How a septic tank works: device diagram and principle of operation of a typical design. How to make a country sewer Sewerage with a double septic tank

An urgent question that torments everyone who wants to live in private country houses without the ability to connect to a central water supply and sanitation is how to make an autonomous sewer. Indeed, without it, it is not possible to fully use such benefits of civilization as a bath, shower, sink in the kitchen, washing machine and much more. Sewerage in a private house can be equipped different ways, which we will discuss in this article. Choosing the right system for your individual conditions and needs, even more important than bringing it to life.

What can be a sewerage system - a private house with permanent and temporary residence

The option of arranging the drainage system in private homes is selected depending on several conditions:

House with permanent or temporary residence.
How many people permanently live in the house.
What is the daily water consumption per person in the house (depends on the number of water consumers, such as a bathroom, shower, toilet, sink, washbasin, washing machine, etc.)
What level of occurrence ground water.
What is the size of the plot, how much space can be used for treatment systems.
What is the structure and type of soil on the site.
Climatic conditions of the area.

More detailed information about the requirements can be found in the relevant sections of SanPin and SNiP.

Conventionally, all sewage systems in a private house can be divided into only two types:

Accumulation systems(cesspool without a bottom, sealed container for drains).
Wastewater treatment facilities(the simplest single-chamber septic tank with soil cleaning, a two-chamber septic tank - overflowing wells with natural cleaning, a two - three-chamber septic tank with a filtration field, a septic tank with a biofilter, a septic tank (aerotank) with a constant air supply).

The most ancient, proven for centuries and even millennia, way of arranging sewage is a cesspool. Some 50-70 years ago there was no alternative to this method at all. But at the same time, people did not use such a large amount of water in private homes as they do today.

The cesspool is a well without a bottom. Walls cesspool can be made of brick, concrete rings, concrete or other material. Soil remains at the bottom. When runoff from the house enters the pit, more or less clean water seeps into the soil, being cleansed. Fecal matter and other solid organic waste settle to the bottom, accumulating. Over time, the well is filled with solid waste, then it must be cleaned.

Previously, the walls of the cesspool were not made waterproof, then when filling the pit, they simply dug it in and pulled out a new one in another place.

I would like to note right away that a sewerage device in a private house using a cesspool is possible only if the average daily volume of effluents is less than 1 m3. In this case, soil microorganisms that live in the soil and feed on organic matter have time to process the water that penetrates the soil through the bottom of the pit. If the volume of runoff is more than this norm, the water does not undergo sufficient purification, penetrates into the soil and pollutes groundwater. This is fraught with the fact that wells and other water sources can be contaminated within a radius of 50 m. Adding microorganisms to the cesspool somewhat reduces the unpleasant odor emanating from it, and also speeds up the process of water purification. But still, it's not worth the risk.

Conclusion. A cesspool without a bottom can be built if there are visits to the house 2-3 days a week and do not consume much water. At the same time, the level of groundwater occurrence must be at least 1 m lower than the bottom of the pit, otherwise pollution of the soil and the water source cannot be avoided. Despite the lowest cost of arrangement, the cesspool is not popular in modern country houses and cottages.

Sealed container - storage tank

A sealed container is installed on the site near the house, into which sewage and waste from the whole house flow through pipes. This container can be ready-made, store-bought, and made of plastic, metal, or other material. And it can be mounted independently from concrete rings, the bottom is made of concrete, and the cover is made of metal. The main condition for installing sewerage in a private house of this type is complete tightness. Suitable for sewers corrugated pipes pragma.

When the container is full, it must be emptied. To do this, a sewer machine is called, the call of which costs from 15 to 30 USD. The frequency of emptying the tank, as well as the required volume, depends on the number of drains. For example, if 4 people permanently live in the house, use the bathroom, shower, sink, toilet, washing machine, then the minimum volume storage tank should be 8 m3, it will have to be cleaned every 10 - 13 days.

Conclusion. A sealed cesspool is one of the options for how to sewer in a private house if the groundwater level in the area is high. This will completely protect the soil and water sources from possible pollution. The disadvantage of such a sewage system is that you will often have to call a sewage truck. To do this, from the very beginning it is necessary to correctly calculate the installation location of the tank in order to provide convenient access to it. The bottom of the pit or container must not be deeper than 3 m from the soil surface, otherwise the cleaning hose will not reach the bottom. The container lid must be insulated to protect the pipeline from freezing. For such a sewer in a private house, the cost depends on the material of the container. The cheapest option would be to purchase second-hand eurocubes, the most expensive - concrete pouring or brick. In addition, there are monthly cleaning costs.

