Isu, IA
Lead detected, under the action levels
Latest 90th-percentile lead: 1.2 ppb (monitoring period 2022-2024). 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.
About Isu
Isu serves about 42,000 people through 103 service connections, which makes it a large system under EPA's size classes. It is owned by the state and draws groundwater, in Story County, Iowa. EPA system ID: IA8503528; phone on file: 515-294-3769. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
Against the period ending 2021 (2.2 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Isu is 2.2 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 1.2 ppb |
| 2021 | 2.2 ppb |
| 2018 | 1.5 ppb |
Where this result ranks
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. Isu's 1.2 ppb sits at the 48th percentile in Iowa and the 59th nationally (higher means more lead).
Neighbouring systems
18 other systems share Story County; 6 of them have a higher latest lead result than Isu. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Ames Water Treatment Plant | 55,177 | 0 (not detected) |
| Nevada Water Supply | 6,925 | 0 (not detected) |
| Huxley Waterworks Dept | 4,244 | 1.1 ppb |
| Story City Water Dept | 3,357 | 0 (not detected) |
| Slater Muni Water Dept | 1,548 | 7 ppb |
| Roland Water Supply | 1,394 | 0 (not detected) |
| Gilbert Water Supply | 1,211 | 0 (not detected) |
| Maxwell Water Department | 859 | 4 ppb |
| Colo Water Supply | 853 | 1.1 ppb |
| Cambridge Water Supply | 832 | 2 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Ames, 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 Isu 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.