Mining giant BHP Billiton has reported the "mechanical completion" of Escondida Water Supply project, Chile, with the first water expected in March 2017.

The mega desalination plant project kicked off in 2013, with a view to increasing water supply at Escondida copper mine to support future expansion, including installation of a new copper concentrator.

BHP recorded $3.43 billion of capital expenditure on the desalination plant in the six months to 31 December 2016, saying that the project had come in “on schedule and on budget,” and that it is “99 per cent complete”.

The seawater reverse osmosis desal facility has capacity of 57 million US gallon a day (216,000 m3/d), and is fed by seawater pumped 170 kilometres from the Port of Antofagasta to a reservoir at the mine, 3,100 kilometres above sea level.

Doosan Heavy Industries and Construction won the construction contract for the project in August 2013, and Black & Veatch was selected as engineer of record for the marine works and desalination components. Bechtel provided engineering, project management and construction services for the plant and two 1.07 meter diameter pipelines running between the port and the mine, as well as related infrastructure, including four high-pressure pumping stations. Flowserve supplied pumps and an energy recovery system.