Oil Spills: A Case Study of the Amoco Cadiz Oil Spill

On March 16, 1978, the Amoco Cadiz ran aground on Portsall Rocks, three miles off the coast of Brittany due to failure of the steering mechanism.

The vessel had been en route from the Arabian Gulf to Le Havre, France when it encountered stormy weather which contributed to the grounding. The entire cargo of 1,619,048 barrels, spilled into the sea. A slick 18 miles wide and 80 miles long polluted approximately 200 miles of Brittany coastline. Beaches of 76 different Breton communities were oiled.

The isolated location of the grounding and rough seas restricted cleanup efforts for the two weeks following the incident. Severe weather resulted in the complete break up of the ship before any oil could be pumped out of the wreck. As mandated in the "Polmar Plan", the French Navy was responsible for all offshore operations while the Civil Safety Service was responsible for shore cleanup activities. Although the total quantity of collected oil and water reached 100,000 tons, less than 20,000 tons of oil were recovered from this liquid after treatment in refining plants.

Behavior of Oil

Both Arabian Light and Iranian Light crude oil are medium weight oils with an API gravity of 33.8. Bunker C is a heavy product with an API of between 7 and 14. A 12-mile long slick and heavy pools of oil were smeared onto 45 miles of the French shoreline by northwesterly winds. Prevailing westerly winds during the following month spread the oil approximately 100 miles east along the coast. One week after the accident, oil had reached Cotes de Nord.

Oil penetrated the sand on several beaches to a depth of 20 inches. Sub-surface oil separated into two or three layers due to the extensive sand transfer that occurred on the beaches during rough weather. Piers and slips in the small harbors from Porspoder to Brehat Island were covered with oil. Other impacted areas included the pink granite rock beaches of Tregastel and Perros-Guirrec, as well as the tourist beaches at Plougasnou. The total extent of oiling one month after the spill included approximately 200 miles of coastline.

Oil persisted for only a few weeks along the exposed rocky shores that experienced moderate to high wave action. In the areas sheltered from wave action, however, the oil persisted in the form of an asphalt crust for several years.

Countermeasures and Mitigation

A 2.5 mile long segment of boom protected the Bay of Morlaix. Although it required constant monitoring, the boom functioned properly because this sheltered area was protected from severe weather and from receiving excessive quantities of oil. Boom was largely ineffective in other areas due to strong currents and enormous quantities of oil.

Skimmers were used in harbors and other protected areas. However, skimmer efficiency was limited due to the blocking of pumps and hoses by seaweed. Vacuum trucks were used to remove oil from pier and boat slip areas where the seaweed was thick.

"Honey wagons", vacuum tanks designed to handle liquid manure, were effective in pumping out the emulsified oil along the coast. These wagons were able to pump oil, water, and seaweed. After the water and oil were separated as much as possible, the tanks were emptied through filter-buckets into interim storage tanks.

When interim storage tanks were not available, the oil mixture was stored in large holes that were dug in the ground and lined with plastic sheets.

Stranded oily seaweed was manually removed from the beaches using rakes and front-end loaders. Natural cleaning of the sand by wave action occurred on oil penetrated beaches after ploughing and harrowing of the sediments. Both artificial fertilizers and bacterial cultures were poured on the oily sand before harrowing.

Several brands of diluted and concentrated dispersants, including BP 1100 X, Finasol OSR, BP 1100 WD, and Finasol OSR -5, were used by the French Navy. Good dispersion of oil was difficult since the emulsified oil was several centimeters thick in some places.

Approximately 650 metric tons of oleophilic chalk, Nautex, was applied in an effort to sink the oil and prevent it from entering the "goulet de Brest." After one month at sea, the oil was so viscous that the chalk could not penetrate it.

A rubber powder made from old tires was applied to promote oil absorption. The powder was spread with water hoses aboard French Navy ships or applied manually by workers from small fishing boats. Wave action proved to be insufficient in mixing the powder with the oil. The powder had little effect on the slick because it remained on top of the oil.

High-pressure hot water (fresh water at 2,000 psi, heated to 80º - 140ºC) was very effective in cleaning oil from rocky shoreline areas during the third and fourth months of cleanup. A small amount of dispersant was applied to prevent the oiling of the cleaned rocks during the next high tide. Several of the impacted rivers contained oyster beds and marshes that required manual cleaning. Soft mud river banks were cleaned by using a low pressure water wash to push the oil down the river. To make collection more efficient, a sorbent material was mixed with water and poured in front of the washing nozzles. The oil was later collected by a locally developed device called an "Egmolap." This device was able to collect any material floating in sheltered areas.

