Do-it-yourself septic tank from boards. How to make an effective septic tank without pumping out with your own hands. The principle of operation of the treatment plant

The problem of hygiene and comfort always faces a person who decides to move to permanent place residence in the private sector, where there are often problems with the habitual residents of the "stone jungle" shower, toilet. Indeed, in such cases, it is often not possible to connect your housing to centralized communication systems, including the drainage system. Wastewater. And that is why before building the house itself most of owners land plots planning and furnishing. How to do it, what is needed for this and how difficult is it?

Septic - what is it

Table. The main types of septic tanks.

Cesspool or septic tank - which is better?

For decades and even centuries, people for arranging sewer system(if you can call it that) they built ordinary cesspools near their dwellings and on household plots.

These holes 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 bathrooms, washing and dishwashers, swimming pools;
• complexity of maintenance - too large volumes of wastewater will require pumping out waste several times a week, which can hit your pocket hard;
• there is a high risk of runoff entering groundwater and polluting environment- Cesspools often do not have a sealed bottom and walls at all:
• an unpleasant smell hovering next to the pit;
• problems with neighbors and sanitary inspection services.

All of the above disadvantages cesspool absent from any properly equipped septic tank. It is more efficient, durable, economical, less likely to need cleaning and processing, and there is a special one for this. Although outwardly very similar to an ordinary cesspool, the filtration system in it is much more complicated. Rather, in the cesspool, it can be said to be completely absent.

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

IN country house designed for permanent residence, will not be comfortable without competently organized . The cesspool needs frequent access to the sewers, making life difficult for the residents. Many people don't like the thought of a septic tank that needs to be cleaned several times a year.

But a well-installed septic tank without pumping out - the best choice, which can serve for a very long time without requiring your intervention.

Types of septic tanks for country house differ according to the principle of action:

• Accumulative - sealed containers connected to the drain system coming from the house.
• Septic tanks with soil aftertreatment - consisting of several tank chambers, the last of which does not have a closed surface.
• Stations deep cleaning- set up in places where sanitary norms prohibit the discharge of poorly treated water.

How does a septic tank work

A septic tank without pumping for a private house or cottage is a structure in the ground.

It consists of:

• Several connected containers.
• Ventilation holes in each container.
• Airtight lids for each container.
• Pipes connecting septic tank containers.

Wastes enter the first chamber with a concrete bottom through the sewer pipe, settle, and the sediment sinks to the bottom, where they are gradually processed by anaerobic bacteria. Waste gradually decomposes and emits gas that escapes through the vents.

When the first chamber is filled with water up to the pipe connecting the chambers, the water flows into the second. If it is finite, then it does not have a solid bottom, if not, then it also has a concrete bottom, for settling a dense layer. From this compartment, water flows into the next. The open bottom of the last chamber rests on a cushion of rubble and sand, and the water goes into the ground.

Anaerobic bacteria process almost all organic waste, so a septic tank without pumping out may not need to be cleaned for 15 to 20 years.

It is also important to determine the volume of the septic tank. The standard for daily water consumption per person is 200 liters. The volume is calculated based on three days of continuous water use and. Accordingly, 4 people need a two-chamber septic tank, with a volume of 3 x 3 m each.

Choosing the materials of manufacture

It is possible to equip a septic tank on the site of a private house without pumping out of concrete, reinforced concrete rings, bricks or using special plastic containers. It should be noted that brick and plastic septic tanks will not ensure the operation of a septic tank for more than 10 to 20 years.

The arrangement technology is quite simple if you do everything according to the instructions.

We determine the place for bird

First you need to determine the location of the septic tank, taking into account the level of groundwater and sanitary standards.

• The septic tank should be located at a distance of 1 m from outbuildings and 5 - 7 from residential buildings.
• The septic tank should not be closer than 15 m from open water bodies and 50 m from the water well.
• Between the septic tank and the fence separating the plots, there should be a distance of 2 m.
• The septic tank should not be higher than the house or outbuildings.

Pit preparation

The construction of a septic tank begins with a foundation pit. A common volume of a septic tank is a pit of 8 cubic meters. m with dimensions 2x2x2 m.

Aligning the walls

If the septic tank will consist of plastic containers, they are installed in a pit on an already concreted bottom. In the last container, the bottom is removed and it is placed on a pillow of crushed stone and sand.

