Two senior engineering officers employed by an Italian shipping company admitted in court they deliberately concealed their vessel’s discharge of oily waste into the sea.

Girolamo Curatolo, 50, of Custonaci, Sicily, the chief engineer of the oil tanker M/T Cielo di Milano, pleaded guilty before U.S. District Judge Susan D. Wigenton in a federal court in Newark, New Jersey, to one count of conspiring to violate the Act to Prevent Pollution from Ships. Danilo Maimone, 31, of Furci Siculo, Sicily, the ship’s first assistant engineer, pleaded guilty to a charge of conspiracy to obstruct justice.

According to documents filed in this case and statements made in court, the vessel, owned by D’Amico Shipping Italia S.p.A. and managed by D’Amico Societa di Navigazione S.p.A., visited ports in New Jersey multiple times, as well as ports in Maryland and Florida. Curatolo admitted that the crew had intentionally bypassed required pollution prevention equipment by discharging oily waste from the engine room through its sewage system into the sea. He also admitted that he falsified the vessel’s oil record book, a required log regularly inspected by the U.S. Coast Guard.

Curatolo admitted he made false statements to the Coast Guard during its inspection of the M/T Cielo di Milano in January 2015, instructing lower-level crew members to make false statements and destroying the vessel’s sounding log—which records the contents of storage tanks aboard the vessel, including those containing oily waste—by ripping the pages out and burning it in the vessel’s boiler after the Coast Guard had boarded the vessel.

Maimone admitted concealing the discharge of oily waste as well as causing a false oil record book to be presented to the Coast Guard during its inspection of the vessel. He admitted making false statements and instructing lower-level crew members to make false statements during the January 2015 inspection.

The charges to which Curatolo and Maimone pleaded guilty each carry a maximum penalty of five years in prison and a maximum fine of $250,000 or twice the gross gain or loss resulting from the offenses. Sentencing for both is scheduled for November 21.