Sub-locations
| Name | Sites | Samples |
|---|---|---|
| Harrison County | 0 | 0 |
| Henry County | 3 | 12 |
| Highland County | 10 | 10 |
| Hocking County | 10 | 28 |
| Holmes County | 1 | 1 |
| Huron County | 8 | 14 |
| Jackson County | 3 | 12 |
| Jefferson County | 0 | 0 |
| Lake County | 10 | 20 |
| Lawrence County | 14 | 51 |
| Licking County | 26 | 82 |
| Logan County | 3 | 3 |
| Lorain County | 8 | 42 |
| Lucas County | 12 | 58 |
| Madison County | 4 | 7 |
| Mahoning County | 1 | 1 |
| Marion County | 2 | 5 |
| Medina County | 1 | 18 |
| Meigs County | 5 | 11 |
| Mercer County | 1 | 1 |
| Miami County | 1 | 2 |
| Monroe County | 1 | 1 |
| Montgomery County | 5 | 65 |
| Morgan County | 2 | 2 |
| Muskingum County | 20 | 72 |