(1) Area 4A description. An area including all lands lying within a boundary line beginning at the intersection of the Esquatzel Diversion Channel drain and the Columbia River; thence east along the Esquatzel Channel to its intersection with Road 68; thence southeasterly approximately one mile along Road 68 to its intersection with Fraser Drive near the northeast corner of Section 24, T10N, R28E; thence south approximately four miles along section lines and portions of Fraser Drive and Dent Road to the southwest corner of Section 6, T9N, R29E; thence east approximately eight and one-half miles along section lines and a portion of Foster Wells Road to its intersection with the Bonneville Power Administration power line in Section 4, T9N, R30E; thence southeasterly along the power line until its intersection with the Snake River near the east line of Section 25, T9N, R30E; thence southwesterly along the Snake River until its intersection with U.S. Highway 12 in Section 35, T9N, R30E; thence northwesterly along Highway 12 until its intersection with Interstate 182; thence westerly along Interstate 182 until its intersection with the Columbia River along the east section line of Section 13, T9N, R28E; thence northerly along the Columbia River to the point of beginning.

(2) Area 4A restrictions.

(a) Application by air of use restricted pesticides as defined in WAC 16-231-107 may be made by written permit only.

(b) The use or application of low volatile ester formulations of use restricted herbicides is prohibited: Provided, That hormone sprays may be applied by aircraft to orchards for the prevention of fruit drop.

(c) On and after April 5th through October 31st of each year, all applications of use restricted herbicides are prohibited daily from three hours prior to sunset until two hours after sunrise the following morning: Provided, That applications of use restricted herbicides are exempt from the sunset and sunrise restrictions when using an application rate of forty gallons of water carrier or greater per treated acre and conforming to the manufacturer's specified combination of nozzle type/size and pressure in pounds per square inch (psi) at the nozzle that produces a spray droplet size that falls within the very coarse (or larger) range as defined by the ASABE standards: Provided further, That applications of granular and pellet formulations of the use restricted herbicides are exempt from the sunset and sunrise restrictions: Provided further, That applications of the use restricted herbicides on small experimental plots for research purposes are exempt from the sunset and sunrise restrictions.