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Community Water System · PWS IL1110900

Union

Union, Illinois 60180 - drinking water served from groundwater sources to 594 people, tracked in EPA SDWIS and UCMR5.

594
People served
95
EPA violations
23
Health-based
Untested
UCMR5 result

The verdict

EPA records 95 drinking-water violations at Union, 24% of them health-based - above the Illinois per-system average.

95
Total EPA violations on record
24%
Health-based (MCL / treatment failure)
594
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Union

Union is a local-owned community water system that delivers drinking water to 594 residents in Union, Illinois (McHenry County) through 276 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 95 total violations for this system , of which 23 (24%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 31 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Combined Radium (-226 and -228), recorded in 22 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 Illinois, EPA tracks 5,117 public water systems serving 12,576,876 people, with 355,322 cumulative violations and 52,932 health-based violations on record. About 81% of systems in the state carry at least one violation, and state-wide the average per system is 69.4 violations. Statewide, 199 of 487 UCMR5-tested systems have reported PFAS detections (40.9%).

Union's 95 violations sit above the Illinois 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
594
Total Violations
95
Health-Based Violations
23
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
276
County
McHenry
School/Daycare
No
MCL Violations
23
Monitoring Violations
31
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Combined Radium (-226 and -228) MCL 22 2009
Consumer Confidence Rule Other 11 2025
Public Notice Other 10 2010
Combined Radium (-226 and -228) MR 4 2005
p-Dichlorobenzene MR 3 1991
1,1-Dichloroethylene MR 3 1991
1,2-Dichloroethane MR 3 1991
Barium MR 3 2003
Benzene MR 3 1991
Trichloroethylene MR 3 1991
Carbon tetrachloride MR 3 1991
1,1,1-Trichloroethane MR 3 1991
LEAD AND COPPER RULE REVISIONS RPT 2 2025
Barium MCL 1 1992
Lead and Copper Rule MR 1 1994
Coliform (TCR) MR 1 2000
Gross Alpha, Excl. Radon and U MR 1 1977

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 Union.

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 IL1110900 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Illinois Drinking Water Authority

Illinois EPA, Bureau of Water is the primacy agency that licenses and inspects Union under EPA-delegated authority.

Open IL regulator portal

Source: Illinois EPA, Bureau of Water

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
2025 Consumer Confidence Rule Other 11 SDWIS / IL1110900 / 7000
2025 LEAD AND COPPER RULE REVISIONS RPT 2 SDWIS / IL1110900 / 5200
2010 Public Notice Other 10 SDWIS / IL1110900 / 7500
2009 Combined Radium (-226 and -228) MCL 22 SDWIS / IL1110900 / 4010
2005 Combined Radium (-226 and -228) MR 4 SDWIS / IL1110900 / 4010
2003 Barium MR 3 SDWIS / IL1110900 / 1010
2000 Coliform (TCR) MR 1 SDWIS / IL1110900 / 3100
1994 Lead and Copper Rule MR 1 SDWIS / IL1110900 / 5000
1992 Barium MCL 1 SDWIS / IL1110900 / 1010
1991 p-Dichlorobenzene MR 3 SDWIS / IL1110900 / 2969
1991 1,1-Dichloroethylene MR 3 SDWIS / IL1110900 / 2977
1991 1,2-Dichloroethane MR 3 SDWIS / IL1110900 / 2980
1991 Benzene MR 3 SDWIS / IL1110900 / 2990
1991 Trichloroethylene MR 3 SDWIS / IL1110900 / 2984
1991 Carbon tetrachloride MR 3 SDWIS / IL1110900 / 2982

How Union Compares

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

Metric Union Illinois avg Federal benchmark
Total violations 95 69.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 23 10.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 40.9% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 594 2,458 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 5,117 regulated public water systems in Illinois.

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 Union water safe to drink? ▼
Union (PWS ID: IL1110900) has 95 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 594 people using Groundwater sources.
How many people does Union serve? ▼
Union serves 594 people in Union, Illinois. It is a Local-owned system using Groundwater water sources with 276 service connections.
What type of violations does Union have? ▼
Union has 95 total violations: 23 health-based violations (MCL exceedances or treatment failures), 31 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Union water? ▼
No PFAS testing data is available for Union under the EPA's UCMR5 monitoring program.
What water source does Union use? ▼
Union 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.