SONOMA, CA · Sonoma County
MISSION HIGHLANDS MUTUAL WATER CO. Water System
Consumer Confidence Report status
MISSION HIGHLANDS MUTUAL WATER CO. 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 MISSION HIGHLANDS MUTUAL WATER CO..
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)
- CA4900563
- System type
- Community Water System
- Population served
- 150
- Service connections
- 69
- Ownership
- privately owned
- Water source
- groundwater (wells)
MISSION HIGHLANDS MUTUAL WATER CO. is one of 3,951 community water systems in California in the 500 or fewer people size category, serving 150 people from groundwater.
As of August 1, 2026, its federal record holds 5 entries between 1981 and 2019, all of which EPA lists as closed. Nothing has been added since 2019.
Of the 5, 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 the Miscellaneous Other Rules, the Stage 2 Disinfectants and Disinfection Byproducts Rule, and the Radionuclides and Revised Rad Rule.
Violation history
Monitoring and Reporting (DBP)
—Total Haloacetic Acids (HAA5)
January 1, 2019 – December 31, 2021
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
October 1, 1982 – October 31, 1982
ArchivedMonitoring, Regular
—Gross Alpha, Excl. Radon and U
October 1, 1981 – September 30, 1982
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, 2019 – December 31, 2021 | Monitoring and Reporting (DBP) | Total Haloacetic Acids (HAA5) | — | Resolved |
| September 1, 1984 – September 30, 1984 | Notification, Public | — | — | Archived |
| July 1, 1984 – July 31, 1984 | Notification, Public | — | — | Archived |
| October 1, 1982 – October 31, 1982 | Notification, Public | — | — | Archived |
| October 1, 1981 – September 30, 1982 | 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
- March 23, 2022State Administrative/Compliance Order without penalty issued5 linked violations
Common questions
Is MISSION HIGHLANDS MUTUAL WATER CO. required to publish a Consumer Confidence Report?
- Yes. MISSION HIGHLANDS MUTUAL WATER CO. 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 MISSION HIGHLANDS MUTUAL WATER CO.’s next Consumer Confidence Report due?
- MISSION HIGHLANDS MUTUAL WATER CO.’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does MISSION HIGHLANDS MUTUAL WATER CO. have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for MISSION HIGHLANDS MUTUAL WATER CO..
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
JOHNSTON, TOPPER
415-710-8629
SONOMA, CA 95476