Septic tank of concrete rings: scheme, device, installation steps

A modern country house is equipped with many technological benefits that were inaccessible even a couple of decades ago and require water to function. In addition to cooking and washing hands, there is at least a shower, a washing machine, and maybe also a dishwasher. For all these devices, it is necessary to adjust not only the supply of clean water, but also the discharge of the effluent. This means that the usual level of amenities cannot be imagined without a modern device for the treatment of domestic wastewater. When it is impossible to connect a house to the central collector, a septic tank made of reinforced concrete rings can be one of the few ways that allow competent waste processing and prevent soil contamination.

View of the septic tank of concrete rings in the courtyard of a private house

How does a septic tank

work for a small private house the device of a septic tank of concrete rings is carried out according to the classical scheme, which includes two tanks. If a significant amount of wastewater is expected, three tanks (wells) are installed, different in device and function. The first two wells are made airtight, the third settles the filter from the rubble, through which the water goes into the soil.

Principle of the device of a septic tank from concrete rings

Appointment and device of cameras

• First Septic tank is used to receive and defend sewage. Here, thanks to the work of anaerobic bacteria, precipitation occurs and partial treatment of wastewater (anaerobic bacteria can decompose complex organic matter into simple substances without oxygen). The initially clarified water flows into the second section. The volume of the chamber should be equal to half the total planned volume of the system; its foundation is concreted.

• In the second well (drainage) with hermetic walls and bottom additional filtration takes place. Additional gravel filters can be installed here.

• In the third well, final filtration takes place. The bottom is not concreted here; sand-crushed-stone (or sand) mixture is poured for final filtration.

Advantages and disadvantages of a septic tank made of concrete rings

Due to the peculiarities of its use, design and installation, such a system is the optimal solution in many cases.

Consider all the pros and cons of a septic tank of concrete rings:

Its advantages include:

• simple installation and use technology. It is not necessary to supply electrical power, arrange additional drainage, install a pump;
• robust stand-alone design with high mechanical strength;
• Complete freedom in choosing the dimensions of the structure;
• long service life;
• large usable volume and easy maintenance;
• resistance to aggressive wastewater;
• the weight of the rings is a guarantee that the groundwater will not force the septic tank out of the soil;
• Available materials and reasonable price for the construction of a septic tank.

Additionally, a septic tank can be improved - an example in the video:

Disadvantages of concrete septic tanks:

• Weight of building material. When installing it is difficult to do without construction equipment.

• The need for high-quality sealing of joints between the rings and joints with pipes.

• The hygroscopicity of concrete, which does not allow the method to be used on flooded areas.

• The need for regular cleaning of tanks and pumping drains.

We make the correct calculations: capacity and design

At the design stage, a septic tank is created from concrete rings, then the volume of the future device is determined:

Number of cameras

The number of cameras depends on the number of people using the sewers. If the family is actively using the shower, bathroom and household appliances, the drain into the sewer will be significant. The drains will need thorough cleaning, which will require a septic tank of three wells, two of which will be settling chambers.

The design of the device of a septic tank of concrete rings

Capacity

To determine the volume of wastewater entering the septic tank from kitchens, baths and bathrooms, you need to calculate the daily water consumption. Knowing that the daily rate of household water consumption by one person is equal to 200 liters, it is easy to calculate that a family of 4 people will fill a septic tank at a speed of 800 liters per day.

The quality of the septic tank is improved if the wastewater is retained in the chambers long enough. By increasing the volume, you can improve the quality of wastewater and protect the system from clogging with difficult to decompose fat.

According to construction norms, the installation must contain drains that form in three days (the consumption per day must be multiplied by 3).This number determines the volume of the septic tank and the number of chambers:

• the single-chamber septic tank is installed if the daily drains do not exceed 1 cubic meter;

• dual-chamber - up to 5 cubic meters;

• three-chamber - 8 and more cubic meters.

In a septic tank with two chambers, the first clarifier occupies a volume of 2/3 of the total septic tank, in a three-chamber one half.

What to look for before starting work

If there is a high aquifer in the area:

• Thorough seals are made to seal the septum otherwise, it will constantly be fed by groundwater and overflow. There will be additional expenses to call a cesspool machine.

• The device of the filtration well loses its meaning; for additional treatment and removal of water from the septic tank, another option is needed.

About septic tanks on high groundwater in the video:

Increased Strength Structures:

• To protect the building from possible ground movements and rings moving, they are additionally fastened with metal ties.

• To reduce the drawdown of the septic tank and to improve its thermal insulation and drainage, when installed around, they arrange a pillow of sand, gravel or gravel.

How much will the rings

cost? Concrete rings are selected based on calculations of the volume of the septic tank. The dimensions of the concrete rings for septic tank are indicated on the label. They are characterized by the height, diameter and thickness of the walls of the structure, as well as the type of product:

• COP - wall ring, suitable for wall construction;

• PP - slabs for floors;

• PD - road plates installed on the bottom of the excavation;

The cost of concrete rings is affected by their size and place of production. W / b rings of low surface permeability that are resistant to aggressive media are suitable for sewage.

