PlainWater

Marshall County, Illinois

SDWIS compliance plate

Sheet IL123 · Marshall County 25 sys · 1,633 viol · #2316/3254

VIOL-SEVERE · HEALTH-MID · RANK-LOWER · PHOTO-FINISH · PFAS-NONE · SRC-GW · SYS-SMALL · BOOK-MOST

  • VIOL-SEVERE 84.0% flagged
  • HEALTH-MID 35.5% health
  • RANK-LOWER #2316/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-NONE No UCMR5 set
  • SRC-GW GW lead 100%
  • SYS-SMALL 25 systems
  • BOOK-MOST 6/7 fields

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

According to EPA SDWIS county population served used on /counties, Marshall County ranks #2,316 of 3,254 counties by people served, and #83 of 102 counties in Illinois. See methodology · corpus placement.

Marshall County standing, lower-flagged corpus third

Flagged-system rate 84.0% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 35.5% is health-based share above the upper third (> 24.5%) . No UCMR5 tests in this extract for Marshall County . Population served ranks #2,316 of 3,254 · #83 of 102 in Illinois.

Flagged-rate neighbourhood around Marshall County

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

0% 20% 40% 60% 80% 100% Sangamon · lowest Macon · near DeKalb · near Pulaski · highest 58.8% 84% 84% 84% 84.2% 84.4% 100%

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

Water Systems

Compare beyond Illinois

Lower-flagged peers for Marshall County

Cross-state counties nearest Marshall County on flagged-system share (84.0%) and cumulative violation count (1,633). 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.