Mariposa Pines Mutual, CA
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2022-2024). 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 Pines Mutual serves about 294 people through 89 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Mariposa County, California. EPA system ID: CA2210906; phone on file: 209-742-7130. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2021 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Mariposa Pines Mutual is 2.4 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2017 | 2.4 ppb |
How Mariposa Pines Mutual compares
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 Pines Mutual's reported as 0 (not detected) sits at the 32nd percentile in California and the 18th 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 Pines Mutual. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Mariposa Public Utility Dist | 2,000 | 0 (not detected) |
| 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 |
| 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 |
What to do in your house
Look up your address in Mariposa Pines Mutual'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 Pines Mutual 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. Small systems behave differently: why small systems go over more often.