Saturday, April 28, 2012

Oil and salt


I live in el Culebrón just outside Pinoso. A while ago now I went with the Neighbourhood Association on a coach trip to Madrid to take in a musical. On the way home, as the bus approached Pinoso, the chap in the seat behind me grabbed hold of my shoulder and said, with real emotion in his voice, "Look! It's our mountain." He meant el Cabezo de la Sal

El Cabezo is the hill that overlooks Pinoso. It is 893 metres or 2,902 feet high which makes it some 624 feet lower than Mount Snowdon. It's a salt dome formed during the upper Triassic period about 230 million years ago. That's when the first dinosaurs appeared on Earth, before the Atlantic Ocean existed and when all the land was just one single super-continent called Pangaea.

Cabezo de la Sal is a mountain loaded with 500 million tons of salt. It has been exploited, one way and another, since the reign of Philip II in the 16th Century but it was in 1970 that things changed dramatically with the construction of a pipeline between Pinoso and the coastal town of Torrevieja.

The salt is now mined by digging a borehole and then forcing high pressure water down the hole to dissolve the rock salt. The resultant brine is sent through that pipeline to the salt lagoons at Torrevieja where it is mixed with the already salty sea water. As the water evaporates off the salt yield is very high. They reckon that about 120 of the 500 million tons of salt in the mountain can be extracted using this technology.

The wells go down between 600 and 1200 metres before the process is stopped, the borehole is sealed and the miners move on to drill another hole The end result is a mountain peppered with subterranean caverns. There is currently a controversy about whether the caverns could be used to house Spain's Strategic Reserve of crude oil.

At the moment the Strategic Reserve is in a lot of oil tanks in the Escombreras Valley in Cartagena. The plan is to bring the crude ashore at the tanker terminal there, build a 110km pipeline and pump up to two million cubic metres of the black gold into the disused caverns in our mountain.

The opponents say that there is a high risk of oil spills, that inhaling the vapour from crude causes cancer, that Pinoso is in an area of high European seismic activity, and that the town could become a terrorist target. They say land will have to be compulsorily purchased. There is also the concern that the hill could become a restricted area and that if things went badly wrong Pinoso might have to be evacuated.

The proponents say that there is no risk of fire with oil stored more than 500 metres underground in an oxygen-less environment and that there is no chance of pollution of aquifers or of escape of the crude because the remaining salt and the clays that form the mountain are plastic at depth and naturally self sealing. They say that only in Hollywood films are mountains split apart by earthquakes. They are also keen to point out their environmentalist credentials.

There have been political moves to designate the hill a nature reserve but otherwise all seems relatively quiet at the moment. Time will tell.

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