The vice president of the Government of Cantabria, Dolores Gorostiaga, and the head of the Environment Department, Francisco Martín, accompanied by several mayors and other authorities, opened the supplementary sanitation facilities for the Southern Arc of Santander Bay at the Suesa wastewater treatment plant on 29 April last. The sanitation facilities had a budget of 28 million euro.

Now that the FCC-built facilities have been opened, all of Santander Bay has a sewage and water treatment system. This marked the end to the work begun over a decade ago to clean up pollutant discharges into the bay, a natural environment of great ecological value shared by seven Cantabrian municipalities.

Vice President Gorostiaga announced, "We can finally say all of Santander Bay has a sanitation and water treatment system", and she pointed out in her speech that, with the conclusion of this work, "justice is done for an important area of Cantabria that was not properly seen to at the right time".

The head of the Environment Department, Francisco Martín, stated that the sanitation work proved to be a highly complex operation that was carried out "with clockwork precision and good taste, to provide service for nearly every one of the homes in a number of small towns that together have close to 90,000 inhabitants".

Because of the rough lie of the land and the sprawling distribution of the towns of Marina de Cudeyo and Medio Cudeyo, the sanitation system threw into sharp relief the need for a wastewater discharge collection and treatment system. To avoid the proliferation of small local treatment plants, the Environment Department developed a branching network made up of mains that collect practically all the zone's waste and convey it to a central wastewater treatment plant in Suesa. There the waste is appropriately treated before it is returned to the environment.

The sanitation work along the Arco Sur area of Santander Bay required the construction of fourteen pumping stations. The use of top-quality materials, special attention to details and finish quality and exhaustive quality control helped the established objectives to be achieved.