Today we will find out how to choose an autonomous sewage system in a private house and what is the best way to utilize the liquid waste generated in the process of vital activity of its inhabitants. The correct choice of a waste management system is possible only on the basis of an analysis of the advantages and disadvantages of each system. In the article, we will consider each design, a list of constituent elements, the principle of operation, features, strengths and weaknesses, and also we will discuss in which case it is expedient to use this or that system.
At one time this type of autonomous sewer was the only one and had no alternative.
Device. Cesspools have a simple design and are dug in the area of a sealed container, into which the collector discharges sewage. The pipeline is laid below the freezing level of the soil, if for any reason it is impossible to do so, its insulation is made.
The storage devices used in private households are made mainly of the following materials:
- reinforced concrete rings;
- plastic container;
- monolithic reinforced concrete structure.
Each of the above cesspool constructions has its own characteristics, which must be taken into account when building them.
The store is made of bricks. When constructing a storage ring made of bricks, it is allowed to use only ceramic, which is sufficiently resistant to aggressive media. The optimum shape of this structure is round, if viewed from above, which provides maximum strength.
Reinforced concrete rings. They are mounted using heavy construction equipment. The use of well rings significantly increases the strength of the structure and excludes the possibility of collapse of the walls with prolonged exposure to aggressive wastewater.
Storage tank made of plastic. Has sufficiently thick walls and is made of plastic, resistant to moisture, acids and alkalis. This product is extremely reliable and durable. The relatively small weight of the drive allows for manual installation with the assistance of several assistants. But in this case, you have to spend money on the purchase of the tank itself. On the market there are many manufacturers and their modifications of different capacities.
Monolithic reinforced concrete cesspool. It diffuses directly on the spot in a removable formwork using a high-quality cement-sand mixture and steel reinforcement. On the outer surface of the walls of the cesspool is applied waterproofing to protect the concrete from destruction under the influence of the external environment.
The domestic sewage accumulators are placed taking into account the requirements of SNiP 30-02-97 and SanPiN 42-128 -4690-88:
- The distance to the water lines is at least 10 m, to the wells - no closer than 20 m, to the boundaries of the site - more than 1 meter.
- The maximum depth of the cesspool is 3 m and is determined taking into account the water table.
- The distance to residential buildings and outbuildings should not be less than 10-12 meters. A close arrangement can lead to the erosion of foundations.
Principle of operation. All sewage flows through the pipes to the tank. With the accumulation of effluents, they are pumped out by specialized sewage vehicles. The level of liquid waste in the cesspool should not exceed 0.35 m above ground level. Overflow can lead to leakage to the ground and contamination of soil and aquifers. Cleaning of the cesspool is made as necessary, but not less than once in the half year. With the same periodicity disinfection of storage devices is carried out using special solutions.
+ Pros of cesspools
- The complete tightness of the serviceable drive prevents the possibility of soil and aquifer contamination.
- Simplicity and reliability of the construction, which can be built on its own without the involvement of specialists.
- The relatively low cost of purchasing and installing a finished storage ring made of plastic.
- Completely non-volatile system.
- Disadvantages of cesspools
- The need for periodic cleaning of storage tanks from liquid waste. Such facilities will be optimal only in houses intended for temporary residence of a small number of people.
- With a volume of effluent more than 1 cu. meter per day, even large storage in 6 cu. meters are filled within a week, and their operation is too expensive.
- Very unpleasant odor when carrying out clearing works.
- When the cesspool is located on the site, it is necessary to take into account not only the sanitary norms, but also the possibility of the car entrance for pumping out the drains.
- It is impossible to equip with a high level of groundwater.
In which case it is worth using a cesspool. Cesspool cesspool is used mainly in private houses in cottages, not intended for permanent residence. This is due to the limited capacity, which necessitates frequent cleaning with the use of sewage vehicles. The cost of works with frequent cleaning can be a significant part of the cost of utilities. In this case, it is necessary to take into account that with a high groundwater table it is necessary to use a plastic container. When using other types, it is difficult to achieve full tightness. which will lead to the filling of the pit with groundwater.
The basis of liquid wastes is ordinary water, and the task of autonomous sewage system is to ensure its purification to a safe level. Then there will be no need to collect and store a large number of drains. This problem is solved with the help of septic tanks, which separate from water mechanical, biological and chemical pollution. Separation of water from solid insoluble impurities occurs by the flow of effluents from one container to another. At the same time, the water is not completely cleaned and its post-cleaning is required, which is carried out with the help of various filtration systems. Let us consider in more detail the features of the device and operation of septic tanks with different filtration systems. This will make it possible to choose the most suitable device for specific conditions taking into account all factors.
