Wastewater treatment systems for a private house

Recommendation points

• Cesspools
• Septic tanks
• Deep biological treatment stations

From this article, you will learn about the most common ways of arranging a wastewater treatment system for a private house, the pros and cons, operating features, and the cost of each of the options for these systems.

Competent arrangement of the drainage system can be considered one of the most difficult and responsible tasks in the design of an individual house. The most common ways of arranging a local sewage system are:

• cesspools
• septic tanks of various types
• biological treatment systems

All wastewater treatment systems work with the participation of microorganisms, which in the course of their life absorb contaminants, which are an excellent breeding ground for them. The number and species composition of these bacteria determine the type and quality of the final cleaning. The organization of the process is fundamentally possible only in three ways:

1. Using putrefactive bacteria, without creating additional favorable conditions for them. Wastewater treatment is minimal. This type is typical for various wastewater storage tanks..
2. The use of anaerobic microorganisms living in an oxygen-free environment. The degree of wastewater treatment is on average about 50%. This option is used in the work of various types of septic tanks. Advanced bio-feed devices involve intermittent feeding of cultured microorganisms.
3. The use of aerobic bacteria that require constant oxygen supply. The wastewater treatment process is similar to the natural decomposition of waste, but much faster. At the outlet – 98% purified industrial water. Used in bioremediation systems with aeration tanks.

Thus, it is possible to equip a local sewage system in various ways and at different costs, but the effect will not be the same. The choice of the system remains with the owner of the home, and in order to facilitate it, we will consider the main ways of arranging an autonomous sewage system.

Cesspools

Devices are the simplest storage devices designed to collect sewage. The effluents enter the tank through a pipeline, which must be laid below the freezing level of the soil or additionally insulated. As the pit fills, it is cleared out with a sewer truck. The structure must be sealed, this is the guarantee of its safety. Variants of pits without a bottom or with a filtering layer of sand and gravel arranged at the bottom poison the soil and, accordingly, groundwater, which makes them a serious source of pollution.

An autonomous sewerage system with a cesspool has certain advantages:

1. Extreme simplicity of design.
2. Cheapness of manufacture and installation. In the event that an industrial production capacity is purchased, the costs will be slightly higher.
3. The device requires no maintenance, except for pumping down. Does not depend on the power supply and does not need the arrangement of additional cleaning zones, such as filtration wells or fields.

There are also disadvantages of the system:

1. The need for regular pumping of sewage, which requires certain costs to pay for the services of sewers.
2. A fairly high probability of depressurization of the container and the ingress of effluents into the soil and groundwater. This is especially true for metal structures that are prone to corrosion..
3. Bad smell.
4. The location on the site is limited by sanitary standards, while taking into account the possibility of free access to the pumping facility.
5. Impossibility of arrangement in case of high groundwater level.

There are many options for arranging cesspools. The simplest, but also the most expensive, is the purchase of a ready-made tank. Most often these are plastic containers of various shapes and volumes. They are not subject to corrosion and retain their tightness throughout the entire service life. There are many varieties of these drives. These are “Tank”, “Triton”, “Leader”, “Topas” in various modifications. The cost of devices starts from 9,000 rubles.

Many people prefer to equip cesspools with their own hands. Such structures are made of bricks, concrete, cinder blocks or tires. Another common option is to use a ready-made metal container or make one according to the required dimensions. In any case, choosing a cesspool as an autonomous sewage system, one should evaluate the intensity of its future pumping. Very often, the costs of cleaning are high and nullify the apparent benefit from arranging the cheapest option..

Septic tanks

A septic tank is a technologically connected system of containers in which mechanical treatment of household waste takes place with the participation of anaerobic bacteria. Contaminated liquid flows from one container to another. In each of them, solid fractions settle, which are subsequently decomposed by bacteria. The accumulated sediment must be periodically removed from the system. Septic tanks purify wastewater up to a maximum of 60–70%. All solid insoluble contaminants remain inside the system, and light fractions continue to be present in the water. It needs to be further cleaned. For these purposes, special structures are used, the choice of which is due to the type of soil.

