Wauconda, IL
Exceeded the action level in the past
Latest 90th-percentile lead: 9.6 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. 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.
Who runs the water here
Wauconda serves about 15,349 people through 5,647 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Lake County, Illinois. EPA system ID: IL0971850. Ask the utility on your bill for your address in their service line inventory.
Lead results over time
That is up 9.6 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Wauconda is 16 ppb across 7 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 9.6 ppb |
| 2025 | 0 (not detected) |
| 2025 | 16 ppb over 15 |
| 2025 | 0 (not detected) |
| 2025 | 15 ppb over 10 |
| 2022 | 4.3 ppb |
| 2018 | 9.5 ppb |
How Wauconda 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. Wauconda's 9.6 ppb sits at the 96th percentile in Illinois and the 97th nationally (higher means more lead).
Neighbouring systems
103 other systems share Lake County; 10 of them have a higher latest lead result than Wauconda. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Waukegan | 87,149 | 10 ppb |
| Vernon Hills - Lake Co Pw | 33,207 | 0 (not detected) |
| Mundelein | 31,500 | 4.3 ppb |
| Gurnee | 30,193 | 0.3 ppb |
| Highland Park | 30,176 | 0 (not detected) |
| Round Lake Beach | 27,200 | 0 (not detected) |
| Zion | 24,442 | 11.2 ppb |
| Great Lakes Naval Training Station | 23,000 | 0 (not detected) |
| Grayslake | 21,248 | 11 ppb |
| Libertyville | 20,500 | 5.61 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Wauconda, 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 Wauconda 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. More in what a past exceedance means today.