(a) Each agency head charged with the duty of providing fire protection for any property of the United States is authorized to enter into a reciprocal agreement, with any fire organization maintaining fire protection facilities in the vicinity of such property, for mutual aid in furnishing fire protection for such property and for other property for which such organization normally provides fire protection. Each such agreement shall include a waiver by each party of all claims against every other party for compensation for any loss, damage, personal injury, or death occurring in consequence of the performance of such agreement. Any such agreement may provide for the reimbursement of any party for all or any part of the cost incurred by such party in furnishing fire protection for or on behalf of any other party.

(b) Any agreement heretofore executed which would have been authorized by this subchapter, if this subchapter had been in effect on the date of execution thereof, is ratified and confirmed.