You can’t do without an autonomous sewer system in a dacha, just like you can’t do without a heating system or plumbing. Cesspools are outdated and inconvenient, purchased septic tanks are too expensive, what could be the best option, affordable and not very difficult to install? There is nothing better than building a septic tank from concrete rings with your own hands.

Carrying out calculations and drawing up a diagram

First you need to decide on the number of structures. There may be a different number of them, but the standard set consists of three:

• chamber for settling wastewater;
• chamber for cleaning from contaminants;
• well for filtration (can be replaced with a filtration field).

The varied design of a septic tank made of concrete rings depends on the number of residents.

The water goes through three levels of purification in chambers and a filter well, then further purification in the ground

Two cleaning chambers are necessary if several people live in the house and actively use the washing machine, dishwasher, shower, and bathtub. Discharges into the sewer system will be large, and accordingly, the drains will require more thorough cleaning.

For a small family using a small number of household appliances, one settling tank is quite enough; accordingly, a septic tank made of concrete rings will have two wells.

Septic tanks made from two wells with one cleaning chamber are designed for small families

Suppose 5 people permanently live in a house. On average, each of them uses about 200 liters of water per day, therefore, the total daily consumption is 1000 liters. There are building standards according to which the volume of the cleaning chamber must allow for the flow of wastewater within 3 days, that is, at least 3000 liters. Let's take as an example a concrete ring with a volume of 0.62 m³ - this means that 5 rings are needed for each well. Typically, 2-3 rings are used to build each chamber.

The diagram shows the number of concrete rings, their location and connections

A diagram of a septic tank made of concrete rings is drawn up before construction begins.

Choosing the optimal installation location

When installing a septic tank, the tolerances specified in regulatory documents should be taken into account. Sanitary rules prohibit the location of structures in dangerous proximity to human habitation and sources of drinking water.

The choice of location for installing a septic tank largely depends on the size of the plot

Before marking the site, you must remember the following provisions:

• The distance from the treatment plant to a residential building is at least 5 m.
• A large distance to the house (20 m or more) will cause difficulties and additional costs for the construction of the pipeline.
• The distance from the septic tank to the water source (well, borehole) is at least 50m.
• A prerequisite is access for special vehicles.

At the installation site, the groundwater level should not be high.

When installing a septic tank, do not forget about laying the ventilation pipe

Attention! If the pipeline still turns out to be long, then inspection wells must be installed every 15-20 m and at turns.

Preparing a pit for tanks

In any case, the pit will be large, since both the cleaning chambers and the filter well must fit into it. The ideal option is to use special equipment, it will save time. In the absence of it or if it is impossible to rent, you can also use manual labor, but it will take longer and be harder.

The area of ​​the pit depends on the number of planned wells (2 or 3)

Untreated wastewater should not get into the ground, therefore, a concrete base should be erected at the site where the settling tanks are installed. A sand cushion 40-50 cm thick is used as drainage.

Attention! There are concrete rings that have a solid bottom. They are ideal for settling chambers and do not require additional concreting of the bottom.

Concreting the base of wells prevents the penetration of contaminated wastewater into the soil

The base of the filter well also needs additional preparation. A cushion of sand, gravel and crushed stone with a thickness of 50 cm or more is the best option.

The process of installing concrete rings

Most likely, special equipment will be required. It is difficult to dig a pit by hand, but it is possible, but it will not be possible to install heavy concrete structures without special equipment. Renting a lift for a few hours will pay for itself with high-quality installation of the structures.

For a septic tank, it is better to use castle well rings, their approximate cost is 1,500 rubles per piece

Installing concrete rings is a crucial moment, so it is better to use lifting equipment

Correct installation of a septic tank made of concrete rings involves sequential construction of wells. The rings are installed according to the diagram, tightly connecting to each other and fastening with cement mortar.

If possible ground movements are suspected, metal plates or brackets are used for additional fixation.

After installing the rings, pipes are connected.

Attention! When laying a pipeline, you need to use a pipe with a bend that resembles a water seal; this will protect against the unpleasant smell of wastewater.

Sealing joints and backfilling

The seams between the two rings are sealed using ordinary cement mortar or a ready-made mixture is purchased, for example, “Aquabarrier”. The outside is coated with waterproofing; for reliability, weld-on sealants are used.

