The expansion of the Os Praceres Wastewater Treatment Plant (WWTP) in Pontevedra included the construction of a new marine outfall, a key infrastructure project designed to improve the wastewater network and help protect the surrounding estuarine environment.

As part of this project, we were responsible for carrying out the drilling works using Direct Pipe® technology, a solution that enabled the pipeline to be installed from land to sea without the need for open-cut excavation along the coastline or any direct intervention on the seabed.

Our involvement formed part of the first Direct Pipe® project with an offshore exit ever completed in Spain, marking an important milestone in the application of trenchless technologies for hydraulic infrastructure.

Our scope of work consisted of executing a 690-metre bore to install a 56-inch (1,422 mm) steel pipeline, from the entry point on the shoreline to the exit point located –6 metres beneath the seabed.

The drilling works were completed in 24 consecutive days, achieving drilling rates of up to 70 metres per day.

Throughout the entire alignment, we encountered particularly demanding ground conditions, comprising alternating layers of silts, clays and granite. These varying geological conditions required continuous adjustment of the drilling parameters and precise control of the bore path to ensure the successful installation of the pipeline.

The project required the installation of a large-diameter pipeline while minimising the environmental impact and maintaining a high level of accuracy throughout the drilling process.

Direct Pipe® technology made it possible to excavate and simultaneously install the final pipeline in a single continuous operation, reducing the surface footprint and avoiding intervention along the coastline and on the seabed.

This methodology is particularly well suited to highly complex crossings beneath rivers, roads and railway infrastructure, as well as for land-to-sea connections, where precision and process control are critical to the success of the project.

Every project presents different challenges, and our commitment is to deliver the most appropriate drilling solution for each one.

Our involvement in the construction of the Os Praceres WWTP marine outfall represents one of the most significant projects completed using Direct Pipe® technology, demonstrating our ability to undertake large-diameter, long-distance drilling works in complex geological conditions.

Having contributed to the first Direct Pipe® project with an offshore exit in Spain reinforces our experience in trenchless technologies and our ability to work alongside engineering consultancies and contractors on projects where precision, planning and geological expertise are essential.