Ground water septic tank. Septic tank for a high level of groundwater: how to choose and install on the site. Necessary tools and materials

The high level of groundwater is a factor that is a stumbling block for many owners of suburban areas. It complicates not only the process of erecting buildings, but also the arrangement of an autonomous sewer. After all, the treated wastewater will not be able to leave the septic tank in the already moisture-saturated soil. Consider which version of a septic tank for groundwater is better to choose in order to permanently solve the problem, and how to build a treatment structure with your own hands.

A site in a swampy area makes its own adjustments when arranging a septic tank for autonomous sewage

When arranging a septic tank on a site with high groundwater, the owners face the following problems:

The complexity of installation. Regardless of the type of treatment system chosen, it takes a lot of effort and time to install it.
Sump rise. If the installation technology is not followed with the obligatory stage of arranging the concrete “cushion” and the tank is not properly secured with cables and belts, it is not uncommon for groundwater flows to push the septic tank out of the ground, thereby violating the integrity of the sewer structure.
Water seepage. Such a fate befell septic tanks, in which insufficient attention was paid to waterproofing. In this case, you have to resort to the services of sewers much more often.
Ground water pollution. Through the bottom and walls of leaky structures, sewage seeps into the soil, polluting groundwater and making it unsuitable for consumption.

Important! A prerequisite for the arrangement of a septic tank for groundwater is the tightness of the structure. Otherwise, you risk not only the contents of your wallet, but the health of your loved ones.

The easiest way to determine the groundwater level of an area is to ask your neighbors what the situation is in their areas.

The measurement of water in a nearby well will help to finally clarify the situation.

The groundwater level is measured during the off-season, when the snow melts or during the period after heavy rains. To do this, with the help of a garden drill, several holes are drilled in the area. The distance from the surface of the earth to the “smooth surface” of groundwater is taken into account.

Solutions to the problem

Structures made of brick or concrete rings are not able to provide the necessary tightness. Therefore, such options should be rejected at the design stage of the structure.

Industrial septic tanks

The range of storage tanks on the market for arranging autonomous sewage is quite wide, starting with compact tanks for small country houses and ending with multi-chamber installations for large modern cottages. The choice is limited only by the needs of the customer.

The easiest option for arranging a septic tank for a high level of groundwater is to install an industrial tank

For example, a three-chamber septic tank is a container made of plastic, divided into three chambers: the first acts as a sump, the second and third carry out post-treatment of wastewater. The function of filtering wells, which ensure the rapid absorption of the treated liquid into the soil, is performed by infiltrators.

Attention! When determining the required volume of the reservoir, they are guided by the fact that it must contain a three-day "dose" of water consumption by all households.

On average, the daily consumption of water for a family of three for household and hygiene needs is 600 liters. Therefore, the volume of the autonomous sewage storage tank should be 600 liters x 3 days = 1.8 cubic meters. To the obtained value, experts recommend adding another 20% in reserve.

In addition to the final tank, the sewer structure may include a filter well.

The filter well is a separately located reservoir, through the walls and bottom of which the purified liquid enters the soil

The only drawback of industrial septic tanks is their high cost. With a limited budget, many owners solve the problem by arranging a septic tank from eurocubes and plastic containers.

Plastic eurocubes

Owners of summer cottages intended for seasonal stay solve the problem by installing storage tanks. The use of a plastic eurocube allows you to save not only on the cost of equipment, but also on its installation. Ground installation is also possible, but in this case, the storage tank will take up a lot of space on the site. Yes, and to pump out the contents, you will have to regularly resort to the services of sewers.

Three cubic euros of a cube with rare visits to a summer cottage is more than enough for one season

A septic tank, built with your own hands from Eurocubes, works on the principle of tightness. All the chambers of the device, except for the final chamber, do not allow either runoff to the outside or groundwater to enter the tanks. As the sealed tank is filled, it is pumped out, involving special equipment for this.

Monolithic concrete structures

If industrial solutions to the problem do not suit you for a number of reasons, you can resort to the option of arranging a monolithic reinforced concrete structure. It includes three compartments. The first is a sealed tank in which solid waste and light suspensions are mechanically separated. From it, the liquid enters the second sealed container, where it is released from organic compounds by anaerobic fermentation. Getting into the third section, the liquid is finally filtered and clarified. At the final stage, a submersible pump comes into operation, which raises the treated effluents into the infiltration tunnel. From it, the liquid is discharged into the soil.

The absence of seams in the concrete structure guarantees the tightness of the autonomous sewer

The main difference between such a septic tank and the traditional version of the treatment plant is infiltration tunnels. They are placed directly above the groundwater level, and thanks to the laws of physics, the purified liquid is simply "pulled out" from the well into the "underground".

The diameter of such tunnels is only 150 mm, due to which they can be safely placed in the construction of sewers, even if there is a high occurrence of groundwater. But when arranging shallow infiltration tunnels, in order to prevent freezing and ensure the smooth operation of the structure, it is important to provide thermal insulation for the structure. To do this, a small earthen mound is poured over the underground structure.

