Concrete septic tank: do-it-yourself installation of reinforced concrete rings and a monolithic one, structure and diagram

A septic tank is a container into which, if the site does not have a drain to the central sewer system, household and household wastewater is collected. Inside they accumulate, settle, purify or are simply pumped out. Traditional materials are concrete, brick, and recently ready-made factory containers have been used.

A concrete septic tank - prefabricated or monolithic - can be made with your own hands. Even taking into account materials, excavation work, and delivery services, building will cost less than buying and installing a ready-made factory module. But to do this, you need to understand the principles of operation of the structure and correctly carry out calculations and installation.

Rules and regulations

The guide for the design, construction and operation of septic tanks is the Code of Rules 32.13330.2012 “Updated edition of SNiP 2.04.03-85 “Sewerage. External networks and structures."

When drawing up a network laying diagram, you also need to study:

SNiP 2.04.01-85 Internal sewerage and water supply networks;
SNiP 2.04.03-85 Sanitary protection zones.

Their rules are focused primarily on preserving the quality of soil and water sources near a private home.

Drain modules are located:

From wells and wells of drinking water at a distance of at least 30 m (this is minimal, and works provided that the water intake is located higher in the direction of groundwater flow). For areas with highly permeable sandy soils - 50 m.
From bodies of water (rivers, lakes, streams) - at least 30 m.
From roads - a distance of at least 4 m.
From plantings - at least 4 m.
From the border of the neighboring plot - at least 2 m.

The tank itself is located more than 5 m on the plan from the country house. Sewer pipes should be laid at a distance of at least 3 m from permanent foundations. This will protect both the foundation (from erosion in the event of a breakthrough) and the networks themselves (when the building shrinks, it “pulls” nearby soils with it, damaging communications).

You will have to abandon the septic tank in 2 cases:

if the soils on the site are too low-permeable (for example, clayey), the drained liquid simply cannot filter through them;
when the groundwater level is too high.

Typically, the container and filtration field are located at the lower elevations of the site to facilitate gravity flow. It is advisable to place the diagram on the drawing so that the pipe going into the container has as few turns as possible - they are the ones that become clogged in the first place.

It may be impossible to fulfill all these requirements in a real situation. Therefore, it is necessary to carry out the most critical ones and to include additional volumes and strength in the design beyond the calculated ones.

Tips for choosing a location

When choosing a location for a septic tank, you should take into account the characteristics of the site and the requirements of sanitary standards.

Recommended distances from the septic tank to various objects

The optimal distance from the foundation of the house is from 5 to 15 meters. If the septic tank has to be located at a considerable distance, then inspection wells must be installed every 15 meters, as well as in places where the drain pipeline turns.
Even sealed monolithic septic tanks are recommended to be placed as far as possible from drinking water intake points.
Any septic tank needs periodic pumping, so it must be equipped with access roads for a sewer truck.

Calculation of volume for self-production

If only domestic sewage flows into the tank, then its volume is calculated from the minimum established by SNiP - 0.2 m3 per day per person. The minimum settling period (for consumption less than 5 m3 per day) is 3 days. With higher water consumption – 2.5 days. In total, for 4 people the volume of the container will be from 2.4 m3, and taking into account silt sediment - from 2.7 m3. The larger the reserve volume of the septic tank, the less likely it is that sludge will fill the entire working glass. But you need to remember that the capacity of a standard sewer truck tank is no more than 4 cubic meters.

Construction of a two-chamber concrete septic tank

This structure consists of two compartments. The first section receives sewage water from the house. Heavy waste settles at the bottom, and water and foam flow through the pipe into the second section. The bottom of the chambers must be monolithic. In the second compartment you can cover the bottom with crushed stone. The advantage of such a septic tank is that heavy particles remain at the bottom of the first chamber.

The purified liquid from the second chamber goes into the ground Source sv.decorexpro.com

Types of concrete structures and operating principle

Let's consider various options:

Single-chamber . Suitable for small and irregular volumes of waste discharge - for example, for a summer cottage where people come for the weekend. Wastewater enters, accumulates and settles in a sealed tank. Primary (anaerobic) cleaning is carried out. Mineralized sediment (so-called activated sludge) is pumped out as it accumulates - on average 1-2 times per season. Primary purified water can be used for economic purposes.
Two-chamber . From the first purifier, through an overflow, water enters the aerobic filtration chamber, where it undergoes additional purification. The second compartment, unlike the first, requires ventilation - and therefore is equipped with an air intake and often a compressor. From this chamber the liquid goes to the filtration field.
Three-chamber . In them, work is underway to uniformly drain water into the ground through additionally added layers of sand and crushed stone; a third container is carried out - the purification column.

