According to the Commission, "310,000 citizens living in the area will benefit from a modern and extended waste water treatment system", while the project "will also contribute to protecting the groundwater and reducing pollution in the region".

The is the biggest environmental project in the 2014-2020 financial programme for Slovenia, which has been pushing hard for the support since 2015.

The plan is to upgrade the central treatment facility in Ljubljana and close down the existing overburdened facilities at Brod, Pirniče, Rakova jelša, Vodice and Polje.

The project, which is expected to be completed by 2020, will provide access to the public wastewater discharge and treatment system for almost 22,000 people not currently connected to the public sewage.

More than 130 kilometres of new sewage lines, three vacuum stations, 16 waste water pumping stations and a retention basin are to be built, the Government Office for Development and European Cohesion has explained.