Section R307-421-2 - Applicability(1) This rule applies to new or modified sources of sulfur dioxide or oxides of nitrogen that are located in or impact Salt Lake County or Utah County.(2) A new or modified source shall be considered to impact an area if the modeled impact is greater than 1.0 microgram/cubic meter for a one-year averaging period or 3.0 micrograms/cubic meter for a 24-hour averaging period for sulfur dioxide or nitrogen dioxide.Utah Admin. Code R307-421-2