# Retrofit/Rebuild Requirements for 1993 and Earlier Model Year Urban Buses; Additional Update of Post-Rebuild Emission Levels in 1998
> **Rule** · Final rule. · Published 1998-03-26 · Effective 1998-04-27 · 63 FR 14626
## Document
- **Document number:** 98-7767
- **Category:** other
- **Federal Register citation:** 63 FR 14626
- **CFR reference:** 40 CFR 85
- **Publication date:** 1998-03-26
- **Effective date:** 1998-04-27
- **EPA docket:** FRL-5986-2
## Abstract

This final rule amends regulations governing EPA's Urban Bus Retrofit/Rebuild Program to provide for the revision of post-rebuild particulate levels based on equipment certified by July 1, 1998. This amendment allows equipment manufacturers additional time to certify equipment capable of influencing compliance under Option 2 (the fleet averaging option) of the program. This amendment provides assurance that the two compliance options of the program remain equivalent, and that urban buses utilize the best retrofit technology reasonably achievable as Congress required. In addition, the amendment provides assurance that urban areas realize the full PM benefits of this program.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1998/03/26/98-7767/retrofitrebuild-requirements-for-1993-and-earlier-model-year-urban-buses-additional-update-of)
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