A 2000-page report on the collapse of the Los Frailes tailings dam in 1998 has been submitted to the judge inquiring into the Spanish dam’s failure. The collapse of the tailings dam, at a mine owned by Canadian company Boliden, released a flood of acidic water and toxic mud that affected about 5000ha in Spain. The dam was used to store waste materials from Boliden’s zinc and silver mine.

The report describes the findings by independent geotechnical engineers who investigated the incident. Judge Celia Belhadj-Ben Gomez of Andalusia commissioned the study as part of the inquiry into whether Boliden should be held criminally liable for one of Spain’s worst ecological disasters. Judge Gomez will rule as early as September whether Boliden and other companies can be tried, after considering the report and holding hearings. Witnesses will be called in during the coming weeks to testify on the failure of the dam.

Boliden has maintained that it was not responsible for the spill because it did not design the tailings dam. The mining company has argued the tailings dam failed when it was filled at only half the capacity for which the structure was designed. (See pp12-19 of this issue for an update on tailings dams).