Opinion ID: 2465274
Heading Depth: 1
Heading Rank: 7

Heading: Fugitive Particulate Emissions

Text: [¶ 46] As its final issue, the Sierra Club contends that DEQ improperly failed to model, or require Medicine Bow to model, the impacts of fugitive emissions of particulate matter. Fugitive emissions are emissions which could not reasonably pass through a stack, chimney, vent, or other functionally equivalent opening. WAQSR ch. 6, § 4(a). See also 40 C.F.R. § 52.21(b)(20). Examples might include dust blown by the wind from coal stockpiles or raised by vehicles travelling on unpaved roads. DEQ admits that it did not require modeling of the short term impacts of fugitive emissions, but asserts that it is not required to do so. Medicine Bow supports DEQ's assertion. [¶ 47] Under Wyoming regulations, no air quality permit may be issued unless the applicant shows, to the satisfaction of the Administrator of the Division of Air Quality that [t]he proposed facility will not cause significant deterioration of existing ambient air quality in the Region. WAQSR ch. 6, § 2(c)(iii). In addition, a proposed facility may not receive a permit unless it shows that the predicted impact of its emissions is less than the maximum allowed increment. Id., § 4(b)(i)(A)(I). As explained by the Sierra Club, the permit applicant must analyze the `predicted impact' of the new source's emissions and prove that [the] impact is less than both the maximum allowable increment and the ambient standard. The regulation continues, An analysis of the predicted impact of emissions from the stationary source is required for all pollutants for which standards have been established . . . and which are emitted in significant amounts. An analysis of the impact of other pollutants may be required by the Administrator. Such analysis shall identify and quantify the impact on the air quality in the area of all emissions. . . . The purpose of this analysis is to determine the total deterioration of air quality from the baseline concentrations; however, projections of deterioration due to general non-stationary source growth in the area predicted to occur after the date of application is not required. WAQSR ch. 6, § 4(b)(i)(A)(I) (emphasis in original). As we recently observed, To predict whether the impacts of a proposed source's emissions will exceed [these standards], one tool available to the DEQ is a computer model that estimates what the impacts will be. Powder River Basin Resource Council, ¶ 9, 226 P.3d at 814. The question presented to us now is whether DEQ is required to employ the computer modeling tool to predict the short term air quality impacts of fugitive particulate emissions. [¶ 48] As noted above, DEQ admits that it did not model the short term impacts of fugitive particulate matter emissions. However, the analysis undertaken by DEQ in this case included modeling of the long term impacts of fugitive particulate matter, and of the short term impacts of particulate emissions from point sources. These models predicted no violations of the applicable standards. Instead of requiring modeling of the short term impacts of fugitive particulates, DEQ applied its expertise and experience to analyze various pertinent factors, including the fact that Medicine Bow's fugitive particulate emissions will be relatively smaller than other comparable operations in Wyoming. Based on this analysis, DEQ concluded that the predicted impact of emissions from the Medicine Bow facility will not exceed the applicable standards. This prediction will be verified by actual monitoring of the facility's air quality impacts once it has begun operations. [¶ 49] DEQ explains that it does not require modeling of the short-term impacts of fugitive particulate emissions because such models do not produce realistic results and can significantly overestimate short-term impacts. DEQ cites a long history of technical difficulties in quantifying and modeling fugitive emissions, particularly when used to predict short-term impacts, and of the regulatory uncertainty about how to deal with these difficulties. See, e.g., 48 Fed.Reg. 38742, 38743-47 (August 25, 1983). In 1990, at least in part because of these difficulties and uncertainties, the United States Congress promulgated Section 234 of the federal Clean Air Act, known as the Simpson Amendment, to address modeling issues relating to fugitive emissions: Prior to any use of the Industrial Source Complex (ISC) Model using AP-42 Compilation of Air Pollutant Emission Factors to determine the effect on air quality of fugitive particulate emissions from surface coal mines, for purposes of new source review or for purposes of demonstrating compliance with national ambient air quality standards for particulate matter applicable to periods of 24 hours or less, under section 110 or parts C or D of title I of the Clean Air Act, the Administrator [of the EPA] shall analyze the accuracy of such model and emission factors and make revisions as may be necessary to eliminate any significant over-prediction of air quality effect of fugitive particulate emissions from such sources. Such revisions shall be completed not later than 3 years after the date of enactment of the Clean Air Act Amendments of 1990. Until such time as the Administrator develops a revised model for surface mine fugitive emissions, the State may use alternative empirical based modeling approaches pursuant to guidelines issued by the Administrator. Clean Air Act Amendments of 1990, Pub.L. No. 101-549, § 234 (1990). DEQ and Medicine Bow argue that this statutory provision expressly authorizes the use of alternative means to analyze the short-term impacts of fugitive particulate matter emissions. [¶ 50] The Sierra Club suggests two reasons that this statute does not apply. First, it points out that the statute applies only to emissions from surface coal mines, not to the underground coal mine proposed by Medicine Bow. Federal law, however, defines the term surface coal mine to include the surface operations and