CORTE MADERA, CA · Sonoma County
RANCHO DE SONOMA - INACTIVE Water System
Inactive system
This water system is marked inactive in EPA’s federal records as of September 20, 2012. It is no longer an operating public water system under this PWSID, and no compliance deadlines — including the 2027 Consumer Confidence Report rule — apply to it.
If you are a resident looking for your current water provider, see water systems in Sonoma County, CA.
Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed July 4, 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)
- CA4900845
- System type
- Community Water System
- Population served
- 0
- Service connections
- 98
- Ownership
- privately owned
- Water source
- groundwater (wells)
Violation history
Maximum Contaminant Level Violation, Average
Health-basedArsenic
October 1, 2007 – December 31, 2007
ArchivedNotification, Public
—No contaminant on record
September 1, 1984 – September 30, 1984
ArchivedNotification, Public
—No contaminant on record
July 1, 1984 – July 31, 1984
ArchivedNotification, Public
—No contaminant on record
May 1, 1983 – May 31, 1983
ArchivedMonitoring, Regular
—Gross Alpha, Excl. Radon and U
October 1, 1981 – September 30, 1982
Archived
Archived closed in EPA's records (typically due to age or a data correction)
| Period | Violation | Contaminant / rule | Health-based | Status |
|---|---|---|---|---|
| October 1, 2007 – December 31, 2007 | Maximum Contaminant Level Violation, Average | Arsenic | Health-based | Archived |
| September 1, 1984 – September 30, 1984 | Notification, Public | — | — | Archived |
| July 1, 1984 – July 31, 1984 | Notification, Public | — | — | Archived |
| May 1, 1983 – May 31, 1983 | Notification, Public | — | — | Archived |
| October 1, 1981 – September 30, 1982 | Monitoring, Regular | Gross Alpha, Excl. Radon and U | — | Archived |
Archived closed in EPA's records (typically due to age or a data correction)
Enforcement actions
- July 31, 2008Federal Final Administrative Order issued10 linked violations
- December 20, 1999State Administrative/Compliance Order without penalty issued2 linked violations
Last known contact on file (system is inactive)
RANCHO DE SONOMA
4159452473
CORTE MADERA, CA 94925