Seams and joints are sealed on both sides - internal and external

Sometimes the structure is reinforced with plastic liners - cylinders of suitable volume installed inside the well. Reliable waterproofing of a septic tank made of concrete rings will prevent wastewater from entering the ground, extend the life of the structure and eliminate unpleasant odors.

Due to poor-quality sealing of seams, untreated wastewater enters the ground

Backfilling is done at the end of installation work. The soil removed from the pit is mixed with sand and distributed around the structures, compacting evenly. A lid is placed on top of each tank - a concrete slab with a hole provided for a hatch.

The lid has a large hole for installing a hatch

The seams are sealed according to the same scheme. This completes the installation of a septic tank made of concrete rings; its service life depends on the quality of installation and waterproofing work.

Pros and cons of homemade concrete structures

What is good about a septic tank made from rings?

• Low cost, availability.
• Possibility of independent arrangement.
• Ease of maintenance.

Having installed a septic tank from rings with your own hands, you involuntarily become familiar with its features, so in the future it is easier to monitor its operation.

One of the disadvantages of a septic tank made of concrete rings is incomplete wastewater treatment

Disadvantages noted by summer residents:

• Presence of odor. The tightness of the structure is relative.
• Periodic calling of sewer trucks.

Attention! Using bioactivators, you can reduce the frequency of servicing with vacuum cleaners. Active additives minimize the amount of solid waste.

A septic tank made of concrete rings is an easy-to-maintain budget structure

We can say that a septic tank made of concrete rings is excellent for a summer residence: its operation allows you to provide your family with all the necessary amenities.

Among the new treatment systems that have replaced fetid cesspools, septic tanks are especially popular. But since the cost of ready-made structures is not affordable for everyone, you have to make a septic tank from concrete rings with your own hands.

When the sewage system at a dacha or in a private house cannot be connected to central communications, the question of having your own treatment plant becomes relevant and in this case, a septic tank is the best option. Unlike conventional cesspools, it purifies domestic wastewater, making it safe for the environment, curbs unpleasant odors, and if properly organized, its pumping may not be necessary for many years. When deciding which septic tank to install, preference is often given to structures made of concrete rings.

Types and principle of operation of a septic tank made of concrete rings

The principle of operation of all septic tanks is the same, the only difference is the use of different materials for the construction of a septic tank in a private house and the number of chambers - tanks for collecting sewage.

• It is not advisable to install a single-chamber septic tank, since the filtration process
  will stop as soon as the bottom silts up. It largely depends
  on the amount of wastewater and the volume of the septic tank, but for a long time this
  the treatment plant will not work. Frequent pumping of settled fractions will incur additional costs for the services of a sewer and the introduction of new bacteria.
• The two-chamber septic tank is quite functional. In the first chamber, only fermentation and settling of wastewater occurs with the bottom closed; enough water is transferred to the second chamber.
  treated wastewater that goes into the ground. Filtration speed depends on
  quality of the drainage system.

• A three-chamber septic tank is the most advanced option in terms of disposal of household waste. In this case, the role of settling tanks is performed by the first two containers, the water in them is of varying degrees of purification, and the third acts as a filtration
  fields. Therefore, when deciding which septic tank to build, it is better to choose this option.

Important! In operating condition, the septic tank's settling tanks should be filled to the overflow level, and the filtration fields should contain only a certain amount of purified water.

Calculation of the required volume of a septic tank

The volume of wastewater, and accordingly the volume of the container, is calculated by the formula: the number of people living is multiplied by 200 liters, multiplied by 3 days and divided by 1000, the resulting number determines the required volume of the container in cubic meters.

