Facts & Figures

 ClientÁguas do Algarve
 LocationFaro-Olhão, Portugal
 Operation Start2018
 Project TypeGreenfield
 Process ConfigurationPre-treatment + Nereda + Sand filtration
 Nereda Design Capacity:
  • Dry Weather Flow22 MLD
  • Peak Flow5,048 m3/h
  • PE134,130 PE (PE = 60 gBOD/d)
 In the Media:Waterworld
 Ministro do Ambiente garante resolução dos esgotos na Ria Formosa com inauguração de ETAR Faro-Olhão
 Nova ETAR acaba com esgoto na Ria Formosa
  La apuesta de Acciona Agua por las nuevas tecnologías en el tratamiento de aguas residuales
 ACCIONA Agua wins the prize for the best sustainable infrastructure in the 12th edition of Wex Global

About the Faro - Olhão Nereda WWTP

As part of the consortium Acciona Agua/Oliveiras, Nereda licensee for Portugal and Spain, Acciona Agua was awarded the contract for the construction and start-up of the Faro-Olhão Wastewater Treatment Plant (WWTP) on the Algarve in southern Portugal for Águas do Algarve. It provides a service to a population equivalent of 134,130 PE.


The plant is located one kilometre west of Olhão on a site of great natural beauty, and so it was imperative that the impact of the construction on the landscape was minimised. The completion period for the project was 965 days, including 365 days dedicated to start-up.

Priscilla Ferreria, Project Manager talks about the Nereda process



Using an advanced process of biological treatment, filtering and disinfection, the plant has a flow rate of 21,737 cubic metres (m³) per day, with a peak of 5,048 m³ per hour.

Faro-Olhão WWTP is the first plant where ACCIONA Agua has used Nereda® technology, an innovative method of treating wastewater without chemicals, which can be applied to both new and existing plants. Nereda wastewater treatment solution is already being applied on five continents for municipal and industrial water. It is recognised as the future in efficient and sustainable wastewater treatment, offering competitive capital cost and significantly lower OPEX whilst able to achieve very high levels of nutrient removal in a reliable and compact plant.


Faro-Olhão WWTP is the first full-scale greenfield Nereda® installation treating complete flow in Southern Europe. It represents the largest investment in water sanitation made in the Algarve – and one of the largest in Portugal to date. The capabilities of the plant have also received industry recognition at the WEX Global Awards 2019 in the ‘Innovation in Infrastructure’ category.

Thanks to this new technology it has been possible to reduce the plant’s carbon footprint by 50%, and an energy saving of between 20% and 30% in the energy consumed in the water treatment process is expected. The plant also has solar panels that, with an installed capacity of 50 kW, will produce energy for use by auxiliary services.

The plant also makes use of the patented Aquasuite® technology to deliver a Nereda Controller, which forms the heart of the plant’s automation system where data is continuously monitored and analysed to optimise and maximise the plant’s efficiency.

Nereda installation Faro under construction, October 2017

Faro - Olhão Nereda WWTP on YouTube