Sewerage for a summer residence: types, methods of organization, schemes

City residents are so accustomed to comfort that a full set of “amenities” is required in the country, but a centralized sewage system outside the city is from another life. Therefore, sewerage for a summer residence is the concern of the owners. This is not an easy task, but having understood the intricacies, you can design and build with your own hands. 

Types of autonomous sewage

In order to consciously and correctly choose the type of sewage for a summer residence, one must at least in general terms imagine the advantages and disadvantages of each of the possible options. There are not so many of them:

• Cesspool pit. The most primitive and far from the best way to dispose of wastewater. To begin with, it is very difficult to ensure complete tightness. Even with high-quality processing, some part of the effluent enters the ground. If the source of water is a well or a well, then sooner or later bacteria that live in sewage pits will be found in them. Another drawback is the corresponding smell, which is problematic to deal with due to leaks, and the need for regular pumping. Therefore, such sewerage in the country is being built less and less.
• storage capacity. The essence of this type of sewerage is the same: drains are collected in containers, periodically pumped out. Only these containers are completely sealed, as they are usually made of plastic. The disadvantage is the relatively high price.
  

• Septic tanks. A system of several interconnected containers (two – three, rarely more). Wastewater enters the first place, where it settles and is processed by bacteria. Insoluble residues settle to the bottom, the water rises to the top. With the next flow of effluents, the level rises, the settled water is poured into the next container. Other bacteria “live” here, which complete the cleaning (up to 98%). From the second compartment of the septic tank, the liquid can be removed for further filtration into the ground. She’s almost clean. The design is simple, there is nothing to break. The disadvantage is that the device itself is voluminous, plus a filtration field is needed (where water will be discharged), once a year or two cleaning the septic tank from insoluble sediment.
• VOC or AU – local treatment plants or automatic installations. The principle of operation of a septic tank, but in a more compact size, with electronic filling for control. This type of sewer works only when electricity is available. The maximum battery life is up to 4 hours. The small size of VOCs impose restrictions on a one-time discharge of wastewater: if you flush a bath, you should not flush in the toilet. And the biggest downside is the price.
  

The first two options are just places for collecting sewage, no purification takes place in them. But there is a difference between them, and quite significant. A cesspool is usually made only for an outdoor toilet, but all drains are already taken into the storage tank. That is, this is the most primitive sewage system, albeit without cleaning.

The second two options are already treatment facilities, just with varying degrees of automation. As you can see, there is no perfect way. We have to choose between environmental friendliness and cheapness. And no one can decide but you.

How to organize sewerage in a country house with a septic tank

If the dacha will be visited mainly on weekends, it makes no sense to build any complex system. The most reasonable option in this case is to install a storage tank, or make a cesspool, but be sure to make it airtight. Since visits will be rare, cleaning will be required infrequently, and to make it needed even less often, biological products are used that accelerate the decomposition of organic matter, at the same time reducing the volume of effluents.

With a more active use of the summer cottage, the sewerage system for the summer cottage needs a more serious one. A smart choice is to install a septic tank, make filtration fields according to the instructions, or install an absorbing well. It is better to take a septic tank from the factory, if possible – fiberglass. Of course, it costs a lot of money, but home-made septic tanks, although they cost less during construction, require constant repairs during operation, and besides everything, most of them suffer from leaks. After all, we are talking about a dacha, and everything that gets into the ground ends up on your table as a result – in the form of water, if the water supply is from a well or well, and then in the form of a crop that you water with this water.

If you definitely decide to make a septic tank with your own hands, there are several options:

• Monolithic concrete. It is possible to achieve a high level of sealing, but the amount of work is large and requires a lot of time.
  

• Brick. Not the best option, as it can be destroyed on heaving soils. It can be used provided that the walls are plastered. Tightness can be achieved with the help of modern waterproofing coating materials.
• Concrete septic tank. With proper execution, it works well, but it is operated without problems on soils that are not prone to heaving. On clays and loams, the rings often move from their place, the tightness is broken. Repair is a complex and unpleasant undertaking.
• From metal. The tightness is at a high level, but until the metal corrodes, and this will happen pretty soon.

The easiest way is to make a septic tank in the country from concrete rings. Its volume should be large enough – it is believed that in such a device there should be a place for the accumulation of a three-day supply of wastewater. Consumption per day is taken at 200-250 liters per person, the total consumption is calculated according to the number of people in the country at a time with some margin in case of arrival of guests. For a family of 3-4 people, the usual volume of a septic tank is 2,5-3 cubic meters.

Norms for the location of treatment facilities on the site

There is a lot of confusion in this area. There are many conflicting norms with different distances, and in different regions these norms may differ, so you need to find out for sure in the local plumbing supervision. The most common standards can be grouped:

• From home:
  • to the septic tank – at least 5 m;
  • filtering device (absorption well, sand and gravel filter, filter trench) – at least 8 m;
  • to the filtration field – 15 m;
  • to the aeration unit – at least 15 m;
    

• From the well and well (own or neighbor’s):
  • at least 15 meters if the septic tank is located against the flow of groundwater;
  • at least 30 m if the septic tank is downstream of groundwater;
  • at least 19 m if standing perpendicular;
• To the border of the neighboring site – at least 4 m;
• At least 1 m from the border of your site.

