States → Missouri
State profile · EPA SDWIS + UCMR5
Missouri Drinking Water Quality
2,823 public water systems serve 5,855,885 people across Missouri, with every Safe Drinking Water Act violation and UCMR5 PFAS result on record.
- 2,823
- Water systems
- 201,695
- Total violations
- 95.4%
- Systems w/ a violation
- 70.4%
- PFAS detection rate
The verdict
Across Missouri, 2,692 of 2,823 water systems (95.4%) carry at least one EPA violation, and 162 of 230 UCMR5-tested systems show PFAS.
- 201,695
- Total EPA violations on record
- 27%
- Health-based (MCL / treatment)
- 95.4%
- Systems with ≥1 violation
- 70.4%
- UCMR5 PFAS detection rate
Water Systems
2,823
Total Violations
201,695
Violation Rate
95.4%
PFAS Detection
70.4%
162 of 230 tested
Violation Composition
How Missouri's 201,695 violations break down by type, per EPA SDWIS classification.
Health-based (54,821) Monitoring/Reporting (146,874)
| Metric | Value | Share |
|---|---|---|
| Public water systems | 2,823 | - |
| Population served | 5,855,885 | - |
| Total violations | 201,695 | 100% |
| Health-based violations | 54,821 | 27.2% |
| Systems with violations | 2,692 | 95.4% |
| PFAS detection rate | 162 of 230 | 70.4% |
Health-based violations indicate the contaminant exceeded an EPA Maximum Contaminant Level (MCL) or treatment-technique requirement. Monitoring/reporting violations indicate procedural issues (missed tests, late reports) - not necessarily a contamination event.
Largest Water Systems
MO American St Louis St Charles Counties
Chesterfield, MO · 1,111,000 served
Kansas City PWS
Kansas City, MO · 513,800 served
St Louis City PWS
St Louis, MO · 304,709 served
Springfield PWS
Springfield, MO · 210,898 served
City of Columbia Utilities
Columbia, MO · 126,254 served
Independence PWS
Independence, MO · 120,000 served
St Charles County PWSD 2
O Fallon, MO · 100,587 served
Lees Summit PWS
Lees Summit, MO · 99,400 served
MO American St Joseph
St Joseph, MO · 89,171 served
MO American Joplin
Joplin, MO · 73,728 served
St Charles PWS
St Charles, MO · 73,040 served
Blue Springs PWS
Blue Springs, MO · 61,084 served
St Peters PWS
St Peters, MO · 52,575 served
Wentzville PWS
Wentzville, MO · 41,784 served
University of Missouri Columbia
Columbia, MO · 40,000 served
Cape Girardeau PWS
Cape Girardeau, MO · 39,941 served
Jefferson Co Cons PWSD C 1
Barnhart, MO · 37,000 served
Fort Leonard Wood
Fort Leonard Wood, MO · 34,000 served
Ofallon PWS
O Fallon, MO · 32,515 served
Liberty PWS
Liberty, MO · 30,800 served
Most Violations
#1 The Missing Well Des Peres
1,555 #2 Starlight Village Branson West
1,468 #3 Hidden Valley MHP LLC Warsaw
1,400 #4 Clear Creek RV Park Centertown
1,209 #5 Stately Mansion Mobile Villa Rolla
860 #6 Starrlite Village 4th Addition Reeds Spring
846 #7 Lanagan PWS Lanagan
795 #8 Valle Acres MHP Festus
794 #9 Town of Charmwood Stanton
759 #10 Airport Village MHP Stockton
710 #11 J&m MHP Capital LLC Otterville
697 #12 Crestview MHP Sedalia
683 #13 Sunset MHP Neosho
681 #14 Wellsville PWS Wellsville
651 #15 Little Guys Baseball Club Brookline
637 Counties in Missouri
St. Louis
23 systems · 1,145,619 served
· 1,825 violations
Cass
31 systems · 625,744 served
· 1,771 violations
Jackson
23 systems · 405,266 served
· 559 violations
St. Charles
54 systems · 310,776 served
· 2,706 violations
St. Louis city
1 systems · 304,709 served
· 27 violations
Greene
82 systems · 265,439 served
· 7,132 violations
Boone
13 systems · 228,201 served
· 462 violations
Jefferson
99 systems · 186,057 served
· 6,751 violations
Jasper
40 systems · 141,002 served
· 2,855 violations
Clay
21 systems · 125,248 served
· 851 violations
Andrew
10 systems · 106,510 served
· 578 violations
Taney
117 systems · 75,214 served
· 8,871 violations
Cole
17 systems · 73,799 served
· 1,128 violations
Cape Girardeau
30 systems · 73,133 served
· 2,275 violations
Franklin
84 systems · 71,212 served
· 5,402 violations
Pulaski
24 systems · 64,569 served
· 1,348 violations
Christian
41 systems · 60,446 served
· 3,048 violations
Camden
235 systems · 58,552 served
· 13,676 violations
Johnson
16 systems · 58,397 served
· 514 violations
St. Francois
43 systems · 55,207 served
· 5,269 violations
Platte
20 systems · 54,031 served
· 659 violations
Stone
242 systems · 47,185 served
· 18,773 violations
Lincoln
47 systems · 42,497 served
· 2,765 violations
Callaway
15 systems · 40,194 served
· 568 violations
Lafayette
15 systems · 36,005 served
· 864 violations
Dunklin
13 systems · 35,654 served
· 1,384 violations
Butler
14 systems · 35,253 served
· 1,027 violations
Scott
18 systems · 34,223 served
· 1,233 violations
Laclede
15 systems · 32,039 served
· 1,231 violations
Phelps
29 systems · 30,350 served
· 2,509 violations
Showing top 30 of 115 counties.
Drinking Water Guides
Frequently Asked Questions
How many water systems are in Missouri? ▼
Missouri has 2,823 public water systems serving approximately 5,855,885 people. These include community water systems, non-transient non-community systems, and transient non-community systems regulated under the Safe Drinking Water Act.
How many drinking water violations are in Missouri? ▼
Missouri has 201,695 total drinking water violations on record, with 54,821 classified as health-based violations. 95.4% of water systems in the state have at least one violation.
Has PFAS been found in Missouri drinking water? ▼
Of 230 water systems tested for PFAS in Missouri, 162 had PFAS detected, a 70.4% detection rate. PFAS are persistent "forever chemicals" that do not break down in the environment.
What is the violation rate for Missouri water systems? ▼
Missouri's violation rate is 95.4%. This measures the percentage of public water systems that have at least one recorded violation in the EPA SDWIS database, including both health-based and monitoring/reporting violations.
Where does this Missouri water data come from? ▼
All drinking water data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS is the federal database that tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
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.
Read our methodology - how this data is sourced, computed, and verified.
Related
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.