(a) Except as allowed in paragraphs (b), (c), and (e) of this section, each prewash required by this subpart must be completed and all tank washings must be discharged to a reception facility before the ship leaves the unloading port.
(b) NLS residue from the prewash following the unloading of a Category B NLS may be transferred to a slop tank for discharge under § 153.1126 instead of being discharged under paragraph (a) of this section if the prewash is required solely under § 153.1118(a)(1).
(c) A tank that is required by this part to be prewashed may be prewashed in a port other than the unloading port if the following conditions are met:
(1) The person in charge requests permission from the Commandant (CG-ENG) (tel num: 202-372-1420; email: HazmatStandards@uscg.mil) if the prewash port is a foreign port, or the Captain of the Port having jurisdiction over the unloading port if the prewash port is a U.S. port.
(2) The person in charge supplies with the request required under paragraph (c)(1) of this section -
(i) The name of the ship;
(ii) The name of the owner;
(iii) The name of the NLS;
(iv) The approximate date the tank will be prewashed if the relocation of the prewash port is for one time only;
(v) A written agreement to receive the tank washings by a reception facility in the prewash port;
(vi) When the prewash port or terminal is in a country whose Administration is signatory to MARPOL 73/78, a written attestation from the person in charge of each prewash port or terminal that the Administration has determined the port or terminal to have adequate reception facilities for the NLS residue;
(vii) Written pledges from the person in charge that -
(A) The tank to be prewashed will not be washed or ballasted before being prewashed; and
(B) The ship will be taken to the reception facility and the tank prewashed in accordance with the requirements in § 153.1120; and
(viii) Any additional information the Captain of the Port or Commandant (CG-ENG) requests to evaluate granting the permission.
(3) The Coast Guard or Commandant (CG-ENG) has granted the permission in writing, the permission is carried aboard the ship, and the person in charge of the ship has made an entry in the Cargo Record Book stating that the permission has been granted.
(d) Unless the permission granted under paragraph (c)(4) of this section includes alternate conditions of termination or revocation in writing, the permission is -
(1) Terminated after the tank is prewashed as pledged in paragraph (c)(3)(vii) of this section or loaded with another cargo;
(3) Revoked at any time the ship is not operated in accordance with the pledges in paragraph (c)(3)(vii) of this section and the conditions listed with the granted permission.
(e) A U.S. ship that would otherwise be required by this part to prewash in a port without reception facilities must obtain permission from Commandant (CG-ENG) to prewash in an alternate port.