From typicallyspanish.com

Costa de Almería
Spain finds trenches of radioactive earth buried at Palomares
By h.b.
Apr 10, 2008 - 1:35 PM

Spain has unearthed radioactive trenches which the United States left behind after the 1966 radioactive accident in Palomares in Almería.

At the time the Americans said that they had taken away all the radioactive material, some 1.6 tons of earth contaminated with plutonium but now 42 years later it has been proved not to have been the case.

The accident happened during mid-air refuelling above Almería and resulted in four nuclear bombs falling to earth at Palomares.
Now the United States has given a new undertaking to remove the contaminated earth and has said that 1.26 million € will be spent on the clean up.

The beach at Palomares - Archive Photo EFE
Teresa Mendizábal, the Director of the Energy, Environment, and Technology Investigation Centre, CIEMAT, told El País newspaper that the two three metre deep trenches found each contain 1000 square metres of radioactive material. Each trench was 10 metres wide and 30 metres long, and they are located on the outskirts of Palomares, near the cemetery.

The complex process to completely decontaminate the area started in 2004. Spain cannot reprocess or hold Plutonium and for that reason has called on the United States to remove the contaminated earth now found. Mendizábal said that collaboration was complete and the relationship with the United States authorities was ‘magnificent’.

A formal agreement on the clean up needed was signed by both sides in September 2006 and it was following that when CIEMAT started their indepth investigations into what remained.