
From the U.S. Code Online via GPO Access
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[Laws in effect as of January 23, 2000]
[Document not affected by Public Laws enacted between
  January 23, 2000 and December 4, 2001]
[CITE: 42USC7491]

 
                 TITLE 42--THE PUBLIC HEALTH AND WELFARE
 
            CHAPTER 85--AIR POLLUTION PREVENTION AND CONTROL
 
                  SUBCHAPTER I--PROGRAMS AND ACTIVITIES
 
     Part C--Prevention of Significant Deterioration of Air Quality
 
                    subpart ii--visibility protection
 
Sec. 7491. Visibility protection for Federal class I areas


(a) Impairment of visibility; list of areas; study and report

    (1) Congress hereby declares as a national goal the prevention of 
any future, and the remedying of any existing, impairment of visibility 
in mandatory class I Federal areas which impairment results from manmade 
air pollution.
    (2) Not later than six months after August 7, 1977, the Secretary of 
the Interior in consultation with other Federal land managers shall 
review all mandatory class I Federal areas and identify those where 
visibility is an important value of the area. From time to time the 
Secretary of the Interior may revise such identifications. Not later 
than one year after August 7, 1977, the Administrator shall, after 
consultation with the Secretary of the Interior, promulgate a list of 
mandatory class I Federal areas in which he determines visibility is an 
important value.
    (3) Not later than eighteen months after August 7, 1977, the 
Administrator shall complete a study and report to Congress on available 
methods for implementing the national goal set forth in paragraph (1). 
Such report shall include recommendations for--
        (A) methods for identifying, characterizing, determining, 
    quantifying, and measuring visibility impairment in Federal areas 
    referred to in paragraph (1), and
        (B) modeling techniques (or other methods) for determining the 
    extent to which manmade air pollution may reasonably be anticipated 
    to cause or contribute to such impairment, and
        (C) methods for preventing and remedying such manmade air 
    pollution and resulting visibility impairment.

Such report shall also identify the classes or categories of sources and 
the types of air pollutants which, alone or in conjunction with other 
sources or pollutants, may reasonably be anticipated to cause or 
contribute significantly to impairment of visibility.
    (4) Not later than twenty-four months after August 7, 1977, and 
after notice and public hearing, the Administrator shall promulgate 
regulations to assure (A) reasonable progress toward meeting the 
national goal specified in paragraph (1), and (B) compliance with the 
requirements of this section.

(b) Regulations

    Regulations under subsection (a)(4) of this section shall--
        (1) provide guidelines to the States, taking into account the 
    recommendations under subsection (a)(3) of this section on 
    appropriate techniques and methods for implementing this section (as 
    provided in subparagraphs (A) through (C) of such subsection 
    (a)(3)), and
        (2) require each applicable implementation plan for a State in 
    which any area listed by the Administrator under subsection (a)(2) 
    of this section is located (or for a State the emissions from which 
    may reasonably be anticipated to cause or contribute to any 
    impairment of visibility in any such area) to contain such emission 
    limits, schedules of compliance and other measures as may be 
    necessary to make reasonable progress toward meeting the national 
    goal specified in subsection (a) of this section, including--
            (A) except as otherwise provided pursuant to subsection (c) 
        of this section, a requirement that each major stationary source 
        which is in existence on August 7, 1977, but which has not been 
        in operation for more than fifteen years as of such date, and 
        which, as determined by the State (or the Administrator in the 
        case of a plan promulgated under section 7410(c) of this title) 
        emits any air pollutant which may reasonably be anticipated to 
        cause or contribute to any impairment of visibility in any such 
        area, shall procure, install, and operate, as expeditiously as 
        practicable (and maintain thereafter) the best available 
        retrofit technology, as determined by the State (or the 
        Administrator in the case of a plan promulgated under section 
        7410(c) of this title) for controlling emissions from such 
        source for the purpose of eliminating or reducing any such 
        impairment, and
            (B) a long-term (ten to fifteen years) strategy for making 
        reasonable progress toward meeting the national goal specified 
        in subsection (a) of this section.

In the case of a fossil-fuel fired generating powerplant having a total 
generating capacity in excess of 750 megawatts, the emission limitations 
required under this paragraph shall be determined pursuant to 
guidelines, promulgated by the Administrator under paragraph (1).

