MAMMOTH LAKES, CA · Mono County

MAMMOTH CWD Water System

Current status

No open violations on record as of July 4, 2026.

This system's next federally required Consumer Confidence Report is due July 1, 2027, under the EPA's revised reporting rule.

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): CA2610001
System type: Community Water System
Population served: 8,234
Service connections: 3,818
Ownership: local government
Water source: surface water (rivers, lakes, or reservoirs)

Violation history

Monitoring and Reporting (DBP)
—
Total Haloacetic Acids (HAA5)
January 1, 2023 – December 31, 2023
Resolved
Monitoring and Reporting (DBP)
—
TTHM
January 1, 2023 – December 31, 2023
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
September 1, 1992 – September 30, 1992
Resolved
Treatment Technique (SWTR and GWR)
Health-based
Surface Water Treatment Rule
June 1, 1991 – June 30, 1991
Resolved

Resolved addressed and confirmed by the state

Period	Violation	Contaminant / rule	Health-based	Status
January 1, 2023 – December 31, 2023	Monitoring and Reporting (DBP)	Total Haloacetic Acids (HAA5)	—	Resolved
January 1, 2023 – December 31, 2023	Monitoring and Reporting (DBP)	TTHM	—	Resolved
September 1, 1992 – September 30, 1992	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved
June 1, 1991 – June 30, 1991	Treatment Technique (SWTR and GWR)	Surface Water Treatment Rule	Health-based	Resolved

Resolved addressed and confirmed by the state

Enforcement actions

July 10, 2024State Compliance achieved9 linked violations
November 8, 1993State Administrative/Compliance Order without penalty issued1 linked violation

Contact

BUSBY, MARK

760-934-2596

MAMMOTH LAKES, CA 93546