Modesto, City Of, CA
Above the new 10 ppb level coming in 2027
Latest 90th-percentile lead: 12 ppb (monitoring period 2025-2027). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Under the current 15 ppb rule this is not an exceedance, but it is above the 10 ppb action level that takes over in Nov 2027. Test your own tap; filter if your result shows lead.
About Modesto, City Of
Modesto, City Of serves about 218,915 people through 70,877 service connections, which makes it a very large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Stanislaus County, California. EPA system ID: CA5010010; phone on file: 209-342-4592. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is up 12 ppb from 0 ppb in the period ending 2024. The highest 90th-percentile result EPA holds for Modesto, City Of is 12 ppb across 5 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2027 | 12 ppb over 10 |
| 2024 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2018 | 0 (not detected) |
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. Modesto, City Of's 12 ppb sits at the 98th percentile in California and the 98th nationally (higher means more lead).
Neighbouring systems
59 other systems share Stanislaus County; 1 of them has a higher latest lead result than Modesto, City Of. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Turlock, City Of | 72,888 | 0.97 ppb |
| Ceres, City Of | 54,513 | 0 (not detected) |
| Riverbank, City Of | 25,625 | 21 ppb |
| Patterson, City Of | 24,977 | 0 (not detected) |
| Oakdale, City Of | 23,235 | 0 (not detected) |
| City Of Modesto - Salida | 14,576 | 0 (not detected) |
| City Of Newman-Water Department | 12,389 | 0 (not detected) |
| City Of Waterford | 8,788 | 0 (not detected) |
| Hughson, City Of | 7,977 | 0 (not detected) |
| Keyes Community Services Dist. | 5,672 | 1.48 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Modesto, 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 Modesto, City Of 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. See what changes at 10 ppb in 2027.