# Air Plan Approval; WA; Update to Materials Incorporated by Reference
> **Rule** · Final rule; administrative change. · Published 2025-08-21 · Effective 2025-08-21 · 90 FR 40738
## Document
- **Document number:** 2025-15992
- **Category:** other
- **Federal Register citation:** 90 FR 40738
- **CFR reference:** 40 CFR 52
- **Publication date:** 2025-08-21
- **Effective date:** 2025-08-21
- **EPA docket:** EPA-R10-OAR-2025-0320
## Abstract

The Environmental Protection Agency (EPA) is updating the materials that are incorporated by reference (IBR) into the Washington State Implementation Plan (SIP). The regulations affected by this update have been previously submitted by Washington and approved by the EPA. This update affects the materials that are available for public inspection at the National Archives and Records Administration (NARA) and the EPA Regional Office.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2025/08/21/2025-15992/air-plan-approval-wa-update-to-materials-incorporated-by-reference)
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