How To Make A Septic Tank For A Private House With Your Own Hands - Step By Step Instructions With Photos, Drawings And Video

2024 Author: Bailey Albertson | [email protected]. Last modified: 2024-01-17 22:26

Sewerage in a suburban area: septic tank with your own hands

Summer cottages and country houses have long ceased to be housing with amenities “in the yard”. New technologies and materials make it possible in a short time to build a full-fledged sewerage system, which will provide drainage from the kitchen, toilet, bathroom or bath. Most often, it is not possible to connect the drain line to a centralized network, therefore, the problem of removing sewage from the site has to be solved independently, using the services of a sewer or dumping wastewater into the ground. Of course, in the latter case, you can build a simple drain pit from scrap materials and thereby avoid financial costs, if not for one nuance: direct discharge of sewage into the ground can lead to groundwater pollution in your and neighboring areas.

In order for “both the wolves to be fed and the sheep to be safe,” it is worth spending a small amount and building a septic tank that will clean the drains and make them safe. And so that the costs of its manufacture and operation do not lead to depletion of the family budget, we recommend that you start building yourself.

Content

• 1 Septic tank - a device, how it works
• 2 Advantages and disadvantages of septic tanks

• 3 Design and preparatory activities

  • 3.1 Choice of location on the site. Sanitary standards
  • 3.2 Selection and calculation of material. Required volume
  • 3.3 Photo gallery: drawings of future structures
  • 3.4 Which shape is better
  • 3.5 Required tools and materials
• 4 DIY construction and installation of a suburban septic tank made of monolithic concrete
• 5 Arrangement of filtration structures
• 6 Recommendations for the operation of septic tanks
• 7 Video: homemade concrete structure for a private house

Septic tank - device, how it works

A neatly made septic tank will absolutely not interfere with the site, even if installed in a conspicuous place

The issue of utilizing domestic wastewater in suburban areas can be solved in two ways. The first consists in the accumulation and subsequent removal of sewage using sewage machines, and the second covers a whole range of processes for their filtration, absorption and disinfection.

The storage type septic tank requires regular pumping

The use of a sealed container for collecting wastewater is a good option in the case when they appear in a country house or in a country house on weekends and the amount of water used is small. If you plan to regularly operate the bathroom, toilet and household appliances, then the volume of water increases so much that you will have to pump out the drain pit every week. To avoid this inconvenience, cesspools of a filtration type are constructed, in which the liquid from the sewage system is absorbed into the ground. There, with the help of bacteria, it is processed into water and safe organic substances. In fact, a septic tank is just such a structure, however, its improved design allows you to disinfect wastewater even before it is discharged into the ground.

Site of the Admiral Plant -

Depending on the design, septic tanks can be divided into several types:

1. Single-chamber septic tank of small volume. It is a container with an overflow pipe and is used in small households with a water consumption of no more than 1 cubic meter. m per day. Despite the simple design, the efficiency of sewage treatment leaves much to be desired.
2. Small two-chamber septic tank. Consists of two containers connected by an overflow system. The simplicity and efficiency of such a design makes it the most popular for DIY manufacturing.
3. Multi-chamber structures. Due to the presence of several chambers, wastewater treatment takes place over a long period of time. This allows you to get water at the outlet, which can be safely discharged into natural reservoirs or used for domestic needs. Despite the high degree of purification, multi-chamber systems are few in number in private backyards due to their complexity and high cost.

In order to understand how a septic tank works, consider the most popular two-chamber design.

The device and principle of operation of a two-chamber septic tank

After the sewage gets from the sewer into the first chamber of the treatment plant, it is gravitationally separated into liquid and solids. At the same time, the processing of organic waste by aerobic and anaerobic bacteria begins, which develop in the absence or excess of oxygen. At the same time, not only liquid waste, but also fecal matter is processed into water and harmless organic matter. By the way, the work of microorganisms makes it possible to significantly reduce the volume of the solid fraction, leaving only a small sediment in the form of sludge.

