Sep­tic tank Aquat­e­ch 5M

Often, own­ers of coun­try hous­es or cot­tages are faced with a del­i­cate prob­lem — the need to dis­pose of waste­water gen­er­at­ed as a result of eco­nom­ic activ­i­ties on the site, hygiene pro­ce­dures, wash­ing dish­es, and so on.

Unfor­tu­nate­ly, inclu­sion in the cen­tral­ized sew­er­age sys­tem, as well as water sup­ply, is far from avail­able every­where. This is due to the fact that the infra­struc­ture does not keep pace with the rapid­ly unfold­ing sub­ur­ban con­struc­tion.

The way out of this sit­u­a­tion is to install a sep­tic tank, a local treat­ment sys­tem for a small amount of domes­tic waste­water. A sep­tic tank is a sys­tem in which waste­water is treat­ed through active aer­a­tion, sed­i­men­ta­tion and decom­po­si­tion of par­ti­cles, as well as fil­tra­tion, includ­ing ground­wa­ter.

  • Device and prin­ci­ple of oper­a­tion

  • How to choose a sep­tic tank

  • Tech­ni­cal doc­u­men­ta­tion

  • Instal­la­tion

Device and prin­ci­ple of oper­a­tion

Sep­tic tanks are divid­ed into cat­e­gories, depend­ing on how waste­water is treat­ed:

  1. Sep­tic tanks with dis­per­sion (fil­tra­tion) fields

  2. Biosep­tics (with bio­log­i­cal fil­tra­tion)

Sep­tic tank with dis­per­sion field

The sep­tic tank is quite sim­ple. This is an under­ground sump where waste­water flows through the pipeline. Now most often sep­tic tanks are made of plas­tic, which ensures tight­ness, strength and dura­bil­i­ty. Pre­vi­ous­ly, these devices were built of brick, con­crete, met­al and stone. Sep­tic tanks can be of a stan­dard shape and vol­ume or made specif­i­cal­ly for the needs of cus­tomers. The sep­tic tank can be locat­ed at a dis­tance of 5–20 m from the house. One of the advan­tages of a sep­tic tank is the absence of an unpleas­ant odor. In addi­tion, this device does not con­sume elec­tric­i­ty.

The sed­i­ment con­tained in the efflu­ents set­tles in the sump, and the liq­uid com­po­nent begins to fer­ment under the action of anaer­o­bic bac­te­ria. As a result, methane is formed, which is dis­charged through a spe­cial pipe. At this stage, the degree of purifi­ca­tion of the waste liq­uid is 50–75%. Installing a biofil­ter in the design allows you to increase this para­me­ter up to 90%. In the biofil­ter, which most often con­sists of expand­ed clay, addi­tion­al aer­o­bic (oxy­gen) purifi­ca­tion takes place.

From the sump, clar­i­fied waste­water enters the soil through the drainage net­work (fil­ter field) for post-treat­ment. A drainage net­work is need­ed to ensure that water is even­ly dis­trib­uted in the soil. Drainage is a sys­tem of pipes with small holes, sur­round­ed by rub­ble. It should be arranged in such a way as to avoid flood­ing of the foun­da­tion and base­ments, below the water intake and at a dis­tance of at least 20 m from the well.

Sed­i­ment accu­mu­lat­ing at the bot­tom of the sump must be peri­od­i­cal­ly pumped out using a sewage truck. The reg­u­lar­i­ty of this process depends on the inten­si­ty of use of the sep­tic tank — from once a month to once a year.


In the event that the instal­la­tion of a sep­tic tank with a fil­tra­tion field for some rea­son, for exam­ple, due to a high lev­el of ground­wa­ter or insuf­fi­cient area of ​​​​the site, is impos­si­ble or dif­fi­cult, a sep­tic tank with a bio­log­i­cal fil­ter becomes an ide­al option.

The first stages of clean­ing in a biosep­tic tank fol­low the same prin­ci­ple as in a sep­tic tank with a scat­ter­ing field. Fur­ther, the clar­i­fied water enters a spe­cial com­part­ment with a biofil­ter.

