On October 1, 2015, the United States Environmental Protection Agency finalized its new Ozone National Ambient Air Quality Standard (NAAQS)  The new standard lowers the permissible level of ozone in the surface atmosphere from 75 parts per billion to 70 parts per billion. (The EPA had examined a variety of potential new standards. Many observers believed that the new standard would be even lower than 70 parts per billion.)
Sections 108 and 109 The Federal Clean Air Act require the Environmental Protection Agency (the EPA) to set national ambient air quality standards for ozone and five other pollutants considered harmful to public health and the environment. The Clean Air Act also requires the EPA to review the standards every five years to ensure they provide adequate health and environmental protection and take into account all newly developed scientific information about the pollutant and its effect on human health and the environment. The Supreme Court has held that the EPA may not consider the costs of implementing a new standard in determining what the new standard will be.
Ground level ozone is not admitted directly into the air, but created by chemical reactions between oxides of nitrogen and volatile organic compounds in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors and chemical solvents are considered to be the primary sources of nitrogen oxides and volatile organic compounds. Ozone triggers a variety of health problems, particularly for children, the elderly and people who suffer from lung disease, particularly asthma.
Compliance with standards is determined by measuring the concentration of ozone in the ambient air around a city or region. If concentrations exceed the standard, the Clean Air Act directs EPA to declare the city or region to be a “non-attainment area,” which triggers more stringent controls on emissions of ozone precursors. Those controls, of course, make operation of industrial facilities electric utilities, motor vehicles and use of organic chemical solvents more difficult and expensive. Assuming the operators of those facilities and equipment pass increased costs along to customers, the burdens of the lower standards could be felt across a wide range of the economy.
When EPA makes a NAAQS more stringent, the number of non-attainment areas increase, and states are required to adopt new, more stringent limitations on emissions. A more stringent ozone standard can mean new limits on major stationary sources, but also on regional transportation systems (the Clean Air Act requires that the air quality impact of highway projects and other transportation infrastructure changes be evaluated before they can receive federal funding).
The EPA, after its previous periodic review in 2008, had adopted new standards that set the ambient air quality standard for ozone at 75 parts per billion. Those standards were weaker than the Agency’s own scientists had advised. In 2007, the EPA’s Clean Air Scientific Advisory Committee had stated that its members unanimously recommended that the standard be no higher than 70 parts per billion and that the EPA consider a limit as low as 60.
After the Obama administration took office, EPA Administrator Lisa Jackson wrote a letter to Senator Thomas Carper stating that the EPA believed aid the 2008 standards were not legally defensible. The EPA released its new draft rules in January 2010 suggesting that it would lower the limit to between 60 and 70 parts per billion. In 2011, President Obama unilaterally directed the EPA to withdraw the proposed rules as part of his effort to reduce regulatory burdens and regulatory uncertainty.
In April 2014, though, the United States District Court for the Northern District of California had issued an order requiring the EPA to issue its final rule by June 30, 2015, later extended to October 1, 2015. That order resulted in the issuance of the new standard on October 1, 2015, lowering the standard to 70 parts per billion. The new rule allows states time to implement measures to bring any non-complying areas into compliance with the standard. Depending upon the severity of the non-containment, areas would have until between 2020 and 2037 to meet the standards. During that time, Republican lawmakers have indicated a willingness to fight the EPA’s rule as well. Senator James Inhofe, Chairman of the Senate Environment and Public Works Committee, stated he would be willing to work with his Senate colleagues to enact legislation to revoke the ozone rule. Further, within a week, the first private lawsuit over the new ozone standard had been filed. Murray Energy Corp. brought an action seeking to invalidate the new ozone standard.
Because the EPA, under the American Trucking doctrine above, may not consider the costs that might be associated with implementing the 70 parts per billion standard, and because the EPA’s owns scientific advisory committee believes the standard should be no higher than 70, the basis for a judicial standard is uncertain. It appears that some legislative action would be necessary to overturn the EPA’s new standard. Given Congressional gridlock, any such legislative action is very unlikely, at least until after the 2016 elections.
 80 FR 65292, Oct. 26, 2015
 42 U.S.C. §§7408, 7409
 Id. The ozone standard was initially set at 125 parts per billion. In 1997, EPA lowered the standard to 80 parts per billion. See 40 C.F.R. § 50.10 and Part 50 App. I; 62 Fed. Reg. 38,856 (July 18, 1997)..
 Whitman v. American Trucking Assns., Inc., 531 U.S. 457 (2001)
 42 U.S.C. §§7501-7511f.
 42. U.S.C. §7506(c)
 EPA-CASAC-07-001, dated October 24, 2006, and EPA-CASAC-07-002, dated March 26, 2007
 Correspondence from Lisa P. Jackson, Administrator, EPA, to Senator Thomas R. Carper, July 13, 2011, available at http://www.eenews.net/assets/2011/07/14/document_gw_03.pdf
 75 FR 2938, Jan. 19, 2010
 Statement by the President on the Ozone National Ambient Air Quality Standards, available at https://www.whitehouse.gov/the-press-office/2011/09/02/statement-president-ozone-national-ambient-air-quality-standards
 Sierra Club v. McCarthy, 14-CV-05091 YGR