More and more often owners of summer cottages and private houses install autonomous septic tanks, abandoning the traditional way of arranging local sewers.

A wide range of treatment plants allows you to easily solve the problem of arranging sewage on a personal plot. Let us dwell on the popular model of a septic tank, consider its structure and principle of operation, and also analyze the installation order of the unit.

Content

1. Description of the device septic tank
2. The principle of operation of the treatment plant  video
3. Advantages and disadvantages of a septic tank
4. Choosing the optimal type of septic tank
5. Do-it-yourself tank septic tank installation: instructions and installation features
   • selection of a place for arrangement of an underground sedimentation tank
   • necessary tools and materials
   • important recommendations for installing a septic tank
   • septic tank: do-it-yourself installation  video video
   • features of the installation of a septic tank on soils with high groundwater

Description of the device septic tank

What is a septic tank? This is a balanced and completely independent sewer device for country houses and cottages. It is a cast construction made of polypropylene, which is reinforced with stiffeners.

In order to understand how the installation works, you need to understand the device of the septic tank and know its components:

1. Plastic case (thickness 10-15 mm). It is made of low pressure polyethylene (HDPE) or polypropylene (PP). The septic tank can function under the weight of groundwater and soil mass due to stiffeners (thickness 15-17 mm).
2. The inlet and outlet pipes are sections of the sewer pipeline through which the pipes are connected to the septic tank. The diameter of the nozzles depends on the model of the septic tank.
3. Neck. The number of necks is determined by the volume of the septic tank. Each neck is covered with plugs that protect the device from rain, snow and debris.
4. The partitions separating the chambers from each other are made of the same material as the body. Overflows, membranes and filtering devices are built into the partitions.
5. The aeration and ventilation pipe removes gases accumulating inside the septic tank beyond its aisles. The ventilation system is equipped with a special valve that operates under the pressure of excess gas.
6. Materials (expanded clay, wood, sand, gravel), filtering liquid.

The Septic Tank can be equipped with an infiltrator, which additionally purifies the wastewater before it is discharged into the soil.

The septic tank carries out only mechanical cleaning, no deep biological or chemical processing takes place exclusively natural processes of decay and decomposition.

The principle of operation of the treatment plant

The principle of operation of all types of septic tank is the same, the only difference may be the installation of additional wells or filtration fields.

Filtration equipment makes it possible to reuse filtered water for irrigation of land and technical needs

The entire sewage path through the septic tank can be divided into the following stages:

1. Sewage sewage water enters the first tank of the septic tank through the pipeline and inlet pipe.
2. Primary purification and processing takes place. During natural processing, heat and gas are generated, which flows out through the vent pipe with the valve.
3. The sludge settles to the bottom of the first chamber, and clarified water (conditionally purified) accumulates, rises, and flows through the overflow pipes into the second tank.
4. In the second compartment, high-quality sedimentation takes place. However, it is still not enough to consume water for technical needs (the degree of water purification at this stage is 75-85%).
5. The purified water through the filter enters the third compartment (if this is provided for by the septic tank model) or to the post-treatment facility (filtration field, well or infiltrator).
6. An infiltrator (a device for soil wastewater treatment) purifies water from harmful impurities, and organic substances are oxidized.
7. Purified water from the infiltrate enters directly into the soil without polluting the soil, or into a collection well (preferably for soil with a high clay content).

For better wastewater treatment, microorganism strains can be added inside the septic tank

Advantages and disadvantages of a septic tank

Compared with other cleaning devices, the septic tank has several advantages, namely:

• durability of the installation (life of about 50 years);
• the strength of the structure, able to withstand high soil pressure;
• the ability to adjust the performance of the septic tank;
• in tandem with an infiltrator, the operation of the septic tank is very effective (almost pure water 98-100% goes into the ground);
• the compact dimensions of the device allow it to be used in areas of different sizes;
• non-volatility of the installation (one of the main reasons for the great popularity of the septic tank);
• ease of installation;
• affordable cost of a tank septic tank (the price with installation ranges from 30,000 to 70,000 rubles).

Like any other equipment, a septic tank has its drawbacks:

• the need to control the system and maintain the equipment (annually, using the slurry equipment, it is necessary to remove sediment from the day of the septic tank); the work of specialists each time will have to pay;
• to install a septic tank, you need to dig a deep enough foundation pit, applying a lot of physical strength;
• before installing the septic tank, it is necessary to find out the depth of groundwater (during spring floods, with a high location of groundwater, the septic tank can float);
• if the ventilation ducts of the equipment are faulty, unpleasant odors may increase during the operation of the septic tank.

Choosing the optimal type of septic tank

To ensure efficient and uninterrupted operation of the treatment plant, it is necessary to choose the model of Tank septic tank correctly. The main criteria to consider when buying are:

• number of people living in the house;
• volume of water consumed.

With a standard set of plumbing, water consumption per person per day is about two hundred liters

If at the summer cottage to establish a minimum set of plumbing (washbasin, shower, sink, toilet), then the water consumption will be less.

The range of septic tanks Tank is represented by the following types:

• Tank1    inexpensive and compact model, suitable for a small house for 3 people or for a summer residence (seasonal visit);
• Tank2    for a family of 4 people, the processing capacity of 800 l / day;
• Tank2.5    an excellent choice for a house in which no more than 5 people live;
• Tank3    It is installed for a house where the daily consumption is about 1500 liters per day; suitable for a family of 5-6 people;
• Tank4    It is designed to process 1800 liters per day; can be used for two houses, if the total number of residents does not exceed 9 people.

After determining the type of septic tank, you need to select the appropriate number of infiltrators, which depends on the density and structure of the soil on the plot. Saving on the number of infiltrators is not worth it, since the quality of wastewater treatment can significantly deteriorate.