A biofil­ter is a con­tain­er filled with fil­ter mate­r­i­al, most often expand­ed clay. When waste­water pass­es through expand­ed clay, a film of bac­te­ria and oth­er microor­gan­isms forms on its sur­face, decom­pos­ing organ­ic sub­stances that make up the waste­water. The degree of water purifi­ca­tion in the biofil­ter is up to 90%.

All biosep­tic com­part­ments are locat­ed in one build­ing. Addi­tion­al­ly, a pump can be installed at the waste­water out­let, which pumps the treat­ed waste­water into a ditch or oth­er body of water.

Sep­tic tank Aquat­e­ch 8A

How to choose a sep­tic tank

In order for the treat­ment plant to effec­tive­ly cope with its task, it is nec­es­sary to choose the right sep­tic tank. The most impor­tant para­me­ters that you need to pay atten­tion to are the vol­ume of the con­tain­er and the type of soil.

Sep­tic tank vol­ume

The vol­ume of the sep­tic tank should be equal to three times the dai­ly inflow. In oth­er words, it is nec­es­sary to cal­cu­late how much water the inhab­i­tants of the house spend dai­ly, and mul­ti­ply this fig­ure by three. On aver­age, one per­son con­sumes about 200 liters of water per day. Thus, if 4 peo­ple live in a coun­try cot­tage, they spend 800 liters of water dai­ly. This means that the vol­ume of the sep­tic tank must be at least 2400 liters (or 2.4 cubic meters).

Soil type

When choos­ing a sep­tic tank, it is very impor­tant to con­sid­er the type of soil in the area where it will be installed.

For clay soils, it is best to choose a sep­tic tank with deep biofil­tra­tion. The fact is that the clay is prac­ti­cal­ly imper­me­able, there­fore, to ensure soil fil­tra­tion in such con­di­tions, expen­sive addi­tion­al work must be car­ried out.

In areas with oth­er types of soil (sandy, loamy), sep­tic tanks can be used, both with soil fil­tra­tion and with deep biofil­tra­tion. Please note that in sandy soils, sep­tic tanks will most like­ly need to be fur­ther strength­ened.

Pay atten­tion to the lev­el of ground­wa­ter. If it is low enough, then the sewage can be drained by grav­i­ty, and if the ground­wa­ter lev­el is high, a forced removal sys­tem will be need­ed.

Tech­ni­cal doc­u­men­ta­tion

Instal­la­tion of sep­tic tanks must occur in accor­dance with the fol­low­ing reg­u­la­to­ry doc­u­ments:

  1. SNiP 2.04.03–85 Sew­er­age. Exter­nal net­works and struc­tures. This doc­u­ment is par­tial­ly valid. Accord­ing to the order of the Gov­ern­ment of the Russ­ian Fed­er­a­tion of June 21, 2010 N 1047‑r, sec­tions 2–6, 8, 9 are manda­to­ry.

  2. From 01/01/2013, the Code of Rules 32.13330.2012 “Sew­er­age. Exter­nal net­works and struc­tures”, updat­ed ver­sion of SNiP 2.04.03–85.

Instal­la­tion of a sep­tic tank

You can install a sep­tic tank on the site your­self. To do this, it is nec­es­sary to dig a pit, lay a pipeline and per­form a num­ber of oth­er works. How­ev­er, in order for the treat­ment facil­i­ties to work as they should: they suf­fi­cient­ly clean the drains and do not annoy not only you, but also the neigh­bors with an unpleas­ant smell, you should con­tact a pro­fes­sion­al com­pa­ny whose spe­cial­ists have suf­fi­cient expe­ri­ence in per­form­ing such work.

Please note that before the actu­al instal­la­tion of the sep­tic tank, it is nec­es­sary to coor­di­nate the pre­pared project in the San­i­tary and Epi­demi­o­log­i­cal Sta­tion.

All mod­els of sep­tic tanks on TopClimat.ru »

The arti­cle was pre­pared with the help of spe­cial­ists from the com­pa­ny “Alsel St. Peters­burg.

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