As many as 70,000 gallons of oil per day have been gushing into the waters of the Gulf Coast since an oil rig operated by British Petroleum exploded on Apr. 20. The well itself is located at a depth of about 5,000 feet, presenting formidable obstacles to efforts to shut it down. The spill is expected to ultimately eclipse the 11-million-gallon Exxon Valdez spill in 1989, the worst oil spill in U.S. history. It is not known how much oil could potentially pour into the Gulf before the leak is plugged. The U.S. Environmental Protection Agency (EPA) says water sampling collected on May 1 and 2 along the Louisiana coast found chemicals associated with oil. "However, these results still indicate that water quality does not pose increased risk to aquatic life, such as fish and shellfish," the agency said in a statement.May 14, 2010 -- ATLANTA, Georgia (Inter Press Service) -- With engineers giving a best-case scenario of "weeks" before the catastrophic oil leak in the Gulf of Mexico is sealed, some scientists are warning that the region's ecosystem could face major long-term damage.