Air Plan Approval; Oklahoma; Interstate Transport Requirements for the 2010 SO2 NAAQS
Key claim: EPA has approved Oklahoma’s air-quality plan as sufficient to keep the state’s sulfur dioxide pollution from significantly worsening air quality in other states under the 2010 one-hour SO2 standard.
Abstract
(Rule · Environmental Protection Agency) Pursuant to the Federal Clean Air Act (CAA or the Act), the U.S. Environmental Protection Agency (EPA) is approving portions of the State Implementation Plan (SIP) submittal from the State of Oklahoma demonstrating that the State satisfies the interstate transport requirements of the CAA for the 2010 1-hour sulfur dioxide (SO2) primary National Ambient Air Quality Standard (NAAQS). This provision requires each State’s implementation plan to contain adequate requirements prohibiting the interstate transport of air pollution in amounts that will contribute significantly to nonattainment, or interfere with maintenance, of a NAAQS in any other State.
Why this matters
Interstate transport SIP approvals determine whether upwind states must adopt additional SO2 controls to protect air quality in downwind states. EPA’s finding that Oklahoma’s existing emissions pose no significant downwind impact means no new federal control obligations attach to Oklahoma sources under the 2010 SO2 standard, fitting the broader pattern of good-neighbor approvals for the one-hour SO2 NAAQS.