Chalfant Valley West M.W.C., CA
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2023-2025). 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.
Who runs the water here
Chalfant Valley West M.W.C. serves about 45 people through 15 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Mono County, California. EPA system ID: CA2600699; phone on file: 760-937-0761. They can tell you what your service line is made of and whether they pay to replace it.
Chalfant Valley West M.W.C.'s lead record
Against the period ending 2019 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Chalfant Valley West M.W.C. is 0 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2016 | 0 (not detected) |
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. Chalfant Valley West M.W.C.'s reported as 0 (not detected) sits at the 6th percentile in California and the 3rd nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
17 other systems share Mono County; 13 of them have a higher latest lead result than Chalfant Valley West M.W.C.. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Mammoth Cwd | 8,234 | 1.5 ppb |
| Mountain Meadows Mwc | 525 | 4.4 ppb |
| Usmc - Housing Coleville | 424 | 1.3 ppb |
| Bridgeport Pud | 374 | 1.9 ppb |
| Lower Rock Creek Mutual Water Co. | 310 | 0 (not detected) |
| June Lake Pud - Down Canyon | 310 | 2 ppb |
| Usmc/Mtn Warfare Trng Ctr - Bridgeport | 300 | 1 ppb |
| June Lake Pud Village | 263 | 2.7 ppb |
| Crowley Lake Trailer Park | 230 | 9.4 ppb |
| Lee Vining Public Utility District | 222 | 8 ppb |
Your move
Look up your address in Chalfant Valley West M.W.C.'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 Chalfant Valley West M.W.C. 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. Small systems behave differently: why small systems go over more often.