How to make a cesspool
The construction of any country or country house begins with the construction of a toilet on the site. But this building is temporary and does not meet town planning and sanitary requirements. When constructing a residential building, it is necessary to resolve the issue of disposal of sewage at the site on a global scale. The lack of centralized sewage systems requires the organization of a local sewage treatment system. The simplest, low-cost and affordable way is to organize the cesspool. We will tell you how to make a cesspit. You will also learn about the current regulatory documents governing the rules for its construction and location on the site.
The cesspool is an artificially constructed structure in the ground, into which liquid household waste and sewage flows for accumulation and further utilization by means of an assenizator machine.
Requirements for the waste accumulator are established by construction and sanitary legislation. Since 2013, new building codes have been adopted for the organization of external sewage systems and structures instead of SNiPs. The concept of a cesspool is not mentioned in them. All structures must be completely sealed to prevent the ingress of pollutants into the environment.
According to the legislation, cesspools without bottom are prohibited even with a small amount of sewage. Waste must be completely disposed of from storage tanks or undergo biological treatment with further disposal through filtration fields. Thus, the cesspool is nothing like a sealed septic tank.
The construction of a hermetic drive is laborious and requires certain knowledge and skills. At the same time, the built cesspool will do it by hand to cut the budget for its construction.
Choice of placement
The place for the pit is chosen taking into account the existing building and sanitary standards. According to the building standards, the distance from the house to the drive should be at least 3 m. According to the sanitary standards, this distance is increased and depends on the decision of the homeowner, but not less than 8–10 m.
The minimum distance to the source of drinking water, water should be from 30 to 50 m, depending on the type of soil. The more soil is permeable, the greater the distance.
Volume
For the construction of a sump, a project and a calculation of the volume of the hopper are required. This also applies to the construction of the graveyard. Its volume should correspond to the required accumulation and frequency of disposal. The rate of water consumption per person per day is 150-200 liters. Removal of drains by an aspensor machine - 2 times a month, that is, every 15 days.
The volume of wastewater, which must take a septic tank per person for one accumulation period will be V = 200? 15 = 3000 l or 3 m3.
For a family of 3 people, the volume will be 9 m3. The septic tank should have a reserve in volume for unforeseen cases (for 2-3 days). Total for a family of three, subject to cleaning the pit twice a month, the volume should be 10-11 m3.
The volume of the septic tank can be reduced or increased on the basis of the calculation of the frequency of export of wastewater and the volume of the capacity of the assenizator machine.
Dimensions
By calculating the volume of the drive, you can calculate the size of the sump. Depth is chosen taking into account the groundwater level, but it should not exceed 3 m. At the same time, the bottom of the pit should be below the depth of soil freezing.
Geometric shapes of the pit can be any: cylinder, cube, parallelepiped, etc.
For a cylinder, the diameter and height are calculated from the formula:
V = h * n * r2.
With a height of septic tank of 3 m and a volume of 10 m3 radius will be equal to 1 m.
For cubic and other forms, the length width and height are determined on the basis of the formula:
V = a * b * h.
With a septic tank height of 3 m, the length and width can be equal to 3 m and 1 m, respectively.
Materials for production
The main requirement for the drive - tightness. It is this condition that must be met to save the environment from polluting substances.
The materials from which the refuse will be made must not only ensure the tightness of the walls, the bottom and all joints, but also be resistant to the action of an aggressive environment. For self-construction using the following structural materials:
- solid concrete;
- finished concrete products (rings, bottom, cover);
- brick.
For the septic tank are also sealed plastic containers made in the factory.
Pit construction
The construction begins with the layout plan of the drive and the sewer network on the surface of the land. From the boundaries of the septic tank must be no less than 2 m in each direction. These will be the boundaries of the pit, taking into account the slope of its walls, so that the soil does not crumble to the bottom. According to the marked scheme begins digging the pit. This process is very laborious and with a large volume it is better to attract small-sized special equipment for digging. The pit will be dug carefully, without unnecessary damage to the site and landscaping elements. Special machinery saves time.
At the bottom of the pit is laid sand cushion thickness of 20-30 cm. Subsequently, waterproofing is placed on it.
When the drive is made of precast concrete elements, they are stacked on top of each other in order: bottom, rings, cover. All joints are sealed with concrete. The whole process can be seen in the presented video:
Making a pit of solid concrete is a more laborious and lengthy process. At the same time, there is no need to attract crane services, which saves the budget.
First you need to pour the concrete bottom. For this purpose, a formwork is constructed around the perimeter of the drive. The fittings or reinforcing mesh are placed on the waterproofing. The mesh cell is 200–200 mm, diameter is 6–8 mm.
There should be a gap of at least 3 cm between the reinforcement and the waterproofing. The second row of the reinforcing mesh should be recessed from the surface at the same distance.
Along the perimeter of the bottom, vertical sections of reinforcement are inserted to connect the bottom with the walls. The thickness of the monolithic bottom should be 20–25 cm. Flooded concrete of M100–150 grade is kept for 14 days, after which you can proceed with the installation of formwork for pouring walls. Since the height of the walls is very large, you can use floating formwork for self-casting when the walls are filled with layers. When pouring walls, it is necessary to provide ducts for the installation of sewer pipes. It is also necessary to install a reinforcing mesh in the formwork at a distance of 3 cm from the outer wall of the formwork. The wall thickness should also be 20–25 cm.
After 2 weeks, install formwork to fill the roof of the drive. When installing the formwork, it is necessary to provide a manhole of sufficient size for dismantling and removing the formwork elements from the pit, as well as free entry into the pit for maintenance, if necessary.
The walls of the drain hole can also be laid out of brick, followed by plaster of the inner wall.
The walls, the bottom, the roof of the septic tank are coated with waterproofing. The most budget option - rubber mastic. It should be borne in mind that a thick layer of mastic when freezing can peel off from the fragile concrete surface.
Backfilling is performed either with sand, to reduce frost heaving of the soil, or with clay, arranging the so-called clay castle.
Service
During operation of the pit, measures should be taken for its maintenance, cleaning and disinfection. For such procedures apply various substances.
To eliminate all kinds of microorganisms and bacteria, special chemistry is used for cesspools. Chemical compounds also eliminate odors, but have a negative effect on the structural elements of the septic tank.
Other principles of influence on sewage have biological products. The pits for cesspools contain a complex of live bacteria and enzymes that contribute to the natural decomposition of waste.
Comfortable and safe living in a private house depends not only on the proper construction of the sump, but also on how often an antiseptic is used for the sump to disinfect and prevent the spread of harmful bio-organisms. If you have a question on the construction of cesspools, then ask them to an expert working on our site.