One more moment. If there is a slope on the site, then the well or well should be located above all treatment facilities. To keep all these distances, you will have to conjure over the site plan for a long time. If everything cannot be observed at once, special attention is paid to the distance to the neighbor’s house and the well (well), since a violation is fraught with a complaint, subsequent checks and fines.

Types of sewerage with a septic tank

A septic tank is a container consisting of one, two or three chambers connected by overflow pipes. From the last chamber, purified water enters the filtration field, into the absorbing well, filtering trench. The choice of a specific type of final filtration depends on the type of soil and the level of groundwater.

With filter well

With a low location of groundwater and well-draining soils, a filtration well is made. Usually these are several reinforced concrete rings without a bottom.

With filter box

With a groundwater level of up to 1,5 meters and / or with poor drainage capacity of the soil, runoff is diverted to filtration fields. These are quite extensive areas in which part of the natural soil has been replaced by sand and gravel. Water from the septic tank through perforated pipes enters this field, where, passing through the layers, it is further purified, after which it goes into the lower soil layers.

The structure of this field is layered – sand below, then crushed stone, in which drainage pipes are laid. Ornamental plantings can be planted on top. The location of this purification plant is as far as possible from the garden and fruit trees. The disadvantage of this system is that after a while the rubble silts up, the water stops leaving. It is necessary to open and replace the filtrate (sand with crushed stone).

Into the sewer

If there is a gutter near the septic tank, you can drain the water for further purification into it. To do this, a small pit is dug in front of the ditch, which is covered with rubble. The water is taken out into the rubble, from where it enters the ditch.

This option is possible if the degree of wastewater treatment is high. Typically, such a scheme is offered when installing VOC or AC. But to be sure, it is desirable to have on hand the result of a chemical examination confirming the degree of purification. This document may be needed if neighbors complain and an inspection comes.

You can read about the autonomous sewerage system Topas here, and about the individual sewage treatment plant Tver – here.

 How many chambers are in a septic tank

In SNiP 2.04.03-85, the number of chambers in a septic tank is tied to the daily water consumption:

• up to 1 cubic meter / day – one chamber;
• from 1 to 10 cubic meters / day – two chambers;
• over 10 cubic meters / day – three.

In this case, the volume of the septic tank must be at least 3 times the daily flow rate. One camera is rarely made, just like three. One does not give the desired degree of purification, and three are too expensive.

How to bring the sewer to the septic tank

Judging by the standards, the sewer pipe to the septic tank will have to be at least 7-8 meters. So the trench will be long. It should go with a bias:

• pipe diameter 100-110 mm, slope 20 mm per linear meter;
• 50 mm in diameter – slope 30 mm/m.

Please note that it is undesirable to change the level of inclination in either direction. In the direction of increase, a maximum of 5-6 mm is possible. Why not more? With a large slope, the water will run off very quickly, and heavy inclusions will move much less. As a result, the water will leave, and the solid particles will remain in the pipe. You can imagine the consequences.

The second important condition is that the pipe should not freeze through. There are two solutions. The first is to dig below the freezing depth, which, taking into account the slope, gives a solid depth. The second is to bury about 60-80 cm, and insulate from above.

How deep to dig the tuba

In reality, the depth to which you will bury the sewer pipe coming from the house depends on the location of the septic tank, or rather, its inlet. The septic tank itself must be arranged so that there is only a lid on the soil surface, and the entire “body”, including the neck, is in the ground. Having buried a septic tank (or having decided on its type and model), you will know where to bring the pipe, the required slope is also known. Based on these data, you can calculate at what depth you need to make an exit from the house.

This area of ​​work also has its own nuances. So it is better to dig a trench immediately to the desired depth. If you have to add soil, it must be very well tamped – not just throw in the earth, walk with a rammer to a high density. This is necessary, because just the laid soil will sit down, and the pipe will sag with it. In the place of subsidence, a traffic jam forms over time. Even if it manages to break through, periodically it will appear there again.

Warming

One more thing: the laid and hermetically connected pipe is covered with a layer of sand with a thickness of about 15 cm (so much should be above the pipe), the sand is shed, lightly rammed. An EPPS with a thickness of at least 5 cm is laid on the sand, on both sides of the pipe it must go to a distance of at least 30 cm. The second option for insulating the sewer pipe is the same EPPS, but in the form of a shell of a suitable size.

Other heaters are not recommended. Mineral wool, when wet, loses its properties – it simply stops working. Styrofoam collapses under pressure. If you build a full-fledged sewer trench with walls and a lid, then you can do it. But if the sewer pipe is laid in the ground, the foam may crumple. The second point is that mice like to gnaw on it (EPPS – they don’t like it).