As of July 3, 2011, the air quality measured at the official ozone monitor at 1425 Airport Drive, which is within Shreveport, but located in Bossier Parish, indicated that the design value for the parish is now 76.7 parts per billion (ppb) which exceeds the 75 ppb standard set by EPA in 2008. 40 C.F.R. §50.15. The design value for each monitor is the 3 year average of the 4th highest ozone reading at that monitor each year. The exceedance of the current standard will likely cause the Louisiana Department of Environmental Quality (LDEQ) to propose that EPA designate Bossier Parish, and perhaps Caddo and DeSoto Parishes, as an ozone nonattainment area.

LDEQ was required to submit its recommendation for nonattainment designations under the 2008 ozone standard by March 12, 2009. EPA was then required to act on the proposals and make final designations no later than March 12, 2010. 73 Fed. Reg. 16436, 16503 (Mar. 27, 2008). In its 2009 recommendation, LDEQ did designate Caddo, but not Bossier or DeSoto, parishes as nonattainment. (1) However, when air quality in Caddo parish improved to compliance status over the past several years, LDEQ amended that recommendation in January 2010 to classify Caddo as attainment. (2)

EPA has never acted on the LDEQ recommendations because EPA decided to reconsider whether it should lower the 75 ppb standard to an even lower level before implementing it. On January 6, 2010, the EPA proposed to lower the ozone standard to a level between 60 and 70 ppb. Although it has been widely reported that EPA was to issue this reconsidered rule by the end of July 2011, there is a potential that EPA will instead move forward with implementing the 75 ppb standard while it continues to study whether to lower the standard even further. EPA has stated that should the revised standard differ from the 2008 75 ppb standard, “any requirement to designate areas and implement the 2008 ozone NAAQS would no longer apply.” 75 Fed. Reg. 2936, 2937 (Jan. 19, 2010). However, if EPA decides to move forward with implementing the 75 ppb standard, it could make final designations at any time. Because the Shreveport-Bossier Area has been in and out of compliance with the 75 ppb standard and was initially proposed by LDEQ for nonattainment status, EPA could designate the area to nonattainment within the next year.

Because the 2011 ozone season (May-September) is not complete, and the data not verified, EPA would likely need to wait until after verification before any such designation. Data indicating high readings at the Shreveport/Bossier monitor can be excluded if proved to be invalid or if due to “an exceptional event.” If LDEQ flags such data as invalid, the process to resolve the issue can take more than one year, thus delaying any final nonattainment designation status.

The ozone monitor in Caddo Parish (at Dixie) has a current design value of 72 ppb, which is below the standard; nevertheless, Caddo and DeSoto Parishes could be classified as nonattainment based on the design value at the Bossier Parish monitor. Adjacent areas that contribute to exceedance of ambient air quality are to be considered within the boundary of the nonattainment designation. 42 U.S.C. § 7409(d)(1)(A)(i). According to EPA guidance, presumptively the entire Consolidated Metropolitan Statistical Area (“MSA”) affects ambient air quality. (3)  Bossier, Caddo and De Soto Parishes comprise the Shreveport-Bossier City CMSA. LDEQ would be required to submit documentation showing that Caddo and DeSoto parish air emission sources do not contribute to the ozone values in Bossier Parish – a difficult burden.

Upon designation to nonattainment, any new sources or major modifications to existing sources must follow the more stringent requirements of Nonattainment New Source Review (NNSR) located at LAC 33:III.504 instead of Prevention of Significant Deterioration (“PSD”) found at LAC 33:III.509. (4)   The NNSR program requires the new or modified source to obtain offsets of any VOC or NOx emissions at least a 1.1 to 1 ratio, and it requires the new or modified equipment to employ technology of lowest achievable emission rate instead of best available control technology, the PSD requirement. Further, the LDEQ will be required to develop and submit to EPA for approval a State Implementation Plan (SIP) to move the area into compliance. The SIP must require, at a minimum, that existing major sources employ Reasonably Available Control Technology and may also include measures such as additional planning and control requirements for mobile sources or non-road sources such as diesel fired engines.

The Shreveport-Bossier area will be able to escape these consequences only if air quality improves enough in 2012 to enable the 3 year average ozone value to comply with the standard. If EPA chooses to lower the standard, as proposed, then it is still likely that designations will be based on the design value over 2009-2011 or perhaps 2010-2012, and the same consequences will follow, albeit on a slightly longer time line. Only a significantly improved performance during 2012 could bring the design value down to the level of 67-70 ppb, the level expected to be promulgated by EPA if it moves forward on the reconsideration proposal.

 (1)  Letter from Harold Leggett, Secretary, LDEQ to Lawrence Starfield, Action Administrator, EPA Region 6, Re: State of Louisiana Area Designations 2008 Ozone National Ambient Air Quality Standards (NAAQS) (Mar. 12, 2009). Found at (last visited July 5, 2011).

(2)  Letter from Peggy Hatch, Secretary, LDEQ to Al Armendariz, Administrator, EPA Region 6, Re: State of Louisiana Area Designations Amendments 2008 Ozone National Ambient Air Quality Standards (NAAQS) (Jan. 25, 2011).

(3)  Memorandum from John S. Seitz, Director, Office of Air Quality Planning and Standards, Boundary Guidance on Air Quality Designations for the 8-hour Ozone National Ambient Air Quality Standards (March 28, 2000) found at (last visited July 5, 2011).

(4)  It should be noted that the required nonattainment SIP will likely result in changes to §504. The nonattainment SIP has not been submitted as it is due 18 months after EPA designation.