The COTP may suspend a Certificate of Adequacy if—

(a) Deficiencies recur or significantly affect the adequacy of the reception facility;

(b) Continued operations will result in undue delay to ships calling at the port or terminal;

(c) There is a failure to accept NLS residue from a ship after it's cargo tanks are prewashed in accordance with 46 CFR 153.1120; or

(d) There is a substantial threat of discharge of oil or NLS into or upon the navigable waters of the United States or adjoining shorelines.