The report describes the (Phase I) design of both a limestone dual alkali system at Gulf Power Co.'s Scholz steam plant and a related test program. The limestone dual alkali process will be tested at an existing 20 MWe prototype facility at the Scholz plant. The intent of the project is not only to demonstrate the technical feasibility of the process at a prototype level but also to supply technical and cost information related to the implementation of the process at a full commercial scale. The project is being carried out in three phases: Phase I, project planning; Phase II, procurement, recommissioning, and construction; and Phase III, startup, teating, decommissioning, and data analysis. Recommissioning costs at Scholz were about $800,000. Capital and operating costs (in 1979 dollars) projected for a new 500 MW limestone dual alkali system based on the prototype experience are estimated to be $95/kW and 4.5 mills/kWh, respectively. The process was developed by Combustion Equipment Associates, Inc. and Arthur D. Little, Inc.; CEA's Air Pollution Division was sold to Thyssen-CEA Environmental Systems, Inc. in late 1980.