Autonomous sewerage for a private house

The lack of centralized drainage is an acute problem for a private house or summer cottage. It can be solved by installing an effective autonomous sewage system.

Modern autonomous systems for receiving and treating wastewater meet all sanitary standards, do not spoil the landscape of the site, do not exude odors, and do not require frequent sewage disposal. Models of the new generation purify waste water by 95 - 100%, without requiring constant maintenance. Water after such high-quality cleaning can be used for irrigation, and sludge - for soil fertilization.

Which system to choose and in which case

The choice of an autonomous sewage system should be approached very responsibly, having studied the advantages and disadvantages of all options. It will not be superfluous to perform some mathematical calculations.

There are three models of autonomous sewerage, depending on the method of operation:

1. Cesspools and storage septic tanks.
2. Overflow septic tanks.
3. Stations with deep biological treatment.

Waste volume

Cesspools and storage septic tanks, as a rule, have a small volume and quickly fill. The volume of runoff water practically corresponds to the volume of water consumption, minus the water used for irrigation of the personal plot. Thus, if the monthly water consumption in the house is 10 cubic meters. m., and the volume of the cesspool is 5 cubic meters. m., sewage will need to be carried out every 2 weeks.

The required volume of overflow septic tanks depends on the amount of water consumed by the family for 1 day. The volume of the septic tank should be 3 times the amount of daily sewage. On average, 1 person uses 200 liters of water per day. This means that a family of 4 people consumes 800 liters of water per day or 0.8 cubic meters. m. We increase this indicator three times and we get the recommended volume of the septic tank 2.4 cubic meters. m. It should be remembered that the receiving tank in the upper part has an overflow into the second tank, so the total volume of the tank will be greater than the volume of three-day wastewater.

Experts recommend installing structures with a volume reserve of up to 30%, since there may be unforeseen increases in water consumption associated with seasonality, the arrival of guests, a change in the number of people permanently residing in the house.

If the daily water consumption exceeds 10 cubic meters. m., it will be necessary to install a three-chamber septic tank for the effective treatment of such a quantity of drains.

Plot size

In areas of a small area occupied by buildings or planted with trees, there may not be enough space for the installation of overflow septic tanks or stations with deep biological treatment. In addition, there is a list of permissible distances from neighboring areas (10 - 12 m), residential buildings (8 - 10 m), water pipes (25 m) and gas pipes (5 m).

Tank material

Today, polymer containers are very popular due to their inexpensive cost and relatively low weight. However, when installing a polymer septic tank, it is necessary to properly mount it so that an empty and light tank does not rise during sewage.

Most often, when installing an autonomous sewage system, concrete structures are used. It is extremely rare to give preference to metal containers, due to metal corrosion and short service life. You can make a receiver with your own hands from bricks.

Cost of work and materials

A cesspool is the most budgetary option. Installation of more complex structures will cost several times more, because, in addition to the purchase and delivery of materials, it involves the work of special equipment and the involvement of qualified specialists.

Maintenance and care

The cesspool and sealed drive will have to be pumped out regularly (monthly, and sometimes more often). Overflow septic tanks also require cleaning, but not more often than once a year. Only stations with deep biological treatment do not need such maintenance.

Cesspool

It is a well for the accumulation of effluents. It is quite suitable for a summer cottage or a country house where water consumption is low and, moreover, for only a few months a year. The size of the well depends on the number of people living in the house. Experts recommend not to increase the depth of the cesspool more than three meters, since a large layer of sediment at the bottom will reduce the cleaning efficiency.

Sanitary standards provide for mandatory 2 requirements for cesspools with waste volumes of more than 1 cubic meter. m. per day. This is tightness and the presence of a bottom so that water does not go into the soil and the use of such pits is environmentally friendly.

The cesspool requires regular and fairly frequent cleaning, so you need to choose a place for it on the site that is convenient for the unhindered access of the sewer truck.

Sealed storage

In fact, this is the same cesspool, but in an improved version. A sealed storage tank is a container into which drains are removed from the house and stored until the moment of cleaning. When filling the drive, it is necessary to use the services of sewage equipment and clean the container.

Two-chamber and three-chamber septic tank

For an autonomous sewerage of a private house, a two-chamber overflow septic tank would be a good option. Its significant difference from the previous versions is that the effluents accumulate in the first container, settle, the sediment is fermented with the help of anaerobic bacteria, and after partial purification, water flows by gravity into the second container without a bottom and drains into the soil.

The overflow septic tank can also be three-chambered. In this case, the first two tanks serve for the accumulation and settling of water, and drainage takes place from the third well. A more complex design of a three-chamber septic tank provides high-quality water purification, the purification factor can reach 70%. The overflow septic tank model also requires periodic cleaning, usually once a year. With the help of a suction truck, the sediment is cleaned from the first containers (one or two), in which the water settles.

However, not every site can use such a treatment plant. It is inappropriate to install overflow septic tanks on clay soils and with a high level of groundwater occurrence. In the first case, there will be no effective drainage, and in the second, a serious violation of sanitary standards will occur.

Septic tank with filtration field, biological filter and aeration

A septic tank with deep biological treatment is an ultra-modern model of an autonomous sewage system for a private house. The water purification factor reaches almost 100%, so such a septic tank can be used, regardless of the depth of groundwater. A septic tank with biological treatment absolutely does not require sewage disposal. The only prerequisite is to be connected to the mains, the station does not work without power.

In the process of purification, wastewater passes through several chambers (receiver, aeration tank, sump and finishing section), each of which has its own function. The receiver serves for the accumulation of effluents and separation of fractions. The process of fine bubble aeration takes place in the aeration tank. The jet pump (airlift) pumps water from the receiver to the aeration tank and actively saturates it with air. In the aerobic tank, aerobic bacteria trigger the decomposition of organic matter. The sump serves as a secondary treatment.

Heavy fractions settle to the bottom and form silt, while light fractions are captured and returned to the aerotank for additional treatment. The finishing section receives water that is almost 100% purified, colorless and odorless. By gravity or with the help of a drainage pump, it is removed from the station into a filtration well, a drainage ditch or into a filtration field. A typical filtration field is an underground structure of drainage pipes laid on a sand and gravel bed with natural fluid movement. It can be used for water purification and in the model of overflow septic tanks.