An overflow channel is located in the upper part of the first chamber, through which the purified liquid enters the second chamber, where it is further purified. Below the level of the inlet channel in the second tank there is an outlet pipe, from which the purified liquid is taken for watering the garden or diverting into the ground. In the latter case, they equip filtration fields or wells, which make it possible to increase the area of contact of the treated water with the ground.

Advantages and disadvantages of septic tanks

The question of which is better - a cesspool or septic tank, is best considered in terms of efficiency, as well as cost of manufacture and maintenance. It is important to remember about the safety of the structure.

Note that according to most parameters, it is the septic tank that wins, which stands out with such advantages:

• high degree of purification of domestic wastewater - water at the outlet of the device can be used for economic purposes
• lack of an unpleasant odor on the site;
• hermetically sealed design reduces the risk of sewage entering the groundwater and makes the structure safe for the environment;
• there is no need for regular pumping - the removal of the sludge residue can be carried out once every several years.

The disadvantages of septic tanks include:

• more complex construction;
• increase in construction costs;
• strict requirements for the use of household detergents. Conventional chemistry is detrimental to microorganisms, so you have to use special formulations;
• a decrease in the activity of bacteria with a decrease in temperature - at 4 ° C and below, the process of processing sewage stops.

Despite some nuances, the use of a septic tank allows you to preserve the nature and health of others, and this is a plus that cannot be canceled out by any difficulties and financial costs.

Design and preparatory activities

The apparent simplicity of the design of the septic tank is very deceiving - in order for the constructed structure to be safe and productive, it is necessary to make small calculations and carefully approach the choice of location.

The choice of location on the site. Sanitary standards

Scheme indicating the requirements for the location of the septic tank on the site

When choosing a place for installing a septic tank, they are guided by the norms of sanitary and epidemiological legislation and acts of SNiP:

• local sewerage facilities are allowed to be installed at a distance of at least 5 m from the foundation of a residential building and 1 m - from buildings for economic and domestic purposes located on the site;
• the distance from wells and boreholes is determined depending on the composition of the soil and can range from 20 m for clayey soils to 50 m for sandy soil;
• the installation of a septic tank directly near the roads and borders of the site is prohibited. It is required to maintain a distance of at least 1 m from the fence and 5 m from the road;

In addition, do not forget that from time to time you still have to use a sludge pump, so it is imperative to think about how the sewer truck will drive up to the sewage facilities.

A household fecal pump with a grinder will allow you to do without the services of a sewer

Selection and calculation of material. Required volume

For the device of septic tanks, you can use both ready-made tanks and containers built by your own hands:

• bulky metal barrels;
• wells made of precast concrete structures;
• plastic eurocubes;
• monolithic concrete structures;

• brick wells.

  

  Table of dependence of water consumption on installed equipment

The calculation of the amount of material required depends on the volume of the septic tank, therefore, the main calculated value is the daily amount of discharged wastewater. It is not required to accurately determine this parameter; it is enough to take water consumption of 150-200 liters for each family member who permanently resides in the house. This will be enough for using the bathroom, toilet, washing machine and dishwasher. To determine the volume of the septic tank receiving chamber, the resulting value is multiplied by three. For example, if five people constantly live in a house equipped with all the amenities, then a tank designed for 3 cubic meters will be required. m of liquid waste (5 people × 200 liters × 3 = 3000 liters).

The second chamber is calculated based on the size of the receiving tank. If its volume is taken equal to 2/3 of the total size of the septic tank, then the dimensions of the post-treatment chamber provide the remaining third of the volume of the structure. If we take the example discussed above, then the working volume of the structure will be 4.5 cubic meters. m, of which 1.5 cubic meters. m is taken under the second tank.

Photo gallery: drawings of future structures

When designing a septic tank, you can use drawings and diagrams of working structures.

