Delavan, IL
Exceeded the action level in the past
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest result is under the action level, but this system has gone over 15 ppb before. Lead comes from pipes, not the source water, so a home with a lead service line can still be exposed. Test your own tap.
Who runs the water here
Delavan serves about 1,743 people through 764 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Tazewell County, Illinois. EPA system ID: IL1790150; phone on file: 309-244-7146. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
Against the period ending 2025 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Delavan is 33 ppb across 10 monitoring periods, 2 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 1 ppb |
| 2025 | 33 ppb over 15 |
| 2024 | 32 ppb over 15 |
| 2024 | 2.9 ppb |
| 2023 | 6.1 ppb |
| 2023 | 3.3 ppb |
| 2022 | 4.7 ppb |
| 2019 | 1.4 ppb |
| 2016 | 4.9 ppb |
How Delavan 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. Delavan's reported as 0 (not detected) sits at the 39th percentile in Illinois and the 30th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
28 other systems share Tazewell County; 18 of them have a higher latest lead result than Delavan. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Il American-Pekin | 31,731 | 1 ppb |
| East Peoria | 22,484 | 7 ppb |
| Morton | 17,117 | 0 (not detected) |
| Washington | 14,793 | 0 (not detected) |
| North Tazewell Pwd | 7,625 | 5.1 ppb |
| Creve Coeur | 4,934 | 2.1 ppb |
| Mackinaw | 3,399 | 0 (not detected) |
| Marquette Heights | 2,974 | 1.02 ppb |
| Groveland Township Water District | 2,185 | 5.2 ppb |
| Tremont | 2,114 | 1.2 ppb |
Next steps for Delavan, IL
Test your own tap with a certified lab first-draw sample; Delavan, 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 Delavan whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1400 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. Why an old exceedance still matters: over the limit before, under it now.