Swedish-Canadian mining company Boliden plans to sue the Spanish construction group Dragados over the failure of a tailings dam in 1998, at the Aznalcollar mine in southern Spain.

Dragados has denied any liability for the accident which was described as Spain’s worst environmental disaster. Dragados subsidiaries, Intecsa and Geocisa, were involved in the design and construction of the dam, which held waste from Boliden’s mine. Spanish newspaper Cinco Dias has said Boliden is seeking damages of around US$0.4B.