Public water system record
City of Patterson
Serves Patterson, Stanislaus County, CA · 24,977 people served
Federal records show no health-based violations and no monitoring or reporting issues for City of Patterson 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
- 0
Key facts
- City of Patterson draws water from 6 wells (1 of them for emergency, seasonal or other part-time use).
- Most recent formal enforcement: compliance order (no penalty) by California, May 2007.
- Record on file since 1989, with 3 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 7,132 service lines.
Check whether City of Patterson 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, and no monitoring or reporting violations either.
Full record since 1989
EPA's records for City of Patterson go back to 1989. Before October 19, 2016 they list 3 health-based violations (3 resolved) and 1 monitoring or reporting violation.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1980s | 0 | 1 |
| 1990s | 1 | 0 |
| 2000s | 2 | 0 |
Most recent health-based violation before October 19, 2016: Nitrate (acute), began January 2007, Resolved.
Show all 3 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Nitrate (acute)
Contaminant limit exceeded
|
Jan 1, 2007 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jun 1, 2003 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Nov 1, 1994 | Resolved |
Enforcement actions
California regulators took 2 formal enforcement actions against City of Patterson between 2003 and 2007. The most recent was a compliance order (no penalty) in May 2007.
| Date | By | Action | Violations covered |
|---|---|---|---|
| May 22, 2007 | California | Compliance order (no penalty) | 1 violation (1 health-based): Nitrate |
| Jul 15, 2003 | California | Compliance order (no penalty) | 1 violation (1 health-based): Total Coliform |
Where the water comes from
City of Patterson draws water from 6 wells (1 of them for emergency, seasonal or other part-time use).
Annual water quality report
City of Patterson 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 California.
Certified drinking water labs by state EPA guidance for private wells