Chamisal Mwc, CA
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2024-2026). 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.
Chamisal Mwc at a glance
Chamisal Mwc serves about 84 people through 29 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in San Bernardino County, California. EPA system ID: CA3600071; phone on file: 760-388-4160. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Chamisal Mwc's lead record
That is down 4.1 ppb from 4.1 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Chamisal Mwc is 4.1 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2022 | 4.1 ppb |
| 2018 | 0 (not detected) |
Where this result ranks
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. Chamisal Mwc's reported as 0 (not detected) sits at the 15th percentile in California and the 8th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
146 other systems share San Bernardino County; 34 of them have a higher latest lead result than Chamisal Mwc. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| San Gabriel Valley Wc - Fontana | 228,270 | 0 (not detected) |
| San Bernardino City | 214,665 | 0 (not detected) |
| Cucamonga Valley Water District | 213,375 | 0 (not detected) |
| Ontario Municipal Utilities Company | 185,010 | 0.6 ppb |
| Victorville Water District | 140,721 | 0 (not detected) |
| San Bernardino Valley Wd | 109,608 | - |
| East Valley Water District | 108,600 | 0 (not detected) |
| Hesperia Wd | 101,836 | 0 (not detected) |
| West Valley Water District | 96,123 | 0 (not detected) |
| Chino, City Of | 90,187 | 1 ppb |
Your move
Look up your address in Chamisal Mwc'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 Chamisal Mwc 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. What a 90th-percentile result does and does not tell you: how to read a lead result. A zero today does not rule out a jump later - the rules are tightening in 2027.