CA0707573 · California

DELTA MUTUAL WATER COMPANY

Federal fiscal 2026Q3 · EPA violation and follow-up records

Violation records shown: 18
EPA health-based flag: 18
Health-based records unresolved in this snapshot: 0
Monitoring and reporting records: 0

Counties listed by EPA · Contra Costa County, California

Find the utility’s annual water quality report. For current advisories, check the utility or local drinking-water authority.

Violations and what followed

EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400023 · Arsenic · Arsenic Rule
Noncompliance period start July 1, 2025 · period end September 30, 2025 · first reported March 20, 2026 · EPA return-to-compliance field September 30, 2025

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400022 · Arsenic · Arsenic Rule
Noncompliance period start April 1, 2025 · period end June 30, 2025 · first reported March 20, 2026 · EPA return-to-compliance field June 30, 2025

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400021 · Arsenic · Arsenic Rule
Noncompliance period start January 1, 2025 · period end March 31, 2025 · first reported March 20, 2026 · EPA return-to-compliance field March 31, 2025

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400020 · Arsenic · Arsenic Rule
Noncompliance period start October 1, 2024 · period end December 31, 2024 · first reported February 24, 2025 · EPA return-to-compliance field December 31, 2024

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400019 · Arsenic · Arsenic Rule
Noncompliance period start October 1, 2023 · period end December 31, 2023 · first reported February 15, 2024 · EPA return-to-compliance field December 31, 2023

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400018 · Arsenic · Arsenic Rule
Noncompliance period start July 1, 2023 · period end September 30, 2023 · first reported February 15, 2024 · EPA return-to-compliance field September 30, 2023

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400017 · Arsenic · Arsenic Rule
Noncompliance period start April 1, 2023 · period end June 30, 2023 · first reported August 16, 2023 · EPA return-to-compliance field June 30, 2023

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400016 · Arsenic · Arsenic Rule
Noncompliance period start January 1, 2023 · period end March 31, 2023 · first reported March 31, 2023 · EPA return-to-compliance field March 31, 2023

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400015 · Arsenic · Arsenic Rule
Noncompliance period start October 1, 2022 · period end December 31, 2022 · first reported February 16, 2023 · EPA return-to-compliance field December 31, 2022

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400013 · Arsenic · Arsenic Rule
Noncompliance period start July 1, 2022 · period end September 30, 2022 · first reported November 17, 2022 · EPA return-to-compliance field September 30, 2022

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400014 · Arsenic · Arsenic Rule
Noncompliance period start April 1, 2022 · period end June 30, 2022 · first reported November 17, 2022 · EPA return-to-compliance field June 30, 2022

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400012 · Arsenic · Arsenic Rule
Noncompliance period start January 1, 2022 · period end March 31, 2022 · first reported March 31, 2022 · EPA return-to-compliance field March 31, 2022

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400011 · Arsenic · Arsenic Rule
Noncompliance period start October 1, 2021 · period end December 31, 2021 · first reported February 16, 2022 · EPA return-to-compliance field December 31, 2021

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400010 · Arsenic · Arsenic Rule
Noncompliance period start July 1, 2021 · period end September 30, 2021 · first reported February 16, 2022 · EPA return-to-compliance field September 30, 2021

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400009 · Arsenic · Arsenic Rule
Noncompliance period start April 1, 2021 · period end June 30, 2021 · first reported June 30, 2021 · EPA return-to-compliance field June 30, 2021

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400008 · Arsenic · Arsenic Rule
Noncompliance period start January 1, 2021 · period end March 31, 2021 · first reported June 30, 2021 · EPA return-to-compliance field March 31, 2021

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400007 · Arsenic · Arsenic Rule
Noncompliance period start October 1, 2020 · period end December 31, 2020 · first reported January 5, 2021 · EPA return-to-compliance field December 31, 2020

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued
EPA health-based flag · Archived
Maximum Contaminant Level Violation, AverageViolation 400006 · Arsenic · Arsenic Rule
Noncompliance period start July 1, 2020 · period end September 30, 2020 · first reported January 5, 2021 · EPA return-to-compliance field September 30, 2020

1 linked action

Enforcement and resolution records linked by EPA
Action ID Date Category EPA action type
400045 January 31, 2020 Formal State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

Enforcement and resolution records linked by EPA
Action ID	Date	Category	EPA action type
400045	January 31, 2020	Formal	State Administrative/Compliance Order without penalty issued

EPA data and scope

How to read the records

The enforcement snapshot is federal fiscal 2026Q3. The EPA archive labels its violation file October 13, 2026. EPA says federal reporting can lag by several months. For current advisories, check your utility or local drinking-water authority.

We matched active community water systems by public water system ID between EPA’s system search and SDWIS inventory. We show violations with a recorded noncompliance, initial reporting or return-to-compliance date from 2021 onward, plus earlier records listed as Addressed or Unaddressed.
EPA’s health-based flag identifies violations of contaminant or disinfectant limits or treatment requirements. Monitoring and reporting violations describe required tests or reports. Neither category measures household exposure.
Addressed means EPA records formal enforcement on a violation that remains unresolved in the snapshot. Unaddressed means no formal action is recorded for an unresolved violation. Resolved can mean compliance was restored, the rule ceased to apply, or further action was unnecessary. Archived is a separate status.
We count a violation once per water system and group its distinct linked actions. Conflicting records are set aside. Places are EPA-listed search locations and can include mailing locations. Use the provider name and system ID to identify your service.

EPA data dictionary and files · EPA reporting and enforcement FAQ · Find an annual water quality report · How to get the report from your utility