surface impacts incident to an underground coal mine. 30 U.S.C. § 1291(28)(A). See also 30 U.S.C. § 1266(a) (authorizing the regulation of the surface effects of underground coal mining operations). This supports DEQ's interpretation of the statute as encompassing the surface impacts associated with Medicine Bow's underground mine. Second, the Sierra Club points out that the statute refers to the ISC Model, an older model that has been replaced by one called AERMOD. The Simpson Amendment expressly provides that [u]ntil such time as the Administrator develops a revised model for surface mine fugitive emissions, the State may use alternative empirical based modeling approaches pursuant to guidelines issued by the Administrator. DEQ contends that AERMOD still produces a high degree of uncertainty in modeling short-term fugitive impacts. Accordingly, DEQ and Medicine Bow assert that the Simpson Amendment continues to authorize the use of analytical techniques other than modeling to predict the short-term air quality impacts of fugitive particulate emissions. The Sierra Club has not cited any authority indicating that the EPA has revised either model so as, in the words of the Simpson Amendment, to eliminate any significant over-prediction of air quality effect of fugitive particulate emissions from such sources. [¶ 51] The DEQ also relies on a Memorandum of Agreement it made with the EPA in 1994, in which the two agencies agreed that monitoring could be substituted for short-term modeling of fugitive particulate emissions for mines in Wyoming's Powder River Basin. DEQ admits that the Medicine Bow facility will not be located in the Powder River Basin. However, DEQ also points out that the Memorandum of Agreement was made pursuant to the authority of the Simpson Amendment, which does not limit its scope to the Powder River Basin. Accordingly, DEQ argues that it is legally authorized to, and has, extended the policy of the Memorandum of Agreement to apply throughout Wyoming. [¶ 52] In response to the arguments of DEQ and Medicine Bow, the Sierra Club posits that [m]odels are required under Wyoming law to demonstrate compliance with air quality standards. After a close reading of the Sierra Club's brief, however, we conclude that it has failed to support this argument with reference to any statute, regulation, or policy, either in Wyoming law or from the EPA. The Sierra Club seems to rely on WAQSR ch. 6, § 4(b)(i)(A)(I), quoted above, which requires the permit applicant to analyze the predicted impact of the new source's emissions. However, the Sierra Club has not cited any statutory or regulatory definition equating the term analyze with computer model, or any provision indicating that modeling is a required step in the analysis of predicted air quality impacts. As we recently observed, To predict whether the impacts of a proposed source's emissions will exceed [applicable standards], one tool available to the DEQ is a computer model that estimates what the impacts will be. Powder River Basin Resource Council, ¶ 9, 226 P.3d at 814. Modeling is one tool, but the Sierra Club has not demonstrated that it is the only permissible tool. [¶ 53] The Sierra Club also points to WAQSR ch. 6, § 4(b)(iv), which provides that [a]ll applications of air quality modeling required under paragraph (b)(i) above shall be based on the applicable models, databases, and other requirements specified in Appendix W of 40 CFR part 51 (Guideline on Air Quality Models). This regulation does not require modeling in every instance. It provides only that when modeling is done, it must meet certain standards. [¶ 54] From Appendix W of 40 C.F.R. part 51, the Sierra Club points to language stating that the impacts of new sources that do not yet exist can only be determined through modeling. 40 C.F.R. part 51, Appendix W, subsection 1.0.b. This language should not be read in isolation, however. The purpose of the subsection as a whole is to explain varying uses and limitations of modeling, monitoring, and measuring: Due to limitations in the spatial and temporal coverage of air quality measurements, monitoring data normally are not sufficient as the sole basis for demonstrating the adequacy of emission limits for existing sources. Also, the impacts of new sources that do not yet exist can only be determined through modeling. Thus, models, while uniquely filling one program need, have become a primary analytical tool in most air quality assessments. Air quality measurements can be used in a complementary manner to dispersion models, with due regard for the strengths and weaknesses of both analysis techniques. Measurements are particularly useful in assessing the accuracy of model estimates. The use of air quality measurements alone however could be preferable, as detailed in a later section of this document, when models are found to be unacceptable and monitoring data with sufficient spatial and temporal coverage are available. Id. The phrase cited by the Sierra Club, taken in context, presents the unremarkable observation that sources that do not exist cannot be measured or monitored. See Powder River Basin Resource Council, ¶ 13 n. 1, 226 P.3d at 815 n. 1 (Because Dry Fork was not yet in operation, its actual emissions could not be documented.). The text recognizes modeling as a primary analytical tool in most air quality assessments, but not as the exclusive analytical tool. Taken as a whole, this explanation of modeling does not create a mandate to employ modeling in every instance. [¶ 55] In granting summary judgment to DEQ and Medicine Bow, the Council determined that DEQ's long-standing practice of not requiring modeling of fugitive particulate emissions to demonstrate compliance with the 24-hour standards is consistent with controlling law, and that the Sierra Club failed to show that DEQ's actions were contrary to the law or applicable DEQ rules and regulations. We agree, and conclude that the Council did not err in rejecting the Sierra Club's fugitive particulate emissions claim.