When building a brick septic tank:

• We prepare a pillow of crushed stone and sand, fill the bottom of the waste processing chambers with concrete and reinforce it.
• We lay out the area around the perimeter with bricks. At the same time, we connect with cement and finish the walls from all sides.
• In the last chamber, we do not concrete the bottom, and lay the bricks on minimal amount solution. This contributes to the flow of purified water into the ground.

When arranging it using reinforced concrete rings:

• In the pits we make a pillow of crushed stone and sand. The bottom of the chambers, not counting the last one, is made of reinforced concrete.
• After it hardens, install concrete rings, connecting them to the bottom, and to each other concrete mortar.
• We make holes in the chambers for connecting pipes and ventilation. A piece is suitable for the connecting pipe PVC pipes large diameter. For ventilation, you can use the same pipes of small diameter. The joints between the pipes are reinforced with concrete.

When self-pouring concrete:

• Leveling the bottom.
• For each of them we prepare from sheets, scraps of a plastic sewer pipe. We make holes in the formwork to drain water. To do this, cut out in osb sheets round holes for cutting pipes in increments of 0.3 m. To strengthen the osb along the perimeter of the sheet, after 0.5 m we attach a beam to it with self-tapping screws. Ideally, make a collapsible formwork so that it can be rearranged to other walls of the septic tank. The formwork must be securely reinforced, for this it must be well wedged with a beam in the pit. After that, insert the prepared pipe cuts. They should go deep into the soil by 5 cm.
• At the bottom of the chambers we make a pillow of crushed stone and sand.
• The bottom of all chambers, except for the last one, is poured with concrete mortar and.

• When pouring walls, the work is divided into several stages, since the height concrete walls, poured at the same time should not be higher than 0.4 - 0.5 m. We lay each layer with stones.
• We build a wall from or. It is recommended to make an overflow hole 0.4 m below the sewer pipe leaving the house. Ideally, you need to equip the overflow hole with a sewer tee.
• Upon completion of the finishing, the septic tank without pumping is left open for 2 weeks to dry.

At the end, tightly close the lid on the cameras.

Lids are provided in plastic containers, and for septic tanks made of other materials, it can be made in two versions:

• A lid firmly planted on the upper concrete ring, level with the ground;
• For brick or other, made independently, sheets of steel, tightly laid on the edges of the walls, are suitable.

How to increase the life of a septic tank

Same an important factor is its ventilation, made from a sewer pipe brought to the surface. It will allow the water to partially evaporate.

When using a septic tank, it is prohibited:

• Throw construction debris into the sewer. This will quickly clog the first part of the septic tank.
• Use it for the disposal of polymer waste. Cellophane, cigarette butts, personal hygiene products are not processed by aerobic bacteria.
• Use detergents, which can harm microorganisms that decompose organic matter
• Drain down the drain chemical substances for cleaning pipes, machine oil, acids, alkalis

Permitted to use for:

• Use a septic tank to treat drains
• Throw toilet paper

A competent device and the use of a septic tank in a private house will increase its service life several times. And the periodic use of modern biological preparations, decomposing solid sewage, avoids cleaning the septic tank long time.

A septic tank is a local facility designed for the temporary collection and processing of sewage. Unlike cesspools, a priori, the absolute tightness of the device is implied, and gravitational and biological wastewater treatment in them can reach 98%. However, in order to properly make a septic tank in the country with your own hands, it is necessary to study the elementary issues of arranging a local sewerage system, choosing the location of the structure on the site, and performing construction and installation work with high quality.

It should be borne in mind that there is no universal device used as a local sewage treatment system for a house or a summer residence. Knowledge of structural features various kinds septic tanks, the applied cleaning technologies will allow you to choose an effective construction option, reduce material costs for its installation and subsequent operation.

Appointment and operation of a septic tank

The operation of a septic tank may be the only option for treating wastewater in the absence of central sewerage. The technology of the installation process is based on the separation of the canalized liquid into fractions by the method of settling and anaerobic decomposition. Further, clarified wastewater is pumped out by a sewage machine or subjected to the stage of aerobic biological processing with disposal into the ground.

