De Witt Water Supply, IA
Lead detected, under the action levels
Latest 90th-percentile lead: 3.4 ppb (monitoring period 2023-2025). 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.
Who runs the water here
De Witt Water Supply serves about 5,514 people through 2,166 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 Clinton County, Iowa. EPA system ID: IA2330036; phone on file: 563-659-5324. They can tell you what your service line is made of and whether they pay to replace it.
De Witt Water Supply's lead record
That is up 2.4 ppb from 1 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for De Witt Water Supply is 3.4 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 3.4 ppb |
| 2022 | 1 ppb |
| 2019 | 2 ppb |
| 2016 | 1.2 ppb |
How De Witt Water Supply compares
Of the 1,066 Iowa systems with a lead result, the median latest reading is 1.4 ppb; 4 are over 15 ppb right now and 36 have gone over at some point. De Witt Water Supply's 3.4 ppb sits at the 79th percentile in Iowa and the 85th nationally (higher means more lead).
Nearby utilities
15 other systems share Clinton County; 1 of them has a higher latest lead result than De Witt Water Supply. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Iowa-American Wtr Co-Clinton District | 24,769 | 2 ppb |
| Camanche Water Supply | 4,570 | 2 ppb |
| Wheatland City Water Supply | 775 | 3.2 ppb |
| Grand Mound Water Supply | 615 | 0 (not detected) |
| Delmar Water Supply | 542 | 2 ppb |
| Lost Nation Water Supply | 434 | 5 ppb |
| Charlotte Water Works | 401 | 0 (not detected) |
| Calamus Water Supply | 356 | 0 (not detected) |
| Iowa-American Water (Low Moor) | 250 | 1.6 ppb |
| Goose Lake Muni Water System | 239 | 0 (not detected) |
Next steps for Dewitt, IA
Test your own tap with a certified lab first-draw sample; Dewitt, IA 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 De Witt Water Supply 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. The action level is dropping - the 10 ppb rule from 2027.