Domingo Zarzo Martínez, Technical and R+D+i Director at Sacyr Waterhas more than thirty-four years of experience in the water sector. He has participated in and directed more than seventy desalination projects that have meant more than 15 million m3 per day in constructed facilities for the water cycle sector.

With more than fifteen years of experience, Sacyr Water manages the integral water cycle and the operation of water treatment and transport infrastructures in more than one hundred treatment plants at national and international level.

INTERVIEW

What are the main technologies being used that will shape the future of sustainable management of the full water cycle?

The trend is clearly to move towards increasing the sustainability of all activities; the reduction of the water and CO2 footprint, the recovery of components, reuse and everything related to the circular economy, the increase in energy efficiency and the use of renewable energies and, of course, digital transformation, which complements the tools to achieve these sustainability objectives.

What objectives have been set in the Innovation and Strategic Projects department of Sacyr Agua?

Our department aims to develop or find in the innovation ecosystem -both internal and external- solutions to the problems of our clients and contracts, as well as the challenges posed by the future of water management and its scarcity. From the department we develop all innovation initiatives within the company, but we also provide technical support in those projects that, due to their size, magnitude, client or country, are strategic for Sacyr Agua.

What role does technology play in achieving them?

Technology is the necessary tool to achieve the objectives of efficiency and sustainability and an accelerator of the technologies and processes applied. In Spain we are making rapid progress in technological development and digital transformation and the injection of European Next Generation funds in calls such as the PERTE for Water Digitalisation will help companies and administrations to advance more quickly towards their digital transformation.

The injection of European Next Generation funds will help companies and administrations to move faster towards digital transformation," he said.

At Sacyr Agua, you work on the Water Positive concept. What does it consist of?

Water Positive arose as an idea to increase efficiency in the use of water resources in industry. We are currently working on its development in a working group within the IDA (International Desalination Association), in which I participate, and in which we want to establish the basis for its determination, certification and perhaps in the future the establishment of a water rights market - similar to CO2 bonds - that allows companies that consume a lot of water to compensate this consumption with water production in other areas or industries that are more in need.

At Sacyr, we have joined the working group from the outset and last year, at corporate level, we also certified our water footprint through ISO 14046 for all Sacyr activities in all the countries where we operate. It has been a very intense job given the size and diversity of the company, the difficulty of calculating direct and indirect water consumption through various systems that also analyse aspects of environmental impact, etc. And to say that, thanks to the desalination and reuse activities of Sacyr Agua, the entire Sacyr Group is positive in terms of water generation, it is Water Positive!

There is no turning back from the digital transformation of the water sector. The use of new technologies increases efficiency in the management of water infrastructures, reduces costs and increases environmental sustainability?

One of the company's pillars of action is water desalination. What is the situation in Spain?

Worldwide, there are some 20,000 desalination plants producing some 100 million m3 of desalinated water per day. The largest producers, as might be expected, are the Persian Gulf countries, led by Saudi Arabia.

Spain, since the development of the "Water" programme, is the fifth country in the world in terms of installed desalination capacity, with some 5 million m3 of desalinated water per day, which could supply water to a population of some 30 million inhabitants and currently represents 9% of the drinking water supplied in the country, although there are some islands where the percentages can reach almost 100%. It is also worth highlighting the strength of our industry, not only within Spain. Of the 20 largest desalination companies in the world, 8 are Spanish.

At present, the development of new large desalination plants is not expected, but there are plans to expand some of Acuamed's desalination plants, such as Águilas and Torrevieja, and to implement renewable energies for their electricity supply and reduce their CO2 footprint.

So, based on your experience in several desalination projects, what barriers does the sector currently face?

Large desalination projects encounter all kinds of barriers: financial, risks in certain countries, construction, legislative and environmental risks, etc. However, perhaps the greatest current challenge is to change the negative perception of desalination in society and in some administrations, based on prejudices and opinions with no scientific or technical basis. The three typical negative arguments against desalination are: water is very expensive, energy consumption is very high, or that it harms the environment. These are all mere opinions that are not based on reality.