Most often these are filtration fields. They are spray pipes placed in trenches of a filter element with a minimum thickness of 1 m, under which a drain is laid to drain clean water. Such fields should be equipped at a certain distance from sources of drinking water and fruit plants. In addition, the depth of their laying should be greater than the level of soil freezing, otherwise the system will not be able to work in the cold season. Once every five to seven years, it is necessary to excavate the structure, completely flush or replace the filter layer. In any case, such fields are a very expensive and environmentally unsafe device..

A water purification system for a private house – using a septic tank has undeniable advantages:

1. Complete non-volatility.
2. Relative cheapness of arrangement and installation.

Its disadvantages include:

1. Low level of household wastewater treatment.
2. The need to equip an additional cleaning system such as filtration wells, fields, etc..
3. Regular, although not as frequent as for cesspools, sludge pumping out of the system.

The septic tank can be equipped by yourself. For this, several containers are made, connected to each other. They can be made of concrete, brick, tires. Euro cubes are also used for these purposes. Homemade systems will cost their owner less than industrial septic tanks. However, the latter are distinguished by high reliability and a variety of models, which allows you to choose the option that is optimal for specific conditions..

The main criteria for choosing a septic tank are:

1. The capacity or amount of effluent processed by the device. Measured in cube. m / day.
2. Material quality of containers.
3. The maximum amount of salvo discharge, that is, the volume of wastewater simultaneously entering the device chamber in cubic meters.
4. The degree of purification carried out by the structure.
5. Limit value of short-term loads. For some models, it is permissible to exceed the passport loads for a short time, which must be indicated in the device documents.
6. The ability to install the structure in conditions of high groundwater levels.

As practice shows, it is best to purchase a septic tank from companies specializing in the sale and installation of devices. In this case, you can be sure of the correct selection and installation of the system, which will save you from problems and additional costs for correcting mistakes. In addition, it is necessary to familiarize yourself with the certificate, hygienic conclusion and guarantees. These documents must be present.

Comparative characteristics of the most common models are shown in the table:

	Volume options	Purification degree	Material	Additional benefits	The cost
Tank	From models designed for 1-3 people. up to options for 7-9 people.	Up to 70%, the use of the infiltration system offered by the manufacturer allows you to get up to 98% purified water	Durable plastic up to 17 mm thick, seamless body	Block-modular design makes it possible to assemble systems of the required volume,	From 27,000
Triton	From devices for 1-2 residents to systems for 38-40 people	60%, further post-treatment required	High-strength polyethylene from 14 to 40 mm thick	Low cost of the device, ease of installation	From 20,000
Cleansing	From models designed for 2 people. up to devices for 18 residents	For systems with a biofilter – up to 80%, additional cleaning is required	Polypropylene, fiberglass with a thickness of 10 to 14 mm	Built-in biofilter, additional resistance to large volley discharges, adapted to Russian climatic conditions	From 24,000
Sprout	From options for 1-2 people. up to systems for 8 people.	For devices with biofilter – up to 80%	Polypropylene 10 mm, seamless body	Protection against salvo discharge, a special shape that prevents the device from floating, service is required every 1-2 years	From 25,000

Deep biological treatment stations

Deep biological wastewater treatment – can only be carried out with the help of aeration stations. These are devices that use the principle of natural biological purification, which is ubiquitous in nature. Mechanical purification in combination with the action of bacteria of aerobic and anaerobic types allows to obtain at the outlet 98% purified industrial water and sludge, which can be used as fertilizer.

The principle of operation of the systems is quite simple. The effluent enters the receiving chamber, where large impurities are crushed and the liquid is saturated with oxygen. The wastewater prepared in this way, having passed the coarse filter, is directed to the biological treatment chamber with the help of an airlift. Biomass forms active suspended sludge, on the flakes of which purification processes take place. With the help of airlifts, the waste sludge is transferred to the activated sludge stabilizer.

Treated effluents are freed from suspended particles dissolved in them and discharged into water bodies or to the relief. In addition, such water can be used for technical needs, for example, for irrigation. On average, once a month, the waste sludge is pumped out of the device using a standard pump. It is an excellent source of biofuel and high quality fertilizer.

