Public water system record
Oak Creek Waterworks
Serves Oak Creek, Milwaukee County, WI · 32,104 people served
Federal records show 5 health-based violations and 3 monitoring/reporting issues for Oak Creek Waterworks in the last ten years. The most serious issue in this window was a resolved LEAD AND COPPER RULE REVISIONS violation.
System profile
- Health-based violations, last 10 years
- 5
- Resolved
- 5
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 3
Key facts
- Oak Creek Waterworks draws water from 1 surface water intake.
- Highest measured level in the last 10 years: Total Trihalomethanes (TTHMs), 155.6 µg/L, federal limit 80 µg/L (1.9 times the limit), 2019.
- Record on file since 1991, with 0 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 9,841 service lines.
Check whether Oak Creek Waterworks 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 |
|---|---|---|---|---|
|
LEAD AND COPPER RULE REVISIONS
Treatment technique failure
|
350 | Oct 17, 2024 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 155.6 µg/L, federal limit 80 µg/L (1.9 times the limit)
|
220 | Jan 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 154.8 µg/L, federal limit 80 µg/L (1.9 times the limit)
|
220 | Oct 1, 2018 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 131.7 µg/L, federal limit 80 µg/L (1.6 times the limit)
|
220 | Jul 1, 2018 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 132.7 µg/L, federal limit 80 µg/L (1.7 times the limit)
|
220 | Apr 1, 2018 | 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
|
Oct 17, 2024 | Active |
|
Total Trihalomethanes (TTHMs)
Monitoring and reporting
|
Jan 1, 2021 | Resolved |
|
Haloacetic Acids (HAA5)
Monitoring and reporting
|
Jan 1, 2021 | Resolved |
Full record since 1991
EPA's records for Oak Creek Waterworks go back to 1991. Before October 19, 2016 they list no health-based violations and 50 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1990s | 0 | 2 |
| 2000s | 0 | 44 |
| 2010 to October 18, 2016 | 0 | 4 |
| October 19, 2016 to 2019 | 4 | 0 |
| 2020s | 1 | 3 |
What the violations mean
Total Trihalomethanes (TTHMs)
4 incidentsDisinfection byproduct levels exceeded the federal limit
Long-term TTHM exposure may increase bladder cancer risk
LEAD AND COPPER RULE REVISIONS
1 incidentThe system did not complete a treatment step or action that the LEAD AND COPPER RULE REVISIONS requires (a treatment technique violation).
The utility had to notify customers about this violation.
Where the water comes from
Oak Creek Waterworks draws water from 1 surface water intake. 2 other community water systems buy water from Oak Creek Waterworks.
Community systems that buy water from it
- Franklin Water Utility Franklin, WI
- Village of Caledonia Water Utility - Caledonia, WI
Annual water quality report
Oak Creek Waterworks 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 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.
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 Wisconsin.
Certified drinking water labs by state EPA guidance for private wells