The slide simultaneously performs two tasks: it acts as a heater and hides the tunnel from prying eyes. To make the mound more presentable, it is often decorated as a rockery or rock garden.

Technology for arranging a treatment facility

For the construction of a septic tank, the following materials and tools will be required:

concrete grade B15 and above;
crushed stone and river sand;
superplasticizer;
reinforcing bars D 10 mm;
infiltration element;
sheets of slate or corrugated board;
pipes with a diameter of 100-150 mm;
film for waterproofing;
boards for the construction of formwork;
metal corners for overlapping;
container for mixing the solution.

The volume of materials for cement mortar is calculated on the basis that 400 kg of cement, 600 kg of sand, 1200 kg of crushed stone and 200 liters of water will be required per 1 cubic meter of the finished mixture. To increase the waterproofing properties of concrete, it is desirable to supplement the solution with a hydrophobic additive.

The connection of infiltration tunnels with a septic tank is carried out by means of a submersible pump. The float mechanism included in the package, which reacts to the liquid level, as the well is empty and filled, will turn off and start the pump.

Digging a pit

Having decided on the dimensions of the sewer wells, they begin earthworks. Digging a pit can be done manually or using small-scale mechanization.

Tip: to simplify your task, it is better to choose a dry period for construction, when the groundwater level is not so high.

Pulling out the pit to the required depth, leveling and cleaning the walls

You can make one large pit, inside which all the sewer wells will fit, or dig two separate pits, placing them at a distance of 2 meters from each other.

Construction of the base and walls

Before proceeding with the construction of walls, the waterproofing of the pit is performed. To do this, the walls of the dug pit are covered with a dense film, placing the cuts of the material so that its edges protrude 20-30 cm above the sides of the pit.

When erecting a concrete septic tank, the thickness of the walls of the tanks should be 20 cm, and the thickness of the inner walls between the chambers should be 15 cm

The construction of a reinforced concrete septic tank is carried out in the following sequence:

The bottom of the pit is covered with sand, forming a layer 30 cm thick.
A mesh is laid out from the reinforcing bars, the size of the sections of which is 20x20 cm.
The reinforced bottom is poured with concrete so that the solution covers the mesh by 3-5 cm.
After 15-20 days, when the concrete acquires the necessary strength, they begin to reinforce the walls.
A “sliding” formwork is assembled from edged boards. The solution is poured in layers, each time forming a wall 40-50 cm high. When the cement hardens, the formwork is shifted higher and the procedure is repeated.
When the upper level of the walls hardens, the formwork is removed and the walls are inspected. If small cracks are found, they must be sealed.
Depending on the number of tanks, one or two partitions are constructed. They are erected by arranging double-sided formwork, followed by filling the cavities with cement mortar.
Cover arrangement. Metal corners are laid out on the walls of the structure, on top of which a plank floor is laid. When laying boards, be sure to leave a hole for mounting an inspection hatch and ventilation pipes. The future slab is reinforced with metal rods and poured with mortar.

Attention! When building a two-chamber septic tank, the size of the first tank should be 75% of the total volume. When constructing a three-chamber model, the tanks are divided so that the first chamber occupies half of the total volume, and the second and third compartments - 25%.

If you plan to install a ready-made branded septic tank, you need to take care of fixing the tank. To do this, the bottom of the pit is concreted, constructing a monolithic pillow to fix the structure.

The tank is fixed to the concrete screed by means of a cable and straps.

The concrete screed will not only act as a support for fixing the tank, but also minimize the risk of subsidence of the soil under the weight of the filled cube.

Construction assembly

When installing a septic tank from sealed containers, holes for pipes are made in the walls of the cubes. The height of the holes is determined based on the fact that the effluents freed from heavy particles from the first section through the connecting pipe enter the second chamber. The hole for the pipe in the first chamber is placed at a height of half a meter from the bottom of the tank, in the second - at a level of 15-20 cm. A pump with a float switch is installed in the third compartment, which acts as a filter block.

Important! The inner walls of the overflow holes installed between the chambers must be treated with coating waterproofing.

Both chambers are equipped with ventilation pipes, the upper ends of which rise above the ground at a height of 1.5-2 meters

The ventilation pipe in the first chamber should be 10-15 cm higher than the connecting pipe. This solution makes it possible to use the ventilation hole not only to remove harmful fumes, but also to pump out sewage with special equipment. In the second chamber, the ventilation pipe is deepened so that its lower edge is located 10-15 cm above the drainage pipes.

Having assembled the structure and checked the connecting elements, it remains only to finally fix the container. To protect the cubes from soil pressure on them, the walls of the tanks are lined with sheets of slate or corrugated board from the outside. The voids between the walls of the pit are filled with earth and rammed.

Important! Please note that plastic is sensitive to low temperatures. When operating a septic tank in a cold, harsh climate, it is necessary to provide thermal insulation.

Construction of an infiltration tunnel

The construction of the infiltration tunnel is under way. For its arrangement, next to the wells, they additionally dig a pit half a meter deep. Having laid an infiltration cassette in it, the structure is sprinkled with gravel and sand.

