Construction of a cesspool: rules of organization and waterproofing
The lack of a centralized sewage system causes installation of various types of local treatment facilities in suburban areas. But sometimes instead of an expensive autonomous structure, installing a simple rake is sufficient.
Let's try to figure out how the arrangement of the cesspool and what its types are suitable for self-construction.
Types of modern cesspools
Today, the functional load of the drain hole has increased significantly, since the presence of domestic sewage and elementary cold water supply system increases the volume of wastewater several times.
In this regard, new modifications of sewers, more voluminous and improved in terms of waste management, have appeared.
Remember how the drain hole used to look like - a small well, into which all the waste was methodically drained until it was completely filled. The walls of the well were lined with boards, laid out with stones or reinforced with other material at hand. When the level of the effluent became maximum, they called an aspension machine for pumping.
Of course, there was no talk of any ecology or protection of the environment from pollution at that time. But today everyone wants to preserve the purity of the soil on the site, so they strictly monitor the sealing of sewage treatment plants. Manufacturers choose materials that do not require long-term installation or special waterproofing. An example of modern models are bulk polymer tanks.
Monolithic one- and two-section structures made of concrete, as well as installations of one, two or even three concrete wells, have not lost their popularity.The choice is explained by the relative ease of installation (pouring) and decent (up to 30 years) service life.
The idea of laying out a brick with a brick has disappeared, because installing several rings is much easier than creating solid brickwork. The main quality of new devices is tightness, which protects the soil from pollution by runoff.
At the device of a new cesspool it is necessary to be guided by the requirements stated in Construction Norms and Regulations. Of course, for ease of use, I would like to place it closer to the house, but the distance from the foundation to the tank should be at least 10 m (take into account force majeure circumstances related to the violation of tightness of the foundation and storage tank).
When planning, also note that the fence delineating the boundaries of the site should be no closer than 4 m, and the roadway should be no closer than 5 m. The largest interval - to the water source (well or well) - at least 25 m, with loose sandy soil - up to 50 m. If there is a pond with stagnant water nearby (a pond or lake), then it must be taken into account - 30 m.
Concrete rings - the current type of material
Concrete rings for the construction of drinking wells and septic tanks are so in demand that many factories began to specialize in their production. Moreover, in addition to the main parts, they make rings equipped with a bottom, separate necks, ceilings and upper segments with a hatch. Consider two options for the construction of cesspools, with and without bottom.
An open tank without a bottom, in other words, an absorbing well is a combined version, resembling a conventional accumulation tank, but acting on the principle of a septic tank filter element.
There are conditions under which the construction of a structure with an “open” bottom should be avoided:
- the groundwater level must be at least 100 cm below the base of the sewer well, otherwise the waste liquid will mix with the underground water horizons, which will cause soil contamination with harmful substances;
- soil type must meet the requirements of filtration, that is, be permeable: sandy, gravel or pebble with a high content of sand. Rocks, loams and clays do not have similar properties and can eventually become an insurmountable barrier to runoff.
Subject to the conditions, you can build a well yourself.
- digging a trench to a depth equal to the total height of the rings (2 or 3) plus half a meter on the drainage layer and 20-30 cm on the arrangement of the neck;
- laying a two-layer filtering base of bulk materials - sand, pebbles, rubble, gravel (for example, the bottom layer is sand,upper - large crushed stone); perforated concrete base or geotextiles can be used for cleaning efficiency;
- mounting rings with a crane; the connection of the sewer pipe in the hole previously made by the perforator;
- waterproofing of a well - seal of seams, joints, connections;
Particular attention should be paid to cesspool waterproofing. Fixing the pipe is best done using a tee, followed by sealing all connections with a sealant.
Even when using concrete locking rings, they must be sealed from the inside and outside. From the outside, you can use the pasting bitumen roll material, which fits into several layers, from the inside - a combination of Penetron and Penekrit or cement mortar Aquabarrier.
To ensure the pumping process, in the upper part it is necessary to equip the hatch with a tight-fitting, insulated lid.