Drawing of a two-chamber septic tank

Diagram of a two-chamber septic tank

Drawing of a two-chamber septic tank

Drawing of a two-chamber septic tank

It should be understood that in most regions a septic tank will not freeze in winter due to warm drains coming from the house, soil temperature and the work of microorganisms. Nevertheless, you still have to deepen the structure. The gap between the cover and the upper level of wastewater is taken to be equal to the amount of soil freezing in winter. It is at this depth that the drain pipe enters the septic tank. Therefore, it is necessary to rely on the fact that the calculated working volume will be below this point. In addition, at a higher temperature, bacteria will more actively process sewage, contributing to an increase in the performance of the septic tank.

Diagram explaining the need to deepen the septic tank chambers

Which shape is better

The question of which septic tank is better - round or rectangular can be considered incorrect, since the shape does not at all affect the performance and degree of purification. However, the configuration of the structure makes a huge difference in the choice of materials. Everyone knows that round structures are the most optimal in terms of spending the necessary funds. The septic tank was no exception. If it is made of bricks, then the choice of a cylindrical shape will reduce consumption by 10-15%. In addition, the round walls perfectly withstand mechanical loads from the ground. If you choose a monolithic two-chamber structure, then it is better to make it square or rectangular. Firstly, the reinforced walls will resist bending forces, and secondly, this is necessary for purely practical reasons,associated with the manufacture of formwork for pouring concrete.

The cost of septic tanks from various materials. To eliminate the impact of devaluation, prices are given in USD. e

By the way, we recommend making a concrete structure with your own hands. If we consider the cost of a septic tank, then it will not be much higher than inexpensive brick counterparts (see table). As for the durability and strength of the structure, there can be no question of any comparison, therefore even more labor-intensive technology will justify itself many times over. We will tell you in detail how to build a rectangular two-chamber septic tank made of reinforced concrete.

Required tools and materials

To build a concrete treatment plant you will need:

• crushed stone, sand and cement for the manufacture of concrete;
• steel rods or reinforcement with a diameter of at least 10 mm;
• metal corners, pipes or channels for the construction of floors;
• boards, beams and slats for formwork;
• waterproofing film;
• concrete mixer;
• containers for bulk materials and concrete;
• Bulgarian;
• manual ramming;
• saw on wood;
• a welding machine or wire for making an armored belt;
• a hammer;
• building level;
• roulette.

If it is necessary to insulate a septic tank, this list should be supplemented with a heat insulator used, for example, expanded clay aggregate.

DIY construction and installation of a country septic tank made of monolithic concrete

It is better to dig a pit for a septic tank by asking for help from relatives and friends

1. After determining the size of the structure and choosing a location, they begin to dig a pit. The size of the pit is chosen depending on what kind of formwork will be used. If boards made of boards are planned to be installed on both sides, then the pit is made 40 - 50 cm wider than the size of the tank, taking into account the thickness of its walls. In the case when concrete will be poured between the formwork and the ground, the pit is dug according to the external dimensions of the septic tank. If hired people will be used for this, calculate the cost of their work. Be sure to keep in mind that the soil will have to be removed from the site, and this will entail additional costs for its loading. Perhaps the total cost of all earthworks will approach the cost of operating an excavator. At the same time, he will cope with the work ten times faster.
2. Tamp the bottom of the pit and cover it with a layer of sand 10-15 cm thick. After that, the sand is spilled with water to compact it.

3. Install the formwork around the perimeter of the structure. If a one-sided board fence is used, then the walls of the pit are covered with plastic wrap. This will prevent them from shedding while pouring the walls and base of the septic tank.

   

   Waterproofing pit walls

4. Lay pieces of wooden slats at least 5 cm thick on the bottom. They will be needed as spacers for the reinforcement belt, which will be located inside the concrete base.

5. Build an armored belt from a metal bar or reinforcement. To do this, longitudinal elements are laid on the slats, and the transverse ones are attached to them by welding or tying with wire. The mesh size of the resulting grid should be no more than 20 - 25 cm.

   

   Armopoyas installation

6. Pour the base of the septic tank with concrete and seal it with a bayonet or rammer. The thickness of the bottom should be at least 15 cm. To prepare a mortar from grade 400 cement, you can use the following proportion: 1 part of cement is mixed with 2 parts of sand and 3 parts of crushed stone. When using M-500 cement, the amount of bulk materials is increased by 15 - 20%.

