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
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.