Much of the collected oil was stored at Brest and Tregastel and treated with quick-lime for encapsulation and stabilization.

Other Special Interest Issues

The nature of the oil and rough seas contributed to the rapid formation of a "chocolate mousse" emulsification of oil and water. This viscous emulsification greatly complicated the cleanup efforts. French authorities decided not to use dispersants in sensitive areas or the coastal fringe where water depth was less than 50 meters. Had dispersant been applied from the air in the vicinity of the spill source, the formation of mousse may have been prevented.

At the time, the Amoco Cadiz incident resulted in the largest loss of marine life ever recorded from an oil spill. Mortalities of most animals occurred over the two month period following the spill. Two weeks following the accident, millions of dead mollusks, sea urchins, and other bottom dwelling organisms washed ashore. Diving birds constituted the majority of the nearly 20,000 dead birds that were recovered. The oyster mortality from the spill was estimated at 9,000 tons. Fishes with skin ulcerations and tumors were caught by fishermen in the area. Some of the fish caught in the area reportedly had a strong taste of petroleum. Although echinoderm and small crustacean populations almost completely disappeared, the populations of many species recovered within a year. Cleanup activities on rocky shores, such as pressure-washing, also caused habitat impacts.

The Amoco Cadiz spill was one of the most studied oil spills in history. Many studies remain in progress. This was the largest recorded spill in history and was the first spill in which estuarine tidal rivers were oiled. No follow-up mitigation existed to

deal with asphalt formation and problems that resulted after the initial aggressive cleanup. Addition erosion of beaches occurred in several places where no attempt was made to restore the gravel that was removed to lower the beach face. Many of the affected marshes, mudflats, and sandy beaches, were low-energy areas. Evidence of oiled beach sediments can still be seen in some of these sheltered areas. Layers of sub-surface oil still remain buried in many of the impacted beaches.

Fact sheet courtesy of NOAA/HMRAD OIL SPILL CASE HISTORY.

Amoco Cadiz

Tanker (1f). L/B/D: 1,095.5 × 167.6 × 85.9 (334m × 51.1m × 26.2m). Tons: 109,700 grt; 233,690 dwt. Hull: steel. Comp.: 44. Mach.: diesel, 30,400 hp, 1 screw; 15 kts. Built: Astilleros Españoles, SA, Cadiz; 1974.

The very large crude carrier (VLCC) Amoco Cadiz was built to carry oil between the Persian Gulf and Europe. In early February 1978, she loaded 121,157 tons of oil at Ras Tanara, Saudi Arabia, and then topped off with 98,640 tons at Kharg Island, Iran. (A ton of crude is 7.3 barrels, or 306.6 gallons.) She left the Persian Gulf on February 7, bound for Rotterdam, via Lyme Bay, England, a customary stop to lighten tankers before the passage up the North Sea. Rounding the Cape of Good Hope on the 28th, she made a fueling stop at Las Palmas on March 11. Three days later Amoco Cadiz began to encounter heavy weather, which continued through March 16, by which point she was entering the English Channel, due into Lyme Bay later that day. At about 0916, the tanker was about eight miles north of Ushant when her steering gear failed. Although Captain Pasquale Bandari hoisted the international signal for "Not Under Command" almost immediately, he did not request assistance until 1120, when his engineer determined that the damage was irreparable. The German salvage tug Pacific, under command of Captain Weinert, arrived on the scene at 1220. The first tow was secured at 1425 but parted at 1719. As Amoco Cadiz drifted toward shore, the port anchor was let go at about 2004, but it did not hold. A second tow was secured at 2023, but the sheer mass of Amoco Cadiz in the teeth of Force 10 weather conditions made it impossible for Pacific to do more than slow the ship's coastward drift.

At 2104, Amoco Cadiz touched bottom for the first time, and her hull and storage tanks were ripped open. Half an hour later she grounded on Men Goulven Rocks in 48°36N, 4°46W. Her crew were rescued by helicopter. At 1000 on March 17 the vessel broke in two, spilling 223,000 tons of crude oil. The oil slick spread across 125 miles of the coast of Brittany, destroying fisheries, oyster and seaweed beds, and bathing beaches despite the efforts of 10,000 French soldiers deployed to clean the beaches. The storm continued to pound the ship, and on March 28 she broke into three sections. The French Navy subsequently destroyed the remains of the ship with depth charges. It would be another ten years before the resulting lawsuits were wound up, and in 1988 a U.S. federal judge ordered Amoco Oil Corporation to pay $85.2 million in fines—$45 million for the costs of the spill and $39 million in interest.

