• Untreated wastewater discharge closure

By 2012 the Northern tunnel collector extension will be completed. This will allow to treat 98 - 99% of all wastewater in the city, improve the environmental situation in the historical part of the city and decrease the influence of untreated wastewater discharges on the water quality around the intakes of the Main Waterworks. It will also allow to eliminate the last remaining “hot spot” according to the HELCOM classification for which Vodokanal of St. Petersburg is responsible.

• Reconstruction and extension of the wastewater treatment plants

The construction of the Collector and the closure of untreated wastewater discharges will increase the volume of wastewater collected by the treatment plants. For this purpose, reconstruction (and in the future - extension) of the Northern WWTP is required among other things; then it will be possible to provide sewerage to the new developments (“Severnaya Dolina”, districts of the Northern coastal area, “Kamenka", “Yuntolovo”) and raise the effectiveness of wastewater treatment.

To provide wastewater disposal from new buildings in Pushkin, Pavlovsk, non-residential areas in "Shushary", "Metallostroy”, “Obuchovo” and other areas, the reconstruction and extension of the wastewater treatment plants in Metallostroy are necessary.

Among other projects are construction of a wastewater treatment plant in Lomonosov and modernization of the wastewater treatment plant in Zelenogorsk.

All these projects envisage implementation of UV disinfection technology and enhanced nutrient removal in compliance with HELCOM requirements.