The report gives results of a 4-month study of existing industrial sources of SO2 emissions in the Acid Rain Mitigation Study (ARMS) region, including all the states east of the Mississippi River, as well as MN, IA, MO, AR, LA, ND, SD, NE, KS, OK, and TX. Study aims were to: (1) identify and characterize existing industrial sources of SO2 emissions, (2) identify control techniques that can be used to reduce SO2 emissions from these sources, and (3) estimate the SO2 emission reductin potential and the associated costs in constant 1980 dollars based on application of these controls. Simplifying assumptions were made for the balance of the SO2 sources studied. In addition, since sites were not visited, the remaining useful lives of the sources were not determined, and average FGD unit retrofit factors were estimated. Recommendations concerning the use of study results are discussed.