Septic tank with filtration well
Device septic tank with filtration well. The treatment facilities of this type can be constructed independently from available materials, and it is possible to purchase ready-made, technically equipped devices for these purposes.
A septic tank with a filtration well consists of the following elements:
Inside the tank there are compartments, passing through which the effluents are purified from solid impurities. The filtration well is installed in such a way that its lower edge is above the water table. At the bottom of it a two-layer cushion consisting of coarse-grained river or quarry sand is poured, on top of which gravel of medium and fine fraction is poured.
One of the options for implementing such a disposal of wastewater is the system of overflow wells. The treatment facilities of this type can be built of bricks or concrete rings without the involvement of specialists. This circumstance significantly reduces the costs of their creation and operation.
Principle of operation of a septic tank with a filtration well. Sewage through the pipeline enters a sump with a sealed bottom, solid particles settle to the bottom, and insoluble fats float to the surface. In some cases, there may be several such sedimentation tanks, through which drains pass successively.
Partly clarified water through the connecting manifold, embedded in the wall of the container at a height of 2/3 from the base, is poured into a filtering well. At the bottom of this structure there is a pillow of sand and gravel, through which moisture also seeps. To reduce odors from the sediment bowl, it is recommended to periodically use additives containing cultures of anaerobic bacteria. Microorganisms efficiently decompose biological waste into relatively safe components.
Gradually, the cushioning of the cushion occurs and replacement of the rubble and sand with clean ones is required, after which the well will be able to perform its task again. The process of siltation of the well in this case is significantly slowed down, it is necessary to pump out liquid waste not more often than once a half-year. The time of operation of the structure before the complete siltation of the bottom of the well depends to a large extent on the composition of the soils. Sandy and sandy loam soils absorb water well and, consequently, have a greater resource, clay and loams practically do not absorb liquids, and the wells are quickly clogged. Replacement of the gravel-sand cushion in the filtration well is carried out approximately once every five to six years.
+ Pros of septic tanks with a filtration well
- The main advantages of a septic tank with a well is the simplicity of the design.
- Significant time between the next maintenance operations.
- Complete nonvolatile system.
- Minuses of septic tanks with a filtration well
- It is not possible to locate at a high level of groundwater.
- Not suitable for clay soils.
- The level of sewage treatment is not high.
- It is necessary to cleanse the septic tank regularly of silt, but not as often as from cesspools.
- After 5 - 6 years will have to change the gravel-sand cushion in the well, the operation is very dirty and labor-consuming.
In which case you can use. The productivity of such systems depends heavily on the composition of soils and the level of groundwater. Such treatment plants are used in houses designed for year-round residence of a family of three or four people. The system is unable to cope with salvo discharge, which can lead to overfilling and the flow of liquid waste to the ground. Uninterrupted operation of such a system is guaranteed if it is used on sandy and sandy loam soils, as well as chernozem and loam with a predominance of sand, with a low groundwater table.
Septic with a filtration field
The device is a septic tank with a filtration field. Toughening environmental standards leads to the need to improve autonomous treatment facilities. A multi-stage septic tank with a filtration field is a complex system and consists of such components:
1. Sedimentation tank. 2. The distributing well. 3. Fields of underground filtration. They consist of perforated pipelines and gravel-sand pillows located in the ground, which serve as filters. The thickness of the filter element is from 1 meter or more.
The principle of operation of a septic tank with a filtration field. Sewage from the internal sewer falls into the sump consisting of two or three chambers. In the first compartment, waste is settled, and gradual subsidence and ascent of insoluble contaminants occurs. Clarified water is poured into the following chambers, where the subsequent purification steps take place. Further, the water from the settler enters the distribution well. From the well, water enters the pipes of the filtration field and seeps through the holes in the pipes, it is absorbed almost completely in the fields.
Some systems are equipped with another well that is installed behind the filtering field, as well as a drainage system. In this well, water comes from the drainage system, which is then pumped out to the discharge channel by means of a pump.
To accommodate such structures, large areas of over 30 square meters are needed. meters. The productivity of underground filtration fields depends largely on the composition of the soil: the best option is sand, the worst is clay. Purified water enters the aquifer or is collected in drainage ditches or wells. The service life of the fields before silt is about 10 years, after which the sand-gravel cushion is to be replaced.
+ Pros of a septic tank with a filtration field
- High performance.
- No maintenance required for a long period.
- Disadvantages of a septic tank with a filter field
- Large areas are required for the installation of the filtration field.
- The level of water treatment from pollution in such systems is not high enough for its use, even for irrigation or household needs.
- High cost of construction.
- Approximately in 10 years the filtration system is silted and its reconstruction is needed, which is an expensive and labor-intensive process.