Storage tank of rings
The high level of groundwater (a fairly frequent phenomenon) does not allow the installation of sewage wells without a bottom, so the most successful option would be a simple storage tank. You can use a plastic tank or a large polymer barrel, but we consider a project of concrete rings.
Conveniently, almost all parts can be purchased in finished form. The cost of one well ring with a diameter of 110 cm (wall thickness - 16 cm, height - 89 cm) - from 1,500 to 2,000 rubles., 6-centimeter dobor - 250-300 rubles. etc., therefore, the whole structure in an amount not exceeding 10 000 rubles.
- the device of a ditch (on 50-80 cm wider than a well) with simultaneous laying of trenches under sewer pipes;
- installation and insulation of the pipeline;
- backfilling and tamping of a sand-crushed pillow (30-40 cm thick);
- installation of the concrete bottom (strictly horizontal, with level check); instead of the finished element, you can build reinforced screed;
- installation of main parts;
- waterproofing of joints with a rubber tape, concrete solution with the addition of liquid glass;
- plastering of internal joints with bitumen mastic; external plastering with bitumen waterproofing;
- mounting the top plate with a hole for the hatch, fixing the cover.
One of the products of bacterial waste processing is hazardous methane gas. To prevent its concentration, and at the same time to provide air access to the drains, the well is equipped with a ventilation pipe.
Budget version of rubber tires
The advantages of this project are the availability, cost-effectiveness, ease of installation, the downsides are fragility, lack of good sealing, “disposability” of the structure. It is impossible to repair or modify the installed structure.
The first stage is excavation and pit construction. The depth can be calculated by knowing the number of tires, width - putting one product on the ground and drawing a circle around it, adding 30-40 cm. When the foundation pit is ready, you need to make a drainage hole. It is drilled in the center of the pit with a drill.
A pipe is inserted into the hole so that it rises about 100-120 cm above the base. The meter stock protects the drainage drain from clogging with large solid particles that accumulate at the bottom. In order for the liquid to flow freely into the outlet, its sides are additionally perforated, and the upper end is covered with a protective net. The bottom around the pipe is covered with gravel or rubble.
Tires stack one on another, promazyvaya joints sealant.Approximately in 2 or 3 tires, a hole is cut out from above and the end of the sewer pipe leading from the house is inserted; the junction is also carefully sealed. From above, the construction is closed with a self-made plastic or wood cover with a small notch (diameter = 10 cm) for the ventilation pipe.
Installation of plastic containers
The main advantage of installing a polymer tank is the lack of additional construction measures. It is enough to dig a ditch, connect sewer communications, bury - and the cesspool is ready. Transporting plastic containers is also easy, since, unlike concrete structures, it has a low weight.
A metal barrel will do as well, but it is inferior in its characteristics, as it is susceptible to corrosion, therefore, it will quickly rust and fail.
Before installing the container in the pit, you need to prepare - to make a perforation over the entire surface. For this electric drill we drill holes in a staggered manner, the interval between the holes is 15-20 cm. Perforation is necessary for the device to drain the liquid naturally, this is a kind of filter.
In the upper part or on the side (depending on the sum of the sewer pipe) we cut a hole and install a flange. Special polymer sealants thoroughly coat all joints and joints. You can use bitumen mastic, which plays the role of additional waterproofing. It is desirable that the pipes and fittings were also made of plastic.
To protect the container from the ingress of soil particles, we use geotextiles. It perfectly copes with the function of filtering, does not give in to rotting and fast wear. We wrap the tank on all sides with rolled geotextile, fasten it to the neck with a synthetic cord.
We install the barrel in the prepared pit, attach it to the communications. The slope of the pipes allows the drains to flow naturally into the reservoir.Free space on the sides we fall asleep sand-gravel mixture, sprinkle the top with soil. Cleaning the mini-septic tank should be done, focusing on the degree of filling.
The installation process of the storage tank for full pumping out of waste looks a bit different. It involves immersion in the ground absolutely sealed containers, which are used for the accumulation of brown and mixed masses. As it accumulates, equal to about a third of the volume, it causes a vacuum truck to empty the drive.
