Title I of the CAAA requires the
states to apply the same requirements
to major stationary sources of
NOx as are applied to major stationary
sources of volatile organic compounds
(VOCs). In general, these
new NOx provisions require: (1) existing
major stationary sources to
apply reasonably available control
technologies (RACT); (2) new or
modified major stationary sources to
offset their new emissions and install
Coal-Fired Boiler NOx Emissions Limits (Title IV), lb/million Btu
Phase I Phase II
Implementation Date Jan. 1, 1996 Jan. 1, 2000
Group 1 Boilers
Dry-Bottom, Wall-Fired 0.50 0.46
Tangentially Fired 0.45 0.40
Group 2 Boilers
Wet-Bottom, Wall-Fired
(>65 MWe) NA 0.84
Cyclone-Fired (>155 MWe) NA 0.86
Vertically Fired NA 0.80
Cell Burner NA 0.68
Fluidized Bed NA Exempt
Stoker NA Exempt
controls representing the lowest
achievable emissions rate (LAER);
and (3) each state with an ozone
nonattainment region to develop a
State Implementation Plan (SIP) that,
in most cases, includes reductions in
stationary source NOx emissions beyond
those required by the RACT provisions
of Title I.
More recently, EPA has attributed
part of the problem with nonattainment
to long range transport of ozone and its
precursors, NOx and VOCs. To address
these transported pollutants,
EPA has adopted a regional approach
by promulgating an Ozone Transport
Rule that requires 22 states and the
District of Columbia to amend their
SIPs under CAAA to lower NOx emissions
levels during the “summer” (May
through September) ozone season.
EPA’s rule sets statewide NOx
emissions budgets, which include budget
components for the electric power
industry and certain industrial stationary
sources. These sources are required
to make large NOx emissions
reductions to decrease the
movement of significant amounts
of ozone from one region of the
country to another. The target NOx
emissions limit for utility boilers is
0.15 lb/million Btu