Defiance Water Department, IA
Lead detected, under the action levels
Latest 90th-percentile lead: 1.8 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. 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
Defiance Water Department serves about 250 people through 156 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 Shelby County, Iowa. EPA system ID: IA8315018; phone on file: 712-748-3430. 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 up 1.8 ppb from 0 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Defiance Water Department is 2 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 1.8 ppb |
| 2020 | 0 (not detected) |
| 2017 | 2 ppb |
Against other Iowa systems
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. Defiance Water Department's 1.8 ppb sits at the 55th percentile in Iowa and the 67th nationally (higher means more lead).
Other water systems in Shelby County
7 other systems share Shelby County; 0 of them have a higher latest lead result than Defiance Water Department. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Harlan Municipal Utilities | 5,067 | 1 ppb |
| Shelby Water Supply | 727 | 0 (not detected) |
| Elk Horn Muni Water Works | 631 | 0 (not detected) |
| Earling Water Supply | 397 | 0 (not detected) |
| Irwin Municipal Supply | 313 | 0 (not detected) |
| Panama Water Works | 235 | 0 (not detected) |
| Portsmouth Water Supply | 189 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Defiance, 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 Defiance Water Department 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. 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.