Loading city report
Preparing Mammoth Lakes environmental records...
Review government records associated with Mammoth Lakes, California.
Toxin Scout is in beta. Please verify important findings with the linked sources.
Loading city report
Preparing Mammoth Lakes environmental records...
Check your water bill for your utility name and confirm the reporting year. See EPA’s guide to finding your annual water quality report.
Public water-system records for Mammoth Lakes, CA from EPA SDWIS.
Mammoth Cwd
No active drinking-water issues detected in EPA SDWIS.
Reviewed: active/open records as of Q1 2026
City listed in EPA records · Serves 8,234 people
Data from EPA SDWIS
Reviewed: source records as of Q1 2026
EPA UCMR5 — No PFAS detection records shown for these water systems
Open data source: EPA UCMR5DoD PFAS — No investigation records shown for this report
Open data source: DoD PFASEPA ATTAINS records identify assessed water bodies that do not meet water-quality standards for designated uses.
Mammoth Creek
Reported: Nov 2026
Health-relevant causes: Mercury, Metals (other Than Mercury)
Affected uses: Drinkingwater, Ecological, Fishconsumption, Other
Data from EPA ATTAINS
Reviewed: source records as of Q4 2025
To investigate water contamination, check the sampling locations, dates and results below. For tap water records, see Drinking water quality above.
Reviewed: source records as of 2026
Review historical EPA air pollution records, including monitoring and facility emissions where available. For current conditions, check local air quality on AirNow.
Mono County
Assessment year: 2020
According to EPA, a cancer risk of 20-in-1-million means that for every 1 million people continuously exposed to these air toxics over a 70-year lifetime, an estimated 20 may develop cancer from that exposure. This is in addition to cancer risk from all other causes.
Top modeled source groups
Data from EPA AirToxScreen
EPA designations apply to a specific pollutant and federal air quality standard (NAAQS). EPA can issue a clean-data determination while a formal designation remains in effect.
Maintenance areas
Previously nonattainment; currently meeting the standard and monitored under an EPA maintenance plan.
Mono County; Mammoth Lake Planning Area
PM10 · PM-10 (1987 Standard)
Classification: Moderate
Original designation: Nov 1990
Current design value: 0.7 est. exc. (2023-2025)
Data from EPA Green Book
EPA annual monitor summaries describe past measurements. For current air quality, see AirNow.
Lee Vining
Annual mean: 12.0 Micrograms/cubic meter (25 C)
EPA primary exceedance count: 2 (PM10 24-hour 2006)
Includes measurements flagged for exceptional events.
Observation year: 2025
Annual mean: 4.8 Micrograms/cubic meter (LC)
Includes measurements flagged for exceptional events.
Observation year: 2025
Mammoth Lakes
Annual mean: 21.5 Micrograms/cubic meter (25 C)
EPA primary exceedance count: 2 (PM10 24-hour 2006)
Includes measurements flagged for exceptional events.
Observation year: 2025
Data from EPA AQS
Reviewed: source records as of Q4 2025
Reviewed: source query run Nov 2026
Reviewed: source query run Nov 2026
State environmental agencies maintain cleanup site databases that include state Superfund, voluntary cleanup, and brownfield remediation programs. These programs track additional sites beyond those on the federal NPL.
2 sites with active cleanup or investigation
37 DEGREE 35.64'; 118 DEGREE 58.85', Mammoth Lakes
2.1 miles away · MONO County
Reported: Nov 2026
37 DEG 36.84'; 118 DEG 59.90', Mammoth Lakes
0.4 miles away · MONO County
Reported: Nov 2026
Data from EPA ECHO
No release reports shown in this group.
Reviewed: active/open records as of 2018
Data from EPA UST Finder
No MSHA mine or extraction site records shown for this report.
Mono County, CA
EPA Radon Zone Map (June 2024 release)
Mono County is EPA Radon Zone 2 (moderate potential). EPA defines Zone 2 counties as having predicted average indoor screening levels between 2 pCi/L and 4 pCi/L.