The type and scheme of a septic tank for a summer residence or a house directly depend on such hydrogeological and operational factors as:

1. Location level ground water Location on. Septic tanks without pumping are recommended to be built if groundwater is at a depth of >1 meter from the bottom of the filtering well (field).
2. The level of soil freezing in the area. The installation tanks and wiring must be located below the freezing depth or provide for insulation in order to protect against heaving forces in the winter.
3. The composition of the soil in the area. It is allowed to install septic tanks without pumping out only in sandy soils or sandy loams. Loams and clay weakly or do not pass liquid at all. In this case, as an option, it is necessary to provide for the drainage of liquid from the installation through pipes into the drains. In this case, cleaning before dumping on the landscape should be 95-98%.
4. Site relief. Treatment facilities must be built closer to the lower mark of the territory, if the site has a slope.
5. The number and time of residence of people in the country or in the house. Sanitary standards for water consumption by one family member when using a well or well 50-150 liters / day, excluding the cost of a bathroom, washing machine. The volume of the septic tank is calculated for a 3-day reserve. For example, for a comfortable permanent residence of a family of 3, a septic tank is needed 150 * 3 * 3 \u003d 1.35 m 3.

What happens inside a septic tank

Gravity cleaning technology is based on the settling of heavy impurities to the bottom of the sedimentation tank with the formation of a layer of sludge and flotation (floating up) of light and colloidal fractions. During the settling time between the layers, a liquid is formed with a degree of purification (clarification) of 50-60%, which passes through the pipe into the next section of the septic tank or filter well.

Processes biological treatment based on anaerobic (oxygen-free) fermentation and aerobic post-treatment. Bacteria involved in bioprocesses feed on sewage organic waste. At the same time, the process of decomposition of organic matter occurs with the release of heat, methane and the formation of silt sediment at the bottom of the sections. Methane is discharged through the ventilation pipe, sludge is periodically pumped out by a sewage unit. To maintain the vital activity of aerobic bacteria in energy-dependent septic tanks, oxygen is supplied through aerators.

Even if the degree of wastewater treatment reaches the level of 98%, their unauthorized discharge into natural water bodies is prohibited. To do this, you must obtain permission from local environmental organizations.

Stages of post-treatment after a septic tank

In the absence of sufficient biological clarification of sewage, additional purification of the liquid is arranged by filtration through the soil. To increase the efficiency of this process, either, and also if the drainage capacity of the soil is insufficient, such structures are used as:

1. Filter well. Its bottom is covered with layers of crushed stone with a fraction of 20-30 mm and coarse-grained sand without impurities. Water, passing through these layers and the soil, is additionally purified. Adding a filter trench to the well with a drainage pipe and gravel sand filter increases the discharge area, forms a system called infiltrate. The bottom of the filter well is recommended to be mounted 1 meter above the groundwater level, but below the freezing depth. The structure can be part of a septic tank system or equipped separately.
2. Drainage pump. It is used for pumping liquid with 95-98% degree of purification to the surface. Water is used for irrigation and household needs.
3. Filter field. Its construction is allowed if the groundwater level is at a depth of > 1 m from the outlet of the liquid from the last section of the septic tank. The field increases the area of ​​the filtration zone and the productivity of the treatment facilities. Structurally, the filter field consists of several trenches with drainage pipes connected to each other or arranged in parallel. Pipes are supplied with ventilation going to the surface. Such structures can occupy an area of ​​​​30-60 m 2, so they are not suitable for small summer cottages. The field depth must be > freezing depth, and the distance between the drainage pipes must be more than 2 m.

1. When the groundwater level does not allow the installation of a filter field, after-treatment through the soil is carried out closer to the surface where filter cassettes. Structurally, the cassette is made as follows: a pit with an area of ​​up to 20 squares is dug, the bottom is located 1 m above the groundwater level and is covered with crushed stone of a fraction of 25 - 30 mm. Top stacked drainage pipes with ventilation outlets, covered with rubble, covered with insulation. Backfilling is done with excavated soil during the excavation. It is recommended to mount the filter cassettes below the freezing depth.

Septic tank: advantages and disadvantages

Advantages of using a local cleaning complex:

1. Significant operational resource. Complex without pumping out at correct operation works 10 - 12 years without special costs for maintenance, unlike cesspools or storage tanks, which need to periodically call a vacuum truck for pumping.
2. Energy independence - connection of compressors of aeration modules, sludge scrapers is not required.
3. Simple care. In addition, the complex without pumping is not afraid of frost, it does not require conservation when prolonged absence hosts in winter.

