UWWTP Sopot - Advanced Wastewater Treatment in Sopot, Bulgaria

UWWTP Sopot is a wastewater treatment facility located near the town of Sopot in Plovdiv Province, Bulgaria. The plant serves a population of 3,125 and is designed with a capacity of 25,000 m³ per day, indicating it handles both domestic and possibly industrial flows from the area. The plant employs advanced treatment processes, which go beyond the secondary treatment requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations of this size (under 10,000 population equivalent), the directive typically requires secondary treatment, but Bulgaria has implemented advanced treatment in sensitive areas to protect water quality. The treated effluent is discharged into the local watershed, which ultimately drains into the Maritsa River, a major watercourse in the Balkans. The Maritsa flows through Bulgaria and Greece before reaching the Aegean Sea, supporting diverse aquatic ecosystems and agricultural water use along its course.

The plant discharges into the Maritsa River basin, which flows through the Thracian Plain and eventually into the Aegean Sea. This watershed supports important agricultural activities and provides habitat for various fish species. The advanced treatment helps reduce nutrient loading, protecting downstream water quality in the Maritsa and the Aegean coastal zone.