Public water system · OK1010820
ActiveMadill
At a glance
Madill (PWSID OK1010820) is an active community water system in Marshall County, Oklahoma. It reports serving 3,410 people through 1,713 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
3,410
Service connections
1,713
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Madill compare with other water systems in Marshall County?
By EPA's size categories, Madill is a medium system (3,301 to 10,000 people). Marshall County has 6 active public water systems, and Madill is the largest of them by population served. Its population served is about 167% above the county average of 1,279 people per system, and accounts for 44% of the 7,672 people reported by systems filed under the county. Across Oklahoma, the 1,254 active systems average 2,907 people each. Nationally, the average active community water system reports serving 6,703 people, so Madill is about half of that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Oklahoma has 864 active community water systems, 69% of the state's 1,254 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 175 Oklahoma systems (14%) list surface water as their primary source.
Who owns and regulates Madill?
EPA lists Madill as owned by a local government. The OK state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 4 of the 6 active systems in Marshall County (67%) are also owned by a local government.
Does Madill have drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in January 2026. The violations listed here began between April 2025 and January 2026. By type: 8 contaminant level above the legal limit, 3 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is Haloacetic acids (HAA5) (5 of them). EPA lists 10 as archived and 2 as resolved. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Archived |
| 2025-12-30 | Monitoring and reportingFailure Submit IDSE/Subpart V Plan Rpt · code 35 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2025-12-30 | Monitoring and reportingFailure Submit IDSE/Subpart V Plan Rpt · code 35 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2025-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Archived |
| 2025-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Archived |
| 2025-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Archived |
| 2025-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Archived |
| 2025-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Archived |
| 2025-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Archived |
| 2025-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Archived |
| 2025-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Archived |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Madill: frequently asked questions
Who runs Madill?
Madill (PWSID OK1010820) is a community water system owned by a local government. It is regulated by the OK state drinking water program.
How many people does Madill serve?
Madill reports serving 3,410 people through 1,713 service connections in Marshall County, Oklahoma.
Where does Madill get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Madill have any drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in January 2026. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Madill's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in January 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the OK state drinking water program.
Where can I find Madill's water quality report?
As a community water system, Madill must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Marshall County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Kingston Pwa | Marshall | 1,600 | Community | Groundwater |
| Oakland Pwa | Marshall | 1,050 | Community | Purchased surface water |
| Oakview Water Corp | Marshall | 925 | Community | Groundwater |
| Cardinal Hill Subdivision | Marshall | 475 | Community | Groundwater |
| Texoma Hills | Marshall | 212 | Community | Purchased surface water |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Madill, PWSID OK1010820, Oklahoma”, https://aquacensus.com/water-systems/oklahoma/madill-ok1010820 (data as of October 1, 2026).