UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION6 1445 ROSS AVENUE, SUI T E 1200 DALlAS TX 75202-2733 

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C 0 2 2014

Ms. Deidra Jo hnson, Attorney S upe rvi so r Office of the Secretary, Legal Division Loui siana Department of Environmental Quality P.O. Box 4302 Baton Rou ge, LA 70821-4302 RE: EPA Comments on Proposed Revisions to the Louisiana Prevention of Significant Deterioration (PSD) Permitting Program (AQ349)

Dear Ms. Johnson: Thank you for the opportunity to review and provide comments on the substant ive revisions to the Louisiana PSD Permitting Program at Loui siana A ir Code (LAC) , Title 33, Part Ill, Chapter 5 , Section 509 , contained in AQ349. We understand that the LDEQ has proposed the se revi s ions in re sponse to the EPA 's December 9 , 20 1 3 , final rulemaking to revise the federal PSD requirements at 78 FR 73698. The EPA i s concerned that the proposed revisions in AQ349 li mit the LDEQ's di scr etion when reviewing air permi t applications contrary to the requi rements of the Clean Air Act (CAA). Please see our enclo sed comments. We loo k forward to working with you in the upcoming year as you address our concerns. Please note that our comments today do not constitute final determinations concerning approvability of the revi sions to the Louisiana PSD program or the State Implementation Plan (SIP). If you have any question s about the EPA's review of your proposed rulemaking, please feel free to contact me at 214-665-6435 or contact Ms. Adina Wiley of my staff at 214-665-2115.

Enclosure

cc: Mr. Brya n Johnston Jeff Robinson Chief Ai r Permits Section

Louis i ana Department of Environmental Quality

Internet Address (URL) • http: // www
. epa
.gov/region6 Recycled/Recyclable • Printed with Vegetable O i l Based Inks on 100% Postconsumer, Process Chlorine Free Recycled PaperEnclosure 1. The LDEQ has proposed the adoption of Class I Significant Impact Levels (SILs) at LA C 33:III.509(K ) (2)(a). The EPA proposed Class I SILs, upon which the LDEQ proposed SILs are based, on July 23 , 1996, at 61 FR 38250, 38291

- 38292, but has not issued a final rule codifying those values in the Code ofF ederal Regulations. Since the EPA di d not co mplete this rule and provide a final rulemaking record to show that these SIL value s represent an impact below which no source will cause or contribute to a violatio n of the NAAQS or increments in a Class I area, the LDEQ's rulemaking must provide such a record before the EPA will consider a request to approve use ofthese SILs in the Louis iana SIP in the manner described in the proposed version of LA 33:111.509(K)(2) (a). 2. The proposed language at LAC 33:111.509(K)(2)(a) includes the language vacated by the D.C. Ci rcuit in Sierra Club v. EPA on January 22, 2013 , namely that a demonstration is deemed to have been made if the proposed source or modification's impact is below the listed s ignificance levels. This language was vacated because it removed the permitting authority's discretion to assess the impact ofthe source relative to the standards and to require further analyses, if warranted, to make the necessary demonstration even where a proposed source or modification shows that its impact is below the significance level. The E PA recognizes that the LDEQ has also proposed new language at LAC 33 :III. 509(K)(2)(b) that would enable the state to require a further impact analysis if deem ed necessary. While this provision appears to preserve some discretion for the State to require further air quality analyses even where a source's impacts are below the SILs, it does not appear to leave discretion for the State to consider whether showing that a source has an impact below the SILs is sufficient in each case to make the demonstration required under section 165(a)(3) of the CAA and 40 CFR 51.166(k)(l ). Furthermore, the discretion proposed by the LDEQ to require further analysis is limited to circumstances where the source impacts "could result in violations of a NAAQS or PSD increment." CAA section 165(a)(3) and 40 CFR 51.166(k)(l) require a proposed new or modified source to demonstrate that a facility will not cause or contribute to air pollution in excess of a N AAQS or increment. Thus, the provision should not be limited to circumstances where a source's impacts alone could cause a violation, but also where the source ' s impa cts could contribute to an existing violation. The EPA recommends that the language at LAC 33:III.509(K)(2)(a) be revised to reflect the content and intent of the SIL provisions at 40 CFR 51.165(b )(2), which states that a propo sed new or modified major source "will be considered to cause or contribute" to a NAAQS violation when, at a minimum, the source's impacts exceeds the defined significance level. The EPA believes that such language more clearly preserves the State ' s discretion to evaluate whether proposed construction would cause or contribute to a viola tion of the NAAQS and require further analysis to make this demonstration even in case s where a source's impacts are below such significance levels.