Radon levels can vary from home to home, so EPA recommends testing the property to know its indoor level.
FEMA flood zones describe mapped flood hazards. Look up a specific address with FEMA.
No FEMA flood-zone records shown for this report.
Results use an earlier stored RMP inventory. Current EPA ECHO location coverage is unverified.
EPA ECHO lists facilities linked to the Risk Management Program. Results include facilities with locations that can be matched. Records may be historical. Current operations, chemical inventories, and recent accident history are unverified.
PHMSA tracks incidents involving natural gas and hazardous liquid pipelines. Incidents include leaks, ruptures, and explosions.
Recent Incidents (last 5 years)
AMERIGAS PROPANE LP
Incident date: Apr 1, 2023
Property damage: $300
Data from PHMSA
Health outcomes from County Health Rankings. Values shown alongside state and national averages.
Mono County, CaliforniaPop. 12,978
County Health Rankings edition: 2024
Premature Death
Poor or Fair Health
Poor Physical Health Days
Poor Mental Health Days
Adult Smoking
Adult Obesity
Air Pollution - Particulate Matter
Drinking water violation indicator
Diabetes Prevalence
Life Expectancy
| Indicator | County | State | National |
|---|---|---|---|
| Premature Death | 4,789 | 6,373 | 7,972 |
| Poor or Fair Health | 14.8% | 15.8% | 14.2% |
| Poor Physical Health Days | 3.5 | 3.1 | 3.3 |
| Poor Mental Health Days | 5.2 | 4.7 | 4.8 |
| Adult Smoking | 12.4% | 8.8% | 15.0% |
| Adult Obesity | 29.6% | 27.8% | 34.0% |
| Air Pollution - Particulate Matter | 8.5 | 7.1 | 7.3 |
| Drinking water violation indicator | No | N/A | N/A |
| Diabetes Prevalence | 8.7% | 10.8% | 9.6% |
| Life Expectancy | 98.9 | 79.9 | 77.6 |
This report does not have PFAS sample results for the candidate water systems in Mammoth Lakes.
Check with the utility that serves your address for its testing results.
EPA drinking water records on this page list 4 violations for Mammoth Cwd.
Check your water bill to identify the utility serving your address. Ask that utility about current drinking water advisories.
Nearby EPA monitoring stations provide annual air quality measurements for Mammoth Lakes.
The monitoring station at Lee Vining recorded an annual average of 12 Micrograms/cubic meter (25 C) for particles (PM10) in 2025.
The monitoring station at Lee Vining recorded an annual average of 4.8 Micrograms/cubic meter (LC) for fine particles (PM2.5) in 2025.
The monitoring station at Mammoth Lakes recorded an annual average of 21.5 Micrograms/cubic meter (25 C) for particles (PM10) in 2025.
The radon data for Mammoth Lakes covers Mono County. EPA places this area in Zone 2, with a predicted average indoor radon screening level of 2 to 4 picocuries per liter.
No Superfund or brownfield sites were returned for this city report.
The county data for Mammoth Lakes reports a life expectancy of 98.9 years in Mono County, California.
The figure is from the 2024 edition of County Health Rankings, a University of Wisconsin program that publishes county health statistics.
The county data for Mammoth Lakes reports 4,789 years of life lost to deaths before age 75 per 100,000 residents in Mono County, California. This measure adds up the years lost to early deaths and adjusts for differences in population age.
The figure is from the 2024 edition of County Health Rankings, a University of Wisconsin program that publishes county health statistics.
The county data for Mammoth Lakes lists fine-particle pollution (PM2.5) at 8.5 micrograms per cubic meter in Mono County, California.
The figure is from the 2024 edition of County Health Rankings, a University of Wisconsin program that publishes county health statistics.
Federal pipeline records list an incident involving Amerigas Propane LP near Mammoth Lakes on Apr 1, 2023. The reported release was propane gas.