Chapters 1 - U.S. Fish and Wildlife Service

Chapter 4
Within the South Coast Air Basin, the SCAQMD regulates activities and man-made conditions that
are capable of generating fugitive dust through Rule 403 of the SCAQMD Regulations. Fugitive
dust is defined as any solid particulate matter, other than that emitted from an exhaust stack,
which becomes airborne either directly or indirectly as a result of the activities of any person. The
purpose of Rule 403 is to reduce the amount of particulate matter released into the air as a result
of man-made dust sources by requiring actions to prevent, reduce, or mitigate fugitive dust
emissions. Best available control measures and guidance for reducing dust have been developed by
the SCAQMD and are available in Tables 1 and 2 of Rule 403 (SCAQMD 2005).
Rule 1901 (General Conformity) of the AQMD Regulations applies to Federal actions conducted
within the air basin and was incorporated into the regulations in accordance with Part 51, Subpart
W, Title 40 of the Code of Federal Regulations (CFR). CFR Section 51.850 states the no
department, agency, or instrumentally of the Federal Government shall engage in, support in any
way, or provide financial assistance for, license or permit, or approve any activity which does not
conform to the applicable air quality implementation plan, in this case the SCAQMD’s 2007 AQMP
(SCAQMD 2007). In the South Coast Air Basin, a conformity determination is required for each
pollutant, where the total direct and indirect emissions in a nonattainment or maintenance area
caused by a Federal action would equal or exceed established rates. In nonattainment areas, the
following rates apply:
Ozone (VOCs or NO x) – 25 tons/year,
CO – 100 tons/year,
SO 2 or NO 2 – 100 tons/year,
PM-10 – 70 tons/year,
PM-2.5 direct emissions – 100/tons/year,
PM-2.5 SO 2 – 100/tons/year,
PM-2.5 NO x – 100/tons/year,
PM-2.5 VOC or ammonia – 100/tons/year, or
Pb – 25 tons/year.
In maintenance areas, the following rates apply:
Ozone (NO x, SO 2, NO 2) – 100 tons/year,
Ozone (VOCs) – 50 tons/year,
CO – 100 tons/year,
SO 2 or NO 2 – 100 tons/year,
PM-10 – 100 tons/year,
PM-2.5 direct emissions – 100/tons/year,
PM-2.5 SO 2 – 100/tons/year,
PM-2.5 NO x – 100/tons/year,
PM-2.5 VOC or ammonia – 100/tons/year, or
Pb – 25 tons/year.
The requirements of Rule 1901 do not apply to Federal actions where the total of direct and
indirect emissions is below these emission levels. However, when the total of direct and indirect
emissions of a pollutant from a Federal action represents 10 percent or more of an area’s total
emissions of that pollutant, the action is defined as a regionally significant action.
4.2.8 Greenhouse Gas Emissions
There is general scientific consensus that increases in greenhouse gases (GHGs) in the atmosphere
are a contributing factor to increases in average global temperatures. GHGs trap heat in the
atmosphere, which in turn heats the surface of the Earth. Some GHGs occur naturally and are
4-32 Seal Beach National Wildlife Refuge