The infiltration cassette is an elongated plastic container, the walls of which have the smallest holes.

Through the holes in the walls of the infiltrated tunnel, the liquid seeps into the soil

Tip: if the groundwater is located very close to the surface, the bottom of the pit must first be lined with a layer of sand, then a crushed stone “cushion” 20-30 cm thick should be built, and only after that the infiltration cassette should be laid. Such a three-layer structure can only be covered with earth, having built a small mound.

Recommendations for a septic tank for high groundwater

When arranging a treatment plant, it is necessary to ensure the natural movement of wastewater through the pipeline. To do this, the height of the overflow and the slope of the pipeline towards the final chamber must be maintained. As an option: the second tank is installed 25-40 cm below the first.

To connect the septic tank to the infiltration compartment, a submersible pump is installed in the last compartment. To connect the pump, it is necessary to think over the mechanism for attaching the device in advance and provide for the laying of electrical wiring.

In case of unforeseen situations in which there is a high probability of overflowing the well, experienced owners recommend installing not one pump, but two. At the same time, the floats of the devices are set at different levels so that if the first pump fails, the second one automatically starts.

Video: how septic tanks and VOCs behave in high groundwater conditions

With strict observance of the installation technology, you will receive a septic tank that will serve properly for decades, even in areas with moisture-saturated soils. Expert advice will help you avoid mistakes.

Septic tanks for summer cottages with a high level of groundwater - we make a choice

One of the factors influencing the choice of a septic tank and the features of its installation is such a geological characteristic of the site as the groundwater level. In many territories of Russia, this mark is less than a meter from the surface of the earth, which complicates the local sewerage equipment or renders it unusable.

What are the difficulties associated with high GWL?

Problems with a closely spaced primer can arise both during the installation phase and during the operation of the wastewater disposal system.

1. Almost 90% of the installation of a septic tank is associated with digging and preparing the pit, as well as backfilling. Working while standing in the water is quite difficult and uncomfortable.

2. Difficulties arise with the arrangement of soil post-treatment. The way out is to build a filter layer above the ground. However, such designs will not work without the use of forced pumping of wastewater from the septic tank.

3. With a high GWL, it is difficult to install concrete rings, which are one of the most common materials for arranging local sewage. Prefabricated concrete septic tanks often lose their tightness, and in high primer conditions this will lead not only to environmental pollution, but also to groundwater infiltration into the reservoir. As a result, you will have to call the sewer machine more often to empty the drive, or the settling process in the septic tank that cleans the drains will be disrupted.

Note! Do not underestimate the flooding of the septic tank, since the water, along with the drains, will eventually be forced back into the external pipeline and even the house sewer.

4. Plastic containers are light in weight, so they can float under the action of groundwater. This often leads to a rupture of the sewer line. Prevention of ascent - installation of the container on a concrete base and fastening to it.

To avoid difficulties, reduce them, or at least mentally prepare for them, you need to find out in advance at what depth the groundwater passes, and then install.

How to determine the level of passage of the primer?

The maximum soil moisture occurs during the period of autumn rains or snowmelt. For this reason, it is worth finding out the depth of the primer in spring or autumn. In most cases, reconnaissance is carried out even at the stage of building a house, but this can also be done after the house is inhabited.

There are several methods.

The easiest way is to look into the well, which is located on the site and is fed by groundwater. The distance to the water surface from the surface of the earth is the desired depth.
Vegetation can be appreciated. If moisture-loving representatives of the flora grow on the site, for example, horsetail, alder, this is an indicator of soil watering.
The most accurate method is to drill several observation wells at least 150 cm deep.
You can also ask neighbors.

It is recommended to resort to several methods, which will increase the accuracy of the determination. If exploration has shown that waters rise close to the surface of the earth at least seasonally, then several rules must be observed to equip a waste disposal station.

Features of the construction of local sewerage at high GWL

The simplest option for arranging a waste disposal system is to install a storage tank that is not buried in the ground, which will additionally save effort, time and materials. But such a tank will take up a lot of precious space and is only suitable for small country houses in which no more than 3 people live and some sanitary equipment is installed. Otherwise, you can go broke on the calls of the sewage machine.

For large houses, the drive is not suitable, so you will need to install a soil treatment plant or a wastewater biotreatment station.

The arrangement of such systems on watered soil has its own characteristics at each of the stages:

First you need to decide on the material. It is not recommended to build a prefabricated tank, consisting, for example, of concrete rings, since the seams are prone to loss of tightness. It is best to use plastic containers.

plastic septic tank

You can buy both ready-made tanks, and use, for example, used eurocubes.

A number of rules must also be observed when organizing the evacuation of wastewater from a septic tank.

Often, the presence of such a large list of rules and subtleties when installing a septic tank in areas with a high groundwater level makes the owners refuse to install it themselves, turning to professionals. This is the right decision that can save you from unnecessary expenses and work. So, if the septic tank has already surfaced, you will have to pump out effluent from it, dismantle it, flush the tank and reinstall it.

