---
kind: "section"
citation: "40 C.F.R. § 121.10"
title: "40"
number: "121.10"
heading: "Modification to a grant of certification."
url: "https://uscodex.org/cfr/40/121.10"
---

# §121.10. Modification to a grant of certification.

- (a) Provided that the Federal agency and the certifying authority agree in writing that the certifying authority may modify a grant of certification (with or without conditions), the certifying authority may modify only the agreed-upon portions of the certification. The certifying authority is not required to obtain the Federal agency's agreement on the language of the modification.
- (b) The certifying authority shall not, through a modification pursuant to [paragraph (a)](#a) of this section:
  - (1) Revoke a grant of certification (with or without conditions); or
  - (2) **Change a grant of certification (with or without conditions) into a denial or waiver of certification.**

## Notes

### Authority

Authority: 33 U.S.C. 1251 et seq.

### Source

Source: 88 FR 66661, Sept. 27, 2023, unless otherwise noted.