| Case Number | Case Title | Open Date | Closed Date |
| 01-2775-WS-ORD | AMENDMENT CHAPTER 4901:1-15, OAC | 10/29/2001 | 07/28/2004 |
| 11-5605-WS-ORD | In the Matter of the Commission's Review of Chapter 4901:1-15, OAC, Standards for Waterworks Companies and Sewage Disposal System Companies | 11/02/2011 | |
| 76-0622-WS-ORD | CHAPTER 29 | 08/09/1976 | 01/18/1977 |
| 87-0173-WS-ORD | RULEMAKING PROCEEDING 4901:1-15-02 | 02/02/1987 | 02/10/1987 |