Public water system record
Wonder Lake (Niu)
Serves an area of McHenry County, IL · 1,950 people served
Federal records show no health-based violations and 2 monitoring/reporting issues for Wonder Lake (Niu) in the last ten years.
System profile
- Health-based violations, last 10 years
- 0
- Resolved
- 0
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 2
Key facts
- Wonder Lake (Niu) draws water from 3 wells (1 of them for emergency, seasonal or other part-time use).
- Record on file since 1977, with 4 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 632 service lines.
Check whether Wonder Lake (Niu) serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
None since October 2016.
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Chlorine
Monitoring and reporting
|
Nov 1, 2024 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Nov 1, 2024 | Resolved |
Full record since 1977
EPA's records for Wonder Lake (Niu) go back to 1977. Before October 19, 2016 they list 4 health-based violations (2 resolved, 2 archived by EPA without a recorded fix) and 77 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1970s | 0 | 1 |
| 1990s | 2 | 74 |
| 2000s | 0 | 2 |
| 2010 to October 18, 2016 | 2 | 0 |
| 2020s | 0 | 2 |
Most recent health-based violation before October 19, 2016: Arsenic, began July 2013, Resolved.
Show all 4 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jul 1, 2013 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Apr 1, 2013 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jun 1, 1998 | Archived |
|
Total Coliform
Contaminant limit exceeded
|
Nov 1, 1993 | Archived |
Where the water comes from
Wonder Lake (Niu) draws water from 3 wells (1 of them for emergency, seasonal or other part-time use).
Annual water quality report
Wonder Lake (Niu) must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Where the state allows it, systems serving fewer than 10,000 people may publish the report in a local newspaper or news site instead of mailing it, and must provide a copy on request.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Illinois.
Certified drinking water labs by state EPA guidance for private wells