Procuring 230 Football Fields of Membrane - Strategy, Results and Lessons Learned

Stockholm is currently one of Europe’s fastest growing cities, with its population increasing by approximately 1.5% per year, corresponding to 15,000 to 20,000 people. Sweden’s commitment to the Baltic Sea Action Plan and the EU Water Directive will lead to more stringent effluent requirements (6 mg-Tot-N/l, 0.2 mg-Tot-P/l and 6 mg-BOD₇/l), and wastewater treatment in Stockholm will require major investment to handle these challenges. As Stockholm Vatten’s two wastewater treatment plants (WWTPs) – Bromma, 320,000 people, and Henriksdal, 780,000 people – are both located in or near residential areas in the city, plant development must be coordinated with its needs on economic, political, sustainable and long-term bases. Both WWTPs being facilities located underground also pose a challenge for any extension works.