The Environmental Protection Agency (EPA) last week issued a final rule amending its Cross-State Air Pollution Rule (CSAPR) to include five more states in the ozone season nitrogen oxide (NOx) program. The final rule adds Oklahoma to the CSAPR program (for its ozone-season NOx emissions only), bringing the total number of states covered by the rule to 28.

CSAPR, which was finalized on July 6, is designed to mitigate interstate transport of particulate matter and ozone by limiting sulfur dioxide (SO2) and NOx emissions from most eastern states. In a separate ruling last July, the EPA had also issued a supplemental notice of proposed rulemaking to require six states—Iowa, Kansas, Michigan, Missouri, Oklahoma, and Wisconsin—to make summertime NOx reductions under the CSAPR ozone season control program.

The final rule issued last week is different from another package of “technical amendments” to CSAPR, which changed emission budgets for Texas and other states. That package is still awaiting review at the White House Office of Management and Budget.

The new supplemental action, titled “Federal Implementation Plans for Iowa, Michigan, Missouri, Oklahoma, and Wisconsin and Determination for Kansas Regarding Interstate Transport of Ozone," essentially requires Iowa, Michigan, Missouri, Oklahoma, and Wisconsin to reduce summertime (May through September) NOx emissions as part of the CSAPR ozone season control program.

The agency said it was not finalizing a federal implementation plan (FIP) for Kansas in last week’s action “due to the unique status of Kansas’ state implementation plan for ozone. It said, however, that four of these states—Iowa, Michigan, Missouri, and Wisconsin—in addition to Kansas, are also included in the fine particle control program of the CSAPR, requiring year-round (as opposed to summertime) NOx reductions.

With the rule, the EPA has concluded that Iowa, Kansas, Michigan, Missouri, Oklahoma, and Wisconsin “significantly contribute to nonattainment and/or interfere with maintenance of the 1997 ozone National Ambient Air Quality Standard (NAAQS) in one or more downwind states.” However, because of the status of Kansas’ state implementation plan (SIP) for ozone, the EPA said it does not have authority to finalize a FIP for the state and is not taking action on the inclusion of Kansas in the CSAPR ozone season NOx program.

“Instead, in a separate action, EPA will issue a SIP Call for Kansas to reduce its emissions that contribute to nonattainment and maintenance issues in other states and will give the state 12 months to resubmit an ozone SIP that adequately reduces its contribution to downwind ozone air quality problems. EPA will revisit Kansas’ status in the CSAPR at that time,” it said.

Oklahoma is the only one of these states not included in the CSAPR annual NOx program, or its predecessor, the Clean Air Interstate Rule. “EPA recognizes that the timing of this final action would not allow Oklahoma sources to install new combustion control equipment ahead of the 2012 ozone season,” the agency said. “In addition, EPA acknowledges that Oklahoma sources would not have enough time to shift the distribution of electricity to cleaner generators to meet local electricity demand that is currently being met by oil/gas units.” For those reasons, the EPA said it had adjusted the state’s 2012 budget to a level that reflects its circumstances.

The CSAPR replaces the 2005 Clean Air Interstate Rule (CAIR) starting on Jan. 1, 2012. CAIR, a 2005-issued rule, was struck down and remanded to the agency by the U.S. Court of Appeals for the D.C. Circuit in 2008, leaving existing CAIR programs in place while directing the EPA to replace them with a new rule consistent with the Clean Air Act.

Sources: POWERnews, EPA