Home septic tanks with groundwater. Septic tanks for summer cottages with a high level of groundwater: recommendations and detailed instructions for the selection and installation. Septic tank fixation from surfacing and protection from soil heaving

Waste disposal in wetlands is productive if a septic tank is technically justified: a high groundwater table (GWL) puts forward a number of conditions for the structural qualities of VOCs. In addition, the high groundwater level on the septic tank imposes installation and maintenance restrictions. The specificity of treatment requires compliance with the basic requirements: a high rate of wastewater treatment and reliable operation of the unit. This is possible with the industrial assembly of VOCs, as well as the use of high quality materials, which is achieved only in the factory. Individually, it is impossible to build a septic tank that meets the standards - a high level of groundwater exposes the product to constant contact with aggressive drains from the inside, as well as to extreme exposure to factors from the outside.

Non-volatile septic tanks

Biological treatment plants

Autonomous sewerage

The climatic features of most of the territory of Russia are characterized by an increased GWL (0.4-0.5 m), which affects the choice of a septic tank for a summer residence with a high level of groundwater. Requirements have been established that regulate the choice of a septic tank with a high level of groundwater:

• - obligatory determination of dimensions, productivity, volume, mass, etc .;
• - volatility (or self-control);
• - the integrity of the multi-chamber (mono) case, which guarantees the impermeability of the entire installation;
• - increased tensile strength of materials;
• - resistance to mechanical impact and extreme temperature indicators (provided by stiffening ribs and wall thickness);
• - inertness to microorganisms, chemically active components that pollute sewage.
• - not susceptible to corrosion;
• - equipping the body with fasteners for the possibility of fixing it and preventing it from emerging, etc.

The choice of a septic tank at a high level of groundwater can also be of the accumulating single-chamber type with periodic wastewater withdrawal, as an alternative to functional VOCs.

Filtration field for a septic tank with a high GWL.

The filtration field for a septic tank is equipped for the final (almost 100%) additional purification of sewage before being absorbed into the soil. It is taken into account that the filtration field for a septic tank assumes the presence of a large area. An alternative is a more compact storage tank that stores purified water used for technical and economic purposes. Structures with sewage liquid cleaning with bio material are considered the most promising. All processes take place in a closed case, and the final products of treatment - sludge and liquid are considered environmentally friendly for people and nature. The service life of biosystems with proper use is the highest, while the filtration field for a septic tank is not operated for long, requiring replacement as it becomes silted.

It is preferable to install a septic tank with a high level of groundwater in frozen ground. Underground currents "hide" below the freezing mark, do not interfere with the formation of a pit, a route for a pipeline. Installation of a septic tank with a high level of groundwater in winter conditions is a reason to participate in seasonal discounts and promotions that make treatment systems "affordable" for an ordinary user. Lightweight polymer tanks should be secured, properly filled, ensuring the established distances, while filling with water. It is difficult to do this without special skills. Employees of the required skill level will not only competently carry out the installation of a septic tank at a high level of groundwater, but also connect, if necessary, power units for removing and moving liquid.

Installing a septic tank with a high level of groundwater or their passage above the average mark puts forward additional requirements for the tank. Today, only high quality polymers guarantee that septic tank installation at a high level of groundwater does not harm the environment, because the case is completely sealed. Other benefits:

• - inertness to chemical and biological changes;
• - availability to purchase;
• - durability (up to 50 years of operation);
• - ease of transportation, installation;
• - variations of different performance, etc.

Installation of a septic tank with a high level of groundwater from polymers is a reasonable solution to the problem of drainage from "problem" soils.

The choice of a septic tank with a high level of groundwater.

It is necessary to install a septic tank with high groundwater taking into account the mandatory maintenance, its frequency, and in case of violation of the operating technology and the possibility of repair. A septic tank with high groundwater of a complex design requires the involvement of specialists for work. In various installations, on average, maintenance is carried out every 4 months or even more often. The operating mode of biological units is regulated by automatic equipment, characterized by a six-month interval between service work. To understand which septic tank with high groundwater is suitable for a particular case, specialized specialists will help to correctly position it on the site.

GWL (groundwater level) determines how close to the surface the subsoil water approaches. It is good if it passes below the bottom of the septic tank.

But what if the liquid is located at a depth of only 0.5-1m? What is the danger and how to solve the problem? A septic tank with a high level of groundwater will serve for many years if installed correctly.

The first thing to do is to define the GWL and understand the magnitude of the problem.

Important: the liquid is as close to the surface as possible in spring and autumn. In the first case, the reason is the melting of snow, in the second - prolonged rains.

Here are 5 ways to define it:

1. The easiest way is to ask the locals. Perhaps the neighbors already know at what depth the groundwater level is located or they have a well on the site.
2. Flora as a guide. Certain plant species can only survive when the water comes close enough to the surface. The following table will help you navigate:
   
3. Inspection of the site. If there are wetlands, it means that the groundwater level is located close to the surface or the soil is too clayey. And also inspect the area adjacent to the site.
4. The grandfather's way. To do this, you need a clay pot, a clump of wool, defatted with white spirit and an ordinary chicken egg. A small layer of turf is removed with a shovel in the place where the septic tank will be located. Put wool, on top - an egg and cover with a pot. An examination is carried out in the morning. If water droplets are clearly visible on the egg, then the groundwater level is close to the surface.
5. Drilling holes at several points in a suburban area. This method is rather laborious. But it is 100% reliable. Step-by-step instruction:

• Find a good long drill - at least two meters - and a straight pole to which you mark every 100 mm.
• Identify drilling points on the site. It is not necessary to drill a well only in the intended location of the sump. It is possible that it will need to be relocated, so select multiple points throughout the site.
• Drill wells. Place a waterproof material on top to prevent precipitation from entering the shaft. Wait 24 hours.
• Using the prepared pole, determine the GWL: immerse it in the well, reaching the bottom, pull out and subtract the length of the wet part from the depth of the mine.

Folk omens also help a lot. This is especially true in summer, when drilling cannot guarantee 100% measurement accuracy. The fact is that in the heat, the liquid drains into the nearest reservoirs and the level sometimes drops - very significantly.

