PATTERSON, CA · Stanislaus County
PATTERSON, CITY OF Water System
Consumer Confidence Report status
PATTERSON, CITY OF must publish a Consumer Confidence Report — the annual drinking water quality report covering calendar year 2026 — by July 1, 2027.
As of August 1, 2026, EPA's federal records show no open violations for PATTERSON, CITY OF.
Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed August 1, 2026. This is a record-keeping and public-information tool — it does not replace California’s official records. Always confirm current status with California before making decisions based on this information.
System facts
- System ID (PWSID)
- CA5010017
- System type
- Community Water System
- Population served
- 24,977
- Service connections
- 7,367
- Ownership
- local government
- Water source
- groundwater (wells)
PATTERSON, CITY OF is one of 376 community water systems in California in the 10,001 to 100,000 people size category, serving 24,977 people from groundwater.
As of August 1, 2026, its federal record holds 3 entries between 1989 and 2007, all of which EPA lists as closed. Nothing has been added since 2007.
None of the 3 are monitoring or reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset; these involve water-quality, treatment, or public-notice findings instead. The record involves inorganic chemicals, the Total Coliform Rules, and the Miscellaneous Other Rules.
Violation history
Maximum Contaminant Level Violation, Average
Health-basedNitrate
January 1, 2007 – March 31, 2007
ResolvedMaximum Contaminant Level Violation, Monthly (TCR)
Health-basedColiform (TCR)
June 1, 2003 – June 30, 2003
ResolvedNotification, Public
—No contaminant on record
August 1, 1989 – August 31, 1989
Archived
Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)
| Period | Violation | Contaminant / rule | Health-based | Status |
|---|---|---|---|---|
| January 1, 2007 – March 31, 2007 | Maximum Contaminant Level Violation, Average | Nitrate | Health-based | Resolved |
| June 1, 2003 – June 30, 2003 | Maximum Contaminant Level Violation, Monthly (TCR) | Coliform (TCR) | Health-based | Resolved |
| August 1, 1989 – August 31, 1989 | Notification, Public | — | — | Archived |
Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)
Enforcement actions
No enforcement actions on record for this system.
Common questions
Is PATTERSON, CITY OF required to publish a Consumer Confidence Report?
- Yes. PATTERSON, CITY OF is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.
When is PATTERSON, CITY OF’s next Consumer Confidence Report due?
- PATTERSON, CITY OF’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does PATTERSON, CITY OF have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for PATTERSON, CITY OF.
What is a Consumer Confidence Report?
- A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.
Contact
WILLETT, MIKE
209-895-8065
PATTERSON, CA 95363