---
kind: "section"
citation: "40 C.F.R. § 171.5"
title: "40"
number: "171.5"
heading: "Effective date."
url: "https://uscodex.org/cfr/40/171.5"
---

# §171.5. Effective date.

- (a) **This part is effective March 6, 2017.** Certification plans approved by EPA before the effective date remain approved except as provided in §§ [171.5(b)-(d)](#b..d) and [171.309](/cfr/40/171.309.md).
- (b) **Status of certification plans approved before effective date.** A certification plan approved by EPA before March 6, 2017 remains approved until March 4, 2020, except as provided in [paragraph (c)](#c) of this section and [§ 171.309](/cfr/40/171.309.md).
- (c) **Extension of an existing plan during EPA review of proposed revisions.** If by March 4, 2020, a certifying authority has submitted to EPA a proposed modification of its certification plan pursuant to [subpart D](/cfr/40/subpartD.md) of this part, its certification plan approved by EPA before March 6, 2017 will remain in effect until EPA has approved or rejected the modified plan pursuant to [§ 171.309(a)(4)](/cfr/40/171.309.md?p=a-4) or November 4, 2023, whichever is earlier, except as provided in [paragraph (d)](#d) of this section and [§ 171.309(b)](/cfr/40/171.309.md?p=b).
- (d) **Extension of an existing plan after EPA has approved a revised plan.** Where EPA has approved a certifying authority's modified certification plan pursuant to [§ 171.309(a)(4)](/cfr/40/171.309.md?p=a-4), the certification plan approved by EPA before March 6, 2017 shall remain in effect as specified in EPA's approval of the modified certification plan.
- (e) States, Tribes, or Federal agencies that do not have an EPA-approved certification plan in effect may submit to EPA for review and approval a certification plan that meets or exceeds all of the applicable requirements of this part any time.

## Notes

### Amendments

[82 FR 1029, Jan. 4, 2017, as amended at 86 FR 71838, Dec. 20, 2021; 87 FR 50965, Aug. 19, 2022]

### Authority

Authority: 7 U.S.C. 136-136y.

### Source

Source: 39 FR 36449, Oct. 9, 1974, unless otherwise noted.

### Amendments

[82 FR 1029, Jan. 4, 2017, as amended at 86 FR 71838, Dec. 20, 2021; 87 FR 50965, Aug. 19, 2022]