Attention! When calculating the volume of a septic tank, the “working” size is considered to be the size of the primary treatment tank (with the height from the bottom to the outlet) and the volume of the secondary treatment tank (calculated similarly).

How to make a septic tank on the site

To design a concrete septic tank on a site, you first need to decide on the type of construction itself. A septic tank can be made from ready-made reinforced concrete products, filled in yourself, or purchased completely ready-made.

Each option has certain pros and cons.

Installation of ready-made structures

The finished product is the easiest way to arrange a septic tank. It will not be difficult to select a design at the factory that exactly matches absolutely all the parameters - many manufacturers offer properly designed, reliable septic tanks with overflow holes, hatches, and covers. You can find models that come with sump pumps and not have to worry about where to drain the water from the septic tank.

Having purchased a ready-made reinforced concrete septic tank, it is enough to simply install fittings and pipes. The main advantages of a ready-made septic tank: the sewerage system is installed in the shortest possible time, there is no need to carry out expensive, dirty and heavy concrete work.

It is also worth noting that factory designs guarantee strength, reliability and guarantee protection against errors during the design process.

Disadvantages include the relatively high cost (purchase, delivery, installation on site), the need to use lifting equipment and special vehicles. If the site is small and there is no convenient access, then you will have to consider other options for constructing a septic tank.

Septic tank made of reinforced concrete rings

Water purification using a sewer system created from reinforced concrete rings is carried out according to the same principle as in the case of a ready-made septic tank. It’s just that here you will have to do the bulk of the work yourself.

Stages of constructing a septic tank from reinforced concrete rings:

Choosing a location on a site, performing calculations, digging a pit - it is better to use machinery, but it can also be done manually. The dimensions of the pit should be slightly larger than the dimensions of the septic tank.
Concreting the bottom - you can use a reinforced concrete slab or reinforce it with steel rods and pour the solution yourself.
Installation of rings - they are lowered into the pit using a winch or lifting equipment, and installed one on top of the other. It is advisable to make holes for sewer and ventilation pipes in advance.
Sealing of joints - treatment with waterproofing materials, sealing with cement.
Backfilling can be done with the soil that was dug up, or with sand. Fill them with layers of 10 centimeters and compact them carefully so as not to damage the pipes.

Among the disadvantages of this method, mention should be made of the costs of delivery/installation of rings and the entire system, and the need to attract equipment.

Filled septic tank

Self-pouring a concrete septic tank is the cheapest, but labor-intensive and time-consuming option for arranging a sewerage system. But such a design turns out to be reliable, durable, hermetically sealed, and monolithic.

How to fill a septic tank:

Design, choosing a location, digging a pit in accordance with the volume of the structure, backfilling a layer of sand 20 centimeters thick, tamping.
Creating a mesh with cells of 20x20 millimeters from steel rods with a cross-section of 10 millimeters and knitting wire. Clamps or stones are laid at the bottom of the pit, and a metal mesh is placed on top.
Filling the structure with concrete of minimum strength class B15, compacting, waiting for hardening for 2-14 days.
Pouring walls with preliminary reinforcement and installation of formwork. If the formwork is done carefully, the walls will be smooth; they can be covered with roofing felt or two-layer film (then you can do without backfilling the soil). Before pouring the walls, pipes are installed. The structure must be monolithic, so it is better to fill it at a time.
Dismantling the formwork, filling cracks with mortar (if any), applying a layer of mastic for waterproofing.
Laying a welded frame from a metal angle around the perimeter of the walls (for the cover), fastening the slate, pouring concrete with reinforcement. Wait at least 14 days for the concrete to set.
Installing hatches, backfilling a concrete septic tank with soil or sand.

Such work can be carried out in any area (even where access to special equipment is limited), the design is seamless, monolithic, so groundwater does not get inside and wastewater does not go into the ground.

Designs without pumping: myth or reality

Even if only water from sinks is drained into the container, the liquid inevitably becomes contaminated with solid particles, grease, and food waste. In the primary treatment drain, it decomposes into methane, liquid waste and mineral sediment that forms at the bottom. Cleaning may be required from 3–4 times a year, to once every 5–7 years. But it will be necessary.