Potential flooding sites will help identify midges that sense the proximity of moisture and will swarm in this very place. And you can also navigate by the abundance of dew in the morning and the density of fog in the evening. The more clearly these signs appear, the closer the liquid is to the surface. Obviously, when constructing any underground structures, such places should be avoided.

A similar situation with a drop in the liquid level is observed in the middle of winter. Only the reason is not in the drainage of water, but in the freezing of the upper layer of the soil during severe frosts. Measurements taken during this period can be easily misleading. In case of heavy precipitation, the liquid mark in spring can increase by 2–3 times.

Important: if possible, the determination of the GWL should be carried out several times a year and the smallest value should be taken for calculations.

What problems can there be

The device of a septic tank with a groundwater level closer than two meters from the surface requires additional measures.

Problems arising during the installation of a sedimentation tank in a section with a VUHV can be divided into several groups:

1) When installing. First of all, this increases the complexity of the work. Digging a pit in liquid mud is not very comfortable. We'll have to use a pump for pumping out and organize drainage on the site. Step-by-step instruction:

• deepen the pit as much as possible in one place;
• organize a drain;
• install a vibration pump (motor pump);
• when liquid accumulates in a depression, pump it out;
• while the pump is running, make sure that the hose does not burrow into the ground (the pump may clog);
• in the meantime, excavate the soil with a slope towards the excavation, which should also deepen accordingly.

After the pit has been dug, it is necessary to protect the walls from collapse. For this, wooden or metal dowels are hammered. During the installation of the sump, water is also collected in the recess and removed using a motor pump.

Important: it is much easier to correctly determine the level and take action in time than to deal with the consequences later.

2) Damage. As a result of excessive pressure of subsoil waters, the soil swells, and the container can be easily damaged. Sewer runoff, mixed with underground water veins, can enter the drinking well or come to the surface with the remains of faeces. This situation can provoke infection with dangerous infections, not to mention an unpleasant odor throughout the entire area.

To avoid such sad consequences, it is enough to choose the right material for the cleaner. Ideally, this should be a sealed container buried in the ground. Experts recommend using modern high-strength plastic.

But it is also important to correctly backfill the pit after installing the sump.

The filling is done with a special composition: you need to mix 5 parts of dry sand with 1 part of cement. Layer thickness 100–150 mm. and each must be spilled with water and carefully sealed.

You will have to dig out the container, if the septic tank with high groundwater was nevertheless installed incorrectly and damaged, pump out the contents and find cracks. If the damage is minor, a seal can be performed.

For this, special sealants are used. In especially difficult cases, you will need to apply a patch using a special plastic welding machine. In case of significant damage, the container will have to be replaced.

Important: Damage to the housing can be indirectly diagnosed when an unpleasant odor appears and the soil is silted up at the installation site.

3) The plastic sump may float. To avoid this problem, a reinforced concrete anchor-base is provided at the bottom of the pit (this can be a factory one), to which a septic tank is attached. There is no other way to cope: the container will simply float up.

In case of problems with access of lifting equipment to the place of work, the slab is poured directly into the pit. In the body of the concrete, mortgages are left, to which the tank is attached using metal clamps. Additionally, a layer of sand, 10 cm thick, is poured onto the bottom of the container. Such a structure will reliably hold it and prevent it from floating.

The ascent has already occurred. Step-by-step instruction:

• inspect the sump and make sure that it is not damaged - the container must be airtight;
• use a pump to pump out the contents (it is advisable to immediately call a sewage truck), in case of damage, perform the necessary repairs;
• wash the sump;
• completely remove it from the pit;
• mount correctly (see above).

4) Flooding . Overfilling can be caused by many reasons. And groundwater is only one of them. First of all, it is worth forcibly pumping out all the contents, checking the operation of electrical equipment, the correct connection of hoses and infiltrates.
If, nevertheless, the reason is in excess groundwater, especially if the level is unstable, it is necessary to organize the pumping of liquid by a forced method. To do this, you can use another pump installed in the immediate vicinity of the outlet.

If this method does not help, you will have to use a pipe to divert clean water further, to an area with dry soil. There it can easily be absorbed into the soil, and the sump will not overflow.

To avoid such difficulties, it is better to provide a drainage system for the removal of groundwater in advance, even before the installation of a septic tank.

5) Waterlogging. With a high groundwater level, there is often a problem with the final treatment of wastewater. The soil already has high humidity. The extra moisture simply won't be absorbed. Gradually, the place around the tank will turn into a swamp. To solve the problem, you need to mount a filtering field. Simply put, an artificial embankment, which is arranged in a previously dug pit - to the required level and is filled with rubble and sand 1.5–1.8 m above the ground.

The step-by-step diagram of the device of such a field is as follows:

• The necessary calculations are carried out. On average, 1 person drains 200 l / day into a septic tank (established empirically). The filtration coefficient is determined in accordance with GOST 23278 “Soils. Permeability Field Test Methods "by pouring water into pits. Based on the tests, we determine the steady flow. Let's say it was 4 l / h. Pit dimensions: diameter 250 mm, depth - 100 mm. From here we define the wetted area: bottom - 3.14 * 0.125 2 = 0.05 m 2; walls - 3.14 * 0.25 * 0.1 = 0.1 m 2, S total. = 0.05 + 0.1 = 0.15 m 2. From here, through 1 m 2 per day, 0.15 / 1 * 4 * 24 = 640 l / day will be filtered. Based on these data, we take the required field area.
• A pit is being developed (always dry).
• A cushion is made of 500 mm thick crushed stone.
• Pour 1 m of sand.
• Laying drains (perforated plastic pipes). This design will provide an even distribution of fluid on the field. The length of the pipes should not exceed 20 m. The distance between the drains is no more than 1.5 m. The supply of pre-treated water to the field is provided by a pump. When laying, pipes are protected with geotextiles. Each drain is equipped with a ventilation riser, which must be 0.5 m above the ground.
• Place the filter cloth.
• Backfilling is carried out.

6) Drainage. Sump drainage can be done using a filter well.
Instead of a concrete well, you can use a plastic container without a bottom, the installation of which is much easier. Coarse sand is poured to the bottom, then fine gravel or crushed stone. The thickness of the layers is 200 mm. To exclude the impact on the well, it is sprinkled with expanded clay from the outside.

