Declares that, within urban growth areas designated under RCW 36.70A.110, decisions pertaining to the following activities are exempt from chapter 43.21C RCW: (1) Construction of or location of any residential structures of ten or fewer dwelling units;

(2) Division of land into nine or fewer lots or parcels; and

(3) Any landfill or excavation of five hundred cubic yards throughout the total lifetime of the fill or excavation.