Incident
Name: M/V Megaborg
Subject:
USCG Case History
Incident Date:
6/8/1990
Incident Location:
Gulf of Mexico, 57 miles southeast of Galveston, Texas
Author:
USCG Case History
Latitude:
28 33 N
Longitude:
094 08 W
USCG District:
8
Product:
Angolan Palanca crude oil
Type: 2
Volume:
100000
Source:Tank Vessel
RAR: Shrimp, fish, terns, gulls, beaches.
Dispersants:
Yes
Bioremediation:
Yes
In-Situ Burning:
Yes
Special Interest
Topic(s): Logistical or operational problems, media interest, volunteer response and organization, unusual or experimental cleanup techniques.
Shoreline Type(s)
Impacted: Marshes, fine sand beaches, sand/gravel beaches.
Summary:
On June 8, 1990 at approximately 2330, while the Italian tank vessel Fraqmura was lightering the Norwegian tank vessel Mega Borg, an explosion occurred in the pump room of the Mega Borg. The two ships were in the Gulf of Mexico, 57 miles southeast of Galveston Texas in international waters, but within the U.S. exclusive economic zone. As a result of the explosion, a fire started in the pump room and spread to the engine room. An estimated 100,000 barrels of Angolan Palanca crude was burned or released into the water from the Mega Borg during the next seven days.
Approximately 238 barrels of oil was discharged when the Fraqmura intentionally broke away from the Mega Borg. Explosions on the Mega Borg, caused the stern of the ship began to settle lower in the water and list to the port side. A continuous discharge of burning oil flowed over the aft port quarter of the ship.
Less than an hour after the explosions on the Mega Borg, the U.S. Coast Guard (USCG) in Galveston dispatched two USCG cutters to the scene.
Weather was calm throughout the incident. Winds were generally around 10 to 15 knots and air temperature were between 80 and 90 degrees Fahrenheit.
Behavior:
Palancan crude oil has an API gravity of 38.6, and a pour point of 50 degrees F. Responders believed that abnormally high freshwater runoff from the Sabine River and other rivers in the area would have a tendency to keep the oil offshore. Initially the oil moved northwest toward Corpus Christi. By June 18, the leading edge of the oil slick approached the environmentally sensitive area of Sabine Pass, but was kept offshore by winds and currents. After a few days it began to move to the north and east and first came ashore on the Southwestern Louisiana coast on June 28 in the form of small tarballs scattered over a distance of 18 miles. Shorelines that suffered oiling included Holly Beach and Dung Beach in Texas, Peveto Beach in Louisiana, and the Mermentau River in Louisiana. The tarballs on the shoreline amounted to very little oil.
The floating oil spread out into a light sheen. Much of the spilled crude oil was lost to evaporation (as much as 50%) or burned. Overflight observations generally noted light sheen on the water mixed with tarballs. A small amount of reddish colored mousse was also observed.
Countermeasures/Mitigation: The initial focus of the response effort was to extinguish the fire on the Mega Borg and offload the remaining cargo. Firefighting vessels began to arrive on the morning of June 9. Over 50 commercial vessels and more than a dozen skimmers were used during the response. In addition, a USCG Air-Eye aircraft, equipped with side looking airborne radar (SLAR), was used to determine the distribution of the spilled oil.\\Two more explosions occurred on board the Mega Borg on June 9. The fire was fueled by cargo from the No. 4 tank which was leaking into the engine/pump room. Initially, the vessel was so hot that it was feared that the application of foam to extinguish the fire might be ineffective or increase the possibility of explosion. Firefighters cooled the hull of the ship and attempted to prevent the fire from spreading to the other cargo tanks.\\Six vessels were used to fight the fire. Four of the vessels hosed the Mega Borg with seawater in attempts to contain the fire and cool the vessel, and the other two vessels, which were equipped for foam application, kept the burning stern of the Mega Borg downwind.\\Pump valves on the Mega Borg were secured (hydraulic block valves were operated manually) on 10 June in an attempt to stop the flow of oil. The oil continued to flow from the tanker, and later that day there were a series of new explosions on board. The explosions intensified the fire and caused the stern of the Mega Borg to become partially submerged, increasing the risk that the tanker would sink and release the remainder of its cargo.\\By June 13, firefighting efforts had contained the blaze sufficiently to attempt foam application. The fire was out for almost an hour and a half while the foam was being applied, but then re-ignited. Firefighters resumed hosing the vessel with seawater until June 15, when a second foam application successfully extinguished the fire.\\With the fire out and the vessel stabilized, responders filled the cargo tanks with inert gas to reduce the fire hazard. The remaining 809,500 barrels of oil were lightered off the Mega Borg, using two small tankers. Lightering was completed on July 27.\\In preparation for the possible "worst case" oil release, involving over 833,000 barrels of cargo remaining on the Mega Borg, representatives from the USCG Marine Safety Office (MSO) Galveston, and state and Federal resource agencies met to draft a coastal protection priority plan. \\Most of the sensitive resources in the area are located inside the inlets, and cleanup of the oil in the estuaries would be very difficult. For these reasons, the inlet areas were identified as the highest priority for protection. The protection plan did not focus on strategies for protection of the coastal beaches. The coastal beaches are generally fine grain beaches, allowing only minimal oil penetration into the sediments, and therefore making cleanup easier. In addition, deploying protection equipment (such as deflection boom) on coastal beaches would have been largely ineffective due to the high wave activity and tidal action of the area.