how it works, the scheme, principle of operation, installation of the structure

When building a private house, located far from the central sewage system, there is a need to build an autonomous system. A wastewater treatment facility would be a suitable option, and how well a septic tank will be equipped, it will be more convenient for residents. How should be equipped with a septic tank, the principle of operation and its device in our article.

how it works, the scheme, principle of operation, installation of the structure

The main components of a septic tank for a country house

Device layout and principle of operation of a septic tank

When considering the design and principle actions of the sump, it is found that all treatment facilities have much in common.

Most of the autonomous sewage systems are combined tanks for the phased purification of waste and sediment in the form of insoluble particles of different inclusions.

Tanks are made of various materials (reinforced concrete rings, tires from cars, bricks, flat slate). And also they are made in different configurations.

Principle of operation

The principle of operation of a septic tank equipped according to all the rules is a complex scheme, as a result of which the negative impact on the soil and the environment is minimized. According to the traditional scheme, a septic tank is a sewage treatment plant, and it looks like a device of two or three chambers. The first tank is a repository for waste directly from the sewer line.

Here the mixture decomposes. In the chamber, the sewage disintegrates under the action of bacteria into a silty substance and settled water.

IMPORTANT! The first tank should be with such a volume that it is enough for use for three days, during which the mass decomposes.

After the water has settled and cleared a little, it flows into the second chamber - the filtration well. If the first tank is made hermetically according to SNiP, then the second one should be made with a drainage bottom (gravel, gravel or sand). Water passes through the drainage, is filtered and absorbed into the ground, thereby not polluting it.

how it works, the scheme, principle of operation, installation of the structure

The scheme of the simplest septic tank with soil aftertreatment

Strengths and weaknesses of septic tanks

Depending on how a septic tank was arranged, the living conditions of the family were drastically improved, and this would be the main advantage of such a sewage treatment plant. In addition, he has many other advantages. Consider them in more detail:

  1. Long life.

  2. There are no unpleasant odors in the local area.

  3. Frequently it is not necessary to order an assenizator machine.

  4. The risks of soil contamination are perceptibly reduced.

  5. Easy and reliable installation. Their device also uses ready-made septic tanks "Termite drives" or "Tank" - stations for complete decomposition of waste.

The disadvantages of the settling tanks include a large amount of excavation work at the device and the high cost of polymer septic tanks.

Septic tank or cesspool: the nuances of choice

In a modern house, a large amount of water is consumed for household needs, requiring disposal. When constructing a sewage system, you first have to choose between a simple cesspool and a septic tank. What problems have to face when choosing? Let us examine these details in more detail:

Disposal rules . The cesspool is a simple store for waste, and they remain there until they overflow the store.

how it works, the scheme, principle of operation, installation of the structure

To clean the cesspool, you will need regular services of an assenizator machine

The greater the composition of the family and the water distribution devices, the greater the water consumption. The construction of a septic tank makes it possible to use it not for preservation, but for cleaning up waste; at the same time, wastewater treatment takes place at 70 - 80%.

Number of tanks . The cesspool is a single repository - a classic septic tank includes two or three chambers.

Service . It is necessary to pump out contents from a hole in process of filling. The septic tank needs cleaning much less often, not more often than once a year.

Frequency of use . If the sewage treatment plant is needed at the dacha, where there is seasonal living, then it probably does not make sense to install a volumetric device and, more financially more expensive, a septic tank. The sump will be enough.

On our website you can find contacts of construction companies that offer the service of designing and installing sewage and water supply. Directly to communicate with representatives, you can visit the exhibition of houses "Low-rise Country".

Septic tanks with soil tertiary treatment of household wastewater

The operation of a local sewage treatment plant depends on the processing conditions of household waste. In this regard, septic tanks can be divided into two types: with ground filtration; with full biological cleansing.

how it works, the scheme, principle of operation, installation of the structure

After bio-cleaning, water can be drained into the drainage well

Let us examine in more detail what the difference is between them.

Wastewater treatment plants with soil cleaning

The operation of a septic tank with natural filtration is based on gravity. It is well known that any household waste is 90-95% water.

The remaining five percent are impurities that, after settling the mixture, settle to the bottom. By this principle work septic tanks from two or three chambers.

In the first case, waste is filtered in the second chamber through the crushed stone layer, and in another embodiment, the final purification through the soil takes place in the third tank or on a specially created filtration field (if the groundwater is high).

Septic tanks with complete biological cleansing

Such methods of complete cleaning allow to achieve the greatest effect, since they are based on the decomposition of substances under the influence of biological enzymes.

The recycling of waste in such a purification plant directly depends on the active work of the microorganisms. Therefore, constant monitoring of the process is necessary to prevent the death of live bacteria.

It might be interesting! In the article on the following link read about the septic tank for the toilet.

Design and preparatory measures

The main requests for the construction of septic tanks are indicated in the SNiP (building codes and regulations). Before starting the installation of a sewage treatment plant, it is necessary to coordinate the project at the Sanitary and Epidemiological Station (SES);

how it works, the scheme, principle of operation, installation of the structure

Standards governing the placement of a septic tank in the area

When developing a project for a septic tank, first of all you need to take into account the requirements of SNiP and SES , while they inform about the following:

  • The shortest interval to the building is 5 m.

