The Environmental Protection Agency (EPA) is proposing to approve the State Implementation Plan (SIP) submission from Iowa addressing the Clean Air Act (CAA or Act) interstate transport requirements, also known as the "good neighbor" provision, for the 2010 1-hour primary sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS). The good neighbor provision requires each State's plan to contain adequate provisions 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. The EPA's proposed approval of this rule revision is being done in accordance with the requirements of the CAA.
Source
https://www.federalregister.gov/documents/2026/08/14/2026-16570/air-plan-approval-iowa-interstate-transport-requirements-for-the-2010-sulfur-dioxide-standardCanonical document at the regulator. Always cite this URL — not the Vantage detail page — in compliance evidence.