200 liters is the consumption rate per person, of course, in fact it is much less. 3 days is the time it takes for the water in the septic tank to be purified. If there are often guests in the house, a washing machine or dishwasher is used, it is recommended to add 200 liters to the volume. The volume of the second tank may be less than the first by 30%, and the third by 50%. Based on these calculations and knowing the volume of one concrete circle, it is easy to calculate how many will be required.

tab. REINFORCED CONCRETE WELL RINGS

NAME	OVERALL DIMENSIONS in mm.
		wall thickness	internal diameter	weight
KS -7-5	500	80	700	0,275
KS -7-9	900	80	700	0,410
KS -7-10	1000	80	700	0,457
KS -10-2	300	80	1000	0,200
KS -10-3	300	80	1000	0,200
KS -10-5	500	80	1000	0,200
KS -10-6	600	80	1000	0,400
KS -10-9	900	80	1000	0,610
KS -10-9 s/z	900	80	1000	0,610
KS -10-10 h	1000	80	1000	0,660
KS -12-10	1000	80	1200	1,050
KS -15-3	300	80	1000	0,200
KS -15-6	600	80	1500	0,670
KS -15-9	900	90	1500	1,00
KS -15-10 h	1000	100	1500	1,240
KS -20-6	600	100	2000	1,20
KS -20-9	900	100	2000	1,50

Septic tank made of concrete rings: stages of construction

Sewerage with a septic tank made of concrete rings is reliable, durable and has a high level of treatment of household waste. The price of such a structure will be relatively low, and with excellent waterproofing and the correct design, pumping out the containers will not be required often. Construction difficulties include the need to attract heavy equipment and the peculiarities of installing pipes between concrete sections.

Preparatory stage

The installation of a septic tank is carried out in compliance with all sanitary and construction rules and regulations. They think over the design of the treatment plant, its location on a private plot and coordinate the plan with the relevant authorities. They decide which septic tank is best to install so that the sewage system in a private house is made as comfortable as possible. Correctly calculate the volume of the septic tank and begin construction.

Excavation

The pit for a sewage treatment plant in a private house should be so large that nothing interferes with the installation of the rings. The bottom of the cesspools, where the settling tanks are installed, is concreted. This prevents untreated water from entering the soil.

The foundation for the second or subsequent chambers is made in such a way that water can drain into the soil. To do this, make a filtration cushion up to 1 meter deep from gravel and sand.

Advice! If, when installing a septic tank, the pit under the filtration well reaches the sandy layer of soil, the water will drain out of it as quickly and easily as possible.

The shape of the pit does not have to be round; a standard, square one is also suitable, the main thing is that the rings fit into it freely. In addition, a ready-made concrete slab can be laid at the bottom of a square hole, while only a cement screed can be used in a round hole. At this stage of work, it is also worth remembering that if you place each subsequent well 20-30 cm lower than the previous one, the septic tank and the sewerage system itself will be more functional.

Delivery and installation of reinforced concrete rings

The rings are delivered and installed by freight transport, so it is worth ensuring access to the construction site in advance, taking into account additional economic costs and the turning radius of the crane boom; it should not be interfered with by gas, telephone or electrical communications.
The rings are usually connected to each other with metal staples, and the joints are coated with a solution of cement and sand.

Installation of reinforced concrete rings

When all the wells are installed, holes are made in them and overflow pipes are installed, the external sewage system is connected to the treatment facility through a drain pipe entering the first tank. The entry points of the pipes must be sealed.
The space between the installed rings and the walls of the pit is filled with soil and carefully compacted layer by layer. If the septic tank is installed above the freezing level of the soil, it is insulated, otherwise during the cold season the sewage system will be non-functional.

Advice! It is better to carry out the delivery and installation of concrete rings at the same time, this will help save not only money, but also time. It is worth completing all earthworks in advance and unloading the rings, not just on the site, but immediately, while installing the septic tank.

Waterproofing

Good waterproofing of a septic tank is fundamental to its proper operation. Each builder determines which sealant is best to choose for these purposes. Typically, rubber-bitumen mastic is used to treat seams; polymer mixtures are used less frequently. For longer operation of cesspool structures, internal waterproofing of the seams of the container is also carried out.

If the sealing is done poorly, then the release of untreated wastewater into the ground will be the lesser of two evils. The septic tank containers, especially during the spring thaw, will fill with water, and all its contents will flow out through the plumbing in the house, requiring repeated pumping.

Ventilation

An exhaust pipe up to 4 meters high above the floor level of the septic tank must be installed on the first tank. It is necessary so that the gases formed as a result of fermentation of wastewater can escape and there are no unpleasant odors in the area. If possible, ventilation pipes are installed on each well.

