OAKLEY, CA · Contra Costa County
DELTA MUTUAL WATER COMPANY Water System
Consumer Confidence Report status
DELTA MUTUAL WATER COMPANY 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 DELTA MUTUAL WATER COMPANY.
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)
- CA0707573
- System type
- Community Water System
- Population served
- 333
- Service connections
- 119
- Ownership
- privately owned
- Water source
- groundwater (wells)
DELTA MUTUAL WATER COMPANY is one of 3,951 community water systems in California in the 500 or fewer people size category, serving 333 people from groundwater.
As of August 1, 2026, its federal record holds 3 entries between 1981 and 2023, all of which EPA lists as closed. Nothing has been added since 2023.
Of the 3, 1 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 inorganic chemicals, the Miscellaneous Other Rules, and the Radionuclides and Revised Rad Rule.
Violation history
Maximum Contaminant Level Violation, Average
Health-basedArsenic
October 1, 2023 – December 31, 2023
ArchivedNotification, Public
—No contaminant on record
March 1, 1984 – March 31, 1984
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, 2023 – December 31, 2023 | Maximum Contaminant Level Violation, Average | Arsenic | Health-based | Archived |
| March 1, 1984 – March 31, 1984 | 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
No enforcement actions on record for this system.
Common questions
Is DELTA MUTUAL WATER COMPANY required to publish a Consumer Confidence Report?
- Yes. DELTA MUTUAL WATER COMPANY 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 DELTA MUTUAL WATER COMPANY’s next Consumer Confidence Report due?
- DELTA MUTUAL WATER COMPANY’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does DELTA MUTUAL WATER COMPANY have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for DELTA MUTUAL WATER COMPANY.
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
SKOOG, CONNIE
925-420-6260
OAKLEY, CA 94561