PlainWater
States → Missouri

Community Water System · PWS MO1010546

Mosby PWS

Mosby, Missouri 64024-0000 - drinking water served from surface water sources to 115 people, tracked in EPA SDWIS and UCMR5.

115
People served
185
EPA violations
121
Health-based
Untested
UCMR5 result

The verdict

EPA records 185 drinking-water violations at Mosby PWS, 65% of them health-based - above the Missouri per-system average.

185
Total EPA violations on record
65%
Health-based (MCL / treatment failure)
115
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Mosby PWS

Mosby PWS is a local-owned community water system that delivers drinking water to 115 residents in Mosby, Missouri (Clay County) through 48 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 185 total violations for this system , of which 121 (65%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 38 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is TTHM, recorded in 116 violations (MCL, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Missouri, EPA tracks 2,823 public water systems serving 5,855,885 people, with 201,695 cumulative violations and 54,821 health-based violations on record. About 95% of systems in the state carry at least one violation, and state-wide the average per system is 71.4 violations. Statewide, 162 of 230 UCMR5-tested systems have reported PFAS detections (70.4%).

Mosby PWS's 185 violations sit above the Missouri average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
115
Total Violations
185
Health-Based Violations
121
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
48
County
Clay
School/Daycare
No
MCL Violations
119
Monitoring Violations
38
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
TTHM MCL 116 2025
Coliform (TCR) MR 23 2009
Consumer Confidence Rule Other 9 2023
TTHM MR 5 2020
Revised Total Coliform Rule MON 5 2025
Total Haloacetic Acids (HAA5) MR 5 2020
Public Notice Other 4 2025
Coliform (TCR) MCL 3 1993
Groundwater Rule TT 2 2010

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Mosby PWS.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID MO1010546 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Missouri Drinking Water Authority

Missouri DNR, Public Drinking Water Branch is the primacy agency that licenses and inspects Mosby PWS under EPA-delegated authority.

Open MO regulator portal

Source: Missouri DNR, Public Drinking Water Branch

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2025 TTHM MCL 116 SDWIS / MO1010546 / 2950
2025 Revised Total Coliform Rule MON 5 SDWIS / MO1010546 / 8000
2025 Public Notice Other 4 SDWIS / MO1010546 / 7500
2023 Consumer Confidence Rule Other 9 SDWIS / MO1010546 / 7000
2020 TTHM MR 5 SDWIS / MO1010546 / 2950
2020 Total Haloacetic Acids (HAA5) MR 5 SDWIS / MO1010546 / 2456
2010 Groundwater Rule TT 2 SDWIS / MO1010546 / 0700
2009 Coliform (TCR) MR 23 SDWIS / MO1010546 / 3100
1993 Coliform (TCR) MCL 3 SDWIS / MO1010546 / 3100

How Mosby PWS Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Mosby PWS Missouri avg Federal benchmark
Total violations 185 71.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 121 19.4 Indicates a contaminant exceeded a federal MCL
PFAS detection None 70.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 115 2,074 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,823 regulated public water systems in Missouri.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Mosby PWS water safe to drink? ▼
Mosby PWS (PWS ID: MO1010546) has 185 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 115 people using Surface Water sources.
How many people does Mosby PWS serve? ▼
Mosby PWS serves 115 people in Mosby, Missouri. It is a Local-owned system using Surface Water water sources with 48 service connections.
What type of violations does Mosby PWS have? ▼
Mosby PWS has 185 total violations: 121 health-based violations (MCL exceedances or treatment failures), 38 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Mosby PWS water? ▼
No PFAS testing data is available for Mosby PWS under the EPA's UCMR5 monitoring program.
What water source does Mosby PWS use? ▼
Mosby PWS uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

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 system's figures are rendered directly from 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.