A federal appeals court has ordered the U.S. Environmental Protection Agency to redo or review its ozone air quality designations in several states, including one for Porter County, but said a 2018 ruling for Lake County still stands.
The U.S. Court of Appeals for the District of Columbia Circuit agreed with several environmental groups and municipal and state governments, saying that the EPA made a mistake when it found that certain counties around the U.S. met the 2015 8-Hour Ozone National Ambient Air Quality Standards in 2018.
The EPA will now have to redo the NAAQS designations for Porter County and counties in Wisconsin, Illinois and New Mexico and review the designations for six other counties across the country. The court also denied a petition to review the agency’s “attainment” designation for most of Lake County, calling the designation “perfectly appropriate.”
The Clean Air Act requires the EPA to set NAAQS for six common air pollutants, known as “criteria air pollutants.” The EPA must also determine whether states and tribes meet those standards.
An area with air quality that meets or is better than minimum federal standards is designated an “attainment” area and taken off the list. If an area does not meet those standards, it’s designated a “nonattainment” area and is subject to more actions to improve air quality. If the EPA is not able to determine an area’s status, it is designated “unclassifiable.”
The court found that the way EPA arrived at those designations was “arbitrary and capricious,” saying the agency arriving at different air quality conclusions for counties with similar air quality data.
The three-judge panel said the EPA offered no defense to challenges to its designations for several areas, including Porter County, Indiana.
“[W]e think the best course of action is to treat EPA’s motion as a concession that its explanations fall short of the Clean Air Act’s requirement of reasoned decisionmaking [sic], grant the motion to remand, and impose a deadline on the issuance of revised designations,” the court wrote in its opinion.
The court also ordered the EPA to complete the remand “as expeditiously as practicable.”
Both Lake and Porter Counties were recommended for “attainment” designation in 2016 by Carol S. Comer, the former commissioner of the Indiana Department of Environmental Management, saying the ozone levels in both counties were at levels below the federal standard.
“Based on air quality data and a thorough examination of the additional factors, including emissions data, meteorology, geography/topography and jurisdictional boundaries, IDEM recommends all of the monitored counties in Indiana be designated attainment and all other counties within Indiana be designated as unclassifiable,” Comer wrote in the recommendation.
As evidence of attainment, IDEM included ozone monitoring values from 2005 to 2016 that points to both counties meeting the 2015 ozone standards.
Instead of a maximum contaminant level or total annual average, the method for finding whether or not an area has met those standards requires arcane calculation.
The 2015 ozone standard requires that the annual fourth-highest daily maximum eight-hour average concentration of monitored ozone values, averaged over three years, must not exceed .70 parts per million.
Data provided to the EPA from three monitoring stations in Lake County point to yearly ozone values possibly exceeding the .70 ppm, but the three-year averages at the Gary, Whiting and Hammond monitoring stations skirt but do not exceed .70 ppm.
Porter County monitoring stations at Ogden Dunes and Valparaiso recorded the fourth-highest ozone values at .70 ppm and .071 ppm, respectively, but the latest three-year averages submitted to the EPA are less than .70 ppm.
Despite IDEM’s recommendation, the EPA designated Lake and Porter Counties as being in nonattainment due to the agency including the counties as part of the larger Chicago-Naperville, IL-IN-WI Combined Statistical Area, an area that centers on Chicago and includes nearby areas in Illinois and parts of other states whose air quality may be affected by the larger city and vice versa.
Because of this grouping, Lake and Porter Counties, eight counties from Illinois and a part of one Wisconsin county were all designated as being in nonattainment.
The state of Indiana disagreed with the EPA’s decision and argued for a change in designation.
“[I]ncluding either Lake or Porter County in the Chicago-Naperville nonattainment area is unjustified and unwarranted,” wrote Bruno Pigott, the subsequent IDEM commissioner. “The wrongful inclusion of Lake and Porter Counties within the Chicago nonattainment area will place an unfair and undue burden on those counties when other areas and other sources that have a potentially greater contribution of ozone precursors have been excluded from designation consideration, thus excluded from associated emission control requirements as well.”
The EPA relented, designating all of Porter County as being in attainment and meeting IDEM in the middle on Lake County. The EPA included five townships in Lake County as part of the Chicago-Naperville nonattainment area, but the rest of the county would be recognized as meeting the 2015 ozone standards.
The Lake County designation will still stand, but the EPA will have to reassess its decision on Porter County.
The EPA has also designated both counties as being in nonattainment for a less stringent 2008 ozone standard. IDEM is currently petitioning the EPA to exclude both counties from the Chicago-Naperville nonattainment area designation.
EPA administrator Andrew Wheeler recently announced that the agency would not update the 2015 ozone standards, citing a 4% nationwide reduction in ozone concentrations between 2017 and 2019.