\\In order to implement the protection plan quickly, twelve U.S. Navy Supervisor of Salvage (NAVSUPSALV) skimmers and 6,000 feet of 36-inch boom were staged in Galveston. As the oil continued north, it threatened to impact the Texas Point National Wildlife Preserve at the mouth of the Sabine River. The main inlets in the area were boomed off and three of the Navy skimmers were sent to the Sabine area. The oil continued in an easterly direction, and did not impact the Preserve. Other sensitive areas where boom was deployed included Rollover Pass on the Bolivar Peninsula, High Island and Sea Rim State Park in Texas.\\To reduce the amount of oiled waste onshore, debris was removed from sensitive areas prior to possible oil impact. NOAA recommended that organic debris not be removed from refuge shorelines where erosion was present, so that the shorelines would remain stable. Volunteers were used to remove debris from beaches west of Sea Rim Park through the Adopt A Beach Program supervised by the Texas Land Office.\\Another contingency plan was made in the event of imminent sinking of the Mega Borg. The vessel would be towed inshore and run aground. Two tugs were standing by in the event of such a possibility. It was speculated that if it sank at its offshore location, the vessel might implode and release the remainder of its cargo.\\On June 9, steps were taken to obtain dispersant approval in the event of a major release. Later that day, dispersant use within 5 nautical miles of the Mega Borg was approved, but dispersants were not expected to be used unless large amounts of oil were released. The Regional Response Team (RRT) requested that the dispersant trajectory be monitored and reported to the RRT if dispersants were used. Two commercial C-130 aircraft equipped for dispersant application were contracted from Florida and Arizona.\\On June 10, four thousand gallons of Exxon Corexit 9527 were applied to part of the oil slick. Observers noted a definite change in the texture of the oil slick after dispersant application. Five sorties sprayed a total of 11,300 gallons of dispersant. The winds were very calm during and after the application, which may not have provided enough mixing energy for maximum dispersion.\\Bioremediation tests were conducted on June 15 and 18. These were the first tests of a bioremediation agent on an oil spill in open waters in the United States. The bioremediation agent used was AE BioSea Process, developed by Alpha Environmental, Inc. AE BioSea Process contains oil-metabolizing bacteria and nutrients. The results of the tests were inconclusive.\\In the first few days of the response, skimmers focused on oil localized around the Mega Borg. As the oil spread and approached shorelines in Texas, and the flow of oil from the Mega Borg decreased and more of the skimmers were focused on the leading edge of the slick. During the response, extensive air support was required to direct skimming operations.\\By June 16 the Mega Borg stopped leaking oil. Diver surveys of the vessel revealed that the hull of the Mega Borg was intact and structurally sound. \\Skimming operations were scaled back by June 20, due to the lack of recoverable oil. On June 24, tarballs washed up on the shoreline of Louisiana. Most of the tarballs localized on a five mile stretch of coast near Peveto Beach. Beach crews manually picked up the majority of the tarballs. Some areas with a minimal amount of tarballs were not cleaned. The Louisiana Department of Environmental Quality advised that intervention could cause more environmental damage by erosion than leaving the tarballs on the beach. A total of 13,023 barrels of oil and mousse were recovered in response operations. There were no reports of oiled wildlife from the incident.
Other Special
Interest(s): Media attention to the Mega Borg spill was intense. The USCG set up a media office with 11 USCG photojournalists and conducted two press briefings daily on vessel status and cleanup.\\There were logistical problems associated with communications and response to a spill nearly 60 miles offshore. There were also communications delays with the owners of the vessel. Communications with offshore personnel were facilitated with cellular phones (Petrocom cellular service), high frequency radios and VHF-FM. USCG Air Station Houston became the logistical base for the oil spill; personnel and equipment were transported to the spill site and the Air Station became the staging area for much of the response equipment. USCG Cutter Steadfast, equipped with a flight deck, was very useful for shuttling equipment and personnel to the site.\\Cleanup volunteers were coordinated by the Texas General Land Office and received an abbreviated Occupational Safety and Health Administration (OSHA) training course.
References:
Hoff, R. 1991. A Summary of Bioremediation Applications Observed at Marine Oil Spills. Report HMRB 91-2. Jan. 1991.
Leveille, LCDR T.P. 1991. The Mega Borg Fire and Oil Spill: A Case Study. Oil Spill Conference Proceedings 1991. pp. 273-278.
MMS Worldwide Tanker Spill Database.
NOAA Hotline Reports.
Oil Properties stack, CAMEO SSC (API 1986).
OSIR Oil Spills, International Summary & Review, 1989-1990.
Tanker Advisory Center, Inc. 1991 Guide for the Selection of Tankers. T.A.C. Inc. 1991.
U.S. Coast Guard On-Scene Coordinator's Report.
World Information Systems. Tanker Losses in U.S. Waters: 1978-1990. World Information Systems. 1991.
Last Edit:
9/18/92
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