Unless waived under Sec. 153.491, each ship that discharges Category A, B, or C NLS residue, or Category D NLS residue not diluted to \1/10\th of its original concentration, into the sea under Sec. Sec. 153.1126 and 153.1128 must have an NLS residue discharge system meeting the following:
(a) Minimum diameter of an NLS residue discharge outlet. The outlet of each NLS residue discharge system must have a diameter at least as great as that given by the following formula: [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT] where: D = Minimum diameter of the discharge outlet in meters.Qd = Maximum rate in cubic meters per hour at which the ship
operator wishes to discharge slops (note: Qd
affects the discharge rate allowed under Sec.
153.1126(b)(2)).L = Distance from the forward perpendicular to the discharge outlet in
meters.[phis] = The acute angle between a perpendicular to the shell plating at
the discharge location and the direction of the average
velocity of the discharged liquid.
(b) Location of an NLS residue discharge outlet. Each NLS residue discharge outlet must be located--
(1) At the turn of the bilge beneath the cargo area; and
(2) Where the discharge from the outlet is not drawn into the ship's seawater intakes.
(c) Location of dual NLS residue discharge outlets. If the value of 6.45 for K is used in Sec. 153.1126(b)(2), the NLS residue discharge system must have two outlets located on opposite sides of the ship. [CGD 81-101, 52 FR 7781, Mar. 12, 1987, as amended by CGD 81-101, 53 FR 28974, Aug. 1, 1988 and 54 FR 12629, Mar. 28, 1989; CGD 95-028, 62 FR 51209, Sept. 30, 1997]