San Miguelito 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.
About San Miguelito Mwc
San Miguelito Mwc serves about 1,600 people through 690 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws surface water, in San Luis Obispo County, California. EPA system ID: CA4010003; phone on file: 805-595-2348. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
Against the period ending 2025 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for San Miguelito Mwc is 0 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2020 | 0 (not detected) |
| 2019 | 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. San Miguelito Mwc's reported as 0 (not detected) sits at the 44th percentile in California and the 29th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
71 other systems share San Luis Obispo County; 27 of them have a higher latest lead result than San Miguelito Mwc. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| San Luis Obispo Water Department | 49,534 | 0 (not detected) |
| Atascadero Mutual Water Co | 33,307 | 0 (not detected) |
| City Of Paso Robles Water Division | 31,176 | 0 (not detected) |
| City Of Arroyo Grande Utilities Division | 17,963 | 0 (not detected) |
| California Mens Colony | 15,000 | 0 (not detected) |
| Nipomo Comm Services Dist | 13,771 | 0 (not detected) |
| City Of Grover Beach Public Works Dept | 12,701 | 0 (not detected) |
| Morro Bay Pw Dept - Water Division | 10,757 | 0 (not detected) |
| Templeton Csd | 8,041 | 0 (not detected) |
| Pismo Beach Water Department | 7,944 | 0 (not detected) |
What to do in your house
Look up your address in San Miguelito 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 San Miguelito Mwc whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1520 ppb (copper action level 1,300 ppb).
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. A zero today does not rule out a jump later - the rules are tightening in 2027.