The height can be 290, 590, 800, 900 mm. A typical product with a height of 900 mm may have a diameter of 700, 800, 1000, 1500 and 2000 mm. The average price for it varies from 1,200 to 1,800 rubles. Rings with other parameters can cost from 680-1050 to 1500-2400 rubles.

Rings for a septic tank

It should be remembered that for some rings the inner (useful) diameter is indicated in the marking, for others it is the outer that is important for the selection of covers. The average cost of a reinforced concrete cover or polymer hatch ranges from 1,700 to 2,000 rubles.

When budgeting for a septic tank of concrete rings, the price is added up taking into account additional materials: pipes, cement, sealant, as well as the cost of work (digging, installing rings). The final average price of a turnkey septic tank is in the range from 38,000 to 69,000 rubles.

What materials will be needed

In addition to the required number of reinforced concrete well rings and plates with a hole for the hatch additional materials are needed:

• sand, gravel, cement, crushed stone for the "cushion";

• cement; liquid glass for sealing the joints between the rings;

• sealed ( polymer manholes;

• shovels, perforator;

• pipes and fittings.

Stages of construction

Installation is carried out in the following order:

• A place is selected, an installation diagram is constructed, the parameters of the septic tank are calculated.

• A pit is being dug.

• Rings are installed, pipes are brought.

• Works on sealing and waterproofing are carried out.

• Overlaps are set.

• Backfilling is performed.

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

How to choose the best place for a septic tank

The structure is mounted above the groundwater level. The best placement is at the maximum distance from the house (not less than 7 meters, but not more than 20, so as not to increase the cost of building the pipeline). It is logical to have a septic tank on the border of the site, next to the road. This will reduce operating costs, since access to the system and the length of the hose affect the cost of leaving a cesspool truck. Moreover, with the correct location of the cesspool car, it is not necessary to drive into the courtyard, and the hoses will not roll on the beds or paths (otherwise, when the hose is rolled up, waste may end up in the garden).

The distance to the nearest source of drinking water (well, well) is at least 30 (and as far as possible) meters.

Preparation of the excavation

The excavation work with the use of an excavator takes 2-3 hours. The size of the pit should be somewhat larger than the dimensions of the wells. This is necessary for the smooth installation of rings and their waterproofing. The bottom is covered with rubble and concreted.

Preparing a pit for a septic tank from concrete rings

Assembling rings and sewer pipes

The rings for a septic tank are installed with using lifting equipment, which saves time (compared to manual installation). Fixing the seams is provided with a cement mortar, metal braces (brackets, plates) are put in addition.

Holes are punched in the rings and plastic overflow pipes are supplied. They have a curved shape and work on the principle of a hydraulic seal.

Responsible moment - the process of installing rings

Sealing and waterproofing

Sealing seams of a septic tank of concrete rings is carried out with both sides of the structure. For this purpose, cement and coating protective solutions are used. Inside the well, you can install the finished plastic cylinders. Such additional costs will make the system 100% sealed.

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

Sealing of joints and waterproofing of a septic tank from concrete rings

Installation of the hatch and backfilling

Wells are covered with concrete slabs, with holes for hatches. In the first two wells, the ventilation necessary for the removal of methane is adjusted (gas appears as a result of the vital activity of anaerobic bacteria). For backfilling of installed ceilings, the soil removed from the excavation is used (backfilling).

Backfilling of finished wells

How does the septic tank start up

In order for the system to begin to function effectively, the erected septic tank need to saturate with anaerobic microflora. The natural accumulation process takes several months, so it is accelerated by saturating the septic tank with imported microflora. This can be done in two ways:

• A new septic tank is filled with sewage and defend them for 10-14 days. Then it is loaded silt sediment from the current anaerobic septic tank (2 buckets per cubic meter).

• You can purchase ready-made bioactivators (bacteria strains) in the store (the main thing here is not to confuse them with aerobes that are intended for other treatment systems).

Septic tank ready for start-up from rings

What rules should be observed when servicing the septic tank

There are simple rules that support the quality of the system.

1. Cleaning. Twice a year, in addition to cleaning drains, the septic tank must be inspected and cleaned pipelines. Once in 5 years (or better in 2-3 years), cleaning of bottom heavy fats is carried out. Sludge volume should not exceed 25% of the volume of the tank. When cleaning part of the sludge is left to restore the microflora.
2. Quality of work. The effluent from the system should be 70% clean. Analysis of the effluent in the laboratory will determine the acidity index, which will allow to know the quality of the drainage system.
3. Security measures:

• Works inside the septic tank are allowed only after increased ventilation and using a safety belt (gases generated inside can be dangerous to human life).

• Improved safety measures are required when working with power tools (wet environment).

A septic tank made of concrete rings makes private housing more autonomous and, despite its shortcomings, it is one of the most reliable and durable wastewater treatment options for suburban real estate.