WAC 16-230-170. Desiccants and defoliants — Aerial equipment — Boom length, pressure, nozzle requirement, nozzle height of discharge and smoke device requirements for the entire area under order

The following requirements apply to the entire area under order as listed in WAC 16-230-150 : (1) Boom length restrictions: (a) Fixed wing: The working boom length shall not exceed 3/4 of the distance from the center of aircraft to wing tip on each side of aircraft. (b) Helicopters: The working boom length shall not exceed 6/7 of the distance from the center of rotor to rotor tip on each side of the aircraft for rotors 40 feet or under or 3/4 of the distance from the center of rotor to rotor tip on each side of the aircraft where the rotor exceeds 40 feet while applying use restricted desiccants and defoliants. (2) Aircraft applications shall conform to the manufacturer's specified combination of nozzles, pressure (psi), plates, nozzle orientation, and aircraft speed that produces a droplet class that falls within the coarse (or larger) range as defined by the ASABE standards. (3) Height of discharge requirements by aircraft of use restricted desiccants and defoliants: The nozzles must be closed while either descending onto or ascending from the target field, and also ascending or descending over an obstacle or obstruction within the target field that would alter the height of application more than ten feet. (4) Smoke device requirements: All aircraft applying use restricted desiccants and defoliants shall utilize a smoke device to determine wind directions and temperature inversion situations. (5) The Washington state department of agriculture may issue a permit upon receipt of a written request to apply use restricted desiccants and defoliants within the area under order as described in WAC 16-230-150 with nozzles, nozzle type, drift control additives and/or arrangements other than those allowed herein. The director will consider safety factors and the possible exposure to susceptible crops in the areas of proposed application before a permit will be issued. (6) Diesel and other fuel oils are prohibited in all tank mixes with desiccants and defoliants. (7) Aerial applications of desiccants and defoliants are prohibited within a distance of one mile of the city limits of any incorporated city or town and the same distance from the center of any unincorporated city or town comprised of ten or more inhabited, closely grouped residences.