The device of the filtering well

Septic tanks can be used to clean the wastewater, but such devices can be expensive. If you do not want to pay big money, you will have to work with your own hands. As a sewage treatment plant, you can equip the filter well. This design will remove contaminants from drains and discharge purified water into the ground. A device of the filter well and the technology of its creation, we describe in this article.

What is a filter well?

The design itself will be a tank without a bottom. Filter elements are placed in it. When drains enter a tank, they pass through a filter and are cleaned of solid contaminant fractions. In addition, they are cleaned by microorganisms that live in sludge formed on the filter particles. Then drains seep into the ground.

This design is often used as an additional cleaning device for septic tanks. Such additional processing significantly increases the degree of purification. Depending on the type of septic tank, it can reach up to 95–98%.

The filtering well can be established not on any sites. Here it is necessary to take into account some factors:

1. The soil should be sand or sandy loam. If this is not the case, the water will simply fill the tank and will not be able to penetrate the soil.
2. The depth of groundwater should exceed 2.5 meters. Otherwise, the drains will penetrate into the aquifer, without undergoing sufficient purification.

Preparatory stage

Before proceeding to the construction of a filtering well in a private house, it is necessary to choose the right place. The first is to comply with sanitary requirements. According to them:

• the well should not be closer than 10 meters from a residential building;
• similar structures should not be erected in the immediate vicinity of drinking water sources (well or well). The distance between them must be at least 30 meters. But this option will be optimal if your house is on clay. If the soil has good moisture permeability, then the distance between the water source and the filter well must be increased to at least 50 meters;
• also, it is not worthwhile to build a well in the vicinity of the neighbor’s plot, retreat 3–5 meters.

In addition, the designated site should be enough to build a filter well. Its size may be different, depending on the stock. But overall dimensions should not exceed two by two meters.

Tip! It is necessary to determine the depth of the structure. As a rule, it lies in the range from 2.5 to 3 meters. But here it is necessary to take into account one sanitary requirement - there must be at least 1 m between the bottom of the well and the level of the aquifer.

After that, we determine the filter element. As such, you can use:

• rubble;
• gravel;
• pieces of peat;
• broken brick;
• slag.

Tip! It is very important that the fractions are small, with a maximum size of 30 mm. Experts recommend using several types of filter media at the same time. Small rubble is poured on the bottom, and a broken brick is laid on top of it.

As a result, sludge will form on the particles of the upper layer, in which the bacteria will settle. Passing through such a filter, organic residues in the effluent will be decomposed as a result of the vital activity of microorganisms. Then they will pass through a more dense layer of rubble, and then into the ground.

The very shape of the filter well may be different. Depending on the material used, the structure can be made round, square or rectangular. For the construction of walls, you can use ready-made plastic structures, burned-out red brick, solid concrete, reinforced concrete rings and even old automobile tires.

We are building a filter well

First of all the excavation is dug. Its dimensions should be slightly larger (by 20–30 cm) than the design being created. Then we start building walls. If you use a brick, then they need to be put not closely. It is necessary to make holes 5 cm wide in a checkerboard pattern. It is necessary to divert treated wastewater into the ground. This perforation is done on the height of the filter layer or about 1 m.

If the filtering well is constructed of concrete rings, then you should not buy new ones. Used products with a variety of holes are perfect. In this case, there is no need to do the perforation yourself. You can buy special concrete rings with holes already made.

When laying concrete rings, you can use one trick. Even before digging the pit, place the product on the ground in the place where the well will be located. Then, begin to evenly clean the soil inside the ring. The product under its own weight will begin to go into the ground. As soon as the first ring completely goes into the ground, the second one can be laid on top and continue to dig.

When erecting the walls of the well, do not forget to enter the drain sewer or release of a septic tank. Here it is necessary to take into account one nuance. The outlet of the pipe should rise at least 15 cm above the level of the filtering material. In addition, it is advisable to install a wooden backing on the place where the water jet will hit the bottom. Such a device will allow to evenly distribute wastewater over the entire area of ​​the filter, thereby increasing the degree of purification.

Once the construction of the walls is completed, you can begin to fill the filter material. Many experts recommend the following model. In the center of the well material is filled up with larger fractions, and small - on the sides. In addition to filling the filter elements inside, they also need to fill the space between the external walls of the well and the pit. This way you will improve the flow of water.

The upper part is covered with a wooden shield or reinforced concrete slab. In the ceiling you need to leave space for the manhole (the inspection hatch) and the ventilation pipe. The first is necessary to inspect and clean the filter layer. The hatch itself makes the dimensions of at least 700 mm, so that a person can freely penetrate through it. It is better to make it double and shift the insulation. Ventilation must be done. A pipe with a diameter of 50 mm and a length of 1 m is suitable for this. It can be installed on the side.

After that, the whole structure is covered with roofing material and covered with soil. The thickness of the layer is better to do in half a meter - so you qualitatively warm your filter well. From above, everything can be masked, for example, by placing a flower bed.

Video

In this video, you will see the process of manufacturing a concrete pipe filter well: