This report documents the activities performed and the results obtained from the first six months of the EPA arsenic removal technology demonstration project at the Stewart, MN facility. The main objective of the project is to evaluate the effectiveness of Siemens Type II AERALATER system for iron removal and AdEdge Technologies Arsenic Package Unit (APU)-300 system for subsequent arsenic removal. The effectiveness is evaluated based on the systems ability to remove arsenic to below the new arsenic maximum contaminant level (MCL) of 10 mu g/L. Further, this project also (1) evaluates the reliability of the treatment system for use at small water facilities, (2) determines the required system operation and maintenance (O&M) and operator skill levels, (3) characterizes process residuals generated by the treatment process, and (4) determines the capital and O&M cost of the technology. The types of data collected include system operation, water quality (both across the treatment train and in the distribution system), process residuals, and capital and O&M cost.