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Regional Haze SIP


Background & Original (2010) SIP Submittal
Regional haze reduces visibility and affects the aesthetic value of some of the nation's most pristine and treasured lands. These include national parks and wildlife areas that are designated by the U.S. Environmental Protection Agency (EPA) for visibility protection as federal Class I Areas. The Federal Clean Air Act sets national goals to prevent any future impairment of visibility caused by human-made air pollution in Class I areas, and to restore pristine conditions in those areas. Rules promulgated by EPA on July 1, 1999 require each state to develop and implement a Regional Haze (RH) State Implementation Plan (SIP). The RH SIP development process involves evaluation of existing conditions, actual conditions, and potential sources of visibility impairment, as well as consultation with surrounding states and the Federal Land Managers (FLMs) responsible for managing potentially affected federal Class I areas, and public notice to provide an opportunity for public hearing and comment.

Oklahoma's Wichita Mountains Wilderness Area (WMWA) has been declared a federal Class I area. It is contained within the Wichita Mountains National Wildlife Refuge, and is managed by the U.S. Fish and Wildlife Service. The Refuge is located in Comanche County adjacent to the Fort Sill Military Reservation, a U.S. Army training base. Lawton is the closest population center, and is located 22 miles southeast of the Refuge.

Oklahoma conducted its RH SIP development process, and submitted Oklahoma's Regional Haze State Implementation Plan to EPA Region VI in February 2010. Oklahoma's Regional Haze SIP includes calculations of baseline and natural visibility conditions for WMWA (and potentially affected Class I areas located elsewhere), a Long-Term Strategy (LTS) for regional haze reduction, Reasonable Progresss Goals (RPGs) to achieve natural visibility conditions by 2064, and a monitoring and reporting strategy. The SIP also includes determinations of emission limitations and schedules for compliance representing Best Available Retrofit Technology (BART) for a group of Oklahoma industrial air emissions sources that are subject to BART under national Regional Haze Program requirements. Oklahoma's RH SIP concludes and documents the fact that the state's LTS and RPGs for visibility improvement at the WMWA are limited by the impact of out-of-state emission sources.

EPA Action on Oklahoma's Regional Haze SIP Submittal
Effective January 27, 2012 (76 FR 81727), EPA approved core elements of Oklahoma's Regional Haze SIP, including BART determinations for the majority of emissions units subject to BART. However, EPA disapproved the sulfur dioxide (SO2) BART determinations for several emissions units, and issued a Federal Implementation Plan (FIP) covering SO2 control requirements for those units. As part of this action, EPA also disapproved the State's LTS for regional haze reduction and portions of Oklahoma's Interstate Transport SIP for the 1997 8-hour Ozone and 1997 PM2.5 NAAQS, because they relied on the BART limits in the disapproved determinations. However, the final rule noted in 40 CFR § 52.1928(c) that the FIP satisfied these deficiencies. EPA took no action on Oklahoma's RPGs, pending its evaluation of impacts of out-of-state emission sources.

Regional Haze SIP Revision (including Interstate Transport SIP Revision)
On March 7, 2014, EPA published a notice (79 FR 12944) in the Federal Register approving a SIP revision submitted by Oklahoma to address certain disapproved portions of the Regional Haze SIP related to the BART determination for two coal-fired units located at American Electric Power/Public Service Company of Oklahoma's (AEP/PSO's) Northeastern Power Station in Rogers County, Oklahoma. A separate notice published simultaneously (79 FR 12954) withdrew the EPA-issued FIP as it relates to the subject AEP/PSO facility. The approved revision also satisfies the previously disapproved portions of Oklahoma's Transport SIP and the Regional Haze SIP's LTS, as those portions relate to the subject facility. This SIP revision submittal process included consultation with Federal Land Managers and potentially affected states, public review and comment including a public hearing held at DEQ's OKC offices on May 20, 2013, and EPA's proposed action on August 21, 2013 (78 FR 51686).

Proposed EPA action would affect Texas' & Oklahoma's Regional Haze SIPs
In the December 16, 2014 Federal Register (79 FR 74818), EPA published a proposed action on the final portion of Oklahoma's RH SIP, submitted in February 2010. On January 23, 2015 (80 FR 3536), EPA extended the comment period for the proposal to April 20, 2015.

Oklahoma's RH SIP set the state's Reasonable Progress Goals (RPGs) and Long-Term Strategy (LTS) for visibility improvement at the Wichita Mountains Wilderness Area (WMWA), and, as noted above, documents the fact that Oklahoma's goals and strategies are limited by the impact of out-of-state emission sources. EPA is proposing to disapprove Oklahoma's RPGs for the WMWA in conjunction with its proposed partial approval & partial disapproval of Texas' RH SIP, in part as a result of the impacts of Texas emissions on WMWA, as well as other class I areas. As EPA stated in the notice, "Due to the special interrelationship of the visibility impairing transport of pollution between Texas and Oklahoma, we are proposing action on the remaining portions of the Oklahoma regional haze SIP and all portions of the Texas regional haze SIP simultaneously." The proposal includes a FIP that would limit SO2 emissions from 15 Texas sources. Although the notice also proposes a FIP to replace Oklahoma's RPGs, no additional reductions or other requirements would apply to Oklahoma.

EPA held two Public Hearings on the proposal - on Tuesday, January 13, 2015 in Austin, TX and on Thursday, January 15, 2015 in Oklahoma City.

Next Steps
EPA is currently reviewing Oklahoma's 5-year RH SIP Progress Report. AQD is in the early stages of planning for the RH Second Planning Period, for which a SIP is due in July 2021.

Page last updated: September 13, 2018




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