Water for a big city
SUE “Vodokanal of St. Petersburg” provides drinking water to 5 million citizens and tens of thousands of companies and enterprises. One more task of Vodokanal is to collect and treat wastewater.
Since 2013, endangered pinnipeds - grey seals and (Baltic and Ladoga) ringed seals- have been rehabilitated at the premises of Repino wastewater treatment plant in the Kurortny District of St. Petersburg.
10 October 2013, the biggest environmental project – the Northern Tunnel Collector construction – was completed
Since June 28, 2011 Saint-Petersburg has been fully implementing the Helsinki Commission's recommendations for preservation of the Baltic Sea
SUE "Vodokanal of St. Petersburg" is implementing the following major projects:
This program envisages, among other things, the completion of the extension of the Northern Tunnel Collector, and the modernization of the Northern and Central Wastewater Treatment Plants to comply with new requirements of HELCOM (The Baltic Marine Environment Protection Commission) regarding enhanced removal of nitrogen and phosphorus from wastewater.
The program is financed from the municipal and federal budgets, own funds of SUE “Vodokanal of St. Petersburg” and raised extra-budgetary funds.
The project of the construction of the Northern Tunnel Collector was approved in 1989 by the order of the Council of Ministers of RSFSR. The city's demand for a new, 12 km long section of the Tunnel Collector was dictated by the need for transportation of wastewater from residential houses and industries of Primorsky, Kalininsky, Krasnogvardeisky, partially Nevsky and Central districts to the Northern WWTP in Olgino. Originally, the NTC extension construction was planned for ten years. However, from 1993 to 2000 the construction was suspended due to the lack of financing. In 2001, allocation of funds from the St. Petersburg budget began aiming to maintain the construction works, but those funds were not enough for the planned large-scale works. In 2005, a new stage of the collector construction began. The first line of the NTC extension was put into operation in autumn 2008. It enabled us to channel direct wastewater discharges in the amount of 90,000 cubic meters per day to the sewage system and reach the level of 88% of wastewater treatment. Further connection of direct wastewater discharges to the NTC allowed to reach the level of 91% wastewater treatment by the end of 2009, 93% - by the end of 2010, 94% - by autumn 2011, 97% - by December 2012, 98,4% - since October 2013, 98,5% - since April 2015.
The extension of the NTC is a system of very complex engineering facilities: two lines of main tunnels with length of 12.2 km each and external diameter of 4 m each laid at a depth of 40-90 m; dozens of inlet and distribution chambers; many kilometers of connecting micro-tunnels. Besides, the NTC includes a unique facility – wastewater pumping station; it is a high-capacity pumping facility which regulates velocity of the wastewater stream through the collector to prevent silting.
The completion of the direct wastewater discharges closure in the NTC service area has ensured treatment of 98.4% of wastewater since October 10, 2013.
After that Vodokanal will have to eliminate direct wastewater discharge in the area of the Okhta River and the Karpovka River. Our company plans also to reconstruct wastewater treatment plants in the town of Kolpino and Pontonny settlement.
In December 2014, Vodokanal of St. Petersburg closed nine direct discharges of the Petrovsky Stadium which were the source of thousands cubic meters of untreated wastewater per day coming to the Neva River.
Direct wastewater discharges along Petrogradskaya Embankment were closed in the end of 2014, along Admiralteiskaya Embankment and the Fontanka River Embankment – in 2015.
The important stage of the Neva Untreated Wastewater Discharge Closure Program – the construction of the sewage collector along the part of Admiralteiskaya Embankment from Dvortsovy Proezd to the Senatskaya Square was completed in April 2015. It made it possible to close six untreated wastewater discharges, equivalent to approx. 1000 m3/day, into the Neva. Alongside with the completion of works at the Senatskaya Square, construction of the sewage network at the Repina Square was started. New sewage network enabled to close the direct discharge to the Fontanka River in Lotsmanskaya Street and to channel wastewater for treatment to the Central Wastewater Treatment Plant.
Today, 98.5% of wastewater undergoes treatment in St. Petersburg
In 2010, the construction of a new 350,000 m3/day water treatment block K-6 was completed at the Southern WTP. In early 2011, the supply of water from the new block to the customers began.
The distinctive features of the technological solution used in the design and construction of K-6 block are as follows:
The flush water produced at K-6 Block is treated with the release of sludge, which is disposed separately to prevent the Neva water contamination.
All water treated at K6 Block is disinfected with sodium hypochlorite and ammonium sulfate, then by UV-radiation.
In the coming years, new water treatment blocks will be built at the Northern Water Treatment Plant (800,000 cubic meters per day) and at the Main Water Treatment Plant (500,000 cubic meters per day).
St. Petersburg is the Russia's first city to develop an innovative water supply management system. With such system, parameters of water supplied to the network can be adjusted automatically, and water consumption data can be received online.
In 2010, the results of a pilot project of creating such a system within the area of Uritskaya pumping station - the territory with the population of about 140,000 people - were summarized.
Under this project, the modernization of 12 pumping stations was carried out and the existing pumping equipment was replaced with energy-efficient equipment. Modern network equipment (automated air valves, shock-proof valves) was installed. "Control points" were determined and on the basis of their readings the output pressure is automatically adjusted. Water quality monitoring devices were installed in the networks. Advanced high-precision water meters with online data transfer capability were installed in the networks and on the consumer side.
The water supply management system project in the Uritskaya area showed good results. The energy consumption reduced by almost 43 per cent. The unaccounted-for water reduced by 39 per cent. The number of network breakdowns reduced by 32 per cent.
Now, the water supply management system is being established in the Southern zone of St. Petersburg - with the population of about 1.5 million people. In the future, the system will be extended throughout the whole city.
Today, all the sludge produced by wastewater treatment is burnt at three sludge incineration plants. However, in the previous years (before the incinerators were constructed) sludge was disposed to special landfills. For instance, the area of Severny landfill in Novoselki is about 83 ha.
To eliminate a negative impact of sewage sludge landfills on the environment, a landfill reclamation project was designed on the basis of Geotube technology.
With this technology, special geotubes (filtration geotextile containers) are used where sludge is treated with chemicals. As a result, sludge is disinfected, dewatered and stabilized; odor is removed too. A harmless, odor-free substance is produced, which can be used for preparation of artificial soils.
In 2010, Vodokanal began the reclamation works at Severny landfill. It is expected to process all sewage sludge accumulated in the landfill by 2017.