WONDER LAKE (NIU)
PWS ID: IL1115850 · WONDER LAKE, Illinois 60097
WONDER LAKE (NIU) serves 1,950 people in WONDER LAKE, Illinois using Groundwater water sources. It has 402 recorded EPA violations, including 18 health-based violations. No PFAS contamination was detected in UCMR5 testing.
Water Quality Snapshot: WONDER LAKE (NIU)
WONDER LAKE (NIU) is a local-owned community water system that delivers drinking water to 1,950 residents in WONDER LAKE, Illinois (McHenry County) through 780 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 402 total violations for this system , of which 18 (4%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 374 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.
The most frequently cited contaminant at this system is 1,2-Dichloropropane, recorded in 21 violations (MR). 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. WONDER LAKE (NIU)'s 402 violations sit above the Illinois average. Statewide, 199 of 487 UCMR5-tested systems have reported PFAS detections (40.9%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 780
- County
- McHenry
- School/Daycare
- No
- MCL Violations
- 18
- Monitoring Violations
- 374
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| 1,2-Dichloropropane | MR | 21 | 1993 |
| Benzene | MR | 21 | 1993 |
| Ethylbenzene | MR | 21 | 1993 |
| Tetrachloroethylene | MR | 21 | 1993 |
| cis-1,2-Dichloroethylene | MR | 20 | 1993 |
| Xylenes, Total | MR | 20 | 1993 |
| o-Dichlorobenzene | MR | 20 | 1993 |
| p-Dichlorobenzene | MR | 20 | 1993 |
| 1,1-Dichloroethylene | MR | 20 | 1993 |
| trans-1,2-Dichloroethylene | MR | 20 | 1993 |
| 1,2-Dichloroethane | MR | 20 | 1993 |
| 1,1,1-Trichloroethane | MR | 20 | 1993 |
| Carbon tetrachloride | MR | 20 | 1993 |
| Trichloroethylene | MR | 20 | 1993 |
| Toluene | MR | 20 | 1993 |
| CHLOROBENZENE | MR | 20 | 1993 |
| Styrene | MR | 20 | 1993 |
| Coliform (TCR) | MR | 19 | 2002 |
| Arsenic | MCL | 12 | 2013 |
| Coliform (TCR) | MCL | 6 | 1998 |
| Lead and Copper Rule | MR | 4 | 2004 |
| Revised Total Coliform Rule | MON | 3 | 2024 |
| Chlorine | MR | 3 | 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 WONDER LAKE (NIU).
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 IL1115850 on SDWISSource: EPA SDWIS Federal Reports Search
Illinois Drinking Water Authority
Illinois EPA — Bureau of Water is the primacy agency that licenses and inspects WONDER LAKE (NIU) under EPA-delegated authority.
Open IL regulator portalSource: 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 |
|---|---|---|---|---|
| 2024 | Revised Total Coliform Rule | MON | 3 | SDWIS / IL1115850 / 8000 |
| 2024 | Chlorine | MR | 3 | SDWIS / IL1115850 / 0999 |
| 2013 | Arsenic | MCL | 12 | SDWIS / IL1115850 / 1005 |
| 2004 | Lead and Copper Rule | MR | 4 | SDWIS / IL1115850 / 5000 |
| 2002 | Coliform (TCR) | MR | 19 | SDWIS / IL1115850 / 3100 |
| 1998 | Coliform (TCR) | MCL | 6 | SDWIS / IL1115850 / 3100 |
| 1993 | 1,2-Dichloropropane | MR | 21 | SDWIS / IL1115850 / 2983 |
| 1993 | Benzene | MR | 21 | SDWIS / IL1115850 / 2990 |
| 1993 | Ethylbenzene | MR | 21 | SDWIS / IL1115850 / 2992 |
| 1993 | Tetrachloroethylene | MR | 21 | SDWIS / IL1115850 / 2987 |
| 1993 | cis-1,2-Dichloroethylene | MR | 20 | SDWIS / IL1115850 / 2380 |
| 1993 | Xylenes, Total | MR | 20 | SDWIS / IL1115850 / 2955 |
| 1993 | o-Dichlorobenzene | MR | 20 | SDWIS / IL1115850 / 2968 |
| 1993 | p-Dichlorobenzene | MR | 20 | SDWIS / IL1115850 / 2969 |
| 1993 | 1,1-Dichloroethylene | MR | 20 | SDWIS / IL1115850 / 2977 |
How WONDER LAKE (NIU) Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | WONDER LAKE (NIU) | Illinois avg | Federal benchmark |
|---|---|---|---|
| Total violations | 402 | 69.4 | SDWA compliance — any non-zero count is a recorded breach |
| Health-based violations | 18 | 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 | 1,950 | 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 |
| Nitrate (as N) | 10 mg/L | Acute health risk for infants |
Frequently Asked Questions
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Related Data for Illinois
Read our methodology — how this data is sourced, computed, and verified.