46 CFR § 153.1102 - Handling and disposal of NLS residue: Categories A, B, C, and D.
(a) Except those Category A NLS residues that must be discharged under paragraph (c) of this section, NLS residue from an NLS whose vapor pressure is 5 kPa (50 mbar) or less at 20 °C (68 °F) must be -
The Marine Protection, Research, and Sanctuaries Act allows specific liquids to be discharged to the sea under permits issued by the EPA.
(1) Unloaded to any consignee;
(2) Returned to the shipper;
(3) Discharged to a reception facility;
(4) Retained on the ship; or
(b) Except those Category A NLS residues that must be discharged under paragraph (c) of this section, NLS residue from an NLS whose vapor pressure is greater than 5 kPa (50 mbar) at 20 °C must be -
(1) Handled in the same way as the NLS residue under paragraph (a) of this section; or
(2) Ventilated following a ventilation procedure in the approved Procedures and Arrangements Manual.
The Clean Air Act (42 U.S.C. 7401et seq) allows states to regulate emissions from tank ventilation. There may be other regulations, both local and Federal, that affect the use of tank ventilation for safety or environmental purposes.