Protection of the Baltic Sea

One of Vodokanal’s priority tasks is to mitigate negative impact of the megalopolis on the environment, thus improving the environmental conditions in the Baltic Sea Region.   

Within the commitments undertaken by the Russian Federation to fulfil the Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea, St. Petersburg Vodokanal implements large-scale activities targeted to the reduction of untreated wastewater discharges and removal of nutrients (nitrogen and phosphorus) from wastewater.    

The Convention on the Protection of the Marine Environment of the Baltic Sea (Helsinki Convention) was signed by all Baltic Sea states in 1974. The Convention for the first time dealt with all polluters located in the catchment area of the Baltic Sea. After political changes stemmed from the collapse of the USSR, establishment of new independent states, unification of 2 Germanys and development of the international environmental law, the new Helsinki Convention was signed in 1992 by the states located along the coast of the Baltic Sea and the European Community. It was put into effect upon the ratification on January 17, 2000. The Russian Federation approved the 1992 Helsinki Convention in October 1998. 

The main purpose of the Convention is to protect the marine environment of the Baltic Sea, restore and preserve the environmental balance in the Baltic Sea region and ensure sustainable use of its resources.

Member-countries committed to take all necessary legislative, administrative and other measures to prevent the Baltic Sea pollution and eliminate the existing pollution sources for the purpose of the Baltic Sea ecosystem rehabilitation.

Prevention of the Baltic Sea pollution with nitrogen and phosphorus is a pressing problem for all Baltic Sea states.

The governing body of the Convention is the Helsinki Commission, the Baltic Marine Environment Protection Commission (HELCOM), which in particular issues recommendations (regulations) for municipal wastewater treatment.   

In the 1990s, for the first time ever, the Helsinki Commission adopted uniform parameters for nutrients (nitrogen and phosphorus) removal for all Baltic Sea states. These parameters are constantly made more stringent.

New recommendations for municipal wastewater treatment adopted on November 15, 2007 set forth much more stringent requirements to wastewater treatment. Discharges of effluent into water bodies had to meet the following parameters: total nitrogen -10 mg/l, total phosphorus – 0.5 mg/l.

SUE “Vodokanal of St. Petersburg” all-time improves biological wastewater treatment technologies, in particular, to fulfil stringent requirements to phosphorus compounds removal.   

To meet new requirements and stabilize nutrient removal process at wastewater treatment plants of St. Petersburg, as long as in 2005, the enhanced biological treatment and chemical phosphorus precipitation were introduced at wastewater treatment plants.

In June 2011, St. Petersburg fully met new recommendations of the Helsinki Commission: content of phosphorus in the total municipal wastewater discharge did not exceed 0.5 mg/l.

The President of Finland Tarja Halonen participated in the official ceremony marking this event. 

By now, the enhanced nutrient removal processes have been implemented at all wastewater treatment plants of St. Petersburg.

Achievement of stable treatment parameters is facilitated by constant reconstruction of existing facilities.

Thus, the wastewater treatment plant in the town of Petrodvorets with the capacity of 50,000 m3/day was accepted for operation in 1976. As housing construction expanded, the hydraulic load on this plant also increased. 

In 2011, Petrodvorets wastewater treatment plant was set into operation after reconstruction. The capacity of the reconstructed plant is 65,000 m3/day in dry season and 72,000 m3/day in wet season.   

The distinctive feature of this plant is the tertiary treatment stage in the process flow. At the last treatment stage the treated effluent undergoes ultraviolet disinfection.

An important project targeted to the fulfilment of HELCOM recommendations is the completion of the Northern Tunnel Collector. 

In December 2012, Vodokanal closed five untreated wastewater discharges along the Pirogovskaya Embankment, which total flow was 30,000 m3/day. Now, this wastewater is channeled via the Northern Tunnel Collector to the Northern Wastewater Treatment Plant. As a result wastewater treatment level in St. Petersburg reached 97%.

The construction of the Northern Tunnel Collector was completed in October 2013. Channeling of the remaining untreated wastewater discharges to the collector allowed to ensure treatment of 98.4% of all municipal wastewater.

In December 2014,   Vodokanal closed nine untreated wastewater discharges from the Petrovsky Stadium with a total volume of about 1,000 m3/day. Moreover, at the end of 2014, untreated wastewater discharges were closed along the Petrogradskaya Embankment; in 2015 – along the Admiralteiskaya Embankment and the Fontanka Embankment. 

In April 2015, an important stage of the Neva Untreated Wastewater Discharges Closure Program was completed – the construction of the sewage collector along Admiralteyskaya Embankment from Dvortsovy Proezd to the Senatskaya Square. As a result, six untreated wastewater discharges into the Neva equivalent to about one thousand cubic meters in total were diverted. Simultaneously with the completion of works in the Senatskaya Square, works on the construction of the sewer network in the Repina Square began. Thanks to the new sewer networks, the untreated wastewater discharge into the Fontanka was closed in Lotsmanskaya Street. Now, the wastewater goes to Central WWTP to undergo a full treatment cycle.

In 2016, Okhta tunnel collector was actively constructed. The Okhta tunnel collector construction is one of the key measures for untreated wastewater direct discharge elimination. The Okhta tunnel collector construction would enable elimination of wastewater without treatment discharge into the Okhta River and real estate development of St.Petersburg and Leningrad region.

In addition, “Reconstruction of storm water sewerage system within the Murinsky park territory landscaping program” project works were carried out in 2016 within the program for surface runoff discharge to surface water bodies elimination in order to reduce negative environmental impact.

Today, 98,5% of wastewater is treated in St.Petersburg.