EPA revised the federal implementation plans promulgated on August 8, 2011, to reduce interstate transport of fine particulate matter and ozone regarding post-combustion pollution control equipment and immediate-term operational requirements.

EPA revised the federal implementation plans promulgated on August 8, 2011, to reduce interstate transport of fine particulate matter and ozone regarding modeling assumptions, allowance allocations, and assurance penalty provisions. 

SIP Approval: Missouri (attainment of the lead NAAQS for the Herculaneum nonattainment area).

EPA finalized NESHAPs from coal- and oil-fired electric utility steam-generating units and the standards for fossil-fuel-fired electric utility, industrial-commercial-institutional, and small industrial-commercial-institutional steam-generating units.

EPA granted a waiver of preemption and authorization to the California Air Resources Board to adopt and enforce California's truck idling requirements for 2008 and subsequent model-year heavy-duty diesel engines. 

EPA designated all areas in the United States as "unclassifiable/attainment" for the 2010 primary nitrogen dioxide NAAQS.

EPA proposed numerous amendments to the NESHAP for the secondary aluminum production source category.

United States v. NL Industries, Inc., No. 8:12-cv-00059 (D. Neb. Feb. 9, 2012). A settling CERCLA defendant responsible for violations at the Omaha Lead Superfund site must pay $624,000 in U.S. response costs incurred at the site and must pay $26,000 to the state of Nebraska.

FWS determined endangered status for the rayed bean and snuffbox mussels throughout their ranges under the ESA. 

FWS designated approximately 4,216 acres in Bexar County, Texas, as critical habitat for nine invertebrates and denied removal of one area from critical habitat designation.