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How EPA Works with States on SIPs

This page summarizes state and federal roles for developing air quality State Implementation Plans (SIPs).

States' role:

  • Each state's SIP must contain a number of elements required by the Clean Air Act, and must be developed and adopted through a process allowing public input.
  • Once adopted by the state, each required SIP element must be submitted by the Governor's designee to EPA.
  • As the NAAQS change, states must submit revisions to the SIP to demonstrate attainment and maintenance of those new or revised NAAQS and to meet other statutory requirements.

EPA's role:

  • EPA must review and act to approve or disapprove each element.
  • The public has an opportunity to comment on EPA's proposed action.
  • EPA considers public input before taking final action on a state's plan.
  • If EPA approves all or part of a SIP, those control measures are enforceable in federal court.
  • If a state fails to submit an approvable plan or if EPA disapproves a plan, EPA is required to develop a federal implementation plan (FIP).
  • EPA makes state SIP submissions available to the public no later than the time EPA's proposed rulemaking (NPR) on the SIP is published in the Federal Register. In each NPR, EPA provides information on how to locate the electronic docket at for reviewing and submitting comments.
  • SIP Lean Toolkit for Collaboration Between EPA and Air Agencies