CRITICAL LOADS AND DEVELOPMENT OF ACID-RAIN CONTROL OPTIONS

The present paper describes the result of a demonstration project in w hich optimization models were used to identify efficient and equitable SO2 control strategies that satisfy environmental quality standards a t sensitive receptor locations in Maryland. Notable in the modeling is the use of location-specific critical-load estimates. These estimates -the critical loads-represent maximum allowable sulfur-deposition rate s, that is, rates below which continued acidification and its attendan t possible ecological consequences are believed not to occur. The anal yses include scenarios that involve 10,000,000 t/yr SO2 reductions in the United States, uniform percentage-reduction scenarios, and state-l evel sensitivity analyses.