(Astoria, OR) -- The Coast Guard is working to clean up a major oil spill on the Columbia River near Astoria. Coast Guard officials say the spill sprang from a 20-foot-long tank underneath the Cannery Pier. The tank has a maximum spill potential of 42-hundred gallons, and Coast Guard officials aren't yet sure how much oil has already spilled into the river. Crews are currently working to minimize the environmental impacts.