Antiseptic container for sewerage. Do-it-yourself septic tank - operating principle, design diagrams and rules for installing a septic tank (100 photos). Septic tanks made of reinforced concrete rings

Dachas and country houses have long ceased to be housing with amenities “in the yard.” New technologies and materials make it possible to quickly build a full-fledged sewage system that will ensure the removal of wastewater from the kitchen, toilet, bathroom or bathhouse. Most often, it is not possible to connect the drainage line to a centralized network, so the problem of removing sewage from the site has to be solved independently, using the services of a sewage truck or discharging wastewater into the ground. Of course, in the latter case, you can build a simple drainage pit from scrap materials and thereby avoid financial costs, if not for one caveat: direct discharge of sewage into the ground can lead to contamination of groundwater in your and neighboring areas.

In order for “both the wolves to be fed and the sheep to be safe,” it is worth spending a small amount and building a septic tank that will clean the wastewater and make it safe. And so that the costs of its production and operation do not lead to depletion of the family budget, we recommend that you start building it yourself.

Septic tank - device, how it works

A carefully made septic tank will absolutely not interfere with the site, even if installed in a visible place

The issue of recycling household waste in suburban areas can be solved in two ways. The first consists of the accumulation and subsequent removal of sewage using sewage disposal machines, and the second covers a whole range of processes for their filtration, absorption and disinfection.

A storage type septic tank requires regular pumping

Using a sealed container to collect wastewater is a good option when the water in a country house or dacha appears on weekends and the amount of water used is small. If you plan to regularly use the bathroom, toilet and household appliances, then the volume of water increases so much that you will have to pump out the drainage pit weekly. To avoid this inconvenience, filtration-type cesspools are constructed in which liquid from the sewer is absorbed into the soil. There, with the help of bacteria, it is processed into water and safe organic substances. In fact, a septic tank is just such a structure, however, its improved design allows wastewater to be disinfected before it is discharged into the ground.

Depending on the design, septic tanks can be divided into several types:

1. Single-chamber septic tank of small volume. It is a container with an overflow pipe and is used in small households with water consumption of no more than 1 cubic meter. m per day. Despite the simple design, the efficiency of sewage treatment leaves much to be desired.
2. Small two-chamber septic tank. Consists of two containers connected by an overflow system. The simplicity and efficiency of this design makes it the most popular for DIY.
3. Multi-chamber structures. Thanks to the presence of several chambers, wastewater treatment occurs over a long period of time. This allows you to obtain output water that can be safely discharged into natural reservoirs or used for household needs. Despite the high degree of purification, multi-chamber systems are rare in private households due to their complexity and high cost.

In order to understand how a septic tank works, let's consider the most popular two-chamber design.

Design and principle of operation of a two-chamber septic tank

After the sewage enters the first chamber of the treatment plant, it is separated by gravity into liquid and solids. At the same time, the processing of organic waste by aerobic and anaerobic bacteria begins, which develop in the absence or excess of oxygen. At the same time, not only liquid waste, but also fecal matter is processed into water and harmless organic matter. By the way, the work of microorganisms makes it possible to significantly reduce the volume of the solid fraction, leaving only a small sediment in the form of sludge.

At the top of the first chamber there is an overflow channel, through which the purified liquid enters the second chamber, where it is further purified. Below the level of the inlet channel in the second tank there is an outlet pipe, from which purified liquid is taken for watering the garden or discharged into the ground. In the latter case, filtration fields or wells are installed to increase the area of ​​contact of purified water with the ground.

Advantages and disadvantages of septic tanks

The question of which is better, a cesspool or a septic tank, is best considered from the point of view of efficiency, as well as the cost of manufacture and maintenance. It is important to remember the safety of the structure.

Note that in most respects it is the septic tank that wins, which stands out for the following advantages:

• high degree of purification of domestic wastewater - the water leaving the device can be used for household purposes;
• absence of unpleasant odor in the area;
• hermetic design reduces the risk of sewage entering groundwater and makes the structure safe for the environment;
• there is no need for regular pumping - removal of sludge residue can be carried out once every few years.

The disadvantages of septic tanks include:

• more complex design;
• increase in construction costs;
• strict requirements for the use of household detergents. Conventional chemistry is destructive to microorganisms, so you will have to use special compounds;
• decrease in bacterial activity when the temperature decreases - at 4°C and below, the waste processing process stops.

Despite some nuances, the use of a septic tank allows you to preserve nature and the health of others, and this is a plus that cannot be erased by any difficulties or financial expenses.

Design and preparatory activities

The apparent simplicity of the septic tank design is very deceptive - in order for the constructed structure to be safe and productive, it is necessary to make small calculations and carefully select a location.

Choosing a location on the site. Sanitary standards

Diagram indicating the requirements for the location of the septic tank on the site

When choosing a place to install a septic tank, they are guided by the norms of sanitary and epidemiological legislation and SNiP acts:

• local sewerage structures are allowed to be installed at a distance of at least 5 m from the foundation of a residential building and 1 m from utility and domestic buildings located on the site;
• distance from wells and boreholes is determined depending on the composition of the soil and can range from 20 m for clay soils to 50 m for sandy soil;
• Installing a septic tank directly near roads and site boundaries is prohibited. It is required to maintain a distance of at least 1 m from the fence and 5 m from the road;

In addition, we must not forget that from time to time you will still have to use a suction pump, so it is necessary to think about how the sewage disposal truck will approach the sewage facilities.

A household fecal pump with a grinder will allow you to do without the services of a vacuum cleaner

You can do without the services of a sewer truck if you pump out the sludge using a fecal pump purchased for this purpose, and use the sludge from the septic tank as fertilizer for the garden.

Selection and calculation of material. Required volume

To install septic tank chambers, you can use both ready-made tanks and containers built by yourself:

Calculation of the amount of material required depends on the volume of the septic tank, so the main calculated value is the daily amount of wastewater discharged. There is no need to accurately determine this parameter; it is enough to assume water consumption of 150–200 liters for each family member permanently residing in the house. This will be enough to use the bathroom, toilet, washing machine and dishwasher. To determine the volume of the septic tank's receiving chamber, the resulting value is multiplied by three. For example, if five people permanently live in a house equipped with all amenities, then you will need a tank designed for 3 cubic meters. m of liquid waste (5 people × 200 liters × 3 = 3000 liters).

