| Case Number | Case Title | Open Date | Closed Date |
| 76-0454-WS-COI | CHAPTER 29 | 06/16/1976 | 01/18/1977 |
| 77-1073-WS-COI | OHIO UTILITIES COMPANY | 08/17/1977 | 07/06/1978 |
| 81-0883-WS-COI | SENECA HILLS SERVICE COMPANY | 07/28/1981 | 10/14/1981 |
| 86-1561-WS-COI | LAKE ERIE UTILITIES CO. | 08/05/1986 | 10/18/1988 |
| 86-2046-WS-COI | INVESTIGATION INTO WATER/WASTEWATER | 10/22/1986 | 11/02/1995 |
| 86-2047-WS-COI | WATER/SEWER - 4901:1-15-12 & 13 OAC | 10/22/1986 | 11/08/1988 |
| 88-1061-WS-COI | INVESTIGATION/WATERWORKS COMPANY | 07/14/1988 | 08/02/1988 |
| 91-1684-WS-COI | PENINSULA WATER WORKS, INC. | 09/12/1991 | 09/21/1994 |
| 92-0550-WS-COI | OHIO UTILITIES/CITIZENS UTILITIES | 03/30/1992 | 05/15/1997 |