Another reason that EPA held off issuing regional haze regula- 

 tions was because the agency expected that implementation of title 

 IV of the 1990 amendments, the acid rain control measures, would 

 significantly reduce visibility impairment caused by sulfur dioxide 

 and nitrogen oxide emissions. 



I know that you will probably remember, Mr. Chairman, when 

 we were here 4 years ago that Mr. Rosenberg, then the Assistant 

 Administrator for Air, repeatedly made this promise, but EPA has 

 since concluded that in fact title IV will not solve all of its visibility 

 problems. In the East the agency projects visibility to improve by, 

 roughly, 20 percent on an average day. 



We have here a couple of computer-simulated pictures of Shen- 

 andoah, and perhaps Mr. McGee might just explain what they tell 

 us. 



Mr. McGee. As you indicated in your opening remarks, Mr. 

 Chairman, that there would be some visibility improvement ex- 

 pected in the East thanks to the title IV provisions, and these pic- 

 tures attempt to depict what that improvement would be on an av- 

 erage day. Now, it is important to point out that on some days the 

 improvement would be much more significant. 



[Slides shown.] 



[The pictures referred to can be found in the appendix.] 



Mr. McGee. This is a composite-aggregated average of what the 

 visibility looks like now. The picture on the far right, and the one 

 on the left depicts the improvement on an average day, and you 

 can see it is not all that dramatic. 



Ms. Steinhardt. In fact, I defy you to see the difference. Even 

 on a real day, not a computer-simulated day, Park Service officials 

 say it will not be apparent to many park visitors. More impor- 

 tantly, perhaps in the West, where most of the class I areas are, 

 EPA projects little or no change in visibility as a result of title IV. 

 And I think you can see we have a map that lays out the 158 class 

 I areas, and 80 percent of them are all in the West. The remaining 

 20 percent are in the East. That 80 percent will not be affected at 

 all by the acid rain provisions because it is expected that the reduc- 

 tions in current emission levels in the West will be offset by a 

 growth in new sources. 



Although we might be critical of EPA for not doing more to get 

 the information it claims to need, we also recognize that the Park 

 Service has been saying for some years now that modeling and 

 monitoring techniques are available to begin to develop regional 

 haze regulations. The National Research Council, and I know Dr. 

 White, who will talk more about this, has since confirmed this, not- 

 ing that while additional research would be worthwhile, current 

 scientific knowledge is adequate and the control technologies are 

 available for taking regulatory action to improve visibility. 



So while there may be a need for more data to fully refine re- 

 gional haze regulations, we believe the burden of proof now rests 

 with EPA to justify why it should not begin the regulatory process. 

 We think the Park Service and the National Research Council have 

 made convincing arguments, and we believe the EPA Adminis- 

 trator ought to begin now to develop a control strategy for address- 

 ing visibility impairment. 