Single-chamber septic tank - the simplest option for soil cleaning

A single-chamber septic tank is not far from the cesspool, very often it is called that. It is a well, at the bottom of which crushed stone is covered with a layer of at least 30 cm, and coarse-grained sand is covered with the same layer on top. Wastewater flows through pipes into a well, where water, seeping through a layer of sand, gravel, and then soil, is cleaned by 50%. Adding sand and gravel improves the quality of water purification and partially faeces, but does not solve the problem radically.

Conclusion. Sewerage in a private house using a single-chamber septic tank is impossible with permanent residence and large volumes of drains. Only for temporary residences and low level ground water. After some time, crushed stone and sand will need to be completely replaced, as they will silt.

Two-chamber septic tank - overflow settling wells

as one of economical options sewers, which can be mounted independently, the arrangement of overflow settling wells and filter wells is universally popular.

This sewerage system in a private house consists of two wells: one with a sealed bottom, the second without a bottom, but with powders, as in the previous method (crushed stone and sand). Wastewater from the house enters the first well, where solid organic waste and feces sink to the bottom, fatty ones float to the surface, and more or less clarified water forms between them. At a height of about 2/3 of the first well, it is connected to the second well by an overflow pipe, located slightly at an angle so that water can flow there unhindered. Partially clarified water enters the second well, where it seeps through a powder of crushed stone, sand and soil, it is cleaned even more and leaves.

The first well is a sump, and the second is a filter well. Over time, the first well accumulates critical mass feces, for the removal of which it is necessary to call a sewage machine. You will have to do this about once every 4 to 6 months. To reduce the unpleasant smell, microorganisms are added to the first well, which decompose the feces.

Overflow sewerage in a private house: photo - example

A two-chamber septic tank can be made independently from concrete rings, concrete or brick, or you can purchase a ready-made (plastic) one from the manufacturer. In the finished two-chamber septic tank, additional cleaning will also take place with the help of special microorganisms.

Conclusion. It is possible to install a sewerage system in a private house from two overflow wells only if the groundwater level, even during a flood, is 1 m lower from the bottom of the second well. Ideal conditions is sandy or sandy loamy soil on the site. After 5 years, crushed stone and sand in the filter well will have to be replaced.

Septic tank with filtration field - biological and soil treatment

We turn to the description of more or less serious cleaning systems that allow you not to worry about environmental pollution.

This type of septic tank is one container, divided into 2 - 3 sections or several individual containers wells connected by pipes. Most often, having decided to equip just this type of sewage system, a factory-made septic tank is purchased.

In the first tank, wastewater settles, as in the previous method (settlement well). Through the pipe, partially clarified water enters the second tank or section, where anaerobic bacteria decompose organic debris. Even more clarified water enters the filtration fields.

Filtration fields are an area underground where wastewater is treated by soil. Due to the large area (about 30 m2), the water is purified by 80%. The ideal case is if the soil is sandy or sandy, otherwise it will be necessary to equip an artificial filtration field of crushed stone and sand. After passing through the filtration fields, water is collected in pipelines and discharged into drainage ditches or wells. Trees or edible vegetables cannot be planted above the filtration fields, only a flower bed is allowed.

Over time, the fields silt up, and they need to be cleaned, or rather, crushed stone and sand should be replaced. You can imagine how much work will have to be done, and what your site will turn into after that.

Conclusion. Laying a sewer in a private house, assuming the presence of a filtration field, is possible only if the groundwater level is below 2.5 - 3 m. Otherwise, it is quite constructive solution provided there is sufficient free space. Also, do not forget that the distance from the filtration fields to water sources and residential buildings should be more than 30 m.

Septic tank with biofilter - natural treatment station

The deep cleaning station allows you to complete the installation of sewage in a private house, even if the groundwater level is very high.

The septic tank is a container divided into 3 - 4 sections. It is better to purchase it from a trusted manufacturer, after consulting with professionals about the required volume and equipment. Of course, the price for such a sewer in a private house is not the lowest, it starts from 1200 USD.

