34 



Mr. Synar. So even if we applied all the controls commercially 

 available, we would still have visibility problems? 



Mr. White. That is right. 



Mr. Synar. Professor White, you are an expert in tracing emis- 

 sions back to their sources. Given the complexity of that task, in- 

 cluding the large number of potential sources which may affect vis- 

 ibility, is tracing specific emissions back to their sources a useful 

 way to regulate threats to visibility? 



Mr. WHITE. I think it is a very, very difficult way to go about it, 

 and the experience with the Grand Canyon and the regulation of 

 the Navajo Generating Station provides a good example. That is a 

 large plant just 25 kilometers from the park boundary. 



Mr. Synar. What about revising the national ambient air quality 

 standards for particulate matter to focus on small size particles? 

 What is the feasibility of this approach to try to improve visibility? 



Mr. White. That is certainly worth consideration. It would be a 

 secondary standard for fine particles because visibility degradation 

 is predominantly due to fine particles. One concern is that the 

 standard that would protect visibility in the West might be too 

 strict to be at all achievable in the East and conversely that if you 

 set a standard in the East that could be met by reducing anthropo- 

 genic emissions, it would not protect visibility in the West. 



Mr. Synar. What is the cost of that strategy, do you have any 

 idea? 



Mr. White. No. 



Mr. Synar. Your report and testimony conclude that current sci- 

 entific knowledge is adequate — and control technologies are avail- 

 able — for taking regulatory action now to improve this visibility. 

 You recommend, I think, actions based on the use of a series of in- 

 creasingly sophisticated models to access the contribution of 

 sources or groups of sources. 



How would those models help support the new regulations? 



Mr. White. The models would help identify the types of sources 

 that should receive the most attention, the most initial attention, 

 and they could also identify regions that should receive attention. 



Mr. Synar. What about the more sophisticated hybrid models, 

 are they available? 



Mr. White. The elements of those models are available, and with 

 the commitment to building them they could be put together in the 

 next — in the near term future. 



Mr. Synar. Professor, you heard a couple minutes ago that EPA 

 has not requested funds for atmospheric research for fiscal year 

 1995. What do you view as the most important types of research 

 that will not be funded or will be discontinued because of that 

 budget request? 



Mr. WHITE. Well, certainly monitoring is an important priority. 

 We are embarked on substantial experiments in reducing emissions 

 across a large area in the East and reducing emissions at the Nav- 

 ajo Generating Station near Grand Canyon. 



It would be a real waste and shame to pass up the opportunity 

 to track the effects of these emissions reductions in the atmos- 

 phere. 



