Opening a faucet with cold or hot water in the morning, none of us thinks about the fact that a hundred years ago this level of comfort was absolutely inaccessible for the overwhelming population of our planet.

Only wealthy owners of comfortable apartments in big cities could afford the use of water supply and sewerage.

The overwhelming majority of the population, like thousands of years ago, had to carry water in buckets from the nearest well, stream, or at best from a standpipe.

The twentieth century has radically changed the way of life of man. It was a century of revolutionary changes in many spheres of life, including the public sector.

Water supply and sewerage came to literally every house and from a luxury item they became an urgent need for both urban and rural life. However, not all residents of city apartments understand how the water supply system of their house is arranged, where water comes from and where it leaves the sink, bath or toilet.

Water purification

We all know that today drinking water drawn from a river or lake without first filtering and boiling it is dangerous for health. But the water that fills our water pipes is usually drawn from the nearest large body of water. Of course, it first goes through a complex cleaning system at the water intake station.


Water purification is carried out in several stages. First, river water is pumped from the river into the station's storage tank with powerful pumps. There it passes through several filter pipes with gratings, being cleaned of large debris - fragments of wood, algae and other contaminants.

Then you should catch and precipitate small particles of sand, silt, pieces of algae. To do this, water is passed through several filters, first filled with coarse gravel, then finer. From the smallest particles of dirt, water is purified by passing through a filter made of washed river sand.

The next stage is disinfection, which is performed either by adding a disinfectant to the water or by ultraviolet irradiation. The second method is more modern and completely harmless to human health. However, in some regions, water is still disinfected by chlorination.

City water supply

The water supply system of a modern large city is a complex engineering structure, consisting of several main lines and numerous branches suitable for individual houses and apartments.

In the past, in order for water to flow through pipes, a water tower was used with a reservoir located at a high altitude. Water was pumped into the reservoir, and from there it was supplied through pipes to houses and apartments.

In a modern city, this system would not be able to meet the needs of even one microdistrict. And how high would a tower be needed to create enough pressure to supply water to the 25th floor? Therefore, the necessary pressure in the pipes is created by powerful electric pumps located in the most important nodes of the water supply network.


True, in the event of a major power outage, an urban area can be left not only without electricity, but also without water. To avoid this, pumping stations are equipped with independent or backup sources of electricity.

In order to reach your home, river water must pass through a system of filters, through several powerful pumps, and through a labyrinth of pipes. And if it is hot water, then through the boiler of the boiler station that provides heat to your area.

Sewer system

Bringing water to every house and apartment is only half the problem. When you turn on the faucet to wash your face or wash the dishes, the used water flows out into the sink hole. But where does she go then?

Wastewater from the kitchen sink, bathtub, shower and toilet drains into the sewer pipe, and from there it goes into the central sewer line. Waste water from many apartments and houses is collected there.

With the help of special fecal pumps designed for pumping dirty clogged water, sewage is diverted from residential areas and industrial enterprises.

Unfortunately, it is by no means possible to simply dump wastewater into the river. They contain a lot of harmful and poisonous pollution, which, once in the river, will quickly poison all living things in it, turning it into the same sewer, only on a larger scale. Therefore, waste water must be treated without fail.

Each city has a special treatment plant (and in large cities there are usually several), where the water is completely freed from dirt and becomes suitable for discharge into the river or for reuse.

Cleaning is carried out, as in the case of tap water, in several stages. But even purified water is not suitable for drinking - it is discharged into the irrigation systems of nearby agricultural enterprises.


In order for us to use the things familiar from childhood - a water tap and a bathroom - utilities do a great job every day. Do not forget about it and do not waste water in vain, because it is our wealth!

After arranging a local treatment plant, you should think about where to divert treated water. The constant call of a sewage truck is not the most financially profitable option, especially in the case of intensive use of autonomous sewage. There are several ways to organize a drain from a septic tank without violating the ecology of the site and the surrounding area.