The advantages of using such a system are obvious:

1. High degree of wastewater treatment, reaching 99%, which allows you to freely discharge the received industrial water or use it for household needs.
2. Compact dimensions of the units, allowing to minimize the work on the arrangement of autonomous sewerage.
3. Extremely easy to maintain.
4. Lack of unpleasant odors.
5. Easy installation of the device, which does not require special equipment.
6. Can be installed in any type of soil.
7. Additional materials in the form of various biological products are not required for the normal functioning of the system.
8. No restrictions on the location of the installation.
9. The polymeric materials from which the structure is made allow to obtain an ultimate durability of at least 50 years, high strength comparable to metal and concrete, and sufficient thermal insulation of the body.

The most significant design flaws are:

1. Volatility, since electricity is required to operate the compressor supplying oxygen to the bioreactor.
2. The rather high cost of such installations.

The selection of a suitable model of a biological treatment plant should be based on the following parameters:

1. Number of plant users and average daily waste water volume. In this case, only the number of people permanently living in the building should be taken into account. If their number increases from time to time, for example, guests come, then the average water consumption should be slightly increased and a model designed for a slightly larger volume should be chosen..
2. Jacuzzi and bath volume. The value of a possible salvo discharge.
3. Number of drainage points. These include washing machines, sinks, bathtubs, toilets, etc..
4. Possibility of simultaneous use of showers and baths.
5. Method for draining clean water. There are three options: forced drainage using an additional pump, used for clay soils, gravity, used for sandy soils, and combined.
6. Approximate amount and type of disinfectants, detergents and cleaning agents used in the home.
7. The need for an additional disinfection system, built-in pumping sewage station, etc..

The range of aeration units is very wide. Among them, you can find both devices designed for the processing of wastewater from residential buildings, and facilities in which wastewater is purified from farms. Deep cleaning stations include “Topas”, “Topol”, “Unilos”, “Clarofix” and others. Let’s take a closer look at some of them..

Topas systems are represented by a wide variety of options. The sizes of the devices range from installations for 5 people to systems for 150 people. One-piece equipment cases are made of high performance three-layer polypropylene sheet. This allows the systems to be installed in any soil.

Deep cleaning units use in their work a classic continuous aeration system with a storage tank. Depending on the model, the energy consumption of the devices ranges from 1.5 to 30 kW / day. Available in standard and extended models with gravity drainage of clean water. As well as standard and extended equipment marked “Pr”, equipped with an additional pump for forced removal of purified water. The cost of devices starts from 79,000 rubles.

Installations “Topol” are distinguished by a wide range of applications: from individual devices designed for 1–5 people, to collective stations serving from 100 to 150 people. Expanded polypropylene, from which the body is made, is not only non-corrosive and very durable, but also an excellent heat insulator. That allows you to operate the equipment at low temperatures. The system is compact and can be installed in any type of soil. It is possible to operate the device in the absence of sewage.

The power consumption of aeration plants, depending on the model, varies from 1.2 to 24.3 kW per day, which can be considered very economical. Available in standard and extended versions. In addition, the models differ in the purified water drainage system: both gravity-flow devices and with an additional pump for forced discharge are available. The latter are specially marked. The cost of devices starts from 70,000 rubles.

The new generation Clarofix systems are designed to treat a relatively small amount of wastewater and maintain buildings that house 4 to 50 people. There are four standard sizes of devices. The body, reinforced with ribs of strength, is made of high-strength polymer, as an option, monolithic reinforced concrete can be used. In this case, the housing is filled directly at the installation site. A distinctive feature of the design is the minimum time spent on the biological purification cycle. This value is two to three times less than the indicator of similar systems..

The automatics with which the device is equipped, depending on the amount of incoming wastewater, independently selects the operating mode, including, if necessary, an energy-saving cycle. The aeration system is also original, designed in such a way that the possibility of clogging of the aerator is completely excluded. In general, the device minimizes the risks of clogging, breakdown or overloading of equipment. Prices for installations start from 162,000 rubles.

It is possible to organize an autonomous sewage system for a country house or summer cottage in different ways. If you do not plan to permanently reside, a sealed industrial-made or self-made drive is quite suitable. For a house with a small number of residents, a septic tank will be good. If you need to equip a sewerage system in a cottage with permanent residence, the best choice is a deep biological treatment station. Despite the somewhat frightening cost, such devices are durable, reliable and very cheap to maintain. Whereas at first glance, inexpensive cesspools and septic tanks require rather expensive and laborious maintenance, for example, cleaning or replacing the filter layer.