CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER O—CERTAIN BULK DANGEROUS CARGOES (parts 150 to 155) > PART 153—SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS > SUBPART C—Operations (§153.900 to §153.1504) > 153.1126—Discharge of NLS residue from a slop tank to the sea: Categories A, B, C, and D.

153.1126—Discharge of NLS residue from a slop tank to the sea: Categories A, B, C, and D.

NLS residue in a slop tank may not be discharged into the sea unless—
(a) The ship meets the conditions for discharging the NLS residue from a cargo tank in § 153.1128; and
(b) For Category B NLS residue transferred to the slop tank under § 153.1119(b), the NLS is discharged—
(1) Through an NLS residue discharge system with the flow recording equipment required in § 153.481(b)(2) operating; and
(2) At a rate maintained at or below Q in the following:
For tank contents that are miscible
For tank contents that are immiscible

Code of Federal Regulations

Q=KU1.4 L1.6×10−5 m3/hr
where:
Q=maximum permissible slops discharge rate in cubic meters per hour.
V=volume of slops in the tank in cubic meters.
K=4.3, except K=6.45 if Q is distributed between two NLS residue discharge outlets on opposite sides of the ship (see §§ 153.470(c) and 153.481(b)).
U=ship's speed in knots.
L=ship's length in meters.
N=number of tanks containing Category B NLS residue pumped into the slop tank.