Ravda Wastewater Treatment Plant – Nessebar–Sunny Beach–Ravda Urban Area

The Ravda Wastewater Treatment Plant serves the sewer systems of the town of Nesebar, the Sunny Beach resort complex, the village of Ravda, the village of Kosharitsa, the town of Aheloy, the village of Tankovo, and part of the town of Sveti Vlas (the old town and the eastern part of the neighborhoods below the main road), and is located within the municipal boundaries of Aheloy. The plant was originally commissioned in 1968. In 2005, a major reconstruction was carried out, during which the technology was completely overhauled and four SBR units were commissioned with a total capacity of 75,000 PE and a hydraulic load of 19,400 m³/d.
In 2012, the Municipality of Nessebar, in partnership with the Municipality of Pomorie, implemented a project titled “Collection, Treatment, and Disposal of Wastewater from the Nessebar–Sunny Beach–Ravda Agglomeration.” The project is being implemented with financial support from the “Environment 2007–2013” Operational Program, co-financed by the European Cohesion Fund. The total project budget amounts to 95,842,113.85 BGN, of which 92,931,940.64 BGN is grant funding and self-financing of 2,910,173.22 BGN.
In 2015, the project was completed and a second (new) line was commissioned with a capacity of 156,000 PE and an authorized hydraulic capacity of 36,500 m³/d during the summer season, and 11,350 m³/d during the winter season, for an annual water volume of 20,367,000 m³/y. The total capacity of the Ravda WWTP amounts to 222,000 PE.
The treatment plant has been transferred to “Water Supply and Sewerage” EAD, Burgas, for management, maintenance, and operation. The

main facilities at the Ravda WWTP are: SBR
line – 75,000 PE:
• primary treatment – 3 step screens with a compactor and a grit chamber;
• biological treatment – SBR reactors;
• reagent plant for dephosphatization.
New line – 156,000 PE:
• primary treatment – screens, sand trap, primary clarifier;
• biological treatment – a bio-reactor with integrated denitrification, internal recirculation, and simultaneous chemical phosphorus removal;
• secondary clarifiers;
• sludge treatment – primary sludge thickeners, mechanical thickening plant, anaerobic sludge stabilization in methane tanks, stabilized sludge thickeners, screw presses for mechanical sludge dewatering;
• reagent storage facility for dephosphatization;
• Disinfection – UV system for disinfecting the treated water prior to discharge into a deep-water outfall.

The treated wastewater is discharged into the Black Sea via a deep-water outfall.