# Determination That Pre-existing National Ambient Air Quality Standards for PM-10 No Longer Apply to Ada County/Boise; State of Idaho
> **Rule** · Final rule. · Published 1999-03-12 · Effective 1999-03-12 · 64 FR 12257
## Document
- **Document number:** 99-5380
- **Category:** air-emissions
- **Federal Register citation:** 64 FR 12257
- **CFR reference:** 40 CFR 52
- **Publication date:** 1999-03-12
- **Effective date:** 1999-03-12
- **State:** ID
- **EPA docket:** ID23-7003
## Abstract

The Environmental Protection Agency (EPA) has determined that the national ambient air quality standards (NAAQS) for particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers (PM-10) that existed before September 16, 1997, shall no longer apply to the Northern Ada County/Boise, Idaho area and EPA is revoking the nonattainment designation associated with those standards. The State of Idaho has satisfied the requirements of the Clean Air Act (CAA) as well as EPA's regulations and Guidance for Implementing the 1- Hour Ozone and Pre-existing PM-10 NAAQS dated December 29, 1997.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/03/12/99-5380/determination-that-pre-existing-national-ambient-air-quality-standards-for-pm-10-no-longer-apply-to)
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