(c) Exemptions

    (1) The Administrator may, by rule, after notice and opportunity for 
public hearing, exempt any major stationary source from the requirement 
of subsection (b)(2)(A) of this section, upon his determination that 
such source does not or will not, by itself or in combination with other 
sources, emit any air pollutant which may reasonably be anticipated to 
cause or contribute to a significant impairment of visibility in any 
mandatory class I Federal area.
    (2) Paragraph (1) of this subsection shall not be applicable to any 
fossil-fuel fired powerplant with total design capacity of 750 megawatts 
or more, unless the owner or operator of any such plant demonstrates to 
the satisfaction of the Administrator that such powerplant is located at 
such distance from all areas listed by the Administrator under 
subsection (a)(2) of this section that such powerplant does not or will 
not, by itself or in combination with other sources, emit any air 
pollutant which may reasonably be anticipated to cause or contribute to 
significant impairment of visibility in any such area.
    (3) An exemption under this subsection shall be effective only upon 
concurrence by the appropriate Federal land manager or managers with the 
Administrator's determination under this subsection.

(d) Consultations with appropriate Federal land managers

    Before holding the public hearing on the proposed revision of an 
applicable implementation plan to meet the requirements of this section, 
the State (or the Administrator, in the case of a plan promulgated under 
section 7410(c) of this title) shall consult in person with the 
appropriate Federal land manager or managers and shall include a summary 
of the conclusions and recommendations of the Federal land managers in 
the notice to the public.

(e) Buffer zones

    In promulgating regulations under this section, the Administrator 
shall not require the use of any automatic or uniform buffer zone or 
zones.

(f) Nondiscretionary duty

    For purposes of section 7604(a)(2) of this title, the meeting of the 
national goal specified in subsection (a)(1) of this section by any 
specific date or dates shall not be considered a ``nondiscretionary 
duty'' of the Administrator.

(g) Definitions

    For the purpose of this section--
        (1) in determining reasonable progress there shall be taken into 
    consideration the costs of compliance, the time necessary for 
    compliance, and the energy and nonair quality environmental impacts 
    of compliance, and the remaining useful life of any existing source 
    subject to such requirements;
        (2) in determining best available retrofit technology the State 
    (or the Administrator in determining emission limitations which 
    reflect such technology) shall take into consideration the costs of 
    compliance, the energy and nonair quality environmental impacts of 
    compliance, any existing pollution control technology in use at the 
    source, the remaining useful life of the source, and the degree of 
    improvement in visibility which may reasonably be anticipated to 
    result from the use of such technology;
        (3) the term ``manmade air pollution'' means air pollution which 
    results directly or indirectly from human activities;
        (4) the term ``as expeditiously as practicable'' means as 
    expeditiously as practicable but in no event later than five years 
    after the date of approval of a plan revision under this section (or 
    the date of promulgation of such a plan revision in the case of 
    action by the Administrator under section 7410(c) of this title for 
    purposes of this section);
        (5) the term ``mandatory class I Federal areas'' means Federal 
    areas which may not be designated as other than class I under this 
    part;
        (6) the terms ``visibility impairment'' and ``impairment of 
    visibility'' shall include reduction in visual range and atmospheric 
    discoloration; and
        (7) the term ``major stationary source'' means the following 
    types of stationary sources with the potential to emit 250 tons or 
    more of any pollutant: fossil-fuel fired steam electric plants of 
    more than 250 million British thermal units per hour heat input, 
    coal cleaning plants (thermal dryers), kraft pulp mills, Portland 
    Cement plants, primary zinc smelters, iron and steel mill plants, 
    primary aluminum ore reduction plants, primary copper smelters, 
    municipal incinerators capable of charging more than 250 tons of 
    refuse per day, hydrofluoric, sulfuric, and nitric acid plants, 
    petroleum refineries, lime plants, phosphate rock processing plants, 
    coke oven batteries, sulfur recovery plants, carbon black plants 
    (furnace process), primary lead smelters, fuel conversion plants, 
    sintering plants, secondary metal production facilities, chemical 
    process plants, fossil-fuel boilers of more than 250 million British 
    thermal units per hour heat input, petroleum storage and transfer 
    facilities with a capacity exceeding 300,000 barrels, taconite ore 
    processing facilities, glass fiber processing plants, charcoal 
    production facilities.

(July 14, 1955, ch. 360, title I, Sec. 169A, as added Pub. L. 95-95, 
title I, Sec. 128, Aug. 7, 1977, 91 Stat. 742.)


                             Effective Date

    Subpart effective Aug. 7, 1977, except as otherwise expressly 
provided, see section 406(d) of Pub. L. 95-95, set out as an Effective 
Date of 1977 Amendment note under section 7401 of this title.

                  Section Referred to in Other Sections

    This section is referred to in sections 7492, 7604 of this title.
