Water quality in Onawa, Iowa
Onawa is in Monona County. 14 active public water systems serve the county; 8 had an EPA violation in the past three years.
Most likely your provider
Other community water systems in Monona County
7 systems, nearest first| System | Serves | Status | Rules violated, 3 yr | Distance |
|---|---|---|---|---|
| Whiting Water Supply Whiting |
727 | 0 | 6.2 mi | |
| Blencoe Municipal Waterworks Blencoe |
224 | 0 | 8.1 mi | |
| Castana Municipal Water Supply Castana |
103 | 0 | 11.9 mi | |
| Moorhead Water Supply Moorhead |
189 | 2 | 17.2 mi | |
| Soldier Water Supply Soldier |
180 | 2 | 19.2 mi | |
| Mapleton Municipal Water Plant Mapleton |
1,124 | 1 | 20.4 mi | |
| Ute Water Supply Ute |
338 | 4 | 22.8 mi |
Non-community systems in Monona County (6: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Onawa KOA Onawa |
250 | 1 | 0 | |
|
Lewis and Clark State Park Onawa |
67 | 2 | 1 | |
|
Sunset at the Oasis RV Campground Onawa |
25 | 2 | 0 | |
|
Divide Hill Bar & Grill Castana |
50 | 1 | 1 | |
|
Timber Ridge Lodge Recreation, Ltd. Castana |
250 | 0 | 0 | |
|
Peters Park Rodney |
32 | 0 | 0 |
About this data
Water systems are matched to Monona County, nearest to Onawa 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.
Town locations and ZIP code areas come from U.S. Census Bureau 2020 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.