Efficient pumping supports wastewater management in Ibiza

12 May, 2025

Ibiza is renowned for its beaches and stunning landscapes, which attract hundreds of thousands of visitors each year. The extra population creates huge volumes of wastewater that need to be treated to ensure the rivers and beaches remain in excellent condition.

Challenging heights

The most recent addition to the sewerage infrastructure on the island was an intermediate pumping station that needed to be located in the heart of a popular tourist area, but thanks to its design, it will not be noticed by all those enjoying the local hospitality. To avoid any unpleasant odours, the wastewater treatment plant is located away from the urban areas, but it is 120 meters above the pumping station, creating a design challenge as an intermediate pumping station was not an option in this case.

Typical wastewater installations use gravity wherever possible to minimize the use of pumps, but they are essential in many situations. A network of pumping stations is used to transfer wastewater to the local treatment works, which are usually positioned close to a water course to accept the treated effluent.

However, the situation in Ibiza is more challenging. In this case, the town’s winter population of 160’000 swells to around 450’000 in the summer, requiring a considerable increase in pumping capacity. The designers of the new pumping station also knew that, to
achieve the head of 120 m, they would need to arrange several sets of two pumps in series.

Proving capabilities

While creating the basic layout, the designers also needed to source the pumps that would be installed in the station. However, the exact specifications required fine-tuning along with the control philosophy and the precise layout of the pipework. Sulzer’s expertise in water management and pump design made the manufacturer a clear favourite to support the project.

Despite the unusual nature of this type of installation, Sulzer was able to successfully provide valuable know-how hammer” effect, when pumps start and stop operating. This is especially important in high head and long pipe installations.

Design expertise

While the initial design was drafted, much of the details were incomplete, especially relating to the pipe diameters, pump connections and control principles. Sulzer was able to contribute extensive knowledge to define all the parameters and complete the design before construction started.

In the meantime, since the pump specifications had been agreed, Sulzer set out to deliver the 12 XFP pumps in line with the build schedule, which was slightly unusual in that they would be assembled in position with the collection manifold before the building was erected around them. Those in the wet well were arranged vertically, while the pumps in the dry well were installed horizontally. All the pumps were equipped with special in similar installations in different countries. The basic design for the pumping station called for 12 pumps, 6 in a wet well with each one connected in series to its pair in the dry well. The outflow from the dry well is gathered in a common collector that is connected to a pressure vessel, which absorbs any pressure spikes, known as a “water high-pressure mechanical seals to enable them to operate in both wet and dry locations.