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Counties → Oregon

Columbia County, Oregon

SDWIS compliance plate

Sheet OR009 · Columbia County 56 sys · 9,494 viol · #1104/3254

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

  • VIOL-SEVERE 100.0% flagged
  • HEALTH-LOW 7.6% health
  • RANK-UPPER #1104/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-HIGH 50.0% detect
  • SRC-GW GW lead 82%
  • SYS-MID 56 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Multnomah County (+ 0 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Columbia County ranks #1,104 of 3,254 counties by people served, and #19 of 36 counties in Oregon. See methodology · corpus placement.

Columbia County standing, mid-flagged corpus third

Flagged-system rate 100.0% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 7.6% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 50.0% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #1,104 of 3,254 · #19 of 36 in Oregon.

Flagged-rate neighbourhood around Columbia County

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

0% 20% 40% 60% 80% 100% Polk · lowest Wheeler · highest Benton · near Coos · near 86.2% 100% 100% 100% 100% 100% 100%

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

Water Systems

System Name Population Violations PFAS
St Helens, City Of 13,410 69 Detected
Scappoose, City Of 8,710 92 Clean
McNulty Water PUD 2,500 155 -
Clatskanie, City Of 2,188 21 -
Vernonia, City Of 2,100 250 -
Warren Water Association 2,050 39 -
Columbia City Mun Waterworks 1,995 81 -
City of Rainier 1,932 301 -
Rainier SD #13 950 114 -
Western Hills Mh Estates 375 147 -
Fishhawk Lake Reserve and Community 350 112 -
Quincy Water Association 300 165 -
Columbia Co Pks-Camp Wilkerson 200 20 -
Columbia Co Pks-Hudson/Parcher 200 24 -
Midland Water Association 160 444 -
Rainier OR Lds Church 150 6 -
Columbia Co Pks-Big Eddy 125 21 -
Columbia Acres Water Assoc 110 118 -
Deer Island Village MHP 100 185 -
Lost Creek Heights Wtr Assoc 100 93 -
Alston Corners-Assembly of God 100 24 -
Shell Star Mart 100 50 -
Scappoose Brew & Thru 100 24 -
Country Villa Mobile Estates 90 145 -
Deer View Cooperative 90 314 -
Deer Island Waterworks 90 311 -
Paradise Moorage 90 179 -
Alston Country Store 90 53 -
Rainier Congregation of Jw 90 11 -
Goble Water Association 85 158 -
Columbia Hills HOA 84 344 -
Tamarack Mobile Home Park 80 200 -
Olympic Forest Products 80 461 -
Prescott, City Of 70 530 -
Maple Terrace Mobile Home Park 70 31 -
Laurel Ridge MHP 70 473 -
Marshland Water Association 70 829 -
McCuddys Landing 70 103 -
Columbia River Nitrogen, LLC 65 65 -
Deer Island Heights WS 60 763 -
Cedar Tree Mobile Home Park 50 227 -
Valley of the Moon 46 23 -
J & M Mobile Home Park 45 400 -
Dikeside Moorage 45 276 -
Berndt Creek Water Corp 45 106 -
Columbia River PUD 45 80 -
Island Community LLC 41 110 -
Hogg Heaven MHP 40 108 -
Swedetown Water Assoc 40 110 -
Pge Beaver Generating Station 30 176 -

Compare beyond Oregon

Mid-flagged peers for Columbia County

Cross-state counties nearest Columbia County on flagged-system share (100.0%) and cumulative violation count (9,494). 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.