Thermalito Water & Sewer Dist, 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.
Thermalito Water & Sewer Dist at a glance
Thermalito Water & Sewer Dist serves about 12,209 people through 3,213 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Butte County, California. EPA system ID: CA0410008; phone on file: 530-533-0740. They can tell you what your service line is made of and whether they pay to replace it.
Thermalito Water & Sewer Dist'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 Thermalito Water & Sewer Dist is 4.6 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 (not detected) |
| 2016 | 4.6 ppb |
Where this result ranks
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. Thermalito Water & Sewer Dist's reported as 0 (not detected) sits at the 54th percentile in California and the 37th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Butte County
41 other systems share Butte County; 14 of them have a higher latest lead result than Thermalito Water & Sewer Dist. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Cal-Water Service Co.-Chico | 110,473 | 0 (not detected) |
| South Feather W&P - Miners Ranch | 22,638 | 0 (not detected) |
| Cal-Water Service Co.-Oroville | 11,047 | 0.9 ppb |
| Del Oro Water Co.-Paradise Pines | 10,738 | 0.54 ppb |
| Paradise Irrigation District | 9,114 | 0 (not detected) |
| City Of Gridley | 7,269 | 0 (not detected) |
| City Of Biggs | 2,060 | 6.91 ppb |
| Durham Irrigation District | 1,581 | 0.74 ppb |
| Del Oro Water Co.-Lime Saddle Marina | 954 | 0 (not detected) |
| Del Oro Water Co.-Stirling Bluffs | 512 | 4.55 ppb |
Your move
Look up your address in Thermalito Water & Sewer Dist'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 Thermalito Water & Sewer Dist 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.