Which is better - a septic tank or a cesspool?

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Which is better - a septic tank or a cesspool?
Which is better - a septic tank or a cesspool?

Features of the choice of sewerage for a summer residence. The device of septic tanks and cesspools, their differences, pros and cons, principle of operation. Recommendations for effective cleaning of storage facilities. When, in the process of building a country house, it comes to creating a sewer system, many owners have doubts about the choice of a method for collecting and disposing of effluents. In the question of which is better - a septic tank or a cesspool, we will try to figure it out today.

The main differences between a septic tank and a cesspool

Cesspool scheme

There are technical differences between these two types of sewer structures that should be considered before building any of them:

  • Principle of operation… A cesspool is a reservoir of contaminated wastewater, which is stored in it until it is pumped out by a sewage machine. The more intensively it is filled, the more often you will need to order the services of such equipment. The main purpose of the septic tank is the sedimentation of waters and their biological post-treatment. The degree of extraction of contaminants in such a structure is about 80%. The processes involve preparations based on biological enzymes.
  • Number of working containers… Unlike a cesspool, which is a single reservoir, a septic tank can include in its cleaning scheme two or three tanks connected in series to each other.
  • Service… The contents of the cesspool need to be pumped out more often than to empty the septic tanks from the sediment. In the second case, this happens no more than 1 time / year.
  • Price… The device of a septic tank always costs more than digging and arranging a cesspool. But its maintenance will require less costs due to the fact that the services of sewer workers are required less often than in the second case.
  • Environmental Safety… If the cesspool is completely sealed, then it does not pose a threat to the external environment. But if it is manufactured as a filter element, there is a risk of soil and groundwater contamination. Septic tanks, if properly designed and installed, observing the technology, will not cause any harm to the environment.

Advantages and disadvantages of a septic tank and a cesspool

Septic tank scheme

After determining how a septic tank differs from a cesspool, it will be useful to evaluate the advantages and disadvantages of the presented options for the disposal of sewage. This will help you choose the most suitable one for your site.


It is worth noting that the disadvantages of structures of this type are more weighty than advantages.

Positive factors include:

  • Cheapness of manufacture. To dig and arrange a cesspool, you will need a shovel and improvised materials that remain with a good owner after construction or repair. Therefore, such a structure can generally cost free.
  • Simplicity of the scheme. In addition to pipes and a drain pit, there is nothing else in it. Therefore, it is quite within the power of any owner to dig a cesspool and connect the sewer lines with the house, regardless of his special skills.

The disadvantages of cesspools include:

  1. Lack of environmental safety. Sealed pits in summer cottages are rare. Usually, the owners of country houses do not bother with the construction of impenetrable walls and the bottom of such structures.
  2. Poor performance. If the daily volume of drains is small, a cesspool will do. If you want to use a bathroom or other devices that increase water consumption in the country, it is advisable to mount a septic tank.
  3. Unpleasant odors are common near cesspools.

Attention! In most regions of the country, the installation of filter pits is prohibited by law. Therefore, the construction of such a sewage system is considered an administrative violation. A way out of this situation can be the creation of a septic tank or a sealed tank in the case of a cesspool.

Septic tank

The main advantages of septic tanks used in suburban sewage systems are as follows:

  • Complete autonomy, inexpensive maintenance. The septic tank does not need the intervention of the owners and sewage services until it is cleaned. And this happens once a year or less.
  • Variety of options. Such equipment can be purchased or manufactured by yourself. Factory septic tanks have a plastic body. Homemade ones are made of stone or concrete, that is, materials with anti-corrosion properties.
  • The ability to select the performance of the factory model of a septic tank, based on the volume of wastewater.
  • No smell. If the septic tank is working properly, the air in the area is clean and fresh.

The disadvantages of using septic tanks also have a place to be. These include:

  1. The need for additional wastewater treatment. Even an ultra-modern septic tank will not purify water by more than 80% without it. Therefore, the post-treatment procedure is mandatory.
  2. High cost. The creation of a septic tank on the site requires an investment of money. Even if you do not buy ready-made tanks, but make them yourself, you will still need component materials and rent of special equipment. Installation of post-treatment devices will also require additional costs.

The septic tank is superior to the cesspool due to the use of a biological treatment method. During the anaerobic process taking place inside the sump, large fragments of sewage are converted into harmless sludge.

Features of the sewerage system

We will understand the principle of the device and operation of the simplest options for a septic tank and a cesspool, that is, those that are available for independent execution.

Cesspool device

Cesspool on the site

It is not difficult to make such a sewage system. This will require:

  • Dig a hole with a shovel or excavator.
  • Below the freezing point of the soil, mount a sealed container or, using formwork, concreted the walls of the pit and its bottom.
  • Connect the installed tank with a 110 mm pipe to the house. Through it, sewage contaminated with household and biological waste will flow into the pit.
  • Cover the cesspool from above with a concrete slab with a hole for gas removal and the possibility of pumping out using the hose of a sewage machine. A cover must be provided for the hole.

