Wonder Lake (niu)
EPA ID: IL1115850 · 1,950 people served · 4 ZIP codes
Five years of EPA monitoring have produced no violations for Wonder Lake (niu) — the supplier serving 1,950 residents has kept every contaminant level within federal limits, a result that places it among the top-performing utilities for systems with a service population of comparable size.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 3 (2023) to 1 (2025). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Wonder Lake (niu) Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Wonder Lake (niu) serves a community with a median household income of $91,807 and an estimated 77,546 residents across its service area. Approximately 55% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Wonder Lake (niu)'s water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 1% of homes in McHenry County, Illinois rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Wastewater Proximity Note: This service area ranks in the 80th percentile nationally for proximity to wastewater discharge points.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 8 detections recorded. 2 exceed federal EPA limits (4 ppt for PFOA/PFOS). 1 exceeds state limits.
Comparable Water Systems
Similar-sized systems in Illinois
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Wonder Lake (niu) (EPA ID: IL1115850) is a community water system in Illinois that serves approximately 1,950 people from groundwater sources.
This system provides water to 4 ZIP codes across 4 communities.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by IL or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Wonder Lake (niu) (IL1115850) on EPA.gov.
Frequently Asked Questions
Is Wonder Lake (niu) water safe to drink?
Based on EPA records, Wonder Lake (niu) has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Wonder Lake (niu) serve?
Wonder Lake (niu) serves approximately 1,950 people across 4 ZIP codes in Illinois.
Where does Wonder Lake (niu) get its water?
The primary water source is groundwater.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.