(1) Assessments levied. There is hereby levied and there shall be collected by the commission, as provided in chapter 15.66 RCW, upon all seed potatoes of commercial quantities grown in the state an annual assessment which shall be paid by the producer thereof upon each and every hundredweight of seed potatoes sold, processed, delivered for sale or processing by him or her or stored or delivered for storage when such storage or delivery for storage is outside the boundaries of this state. The assessment shall then be set by the seed potato commission at a regular meeting before July 15th of each year, to become effective from September 1st of the same year to August 31st of the following year. The assessment shall not be less than one cent or more than ten cents per hundredweight. No assessment may be collected on the following:

(a) Seed potatoes of a producer's own production used by him or her on his or her own premises for seed, feed or personal consumption;

(b) Seed potatoes donated or shipped for relief or charitable purposes; or

(c) Sales on a producer's premises by a producer direct to a consumer of five hundred pounds or less of seed potatoes from a producer's own production.

No assessment levied or made collectable by the act under this order shall exceed three percent of the total market value of all such seed potatoes sold, processed or delivered for sale or processing by all producers of seed potatoes for the fiscal year to which the assessment applies.

(2) Collection of assessment.

(a) All assessments made and levied pursuant to the provisions of the act under this marketing order shall apply to the respective producer who shall be primarily liable therefore. To collect the assessments, the commission may require:

(i) Stamps to be known as "Washington seed potato commission stamps" to be purchased from the commission and fixed or attached to the containers, invoices, shipping documents, inspection certificates, releases or receiving receipts or tickets. Any stamps shall be canceled immediately upon being attached or fixed and the date of the cancellation shall be placed thereon;

(ii) Handlers receiving seed potatoes from the producer, including warehousemen and processors, to collect producer assessments from producers whose production they handle and all moneys so collected shall be paid to the commission on or before the twentieth day of the succeeding month for the previous month's collections. Each handler shall at the times as required by rule, file with the commission a return under oath on forms to be furnished by the commission, stating the quantity of seed potatoes handled, processed, delivered and/or shipped during the period prescribed by the commission.

(iii) In the event payment of producer assessments occur before the seed potatoes are shipped off the farm or occur at different or later times, such person subject to the assessment shall give adequate assurance or security for its payment as the commission shall require.

(b) The commission is authorized to make reasonable rules in accordance and conformity with the act and with this section to effectuate the collection of assessments. On or before the beginning of each marketing season, the commission shall give reasonable notice to all producers, handlers and other affected persons of the method or methods of collection to be used for that marketing season.

(c) No hundredweight unit or units of seed potatoes shall be transported, carried, shipped, sold, stored or otherwise handled or disposed of until every due and payable assessment has been paid and the receipt issued or stamp canceled, but no liability or obligation applies to common carriers in the regular course of their business. When any seed potatoes for which an exemption is claimed, as provided for in subsection (1) of this section, are shipped either by railroad or truck, there shall be plainly noted on the bill of lading, shipping document, container or invoice, the reasons for the exemption(s).

(d) Any producer or handler who fails to comply with the provisions of this section as herein provided shall be guilty of a violation of this order.

(3) Funds.

(a) Moneys collected by the seed potato commission pursuant to the act and this marketing order as assessments shall be used by the commission only for the purposes of paying for the costs or expenses arising in connection with carrying out the purposes and provisions of the act and this marketing order.

(b) At the end of each fiscal year the commission shall credit each producer with any amount paid by such producer in excess of three percent of the total market value of all seed potatoes sold, processed, delivered for sale or processing or delivered for storage or stored when such storage or delivery for storage was outside the boundaries of this state during that period. Refund may be made only upon satisfactory proof given by the producer which may include, bills of lading, bills of sale or receipts.