Public water system · AR0000550
ActiveEl Dorado Waterworks
At a glance
El Dorado Waterworks (PWSID AR0000550) is an active community water system in Union County, Arkansas. It reports serving 17,932 people through 8,333 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, 11 are health-based, and the most recent began in October 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
17,932
Service connections
8,333
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does El Dorado Waterworks compare with other water systems in Union County?
By EPA's size categories, El Dorado Waterworks is a large system (10,001 to 100,000 people). Union County has 25 active public water systems, and El Dorado Waterworks is the largest of them by population served. Its population served is about 11 times the county average of 1,582 people per system, and accounts for 45% of the 39,541 people reported by systems filed under the county. Across Arkansas, the 853 active systems average 3,592 people each. Nationally, the average active community water system reports serving 6,703 people, so El Dorado Waterworks is about 168% above 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. Arkansas has 660 active community water systems, 77% of the state's 853 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 461 Arkansas systems (54%) list groundwater as their primary source.
Who owns and regulates El Dorado Waterworks?
EPA lists El Dorado Waterworks as owned by a local government. The AR state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 13 of the 25 active systems in Union County (52%) are also owned by a local government.
Does El Dorado Waterworks have drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in October 2025. The violations listed here began between April 2007 and October 2025. By type: 11 contaminant level above the legal limit and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 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 |
|---|---|---|---|---|
| 2025-10-01 | 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 | Total trihalomethanes (TTHM)code 2950 | Yes | Archived |
| 2022-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Asbestoscode 1094 | Yes | Resolved |
| 2020-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Asbestoscode 1094 | Yes | Resolved |
| 2020-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Asbestoscode 1094 | Yes | Resolved |
| 2009-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | 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.
El Dorado Waterworks: frequently asked questions
Who runs El Dorado Waterworks?
El Dorado Waterworks (PWSID AR0000550) is a community water system owned by a local government. It is regulated by the AR state drinking water program.
How many people does El Dorado Waterworks serve?
El Dorado Waterworks reports serving 17,932 people through 8,333 service connections in Union County, Arkansas.
Where does El Dorado Waterworks 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 El Dorado Waterworks have any drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in October 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 El Dorado Waterworks' 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, 11 are health-based, and the most recent began in October 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the AR state drinking water program.
Where can I find El Dorado Waterworks' water quality report?
As a community water system, El Dorado Waterworks 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 Union County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Smackover Waterworks | Union | 2,821 | Community | Groundwater |
| Parkers Chapel Public Water | Union | 2,391 | Community | Groundwater |
| Wildwood Water Association | Union | 1,350 | Community | Groundwater |
| Faircrest Water Association | Union | 1,329 | Community | Groundwater |
| Old Union Public Water Authority | Union | 1,200 | Community | Groundwater |
| New Hope Water Association | Union | 1,136 | Community | Groundwater |
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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, “El Dorado Waterworks, PWSID AR0000550, Arkansas”, https://aquacensus.com/water-systems/arkansas/el-dorado-waterworks-ar0000550 (data as of October 1, 2026).