PlainWater

Community Water System · PWS MO5010829

Walnut Grove PWS

Walnut Grove, Missouri 65770-0000 - drinking water served from groundwater sources to 665 people, tracked in EPA SDWIS and UCMR5.

665
People served
197
EPA violations
24
Health-based
Untested
UCMR5 result

The verdict

EPA records 197 drinking-water violations at Walnut Grove PWS, 12% of them health-based - above the Missouri per-system average.

197
Total EPA violations on record
12%
Health-based (MCL / treatment failure)
665
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Walnut Grove PWS

Walnut Grove PWS is a local-owned community water system that delivers drinking water to 665 residents in Walnut Grove, Missouri (Greene County) through 309 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 197 total violations for this system , of which 24 (12%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 160 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 Coliform (TCR), recorded in 24 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%).

Walnut Grove PWS's 197 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
665
Total Violations
197
Health-Based Violations
24
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
309
County
Greene
School/Daycare
No
MCL Violations
24
Monitoring Violations
160
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 24 2011
Nitrate-Nitrite MR 8 2019
Lead and Copper Rule MR 6 2023
Coliform (TCR) MR 6 2015
Revised Total Coliform Rule RPT 5 2025
Radium-228 MR 4 2013
1,2,4-Trichlorobenzene MR 4 2017
cis-1,2-Dichloroethylene MR 4 2017
Xylenes, Total MR 4 2017
p-Dichlorobenzene MR 4 2017
Vinyl chloride MR 4 2017
1,1-Dichloroethylene MR 4 2017
trans-1,2-Dichloroethylene MR 4 2017
1,2-Dichloroethane MR 4 2017
1,1,1-Trichloroethane MR 4 2017
1,2-Dichloropropane MR 4 2017
Toluene MR 4 2017
Ethylbenzene MR 4 2017
Barium MR 4 2017
Cadmium MR 4 2017
Chromium MR 4 2017
CYANIDE MR 4 2017
Fluoride MR 4 2017
Beryllium, Total MR 4 2017
Thallium, Total MR 4 2017
Selenium MR 4 2017
Antimony, Total MR 4 2017
Radium-226 MR 4 2013
Carbon tetrachloride MR 4 2017
DICHLOROMETHANE MR 4 2017

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 Walnut Grove 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 MO5010829 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 Walnut Grove 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 Revised Total Coliform Rule RPT 5 SDWIS / MO5010829 / 8000
2024 Consumer Confidence Rule Other 3 SDWIS / MO5010829 / 7000
2024 LEAD AND COPPER RULE REVISIONS RPT 2 SDWIS / MO5010829 / 5200
2023 Lead and Copper Rule MR 6 SDWIS / MO5010829 / 5000
2019 Nitrate-Nitrite MR 8 SDWIS / MO5010829 / 1038
2019 Revised Total Coliform Rule MON 4 SDWIS / MO5010829 / 8000
2017 1,2,4-Trichlorobenzene MR 4 SDWIS / MO5010829 / 2378
2017 cis-1,2-Dichloroethylene MR 4 SDWIS / MO5010829 / 2380
2017 Xylenes, Total MR 4 SDWIS / MO5010829 / 2955
2017 p-Dichlorobenzene MR 4 SDWIS / MO5010829 / 2969
2017 Vinyl chloride MR 4 SDWIS / MO5010829 / 2976
2017 1,1-Dichloroethylene MR 4 SDWIS / MO5010829 / 2977
2017 trans-1,2-Dichloroethylene MR 4 SDWIS / MO5010829 / 2979
2017 1,2-Dichloroethane MR 4 SDWIS / MO5010829 / 2980
2017 1,1,1-Trichloroethane MR 4 SDWIS / MO5010829 / 2981

How Walnut Grove PWS Compares

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

Metric Walnut Grove PWS Missouri avg Federal benchmark
Total violations 197 71.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 24 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 665 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 Walnut Grove PWS water safe to drink?
Walnut Grove PWS (PWS ID: MO5010829) has 197 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 665 people using Groundwater sources.
How many people does Walnut Grove PWS serve?
Walnut Grove PWS serves 665 people in Walnut Grove, Missouri. It is a Local-owned system using Groundwater water sources with 309 service connections.
What type of violations does Walnut Grove PWS have?
Walnut Grove PWS has 197 total violations: 24 health-based violations (MCL exceedances or treatment failures), 160 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Walnut Grove PWS water?
No PFAS testing data is available for Walnut Grove PWS under the EPA's UCMR5 monitoring program.
What water source does Walnut Grove PWS use?
Walnut Grove PWS uses Groundwater 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.
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.