Waterloo Waterworks, WI
Exceeded the action level in the past
Latest 90th-percentile lead: 1.3 ppb (monitoring period 2023-2023). 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
Waterloo Waterworks serves about 3,520 people through 1,303 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 Jefferson County, Wisconsin. EPA system ID: WI1280115. Ask the utility on your bill for your address in their service line inventory.
Every lead result on file
That is down 1.1 ppb from 2.4 ppb in the period ending 2023. The highest 90th-percentile result EPA holds for Waterloo Waterworks is 18 ppb across 4 monitoring periods, 2 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 1.3 ppb |
| 2023 | 2.4 ppb |
| 2020 | 17 ppb over 15 |
| 2017 | 18 ppb over 15 |
How Waterloo Waterworks compares
Of the 947 Wisconsin systems with a lead result, the median latest reading is 1.33 ppb; 6 are over 15 ppb right now and 71 have gone over at some point. Waterloo Waterworks's 1.3 ppb sits at the 49th percentile in Wisconsin and the 61st nationally (higher means more lead).
Neighbouring systems
18 other systems share Jefferson County; 10 of them have a higher latest lead result than Waterloo Waterworks. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Watertown Waterworks | 23,945 | 15 ppb |
| Fort Atkinson Waterworks | 12,390 | 13 ppb |
| Jefferson Waterworks | 7,926 | 3.5 ppb |
| Lake Mills Waterworks | 6,211 | 4.6 ppb |
| Johnson Creek Waterworks | 3,318 | 2.8 ppb |
| Palmyra Waterworks | 1,756 | 3.8 ppb |
| Autumn Ridge Water System Llc | 575 | 0.59 ppb |
| Spacious Acres Mobile Home Community | 525 | 0.73 ppb |
| Tremain Mobile Home Park | 475 | 1.46 ppb |
| Lakewood Village | 160 | 2.58 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Waterloo, WI 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 Waterloo Waterworks 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. More in what a past exceedance means today.