Little Potato Slough Mutual, 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.
Little Potato Slough Mutual at a glance
Little Potato Slough Mutual serves about 560 people through 202 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws surface water, in San Joaquin County, California. EPA system ID: CA3910022; phone on file: 209-339-1602. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Little Potato Slough Mutual's lead record
Against the period ending 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Little Potato Slough Mutual is 1.6 ppb across 9 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2020 | 1.6 ppb |
| 2020 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2017 | 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. Little Potato Slough Mutual's reported as 0 (not detected) sits at the 38th percentile in California and the 23rd nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in San Joaquin County
92 other systems share San Joaquin County; 12 of them have a higher latest lead result than Little Potato Slough Mutual. 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) |
Your move
Look up your address in Little Potato Slough Mutual'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 Little Potato Slough Mutual 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. A zero today does not rule out a jump later - the rules are tightening in 2027.