Disadvantages of septic tanks:

1. Periodic cleaning of deposits of silt and other solid fractions in tanks.
2. Pumping water in case of insufficient soil permeability in the area.
3. When using intensive biological treatment, it is necessary to aerate the liquid to support the vital activity of bacteria. The complex includes an aeration reactor. The forced aeration compressor supplies air under pressure to the appropriate tank of the complex. The solution is saturated with oxygen, the activity of aerobic and anaerobic bacteria increases, the organic mass of sewage waste is processed faster. Air supply additionally provides ventilation of the reactor. This makes the installation volatile, requires human participation, which is not desirable for seasonal living in the country.
4. A reliable cleaning cycle with a septic tank and filtration fields will require a lot of space, which limits the use of such facilities in areas of 6-10 acres.

1. A septic tank without pumping can not be installed at a high level of groundwater.

Placement of treatment facilities on the site

According to the environmental laws of the Russian Federation, each person is assigned the right to live in an ecologically clean environment. On the other hand, every citizen is obliged to support the environment, to prevent soil and groundwater pollution.

The choice of the location of the cesspool or septic tank on the territory of the site is carried out in accordance with the norms and rules of SP 53.13330-2010 (SNiP 30-02-97 *). Right choice septic tank schemes for a private house and the placement of the device will avoid problems with SES inspectors, keep the environment clean for your family and neighbors living nearby.

According to the new rules of SP 53 (SNiP 30-02-97 * clause 8.7), the construction of cesspools is allowed only after agreement with the local authorities of the SES.

1. From the foundation of the house to the septic tank - 4 m.
2. To other capital buildings on the site> 2m.
3. To an artesian well > 30 m.
4. To wells > 8 m.
5. From tree trunks - 4m, shrubs - 1m.
6. To the border with the neighboring site> 4m.
7. From the red line> 3m with the arrangement of the entrance to the manhole of the facility for pumping waste with a cesspool machine.

A septic tank with a high level of groundwater can infect the soil and soil. If sanitary distances are not observed, plants die, corrosion of the supply lines occurs. metal pipes, water in wells, air over the adjacent territory is polluted.

When the size of the site does not allow the sanitary standards recommended by SNiP to be met, it is necessary to coordinate the location of the septic tank with the SES, the architecture department of the administration, and obtain permission from the neighbors. You may have to be content with a large volume sealed drive.

Types of septic tanks for a private house or cottage

Treatment local facilities for a summer residence or a house are selected based on the following criteria:

• the size of a summer cottage or personal plot;
• the number of people living in a private house, in the country;
• seasonality of installation use;
• features of hydrogeological conditions (groundwater level), soil composition at the installation site of the device, seasonal freezing depth;
• the possibility of discharging treated effluents into nearby water bodies, onto the landscape, organizing soil post-treatment;
• the required degree of purification;
• the possibility of connecting to electricity;
• estimated costs for the installation of a septic tank and its subsequent operation;
• consideration of options for installations of factory or self-manufactured.

Storage type installations

These are the simplest structures, consisting of one sealed container. The principle of the purification (sedimentation) process is the gravitational separation of wastewater into heavy particles that precipitate as sludge and light floating fractions.

At self-manufacturing storage tank are used various materials- brick, concrete, iron, reinforced concrete rings, wood, car tires. However the best option- use of factory plastic containers. The main requirement for the storage tank is tightness, and its volume is determined based on the frequency of calls to the sewer machine for pumping.

The shape of the sump is not regulated. It depends on the size of the site and the depth of freezing of the soil. It is recommended to bury tanks and sewerage network leads to it below the freezing depth, as well as additionally insulate. The evacuation outlet must have a sealed cover with a diameter that allows the evacuation hose to be freely lowered.

The storage tank can also be installed after the septic tank to collect the liquid that has already been clarified, for example, with a weak filtration capacity of the soil. Such liquid is used for irrigation or pumped out over time.

Double-circuit septic tanks without pumping

Simple local treatment facilities without pumping out consist of two tanks. The process of cleaning sewage in such septic tanks takes place in three stages.

