(1) The department shall review and approve all sewage tank design and construction plans.

(2) Prefabricated tank models and sizes built from approved design and construction plans must be registered with the department.

(3) Cast-in-place tanks are project specific and must be constructed using a design and construction plan approved by the department.

(4) Designers and design engineers shall specify only prefabricated tanks registered with the department or a cast-in-place tank approved by the department in their on-site sewage system designs, plans, and specifications.

(5) Installers shall install only prefabricated tanks registered with the department or construct only cast-in-place tanks that the department has reviewed and approved.

(6) A manufacturer or agent shall sell only prefabricated tanks registered with the department in Washington.

(7) Local health officers and the department shall approve only on-site sewage system designs and installations specifying either a prefabricated tank registered with the department or a cast-in-place tank approved by the department.