Topas septic tank prices

septic tank Topas

DKS septic tanks for soils with high GWL

Topas - septic tank with aerobic cleaning

The optimal season for determining the level of groundwater is spring or autumn. The snow melts in spring, and the longest torrential rains come in autumn.

Determine the level of groundwater

In order to independently calculate how deep the underground water arteries flow, you must use the following inventory:

garden drill at least 200 cm long;
a long and strong rod (if you can choose, a wood rod is better);
spoon drill with a length of at least 500 cm.

Note. Sometimes, in order to make the most accurate calculations, 2 or more wells may be needed. At the very least, it will be easier to track the approximate level of water lying under the ground.

You can start drilling the well. The water layer closest to the surface is located no deeper than 4-4.5 m. Precipitation and melt water serve to form this layer. It is partially or completely absent in areas with increased levels of drought or prolonged frost.

Due to their proximity to the surface, these waters cannot be called the cleanest. They contain a huge amount of impurities that penetrate the soil along with rainfall. Impurities include not only various kinds of pollution, but also bacteria, which, after entering the human body, can cause gastrointestinal disorders, diarrhea, and so on. Therefore, such waters are used exclusively for irrigation.

But groundwater is located much lower: on average, at least 8-9 m from the soil surface. Therefore, the further the site is located from a natural source of water, the deeper you have to drill.

After the wells are drilled, they are left for at least 24 hours. This is necessary in order for liquid to enter the well, after a lapse of time the level of which is measured using a wood rod. You can use iron or aluminum, but this is not very convenient, because:

First, because when wet, iron does not change color, as happens with a wooden rod;
Secondly, iron is, in principle, heavier than wood, and therefore, depending on the initial length of the rod, it will be extremely difficult to manipulate it.

In order to calculate the approximate location of groundwater from the surface, you can use the signs of our ancestors. For example, if lingonberries with blackberries went into dense growth, it means that an underground water artery flows near the surface - no deeper than 70-80 cm. While for a cherry, apricot or cherry plum tree, an average depth of 150-160 cm will be optimal.

How septic tanks work

There are a number of models of septic tanks for a private house, which differ depending on certain modifications.

Accumulative septic tanks: the principle of operation

Accumulative septic tanks are divided into:

concrete;
metal;
polyethylene;
made from fiberglass.

Such systems are convenient for location in small areas where the runoff volume of underground flows does not exceed the “below average” bar. The septic tank collects waste water and is pumped out using a sewage truck. On average, the number of pumpings does not exceed 3-4 times a year. But depending on the relief and certain geographical features, the number of requests for sewage services may increase or decrease by the nth number of times.

If the ground flow is strong enough, then using a septic tank with a sufficiently low weight (polyethylene or made of fiberglass) is not recommended. The reason is simple - such devices will simply be pushed out of the soil over time, even weighting agents laid on top of the accumulative apparatus will not be able to hold.

However, if the groundwater level is high with a low flow force, it is better to use a polyethylene septic tank. This choice of a septic tank will solve a lot of problems with its transportation and subsequent installation, unlike concrete or metal. These two options, including a high water concrete septic tank, although heavy enough, are able to withstand the strong flows of groundwater arteries.

Note. Polyethylene septic tanks are the most hermetic and can live a significantly longer operating life, unlike summer cottages made of concrete or metal.

Given the strict law on sanitary standards for the arrangement of cesspools, there can be no better alternative than storage septic tanks for summer cottages with a high level of groundwater. Thus, in a site where groundwater is high enough to the surface of the earth, a storage septic tank with a high level of groundwater will be the best solution.

Septic tanks with mandatory filter fields

Such models with filtration of sewage for a high level of groundwater are especially relevant for summer cottages. It is they who carry out water purification and are a key link in the sewerage system. The filtration field is a layered structure of sand cushion, crushed stone and irrigation pipes. In addition, it is easy to do it yourself even for a reinforced concrete structure made of rings.

The area of the filtering field is easy to determine, it is enough to know the following indicators:

the exact area of the land plot where it is planned to install a septic tank for a summer residence with a high level of ground flows;
how much water is filtered daily, weekly, quarterly and annually;
in what seasons do large volume flows of liquid arrive;
in what seasons do the minimum volumes of fluid flow enter;
which septic tank in terms of capacity: the volume of the tank (rings or plastic - for each system, the tank parameter is required).

DIY filter field

How to make a septic tank if groundwater is close? Due to the large volume of work, special equipment will be required to set up a filtering field, because manually digging trenches of the order of 20-25 meters and a depth of at least 1 meter is almost impossible.

It is necessary to determine the place for future installation. The minimum distance that must be retreated from any structures and natural wells is about 14-16 meters;
Based on the area of the site and the area on which it will be possible to turn around, the area under the filtration field is calculated, the minimum area of which should not be less than 15 square meters. For a more accurate calculation, it is recommended to contact specialists;
Next, you need to dig trenches. A prerequisite for the compliance of average indicators:

depth not less than 1 meter;
the width of each strip is at least half a meter.

Important! If a depth of less than 1 meter is taken, then it will be necessary to increase the cost of insulating the filter field in the winter.

