PDFWAC 246-273-020
Applicability.
(1) After July 1, 1994, no person shall use, sell, or distribute an on-site sewage disposal system chemical additive in Washington state.
(2) After January 1, 1996, no person shall use, sell or distribute an on-site sewage disposal system additive whose ingredients have not been approved by the department in accordance with requirements of chapter 70A.105 RCW and this chapter.