New outfall to improve wastewater treatment in Sa Coma

Works will facilitate the safe release of treated water from the Sant Llorenç treatment plant

What does it consist of?

The construction of a marine outfall for the Sa Coma treatment plant will enable more efficient management of treated water and put an end to discharge in infiltration wells, a practice that had caused problems in the local network. The works come in addition to other actions aimed at improving the water cycle in the coastal area.

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Data

PROJECT TITLE IN THE CALL
Construction of the sea outfall of the Sa Coma wastewater treatment plant.
LOCATION
Mallorca (Sant Llorenç des Cardassar)
Entity submitting the PROJECT
Conselleria de la Mar i del Cicle de l'aigua
Entity that executes the project
Ajuntament de Sant Llorenç des Cardassar
Project code
ITSE2023-165
Total project amount
5.472.250 €
ITS granted amount
5.472.250 €
Executed amount
0 €
Call year
2023E
Budget implementation status
Started
Purpose
Environment
Budget execution
Executed: 0%
Last updated
26.02.2026

The project

The Sa Coma wastewater treatment plant, refurbished in 2016, serves the entire municipality of Sant Llorenç des Cardassar and can treat up to 11,500 m³ of wastewater per day. Despite the effort to reuse as much recycled water as possible, the system still generates a surplus that must be released safely.

In order to address this challenge, a new marine outfall has been designed to extend the current land section and allow the treated water to be carried up to 2,900 metres out to sea, at a depth of 32 metres. This distance and depth ensure a good dilution of the effluent, with parameters well below the legal limits and a minimum environmental impact.

The project involves an investment of 5,472,250 euros and has been considered a priority by Sant Llorenç Town Council, which has called it as one of the most important interventions in recent years. In addition to its technical complexity, it plays a key role in the completion of the recycled water system along the entire coastline of the municipality.

At present, the effluent from the WWTP is discharged into the subsoil via infiltration wells, a system that has proven to have limitations. This infrastructure eliminates the above risk and enables progress towards more efficient water management in line with long-term environmental sustainability criteria.