Conventionally, “without pumping” you can make containers that:

They have sufficient volume.
They are operated regularly (or properly “started up” at the beginning of each operating season).
They are not forced to work with complex contaminants (chlorination, soaping, aggressive cleaning agents, accumulated fat - all this harms the bioflora, and active siltation occurs).

Selection of design scheme

The number of containers is selected based on the task at hand. That is, the cleaner the water should be at the outlet, the more compartments there should be inside the septic tank. Therefore, there may be one, two or three.

One camera

This is not much different from a cesspool because the sewage is collected inside a constructed container. This is where solid particles settle. Partially clarified water forms on top.

Not the best option, because the efficiency of sewage treatment here is low.

Two cameras

As stated above, this is a frequently used design. This is a large septic tank - monolithic reinforced concrete, which is divided by a partition. The height of the latter is 10 cm less than the same size of the container itself. This is done on purpose so that the water accumulated in the first compartment can easily flow into the second. Here it will be purified further due to the precipitation of small particles of sewage. This partition is called overflow.

There is another option when this wall is made the same height as the others. Then holes are made in it to drain the water.

Three cameras

This type is not often used because it is more expensive to construct. But the efficiency of wastewater treatment is maximum here. Purely structurally, this is a two-chamber version, to which another overflow has been added. The photo below shows this option.

Attention! The first chamber for receiving sewage from the house is made twice as large as the others. It is she who takes on the main share of the cleansing process.

Concrete: pros and cons

Advantages:

Price. Even taking into account delivery, installation with the work of a crane and earth-moving machines, a self-made concrete drain will still cost 5–7 times more than a finished one of a similar container.
Massiveness. Freezing soil with a lot of water, expanding, can push the container out. Therefore, light tanks require additional anchoring. Concrete products are held under their own weight.
Strength. Factory sections or self-made containers that have achieved the design strength can withstand compression, impacts, and heavy weight without cracking.
Possibility of repair. Even in the event of a leak or corrosion, it is possible to repair the damaged area yourself.

Flaws:

It is necessary to take into account all operating conditions and site features. Incorrect slopes, clogging, freezing, and uneven shrinkage can make the drain ineffective.
Large volume of concreting, heavy sections, sometimes problems with the tightness of joints.

Concrete septic tanks can be made independently from start to finish. Wherein:

no need to deliver and install heavy sections;
it is possible to produce a product of non-standard diameter;
fewer sealed joints;
it is easier to make holes for communications;
the cost of the product is lower.

Manufacturing a septic tank from monolithic concrete

You can make a septic tank from concrete with your own hands - for this you will need to perform a number of tasks, involving the necessary tools, materials, and labor.

The main advantages of this approach are the ability to save on special equipment (to install reinforced concrete rings, for example, you will have to call a crane) and make a structure of the required volume, size, shape, configuration.

The main stages of constructing a concrete septic tank:

Design: searching the area, calculating the volume of the structure, determining the required amount of building materials
Digging a pit for installing a septic tank, compacting the earth, strengthening the bottom
Creation of a metal frame, formwork
Installation of overflow pipes
Pouring concrete
Installation of enclosing structure and ventilation system

It is not difficult to build a concrete septic tank with your own hands, but the quality of the entire structure, the features of its service and the duration of operation will directly depend on compliance with the technology and the choice of good materials.

Work cycle and material consumption

The sewer pipe leaving the dacha must be thermally insulated and laid to a depth of half a meter (depending on the degree of soil freezing). Its slope is 1.5–2 cm per linear meter (preferably 3 cm), an inspection is installed every 15 m. It is insulated, usually with polystyrene foam; it is also possible to lay a heating electric cable, which is connected in cold weather. The final level of the outlet pipe will be the height of the entry into the first tank.

The bottom of the chamber is at a level of at least 3.5 m - this is the length of the pump of the sewer truck.

We calculate materials

The volume of a reinforced concrete ring with a diameter of 1 m is 0.7 m3;

1.5 m – 1.59 m3;

2 m – 2.83 m3.

For a typical reinforced concrete septic tank with two chambers, two one and a half meter rings or four one-meter rings will be sufficient.

If you make your own casting for a similar structure, you will need about 400 kg of Portland cement, 600 kg of sifted sand, 200 liters of water, as well as reinforcing bars, formwork boards, and plastic film.

Scheme of a two-chamber version

In this system, water undergoes preliminary settling before being discharged or pumped. According to sanitary standards, such water can be discharged into the ground. The advantages of this system lie in its compactness. With the same volume, two free-standing containers made of reinforced concrete rings take up more space than a monolithic concrete structure.

