SANTA ROSA, CA · Sonoma County
SONOMA MOUNTAIN COUNTY WATER DISTRICT Water System
Consumer Confidence Report status
SONOMA MOUNTAIN COUNTY WATER DISTRICT 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 SONOMA MOUNTAIN COUNTY WATER DISTRICT.
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)
- CA4900580
- System type
- Community Water System
- Population served
- 181
- Service connections
- 56
- Ownership
- local government
- Water source
- groundwater (wells)
SONOMA MOUNTAIN COUNTY WATER DISTRICT is one of 3,951 community water systems in California in the 500 or fewer people size category, serving 181 people from groundwater.
As of August 1, 2026, its federal record holds 6 entries between 1980 and 2015, all of which EPA lists as closed. Nothing has been added since 2015.
Of the 6, 3 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 the Miscellaneous Other Rules, the Radionuclides and Revised Rad Rule, and the Total Coliform Rules.
Violation history
Monitoring, Routine Major (TCR)
—Coliform (TCR)
September 1, 2015 – September 30, 2015
ResolvedNotification, 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
ArchivedMonitoring, Regular
—Gross Alpha, Excl. Radon and U
October 30, 1980 – October 29, 1981
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 |
|---|---|---|---|---|
| September 1, 2015 – September 30, 2015 | Monitoring, Routine Major (TCR) | Coliform (TCR) | — | Resolved |
| 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 |
| October 30, 1980 – October 29, 1981 | Monitoring, Regular | Gross Alpha, Excl. Radon and U | — | 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 SONOMA MOUNTAIN COUNTY WATER DISTRICT required to publish a Consumer Confidence Report?
- Yes. SONOMA MOUNTAIN COUNTY WATER DISTRICT 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 SONOMA MOUNTAIN COUNTY WATER DISTRICT’s next Consumer Confidence Report due?
- SONOMA MOUNTAIN COUNTY WATER DISTRICT’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does SONOMA MOUNTAIN COUNTY WATER DISTRICT have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for SONOMA MOUNTAIN COUNTY WATER DISTRICT.
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
ADAMS, KRISTINE
707-328-5814
SANTA ROSA, CA 95404