(a) Pursuant to section 122(h)(4) of CERCLA, 42 U.S.C. 9622(h)(4), any participating PRP who has resolved his or her liability for an EPA claim through a final decision reached pursuant to the procedures established by this part shall not be liable for claims for contributions regarding matters addressed by the final decision.

(b) The final decision shall be binding and conclusive upon the parties as to issues that were jointly submitted by the parties for resolution and addressed in the decision.

(c)(1) If any award made in the final decision is not paid within the time required by § 304.33(f) of this part, the final decision may be enforced as a settlement under section 122(h) of CERCLA, 42 U.S.C. 9622(h), by the Attorney General on behalf of EPA in any appropriate Federal district court pursuant to section 122(h)(3) of CERCLA, 42 U.S.C. 9622(h)(3). Pursuant to section 122(h)(3) of CERCLA, the terms of the final decision shall not be subject to review in any such action.

(2) In any such enforcement action initiated by the United States, the final decision may be challenged by any party if:

(i) It was achieved through fraud, misconduct, or partiality on the part of the Arbitrator;

(ii) It was achieved through fraud or misconduct by one of the parties affecting the result;

(iii) The Arbitrator exceeded his or her jurisdiction under § 304.20 of this part or failed to decide the claim within the bounds of his or her authority under this part; or

(iv) It violates public policy.

(3) Except as necessary to show such fraud, misconduct, partiality, excess of jurisdiction or authority, or violation of public policy, in any such enforcement action, a party may not raise, for the purpose of overturning or otherwise challenging the final decision, issues arising in the claim that were not submitted for resolution by arbitration.

(d) Except as provided in paragraph (c) of this section, and except as necessary for a participating PRP to defend against an action seeking contribution for matters addressed by the final decision, no final decision shall be admissible as evidence of any issue of fact or law in any proceeding brought under any provision of CERCLA or any other provision of law.

(e) Neither the initiation of an arbitral proceeding nor the rendering of a final decision on an EPA claim shall preclude or otherwise affect the ability of the United States, including EPA, to:

(1) Seek injunctive relief against any participating PRP for further response action at the facility concerned pursuant to CERCLA or any other applicable statute, regulation or legal theory; or

(2) Take further response action at the facility concerned pursuant to CERCLA or any other applicable statute, regulation or legal theory; or

(3) Seek reimbursement from any participating PRP for any costs not the subject of the arbitral proceeding pursuant to CERCLA or any other applicable statute, regulation or legal theory; or

(4) Seek any relief for any violation of criminal law from any participating PRP; or

(5) Seek damages for injury to, destruction of, or loss of natural resources from any participating PRP; or

(6) Seek any relief, civil or criminal, from any person not a party to the arbitral proceeding under CERCLA or any other applicable statute, regulation or legal theory.