Mammoth Cwd
EPA ID: CA2610001 · 8,234 people served · 1 ZIP code
ZipCheckup's reading of EPA records for Mammoth Cwd (CA2610001): 2 violations on record since 2021. Per the federal file, all 2 violations logged for Mammoth Cwd carry a resolved status, and around 8,234 people get water from this system.
Data: EPA SDWIS
Service Area Map
Coverage area for Mammoth Cwd Source: EPA SDWIS service area boundaries.
Service area boundary - average Home Safety grade of mapped ZIPs: B
Demographics of ZIP Codes Served
The ZIP codes associated with Mammoth Cwd have a median household income of $96,481 and about 8,803 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 66% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Mammoth Cwd's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in California
System Overview
Mammoth Cwd (EPA ID: CA2610001) is a community water system in California that serves approximately 8,234 people from surface water sources.
This system serves ZIP code 93546 in Mammoth Lakes.
ZIP-Area Home Safety Context: B (74/100)
This is the average Home Safety Score for 1 of 1 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Status breakdown for accepted records with record years 2021-2026: 2 resolved, 0 archived, 0 addressed, and 0 unaddressed. Under this source contract, current noncompliance is the sum of addressed and unaddressed records. Archived and resolved records are excluded from current noncompliance.
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| January 1, 2023 | Total Haloacetic Acids (HAA5) | Non-health-based | Resolved |
| January 1, 2023 | TTHM | Non-health-based | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Total Haloacetic Acids (HAA5) | Monitoring & Reporting | 1 | No |
| TTHM | Monitoring & Reporting | 1 | No |
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| Below the reporting limit | No | 2023-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
1 of 1 ZIP records with known zones is in EPA Radon Zone 2.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by CA or modeled from parcel and building-footprint data.
- 93546 - Mammoth Lakes
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View available EPA compliance records for Mammoth Cwd (CA2610001) on EPA.gov.
Frequently Asked Questions
Is Mammoth Cwd water safe to drink?
The accepted 2026Q2 ECHO snapshot shows no current noncompliance for Mammoth Cwd; its 2 accepted 2021-2026 records are resolved or archived. Historical compliance status does not establish conditions at a specific tap.
How many people does Mammoth Cwd serve?
Mammoth Cwd serves approximately 8,234 people across 1 ZIP code in California.
Where does Mammoth Cwd get its water?
The primary water source is surface water.
Federal UCMR5 PFAS Monitoring: No PFAS Reported Above Reporting Levels
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were reported above UCMR5 minimum reporting levels.
EPA's April 2024 PFAS rule sets MCLs of 4 ppt for PFOA and PFOS and 10 ppt for PFHxS, PFNA and HFPO-DA (GenX); water systems must comply from 2029. Other PFAS compounds have no individual federal MCL. A state standard is shown only where this system's state has its own enforceable PFAS limit. Detection results are EPA UCMR5 samples, not a measurement at your tap.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Mammoth Cwd (CA): 2 EPA Violations. https://zipcheckup.com/water-system/ca2610001/
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author = {{ZipCheckup}},
title = {{Mammoth Cwd (CA): 2 EPA Violations}},
year = {n.d.},
url = {https://zipcheckup.com/water-system/ca2610001/}
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What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Mammoth Cwd (EPA ID: CA2610001) - request the latest Consumer Confidence Report or ask about specific contaminants.