; and (3) at the end of that period, if the concerns of the Secretary are not resolved, the Secretary shall provide to Congress an explanation of the concerns. (f) Acid mine drainage treatment (1) In general Subject to paragraph (3), a State or Indian tribe that receives funds under this section may retain such portion of the funds as is necessary to supplement the acid mine drainage abatement and treatment fund of the State or Indian tribe established under section 402(g)(6)(A), for future operation and maintenance costs for the treatment of acid mine drainage associated with the individual projects funded under this section. (2) Application A State or Indian tribe shall specify the total funds allotted for costs described in paragraph (1) in the application of the State or Indian tribe submitted under subsection (d)(2)(B). (3) Condition A State or Indian tribe may retain and use funds under this subsection only if the State or Indian tribe demonstrates that the annual grant distributed to the State or Indian tribe pursuant to section 401(f), including any interest from the acid mine drainage abatement and treatment fund of the State or Indian tribe that is not used for the operation or maintenance of preexisting acid mine drainage treatment systems, is insufficient to fund the operation and maintenance of any acid mine drainage treatment system associated with an individual project funded under this section. (g) Project planning and administration (1) States and Indian tribes (A) In general A State or Indian tribe may use up to 10 percent of the amounts distributed to the State or Indian tribe under this section for project planning and the costs of administering this section. (B) Planning requirements Planning under this paragraph may include— (i) identification of eligible projects; (ii) updating the inventory referred to in section 403(c); (iii) developing project designs; (iv) preparing cost estimates