The second chamber is calculated based on the size of the receiving tank. If its volume is taken to be equal to 2/3 of the total size of the septic tank, then the dimensions of the post-treatment chamber provide the remaining third of the structure’s volume. If we take the example discussed above, the working volume of the structure will be 4.5 cubic meters. m, of which 1.5 cubic meters. m are allocated for the second tank.

Photo gallery: drawings of future structures

When designing a septic tank, you can use drawings and diagrams of working structures.

Scheme of a two-chamber septic tank Drawing of a two-chamber septic tank Drawing of a two-chamber septic tank

Calculations of external dimensions are carried out using well-known geometric formulas to determine the volume of a cylindrical structure and a rectangular container.

It should be understood that in most regions the septic tank will not freeze in winter due to warm wastewater coming from the house, soil temperature and the work of microorganisms. However, the structure will still have to be deepened. The gap between the cover and the upper level of wastewater is taken equal to the amount of soil freezing in winter.

It is at this depth that the drain pipe enters the septic tank. Therefore, we must rely on the fact that the calculated working volume will be below this point. In addition, at a higher temperature, bacteria will more actively process sewage, helping to increase the productivity of the septic tank.

Diagram explaining the need to deepen the septic tank chambers

Which form is better

The question of which septic tank is better - round or rectangular - can be considered incorrect, since the shape does not at all affect the performance and degree of purification. However, the configuration of the structure has a huge impact on the choice of materials. Everyone knows that round buildings are the most optimal in terms of spending the necessary funds. The septic tank was no exception. If it is made of brick, then choosing a cylindrical shape will reduce consumption by 10 - 15%. In addition, round walls perfectly resist mechanical loads from the ground. If you choose a monolithic two-chamber structure, then it is better to make it square or rectangular. Firstly, reinforced walls will resist bending forces, and secondly, this is necessary for purely practical reasons related to the manufacture of formwork for pouring concrete.

Cost of septic tanks made of various materials. To eliminate the impact of devaluation, prices are given in yuan. e

By the way, we recommend making the concrete structure yourself. If we consider the cost of a septic tank, it will not be much higher than its inexpensive brick counterparts (see table). As for the durability and strength of the structure, there can be no question of any comparison, therefore even a more labor-intensive technology will justify itself many times over. We will tell you in detail how to build a rectangular two-chamber septic tank from reinforced concrete.

Required tools and materials

• To build a concrete treatment plant you will need:
• crushed stone, sand and cement for making concrete;
• steel rods or fittings with a diameter of at least 10 mm;
• metal corners, pipes or channels for the construction of floors;
• boards, timber and slats for formwork;
• film for waterproofing;
• containers for bulk materials and concrete;
• Bulgarian;
• manual rammer;
• wood saw;
• welding machine or wire for making an armored belt;
• hammer;
• building level;
• roulette.

If it is necessary to insulate the septic tank, this list should be supplemented with the heat insulator used, for example, expanded clay chips.

Construction and installation of a country septic tank from monolithic concrete with your own hands

It is better to dig a pit for a septic tank by asking for help from relatives and friends

1. After determining the size of the structure and choosing a location, they begin to dig a pit. The size of the pit is chosen depending on what formwork will be used. If board panels are planned to be installed on both sides, then the pit is made 40–50 cm wider than the size of the tank, taking into account the thickness of its walls. In the case where concrete will be poured between the formwork and the ground, the pit is dug according to the external dimensions of the septic tank. If hired people will be used for this, calculate the cost of their work. Be sure to take into account that the soil will have to be removed from the site, and this will entail additional costs for its loading.
   

   Perhaps the total cost of all excavation work will approach the cost of operating an excavator. At the same time, he will cope with the work tens of times faster.

2. You should not remove all the soil from the site. Be sure to leave some of it for backfilling the septic tank.
3. Compact the bottom of the hole and fill it with a layer of sand 10–15 cm thick. After this, the sand is spilled with water to compact it.

   Install formwork around the perimeter of the structure. If a one-sided board fencing is used, then the walls of the pit are covered with plastic film. This will prevent them from falling off while pouring the walls and base of the septic tank.

4. Waterproofing pit walls
5. Place pieces of wooden slats at least 5 cm thick on the bottom. They will be needed as spacers under the reinforcement belt, which will be located inside the concrete base.

   Build an armored belt from a metal rod or reinforcement. To do this, longitudinal elements are laid on the slats, and transverse elements are attached to them by welding or tying with wire. The size of the cells of the resulting lattice should be no more than 20–25 cm.

6. Fill the base of the septic tank with concrete and compact it with a bayonet or tamper. The thickness of the bottom must be at least 15 cm. To prepare a mortar from grade 400 cement, you can use the following proportion: 1 part cement is mixed with 2 parts sand and 3 parts crushed stone. When using M-500 cement, the amount of bulk materials is increased by 15 - 20%.

   Pouring the base of a septic tank with concrete

7. After the concrete base has finally set, they begin to construct the formwork for the walls and partitions of the septic tank. Reinforcement is also installed inside the formwork to strengthen the structure of the structure.
   

   If there are not enough boards to construct the formwork for the entire height, then you can use a low sliding structure, which is poured with concrete, and after it sets, it is moved upward.

8. At the level of overflow channels and the entry and exit points of sewer pipes, windows are made by installing sections of large diameter pipes into the formwork or constructing wooden frames.

   Construction of formwork for walls and internal partitions

9. After the septic tank chambers reach the required height, construction of the ceiling begins. To do this, support elements made of steel angles or profile pipes are laid on top of the walls. It is important to ensure sufficient strength, since concrete has significant weight.
10. When installing formwork and reinforcement, take care of the openings for hatches.

    Installation of floor support elements

11. Fill the septic tank lid with concrete and cover the structure with plastic film.

    Before pouring the ceiling, be sure to install a ventilation pipe

12. After the ceiling has dried, a sewer line is inserted into the receiving window of the first chamber, and the exit of the structure is connected to drainage structures.
13. The septic tank is filled with soil, constantly compacting and leveling it. It is important that the soil level above the septic tank is slightly higher than the level of the entire site. This will prevent the treatment plant from flooding during heavy rains or floods.

Arrangement of filtration structures

In order to drain purified water into the ground, various types of drainage systems are used. The most common structures are filtration fields and drainage wells.

Filtration field design

The first are a system of pipelines placed in the ground and connected to the outlet pipe of the septic tank. Thanks to the installation at an angle, the movement of purified waste through the pipes is ensured, and their absorption is made possible thanks to a system of holes and a drainage layer in which the entire structure is placed.