The cesspool for filtering purposes is arranged somewhat differently. Its depth is usually about 3 m and its area is about 4 m.2… The bottom of such a pit is covered with rubble. Otherwise, everything is very similar to the previous version.

The pit functions according to the following principle:

  1. Waste flows from the house into the pit;
  2. Filtered by gravel and soil;
  3. Dehydrated fractions emit methane during fermentation; it is discharged outside through a special hole.

When in a few years there is a need to clean the pit, you can order the services of a sewer truck. After pumping out the sewage, it can be used again.

However, the device of the filter pit delivers a lot of problems to the owner of the site. If, when digging, you do not reach the depth of the sandy layer, but stop at the loam, then the water will seep into the ground much more slowly. Because of this, it will be necessary to frequently monitor the volume of effluent entering the pit to avoid overfilling. You also need to take into account the flow of flood waters into it. After pumping out sewage from the pit, you have to replace the old layer of rubble from its bottom and remove a small layer of soil. If this is not done, the carrying capacity of the soil will be insufficient for the functioning of the structure.And finally, the gas that is constantly released from it during the fermentation of sewage can acquire a toxic concentration and become dangerous.

However, this version of the pit is considered the cheapest. Therefore, many use it, practically without thinking about the harm that can be caused to the soil and nature as a whole.

Advice! It is convenient to control the filling level of the cesspool using a simple alarm. The system consists of a float sensor installed in the tank and an incandescent lamp located outside. Both elements are wired. When the pit is filled to a predetermined level, an alarm is triggered and the lamp comes on, notifying the owners that it is time to call the flushers.

Septic tank device

Septic tank on the site

Unlike a cesspool, a septic tank is more complicated, although, in fact, it is a kind of it. The septic tank circuit consists of three main elements - a receiving sump, a secondary sump and a filter well.

Both sedimentation tanks are completely sealed and designed to free the water from insoluble waste. For high-quality sludge settling, the tanks must have a sufficient volume. The settling process lasts at least 3 days. Therefore, sedimentation tanks must contain the volume of wastewater that comes from the house for at least 72 hours.

The receiving chamber always has the largest volume. With a two-chamber system, the receiver accounts for 75% of the waste volume. All tanks are connected by pipes, which are overflow devices.

Waste waste is fermented in the septic tank. To increase the efficiency of the process, anaerobic bacteria are recruited. When organic matter decomposes with their help, the gas is neutralized, and the waste becomes a homogeneous mass that does not have an odor. This mass is usually used as fertilizer.

The complete chemical decomposition of the waste liquid allows the treated water to be used again, for example, for technical needs or for irrigation. The particles settled in the sedimentation tanks must be pumped out every 1.5-2 years.

Tank Cleaning Tips

Sump cleaning

The procedure for cleaning the drain pit can be performed independently or with the involvement of a sewage machine, the order of which costs money. However, using this technique, it will not be possible to completely solve the problem of removing sewage from the pit. After all, the machine pumps out only liquid waste, and all the sediment remains at the bottom. Therefore, after a certain time, the need for pumping will arise more and more often.

To solve this problem, drugs specially created for cleaning cesspools help. In the warm season, it is recommended to use environmentally friendly biological activators, which are highly effective. The composition of the products contains microorganisms that accelerate the decomposition of organic matter contained in waste. Biopreparations are capable of working only at positive temperatures from 4 to 30 degrees.

In winter, it is recommended to use chemical agents - nitrate oxidants. However, it is very difficult to call them completely safe.

Important! The maximum liquid level in the storage tank should not exceed 30 cm from the outside ground level. Therefore, the degree of filling of the cesspool must be monitored. Otherwise, waste may appear on the site.

Sewerage selection

Sewer system diagram

There is no definite answer to the question of choosing between a cesspool or a septic tank. Both options need to be considered for each specific case. For example, with an insignificant volume of drains, it will be rational to dig a cheap cesspool. If the amount of waste water is large, then it is worth considering a septic tank. Although this is not the only guide to action. There are inexpensive mini septic tanks on sale that are suitable for systems with a small volume of drains.

Sometimes the most rational solution is the construction of a sealed drain pit, from which waste can be pumped out during the filling process.This option is possible if the soil on the site is clayey, and the drainage of wastewater from the septic tank cannot be organized.

Local conditions are of great importance for the calculations of an autonomous sewage system. It is imperative to take into account the volume of wastewater to be disposed of, the geological characteristics of the soil, the presence of plantations and various buildings on the site. In addition, it is recommended to find out whether it is possible to use sewage trucks and what is the price of such services.

Comparing the pros and cons of a septic tank and a pit, it should be noted that the first structure is better than the second in all characteristics, except for the price. In the case when there is no financial opportunity to make a septic tank, you can make a cesspool that meets sanitary standards.

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