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Community Water System · PWS IL0110700

Neponset

Neponset, Illinois 61345 - drinking water served from groundwater sources to 427 people, tracked in EPA SDWIS and UCMR5.

427
People served
1,195
EPA violations
657
Health-based
Untested
UCMR5 result

The verdict

EPA records 1,195 drinking-water violations at Neponset, 55% of them health-based - above the Illinois per-system average.

1,195
Total EPA violations on record
55%
Health-based (MCL / treatment failure)
427
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Neponset

Neponset is a local-owned community water system that delivers drinking water to 427 residents in Neponset, Illinois (Bureau County) through 200 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 1,195 total violations for this system , of which 657 (55%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 275 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 414 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%).

Neponset's 1,195 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
427
Total Violations
1,195
Health-Based Violations
657
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
200
County
Bureau
School/Daycare
No
MCL Violations
655
Monitoring Violations
275
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Combined Radium (-226 and -228) MCL 414 2013
Gross Alpha, Excl. Radon and U MCL 229 2012
Public Notice Other 187 2025
Coliform (TCR) MR 55 2015
Combined Radium (-226 and -228) MR 27 2010
Consumer Confidence Rule Other 21 2025
Gross Alpha, Excl. Radon and U MR 17 2004
Coliform (TCR) MCL 12 2010
Xylenes, Total MR 9 1993
o-Dichlorobenzene MR 9 1993
1,1-Dichloroethylene MR 9 1993
1,1,1-Trichloroethane MR 9 1993
Carbon tetrachloride MR 9 1993
1,2-Dichloropropane MR 9 1993
Trichloroethylene MR 9 1993
CHLOROBENZENE MR 9 1993
Toluene MR 9 1993
Ethylbenzene MR 9 1993
trans-1,2-Dichloroethylene MR 9 1993
Benzene MR 9 1993
Combined Uranium MR 9 2010
p-Dichlorobenzene MR 9 1993
cis-1,2-Dichloroethylene MR 9 1993
Tetrachloroethylene MR 9 1993
Styrene MR 9 1993
Lead and Copper Rule MR 8 2021
1,2-Dichloroethane MR 8 1993
Chlorine MR 4 2015
Fluoride MR 3 1999
LEAD AND COPPER RULE REVISIONS TT 2 2024

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 Neponset.

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 IL0110700 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 Neponset 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 Public Notice Other 187 SDWIS / IL0110700 / 7500
2025 Consumer Confidence Rule Other 21 SDWIS / IL0110700 / 7000
2025 LEAD AND COPPER RULE REVISIONS RPT 2 SDWIS / IL0110700 / 5200
2024 LEAD AND COPPER RULE REVISIONS TT 2 SDWIS / IL0110700 / 5200
2021 Lead and Copper Rule MR 8 SDWIS / IL0110700 / 5000
2015 Coliform (TCR) MR 55 SDWIS / IL0110700 / 3100
2015 Chlorine MR 4 SDWIS / IL0110700 / 0999
2013 Combined Radium (-226 and -228) MCL 414 SDWIS / IL0110700 / 4010
2012 Gross Alpha, Excl. Radon and U MCL 229 SDWIS / IL0110700 / 4000
2010 Combined Radium (-226 and -228) MR 27 SDWIS / IL0110700 / 4010
2010 Coliform (TCR) MCL 12 SDWIS / IL0110700 / 3100
2010 Combined Uranium MR 9 SDWIS / IL0110700 / 4006
2004 Gross Alpha, Excl. Radon and U MR 17 SDWIS / IL0110700 / 4000
1999 Fluoride MR 3 SDWIS / IL0110700 / 1025
1993 Xylenes, Total MR 9 SDWIS / IL0110700 / 2955

How Neponset Compares

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

Metric Neponset Illinois avg Federal benchmark
Total violations 1,195 69.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 657 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 427 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 Neponset water safe to drink? ▼
Neponset (PWS ID: IL0110700) has 1195 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 427 people using Groundwater sources.
How many people does Neponset serve? ▼
Neponset serves 427 people in Neponset, Illinois. It is a Local-owned system using Groundwater water sources with 200 service connections.
What type of violations does Neponset have? ▼
Neponset has 1,195 total violations: 657 health-based violations (MCL exceedances or treatment failures), 275 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Neponset water? ▼
No PFAS testing data is available for Neponset under the EPA's UCMR5 monitoring program.
What water source does Neponset use? ▼
Neponset 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.