This is the other major area of influence of the IMO and much has been done to reduce pollution of the seas and the sea shores by pollution from ships; the convention covering this aspect is MARPOL. Pollution can arise from any form of waste being dumped overboard, including sewage and domestic garbage. These areas are incorporated in MARPOL but the greatest problem it deals with is pollution by oil. There are two International Conventions governing compensation for oil pollution damage and clean-up costs. Originally introduced in the 1960s and 1970s, they have been regularly up-dated through the years. The latest amendments rest with The Civil Liability Convention 1992 and the Fund Convention 1992. Basically, under the Civil Liabilities Convention (CLC), the shipowner is entitled to limit his liability in respect to oil pollution to an amount linked to the tonnage of the vessel. Where this is insufficient, or the shipowner can invoke one of the CLC exemptions or the shipowner proves to be incapable of meeting his legal obligation and his insurance proves to be inadequate, additional compensation is provided under the Fund Convention, which is financed by the oil industry itself. The United States legislation regarding oil pollution is, at present, unique. The USA initially signed both the early versions of the CLC and the Fund Convention but subsequently ratified neither. Instead, the USA unilaterally introduced their Oil Pollution Act 1990 (OPA90).