Grand Ridge, IL
Above the federal action level
Latest 90th-percentile lead: 31.6 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.
Grand Ridge at a glance
Grand Ridge serves about 515 people through 249 service connections, which makes it a small 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: IL0990200; phone on file: 815-674-6176. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is up 31.6 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Grand Ridge is 31.6 ppb across 6 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 31.6 ppb over 15 |
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2024 | 0 (not detected) |
| 2021 | 1.28 ppb |
| 2018 | 0 (not detected) |
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. Grand Ridge's 31.6 ppb sits at the 100th percentile in Illinois and the 100th nationally (higher means more lead).
Other water systems in Lasalle County
34 other systems share Lasalle County; 0 of them have a higher latest lead result than Grand Ridge. 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 |
| 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 |
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 Grand Ridge 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. The action level is dropping - the 10 ppb rule from 2027.