PlainWater

Marion County, Illinois

SDWIS compliance plate

Sheet IL121 · Marion County 18 sys · 810 viol · #1058/3254

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

  • VIOL-SEVERE 88.9% flagged
  • HEALTH-MID 28.5% health
  • RANK-UPPER #1058/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-CLEAN 0.0% detect
  • SRC-SW SW lead 94%
  • SYS-SMALL 18 systems
  • BOOK-FULL 7/7 fields

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

According to EPA SDWIS county population served used on /counties, Marion County ranks #1,058 of 3,254 counties by people served, and #32 of 102 counties in Illinois. See methodology · corpus placement.

Marion County standing, lower-flagged corpus third

Flagged-system rate 88.9% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 28.5% is health-based share above the upper third (> 24.5%) . UCMR5 detect rate 0.0% is UCMR5 detect rate at or below the tested-pool lower third (≤ 0.0%) . Population served ranks #1,058 of 3,254 · #32 of 102 in Illinois.

Flagged-rate neighbourhood around Marion County

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

0% 20% 40% 60% 80% 100% Sangamon · lowest Knox · near Fulton · near Pulaski · highest 58.8% 88.9% 88.9% 88.9% 88.9% 88.9% 100%

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

Water Systems

System Name Population Violations PFAS
Centralia 12,182 23 Clean
Salem 7,905 30 Clean
Raccoon Water Company 7,080 41 Clean
North East Marion County Water Cmpny 3,220 26 Clean
Fmc Water Company 2,945 22 -
Odin 2,543 21 -
Sandoval 1,528 37 -
Walnut Hill 1,180 8 -
Wamac 1,030 24 -
Kinmundy 940 137 Clean
Patoka 603 217 -
Junction City 494 24 -
Iuka 486 18 -
Alma 336 146 -
W G Murray Development Center 290 33 -
Wal Mart Supercenter Salem 25 0 -
Icehouse Salem 25 3 -
Twice the Ice Herrin 25 0 -

Compare beyond Illinois

Lower-flagged peers for Marion County

Cross-state counties nearest Marion County on flagged-system share (88.9%) and cumulative violation count (810). 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
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.