In short

Name : Amoco Cadiz Date : 16 February 1978Place : France

Ship type: oil tankerShip-building date: 1974Flag: LiberianAccident area: Portsall, BrittanyCargo: crude oilTransported quantity: 227,000 tonnesKind of pollutant: crude oil

Spilled quantity: 227,000 tonnes

Last update: May 2004Photos Source Cedre

On 16 March 1978, the oil tanker Amoco Cadiz, transporting 227,000 tonnes of crude oil, ran aground on Portsall Rocks, Brittany coast after a failure of her steering mechanism, long negotiations with a German tug boat and two unsuccessful towing attempts. The whole cargo spilled out as the breakers spilt the vessel in two, progressively polluting 360 km of shoreline from Brest to Saint Brieuc.

 

Amoco Cadiz shipwreck

 

This was the largest oil spill by tanker grounding ever registered in the world. It led the French Government to revise its oil fighting plan (the POLMAR plan), to acquire equipment stocks (POLMAR stocks), to impose traffic lanes in the Channel and to create Cedre.

The French Government along with damaged villages prosecuted the Amoco company in the United States. After 14 years of difficult proceedings, they eventually obtained 1,257 million Francs (190 million Euros), half the claimed amount.

This dossier provides a general overview of this terrible spill: circumstances of accident, huge dimension of pollution, shock, response, consequences (heading:

Archives).

 

The accident

On 16 March 1978 in the morning, the oil tanker Amoco Cadiz en route from the Persian Gulf to Rotterdam with 227,000 tonnes of crude oil drifted towards Breton coasts in heavy storm after a failure of her steering system. Negotiations with a German assisting tug boat were difficult and the first towrope, thrown at 1:30 a.m. broke three hours later. Despite all the efforts made by the crews of both ships, the Amoco Cadiz ran aground at 10:00 p.m. off the small port of Portsall. Many tanks broke off and the first oil slicks quickly reached the coast. The biggest oil slick due to a stranded tanker had just begun.

Amoco Cadiz stranding

 

Amoco Cadiz shipwreck

Effect of wind orientation on the oil slick movement

Within two weeks, the whole cargo spilled out into the sea and, dragged by the winds and currents, polluted more than 300 km of coast among the most beautiful

and natural of Europe. Seething with rage, inhabitants of damaged villages started a desperate fight against this disaster. France discovered on television the apocalyptic images of a large oil slick.

Not an isolated accident

On 18 March 1967 the Torrey Canyon grounding off Lands End (English Cornwall) already constituted a large-scale warning. Breton shoreline had been touched by oil slicks drifting in the Channel; first in April between Morlaix and Plouescat (in the Northwest) and then mid-May in Douarnenez and Audierne bays (in the south west).

Oil slicks around Brittany

 

And the Amoco Cadiz disaster did not put an end to this:

- On 28 April 1979, the bulk carrier Gino loaded with a BOSCAN heavy fuel cargo (higher density than water) sank off Ushant island after a collision.- On 7 March 1980, the oil tanker Tanio spilt in two part during a storm off Batz island and her stern part sank with 6,000 tonnes of heavy fuel.- On 31 January 1988, a tank of the Italian oil tanker Amazzone lost 2,100 tonnes of crude oil in a storm off Penmarc’h.

First day's response

 

One had soon to realise that the 14 km-floating booms available in the POLMAR stocks (emergency equipment stocks for marine oil spill response) were far from being large enough to content the hundred thousand tonnes of “chocolate mousse” (emulsion made of oil and water) drifting towards the coasts.

    Last update: May 2004

Photos source Cedre

One had soon to realise that the 14 km-floating booms available in the POLMAR stocks (emergency equipment stocks for marine oil spill response) were far from being large enough to content the hundred thousand tonnes of “chocolate mousse”

(emulsion made of oil and water) drifting towards the coasts. Shovels, buckets, floating pumps, slurry spreaders, dump trucks, rail tanks and everything else that can help collecting and transporting oil towards temporary stocking pits were used.

Farmer's slurry spreaders used to stock oil pumped on the shore

 

Oil pumping

Within a few days, 7,000 volunteers and the same number of soldiers were gathered and started cleaning the rocks, beaches and most damaged areas. In a few weeks they collected about 15,000 tonnes of oil and three times as much seaweed, sand and other polluted items.

Oiled birds clinics were settled in Finistère and Côtes d’Armor, but only one treated bird out of twenty can be saved.

