Public water system · OK3003404
ActiveCornish
At a glance
Cornish (PWSID OK3003404) is an active community water system in Jefferson County, Oklahoma. It reports serving 41 people through 59 service connections. Its primary water source is purchased groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
41
Service connections
59
Primary source
GWP
Purchased groundwater
System type
CWS
Community water system
System record
How does Cornish compare with other water systems in Jefferson County?
By EPA's size categories, Cornish is a very small system (500 people or fewer). Jefferson County has 6 active public water systems, and Cornish is the 6th-largest of them by population served. Its population served is well below the county average of 2,154 people per system, and accounts for 0.3% of the 12,925 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 Cornish is well below 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. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own. 67 Oklahoma systems (5.3%) list purchased groundwater as their primary source.
Who owns and regulates Cornish?
EPA lists Cornish 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. 6 of the 6 active systems in Jefferson County (100%) are also owned by a local government.
Does Cornish have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025. The violations listed here began between October 2014 and July 2025. By type: 7 monitoring and reporting, 2 monitoring, 1 public notice, recordkeeping or other, 1 required treatment not met and 1 reporting. The contaminant or rule involved most often is Lead and Copper Rule (3 of them). EPA lists 11 as resolved and 1 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Unaddressed |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Resolved |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Resolved |
| 2017-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2017-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2017-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2017-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2017-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2016-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2015-07-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2014-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2014-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
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.
Cornish: frequently asked questions
Who runs Cornish?
Cornish (PWSID OK3003404) is a community water system owned by a local government. It is regulated by the OK state drinking water program.
How many people does Cornish serve?
Cornish reports serving 41 people through 59 service connections in Jefferson County, Oklahoma.
Where does Cornish get its water?
EPA SDWIS lists this system's primary water source as purchased groundwater. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own.
Does Cornish have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025. 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 Cornish'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, one is health-based, and the most recent began in July 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the OK state drinking water program.
Where can I find Cornish's water quality report?
As a community water system, Cornish 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 Jefferson County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Jefferson Co Cons Rwd #1 | Jefferson | 8,398 | Community | Purchased surface water |
| Waurika Public Works Authority | Jefferson | 2,100 | Community | Surface water |
| Ringling | Jefferson | 1,200 | Community | Groundwater |
| Ryan Utilities Authority | Jefferson | 800 | Community | Purchased surface water |
| Terral | Jefferson | 386 | 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, “Cornish, PWSID OK3003404, Oklahoma”, https://aquacensus.com/water-systems/oklahoma/cornish-ok3003404 (data as of October 1, 2026).