UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION6 

1445 ROSS AVENUE, SUITE 1200 

DALlAS TX 75202-2733 

DEC 0 2 2014 

Ms. Deidra Johnson, Attorney Supervisor 

Office ofthe Secretary, Legal Division 

Louisiana Department of Environmental Quality 

P.O. Box 4302 

Baton Rouge, 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 substantive revisions to 

the Louisiana PSD Permitting Program at Louisiana Air Code (LAC), Title 33, Part Ill, 

Chapter 5, Section 509, contained in AQ349. We understand that the LDEQ has proposed these 

revisions in response to the EPA's December 9, 2013, final rulemaking to revise the federal PSD 

requirements at 78 FR 73698. 

The EPA is concerned that the proposed revisions in AQ349 limit the LDEQ's discretion when 

reviewing air permit applications contrary to the requirements of the Clean Air Act (CAA). 

Please see our enclosed comments. 

We look 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 revisions to the Louisiana PSD program or the State Implementation Plan (SIP). If you have 

any questions 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. Bryan Johnston 

Jeff Robinson 

Chief 

Air Permits Section 

Louisiana Department of Environmental Quality 

Internet Address (URL) • http://www.epa.gov/region6 

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Enclosure 

1. The LDEQ has proposed the adoption of Class I Significant Impact Levels (SILs) at LAC 

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 did 

not complete this rule and provide a final rulemaking record to show that these SIL 

values represent an impact below which no source will cause or contribute to a violation 

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 of these SILs in the 

Louisiana 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. Circuit 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 significance levels. This language was vacated because it removed the permitting 

authority's discretion to assess the impact of the 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 EPA 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 

deemed 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 NAAQS 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 

impacts 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 

proposed 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 violation of the NAAQS and require further analysis to make this demonstration even in 

cases where a source's impacts are below such significance levels.