Sierra Twain Harte Mhp, 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 Sierra Twain Harte Mhp
Sierra Twain Harte Mhp serves about 129 people through 46 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: CA5500096; phone on file: 209-630-8876. They can tell you what your service line is made of and whether they pay to replace it.
Sierra Twain Harte Mhp's lead record
That is down 3.36 ppb from 3.36 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Sierra Twain Harte Mhp is 9.3 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 0 (not detected) |
| 2021 | 3.36 ppb |
| 2018 | 9.3 ppb |
How Sierra Twain Harte Mhp 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. Sierra Twain Harte Mhp's reported as 0 (not detected) sits at the 22nd percentile in California and the 12th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
48 other systems share Tuolumne County; 16 of them have a higher latest lead result than Sierra Twain Harte Mhp. 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) |
Next steps for Jamestown, CA
Look up your address in Sierra Twain Harte Mhp'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 Sierra Twain Harte Mhp 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.