   

   Pouring the base of the septic tank with concrete

7. After the concrete base has finally set, they begin to form the walls and partitions of the septic tank. Reinforcement is also installed inside the formwork to strengthen the structure of the structure.

8. At the level of overflow channels and entry-exit points of sewer pipes, windows are made, installing large-diameter pipe sections into the formwork or constructing plank frames.

   

   Formwork for walls and internal partitions

9. After the septic tank chambers reach the required height, they begin to build the floor. For this, support elements made of steel corners or shaped pipes are laid on top of the walls. In doing so, it is important to ensure sufficient strength, since concrete has a significant weight.

10. When installing formwork and reinforcement, take care of the openings for the hatches.

    

    Setting floor support members

11. Fill the septic tank lid with concrete and cover the structure with plastic wrap.

    

    Before pouring the ceiling, be sure to install a ventilation pipe

12. After the overlap has dried, a sewer main is brought into the receiving window of the first chamber, and the outlet of the structure is connected to drainage structures.
13. They fill the septic tank with soil, constantly tamping and leveling it. It is important that the ground level above the septic tank is slightly higher than the level of the entire site. This will prevent the wastewater treatment plant from flooding during heavy rains or floods.

Arrangement of filtration structures

In order to drain the treated water into the ground, different types of drainage systems are used. The most common structures are filtration fields and drainage wells.

Filtration field device

The first is a system of pipelines located in the ground and connected to the outlet of the septic tank. Thanks to the installation at an inclination, the movement of treated wastewater through the pipes is ensured, and their absorption becomes possible thanks to the system of holes and the drainage layer into which the entire structure is placed.

The latter are a special case of a cesspool without a bottom and can be constructed from perforated concrete rings, staggered bricks, or old car tires. To ensure the absorption capacity, the bottom of the filtration well is covered with a thick layer of rubble. I must say that, unlike a cesspool, the performance of a structure connected to a septic tank practically does not decrease over time. This is due to the absence of solid particles and suspensions that can clog drainage holes and pores.

Recommendations for the operation of septic tanks

Using a septic tank, it is necessary to radically reconsider the approach to the use of sewage. From the day the system is put into operation, it is forbidden to use chemical detergents and to pour any aggressive substances into the toilet or sink. It must be remembered that from now on, living beings - bacteria and other microorganisms - are engaged in wastewater treatment. Of course, this does not mean that you will now have to use ash and simple laundry soap for washing and cleaning, like our ancestors. When using household detergents marked "Bio" or "Eco", the fragile ecosystem of the septic tank will not be threatened, and you will get good results when cleaning and washing.

The use of detergents free of aggressive chemicals will allow the septic tank to work at full strength

Do not pour into the sewer and inorganic waste and garbage - there is a trash can for this. Getting into the storage tank of the sewage structure, they will collect at the bottom and interfere with its normal operation, and when pumping out sludge, they can clog the hoses of the fecal pump.

To improve the performance of the septic tank, special bioactivators are periodically added to the receiving chamber, which include several types of aerobic and anaerobic bacteria. When choosing biological products, it is imperative to pay attention to their purpose, since such compositions are produced both for normal operating conditions and for cleaning heavily contaminated walls of septic tanks, drains with an increased fat content, etc. manufacturer on the packaging, otherwise bacteria may die.

The use of bioactivators improves septic tank performance

From time to time you will have to check the sediment level. The fact is that their accumulation leads to a decrease in the useful volume and a decrease in the performance of the septic tank, therefore, from time to time, sludge will need to be pumped out or removed using a sludge pump, fecal pump or a long pole with a scoop device. Of course, mechanized pumping methods will be preferable.

Video: homemade concrete structure for a private house

Despite the fact that the process of manufacturing a septic tank is associated with certain time and material costs, in the future, a self-constructed treatment plant will justify itself more than once. You do not have to constantly think that the sewage system can "get up" at the most inopportune moment or worry about regular pumping out of the tank. The septic tank will be able to function for many years without polluting the environment and without causing any problems.