Yosemite Vista Estates, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 6.6 ppb (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. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
Who runs the water here
Yosemite Vista Estates serves about 80 people through 60 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Tuolumne County, California. EPA system ID: CA5500119; phone on file: 209-962-5988. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
That is up 6.6 ppb from 0 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Yosemite Vista Estates is 6.6 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 6.6 ppb |
| 2021 | 0 (not detected) |
| 2018 | 0 (not detected) |
How Yosemite Vista Estates 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 Vista Estates's 6.6 ppb sits at the 95th percentile in California and the 94th nationally (higher means more lead).
Nearby utilities
48 other systems share Tuolumne County; 6 of them have a higher latest lead result than Yosemite Vista Estates. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Tud - Upper Basin Water System | 13,331 | 0 (not detected) |
| Tud - Sonora/Jamestown Water System | 11,113 | 0 (not detected) |
| Tud - Columbia Water System | 5,482 | 5.4 ppb |
| Cdcr - Sierra Conservation Center | 3,571 | 0 (not detected) |
| Groveland Community Serv Dist | 3,400 | 0 (not detected) |
| Twain Harte Community Services District | 2,378 | 0 (not detected) |
| Tud - Tuolumne Water System | 1,798 | 0 (not detected) |
| Tud - Ponderosa | 1,781 | 0 (not detected) |
| Cold Springs Water Co | 1,771 | 2.8 ppb |
| Lake Don Pedro Csd | 1,700 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Groveland, CA may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Yosemite Vista Estates 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. Size matters more than most people expect: small vs large water systems.