The latter are a special case of a cesspool without a bottom and can be constructed from perforated concrete rings, bricks laid out in a checkerboard pattern, or old car tires. To ensure absorption capacity, the bottom of the filtration well is covered with a thick layer of crushed stone. It must be said that, unlike a cesspool, the performance of a structure connected to a septic tank practically does not decrease over time. This is due to the absence of solid particles and suspensions that can clog drainage holes and pores.

When using a septic tank, it is necessary to radically reconsider the approach to the use of sewerage. From the day the system is put into operation, it is prohibited to use chemical detergents and pour any aggressive substances into the toilet or sink. It must be remembered that wastewater treatment is now carried out by living beings - bacteria and other microorganisms. Of course, this does not mean that for washing and cleaning you will now have to use ash and simple laundry soap, like our ancestors. When using household detergents marked “Bio” or “Eco”, nothing will threaten the fragile ecosystem of the septic tank, and you will get good results when cleaning and washing.

Using detergents free from aggressive chemicals will allow the septic tank to work at full capacity

Inorganic waste and garbage should not be poured into the sewer - there is a trash can for this. Once in the wastewater storage facility, they will collect at the bottom and interfere with its normal operation, and when pumping out sludge, they can clog the hoses of the fecal pump.

To improve the performance of the septic tank, special bioactivators are periodically added to the receiving chamber, which include several varieties of aerobic and anaerobic bacteria. When choosing biological products, you must pay attention to their purpose, since such compositions are produced both for normal operating conditions and for cleaning heavily contaminated walls of septic tanks, wastewater with an increased fat content, etc. By the way, the compositions must be used exactly as indicated manufacturer on the packaging, otherwise the bacteria may die.

The use of bioactivators improves the performance of the septic tank

From time to time you will have to check the level of sediment. The fact is that their accumulation leads to a decrease in the useful volume and a decrease in the productivity of the septic tank, so periodically the sludge will need to be pumped out or removed using a sludge pump, fecal pump or a long pole with a scoop device. Of course, mechanized pumping methods will be preferable.

Thanks to my varied hobbies, I write on various topics, but my favorites are engineering, technology and construction. Perhaps because I know many nuances in these areas, not only theoretically, as a result of studying at a technical university and graduate school, but also from the practical side, since I try to do everything with my own hands.

The problem of hygiene and comfort always faces a person who decides to move to a permanent place of residence in the private sector, where problems often arise with the shower and toilet familiar to a resident of the “concrete jungle”. Indeed, in such cases, there is often no opportunity to connect your home to centralized communications systems, including the wastewater disposal system. And that is why, before building the house itself, most land owners also plan landscaping. How to do it, what is needed for this and how difficult is it?

Septic tank - what is it?

Table. The main types of septic tanks.

Cesspool or septic tank - which is better?

For decades and even centuries, people built ordinary cesspools near their homes and on their plots to arrange a sewer system (if you can call it that).

These pits have the following disadvantages:

• fragility of use;
• an ordinary cesspool is not able to cope with large volumes of wastewater, which have increased significantly over the past decades, because private homes now have bathrooms, washing machines, dishwashers, and swimming pools;
• difficulty of maintenance - too large volumes of wastewater will require pumping out waste several times a week, which can hit the pocket hard;
• there is a high risk of wastewater getting into groundwater and environmental pollution - cesspools often do not have a sealed bottom and walls at all:
• an unpleasant odor hovering near the pit;
• problems with neighbors and sanitary inspection services.

All of the above disadvantages of a cesspool are absent in any properly equipped septic tank. It is more effective, durable, economical, needs cleaning and processing less often, and there is a special one for this. Although it looks very much like a regular cesspool, its filtration system is much more complex. Or rather, in the cesspool it can be said to be completely absent.

However, the construction of a septic tank must also be carried out in accordance with certain sanitary standards - you cannot equip it anywhere and at random. A septic tank can now be purchased in a specialized store or ordered to be built by craftsmen. But it is much cheaper to equip it yourself. Before you start building a septic tank, you will need to create its diagram, determine its dimensions and location.

Sewerage installation in a private home can be done in different ways. The situation is easiest if there is a centralized sewerage system - in this case it will be enough to simply connect to it. In all other cases, you will have to create an autonomous network, and there are several solutions here too. The best option for most situations is a septic tank. This article will discuss how to properly make a septic tank with your own hands.

The principle of operation of a septic tank

Let's first understand what a septic tank is and how it works, and also consider its types. A septic tank is a sewerage structure that provides the maximum possible treatment of wastewater. Purification is carried out by decomposing wastewater into separate components that do not pose a danger to the environment - water and activated sludge. The direct processing of waste is carried out by microorganisms located inside the septic tank and using the substances that enter there as food.

There are two types of microorganisms - aerobic and anaerobic. The former are able to work only in an environment saturated with oxygen, while anaerobic bacteria live without problems even in a sealed container. The tank itself is always sealed (this is done to prevent sewer odor from escaping), so when using aerobic bacteria you have to supply oxygen to the septic tank you assembled yourself without pumping it out for the dacha.

All types of septic tanks without pumping for a private home work according to the same principle, including the following steps:

• Accumulation of wastewater and its separation into degradable substances and non-biodegradable components;
• Processing of wastewater by microorganisms, as a result of which only sludge and water remain;
• Continuation of wastewater treatment, as a result of which all the sludge settles at the bottom of the device;
• Discharge of treated wastewater outside the sewer system.

Of course, the entire work process does not happen instantly - it takes a lot of time to fully process wastewater. As wastewater is purified, it flows from one compartment to another, which is done through overflow holes or special tubes. The separated liquid, having passed through all levels of the septic tank, is sent to the ground.

After processing, sludge remains in the septic tank, which can be called active or neutral. Both versions of the name are considered correct - the main thing is that the resulting mass is completely safe for the environment. In addition, such sludge can later be used as fertilizer.

The activity of sludge is determined by the fact that it constantly contains bacteria that process the harmful particles contained in it. For bacteria, such an environment is a normal habitat, suitable for living and reproducing. This feature allows you to do without the regular supply of microorganisms to the septic tank.

However, independent reproduction of bacteria may well reach negative values. The thing is that microorganisms intended to enter the septic tank are completely unable to resist the effects of most aggressive substances, incl. chlorine, antibiotics, various technical oils and solvents.

