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How EPA Works with States on SIPs

State implementation Plan (SIP) Lean Toolkit 

A State Implementation Plan  or SIP is a collection of regulations and documents used by a state, territory, or local air district to attain and maintain clean air.  EPA works collaboratively with air agencies throughout the SIP development process, as well as during EPA’s review and action process.  To support this work, EPA has shared “State implementation Plan(SIP) Lean Toolkit for Collaboration Between EPA and Air Agencies” or “SIP Lean Toolkit” with its state and local clean air partners.  This Toolkit is intended to support early engagement between air agencies and EPA in the SIP development process. The Toolkit provides checklists, templates and other tools to help operationalize early engagement.   EPA appreciates the comments we received from a number of states on the draft version of this document circulated for review in October.  EPA looks forward to using these tools in partnership with state and local agencies to further strengthen and improve the SIP development and approval process so critical to our shared success in improving air quality. 

SIP Lean Toolkit 

The Air Agency's Role in State Implementation Planning

  • Each air agency'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 air agency, each required SIP element must be submitted by the Governor's designee to EPA.
  • As the NAAQS change, air agency must submit revisions to the SIP to demonstrate attainment and maintenance of those new or revised NAAQS and to meet other statutory requirements.

The EPA’s Role in State Implementation Planning

  • EPA works collaboratively with air agencies throughout the air agency SIP development process, as well as during EPA’s review and action process.
  • 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 air agency's plan.
  • If EPA approves all or part of a SIP, those control measures are enforceable in federal court.
  • If an air agency 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.