Comfortable life outside the city on a summer cottage is determined by three communication networks: water supply, sewage and heating. When constructing these systems, you can save money only on sewers, if you select a cesspool as a collection of sewage and sewage. Purely structurally, this is a sealed tank of a certain volume, which is often assembled from ready-made reinforced concrete rings mounted on top of each other. The device of the cesspool of concrete rings must be approached from the position of accurate calculation and competently performed installation.
Features of cesspools
Previously, sewer tanks were made directly in the ground. Therefore, water partially penetrated into it. Today, this cannot be allowed by sanitary standards, because in this way environmental damage is caused. It is necessary to build airtight structures.
A cesspool is not a septic tank. There is no waste disposal in it. Sewage simply accumulates, and then is pumped out and taken away. And this should be done often enough, so the larger the pit volume, the less often it will have to be serviced.
Advantages and disadvantages
The biggest plus is the small budget for the construction. If owners rarely visit the cottage, a cesspool is the best option.
By cons include:
- pumping is a payment for the services of a sewage machine; you can organize an independent export, but this work is dirty and unpleasant;
- very low degree of sewage treatment;
- unpleasant odor, which will need to be disposed of.
The last drawback is easily solved with the help of a ventilation pipe. It is installed in the cover of a concrete structure.
Design and calculations
To properly make a sewer pit out of concrete or plastic rings, you must first draw up a project and accurately calculate the volume of the structure. You need to start with the choice of installation location, which is strictly determined by sanitary standards. SanPiN denotes the minimum distance from the pit to objects located on a suburban area or village:
- to the foundation of the house - 5 m;
- to a drinking well or well - 50 m;
- to open reservoirs - 30 m;
- to green spaces - 3 m;
- to the carriageway - 5 m.
It is important to ensure the convenience of the access of the sewage machine, therefore, a path is made to the cesspool or a well is built near the fence bordering the village road.
Volume calculation
The calculation is based on two indicators:
- daily water consumption per person, which is equal to 200 liters or 0.2 m³;
- the number of people permanently living in the country.
For example, if 4 people live in a house, in one day it will merge into a sewer tank: 0.2x4 = 0.8 m³ of sewage. Given that the sewage machine will arrive on certain days, the figure obtained must be additionally multiplied by the number of days. If pumping is carried out once a week, the volume of the tank will be equal to: 0.8x7 = 5.6 m³.
Based on these values, reinforced concrete rings are selected for septic tanks and cesspools. They are presented on the market in a large diameter standard size with a standard product height of 50 or 90 cm. The diameter varies in the range of 1-2 m. The most popular type that all plants produce is: height 0.9 m, diameter 1 m. Its internal volume is 0.71 m³.
To withstand an indicator of 5.6 m³, 8 rings will be required, which is very inconvenient because they will have to be buried to great depths.For such a volume, it is better to choose concrete products with a diameter of 2 m, in which the capacity is 2.83 m³. That is, only 2 rings are required.
Cesspool construction technology
The whole process of constructing a cesspool is divided into two stages.
Earthwork and pit preparation
You can dig a pit manually or use the services of an excavator. The second way is quick but expensive. The pit in diameter must be larger than the width of the rings by 30-50 cm at least on each side. The bottom of the structure is leveled and covered with a layer of rubble and sand with a thickness of 30-60 cm. The laid material is leveled and compacted.
Installation of reinforced concrete rings
Since the cesspool is an airtight structure, a solid and even foundation must be installed at the bottom of the excavated pit. There are two options:
- pour the bottom with concrete mortar, having previously laid the reinforcing frame of steel reinforcement;
- purchase a ready-made bottom at a reinforced concrete plant for the dimensions of reinforced concrete rings.
The second option is easier in terms of installation and the speed of installation operations. But, as in the case of concrete rings, the bottom will have to be installed in the well with a crane. The main task is to set it exactly horizontally.
All concrete parts (rings, bottom and top cover) have connecting grooves that ensure a tight fit of the products to each other and form a tight lock through which water can not leak. However, in any case, the connection must be sealed separately. For this, different materials are used. The most effective is a rubber band, which is placed in the connecting lock between the two elements of the well. There are other options:
- hydraulic seals that expand when solidified, filling the grooves of the connecting lock;
- special solutions that are applied inside and outside the concrete structure at the joints;
- cement slurry with the addition of water glass;
- all kinds of water-based sealants;
- jute, hemp or linen cords impregnated with fibroresin.
Installation of the cesspool is completed when a cover with a hole for the hatch is installed on the last concrete ring. It is also a ready-made reinforced concrete product manufactured at the precast concrete plant.
In the upper ring, you need to make a hole for the sewer pipe. To do this, the pipe circuit from the house to the pit is pre-assembled. A trench is dug up, where plastic pipes are laid at an angle of 2-3 °, since the sewage system in the country is a gravity-free system. The latter must be insulated. The failed circuit determines the location of the hole in the sewer well, which must be made a perforator. The most important thing is that the pipe inlet must be sealed with cement-sand mortar.
Rules of operation and maintenance
The most important thing is to pump out accumulated sewage in time. The second rule of operation is to ensure that unpleasant odors do not spread throughout the suburban area, so the cesspool must be equipped with ventilation. This is an ordinary plastic pipe, which is cut into the cover of the structure.
Manufacturers of reinforced concrete products offer two varieties of caps: with and without ventilation holes. If the second option was purchased, you will have to make a hole with a puncher exactly under the diameter of the installed pipe. The length of the latter is not less than 3 m.
Concrete Ring Prices for Cesspools
The cost of concrete rings varies by region. The table shows the averaged values.
| Model | Diameter m | Height, m | price, rub. |
| KC10-9 | 1 | 0,9 | 1500 |
| KS12-10 | 1,2 | 1 | 2500 |
| KC15-9 | 1,5 | 0,9 | 2600 |
| KS20-9 | 2 | 0,9 | 5000 |
The prices of plastic rings for cesspools are much lower. These products are gradually gaining popularity, but the bulk of the owners of suburban real estate use concrete parts.