In addition, bacteria can die for other reasons, one way or another related to improper operation of the septic tank. One of these reasons is mistakes made when preserving equipment before the winter period. The main mistake is to completely empty the device for the winter - in this case, the bacteria remaining in the compartments simply have nothing to feed on, and they die.

Subject to proper operation and proper installation, the septic tank will be able to correctly perform its functions. Good insulation will not completely protect the drains from freezing, but even with partial freezing, the septic tank will not float or crack. That is why it is important to pay attention to the installation and use of such equipment, and this must be done before making a septic tank without pumping with your own hands.

The water that remains during the wastewater treatment process is not suitable for domestic needs, since the degree of its purification is not so high. However, it is still worth collecting it - completely purified wastewater can be used as process water, for example, for watering a site. If there is no need for water, it can simply be removed using a filtration well or filtration field, from where the purified liquid will flow into the ground.

The sludge that settles at the bottom of the equipment is not removed anywhere on its own. As a result, the internal volume of the tank gradually decreases and at a certain point reaches a critical value. A special pump is used to clean the septic tank. An important point is that you have to pump out wastewater from a septic tank an order of magnitude less frequently than from a cesspool. In addition, there are no unpleasant odors in the process, since neutral sludge does not have them.

Comparison of a septic tank and a biological treatment station

By and large, there is no particular need to create a septic tank yourself - it can always be purchased ready-made. Modern local treatment plants (LCPs) are powerful systems characterized by high reliability, performance and ease of operation.

On the market you can find fairly compact devices, the inside of which is divided into several compartments connected by overflows. Effluents in simple VOCs are processed independently, without the use of additional means. If the device is classified as a biological treatment station, then it has a pump and an aeration system that supplies oxygen to the device. The key difference between such stations is their dependence on electricity.

Most standard VOC models are initially well insulated and equipped with a sealed lid. If the device is intended for high purification of wastewater, then its design is complemented by a compressor that pumps air into the internal space of the containers. Thanks to this, it becomes possible to simultaneously use aerobic and anaerobic bacteria, which ultimately makes it possible to achieve a purification rate of up to 95%.

However, in addition to the advantages, it is worth noting the disadvantages of local cleaning systems, which come down to the following list:

1. Firstly, any biological treatment station is very expensive. The high cost manifests itself not only during purchase, but also during operation - the device constantly requires electricity to operate, the costs of which will lead to increased utility costs.
2. Secondly, there are simple VOC options that are not equipped with additional components. Of course, such equipment is much cheaper, but structurally it is more like a modernized cesspool than a high-tech cleaning system. The maximum degree of purification in such systems does not exceed 70%, and purified water can be used for technical needs only after additional filtration.

The described disadvantages are quite serious, so most owners of private houses give preference to self-equipped septic tanks, which do not have to be constantly cleaned. Of course, the time and labor costs will be great, and the corresponding skills will not hurt - but a septic tank assembled at the dacha with your own hands without pumping will be at least no worse than a ready-made device.

In addition, homemade septic tanks end up being much cheaper than purchased treatment facilities.

Autonomous sewer design

The design process of an autonomous sewer system consists of several stages and takes into account a number of parameters. First of all, you need to decide where the sewage system will be located in the dacha without pumping - and for this it is necessary, in turn, to calculate the volume of the device in order to build on the data obtained.

The calculation is quite simple - the number of people living in the house is multiplied by 200 liters (daily water consumption). The calculation result needs to be increased by another 20% to get the final figure, which will reflect the full volume of the future capacity. During construction, about 30% of the volume is allocated to the filtration well, and the rest of the space is occupied by septic tank compartments. However, specific numbers may vary depending on how the septic tank is designed without pumping in each individual case.

If the device has rectangular sides, then its volume is calculated as the product of length, width and height. In the case of cylindrical containers, you need to multiply the height of the structure by the area of ​​the base. To find the area of ​​a circle, you need to multiply the square of its radius by pi.

When calculating the parameters of a septic tank, it is necessary to take into account that the distance between the bottom of the septic tank and the entrance of the sewer pipeline must be at least 80 cm. These calculations are also affected by the slope of the pipe, which must be taken into account before making a simple septic tank.

When deciding where the sewage system will be located without pumping and odor, you need to build on a number of sanitary standards:

• The septic tank must be located at a distance of more than 10 meters from residential buildings and water supply networks;
• The minimum distance from the septic tank to the nearest source of drinking water is 30 meters;
• Distance to fruit trees – over 3 meters;
• The distance to the road is more than 5 meters.

The increase in the volume of the septic tank is directly related to the tightening of the standards governing its placement. Thus, in the relevant sections of SNiP and SanPin there is more detailed information about the rules for maintaining the purity of groundwater. In particular, the minimum distance between soil water and the bottom of the structure can be at least 1 m. This aspect must be taken into account before making a septic tank with your own hands.

If the groundwater is high, another requirement is imposed - a do-it-yourself septic tank for a home or cottage must be absolutely sealed. This requirement is met only by factory storage tanks and Eurocubes, which are actively used in the independent construction of autonomous sewer systems.

Finally, before building a septic tank in a private house, you need to take into account the possibility of vehicle access to it. The thing is that to clean a septic tank, pumps based on specialized vehicles are used, and the difficulty of accessing the device directly affects the difficulty of pumping out the sludge remaining after wastewater treatment.

Septic tank made of concrete rings

One of the most common options for home-made structures are septic tanks made of concrete rings. The main advantage of this solution is that such a sewage system without pumping in a private house is very easy to install, which is due to the fact that there is no need to pour a concrete form.

You need to install such treatment facilities yourself in the following sequence:

• Marking the area allocated for the septic tank;
• Preparation of a pit of the required dimensions;
• Installation of concrete rings;
• Filling the bottom of the pit;
• Connecting the sewer pipeline and overflow holes;
• Waterproofing and sealing of all joints;
• Backfilling of the structure;
• Installation of the upper ceiling and cover.

Since rings will be used for the arrangement, the pit should have a cylindrical shape. The number of pits is determined depending on the number of compartments of the device. When setting up a simple septic tank at your dacha with your own hands, it is better to choose a scheme with two chambers - in the first one will settle and process wastewater, and the second will drain water through a sand and gravel layer.

When figuring out how to make a septic tank in a private house, you should give preference to the option with three compartments. The roles of the different compartments do not change, except that the first two compartments will be used as a sump. The cameras should be placed at a distance of about half a meter from each other.