Requirements for a purification device with a high groundwater level

1. The housing is made of durable plastic and must be sealed.
2. The structure should have a low height.
3. The volume of the tank should correspond to the daily flow rate multiplied by three.
4. Septic tanks intended for high groundwater must be securely anchored to a concrete base.

The following types of septic tanks are ideal for the drainage of sewage during VUHV:

1. Sealed storage tank. The most commonly used prefabricated plastic construction. It is guaranteed not to leak and can have a volume of up to 300 liters. Such a system is good in a country house or in a small private house, if the owners live there periodically. But she will not solve the problems with the permanent residence of a large family. The main disadvantage of this design of a septic tank is the regular pumping of sewage.
2. Three-section anaerobic device. The first compartment (sump) serves to separate waste into fractions as a result of the separation of fats and precipitation of solid parts. In the last two, preliminary wastewater treatment takes place. The supply of waste from one compartment to another is provided by an overflow pump. It is impossible to dump waste without additional filtration through the soil, since this leads to a violation of sanitary standards.
3. VOC (local cleaning station)... Waste goes through a full cycle of biological treatment. With the help of bacteria, the effluent is broken down into sludge and water. Such devices are quite expensive, but the costs are worth it, if you equip such a system on the site, then you can forget about pumping out the sewage system for many years.

Required tools and materials

Below we will consider in more detail the process of installing a storage tank. For self-installation, you will need the following tools:

• motor pump;
• shovels;
• metal cable;
• building level;
• jigsaw.

You need to prepare the following materials:

• wooden or metal tongue;
• formwork boards, reinforcement AIII Ø12 mm, concrete B12.5 (with a monolithic foundation) or prefabricated reinforced concrete slab;
• clamps for attaching the container to the base;
• sealant.

DIY installation and work plan

Sump installation consists of the following steps:

1. Development of a pit and a forced drainage device (details are discussed in more detail above).
2. The pit slopes are fastened to ensure safety and protection from collapse. During the work, there should be no liquid in the pit. It is pumped out using a motor pump. But it is recruited again overnight. This can cause the walls to collapse if they are not secured.
3. Installation of a concrete slab or concreting of the base. The process is as follows:

• The bottom of the pit is leveled using a building level for control.
• Then arrange a sand bed with a thickness of 150 mm. The sand is spilled with water and carefully compacted.
• The next layer is waterproofing. Experts recommend using two layers of roofing material.
• Formwork and reinforcement cage are installed on the waterproofing, concrete is poured. It should be laid in even layers, vibrating. It is advisable not to stop work for more than 4 hours. If conditions allow the passage of equipment, you can use a ready-made reinforced concrete slab, which will significantly reduce labor intensity. With a monolithic structure, mortgages must be left in the concrete body for fastening the tank.
• We install a ready-made plastic container on the prepared base, having previously calculated the required volume and checking its tightness. With special clamps we attach the tank to the embedded parts of the "foundation" by welding or bolts. Now there is no need to be afraid that it will emerge.
• We connect the supply pipe, carefully seal all joints and insulate the septic tank and all pipelines.
• We carry out backfilling with protection against heaving of the soil as a result of the drop in groundwater level (with a mixture of sand and cement with layer-by-layer spillage and compaction).

Important:

1. Around the container should be covered with a layer of expanded clay with a thickness of at least 200 mm. This will prevent freezing and reduce the negative impact of external factors.
2. During filling, it is necessary to gradually fill the container with liquid so that the water level is always above the filled level. In this way, you can protect the septic tank from damage.

Operation in VUHV conditions, as well as installation, requires special measures:

1. It is forbidden to clog the system with large debris. This will lead to clogging.
2. The sewer pipe and sump must be carefully insulated.
3. You need to pump out the drains regularly. Do not allow the tank to be more than 2/3 full.
4. When used as a natural filter, it is worth remembering that any chemistry will kill them.

Compliance with these simple rules will make the operation of the sewer system easy and save you from unnecessary problems and an unpleasant smell.

Autonomous - the only way out at high ground level.

Useful video

In detail and step by step:

Installation of concrete:

If you are lucky enough to have a site in a swampy area (that is, where the level of groundwater flow is close to the surface), then equipping the sewerage system will become a task for you that requires a careful approach. Since it is impossible to arrange a septic tank for high groundwater with a drainage bottom.

Such installation of a standard sewage tank threatens a mini-ecological disaster at least for a specific site, and on a larger scale - for all neighbors. Since wastewater, getting through the drainage chamber into the ground, will merge with groundwater, and from there it will be sent to the nearest wells, wells, garden crops, etc.

What is the solution to the problem for the "happy" owners of a summer cottage or suburban area in a swampy area, we understand our material. And for clarity, we attach the video below.

Important: with a high groundwater level (groundwater level) on the site, it is imperative to make an adjustment for this factor at the time of design and installation of all communications related to water.

If you understand that a standard cesspool, even for a seasonal dacha, is not your case, since there is a risk of poisoning the entire perimeter of land holdings, then we suggest you understand even more thoroughly the features of a swampy area and understand how difficult it is to install a sewage system. In addition, here you will find out what risks may await at the time of construction and operation of a sealed septic tank for pumping on such soils. As they say, forewarned is forearmed.

• So, even the simplest single-chamber design of a septic tank will require remarkable efforts for its installation. And it's all about the mobility of moist soil. Therefore, you have to tinker in order to securely fix the chamber of the treatment plant in the ground. Most often, either a concrete slab is used for this (if a plastic septic tank is installed), or a cleaning well is mounted from concrete rings. In any case, the installation process will take longer than installing a septic tank on standard soil with low GWL.
• The ascent of the septic tank chamber during the season of melting snow or lingering rains. This is especially true for plastic tanks. The fact is that plastic drives are identical to water floats. So, even in a filled state, such chambers are subject to a powerful pressure of soil sprinkled with water. As a result of the ascent or tilt of the septic tank, the tightness of all joints will be broken. There is a risk of seepage of both dirty water into the ground, which is dangerous for the environment, and groundwater into the chambers of the septic tank, which will require frequent invitation of sewage equipment. And this will hit the family's pocket.
• Complete flooding of all septic tanks. This can also happen as a result of shifts in the tank and a violation of its tightness due to violations of the installation rules. As a result, you will have to face a local disaster. All water sources will be poisoned, ponds and reservoirs may bloom, and garden and horticultural crops will become unusable.

