PlainWater
Counties → Missouri

Johnson County, Missouri

Water Systems
16
Population Served
58,397
Total Violations
514
163 health-based
PFAS Detected
5
of 5 tested

Violation Analysis

93.8%
Systems with Violations
32.1
Avg Violations per System
31.7%
Health-Based Violations

Water Source Types

GW
14 systems (88%)
SW
2 systems (13%)

PFAS Contamination

5
Systems Tested
5
PFAS Detected
100.0%
Detection Rate

PFAS (per- and polyfluoroalkyl substances) are persistent chemicals found in drinking water. The EPA has set enforceable limits for several PFAS compounds under UCMR5 monitoring.

Compliance Snapshot

Johnson Missouri water systems by violation status, EPA SDWIS records.

No violations on record (1) One or more violations (15)

Violation history is cumulative, many flagged systems have already returned to compliance. Detail pages show per-system context.

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 -

Other Counties in Missouri

St. Louis County
23 systems · 1,145,619 served · 1,825 violations
Cass County
31 systems · 625,744 served · 1,771 violations
Jackson County
23 systems · 405,266 served · 559 violations
St. Charles County
54 systems · 310,776 served · 2,706 violations
St. Louis city County
1 systems · 304,709 served · 27 violations
Greene County
82 systems · 265,439 served · 7,132 violations

Drinking Water Guides

Frequently Asked Questions

How many water violations are in Johnson County? ▼
Johnson County has 514 total drinking water violations across 16 water systems, of which 163 are health-based violations. 93.8% of systems have at least one violation.
How many people get water from Johnson County systems? ▼
Water systems in Johnson County serve approximately 58,397 people through 16 public water systems.
Has PFAS been detected in Johnson County water? ▼
Of 5 water systems tested for PFAS in Johnson County, 5 had PFAS detected (100.0% detection rate).
What types of water sources supply Johnson County? ▼
Water systems in Johnson County use GW (14 systems), SW (2 systems) as their primary water sources.
Are health-based violations serious? ▼
Health-based violations indicate that drinking water exceeded Maximum Contaminant Levels (MCLs) set by the EPA or failed treatment technique requirements. 31.7% of Johnson County's violations are health-based. Not all violations indicate immediate health risk, but they require corrective action.
Data Sources & Methodology

Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.

Violations are categorized as health-based (Maximum Contaminant Level exceedances, treatment technique failures) or monitoring/reporting violations. Not all violations indicate an immediate health risk.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

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.