This enclosure includes comments on Missouri Department of Natural Resources' proposed rule revisions as provided on State's Regulatory Action Tracking System webpage and posted for 60-day public comment from 4/06/18 to 6/05/18.  The EPA's comments are based upon the available information for each rule including, the Draft Text document, Regulatory Impact Report and Rulemaking Report. These detailed comments are provided to help improve clarity and to simplify the proposed rule changes where possible, in line with MoDNR's efforts to streamline rules.
Rule Specific Comments:
10 CSR 10-2.230 Control of Emissions from Industrial Surface Coating Operations
 The draft rule adds several new definitions. However, some of the new definitions (e.g., light-duty truck, side seam coating (three (3)-piece), topcoat) are different than what are currently in the rule, 10 CSR 10-6.020 Definitions and Common Reference Tables. For clarity, the EPA recommends that these definitions match. If definitions are purposefully different, then EPA recommends that the MoDNR explain which definition supersedes. 
 Where the MoDNR is introducing definitions not previously used (e.g., can coating), the EPA recommends that the MoDNR use already codified definitions found in the Code of Federal Regulations (CFR) or in the State Implementation Plan where available. 
 Eight terms, including (can coating, end exterior coating, exterior coating (two (2)-piece), extreme performance coating, fabric coating, interior body spray (two (2)- and three (3)-piece), side seam coating (three (3)-piece), and vinyl coating are defined in the draft rule text, however, only part of the term is used again in the rule text, primarily in tables with the words "coating" or "adhesive" used in the heading. The EPA recommends that the MoDNR refer to the complete term throughout the rule.
 The Rulemaking Report indicates that the MoDNR is revising 10 CSR 10-2.230 so that the rule consistent with a similar rule applicable to the St. Louis area, 10 CSR 10-5.330. In particular, the MoDNR is adding exemptions to 10 CSR 10-2.230 at subsection (1)(C).  The MoDNR will need to submit a demonstration showing how the added exemptions to the SIP submission meets the requirements of Clean Air Act section 110(l) and 193 of the also known as the "anti-backsliding" provisions. These sections relate to the EPA's authority to approve a SIP revision that removes or modifies control measure(s) in the SIP only after the state has demonstrated that such a removal or modification will not interfere with attainment of the National Ambient Air Quality Standards, Rate of Progress, Reasonable Further Progress or any other applicable requirement of the CAA.
