Facts and figures
Many spillages of oil and petroleum
products occur every day all over the world, when filling, emptying and
cleaning tanks or pipes, or in the everyday running of factories, pipelines,
or oil wells on land. These
spills may result from technical failure, negligence, vandalism, accidents
or armed conflict.
Some components of all oil products are partially volatile and degradable. Products such as those which form petrol for vehicles contain a large quantity of components that evaporate quickly, reducing residual volumes. However, they remain toxic before evaporation.
A detailed statistical report exists, providing estimations of the volume of oil spilled due to accidents in storage facilities, industrial plants, pipelines, trucks and railways. It was published up until 2000 by the American editor Aspen Publisher Inc., in International Oil Spill Statistics. Other sources, such as the International Maritime Organization (IMO), maintain statistics on shipping losses for the international community, which provides a partial picture of the magnitude of oil spill issues.
The Aspen statistics show significant peaks in certain years due to one or two major accidents. Thus in the period 1986-2000 there are three peaks, one caused by a war (1991), one by oil well eruptions (1992) and one by a leak in a damaged pipeline (1994).
After a spill, the majority of the product evaporates and the rest is biodegraded
during its journey as run-off or through the sewer or drainage system. Other
more persistent substances may flow into this system and end up in the sea,
where they contribute to shoreline pollution by forming sheen,
tar balls and patches.
In Europe and North America, these spills concern sufficiently small quantities of oil that we do not generally find images of widespread oiling of sites, as with major oil spills.
Gas pipeline linking the Argentinean and Chilean networks
However, some regions of the world are affected by such forms of chronic pollution on a near permanent basis. The surrounding shores are constantly marked by oily slicks and tar balls, which, when put together, can create localised oil spills.
During the 1990s, multiple leaks in certain pipelines
in the former USSR reached such an extent that the European Union feared
major water pollution in the Baltic Sea. As a consequence, a project was
set up to assist in the rehabilitation of these systems.
In 1999, the new independent States of the former USSR signed an agreement with the European Union for the modernisation and extension of their pipeline networks. Within the scope of this agreement, the Interstate Oil and Gas Transport to Europe (INOGATE) project provides technical support for the rehabilitation, rationalisation and modernisation of the oil and refined product supply networks in the participating countries.
The physical safety of on land oil transportation
networks and depots is one of the operators’ and authorities’
major concerns. It is therefore an important area for cooperation. Thus
in 2002-2003, the European Union provided 10 million Euros to finance a
regional study on a satellite surveillance system for the prevention of
accidents and the detection of leaks in oil infrastructures.
According to the US National Academy of Sciences, release from land-based industry and urbanisation are the main sources of oil spills in the world.
Pipeline network in Venezuela
Thanks to stricter regulations and greater awareness in industry, these spills fell from 2.7 million tonnes in 1973 to 1.2 million in 1981, and their proportion of all spills from 46% to 36%. The increase in industrial activity caused their input to rise in 1989 to 50%. These figures, published in 2003 by the US National Academy of Sciences in Oil in Sea III: Inputs, Fates and Effects, should be treated with some caution, as they are not statistics but rather represent the estimates of experts involved in the programme.
Pollution from a pipeline in Alaska due to an irresponsible
In October 2001, American news agencies
and specialised bulletins devoted numerous pages to an exceptional event: the perforation of a pipeline transporting crude oil from Prudhoe Bay to the port of Valdez by a bullet fired by a drunken reveller.
This was not the first time such an incident had occurred. There have been around fifty known cases of angry or inebriated gunmen targeting the pipeline, without ever actually piercing it. However one bullet hole was enough to cause significant damage. The hole was scarcely 1.2 cm in diameter, but it was positioned just above a valve and at the bottom of a hill. The oil spurted out under pressure, to over 20 metres, and took two days to stem using a watertight
clamp. In total, 970 tonnes of crude oil were released over a hectare of tundra. The response involved 200 people and considerable resources for initial clean-up, which was completed in the spring after the thaw. The person responsible was severely fined.