Tidal marine life suffered a lot all along the 300 km of damaged coasts and died either stuck under oil or because of high pressure flushing and of cleaners’ shovels. A few dead grey seals were even found on the Côtes d’Armor beaches.

Organising the response   After the panic of the first days, the response action became more

organised.   

Last update: May 2004

Photos source Cedre

After the panic of the first days, the response action became more organised. Offshore the use of sinking agents and dispersants as well as wind reversals kept oil slicks from spreading beyond Brehat island.

Manual collecting, source IFP

Beaches’ clean-up was composed of two stages: first the pumping of the still liquid oil and then the clearing of hydrocarbons polluted waste. All things considered, more than 100,000 tonnes of “chocolate mousse” and other waste were collected and a large part of solid waste was neutralised with quicklime.

Waste storage, source IFP

As far as professional activities were concerned, the first affected people were the 1,300 fishermen of the maritime districts of Brest, Morlaix and Paimpol; a fishing ban was indeed ordered from the day of the spill to the end of April. The oyster-farming sector was also touched as oysters from polluted areas were no longer edible and had to be destroyed. The only thing fishermen on foot could do was coming on high tide days and observing the damages. Tourism industry professionals were concerned for their summer season. The public services for maritime affairs set up financial aids for the fishermen and shellfish breeders concerned.

Polluted wave Oil accumulation on the beach

Oil accumulation, source NOAA

Amoco Cadiz

WikipediaAmoco Cadiz

Summary

The Amoco Cadiz was a supertanker, owned by Amoco in the United States of America, that split in two, after running aground on Portsall Rocks, three miles off the coast of Brittany in March 16, 1978, resulting in the 5th largest oil spill in history.

En route from the Arabian Gulf to Le Havre, France when it encountered stormy weather with gale conditions and high seas and a seemingly minor failure in the ship's steering gear started a slow drift to the French coastline.

The entire cargo of 1,619,048 barrels, spilled into the sea. A slick 18 miles wide and 80 miles long covered approximately 200 miles or 120 km of Brittany coastline. Beaches of 76 different Breton communities were oiled.

The isolated location of the grounding and rough seas restricted cleanup efforts for the two weeks following the incident. Severe weather resulted in the complete break up of the ship before any oil could be pumped out of the wreck.

As mandated in the "Polmar Plan", the French Navy was responsible for all offshore operations while the Civil Safety Service was responsible for shore cleanup activities. Although the total quantity of collected oil and water reached 100,000 tons, less than 20,000 tons of oil were recovered from this liquid after treatment in refining plants.

After long negotiations on financial terms betwenn the ship's captain and the master of a West German tug boat and two unsuccessful towing attempts, the towline finally broke during the argument and the ship drifted on the rocks.

Type of Oil

Both Arabian Light and Iranian Light crude oil are medium weight oils with an API gravity of 33.8. Bunker C is a heavy product with an API of between 7 and 14. A 12-mile long slick and heavy pools of oil were smeared onto 45 miles of the French shoreline by northwesterly winds.

Prevailing westerly winds during the following month spread the oil approximately 100 miles east along the coast. One week after the accident, oil had reached Cotes de Nord.

Oil penetrated the sand on several beaches to a depth of 20 inches. Sub-surface oil separated into two or three layers due to the extensive sand transfer that occurred on the beaches during rough weather. Piers and slips in the small harbors from Porspoder to Brehat Island were covered with oil.

Other impacted areas included the pink granite rock beaches of Tregastel and Perros-Guirrec, as well as the tourist beaches at Plougasnou. The total extent of oiling one month after the spill included approximately 200 miles of coastline.

Oil persisted for only a few weeks along the exposed rocky shores that experienced moderate to high wave action. In the areas sheltered from wave action, however, the oil persisted in the form of an asphalt crust for several years.

Environmental Impact

The nature of the oil and rough seas contributed to the rapid formation of a "chocolate mousse" emulsification of oil and water. This viscous emulsification greatly complicated the cleanup efforts. French authorities decided not to use dispersants in sensitive areas or the coastal fringe where water depth was less than 50 meters. Had dispersant been applied from the air in the vicinity of the spill source, the formation of mousse may have been prevented.

At the time, the Amoco Cadiz incident resulted in the largest loss of marine life ever recorded from an oil spill. Mortalities of most animals occurred over the two month period following the spill. Two weeks following the accident, millions of dead mollusks, sea urchins, and other bottom dwelling organisms washed ashore.

