This chapter is adopted under the authority of chapter 70.138 RCW, Incinerator ash residue, to protect human health, the environment, and employees during the management and disposal of special incinerator ash. It is also the purpose of this chapter to enhance and encourage the higher waste management priorities as spelled out in chapter 70.138 RCW. This chapter is intended to establish consistent, enforceable management requirements for special incinerator ash that otherwise would be regulated as hazardous waste under chapter 70.105 RCW, the Hazardous Waste Management Act. This chapter is not intended to address ash residues that are classed as hazardous waste under federal rules, 40 C.F.R. Part 261, unless the Environmental Protection Agency decides those wastes are not subject to Subtitle C of the Resource Conservation and Recovery Act.