Public water system record
Cooksville
Serves Cooksville, McLean County, IL · 157 people served
Federal records show 6 health-based violations and 2 monitoring/reporting issues for Cooksville in the last ten years. The most serious issue in this window was a resolved Haloacetic Acids (HAA5) violation.
System profile
- Health-based violations, last 10 years
- 6
- Resolved
- 6
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 2
Key facts
- Cooksville draws water from 2 wells.
- Highest measured level in the last 10 years: Total Trihalomethanes (TTHMs), 0.111 mg/L, federal limit 0.08 mg/L (1.4 times the limit), 2019.
- Most recent formal enforcement: compliance order (no penalty) by Illinois, August 2025.
- Record on file since 1977, with 36 health-based violations before October 19, 2016.
Check whether Cooksville 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.
| Contaminant | Rule family | Start date | Status | Acute |
|---|---|---|---|---|
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 0.076 mg/L, federal limit 0.06 mg/L (1.3 times the limit)
|
220 | Apr 1, 2025 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.091 mg/L, federal limit 0.08 mg/L (1.1 times the limit)
|
220 | Apr 1, 2025 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.081 mg/L, federal limit 0.08 mg/L (at or just above the limit)
|
220 | Jan 1, 2020 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.098 mg/L, federal limit 0.08 mg/L (1.2 times the limit)
|
220 | Oct 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.097 mg/L, federal limit 0.08 mg/L (1.2 times the limit)
|
220 | Jul 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.111 mg/L, federal limit 0.08 mg/L (1.4 times the limit)
|
220 | Apr 1, 2019 | Resolved | No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Public Notice
OTHER
|
May 30, 2025 | Resolved |
|
Public Notice
OTHER
|
May 30, 2025 | Resolved |
Full record since 1977
EPA's records for Cooksville go back to 1977. Before October 19, 2016 they list 36 health-based violations (34 resolved, 2 archived by EPA without a recorded fix) and 43 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1970s | 0 | 1 |
| 1990s | 1 | 25 |
| 2000s | 30 | 15 |
| 2010 to October 18, 2016 | 5 | 2 |
| October 19, 2016 to 2019 | 3 | 0 |
| 2020s | 3 | 2 |
Most recent health-based violation before October 19, 2016: Total Trihalomethanes (TTHMs), began July 2015, Resolved.
Show all 36 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.082 mg/L, federal limit 0.08 mg/L (at or just above the limit)
|
Jul 1, 2015 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Feb 1, 2012 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jul 1, 2010 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Apr 1, 2010 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Jan 1, 2010 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Oct 1, 2009 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jul 1, 2009 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Apr 1, 2009 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 90 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
Apr 1, 2009 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jan 1, 2009 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 93 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
Jan 1, 2009 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Oct 1, 2008 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jul 1, 2008 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Apr 1, 2008 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jan 1, 2008 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Oct 1, 2007 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Jul 1, 2007 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Apr 1, 2007 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.013 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
|
Jan 1, 2007 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.013 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
|
Oct 1, 2006 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.013 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
|
Jul 1, 2006 | Resolved |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
|
Oct 1, 2005 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Oct 1, 2005 | Resolved |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
|
Jul 1, 2005 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Jul 1, 2005 | Resolved |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
|
Apr 1, 2005 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Apr 1, 2005 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Jan 1, 2005 | Resolved |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
|
Jan 1, 2005 | Resolved |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
|
Oct 1, 2004 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Oct 1, 2004 | Resolved |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
|
Jul 1, 2004 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Jul 1, 2004 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Apr 1, 2004 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Feb 1, 2000 | Archived |
|
Total Coliform
Contaminant limit exceeded
|
Oct 1, 1996 | Archived |
Enforcement actions
Illinois regulators took 4 formal enforcement actions against Cooksville between 2005 and 2025. The most recent was a compliance order (no penalty) in August 2025.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Aug 20, 2025 | Illinois | Compliance order (no penalty) | 2 violations (2 health-based): Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5) |
| Mar 25, 2009 | Illinois | Signed compliance agreement | 2 violations (2 health-based): Total Trihalomethanes (TTHMs) |
| Mar 19, 2007 | Illinois | Signed compliance agreement | 15 violations (15 health-based): Arsenic |
| Jan 13, 2005 | Illinois | Signed compliance agreement | 13 violations (13 health-based): Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5) |
What the violations mean
Total Trihalomethanes (TTHMs)
5 incidentsDisinfection byproduct levels exceeded the federal limit
Long-term TTHM exposure may increase bladder cancer risk
Haloacetic Acids (HAA5)
1 incidentHaloacetic acid byproducts exceeded the federal limit
Long-term exposure to HAAs may increase cancer risk
Where the water comes from
Cooksville draws water from 2 wells.
Annual water quality report
Cooksville 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.
Systems serving 500 or fewer people may meet the rule by telling customers the report is available on request, so you may need to ask Cooksville for a copy.
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