The article discusses a computer program for determining the cost of building and operating wet scrubbers on individual coal-fired utilities in states where emissions are likely to affect the acid rain problem in the eastern U.S. The program differs from other estimates since it calculates the cost for each of 831 individual sites. The capital costs for installing scrubbers on the top 50 SO2 emitting plants will be about $20 billion and will result in a mean increase in the cost of electricity of 0.88 cents/kWh and a reduction of SO2 emissions from 1980 of 7.1 million tons per year (TPY). An added reduction of at least 1.0 million TPY would require all plants burning oil to burn low sulfur oil. These figures assume that utilities will use least-emissions dispatching and local coals containing at least 3.5% sulfur. The use of local coals should result in a saving of at least 0.2 cents/kWh; this should make available a large supply of low sulfur coal which could reduce SO2 emissions by up to 1 million TPY. The SO2 reductions will be continued for at least the next 13 years and have a very significant effect through the year 2010. (Copyright (c) 1988 Air Pollution Control Association .)