Mariposa Public Utility Dist, CA
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2023-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Who runs the water here
Mariposa Public Utility Dist serves about 2,000 people through 684 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Mariposa County, California. EPA system ID: CA2210001; phone on file: 209-966-2515. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Mariposa Public Utility Dist's lead record
Against the period ending 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Mariposa Public Utility Dist is 0 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2016 | 0 (not detected) |
Where this result ranks
Of the 2,884 California systems with a lead result, the median latest reading is 0 ppb; 30 are over 15 ppb right now and 215 have gone over at some point. Mariposa Public Utility Dist's reported as 0 (not detected) sits at the 45th percentile in California and the 31st nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
10 other systems share Mariposa County; 5 of them have a higher latest lead result than Mariposa Public Utility Dist. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Yosemite Nps-Yosemite Valley | 1,000 | 0 (not detected) |
| Ponderosa Basin Mutual Wtr Co | 798 | 0 (not detected) |
| Yosemite Nps-El Portal | 635 | 0 (not detected) |
| Yosemite West Water System | 420 | 2.2 ppb |
| Mariposa Pines Mutual | 294 | 0 (not detected) |
| Mpwd-Coulterville Csa 1 | 193 | 1.4 ppb |
| Yosemite Nps-Wawona | 150 | 0 (not detected) |
| Yosemite Terrace Estates | 130 | 6.6 ppb |
| Mcclure Boat Club, Inc. | 36 | 10 ppb |
| Cedar Lodge | 28 | 3.7 ppb |
Next steps for Mariposa, CA
Look up your address in Mariposa Public Utility Dist's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Mariposa Public Utility Dist whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. Why sampled homes are the worst-case ones is in the guide to reading the number. A zero today does not rule out a jump later - the rules are tightening in 2027.