Factbox: Laws that could be used in oil spill prosecution

WASHINGTON (Reuters) - Following are federal laws that could be used to prosecute the companies involved in the oil spill in the Gulf of Mexico, including BP Plc, Transocean Ltd, Halliburton Co and Cameron International Corp, among others.

Clean Water Act - This is the primary law aimed at keeping U.S. waters clean by making it illegal to discharge any pollutants, unless a permit was obtained. It has been used to prosecute offenders who leak pollution into major bodies of water including the Gulf of Mexico as well as lakes, streams and rivers. Civil penalties can include $1,100 per barrel or up to $4,300 per barrel if negligence is found. There are also criminal misdemeanor or felony charges that could be pursued.

Oil Pollution Act - The 1990 law was passed after the 1989 Exxon Valdez spill and expanded the Clean Water Act. It broadened enforcement authority, boosted damages and liabilities as well as mandated contingency planning. It enables the government to hold parties liable for the costs of cleanup and force reimbursement for the government’s efforts.

There is a $75 million cap on damages but removal costs are not subject to that limit. Further that cap can be waived if the violator is found to have engaged in gross negligence, willful misconduct or violated federal safety, construction or operating regulations.

Migratory Bird Treaty Act - The law is aimed at protecting migratory birds and makes it illegal to harm some 836 species of birds as well as their nests or eggs. There is no requirement that intent be proven for there to be a violation, an injured or dead bird would constitute a violation.

Endangered Species Act - Passed in 1973, this law makes it illegal to harm or kill any animal on the endangered species list. That includes actions that change or degrade the habitat, feeding, breeding or sheltering of the endangered wildlife. Permits are sometimes issued for violating those restrictions but usually only for conservation and scientific purposes.

SOURCE: U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service.

Reporting by Jeremy Pelofsky, editing by Cynthia Osterman