Federal officials now estimate that more than 1 million gallons (3.8 million liters) of oil may have spilled into a major river in southern Michigan, and the governor is sharply criticizing clean-up efforts as «wholly inadequate.» The U.S. Environmental Protection Agency released the update Wednesday night, shortly after Gov. Jennifer Granholm lambasted attempts to contain the oil flowing down the Kalamazoo River. She warned of a «tragedy of historic proportions» if the oil reaches Lake Michigan, which is still at least 80 miles (130 kilometers) downstream from where oil has been seen, according to AP. Granholm called on the federal government for more help, saying resources being marshaled by the EPA and Enbridge Inc., which owns the pipeline that leaked the oil, were «wholly inadequate.» Calgary, Alberta-based Enbridge said earlier Wednesday that it had redoubled its efforts to clean up the mess. Chief executive Patrick D. Daniel said the company had made «significant progress,» though he had no update on a possible cause, cost or timeframe for the cleanup. The company didn't return messages for comment after Granholm's statements. The overall work force on the spill Wednesday was likely more than 400 people. EPA officials said they're ramping up efforts with air and water testing. Local officials said they weren't concerned about municipal water supplies. Tom Sands, deputy state director for emergency management and homeland security, said during a conference call with Granholm that he had seen oil past a dam at Morrow Lake. The lake is a key point in the river near a Superfund site upstream of Kalamazoo, the largest city in the region. But his report could not be immediately confirmed. The company's latest update statement Wednesday said oil was about seven miles short of the opening to Morrow Lake. A news conference scheduled for late Wednesday, which was to include company and EPA officials, was canceled for what a company spokesman called scheduling conflicts. State and company officials previously said they didn't believe the oil would spread past that dam. «It's going to hit a Superfund site unless somebody like the EPA and the company get very serious about providing significant additional resources,» Granholm said. The spill has killed fish and coated wildlife as it made its way westward about 35 miles downstream past Battle Creek, a city of 52,000 residents about 110 miles (177 kilometers) west of Detroit. Both company and EPA officials have said oil is no longer leaking. Enbridge has been working to clean up the spill since the leak was reported early Monday. Before the EPA announced its new estimate, Enbridge reiterated its belief that about 819,000 gallons (3,100,161 liters) of oil spilled into Talmadge Creek, which flows into the Kalamazoo River. State officials said they were told during a company briefing Tuesday that about 877,000 gallons (3,319,708 liters) spilled, but company officials disputed the number. Granholm has declared a state of disaster for some areas along the river, and President Barack Obama called Granholm to offer federal support. An oily reflective sheen could be seen in patches along the Kalamazoo, and the affected area still had a strong odor, although not as strong as on Tuesday. Anil Kulkarni, a mechanical engineering professor at Penn State University, said a quick response was vital to the river's ecology. Snails, frogs, muskrats and even birds eat, live and nest on or near the riverbank. «The river banks are nearby. It has more potential to inflict damage because of the proximity to land. Anything that comes in contact with oil is going to be affected badly. It prevents the natural life of species, whether it's collecting food or anything else.» Enbridge affiliates have previously been cited for skirting environmental regulations in the Great Lakes region. Houston-based Enbridge Energy Co. spilled almost 19,000 gallons (71,921 liters) of crude oil onto Wisconsin's Nemadji River in 2003. Another 189,000 gallons (715,422 liters) of oil spilled at the company's terminal two miles from Lake Superior, though most was contained. In 2007, two spills released about 200,000 gallons (757,060 liters) of crude in northern Wisconsin as Enbridge was expanding a 320-mile (515-kilometer) pipeline. The company also was accused of violating Wisconsin permits designed to protect water quality during work in and around wetlands, rivers and streams, the Wisconsin Department of Natural Resources said. The violations came during construction of a 321-mile (517-kilometer), $2 billion oil pipeline across that state. Enbridge agreed to pay $1.1 million in 2009. The Michigan leak came from a 30-inch (76-centimeter) pipeline, which was built in 1969 and carries about 8 million gallons (30 million liters) of oil daily from Griffith, Indiana, to Sarnia, Ontario. The river already faced major pollution issues. An 80-mile (130-kilometer) segment of the river that begins at Morrow Lake and five miles of a tributary, Portage Creek, have unsafe levels of PCBs and were placed on the federal Superfund list of high-priority hazardous waste sites in 1990. The Kalamazoo site also includes four landfills and several defunct paper mills.