Natalia Ipatova
For St. Petersburg, the Neva is the only source of drinking water. The river originates in Lake Ladoga and is a natural drainage route to the city. Therefore, the condition of the water in Ladoga is extremely important.
98% of the drinking water supplied to the city comes from the Neva. Another 2% is groundwater, which is used to supply water to suburbs, mainly in the southeast.
The Neva comes to the city already polluted. On the way from Ladoga to St. Petersburg, it receives untreated wastewater from other populated areas, runoff from agricultural fields and discharges from enterprises.
The Neva comes to the city already polluted. On the way from Ladoga to St. Petersburg, it receives untreated wastewater from other populated areas, runoff from agricultural fields and discharges from enterprises. Moreover, the Neva is the final link of the entire unified water system of the North-West (it includes Lake Onega, Lake Ilmen, Lake Ladoga with their drainage basins). Therefore, the water utility always says that it is impossible to restore order only in “its” area. Pollution has no boundaries, and the issue of wastewater treatment in the Leningrad region, Karelia and other regions of the North-West must be urgently resolved. That's what we do.
Is tap water really “drinkable”?
This may surprise some, but drinking water is first and foremost water from centralized drinking water supply systems, water at the outlet of water supply stations, from street pumps and reservoirs. And only then – bottled
non-mineral water. In other words, the water that comes from the tap is officially
Suitable for drinking without prior filtration and boiling.
Corrosion products may appear in drinking water. However, in such quantities they are not dangerous to the health of citizens
Natalia Ipatova
Director of the Department of Information and Public Relations
State Unitary Enterprise "Vodokanal of St. Petersburg"
Drinking water in St. Petersburg is guaranteed to be safe and harmless. This means that drinking water from the tap will not cause any harm to your health.
Those rare cases when deviations from standard values are recorded in tap water are associated exclusively with the iron content in it. The fact is that Neva water is naturally soft. Therefore, it is suitable for preparing drinks and using at home. Thus, washing machines and dishwashers in the homes of St. Petersburg residents do not require special water softeners. But it is the natural softness of our water that makes it corrosive. During the period of active development of Leningrad (1970s-1980s – Author’s note) water pipes were made of steel, which, unfortunately, is very susceptible to corrosion processes. Because of this, corrosion products can sometimes appear in drinking water. However, in such quantities they are not dangerous to the health of city residents and only affect the taste properties of water.
On this issue, the opinions of Vodokanal and environmental organizations differ somewhat:
Healthy people, of course, can drink tap water and nothing will happen to them. But asthmatics or allergy sufferers may already have problems
Yuri Shevchuk
Chairman of the North-West interregional public environmental organization "Green Cross"
It is important to understand that Vodokanal works with standards, and, therefore, focuses on healthy people. They, of course, can drink tap water and nothing will happen to them. But asthmatics or allergy sufferers may already have problems. These are the people who most often complain about contaminated water.
In general, water quality is assessed by three indicators: bacteriological composition, chemical and mineral. There are almost no bacteria in drinking water in St. Petersburg (which is why, by the way, people rarely get hepatitis here). In terms of chemical indicators, the situation is already twofold: Vodokonal works well, the water is completely purified from harmful chemical elements. However, passing through urban, often outdated networks, it becomes polluted again. If we take an old pipe and cut it, we will find a greenish coating inside (these are microorganisms), as well as rust. You can get rid of them only with the help of local filters: either in the apartment or throughout the house. But this is a subjective reason for poor water quality.
The water in Lake Ladoga is ultra-fresh, it contains few mineral compounds that are so necessary for humans
And the objective reason and the saddest characteristic of St. Petersburg drinking water is its mineral composition. The water in Lake Ladoga is ultra-fresh, it contains few mineral compounds that are so necessary for humans. Therefore, city residents are often prescribed to take magnesium and calcium - bones become very fragile due to such water.
How does Vodokanal combat pollution?
Natalia Ipatova
Director of the Department of Information and Public Relations
State Unitary Enterprise "Vodokanal of St. Petersburg"
The Neva is a navigable river, and Vodokanal is certainly obliged to take this into account. Therefore, several years ago, all water stations in St. Petersburg installed dosing units for powdered activated carbon. They purify water from petroleum products. The same installations are used during seasonal deteriorations in water quality in the Neva, for example, during floods.
