B75/100
MAMMOTH CWD — Water Quality Report 2026
Serving 8,234 people · California
Water Source
Surface Water
County
—
System ID
CA2610001
Violations
5
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.40 mg/L | 1.30 mg/L | Over Limit |
EPA Violation History
2
Violations (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2023 – December 31, 2023Rule: Stage 2 DBPREnforcement: Formal — state order issued
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2023 – December 31, 2023Rule: Stage 2 DBPREnforcement: Formal — state order issued
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Frequently Asked Questions About MAMMOTH CWD
Is MAMMOTH CWD water safe to drink?
MAMMOTH CWD water receives a grade of B (75/100), which is considered good. Out of 52 contaminants tested, 1 exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has MAMMOTH CWD detected?
52 contaminants were tested in MAMMOTH CWD's water. Notable contaminants include Copper (90th percentile). 1 exceed EPA legal limits (MCLs). 1 exceed EPA health goals (MCLGs).
Does MAMMOTH CWD have any EPA violations?
Yes, MAMMOTH CWD has 5 EPA violation(s) on record, with the most recent in 2023. Violation types include MR, TT, MCL. 3 are health-based violations.
How many people does MAMMOTH CWD serve?
MAMMOTH CWD serves approximately 8,234 people, California.
What type of water does MAMMOTH CWD provide?
MAMMOTH CWD sources its water from surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is CA2610001.
How does MAMMOTH CWD compare to other utilities in California?
MAMMOTH CWD scores 75/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our California state page for a full comparison of water systems.