Princeton, IL
Above the federal action level
Latest 90th-percentile lead: 21 ppb (monitoring period 2026-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. In the most recent monitoring period, more than 10% of the sampled homes measured above 15 ppb. Use a filter certified to NSF/ANSI 53 for lead for drinking and cooking now, and test your own tap.
Who runs the water here
Princeton serves about 7,832 people through 3,810 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 Bureau County, Illinois. EPA system ID: IL0110850; phone on file: 815-872-0811. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Princeton's lead record
That is up 21 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Princeton is 44 ppb across 17 monitoring periods, 6 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 21 ppb over 15 |
| 2025 | 0 (not detected) |
| 2025 | 3.1 ppb |
| 2025 | 27 ppb over 15 |
| 2025 | 44 ppb over 15 |
| 2024 | 43 ppb over 15 |
| 2024 | 8.5 ppb |
| 2023 | 9.8 ppb |
| 2023 | 7.6 ppb |
| 2022 | 8.9 ppb |
| 2022 | 7.6 ppb |
| 2021 | 6.8 ppb |
| 2021 | 9.6 ppb |
| 2020 | 21 ppb over 15 |
| 2020 | 10 ppb |
| 2019 | 27 ppb over 15 |
| 2016 | 13 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. Princeton's 21 ppb sits at the 99th percentile in Illinois and the 99th nationally (higher means more lead).
Nearby utilities
23 other systems share Bureau County; 1 of them has a higher latest lead result than Princeton. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Spring Valley | 5,582 | 0 (not detected) |
| De Pue | 1,838 | 0 (not detected) |
| Walnut | 1,311 | 5.4 ppb |
| Ladd | 1,263 | 0 (not detected) |
| Wyanet | 886 | 19.5 ppb |
| Sheffield | 821 | 1.4 ppb |
| Tiskilwa | 740 | 0 (not detected) |
| Dalzell | 663 | 0 (not detected) |
| Lamoille | 660 | 22.3 ppb |
| Cherry | 490 | 13.8 ppb |
What to do in your house
Use a filter certified to NSF/ANSI 53 for lead on the tap you drink and cook from, now, before you test. Then test your own tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Princeton 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. Systems that went over once often dip back under; here is what that means.