Water Quality Report
ChlorineDisinfectant kept in the pipes on purpose. 1 mg/L Average; range 0–1.8 4.0 mg/LDisinfectant limit (MRDL) · goal 4 2025 Seattle Public Utilities 2025 Drinking Water Quality Report

ppb = parts per billion (µg/L), ppt = parts per trillion (ng/L). The bar shows the result against the limit (black line). Limits: EPA drinking water regulations, PFAS rule, Lead and Copper Rule Improvements. “Not detected” means below the lab’s reporting level, not zero.

EPA violations

EPA’s SDWIS database lists 1 violation record for Seattle Public Utilities since 2015, 1 of them health-based. All have a return-to-compliance date.

Dec 2015 · Treatment technique Surface Water Treatment Rule Health-based Back in compliance Jan 26, 2016

Shown: health-based violations and everything from the last 10 years. Source: EPA SDWIS record, WA5377050, retrieved Oct 13, 2026.

How hard is Seattle water?

Seattle Public Utilities’ 2025 water quality report does not list hardness. Hardness has no federal health limit. A test kit or a lab test measures it at your tap (see how to test water hardness).

What to do with these numbers

Only what the data above points to.

Lead · 1.6 ppb

Lead comes from home plumbing

EPA’s goal for lead is zero. Older faucets, lead solder and lead service lines can add lead at your tap. A filter certified to NSF/ANSI 53 for lead reduces it.

Certified to reduce lead. Lead is not necessarily in your water.

All filters compared →
Your tap, not the system

Test your own water

Seattle Public Utilities’ numbers come from its own sampling sites. A certified lab test of your faucet shows lead and copper from your plumbing. How to test your own tap for lead, starting with your water utility.

All water tests compared →

Questions people ask

Does Seattle tap water have lead?
In 2025 sampling, Seattle Public Utilities’ lead 90th percentile was 1.6 ppb (90th percentile reported to EPA; previous round (2024): 3.5 ppb). The federal action level is 15 ppb, and EPA’s goal is zero. Lead usually enters water from home plumbing, so only a test of your own tap shows your level.
Does Seattle tap water have PFAS?
In EPA’s UCMR 5 testing (Mar 2023 – Dec 2023), none of 29 PFAS were found at or above reporting levels at 2 entry points of Seattle Public Utilities’ system. The federal limit for PFOA and PFOS is 4.0 ppt each. Utilities must comply from 2029. On May 18, 2026 EPA proposed letting systems ask for two more years, to 2031, and dropping the 2024 limits for PFHxS, PFNA, HFPO-DA and PFAS mixtures (the Hazard Index).
Does Seattle use chlorine or chloramine?
Seattle Public Utilities disinfects with chlorine. The 2025 average was 1 mg/L; the federal limit (MRDL) is 4.0 mg/L.
Has Seattle Public Utilities had EPA violations?
EPA’s SDWIS database lists 1 violation record for Seattle Public Utilities since 2015, 1 of them health-based. All have a return-to-compliance date. EPA lists no violations since 2015.
Who supplies water in Seattle?
Seattle Public Utilities (EPA ID WA5377050), a community water system serving 1,161,961 people through 195,204 connections. Main source: surface water.

Sources and nearby

Seattle Public Utilities 2025 Drinking Water Quality Reportseattle.gov EPA record for Seattle Public Utilities (WA5377050)echo.epa.gov EPA UCMR 5 data (PFAS and lithium)epa.gov Washington State water quality by cityWA Tacoma tap waterWABellingham tap waterWAPortland tap waterOR How we researchMethod