Septic tanks, autonomous sewerage. Design and operation of treatment facilities

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Modern wastewater treatment systems (septic tanks) are the best solution to the problem of drainage and purification of water in a country house. However, this equipment must not only be correctly installed, but also preliminarily evaluate the land plot itself, on which the autonomous sewage system will be located, find out the composition of the soil, and correctly calculate the daily water consumption. It is these parameters that will significantly affect not only the cost of the septic tank and the work on its installation, but will also affect the further costs of maintaining the autonomous sewage system. How to correctly calculate, choose and install a septic tank, make a drainage system, what to look for during the installation of a septic tank, we will tell you in our article. We hope that this information will allow you to minimize your costs for the equipment and maintenance of an autonomous sewage system in the house..

Autonomous sewerage service

A country house or dacha is not only a rest from working everyday life, caring for a personal plot, enjoying nature but also, no matter how rude it sounds, human life, which is associated with the emergence of a certain kind of waste that needs to be accumulated and disposed of in a certain way. Today, the article will focus on septic tanks (local treatment facilities), autonomous sewerage systems. Water supply and sewerage are the elements without which it is impossible to imagine a modern home..

Even an ordinary cesspool that is built according to all the rules is a huge step forward towards preserving the environment. Discharge of untreated waste, pollution of land and water bodies is simply unacceptable. However, it is not always possible to connect a cottage or a country house to the central sewerage system, in rural areas there are no such systems at all. But without a bathroom, it is simply impossible to imagine a human habitat. What is the way out in this situation, except for the equipment of a conventional drain pit?

Waste collection systems in individual housing construction

A modern house is simply impossible to imagine without heating, lighting, water. But it is also impossible to imagine a modern house without a sewer. The presence of a cesspool in the house, or, we can say a little differently – the absence of a central sewage system in the house is such a significant factor that significantly reduces the cost of the entire facility as a whole. In addition, one should not forget that a cesspool is not only a certain inconvenience, it is an object that needs your constant attention and, under certain conditions, can pose a danger to the health of yours and those around you. In addition, according to the standards, a cesspool is used when the volume of wastewater does not exceed 1 cubic meter. per day. Modern technologies can successfully solve such problems. The use of septic tanks allows you to achieve a high degree of purification of any wastewater with minimal maintenance costs for this system.

Let’s take a closer look at the device and how the septic tank works. First of all, you have to decide on the volume of wastewater and the degree of their pollution. The choice of this or that septic tank will largely depend on this. It is also very important to know the structure of the soil on your site, the presence (absence) of groundwater, the relief of the site.

Waste collection systems

A septic tank is a kind of sump made of modern waterproof materials (most often it is a special plastic, fiberglass). Wastewater treatment in such systems occurs due to sedimentation (precipitation of particles or – gravitational separation), as well as due to anaerobic decomposition (decomposition due to the activity of microorganisms) of biological material that is present in wastewater. In the process of fermentation, gas is released, due to which additional flotation treatment of wastewater occurs (gas bubbles constantly set the liquid to be purified in motion). Septic tanks are single-chamber and multi-chamber (depending on the volume of wastewater) and are located no closer than 5-7 meters from the object (cottage, house). The volume of the septic tank should be at least 3 times the planned volume of wastewater intake per day.

The sewerage system, through which wastewater flows, is most often equipped with gravity, which significantly reduces the costs of building a sewerage system and a treatment facility. Wastewater that enters the septic tank from our homes can be rather conditionally divided into two groups:

  • fecal or “black” wastewater (coming from toilets, urinals, etc.);
  • household or “gray” wastewater (comes from kitchen sinks, washing machines, washbasins, etc.).

These effluents are regulated by a certain GOST (GOST 25298), according to which: BOD (biochemical oxygen demand) (full) must be higher than 375 mg / l; the content of suspended solids does not exceed 325 mp; the wastewater temperature should not be lower than 6 ° С. These are prerequisites, since all septic tank manufacturers are guided by these indicators. Otherwise, the result of wastewater treatment will be negative. When designing septic tanks, some features should be taken into account. So, for example, the inlet sewer pipe should be located in the septic tank at a height of approximately 0.1 m above the liquid level. It is advisable to equip the branch pipes through which the liquid enters and discharges in such a way as to prevent the ingress of particles floating on the surface. All chambers of the septic tank must be equipped with ventilation pipes (with a diameter of at least 100 mm, a height above the ground of at least 800 mm). Given the fact that the septic tank periodically needs preventive cleaning, it is imperative to provide for the possibility of access to the inside of the septic tank.

