((a)) ** Discharge or discrimination prohibited** No employer may discharge any employee or otherwise discriminate against any employee with respect to his compensation, terms, conditions, or privileges of employment because the employee (or any person acting pursuant to a request of the employee)—

((1)) commenced, caused to be commenced, or is about to commence or cause to be commenced a proceeding under this chapter or a proceeding for the administration or enforcement of any requirement imposed under this chapter or under any applicable implementation plan,

((2)) testified or is about to testify in any such proceeding, or

((3)) assisted or participated or is about to assist or participate in any manner in such a proceeding or in any other action to carry out the purposes of this chapter.

((b)) ** Complaint charging unlawful discharge or discrimination; investigation; order**

((1)) Any employee who believes that he has been discharged or otherwise discriminated against by any person in violation of subsection (a) may, within thirty days after such violation occurs, file (or have any person file on his behalf) a complaint with the Secretary of Labor (hereinafter in this subsection referred to as the “Secretary”) alleging such discharge or discrimination. Upon receipt of such a complaint, the Secretary shall notify the person named in the complaint of the filing of the complaint.

((2))

((A)) Upon receipt of a complaint filed under paragraph (1), the Secretary shall conduct an investigation of the violation alleged in the complaint. Within thirty days of the receipt of such complaint, the Secretary shall complete such investigation and shall notify in writing the complainant (and any person acting in his behalf) and the person alleged to have committed such violation of the results of the investigation conducted pursuant to this subparagraph. Within ninety days of the receipt of such complaint the Secretary shall, unless the proceeding on the complaint is terminated by the Secretary on the basis of a settlement entered into by the Secretary and the person alleged to have committed such violation, issue an order either providing the relief prescribed by subparagraph (B) or denying the complaint. An order of the Secretary shall be made on the record after notice and opportunity for public hearing. The Secretary may not enter into a settlement terminating a proceeding on a complaint without the participation and consent of the complainant.

((B)) If, in response to a complaint filed under paragraph (1), the Secretary determines that a violation of subsection (a) has occurred, the Secretary shall order the person who committed such violation to (i) take affirmative action to abate the violation, and (ii) reinstate the complainant to his former position together with the compensation (including back pay), terms, conditions, and privileges of his employment, and the Secretary may order such person to provide compensatory damages to the complainant. If an order is issued under this paragraph, the Secretary, at the request of the complainant, shall assess against the person against whom the order is issued a sum equal to the aggregate amount of all costs and expenses (including attorneys’ and expert witness fees) reasonably incurred, as determined by the Secretary, by the complainant for, or in connection with, the bringing of the complaint upon which the order was issued.

((c)) ** Review**

((1)) Any person adversely affected or aggrieved by an order issued under subsection (b) may obtain review of the order in the United States court of appeals for the circuit in which the violation, with respect to which the order was issued, allegedly occurred. The petition for review must be filed within sixty days from the issuance of the Secretary’s order. Review shall conform to chapter 7 of title 5. The commencement of proceedings under this subparagraph  shall not, unless ordered by the court, operate as a stay of the Secretary’s order.

((2)) An order of the Secretary with respect to which review could have been obtained under paragraph (1) shall not be subject to judicial review in any criminal or other civil proceeding.

((d)) ** Enforcement of order by Secretary** Whenever a person has failed to comply with an order issued under subsection (b)(2), the Secretary may file a civil action in the United States district court for the district in which the violation was found to occur to enforce such order. In actions brought under this subsection, the district courts shall have jurisdiction to grant all appropriate relief including, but not limited to, injunctive relief, compensatory, and exemplary damages.

((e)) ** Enforcement of order by person on whose behalf order was issued**

((1)) Any person on whose behalf an order was issued under paragraph (2) of subsection (b) may commence a civil action against the person to whom such order was issued to require compliance with such order. The appropriate United States district court shall have jurisdiction, without regard to the amount in controversy or the citizenship of the parties, to enforce such order.

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

((f)) ** Mandamus** Any nondiscretionary duty imposed by this section shall be enforceable in a mandamus proceeding brought under .section 1361 of title 28

((g)) ** Deliberate violation by employee** Subsection (a) shall not apply with respect to any employee who, acting without direction from his employer (or the employer’s agent), deliberately causes a violation of any requirement of this chapter.