104 STAT. 2438 PUBLIC LAW 101-549—NOV. 15, 1990 "(3) ENFORCEMENT UNDER SECTION 185.—By December 31, 2000, the State shall submit a plan revision which includes the provisions required under section 185. Any reference to the term 'attainment date' in subsection (b) or (c), which is incorporated by reference into this subsection (d), shall refer to the attainment date for Severe Areas. "(e) EXTREME AREAS.—Each State in which all or part of an Extreme Area is located shall, with respect to the Extreme Area, M make the submissions described under subsection (d) (relating to Severe Areas), and shall also submit the revisions to the applicable implementation plan (including the plan items) described under this subsection. The provisions of clause (ii) of subsection (c)(2)(B) (relating to reductions of less than 3 percent), the provisions of paragaphs (6), (7) and (8) of subsection (c) (relating to de minimus rule and modification of sources), and the provisions of clause (ii) of subsection (b)(l)(A) (relating to reductions of less than 15 percent) shall not apply in the case of an Extreme Area. For any Extreme Area, the terms 'major source' and 'major stationary source' includes (in addition to the sources described in section 302) any stationary source or group of sources located within a contiguous area and under common control that emits, or has the potential to emit, at least 10 tons per year of volatile organic compounds. "(1) OFFSET REQUIREMENT. — For purposes of satisfying the offset requirements pursuant to this part, the ratio of total emission reductions of VOCs to total increased emissions of such air pollutant shall be at least 1.5 to 1, except that if the State plan requires all existing major sources in the nonattainment area to use best available control technology (as defined in section 169(3)) for the control of volatile organic compounds, the ratio shall be at least 1.2 to 1. "(2) MODIFICATIONS—Any change (as described in section lll(a)(4)) at a major stationary source which results in any increase in emissions from any discrete operation, unit, or other pollutant emitting activity at the source shall be considered a modification for purposes of section 172(c)(5) and section 173(a), except that for purposes of complying with the offset requirement pursuant to section 173(a)(l), any such increase shall not be considered a modification if the owner or operator of the source elects to offset the increase by a greater reduction in emissions of the air pollutant concerned from other discrete operations, units, or activities within the source at an internal offset ratio of at least 1.3 to 1. The offset requirements of this part shall not be applicable in Extreme Areas to a modification of an existing source if such modification consists of installation of equipment required to comply with the applicable implementation plan, permit, or this Act. "(3) USE OF CLEAN FUELS OR ADVANCED CONTROL TECH- NOLOGY. —For Extreme Areas, a plan revision shall be submitted within 3 years after the date of the enactment of the Clean Air Act Amendments of 1990 to require, effective 8 years after such date, that each new, modified, and existing electric utility and industrial and commercial boiler which emits more than 25 tons per year of oxides of nitrogen— "(A) burn as its primary fuel natural gas, methanol, or ethanol (or a comparably low polluting fuel), or
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