Peru, IL
Above the new 10 ppb level coming in 2027
Latest 90th-percentile lead: 10.5 ppb (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. 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.
Who runs the water here
Peru serves about 9,896 people through 5,211 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: IL0990850; phone on file: 815-224-6020. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
That is up 10.5 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Peru is 10.5 ppb across 7 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 10.5 ppb over 10 |
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2022 | 5 ppb |
| 2019 | 2.37 ppb |
| 2016 | 6.1 ppb |
Against other Illinois systems
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. Peru's 10.5 ppb sits at the 96th percentile in Illinois and the 97th nationally (higher means more lead).
Other water systems in Lasalle County
34 other systems share Lasalle County; 2 of them have a higher latest lead result than Peru. 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) |
| La Salle | 9,700 | 0 (not detected) |
| 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 |
What to do in your house
Test your own tap with a certified lab first-draw sample; Peru, 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 Peru 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. The lead result guide covers how utilities pick the homes they sample. See what changes at 10 ppb in 2027.