When discharging wastewater in a country house, a mandatory measure is their treatment. Since the environmental issue remains relevant, it should be remembered that the discharge of untreated water into the soil is prohibited. In this regard, in addition to treatment systems, underground filtering facilities in country houses should be provided.
To treat wastewater, septic tanks are used, after which a filtration well is installed. Such measures are prescribed in existing sanitary standards. Having familiarized yourself with them, you will be able to understand that the presence of underground filtration fields, sand and gravel filters and filtering trenches is also important. The choice of a building will depend on:
- groundwater depths ;
- type of soil;
- the presence of aquifers and other factors.
For biological wastewater treatment, today most often still used filtration wells.
Description
A filter well is a structure whose main purpose is the biological treatment of domestic wastewater in the local sewage system. Such treatment facilities are arranged when it is not possible to divert sewage into a body of water through a drainage system. In such cases, the house is removed from the reservoir or the site is not sufficiently biased. In this regard, it becomes necessary to drain sewage into the ground.
The filtration well is an independent drainage structure or a means for cleaning sewage. In the first case, the well is located on the site, if the volume of wastewater is not more than one cubic meter per day. The second case involves the use of a well for tertiary treatment of sewage before they are discharged into the soil.
Features of filter wells
Filter wells are used for wastewater treatment, when the water flow per day does not exceed 50 cm 3 . This indicates that no more than 3 people should live in the house. If we are talking about sandy loams, then the norm of the well area for such soil is 1.5 m 2 . As for sandy soils, this parameter is 1 m 2 . When the water flow does not exceed 1 m 3 , then one well can be installed for 5 people, its size should be 2 m 2 for sandy loam and 1.5 m 2 for sandy soil.
Where to put the well
Before you build a filtration well, you need to collect information about the soil. Wells can only be located in those soils that are suitable for this. This should include:
- sandy soils;
- peat;
- clay loam with a low content of clay particles.
If we are talking about loams and clays that have a low filtration coefficient, then installing wells in them is pointless, because filtration facilities cannot be operated effectively under such conditions. Installing wells is unacceptable for biological treatment in fractured rock formations, this is because water filtration does not occur.
In the absence of organized runoff, water can even get into drinking water sources. In areas with soil that is characterized by insignificant filtration properties, other methods of sewage treatment should be used.
The soil condition also affects the well filtration area. The filtration area, among other things, determines the life of the well: the filter well can serve longer if the filtration area is significant. The filtration well for the septic tank can be effectively operated only if all the work is carried out correctly, taking into account the depth of the underground water. This level should be located below the filter bottom by 0.5 m.
The base of the drainage system should be located above the groundwater level by 1 m. If the groundwater in the area is quite high, then you can not install a well. It is important to remember also about the depth of freezing. A do-it-yourself filtration well is installed below the level of soil freezing, which depends on climatic conditions. For example, in central Russia, this parameter is 1.3 m from the surface of the earth.
Making a plastic well
If the filter well from plastic could not be purchased, then it can be done independently. For this, a corrugated pipe of the required diameter is used, the last of which can be equal to 925 mm. The required length is cut from the pipe, which will become the height of the well. Holes are made in the structure, and rubber cuffs can be used at the pipe passage.
If necessary, the seams are sealed with bitumen mastic. After installing such a well, preparation is laid at the bottom, pipes are connected, and, if necessary, also a pump. The voids between the walls and the well can be covered with rubble, a hatch is installed on top.
Installation of a local bottom well
If you are thinking about how to install a filtration well, you can familiarize yourself with the local bottom structure, the main elements of which are:
- walls;
- overlapping;
- bottom filter.
The latter has the form of backfill from crushed stone, sintered slag, gravel, as well as brick fragments. The diameter of the fraction of these materials can vary from 10 to 70 mm. This filling is carried out to a height of 1 m. The liquid purified from suspended particles will enter the well through the pipe from the septic tank. Therefore, the pipe must be positioned above the surface of the filter. This distance is usually 0.2 m. The place where the stream will fall on the filter should be covered with an antiseptic shield that will distribute sewage in the well. This measure eliminates the erosion of backfill.
Well walls
Quite often, owners of suburban real estate wonder about how to properly install a filtration well. Its walls can be made of:
- old barrel;
- reinforced concrete rings;
- rubble stone;
- solid clay brick.
Particular attention must be paid to the fact that holes should be present in the walls. They should be left or pierced. They should be distributed as evenly as possible along the height of the filter. They are staggered, and their diameter can vary from 4 to 6 cm. The area of the holes should not exceed 10% of the surface of the walls. The walls of the well from the outside must be covered with material that was used to lay the bottom filter. The height of the backfill should be equal to the height of the filter, while the thickness is usually equal to the limit of 30 to 50 cm.
Ventilation and ceiling
The filter well and septic tank must be equipped with a ventilation pipe. It is located in the ceiling of the treatment plant. The upper part of the pipe is located above the soil surface of 70 cm. It is important to equip the element with a fly lamp.
The most optimal pipe diameter is 10 cm. If it spoils the landscape, then you can solve the problem by masking the element with climbing plants. In the ceiling, a hatch should be installed, the diameter of which is 70 cm. Two covers act as its feature. One of them will be bearing, while the second will be weighting, it must be positioned below. Between the covers should be left a distance that is filled with insulation material, such as bags with perlite sand or mineral wool.
Specialist recommendations
Today, filter wells rarely have a diameter of more than 2 m. Their depth is usually 3 m or less. If the area of the treatment plant is large, then several small wells should be installed on the territory. This need arises when the well area is more than 4 m 2 , because the volume of wastewater can be impressive. It is important to remove them from an existing drinking water source of 30 m or more.
Standards and Rules
A slate filtration well can also be done independently. For this, the sheets can be connected using a solution, holes are pre-made in the canvases, their parameters have been described above. At the bottom of the structure, lay a layer of granular loading through which water will pass. The walls of the well can be overlaid with square bricks or natural stone. It is important to leave technological gaps or drill holes in the finished product.
Features of conical wells
Conical filtration well is very popular among consumers today. It is made of plastic and can have a height of up to 2.5 m. The conical structure allows you to install such systems in different soils, including heaving clay. The upper part of the structure has a diameter of 600 mm, while from the bottom this value reaches 1000 mm.
A system is supplied with a cast-iron or polymer-sand hatch; in this case, a floor slab is not required. The body is based on a corrugated pipe, and the pipes are connected locally. The neck is attached to the body of the well at the manufacturing stage. The top cover will look great on pedestrian areas and lawns. Well conical with perforation filtering can have a double-walled design and an open top. The wall of the well is hollow, while the lower part is open, and for the upper part you can use any standard hatch as desired. Such a well can be installed for house maintenance for 10 people. The advantages of such structures should be highlighted:
- low weight compared to reinforced concrete structures;
- lack of toxic discharge into the soil;
- long term of operation is up to 50 years.
The well is quite simple to install on your own.
Conclusion
In order for the cleaning object in the form of a filtration well to cope with the tasks assigned to it, it should be located on the site where groundwater is below the level at which the filtering bottom of the crushed stone pillow is located. The distance to the bottom from the water of the treatment facility should be 0.5 m. The base of the well should be 1 m above the groundwater surface.
If the groundwater lies quite high in the territory, it is recommended to abandon the construction of a filter well. It is important to place the sewer elements of the system even below the level of soil freezing. If we are talking about the middle zone of Russia, then this value is equal to the limit from 1.3 to 1.4 m.
When arranging the described structures, it is especially important to follow the recommendations and technology, because otherwise the design will not function correctly. This will cause an environmental disaster. The source of drinking water may be contaminated.