History Detail
Incident Name: Urquiola

Subject: USCG Case History

Incident Date: 5/12/1976

Incident Location: La Coruña, Spain

Author: USCG Case History

Latitude: 43 22 N

Longitude: 008 23 W

Product: Light Arabian crude oil, Bunker fuel

Type: 3, 4

Volume: 733000

Source:Tank Vessel

RAR: Recreational beaches, marinas, waterfowl, gulls, wading birds, commercial fisheries, power plant water intakes, sand/gravel beaches, exposed rocky shores, marshes, tidal mudflats, clams, oysters, mussels.

Dispersants: Yes

Bioremediation: No

In-Situ Burning: Yes

Special Interest Topic(s): Adverse weather conditions, closure of commercial fishing areas, effects to tourism, habitat impact due to oil, habitat impact due to cleanup operations, logistical or operational problems, research conducted.

Shoreline Type(s) Impacted: Sand/gravel beaches, exposed rocky shores, marshes, tidal mudflats.

Summary: On May 12, 1976, the Tank Vessel Urquiola struck a submerged object while approaching the Coruña Oil Terminal at La Coruña, Spain. The vessel began to leak cargo from the damaged bow section. Due to the threat of explosion and fire, the Port Commandant ordered the Urquiola out of the harbor, away from the refinery and town of 200,000 inhabitants. While being assisted out of the harbor by two tugs, the leaking vessel grounded again, further rupturing the bow tanks. All of the crew, except for the captain and pilot, abandoned the ship when it began to list. Two hours later the vessel exploded, killing the captain. Approximately 513,000 barrels of oil burned in the subsequent 16-hour fire. Burning oil spread out from the vessel and was eventually extinguished by the cooling effect of the seawater. Dense clouds of smoke were blown over the town of La Coruña. A safety zone one mile in radius was established around the vessel after air monitors detected high levels of volatile gases. Despite these precautions, a second explosion and fire rocked the vessel on the morning of May 14. Between May 12 and May 21, oil was estimated to be leaking at a rate of 2,200 barrels per day. An estimated 180,000-220,000 barrels of the cargo polluted the Spanish coast. On May 21, a smaller tanker and tug began lightering the Urquiola. About 50,000 barrels of crude oil had been removed from the vessel by May 25, when lightering operations were halted by rough seas. Ten to fifteen foot seas detached a large section of the bow. On June 8, the stern section, containing an estimated 22,000 barrels of bunker fuel, was towed to a more protected area five miles to the west. The stern was partially lightered before developing a crack in one of the tanks that resulted in further, limited leakage. Following the fire, the Spanish Navy and a fleet of commercial vessels applied over 2,000 tons of chemical dispersants to the Urquiola and surrounding waters in spite of resistance mounted by Spanish oceanographers. Cleanup of the oiled shoreline was primarily accomplished by manual labor. Skimmers and booms were used for water recovery with mixed results.

Behavior: Arabian Light crude oil is a medium weight product with an API gravity of 33.4 and a pour point of -30 degrees F. Bunker fuel oil is a heavy product with an API gravity that ranges from 7 to 14. Prevailing northwest winds blew the oil onshore. The smoke from the fires rained oil droplets on the city of La Coruna. Oil escaping from the vessel was spread toward shore by a weak northerly coastal current and onshore winds. The heaviest oiling occurred within the bays closest to the grounding site. The three bays, or rias, that experienced the most oiling were Rias de La Coruna, Rias Area, and Rias Betanzos. Some oil coverage in excess of 65 per cent was reported along the shoreline areas of these bays. Beaches at Raso and Perbes were severely oiled. Even though oil quickly entered these bays, it took nearly a week before the marshes and tidal flats at the heads of the bays were oiled. These marshes and tide flats may have been protected if boom had been deployed during the previous week. Along the outer coast, moderate oiling was observed as far north as Playa de Doninos, approximately 10 miles from the grounding site. By May 19, oil had come ashore further to the north, near Frouxeria and Pantin. Large slicks of oil were spotted offshore of Ria de Cedeira, but no shoreline oiling occurred in this area. Oiling was observed to the southwest near Barranan on May 21. Strong northeast winds on May 25 and 26 resulted in further westward movement of the slicks. On May 31, westward contamination stretched to Playa de Beo, 28 miles from the grounding. Beach areas between La Coruña and Playa de Beo were lightly oiled, mainly in the form of oil swashlines. By June 1, nearly 215 kilometers of the northwestern Spanish coast was oiled. Moderate (25-65 percent coverage) and heavy (greater than 65 percent coverage) oiling occured on 37 miles of shoreline. Much of the floating oil became emulsified and mixed with seaweed and debris, making recovery difficult. Some emulsions were up to a half-meter thick. Many of the recreational beaches were heavily oiled. Oil penetrated several feet deep in the intertidal zone of some exposed beaches. The chemical dispersant application was believed to have dissipated several thousand barrels of the light crude oil into the 18°C water of the inner bays.

