La Salle, IL
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
La Salle serves about 9,700 people through 3,967 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Lasalle County, Illinois. EPA system ID: IL0990300; phone on file: 815-223-3755. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2025 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for La Salle is 20 ppb across 10 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2025 | 9.03 ppb |
| 2025 | 8.07 ppb |
| 2024 | 5.5 ppb |
| 2023 | 20 ppb over 15 |
| 2022 | 7 ppb |
| 2019 | 6.5 ppb |
| 2016 | 11 ppb over 10 |
| 2016 | 11 ppb over 10 |
Where this result ranks
Of the 1,744 Illinois systems with a lead result, the median latest reading is 0 ppb; 22 are over 15 ppb right now and 152 have gone over at some point. La Salle's reported as 0 (not detected) sits at the 51st percentile in Illinois and the 37th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
34 other systems share Lasalle County; 17 of them have a higher latest lead result than La Salle. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Il American-Streator | 19,000 | 1 ppb |
| Ottawa | 18,097 | 0 (not detected) |
| Peru | 9,896 | 10.5 ppb |
| Mendota | 7,100 | 7.06 ppb |
| Marseilles | 5,061 | 0 (not detected) |
| Il American-Lake Holiday | 4,750 | 2 ppb |
| Oglesby | 4,500 | 0 (not detected) |
| Seneca | 2,353 | 0 (not detected) |
| Sheridan Correctional Center | 1,670 | 3.6 ppb |
| Earlville | 1,613 | 3.4 ppb |
Next steps for La Salle, IL
Test your own tap with a certified lab first-draw sample; La Salle, IL 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 La Salle 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. Why an old exceedance still matters: over the limit before, under it now.