Water quality for ZIP code 53940
ZIP 53940 covers Lake Delton in Sauk County, Wisconsin, one of 14 ZIP codes in the county. 194 active public water systems serve the county; 32 had an EPA violation in the past three years.
Most likely your provider
Other community water systems in Sauk County
24 systems, largest first| System | Serves | Status | Rules violated, 3 yr |
|---|---|---|---|
| Reedsburg Waterworks Reedsburg |
9,984 | 0 | |
| Prairie DU Sac Waterworks Prairie Du Sac |
4,006 | 2 | |
| Sauk City Waterworks Sauk City |
3,518 | 1 | |
| Lake Delton Waterworks Lake Delton |
2,914 | 1 | |
| Spring Green Waterworks Spring Green |
1,626 | 0 | |
| West Baraboo Waterworks West Baraboo |
1,414 | 0 | |
| Plain Waterworks Plain |
792 | 2 | |
| North Freedom Waterworks North Freedom |
589 | 1 | |
| Bluffview Sanitary District Prairie Du Sac |
450 | 2 | |
| Merrimac Waterworks Merrimac |
440 | 3 | |
| LA Valle Waterworks La Valle |
365 | 1 | |
| Loganville Waterworks Loganville |
300 | 0 | |
| Spring Green Estates Spring Green |
300 | 0 | |
| Rock Springs Waterworks Rock Springs |
292 | 1 | |
| Ironton Waterworks La Valle |
253 | 4 | |
| Maple Park Condominiums Prairie Du Sac |
150 | 2 | |
| Glacier View Subdivision Baraboo |
75 | 3 | |
| Lower Dells MHC Lake Delton |
75 | 0 | |
| Equinox Rei LLC Dellwood Estates Reedsburg |
70 | 0 | |
| Summer Oaks Condo Assoc Merrimac |
70 | 0 | |
| Dell Creek Estates Reedsburg |
50 | 3 | |
| Spring Green Estates South Spring Green |
40 | 2 | |
| Merrimac Estates MHP Merrimac |
37 | 0 | |
| Spring Green Estates North Spring Green |
32 | 2 |
Non-community systems in Sauk County (169: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
About this data
Water systems are matched to Sauk County, the county this ZIP code lies in, largest first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility.
ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Wisconsin records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.