Lombard, IL
Above the new 10 ppb level coming in 2027
Latest 90th-percentile lead: 10.6 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. Under the current 15 ppb rule this is not an exceedance, but it is above the 10 ppb action level that takes over in Nov 2027. Test your own tap; filter if your result shows lead.
Lombard at a glance
Lombard serves about 44,476 people through 13,117 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 Dupage County, Illinois. EPA system ID: IL0430600; phone on file: 630-620-5766. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lombard's lead record
That is down 1.1 ppb from 11.7 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Lombard is 13.8 ppb across 6 monitoring periods, none of them over 15 ppb (4 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 10.6 ppb over 10 |
| 2025 | 11.7 ppb over 10 |
| 2025 | 11.1 ppb over 10 |
| 2023 | 3.47 ppb |
| 2020 | 3.33 ppb |
| 2017 | 13.8 ppb over 10 |
Against other Illinois systems
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. Lombard's 10.6 ppb sits at the 97th percentile in Illinois and the 97th nationally (higher means more lead).
Other water systems in Dupage County
47 other systems share Dupage County; 0 of them have a higher latest lead result than Lombard. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Naperville | 156,406 | 6.1 ppb |
| Wheaton | 53,970 | 2.32 ppb |
| Downers Grove | 49,425 | 4.98 ppb |
| Elmhurst | 45,000 | 5.52 ppb |
| Carol Stream | 39,854 | 1.05 ppb |
| Addison | 38,017 | 2 ppb |
| Woodridge | 33,566 | 0 (not detected) |
| Glendale Heights | 33,176 | 0 (not detected) |
| Glen Ellyn | 28,500 | 1.87 ppb |
| West Chicago | 25,166 | 0.52 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Lombard, 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 Lombard 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. This system is in the band the 2027 10 ppb rule changes.