The U.S. Environmental Protection Agency's Office of Research and Development entered into a cooperative agreement with the Exxon Company to initiate a bio-remediation study as part of an effort to clean up oil on the shorelines of Prince William Sound, Alaska. The presence of oil was the result of an 11-million gallon spill of crude oil from the tanker, Exxon Valdez, on March 24, 1989. The study was designed to determine the feasibility of using nutrients to enhance microorganisms that live in the waters and sediments to degrade the oil and, thus, reduce its detrimental effects. Two types of fertilizer, a water soluble and an oleophilic, were applied on both physically cleaned and untreated beach sediments. Several sampling and field testing methods were used to observe changes in the composition of the oil, to monitor the movement of added nutrients in the test beaches, to detect changes in the number of bacteria present as the test proceeded and to assess the degradation of the oil. Based on available results of ORD's research, Exxon proposed to begin bioremediation on nearly 6,000 yards of shoreline in the Sound. The application began August 1, 1989.