The main task of any septic tank is the temporary accumulation of wastewater and their subsequent treatment. Such a structure can be made independently or purchased a finished product. In this case, the degree of wastewater treatment will depend on the complexity and technological equipment of this design. In this regard, septic tanks can be divided into several main types:

• Single-chamber sump (degree of purification< 70%). Это герметичная емкость, куда попадают стоки непосредственно из канализационной трубы. Под воздействием естественных процессов жидкие бытовые отходы разлагаются на ил, газ и осветленную воду. Ил скапливается на дне камеры, газовая фракция выводится в атмосферу с помощью вентиляционного отверстия, а осветленная вода поступает в фильтрующий колодец, где подвергается почвенной доочистке.

Single-chamber septic tank with soil aftertreatment

• Two-chamber sump (70-75%). This design consists of a primary and secondary clarifier. Heavy fractions settle to the bottom in the first chamber, and lighter organic compounds enter the second compartment, where they decompose under the influence of anaerobic bacteria. As in the first option, draining water from such a septic tank requires additional treatment.

Scheme of a two-chamber treatment plant

• Deep biological treatment (85-98%). Structurally, such septic tanks are a solid block consisting of several chambers and a number of special equipment. In addition to the standard settling stage, here the water is exposed to the action of aerobic bacteria, which require oxygen supplied by the compressor for their vital activity. This technology significantly accelerates the process of decomposition of organic compounds and increases the degree of water purification to very high levels.

Where to drain water from a septic tank: important nuances

There are several ways to remove clarified water:

• on relief;
• into the ground;
• into the reservoir.

In any of these cases, preliminary cleaning must be of high quality. First of all, this concerns the complete absence of inorganic debris. In addition, if the cleaning level does not exceed 70%, then the septic tank is drained only through additional filtration. It is forbidden to bring such water to the surface, given the high probability of contamination of the upper layers of the soil with harmful bacteria.

It is important to know. Anaerobic bacteria in the primary septic tanks contribute to the decomposition of organic matter with the release of heat and explosive gases. After exposure, silt remains, which contains pathogens of many infections. These residues must be regularly removed with a vacuum cleaner.

Sludge from the septic tank should be removed at least once a year

Stations for deep biological treatment allow water to be drained to the surface, since activated sludge based on aerobic microorganisms allows you to decompose dirt without releasing components harmful to the soil. Many manufacturers claim almost 100% efficiency of such structures and allow the discharge of purified water into the reservoir. However, with the organization of the drain from the septic tank to a natural source, some difficulties may arise, which will be discussed at the end of the article.

Discharge of clean water into a ditch

The easiest way to drain clarified water is to organize a drain from the septic tank into a ditch, pit or ravine, which are located next to the site. This option is usually used in dachas or in cottage villages with a low building density.

If the water meets sanitary standards, then the drain will not have a detrimental effect on the ecology of the surrounding area. On the other hand, there may be problems with neighbors. Not everyone will like the fact that, although purified, but still household drains will flow next to their site. Therefore, the drain outlet is best positioned in such a way as not to cause discomfort to others.

Note. Water withdrawal outside its territory may be limited based on the results of the general meeting of residents of the village. Based on this, it is better not to enter into conflict with neighbors, but to try to find a solution that satisfies all parties.

Before leading the drain directly into the ditch, it is advisable to equip an additional filtration zone. To do this, the drain from the septic tank is led into a filter trench with a drainage pipe, which is located below the freezing level of the soil and sprinkled with rubble.

Organization of draining water from a septic tank into a ditch: 1 - treatment plant; 2 - filtering trench with a drainage pipe; 3 - gravel-sand filter; 4 - ditch; 5 - groundwater level

Soil treatment options

If groundwater is located at a sufficient depth from the surface, then soil post-treatment of water can be applied. This drain option is often used for one- or two-chamber septic tanks, where the level of wastewater treatment is not high enough to bring to relief.

absorption well

A filter well can be made from bricks, concrete rings, cast-in-place concrete, and even car tires. The bottom in such a design is not concreted, but is covered by 30-40 cm with gravel or crushed stone. Clarified water from the septic tank with the help of a pipe enters the well, from where it seeps into the ground through a gravel cushion. The main condition, which, however, applies to all options for soil post-treatment, is that the filter zone must be located at least 20 m from the source of drinking water.

