F0/100
Mariposa Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 2,000 residents · California
What's In Mariposa's Tap Water?
2
Contaminants Tested
1
Exceed EPA Limits
0
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.50 mg/L | 1.30 mg/L | Over Limit |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2013.
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
Water Utility Details
MARIPOSA PUBLIC UTILITY DIST
Population Served
2,000
Water Source
Surface Water
System ID
CA2210001
Frequently Asked Questions About Mariposa Water
Is Mariposa tap water safe to drink?
Mariposa, California tap water receives a grade of F (0/100), which is considered failing. 1 contaminant(s) exceed EPA maximum contaminant levels and 51 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Mariposa's water?
Of the 2 contaminants tested in Mariposa's water supply, the most notable include Copper (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Mariposa have any water quality violations?
Yes, Mariposa has 51 EPA violation(s) on record, with the most recent in 2013. Violation types include MCL, TT, MR. 47 of these are health-based violations, which are the most serious category.
Do I need a water filter in Mariposa?
Based on EPA data, using a water filter in Mariposa is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Mariposa's tap water come from?
Mariposa's drinking water is sourced from surface water and supplied by MARIPOSA PUBLIC UTILITY DIST. The system serves approximately 2,000 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Mariposa's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Mariposa's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Mariposa's water compare to other cities in California?
Mariposa's water quality score of 0/100 earns a grade of F, which is considered failing. This is a concerning score that suggests significant water quality issues. Visit our California state page to see how all cities in the state compare.
What should I do if I'm concerned about Mariposa's water quality?
If you have concerns about Mariposa's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (MARIPOSA PUBLIC UTILITY DIST) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.