In addition, Vodokanal has a system for early detection of pollution in the river. It includes a biomonitoring system using crayfish. The crayfish's workplace is an aquarium, into which Neva water is supplied from the water intake, which has not undergone treatment. Special sensors are attached to the cancer's shell, which record the cancer's heart rate and stress index online. The system is based on the fact that, if hazardous substances enter the Neva water, the crayfish reacts instantly: its heart begins to beat much faster, and the corresponding signal is immediately sent to dispatchers.
There is also an early detection system for oil products in the Neva. Before the Neva enters the city, in front of the first water intake of Vodokanal, special equipment is installed on the bridge - the so-called “crabs”. These are devices that measure the thickness of the oil film on the surface of the water and the concentration of oil products in it. All received data is transmitted to the control room - and then they decide whether to turn on the dosing units for activated powdered carbon or not.
Foreign experience
Piterstory selected several cities where the purity of tap water is almost a source of pride, and buying it in plastic bottles is considered bad taste.
Stockholm
Sweden has many natural lakes, the largest of which are Vänern, Vättern and Mälaren. Stockholm is located on the east coast of the latter. Firstly, the water in the lake itself is perfectly clean, a sure indicator of which is the salmon and trout that live there.
Secondly, in Sweden, quite tasty drinking water is obtained by treating wastewater.
Helsinki
Water comes to the capital of Finland from Lake Päijänne through a 120-kilometer-long tunnel. At the initial stage, it passes through a water intake, then enters through a tunnel to water treatment complexes, is ozonized, undergoes normalization of the acid-base balance, is filtered again and, finally, purified by an ultraviolet disinfection system.
Vein
Every day Vienna receives 400,000 cubic meters of water through two pipelines from mountain springs in the areas of Schneeberg, Rax, Schneealpe and Hochschwab. Therefore, you can safely drink tap water, especially since it is served with coffee in any establishment.
And the water tower in the style of “industrial historicism” remained in Vienna solely as a monument.
Zurich
Not only in Zurich, but also in any other Swiss city, the water is crystal clear for a very obvious reason - it comes from the mountains. In addition, the country has abandoned the use of pesticides in agriculture. Well, the Romandian Consumer Federation claims that tap water in Switzerland is 1000 times more environmentally friendly and 500 times cheaper than bottled water.
Even St. Petersburg residents do not all know from what source the water is supplied to their taps, although most know - from the Neva. And in other cities of Russia, where does water for water pipes come from?
Reservoirs – natural-man-made reservoirs with drinking water
For example, the capital is supplied with water from a reservoir. A reservoir is a dam on a river with an artificially widened bed and a reinforced bottom.
The water accumulated in the reservoir is purified and supplied to the water supply systems of populated areas. Like Moscow, water is withdrawn from reservoirs in Irkutsk, Yuzhno-Sakhalinsk and many other cities.
Water intake from rivers flowing through the city
Other settlements - these include, for example, Yakutsk and our native St. Petersburg - are supplied with water from rivers flowing through the city. But there are regions where natural reservoirs are so far from populated areas that the financial component of developing water supply systems does not allow using them as sources of water intake. Wells are drilled in such places: this is how Tula and the Tula region (and not only) are supplied.
Spring water from the tap
Kronstadt is in a special position. Surrounded by water, the island of Kotlin, on which Kronstadt stands, cannot provide itself with drinking water from the Gulf of Finland, since it will have to be additionally desalinated. Delivering water from the Neva River will be too expensive. The problem was solved in a unique way: in the Lomonosov district of the Leningrad region there are natural springs - Goslitsky springs. After going through the water treatment process (the water is disinfected at the stations with sodium hypochlorite, the strongest and most effective antiseptic), the water is sent through the conduit to the siphon. Duker is a tunnel stretching along the bottom of the Gulf of Finland from the southern coast to Kotlin Island. So the Kronstadt residents drink spring water.
Problems with water wells
Underground springs are also used by residents of some areas of the Sakhalin region. Water, as in the Lomonosov district of the Leningrad region, is disinfected with chemical reagents and iron-free using the technology of biological reduction of iron concentration, developed by scientists from the Far East.
During operation, water wells gradually age and fail. Thus, in Yuzhno-Kurilsk it was necessary to reconstruct the entire water supply system, since fifty percent of the wells stopped producing water, and the remaining ones could fail at any moment. Major modernization of the underground water pipeline and the drilling of new wells ensured a continuous supply of water to the water supply system of Yuzhno-Kurilsk.
Do you know?..
In Kalmykia, where there are a sufficient number of lakes and rivers, including the Volga, there is a problem with drinking water. On average, one resident of Kalmykia uses eight (!) liters of water per day.
