PlainWater

Johnson County, Missouri

SDWIS compliance plate

Sheet MO101 · Johnson County 16 sys · 514 viol · #860/3254

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

  • VIOL-SEVERE 93.8% flagged
  • HEALTH-MID 31.7% health
  • RANK-UPPER #860/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-CLEAN 0.0% detect
  • SRC-GW GW lead 88%
  • SYS-SMALL 16 systems
  • BOOK-FULL 7/7 fields

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

According to EPA SDWIS county population served used on /counties, Johnson County ranks #860 of 3,254 counties by people served, and #19 of 115 counties in Missouri. See methodology · corpus placement.

Johnson County standing, mid-flagged corpus third

Flagged-system rate 93.8% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 31.7% 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 #860 of 3,254 · #19 of 115 in Missouri.

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% Shannon · lowest Bates · near Johnson · this county Mercer · highest 69.6% 93.3% 93.3% 93.3% 93.8% 93.8% 100%

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

Water Systems

System Name Population Violations PFAS
MO American Warrensburg 18,500 10 Clean
Johnson County PWSD 2 12,490 27 Clean
Whiteman Air Base 10,106 25 Clean
Johnson County PWSD 3 4,700 15 Clean
Johnson County PWSD 1 3,730 7 Clean
Knob Noster PWS 2,863 37 -
Holden PWS 2,683 44 -
Pettis/Johnson/Saline PWSD 1 1,000 116 -
Leeton PWS 601 29 -
Chilhowee PWS 382 32 -
Kingsville PWS 345 37 -
MO American East Warrensburg 335 0 -
Centerview PWS 272 26 -
Knob Noster State Park Shawnee 160 9 -
Country Acres Subd 130 42 -
Confluence Rivers M & M MHP WTP 100 58 -

Compare beyond Missouri

Mid-flagged peers for Johnson County

Cross-state counties nearest Johnson County on flagged-system share (93.8%) and cumulative violation count (514). 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.