The pits need to be deepened only enough so that the rings fit completely, taking into account the height of the bottom of the structure. The last pit is not concreted - the bottom is used as a filter. The easiest way to dig is to use an excavator or similar special equipment. However, to make a septic tank without pumping for a private home, you can do the digging yourself - but you need to understand that the labor costs in this case will be too high.

To make a septic tank with your own hands at the dacha or in a private house, you must take into account the characteristics of the local soil:

1. With dense clay soils, the question of how to make a septic tank is solved extremely simply. In this case, you can simply dig a pit and then immerse the rings in it.
2. If the selected location is located on sandy soil, you will have to install the rings, and then gradually select the soil from their inner part. As a result of these manipulations, the rings will gradually sink into the ground.

After preparing the pit and installing the rings, you can start filling the bottom of the septic tank. The standard composition is a mixture of cement, sand and water in a ratio of 2:2:1. This composition is simply poured onto the bottom of the rings. Before making the septic tank on the site available for use, you should wait until the solution has completely hardened - in this case, the strength of the structure will be maximum.

The gaps between the rings must be coated with a solution inside and outside. Dry building mixtures intended for use in areas with high humidity are best suited for sealing. After treatment, the joints also need to be coated with waterproofing materials so that the septic tank scheme at the dacha can be implemented with your own hands as correctly as possible.

The trench in which the sewer pipe will be located must be placed with a slope. Where the self-assembled sewage system without pumping will connect to the pipe, a hole of the required diameter is made. Overflow pipes are located in the same way. All contact points between the tank and pipes are covered with mortar and coated with waterproofing.

In the last compartment, the role of the bottom is played by a filter made of sand and gravel. At the very bottom there is a sand layer, and above it there is a gravel backfill (instead of gravel you can use crushed stone of the same fraction). The total thickness of the sand and gravel filter should be about 30-40 cm - in this case, septic tanks without pumping for the home work correctly.

The assembled septic tank compartments are covered from above with round concrete slabs. Such covers can be purchased complete with the rings themselves. After installation is completed, the pit is filled in, the soil is leveled, after which the self-assembled septic tank for the dacha can be considered put into operation (of course, if the concrete at the bottom and seams of the structure has already hardened).

Alternative septic tank designs

In addition to the most common design of concrete rings, there are other options for arranging septic tanks. To decide which septic tank to make, it is worth considering the most popular devices. One of them is the Eurocube already mentioned above, which is a sealed plastic tank. Installation of such devices is quite simple - Eurocubes are lightweight.

However, low weight is also a disadvantage - during spring floods, a plastic septic tank can float to the surface of the earth. To compensate for this factor, a heavy slab equipped with hinges can be placed under the septic tank. Another option is to weigh down a homemade septic tank for a summer residence with a heavy object and secure it above the device.

As a material for forming a septic tank, you can use ordinary concrete mortar. In this case, you won’t have to dig several pits – a simple rectangular hole will be enough. First of all, the bottom of the structure is poured, and then the walls are created using formwork. Walls are also being built inside the device itself, which will divide the septic tank into compartments, and the sewage system in the house will be able to function normally without pumping.

With further arrangement, holes are created in the walls through which wastewater will flow. The last step, directly related to how to build a septic tank, is to fit a concrete slab with a cut-out opening for the lid. The lid must be sealed and large enough, since it is through it that the autonomous sewage system will be serviced.

Using a very similar technology, a brick septic tank is installed without pumping. First, the bottom is poured, then brick walls are erected, and then the structure is covered with a concrete slab. The internal surfaces of the septic tank are treated with waterproofing so that the structure ultimately becomes airtight.

By and large, you can make a simple septic tank (although this will mostly be just an imitation) from almost any materials. There are even options made from car tires, where the compartments are formed from old tires. Of course, this option is much closer to cesspools than to septic tanks, but even such solutions may be suitable for solving certain problems.

However, not every design can be called a full-fledged septic tank. A high-quality, self-installed septic tank for a private home, firstly, provides a fairly high degree of wastewater treatment, and secondly, its service life is much longer than that of home-made structures made from improvised materials in a hurry.

Conclusion

A self-assembled septic tank is a fairly effective and reliable design that is relatively easy to install and maintain. Of course, septic tanks are inferior in efficiency to local treatment plants, but this difference is fully compensated by the low cost of installing and operating septic tanks.

The problem of sewerage and wastewater is very close to the owners of private houses. After all, it is difficult for residents of megacities to imagine life without sewerage. And it’s not just a matter of imagining such a life, it’s more likely that no one will be able to imagine life without it due to an irreplaceable need. But in private houses in the suburbs this is a major problem. Moreover, everyone is forced to solve it on their own.

How to arrange a sewer system, and most importantly, where to dispose of the waste? Of course, nowadays there are a lot of options.

The easiest way out is to build a cesspool. But then another problem arises: sooner or later, depending on the size of the pit, waste pumping will be necessary. Which, in turn, will entail additional cash expenses, which, in fact, can be avoided. Moreover, the construction of a sewer system in a private house, taking into account a cesspool, can lead to overflow of the well on the site. But losing drinking water in a private home is a much more serious problem.

Based on this, the most practical option would be to build a septic tank. We will tell you how to make a septic tank with your own hands later. We’ll also talk about their varieties, features and simple installation. We will help you make simple calculations to choose the volume that is right for your family. A septic tank is most practical when used in a private home. This is because it will help you make an autonomous sewer system. Thanks to it, wastewater naturally decomposes into water, carbon dioxide and many other environmental elements, which then fall into the ground and do not harm it. This way you avoid the problem of sewage and do not harm the environment.

A septic tank is a very simple construction that can be easily done by almost anyone with their own hands without special construction skills, which will help avoid the cost of workers.

Many, relying on ancient methods, still decide to build cesspools on their site, when more advanced residents are already thinking about how to make a septic tank with their own hands.

Essentially, both members of the population have the right to make this choice. In order to understand which is more profitable, convenient and environmentally friendly, you just need to understand the mechanism of both buildings.

Let's start with the cesspool. Already in the title a lot becomes clear. This is a storage pit for waste waste, which is connected to the sewer system of a private house. Everyone understands that the drains from it do not evaporate and over time it will fill up. Then a new problem arises: pumping out the cesspool. And these are additional costs, which can be considerable if the site is located in the outback or if sewer trucks are used frequently. From this follows the logical assumption that you can save money and simply make a larger hole. But there is no point in making it larger than the car tank, because then you will need to call more than one such car to pump it out, which may be even more expensive than you expected. It is also wrong to assume that you will need to call cars so rarely that these expenses will not become significant.

