Coal City, IL
Exceeded the action level in the past
Latest 90th-percentile lead: reported as 0 (not detected) (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. 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.
About Coal City
Coal City serves about 5,845 people through 2,431 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 Grundy County, Illinois. EPA system ID: IL0630200; phone on file: 815-634-8608. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Coal City's lead record
Against the period ending 2024 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Coal City is 39 ppb across 9 monitoring periods, 2 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2024 | 0 (not detected) |
| 2023 | 7.67 ppb |
| 2022 | 5 ppb |
| 2021 | 4.43 ppb |
| 2021 | 7.3 ppb |
| 2020 | 12.1 ppb over 10 |
| 2020 | 39 ppb over 15 |
| 2017 | 16.8 ppb over 15 |
How Coal City compares
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. Coal City's reported as 0 (not detected) sits at the 48th percentile in Illinois and the 35th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
18 other systems share Grundy County; 5 of them have a higher latest lead result than Coal City. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Morris | 14,775 | 0 (not detected) |
| Minooka | 12,800 | 0 (not detected) |
| Diamond | 2,508 | 0 (not detected) |
| Gardner | 1,361 | 0 (not detected) |
| Mazon | 994 | 0 (not detected) |
| Shady Oaks Mhp | 912 | 0 (not detected) |
| Braceville | 800 | 2.08 ppb |
| South Wilmington | 710 | 0 (not detected) |
| Bookwalter Woods Mhp | 389 | 0 (not detected) |
| Carbon Hill | 370 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Coal City, 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 Coal City 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.