Washington Administrative Code
Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508)
Chapter 173-308 - Biosolids management
Section 173-308-193 - Management and exemptions for septage from composting toilets

(1) The residual solids from composting toilet systems (also known as "waterless toilets") that receive only domestic waste are considered to be septage.

(2) Septage from composting toilet systems must either be sent to a permitted facility for further treatment, or it must be managed in accordance with the requirements in WAC 173-308-270 and other applicable sections of this chapter.

(3) Unless a permit is otherwise required by the department, persons who land apply septage from composting toilet systems and sites where the septage is applied are exempt from the reporting requirements in WAC 173-308-295 and the permitting requirements in WAC 173-308-310.

(4) All other applicable requirements of this chapter must be met.

(5) All other local, state, and federal regulatory requirements must be met.