OSG had already been ordered to pay $7 million in fines last year. Both fines were part of a $37 million settlement involving 33 felony counts and 12 OSG vessels.
The settlement with federal prosecutors was reached last year for offences which took place between June 2001 and March 2006 including violations of the Clean Water Act, as amended by the Oil Pollution Act of 1990, the APPS, conspiracy, false statements, and obstruction of justice.
The violations took place at several US ports including San Francisco, Beaumont, Boston, Portland, and Maine.
In pleading guilty, OSG admitted that it deliberately falsified the Oil Record Book of various ships, made discharges at night, and concealed bypass methods used to circumvent required pollution prevention equipment during US port calls so that the Coast Guard would not discover the criminal activity, reported MarineLog.