# Air Plan Approval; Guam; Base Year Emissions Inventory for the 2010 1-Hour Sulfur Dioxide National Ambient Air Quality Standard for the Piti-Cabras Nonattainment Area
> **Rule** · Direct final rule. · Published 2025-07-16 · Effective 2025-10-14 · 90 FR 31877
## Document
- **Document number:** 2025-13328
- **Category:** air-emissions
- **Federal Register citation:** 90 FR 31877
- **CFR reference:** 40 CFR 52
- **Publication date:** 2025-07-16
- **Effective date:** 2025-10-14
- **EPA docket:** EPA-R09-OAR-2025-0268
## Abstract

The Environmental Protection Agency (EPA) is taking direct final action to approve a revision to Guam's State Implementation Plan (SIP) under section 110(k)(3) of the Clean Air Act (CAA or "the Act"). This revision concerns the base year emissions inventory for the Piti-Cabras, Guam sulfur dioxide (SO<INF>2</INF>) nonattainment area ("Piti-Cabras area" or NAA) for the 2010 1-hour SO<INF>2</INF> National Ambient Air Quality Standard (NAAQS, "standard," or "2010 SO<INF>2</INF> NAAQS").

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2025/07/16/2025-13328/air-plan-approval-guam-base-year-emissions-inventory-for-the-2010-1-hour-sulfur-dioxide-national)
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