The new facility will replace an existing plant serving various municipalities in the Helsinki region. It is expected to start operations from the end of 2020.
It will occupy a surface area of about 13ha, of which 10ha will be underground. The facility will treat wastewater for a population of about 550,000.
The EIB said with respect to the sensitive ecosystem of the Baltic Sea, the facility is designed to treat the wastewater to very high standards. It exceeds the goals of EU urban wastewater treatment legislation and local environmental objectives.
Biogas will be generated by treating and digesting the sewage sludge. Heat produced during the facility’s operation will also be recovered to produce thermal energy.
HSY will process residual solids into agricultural fertilizers with a high organic and nutrients content.
EIB vice-president responsible for lending in Finland Jonathan Taylor said: "Support for sustainable drinking water supply services, wastewater treatment and improvement of aquatic biodiversity is one of the goals of the European Investment Bank.
"We are glad to be partnering with HSY in this project, as it will significantly reduce the pollution of receiving waters by sewage, address climate risks through energy recovery and improve conditions for the inhabitants of the Helsinki region and the Baltic Sea generally."
Image: Blominmaki waste water treatment plant. Photo: courtesy of HSY.