Important: a septic tank for a site with a high GWL must be completely sealed in all chambers. There should be no drainage into the soil.

How to correctly find out the level of groundwater at the site

In order to make sure that your site is located in a swampy area, you should make some observations. As a rule, the groundwater level on the site is fully manifested in the season of snow melting or autumn lingering rains.

To check the groundwater level, you need to drill depressions in the garden at the right time. For work, use a simple auger garden drill. Depressions are made until they hit the water.

Important: it is necessary to make several control grooves at once at different ends of the site. This is done in order to make a reconciliation of the data obtained throughout the territory.

If you don't feel like messing around with drilling and tracking, then you can just chat with your neighbors. The long-livers of your village definitely have information about the GWL, which will facilitate the subsequent installation of a septic tank.

Important: almost the entire middle zone of Russia is located on a swampy area. Sometimes the groundwater level can be only 20-40 cm from the earth's surface. This once again indicates that a private sewage system in the form of a septic tank should be extremely tight and only for pumping.

Important principles of a septic tank with a high GWL

In order to make a private sewage system with your own hands for a summer residence or a country house with a high GWL, you need to strictly follow several important principles:

• Firstly, only plastic should be used as a material for the cleaning structure, and preferably fiberglass. Its compressive strength is much higher than other types of PVC material. Moreover, the plasticity of such a container is also better. It is better to forget about septic tanks made of concrete rings or bricks right away. These materials have joints and are very hygroscopic, and therefore, with an increased attack of water from both sides, they will soon give up their positions. Even if at the installation stage you make a special coating with waterproofing mastic. And it will be too difficult to install a septic tank made of concrete, and even more so a brick on watery soil.

Important: the tightness of the septic tank chambers in the case of high GWL is first of all! Therefore, the choice of material for the storage tank must be well thought out.

• The ideal option would be a septic tank specially designed and created by modern manufacturers. The design of such inventions has two or three chambers interconnected by overflow tubes. A completely finished plastic septic tank only needs to be installed in the ground, and you can operate it after connecting the sewer pipe. Such a septic tank works very effectively, accumulating wastewater from all over the house, defending it and completely purifying it. As a result, there will be only clean water in the third chamber of the treatment system, which will remain to be pumped out.

Important: if your site is close to a reservoir, then you can save on the services of an assimator and simply dump water into it. According to SNiP, household wastewater that has been treated through an industrial septic tank is considered 98% clean. And provided that aerobic bacteria are used in the septic tank, it is possible to reduce the amount of residual sludge in the chambers, and later use it as fertilizer for the garden or vegetable garden. Thus, having made the right choice, you will again be able to save on assimilation equipment.

• It is worth remembering that a reliable sealed septic tank for an area with a high groundwater level needs to be cleaned as it is filled. Otherwise, overflow of drains may occur. So you should not neglect the pumping of wastewater.

If the option of a ready-made septic tank is not suitable

If you decide to save money and build a septic tank with your own hands, then here you will have to use either a monolithic concrete fill or ready-made plastic cubes. Let's consider both options of the device.

Septic tank made of PVC cubes... For a high-quality installation of the chambers, it is necessary to prepare a pit, which should exceed the parameters of the cubes by 20-30 cm. The bottom of the pit is well compacted and a layer of sand 30 cm thick is poured into it. A concrete slab is placed on the sand, which will become a reliable anchor for plastic. With the help of anchors and chains, the septic tank is reliably anchored.

After that, it is necessary to make a cement-sand sprinkling of the containers. The septic tank chamber is filled with liquid by 30 cm and sprinkling begins from the outside to the same height. Continuing to fill the chamber with water in stages and the distance between the septic tank and the walls of the pit, they move to the top. This technology makes it possible to insure treatment tanks against soil pressure and subsequent deformation.

After all the cubes are mounted, it is necessary to provide their overflow part with pipes. In this case, be sure to take care of sealing all joints. Lastly, the septic tank is covered with a stove to securely fix it. A ventilation pipe is brought out and provided access to the hatches, as indicated in the video below.

Monolithic concrete septic tank

For the device of a private sewage system in a swampy area, you can also make a monolithic septic tank made of concrete with your own hands. This choice is correct: the structure has no joints, which means it will be a reliable reservoir for domestic wastewater.

• So, first we dig a foundation pit. We strengthen its walls with formwork and at the same time form a shape for the concrete pouring to the size of the pit. Immediately it is worth making all the partitions with pipes for overflow into them.
• A reinforcing mesh is installed in the center of the formwork and along its entire height. It will make the concrete stronger after drying.
• The mortar, reinforced with a hydrophobic additive for resistance to moisture, is poured into the formwork and left for 2-3 days. Under good weather conditions, the solution will set during this time. And it will take 7 to 10 days to completely dry.

Important: in the process of pouring the solution for its high-quality compaction, it is better to use a construction vibrator. So the finished monolithic septic tank will be practically pore-free.

• After the tank has dried, it is advisable to coat it with a sealant from the inside.
• The next step is to fill the bottom. First, the bottom of all three chambers is well rammed. After that, a layer of sand is poured, which is also carefully tamped.
• A reinforcing mesh is laid on the sand and a solution is poured. They are waiting for it to dry completely.
• Last but not least, a concrete floor is made. For this, the walls of the septic tank are covered with metal corners - stiffening ribs. Planks are laid on top perpendicular to the width of the chamber. If it is more than 1.5 m, then you will have to install the support pillars from below. Otherwise, the finished concrete fill will simply push the walls of the septic tank with its weight.
• A mesh for reinforcement is laid on the boards, formwork is placed and mortar is poured. Do not forget about hatches and holes for the ventilation pipe.

It remains to connect the sewer pipe to the septic tank and start operating it, as shown in the video below.

If your site in a swampy area is used as a summer residence for seasonal visits, then here you can simply mount a storage tank in which drains will be collected. Over time, they will have to be pumped out using a sewer.

