(a) Modifications to approved certification plans. A State, Tribe, or Federal agency may make modifications to its approved certification plan, provided that all of the following conditions are met:

(1) Determination of plan compliance. Before modifying an approved certification plan, the State, Tribe, or Federal agency must determine that the proposed modifications will not impair the certification plan's compliance with the requirements of this part or any other Federal laws or regulations.

(2) Requirement for Agency notification. The State, Tribe, or Federal agency must notify the Agency of any plan modifications within 90 days after the final State, Tribal, or Federal agency plan modifications become effective or when it submits its required annual report to the Agency, whichever occurs first.

(3) Additional requirements for substantial modifications to approved certification plans. Before making any substantial modifications to an approved certification plan, the State, Tribe or Federal agency must consult with the Agency and obtain Agency approval of the proposed modifications. Substantial modifications include the following:

(i) Addition or deletion of a mechanism for certification and/or recertification.

(ii) Establishment of a new private applicator category, private applicator subcategory, commercial applicator category, or commercial applicator subcategory.

(iii) Any other changes that the Agency has notified the State, Tribal or Federal agency that the Agency considers to be substantial modifications.

(4) Agency decision. The Agency shall make a written determination regarding the modified certification plan's compliance with the requirements of this part. The Agency shall give the certifying authority submitting a certification plan notice and opportunity for an informal hearing before rejecting the plan. The Agency's approval may be subject to reasonable terms and conditions. If the Agency approves modifications to a certification plan, that approval shall specify a schedule for implementation of the modified certification plan.

(b) Withdrawal of approval. If at any time the Agency determines that a State, Tribal, or Federal agency certification plan does not comply with the requirements of this part or any other Federal laws or regulations, or that a State, Tribal, or Federal agency is not administering the certification plan as approved under this part, or that a State is not carrying out a program adequate to ensure compliance with FIFRA section 19(f), the Agency may withdraw approval of the certification plan. Before withdrawing approval of a certification plan, the Agency will notify the State, Tribal, or Federal agency and provide the opportunity for an informal hearing. If appropriate, the Agency may allow the State, Tribe, or Federal agency a reasonable time, not to exceed 90 days, to take corrective action.