Attainment State Implementation Plans

What is an Attainment State Implementation Plan?

If air quality does not meet a standard, EPA may classify the affected area as nonattainment, meaning the area does not meet national air quality standards. A state implementation plan (SIP) outlines actions to improve air quality.

The federal Clean Air Act requires an Attainment State Implementation Plan be developed for an area that does not meet national air quality standards. The plan describes how an area will be brought back into compliance with federal standards within a specific time frame.

An Attainment State Implementation Plan includes:

• A current, comprehensive inventory of emissions
• Enforceable measures to reduce emissions; these measures may include a combination of state, local, and federal rules, plans, administrative orders, and permits for specific sources
• A demonstration that the measures in place will bring the area back into attainment within a specific deadline
• Contingency measures that will be implemented if the area does not meet the standard by the deadline

Process to develop plans

We must submit complete attainment plans to EPA for approval. If we don't meet deadlines, EPA can issue sanctions or implement a federal plan for Washington.

When we develop a State Implementation Plan, we follow a process:

1. We hold a public comment period on an attainment state implementation plan.
2. We send the plan to EPA for approval.
3. EPA holds another public comment period.
4. EPA approves the attainment plan which then becomes enforceable.
5. When an area is back in compliance, we ask EPA to re-classify the area as in attainment or maintenance.

Once an area meets air quality standards, we have additional requirements to make sure the area will continue meeting air quality standards. We work with local clean air agencies and affected communities to develop two 10-year maintenance state implementation plans to stay in compliance.