Countermeasures/Mitigation: The largest mobilization of resources occurred during the dispersant application. As many as eleven vessels were involved in applying the hydrocarbon based chemical products. Many different products were reportedly used during the operations, including BP 1100X, BP 1100WD, Finasol, OSR2, Shell Dispersant LT, Solufax 85, Seaklin 1100NT, Kraken MC563, CEPSA 3 Marine Dispersant, and Marlu. However, some observers believed that all the dispersant applied was of Spanish origin. Several hundred empty dispersant drums labeled with old product names were seen being filled from tank trucks.\\Some attempts were made to contain floating oil with boom. Due to the lack of an oil spill response or contingency plan, booming equipment was not available locally. A 36-inch French-made boom was borrowed from a nearby refinery, but sank after three days of use. American Marine Optimax and 18-inch Uniroyal boom were flown in from Great Britain. These two booms managed to contain oil but broke loose because of wind and sea conditions.\\Komara skimmers were used to recover floating oil at various locations. One skimmer was staged near a power plant intake to prevent the oiling of the water intake. Very little oil appeared near the plant, and the skimmer was put on standby. The Komara skimmer was tested at Conabal Bay and Mera Bay. At these locations the emulsified oil was up to half a meter thick. Recovery rates in these conditions were about 15 barrels per hour. The Petroliba oil refinery provided a Vikoma skimmer that had recently been delivered. The Vikoma skimmer immediately clogged with debris and was damaged. After being repaired with parts shipped from Great Britain, the skimmer failed to pick up the thick emulsions of oil that were collected in booms. A large British Petroleum Seaskimmer was also quickly clogged by oiled debris and thick weathered oil. The use of both the Vikoma and Seaskimmer equipment was discontinued.\\Skimming equipment was also flown in to aid the cleanup effort. Oil Mop (UK) Ltd. negotiated a 30 day contract to conduct oil recovery. Oil Mop personnel claimed they would recover 733-1100 barrels per day, but were only able to recover an average of about 220 barrels per day. The Oil Mop scavenger unit did, however, compare favorably to the recovery rates of the other skimmers and was also able to follow and recover oil in areas otherwise inaccessible from shore.\\Cleanup of the oiled beaches was a slow and methodical process. Many of the affected areas were unsuitable for the use of mechanical cleanup equipment. The decision was made by local authorities to spend available money to employ the local people rather than purchase complex equipment. Cleanup operations were very slow where oiling was extremely heavy. Much of the cleanup was conducted simply by using buckets and shovels. A 12-foot tidal range contributed to the difficult task of removing heavy concentrations of oil. In some areas, cleanup techniques were improperly applied. The application of sawdust as an absorbent proved ineffective in areas with heavy oil accumulation. A front-end loader and grader were later used unsuccessfully to aid the cleanup of beaches. Repeated working of the beach with heavy equipment forced oil deeper into the sediments. Removal of large quantities of sand threatened to destabilize the beaches. This threat was augmented by additional cleaning required by reoiling\\The most successful cleanup operation involved the combination of machinery and manual removal. Trenches were dug above the high tide line with mechanical equipment. Laborers swept or hosed floating oil into the trenches where it was recovered by vacuum trucks.\\Beaches were initially hosed with chemical dispersants. This was soon abandoned due to a lack of pumps. Oil penetration into the sediments at La Coruña may have resulted from this initial washing of the beach with dispersants.

Other Special Interest(s): The shellfish stocks of the La Coruña area are among the most important in Spain. The spill's effect on the local shellfish fisheries was noticed almost immediately. By May 17, nearly 20 percent of the Cockle (Cerastoderma edule) population in the Rio de Burgo area was dead. Many of the survivors were moribund and thought likely to die. Mortality in some areas was as high as 70 percent. There was concern about the reproduction of these stocks, and recovery rates were expected to be slow. Slow growth rates of clams, oysters, and mussels suggested that recovery for these organisms would also be a very slow process.\\Observed effects to bird populations were minimal. Except for gulls, very few seabirds or shorebirds were seen in the area. A few oiled wading birds were spotted, but the only observed bird mortality was a duck.\\The inshore fisheries of the area, which include sardines and hake, were shut down. The fishermen chose not to fish due to fears of oiled nets, tainted fish, and depleted stocks. However, the offshore fisheries remained open during the duration of the spill, and unusually large catches of certain species were made the following year.

References: •1991 World Almanac •8/9/91 & 8/28/91 Letters from Daniel Owen at ITOPF •Genwest Systems, Inc. communications with ITOPF representatives. •Gundlach, E.R. and Hayes, M.O. 1977. The Urquiola Oil Spill, La Coruña, Spain: Case History and Discussion of Methods of Control and Clean-up. Marine Pollution Bulletin. v.8, n.6. pp. 132-136. •Gundlach, et al. 1978. Some Guidelines for Oil-Spill Control in Coastal Environments, Based on Field Studies of Four Oil Spills. Chemical Dispersants for the Control of Oil Spills, ASTM STP 659. L.T. McCarthy, Jr., G.P. Lindblom, and H.F. Walter, Eds. American Society for Testing and Materials. pp. 98-118. •Hooke, N. Modern Shipping Disasters 1963-1987. Lloyds of London Press. 1987. •MMS Worldwide Tanker Spill Database •Robertson, et al. 1976. The Urquiola Spill, La Coruña, Spain. Environment Canada. Spill Technology Newsletter. v.1. pp. 54-57. •Tanker Advisory Center, Inc. 1991 Guide for the Selection of Tankers. T.A.C. Inc. 1991.

Last Edit: 9/21/92<