Section 153.491 - Waiver of certain equipment for dedicated cargo tanks(a) The Coast Guard waives §§ 153.440(a)(3) , 153.480 , 153.481 , 153.482 , and 153.488 and endorses a ship's Certificate of Inspection or Certificate of Compliance allowing a cargo tank to carry a single, specific NLS cargo and no other cargo if the ship's owner- (1) Requests a waiver following the procedures in § 153.10 ; and(2) Pledges in writing that while any waiver is in effect the cargo tank will-(i) Carry only the NLS cargo listed on the Certificate of Inspection or Certificate of Compliance;(ii) Carry no cargo other than the NLS; and(iii) Not be washed or ballasted unless the wash water or ballast water is discharged to a reception facility.(b) The Coast Guard waives §§ 153.470 and 153.490(a)(2) if-(1) The ship's owner requests a waiver following the procedures in § 153.10 ;(2) The Coast Guard has issued a waiver to each of the ship's NLS cargo tanks under paragraph (a) of this section; and(3) The ship's owner adds to the ship's operational manual any provisions for preventing NLS discharge specified by the Commandant (CG-ENG) as a condition for issuing the waiver.CGD 81-101, 52 FR 7781, Mar. 12, 1987, as amended by CGD 81-101, 53 FR 28975, Aug. 1, 1988 and 54 FR 12629, Mar. 28, 1989