((a)) ** General rule** Except as otherwise provided in subsection (b), any aggrieved person may commence a civil action for mandatory or prohibitive injunctive relief, including interim equitable relief, against the Secretary or the head of any Federal agency which has a responsibility under this chapter if there is an alleged failure of the Secretary or such agency head to perform any act or duty under this chapter which is not discretionary. The United States district courts shall have jurisdiction over actions brought under this section, without regard to the amount in controversy or the citizenship of the parties.

((b)) ** Notice to Secretary or agency head** No action may be commenced under subsection (a) before the 60th calendar day after the date on which the plaintiff has given notice of such action to the Secretary or the agency head involved. Notice under this subsection shall be given in such manner as the Secretary shall prescribe by rule.

((c)) ** Authority of Secretary to intervene** In any action brought under subsection (a), the Secretary, if not a party, may intervene as a matter of right.

((d)) ** Costs of litigation** The court, in issuing any final order in any action brought under subsection (a), may award costs of litigation (including reasonable attorney and expert witness fees) to any party, whenever the court determines such award is appropriate.

((e)) ** Other remedies to remain available** Nothing in this section shall restrict any right which any aggrieved person (or class of aggrieved persons) may have under any statute or common law to seek enforcement of this chapter or any rule thereunder, or to seek any other relief (including relief against the Secretary or the agency head involved).