Garnavillo Water Supply, IA
Lead detected, under the action levels
Latest 90th-percentile lead: 2.4 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.
Garnavillo Water Supply at a glance
Garnavillo Water Supply serves about 763 people through 397 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 Clayton County, Iowa. EPA system ID: IA2234074; phone on file: 563-964-2331. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
That is down 4.6 ppb from 7 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Garnavillo Water Supply is 7 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 2.4 ppb |
| 2021 | 7 ppb |
| 2018 | 3.5 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. Garnavillo Water Supply's 2.4 ppb sits at the 71st percentile in Iowa and the 77th nationally (higher means more lead).
Nearby utilities
15 other systems share Clayton County; 7 of them have a higher latest lead result than Garnavillo Water Supply. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Guttenberg Water Utility | 1,817 | 1.6 ppb |
| Monona Municipal Water Dept | 1,471 | 3.5 ppb |
| Elkader Muni Water Dept | 1,219 | 5.4 ppb |
| Strawberry Point Water Supply | 1,155 | 2 ppb |
| Edgewood Water Supply | 939 | 3.7 ppb |
| Mcgregor Water Dept | 747 | 9.01 ppb |
| Marquette Water Supply | 429 | 7.4 ppb |
| Luana Water Works | 301 | 0 (not detected) |
| Farmersburg Waterworks | 276 | 1.2 ppb |
| Volga Water Supply | 203 | 1 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Garnavillo, 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 Garnavillo 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. What a 90th-percentile result does and does not tell you: how to read a lead result. Size matters more than most people expect: small vs large water systems.