The diagram shows the proportions of the septic system. The optimal size of the receiving chamber should exceed the volume of the second settling tank in a ratio of 1:3 (+)

This septic tank has an internal concrete partition, which allows the water to settle in two stages. In addition, it can be equipped with a sensor that signals overflow.

The second overflow at the opposite end of the container is located slightly lower than the first, which eliminates the return of wastewater to the receiving compartment and ensures spontaneous overflow of the settled liquid into the next chamber.

A two-chamber drain pit needs to be pumped out once a year, a single-chamber pit - every 3-6 months, i.e. 2-3 times more often. A two-chamber will require more construction costs, but in the long run, exceeding the budget will quickly pay off

How to build a two-chamber septic tank using concrete rings is written here. We recommend that you familiarize yourself with this material.

Installation of reinforced concrete rings

Concrete rings for the septic tank are placed sequentially (small sections can be laid using a winch, but large ones will require a truck crane), and you need to ensure the verticality of the structure and the alignment of the embedded parts, which are then welded.

The seam is sealed. The outer and inner surfaces of the rings are waterproofed: from the inside - with liquid glass or special mastic, from the outside - with roofing felt or bitumen mastic. Internal waterproofing should not be chemically aggressive - this will disrupt the operation of the system. However, damage to the seal will lead to rapid destruction of the concrete. The upper part of the structure is thermally insulated up to the freezing limit of the soil (usually with polystyrene foam blocks).

Turnkey installation: what is included in the price

Companies involved in the sale and installation of treatment systems offer a catalog of septic tanks designed for different initial parameters. What they all have in common is that when ordering a turnkey septic tank, all responsibility for the result of the work passes to the construction company, which is stated in the contract.

Even if the sealing of the overflows deteriorates, you can request warranty repairs Source pochtidoma.ru

After choosing a model, the customer and the construction organization enter into an agreement under which they pay for:

Construction Materials

The company prepares the necessary construction material, delivers it to the site and unloads it. If the distance to the site exceeds what is included in the basic package of services, it will be paid additionally.

Concrete rings, floor slabs and cement are delivered at the scheduled time. We also deliver overflows, pipes and hatches (polymer).

Excavation

Having chosen a suitable location, workers prepare a pit and trenches. The seized soil is distributed on site or removed from the site (the option is paid additionally).

Stages of installing a septic tank floor key on video:

https://youtube.com/watch?v=qjiqpiFVZk8

Septic tank installation

Performed using a crane. If there is no access to the construction site, concrete rings are installed manually; in this case, the cost and installation time increase. Installation of a turnkey septic tank made of concrete rings, the price and design of which is selected individually, proceeds in the following order:

The main parts of the structure (plates and rings) are installed.
Joints and seams are consistently sealed.
Overflows are installed and insulated.
Concrete necks and hatches are installed.
A pipe is laid from the building, its slope is controlled by a level (a device that determines the difference in heights of selected points).
Wells are being backfilled.

Professional approach - order on the construction siteSource pinterest.co.uk

Construction and concreting of a monolithic two-, three-chamber

The simplest septic tank is rectangular, the pit for which (with the most even bottom and wall) will become the outer formwork. When calculating the proportions, remember that the distance from the water level to the bottom should be no less than 1.2 m and no more than 3.5 m. The length and width of the pit is from 750 to 1000 mm (the best ratio is 1:2–1:3).

After laying the pillow in the hole and compacting it, the walls and bottom are lined with film. Next, a reinforcement structure is erected (rods 10 mm thick, cell 20 cm), internal formwork (usually made of boards) and spacers are installed.

The thickness of the external walls is at least 20 cm, the internal walls are from 15 cm, the reinforcement is covered with a layer of at least 3 cm of concrete. The input and output holes are filled using scraps of plastic pipe with a diameter of 15 cm.

DIY installation of a monolithic septic tank in 7 simple steps

To make a monolithic septic tank with your own hands, it is enough to carefully study all the main stages of the work and strictly follow the instructions.

How to prepare a pit

First, they dig as smooth as possible, remove the soil with buckets or special equipment, and trim the edges manually. It is advisable to check the evenness of the surface with a level; the corners are made according to the construction angle. Excess soil is removed or distributed throughout the site. After the pit has been dug, the soil must be sprinkled with a layer of sand 20 centimeters thick, a layer of crushed stone 5 centimeters thick, thoroughly compacted, and a plastic film laid on top of the bottom.

