As used in this act, unless the context clearly requires otherwise:

(a) “Air contaminant” means dust, fumes, smoke, other particulate matter, vapor, gas, odorous substances, or any combination thereof, but not including water vapor or steam condensate.

(b) “Air contamination” means the presence in the outdoor atmosphere of one or more air contaminants.

(c) “Air pollution” means the presence in the outdoor atmosphere of one or more air contaminants in such quantities and duration as is, or tends significantly to be, injurious to human health or welfare, animal or plant life, or property, or would unreasonably interfere with the enjoyment of life or property, or would contribute to the formation of regional haze.

(d) “Alter” means any physical change in, or change in the method of operation of, an air contaminant emission stationary source which increases the amount of any regulated air pollutant emitted by such source or which results in the emission of any regulated air pollutant not previously emitted.

(e) “Emission” means a release into the outdoor atmosphere of air contaminants.

(f) “Deciview” means an atmospheric haze index that expresses changes in visibility conditions as defined in 40 C.F.R. § 51.301 as in effect on July 1, 2005.

(g) “Facility” means any building, structure, machine, equipment, device or installation (or group of buildings, structures, machines, equipment, devices or installations), whether temporary or permanent, located on one or more contiguous or adjacent properties and under common control of the same person (or persons under common control). Such term shall not include locomotives, diesel trucks or truck tractors unless otherwise required by the federal clean air act, as amended in November 1990.

(h) “Modify” or “modification,” when used in conjunction with an approval or permit action, means an amendment to an existing approval or permit initiated by the permittee. When used to describe a change in any air contaminant emission stationary source, “modify” shall have the same meaning as the term “alter.”

(i) “Permittee” means the holder of an approval or the holder of a permit and includes both the owner and the operator of any approved or permitted air contaminant emission source.

(j) “Person” means any individual, partnership, firm, association, municipality, public or private corporation, subdivision or agency of the state or federal government, trust, estate or any other legal entity.

(k) “Regional haze” means visibility impairment, measured in deciviews, occurring over a large geographic area caused by the cumulative emissions of gaseous and particulate air contaminants from numerous sources.

(l) “Reopen” means to seek an amendment to an existing approval or permit initiated by any person other than the permittee.

(m) “Secretary” means the secretary of health and environment.

(n) “Stationary source” means any building, structure, facility or installation which emits or may emit any air contaminant.