Another solution may be to choose a special drainage fecal pump, which will be able to raise the wastewater to a higher level and send it to a storage device located on the surface without burying it in the ground. But this option for a do-it-yourself sewage system is also optimal only for a temporary or seasonal dacha.

The topic of today's publication is the use of a septic tank for a summer residence with a high level of groundwater. Successful implementation of such a project will help to solve the problem of waste disposal with minimal costs.

Read in the article:

Creation of an autonomous sewage system for summer cottages with a high level of groundwater

Even if you decide to entrust all the work to professionals, your own knowledge on this topic will come in handy. They will help you buy a septic tank for high groundwater without overpayments, control the actions of performers when performing installation operations. It is necessary to clarify the operating rules in advance so as not to create unnecessary difficulties in the future. The extension of the service life is very important, since a large amount of earthworks, leveling of the surface, and the use of landscape design are expected. Repeatedly performing such actions is associated with significant costs.

You have to choose a reliable design that is able to ensure tightness over a long service life. During operation, the liquid washes away the soil, pushes the container up. Such influences can damage the connection to the transport system. In winter, it is necessary to prevent freezing of the installation, think over protection against heaving forces. Here are the main tasks that will have to be solved in practice. Based on this information, we will evaluate specialized equipment as a whole and its individual components, cleaning technologies, factory products and homemade products.

Determination of the groundwater level

Similar surveys are done during the creation of an autonomous water supply

Geological research is preceded by the construction of a house to clarify the depth of the foundation installation, the calculation of the drainage system. If this information is not available, the check can be done using a conventional garden drill. They also dig pits, but this method is accompanied by significant physical exertion.

Surveys are planned for the period of spring floods, when the highest groundwater level (GWL) is assumed. The drilling scheme is determined in advance, taking into account the expected installation site of the main structural elements of the septic tank itself and the sewage routes.

Purpose and principle of operation of septic tanks for summer cottages with a high level of groundwater

Such structures are installed if it is impossible or too expensive to connect to the main municipal sewage system. Cesspools are characterized by low productivity. These outdated cleaning products are still used in summer cottages. But septic tanks are much more convenient for year-round operation.

The principle of operation of septic tanks for summer cottages

The figure shows the main components of a modern set of equipment. Domestic wastewater flows through a gravity pipeline by gravity into the first part of the tank. Here solids sink to the bottom. The processes of biological decomposition immediately begin. Partially purified effluents enter the second section, where a "biofilter" with aerobic bacteria is installed to speed up the work processes. To increase efficiency, such installations are supplemented with forced air supply devices. From here, the liquid enters the infiltrator. This block distributes wastewater over a large area.

For your information! With the use of such a scheme, it is possible to obtain a purification level of up to 97-98%. It is completely safe for the environment. To obtain such a result, you need to make the correct calculation and not violate the rules for operating a septic tank for a summer residence with a high level of groundwater.

Special anaerobic bacteria are also used. They are cultivated using special techniques in an environment without access to oxygen. Beneficial decomposition processes using such agents take place inside the effluent. The obvious advantage is the simplification of the design due to the elimination of the aerator, and there is a decrease in energy costs. But to maintain the activity of such fillers, it is recommended to add a new portion of activators at least twice a month.

Expert opinion

Ask a specialist

“In any of the options, it is necessary to create favorable conditions for the vital activity of beneficial microorganisms. It is necessary to exclude the ingress of chlorine and other harmful compounds, antibiotics into sewer drains. Don't forget about vents and pipes. They are needed to remove gases that are released during fermentation. ”

Basic rules for installing a septic tank on the site

Please note that the figure shows the permitted distances to any part of the treatment plant. To clarify the data, you need to study the current legislation:

Standards	Document	Scope of application, features
Building codes and regulations (SNiP)	2.04.03-85	Construction of local treatment systems, transport highways for the movement of effluents.
SNiP	2.04.01-85 (2.04.4-85)	Location of sources and components of the water supply system in relation to treatment facilities.
Sanitary rules and norms (SanPiN)	2.1.5.980-00	Restrictions on protected areas near open water bodies.
SanPiN	2.2.1/2.1.1.1200-03	The boundaries of free space near septic tanks and other objects that can harm the environment.

The list of restrictions is too long to be considered in detail within a single publication. But it should be noted that the approved rules provide for many important factors:

• filtration and throughput capacity of different types of soils;
• the impact of effluents on different types of plants;
• direction of groundwater flow.

The minimum distance from the septic tank to various types of buildings is set as follows:

• residential building - 3 m;
• workshops, garages, other outbuildings - 1m;
• buildings intended for keeping poultry, small livestock - 4 m.

The distance to the border of the neighboring area must be at least 2 m. It is imperative to take into account the distance of the location of the marked objects in the adjacent territories.

Scope calculation and formulation of technical requirements

If you are guided by the provisions of SNiP 2.04.03-85, single-chamber septic tanks for summer cottages with a high water level are suitable for a wastewater volume of no more than 1 m³ per day. In such a structure, new ones are constantly added to the accumulated pollution. Poorly soluble fatty waste blocks the cleansing function. Quite often you have to use the services of sewers.

A two-chamber structure is used with a wastewater volume of 1-10 m³ / day

In some systems, the bottom of the second container is removed. Pebbles and other granular materials are poured there to create an additional filtration layer. But such a solution is not suitable for a summer residence with a high level of groundwater. In the project under consideration, all septic tanks are made airtight.

With a large amount of wastewater (> 10 m³ / day), three-chamber purification systems are used. The capacity of the containers can be distributed in the proportion of 50% -30% -20%. But these numbers are optional. The use of certain technologies is essential.

You also need to correctly calculate the required total volume. For accurate calculations, you can find a thematic calculator. The engineering formula takes into account several parameters:

• storage / processing time of effluents;
• standard standard for one person;
• the content of suspended impurities in the outlet pipe;
• temperature of the incoming fluid.

Related article:

After reviewing the information provided, you can get a more complete picture of the home sewage system and wastewater treatment system and already consciously start choosing the design of the treatment plant.