After the wastewater has been purified in a septic tank, it flows through pipes either to filtration wells or to filtration fields. The drainage field and the drainage well perform the same role and have a fairly similar structure. The main task of drainage fields and wells is to allow pre-treated drains to go into the soil.

Drainage system (drainage fields and drainage wells)

The device of the drainage field is quite simple. First of all, you need to know exactly what kind of soil on your site. After that, special drainage pipes (pipes with holes) are buried in the ground. Drainage pipes are placed on a special filter material – gravel and sand. It is there that the anaerobic post-treatment of wastewater takes place (purification with the help of bacteria). The air needed by the bacteria enters through a special ventilation system of the drain pipes. Drainage pipes are installed at the rate of 10-12 meters of pipe per one water consumer in the house. If the soil on the site absorbs moisture well, then 7–8 meters will be enough. Drainage pipes are laid to a depth of 2 meters, the distance between the pipes is also up to 2 meters. It must be remembered that it is prohibited to build any structures or plant trees on drainage fields..

Drainage pipes

With small volumes of wastewater and if it is impossible to arrange a drainage field (for example, clay soil, which does not absorb moisture well), drainage wells are equipped. A special filtering layer is made in the drainage well (in its lower part), which also consists of large rubble, sand, broken brick.

Drainage fields and wells, or rather the filtration layer, also needs cleaning. Approximately once every 8–12 years, it is necessary to either replace the filter layer or flush it. You will not be able to carry out such work on your own – very few people will be able to master the flushing of 3–40 cubic meters of drainage. Naturally, drainage wells have to be cleaned more often, but the volume of work performed will be many times less than when replacing drainage in the filtration field.

There are more modern systems for the removal of treated wastewater – these are the so-called drainage systems. One of the important conditions for the use of such systems is the absence of clay soil and the occurrence of groundwater at a depth of at least 1 meter from the surface. One drainage block replaces about 850 kg of drainage material (sand, gravel) or 12-15 meters of drainage pipe. Before installation, such blocks are wrapped in a special geotextile, which allows moisture to freely penetrate into the soil..

Drainage fields and wells

Some manufacturers claim that there is no need to set up drainage fields for their equipment. However, this is more of a publicity stunt than reality. Think for yourself – will you really allow your children to play near the sewer pipe, through which, though purified, but still sewage flows.

Autonomous sewerage system for a country cottage

Knowing the features of the device and operation of an autonomous sewage system, let’s try to choose the necessary equipment. Let’s say that a family of 4 will live in the house. The volume of wastewater for such a number of people will not exceed 1.5-2 cubic meters per day, even if you use water almost continuously or guests come to you.

The Russian market offers a wide variety of septic tanks. Firm “Inzhkom” offers Uponor Bio septic tank for deep biochemical wastewater treatment. Uponor Bio septic tank treats up to 1100 liters of wastewater per day.

Uponor Bio septic tank

In this septic tank, it is possible to monitor the performance of the autonomous sewage system. Thanks to special sensors that are installed during the installation of the septic tank, the user will be promptly notified of the need to service the septic tank.

The AirMaster 6 deep biological treatment system can treat up to 1 cubic meter of wastewater per day. This is also good enough performance for a stand alone waste water treatment system. Complete with an ultraviolet disinfectant, it is allowed to discharge purified water into water bodies. This indicates the high efficiency of this septic tank. The cost of the septic tank itself is about 80,000 rubles.

Deep biological cleaning system AirMaster 6

The GRAF 300 drainage block will allow you to save a significant amount of money for setting up a drainage field or drainage well. This unit is very easy to install and has a high degree of reliability. If necessary, replacing such a block will cost you much less than replacing the drainage layer in the field or in a well. Moreover, this block has a service life of about 30 years, which makes it even more attractive to a potential buyer..

Drainage block GRAF 300

Ventilation and sewer pipes are widely represented in our market. You can independently choose products from any manufacturer (depending on your financial capabilities). All connection points of the septic tank and sewer pipes are made according to a single standard.

We hope that this information will allow you to more fully imagine what is hidden under this name “septic tank” and you will not have any difficulties with choosing all the necessary equipment. As for the correct installation of an autonomous sewerage and wastewater treatment system, contact the services of specialists who not only sell, but also install and maintain such systems. You will receive not only a guarantee of performance, but you will also be sure that no waste water will ruin your life in your country house. Happy and correct choice.

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