Technology Transfer Network - Air Toxics Web Site
Section 112(a)-Definitions
(a) Definitions: Defines eleven terms found in Section 112: "major source", "area source", "stationary source", "new source", "modification", "hazardous air pollutant", "adverse environmental effect", "electric utility steam generating unit", "owner or operator", "existing source" and "carcinogenic effect".
The definitions as in CAA Section 112(a) follow:
SEC. 112. HAZARDOUS AIR POLLUTANTS.
(a) Definitions. - For purposes of this section, except
subsection (r) -
(1) Major source. - The term "major source" means any
stationary source or group of stationary sources located within
a contiguous area and under common control that emits or has
the potential to emit considering controls, in the aggregate,
10 tons per year or more of any hazardous air pollutant or 25
tons per year or more of any combination of hazardous air
pollutants. The Administrator may establish a lesser quantity,
or in the case of radionuclides different criteria, for a major
source than that specified in the previous sentence, on the
basis of the potency of the air pollutant, persistence,
potential for bioaccumulation, other characteristics of the
air pollutant, or other relevant factors.
(2) Area source. - The term "area source" means any
stationary source of hazardous air pollutants that is not a
major source. For purposes of this section, the term "area
source" shall not include motor vehicles or nonroad vehicles
subject to regulation under title II.
(3) Stationary source. - The term "stationary source" shall
have the same meaning as such term has under section 111(a).
(4) New source. - The term "new source" means a stationary
source the construction or reconstruction of which is commenced
after the Administrator first proposes regulations under this
section establishing an emission standard applicable to such
source.
(5) Modification. - The term "modification" means any
physical change in, or change in the method of operation of, a
major source which increases the actual emissions of any
hazardous air pollutant emitted by such source by more than a
de minimis amount or which results in the emission of any
hazardous air pollutant not previously emitted by more than a
de minimis amount.
(6) Hazardous air pollutant. - The term "hazardous air
pollutant" means any air pollutant listed pursuant to subsec-
tion (b).
(7) Adverse environmental effect. - The term "adverse
environmental effect" means any significant and widespread
adverse effect, which may reasonably be anticipated, to
wildlife, aquatic life, or other natural resources, including
adverse impacts on populations of endangered or threatened
species or significant degradation of environmental quality
over broad areas.
(8) Electric utility steam generating unit. - The term
"electric utility steam generating unit" means any fossil fuel
fired combustion unit of more than 25 megawatts that serves a
generator that produces electricity for sale. A unit that
cogenerates steam and electricity and supplies more than
one-third of its potential electric output capacity and more
than 25 megawatts electrical output to any utility power
distribution system for sale shall be considered an electric
utility steam generating unit.
(9) Owner or operator. - The term "owner or operator" means
any person who owns, leases, operates, controls, or supervises
a stationary source.
(10) Existing source. - The term "existing source" means
any stationary source other than a new source.
(11) Carcinogenic effect. - Unless revised, the term
"carcinogenic effect" shall have the meaning provided by the
Administrator under Guidelines for Carcinogenic Risk Assessment
as of the date of enactment. Any revisions in the existing
Guidelines shall be subject to notice and opportunity for
comment.