Community Water System · PWS OK1221644
Seneca-Cayuga Nation
Grove, Oklahoma 74345-3220 - drinking water served from groundwater sources to 400 people, tracked in EPA SDWIS and UCMR5.
- 400
- People served
- 1,329
- EPA violations
- 5
- Health-based
- Untested
- UCMR5 result
The verdict
EPA records 1,329 drinking-water violations at Seneca-Cayuga Nation - above the Oklahoma per-system average.
- 1,329
- Total EPA violations on record
- 0%
- Health-based (MCL / treatment failure)
- 400
- People served by this system
- N/A
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Seneca-Cayuga Nation
Seneca-Cayuga Nation is a native american-owned community water system that delivers drinking water to 400 residents in Grove, Oklahoma (Delaware County) through 45 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 1,329 total violations for this system , of which 5 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 1,242 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 Revised Total Coliform Rule, recorded in 60 violations (MON). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.
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%).
Seneca-Cayuga Nation's 1,329 violations sit above 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
- Native American
- Connections
- 45
- County
- Delaware
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 1,242
- Treatment Tech Violations
- 5
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Revised Total Coliform Rule | MON | 60 | 2024 |
| Chlorine | MR | 54 | 2024 |
| Consumer Confidence Rule | Other | 39 | 2025 |
| o-Dichlorobenzene | MR | 34 | 2023 |
| p-Dichlorobenzene | MR | 34 | 2023 |
| Vinyl chloride | MR | 34 | 2023 |
| 1,1-Dichloroethylene | MR | 34 | 2023 |
| trans-1,2-Dichloroethylene | MR | 34 | 2023 |
| Carbon tetrachloride | MR | 34 | 2023 |
| 1,2-Dichloropropane | MR | 34 | 2023 |
| Tetrachloroethylene | MR | 34 | 2023 |
| CHLOROBENZENE | MR | 34 | 2023 |
| Benzene | MR | 34 | 2023 |
| Toluene | MR | 34 | 2023 |
| 1,2,4-Trichlorobenzene | MR | 34 | 2023 |
| Xylenes, Total | MR | 34 | 2023 |
| DICHLOROMETHANE | MR | 34 | 2023 |
| Trichloroethylene | MR | 34 | 2023 |
| 1,1,2-Trichloroethane | MR | 34 | 2023 |
| cis-1,2-Dichloroethylene | MR | 34 | 2023 |
| Styrene | MR | 34 | 2023 |
| Ethylbenzene | MR | 34 | 2023 |
| 1,1,1-Trichloroethane | MR | 34 | 2023 |
| Public Notice | Other | 28 | 2024 |
| Coliform (TCR) | MR | 27 | 2015 |
| 1,2-Dichloroethane | MR | 26 | 2023 |
| Lead and Copper Rule | MR | 25 | 2025 |
| Nitrate-Nitrite | MR | 17 | 2023 |
| TTHM | MR | 10 | 2020 |
| Total Haloacetic Acids (HAA5) | MR | 10 | 2020 |
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 Seneca-Cayuga Nation.
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 OK1221644 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 | Consumer Confidence Rule | Other | 39 | SDWIS / OK1221644 / 7000 |
| 2025 | Lead and Copper Rule | MR | 25 | SDWIS / OK1221644 / 5000 |
| 2025 | Dalapon | MR | 9 | SDWIS / OK1221644 / 2031 |
| 2025 | Endothall | MR | 9 | SDWIS / OK1221644 / 2033 |
| 2025 | Glyphosate | MR | 9 | SDWIS / OK1221644 / 2034 |
| 2025 | Simazine | MR | 9 | SDWIS / OK1221644 / 2037 |
| 2025 | Di(2-ethylhexyl) phthalate | MR | 9 | SDWIS / OK1221644 / 2039 |
| 2025 | Dinoseb | MR | 9 | SDWIS / OK1221644 / 2041 |
| 2025 | Heptachlor | MR | 9 | SDWIS / OK1221644 / 2065 |
| 2025 | 2,4-D | MR | 9 | SDWIS / OK1221644 / 2105 |
| 2025 | 2,4,5-TP | MR | 9 | SDWIS / OK1221644 / 2110 |
| 2025 | Pentachlorophenol | MR | 9 | SDWIS / OK1221644 / 2326 |
| 2025 | 1,2-DIBROMO-3-CHLOROPROPANE | MR | 9 | SDWIS / OK1221644 / 2931 |
| 2025 | ETHYLENE DIBROMIDE | MR | 9 | SDWIS / OK1221644 / 2946 |
| 2025 | Endrin | MR | 9 | SDWIS / OK1221644 / 2005 |
How Seneca-Cayuga Nation Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Seneca-Cayuga Nation | Oklahoma avg | Federal benchmark |
|---|---|---|---|
| Total violations | 1,329 | 266.8 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 5 | 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 | 400 | 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 Seneca-Cayuga Nation water safe to drink? ▼
How many people does Seneca-Cayuga Nation serve? ▼
What type of violations does Seneca-Cayuga Nation have? ▼
Has PFAS been detected in Seneca-Cayuga Nation water? ▼
What water source does Seneca-Cayuga Nation 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.