The first layer is a sand cushion, at least 30 cm thick;
The next layer, which fills the trench, is made of gravel, also at least 30 cm thick. The thicker the filtration layer, the cleaner the water will flow;
A pipe is laid on top of the gravel - a drain;
The final layer is crushed stone, at least 10-15 cm;
The whole system is covered with a geotextile film, which will help to ensure that the autonomous cleaning system does not freeze in especially severe frosts.

Note. The use of a geotextile film will also help to avoid silting, which will significantly extend the operational life of the Tank septic tank installation.

Aerobic septic tanks: which one is better

The question "Which is better to choose an aerobic cleaning system in a private house?" every second owner of suburban housing is asked, whether it is temporary or permanent housing. An aerobic septic tank for high groundwater guarantees a high percentage of cleaning - at least 98%. Such a system will ideally fit into the everyday life of home ownership, where previously there was no permanent sewage system, and you don’t want to lose the quality of life.

Of course, if you use a septic tank with high groundwater, you will have to ensure its long service life. But usually several pumpings of the septic tank are enough at a high level of flows by a sewage machine per year (depending on the number of regular users).

The septic tank device belongs to eco-friendly models. Septic tanks for summer cottages with a high level of groundwater are relevant for owners of suburban real estate, who spend most of their time outside the city and rarely use autonomous sewage with an aerobic purification method.

Disadvantages of the model:

Most models are directly dependent on electricity, therefore, not everywhere it is possible to use such an installation;
If the system fails, costly repairs to the installed device will be required;
The high cost of parts (in case of failure due to power outages, it does not pay off, despite the almost 100% cleanliness of the liquid streams).

Advantages of the cleaning system:

Installing a septic tank implies almost silent operation of the device (which cannot be said about other models);
Deep cleaning of the soil;
The ability to use purified water in domestic conditions (98% - an indicator comparable to the level of purification of running water);
If there are no power outages, a septic tank with a high GWL is able to work for about 5 years without any human intervention, including pumping out with a sewer;
The system is installed in any soil, it is not pretentious, moreover, it is quite tight and durable.

TOP 6 models 2016-2017

Official dealer in Russia ECO-DACHA (septic tank in the area with a high level of groundwater Topas);
Manufacturer of treatment facilities Eco-Grand (a septic tank for summer cottages with a high level of soil brand "Poplar").

Moscow manufacturer "Bioxi" - installation of a septic tank of this brand will not take long due to the lightness of the plastic construction;
Triton-Plastic LLC is a world-famous manufacturer, the Tank septic tank is the best among autonomous stations, after which a septic tank made of concrete rings at a high groundwater level looks less effective.

According to Internet research and user surveys, DKS-Optimum occupies a leading position among inexpensive devices with a high level of pollution removal;
The installed septic tank for high groundwater brand Elgad for a large number of users is in the best demand, unlike other analogues in this price category.

The rating was compiled according to the number of search queries, as well as according to Internet surveys of users of autonomous sewers, for summer cottages and private houses with the inability to connect to the central sewer. In most of the leading positions, models of famous brands with a small volume of the tank, as well as with additional filtration for the possibility of further use of purified water in the domestic environment.

For example, Elgad S 1400 is in great demand among summer residents with a small plot, while the energy-dependent septic tank that won the majority of votes in its category ECO-Grand 15 has a six-cubic capacity and good performance (about 2 cubic meters per day a good system can process, which is especially true for a large site with more than 7-9 regular users).

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Owners of suburban areas with high groundwater usually experience difficulties with the arrangement of autonomous sewage and drains. In wetlands, cesspools quickly fill with sewage, and the cost of sewer maintenance becomes quite high. But it is possible to arrange an effective septic tank with a high level of groundwater if the owner of the site is ready to increase the volume of construction and incur additional costs for the purchase of a finished installation. The investment of additional funds will subsequently pay off with the impeccable operation of the sewerage system and the absence of problems with its maintenance.

A septic tank, in fact, is a combination of a cesspool and a treatment plant, where wastewater enters, which is formed during the life of residents of private housing construction. As a result of using the toilet, bathroom, washing machines and dishwashers, a large amount of wastewater is generated, which must be disposed of without harm to the environment.

Modern septic tanks provide accumulation, biological treatment, wastewater disposal in two stages:

Contaminated effluents enter the first chamber of the reservoir, where they are settled and primary treatment takes place. Solid heavy particles quickly sink to the bottom, and the water purified from them enters the next chamber.
In the second chamber, the organic compounds that make up sewage are decomposed with the help of anaerobic microorganisms. The water becomes even purer and enters the third tank or system of special filters for final purification.

Understanding the principle of operation of a septic tank will greatly facilitate the selection and installation of the owner of a suburban area.

What problems does the high level of groundwater create?

High is the height of waters occurring at a distance of 0.5-1 m from the surface of the earth. With such a depth of occurrence, problems with sewerage inevitably appear, and difficulties arise with its maintenance.

