Yosemite Terrace Estates, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 6.6 ppb (monitoring period 2021-2023). 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.
About Yosemite Terrace Estates
Yosemite Terrace Estates serves about 130 people through 53 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: CA2210925; phone on file: 209-878-3847. They can tell you what your service line is made of and whether they pay to replace it.
Yosemite Terrace Estates's lead record
That is up 6.6 ppb from 0 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Yosemite Terrace Estates is 13 ppb across 3 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 6.6 ppb |
| 2020 | 0 (not detected) |
| 2017 | 13 ppb over 10 |
Against other California systems
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 Terrace Estates's 6.6 ppb sits at the 95th percentile in California and the 94th nationally (higher means more lead).
Nearby utilities
10 other systems share Mariposa County; 1 of them has a higher latest lead result than Yosemite Terrace Estates. 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 Nps-Wawona | 150 | 0 (not detected) |
| Mcclure Boat Club, Inc. | 36 | 10 ppb |
| Cedar Lodge | 28 | 3.7 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Greeley Hill, 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 Terrace 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. Why sampled homes are the worst-case ones is in the guide to reading the number. The action level is dropping - the 10 ppb rule from 2027.