South Elgin, IL
Lead detected, under the action levels
Latest 90th-percentile lead: 1.4 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.
Who runs the water here
South Elgin serves about 23,648 people through 8,725 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 groundwater, in Kane County, Illinois. EPA system ID: IL0890800; phone on file: 847-695-2742. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2025 (1.1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for South Elgin is 8.4 ppb across 21 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.4 ppb |
| 2025 | 1.1 ppb |
| 2025 | 2.2 ppb |
| 2024 | 1.9 ppb |
| 2024 | 1.6 ppb |
| 2023 | 1.4 ppb |
| 2023 | 2 ppb |
| 2022 | 1.4 ppb |
| 2022 | 2 ppb |
| 2021 | 1.8 ppb |
| 2021 | 1.8 ppb |
| 2020 | 2.1 ppb |
| 2020 | 2.8 ppb |
| 2019 | 8.4 ppb |
| 2019 | 2 ppb |
| 2018 | 3.5 ppb |
| 2018 | 3.1 ppb |
| 2017 | 2.8 ppb |
| 2017 | 4.8 ppb |
| 2016 | 6 ppb |
| 2016 | 5.3 ppb |
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. South Elgin's 1.4 ppb sits at the 67th percentile in Illinois and the 62nd nationally (higher means more lead).
Other water systems in Kane County
38 other systems share Kane County; 20 of them have a higher latest lead result than South Elgin. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Aurora | 183,000 | 25.7 ppb |
| Elgin | 114,797 | 18.5 ppb |
| Carpentersville | 37,983 | 1.1 ppb |
| St Charles | 33,081 | 3.9 ppb |
| Montgomery | 28,956 | 0 (not detected) |
| Batavia | 26,098 | 3.82 ppb |
| Geneva | 21,247 | 5.35 ppb |
| North Aurora | 18,261 | 6.2 ppb |
| Sugar Grove | 11,243 | 0 (not detected) |
| Pingree Grove | 10,365 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; South Elgin, 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 South Elgin whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1500 ppb (copper action level 1,300 ppb).
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. Systems that went over once often dip back under; here is what that means.