Water quality for ZIP code 50579
ZIP 50579 covers Rockwell City and Twin Lakes in Calhoun County, Iowa, one of 10 ZIP codes in the county. 14 active public water systems serve the county; 7 had an EPA violation in the past three years.
Most likely your provider
Your location is within the outer bounds of this system's EPA service area.
Other community water systems in Calhoun County
11 systems, nearest first| System | Serves | Status | Rules violated, 3 yr | Distance |
|---|---|---|---|---|
| Twin Lakes Utilities Rockwell City |
300 | 1 | 5.5 mi | |
| Jolley Water Supply Jolley |
28 | 0 | 7.2 mi | |
| Rinard Water Supply Rinard |
38 | 0 | 8.6 mi | |
| Lohrville Water Supply Lohrville |
381 | 0 | 9.8 mi | |
| Lake City Water Supply Lake City |
1,731 | 1 | 10.0 mi | |
| Knierim Water Supply Knierim |
53 | 1 | 10.1 mi | |
| Somers Water Works Somers |
128 | 1 | 10.7 mi | |
| Pomeroy Water Supply Pomeroy |
671 | 2 | 10.8 mi | |
| Manson Water Supply Manson |
1,727 | 2 | 10.8 mi | |
| Lytton Water Department Lytton |
282 | 0 | 11.5 mi | |
| Farnhamville Water Supply Farnhamville |
379 | 0 | 14.3 mi |
Non-community systems in Calhoun County (2: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Twin Lakes Golf Club Rockwell City |
39 | 0 | 0 | |
|
Yetter Municipal Water Supply Yetter |
25 | 0 | 0 |
About this data
Water systems are matched to Calhoun County, the county this ZIP code lies in, nearest to the ZIP code's centre 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. Distances are measured to the centre of the service area EPA publishes for the system or, for systems without one, to the centre of the first town EPA lists the system as serving, from Census Bureau place files.
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 Iowa 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.