Approach to Developing 'De Minimis' Values for the Noncriteria Air Pollutants

摘要

In analyzing the basis for de minimis emissions rates, it is apparent that two distinct classes of pollutants are involved. The class which is addressed in this paper consists of the noncriteria pollutants for which no ambient air quality criteria documents exist. Rather, these pollutants are only regulated within either the New Source Performance Standards (NSPS) or the National Emission Standards for Hazardous Air Pollutants (NESHAPs), both of which are based on a national emissions standards, rather than an air quality management approach. Thus, it appears reasonable to develop de minimis cutoffs from separate perspectives--that is, to base criteria pollutant de minimis emission cutoffs on air quality 'design values' and to base the noncriteria pollutants de minimis values on the emission rates embodied in the NSPS and NESHAP.