In which case you can use. Use of septic tanks with filtration fields is possible only on large areas of land. The high productivity of such structures allows them to be used in houses with a large number of residents. On the sites, under which the filtration fields are located, it is possible to break up flower beds and lawns, it is forbidden to plant cultivated plants, trees and shrubs. Accumulation of harmful substances in fruits of cultivated plants can lead to an outbreak of gastrointestinal diseases.
Septic tank with infiltrator
The infiltrator is a replacement for drainage pipes, and its main advantage is a much smaller area, in comparison with the filtration field. The infiltrator is a long plastic tank, reminiscent of a trough. Only it is installed by the bottom to the top and has an inlet and an outlet. Infiltrator capacity of 400 liters is able to replace about 35 meters of filtration field pipes.
The device is a septic tank with an infiltrator. According to the device, septic tanks with an infiltrator are of two types: with an intermediate well located between the septic tank and the infiltrator and without it.
A septic tank with an infiltrator consists of the following components:
1. Septic; 2. Trumpet; 3. Pillow of rubble; 4. Infiltrator; 5. Ventilation.
A septic tank with an infiltrator and an intermediate well consists of the same elements, but additional devices are added here, which you can see on the infographics below.
Infiltrator in the section.
The process of installing infiltrators.
The principle of the septic tank with an infiltrator. First, let's look at the principle of the operation of an infiltrator without a well. Sewage drains enter the septic tank where, passing through several chambers, they undergo a certain purification. Further, by gravity through the pipeline, they enter the capacity of the infiltrator and are absorbed into the rubble.
The principle of the infiltrator with an intermediate well. The drains pass through the septic tank and enter the intermediate well, where there is a drain pump with a float that rolls water into the infiltrator. Further the sinks are absorbed into the pillow from the rubble. Such a system is used to prevent the sewage from entering the septic tank. The system is designed for use in areas with a high level of groundwater and poorly absorbed soils.
+ Pros of a septic tank with an infiltrator
- Does not occupy a large area.
- Simple installation.
- An infiltrator with an intermediate well and a pump can be installed in areas with a high level of groundwater.
- Copes with volley discharge of drains.
- Rare maintenance of the system.
- Disadvantages of septic tank with infiltrator
- Over time, the infiltrator will have to be cleaned, and the pillow will be replaced from rubble, but it will not happen soon.
- A septic tank with an infiltrator and an intermediate well with a pump is volatile.
- The level of water purification is not high enough.
- The area above the infiltrator can only be used as a lawn.
In which case is it necessary to use a septic tank with an infiltrator. It is expedient to place this system on well-absorbing soils, such as sand, chernozem, loam with small clay inclusions and low groundwater level. Facilities of this type are able to absorb a large number of drains, including volleys, when a large amount of water enters the septic tank at the same time. It is possible to use in houses with a large number of residents.
In which case it is necessary to use a septic tank with an infiltrator and an intermediate well. A system with an intermediate well and a pump is advisable to use in areas with a high level of groundwater. The use of an intermediate well with a pump and a non-return valve prevents the sewage from entering the septic tank again, if the effluent reaches the infiltrator very slowly.
A high level of groundwater and limited land does not allow the use of traditional methods of water treatment. In such conditions, and for the protection of the environment, the use of factory-made biological purification systems is recommended. There are several varieties of such structures on the market that can provide almost complete purification of water from pollution.
Septic with biofilter
Device septic tanks with biofilter. Septic tanks with biofilters are used in private households and organizations. In general, the device consists of a septic compartment and a compartment with a biofilter. In the compartment with the biofilter there is a backfill from a certain non-rotting material: expanded clay, polystyrene, synthetic fibers. In the process of the septic tank, a biofilm consisting of numerous bacterial colonies is formed on the surface of the backfill. Now let's look at what constituent elements are composed of various septic tanks with biofilters.
1. Membrane with holes; 2. Ventilation; 3. Ring number 1; 4. Blanking plug; 5. Ring number 2; 6. Bacterial stop; 7. The corps of LOU; 8. Biofilter with loading; 9. Flat filter.
Examples of other septic tanks with biofilter:
The principle of the septic tank with biofilter. Sewage through the input collector enters the first compartment of the septic tank, which serves as a settler. Here there is a settling of solid particles and separation of fats with their subsequent ascent. The wall between the compartments is a membrane with a plurality of calibrated holes through which the conditionally clarified water is transferred to the second chamber. Here, the liquid passes through a coarse filter, where solid particles are removed. For this purpose, a special fabric or other material is used.
The last stage of water purification takes place in a chamber with anaerobic bacteria, which in the process of vital activity destroy organic compounds. After that, the filtrate enters the storage tank and can be used for technical needs. It is allowed to discharge water to the ground or to a drainage ditch, the level of residual pollution is not sufficient to have a significant impact on the environment.
