Portable desalination plants. Tedagua’s commitment to the water emergency on La Palma

The pandemic, its consequences, and the increase in the price of raw materials were eclipsed for a while by the magnitude of this natural phenomenon. Fascination and helplessness in the face of larger-than-human forces hit us as we watched in the media the evacuations of residents and the material damage caused by the lava flows of the volcano, which have no regard for property boundaries, municipal boundaries or economic interests.

The lava flows directly affected almost 3,000 buildings and 1,220 hectares. In addition, sections of 6 roads were buried, as well as electrical and water networks.

The lava destroyed the water conveyance network that supplies water from the north of the island to the irrigated area in the south, where most of the island’s banana plantations are located.

The island's economy relies heavily on agriculture, and specifically on the production of bananas, so the eruption also threatened the livelihoods of many residents. Faced with this fact, at the end of September, the Regional Government of the Canary Islands, with the technical support of the Technology Institute of the Canary Islands (ITC), urgently sought the possibility of immediately implementing a portable seawater desalination plant to produce irrigation water for the banana plantations in the southern part of the island, since the existing water conveyance system had been severed by the volcano's lava. Tedagua responded to this call by offering two containerized desalination plants designed to produce 2,800 m³/day of water each.

The ash cloud from the Cumbre Vieja volcano spread to the work zones.

Tedagua was founded in 1983 in Gran Canaria, initially dedicated to the construction and operation of containerized desalination plants to supply the incipient demand of the Canary Islands. In the early years, its activity focused on irrigation and hotel facilities. From Tedagua's workshop in Telde, Gran Canaria, dozens of these plants have been designed and built and continue to be serviced. Tedagua was bought by the Cobra Group in 2001 and its main market changed, moving towards large treatment plants around the globe, with an emphasis on innovation and international clients. Tedagua provides comprehensive water cycle services, from construction to operation, as well as providing services through concession contracts. But at no time have its original activity or facilities been abandoned: they have continued to manufacture plants and provide uninterrupted service throughout almost forty years of history. Tedagua has a portfolio of plants of different capacities that can be manufactured ad hoc or rented for a certain period of time. The two business lines do not conflict; rather, they have always been understood as complementary. Often the most urgent commissioning projects have been supported by temporary facilities provided by our workshop, or certain industrial plants have been built there as well. On other occasions, central services or site personnel provide support for specific issues in the Canary Islands market. Tedagua has always perceived its workshop and its people as a differentiating element that offers further capabilities to stand out from the competition.

And suddenly, when faced with the request from the Canary Islands Government, everything made even more sense. Immediately, resources were mobilized from the head office and from the Telde workshop to undertake a great challenge: within three weeks we had to be producing water, the banana plantations would not last any longer. And so it was done. It was not simply a question of delivering containerized plants, it also entailed building an intake with beach wells, distribution pipes, storage tanks, a pumping group and the electrical system to feed all of the above, with power supply from the grid.

The work was organized immediately, thanks to the experience and know-how of our staff. The plants were quickly set up in the workshop, while personnel from our central departments went to the site to define, together with the ITC, the Canary Islands Government and the local government all the necessary details for the facilities. The whole company rose to the challenge; it was impossible to manufacture equipment for the plant within those deadlines, so it was necessary to look for it everywhere, searching for all possible options, requiring a great coordination effort.

The location chosen for the plants was Puerto Naos, a beautiful tourist town located to the south of the area affected by lava flows

The location chosen for the plants was Puerto Naos, a beautiful tourist town located to the south of the area affected by the lava flows. The whole town had been previously evacuated by the security forces, since it was within the boundaries of the safety exclusion zone. In order to access the area, you had to have a special authorisation subject to certain controls. Two wells were drilled next to the beach to withdraw the raw water and convey it to the plants. The osmosis permeate would be stored in a tank and then pumped into the irrigation water distribution network, which operates at high pressure.

While the plants were being commissioned, the government hired the services of a tanker vessel to transport water and convey it through a floating pipeline into the same tank used to store the water produced by the desalination plants. The system was designed and built to accept both sources of water interchangeably. The construction of the tanker’s piping systems to convey the water was also part of the scope of Tedagua’s project.

The work was executed flawlessly, relying on our usual subcontractors for assembly, who have been with us on a multitude of projects. As in all our projects, the work was executed with the highest safety standards, in this case even more so, given the logistical difficulties involved. The days were very long, with personnel working as volcanic ash fell from the sky and having to evacuate the site on several occasions due to the risk of lava flows. When they returned to the hotel in the evenings, they had to remove the ash that completely covered them.

The same hotel where the planning and follow-up meetings were held was a temporary home for many families displaced by the volcano. A place of contrasts. Entire families, displaced, without knowing for certain what will happen in the short-term, whose routine has been disturbed without warning, and with no possibility of going back. Children, who have to play and learn; adults, who have to mourn their losses, wait for help and look for a future... All of them, our staff, the journalists... all brought there by the random fate of a volcano.

Watching the daily news about the eruption, we at Tedagua felt something else, a sense of belonging and a common challenge, even stronger than the one experienced by the country as a whole. We were there, and we were not going to fail.

During those weeks a very strong feeling resurfaced, a sense of purpose as we did our jobs: this is why we are engineers, to provide water where it is needed and to protect the environment. And we never felt alone in this: clients, collaborators, and suppliers were interested in the project and thanked us for our involvement in it.

In order to meet the deadlines, all available resources were mobilized: the design was made and adjusted. The objective was not to make the ideal plant, it was not to optimize CAPEX or OPEX; rather, it was to build a robust and reliable plant, and to adapt the design to the elements available in the area or accessible in a short time. The bill of materials was cross-checked by engineering with the available stock in the warehouses and went back to the drawing board to adjust it again. Spare parts from other Tedagua plants were rushed to La Palma; stock material was sought from all national suppliers. The logistics department did an excellent job ensuring fast transport to the project site, and we even had a Navy ship transport a centrifugal pump to the area. The objective was clear, and the whole country was supporting La Palma; it was clear that a volcano was not going to defeat us.

And we achieved our objective, indeed. Within three weeks of the order, water was delivered, and the facility has not stopped working since. Likewise, we have not stopped improving and expanding it.

The objective was to build a robust and reliable plant, and adapt the design to the elements available or accessible in a short time

This article does not talk about technical features or innovative materials and technologies (which we also use in other projects). It is about the team experience, that which allows us to adopt innovative solutions because we master the technology. It talks about the flexibility of an organization to adapt to a challenge, which allows us to immediately redirect human and material resources so that we all function as the great team that we are. It speaks of the human dimension of the need for water, of the drama experienced by all the families affected and who still today have not recovered their way of life, despite the fact that other news – inflation, wars – have displaced them from the headlines.

From Tedagua we want to express our gratitude to the Government of the Canary Islands for counting on us, and our utmost solidarity with the affected families in La Palma; it has been a privilege to be able to work with and for them.