Watseka, IL
Lead detected, under the action levels
Latest 90th-percentile lead: 3 ppb (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. 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 Watseka
Watseka serves about 4,767 people through 2,500 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Iroquois County, Illinois. EPA system ID: IL0750900; phone on file: 815-432-2960. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
That is down 3 ppb from 6 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Watseka is 7.9 ppb across 10 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 3 ppb |
| 2025 | 6 ppb |
| 2025 | 5 ppb |
| 2025 | 6.7 ppb |
| 2024 | 3.1 ppb |
| 2023 | 7.9 ppb |
| 2022 | 1.6 ppb |
| 2021 | 2.2 ppb |
| 2020 | 2.8 ppb |
| 2017 | 0 (not detected) |
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. Watseka's 3 ppb sits at the 81st percentile in Illinois and the 82nd nationally (higher means more lead).
Other water systems in Iroquois County
24 other systems share Iroquois County; 3 of them have a higher latest lead result than Watseka. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Gilman | 1,793 | 2.8 ppb |
| Clifton | 1,500 | 2.2 ppb |
| Onarga | 1,409 | 0 (not detected) |
| Milford | 1,306 | 21 ppb |
| Chebanse | 1,044 | 1.6 ppb |
| Sheldon | 900 | 0 (not detected) |
| Cissna Park | 846 | 2.88 ppb |
| Ashkum | 800 | 5 ppb |
| Lake Iroquois Association | 800 | 2 ppb |
| Crescent City | 650 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Watseka, 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 Watseka 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. Size matters more than most people expect: small vs large water systems.