Over a four-day period, 292,000 gallons entered the water.
Investigators believe the denatured ethanol was released into the Mississippi River and quickly mixed into the water column, making the released product unrecoverable.
Authorities have informed water intake facilities in the area of the release.
The barges were damaged in an allision with the Helena Highway Bridge, which took place at around 10 p.m., Monday. Lightering operations began at approximately 11:30 a.m., Wednesday.
The Coast Guard is working with NOAA, the State of Arkansas, the State of Mississippi, and National Response Corporation, a pollution recovery company.
The incident is under investigation.