(1) When biosolids are placed in a municipal solid waste landfill unit they are considered solid waste (sewage sludge).

(2) Any landfill accepting sewage sludge for disposal must be in compliance with the requirements of chapter 173-351 WAC and 40 C.F.R. Part 258.

(3) Sewage sludge that is disposed in a municipal solid waste landfill must meet the liquids in landfills restrictions of chapter 173-351 WAC.

(4) Sewage sludge that is disposed in a municipal solid waste landfill must not be hazardous waste as defined in chapter 173-303 WAC or 40 C.F.R. Part 261.

(5) Daily cover. The use of sewage sludge as daily cover or as an amendment to daily cover is not a beneficial use and is considered disposal.

(6) Intermediate or final cover. The use of biosolids as a component of landfill intermediate or final cover is considered a beneficial use if the following conditions are met:

(a) The use is consistent with an approved landfill plan of operations or closure/post-closure plan.

(b) The biosolids are used for the purposes of establishing a vegetative cover.

(c) If the biosolids are nonexceptional quality, the department has approved a site specific land application plan that meets the requirements of WAC 173-308-310(8). For the purposes of this subsection, a site specific land application plan may recognize an approved plan of operations or closure/post-closure plan that addresses the substantive requirements of WAC 173-308-310(8).

(7) Disposal on an emergency basis.

(a) Facilities wishing to dispose of sewage sludge in a municipal solid waste landfill on an emergency basis must meet the conditions of this subsection and those in chapter 173-351 WAC.

(b) The person proposing to dispose of sewage sludge must obtain a written determination from the local health jurisdiction where the sewage sludge is proposed for disposal that a potentially unhealthful circumstance exists under present conditions of management or would result from land application, and that other management options are unavailable or would pose a threat to human health or the environment.

(c) Upon making the determination in (b) of this subsection, the local health jurisdiction must notify the department in writing of its findings and the basis for its determination. In its notification, the local health jurisdiction must state the date on which disposal is approved to commence, any conditions, and the date after which disposal is prohibited.

(8) Disposal on a temporary basis.

(a) Any person wishing to dispose of sewage sludge in a municipal solid waste landfill on a temporary basis must submit a plan for approval to the department. The plan must include the following information:

(i) The conditions that make disposal necessary.

(ii) The steps that will be taken to correct the conditions that make disposal necessary so that disposal will not become a long-term management option.

(iii) A time table for implementing the steps to be taken to correct the conditions that make disposal necessary.

(b) The person proposing to dispose must provide the department with written approval for disposal from the local health jurisdiction in the receiving jurisdiction.

(9) Disposal on a long-term basis.

(a) Any person wishing to dispose of sewage sludge in a municipal solid waste landfill on a long-term basis must have authorization to do so in a valid NPDES or state waste discharge permit issued under chapter 90.48 RCW or a permit issued under this chapter, and the person must submit for approval to the department an evaluation of the various management options that demonstrates to the satisfaction of the department that options for beneficial use are economically infeasible.

(b) The person proposing to dispose must provide the department with written approval for disposal from the local health jurisdiction in the receiving jurisdiction.