The May 4, 2016, Federal Register contains a notice of the Environmental Protection Agency’s (“EPA’s”) final decision that the Baton Rouge ozone nonattainment area has attained the 2008 8-hour ozone National Ambient Air Quality Standard (“NAAQS”). 81 Fed. Reg. 26,697. (The Baton Rouge nonattainment area consists of the parishes of Ascension, East Baton Rouge, Iberville, Livingston, and West Baton Rouge.) EPA found that the ambient monitoring data for 2012-2014 demonstrated attainment with the 2008 8-hour ozone standard. Although this 8-hour ozone standard was revoked in 2015 and replaced with a more stringent standard, some of the State Implementation Plan (“SIP”) requirements associated with the old 8-hour standard have been continued under the Clean Air Act’s “anti-backsliding” provisions. The EPA action, known as a “Clean Data Policy Determination,” formally suspends several requirements associated with the Louisiana Department of Environmental Quality’s (“LDEQ’s”) SIP, so long as the Baton Rouge Area continues to achieve the 2008 8-hour ozone standard. These suspended requirements include reasonable further progress (“RFP”) requirements, attainment demonstrations, reasonable available control measures (“RACM”), contingency measures, and other state planning requirements related to attainment of the 2008 8-hour ozone standard.

A Clean Data Determination is not equivalent to a redesignation, and the state must still meet the statutory requirements for redesignation in order to be redesignated to attainment. The full redesignation requires not only a Clean Data determination, but also approval of a maintenance plan to ensure continued attainment of the standard. In the March 20, 2016, Louisiana Register, LDEQ provided notice that it would submit to EPA a proposed redesignation request and ozone maintenance plan for the 2008 8-hour ozone NAAQS for the Baton Rouge Area. See LR 42:496. The deadline to submit comments was April 29, 2016. It is expected that LDEQ will soon submit its redesignation submittal, formally requesting that EPA redesignate the Baton Rouge Area to full attainment with the 2008 8-hour ozone standard.

It should be noted that the determination of attainment for the Baton Rouge Area applies to the 2008 8-hour ozone standard, not to the more stringent 2015 8-hour ozone standard. On October 1, 2015, EPA lowered the 8-hour ozone standard from 75 parts per billion (“ppb”) to 70 ppb. 80 Fed. Reg. 65,292 (Oct. 26, 2015). Based on current design values (“DVs”), the only area of the state that does not comply with the new standard is the Baton Rouge Area (DV = 71 ppb). However, final designations under the new ozone standard will be based on 2014 – 2016 air quality data. Designations will not be effective until on or about October 1, 2017.

The EPA Federal Register notice of the Clean Data Policy Determination for Baton Rouge is available here.