(a) Any State agency desiring to enter into an agreement pursuant to section 513 of the Act shall submit a State plan in such form and in such detail as the Secretary shall direct.
(b) Each such plan shall include, at least, the following:
(1) The delegation sought;
(2) The State authority for performing such delegated functions;
(3) A description of the manner in which the State intends to carry out such functions; and
(4) The estimated cost of carrying out such functions.