Warren, IL
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Who runs the water here
Warren serves about 1,323 people through 720 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 Jo Daviess County, Illinois. EPA system ID: IL0850500; phone on file: 815-745-3315. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
Against the period ending 2024 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Warren is 0 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2024 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2018 | 0 (not detected) |
How Warren 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. Warren's reported as 0 (not detected) sits at the 36th percentile in Illinois and the 28th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
13 other systems share Jo Daviess County; 5 of them have a higher latest lead result than Warren. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Galena | 3,308 | 4.35 ppb |
| Il American-Galena | 2,294 | 11 ppb |
| Stockton | 1,728 | 0 (not detected) |
| East Dubuque | 1,565 | 0 (not detected) |
| Il American-Apple Canyon | 931 | 3.6 ppb |
| Hanover | 863 | 0 (not detected) |
| Elizabeth | 802 | 0 (not detected) |
| Il American-Bahl Water Company | 700 | 2 ppb |
| Mount Vernon Association Inc | 438 | 0 (not detected) |
| Scales Mound | 436 | 4.82 ppb |
What to do in your house
Look up your address in Warren's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Warren 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. A zero today does not rule out a jump later - the rules are tightening in 2027.