Do-it-yourself tank septic tank installation: instructions and installation features

Choosing a place for arranging an underground sump

You can significantly save the budget if you install the septic tank Tank yourself. At the same time, it is important to adhere to the recommendations specified in the instructions and take into account the features of your site (relief, the location of buildings, ponds, roads, plantings).

In order not to cause difficulties during the operation and maintenance of the septic tank, it must be placed adhering to the following rules:

• the distance from the source of drinking water to the infiltrator should be at least 30-50 meters, from an open source at least 30 meters;
• the distance between the house and the septic tank is not less than 3 meters (this is enough so that in case of equipment breakdown, the foundation of the apartment building is not flooded);
• the distance to the trees is at least 3 meters, so that the root system of the plants does not damage the septic tank;
• the location of the septic tank should allow the scavenger machine to freely approach the septic tank to pump waste from the first section; when calculating, it must be taken into account that the hose of the car is 7 meters, so the camera hatch should be at a distance of 4-5 meters from the road or other entrance of the car;
  
• it is desirable that the pipe leading from the house does not have turns, but goes in a straight line;
• to the fence of the adjacent area from the septic tank should be at least 3-5 meters.

You can plant flowers or plant a lawn above the infiltrate. It is forbidden to equip a path, plant vegetable and fruit crops

Necessary tools and materials

To organize an autonomous sewage system on the site, in addition to the tank septic tank and the infiltrator itself, it is necessary to purchase and prepare additional materials and tools:

• pipes and fittings for the external sewage pipe;
• drainage pump or motor pump (may be needed when filling the pit with groundwater);
• bayonet shovel;
• boards that can be used to strengthen the walls of the pit;
• ropes or rope;
• wire diameter (3-5 mm);
• winch;
• sealant for assembling joints;
• jigsaw;
• sand;
• dry cement;
• crushed stone;
• building plastic mesh.

Important recommendations for installing a septic tank

Uninterrupted operation of the cleaning device is possible only with proper installation of equipment. There are some working points to consider when installing a tank septic tank:

1. Possible defects in the septic tank must be identified and eliminated in advance, before installation. Undetected malfunction can cause a lot of trouble (flooding the foundation, pollution of groundwater).
2. The length and width of the pit should be more than the size of the septic tank by 25-30 cm.
3. When determining the depth of the pit, it is necessary to calculate that the end of the pipeline in the trench coincides with the location of the inlet pipe, while it should be borne in mind that for each meter of the pipe there is 20 mm of the slope of the sewer pipeline.
4. To carefully lower the septic tank into the pit, it is not necessary to call a crane, you can use cables, ropes, belts or a winch.
5. Sand, gravel and crushed stone for dusting the septic tank should be medium-sized and non-pointed fractions.
6. In parallel with filling the septic tank, it must be filled with water, while the water level should be 20 cm above the level of dusting.
7. Tamping the soil and sprinkling is done only by hand, without special equipment.

Septic Tank: DIY installation

Consider the sequence of work on installing the septic tank:

1. Digging pits and trenches for equipment placement. Operating time can be reduced by using earthmoving equipment.
2. The bottom of the trench and foundation pit must be compacted, the roots of plants, large stones removed.
3. A sand pillow is created (the height of the pillow for the excavation is 30 cm, the trench is 20 cm).
4. The septic tank sinks to the bottom of the pit and is installed exactly in the center.
5. Inlet / outlet pipes are attached to the septic tank nozzles and sealed (silicone can be used).
6. To fill the pit, you need to use a dry mixture of sand and cement (ratio 5: 1). The mixture is poured between the side of the pit and the walls of the septic tank. The cement-sand mixture must be rammed every 20 cm backfill.
7. In parallel with the filling, the septic tank is filled with water.
8. The piping of the external sewage system is covered with sand, tamping well on the sides.
9. It is desirable to cover the upper side of the septic tank with a heater.
10. Final filling of the septic tank and tamping of the soil. As a result, the neck of the hatch, which must be covered with a lid, remains visible above the surface of the earth.

The installation procedure for the infiltrator is as follows:

1. Digging a rectangular pit (distance to the septic tank about 1 meter).
2. The side walls of the pit are laid out with a geotextile.
3. A layer of gravel is poured at the bottom of the pit (layer height 40 cm).
4. An infiltrator is installed in the pit.
5. The infiltrator is connected to the sewer pipe.
6. At the outlet of the infiltrate, a ventilation pipe is mounted.
7. The gaps between the walls of the pit and the casing of the infiltrate are covered with sand.
8. The upper part of the infiltrator is covered with insulation and is covered with earth.

If the length of the pipes is large, then it is necessary to install inspection wells, this will greatly facilitate the cleaning of pipes when they are clogged. In addition, inspection wells are required to be installed in places where the pipeline turns.

Features of the installation of a septic tank on soils with high groundwater

Installation of a septic tank on a site where groundwater is high has the following features:

1. The bottom of the pit must be concreted before installing the septic tank. Concrete is poured on top of the sand cushion (10 cm high). The septic tank case is attached to the concrete base with the help of nylon harnesses and special fasteners.
2. Before backfilling, the walls of the pit must be strengthened with boards.
3. Infiltrate is better to mount not in the pit, but on the surface of the soil. A shallow trench is made (50 cm), strewn with rubble and an infiltrate is established. Since the equipment is outside, it must be well insulated. Soil is poured on top of the insulation and a flower bed is arranged.

Following all the recommendations for the selection and installation of a tank septic tank, you can organize an efficient and affordable sewage system on the site, independent of electricity and not requiring excessive attention.

Author: Sergey and Svetlana Khuentsov

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