How to make a septic tank of concrete rings: autonomous

How does the simplest single-chamber septic tank work? How is wastewater treated in it? How to make a septic tank of concrete rings?

Where to place it on the site and what size should adhere to when designing? Let's figure it out.

Principle of action

В основе механизма работы простейшего септика лежит механическая сепарация бытовых стоков на воду и твердые отходы. Вода утилизируется  - впитывается в грунт. Поскольку она составляет 98-99 процентов объема стоков, очистка отстойника, где накапливаются отходы, требуется не чаще раза в год (см.также статью «Железобетонные кольца для колодца: технические характеристики»).

Let's describe the path of the effluent inside the septic tank in more detail.

1. They enter the settling tank and spend at least three days there.. During this time, in the absence of mixing, the drains are divided into fractions: light impurities are collected on the surface, and heavy ones are deposited on the bottom. Relatively clean water remains in the middle.
2. Through a special form, the overflow of the distilled water is taken below the surface and enters the filter well - a tank without a bottom, where it is absorbed by the soil.

Please note: several settlers can be combined in a sequential chain. The more of them, the higher the quality of water treatment and the slower the filter well will be silted.

A septic tank of any type is usually buried in the ground.

There are several reasons for this.

• Wastewater flows by gravity. Obviously, the final destination of their route should be located lower than the sewer exit from the house.
• Recessed tanks do not occupy space on the site and do not spoil its appearance.
• Finally, the ground protects drains from freezing in the winter cold. Below the freezing level, the soil temperature stably keeps at the level of 8 - 10 degrees.

Location

Где лучше расположить самодельный септик из бетонных колец? Для участка с уклоном очевидно его расположение ниже дома по склону - иначе емкость придется закапывать слишком глубоко. Остальные требования к его размещению сводятся к минимальным расстояниям до объектов разных типов (читайте также статью «Бетонные кольца для канализации: строим простейший септик»).

Dimensions

Sump

The minimum size of the sump is taken equal to the three-day volume of wastewater More is better: with an increase in volume, the contents of the settler will be less intensively mixed by the incoming stream.

How to estimate the daily volume of wastewater?

• In the presence of a water meter - on changes in his testimony.
• In his absence, consumption is usually taken equal to 200 liters per person per day.

Accordingly, for a family of 4 people the minimum volume of the settling tank will be 200 x 4 x 3 = 2,400 liters, or 2.4 m3. Further - simple calculation.

Объем цилиндра равен произведению его высоты на число «пи» и на квадрат радиуса.

When using concrete rings of a meter diameter 90 cm high for the construction of a septic tank, 2.4 / ((3.14 x 0.5 ^ 2) x 0.9) = 4 (rounded up to a whole number to the larger side) of the ring is required.

An important point: the effective volume of the settler is limited by the height of the overflow, which is usually noticeably below the edge of the upper ring.

Filter well

How to calculate the size of the filter well with your own hands?

First you need to assess the need for the area of ​​the absorbent surface. She, in turn, is tied to the absorbency of the soil, which values ​​for different soils are easy to find in reference books.

For the above case of a family of 4, provided that at the construction site there is sandy soil, the filter well must have an absorbing surface of 2400/50 = 48 m2.

It would seem that it does not look very realistic: the bottom of the pit with an area of ​​a two-room apartment is an obvious search. However, there is a little trick here. Absorbent surface can be not only the bottom, but also the walls of the pit; in this case, we will need a pit with a side (in the case of its ideal cubic shape) 3 meters 10 centimeters.

How to ensure water contact with the walls throughout their area?

1. The first ring is installed on a drainage bed of crushed stone, boulders or a brick wall with a thickness of at least 30 cm.
2. A similar drainage pit is filled up after installing all the rings and cover.

Строительство

With the planning, we figured out; You can go to the construction. So, how to make a septic tank of concrete rings?

Sump

In an open pit, a carefully leveled bottom is covered with sand for 10-15 centimeters and watered for maximum shrinkage.

The first is set the ring with the bottom (KCD). Its price is slightly higher than the rings of the COP; but its use will relieve us from the need to concrete the bottom, and at the same time from leakage that pollutes groundwater.

The next ring is lowered onto the previous solution laid out on the edge of 1 part of cement, 3 parts of sifted sand and 0.1 parts of liquid glass. The viability of the solution - no more than half an hour, so it is prepared in small portions.

The cover with the hatch keeps within on a pillow from usual sand-cement mortar.

Filter well

It uses only the rings of the COP. The permeability of the seams in this case does not matter, so that they can use the usual solution without the addition of liquid glass. Sometimes, to improve the drainage of water between the rings, bricks are placed under them during installation; An alternative solution is a few additional holes made in the walls.

Overflow

It is laid with a slope of 2 cm per linear meter. A sewage tee is used in a vertical position to remove water in the sump: the lower drainage system draws water below the surface, the upper one serves for cleaning.

After installing the overflow, the holes for it are sealed with cement mortar with the addition of liquid glass.

Useful: in order to make holes in the rings, traditionally used punch. However, diamond drilling of holes in concrete is much more convenient in that the edges remain perfectly smooth, without chipping. In addition, it, like cutting reinforced concrete with diamond circles, allows you to pass reinforcement without a tool change.

Ventilation

Installation of ventilation pipes is practiced both in the sump and in the filter well. However, it is much easier to get the fan pipe out of the top of the in-house sewage system: the thrust created in it is enough for lack of odors.

Conclusion

We hope that our recommendations will help the reader to avoid mistakes in construction (learn here how to make forms for concrete rings).

As always, you can find additional thematic materials in the attached video in this article. Successes!