We found 20 public water systems in Oregon county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Thayer | Thayer | 2,500 | 0 | 11 |
| Alton | Alton | 1,100 | 0 | 10 |
| Starview Drive-in | Starview Drive | 1,000 | 0 | 0 |
| Oregon Co Pwsd 1 | Alton | 850 | 0 | 7 |
| Midway Cafe | Midway Cafe | 418 | 0 | 0 |
| Couch R 1 School | County of Oregon | 292 | 0 | 14 |
| Koshkonong R-iii School | County of Oregon | 280 | 0 | 0 |
| Koshkonong | Koshkonong | 240 | 0 | 20 |
| Oregon Co Pwsd 2 | Myrtle | 125 | 0 | 13 |
| Usfs-mccormack Lake Campgr | Winona | 67 | 0 | 0 |
| Usfs Greer Crossing | Winona | 50 | 0 | 0 |
| Usfs-mc Cormack Lake Picnic Ground | Winona | 50 | 0 | 0 |
| Argo's Trading Post | Trading Post | 28 | 0 | 0 |
| Martin Grocery Station | Martin Groc Sta | 25 | 0 | 0 |
| Thayer Airport | Thayer Airport | 25 | 0 | 0 |
| All About Kids Daycare & Learning Center | County of Oregon | 25 | 0 | 0 |
| Many Springs Baptist Church | Baptist Church | 25 | 0 | 0 |
| Macedonia Baptist Church | Baptist Church | 25 | 0 | 0 |
| Indian Country Junction Store | County of Oregon | 25 | 0 | 0 |
| Thomasville Methodist Church | Methodist Churc | 25 | 0 | 0 |