Mount Sterling Waterworks, WI
Exceeded the action level in the past
Latest 90th-percentile lead: 1.3 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. 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
Mount Sterling Waterworks serves about 206 people through 76 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Crawford County, Wisconsin. EPA system ID: WI6120246. Ask the utility on your bill for your address in their service line inventory.
Mount Sterling Waterworks's lead record
That is down 3.2 ppb from 4.5 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Mount Sterling Waterworks is 28 ppb across 5 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.3 ppb |
| 2025 | 4.5 ppb |
| 2023 | 28 ppb over 15 |
| 2020 | 8.05 ppb |
| 2017 | 7.45 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. Mount Sterling Waterworks's 1.3 ppb sits at the 49th percentile in Wisconsin and the 60th nationally (higher means more lead).
Other water systems in Crawford County
8 other systems share Crawford County; 5 of them have a higher latest lead result than Mount Sterling Waterworks. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Prairie Du Chien Waterworks | 6,005 | 0 (not detected) |
| Wauzeka Waterworks | 711 | 1.31 ppb |
| Soldiers Grove Waterworks | 592 | 0 (not detected) |
| Gays Mills Waterworks | 490 | 1.33 ppb |
| Eastman Waterworks | 342 | 0 (not detected) |
| Bridgeport San Dist No 1 | 300 | 1.58 ppb |
| Seneca Sanitary Dist No 1 | 250 | 1.32 ppb |
| Homesteader Llc The | 200 | 1.33 ppb |
Next steps for Mt Sterling, WI
Test your own tap with a certified lab first-draw sample; Mt Sterling, 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 Mount Sterling 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. Why an old exceedance still matters: over the limit before, under it now.