To understand the whole problem, let's turn to simple calculations. As stated in building codes and regulations, an average of two hundred liters of waste water per person per day, when calculating the sewage system. The tank of sewer trucks has a maximum capacity of ten thousand liters. Let's say you save a lot of water. But even with a great desire, you will not be able to reduce this figure below fifty liters per day per resident of the house. And we are already silent about the fact that most often more than one person lives in a house.

Now do you understand the scope of the problem? Of course, many decide to simply discharge wastewater into ditches or nearby rivers. But you understand, this is not a solution. Moreover, this way you spoil the environment around you.

Therefore, it would be an excellent solution to the problem to build a septic tank on the site. Moreover, this construction is very simple and works on the flow principle. Effluents do not accumulate. From here there will be no overflow problems. Under the influence of anaerobic bacteria that are present in the septic tank, waste naturally decomposes into substances and then enters the soil. If necessary, wastewater can be further purified. Thus, under any circumstances, substances end up in the ground naturally. This eliminates the possibility of overflow and the need for pumping.

It is worth highlighting the environmental properties of the septic tank. All processes occur naturally.

Therefore, organic substances formed as a result of the action of a septic tank return to nature and participate in the cycle of substances in nature. Most importantly, they do not harm the environment in any way, and therefore will not harm the owners of the site and the surrounding areas.

Let us remember one of the main laws of the existence of organisms in nature, which we all learned in school: nothing disappears or appears out of nowhere. Hence the well-known law of the cycle of substances in nature. Wastewater is made up of billions of bacteria. They will be the best means for processing wastewater and separating it into organisms.

For microorganisms to work most efficiently, they should be provided with the best conditions for their life. This is exactly what current septic tanks for private homes do. We will talk later about how to make a septic tank with your own hands without pumping. The main thing to remember is that the design is very simple and does not require special knowledge to build it, which means you can actually do everything yourself. According to the principle of their operation, they are similar to the natural cycle of substances. What is the most common septic tank? In a standard situation, it includes several cameras. The first is most often called a sump. Because it is in this chamber that microorganisms are most active. All wastewater ends up here, and bacteria separate it into standard forms: solid, liquid and gaseous. Solid tailcoats form sediment. But microorganisms continue to decompose them into their usual forms, which eliminates the possibility of accumulation and overflow.

But the next camera is much more complex in its structure and functionality.

This is where gas fractions are collected. Under the influence of bacteria, upon accumulation, separation occurs into carbon dioxide and clean water. The gas is released into the air as the chamber overflows through the vent. But clean water, through a special well with filters, is released into the ground practically without impurities or goes down into a ditch without harming the environment.

If you want absolute wastewater treatment, then equip a third chamber. It will already have a sand and gravel filter for absolute water purification. The result is obtained thanks to soil microorganisms. They will act as an additional filter in your system.

For a more detailed idea, it’s worth typing into a search engine: how to make a septic tank in a private house with your own hands video.

Now I think it’s clear that the septic tank mechanism is based on the constant flow of wastewater. This helps avoid the need for pumping in almost everyone. But for an ideal result, we will next tell you how to properly make a septic tank in a private house with your own hands.

Do not forget that according to building codes and regulations, a septic tank is only part of the cleaning systems. Therefore, water after such purification can only be used for technical needs or for watering the land on the owner’s property.

Like any construction, the main thing is to start with a construction project. In principle, in this construction the materials from which you plan to build a septic tank on your site are not at all important. The main role here will be played by the volume of cameras that you plan to use.

At the same time, the large volume that the desire to build immediately arises has its drawbacks. And all because bacteria work longer in a large chamber. Consequently, the water will be purified more for further processing. But with a large container, the drainage slows down. Hence, precipitation occurs for a long time and unevenly. Which can lead to clogging of the channels between the chambers and filters. As a result, less and less water will flow into the ground.

After this, we will still discuss how to make a septic tank without pumping with your own hands to avoid flooding. There are a lot of options for making cameras. Moreover, they are all simple. One option would be to purchase ready-made plastic containers with the required volume. You can also use concrete rings, which are most often used for the construction of wells. And the most difficult option is to make concrete chambers yourself. The main thing to remember here is the slope of the sewer pipes. Drains should not linger inside it.

Do-it-yourself plastic septic tank for a private house

Ready-made plastic septic tanks make life much easier for owners. The design is sold assembled and this is the main advantage. The walls of the chambers are very thick for such purposes, which increases the service life due to the strength of the septic tank materials. They are able to withstand the pressure of the earth and the work of a microorganism inside for a long time. In terms of service life, they are almost equal to their concrete counterparts. But the cost is much cheaper, which can be a major bonus when choosing a septic tank of this type.

How to properly make a septic tank in a private house with your own hands? The manufacturers thought for you here. The varieties of these products are very huge. The containers can be the simplest, with varied uses of the septic tank. So there may already be a fully functional septic tank. It’s enough just to bury it and bring the sewer at the right angle, as we talked about earlier.

DIY septic tank for a private home made of concrete rings

In this case, the work will be very convenient. The shape of such chambers will be in the form of cylinders. At the same time, the walls of the structure can be made airtight, thanks to a variety of sealants and concrete fillers.

The most common problem with septic tanks made of concrete rings is the depth of the pit itself and the small area of ​​the sump. If the amount of wastewater is very large, then this will interfere with the leaching of decomposing substances by the activity of microorganisms, due to the huge layer accumulated. The solution to this problem is stirring. Here it is necessary to prepare a mechanism for such mixing in the structure of the building.

Monolithic concrete septic tank

Perhaps this will be the most optimal way to build a septic tank with your own hands for a private home.

How to make a septic tank with your own hands? There will already be several options for the master. You can use waterproof concrete or brickwork with concrete insulation as a finish.

From the selected material, it is worth making the bottom and walls of the first chamber and subsequent ones. This process will be the most labor-intensive. Also, in terms of construction costs, it will be the most expensive construction option. If you calculated everything correctly and the work itself was performed at the highest level, then the final result will be the best of the proposed options.

Do-it-yourself septic tank volume for a private home

Now let’s talk about the most important thing in our DIY septic tank construction. This is volume.

