At the end of each fiscal period, funds in excess of the committee's expenses may be placed in an operating reserve not to exceed approximately 1 fiscal year's operational expenses or such lower limits as the committee, with the approval of the Secretary, may establish. Also, the committee, with the approval of the Secretary, may include in its budget an item for such reserve. Funds in the reserve shall be available for use by the committee for expenses authorized pursuant to § 958.40. Funds in excess of those placed in the operating reserve shall be refunded to handlers. Each handler's share of such excess shall be the amount he paid in excess of his pro rata share of the expenses of the committee.