19 CFR 4.66b - Pollution of coastal and navigable waters.
(a) If any Customs officer has reason to believe that any refuse matter is being or has been deposited in navigable waters or any tributary of any navigable waters in violation of section 13 of the Act of March 3, 1899 ( 30 Stat. 1152; 33 U.S.C. 407), or oil or a hazardous substance is being or has been discharged into or upon the navigable waters of the United States, adjoining shorelines, or into or upon the waters of the contiguous zone in violation of the Federal Water Pollution Control Act, as amended ( 33 U.S.C. 1251, 1321), he shall promptly furnish to the port director a full report of the incident, together with the names of witnesses and, when practicable, a sample of the material discharged from the vessel in question.
(b) The port director shall forward this report immediately, without recommendation, to the district commander of the Coast Guard district concerned and a copy of such report shall be furnished to Headquarters, U.S. Customs Service.