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Community Water System · PWS AR0000559

Old Union Public Water Authority

El Dorado, Arkansas 71730 - drinking water served from groundwater sources to 1,200 people, tracked in EPA SDWIS and UCMR5.

1,200
People served
106
EPA violations
41
Health-based
Untested
UCMR5 result

The verdict

EPA records 106 drinking-water violations at Old Union Public Water Authority, 39% of them health-based - above the Arkansas per-system average.

106
Total EPA violations on record
39%
Health-based (MCL / treatment failure)
1,200
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Old Union Public Water Authority

Old Union Public Water Authority is a local-owned community water system that delivers drinking water to 1,200 residents in El Dorado, Arkansas (Union County) through 482 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 106 total violations for this system , of which 41 (39%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 11 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is TTHM, recorded in 39 violations (MCL, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Arkansas, EPA tracks 1,016 public water systems serving 3,049,400 people, with 53,437 cumulative violations and 21,598 health-based violations on record. About 94% of systems in the state carry at least one violation, and state-wide the average per system is 52.6 violations. Statewide, 57 of 172 UCMR5-tested systems have reported PFAS detections (33.1%).

Old Union Public Water Authority's 106 violations sit above the Arkansas 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
1,200
Total Violations
106
Health-Based Violations
41
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
482
County
Union
School/Daycare
No
MCL Violations
41
Monitoring Violations
11
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
TTHM MCL 39 2019
Revised Total Coliform Rule RPT 27 2023
Public Notice Other 12 2023
Revised Total Coliform Rule MON 4 2022
Lead and Copper Rule MR 4 2022
Coliform (TCR) MR 3 2015
Revised Total Coliform Rule MCL 2 2022
Consumer Confidence Rule Other 2 2022

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 Old Union Public Water Authority.

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 AR0000559 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Arkansas Drinking Water Authority

Arkansas'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 AR 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
2023 Revised Total Coliform Rule RPT 27 SDWIS / AR0000559 / 8000
2023 Public Notice Other 12 SDWIS / AR0000559 / 7500
2022 Revised Total Coliform Rule MON 4 SDWIS / AR0000559 / 8000
2022 Lead and Copper Rule MR 4 SDWIS / AR0000559 / 5000
2022 Revised Total Coliform Rule MCL 2 SDWIS / AR0000559 / 8000
2022 Consumer Confidence Rule Other 2 SDWIS / AR0000559 / 7000
2019 TTHM MCL 39 SDWIS / AR0000559 / 2950
2015 Coliform (TCR) MR 3 SDWIS / AR0000559 / 3100

How Old Union Public Water Authority Compares

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

Metric Old Union Public Water Authority Arkansas avg Federal benchmark
Total violations 106 52.6 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 41 21.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 33.1% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 1,200 3,001 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,016 regulated public water systems in Arkansas.

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 Old Union Public Water Authority water safe to drink? ▼
Old Union Public Water Authority (PWS ID: AR0000559) has 106 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,200 people using Groundwater sources.
How many people does Old Union Public Water Authority serve? ▼
Old Union Public Water Authority serves 1,200 people in El Dorado, Arkansas. It is a Local-owned system using Groundwater water sources with 482 service connections.
What type of violations does Old Union Public Water Authority have? ▼
Old Union Public Water Authority has 106 total violations: 41 health-based violations (MCL exceedances or treatment failures), 11 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Old Union Public Water Authority water? ▼
No PFAS testing data is available for Old Union Public Water Authority under the EPA's UCMR5 monitoring program.
What water source does Old Union Public Water Authority use? ▼
Old Union Public Water Authority 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.