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developing consensus on some procedursl improvements related to 

 Class I areas (e.g., methods for providing FLMs with notice of 

 pending permit applications) . However, the Subcommittee has 

 struggled with and failed to achieve consensus on the substantive 

 aspects of the program. The stalamats stems from the lack of any 

 effective regulatory means for addressing existing adveree impacts. 

 Until EPA develops requirements to mitigate existing impacts, such 

 as those recommended above, the stalemate will continue. In any 

 event, the new source review program must provide mechanism* for 

 preventing significant deterioration of air quality, including 

 adveree impacts on AQRVs. 



As mentioned above, SPA has a duty under section 166 of the 

 Act to develop measures for all pollutants to protect AQStVs and 

 fulfill the purposes of the PSD program. Pollution increments for 

 sulfur dioxide, particulate matter, and nitrogen dioxide have 

 already been established. However, in 1990, the U.S. Court of 

 Appeals for the District of Columbia Circuit remanded nitrogen 

 dioxide increments promulgated by EPA because the Agency did not 

 adequately coneider the requirements of section 166(a). 

 Environmental Defense Fund v. EPA. 198 F.2d 1S3 (O.C. Cir. 1990). 

 efa has not yet taken any action in response to that remand. In 

 addition, EPA has establishsd no measures to limit osone 

 concentrations in Class I arsas. 



EPA must directed to carry out its duty under section 166 to 

 address other pollutants of concern. In developing additional 

 measures, EPA must consider the fact that it would be inconsistent 

 with the purposes of the PSD program to allow incremental increasae 

 in some pollutants if those pollutants are already causing adveree 

 impacts. EPA should consider more creative approaches, such as a 

 HOx emissions cap or establishment of "critical loads** to avoid any 

 further deterioration of air quality in Class X areas. 



In addition to establishing numerical standards for Class I 

 areas that ensure protection of all AQRVs, EPA must clarify that 

 FLMs, as the stewards of our most precious national park and 

 wilderness resourcos, have the authority and responsibility to 

 identify air quality related values and. determine whether adverse 

 impacts are occurring. If the FLM certifies that adverss impacts 

 are occurring and providee a rational basis for that determination, 

 the only relevant inquiry for the permitting authority should be 

 to assess whether a new eource or modification emits any pollutant 

 that would contribute to that impact. Permitting authorities must 

 be prohibited from using "impact-based" teets to allow construction 

 of nsw facilities that do not have a significant impact on existing 

 adverse impacts or documented increment exceedancee. impact-based 

 tssts frustrate resource protection goals. In reality, few sources 

 havo a "significant" impact on pollution concentrations, even 

 though their emissions contribute to ambient concentrations. EPA 

 ehould insist on an emissions-based test, similar to the one used 

 in nonattainment areas, ones adveree impacts have occurred. This 



