The failure of a tailings dam on 9 September 2000 at the Aitik open pit copper mine in northern Sweden, released mine tailings and water into the nearby Angesan watershed, near Gallivare, north of the Arctic circle. The mine, operated by the Swedish-Canadian consortium Boliden, is the largest copper mine in Europe.

Boliden attributed the incident to the failure of a 100m section of the containment pond wall, which separates the coarse tailings area from the water settling stage of the waste containment facility. The failure released water and tailings into the settling pond, from which about 1M m3 of water contaminated with 6kg of copper was released into the surrounding watershed. Prod- uction at the mine resumed on 10 September and was reported to be unaffected by the incident.

Boliden said independent consultants and company personnel were investigating the incident. The Swedish environment authority has said the incident could not be considered a natural catastrophe and that the waste was not toxic but could affect fish habitats and harm riverine life.

Boliden was put under the international spotlight in April 1998 with the failure of its tailings dam at the Los Frailes mine in Spain. A flood of acidic water and toxic mud affected over 5000ha. Boliden maintains that it was not responsible for the spill because it did not design the tailings dam, which failed when filled to only half the capacity for which it was designed. A Spanish inquiry into the incident was expected to decide, as IWP&DC went to press, whether Boliden should be held criminally responsible for one of Spain’s worst ecological disasters.

A spokesman for the company said that the incident in Sweden was not related to the Los Frailes failure. (See article about tailings dams on p38-40 of this issue.)