Scheme of installation of the absorption well

From a technical point of view, an infiltrator is the common name for all soil treatment devices. However, most often this term is understood as a specific type of structure, which is a hybrid of an absorption well and a filter trench. Such a drain from a septic tank has a wide filtration zone, which allows you to remove treated effluents even in conditions of low permeability of the soil.

Advice. If the soil does not absorb moisture well, which primarily applies to clay, it is necessary to increase the filtration area. To do this, you can use a larger infiltrator or use several designs.

The infiltrator allows you to remove wastewater in a larger volume than a simple absorption well

Filter field

The most effective method of soil post-treatment is the use of a filtration field. This is a complex of filtering trenches, consisting of several drainage pipes connected to each other. This design allows you to remove and clean a large amount of liquid. And most importantly, the area of ​​the zone is selected based on the needs of the consumer.

In order for the system to work more efficiently, a ventilation riser is installed at the end of each pipe. Thus, the field elements communicate with the atmosphere, which improves the cleaning process.

Typical design of the filtration field

Draining water into a natural reservoir

The owners of sites located in the immediate vicinity of a lake or river often have a question - is it possible to drain water from a septic tank directly into a reservoir? Manufacturers of some deep cleaning systems, such as Topas, Bioksi, etc., assure that the degree of purification is quite high, so that treated effluents can be discharged into a natural source without any problems. However, is everything so clear? On the one hand, cleaning at the level of 98% (again, according to manufacturers) meets sanitary standards. On the other hand, there are some points that make one think about the advisability of such an undertaking.

• Purified water must first be submitted for analysis. It must meet the standards for several dozen chemicals.
• The local treatment plant will have to be officially registered as a separate facility.
• The operation of the septic tank will need to be constantly monitored so that its mode and operating conditions comply with technical standards.

Obtaining permission to discharge waste into a reservoir is accompanied by many bureaucratic procedures

What can be the conclusion? Theoretically, it is possible to drain water from a deep-cleaning septic tank into a reservoir after receiving official permission. In practice, few people are legalizing such a procedure. Many simply do not advertise their intentions, risking running into a large fine. In this situation, it is better to give preference to soil purification or, in extreme cases, organize a drain from the septic tank into a ditch. And the most correct option is to turn to specialists. Then there will be no problems either with the quality of the drain or with the law.

Possessing natural curiosity, many of us at least once in our lives wondered where sewer water flows.

Sewer types

Depending on the type of sewage, its contents flow in the following directions:

• designed to drain water that is formed from precipitation of rain, snow, storm sewers drain into nearby water bodies;
• the contents of industrial sewage flows into a special, local cleaning system and, having passed it, is returned for use in production needs;
• domestic, household sewage passes in the following way - first it flows in the direction of treatment facilities (either into the general city sewerage system, or into a septic tank - separately built near the house, holiday village). Further, wastewater is pumped by sewer pumping stations to the treatment facilities of the city or village.

Industrial enterprises in many cities are also connected to the city sewer system.

Wastewater treatment plant

Water purification devices play a major role in the entire chain, since after passing through all the stages, the water enters the reservoir.

The first step is mechanical cleaning, that is, heavy and large particles are separated from the effluents that have entered the treatment plant. This is followed by the stage of cleaning the total mass of contaminants that have not dissolved. Next comes the biological treatment (disinfection) of wastewater, sanitary control. Only after all this water enters the reservoir.

The process of wastewater treatment is associated with the formation of sediments, so the processing of these is an important task.

As a rule, treatment plants have methanetanks (sludge digestion device) into which wet sludge enters. If there are no digesters, then the sediments, having passed the primary settling tanks, enter the biological treatment plant (sometimes along with chemical treatment), are dehydrated and discharged into the reservoir. During the chemical cleaning process, coagulation agents are added.