Water shortages are linked to environmental problems in the region. The authorities promise to build the reservoir as early as 2015, and by 2018 to fully provide the region with drinking water.
"Where does water come from in the plumbing system?" BC "POISK", tell friends: May 20th, 2017
Perhaps everyone knows that the huge boiler-cooling towers and striped chimneys emitting smoke, which are visible from anywhere in the city, belong to the thermal power plant. Moreover, many people know that these colossuses provide our homes with light, heating and hot water. But what exactly is the process of heat generation and how cooling tower columns are involved in it is a rather confusing question.
Consumables
The entire process of CHP operation begins with water preparation. Since it is used here as the main coolant, it requires preliminary cleaning before entering the steam boiler, where the main metamorphoses will occur with it. To prevent scale on the walls of boilers, the water is first softened - its hardness sometimes needs to be reduced by 4000 times, and it also needs to be removed from various impurities and suspended matter.
As a rule, gas, coal or peat are used as fuel for heating water boilers at various power plants. The combustion of these materials releases thermal energy, which is used at the station to operate the entire power unit. Coal is ground before use, and the incoming gas is purified from mechanical impurities, hydrogen sulfide and carbon dioxide.
Steam production
The huge steam boiler in the turbine hall - the height of a 9-story building is not the limit - can be called the heart of the thermal power plant. It is powered by prepared fuel, releasing a huge amount of energy. Under its force, the water in the boiler turns into steam with an outlet temperature of almost 600 degrees. Under the pressure of this steam, the generator blades rotate, resulting in the creation of electricity.
The thermal power plant also produces thermal energy intended for heating and hot water supply to the region and city. For this purpose, there are selections on the turbine that remove part of the heated steam before it reaches the condenser. The exhausted steam is transferred to a network heater, which acts as a heat exchanger.
Heating network
Once in the tubes of network heaters, the water is heated and transferred through underground pipelines further into the heating network due to pumps driving the water through the pipes. Heating networks, as a rule, carry water at 70-150 degrees - it all depends on the temperature outside: the lower the degree outside, the hotter the coolant.
The central heating point (CHS) becomes the transfer point for the coolant. It serves an entire system of buildings, an enterprise or a microdistrict at once. This is a kind of intermediary between the object that creates heat and the direct consumer. If water in a boiler room is heated due to fuel combustion, then the central heating station works with an already heated coolant.
Hot water recipe
The supply of coolant ends at the entrance to the central heating substation or ITP (individual heating substation) - thus, the coolant is transferred for further actions into the hands of the HOA or other management company. It is at the heating point that the hot water that we are used to dealing with is created - the water coming here from the thermal power plant heats clean cold water from the water intakes in the heat exchanger and turns it into the very hot water that flows in our taps.
After heating the building and room, this water gradually cools, its temperature drops to 40-70 degrees. Part of this water is mixed with the coolant and supplied to our hot water taps. The road to the other part is back to the station, here the cooled water will be warmed by network heat exchangers.
What are cooling towers for?
The majestic and massive towers, called cooling towers, are not the reactors and centers of action in a thermal power plant and actually play a supporting role. Surprisingly, they are used in heating plants to cool water. But why let water that is constantly heated cool?
Cooling towers use the second part of the “return”, which has gone through a heating-cooling cycle. But its temperature is still quite high: 50 degrees is too high for further use. The water that has been in cooling towers is used to cool the condensers of steam turbines. This is necessary so that the steam that has passed through the steam turbine can enter the condenser and condense on the cold pipes inside it. These pipes are precisely cooled by the water that has passed through the cooling tower, the temperature of which is now about 20 degrees. If they are not cooled, then there will be no steam flow through the turbine, and then it will not be able to work. The condenser will again turn the steam into water, which will be recirculated.
People cannot imagine their life without water. Land owners have the opportunity to build a well and take water from it for all household needs.
The situation is completely different in apartment buildings and urban areas. To provide residents with water, city authorities allocate a significant percentage of budget funds. This money goes towards installing water supply systems and their ongoing repairs. A minor breakdown in the system can have catastrophic consequences.
Throughout human life, water surrounds us: in the form of drinking, an ingredient for cooking and as a means of hygiene. Natural reservoirs, artificially created ponds, wells and wells have different purposes, but their importance is invaluable. Desert dwellers and nomadic tribes value water above all else.
