Response at sea
As soon as the Tanio’s SOS was received, the tug boats Malabar, Abeille Languedoc and Abeille Flandre sailed at once to the place of the incident. They arrived on site before dark despite a low, heavy swell and strong winds. There was no trace of pollution in the wake of the stern. The bow was drifting eastward in the direction of the Barnouic’s plateau shallows with 8,000 cubic metres of fuel remaining on board. It had to be towed rapidly, but the wind made response impossible.
The following day, the wind dropped slightly. Around 11 am, in spite of 7 metre high waves and 55 km/h wind, two rescuers from the Abeille Languedoc managed to board the Tanio. Twelve men from a rescue team arrived soon after by helicopter. A tow line was fitted straight away, at avoid grounding. The Tanio was only 1,000 metres away from the breakers.
Waiting for a safe haven, the Abeille Languedoc headed northwest. After negotiations, she was directed towards Le Havre, at the entrance of the river Seine estuary. She arrived there three days later.
Discharging of fuel oil started on 15 March. The oil was pumped after being heated by the Tanio’s boiler. The operation ended one week later. 8,000 cubic metres were successfully unloaded. The wreck was taken to a dry dock for assessment and eventually towed to Santander (Spain) on 21 June for scrapping.
The problem of the Tanio’s oil
Scientists from Cedre, the French Oil Institute (IFP), oil companies and the Scientific and Technical Institute for Maritime Fishing (ISTPM) noticed that the fuel, which was heated in the Tanio’s tanks, became a sticky and thick emulsified product on contact with cold seawater. It did not evaporate, and its biodegradation was poor (less than 10 %) and slow. Moreover, it was too viscous to be pumped and the use of dispersants would have been ineffective. Onshore, its weathering process was very slow, and once the emulsion was broken the fuel became black and hard, making it particularly difficult to recover.
Offshore oil response plan (Polmar Sea Plan)
The Maritime Prefect for the Atlantic activated the Polmar Sea Plan (offshore oil response plan) as soon as the incident was announced. However offshore response was delayed for 48 hours because of the meteorological conditions. However, dispersants would have been useless as the Tanio’s oil was too viscous. As a consequence and because they did not have any adequate tools, authorities renounced recovering the oil offshore.
The day after the incident, a prediction model of the fate and movements of the oil slick (from 7 to 20 March) was set up by Cedre, Météo France and the electricity board's hydraulics laboratory to evaluate the extent of the pollution. This model, created by Météo France, took into account, in real time, the weather forecast. It predicted that the Côtes d’Armor region would be the first to be hit. Civilian and military aerial missions (Maritime Affairs, Customs, Civil Defense, French Navy) conducted observation of the pollution off and onshore.
The Prefect for the Côtes d’Armor waited before activating the Polmar Land Plan (onshore oil response plan). He first wanted to establish the extent of the pollution. Following the weather forecast of 7 March, he gathered pollution response equipment in the city of Tréguier. A first 4 km-long oil slick was observed off the coast, then large ones 30 km north of Batz Island. Polmar floating booms were immediately set up to protect the shoreline. A team from the Belgian disaster and emergency services set up a 760 m long boom on the island of Ile Grande. Lannion’s headquarters reinforced the measures by organising the gathering of new booms from private suppliers. In total, 15 km of booms were deployed in the Côtes d’Armor. Synthetic material sheets completed the boom protection process as “shore carpets”, but they proved to be relatively inefficient due to the prevailing wind and swell conditions.
On 9 March, a slick one kilometre long by 20 to 30 metres wide was signalled off Trégastel and Sept Iles. It was pushed by a northwest wind and reached Ploumanac’h and Trégastel. Dead scallops appeared in the Primel Bay and in the river Léguer. On 10 March, the Polmar Land Plan was eventually activated. Headquarters were set up in Saint Brieuc, Lannion and Trégastel for this purpose.
Between the 9 and 15 March, persistent westerly winds and tidal currents made oil drift eastwards, affecting in turn Port-Blanc, Plouha and Saint Brieuc. It was the beginning of a massive and continuous influx of pollutant which impacted the Côtes d’Armor coast for a week.
Pollution reaching the North of Finistère
Oil which had landed in the Côtes d’Armor started being reclaimed by the sea. At the same time southwesterly winds pushed the oil slick towards the north Finistère coasts. The product, aged and mixed with seaweed reached Roscoff on 20 March. 20 km of coasts were damaged. The Maritime Prefect for Finistère activated the Polmar Plan on 22 March. Permanent headquarters were set up in Quimper and an operational centre was created in Morlaix. The following week, oil was still spreading and polluted previously cleaned beaches, affecting Brignogan and Guisseny.
During the first week, 15 oil recovery sites were set up. Vacuum trucks and slurry spreaders were widely used during this stage of the clean-up operations to recover most of the oil polluting the beaches. Soldiers were sent to Trégastel and Perros-Guirrec, and firemen were sent to other towns and villages. Numerous islands and islets were cleared of pollutant, but waste evacuation raised logistical problems.
The Côtes d’Armor beaches were quickly cleared of oil accumulations, despite frequent rebeaching. Some beaches were only coarsely cleaned, whereas others were subject to a more selective manual cleaning (waste containing only 20 % sand). This method required considerable manpower, so mechanical recovery was used as a complement. On the Grève Blanche cleaning site, civil engineering vehicles recovered thick homogeneous slicks. The estimated quantity of landed oil was about 400 tonnes. To reduce the volume of waste, Cedre tested potentially more selective machines, and engineers adapted and improved the recovery equipment used during the clean-up operations after the Amoco Cadiz incident in 1978.
