Aqua Illinois-Willowbrook, IL
Lead detected, under the action levels
Latest 90th-percentile lead: 1.9 ppb (monitoring period 2024-2026). 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
Aqua Illinois-Willowbrook serves about 5,100 people through 805 service connections, which makes it a medium-sized system under EPA's size classes. It is privately owned and draws groundwater, in Will County, Illinois. EPA system ID: IL1977870; phone on file: 224-602-6779. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
Against the period ending 2023 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Aqua Illinois-Willowbrook is 3.6 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.9 ppb |
| 2023 | 1 ppb |
| 2020 | 1.7 ppb |
| 2017 | 3.6 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. Aqua Illinois-Willowbrook's 1.9 ppb sits at the 72nd percentile in Illinois and the 69th nationally (higher means more lead).
Neighbouring systems
49 other systems share Will County; 18 of them have a higher latest lead result than Aqua Illinois-Willowbrook. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Joliet | 160,000 | 6.53 ppb |
| Il American-West Suburban | 73,978 | 0 (not detected) |
| Romeoville | 50,458 | 8.22 ppb |
| Plainfield | 50,000 | 0 (not detected) |
| New Lenox | 29,200 | 0 (not detected) |
| Il American-Homer Township | 24,543 | 0 (not detected) |
| Frankfort | 24,000 | 0.98 ppb |
| Lockport | 23,100 | 7.6 ppb |
| Crest Hill | 20,223 | 2.14 ppb |
| Mokena | 19,887 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Glenview, 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 Aqua Illinois-Willowbrook 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.