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Community Water System · PWS IL0950250

Henderson

Henderson, Illinois 61439 - drinking water served from groundwater sources to 375 people, tracked in EPA SDWIS and UCMR5.

375
People served
103
EPA violations
33
Health-based
Untested
UCMR5 result

The verdict

EPA records 103 drinking-water violations at Henderson, 32% of them health-based - above the Illinois per-system average.

103
Total EPA violations on record
32%
Health-based (MCL / treatment failure)
375
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Henderson

Henderson is a local-owned community water system that delivers drinking water to 375 residents in Henderson, Illinois (Knox County) through 150 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 103 total violations for this system , of which 33 (32%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 53 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 Coliform (TCR), recorded in 18 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%).

Henderson's 103 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
375
Total Violations
103
Health-Based Violations
33
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
150
County
Knox
School/Daycare
No
MCL Violations
31
Monitoring Violations
53
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 18 2005
Coliform (TCR) MR 13 1999
Lead and Copper Rule MR 13 2022
Fluoride MCL 13 1985
TTHM MR 10 2025
Total Haloacetic Acids (HAA5) MR 8 2025
Chlorine MR 5 2017
Consumer Confidence Rule Other 4 2025
LEAD AND COPPER RULE REVISIONS RPT 4 2025
Revised Total Coliform Rule MON 3 2017
Public Notice Other 3 2025
LEAD AND COPPER RULE REVISIONS TT 2 2024
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 Henderson.

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 IL0950250 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 Henderson 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 TTHM MR 10 SDWIS / IL0950250 / 2950
2025 Total Haloacetic Acids (HAA5) MR 8 SDWIS / IL0950250 / 2456
2025 Consumer Confidence Rule Other 4 SDWIS / IL0950250 / 7000
2025 LEAD AND COPPER RULE REVISIONS RPT 4 SDWIS / IL0950250 / 5200
2025 Public Notice Other 3 SDWIS / IL0950250 / 7500
2024 LEAD AND COPPER RULE REVISIONS TT 2 SDWIS / IL0950250 / 5200
2022 Lead and Copper Rule MR 13 SDWIS / IL0950250 / 5000
2017 Chlorine MR 5 SDWIS / IL0950250 / 0999
2017 Revised Total Coliform Rule MON 3 SDWIS / IL0950250 / 8000
2005 Coliform (TCR) MCL 18 SDWIS / IL0950250 / 3100
1999 Coliform (TCR) MR 13 SDWIS / IL0950250 / 3100
1985 Fluoride MCL 13 SDWIS / IL0950250 / 1025
1977 Gross Alpha, Excl. Radon and U MR 1 SDWIS / IL0950250 / 4000

How Henderson Compares

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

Metric Henderson Illinois avg Federal benchmark
Total violations 103 69.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 33 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 375 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 Henderson water safe to drink? ▼
Henderson (PWS ID: IL0950250) has 103 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 375 people using Groundwater sources.
How many people does Henderson serve? ▼
Henderson serves 375 people in Henderson, Illinois. It is a Local-owned system using Groundwater water sources with 150 service connections.
What type of violations does Henderson have? ▼
Henderson has 103 total violations: 33 health-based violations (MCL exceedances or treatment failures), 53 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Henderson water? ▼
No PFAS testing data is available for Henderson under the EPA's UCMR5 monitoring program.
What water source does Henderson use? ▼
Henderson 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.