In the Côtes d'Armor, the jagged rocky coasts, headlands and deep bays made cleaning operations difficult. Manual recovery quasi-inaccessible areas was dangerous for the civil servants and volunteers who intervened.
In some cases, the oil accumulations on and under the rocks could be removed by using low-pressure, high-flow sea water hoses. The pollutant floating on the sea surface was then sent in the direction of an EGMOPOL-type recovery barge like the one in Ploumanac'h, or naturally diverted toward a recovery point by sea currents, tide or winds. Some oyster barges, equipped with drags, were used as a floorcloth to collect gummy and sticky fuel. Depending on their consistency (liquid, sticky or solid), the recovered pollutants were stored in pits dug on top of the beaches and protected by plastic covers. These wastes were then loaded and sent to a treatment site.
The island’s specific case
In the Côtes d'Armor, pollution was very important on the islands and islets, particularly on Bono, Sept Iles, Saint Gildas and on other islets. On some uninhabited islands, landing manpower and the implementation of logistical operations concerning the transport of equipment (particularly pumping systems) was an extra difficulty. Low-pressure sea water pumps embarked on rafts appeared to be the best solution. However in the areas where fresh water supply was impossible, the use of sea water pumps was not always possible. Thus, only the oiled seaweed was put in bags and then sent towards the mainland. Sometimes, the polluted sites were exposed enough to natural cleaning. The rough sea cleaned the oil, even if it was to the detriment of water quality which remained oil-charged.
Fine clean-up of the beaches and rocks
Fine clean-up of the beaches and rocks began on 15 April in the Côtes d'Armor. As daily productivity obtained for rock cleaning was insufficient, Cedre tried to improve the techniques using high-pressure hot water pumps. Tests on a series of cleaning products were performed and finally, Cedre recommended cleaning the rocks with hot water. Direct pumping in the trenches dug on the beaches was used to recover significant quantities of oil cleaned from the rocks, whereas low quantities were recovered with the help of sorbents. Second generation dispersants used at a very low concentrations were recommended in the areas where recovery was difficult.
Once the rocks were cleaned, the fine clean-up process of beaches began. Several options were advised by Cedre, according to the nature of the beach (partially affected sandy beaches, coarse-sand beaches retaining water at low tide or pebble beaches): water cleaning and recovery by pumping, ploughing using sorbents, sea water cleaning operations or high-pressure water cleaning with sorbent products.
On top of the equipment provided by the towns and the different Polmar Plans, town councils used agricultural equipment. In exchange for material compensation at the end of each week, each town of the Côtes d'Armor gathered the trailers, tractors and slurry spreaders necessary for the pumping operations and the transport of waste to intermediary storage areas.
On 14 March, refuse lorries were used at Trégastel and Perros-Guirec saturated pits. Despite their turbines and their very powerful vacuum pumps, they hardly removed the fresh, liquid and viscous products from the coasts. Cedre tried to implement flux systems to pump oil and send it to the oil depot. Liquid products rich in fuel were treated in a deballasting station. Thick residues and waste underwent a first quicklime treatment in a pit next to the coast. Then they were sent toward Louargat where they were treated once again. All things considered, 52,000 tonnes of polluted sand were treated with lime. A large part was used as an embankment to build the main road number 12 in the Côtes d'Armor.
The results of Polmar operations
Pollution, which first massively affected the Côtes d'Armor and then Finistère, settled over 150 km of coasts. Oil response operations involved more than 3,000 people among whom 2,500 were soldiers. No less than 200 cleaning sites spread over 38 different places, were necessary to eradicate any trace of pollution in the two regions (Côtes d'Armor and Finistère). Nearly 28,000 tonnes of oiled waste were recovered and treated for 6,000 tonnes of spilled hydrocarbons.
The threat of a delayed pollution
Less than 10 hours after the incident, the bow part of the Tanio sank with 7,500 tonnes of oil, lto a depth of 90 m. Thanks to its sonar, an escort-sloop found the wreck which was then explored by the minesweeper the Cybèle to determine the exact position of the wreck.
On 8 March, the Maritime Prefect for the Atlantic addressed a formal demand to the shipowners, asking them to take the necessary measures to stop the risk of pollution. On 13 March, the insurers announced that the wreck was to be examined by British Oceanics. An observation submarine was boarded onto the British Voyager and explored the bow section of the Tanio. Experts spotted three leaks on tanks number 4 and 5. They estimated that between three and ten tonnes of fuel were leaking from the wreck daily.
In mid-April, after the spring tides, the sealing of the leaks began. The divers of the submarine Intersub IV installed casing and injected resin (11 dives in 12 days). However the ship location and bad weather conditions made the operations difficult. Once the sealing was finished, at the end of April, the “Mission Interministérielle de la mer” put the French Navy in charge of seeking a means to definitively destroy the content of the wreck’s tanks. The Tanio’s insurers gave in and assumed the responsibility for the rest of the operations.
The consultative committee which was set up preferred the pumping solution rather than containing the remaining oil and lightering the wreck after it had been refloated. A process created by the French Petroleum Institute was accepted to recover oil and an emergency plan was foreseen to avoid accidental pollution. Work estimated at 50 millions francs (about 7 million euros) was entrusted to Comex. It was to be finished before the beginning of September, because of equinoctial tides and storms. Unfortunately, technical complications as well as a series of storms slowed down the pumping operations. The work was put on hold over the winter and started again in spring 2001. The operation came to an end on 18 August 1981. 6,500 tonnes of fuel were recovered, in operations costing 250 millions francs (about 38 million euros).