Section 2773.3 does not apply to either of the following:
(a) Any surface mining operation in existence on January 1, 2003, for which the lead agency has issued final approval of a reclamation plan and the financial assurances prior to September 1, 2002.
(b) Any amended reclamation plan or financial assurances that are necessary for the continued operation or expansion of a surface mining operation in existence on January 1, 2003, that otherwise satisfies the requirements of subdivision (a).