Rockford, IL
Lead detected, under the action levels
Latest 90th-percentile lead: 10 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. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
Who runs the water here
Rockford serves about 147,051 people through 51,060 service connections, which makes it a very large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Winnebago County, Illinois. EPA system ID: IL2010300; phone on file: 779-348-7654. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
That is up 1.6 ppb from 8.4 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Rockford is 14 ppb across 8 monitoring periods, none of them over 15 ppb (2 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 10 ppb |
| 2025 | 8.4 ppb |
| 2025 | 14 ppb over 10 |
| 2024 | 6 ppb |
| 2023 | 5.3 ppb |
| 2022 | 13 ppb over 10 |
| 2019 | 4.1 ppb |
| 2016 | 4 ppb |
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. Rockford's 10 ppb sits at the 96th percentile in Illinois and the 97th nationally (higher means more lead).
Neighbouring systems
22 other systems share Winnebago County; 1 of them has a higher latest lead result than Rockford. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| North Park Pwd | 35,580 | 2.3 ppb |
| Loves Park | 23,335 | 2.1 ppb |
| Il American-South Beloit | 7,893 | 4 ppb |
| Rockton | 7,863 | 3.2 ppb |
| Cherry Valley | 4,731 | 0 (not detected) |
| Winnebago | 2,940 | 0 (not detected) |
| Otter Creek Lake Utilities District | 2,342 | 0 (not detected) |
| Pecatonica | 2,195 | 2.6 ppb |
| Il American-Westlake | 1,493 | 1 ppb |
| Durand | 1,427 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Rockford, 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 Rockford 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.