(a) Requirement for payment. Each handler shall pay the Board, on demand, his or her pro rata share of the expenses authorized by the Secretary for each marketing year. Each handler's pro rata share shall be the rate of assessment per inshell pound of walnuts fixed by the Secretary times the pounds of walnuts received by him or her for his or her own account (except as to receipt from other handlers on which assessments have been paid). At any time during or after the marketing year the Secretary may increase the assessment rate as necessary to cover authorized expenses and each handler's pro rata share shall be adjusted accordingly.

(b) Assessment rate. The assessment rate set out may be modified by the Secretary, based upon a recommendation of the Board or other available data.

(c) Late payment. If a handler does not pay assessments within the time prescribed by the Board, the assessment may be increased by a late payment charge and/or an interest rate charge at amounts prescribed by the Board with approval of the Secretary.

(d) Accounting. If at the end of a marketing year the assessments collected are in excess of expenses incurred, such excess shall be accounted for in accordance with one of the following:

(1) If such excess is not retained in a reserve, as provided in paragraph (d)(2) or (3) of this section, it shall be refunded to handlers from whom collected, and each handler's share of such excess funds shall be the amount of assessments he or she has paid in excess of his or her pro rata share of the actual expenses of the Board.

(2) Excess funds may be used temporarily by the Board to defray expenses of the subsequent marketing year provided each handler's share of such excess shall be made available to him or her by the Board within five months after the end of the year.

(3) The Board may carry over such excess into subsequent marketing years as a reserve: Provided, that funds already in reserve do not exceed approximately two years' budgeted expenses. In the event that funds exceed two marketing years' budgeted expenses, future assessments will be reduced to bring the reserves to an amount that is less than or equal to two marketing years' budgeted expenses. Such reserve funds may be used:

(i) To defray expenses, during any marketing year, prior to the time assessment income is sufficient to cover such expenses;

(ii) To cover deficits incurred during any year when assessment income is less than expenses;

(iii) To defray expenses incurred during any period when any or all provisions of this part are suspended; and

(iv) To meet any other such costs recommended by the Board and approved by the Secretary.

(e) Advanced assessments and commercial loans. To provide funds for the administration of the provisions of this part during the part of a marketing year when neither sufficient operating reserve funds nor sufficient revenue from assessments for the current marketing year are available, the Board may accept payment of assessments in advance or may borrow money from a commercial lending institution for such purposes.

(f) Termination. Any money collected from assessments hereunder and remaining unexpended in the possession of the Board upon termination of this part shall be distributed in such manner as the Secretary may direct.