Columbia Energy Center is located in Pardeeville, Wisconsin.

The CCR units and regulatory designation of units at Columbia are:

• COL Primary Ash Pond (existing surface impoundment)
• COL Secondary Pond (inactive surface impoundment)
• COL Dry Ash Disposal Facility - Module 1 (existing landfill)
• COL Dry Ash Disposal Facility - Module 2 (existing landfill)
• COL Dry Ash Disposal Facility - Module 3 (existing landfill)