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Counties → Washington

Snohomish County, Washington

SDWIS compliance plate

Sheet WA061 · Snohomish County 170 sys · 8,193 viol · #61/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · PHOTO-FINISH · PFAS-LOW · SRC-GW · SYS-LARGE · BOOK-FULL

  • VIOL-SEVERE 97.6% flagged
  • HEALTH-LOW 6.7% health
  • RANK-TOP #61/3254
  • PHOTO-FINISH ±0.1 pp
  • PFAS-LOW 10.5% detect
  • SRC-GW GW lead 72%
  • SYS-LARGE 170 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Skagit County (+ 0.1 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Snohomish County ranks #61 of 3,254 counties by people served, and #3 of 39 counties in Washington. See methodology · corpus placement.

Snohomish County standing, mid-flagged corpus third

Flagged-system rate 97.6% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 6.7% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 10.5% is UCMR5 detect rate in the tested-pool middle third (≤ 33.3%) . Population served ranks #61 of 3,254 · #3 of 39 in Washington.

Flagged-rate neighbourhood around Snohomish County

Lowest/highest poles plus in-state counties nearest Snohomish County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% Grant · lowest Snohomish · this county Island · near Wahkiakum · highest 69.8% 97.1% 97.6% 97.7% 97.7% 98.3% 100%

Source: EPA SDWIS (county aggregates) As of 2026-05-15

Water Systems

System Name Population Violations PFAS
Everett Public Works Dept. City Of 215,774 5 Clean
Alderwood Water District 200,000 6 Clean
Marysville Utilities 88,589 21 Clean
Lynnwood City Of 68,204 8 Clean
Sno PUD 1 - Lake Stevens 60,064 25 Clean
Silver Lake Water & Sewer District 56,582 17 Clean
Edmonds City Of 34,023 0 Clean
Mountlake Terrace City Of 26,402 12 Clean
Mukilteo Water & Wastewater Distr 25,182 4 Clean
Monroe Water System 23,467 27 Clean
Cross Valley Water District 23,054 33 Detected
Arlington City Of 20,418 1 Detected
Olympic View Water & Sewer District 16,403 14 Clean
Stanwood Water Dept City Of 13,785 179 Clean
Snohomish City Of 11,258 111 Clean
Sultan Water Department 7,160 92 Clean
Granite Falls City Of 6,926 6 Clean
Seven Lakes Water Association 5,823 58 Clean
Roosevelt Water Association 3,493 17 -
Highland Water District 3,121 5 -
Sno PUD 1 - Warm Beach 2,890 19 -
Gold Bar City Of 2,745 85 Clean
Darrington Town of 2,246 44 -
Three Lakes Water Association 2,198 6 -
Sno PUD 1 - May Creek 1,364 4 -
Warm Beach Conference Grounds 1,190 46 -
Kayak Point County Park 978 9 -
Whitehorse Mercantile Water System 930 22 -
Sno PUD 1 - Storm Lake Ridge 786 29 -
Wallace Falls State Park 759 4 -
Wilderness Ridge Community Club 664 50 -
Startup Water District 643 26 -
Priest Point Beach Water Inc 624 63 -
Rivershore Water District #1 572 17 -
Sno PUD 1 - Sunday Lake 561 30 -
Zekes Drive-IN 502 5 -
Lake Alyson 463 13 -
Wilkshire Lane Water District Inc 460 6 -
Wandering Creek Homeowners Assoc 457 5 -
Thunderbird Park 454 94 -
Craven Farm Water System 431 9 -
Index Water Dept 420 130 -
Big Bend Landowners Association 419 194 -
Sno PUD 1 - Skylite Tracts 415 23 -
Tatoosh Water Company 387 34 -
Hat Island Community Inc 348 327 -
Sultan Estates Water System 340 10 -
Kackman Creek 330 34 -
Machias Ridge Homeowners Assoc. 324 10 -
Cedar Springs Camp 308 47 -

Compare beyond Washington

Mid-flagged peers for Snohomish County

Cross-state counties nearest Snohomish County on flagged-system share (97.6%) and cumulative violation count (8,193). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

4 peers

Read our methodology · Check your water system - 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

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.