Jefferson Water Department, IA
Lead detected, under the action levels
Latest 90th-percentile lead: 0.8 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.
About Jefferson Water Department
Jefferson Water Department serves about 4,182 people through 2,080 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 Greene County, Iowa. EPA system ID: IA3742004; phone on file: 515-386-2611. 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 2022 (1.2 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Jefferson Water Department is 2 ppb across 7 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0.8 ppb |
| 2022 | 1.2 ppb |
| 2019 | 0 (not detected) |
| 2018 | 1.3 ppb |
| 2017 | 1 ppb |
| 2017 | 1.2 ppb |
| 2016 | 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. Jefferson Water Department's 0.8 ppb sits at the 37th percentile in Iowa and the 48th nationally (higher means more lead).
Nearby utilities
3 other systems share Greene County; 3 of them have a higher latest lead result than Jefferson Water Department. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Grand Jct Municipal Water Dept | 725 | 1 ppb |
| Scranton Water System | 511 | 17 ppb |
| Churdan Water Supply | 375 | 1.2 ppb |
Next steps for Jefferson, IA
Test your own tap with a certified lab first-draw sample; Jefferson, 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 Jefferson Water Department whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1410 ppb (copper action level 1,300 ppb).
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.