At the first stage, sewage flows through pipes into the first tank, where the fractions are separated into heavy and light ones. The settled water enters the second section.

The second tank is made with an open bottom, covered with layers of gravel with fractions of 25-40 mm and coarse-grained sand without impurities. Water passes through gravel, sand, is additionally cleaned, seeps into the ground. In order to increase the productivity of the treatment plant, the system includes filtration fields or cassettes that increase the filtration area.

The shape and size of the tanks are determined by the design capacity of the cleaning system. Double-circuit systems are subject to the rules for location and installation as for storage tanks. The ratio of the volumes of the first and second containers is recommended to be 3:1.

Double-circuit septic tanks can be made from factory large-sized containers or with your own hands from brick, concrete, metal, precast concrete. The tightness requirements remain. Recommended inner surface brick and concrete tanks, seams, joints, pipe passage holes should be treated by gunning. This will significantly increase the sealing and service life of the tanks.

Three-section septic tanks

In such a septic tank, a biological one is added to the gravitational cleaning system. These facilities are called treatment plants. During biological treatment, activated sludge with bacteria that feed on the organic components of sewage waste is loaded into tank 2.

To ensure the vital activity of bacteria, aerators are installed at the bottom of the biological treatment tank. Through them, the compressor forcibly pumps air and saturates the liquid with oxygen necessary for bacteria. Dimensions, material of manufacture are similar to double-circuit septic tanks.

Complete wastewater treatment plants

Industry produces stations that include, in addition to gravitational and biological, dosed chemical cleaning. Such stations are configured to any requirements of the solar power plant - after them, the effluents after them can be guaranteed to be discharged into a lake or river.

Fully automated, prefabricated units are designed to be integrated into the smart home system. Built-in ACS sensors monitor every step of the workflow. The program decides to stop in case of failure or emergency, displays a message on the phone when a problem occurs.

What are do-it-yourself septic tanks made of

You can make a local cleaning complex yourself. Many of the available Construction Materials, For example:

• monolithic concrete,
• concrete slabs,
• concrete rings,
• brick,
• eurocubes from plastic.

More exotic and simple options. For example, a do-it-yourself septic tank made from barrels in the country according to your own scheme or a tank from car tires. The main thing is to follow the rules, the requirements of SNiP, and you also need to have some skills in construction.

Septic tanks of finished factory design

For the device of a local cleaning system in the country or personal plot private house the best option is to purchase a ready-made complex industrial production. Foreign and Russian manufacturers produce products of any size and type required by productivity calculations, with wide choice materials and accessories.

The top five well-known manufacturers in Russia include the following brands:

• biodekc,
• Rostok,
• biotank,
• Eurolos,
• Aster.

The purchase of a septic tank directly from a well-known manufacturer or its sales representative takes place on favorable terms. The company will provide a range of services - equipment delivery, project preparation, installation and commissioning. The buyer will have to accept ready-made treatment facilities with an official guarantee.

Hi all! Marat Nauruzbaev is in touch with you. Today, the article is not on a computer topic, but a household issue from personal life. In this article I will tell you how to build a septic tank with your own hands without pumping out for 10 years for a house and a summer residence. I will tell you how to properly build a septic tank with a filtration well made of concrete rings, with high groundwater and how I built it, what materials I used for construction, I will calculate the cost, show the septic tank in a 3D view and show the construction process in photos and videos.

A septic tank (sump) is designed to collect and treat household wastewater from individual residential buildings, low-rise buildings, cottages in the absence of a central sewerage system. The work of the septic tank is based on the principle of gravitational settling and biological post-treatment using bioenzymatic preparations ... Link to Wikipedia.

Who lives in the private sector, the issue of draining sewage is the most acute. Someone is digging a simple drain hole, someone digs in concrete rings and it turns out a drain well (most of them are), and someone builds a septic tank with their own hands from concrete rings ( best option) as I did.

In general, initially I wanted to make a septic tank for a permanent residence completely monolithic from reinforced concrete. This is the best stand-alone version of a septic tank, although labor-intensive. Why is it the best, because it is the maximum in terms of the area of ​​waste drainage into the ground. I have already made all the calculations for the quantity and price of materials, drew drawings and a 3D sketch of this septic tank, and then, due to lack of time to build it, I decided to make a septic tank from concrete rings 🙂

For those who are interested in the option of a monolithic concrete septic tank, below I will give you a ready-made Excel file for calculating materials for a septic tank.