The correct solution to everyday tasks is quite acceptable using a simplified calculation. A suitable septic tank for a summer cottage with a high level of groundwater should contain enough waste so that there is enough time for it to be efficiently treated. Difficulties arise here, which are explained by the different positions of the regulatory authorities. According to building codes, the capacity of such a structure must be at least 3 days' volume of sewage. The sanitary standards indicate the minimum level of contamination that is allowed to be sent for final cleaning in a natural way into the ground.

With average levels of pollution, a proportion of 1.7-2.2 m³ per user can be used. Thus, 5.5 m³ is enough for a family of three. It is better to make a stock of 10-15% to exclude insufficient cleaning when the volume of wastewater increases.

For your information! For an accurate assessment, it is necessary to take into account the salvo discharge. This indicator denotes the ability to save functions while quickly passing the maximum number of drains.

If we are talking about a storage capacity, then you will have to increase the size. The average amount of waste water per person is 200 liters. The capacity of the tanks of standard sewage disposal equipment is from 4 to 5.5 m³. If you save too much on the initial investment, you will have to use the appropriate services more often.

When installing a compact septic tank for a summer residence with a high level of groundwater with a volume of 2 m³, it will be necessary to call specialists for removal every three days

Varieties of septic tanks with high GWL

Accumulative septic tanks with a high level of groundwater - an analogue of a cesspool

A large tank is installed underground to save space on the site

The location of the structure is chosen in accordance with the considered rules. The depth is determined by the level of soil freezing. It must be higher than the main tank. A suitable neck is selected accordingly.

In this variant, one camera is sufficient. To simplify control, a float sensor is installed, which signals the fullness of the tank. Since a fairly frequent emptying is assumed, the installation site is chosen closer to the border of the land plot, a wide and durable passage for freight transport is equipped.

Expert opinion

Design Engineer VK (water supply and sewerage) LLC ASP North-West

Ask a specialist

"Remember the standard distance to public roads - at least 5 m."

Budget septic tanks for summer cottages without pumping

Wiring diagram for installing a septic tank for a summer residence

These kits are available in different designs. The main container is divided by partitions into 2-3 functional parts. The standard equipment includes a cover, an inspection ladder, a ventilation pipe, and other components. As a rule, the model range is compiled taking into account typical needs. It is easy to find an option suitable for a particular property.

For your information! With the right choice of equipment parameters, the removal of solid waste will be required no more than once a year.

Biological treatment plants

What does a biological treatment plant consist of?

After multi-stage treatment of effluents, a good level of purification is ensured. Modern stations are capable of removing up to 97-98% of all impurities, which corresponds to the best multi-chamber septic tanks for summer cottages. Such structures are ideal for areas with high groundwater levels. They are sealed and perform their functions without an additional drainage field. Regular removal of solid sediments is not required in this case. Routine flushing can be performed independently or with the help of a service department.

Comparative analysis of different septic tanks for summer cottages with high groundwater levels

Septic tank type	Advantages	disadvantages
Cumulative	Light weight, reasonable cost, structure tightness. Lack of filtration fields, complex mechanisms and technologies. Ease of maintenance.	The need for regular use of the services of sewage services. Significant loads on the road coverage.
Multi-chamber	Long-term preservation of working capacity without calling the sewage equipment. High level of cleaning.	Possibility of environmental pollution due to incorrect installation of the filtration field. Decreased efficiency in the presence of hazardous microorganisms in the effluent.
Biological treatment station	Compactness. Ease of installation. Lack of additional cleaning area.	High price. Such equipment must be connected to the mains. Its complexity implies an increased likelihood of breakdowns.

Features of materials for the manufacture of cameras

Concrete septic tank with a high level of groundwater

A septic tank consists of many components - basic and additional.

The standard solution for our project will not work. Septic tanks for summer cottages with high groundwater levels are well insulated to prevent environmental pollution. To do this, close the bottom of the third tank, remove the drains from it to the drainage field.

High-quality prefabricated reinforced concrete products remain intact for decades. They are designed to withstand significant mechanical stress. They are not damaged by aggressive chemical compounds. However, it is necessary to take into account the difficulties in transportation, in the course of unloading and installation operations. To install large products, you need to dig a large pit. You will need a thorough sealing of the joints, additional equipment with a hatch, connecting pipes.

With the use of standard reinforced concrete products, it will not be possible to optimize the volume. With the heaving of the soil in winter, displacement of the rings is not excluded. In such a situation, soil pollution occurs. To restore the integrity of the structure and joints, a complex set of works is performed.

Plastic, composite materials

In such products, protection against loads is provided by a metal frame. Will come in handy:

• tightness;
• chemical neutrality;
• light weight.

But, as in the previous example, you have to handle standard containers of a certain volume. Additional equipment will be required with a neck, a large hatch, and connecting pipes. The overall financial and labor costs will be quite large.

It is more profitable to purchase a ready-made kit

The photo shows typical features:

• flat support (1) for good stability;
• stiffening ribs (2) to strengthen the structure while maintaining a low weight;
• separate functional chambers (3) designed for sequential wastewater treatment;
• built-in branch pipes (4);
• shafts (6) and hatches (5).

With a low weight, such a structure is pushed upward when the groundwater level rises. It needs to be fixed in its normal position. The disadvantages include limited strength.

Metal

Related article:

The device, the principle of operation, the requirements for the location, the independent equipment of treatment facilities for a private house - read in the publication.

Such a product can be made by yourself with the appropriate skills or by ordering from a specialized workshop. In any of the selected options, it is permissible to use the required dimensions, shape, placement of internal partitions, and other unique solutions. By using a sufficiently thick sheet, it is not difficult to provide the necessary strength.

However, it should be noted the significant cost of a high-quality steel septic tank. The work of a qualified welder is highly valued.

A layer that protects against corrosion is imperative. It can be damaged during installation. Therefore, you will need special care, careful preparation of the base.

