united states office of air quality environmental protection planning and standards november 2002 agency research triangle park nc 27711 final report economic impact analysis the proposed stationary combustion turbines neshap mact standard prepared for john l sorrels us innovative strategies economics group iseg md 15 by michael p gallaher alan c o connor brooks m depro rti health social 27709 epa contract number 68 d 99 024 project 7647 004 385 iii table contents section page 1 introduction