Inhabitants served

Water collected directly from the Pacific Ocean

The plant, located in the Atacama region of Chile, uses reverse osmosis desalination technology, a particularly interesting technique because of its adaptability, enabling the treatment of different types of untreated water, and because it is financially competitive and environmentally friendly. The end use of the water is industrial.

The pre-treatment stage uses ACCIONA's proprietary technology to protect membranes from phenomena like "red tides" or jellyfish proliferation, which often occur in this area of the Pacific Ocean.


Water is taken from the Pacific Ocean at a depth of 17 m and transferred to a well for pumping to the desalination plant, located 1,300 m from the shore. On arrival, the water goes through the desalination and remineralisation process, and the resulting brine is returned to the ocean using a system of diffusers to prevent salt concentrations that would harm the marine ecosystem.


  • Location: Puerto Punta Totoralillo, Copiapó (Atacama Region), Chile
  • Client: CAP (Pacific Steel Company)
  • Capacity: 34,560 m3/day
  • Type of contract: EPC + O&M (20 years)
  • Population: 230,400 inhabitants


The implementation of a desalination plant in this location is important as a water solution, because the Atacama Desert - rich in mineral resources - is considered the most arid desert on the planet.

The following activities have been carried out in the zone:

  • Compensation and restoration of living conditions due to expropriation.
  • Educational campaigns for the community, through Environmental Campaigns: Resources are allocated to carry out environmental awareness campaigns: 'Let's take care of our environment' and 'Resource segregation campaign'.  
  • Social impact mitigation measures or community support.
  • Cleaning of the seabed at the Caldera wharf during the month of the sea.  
  • Rubbish collection in the Piedras Zoo sector: A large amount of domestic rubbish left by tourists and truck drivers who use the area as a rest area was collected.  
  • Improvement of the social welfare of vulnerable groups, through collections from the disadvantaged population with the help of Cruz Roja; donation of books to schools in the area, donation of wood to the Municipality of Cladera, organisation of cultural and recreational activities for children in the areas of the project.  
  • Volunteering activities, taking advantage of the celebration of World Environment Day, for the second year in a row the 'Volunteering Day' was held, where ACCIONA employees imparted knowledge of sustainability in several schools in the Caldera community, for approximately 550 children. The aim of the activity is to participate with the students in an entertaining day and to generate a lasting impact on the students so that they become aware of sustainable development and the appropriate use of resources. Over the past two years, more than 1,000 children in the area have benefited.

Technology and innovation

Reverse osmosis

This is the most widespread and advanced desalination system in the world. Its implementation represents more than 60% in comparison to the rest of the methods. This water treatment process is carried out thanks to the contribution of external energy in the form of pressure, which overcomes the natural osmotic pressure present in the solution.


A desalination water pretreatment system that combines flotation and filtration with a granular medium bed in a single tank. The area of the Pacific Ocean closest to Copiapó has frequent temperature changes that favour the appearance of red tides, an abundance of jellyfish and other phenomena that can affect the process of a conventional desalination plant. Installing ACTIDAFF® counteracts the effects of algal bloom in the plant. This system has multiple applications: treating water with algae, water with high concentrations of oils and fats and suspended solids.

Awards and recognitions

Key figures


equivalent population


m3 per day


years of EPC + O&M contracts

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