The Environmental Protection Agency said Sept. 22 it will implement the Bush-era ozone air quality standard of 0.075 part per million that has been blocked by the Obama administration.

Administrator Lisa Jackson told a House Energy and Commerce panel that EPA is legally required to implement the standard, which was set in 2008 under the Bush administration and which Jackson previously described as legally indefensible.

Gina McCarthy, EPA assistant administrator for air and radiation, sent letters to states Sept. 22 saying the agency intends to finalize nonattainment designations by mid-2012. The agency projects that 52 areas will not meet the requirements of the 0.075 ppm standard. (See related article in this issue.)

EPA had been working on a reconsideration of the Bush-era standard, but President Obama announced Sept. 2 that EPA would drop its reconsideration