Elkhorn Waterworks, WI
Above the new 10 ppb level coming in 2027
Latest 90th-percentile lead: 13 ppb (monitoring period 2026-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Under the current 15 ppb rule this is not an exceedance, but it is above the 10 ppb action level that takes over in Nov 2027. Test your own tap; filter if your result shows lead.
Who runs the water here
Elkhorn Waterworks serves about 10,317 people through 3,821 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Walworth County, Wisconsin. EPA system ID: WI2650062. Ask the utility on your bill for your address in their service line inventory.
Every lead result on file
Against the period ending 2025 (14 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Elkhorn Waterworks is 18 ppb across 6 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 13 ppb over 10 |
| 2025 | 14 ppb over 10 |
| 2021 | 14 ppb over 10 |
| 2021 | 14 ppb over 10 |
| 2020 | 18 ppb over 15 |
| 2017 | 5.1 ppb |
Against other Wisconsin systems
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. Elkhorn Waterworks's 13 ppb sits at the 99th percentile in Wisconsin and the 98th nationally (higher means more lead).
Other water systems in Walworth County
26 other systems share Walworth County; 1 of them has a higher latest lead result than Elkhorn Waterworks. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Whitewater Waterworks | 14,000 | 10 ppb |
| Delavan Waterworks | 9,028 | 10 ppb |
| Lake Geneva Utility Commission | 7,107 | 8 ppb |
| East Troy Waterworks | 5,054 | 4.4 ppb |
| Bloomfield, Village Of | 4,071 | 1.95 ppb |
| Lake Como Sanitary Dist 1 | 3,038 | 2.5 ppb |
| Genoa City Waterworks | 2,766 | 4.56 ppb |
| Williams Bay Waterworks | 2,601 | 45 ppb |
| Walworth Waterworks | 2,304 | 6.3 ppb |
| Geneva National Community Services | 2,250 | 0.71 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Elkhorn, 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 Elkhorn 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. Why sampled homes are the worst-case ones is in the guide to reading the number. See what changes at 10 ppb in 2027.