In the first chamber of the septic tank, water is settled, in the second - the decomposition of organic matter by anaerobic microorganisms, the third chamber serves to separate water, since in the fourth chamber organic matter is decomposed with the help of aerobic bacteria, which need a constant supply of air. To do this, a pipe is mounted above the chamber, rising 50 cm above the ground level. Aerobic bacteria are planted on a filter installed on a pipe leading from the third section to the fourth. In fact, this is the filtering field - only in miniature and concentrated. Due to the small area of water movement and the high concentration of microorganisms, thorough cleaning water up to 90 - 95%. Such water can be safely used for technical needs - watering the garden, washing the car and much more. To do this, a pipe is diverted to their fourth section, leading either to a tank for accumulating treated water, or to a drainage ditch or well, where it simply soaks into the ground.

Sewage treatment in a private house - scheme of work:

Conclusion. Septic tank with biofilter - good decision for a private house permanent residence. Microorganisms can be added to the septic tank by simply pouring them into the toilet. There are no restrictions on the use of such a treatment plant. An undeniable advantage is that it does not require electricity. The only drawback is that sewerage wiring in a private house requires permanent residence, since without the constant presence of sewage, bacteria die. When new strains are introduced, they begin active activity only after two weeks.

Septic tank with forced air supply - artificial cleaning station

An accelerated cleaning station, where natural processes occur artificially. The construction of a sewerage system in a private house using an aeration tank will require electricity to be connected to the septic tank to connect an air pump and an air distributor.

Such a septic tank consists of three chambers or separate containers interconnected. Water enters the first chamber through sewer pipes, where it settles, and solid waste precipitates. Partially clarified water from the first chamber is pumped into the second.

The second chamber is actually the aeration tank, here water is mixed with activated sludge, which consists of microorganisms and plants. All microorganisms and bacteria of activated sludge are aerobic. It is for their full-fledged life that forced aeration is needed.

Water mixed with sludge enters the third chamber - a sump for deeper cleaning. Then the sludge is pumped back to the aeration tank by a special pump.

Forced air supply provides quite fast cleaning wastewater, which can then be used for technical needs.

Conclusion. Aerotank is an expensive, but necessary pleasure in some cases. The price starts from 3700 USD. There are no restrictions on the installation of such a sewer. Disadvantages - the need for electricity and permanent residence, otherwise activated sludge bacteria die.

Water supply and sewerage of a private house - general rules

Certain restrictions apply to the location of sewer facilities.

septic tank should be located:

no closer than 5 m from a residential building;
no closer than 20 - 50 m from the water source (well, well, reservoir);
no closer than 10 m from the garden.

House must be removed:

8 m from filter wells;
25 m from the filter fields;
50 m from aeration treatment plants;
300 m from drain wells or stations.

The pipes leading to the septic tank must be insulated so that they do not freeze through in winter. To do this, they are wrapped with heat-insulating material and inserted into asbestos-cement pipes. External sewerage wiring in a private house is carried out with pipes with a diameter of 100 - 110 mm, the slope should be 2 cm by 2 m, i.e. 2 °, in practice they do a little more - 5 - 7 ° (with a margin). But you shouldn’t joke with this matter, since a larger slope will lead to the fact that water will quickly pass through the pipes, and feces will linger and clog them, and a smaller angle of inclination will not ensure that wastewater moves through the pipes at all. It is advisable to lay the pipes in such a way that there are no turns and corners. For internal wiring of sewer pipes, 50 mm in diameter is sufficient. If the house has more than one floor, and bathtubs, sinks, and a toilet are also installed on the upper floors, then a riser with a diameter of 200 mm is used to drain wastewater down.

If you decide that you can handle the sewerage of a private house with your own hands, be sure to take into account all the restrictions of SanPin and SNiP regarding the location and design of the sewerage system. In order not to spoil relations with neighbors, consider the location of their water sources and other buildings.

The sewerage project of a private house is extremely important; you should not try to do without it. Sewerage is not a system that tolerates approximation. Contact design bureaus or architects, let the professionals create a working draft for you, taking into account all the features of the soil, site, climate and operating conditions. It is better if this project is completed along with the project of the house itself before the start of its construction. This will greatly facilitate installation.

