Community Water System · PWS OK3004009
Leflore Co. RWD #18
Wister, Oklahoma 74966 - drinking water served from surface water sources to 3,870 people, tracked in EPA SDWIS and UCMR5.
- 3,870
- People served
- 111
- EPA violations
- 51
- Health-based
- No PFAS
- UCMR5 result
The verdict
EPA records 111 drinking-water violations at Leflore Co. RWD #18, 46% of them health-based - below the Oklahoma per-system average.
- 111
- Total EPA violations on record
- 46%
- Health-based (MCL / treatment failure)
- 3,870
- People served by this system
- 0
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Leflore Co. RWD #18
Leflore Co. RWD #18 is a local-owned community water system that delivers drinking water to 3,870 residents in Wister, Oklahoma (Le Flore County) through 1,548 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 111 total violations for this system , of which 51 (46%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 48 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 37 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 Oklahoma, EPA tracks 1,262 public water systems serving 3,699,452 people, with 336,706 cumulative violations and 113,804 health-based violations on record. About 98% of systems in the state carry at least one violation, and state-wide the average per system is 266.8 violations. Statewide, 101 of 166 UCMR5-tested systems have reported PFAS detections (60.8%).
Leflore Co. RWD #18's 111 violations sit below the Oklahoma average.
All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 1,548
- County
- Le Flore
- School/Daycare
- No
- MCL Violations
- 50
- Monitoring Violations
- 48
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| TTHM | MCL | 37 | 2023 |
| Total Haloacetic Acids (HAA5) | MR | 16 | 2018 |
| TTHM | MR | 16 | 2018 |
| Total Haloacetic Acids (HAA5) | MCL | 13 | 2025 |
| Coliform (TCR) | MR | 11 | 2003 |
| Chlorine | MR | 5 | 2015 |
| LEAD AND COPPER RULE REVISIONS | RPT | 1 | 2024 |
| LEAD AND COPPER RULE REVISIONS | TT | 1 | 2024 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 149 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| NMeFOSAA | 7/30/2025 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 7/30/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 7/30/2025 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFTA | 7/30/2025 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFPeA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBA | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 7/15/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFHpS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 7/15/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDoA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 7/15/2025 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFEESA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 7/15/2025 | <20.00 ppt | 20.00 ppt | Not Detected |
| 6:2 FTS | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHpS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| ADONA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBA | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 7/15/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 7/15/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 7/15/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 7/15/2025 | <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 Leflore Co. RWD #18.
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 OK3004009 on SDWISSource: EPA SDWIS Federal Reports Search
Oklahoma Drinking Water Authority
Oklahoma's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.
Find OK regulator via EPA SDWISViolation 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 | Total Haloacetic Acids (HAA5) | MCL | 13 | SDWIS / OK3004009 / 2456 |
| 2024 | LEAD AND COPPER RULE REVISIONS | RPT | 1 | SDWIS / OK3004009 / 5200 |
| 2024 | LEAD AND COPPER RULE REVISIONS | TT | 1 | SDWIS / OK3004009 / 5200 |
| 2023 | TTHM | MCL | 37 | SDWIS / OK3004009 / 2950 |
| 2018 | Total Haloacetic Acids (HAA5) | MR | 16 | SDWIS / OK3004009 / 2456 |
| 2018 | TTHM | MR | 16 | SDWIS / OK3004009 / 2950 |
| 2015 | Chlorine | MR | 5 | SDWIS / OK3004009 / 0999 |
| 2003 | Coliform (TCR) | MR | 11 | SDWIS / OK3004009 / 3100 |
How Leflore Co. RWD #18 Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Leflore Co. RWD #18 | Oklahoma avg | Federal benchmark |
|---|---|---|---|
| Total violations | 111 | 266.8 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 51 | 90.2 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | None | 60.8% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 3,870 | 2,931 | Sizing context for compliance burden |
Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,262 regulated public water systems in Oklahoma.
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 Leflore Co. RWD #18 water safe to drink? ▼
How many people does Leflore Co. RWD #18 serve? ▼
What type of violations does Leflore Co. RWD #18 have? ▼
Has PFAS been detected in Leflore Co. RWD #18 water? ▼
What water source does Leflore Co. RWD #18 use? ▼
Where does this data come from? ▼
Read our methodology - how this data is sourced, computed, and verified.
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.