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Community Water System · PWS OK2003518

Wapanucka

Wapanucka, Oklahoma 73461 - drinking water served from groundwater sources to 420 people, tracked in EPA SDWIS and UCMR5.

420
People served
228
EPA violations
14
Health-based
Untested
UCMR5 result

The verdict

EPA records 228 drinking-water violations at Wapanucka, 6% of them health-based - below the Oklahoma per-system average.

228
Total EPA violations on record
6%
Health-based (MCL / treatment failure)
420
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Wapanucka

Wapanucka is a local-owned community water system that delivers drinking water to 420 residents in Wapanucka, Oklahoma (Johnston County) through 207 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 228 total violations for this system , of which 14 (6%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 182 monitoring and reporting violations are on file. The most recent violation on record dates to 2021.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 35 violations (MR). 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%).

Wapanucka's 228 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.

Population Served
420
Total Violations
228
Health-Based Violations
14
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
207
County
Johnston
School/Daycare
No
MCL Violations
14
Monitoring Violations
182
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 35 2015
Arsenic MR 18 2005
Coliform (TCR) MCL 14 2007
Lead and Copper Rule MR 5 2010
Consumer Confidence Rule Other 4 2016
Endrin MR 4 2021
BHC-GAMMA MR 4 2021
Methoxychlor MR 4 2021
Dalapon MR 4 2021
Diquat MR 4 2021
Endothall MR 4 2021
Glyphosate MR 4 2021
OXAMYL MR 4 2021
Di(2-ethylhexyl) phthalate MR 4 2021
Hexachlorocyclopentadiene MR 4 2021
Carbofuran MR 4 2021
LASSO MR 4 2021
Heptachlor MR 4 2021
Heptachlor epoxide MR 4 2021
2,4,5-TP MR 4 2021
Pentachlorophenol MR 4 2021
ETHYLENE DIBROMIDE MR 4 2021
Chlordane MR 4 2021
HEXACHLOROBENZENE MR 4 2021
Toxaphene MR 4 2021
Total Polychlorinated Biphenyls (PCB) MR 4 2021
Di(2-ethylhexyl) adipate MR 4 2021
Picloram MR 4 2021
Atrazine MR 4 2021
1,2-DIBROMO-3-CHLOROPROPANE MR 4 2021

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 Wapanucka.

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 OK2003518 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

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 SDWIS

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
2021 Endrin MR 4 SDWIS / OK2003518 / 2005
2021 BHC-GAMMA MR 4 SDWIS / OK2003518 / 2010
2021 Methoxychlor MR 4 SDWIS / OK2003518 / 2015
2021 Dalapon MR 4 SDWIS / OK2003518 / 2031
2021 Diquat MR 4 SDWIS / OK2003518 / 2032
2021 Endothall MR 4 SDWIS / OK2003518 / 2033
2021 Glyphosate MR 4 SDWIS / OK2003518 / 2034
2021 OXAMYL MR 4 SDWIS / OK2003518 / 2036
2021 Di(2-ethylhexyl) phthalate MR 4 SDWIS / OK2003518 / 2039
2021 Hexachlorocyclopentadiene MR 4 SDWIS / OK2003518 / 2042
2021 Carbofuran MR 4 SDWIS / OK2003518 / 2046
2021 LASSO MR 4 SDWIS / OK2003518 / 2051
2021 Heptachlor MR 4 SDWIS / OK2003518 / 2065
2021 Heptachlor epoxide MR 4 SDWIS / OK2003518 / 2067
2021 2,4,5-TP MR 4 SDWIS / OK2003518 / 2110

How Wapanucka Compares

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

Metric Wapanucka Oklahoma avg Federal benchmark
Total violations 228 266.8 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 14 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 420 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 Wapanucka water safe to drink? ▼
Wapanucka (PWS ID: OK2003518) has 228 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 420 people using Groundwater sources.
How many people does Wapanucka serve? ▼
Wapanucka serves 420 people in Wapanucka, Oklahoma. It is a Local-owned system using Groundwater water sources with 207 service connections.
What type of violations does Wapanucka have? ▼
Wapanucka has 228 total violations: 14 health-based violations (MCL exceedances or treatment failures), 182 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Wapanucka water? ▼
No PFAS testing data is available for Wapanucka under the EPA's UCMR5 monitoring program.
What water source does Wapanucka use? ▼
Wapanucka 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.

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.