15A NCAC 02D .0521 CONTROL OF VISIBLE EMISSIONS (a) Purpose. The intent of this Rule is to prevent, abate and control emissions generated from fuel burning operations and industrial processes where an emission can reasonably be expected to occur, except during startup, shutdowns, and malfunctions approved according to procedures set out in Rule .0535 of this Section. (b) Scope. This Rule shall apply to all fuel burning sources and to other processes that may have a visible emission. However, sources subject to a visible emission standard in Rules .0506, .0508, .0524, .0543, .0544, .1110, .1111, .1205, .1206, .1210, .1211, or .1212 of this Subchapter shall meet that standard instead of the standard contained in this Rule. This Rule does not apply to engine maintenance, rebuild, and testing activities where controls are infeasible, except it does apply to the testing of peak shaving and emergency generators. (In deciding if controls are infeasible, the Director shall consider emissions, capital cost of compliance, annual incremental compliance cost, and environmental and health impacts.) (c) For sources manufactured as of July 1, 1971, visible emissions shall not be more than 40 percent opacity when averaged over a six-minute period. However, except for sources required to comply with Paragraph (g) of this Rule, sixminute averaging periods may exceed 40 percent opacity if: (1) (2) (3) No six-minute period exceeds 90 percent opacity; No more than one six-minute period exceeds 40 percent opacity in any hour; and No more than four six-minute periods exceed 40 percent opacity in any 24-hour period. (d) For sources manufactured after July 1, 1971, visible emissions shall not be more than 20 percent opacity when averaged over a six-minute period. However, except for sources required to comply with Paragraph (g) of this Rule, sixminute averaging periods may exceed 20 percent opacity if: (1) (2) (3) No six-minute period exceeds 87 percent opacity; No more than one six-minute period exceeds 20 percent opacity in any hour; and No more than four six-minute periods exceed 20 percent opacity in any 24-hour period. (e) Where the presence of uncombined water is the only reason for failure of an emission to meet the limitations of Paragraph (c) or (d) of this Rule, those requirements shall not apply. (f) Exception from Opacity Standard in Paragraph (d) of this Rule. Sources subject to Paragraph (d) of this Rule shall be allowed to comply with Paragraph (c) of this Rule if: (1) (2) The owner or operator of the source demonstrates compliance with applicable particulate mass emissions standards; and The owner or operator of the source submits data necessary to show that emissions up to those allowed by Paragraph (c) of this Rule shall not violate any national ambient air quality standard. The burden of proving these conditions shall be on the owner or operator of the source and shall be approached in the following manner. The owner or operator of a source seeking an exception shall apply to the Director requesting this modification in its permit. The applicant shall submit the results of a source test within 90 days of application. Source testing shall be by the appropriate procedure as designated by rules in this Subchapter. During this 90-day period the applicant shall submit data necessary to show that emissions up to those allowed by Paragraph (c) of this Rule will not contravene ambient air quality standards. This evidence shall include an inventory of past and projected emissions from the facility. In its review of ambient air quality, the Division may require additional information that it considers necessary to assess the resulting ambient air quality. If the applicant can thus show that it will be in compliance both with particulate mass emissions standards and ambient air quality standards, the Director shall modify the permit to allow emissions up to those allowed by Paragraph (c) of this Rule. (g) For sources required to install, operate, and maintain continuous opacity monitoring systems (COMS), compliance with the numerical opacity limits in this Rule shall be determined as follows excluding startups, shutdowns, maintenance periods when fuel is not being combusted, and malfunctions approved as such according to procedures approved under Rule .0535 of this Section: (1) (2) No more than four six-minute periods shall exceed the opacity standard in any one day; and The percent of excess emissions (defined as the percentage of monitored operating time in a calendar quarter above the opacity limit) shall not exceed 0.8 percent of the total operating hours. If a source operates less than 500 hours during a calendar quarter, the percent of excess emissions shall be calculated by including hours operated immediately previous to this quarter until 500 operational hours are obtained. In no instance shall excess emissions exempted under this Paragraph cause or contribute to a violation of any emission standard in this Subchapter or 40 CFR Part 60, 61, or 63 or any ambient air quality standard in Section 15A NCAC 02D .0400 or 40 CFR Part 50. History Note: Authority G.S. 143-215.3(a)(1); 143-215.107(a)(5); Eff. February 1, 1976; Amended Eff. January 1, 2009; July 1, 2007; January 1, 2005; June 1, 2004; April 1, 2003; April 1, 2001; July 1, 1998; July 1, 1996; December 1, 1992; August 1, 1987; January 1, 1985; May 30, 1978.