Human error is often a significant casual factor.
To consistently achieve success, we must focus on reducing the risk of collisions, allisions and groundings. Major oil spills occur infrequently, but may have devastating short-term consequences to the local environment and economy when wildlife are killed, fisheries tainted, and tourism and marine transportation disrupted. Since 1990, in conjunction with our partners and stakeholders, we have made tremendous progress in preventing oil spills. The average number of oil spills over 10,000 gallons has dropped 50 percent from pre-1991 levels in the United States. Since 1990, there have been no spills over one million gallons in the United States.