PlainWater

Johnson County, Illinois

SDWIS compliance plate

Sheet IL087 · Johnson County 7 sys · 587 viol · #2518/3254

VIOL-SEVERE · HEALTH-LOW · RANK-LOWER · PHOTO-FINISH · PFAS-NONE · SRC-SW · SYS-TINY · BOOK-MOST

  • VIOL-SEVERE 100.0% flagged
  • HEALTH-LOW 13.8% health
  • RANK-LOWER #2518/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-NONE No UCMR5 set
  • SRC-SW SW lead 71%
  • SYS-TINY 7 systems
  • BOOK-MOST 6/7 fields

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

According to EPA SDWIS county population served used on /counties, Johnson County ranks #2,518 of 3,254 counties by people served, and #89 of 102 counties in Illinois. See methodology · corpus placement.

Johnson 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 13.8% is health-based share in the middle third (≤ 24.5%) . No UCMR5 tests in this extract for Johnson County . Population served ranks #2,518 of 3,254 · #89 of 102 in Illinois.

Flagged-rate neighbourhood around Johnson County

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

0% 20% 40% 60% 80% 100% Sangamon · lowest Pulaski · highest Bond · near Massac · near 58.8% 100% 100% 100% 100% 100% 100%

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

Water Systems

System Name Population Violations PFAS
Burnside Pwd 2,702 30 -
Vienna 1,618 458 -
Shawnee Correctional Center 1,617 19 -
Goreville 1,068 32 -
Belknap 516 14 -
Vienna Correctional Center 501 29 -
Twice the Ice Vienna 25 5 -

Compare beyond Illinois

Mid-flagged peers for Johnson County

Cross-state counties nearest Johnson County on flagged-system share (100.0%) and cumulative violation count (587). 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.