Detection and response

On the night of December 4, 1986, as the Amazon Venture began offloading its cargo,^[7] oil began spilling from the ship due to three faulty valves.^[3] Approximately 3 hours after this began, the U.S. Customs Service became aware of oil in the river and contacted the Marine Safety Office (MSO) of the U.S. Coast Guard based in Savannah.^[9] The Coast Guard was notified at 11:30 p.m. and personnel were present at the scene approximately 30 minutes later.^[11] They gave an initial estimate of a minor spill involving 2,000 US gallons (7,600 L),^{[note 2]} a figure still large enough that the spill was of federal concern.^[9] With this, several federal and state agencies were brought in to assess the situation and oil samples from ships at the dock were collected to be chemically analyzed to see if they matched the oil found in the river.^[9] While oil testing such as this would normally have been conducted at the Coast Guard's Central Oil Identification Laboratory in Groton, Connecticut, arrangements were made to have the tests performed in a more timely manner by the South Carolina Department of Health and Environmental Control at their facilities in Columbia, South Carolina.^[11] After the discovery of oil in the river, the Amazon Venture was ordered to stop offloading, but after an initial inspection found no evidence of leaking, it began offloading again at 12:40 a.m. on December 5.^[11] It would continue until its offloading was completed at 3:18 a.m. on December 6.^[11]

At daybreak on December 5, the Coast Guard began to perform surveys on the area of the river near the port to determine the size and scope of the spill.^[9] These surveys showed oil contamination along an 8 miles (13 km) section of the river, stretching upriver to the Houlihan Bridge and downriver to the port's East Coast Terminal.^[9] The same day that the surveys were being conducted, the Coast Guard set up booms around the terminal to prevent the oil from spreading. Over the following several days, booms were placed near the terminal, in the Savannah National Wildlife Refuge, and along the Wilmington River, which connected to the Savannah River downstream from the spill. However, due to strong tidal currents, the booms were mostly ineffective and contained only a small amount of the oil.^{[9][note 3]} On the evening of December 5, a diver discovered a crack on the hull of the Amazon Venture, though further sounding of the oil tanks did not show water had entered them.^[11] However, on the morning of December 6, chemical analysis revealed that the oil had come from the Amazon Venture, though it was still unknown what had caused the oil spill to occur.^[16] Later that day, the Coast Guard updated their estimates from 2,000 US gallons (7,600 L) to 11,000 US gallons (42,000 L),^[17] which qualified as a medium spill.^[9] Around the same time, aerial surveys conducted on a daily basis by the National Oceanic and Atmospheric Administration (NOAA) and the Coast Guard led them to believe that the spill was much larger than previously estimated.^[9] As a result, five members of the Coast Guard's Gulf Strike Team in Mobile, Alabama who were trained in managing oil spills were brought in to help with surveying.^[9] As a result of the surveys, on December 7, the estimate was updated from 11,000 US gallons to 50,000 US gallons (190,000 L), which still categorized it as a medium spill.^{[9][note 4]} That evening, the cause of the spill was determined: while offloading the oil, the ship was also pumping oil through its ballast piping system, which was then discharged from the ship's sea chest on its port side.^[17] This action was the result of three valves that had all malfunctioned at the same time,^[17] and later analyses of these valves revealed that the most likely cause for these failures was a section of 0.5-inch (1.3 cm)-diameter rope measuring between 10 and 15 feet (3.0 and 4.6 m) that had become stuck in the valves and prevented them from seating.^[18] This inspection also led investigators to believe that the grounding was not the cause of the spill.^[15] As a result of the discovery, the Coast Guard ordered that the three valves be removed and steel plates put in their place to physically prevent flow through that piping system.^[18] After this discovery was made, Calluna Maritime accepted responsibility for the spill and subsequent cleanup.^[17][19]

