On August 22, 2017, EPA released its proposed area designations in the latest round of designations under the 2010 SO2 National Ambient Air Quality Standard (NAAQS).  The proposed designations largely track the states’ recommendations; however, EPA has identified a number of areas, recommended by states as “attainment,” that EPA believes “may be violating” the standard, including areas in Florida, Guam, Indiana, Louisiana, Minnesota, Ohio, Puerto Rico, and Wisconsin.  In addition, EPA has proposed to designate some areas as unclassifiable as opposed to unclassifiable/attainment.  EPA has published a table that compares its intended designations with the state recommended designations.  https://www.epa.gov/sulfur-dioxide-designations/intended-sulfur-dioxide-area-designations-august-2017

Under Section 107(d)(1)(B) of the Clean Air Act, EPA must issue notifications to states 120 days prior to finalizing area designations if the Agency intends to make any modifications to a state’s recommendations.  While not required, EPA is also soliciting public comment on its proposed designations.  Final designations must be issued by December 31, 2017.

EPA is conducting area designations under the 2010 SO2 standard in four rounds over a seven-year period.  The statute requires final area designations within two years of promulgation of a new ambient standard, and the Agency may extend that deadline up to one year if the Agency has insufficient information for the designations.  The Agency completed an initial round of area designations in July 2013 and was subsequently sued by several citizen groups for failing to issue designations for the rest of the country.  In settlement of that suit, EPA agreed to enforceable deadlines for the remaining area designations, and the deadlines were also codified in EPA’s SO2 Data Requirements Rule (DRR) in November 2015.  Under the DRR, EPA was required to complete a second round of designations in 2016, and EPA must issue final designations for Round 3, the current round, by December 31, 2017.  Round 3 covers all remaining areas except for those that have elected to install new monitors and have their designations based on three years of monitored data.  Designations for that final round must be complete by December 31, 2020.

The Round 3 120-day letters for each state can be accessed at https://www.epa.gov/sulfur-dioxide-designations/so2-designations-round-3-state-recommendations-and-epa-responsesand the accompanying Technical Support Documents are posted on EPA’s website at https://www.epa.gov/sulfur-dioxide-designations/initial-technical-support-documents-area-designations-round-3.  EPA has also prepared a notice of availability for publication in the Federal Register and plans to allow 30 days for public review and comment on its Round 3 recommendations.  In the notice, EPA states that, while it is in agreement with many of the recommendations, “some warrant further discussion.”  The notice seeks input from “interested parties, other than the state, territories, and tribes to which we have sent notification letters….in order to gather additional information for EPA to consider before making final designations.”