Fixation of the septic tank from surfacing and protection from soil heaving

Algorithm of assembly operations:

1. The pit is dug in accordance with the scheme provided by the manufacturer's instructions. Observe the established slope of the walls.
2. At the bottom, a sand bed is made of 250-350 mm, followed by compaction.
3. Install a reinforced concrete slab. An additional layer of sand is made from above (without stones and other large fractions) with a thickness of 150-200 mm.
4. Lower the septic tank. Install supports if there are no flat supports.
5. Fill the container by ½ of the nominal volume with water.
6. Anchors are screwed into the reinforced concrete slab. Cables (tapes) are connected to them. Fix the septic tank in the desired position.
7. The free space in the pit is filled up in layers (200-300 mm) with a rammer. Water is added at the same time.
8. To prevent damage from heavy vehicles, a reinforced concrete slab with a hole for the hatch neck is installed on top.

When installed in clay soil, the septic tank is pushed out by heaving forces. They form in places where water is converted to ice and then expanded. To prevent damage, the container is installed at a depth below the freezing level. It is also useful to replace the original soil with sand, which allows moisture to pass through and performs damping functions.

Installation of an aboveground filtration field

If there are no natural elevations, create an artificial embankment. To supply wastewater there, a pump is installed in the distribution well. The pumping equipment is selected taking into account the contamination of the liquid.

For your information! The location of the finishing part of the cleaning at ground level and above increases the cost of the project.

Rating of manufacturers of septic tanks for high groundwater levels

A place	Brand name	Features of the lineup	Notes, positive features
1.	Topas	The range includes models with a cleaning capacity - from 0.8 to 3 m³ or more per day. To increase efficiency, the manufacturer offers multi-stage processing in multi-chamber septic tanks (up to 5 working volumes).	The manufacturer's narrow specialization helped to take a leading position in the market. Experts and users note the high quality of cleaning, reliability, timely introduction of the latest specialized technologies.
2.	Tank	Septic tanks under this brand are represented by the domestic enterprise "Triton Plastic". Productivity of popular models: 0.6-1.8 m³ / day.	Reasonable pricing is complemented by meticulous attention to detail. These wastewater treatment plants are well equipped to withstand harsh conditions.
3.	Triton	A special series of the production enterprise "Triton Plastic". The current model range includes storage tanks and multi-chamber septic tanks.	Affordable cost, wide assortment, ease of installation on your own.
4.	Termite	Productivity of popular septic tanks (m³ / day): 0.4; 0.6; 1. The range includes models specially adapted for installation in areas with high groundwater levels.	Seamless molding technology allows you to create strong, durable structures without defects. Each product is checked by a special set of tests before shipment to the retail network.
5.	Poplar	The manufacturer offers specialized equipment for household and commercial use. With the appropriate equipment, a large septic tank of this brand is capable of purifying more than 20 m³ of wastewater per day.	The equipment of this brand is distinguished by the high quality of compressors and other additional components. A higher position does not allow us to take the limitation of technological solutions.

Estimated prices for septic tanks for summer cottages

Brand / Model	price, rub.	Specifications, notes
	79800−82300	Productivity - 0.8 m³ / day. Salvo discharge - up to 175 liters. Designed for a family of four.
	35 800−37200	Storage device. Volume - 3 m³. Weight −135 kg.
	48 500−49800	Multi-chamber septic tank for summer cottages with a high level of groundwater. Volume - 2.4 m³. Productivity - up to 0.9 m³ / day.
	92 400−96500	The volume of processing per day is up to 1.9 m³. Salvo discharge - 470 liters. Electricity consumption - 50 W / h.
	71 500−73600	Cleaning performance - 0.5 m³ / day. For a family of 2-3 people. The set includes a compressor with a power of 40 watts.

For a detailed acquaintance with the parameters of the models you like, you can find the corresponding reviews on the Internet.

qwelle13, Moscow: Pluses: comfort! Fast installation, no dirt on the site! The installation of a septic tank takes place in one day. In the morning, at 10:00, work began and ended at 16:00. Turnkey works, that is, you can immediately use the toilet. The total cost includes the price of a septic tank, delivery, installation, commissioning.

Disadvantages: maintenance is required once a year, but, apparently, you cannot do without it.

More details on Otzovik: http://otzovik.com/review_619103.html.

What is the best septic tank with a high level of groundwater

Correct conclusions can only be drawn after a careful preliminary study of the real conditions on the land. In addition to the groundwater level, the possibility of placing the equipment is checked in accordance with the current rules and regulations. Clarify the usual and maximum needs, the mode of use. Based on the collected data, a search for a suitable model is performed.

Use the appendix to the publication for answers to additional questions. Here you can also post your own comments on the cleaning methods, the peculiarities of the operation of specific septic tanks for summer cottages with a high level of groundwater.

Video (installation of equipment for wastewater treatment):

In the event that it is not possible to connect the house or summer cottage to the central drainage system, you have to build a sewage system that works autonomously. In doing so, it is necessary to take into account local conditions, including such an important factor as the level at which the soil water is deposited. So, if in a given area there is a high level of groundwater, a septic tank will have to be built using a special technology. Let's see how this can be done.

Among the most popular options for an autonomous treatment plant, a septic tank is worth highlighting. This installation allows not only to accumulate, but also to purify wastewater. This is its significant advantage over drives that require regular pumping.

At the same time, septic tanks are much cheaper than modern biological treatment plants. And, unlike the latter, they are non-volatile. The use of a conventional septic tank with a high groundwater level (GWL) is excluded, since the purified water simply will not be absorbed into the waterlogged soil.

In addition, there is a risk that the sedimentation tanks will be flooded with groundwater. Consider what construction methods are used under such conditions.

Basic installation rules

If the groundwater is at a depth of 2 meters from the soil surface and above, then this level is considered high. A septic tank for high groundwater must have the following qualities:

• Complete waterproofing of cameras;
• The need to protect against surfacing;
• The need to prevent damage to the hull due to heaving of the soil during freezing and thawing.

Let's consider these points in more detail.

Tightness of chambers

Tightness is an important condition for the construction of any septic tank. However, if a wastewater treatment plant is being built with a high GWL, this factor needs to be given special attention. If cameras are not waterproof enough, there is a risk of contamination entering the groundwater.

And this is very dangerous, especially if the pollution reaches the aquifers. Carelessness in the construction of a septic tank can cause contamination of drinking water and provoke a surge in the disease of people living in this area.