If you are interested in the question of how to make a sewer in a private house at high groundwater levels, then based on all of the above, it can be such options:

Sealed container for accumulation of waste.
Septic tank with biofilter.
Aeration cleaning station (aerotank).

Direct installation work sewer system in a private house - not so complicated. It is necessary to lay pipes around the house that will collect drains from various sources, connect them to a collector and run through the foundation or under it along the ground to the septic tank. Earthworks can be done independently, or you can hire an excavator. But choosing the right sewerage system and drafting a project is much more important.

Sewerage in a private house: video - example

A country house is intended not only for a short vacation, but is also often used as a place of permanent residence. Therefore, the issue of arranging a modern country sewerage system is always relevant. Let's try to figure out which method of waste disposal is appropriate in certain conditions.

The choice of sewer system should be carried out taking into account specific conditions land plot, design features of the building, the number of residents, the frequency of use of the house. The right decision will help to make an analysis of the main existing species autonomous sewerage systems.

The oldest method of waste disposal, typical for small country houses for seasonal use. A cesspool is a container dug into the ground that receives liquid waste from a collector. To prevent problems with winter period, the pipeline is laid below the level of soil freezing, or insulated.

Storage tanks are made of brick, reinforced concrete rings, plastic, monolithic reinforced concrete.

The brick storage is mainly made in the form of a cylinder, which provides it with maximum strength. used silicate brick- as the material most resistant to the action of an aggressive environment.

Reinforced concrete rings form solid construction, which withstands the long-term aggressive impact of country sewage effluents. For the construction of a cesspool of reinforced concrete rings, heavy construction equipment is involved.

Plastic containers made of durable synthetic materials are reliable and durable. Plastic does not react to the destructive action of acids and alkalis, does not allow moisture to pass through. True, the cost of the tank is relatively high, but the installation can be done manually by a small team of workers.

A cesspool made of monolithic reinforced concrete is arranged on site using a removable formwork. Outside the drive, a waterproofing layer is required to protect the concrete from destruction by groundwater.

Storage tanks are installed in accordance with the requirements of building and sanitary standards:

The depth of the cesspool is determined taking into account the level of groundwater, and is not more than 3 m. The volume per tenant cannot be less than 0.5 m3, but it should be foreseen that the number of residents may increase.
The distance to sources of drinking water should be no closer than 20 m, to water conduits - no closer than 10 m, to the boundaries of the land plot - at least 1 m.
Distance from a residential building and outbuildings - at least 10-12 m.
The distance from the ground level to the maximum sewage mark in the pit should not be less than 35 cm, otherwise sewage waste may pollute the soil and water sources.

If groundwater passes close to ground zero, only a plastic tank can be used - other materials will not be able to completely seal the cesspool

The cesspool is cleaned at least twice a year. Simultaneously with cleaning, mandatory disinfection measures. A cesspool-type sewerage device is justified in seasonal residences if there are access roads for sewage trucks.

Septic tanks

The task of the septic tank is to separate solid impurities and purify wastewater to a sanitary safe level. Such separation is carried out by flowing sewage from one container to another. Final cleaning is carried out using filtration systems. Let us consider in more detail the work and arrangement of septic tanks for country sewerage.

Septic tanks with filtration well

In the filtration well, sewage is cleaned due to the biological film that is formed by microorganisms on the filter media. biological compounds contained in waste water, serve as food for biofilm microorganisms and are processed by them.

A septic tank with a filter well works as follows: dirty water It enters the settling tank through pipes (or passes through several settling tanks), while solid impurities settle to the bottom, and insoluble fatty particles rise to the surface.

Partially purified water is poured into the filtration well through a collector cut into the wall of the sump, and then passes through a filter made of sand and gravel with artificial components containing cultures of anaerobic microorganisms. Bacteria decompose biological waste, and purified water goes into the soil.

Wells are made of brick or reinforced concrete rings. A septic tank with a filter well is installed if the sewer inflow is not more than 1 m3 / day, and only on sandy soils and sandy loams: clay soils and loams, the well will be constantly clogged due to the low water absorption of soils. Replacement of sand and gravel cushion is made every 5-6 years.

Septic tanks with seepage wells they do a good job of cleaning wastewater in country cottages, designed for permanent residence of a family of 3-4 people.

