<html xmlns="http://www.w3.org/1999/xhtml"><head><meta charset="UTF-8" /><title></title><meta name="Generator" content="PowerTools for Open XML" /><style>span { white-space: pre-wrap; } p.s60ad8867-c61a-4ef6-9fa5-374b15ec6362P0 { margin-top: 0; margin-bottom: 0; margin-left: 0; margin-right: 0; text-indent: 0.00in; text-align: justify; background: white; font-family: 'Times New Roman', 'serif'; font-size: 12pt; line-height: 108%; } span.s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0 { background: white; font-family: 'Times New Roman', 'serif'; font-size: 12pt; font-style: normal; font-weight: normal; margin: 0; padding: 0; } span.s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000000 { color: #0000FF; background: white; font-family: 'Times New Roman', 'serif'; font-size: 12pt; font-style: normal; font-weight: bold; margin: 0; padding: 0; } span.s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000001 { background: white; font-family: 'Times New Roman', 'serif'; font-size: 12pt; font-style: normal; font-weight: bold; margin: 0; padding: 0; } span.s60ad8867-c61a-4ef6-9fa5-374b15ec6362000002 { background: white; font-size: 12pt; font-style: normal; font-weight: normal; margin: 0; padding: 0; } span.s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000003 { color: #0000FF; background: white; font-family: 'Times New Roman', 'serif'; font-size: 12pt; font-style: normal; font-weight: normal; margin: 0; padding: 0; } </style></head><body><div><p dir="ltr" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362P0"><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">    </span><a href="https://sdlegislature.gov/Rules?Rule=74:36:21:04"><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000000">74:36:21:04</span></a><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000001">.  Visibility impact analysis.</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> </span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">An air quality construction permit for</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> a new major source or modification to a major source </span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">must</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> demonstrate to the department that the potential to emit from the new major source or modification to a major source</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> may be issued only if it has been shown that the operation of the new major source or modification to a major source</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> will not contribute to adverse impact on visibility in any mandatory Class I federal area.</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> Adverse impact on visibility must be based on a case-by-case basis, taking into account the geographic extent, intensity, duration, frequency, and time of visibility impairment, and how these factors correlate with times of visitor use of a mandatory Class I federal area and the frequency and timing of natural conditions that reduce visibility. If air pollution dispersion modeling is required, the modeling must be performed in accordance with the air quality modeling guidance</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> in 40 C.F.R. </span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">Part </span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">51, </span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">Appendix</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> W (July 1, 20</span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">24</span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">)</span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">, and is not affected by stack height that exceeds good engineering practice or by any other dispersion technique as defined in 40 C.F.R. § 51.100 (July 1, 2024)</span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">.</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> A source contributes to adverse impact on visibility if the source exceeds the threshold of the ninety-eighth percentile, eighth highest value, of the modeling results, based on one year of the three years of meteorological data modeled, equals or exceeds five-tenths deciviews.</span></p><p dir="ltr" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362P0"><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362000002"> </span></p><p dir="ltr" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362P0"><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">    </span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000001">Source:</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> 37 SDR 111, effective December 7, 2010; 39 SDR 219, effective June 25, 2013; 42 SDR 52, effective October 13, 2015; 44 SDR 43, effective September 13, 2017; 46 SDR 64, effective November 25, 2019</span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">; 52 SDR 27, effective September 17, 2025</span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">.</span></p><p dir="ltr" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362P0"><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">    </span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000001">General Authority:</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> SDCL </span><a href="https://sdlegislature.gov/Statutes?Statute=34A-1-6"><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000003">34A-1-6</span></a><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">.</span></p><p dir="ltr" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362P0"><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">    </span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000001">Law Implemented:</span><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0"> SDCL </span><a href="https://sdlegislature.gov/Statutes?Statute=34A-1-1"><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000003">34A-1-</span><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0-000003">1</span></a><span class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362C0">.</span></p><p dir="ltr" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362P0"><span xml:space="preserve" class="s60ad8867-c61a-4ef6-9fa5-374b15ec6362000002"> </span></p></div></body></html>