The throughput of the station, its capabilities vary, therefore biological treatment can be complete and incomplete.

It is much easier and more economical not to build a separate sewer system for industrial waste and bring it to the citywide system, but ... in the case of such negligence, the treatment cycle is disrupted. Most of all in such cases, the biological stage of purification suffers, since many beneficial microorganisms die under the action of acids, alkalis, chromium cyanides and other chemical elements.

Even if they neglected a separate sewerage system for industry, there should be at least a preliminary treatment of industrial wastewater at the entrance to the citywide sewer system.

The organization of the sewer system in the private sector is a little easier. Here, the sewage treatment plant is a collector of two tiers or a septic tank. After treatment in them, wastewater flows through the drainage system or directly into the ground. Precipitation (sludge) formed after cleaning is accumulated in a special tank and periodically pumped out by special equipment.

The Village continues to tell how the things that the townspeople use every day work. In this issue - the sewerage system. After we press the flush button on the toilet, turn off the faucet and go about our business, tap water turns into sewage and begins its journey. To get back into the Moscow River, she needs to go through kilometers of sewer networks and several stages of cleaning. How this happens, The Village found out by visiting the city's wastewater treatment plant.

Through the pipes

At the very beginning, water enters the internal pipes of the house with a diameter of only 50-100 millimeters. Then it goes along the network a little wider - courtyards, and from there - to street ones. At the border of each yard network and at the point of its transition to the street, a manhole is installed, through which you can monitor the operation of the network and clean it if necessary.

The length of city sewer pipes in Moscow is more than 8 thousand kilometers. The entire territory through which the pipes pass is divided into parts - pools. The section of the network that collects wastewater from the pool is called a collector. Its diameter reaches three meters, which is twice as large as the pipe in the water park.

Basically, due to the depth of the foundation and the natural topography of the territory, the water flows through the pipes itself, but in some places pumping stations are required, there are 156 of them in Moscow.

Wastewater enters one of the four treatment facilities. The cleaning process is continuous, and the peaks of the hydraulic load occur at 12 noon and 12 noon. Kuryanovskie treatment facilities, which are located near Maryin and are considered one of the largest in Europe, receive water from the southern, southeastern and southwestern parts of the city. Effluent from the northern and eastern parts of the city is fed to treatment plants in Lyubertsy.

Treatment

Kuryanovsk treatment facilities are designed for 3 million cubic meters of wastewater per day, but only one and a half comes here. 1.5 million cubic meters is 600 Olympic pools.

Previously, this place was called the aeration station, it was launched in December 1950. Now the treatment plant is 66 years old, and Vadim Gelievich Isakov worked here for 36 of them. He came here as a foreman of one of the workshops and became the head of the technological department. When asked if he expected to spend his whole life in such a place, Vadim Gelievich replies that he no longer remembers, it was so long ago.

Isakov says that the station consists of three cleaning units. In addition, there is a whole complex of facilities for the treatment of sediments that are formed in the process.

mechanical cleaning

Muddy and foul-smelling sewage comes to the treatment plant warm. Even in the coldest time of the year, its temperature does not fall below plus 18 degrees. Waste water is met by a receiving and distributing chamber. But what happens there, we will not see: the cell was completely closed so that the smell did not spread. By the way, the smell on the huge (almost 160 hectares) territory of the treatment plant is quite tolerable.

After that, the stage of mechanical cleaning begins. Here, on special gratings, garbage that floated along with the water is retained. Most often, these are rags, paper, personal hygiene products (napkins, diapers), as well as food waste - for example, potato peelings and chicken bones. “What you will not meet. It used to be that bones and skins from meat processing plants sailed, ”they say with a shudder in the sewage treatment plants. Of the pleasant - only gold jewelry, although we did not find eyewitnesses of such a catch. Seeing the trash-retaining grate is the most terrible part of the tour. In addition to all the nastiness, many, many circles of lemons were stuck in it: “You can guess the time of the year by the contents,” the employees say.