Diving birds constituted the majority of the nearly 20,000 dead birds that were recovered. The oyster mortality from the spill was estimated at 9,000 tons. Fishes with skin ulcerations and tumors were caught by fishermen in the area.

Some of the fish caught in the area reportedly had a strong taste of petroleum. Although echinoderm and small crustacean populations almost completely disappeared, the populations of many species recovered within a year. Cleanup activities on rocky shores, such as pressure-washing, also caused habitat impacts.

The Amoco Cadiz spill was one of the most studied oil spills in history. Many studies remain in progress. This was the largest recorded spill in history and was the first spill in which estuarine tidal rivers were oiled. No follow-up mitigation existed to deal with asphalt formation and problems that resulted after the initial aggressive cleanup.

Additional erosion of beaches occurred in several places where no attempt was made to restore the gravel that was removed to lower the beach face. Many of the affected marshes, mudflats, and sandy beaches, were low-energy areas. Evidence of oiled beach sediments can still be seen in some of these sheltered areas. Layers of sub-surface oil still remain buried in many of the impacted beaches.

Legal Claims

In 1979, it was estimated to have caused $250 million in damage to fisheries and tourist amenities. The French government presented claims totalling $2 billion to United States courts.

External links

Oil Spills: A Case Study of the Amoco Cadiz Oil Spill   :: Green Nature   :: - Case Study of Amoco Cadiz oil spill

Those were the days - Some information on March 18-24 Amoco_Cadiz - Information accompanied by text, including information on legal dispute

Cadiz spill brings disaster

March 18-24: The supertanker Amoco Cadiz finally split in two off the coast of Brittany spilling the last of 220,000 tons of crude oil into the Channel. Pollution experts believed the spill was the worst in marine history.

After covering 70 miles of Brittany coastline there were fears the slick could destroy Jersey's beaches if the wind changed direction. An inquiry began into claims the disaster was caused by an argument over financial terms between the tanker's captain and the master of a West German tug called to the rescue after the ship's steering broke in heavy seas. During the argument the towline broke and the ship drifted on to rocks.

August 6: Pope Paul VI died in Rome and 1978 became the year of the three Popes. Paul's successor, John Paul I, was a popular and promising leader who inherited a mixed bag of Catholic fortunes. His predecessor had taken the radical step of ending the use of Latin as the sole language for celebrating Mass. Thanks, to him, the most sacred Christian ceremony was being conducted around the world in hundreds of languages and local dialects, bringing the Church ever closer to the people.

And yet Paul had not shifted an inch on one of the most controversial Catholic doctrines. In his encyclical, Humanae Vitae, he firmly repeated the Church's age-old ban on artificial birth control. Would John Paul I take the same strict line? The world would never know. After a reign of only 33 days he died of a heart attack.

His successor was the first non-Italian Pope for more than 400 years, the Polish Cardinal Karol Wojtyla. He took the name John Paul II and a new era of Catholicism began.

July 25: A fair-haired girl weighed in at 5lb 12oz at Oldham General Hospital became the world's first test-tube baby. Louise Brown and mother Lesley were in excellent shape after the Caesarian birth just before midnight while dad John, not present at the 20-minute operation, was said to be over the moon. "She's beautiful, beautiful," he was told by an excited Patrick Steptoe, the man who helped pioneer the test-tube baby technique.

The Browns had wanted a child for years but having a baby in the normal way was ruled out because Mrs Brown's fallopian tubes were blocked. The birth was a triumph after 10 years of painstaking research by Mr Steptoe and Cambridge scientist Dr Robert Edwards.

September 19: Paperboy Carl Bridgewater was shot in the head at point-blank range after disturbing thieves raiding an isolated farmhouse. He died instantly from the shotgun blast in the living room at Yew Tree Farm, Prestwood, near

Stourbridge. There was no sign of a struggle and the police chief leading the murder hunt called it a "completely cold-blooded killing".

The 13-year-old was found dead by a friend of the elderly couple at the farm, who were out for the day. Carl, of Ascot Gardens, Wordsley, was near the end of his evening paper round when he was shot.

His father Brian said he was late on his round because he had been to the dentist. He normally slipped a copy of the Express & Star just inside the hallway and and had two more papers to deliver after the farm.

November 29: More than 900 members of an American religious cult were found dead in the Guyanan jungle in the modern world's largest instance of mass suicide. Survivors claimed their leader the Reverend Jim Jones forced them all to drink a cyanide cocktail in an act of "revolutionary suicide". Earlier the bodies of US Congressman Leo Ryan and five others, who had been sent to investigate, were found near the campsite.