Comment:   Some commenters raised concerns about a statement in the
proposal that “[i]n addressing a nonattainment area having military
training, testing and operational activities occurring within it, the
State should not need to target these activities for emission
reductions.”  Some commenters interpreted this statement as an
exemption from any emission reduction requirements for military sources.
 

	Response:  The statement in the proposal was not intended as an
exemption for all military activities.  Emissions potentially
contributing to PM2.5 concentrations at military installations originate
from a variety of sources:  basic operational activities (such as power
generation, other fuel combustion, and transportation to and from
residences, offices, and schools); and from field training and testing
activities (such as personnel training, obscurants used in training,
operation of nonroad vehicles and equipment, and related prescribed
burning operations).  The EPA believes that in evaluating emissions for
a specific nonattainment area having military activities occurring
within it, the State should consult with DOD for information on the
nature of these activities and their associated emissions. 

	With regard to military training activities specifically, such
activities are periodic in nature, and when they do occur, the principal
type of emissions generated by these activities is dust (e.g. inorganic
direct PM dust emissions) from field operations.  Other pollutants may
be emitted to a lesser degree from certain onroad and nonroad motor
vehicles.  While dust from military training activities may contribute
some degree of primary PM2.5 emissions to certain nonattainment area
inventories, the fugitive dust generated from military training
activities is expected to be predominantly composed of coarse PM rather
than fine PM.  

	Based on data from the PM2.5 speciation monitoring network operated by
EPA and the States, the contribution of inorganic dust to total PM2.5
mass on an annual average basis is relatively low in most nonattainment
areas, on the order of 0.5 to 1.5 micrograms per cubic meter (generally
10% or less of total PM2.5 mass).  Dust from military training
activities would be a subset of these annual average levels.  Depending
on the available information and specific circumstances for a particular
area, it is possible that a State could find in its SIP development
analyses that direct PM2.5 emissions from military training activities
do not significantly contribute to annual average PM2.5 concentrations
in the nonattainment area, and therefore would not need to target
military training activities for emission reductions in its attainment
plan.  

 for attaining the annual standard.  

 Windblown dust from agricultural tilling activities also can be a
periodic source of inorganic PM in some areas. In some cases such dust
would be expected to be predominantly composed of coarse PM rather than
fine PM.  Depending on the available information and specific
circumstances for a particular area, it is possible that a State could
find in its SIP development analyses that direct PM2.5 emissions from
agricultural tilling activities do not significantly contribute to
annual average PM2.5 concentrations in the nonattainment area, and
therefore would not need to require emission reductions from
agricultural tilling activities in the plan for attaining the annual
standard.  However, States should be mindful of the contribution of
these sources to 24-hour fine particle concentrations.

