# Approval and Promulgation of Implementation Plans
> **Rule** · — · Published 1999-03-23 · 64 FR 13916
## Document
- **Document number:** 99-55511
- **Category:** other
- **Federal Register citation:** 64 FR 13916
- **CFR reference:** 40 CFR 52
- **Publication date:** 1999-03-23
## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/03/23/99-55511/approval-and-promulgation-of-implementation-plans)
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