REDWOOD CITY, CA · San Mateo County
COUNTY SERVICE AREA 11 Water System
Consumer Confidence Report status
COUNTY SERVICE AREA 11 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 COUNTY SERVICE AREA 11.
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)
- CA4100582
- System type
- Community Water System
- Population served
- 642
- Service connections
- 104
- Ownership
- local government
- Water source
- groundwater (wells)
COUNTY SERVICE AREA 11 is one of 728 community water systems in California in the 501 to 3,300 people size category, serving 642 people from groundwater.
As of August 1, 2026, its federal record holds 2 entries in 2004, all of which EPA lists as closed. Nothing has been added since 2004.
All 2 are monitoring and reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset — rather than findings about the water itself. The record involves volatile organic chemicals.
Violation history
Monitoring, Regular
—1,1,2-Trichloroethane
January 1, 2004 – December 31, 2004
ResolvedMonitoring, Regular
—Xylenes, Total
January 1, 2004 – December 31, 2004
Resolved
Resolved addressed and confirmed by the state
| Period | Violation | Contaminant / rule | Health-based | Status |
|---|---|---|---|---|
| January 1, 2004 – December 31, 2004 | Monitoring, Regular | 1,1,2-Trichloroethane | — | Resolved |
| January 1, 2004 – December 31, 2004 | Monitoring, Regular | Xylenes, Total | — | Resolved |
Resolved addressed and confirmed by the state
Enforcement actions
- February 27, 2018State Compliance achieved26 linked violations
Common questions
Is COUNTY SERVICE AREA 11 required to publish a Consumer Confidence Report?
- Yes. COUNTY SERVICE AREA 11 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 COUNTY SERVICE AREA 11’s next Consumer Confidence Report due?
- COUNTY SERVICE AREA 11’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does COUNTY SERVICE AREA 11 have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for COUNTY SERVICE AREA 11.
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
NEWMAN, TORY
650-599-7390
REDWOOD CITY, CA 94063