Yosemite Nps-Wawona, 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.
About Yosemite Nps-Wawona
Yosemite Nps-Wawona serves about 150 people through 141 service connections, which makes it a very small system under EPA's size classes. It is federally owned and draws surface water, in Mariposa County, California. EPA system ID: CA2210510; phone on file: 209-379-1055. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
That is down 9.6 ppb from 9.6 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Yosemite Nps-Wawona is 9.6 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 0 (not detected) |
| 2021 | 9.6 ppb |
| 2018 | 7.07 ppb |
How Yosemite Nps-Wawona 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. Yosemite Nps-Wawona's reported as 0 (not detected) sits at the 23rd percentile in California and the 13th 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 Yosemite Nps-Wawona. 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 |
| Mariposa Pines Mutual | 294 | 0 (not detected) |
| Mpwd-Coulterville Csa 1 | 193 | 1.4 ppb |
| Yosemite Terrace Estates | 130 | 6.6 ppb |
| Mcclure Boat Club, Inc. | 36 | 10 ppb |
| Cedar Lodge | 28 | 3.7 ppb |
Next steps for Yosemite Np, CA
Look up your address in Yosemite Nps-Wawona'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 Yosemite Nps-Wawona 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. The lead result guide covers how utilities pick the homes they sample. Small systems behave differently: why small systems go over more often.