There are other options for purchased septic tanks or autonomous sewers, but we do not consider this option in the article, since they are much more expensive and require electricity and regular maintenance.

I made a single-chamber septic tank with a filter well and an additional filter cassette from cast iron bath.

In general, there is nothing difficult to build a septic tank from concrete rings. In general terms, the construction of a septic tank consists of these parts:

Calculation of the volume of a septic tank

In general, I did not go much into the theoretical part of the calculation of the septic tank, I read only some articles by A. Ratnikov, a recycling specialist liquid waste and water supply of country cottages.

According to the rules the volume of the septic tank should be equal to three times the daily inflow of wastewater. During this period, bacteria must process this volume of sewage.

The daily norm for one person is 200 liters.. From these figures, the entire calculation of the volume of the septic tank is made.

Those. if you have family of 4, calculation of the volume of the septic tank: 4 * 200 * 3 \u003d 2400 liters (2.4 m 3).

Therefore, when using for example well rings(Ks 15-9) (diameter - 1.5 m., volume - 1.59 m 3), you when building a single-chamber septic tank, you will need two such rings. Keep in mind that the volume of the rings is “dirty”, that is, you will not be able to fully use the volume of the upper ring, since it will not be completely filled with drains.

Much still depends on the filtering capacity of your soil and the level of groundwater. Septic tanks for giving with high level groundwater (GWL) is preferably built at a shallow depth and should have a shallow filtering well, preferably to the surface of the groundwater.

If the soil is mainly made of clay, it is necessary to increase the area of ​​​​the filtration well several times, because. clay does not filter water very well.

The working depth of the septic tank, equal to the distance from the level of wastewater in the septic tank to its bottom, must be at least 1.2 m, width 0.75 m (or 1 m in diameter for round septic tanks). The greatest working depth of sewage in a septic tank should not exceed 2.5 m.

So, for a family of four, a septic tank with a volume of at least 2.4 m 3+ filtration well (FC), with a volume and area sufficient for your type of soil + preferably a filtration cassette for a “volley” discharge of wastewater (for example, after draining a bath) or if the FC will not cope with the filtration of wastewater.

Digging a pit for a septic tank

After you have decided on the volume of the septic tank and the filtration well, as well as the number of chambers in the septic tank, you need to dig a pit (pit) for it. The fastest way to do this is with an excavator, and with a low groundwater level, this is the only digging option, since digging manually with a shovel in the mud is not very easy 🙂.

In order to save money, I decided to make a single-chamber septic tank with a filtration well and a filtration cassette (infiltrator).

The septic tank will consist of two reinforced concrete rings with a diameter of 1.5 meters and a height of 90 cm, set on top of each other. bottom ring the septic tank should be with a bottom, so it’s more correct from the point of view of ecology and sanitary and epidemiological checks. I made it without a bottom, because I wanted to increase the filtration capacity and its efficiency in general 🙂 .

The filtration well (FC) will also be made of two reinforced concrete rings, but without a bottom, since there will already be settled drains (cleaner) from the septic tank. In the FC, wastewater will be filtered into the ground.

I made a filtration cassette (infiltrator) from an inverted cast-iron bath. It is intended for additional filtration of wastewater, if the FC starts to fail to cope with wastewater or for a “volley” discharge of wastewater. You can make a filtration cassette out of two or even three tubs or other containers that can withstand a lot of soil under them and not collapse for a long time.

So, the size of the pit should be under approximate size septic tank + FC + infiltrator. My pit size was 400 cm long, 200 cm wide and 200 cm deep

Nearby, I dug another hole for a filtration cassette 200 cm long, 100 cm wide and 100 cm deep. All sizes are approximate and naturally “dance” while digging with an excavator 🙂

Since my groundwater level (GWL) is high (about 1.5 meters), the dug pit immediately began to fill with groundwater! It was necessary to fill the bottom of the pit with crushed stone as soon as possible for drainage and better filtration of wastewater.

Backfilling the pit with rubble

So that the bottom of the filtration well (FC) does not silt up as long as possible and for better drainage of wastewater, it is necessary to fill the bottom of the FC with crushed stone with a thickness of at least 20 cm. Crushed stone for drainage is needed large (fraction 40-70 mm).