Pouring the base

The walls of the pit are reinforced with boards to prevent collapse. Formwork made of wooden panels is installed around the perimeter, and a reinforcement frame is placed inside on stones or clamps. Next, the bottom is filled with concrete of at least M300 grade and wait several days until it hardens.

How to install formwork

After the concrete base has completely hardened, you need to make a reinforcement frame to strengthen the walls and internal partitions of the septic tank. Next, the wooden panels are mounted inside and outside using plywood and edged boards. The formwork parts are fastened together, with the obligatory installation of internal struts and external supports so that the structure is motionless and rigid.

Installation of overflow pipes

For installation, two straight pipes are used. The first is put on a sewer pipe that leaves the building: they cut a hole of appropriate size in the plywood and bring the end into the receiving tank. Secure the pipe to the pipe with sealant or a rubber ring, and point the drain hole down. A pipe about 40 centimeters long is inserted between the two containers on the partition, fixed in plywood on both sides of the chambers, and pipes are placed on the pipes with the drain holes directed downward.

Calculation of concrete composition, how to mix and pour concrete solution

The mortar is made strong, since the thickness of the walls is relatively small (about 15 centimeters) and they must be strong. In a container for mixing concrete mortar, mix cement and sand-gravel mixture in a ratio of 1:3. Water is added in the volume required to obtain a thick consistency.

The entire volume is poured in a day, then the concrete is allowed to set, protected during the drying process with polyethylene or wet sawdust. It is better to carry out work in warm weather, when there is no risk of the concrete layer freezing.

Installation of the upper ceiling and ventilation system

For the top floor of the septic tank, reinforced concrete slabs are used or monolithic construction is performed with inspection hatches and holes where a ventilation pipe can be installed (in all chambers). After the concrete of the walls has hardened and the formwork has been dismantled, the structure is inspected, defects are eliminated, and the formwork for the ceiling is installed.

Where hatches and holes for pipes are supposed to be made, formwork is installed from sewer pipes, plywood or boards. Reinforcement of the floor is made of two layers of metal rods or reinforcing mesh with a rod thickness of at least 12 millimeters. The solution is poured inside the formwork and allowed to harden completely.

How to make manhole covers

To avoid hypothermia of the concrete septic tank and protect it from water and debris, hatches are installed. Lids are made of wood and metal. The internal wooden cover protects the septic tank from temperature changes and is insulated. Usually mounted from boards or plywood, nailed together into a shield, the structure is removable, without fastening.

It is better to make the external hatch metal: weld a rim for the lid from a 40x40 construction corner, attach it to the base with anchors, and cut the hatch from a sheet of metal to the size of the rim. The edges of the hatch are processed with a grinding attachment for an angle grinder, and the canopies are attached to the cover with bolts or welding. Then the hatch needs to be attached to the rim.

Making a concrete septic tank with your own hands is a very real task. In order for the treatment plant to be reliable and fulfill its functions, everything must first be carefully calculated, designed, and then created a septic tank using any of the technologies described above.

Maintenance and operation

Small amounts of food residue, paper, and detergents are allowed to enter drains. There are a number of parameters that must be observed when operating the sewer:

Once a year you need to clean the chamber from solid fractions. You can reduce the frequency of cleaning insoluble sludge to pumping every 3–5 years. To do this, a drug with bacteria is added to the system, which liquefies it.
It is unacceptable for antibacterial materials to enter drains: alcohol, chemicals, medications, antifreeze and similar alkalis or acids.
Do not allow aggressive bacteria, which may be contained in rotting food or pickles, to enter the sewer system.
In winter, it is forbidden to keep the inspection hatch open for a long time.
A break in the operation of the septic tank for more than two weeks is unacceptable. If the house is used only periodically, then the system must be “mothballed”. Clean water is poured into the tank at 50–70% of the total volume to prevent the death of bacteria and the soil pushing the tank out.

Three-chamber concrete septic tank

The installation of such a sewer requires a lot of labor and material costs. It is better to arrange it in a private house where people permanently live. The first section of the septic tank serves to settle the wastewater. Bacteria break down solid particles into simpler ones. Water flows through the connecting pipe into the second section. There, the compressor periodically supplies oxygen, which promotes the proliferation of aerobic microorganisms. Further wastewater treatment takes place. In the last chamber, the water goes through the final stage of purification. Using a pump, it is forcibly discharged into the drainage system.

