Williams Mutual Water Company, CA
Exceeded the action level in the past
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2025-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. The latest result is under the action level, but this system has gone over 15 ppb before. Lead comes from pipes, not the source water, so a home with a lead service line can still be exposed. Test your own tap.
Who runs the water here
Williams Mutual Water Company serves about 165 people through 50 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Tulare County, California. EPA system ID: CA5400718; phone on file: 559-783-7503. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Williams Mutual Water Company's lead record
Against the period ending 2024 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Williams Mutual Water Company is 21 ppb across 7 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2024 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2022 | 21 ppb over 15 |
| 2019 | 0 (not detected) |
| 2016 | 0 (not detected) |
How Williams Mutual 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. Williams Mutual Water Company's reported as 0 (not detected) sits at the 25th percentile in California and the 14th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
90 other systems share Tulare County; 16 of them have a higher latest lead result than Williams Mutual Water Company. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Cws - Visalia | 153,522 | 0 (not detected) |
| Tulare, City Of | 72,241 | 0 (not detected) |
| Porterville, City Of | 63,487 | 0 (not detected) |
| Dinuba, City Of | 27,641 | 0 (not detected) |
| Lindsay, City Of | 12,659 | 0 (not detected) |
| Exeter, City Of | 11,169 | 11 ppb |
| Farmersville, City Of | 10,243 | 1.3 ppb |
| Orosi Public Utility District | 8,300 | 0 (not detected) |
| Woodlake, City Of | 7,918 | 0 (not detected) |
| Earlimart Pud | 7,679 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Porterville, CA may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Williams Mutual 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. Why sampled homes are the worst-case ones is in the guide to reading the number. More in what a past exceedance means today.