Antamina Tailings Dam

The Antamina Tailings Dam, also known as the Antamina Tailings Impoundment Facility, is a tailings dam located in the Huincush Ravine 55 km east of Huaraz in the Ancash Region of Peru. The purpose of the dam is to store tailings processed at the nearby Antamina mine. In 2003, Golder Associates, Burnaby, B.C. was awarded the 2002 Canadian Consulting Engineering Award for its innovative design of the dam.

Background
The dam was designed by Golder Associates, Burnaby, B.C. and Ingetec SA between 1998 and 1999. Construction on the 130 m high concrete-face rock-fill starter dam began in 2000 was complete in April 2001. A 15000000 m3 reservoir was filled behind the dam assist the concentrater. By April 2003, the dam was raised from its original elevation of 4010 m above sea level to 4045 m. The dam will continually be raised until it reaches 240 m tall at an elevation of 4125 m and length of 1.3 km. Currently the dam is undergoing its fourth raising to 215 m in height.

Design and operation
As a base for the dam, a 130 m concrete-face rock-fill dam was constructed. From there, the dam is being raised with rock-fill with the upstream side being protected by a concrete slab. The original starter dam was 1050 m in length and when the dam reaches its final height of 240 m, it will be 1300 m long. The dam will hold 570000000 MT of tailings and the mine is expected to produce 546000000 MT. Upstream of the dam, a series of channels and embankments divert water from the Ayash River from entering the reservoir. This helps the environment and protects the stability of the dam. The reservoir is lined with a geomembrane which controls seepage of tailings into the environment. Water released into the environment is purified to meet standards and discharges from the dam are maintained at at least 150 liters per second.