Cleanup efforts

Aerial view of the Savannah National Wildlife Refuge, 2013

On December 9, in an effort to slow the movement of the oil upriver towards the wildlife refuge, the U.S. Army Corps of Engineers temporarily opened tidal gates on the Back River, a channel that was bifurcated from the main channel of the Savannah River.^[9][20] These gates would remain open until December 16 and aided in the cleanup process, which was led by the Coast Guard and involved six private contractors, including two that had been hired directly by Calluna Maritime.^{[9][note 5]} Calluna retained the International Tanker Owners Pollution Federation of London to oversee its part of the cleanup efforts, and O'Brien's Oil Pollution Service, Inc. of Gretna, Louisiana was designated as the prime cleanup coordinator.^[19] Approximately 60 people were involved in the cleanup, which included the use of 15,000 feet (4,600 m) of containment booms, 6,000 feet (1,800 m) of absorbent booms, and nine vacuum trucks. The wildlife refuge was of significant importance to the cleanup efforts,^[21] as two contractors focused exclusively on the area, and 6,500 feet (2,000 m) of the total boom length was deployed in the refuge.^[9] This emphasis on the refuge was echoed by Savannah Mayor John Rousakis, who stated that the refuge might be the area most affected by the spill.^[22] Additional focus was placed on Abercorn Creek, due to its water intake.^[23] However, the containment efforts were hindered due to both strong tidal currents and the inability to spread the booms across the width of the river.^[24] The presence of oil in areas thought to be protected by the booms was confirmed in part by oil found in the meat of shellfish from these areas.^[24]

On December 11, the estimate for how much oil had spilled rose from 50,000 to 500,000 US gallons (1,900,000 L),^[8] which categorized the incident as a major spill.^[24] This followed gauge measurements taken on December 8 that had shown a discrepancy of 500,000 US gallons between the amount of oil that had left the ship and the amount of oil that had been received at the terminal.^[17] With the declaration of a major spill, a Regional Response Team was officially mobilized, although many of the constituent agencies that made up the team were already involved in handling the spill.^[17] Also on December 11, the Amazon Venture departed from the port after the ship's insurer gave assurances to the Coast Guard that they would pay for the cleanup and posted a $5.2 million bond in a United States district court to cover any civil damage claims.^[8] By December 13, approximately 82,280 US gallons (311,500 L) of oil had been removed, though on that same day, a representative for the Coast Guard stated that much of the oil would not be able to be recovered,^[3] with the remaining contaminant allowed to dissipate naturally.^[24] According to a representative for the Coast Guard, "It's not a situation where the whole river has been covered with oil. It's a situation where you have patches of oil and there'll probably be an oil sheen for a while to come. But with the activity on the river at the port and with dredging, the nature of the river front means you're going to have some oil sheen."^[3] In the case of marshlands that had been contaminated with oil, NOAA recommended on allowing the oil to naturally dissipate, as a manual cleanup could have caused additional damage to that environment.^[25]

On December 14, United Press International reported that sheen from the oil was present 10 miles (16 km) upriver and 15 miles (24 km) downriver, to the mouth,^[3] having been moved that far due to the flow of the river and through the tide.^[8] However, at the time there were no reports of fish kills or dead birds, though birds with oil-soaked wings had been spotted in the contaminated area.^[3] That same day, cleanup efforts shifted from removing oil from the river to removing contamination that had accumulated on the shoreline.^[3] Around this same time, Mayor Rousakis stated that the Georgia Ports Authority had been unprepared to respond to a situation like the spill.^[22] By December 17, the Associated Press reported that cleanup efforts had shifted towards the Wassaw Sound near the mouth of the Savannah River at the northern coast of Tybee Island, which was home to large populations of shellfish.^[8] Additionally, about 100,000 US gallons (380,000 L) of oil had been recovered by this time, and the Georgia Department of Natural Resources reported that little oil had reached the sound through the three tidal creeks that connected the sound to the river.^[8] That same day, it was reported that oil was visible 16 miles (26 km) both up and downriver, but that much of the thick oil globules had been recovered.^[8] Cleanup operations continued for the next several weeks, and by December 30, over 200,000 US gallons (760,000 L) of oil-water mixture had been recovered, as well as 160 cubic yards (120 m³) of oil-based debris, such as tarballs.^[24] By January 12, 1987, the surface of the Savannah River appeared to be free of any recoverable oil or oil-based debris.^[24]

On March 13, the Federal On Scene Coordinator, Coast Guard Captain John E. Shkor (the captain of the port for the United States Coast Guard sector that covered Savannah) officially declared the cleanup complete,^[17] finishing approximately two weeks ahead of schedule.^[19] The results of the cleanup included the removal of approximately 140,000 US gallons (530,000 L) of oil,^{[note 6]} 200 cubic yards (150 m³) of oil-based debris,^[17] and 200,000 US gallons (760,000 L) of oil-water mixture.^[27] Of the oil that had not been collected, it was estimated that 50,000 to 100,000 US gallons (190,000 to 380,000 L) naturally evaporated, 150,000 US gallons (570,000 L) was on vegetation near the shore, and 100,000 to 150,000 US gallons (380,000 to 570,000 L) were unaccounted for.^[26] An estimated 50,000 US gallons of oil entered the wildlife refuge, of which approximately 200 US gallons (760 L) were recovered.^[28]