Let's look at how water gets into the taps of a city apartment. The first step on this path is water intake stations. They pump water from natural sources or from reservoirs. After this, it goes into special large tanks. They contain sophisticated Aquaphor water purification filters that can purify large volumes of liquid. Contaminants, in the form of sediment and other mechanical particles, remain outside and do not enter the containers. The water in these reservoirs undergoes additional purification with special solutions that remove organic compounds and disinfect it.
Purified water, with the help of powerful pumping communications, passes into the pipes under high pressure. Each water intake station is designed for a certain capacity and can supply both the minimum amount of water and the maximum possible. To do this, observations are made of water consumption at certain time periods and depending on the time of year. The stations must have backup pumps and other equipment necessary in cases of breakdown of the main one and during repairs. If emergencies occur, their presence is vital for the people who are provided with water from this source of supply.
The pumping station consists of a system of pumps on which reverse osmosis filters are installed, internal motors and electrical supplies. For uninterrupted operation of pumping and filtering equipment, electrical power is required. It should not be interrupted because water supply to the population is a priority. Equal in importance to water supply are fire safety and emergency medical services.
The power sources of each water intake station are central power supply and stationary, switched on in emergencies. On the territory of the station there are generators that can have a diesel or gasoline operating principle. The power of the generators is designed to provide, in a minimum mode, all the needs of people not only in the “dormitory areas”, but also in the industrial zones of the city.
The equipment of water intake stations is constantly inspected. If malfunctions occur, they are eliminated in the shortest possible time. Every day, water samples are taken at the outlet to the city system. Sanitary and epidemiological stations conduct analyzes that examine the presence of dangerous chemical elements and pathogenic bacteria.
Uninterrupted operation of water supply systems and excellent water quality indicators are the key to public health.
Beware of the water we drink. The latest data, current research O. V. Efremov
Chapter 1. Where does the water in the tap come from?
First, let's look at where the water in the tap comes from, how it gets there, and what kind of cleaning it goes through along the way. Water can get into the city water supply from two sources: using a water intake on the river and from artesian wells, which are drilled specifically for these purposes.
How does water intake occur on the river? Hydraulic jacks are laid on the shore, with the help of which the river bottom is pierced with steel pipes. The water, partially filtered by sand and clay, flows through pipes into the water intake structure. Here, large mechanical impurities are retained with the help of meshes and gratings. Then the water enters treatment stations, passes through numerous filters, is freed from the remaining suspended matter, while moving rather slowly and undergoing chemical treatment before entering settling tanks. The water then passes through filters, and the treatment plant is capable of removing 99% of the bacteria contained in natural water, and the water is considered potable. However, in each city or town, the degree of purification, despite all-Russian standards, may be different. The time of year also matters - during a flood, when melting snow penetrates the water intakes, the water will be dirtier and the risk of catching any infection increases.
Water is supplied from artesian wells according to a slightly different pattern. Conventionally, it can be considered cleaner, because in this case the water is raised from a depth of 100 or even more meters - at such a depth it is sufficiently filtered by the soil and is less susceptible to environmental pollution. At artesian wells, deferrization stations are usually installed, which make it possible to remove excess salts and metals from the water; the rest of the purification is carried out according to the plan already described.
But the greatest danger to the population is not the water that enters the water supply, but the water that comes out of it. The fact is that in large cities, water supply systems are gigantic complex and branched networks, which require considerable effort and money to maintain in proper condition. Over time, the pipes become overgrown with all kinds of deposits, and the walls corroded by corrosion burst. And while the water purified at the station reaches the apartment, it is again “saturated” with harmful impurities. The water receives so-called “secondary pollution”. As a result, the water that flows from the tap is not suitable for drinking and cooking without additional purification.
Under continuous exposure to water, water pipes corrode, rust and become thinner. Rust itself is a very “nutrient” environment for the development of various pathogenic bacteria and microorganisms that have adapted to chlorine. And, I must say, there are many of them.
Tap water can contain various insoluble impurities - sand, rust and sediment that “flakes off” from corroded pipes; various construction waste that enters the water supply system after repair work, etc.
Particularly dangerous to our health are salts of heavy metals that may be contained in drinking water. The worst thing is that heavy metals have the ability to accumulate in the body. And if such “enriched” water is used for many years, the concentration of heavy metals can reach alarming levels and cause extremely negative changes in the human body. The source of heavy metals in “secondary pollution” can be copper pipes, various adapters, taps, valves made of non-ferrous metals, low-quality solder that was used when welding water pipes, etc.
This text is an introductory fragment.