Advice! When planning to build a septic tank and finding that the groundwater level on the site is high, it is worth abandoning the use of bricks or reinforced concrete rings as a material. The ideal solution would be a plastic septic tank or a monolithic reinforced concrete structure.

The easiest option is to buy a ready-made factory-made septic tank. Such models are made of plastic (less often fiberglass) and have an absolutely waterproof case. The disadvantage of this option is that with a high level of groundwater at the site, the risk of the treatment plant floating up significantly increases.

Ascent protection

In the event that it is planned to install a septic tank with a plastic case, you need to take care that the light case does not float up, lifted by groundwater. Such an emergency will lead to the complete destruction of the sewerage system and may contribute to environmental pollution.

Therefore, when installing a septic tank with a light plastic body, a technique called anchoring is used. This part of the work is done like this:

• In the prepared pit, the bottom is leveled. The quality of work is controlled by the level;

• A layer of sand 30 cm high is poured onto the bottom, it is compacted;
• A reinforced concrete slab is laid on top of the sand, then a septic tank is installed;
• Throwing the bandage straps over the top cover, fix them on the metal hinges of the embedded parts.

Advice! If it is not possible to use lifting equipment, it is not possible to lay the slab on the bottom of the excavation. In this case, the bottom of the pit should be poured with concrete mortar with the installation of embedded metal fasteners.

Homemade sealed design

If the owners want to build a septic tank with a high groundwater level with their own hands, then the most acceptable option is to install a monolithic concrete structure. All prefabricated septic tanks are not tight enough. Building a monolithic septic tank with your own hands is a laborious task. The main stages of work:

• preparation of the pit, device at the bottom of the sand cushion;
• pouring the bottom with concrete mixture with preliminary laying of metal reinforcement;
• construction of formwork for concreting the side walls of the tank and creating an internal partition. When constructing the formwork in the places of future overflows, as well as inlet and outlet channels, pipe sections of the required diameter are inserted. Since after the concrete has hardened, it will be difficult to make holes in the walls of the tank;

• pouring concrete mortar into the prepared formwork;
• connection of pipes;
• formwork for the floor slab with hatches for cleaning the tank and installing ventilation pipes.

The main difficulty in building this type of septic tank is the need to mix a large amount of solution. It is not easy to do this work with your own hands, therefore, if possible, it is better to rent a concrete mixer.

Protection against soil heaving

When the soil freezes and thaws, it moves. During the off-season, freezing and thawing cycles can be repeated several times a day. If a septic tank with a plastic housing is used, then such ground movements can lead to deformation or damage to the housing.

To protect the septic tank from such effects, a special backfill is used, consisting of five parts of sand and one part of dry cement. When digging a pit, the size of the pit is selected taking into account the fact that after installation between the wall of the body and the slope of the pit there were gaps of 15 cm wide on each side.

Backfilling is carried out in layers with compaction and water pouring of each of the layers.

Advice! In order to prevent deformation of the septic tank body during filling, it is necessary to simultaneously fill the chambers with water. Moreover, you need to ensure that the water level is always above the level of the backfill at the moment.

Organization of soil post-treatment

With a high groundwater level, it is not possible to build a drainage well or a conventional filtration field. In this case, it is necessary to construct a subsoil filter cassette. And since such a cassette will be located above the septic tank itself, then a sealed storage well with a booster pump will need to be included in the circuit.

Water from the septic tank will be supplied to the well, and then pumped into the filter cassette by a pump. Installation of the cassette is done as follows:

• The fertile soil layer is removed (30-40 cm);
• Sand is poured to ground level;
• Concrete bars with a height of 30-40 cm are installed along the contour of the pit. The bars are fastened together;
• Crushed stone is poured into the formed cavity;
• An infiltrator is installed on top (a plastic container that does not have a bottom), under which a supply pipe is fed;
• The infiltrator is carefully insulated. For this purpose, use foam or expanded clay;
• Then the cassette is covered with soil with a layer of at least 30 cm. After that, the resulting slide can be decorated.

Construction of a septic tank in clay

Difficulties also arise during the construction of a septic tank in clay soil, significant difficulties arise when filtration fields are being set up. On clay soil, filtration fields are built as follows:

• if the groundwater level is below 1.5 meters, semi-buried filters or filter cassettes are arranged;
• at a high ground level, they arrange a surface filtering cassette, constructing a sand and gravel cushion.

Since the layer of clay soil, most often, has a thickness of no more than 2.5-3 meters, then at a low level of GWL it is possible to install a filter well.

Advice! To choose the appropriate option for a septic tank in clay soil with your own hands, you need to study the types of soil on the site. The most accurate information can be obtained by ordering geological exploration, however, this will require additional costs.

When building filtration fields in clay soil with your own hands, you must first of all calculate their area. This indicator depends on the number of drains. So, with a daily water consumption of 0.5 cubic meters, a meter per meter area will be enough.

If the volume of wastewater is doubled, it will be necessary to build filtration fields with an area of ​​2 square meters. When building filtration fields with your own hands, the following rules should be observed:

• the distance from the bottom of the filtering ditches to the occurrence of groundwater must be at least 1 meter;
• a drainage mesh is laid on the bottom of the prepared ditches, on top of which rubble and sand are poured;
• drainage pipes are laid with a slope of 1 cm per meter of length.

Since clay hardly absorbs water, you need to take care not only of the construction of filter cassettes, but also of the drainage of the liquid. To do this, you should build a drainage system with your own hands. This system will remove not only treated, but also rainwater.

It is recommended to construct a ring drain around the septic tank. To do this, dig a trench so that its bottom is 20 cm below the freezing level of the soil. A sand cushion is poured inside and geotextiles are laid. Drainage pipes are laid with a slope, covered with sand and gravel and wrapped in geotextiles laid earlier.

• The installation of a septic tank should be carried out starting in mid-summer or early autumn. At this time, the GWL is the lowest;
• If the pit is filled with water, then installation cannot be performed, you must first pump out the water;
• With a high groundwater level, the septic tank should not be deeply buried. It is more profitable to install it at a minimum depth, and then insulate it well.

With a high GWL, septic tanks may well function. Only these treatment facilities will need to be built using a special technology, taking into account the specific conditions of the area.