Des Plaines, IL
Lead detected, under the action levels
Latest 90th-percentile lead: 5.7 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.
About Des Plaines
Des Plaines serves about 60,675 people through 17,080 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 Cook County, Illinois. EPA system ID: IL0310630; phone on file: 847-391-5468. 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 5.38 ppb from 0.32 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Des Plaines is 5.7 ppb across 12 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 5.7 ppb |
| 2025 | 0.32 ppb |
| 2025 | 2.27 ppb |
| 2025 | 3.8 ppb |
| 2025 | 3.43 ppb |
| 2023 | 4.72 ppb |
| 2020 | 0 (not detected) |
| 2019 | 2.1 ppb |
| 2018 | 2.13 ppb |
| 2017 | 0 (not detected) |
| 2017 | 2.83 ppb |
| 2016 | 0 (not detected) |
How Des Plaines 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. Des Plaines's 5.7 ppb sits at the 90th percentile in Illinois and the 92nd nationally (higher means more lead).
Neighbouring systems
154 other systems share Cook County; 46 of them have a higher latest lead result than Des Plaines. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Chicago | 2,721,308 | 6.4 ppb |
| Cicero | 83,000 | 5 ppb |
| Schaumburg | 75,750 | 0.87 ppb |
| Evanston | 74,486 | 6.5 ppb |
| Arlington Heights | 73,320 | 7.6 ppb |
| Palatine | 70,875 | 8.9 ppb |
| Skokie | 66,422 | 9.77 ppb |
| Oak Lawn | 58,362 | 9.3 ppb |
| Orland Park | 58,020 | 0 (not detected) |
| Berwyn | 57,250 | 2.35 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Des Plaines, 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 Des Plaines 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. Size matters more than most people expect: small vs large water systems.