Let's start by remembering the building codes and rules for the construction of sewers and calculating the volume of daily wastewater in your home. Next, we need to decide on the number of chambers in our septic tank.

Let's look at the option with two cameras. For any options, the volume of the first chamber must be greater than three daily norms of daily wastewater from a private house, according to the standards. In this option, the first chamber should make up 75% of the total volume of our structure.

Therefore, we have 25% left for the second camera.

Option with three cameras. The first chamber rule remains the same under building codes. But in this case, it will already be half the volume of our septic tank. But the next two chambers will each be 25% of the total volume of the septic tank.

For a better understanding, we will look at calculating the volume of a septic tank using a specific example.

Let's remember the building codes and regulations. According to which, the daily rate of waste waste is 200 liters per person. Let's say our family consists of four people. After simple calculations, we find out that the daily amount of sewage waste in our house is 800 liters. Maybe it will be easier for someone if we say that it is 0.8 cubic meters. We recall the rule of the first chamber, which states that its volume must be at least three daily norms of waste from a private house. In our case, the daily norm was 800 liters. Let's multiply it by three. It follows that the volume of the first chamber must be at least 2400 liters or 2.4 cubic meters.

We also refer to building codes and regulations. According to the standards, the septic tank must be placed at a distance of five meters from the foundation of a residential building. In practice, if you have organized everything correctly, completed the necessary waterproofing, the ventilation in the septic tank is excellent, and the drains are located outside the foundation, then the septic tank can be built close to the foundation of the house to save space on the site. Of course, with such construction, you can only use concrete construction options with sufficient wall thickness that can compensate for the pressure of the building’s foundation.

Also, you should not build a septic tank on a site very far from the house. This will greatly complicate the position of the sewer pipes, which need to be made at an angle, which will lead to the deepening of the structure itself and its further drainage.

Also, the main factor when choosing the placement of a septic tank will be the wall of the nearest water.

The distance between them should not be less than fifty meters. But the slope of the sewer system should be calculated based on the volume of the pipe itself. The main rule applies here: the smaller the diameter of the pipe, the larger the slope should be.

Do not forget about the temperature regime of the septic tank itself. It should not freeze, so the placement depth should be below the freezing layer of the soil. For the best effect, it is worth insulating the septic tank with construction insulation, of which there are many on the market now.

It’s rare that a suburban village or partnership, even near Moscow, can boast of having a main water supply and sewerage system; in general, the owners of suburban real estate have to acquire their own amenities. And in order not to pollute the environment, including the aquifer, with waste from their own vital activity, wastewater treatment systems have long outgrown the simplest cesspools, turning into more advanced structures.

There are a lot of different treatment plants and stations on sale for treating wastewater from mechanical impurities, but despite all their effectiveness, their significant drawback is their considerable cost. Therefore, for many private owners, the best option is homemade devices, which are deservedly popular among FORUMHOUSE craftsmen. Let's consider what a septic tank is, existing sanitary standards, parameters for choosing systems and the most popular varieties.

• Septic tank operation diagram
• How to choose a septic tank
• Construction of a septic tank made of concrete rings
• Features of monolithic reinforced concrete septic tanks
• Plastic septic tanks from Eurocubes

Septic tank operation diagram

A septic tank is one of the elements of a complex autonomous (individual) domestic wastewater treatment system designed for collecting, settling and purifying wastewater. Accumulation and sedimentation occurs in a sealed container (when there are several chambers) or containers; from the settling tanks, the wastewater flows into a filtration well or onto soil filtration fields (underground, aboveground). The law prohibits the discharge of even settled and treated wastewater from a septic tank onto open areas of land. The system necessarily includes inspection/cleaning wells and ventilation risers; the vent riser is brought to the roof level to prevent the possibility of characteristic odors. Septic tanks are periodically cleared of sediment by a sewage disposal machine; if the volume of the septic tank is correctly selected, this procedure, even if you live permanently in the house, is required no more than once a year, or even several years.

Sanitary and building codes and standards governing the location, design and construction of septic tanks

Until recently, the main regulatory documents relating to septic tanks and biological protection stations were SNiPs and SanPiNs, developed at the end of the last century and the beginning of this one:

• SNiP No. 2.04.03-85 (recommendatory), SP 32.13330.2012 (current standard) - parameters for the organization of external sewer networks and structures.
• SNiP 2.04.04-84 and SNiP 2.04.01-85 - parameters for organizing internal and external water supply (outside the city, water supply is most often from a well and a well, and some provisions intersect with the rules for organizing septic tanks).
• SanPiN 2.1.5.980-00 – protection of surface waters.
• SanPiN 2.2.1/2.1.1.1200-03 – septic tanks are classified as environmentally hazardous objects; this set of rules regulates the creation of protective zones around them.

Last year, a new standard for organizing autonomous sewage systems with septic tanks and soil (underground) filtration of wastewater was adopted - STO NOSTROY 2.17.176-2015. Now this is the main document that contains the design and installation rules, as well as the requirements for the results of the work.

The following rules apply for the location of treatment facilities relative to other objects on the site:

• There is 5 meters between the septic tank and the house.
• Between the septic tank and the water intake (well, borehole) - at least 20 meters, if there is no connection between the aquifer layer and the filter field through soil with high filtering capacity, from 50 to 80 meters if the segment has loamy, sandy or sandy loam soils.
• Between the septic tank and the side of the road - 5 meters.
• Between the septic tank and the border of the site - 4 meters.
• Between the septic tank and trees - 3 meters (1 meter to bushes).
• Between the septic tank and a reservoir with running water (stream, river) - 10 meters.
• Between the septic tank and a body of standing water (lake, pond) - 30 meters.
• There is 5 meters between the septic tank and the underground gas main.

The main operating characteristic of a septic tank, on which its performance, the efficiency of wastewater treatment and the frequency of pumping will depend, is volume. It is calculated based on the number of household members, daily consumption rates and the capacity of the structure. According to sanitary standards, one person consumes 200 liters (0.2 mᶟ) per day. Throughput is the capacity of sedimentation tanks with a three-day reserve, plus a small increase for bottom sediments. To operate normally, a septic tank for a family of four requires a volume of 2.7 mᶟ (0.2x4x3+0.3=2.7). The volume of all chambers is calculated, but from the bottom to the level of the overflow pipes. To be on the safe side, you should add on a salvo release or the arrival of relatives and make the volume a little more than the calculated one, as the super-moderator of our portal’s forum advises.