Septic tanks with filtration field

The filtration field is a system of soil wastewater treatment, located under the soil layer and consisting of perforated sewer pipes and sand and gravel filter pads, at least 1 m thick. The area of the filtration field must be at least 30 m2.

Sewer drains go through several stages of treatment. First, they pass through pipes into a 2- or 3-chamber sump. In the first chamber, solid suspensions and water-insoluble fats are separated from water. Then water is coming into the following compartments, where it is additionally cleaned, and enters the distribution well.

From the distribution well, water passes into the perforated pipes of the filtration field, and through the holes in them enters the layers of sand and gravel, where it is completely absorbed. Over time, the filtration fields become silted up and the sand and gravel filter needs to be replaced. Septic tanks with a filtration field can be installed if the groundwater level is 2-3 m below the filtration cushions.

According to sanitary standards, the distance from the filtration field to residential buildings and water sources must be at least 30 m. Trees and horticultural crops. Only flower beds are allowed.

Such cleaning systems are suitable for large areas, and are designed for a large number of people, all year round living in the house.

Septic tanks with infiltrator

The infiltrator is an elongated plastic container without a bottom, installed on the filter bed of a gravel-sand mixture. It has an inlet pipe through which wastewater enters, which is then directed into the ground, and a ventilation pipe.

The infiltrator is located at a distance of 1-2 m from the septic tank. Options are possible when several infiltration tanks are placed in series. This design replaces the filtration field in small areas.

Wastewater passes through a septic tank where it is pre-treatment. Then, through the pipes, the clarified water goes to the infiltration tank, and is finally cleaned in the filtering gravel-sand layer, being completely absorbed into it.

Between the septic tank and the infiltrator, if necessary, mount an intermediate well with drainage pump, preventing the return of sewage into the septic tank. Such a purification system is needed if the estate is located on soils with low water absorption, and with a high occurrence of groundwater.

Septic tanks with an infiltrator are convenient to use on small areas, in houses with permanent residence of a large number of people.

Septic tanks with biofilter

The design consists of several chambers. In the first chamber, the sewage flowing through the inlet pipes is settled and separated into settled solid fractions and floating fatty compounds. Then, through a special membrane with holes, the clarified water passes into the next compartment, where it is coarsely cleaned from solid particles.

The final purification stage is carried out in a chamber with anaerobic microorganisms that process the remaining organic matter. Purified water enters the reservoir or drainage ditch. Water that has gone through all stages biological treatment can be used for technical needs.

Biofilter septic systems are used in permanent residences. It is convenient that you can introduce bioculture into the system by pouring the agent with them into the toilet. The only condition: the cleaning system should not be idle, as the bacteria can die, and the settlement of new ones takes place within two weeks.

Stations for biochemical treatment (aerotanks)

Such installations may consist of a single vessel divided into several compartments, or of several separate units. Sewage flows into the sump, where primary treatment takes place: all solid fractions settle on the filter.

Then, with the help of a pump, the liquid is fed into the aerotank - a reservoir rectangular shape, through which wastewater passes, mixed with activated sludge, consisting of algae and aerobic bacteria. With the help of microorganisms, all organic compounds in the wastewater are destroyed.

For the vital activity of aerobic microorganisms, a constant supply of oxygen is necessary, which is provided by pneumatic (through special diffusers) or mechanical (using blades, mixers) methods.

Water with sludge flakes leaves the aeration tank to the next settling tank, where the sludge settles, and clean water is discharged into a storage tank or drainage ditch. Water can be used for technical purposes. The settled sludge is fed back to the aeration tank for the next water treatment cycle.

Biochemical treatment stations are installed on any soil, in houses with a large number of residents. Provide a high percentage of sewage treatment. Their maintenance requires a constant supply of electricity. The cost of such installations is quite high.

Offers from MosKomplekt

When choosing a country sewerage system, it is necessary to take into account: the purpose of the house (for permanent or temporary residence), the composition of the soil, the level of groundwater, the size of the site, the planned volume of effluents, the financial capabilities of the owners and other conditions.

In order to correctly assess these conditions, you need to get expert advice. Our company offers services for the design and installation of sewer cleaning systems for country houses. MosKomplekt specialists guarantee high quality survey, design and installation works.

The cost of installation of turnkey autonomous sewage systems is from 80,000 rubles. The price depends on many factors, so the final cost of the work is determined by a detailed estimate.

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