PlainWater
Counties → Washington

King County, Washington

Water Systems
217
Population Served
3,193,095
Total Violations
20,636
823 health-based
PFAS Detected
9
of 44 tested

Violation Analysis

96.8%
Systems with Violations
95.1
Avg Violations per System
4.0%
Health-Based Violations

Water Source Types

SW
32 systems (15%)
GW
18 systems (8%)

PFAS Contamination

44
Systems Tested
9
PFAS Detected
20.5%
Detection Rate

PFAS (per- and polyfluoroalkyl substances) are persistent chemicals found in drinking water. The EPA has set enforceable limits for several PFAS compounds under UCMR5 monitoring.

Compliance Snapshot

King Washington water systems by violation status, EPA SDWIS records.

No violations on record (2) One or more violations (48)

Violation history is cumulative, many flagged systems have already returned to compliance. Detail pages show per-system context.

Water Systems

System Name Population Violations PFAS
Seattle Public Utilities 1,091,904 29 Clean
Bellevue City Of 317,330 11 Clean
Kent Water Department 166,421 37 Detected
Redmond Water System City Of 163,335 2 Detected
Lakehaven Water and Sewer District 118,273 78 Detected
Highline Water District 115,950 9 Clean
Auburn City of 113,095 127 Detected
Renton City Of 107,119 59 Detected
Northshore Utility District 105,105 5 Clean
Sammamish Plateau Water & Sewer 79,362 77 Detected
Kirkland City Of 67,107 1 Clean
Soos Creek Water & Sewer District 64,534 1 Clean
Woodinville Water District 59,873 5 Clean
Covington Water District 52,276 21 Detected
Port of Seattle/Seatac Airport 49,483 14 Clean
Tukwila Water Department 45,374 0 Clean
Issaquah Water System 43,584 257 Clean
King County Water District #20 38,974 3 Clean
Bothell Water City Of 33,643 1 Clean
North City Water District 31,744 4 Clean
Mercer Island City Of 30,689 8 Clean
Cedar River Water & Sewer District 28,671 0 Detected
Lake Meridian Water District 24,231 9 Clean
Enumclaw Water Department 23,276 39 Clean
King County Water District No 90 20,100 262 Clean
King County Water District #125 17,546 7 Clean
King County Water District #49 16,065 9 Clean
Coal Creek Utility District 15,989 12 Clean
Snoqualmie Water 15,848 39 Clean
Skyway Water & Sewer 12,036 4 Clean
Duvall City Of 10,267 6 Clean
Union Hill Water Association Inc 8,720 312 Clean
NE Sammamish Sewer & Water District 8,516 19 Clean
Pacific City Of 7,925 16 Clean
North Bend City Of 7,228 5 Clean
Sallal Water Association Inc 6,600 15 Clean
Snoqualmie Pass Utility District 5,805 322 Clean
King County Water District #54 5,037 20 Clean
Stevens Pass Water System 4,053 35 Clean
King County Water District 119 3,796 3 Clean
Water District 19 3,723 572 Clean
Ames Lake Water Assoc Inc 3,224 178 -
Algona Water Dept 3,180 13 -
Lake Forest Park Water District 3,171 9,527 Clean
Fall City Water Dist. #127 2,987 15 -
Black Diamond Water Dept 2,420 194 -
Carnation Water System City Of 2,400 12 -
Cherokee Bay Community Club Inc 2,400 25 -
Mirrormont 2,083 31 -
Heights Water 2,051 6 Clean

Other Counties in Washington

Pierce County
359 systems · 1,138,508 served · 14,826 violations
Snohomish County
170 systems · 947,238 served · 8,193 violations
Spokane County
164 systems · 621,798 served · 9,829 violations
Clark County
72 systems · 615,931 served · 9,864 violations
Thurston County
322 systems · 395,780 served · 24,330 violations
Kitsap County
221 systems · 331,366 served · 12,667 violations

Drinking Water Guides

Frequently Asked Questions

How many water violations are in King County? ▼
King County has 20,636 total drinking water violations across 217 water systems, of which 823 are health-based violations. 96.8% of systems have at least one violation.
How many people get water from King County systems? ▼
Water systems in King County serve approximately 3,193,095 people through 217 public water systems.
Has PFAS been detected in King County water? ▼
Of 44 water systems tested for PFAS in King County, 9 had PFAS detected (20.5% detection rate).
What types of water sources supply King County? ▼
Water systems in King County use SW (32 systems), GW (18 systems) as their primary water sources.
Are health-based violations serious? ▼
Health-based violations indicate that drinking water exceeded Maximum Contaminant Levels (MCLs) set by the EPA or failed treatment technique requirements. 4.0% of King County's violations are health-based. Not all violations indicate immediate health risk, but they require corrective action.
Data Sources & Methodology

Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.

Violations are categorized as health-based (Maximum Contaminant Level exceedances, treatment technique failures) or monitoring/reporting violations. Not all violations indicate an immediate health risk.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.