+ Pros of septic tank with biofilter
- A good degree of water purification is 85 - 95%.
- Do not require frequent maintenance, just once a month pour into the toilet bowl containing drugs.
- The system does not require electricity.
- Does not exude unpleasant odors.
- Installation is quite simple and does not take much time.
- Disadvantages of septic tank with biofilter
- Do not allow a long simple system (2-3 weeks), as a result of which the death of bacteria can occur.
- Bacteria do not tolerate chlorine and many chemical detergents used in everyday life.
- There is a need to add biologics.
- The cost of the system is more expensive than a normal septic tank.
In which case should you choose a septic tank with a biofilter. A septic tank with bio-purification can be used in individual houses that are used for permanent residence. Such facilities do not require frequent maintenance and are easy to handle, so the introduction of cultures of microorganisms can be carried out through the toilet. The main disadvantage is the possible death of anaerobic bacteria in the long idle time of autonomous sewerage. The cycle from the introduction of new crops to achieve maximum efficiency reaches 14 -15 days.
The station of deep biological purification with forced air supply
The device is a system with forced air supply. To determine how to choose an autonomous sewer for a private house with a large number of tenants, let us consider the possibilities of stations of deep biological purification. Such systems are characterized by high performance, over 1.5 cubic meters. meter drainage of household origin per day. The septic tank with forced air supply is located in one housing, divided into several compartments:
1. Issue; 2. Tertiary clarifier; 3. Aerotank of the first stage; 4. Secondary clarifier; 5. Aerotank of the second stage; 6. Grain settler for collecting silt, sand, fats; 7. Log drains.
Example of the device of another deep bio-cleaning station:
Deep cleaning system with open hatch.
The process of installing a deep wastewater treatment system.
Examples of water removal from the station:
Through the absorbing well, it is applied on soils with good coagulability.
On the relief in the ditch.
On the relief, through the distribution well, for the use of purified water.
The principle of the deep biofeed station. The effluents fall into the sedimentation tank, in which the process of separation of fat takes place with the help of a special device and the settling of insoluble particles with the formation of silt. Further, the filtrate is mixed with the active silt consisting of algae and microorganisms of aerobic type. To intensify the processes of their vital activity, the compartment is aired with external air, which is pumped by an electric pump. In the last compartment, sedimentation of the sludge occurs, which is subsequently pumped into the aerotank for reuse and creation of a closed cycle. Water, purified to the level of 98-99%, merges into drainage or used for household needs.
+ Pros of a deep biofeed station
- The water passes a sufficiently deep purification, which is 98 - 99% and can be used for technical needs.
- The plants are compact enough.
- Do not publish unpleasant odors.
- The installation is quite simple.
- Installed in any areas, regardless of the level of soil and soil type.
- Do not need consumables in the form of various biologics.
- The system is quite durable and is designed for decades.
- Cons of a deep biofeed station
- For the functioning of the system, constant air supply is necessary, and hence constant supply of the installation with electricity.
- Without air supply, aerobic bacteria begin to die.
- Systems of this type are quite expensive.
- A prolonged absence of effluents leads to the death of bacteria and microorganisms that make up the active sludge.
- Over time, sludge accumulates a significant amount and it must be removed, this procedure is carried out 2 times a year.
In which case is it worth using. The main advantage of a septic tank with forced air supply is high productivity and the degree of water purification. Such equipment has no restrictions on use, it is optimal for houses with a large number of residents and practically does not require maintenance. It can be installed on any ground, regardless of the level of ground water.
General criteria for selecting a septic for a country house
The issues of the device of autonomous sewerage in each case are solved individually, taking into account a number of factors. The main criteria for choosing an independent sewage system for an apartment building:
1. Purpose of the building: for permanent or temporary residence.
Some types of purification equipment do not allow long downtime. For cottages and small houses a cesspool of a cumulative type of calculated volume is suitable.
2. The size and geology of the land, as well as the composition of the ground and the level of groundwater.
On small sites it is impossible to use septic tanks with fields of underground filtration. It is not allowed to use septic tanks with a filtration well at a high level of groundwater.
3. Daily volume of effluent and volley discharge.
It is calculated on the basis of the number of permanent residents in the house and the number of guests who regularly visit the owners. Knowledge of this indicator is necessary to determine the productivity of the septic tank, which is indicated in the technical documentation.
4. Financial Possibilities of the homeowner.
High-tech equipment, taking into account the cost of installation and maintenance will be quite expensive. To reduce costs, it is recommended that one- or two-chamber septic tanks be constructed from available materials and without the involvement of specialists.
To determine which autonomous sewerage to choose for a private home, all the above factors should be taken into account and, if necessary, consulted and brought to the work of specialists. Errors in the design and installation of autonomous sewage systems can cause extremely negative consequences.