Flooding. Devices made of bricks or concrete rings are often flooded due to the movement of groundwater and heaving of the soil. The lack of tightness in such installations facilitates the penetration of liquid into the interior, as a result of which the volume of effluents in the device quickly increases. In the best case, the owner of the house building has to call a sewage truck more often, in the worst case, sewage mixed with feces can get into the sewer and flow through it into the toilet and bathroom. If the device is overfilled, its contents may fall into the area and spoil the soil.
Ascent. The accumulation of groundwater during heavy rainfall or melting snow can push a lightweight plastic installation up if it has not been secured with a concrete pad. In the process of pushing out, the septic tank may tilt, fecal masses splash out and fall into the soil. And when the structure is shifted, a sewer breakthrough may occur, the owner of the site will incur unplanned costs for its restoration.
Drainage. According to SNiP, between groundwater and the filtration field filtering water at the last stage of purification, there must be at least 1 m of earthen layer. With a high occurrence of groundwater, this condition is simply impossible, as a result, pollution of the surrounding water bodies occurs due to insufficiently purified water entering the soil.
Destruction. Groundwater with high acidity or alkalinity gradually destroys the material from which the septic tank is made, especially concrete or brick. In addition, the housing or sewer pipes can be damaged by sharp pebbles that are brought in by moving groundwater.
Complicated installation. When installing the structure, due to the accumulation of water, the process of digging a pit and pouring a concrete pad is complicated. Installing ready-made purifiers becomes more labor intensive.

How to determine the depth of groundwater

Before installing a septic tank, it is necessary to accurately measure the height of groundwater in order to avoid errors during installation and further operation. There are several ways to do this.

There are 4 ways to self-measure GWL. Each of them allows you to accurately determine the depth of the aquifer.

Drilling rig. For this method, you will need a garden drill and a rod with a length of at least 2 m. On the rod, markings are made along the length with an interval of 10 cm. Next, you need to drill a well to the entire depth of the drill and wait a day for moisture to accumulate. Sometimes water appears immediately after drilling, but these are rather isolated cases. The next day, the height of the water is measured with a rod. For measurement accuracy, you can make a number of wells throughout the site and measure the level for several days in a row. For tank design, the smallest value from the results obtained is taken.
By vegetation. You can determine the GWL on the site by growing wild plants on it. Below is a table of indicator plants, the presence of which can be used to judge the proximity of the aquifer. In addition to these plants, high humidity can be judged by the rich growth of sorrel and the rapid development of currant bushes.
For nearby water bodies. If there are dug wells nearby, the necessary information can be obtained by looking into them and determining how far from the surface the water mirror is located in them. It is best to do this after a heavy rainfall to get an accurate idea of the possible rise in groundwater. The presence of wetlands in the district indicates that groundwater is located close to the surface.
According to omens. There are some folk signs, based on which we can conclude about the desired parameter in the summer cottage. Morning dew and evening fog are sure signs of a shallow aquifer. The abundance of midges, mosquitoes and the absence of rodents in the local area can also tell about high humidity.

Location selection

It is necessary to start the construction of a septic tank at high groundwater by determining a suitable place, while it is important to take into account all SNiPs.

The optimal location of the sump must meet important conditions:

The distance to housing construction and other buildings on the territory of one's own and neighboring plots, as well as to the road zone, must be at least 5 m;
The distance from the sewer to the nearest water bodies is at least 30 m;
It is supposed to measure at least 50 m to a well with drinking water.

Model selection

After determining the optimal location for installation, you should decide on the type of septic tank. First of all, calculate the required volume of the device. To calculate the volume of wastewater accumulated per day, it is multiplied by 3.

The device, which will be installed in a site with a high GWL, must meet a number of requirements:

Full tightness;
Good strength;
Reliable fastenings;
Proper drainage.

To equip a septic tank in the vicinity of the aquifer, experts recommend purchasing models assembled at the factory. Such products are completely sealed, made of strong durable materials and are ready for installation.

Sometimes the owners of the sites prefer to build septic tanks from the building materials they are used to with their own hands or with the involvement of professional builders. The devices are additionally equipped with reinforced waterproofing. The device is usually built using concrete, brick, or old iron/plastic barrels.

concrete septic tank

When choosing concrete as a building material, it is undesirable to use reinforced concrete rings, since the installation of them quickly collapses and loses its tightness. A three-chamber concrete septic tank with a high level of groundwater is best done in the form of a monolith. Monolithic concrete devices are easier to give the necessary tightness, they are able to withstand high pressure, do not float, their service life will be much longer than that of a reinforced concrete ring. An additional advantage of concrete septic tanks is their low cost compared to more expensive materials.

Installation of a concrete monolith consists of the following steps:

Digging a pit;
formwork construction;
Formation of a reinforcing lattice;
Filling the bottom with concrete;
Filling of external walls and partitions;
Roof formwork construction;
Roof filling;
Ground embankment device;
Installation of ventilation and hatches.

brick septic tank

When installing a brick sump, the proximity of the aquifer will create difficulties when laying its bottom and walls. Ready-made brick installations need reinforced waterproofing to prevent fecal matter from entering the soil.