The scheme of a three-chamber septic tank is the most complex and requires high costs Source masterseptika.ru

Possible problems and their solutions

1. The septic tank gets clogged too quickly.

This is due to disruption of the microorganisms inside. It is necessary to pump out excess sludge from the first tank, leaving 15% sludge, and fill it with clean water, adding a bioactivator. If there is excess fat or lathering, you need to remove it using a special product. Microbes also die from low temperatures (you need to additionally insulate) or water that is too contaminated with detergents (you need to add a bioactivator and limit the aggressiveness of the drain).

2. An overflow has occurred. If the volume of the tank is incorrectly calculated, this is due either to blockages and growths in the pipes, or to siltation of the soil. They need to be cleaned both through inspection and with the help of drugs against growths. Blockages are common in pipes with L- and T-shaped joints, as well as a low slope.

3. Damaged walls of the product with cracks or shifts of 1 cm or more in size are plugged with glass-basalt reinforcement. Then they are filled with a waterproofing quick-setting mixture (special mixture or cement-sand mortar with liquid glass). 7 days after hardening, the damaged area is re-coated with waterproofing.

Scheme of a two-chamber version

The diagram shows the proportions of the septic system. The optimal size of the receiving chamber should exceed the volume of the second settling tank in a ratio of 1:3 (+)

This septic tank has an internal concrete partition, which allows the water to settle in two stages. In addition, it can be equipped with a sensor that signals overflow.

How to build a two-chamber septic tank using concrete rings is written here. We recommend that you familiarize yourself with this material.

Inexpensive alternative

In terms of financial and time costs, the option of making a septic tank for a summer house from barrels with your own hands is quite attractive. In an open, but fully functional state, it looks like this:

It is clear that such a structure is assembled and installed in a few days. The main thing is not to forget: you need to drill holes in the original lids and insert tubes into them. One more point: the barrels must be firmly secured in the ground.

The minimum volume of barrels should be about 200 liters; you should not mess with 50-60 liter barrels. The price of new containers of the displacement of interest is about 2.5 thousand rubles apiece, but you can find used ones, cheaper, and keep it within 5-6 thousand rubles.

Such a septic tank is quite sufficient for a dacha where guests do not appear often and stay for a couple of days at most, or where one person lives permanently and uses up to 100 liters per day. In principle, at any water flow, improvised tanks are protected from overflowing, but the liquid leaving the septic tank will not have time to be cleaned (it will not even go through the settling phase). For a summer cottage, this is, in most cases, uncritical.

The advantage of a septic tank assembled from barrels is the ability to periodically independently clean the tank from dense sediment using a scoop attached to a comfortable long handle.

Why from concrete rings

There are several materials from which you can build a cesspool for domestic sewage - brick, reinforced concrete, plastic pipes. Each of them has its own pros and cons, which every builder takes into account in search of the optimal solution.

The choice in favor of concrete rings is made according to the following criteria:

The products are specially designed for underground operation in conditions of high lateral and vertical pressure. The round shape ensures uniform load distribution over the entire pipe area. Compression makes it even stronger.
Affordable price. The manufacturing process of products is worked out to the smallest detail and is largely automated. The financial costs for one ring are much less than for the construction of the same object from other materials.
Optimal combination of ingredients. Concrete gives the pipes strength, and metal gives elasticity. The addition of plasticizers increases the resistance of the material to acidic and alkaline environments.
Ease of transportation. Products can be unloaded manually, without the use of lifting equipment. Reinforced concrete products are moved around the site by rolling them with little physical effort.
Wide range of manufactured models. The standard pipe height is 90 cm, with a diameter of 100, 150 and 200 cm. Models with bottoms, top plates under the hatch, with and without hinges are available for sale. There are series with built-in brackets for lowering into a constructed well. Docking is carried out on flat faces or using a tongue-and-groove system.

How to use treated wastewater

Treated wastewater can be used to water everything that grows on the site, including trees, shrubs, vegetables and flowers. The percentage of contamination in settled and disinfected waste does not exceed 10-15%. Reusing the liquid allows you to reduce water consumption for irrigation.

The pump that pumps out wastewater from the second and third tanks can be powered by a solar battery, and in this case, the construction of the system will pay for itself in 2 years. The sludge that accumulates in the receiving tank is suitable for use as fertilizer. It can be applied separately or mixed with other organic matter.

By adding sludge to the compost bin, you can improve the quality of the compost. The substance is used as follows: a layer of leaves, grass or sawdust is placed at the bottom of the hole, silt is added, then other components are added again, and so on, alternating until the hole is filled. After ripening, they are used for gardening needs.

