PORRERES Wastewater Treatment Plant, Porreres, Illes Balears, Spain

The PORRERES wastewater treatment plant is located in Porreres, on the island of Mallorca in the Illes Balears region of Spain. It serves a population of 7,329 and operates with advanced treatment processes, ensuring high-quality effluent. The plant has a designed capacity of 5,500 m³/day and currently discharges 810.35 m³/day of treated wastewater. As an advanced treatment facility, PORRERES goes beyond secondary treatment to remove nutrients and other pollutants, meeting stringent EU standards. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), plants in sensitive areas like the Balearic Islands often require tertiary treatment to protect coastal and marine environments. The plant's capacity utilization is low, indicating it has room for future growth. The treated effluent from PORRERES is discharged into the local watershed, which ultimately drains into the Mediterranean Sea. The Balearic Islands are ecologically sensitive, with diverse marine life and seagrass meadows that depend on clean water. By providing advanced treatment, the plant helps reduce nutrient loading and protects the coastal ecosystem from eutrophication.

PORRERES plant discharges into the Pla de Mallorca basin, which flows to the Mediterranean Sea. The coastal waters around Mallorca support Posidonia oceanica seagrass meadows, a critical habitat for fish and marine biodiversity. Advanced treatment reduces nitrogen and phosphorus, preventing algal blooms and preserving water quality in this ecologically sensitive region.