Covering the septic tank

The task of covering is not only to close the pit, it must ensure the tightness of the containers. As a rule, the chambers are covered with ready-made reinforced concrete slabs, on which there is a hole for a hatch made of cast iron or thick plastic. Then the structure is covered with a small layer of soil. Hatches on each of the wells will help monitor the condition and filling of the septic tank, and will also make it possible to periodically add mixtures of active bacteria for cesspools.

Septic tank maintenance

After launching the sewerage system in a private
home, it is necessary to take measures that will extend its service life.
When evacuating the contents of the container, some of the accumulated sludge is left at the bottom to ensure further normal filling of the chambers with active bacteria.
Pumping out the contents of the septic tank is carried out using sewage disposal equipment, which takes the wastewater through the discharge pipe.

There are also biological cleaning methods, the use of so-called bacteria for septic tanks and cesspools. They will help to significantly reduce the amount of sediment, and, therefore, pumping out liquid will be required less often.
It is strictly not recommended to flush rags, matches, napkins, hygiene products and even toilet paper down the drain.

Installing a septic tank from concrete rings: video

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Issues of waste disposal in suburban areas concern both summer residents and owners of private houses. Most dacha areas and many small settlements in the country are not provided with the ability to connect to centralized networks. It’s hard to come to terms with this situation, isn’t it?

A two-chamber septic tank made of concrete rings, the construction of which will require a minimum of money and effort, will allow you to get rid of problems. You can build such a system with your own hands without any problems. However, even if you plan to attract workers, it is simply necessary to know the rules and features of the device. After all, the structure must operate without failure.

We suggest that you familiarize yourself with reliable information about the construction of concrete septic tanks, the basics of designing an autonomous treatment plant and its organization. In addition to valuable information, we have selected photos, diagrams and video tutorials.

A septic tank, consisting of two chambers, is a practical treatment facility capable of processing organic waste.

The cleaning mechanism is based on the operation of two communicating compartments, inside of which the liquid component and the insoluble solid component are separated by settling.

Image gallery

If everything is clear with sewerage in the city, then what about its arrangement in the private sector or on a summer cottage? Fortunately, there is a solution. You can build a septic tank. Moreover, it can be made from various materials. And concrete rings are considered one of the most popular technologies for creating this structure.

Design and principle of operation

A septic tank is a structure designed to clean sewage that is formed as a result of the use of a bathtub, dishwasher and, of course, toilet. It is a structure made of several tanks connected by pipes at a certain height so that water entering the septic tank can flow from one chamber to another. Typically this structure has two or three chambers - their number often depends on the volume of drainage. In this case, as a rule, one of the sections of the septic tank is a filtration well, where an additional cleaning process takes place and the liquid is discharged into the environment.

The principle of operation of a three-chamber septic tank is as follows: wastewater, flowing through the drainage sewer pipe, enters the first chamber, where the primary stage of purification occurs - large inclusions, according to the laws of gravity, begin to settle to the bottom of the tank. Further, as the chamber is filled, partially purified water passes through a pipe located at a certain level (but located lower than the inlet pipe) into the next chamber - the secondary settling tank. There it settles further, and some of the lighter particles also have time to settle to the bottom.

On a note! Additionally, anaerobic bacteria can work to purify the water in the second purification chamber, which process pollutants. For them, this is their favorite “delicacy.”

The third chamber is a filtration well, which, unlike the previous two, has a bottom that is not sealed, but through, but covered with sand and crushed stone. The liquid begins to seep and go into the ground, further purifying itself in this layer. Such a septic tank, one might say, does not need, since the water goes into the soil layers on its own. But still, every few years it is necessary to remove sediment deposited at the bottom from it. Vacuum trucks are called in for this purpose.

A septic tank consisting of two compartments works on the same principle, only the water after the first chamber immediately enters the drainage well and goes into the ground. By the way, soil purification can also be carried out on filtration fields or using biofilters, and not only in filter wells.

What are the benefits of septic tanks made from concrete rings?

One of the most common and inexpensive ways to build a septic tank with your own hands is to make it from concrete rings. Such rings come in different sizes, and can also have additional parameters - a certain thickness, the presence of holes in the walls, etc. In addition to these products, round bottoms and covers are also produced, in which a hole is provided for installing a hatch.