Waterproofing the inner surface of the rings

By sealing the seams, the structure is sealed, but there is a risk that the concrete will collapse after some time under the influence of sewage. Joints are also a vulnerable spot, especially if they are sealed with cement and sand.

The work is carried out in several stages:

clean the surface;
prime;
apply mastic.

Dirt on the surface impairs adhesion, so the concrete must be cleaned before the main work begins. Seal all cracks and defects, not leaving small ones unattended. For repairs, sealants or putty are used.

Next, proceed to priming the surface with bitumen dissolved in diesel fuel, using a brush or roller. The coating is two-layer, the second is done after the first has completely dried. After a day, when the soil is absorbed into the concrete, work continues.

The protective layer is a mastic, of which there are many varieties on sale. The container with it is opened immediately before use. Prepare for use by stirring with an electric drill with a mixer attachment. If necessary, add a solvent, the brand of which is indicated in the instructions. Cover the surface with a brush.

When the mastic dries, cracks will be visible. The challenge when applying the second layer is to cover them, but the surface is completely covered. If necessary, apply another layer so that the protection becomes flawless. Allow time between operations to allow the mastic to dry.

Concrete structure project ↑

A thoughtful, calculated, pre-prepared project is 50% of success. Many problems can be solved at this stage, when choosing a successful scheme or drawing up an estimate. Let us dwell in more detail on the issues on which the efficiency of using a septic tank depends: the choice of volume, location and number of tanks.

Volume calculation ↑

The volume of the chambers depends on the total amount of wastewater. There is an average value - 200 liters per person, respectively, for 4 people - 800 liters. This figure must be multiplied by 3 - the maximum number of days that the wastewater spends in the chamber is 2400 liters, that is, the volume of each working container should not be less than 2.4 m³.

Using this simple formula, we calculate the volume required to build the planned facility

But some other factors need to be taken into account. For example, the frequency of visits to a dacha or permanent residence in a country house - these calculations are relevant for the second option

If you use a suburban area exclusively during the warm season or visit only on weekends, there is no need for a bulk septic tank. It is enough to build a small one- or two-chamber septic tank with a filtration well.

Three-chamber treatment facility designed for a family of 5-6 people

Optimal number of cameras ↑

The maximum number of cameras in factory devices is 3; in homemade analogues you also need to focus on this figure. It is irrational to build a fourth reservoir. But three are also not always necessary. For example, in the case of a country septic tank for a small family that rarely goes out to the country, a single-chamber design, essentially a cesspool, is sufficient. The accumulated masses are processed by anaerobic bacteria, then the liquid goes into the ground, and the deposited sediment, as it accumulates, is pumped out and removed by a sewer truck.

Scheme of a two-chamber septic tank

Two-chamber septic tanks allow you to use vacuum cleaners less often. The drain liquid goes through two stages of purification - with the help of anaerobes and aerobes, and enters the soil already clarified. The second reservoir is often filled with crushed stone to increase the drainage effect. Additional treatment is carried out on the filtration field.

Three-chamber structures are real biological treatment devices. In the first chamber, the sewage masses are divided into fractions (sediment falls to the bottom, fat floats), in the second they undergo aerobic purification (air is pumped in using a compressor), in the third they are finally clarified, and only after that they are sent to the drainage field.

To build a concrete septic tank with your own hands, the preferred option is a two-chamber design. It cleans drains effectively and is easy to maintain.

Selecting a location ↑

If you incorrectly determine the location of sewerage facilities, you can violate sanitary standards. These are not bureaucratic requirements, but rules aimed at preserving the cleanliness of the environment, as well as caring for the health of the owners of the site.

Ideally, the direction of movement of groundwater should be determined and a location located “downstream” should be selected. In practice, this is quite difficult to do, so they adhere to standards regarding the distance from the treatment plant to significant dacha facilities.

The distance to an autonomous source of water supply (well, borehole) must be at least 50 m (for clay soils - from 30 m), to a residential building - 5 m or more, a busy transport highway - also 5 m, dividing fence - 3 m. It is better to move garden plantings further away, up to 4-5 m, since tree roots can eventually break the tightness of the underground structure.

Location of a monolithic septic tank relative to the house

The best solution is an open area 5-7 m from the house, to which sewer pipes are routed directly. After installation and backfilling, the area is fenced off or camouflaged using country decor.

How to determine the required volume?

