A programme to improve potable water quality is ongoing in Moscow. ‘Today is a big day for the Rublyovskaya Water Treatment Station, and for millions of Muscovites in 26 city districts who use water from the station,’ Moscow Mayor Sergei Sobyanin said during his inspection of the facility, where there has been a major renovation effort. The station uses the ozonation-sorption method in order to achieve a marked improvement of the quality of water, which becomes odourless and more transparent.
Water in the Moskvoretskaya Water System is worse than in the Volzhsky Water Source, which explains why the Rublyovskaya Station was the first to install the complex treatment systems. ‘These are not simple projects. Still, I just issued an instruction to begin design work at the Zapadnaya Station to fully upgrade it for the use of this new technology. As a result, these stations, which are at the forefront of ensuring the quality of water we consume, will have new technology to bring water treatment to a level that conforms with the European standards,’ the Mayor said.
The Moscow office of Rospotrebnadzor, Russia’s consumer rights watchdog, monitors the water quality at all the four stations: Rublyovskaya, Zapadnaya, Severnaya and Vostochnaya. ‘We look at water quality at 203 sites,’ says Yelena Andreyeva, Moscow’s Chief Sanitary Officer, who heads water monitoring efforts, ‘and we conduct around 5,000 tests across 80,000 indicators during the year.’ The tests cover organoleptic, physico-chemical, microbiological, virological and radiological indicators. The results show that Moscow’s water meets the requirement of Sanitary Rules and Regulations.
‘What is interesting about this new block, which is going live today, is that it uses a highly efficient method of water purification,’ Yelena Andreyeva said. ’The method features two stages, namely, ozonation and sorption, or water purification.’ She added that Moscow’s water quality has significantly improved: ‘Moscow’s water is completely safe given the amount of oversight and monitoring conducted by various bodies. Even tap water is safe to drink.’
Oldest water treatment station
The Rublyovskaya Water Treatment station is located on the right bank of the Moscow River. It supplies water to the 26 districts in western, northwestern and central Moscow with a population of 2.3 million: Mitino, Strogino, Krylatskoe, Northern and Southern Tushino, Shchukino, Sokol, Kurkino, Begovoi, Presnensky, Kuntsevo, Fili-Davydkovo, Filyovsky Park, Dorogomilovo, Ochakovo-Matveyevskoye, Ramenki and others. It also supplies water to several towns in the Moscow Region.
The station entered service in 1903, and today it is the oldest of the four facilities. In the early 20th century it featured a water intake unit on the riverbank, a pump station with steam-powered piston pumps, sedimentation reservoirs, and slow, or ‘English’, filters. Water then flowed through on its own into fresh water reservoirs in Vorobyovy Gory.
The Ryublyovskaya Station was built according to architect Maxim Geppener’s designs. His mastery and unorthodox approach produced structures that were extremely well-built and thought-out, as well as being beautiful both individually and as a complex. Access to the top of the Vorobyovsky Reservoir, for instance, offered spectacular views of Moscow. The Vorovyovo Village was a well-known place to take a stroll, and the open area on the top of the reservoir became the first step on the road to the present-day view spot in Vorobyovy Gory.
The station was designed to treat 175,000 cubic metres a day, but treated only 133,000 in 1917. In the 1920s, the facility was expanded and received a mixer, new sedimentation reservoirs and filters, and centrifugal pumps to replace the older models. The construction of a new dam lead to a new intake unit, which supplied water to the Rublyovskaya Station and the Cherepkovsky treatment facilities. Another renovation took place in the 1960s and 1970s. The ‘slow filter’ building was demolished and a new water collection and pump station were built.
Ozonation-sorption and filtration
In order to improve water quality, Treatment Block 4 was put into operation at the Rublyovskaya Station in 2002, which utilises modern technologies of ozonation-sorption and membrane filtration. The block has the capacity of 240,000 cubic metres of water a day.
A similar facility, Block 1, with the capacity of 400,000 cubic meters went live in 2010. Construction of Block No 2 was concluded in 2016. The facility, which entered operation in August, 2017, has four separate operation lines and the capacity of 320,000 cubic metres a day. Each line can operate independently to employ different treatment regimes and provide for maintenance and repairs efforts if needed. All the processes are automatic and managed by a central control point.
Block No 2 features:
– water clarification facilities: intake tanks, carbonization tanks, mixers, flocculation tanks, sedimentation tanks, fast filters;
– ozonation-sorption facilities: contact ozonation reservoirs, carbon filters;
– compressor station for filter washing;
– reagent facilities, ozonizer, destruction unit;
– facilities and the system of storage, loading and unloading of activated coal and sand;
– external pipelines and utility lines.
A total of 32 sand and carbon filters, equipped with the Triton drainage system, have been installed. The characteristic feature of the block is its use of Russia-made high-capacity ozonizers (KO75C). Moskovskiye Ozonatory (Moscow Ozonizers) in cooperation with other Russian companies produce the systems. The KO75C complex is on a par with world’s best devices.
Unlike under classical schemes, water purified by the new block is more transparent and has almost no odour.
Before Block 2 went live, the Rublyovskaya Station supplied around 640,000 cubic metres of water treated under the new scheme. The figure has since grown to 850,000 cubic meters, which represents 30 percent of total water consumption in the city.
This level can become 960,000 if the block reaches its design capacity. Correspondingly, less water is coming from the Severnaya Station, which still uses traditional treatment methods.
Steps towards clean water
Mosvodokanal, Russia’s largest water organisation, is responsible for the supply of water to nearly 15 million residents of Moscow and several towns in the Moscow Region.
Apartments in Moscow receive water from surface sources of the Moskvoretskaya, and the reserve Vazuzskaya (Moskva River) and Volga River water systems with the water catchment area of 50,000 square kilometres. Every day, consumers receive nearly 3 million cubic metres of water.
Treatment takes place at the four stations: Rublyovskaya, Severnaya (built in 1952), Vostochnaya (1937) and Zapadnaya (1964). Each station’s area of responsibility is based on its geographic location.
In 2012, sodium hypochlorite (NaOCl) replaced liquid chlorine as a water disinfection agent at all the four stations. Hypochlorite is as efficient at killing bacteria as chlorine but, unlike the latter, it is non-flammable, non-explosive and low-toxic. It is supplied to the stations by vehicles, which cuts the cost of expensive railroad deliveries.
The transition to hypochlorite:
– increases water supply reliability and safety;
– increases water supply system stability against possible acts of terror;
– removes a highly toxic agent from the process, chlorine;
– puts a stop to the rail transportation of 3,400 tonnes of chlorine across the Moscow region every year;
– reduces emergency risks.
In 2015, Mosvodokanal built its own sodium hypochlorite production plant.
In addition, between 2002 and 2017, the Ryublovskaya and Zapadnaya stations saw the construction of new treatment blocks that employ modern technologies of ozonation-sorption, or water treatment using granular activated coal, and membrane filtration, or pushing water through a semipermeable membrane. The new techniques complement the older methods of sedimentation, filtration and purification through reagents.
After Treatment Block 2 was commissioned at the Rublyovskaya Station, the volume of water treated with ozonation, ozonation-sorption, and membrane filtration reached 64 percent, or over 1,8 million cubic metres out of around 3 million cubic metres a day.