Table. Types of concrete rings.

View	Characteristic
	Such rings are also called additional rings. They are only used in situations where standard rings are not suitable. Such designs are made to order.
	Ideal for use when installing wells and other various communications. For example, they make excellent drainage wells, water canals, gas pipelines and others.
	A neck can be formed from such rings during the construction of a septic tank. They are used for the manufacture of the upper part of any types of communications and wells.
	Prefabricated, closed with a bottom, with ceilings, with a lock, etc.

A septic tank made of concrete rings is a time-tested design. But during installation you will have to work hard. Most likely, to install the rings in the pit prepared for the septic tank, you will have to call in special equipment - a truck crane. It is very difficult to move such structures on your own - they have considerable weight. There are, of course, options for installing and digging reinforced concrete rings into the ground without the use of machinery, but the problem is that the ring itself is, nevertheless, quite fragile. If such an element is dropped even from a small height, it can easily break.

The disadvantage of using concrete rings as the basis for a septic tank is the need for a large space. In a small area, it is unlikely that such a design will be implemented in compliance with all rules and regulations. Also, when building a septic tank from concrete rings, great attention should be paid to sealing seams and joints. "How does it happen? , you can look in our article.” The advantages of a septic tank made of reinforced concrete rings are as follows:

• these structures are not afraid of exposure to aggressive chemicals that enter the drain. And the waste water itself is far from having the most harmless composition;
• such a septic tank will not be afraid of temperature changes;
• the structure will cope perfectly with the unexpected influx of large volumes of water.

On a note! When choosing rings for a septic tank, it is best to choose those that have fittings inside. Such rings are much stronger than ordinary concrete ones and will last as long as possible.

Calculating sizes

Calculating the dimensions of the future structure is an important point in the design of a structure. The parameters of the space occupied, as well as the amount of materials needed, will directly depend on this. The first step is to calculate the volume of the septic tank, which depends on the volume of wastewater, which, in turn, depends on water consumption. On average, a person uses about 200 liters of water during the day. This means that a family of three will spend 600 liters per day. However, according to the standards, the septic tank must be three times larger in volume. This means that it must contain at least 1800 m 3 of liquid.

Now we need to calculate the internal volume of one concrete ring. It’s easier to figure it out using the formula for the volume of a cylinder. This V = 3.14*D 3 *H/4, where H is the height of the structure, D is its internal diameter, and V is the volume required for further calculations. Let's say the ring has a diameter of 1 m. Then its volume will be equal to 0.79 m 3. In this case, the height of the ring does not need to be measured - this is a standard value and is equal to 1 m. Although sometimes there are rings with a height of 0.9 m on sale. Additional rings can have very small dimensions.

Attention! When making calculations, it is important to remember that the last, upper ring should never be filled entirely with liquid, but only 1/3. Thus, the working volume of the upper ring is 0.79/3 = 0.26.

Based on the calculations described above, you can deduce the number of rings that need to be purchased. Thus, one section of the septic tank will need 3 rings. To build a structure of three chambers, 9 reinforced concrete rings will be required.

The rings that are sold in stores usually have standard sizes and can be of different diameters - 70, 100, 120, 150, 200 cm. If the sewer system will be built for a house where many people live, then it is better to use structures with a diameter of at least 100 cm For small families, you can purchase 70 cm rings. The larger the ring, the heavier it is, and therefore to install a septic tank made of products 100 cm or more in diameter, you will definitely have to call a truck crane, since the weight of these rings varies between 700-900 kg.

Advice! When making calculations, it is worth remembering that the upper ring should protrude above the ground by about 20-30 cm.

The achievements of engineering in construction do not shake the imagination like discoveries in the field of high technology. Nevertheless, in terms of their significance for our lives, they are not inferior to them. A good example is a septic tank made of concrete rings for a private house, which replaced a cesspool. In this building, a process that is most important for the environment takes place – the purification of sewage by microorganisms. Dirty water that has passed through a septic tank becomes safe for humans and nature.