  • Distance to the nearest water intake (well, well) - 50 m.

  • Distance to the flowing origin of water (river, stream) - 10 m.

  • Interval to a source with standing water - 30 m .

For competent drafting a project for a septic tank, you need to present for yourself the prices on m installation work, and also know the approximate prices for materials. In addition to this cost, it is necessary to take into account the cost of the land works, which are inevitable for such a purification plant.

Preparatory work

Before proceeding with the installation of a septic tank, it is necessary to prepare. It implies ground work and the calculation of parameters affecting the correct choice of location and the efficiency of the treatment plant.

Preparatory work includes:

  • Analysis of the soil structure and the relief of the planned area for the septic tank.

  • Checking the depth of groundwater. From this parameter depends on the deepening of the installation, as well as the filtering method.

how it works, the scheme, principle of operation, installation of the structure

For high groundwater, the design of a volatile septic tank with a drainage pump
  • Preparing the site for the future septic tank. (Clearing the area of ​​foreign objects).

  • Markup.

  • Digging a pit for a structure and trenches for sewer pipes.

After the excavation has been dug with the dimensions for the installation, you can proceed to the installation.

Installation of septic tanks: some tips from professionals

Consider what might be the difficulties when installing a finished septic tank. First, you need to choose a reliable, competent installation company that installs a sewage treatment plant.

Secondly, take into account what material the septic tank is made of - propylene or polyethylene, and what is the thickness of the walls. Thirdly, it is necessary to ask not only the price of equipment and the cost of installation, but also the cost of servicing the service (the cost of pumping out).

It is advisable to acquire septic tanks of well-known brands, since in such a case it is possible to hope that spare parts and a service company are available in this region.

In order to determine the size of a septic tank, it is necessary to take into account, first of all, the number of water fittings installed in the house, and what a one-time discharge of water.

how it works, the scheme, principle of operation, installation of the structure

If there are a small number of people living in the house, then you can consider the option of a small septic tank such as “Baby”
This can be interesting! In the article on the following link read about the distance from the house to the septic tank.

According to statistics, in our country water consumption per person is taken at the rate of 250 liters per day. But if someone from the family likes to take a bath often or there is a frequent wash, then this factor should also be taken into account when choosing the volume of the septic tank.

In order for the septic tank to serve for a long time and regularly, it is necessary to regularly do a routine inspection to it.Also, plastic bags, garbage, chemicals, drugs, especially antibiotics (they are killers of living microorganisms in the septic tank) must not be allowed to enter the sewage system.

How wastewaters are cleaned in a septic tank

Different purification schemes are used to filter wastewater.

The traditional scheme

A classic septic tank is a three-chamber capacity. The first two tanks are airtight, and anaerobic (without air access) decomposition of the effluent occurs in them.

When being cleaned, water gradually flows through an overflow pipe into the third - a filtration well, in which it passes through a layer of rubble and is absorbed into the ground.

ON NOTE! Since during the decomposition of organic matter gas is released, the settling chambers are equipped with ventilation pipes.

how it works, the scheme, principle of operation, installation of the structure

Classical operation of the septic tank

Scheme with filtration area

This method is used in case of high groundwater . In this septic tank, the substance also decomposes into smaller fractions, resulting in a clay powder.

But purified water does not flow into the well, but is forced by pumps pumped out to the filtration field, which are trenches dug at the top, covered with rubble.

Using a biofilter to filter household waste

A simple biofilter is a tank filled with drainage material. Such a filter can be plastic "ruffs", expanded clay, crushed stone. But the main condition for successful cleaning here is a large area, since such an area is necessary for the resettlement of colonies of microorganisms.

And with this method, wastewater treatment occurs up to 95% instead of 85% in the previous septic tank. Here, the previously purified water enters the biofilter from above, passes through the drainage, and simultaneously undergoes mechanical and biological cleaning.

You can see clearly about the septic tank with the biofilter in the video:

Forced aeration

In the case of the septic tank equipment, the aero-tank camera turns from a traditional settler into an installation biological treatment. Such a station is adapted to provide the highest filtration quality, therefore such a purification plant does not need either a well or a filtration area.

Basically, the purification here takes place in the aeration tank. The symbiosis of aerobic bacteria effectively decomposes organics by dividing complex compounds into protozoa. This septic tank is not necessary to be cleaned with an aspenser machine: they are provided with additional fecal pumps for pumping out the silt.

Cleaning should be done at least once a quarter, otherwise the pump can silt, stop working and the station will fail.

You can see a video about a septic tank with a biofilter:

It might be interesting! In the article, see the following link for a septic tank to give.


Thus, the principle of operation of the sewage treatment plant is simple. In septic tanks used natural wastewater treatment processes occurring in nature. Due to the competent design of installations, septic tanks effectively filter water, in this regard, their use protects the soil from pollution and is safe from an environmental point of view.


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