The process of building a brick septic tank is similar to installing a concrete one. Instead of the stages of construction of the formwork and pouring of concrete, the laying of the bottom, walls and roof of the device is carried out.

plastic septic tank

The material for the construction of plastic devices is usually plastic containers and eurocubes. Plastic septic tanks are not as practical as buildings made from heavier materials, but they are quite suitable for building a sewer system in the country with your own hands. The disadvantages of such materials are the risk of floating due to their low weight, the possibility of cracks in the heaving of soils.

Before installing plastic septic tanks, it is necessary to put a concrete slab at the bottom of the pit for anchoring easy installation. Plastic firmly fixed to a concrete slab will not be able to float with an increase in GWL.

Factory septic tanks

The best option for arranging an autonomous sewage system in a house adjoining area with a high level of groundwater is septic tanks made at the factory. The modern market of plumbing fixtures and devices offers products of different volumes and the most diverse modifications. Owners of suburban areas have the opportunity to choose the product that is most suitable for their sewer project.

The disadvantages of factory septic tanks are their high price and attachment to electrical networks. Cleaning tanks must be constantly supplied with fresh air, which is supplied by electrical equipment.

If the owner of the site has the skills to carry out construction work, he may well install a factory septic tank on his own, with the help of auxiliary workers. Installation is carried out in several stages:

Pit dig. When digging a pit by hand, the main problem is the water that comes in during the digging process. It is necessary to scoop out the incoming moisture at the same time as digging, sometimes you even have to connect special equipment for pumping. When using an excavator or other equipment for digging, a lot of liquid does not have time to run, and nothing interferes with the process of installing the device.
Construction of a sand cushion. At the bottom of the dug pit, sand up to 10 cm thick is poured.
Installation of a concrete base. A concrete slab with fasteners for fixing the septic tank is lowered onto the sand cushion. Sometimes, instead of a finished slab, a formwork with reinforcement is installed and concrete is poured. In the case of pouring, it is necessary to wait a week until the concrete has completely hardened.
Training. A heating cable is mounted on the septic tank and waterproofing is sprayed.
Installation. The prepared installation is lowered into the pit and installed on a concrete base.
Fixation. With the help of special fasteners, the septic tank is attached to a concrete slab.
Line of communications. Sewer pipes are connected to the device, the joints are sealed.
Sand filling. After connecting the communications, they check the operation of the heating cable and fill the septic tank with sand, immediately equipping the soil embankment on top of the cleaner.

After installing a septic tank, a filtration field or a filtration cassette is constructed next to it for the final purification of the filtrate.

TOP 10 factory cleaners

Tank. Excellent value for money. Energy independent. Rugged housing. A wide range of models with different volume and device.
Triton. Excellent service life up to 50 years. Septic tanks of this brand require anchoring during installation. A wide range of models of different sizes and shapes.
Leopard. Three-chamber cleaners with 2-level biofiltration. Consumers note strength, reliability and durability.
Tver. high throughput models. They require a constant source of electricity and regular maintenance.
Leader. 6-chamber septic tanks with airlift and aerators. Do not require biological additives for wastewater treatment.
Ecopan. Withstand heavy loads. Recommended for installation in heaving soils.
Unilos. A complex wastewater treatment process, consisting of mechanical and biological stages. Reliable, easy-to-maintain models.
Yubas. Durable septic tanks suitable for efficient operation with long breaks up to 3 months.
Poplar. Resistant to temperature extremes and loads. Equipped with airlifts, compressors and aerators. manual and mechanical sludge removal is provided.
Topas. Reliable autonomous sewage system made of high quality materials. It is in demand among Russian consumers.

Operation features

An autonomous sewage system will last a maximum period if you follow the recommendations of experts and the basic rules of use:

Do not throw large debris into the sewer;
It is good to insulate and waterproof the system;
Regularly pump out accumulated sewage from the septic tank;
Avoid the ingress of fats with the help of special grease traps;
Do not use chemicals in the case of using bio-treatment of wastewater in the septic tank chamber.

If you approach the installation of a septic tank responsibly, take the time to draw up a project, select materials, follow the rules of operation - the autonomous sewage system will function without failure for many years.

In the private sector, towns, villages, there is often no central sewage system. Residents independently solve the problems of disposal of wastewater from toilets, bathtubs, washing machines and dishwashers.

How does a septic tank work. What threatens the high level of groundwater
Consequences of infection in the region
How to determine the depth of groundwater
Garden drill and rod 2 meters long
Attention - plants
Folk signs - assistants in the construction of VOCs
How to choose a septic tank for a site with a high GWL
Homemade septic tanks
How to protect a septic tank from surfacing
Industrial septic tanks
Topas
Tank
Triton
Leopard
Tver
Leader a>
Ecopan
Unilos
Yubas
Poplar

Cesspool is yesterday. Its content has to be pumped out regularly. You can’t just bring the pipe into the nearest ditch. Fines for such actions amount to hundreds of thousands of rubles.

The best option is local sewerage or. The task becomes more complicated if groundwater is separated from the surface of the earth by one bayonet of a shovel. It can be solved if you correctly assess the geological structure of the territory, calculate the needs of the household.