Unlike a cesspool, which accumulates sewage and is not able to absorb a large volume of water, a septic tank copes with this task perfectly. Three processes simultaneously occur in it: dilution of wastewater, sedimentation and decomposition of organic sediment. The rate of biological treatment in a septic tank is hundreds of times higher than in a cesspool. Thanks to the active processing of organic matter, the volume of bottom sediment in it is minimal, which allows pumping once every 2-3 years.

The question arises, what is good about the option of reinforced concrete rings, since you can use a monolithic or plastic container instead?

There are several arguments in favor of this decision:

• Installation of a prefabricated reinforced concrete structure is simpler, easier and faster than working with concrete, reinforcement and formwork;
• When using plastic containers, it becomes necessary to anchor them to a concrete slab. Otherwise, groundwater may push them out of the ground;
• A septic tank made of reinforced concrete rings is stronger and more durable than plastic.

To successfully build such a structure, you need to have an idea of ​​its calculation and the main stages of installation. You will find useful information on this topic in our article.

The volume of wastewater is a basic value taken into account when designing any treatment facility. Sanitary standards set it at 200 l/day per person. In addition, the capacity of the septic tank should be equal to the 3-day volume of sewage. Based on these two conditions, the capacity of the structure can be calculated. So, for example, a family of 4 people will need a septic tank with a volume of: 4 x 200 l/person x 3 = 2,400 l. (2.4m3).

The second issue that needs to be resolved is the number of cleaning chambers: one, two or three. If no more than 3 people permanently live at the dacha, then you can limit yourself to one camera.

With a larger number of residents (4-6 people), the sewage system in the dacha is made of concrete rings and is made of two chambers. It copes better with large sewer flows. Three cleaning tanks are used in houses where several families live.

Each septic tank chamber performs certain tasks:

• In the first, sedimentation of wastewater and anaerobic (oxygen-free) decomposition of organic matter occurs. Heavy particles settle to the bottom here, and light particles float to the top. Clarified water flows through the pipe into the second chamber;
• In the second tank, the wastewater undergoes additional bacterial purification and is discharged into a filter trench or well. Oxygen (aerobic) decomposition of organic matter occurs here.

The choice of filtration method depends on the groundwater level and soil type. In a resorption well, water goes into the ground through perforated walls and a bottom covered with small crushed stone.

Two-chamber septic tank made of reinforced concrete rings with a filter well

When the level of soil water is high and the soil does not absorb moisture well (clay, loam), a resorption trench (filtration field) is made. A perforated pipe wrapped in geotextile is placed in it and covered with drainage material (crushed stone, gravel + sand). Due to the long length of the pipe and the presence of a filter bed, the final cleaning process proceeds normally even in heavy and wet soil.

Three-chamber septic tank with filter trench

Having determined the capacity, the number of chambers and the type of filtration structure, you can proceed to choosing a location on the site. The diagram will help you in this matter. It indicates the minimum permissible distances from the treatment plant to water sources, trees and roads.

Sanitary gaps between the septic tank, water source and other objects

From this diagram it can be seen that the greatest distance of the sewerage structure should be from the source of drinking water (50 meters). On a dacha plot of 5 acres, this requirement is impossible to fulfill. Here you will have to install a device for disinfecting drinking water with an ultraviolet lamp or use imported bottled water.

In addition to observing sanitary gaps, the septic tank must be placed so that its chambers can be reached with the hose of a sewer truck.

Construction materials

In order to make a septic tank from concrete rings with your own hands, you need to buy the following materials:

• polypropylene pipes with a diameter of 12-15 cm (the length is determined by the length of the sewerage route);
• pipes for ventilation of chambers (diameter 8-10 cm);
• plastic tees of the same diameter;
• concrete rings (diameter depends on the volume of the chambers);
• cement-sand mortar for sealing joints;
• hydrophobic impregnation for concrete or bitumen mastic for waterproofing;
• concrete cover with inspection hatch;
• plastic perforated pipes with a diameter of 10-15 cm for the drainage trench (filtration field).

The correct choice of the type and diameter of the rings is of great importance for the normal operation of the septic tank. It is best if you buy concrete rings with a bottom at a construction warehouse. This will free you from the need to fill a monolithic slab and seal the contact area.

