“We want to make sure we exhaust all of our options because meeting the regional haze requirement is going to be a significant amount of investment that will affect our customers,” O'Shea said.
OG&E's implementation costs could include installing scrubbers on coal units or retrofitting the units to use natural gas. The regional haze rules cover OG&E's four coal units at its Red Rock and Muskogee plants. The Wichita Mountains National Wildlife Refuge is the only federal area in Oklahoma affected by the visibility rules.
Earlier this month, OG&E received an extension of a stay blocking implementation of the EPA's haze rule until the final disposition of the case. If the stay is lifted, the utility would have between 52 and 55 months to comply.
Tulsa's Public Service Co. of Oklahoma reached a settlement with the EPA and other groups in 2012 to retire the last of its coal units in Oklahoma by 2026 to meet regional haze and other environmental rules.
PSO estimates its compliance plan could cost more than $350 million.