Water Quality: Mammoth Lakes, CA
3 water systems • 8,979 people served
Multiple Health ViolationsWater Quality Summary
Mammoth Lakes is served by 3 public water systems with a combined service population of 8,979 people, and has 52 EPA Safe Drinking Water Act violations on record. Critically, 44 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Mammoth Lakes's violation count is 8% above the national average for California. Contaminants associated with violations include Contaminant 4109, Fecal Coliform, Gross Alpha, Haloacetic Acids.
Contaminants Found
Indicates direct fecal contamination; associated with diarrhea, cramps, nausea, and potential severe illness.
Common source: Human and animal fecal waste
EPA limit: Zero tolerance (any positive triggers violations)
Alpha-emitting radioactive particles increase cancer risk, particularly from bone and other internal cancers.
Common source: Natural uranium and radium in geological formations
EPA limit: 15 pCi/L (excluding radon and uranium)
Linked to increased cancer risk and potential reproductive and developmental effects with long-term exposure.
Common source: Reaction of chlorine disinfectants with organic matter in treated water
EPA limit: 0.060 mg/L (60 ppb)
Water Systems Serving Mammoth Lakes
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| MAMMOTH CWD | CA2610001 | Surface Water | 8,234 | 4 |
| MOUNTAIN MEADOWS MWC | CA2600620 | Groundwater | 505 | 1 |
| PINE CREEK VILLAGE | CA1400006 | Groundwater | 240 | 47 |
Concerned About Your Water?
A home water filter can remove common contaminants. NSF-certified filters are tested against EPA standards.
Consider a reverse osmosis system for comprehensive filtration or a carbon filter for basic improvement.
Other Cities in California
Data Sources
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). Data includes all recorded violations for active community water systems.