If such products are not available, then buy standard circles, but only with a locking connection, which increases the tightness and strength of the joints. The diameter of the sections and their number are selected based on the estimated capacity of the primary and secondary chambers.

Cylinder volume formula

The number of concrete circles is determined by dividing the volume of the cleaning chambers by the volume of one circle. If the number turns out to be odd, for example, 7 pieces, then add one circle to an even number. For each container in a two-chamber septic tank, there will thus be 4 concrete circles.

The number of round concrete sections for the filter well can be taken equal to the number of chamber rings. If the groundwater is deep, then the well can be dug 1-2 meters deeper.

Construction technology

The construction of a septic tank from concrete rings begins with digging a pit. Its size should be equal to the outer diameter of the chambers plus 30-40 cm for the mounting gap on each side and 5-10 cm of space between the rings.

If circles with a bottom are purchased, then a sand cushion 15-20 cm thick is made under them. It is needed to evenly distribute the weight of the concrete onto the ground. When determining the depth of the pit, do not forget to take into account the thickness of the bedding!

When using ordinary well circles without a bottom, you will have to pour a concrete slab with a thickness of at least 10 cm under them. It must be protected from cracks with reinforcing mesh (rod diameter 10-14 mm, pitch 10-15 cm).

Installation of concrete rings for sewerage is carried out using M500 cement mortar. It is evenly distributed over the entire contact surface. Having completed the installation, holes are marked and punched in the upper part of the chambers for the passage of pipes: sewer, overflow and leading to the filter well (trench).

A plastic “tee” is put on the end of the sewer pipe entering the primary chamber. The same is done with the overflow and outlet pipes. Tees perform an important function: they prevent contaminants floating on the surface of the water from clogging the pipes and moving into other compartments of the treatment plant.

Having installed the rings, they are treated with hydrophobic impregnation on the outside and inside. Having covered the compartments with concrete covers, inspection hatches are attached to them. Holes are punched in the covers of the primary and secondary chambers and ventilation pipes are installed in them.

An important nuance is the creation of the correct slope from the exit point of the internal sewer system to the entrance to the first chamber. Its optimal value is 2% (per 1 meter of length 2 cm of height difference). In order to do this work without errors, we suggest studying the sketch of the treatment plant in the figure.

Scheme of a two-chamber septic tank with a drainage ditch

If your septic tank will work with a filtration well, then it is better to buy round sections with drainage holes.

Circles for drainage well

It should be remembered that the drainage well is made only in soil that absorbs moisture well (sand, sandy loam). In loams and clays, for final cleaning, a filtration field is set up or a drainage trench is dug.

Before laying perforated pipes, the bottom of the trench is covered with fine crushed stone (layer 20-30 cm) or gravel to create an absorbent substrate. The pipe is wrapped in geotextile. It will protect it from silting by soil particles carried by storm water.

Cost of concrete rings

Estimated prices for reinforced concrete for 2017 for a wastewater treatment plant look like this:

• An ordinary ring with a KS 10-9 lock (inner diameter 100 cm, height 90 cm) in different regions can cost from 1700 to 2300 rubles/piece;
• KS 15-9 – RUB 3,000-3,600/1 piece;
• Cover with a hole for the hatch 1PP 10-1 (diameter 100 cm, thickness 15 cm) – 1200-1700 rub./piece;
• 1PP 15-1 - 2,400-3,000 rub./piece;
• Ring with bottom KCD 10-9 (diameter 100 cm, height 90 cm) – 2600-3200 RUR/piece;
• KCD 15-9 – 4700-5700 rub./piece.

Putting the septic tank into operation

Having completed the installation and filling the pit bosoms with the excavated soil, the septic tank chambers need to be filled with clean water. Its level should be several centimeters below the bottom of the upper overflow pipe connecting the primary and secondary chambers.

Some owners make the mistake of thinking that it is better to fill the treatment plant with sewage. Let us remind them that the principle of operation of a septic tank is to dilute sewage, and not to accumulate it. Therefore, before starting work, there must be clean water in it.

There is one more important nuance. For effective cleaning, special cultures of bacteria that decompose organic matter must be introduced into the containers. They can be purchased at hardware stores in the form of a dry concentrate.