County profile · EPA SDWIS + UCMR5
Johnson County, Illinois
7 SDWIS-listed public water systems serve 8,047 people in Johnson County. Violation rates use that full inventory; PFAS rates use only the UCMR5-tested subset.
- 7
- SDWIS water systems Smaller third of counties
- 587
- Total violations Lower third of counties
- 100.0%
- SDWIS systems w/ a violation Middle third of counties
- -
- UCMR5 PFAS (none tested) No UCMR5 tests
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.
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.
Similar violation load
Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).
Read our methodology · Check your water system - how this data is sourced, computed, and verified.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.