V.B.1.

Code of Colorado Regulations · Regulation Number 23

REGIONAL HAZE LIMITS 5 CCR 1001-27

Colorado Regulation Number 23 sets regional haze limits for sources subject to Best Available Retrofit Technology (BART) and Reasonable Progress (RP) requirements. The regulation includes the substantive limits and the statements of basis and authority for those limits.

I.

Section I applies to existing stationary facilities that are BART eligible sources (as defined in Section II.M.) and to reasonable progress sources. Section IV (Regional Haze Determinations) and Section V (MRR) are incorporated into Colorado's Regional Haze State Implementation Plan; all other sections of Regulation Number 23 are State-Only.

II.A.

"Adverse Impact on Visibility" means visibility impairment that interferes with managing, protecting, preserving, or enjoying the visitor's visual experience of a Federal Class I area. The determination is made case-by-case, considering the geographic extent, intensity, duration, frequency, and timing of the impairment and how those factors line up with times of visitor use and the frequency and timing of natural conditions that reduce visibility. The term does not include effects on integral vistas.

II.B.2.

All other areas of Colorado are designated Class II unless Congress, the Colorado legislature, or the Commission redesignates them under Regulation Number 3, Part D, Section IX. However, in certain areas as they existed on August 7, 1977 – including Florissant Fossil Beds, Colorado, Dinosaur, and Great Sand Dunes National Monuments; Uncompahgre Mountain and Wilson Mountain Forest Service Primitive Areas; the Gunnison Gorge Recreation Area; and Black Canyon of the Gunnison National Park (non-wilderness portions) – the allowable increase in sulfur dioxide concentrations over baseline is the same as the increase set for Class I areas, except that it may not be allowed if a Federal Land Manager makes an adverse impact determination under Regulation Number 3, Part D, Section XIII.C. with which the Division concurs, and it may be exceeded by compliance with Sections XIII.D., XIII.E., or XIII.F. of Regulation Number 3, Part D.

II.B.2.c.

Lands administered by the Federal Bureau of Land Management in the Gunnison Gorge Recreation Area as of October 27, 1977 are among the areas where the increase allowed in sulfur dioxide concentrations over the baseline concentration is the same as the increase established by Section 163(b) of the Federal Act for Class I areas, with the exceptions stated in the parent text. All areas designated Class II under this section may be redesignated as provided in Regulation Number 3, Part D, Section IX.