GreeceWastewater treatment servicesOpen Greece – Wastewater treatment plant operation and sludge management for the Municipality of Serres ΔΗΜΟΤΙΚΗ ΕΠΙΧΕΙΡΗΣΗ ΥΔΡΕΥΣΗΣ ΑΠΟΧΕΤΕΥΣΗΣ ΣΕΡΡΩΝ (Δ.Ε.Υ.ΑΣ) Submission deadline November 11, 2026 Time not stated Contract value €5,844,800