Farmington Water Company, 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.
About Farmington Water Company
Farmington Water Company serves about 270 people through 80 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in San Joaquin County, California. EPA system ID: CA3900505; phone on file: 209-886-5346. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
Against the period ending 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Farmington Water Company is 0.9 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2019 | 0.8 ppb |
| 2016 | 0.9 ppb |
How Farmington Water Company 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. Farmington Water Company's reported as 0 (not detected) sits at the 31st percentile in California and the 18th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
92 other systems share San Joaquin County; 12 of them have a higher latest lead result than Farmington Water Company. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| City Of Stockton | 192,702 | 0 (not detected) |
| California Water Service - Stockton | 182,775 | 0 (not detected) |
| Tracy, City Of | 98,215 | 0 (not detected) |
| Manteca, City Of | 84,928 | 0.4 ppb |
| Lodi, City Of | 67,093 | 0 (not detected) |
| City Of Lathrop | 38,596 | 0 (not detected) |
| City Of Mountain House | 26,400 | 0 (not detected) |
| Ripon, City Of | 15,753 | 0 (not detected) |
| Escalon, City Of | 7,232 | 0 (not detected) |
| San Joaquin County - Lincoln Village | 5,841 | 0 (not detected) |
What to do in your house
Look up your address in Farmington Water Company'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 Farmington Water Company 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. Small systems behave differently: why small systems go over more often.