Surface disturbances caused by an underground metals mining and milling operation are subject to the requirements of this chapter if the operation is proposed after June 30, 1999. An operation is proposed when an agency is presented with an application for an operation or expansion of an existing operation having a probable significant adverse environmental impact under chapter
43.21C RCW. The department of ecology shall retain authority for reclamation of surface disturbances caused by an underground operation operating at any time prior to June 30, 1999, unless the operator requests that authority for reclamation of surface disturbances caused by such operation be transferred to the department under the requirements of this chapter.