# Modification of the Ozone Monitoring Season for Washington and Oregon
> **Rule** · Direct final rule. · Published 1999-01-20 · Effective 1999-03-22 · 64 FR 3028
## Document
- **Document number:** 99-1121
- **Category:** air-emissions
- **Federal Register citation:** 64 FR 3028
- **CFR reference:** 40 CFR 58
- **Publication date:** 1999-01-20
- **Effective date:** 1999-03-22
- **State:** OR
- **EPA docket:** ORWA-010799-a
## Abstract

The Environmental Protection Agency (EPA) is amending 40 CFR part 58, Appendix D, section 2.5, to shorten the ozone monitoring season in Washington and Oregon from April 1 through October 31 to May 1 through September 30.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/01/20/99-1121/modification-of-the-ozone-monitoring-season-for-washington-and-oregon)
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