Corwith Water Supply, IA
Exceeded the action level in the past
Latest 90th-percentile lead: 2 ppb (monitoring period 2021-2023). 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
Corwith Water Supply serves about 266 people through 159 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Hancock County, Iowa. EPA system ID: IA4109077; phone on file: 515-583-2342. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is up 2 ppb from 0 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Corwith Water Supply is 34 ppb across 6 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 2 ppb |
| 2020 | 0 (not detected) |
| 2019 | 1 ppb |
| 2018 | 0 (not detected) |
| 2018 | 2 ppb |
| 2017 | 34 ppb over 15 |
How Corwith 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. Corwith Water Supply's 2 ppb sits at the 62nd percentile in Iowa and the 71st nationally (higher means more lead).
Nearby utilities
7 other systems share Hancock County; 4 of them have a higher latest lead result than Corwith Water Supply. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Garner Water Works | 3,065 | 2 ppb |
| Britt Water Works | 2,064 | 3 ppb |
| Kanawha Water Supply | 658 | 2.53 ppb |
| Klemme Water Works | 441 | 0 (not detected) |
| Crystal Lake Water Supply | 255 | 0 (not detected) |
| Woden Water Supply | 188 | 4 ppb |
| Goodell Water Supply | 140 | 3 ppb |
Next steps for Corwith, IA
Test your own tap with a certified lab first-draw sample; Corwith, 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 Corwith 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. Why an old exceedance still matters: over the limit before, under it now.