A lot of sand comes with wastewater, and so that it does not settle on structures and clog pipelines, it is removed in sand traps. Sand in liquid form enters a special area, where it is washed with technical water and becomes ordinary, that is, suitable for landscaping. Wastewater treatment plants use sand for their own needs.

The stage of mechanical cleaning in the primary settling tanks is being completed. These are large tanks in which fine suspension is removed from the water. Here the water comes in cloudy, and leaves clarified.

Biological treatment

Biological treatment begins. It takes place in structures called aerotanks. They artificially support the vital activity of a community of microorganisms, which are called activated sludge. Organic pollution in water is the most desirable food for microorganisms. Air is supplied to the aeration tanks, which does not allow the sludge to settle, so that it comes into contact with the wastewater as much as possible. This goes on for eight or ten hours. “Similar processes take place in any natural reservoir. The concentration of microorganisms there is hundreds of times lower than what we create. Under natural conditions, this would last for weeks and months,” Isakov says.

The aerotank is a rectangular tank divided into sections, in which waste water snakes. “If you look through a microscope, then everything is crawling, moving, moving, swimming. We make them work for our benefit,” our guide says.

At the outlet of the aeration tanks, a mixture of purified water and activated sludge is obtained, which now need to be separated from each other. This problem is solved in secondary settling tanks. There, the sludge settles on the bottom, is collected by sludge pumps, after which 90% is returned to the aeration tanks for a continuous cleaning process, and 10% is considered excess and is disposed of.

Return to the river

Biologically purified water undergoes tertiary treatment. To check it, it is filtered through a very fine sieve, and then it is dumped into the outlet channel of the station, on which there is an ultraviolet disinfection unit. Ultraviolet disinfection is the fourth and final stage of cleaning. At the station, the water is divided into 17 channels, each of which is illuminated by a lamp: the water in this place acquires an acidic hue. This is a modern and the largest such block in the world. Although according to the old project it was not, earlier they wanted to disinfect the water with liquid chlorine. “It’s good that it didn’t come to that. We would have killed all living things in the Moscow River. The reservoir would be sterile, but dead,” says Vadim Gelievich.

Simultaneously with water treatment, sludge is dealt with at the station. Sludge from the primary clarifiers and excess activated sludge are treated together. They enter the digesters, where, at a temperature of plus 50-55 degrees, the process of fermentation goes on for almost a week. As a result, the sediment loses its ability to rot and does not emit an unpleasant odor. This sludge is then pumped to dewatering facilities outside the Moscow Ring Road. “30–40 years ago, the sediment was dried on silt beds under natural conditions. This process lasted from three to five years, but now the dehydration is instantaneous. The sediment itself is a valuable mineral fertilizer, in Soviet times it was popular, state farms took it with pleasure. But now no one needs it, and the station pays up to 30% of the total cleaning costs for disposal, ”says Vadim Gelievich.

A third of the sludge breaks down, turning into water and biogas, which saves on disposal. Part of the biogas is burned in a boiler house, and part is sent to a combined heat and power plant. A thermal power plant is not an ordinary element of treatment facilities, but rather a useful addition that gives treatment plants relative energy independence.

Fish in the sewer

Previously, there was an engineering center with its own production base on the territory of the Kuryanovsky wastewater treatment plant. Employees set up unusual experiments, for example, they bred sterlet and carp. Some of the fish lived in tap water, and some in the sewer, which was cleaned. Now, fish is found only in the discharge channel, there are even signs “Fishing is prohibited” hanging there.

After all the purification processes, the water goes through the discharge channel - a small river 650 meters long - into the Moscow River. Here and everywhere, where the process takes place in the open air, many seagulls swim on the water. “They do not interfere with the processes, but spoil the aesthetic appearance,” Isakov is sure.

The quality of treated wastewater released into the river is much better than the water in the river in terms of all sanitary indicators. But drinking such water without boiling is not recommended.

The volume of treated waste water is equal to approximately one third of all water in the Moscow River above the discharge. If the sewage treatment plants were to fail, the settlements downstream would be on the verge of an ecological catastrophe. But this is practically impossible.