Public water system record
California Water Service - San Carlos
Serves San Carlos, San Mateo County, CA · 35,344 people served
Federal records show no health-based violations and no monitoring or reporting issues for California Water Service - San Carlos 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
- California Water Service - San Carlos buys its water from San Francisco Regional Water System.
- Most recent formal enforcement: compliance order (no penalty) by California, April 2015.
- Record on file since 1993, with 4 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 10,076 unknown out of 10,921 service lines.
Check whether California Water Service - San Carlos 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 1993
EPA's records for California Water Service - San Carlos go back to 1993. Before October 19, 2016 they list 4 health-based violations (4 resolved) and no monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1990s | 3 | 0 |
| 2010 to October 18, 2016 | 1 | 0 |
Most recent health-based violation before October 19, 2016: Surface Water Treatment Rule, began March 2015, Resolved.
Show all 4 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Surface Water Treatment Rule
Treatment technique failure
|
Mar 1, 2015 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jun 1, 1996 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Dec 1, 1995 | Resolved |
|
Surface Water Treatment Rule
Treatment technique failure
|
Jun 1, 1993 | Resolved |
Enforcement actions
California regulators took 2 formal enforcement actions against California Water Service - San Carlos between 1993 and 2015. The most recent was a compliance order (no penalty) in April 2015.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Apr 21, 2015 | California | Compliance order (no penalty) | 1 violation (1 health-based): Surface Water Treatment Rule |
| Jun 30, 1993 | California | Compliance order (no penalty) | 1 violation (1 health-based): Surface Water Treatment Rule |
Where the water comes from
California Water Service - San Carlos buys its water from San Francisco Regional Water System. It lists no wells or intakes of its own. It also has emergency connections to Mid-Peninsula Water District and City of Redwood City. 2 other public water systems have emergency connections to California Water Service - San Carlos.
Buys water from
- San Francisco Regional Water System Burlingame, CA
Emergency or part-time connections to
- Mid-Peninsula Water District Belmont, CA
- City of Redwood City Redwood City, CA
Annual water quality report
California Water Service - San Carlos 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