Public water system · OK2005501
ActiveNichols Hills
At a glance
Nichols Hills (PWSID OK2005501) is an active community water system in Oklahoma County, Oklahoma. It reports serving 4,020 people through 1,924 service connections. Its primary water source is 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 January 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,020
Service connections
1,924
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Nichols Hills compare with other water systems in Oklahoma County?
By EPA's size categories, Nichols Hills is a medium system (3,301 to 10,000 people). Oklahoma County has 113 active public water systems. Its population served is about half of the county average of 7,828 people per system, and accounts for 0.5% of the 884,508 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 Nichols Hills is about 40% 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 701 Oklahoma systems (56%) list groundwater as their primary source.
Who owns and regulates Nichols Hills?
EPA lists Nichols Hills 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. 19 of the 113 active systems in Oklahoma County (17%) are also owned by a local government.
Does Nichols Hills have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in January 2025. The violations listed here began between January 2024 and January 2025. By type: 10 monitoring and reporting, 1 required treatment not met and 1 reporting. The contaminant or rule involved most often is Lead and Copper Rule Revisions (2 of them). EPA lists 10 as resolved and 2 as archived. 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. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2025-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 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 |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Lindane (gamma-BHC)code 2010 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toxaphenecode 2020 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dalaponcode 2031 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 2,4-Dcode 2105 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzo(a)pyrenecode 2306 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Hexachlorobenzenecode 2274 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Endrincode 2005 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Heptachlorcode 2065 | 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.
Nichols Hills: frequently asked questions
Who runs Nichols Hills?
Nichols Hills (PWSID OK2005501) is a community water system owned by a local government. It is regulated by the OK state drinking water program.
How many people does Nichols Hills serve?
Nichols Hills reports serving 4,020 people through 1,924 service connections in Oklahoma County, Oklahoma.
Where does Nichols Hills get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Nichols Hills 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 January 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 Nichols Hills' 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 January 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 Nichols Hills' water quality report?
As a community water system, Nichols Hills 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 Oklahoma County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Oklahoma City | Oklahoma | 644,000 | Community | Surface water |
| Edmond Pwa | Oklahoma | 79,408 | Community | Surface water |
| Midwest City | Oklahoma | 55,935 | Community | Surface water |
| Tinker Air Force Base | Oklahoma | 24,645 | Community | Groundwater |
| Del City | Oklahoma | 22,128 | Community | Surface water |
| Bethany | Oklahoma | 20,307 | Community | Groundwater under influence of surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Nichols Hills, PWSID OK2005501, Oklahoma”, https://aquacensus.com/water-systems/oklahoma/nichols-hills-ok2005501 (data as of October 1, 2026).