To ensure that program participants are in compliance with the terms of the program and to ensure that the leased equipment is being used principally to produce or harvest fresh asparagus, the participating growers must, during each year of their participation, provide the department or its agent a letter:

(1) Certifying that the leased equipment is being used for the program's intended purpose; and

(2) Summarizing the cost and labor savings for that year relative to asparagus production or harvesting.