Concrete pit construction
Not always ready containers fit in shape or size, besides the cost of high-quality volumetric septic tanks does not suit everyone, so this way of constructing a cesspool, such as building a monolithic single or two-chamber concrete tank, is still practiced.Let's get acquainted with the instructions for its manufacture.
How to dig a pit
During construction, one may not be limited to a single-chamber construction, since there will be no fundamental difference or additional complexity during the construction of the second compartment. We'll have to dig a pit twice as large and prepare more building material for formwork and pouring. The first section of the septic tank is designed to lighten the effluent, the second - to filter.
The first stage is the digging of a pit of required size. There are two options for excavation - manually or with the help of construction equipment. The first method is long, but more accurate, the second is fast, but costly and not quite suitable for the subsequent formwork. The fact is that in order to support wooden shields, the smooth edges of the pit are needed. If the soil is solid enough, stable, then the formwork can be made one-sided.
The second chamber is a septic tank - filtering, therefore, part of the pit must be deepened and equipped with a sand-gravel pad with a thickness of about 30 cm. The walls should be leveled, but if the soil is loose, you will have to build a two-sided construction, as if it were a foundation.
Construction of wooden formwork
To the underground wet environment minimally affected the concrete structure, before installing the formwork the pit is covered with rolled geotextile. The canvas is positioned so that the movement of fluid was directed toward the soil. Separate the pieces must be fastened, and the edges should protrude outward about 40 cm.
From the outside, we install a metal frame: steel rods, thick wire, mesh from old beds are suitable for reinforcement. Metal parts can be replaced with fiberglass.When filling, it is necessary to ensure that the solution completely covers the iron elements, otherwise corrosion will cause the formation of cracks.
Panels and boards themselves will not hold, therefore, to fix them, you should build struts from bars or metal pieces. At the junction of pipes, you must pre-make mortgages. The distance from the formwork to the wall of the pit is about 20-25 cm (future wall thickness of the septic tank) If the design is two-sided, then this distance is maintained between the two walls along the entire perimeter.
Concrete pouring and waterproofing
We prepare the solution according to the following scheme: for every 200 kg of cement - 300 kg of sand, 100 liters of water, 2.5 liters of superplasticizer (in liquid form). If you need a filler - add a small amount of crushed stone fine fraction.
Concrete is never poured over the entire volume. If you want the structure to be solid and serve for years, fill it with layers, each of which is no thicker than 40-50 cm. Otherwise, voids are formed in the material, which will cause the structure to collapse soon.To make the mass more dense, use a vibrator.
Experts recommend equipping overflow tee, which will reduce the risk of blockage and prevent the ingress of large particles in the second filtration compartment.
In the course of solidification of the concrete mass will appear small cracks that need to be covered with the same solution. After complete drying, you can increase the tightness of the chambers and make additional internal waterproofing.
The last stage of concreting - the device upper overlap. It is set after complete drying of the walls (a period from 10 days to 2 weeks is required).
- installation of a metal profile - corners;
- laying of the basis - flat slate or wooden boards;
- flooring of ruberoid with the subsequent reinforcement;
- concrete pouring.
Do not forget that you need 2 holes for hatches (according to the number of cameras).
Backfilling and exterior design
Before backfilling we produce waterproofing - we apply on all concrete surfaces, internal and external, a layer of bitumen mastic. It will protect the concrete from moisture penetration and rapid destruction.
Additional thermal insulation is required in the northern regions. To insulate the chambers from the outside along the walls we place the pieces of foam, then fill the remaining space with soil.
Do not forget about the ventilation pipe. For its output we arrange a separate hole or we equip the hatch. A more efficient operation of the septic tank is provided by a set of two pipes, one of which injects fresh air, and the second serves to remove accumulated gases. Pipes should rise 40-60 cm above the ground.
Conclusions and useful video on the topic
Educational videos are a great opportunity to supplement your knowledge with interesting and useful information.
Practical advice - stages of the device of a cesspool:
Compact do-it-yourself tire septic tank:
Monolithic concrete pit - video tutorial and overview:
As you can see, it is quite easy to make a cumulative tank or a simple sewage treatment plant on your own;However, do not forget that consultation with an expert in the field of sewage systems will increase the chances of creating the most functional and efficient construction.