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Counties → Washington

Grant County, Washington

SDWIS compliance plate

Sheet WA025 · Grant County 268 sys · 12,635 viol · #433/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · BELOW-PEER · PFAS-LOW · SRC-GW · SYS-LARGE · BOOK-FULL

  • VIOL-SEVERE 69.8% flagged
  • HEALTH-LOW 8.0% health
  • RANK-TOP #433/3254
  • BELOW-PEER 4.9 pp cleaner
  • PFAS-LOW 20.0% detect
  • SRC-GW GW lead 100%
  • SYS-LARGE 268 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Franklin County (+ 4.9 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Grant County ranks #433 of 3,254 counties by people served, and #12 of 39 counties in Washington. See methodology · corpus placement.

Grant County standing, lower-flagged corpus third

Flagged-system rate 69.8% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 8.0% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 20.0% is UCMR5 detect rate in the tested-pool middle third (≤ 33.3%) . Population served ranks #433 of 3,254 · #12 of 39 in Washington.

Flagged-rate neighbourhood around Grant County

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

0% 20% 40% 60% 80% 100% Grant · this county · lowest Ferry · near Columbia · near 69.8% 74.7% 81.3% 82.3% 83.3% 100%

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

Water Systems

System Name Population Violations PFAS
Moses Lake City Of 32,428 626 Detected
Gorge Amphitheatre 25,015 29 -
Ephrata Water Department 8,620 267 Clean
Quincy Water Department City Of 8,415 281 Clean
Mattawa City of 5,015 227 Clean
Sun Lakes State Park 4,858 17 -
Warden City Of 4,674 219 Clean
Royal City Water 3,389 61 -
Steamboat Rock State Park #1 2,907 6 -
Desert Aire Owner Assn 2,856 518 -
Soap Lake Water Dept 2,399 25 -
Concert Camping Inc 2,040 6 -
Electric City City Of 1,812 36 -
Sunland Estates Homeowners Assn 1,480 84 -
Potholes State Park 1,456 13 -
Grand Coulee Water Dept City Of 1,428 11 -
Pelican Point By Cascadia LLC 1,357 140 -
Lakeview Park Water Assn 1,259 83 -
Weiler-Martin Tracts Water Assn 1,163 79 -
Basin Water Sources Inc 1,158 32 -
Crescent Bar System 1,108 43 -
George City Of 1,035 74 -
Sunserra at Crescent Bar 1,000 161 -
Coulee City Town Of 944 27 -
Winchester Wb Rest Area 944 11 -
Winchester Eb Rest Area 903 11 -
Potholes General Store 877 25 -
Ephrata Raceway Park 700 28 -
Quincy Valley Rest Area 536 10 -
Dry Falls State Park 519 10 -
Port of Royal Slope 447 76 -
Royal Water District 430 75 -
Wilson Creek Water Dept Town Of 386 35 -
Cascade Valley Water District 379 477 -
JR Simplot Co 365 59 -
Smokiam RV Resort 343 26 -
Deep Lake State Park 323 8 -
Stratford Road Estates 312 186 -
Green Acres Orchard 308 0 -
Wanapum Village 305 164 -
Hillcrest Water Users Assn 300 56 -
Midway Mini-Mart 293 18 -
Skyline Water System Inc 293 44 -
Green Acres - Mattawa 271 18 -
Parker Spring Acres Water Assoc 255 26 -
Sunrise Water Association 250 44 -
Hartline Water System 249 69 -
Crescent View Condominium Owners 243 34 -
Ridgeview Estates Water Association 240 9 -
Sentinel Gap Water Assn 226 59 -

Compare beyond Washington

Lower-flagged peers for Grant County

Cross-state counties nearest Grant County on flagged-system share (69.8%) and cumulative violation count (12,635). 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.