11 



we examine several other federal initiatives intended to remedy 

 or prevent visibility impairment in class I areas. 



In short, we found that despite some progress since our last 

 testimony to you, visibility impairment in many class I areas 

 remains a serious problem. 



• First, programs to control air pollution from individual 

 sources near class I areas have had only a limited impact 

 and are, in some respects, costly and difficult to 

 implement. Further, some pollution sources are exempt from 

 the program either because they existed prior to 1977 and 

 were grandfathered or because they fall below an emission 

 threshold. 



• Secondly, regional sources of air pollution are also 

 significant contributors to visibility impairment. Even 

 though these regional sources could be controlled under 

 existing Clean Air Act authorities, Environmental Protection 

 Agency (EPA) has not issued regulations or initiated other 

 control measures to address the problem. 



EFFORTS TO REDUCE VISIBILITY IMPAIRMENT 

 FROM NEARBY SOURCES ARE NOT EFFECTIVE 



As was the case when we testified before this Subcommittee 

 In March 1990 which followed our February 1990 report, 2 the PSD 

 program continues to provide limited opportunities for improving 

 visibility impairment in class I areas. The PSD program 

 prohibits the construction or modification of "major emitting 

 facilities" in areas that have attained national air quality 

 standards unless they demonstrate that they will not exceed 



2 Air Pollution; Protecting Parks and Wilderness Fro m Nearby Pollution 

 Sources (GAO/RCED-90-10, February 7, 1990) 



