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Community Water System · PWS MO1024118

Cass County PWSD 9

Harrisonville, Missouri 64701-0000 - drinking water served from groundwater sources to 6,063 people, tracked in EPA SDWIS and UCMR5.

6,063
People served
11
EPA violations
4
Health-based
No PFAS
UCMR5 result

The verdict

EPA records 11 drinking-water violations at Cass County PWSD 9, 36% of them health-based - below the Missouri per-system average.

11
Total EPA violations on record
36%
Health-based (MCL / treatment failure)
6,063
People served by this system
0
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Cass County PWSD 9

Cass County PWSD 9 is a local-owned community water system that delivers drinking water to 6,063 residents in Harrisonville, Missouri (Cass County) through 2,438 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 11 total violations for this system , of which 4 (36%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 2 monitoring and reporting violations are on file. The most recent violation on record dates to 2010.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 4 violations (MCL, health-based). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

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%).

Cass County PWSD 9's 11 violations sit below 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
6,063
Total Violations
11
Health-Based Violations
4
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
2,438
County
Cass
School/Daycare
No
MCL Violations
4
Monitoring Violations
2
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 4 2010
Coliform (TCR) MR 2 1991

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 58 samples detected PFAS.

Contaminant Date Result MRL Status
9Cl-PF3ONS 4/10/2024 <2.00 ppt 2.00 ppt Not Detected
PFBA 4/10/2024 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 4/10/2024 <5.00 ppt 5.00 ppt Not Detected
PFBS 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFHpS 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFPeS 4/10/2024 <4.00 ppt 4.00 ppt Not Detected
NFDHA 4/10/2024 <20.00 ppt 20.00 ppt Not Detected
PFEESA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFMBA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFPeA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFMPA 4/10/2024 <4.00 ppt 4.00 ppt Not Detected
8:2 FTS 4/10/2024 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 4/10/2024 <5.00 ppt 5.00 ppt Not Detected
ADONA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFNA 4/10/2024 <4.00 ppt 4.00 ppt Not Detected
11Cl-PF3OUdS 4/10/2024 <5.00 ppt 5.00 ppt Not Detected
PFUnA 4/10/2024 <2.00 ppt 2.00 ppt Not Detected
PFHxA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFDoA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFDA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFOA 4/10/2024 <4.00 ppt 4.00 ppt Not Detected
PFOS 4/10/2024 <4.00 ppt 4.00 ppt Not Detected
PFHxS 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFHpA 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 4/10/2024 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 4/10/2024 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 4/10/2024 <7.00 ppt 7.00 ppt Not Detected
4:2 FTS 4/10/2024 <3.00 ppt 3.00 ppt Not Detected
PFTA 4/10/2024 <8.00 ppt 8.00 ppt Not Detected
PFMBA 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
PFBA 10/22/2024 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 10/22/2024 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 10/22/2024 <5.00 ppt 5.00 ppt Not Detected
PFPeA 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 10/22/2024 <2.00 ppt 2.00 ppt Not Detected
PFEESA 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
NFDHA 10/22/2024 <20.00 ppt 20.00 ppt Not Detected
PFPeS 10/22/2024 <4.00 ppt 4.00 ppt Not Detected
PFHpS 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
PFTA 10/22/2024 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 10/22/2024 <7.00 ppt 7.00 ppt Not Detected
PFMPA 10/22/2024 <4.00 ppt 4.00 ppt Not Detected
ADONA 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
NEtFOSAA 10/22/2024 <5.00 ppt 5.00 ppt Not Detected
11Cl-PF3OUdS 10/22/2024 <5.00 ppt 5.00 ppt Not Detected
PFUnA 10/22/2024 <2.00 ppt 2.00 ppt Not Detected
PFHxA 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
PFDoA 10/22/2024 <3.00 ppt 3.00 ppt Not Detected
PFDA 10/22/2024 <3.00 ppt 3.00 ppt Not Detected

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 Cass County PWSD 9.

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 MO1024118 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 Cass County PWSD 9 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
2010 Coliform (TCR) MCL 4 SDWIS / MO1024118 / 3100
1991 Coliform (TCR) MR 2 SDWIS / MO1024118 / 3100

How Cass County PWSD 9 Compares

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

Metric Cass County PWSD 9 Missouri avg Federal benchmark
Total violations 11 71.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 4 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 6,063 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 Cass County PWSD 9 water safe to drink?
Cass County PWSD 9 (PWS ID: MO1024118) has 11 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 6,063 people using Groundwater sources.
How many people does Cass County PWSD 9 serve?
Cass County PWSD 9 serves 6,063 people in Harrisonville, Missouri. It is a Local-owned system using Groundwater water sources with 2,438 service connections.
What type of violations does Cass County PWSD 9 have?
Cass County PWSD 9 has 11 total violations: 4 health-based violations (MCL exceedances or treatment failures), 2 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Cass County PWSD 9 water?
No. Cass County PWSD 9 was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does Cass County PWSD 9 use?
Cass County PWSD 9 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. PFAS data from EPA UCMR5 monitoring program (2023-2025). 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.