In this respect, I would like to give some figures that give us an idea of these prejudices. For example, the price of desalinated water including amortisation is approximately 1 euro/m3, which is equivalent to 0.001 euro per litre; bottled water is paid at 500-1,000 euro/m3; the energy consumption of a seawater desalination plant is approximately 3 Kw-h/m3. Also, the energy needed to desalinate water for a family of four in a year is equal to the consumption of their refrigerator and that the association of water bottlers declares on its website a consumption of 35 Kw-h/m3 in its activities.

When brine discharge is done correctly, by means of diffusers and prior dilution, there is no difference in salinity within a few metres of the discharge point. And the so-called brine is nothing more than concentrated seawater, with no other chemical or toxic components.

What areas of innovation still need to be developed in order to make further progress in the digitalisation of the management of the full water cycle?

There have been many efforts in the water sector to increase it. digitisation of water resources managementAlthough treatment facilities, such as desalination, purification and drinking water treatment plants are usually highly sensorised facilities, with complex control systems and data collection, there is still much to be done in the water cycle in terms of sensorisation, smart metering, predictive models of consumption and demand, platforms and apps for interaction with citizens, etc.

And if much remains to be done in supply, much more remains to be done in the case of sewerage networks. In both cases - in plants and networks - there is a huge amount of information, but there is a long way to go in data management and the application of intelligence and machine learning to obtain the full potential of this information.

Spain is the fifth country in the world in terms of installed desalination capacity, which could supply water to a population of around 30 million inhabitants".

Sacyr Agua and Elliot Cloud developed the SOS Water project. How has the initiative contributed to improving water resources management?

SOS Water XXI is an ambitious project involving a consortium of eight companies and six university research groups aimed at developing 21st century agriculture, efficient in the use of water resources and energy. The project has been under development for just over a year and includes 35 sub-tasks related to the use of non-conventional resources, the quality of water for irrigation, the recovery of nutrients and other compounds of interest from agricultural drainage and desalination brine, predictive models of water and energy consumption, the effect of extreme weather events on infrastructures, and an economic and environmental study of the solutions. All this with a high technological component such as the use of aerial and underwater drones, development of digital twins, data management platforms, etc.

Is there a lack of projects aimed at combating the impact of climate change and meeting the water needs of agriculture?

Of course. Any project that has an impact on increasing sustainability, mitigating the effects of climate change and efficiency, and on the use of water resources, such as the SOS Water XXI project, in which Sacyr Water and Elliot Cloud are participating, is very necessary, given that we are talking about such important things as food, health, sustainability and climate change, and agriculture is by far the activity that consumes the most water worldwide.

And as already mentioned, the use of new technologies will accelerate the application and efficiency of all technical and process advances, so projects that include new technologies and digital transformation are essential.

The Water Positive concept was born as an idea to increase efficiency in the use of water resources in industry?

How relevant do you see public-private partnerships for the growth and development of the digitalisation of the water cycle?

Public-private collaboration is essential in the management of the water cycle. Specialised companies, in collaboration with the administrations, which are not water specialists but must provide a quality service to citizens, are the best tandem for managing water supply and sanitation.

Specifically, in the case of digitisation, this has been understood in the case of the PERTE for digitisation, where the terms of the call encourage private initiative to lead the proposals, due to its greater flexibility and knowledge of the market and technologies, with the necessary authorisation from the owners of the installations and networks, which are the administrations.

What is the outlook for the water sector in terms of digitalisation and sustainability in the coming years?

There is no turning back from the digital transformation of the sector. The use of new technologies increases efficiency in water infrastructure management, reduces costs and increases environmental sustainability.

In the case of sustainability, apart from increasing energy efficiency, reducing consumption and using renewable energies, there is a growing interest in concepts such as the water footprint, even in sectors totally unrelated to water, such as technology companies.