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Counties → Washington

San Juan County, Washington

SDWIS compliance plate

Sheet WA055 · San Juan County 112 sys · 6,963 viol · #1113/3254

VIOL-SEVERE · HEALTH-LOW · RANK-UPPER · PHOTO-FINISH · PFAS-CLEAN · SRC-GW · SYS-MID · BOOK-FULL

  • VIOL-SEVERE 92.0% flagged
  • HEALTH-LOW 8.7% health
  • RANK-UPPER #1113/3254
  • PHOTO-FINISH ±0.5 pp
  • PFAS-CLEAN 0.0% detect
  • SRC-GW GW lead 74%
  • SYS-MID 112 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Jefferson County ( -0.5 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, San Juan County ranks #1,113 of 3,254 counties by people served, and #27 of 39 counties in Washington. See methodology · corpus placement.

San Juan County standing, lower-flagged corpus third

Flagged-system rate 92.0% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 8.7% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 0.0% is UCMR5 detect rate at or below the tested-pool lower third (≤ 0.0%) . Population served ranks #1,113 of 3,254 · #27 of 39 in Washington.

Flagged-rate neighbourhood around San Juan County

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

0% 20% 40% 60% 80% 100% Grant · lowest Jefferson · near Walla Walla · near Wahkiakum · highest 69.8% 91.2% 91.4% 92% 92.8% 93.1% 100%

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

Water Systems

System Name Population Violations PFAS
Moran State Park-Mountain Lake 4,804 10 -
Moran State Park - Summit Lake 4,803 2 -
Moran State Park-Cascade Lake 4,783 19 -
Eastsound Water Users Association 3,711 304 Clean
Friday Harbor Town Of 3,543 56 Clean
Limekiln State Park 2,149 14 -
Roche Harbor Water System Inc 1,985 1,788 -
Fisherman Bay Water Association 1,195 35 -
Rosario 1,031 54 -
Orcas Landing Inc 1,007 770 -
Sucia Island State Park 794 12 -
Sucia Island St Park-Shallow Bay 757 10 -
Spencer Spit State Park 655 11 -
Jones Island State Park 509 29 -
Stuart Is State Park 486 17 -
Doe Bay Water Users Assoc 442 66 -
Lopez School District #144 402 9 -
Olga Water Users Inc 392 37 -
Blakely Is. Maintenance Commission 333 72 -
Camp Nor Wester 281 3 -
Orcas Highlands 260 14 -
Camp Orkila 233 8 -
English Camp 233 4 -
West Sound Water Association 206 65 -
Worldmark Resort at Deer Harbor 190 8 -
American Camp 186 4 -
Odlin Park 162 25 -
Cape San Juan Water District 158 59 -
Oaks the Mobile Home Park 143 34 -
Decatur Shores Community Assoc 140 15 -
MacKaye Harbor Water District 133 11 -
Portland Fair Estates 130 47 -
Snug Harbor Resort Water System 127 42 -
San Juan Golf & Country Club 121 4 -
North Lopez Service 114 48 -
San Juan Co Park 114 3 -
Duck Soup Inn 96 22 -
Center Island Water System 93 15 -
Spring Point Homeowners Association 85 590 -
Harbor on Fisherman Bay 84 32 -
Canoe Island 82 20 -
Limestone Point Water Company Inc 81 86 -
Mitchell Point Water Assn 81 23 -
Raccoon Point Water System 81 623 -
Sunset Ranch Owners Assoc 76 108 -
University Heights 76 30 -
West Beach Resort 76 17 -
Southend Water System 75 28 -
Cormorant Water System 72 5 -
Hannah Heights Owners Association 66 82 -

Compare beyond Washington

Lower-flagged peers for San Juan County

Cross-state counties nearest San Juan County on flagged-system share (92.0%) and cumulative violation count (6,963). 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.