Vadim (spb) Super moderator FORUMHOUSE

Three cubes are enough for four people.

Options for choosing a septic tank

If the location of individual treatment facilities is regulated by standards, and the volume is selected depending on the amount of wastewater, then what type of septic tank will be, the design of the system and the method of organizing soil filtration depends, first of all, on the groundwater level (GWL) and the throughput (filtering) capacity of the soil. At low groundwater levels, almost any composite or monolithic structure is allowed. But if the soil has weak permeability (clayey soils), then it is necessary to increase the area of ​​the filtration field, the length of the filtration tunnel or the layer of drainage cushion under the filtration well.

If the water level is high, then it is permissible to use only monolithic septic tanks (reinforced concrete, plastic containers) with several chambers and an additional sealed storage tank. From the storage tank, through a float drainage pump, the settled wastewater will flow to the bulk filtration field (cassette and tunnel infiltrators are used). Underground filtration directly from the septic tank in a situation with close occurrence of perched water is unacceptable.

Ladomir Moderator FORUMHOUSE

It is necessary that the distance from the bottom of the filter structure to groundwater is at least a meter.

Popular types of homemade septic tanks

Among the participants of our portal, three types of homemade products are most in demand:

• From concrete rings;
• Monolithic reinforced concrete;
• Plastic (from Eurocubes).

Construction of a septic tank made of concrete rings

When the State Water Inspectorate allows, most members of the forum give preference to concrete rings, from which two sealed chambers and a filtration well are usually assembled, connected to each other by overflow pipes. To get the most impermeable structure possible, choose rings with a groove connection; they are not only more resistant to possible ground movements, but it is also easier to achieve the tightness of such a seam. External and internal waterproofing is used with bitumen primers or solutions based on CPS with the addition of liquid glass. There are two options for the arrangement of cameras - sequential and combined.

In the first, settling tanks are placed one after another, and the FCs are placed at a short distance, each with its own neck and inspection cap. The optimal design for a septic tank of this type was developed by one of the participants with the nickname MatrasMSA with the help of a moderator Ladomira.

MatrasMSA User FORUMHOUSE

The plot is 40x60 meters with a slope, a bathhouse/guest house is currently being built, three people live on weekend visits and sometimes guests, in the future there will be a house for permanent residence. The groundwater level is low, it is problematic to get to the water, the well is 88 meters deep, according to neighbors, the soil is loam. I am planning a septic tank like this: the first and second wells are three rings each (1.5 m in diameter) with a concrete bottom, the third well is the same, but the bottom is on the ground.

During the discussion, the following typical recommendations for the device were given.

Ladomir

• A straight tee is placed on the pipe entering the septic tank, the lower part is buried 15-30 cm into the drains, similarly on the outlet pipe.
• The outlet from the septic tank is 5-10 cm lower than the entrance to it, measured along the lower pipe tray.
• The overflow between the chambers is done at a depth of 0.4 m from the height of the drain column in the septic tank.
• The height of the drains into the septic tank is the distance from the bottom to the bottom tray of the pipe coming out of the septic tank.
• The branch pipe entering the filter well does not need to be equipped with a tee; it is routed in such a way that the wastewater flows into the center of the FC.
• Under the filter well, gravel/crushed stone is added, 0.3-0.5 m thick, and sprinkled on the sides, in a layer of up to 0.2 m.

The combined septic tank (designed by A. Egoryshev) is compact due to the arrangement of sedimentation tanks and FC in a triangle and is suitable for small areas. All wells are closed with blind covers, in which inspection holes are cut out, a common neck (service well) is installed on top, and the fan riser is discharged through the cover of the service well. To prevent differences between settling tanks, a concrete slab with a hole for the FC is poured at the bottom of the pit, a drainage pad (filter cassette) made of ASG, 10 cm thick, is poured under the slab, on a double layer of geotextile.

On our portal this scheme was proposed by a craftsman with the nickname s_e_s_h, having laid out the design and a similar construction process back in 2009, it is “alive” to this day, which proves the relevance of systems of a similar operating principle.

s_e_s_h User FORUMHOUSE

The requirements for the septic tank, taking into account the standards and needs of the family, were as follows:

• Good treatment of domestic wastewater at the outlet of the septic tank.
• A volume sufficient for permanent residence in a house of 3-4 people (bath, shower, 3 sinks, washing machine and dishwasher, 2 toilets).
• Winter operation.
• Reliable design with the ability to easily maintain the septic tank itself and underwater communications.
• Neat and discreet final appearance.
• Minimum possible cash costs.

The result was an economical design without sacrificing functionality.

However, both options are suitable only for areas with a low groundwater level; with a high groundwater level, no matter how you isolate the wells, there is a danger of them being flooded with high water and polluting the area with wastewater.

Work of a reinforced concrete septic tank

Monolithic reinforced concrete septic tanks can be used at any level, only the location of the filtration structures will differ. It is difficult to resolve difficulties when digging a pit, but it is possible.

researcher User FORUMHOUSE

To make it faster, the pit is dug with a tractor, on one side it is dug with a bucket that is wider and half a meter deeper than the bottom of the main pit for the septic tank (it seems like a pit), and a regular drainage pump is installed there. All the water from the main pit quietly migrates into the pit and is pumped out from there by a pump and poured out 25-30 meters away. For the duration of work in the pit, pouring and treating hardened concrete with water repellents, this solution is just enough.

Otherwise, the process is standard - formwork, reinforcement cage, pouring with the addition of modifiers to the solution, waterproofing (internal and external). A monolithic design with a low groundwater level was chosen by a portal participant Rybnik.

Rybnik User FORUMHOUSE

From the foundation to the rotary well (PW) - 1.4 m, the PW itself has dimensions of 1x1 m, from the PW to the septic tank there is a trench, 7.5 m long, 40 cm wide and 1 m deep. The pipe will enter the septic tank at a depth of 85 cm from surface (taking into account a slope of 2 cm per 1 meter). A second pipe (from the house) will also enter the septic tank. Next, a pipe of clarified water comes out of the septic tank, which will run 23 m along the fence and enter a filter well measuring 1.5x1.5x4 m.

For the reinforcement frame, rods with a diameter of 8 mm were used, restraints (frogs) were bent from them, cement M500 (intended, among other things, for concreting underwater structures in a fresh environment), a special additive that reduces the permeability of concrete, was used for pouring. Flat slate sheets are used as formwork. Details of the process and a step-by-step photo report are in the topic