Crushed stone must be poured to the bottom of the pit, to the place of the proposed installation of the FC. Since I have a septic tank without a bottom, I covered the rubble over the entire surface of the pit. The crushed stone had to be poured into a pit already flooded with groundwater, and leveled already in the water with a shovel.

The same crushed stone I fell asleep at the bottom of the pit for the filter cassette

Installation of concrete rings

Then we install concrete rings. I did not capture the installation process in the photo, as I was busy directing the reinforced concrete rings while lowering them into the pit with a manipulator.

I didn’t put the rings perfectly exactly on top of each other, but it’s okay, they will hold on 🙂

In general, it was necessary to seal the joints between the reinforced concrete rings, but I did not attach any importance to this and did not bother.

While the reinforced concrete rings were being installed, the pit began to crumble from the sides, as the soil got wet due to the rising level of groundwater. A certain amount fell into the well, I had to climb into the pit in boots and scatter wet soil around the corners of the pit. A certain amount of soil still remained on the rubble, which of course is not good.

Because entrance gate into my yard is narrow, a KAMAZ-manipulator (thief), who brought me reinforced concrete rings, barely squeezed into them and bent the pillars from these gates for me. The situation was aggravated by the fact that he could not pass under the gas pipe that runs over my gate, the end of his tap rested on the pipe. I had to dig in this place the soil by about 30 cm.

Moreover, the manipulator got stuck on this dug area and began to slip, and the driver swears (I noticed this from the malicious facial expressions of his face and the moving lips of J).

The driver had to swear 2 times, since the fourth reinforced concrete ring on the manipulator turned out to be above the level of the gas pipe and he had to unload one ring first outside the yard, and after installing three rings in the pit, return for it ...

In general, everything worked out, I mean gas pipe, but the gate will have to be repaired 🙂 .

So take into account the dimensions of the manipulator and tractor when working on the site!

Installing the filter cassette

To increase the drainage capacity of the septic tank and the filtration well in general, I additionally installed a filtration cassette in the form of an inverted cast-iron bath. Instead of a bath, you can use any other container that can withstand the mass of soil and does not corrode for a long time.

The filtration cassette should also be installed on a layer of coarse gravel, at least 20 cm high.

I inserted a coupling from a sewer pipe (50 mm) into the drain hole of the bath for installation in it ventilation pipe

I inserted a ventilation pipe into this coupling in the form of an ordinary sewer pipe (50 mm) 🙂 and fixed it with two self-tapping screws

I made the ventilation pipe from two halves, connecting them with a coupling, it’s like “fool protection”, if someone wants to pull out this pipe, it will come off at the junction of these two halves above the ground, and not underground, at the junction with the bathroom ... Yes, and it will be more convenient to check the level of drains in the bath through a short pipe, having previously separated them

It turned out such a ventilation pipe, according to the norms, it should be installed 70 cm above ground level

At the end of the bath, I cut a square hole with a grinder for inserting a sewer pipe into the bathroom (110 mm)

And I connected this pipe to the filtration well, having previously drilled a hole in the reinforced concrete ring of the filtration well

Inside the well, I put on a tee with an enlarged lower elbow on this pipe. A tee is used to take a lower layer of wastewater (to retain floating substances)

It turned out like this (without a ventilation pipe)

Sewer pipes

Now it remains to bring the sewer pipes from the house to the septic tank and connect the septic tank and the filtration well with a pipe.

To do this, we dig a trench, lay sewer pipes in it and connect them together.

I used pipes as pipes outdoor sewerage(red) with a diameter of 110 mm and a length of 2 m. I tried to make the slope of the pipe according to the norms - 2 cm / meter.

The distance from the house to the septic tank I got decent - 16 meters

In order to use the effective volume of the septic tank as much as possible, I laid the sewer pipe near the house at a depth of 5 cm underground (from the top wall of the pipe). At the entrance to the septic tank, the depth of the pipe underground was 52 cm.

The hole for the inlet pipe to the septic tank was drilled with a perforator (with a drill for concrete) around the circumference, followed by knocking out the hole with a hammer

I connected a fan (ventilation) pipe to the beginning of the sewer pipe (near the house) and brought it to the roof of the house

Now the septic tank and the filtration well, together with the filtration cassette, will be ventilated with incoming air from the ventilation pipe on the filtration cassette (bath) to the fan pipe on the roof of the house.