The size of the septic tank is determined according to the daily volume of wastewater increased threefold. Moreover, the calculation is taken with a focus on the maximum possible water consumption. In designs with several chambers, such calculations are carried out for the first container and, based on its dimensions, are determined with the remaining chambers. If desired, the size of the septic tank can be made larger than required. This will increase its service life until cleaning. The shape of the concrete septic tank should be rectangular. This will ensure maximum wastewater purification.

Note. When calculating the size of a septic tank, you should take into account the thickness of the walls of the structure.

Determining the location of the future sump

When choosing the location of the septic tank, you should take into account that it must be at least 4 meters away from the housing construction. A long pipeline is also impractical. The longer it is, the more likely the pipes are to become clogged. In this case, you will have to install intermediate wells. They are also necessary in places where the pipeline bends.

When arranging a septic tank, it is necessary to take into account sanitary rules and regulations for such structures

Important! When choosing a place to install a septic tank, it is necessary to take into account the direction of groundwater flow.

If the terrain is uneven, it is advisable for the septic tank to be located below the building. The filtration field must be constructed at a distance of 5 meters from the foundation, 50 meters from the water supply source and at least 30 meters from the reservoir.

Proper care of your septic system

To prevent the septic tank from becoming clogged, it must be cleaned periodically. Because kitchen drains contain grease particles, over time the drain pipes become coated with a thick layer of plaque.

For removal, bacterial or chemical preparations are used, preferably the first option. Products containing microorganisms are harmless to microflora and the material from which the pipes are made, and chemical compounds not only clean the surface, but also destroy beneficial bacteria.

In the cold season, the hatch openings are insulated . This is necessary so that the drains do not freeze and the cleaning speed does not decrease. Insulation is required when the temperature drops to -25°C.

Types of materials

According to this criterion, chimneys can be:

Brick.
Ceramic.
Steel.
Combinational.

The brick version is today considered archaic. It is extremely difficult and expensive to construct and maintain.

And the most popular design today is the “sandwich”. Its advantages are:

Powerful resistance to aggressive factors and mechanical stress.
Simple structure. The design includes two pipes of different diameters. One is placed in the second. The gap between them is filled with basalt wool. Essentially this is the same coaxial option.

Ceramic models are often installed in private homes today. They are popular due to their strengths:

Reliability.
Simplicity of the device.
Ease of installation.
Reasonable price tags.

This chimney consists of a ceramic pipe covered with thermal insulation (most often mineral wool) and placed in a box made of expanded clay concrete.

Video description

The work procedure and installation of a septic tank made of concrete rings in the video:

How to choose the optimal location for a septic tank

The structure is mounted above the groundwater level. The best location is at the maximum distance from the house (at least 7 meters, but no more than 20, so as not to increase the cost of pipeline construction). It is logical to place the septic tank on the border of the site, next to the road. This will reduce operating costs, since the cost of leaving a sewage tank is affected by access to the system and the length of the hose. In addition, with the correct location, the sewage disposal truck does not need to enter the yard, and the hoses will not lie on the beds or paths (otherwise, when the hose is rolled up, waste may end up in the garden).

Pit preparation

Ground work using an excavator takes 2-3 hours. The size of the pit should be slightly larger than the dimensions of the wells. This is necessary for the smooth installation of the rings and their waterproofing. The bottom is covered with crushed stone and concreted.

Preparing a pit for a septic tank made of concrete ringsSource rostovgruz.ru

Installation of rings and sewer pipes

Rings for a septic tank are installed using lifting equipment, which significantly saves time (when compared with manual installation). Fixation of the seams is ensured with cement mortar; additionally, metal ties (staples, plates) are installed.

The crucial moment is the process of installing ringsSource remoskop.ru

Sealing and waterproofing

The seams of a septic tank made of concrete rings are sealed on both sides of the structure. For this purpose, cement and coating protective solutions are used. You can install ready-made plastic cylinders inside the well. This additional cost will make the system 100% sealed.

In the process of waterproofing concrete rings for a septic tank, the connections are treated with liquid glass, bitumen or polymer-based mastic, and concrete mixture. To prevent freezing (and destruction) of the structure in winter, it is recommended to insulate it with a layer of polystyrene foam.

Sealing joints and waterproofing a septic tank made of concrete ringsSource zen.yandex.ru

Hatch installation and backfilling

The wells are covered with concrete slabs, with holes for hatches. In the first two wells, ventilation is installed, which is necessary for the removal of methane (gas appears as a result of the activity of anaerobic bacteria). To backfill the installed floors, use soil taken from the pit (backfill).

Backfilling of finished wellsSource lanshaft.com