The challenges facing desal plants in Chile's north

Though desalination has found a promising niche in northern Chile, mainly thanks to the mining sector’s thirst for water amidst a record drought, the region is not as suited to support the many plants that would be needed to cover both the demand for human consumption and mining operations, experts warn. 

It is essential for future projects to be more efficient and to minimize the impact on the environment, Black & Veatch Chile’s business development director Pablo Peñaranda said, adding that the firm is advancing in solutions to further optimize plants.

“We also count with services that allow an increase in the recovery capacity of water resulting from copper ore processing, such as treating effluents from the concentrate filtering process,” Peñaranda said in a press release.

A November study by the Universidad de Concepción’s environmental sciences center (EULA) and the Milenio socio-ecological coastal institute (SECOS) found that only 4.5% of the coastline between the northernmost Arica y Parinacota region and the Santiago metropolitan region could be labeled “highly appropriate” for installing desalination plants.

In contrast, 60% of the studied area – a distance of some 2,000km as the crow flies – was deemed “little” or “not” appropriate. It also found that 17 plants that are being planned or are in operation are located in unsuitable areas. 

Currently there are 24 desalination plants in operation in Chile with combined capacity of 8,000 liters per second (l/s), with 75% of production going to the mining industry, according to the country’s desalination association ACADES.

Capacity is expected to increase to 10,000l/s by the end of this year, and could reach 40,000l/s by the end of the decade. 

Mining would be the main beneficiary of the desal boom, with 15 planned projects in different development stages, as demand for desalinized water in the copper sector is expected to increase by 167% in 2023 compared to 2021 levels, state copper commission Cochilco reported last month. 

By that year, desalinized water will represent 71% of the copper mining sector’s supply, according to the agency. 

Some of the desalination projects currently being developed for mining operations include Codelco’s US$1bn Distrito Norte plant, which has obtained environmental approval; Antofagasta Minerals’ US$2.2bn INCO plant, which will start operations this year; and Teck’s desalination plant for the US$7.75bn Quebrada Blanca 2 copper project.