The BESIX team of the drinking water treatment plant of La Mé in Ivory Coast, one of West Africa’s largest in the making, celebrated a major milestone with the intake of water from the La Mé river.
24th of May 2020, Paul stared into the distance and overlooked the river La Mé. On his left and right side, his team leaned over the railing, eagerly awaiting the big moment a few meters below. Then, all of a sudden, the river started to overflow its banks and water flowed into the pit leading towards the water intake structure of the plant. This is the milestone moment they’ve been working towards these past months. Soon this water will be piped to the treatment plant itself, 500 meters away, from where it will eventually end up as potable drinking water on the table of 1.5 million Ivorians.
The works on the drinking water treatment plant started 20 months ago. Our co-contractor Veolia has designed the treatment process, BESIX is carrying out the civil engineering works of the factory and the water intake structure. Complex works. The concrete basins, for instance, require a high degree of technical skills. After all, treating 240 million liters of water every day isn’t nothing!
Back at the riverside. One of the targets the engineers and workers pursued was connecting the water intake structure to the river so water could flow in. And as with targets in the construction sector, there was a deadline. A very tangible one in this case: the works had to be finished by end of May-beginning of June, when the rainy season starts. After all, elevated water levels in the river would put the team in deep water.
Late January. “How deep are we digging?” Paul asked Marco and Jean-Claude while looking into the pit, which bordered the river on one side and the water intake structure on the other. “10 and a half meters deep,” Marco says. He looks at him, replying “That’s a lot of ground”. “I know,” Marco smiled. With about 156 concrete secant piles (3,150 m³ concrete – 230 tons of steel) installed as retaining wall structure in the well, he’s confident about this next step to achieve this milestone.
Shortly after, a 10-ton excavator is hoisted into the pit to continue efficiently and safely the excavation up to the bottom foundations' levels. Crane operator Michael drinks some water and gets ready to climb into the machine. It’s not going to be an easy job: the pit is very confined and it’s even more hot and humid down there than at the top. At least he doesn’t have to worry as much about the mosquitos and other bugs this time of the day. Challenge accepted. Later that day, the first of many 7m³-containers is filled with ground, making space to start the execution of the concrete walls.
Paul looks up. Rain is starting to pour down again. Luckily, pumps are available at all time, avoiding the pit to be turned into a giant 10 meters-deep swimming pool.
Fast forward to May. After weeks of pouring lots of concrete, installing the vertical screen and sluice gates the milestone is finally in reach. The team is ready to break through the last barrier between the river and the pit. An excavator is standing on the side of the river. Engines on. With every dig, a little more ground is swept away and water gets closer and closer to the intake structure. Engines off. This wasn’t part of the plan. The machine broke down, prompting the team to abort this first attempt. A first bummer, but they don’t give up. Only a day later, after a satisfying lunch, they try again. With success.
Water is pouring over the last pile of sand towards the intake structure. A joyful moment. As it makes its way through the vertical screen (preventing branches and other big floating objects to enter the intake) and two giant sluice gates preventing the water from entering the structure itself.
Jean-Claude stared into the distance and overlooked the river La Mé, overwhelmed of pride by this successful team effort. They overcame some major challenges, not in the least these last months. Just like the rest of the world, this project was impacted by COVID-19. To respect safe distancing measures, safety measures were put in place. The team was reduced in size and had to rethink the planning. Working hours were cut down and evening and night shifts abandoned. Continuing throughout the weekends helped them to achieve the target. Luckily, the site was never closed down and activities could continue to date.
The civil engineering works will be concluded by the end of the year. Once up and running, the plant will represents a real progress for the living conditions of the people of the Abidjan region faced with the problem of drinking water provision.
Paul Callebaut is Project Director, Jean-Claude Descartes Construction Manager, Marco Berrios the site superintendent for the intake works and Michael the crane operator.
For more info about this project, read here.