I connected the outgoing pipes from the house through a tee (110 / 110x90) to the main pipe

At the beginning and in the middle of the pipe installed revisions

Since the section of the pipe passes under the entrance of the car at the gate, I dressed this section of the sewer pipe in an asbestos pipe

Now it remains to connect the well of the septic tank and the well of the filtration well with a pipe. To do this, I drilled holes in the reinforced concrete rings with a perforator and inserted a 110 mm pipe section into them, thereby connecting these two wells

In the well of the septic tank, I put a tee on the end of this pipe

On the other side of this pipe (in the filtration well), nothing needs to be put on the pipe

I drilled several small holes in the walls of the filtration well and two large holes in opposite sides of the well for sewage drainage.

I inserted a piece of a sewer pipe (50 mm) into one of the large holes. I didn't put anything in the other hole. I don't know which of these holes will drain better...

You can drill more drainage holes in the seepage well, or purchase RC rings with pre-drilled holes right away.

On this, the main work on the construction of a septic tank was carried out. It remains to make a formwork for the revision pipe, dig in a pit and a trench, and make or purchase manhole covers.

Bonuses

Before building a septic tank, I studied this topic a little and talked on the forums. I sketched a drawing of a monolithic concrete septic tank with dimensions on paper. Then I decided to make it in three dimensions. Studied free program for interior design Sweet Home 3D” and made a 3D project of the septic tank, as well as in a two-dimensional view with dimensions. I also took a photo and video from this project, which you can see below.

Since in the program Sweet Home 3D» missing objects sewer pipes and concrete rings, I had to search for them on the Internet and then translate them into a format understandable to this program.

I also created an Excel file for the convenience of counting the materials used in the construction of a septic tank.

And all these developments I I give you a Like!

• Projects of a septic tank from concrete rings and a monolithic concrete septic tank in the Sweet Home 3D program, as well as their photos;
• Additional 3D objects in OBJ format (concrete rings, sewer pipes, bathtub);
• Excel file "Calculation of the cost of materials for a monolithic concrete septic tank with a filtration well";
• A. Ratnikov's book " Autonomous systems sewerage of cottages for dummies" in PDF-format (62 pages).

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A significant number of people dream of a country house. modern dwelling must be comfortable to live in. One of the requirements for it is the presence of sewerage. To cope with this task allows the device of a septic tank for a private house.

What is a septic tank

In other words, the septic tank can be called an autonomous mini treatment plant replacing a cesspool. This is a large volume container, consisting of several sections. It collects, settles and purifies wastewater used for economic and domestic needs.

Septic tanks are elements of local purification systems (LSO). With their help, the problem of sewerage in areas that do not have centralized systems water treatment. The choice of LSO design depends on various factors. Among them:

• the volume of wastewater in need of treatment;
• landscape features of the site on which the sewerage is arranged;
• financial capabilities of owners of private housing construction.

The most primitive and cheapest version of a septic tank is a storage tank. She represents metal barrel dug into the ground. The collection of dirty drains into it occurs in the same way as at the cesspool. A more advanced version of the design distinguishes a metal barrel from the latter. It has a hermetically sealed lid, which limits the spill of sewage in the area and prevents the spread of unpleasant odors.

The disadvantage of the design include the need for constant monitoring of the level of the contents of the tank. For its pumping, a sewage machine is used. It makes sense to install storage tanks only in cottages that are not intended for permanent residence.

Types of septic tanks

According to the principle of sewage treatment, autonomous collections are divided into:

• accumulative;
• with soil filtration;
• with forced aeration.

When arranging LSO for a country house, they try to pick up a septic tank that has the ability to deeply clean wastewater. This eliminates the problem of pumping out the contents of storage tanks. Designs produced by the industry cannot produce complete wastewater treatment. Their post-treatment is carried out with the help of filtration fields.

The maximum degree of wastewater treatment can be achieved only in VOCs, the principle of operation of which is based on biological methods. Such structures are equipped forced system aeration. They must be connected to the electrical network.

Table 1. Types, advantages, disadvantages of septic tanks