How does a septic tank work. What threatens the high level of groundwater

Most of the local treatment facilities consist of two or three chambers for primary sludge, biological treatment. Removes 75-98% of contaminants. To completely get rid of organic matter, a filtration well or a field of layers of sand and gravel is additionally equipped.

If groundwater is in close proximity to the earth's surface, special requirements are placed on the tightness of the station, the quality of the installation. Otherwise, ascents with repair or replacement of equipment are inevitable.

Another unfavorable scenario for the development of events with an increased GWL is the flooding of a septic tank if a design with thin unreliable walls is chosen. Under the pressure of the soil, they will crack, holes will appear that were not originally intended. There is no need to talk about full-fledged wastewater treatment. Permanent "guests" on the site will be sewers with endless bills for pumping out a septic tank.

Consequences of infection in the region

The construction and sanitary standards contain instructions regarding the removal of treatment facilities from residential facilities, wells, reservoirs, trees. This is a guarantee of safety in case of an accident, leakage, equipment failure.

Aerobic or anaerobic bacteria are necessarily settled in factory-made septic tanks. Overflows, pipe ruptures are fraught with the ingress of microorganisms into aquifers with the subsequent spread of intestinal diseases among people and animals. Wells and wells will have to fall asleep. You can't use them anymore.

How to determine the depth of groundwater

Ideally, a contract is concluded with a specialized company. Test drilling is carried out, soil samples are taken and sent for examination. This option takes time and money. Drillers may refuse to go to a dacha association 100 km from the city. In this case, you should pay attention to the methods below.

Garden drill and rod 2 meters long

Marks are made on the rod every 5-10 cm. Next, a small hole is drilled (up to 200 cm). A day later, a dry rod is lowered into the well to the bottom. Then they take it out and check whether it gets wet or not, to what height. If the height of the hole is 200 cm, the rod gets wet by 30 cm, then it is 170 cm to the horizon.

Measurements are taken during periods of snowmelt or heavy rains. Summer figures are not relevant. Wells are drilled for a week or more, at different points in the area. If there is a significant difference in the results, you should focus on smaller readings.

Attention - plants

In areas with a predisposition to swamping, willows, alder, and meadowsweet prevail. If reeds break through in the corners of the cottage, there is no doubt that the water is very close to the surface. The same applies to red currants and sorrel, if they grow well even without watering.

Folk signs - assistants in the construction of VOCs

If for no apparent reason on a hot day there is heavy dew or evening fog on the site, midges swarm over bushes or flower beds, water carriers are located nearby. The absence of ants also indicates excessive moisture. These insects and mice prefer dry patches of soil. They will not live where it is always damp.

How to choose a septic tank for a site with a high GWL

In some situations, it makes sense to dwell on the storage tank. This applies to dachas, houses used on weekends. From time to time, you will have to call vacuum trucks and pay for pumping. But a filtration field will not be required, there will be no threat of swamping.

If the cottage is intended for permanent residence, preference is given to industrial-made stations with a wall thickness of up to 40 mm. The volume is determined by needs, daily discharge.

Advantages of factory treatment facilities:

hermetic design;
long-term operation;
quality cleaning.

In modern models, sensors are provided that signal the overflow of the chambers.

Homemade septic tanks

If you have knowledge and experience, you can build a drive with your own hands. Pumping out - as it is filled, on average, at least 1 time in 5-6 months. You will have to turn to vacuum trucks less often if instead of the bottom you equip a filtration pad made of sand and gravel.

Building materials have both advantages and disadvantages:

reinforced concrete or rings. Suitable for residential homes. Subject to the construction technology, the walls do not allow moisture to pass through, do not collapse under the influence of chemically active preparations.

The service life is calculated for decades without repair and replacement. Special equipment is required for assembly;

eurocubes. The advantages include light weight and easy installation. Minus - special requirements for anchoring and protection from winter heaving;
fiberglass. Differs in the increased durability, resistance to chemical reagents. Requires a quality foundation and anchoring with cables and anchor bolts.

Of all the materials listed, it is better to choose reinforced concrete. It takes a long time to gain strength (up to 30 days). Requires formwork and reinforcing mesh. But there will be no surfacing or deformation during heaving of soils.

How to protect a septic tank from surfacing

Plastic containers are convenient for installation, but require mandatory fixation. If you do not use the sewer in winter, an empty tank will float to the surface in the spring.

Anchoring order:

the bottom of the pit is leveled. A pillow of sand up to 30 cm is filled up and carefully compacted;
on top - a reinforced concrete slab of a suitable size. If desired, it can be poured independently by installing mounting loops along the way;
a tank is installed, filled with water and secured with cables and / or anchor bolts;
backfilling is carried out with a mixture of sand and cement in a ratio of 5: 1 with simultaneous compaction. Layers are spilled with water.

For a septic tank with a high GWL, a filtration well and a cassette will be required for post-treatment of wastewater. Forced pumping of water is provided by a pump. If 1 m3 of sewage is discharged per day, the size of the cassette must exceed 2 m2. The higher the productivity of the station, the higher this indicator.