Septic tank Tver: principle of operation, installation, operation

One of the leaders in the market of local treatment facilities for autonomous sewage is the Tver septic tank. This installation is difficult to classify – it has all three systems for wastewater treatment. Because, probably, it is still better to call it a septic tank, although there are also aeration processes and biofilters. In general, the system is complex, but gives a high degree of purification and is stable in operation. 

Principle of operation

The septic tank Tver combines all three possible wastewater treatment technologies. In the first – receiving – compartment, mechanical cleaning takes place, as is customary for classic septic tanks. In the other two – aeration and processing of wastewater by aerobic microorganisms, like in aeration plants (AU) and in two – processing by anaerobic (without oxygen), and there is also a biofilter at the outlet, which completes the purification. Here is such a complex system, but according to the assurances of the manufacturers, 98% purified water comes out and it can be dumped directly onto the ground or diverted into a reservoir.

The Tver septic tank differs from other installations for an autonomous sewage device in its horizontal layout – successively arranged compartments in which water is poured. Her device can be seen in the photo below.

The cleaning procedure is as follows:

• Effluent enters the first tank – a septic tank. In it, as in a classic septic tank, heavy particles settle to the bottom, light, fat-containing ones rise to the top.
• From this chamber, through the upper overflow, wastewater enters the second compartment – an anaerobic bioreactor. In this chamber there are ruffs on which colonies of microorganisms multiply. Here bacteria process particles that are difficult to oxidize. In parallel, the remaining contamination continues to settle/float.
•  After processing, wastewater enters the aerotank with aerobic bacteria. The pump supplies air here to ensure their vital activity. At the bottom of this chamber is expanded clay, which breaks the air into small bubbles. The activated sludge accumulated at the bottom, which processes wastewater, is mixed with water by streams of air bubbles. Bacteria actively convert organic residues, the degree of purification becomes even higher.
• The next compartment is a sump where contaminants settle/float. The settled sludge, due to the original structure of the walls, falls back into the aerotank.
• Already sufficiently pure water from the sump enters the second aerotank with ruffs, where the purification is completed. There is limestone rubble, which binds phosphorus. It is difficult to remove it in other ways and few people worry about it.
• The last stage is the third settling tank, where sludge settles again and clean water is separated.
• A chlorine cartridge is installed at the outlet of the Tver septic tank. This is a cylindrical device made of porous material. Inside it is a mixture of chlorine and sand. After that, the water can be dumped onto the relief – it has neither color nor smell.

Not to say that the process is simple, there are many nuances, but the cleaning result is not bad and the installation does not require daily attention, it works stably.

The process of building a budget septic tank from concrete rings is described here. 

Features of operation

Such a complex and multi-stage processing process leads to the fact that the system is more stable, in comparison with others, and works with various failures. In general, local sewage treatment plants react rather poorly to deviations from the norm. They work fine under the following conditions:

• They need a guaranteed power supply – aeration installations must work.
• They require a positive temperature – at temperatures below +6 ° C, the activity of microorganisms freezes, and at even lower temperatures they can die. Therefore, during installation they are insulated.
• These systems are demanding on the regularity of “replenishment” with waste products – they need protein. So such installations are more justified in permanent residences. For seasonal visits, conservation for the winter is recommended. The second option is to leave it to winter in working order, but periodically feed it with proteins – at least once a week, pour a liter or two of kefir or pour semolina.

All this is true for the Tver septic tank, only failures are not so critical. Even if aerobic bacteria die without electricity, anaerobic bacteria and sedimentation tanks will work normally. Yes, the quality of cleaning will drop, but the water will still be more or less clean, and the colony will recover in a few weeks.

Freezing a working installation of an autonomous sewage system is generally unlikely – the drains are warm, and heat is released during reactions. In the case of the Tver septic tank, there is another factor: a compressor that pumps air into the aerotanks is installed indoors and drives warm air, additionally heating the drains.

Frequency and methods of cleaning

Any septic tank requires pumping out sediment and maintenance. Another thing is that the timing of pumping can vary significantly, as well as the list of necessary work. Maintenance of a septic tank Tver consists of several types of work:

1. Periodic pumping of sludge from aeration tanks is required. You need to look at the amount of silt. If there is too much of it in the chamber, it must be pumped out. In order to be able to navigate by terms, let’s say that on average such a procedure is required once every six months. Pumping is automatic; for this, several taps must be closed / opened in a certain sequence. First, close tap No. 1, then open tap No. 2 for 3-2 minutes, then close it and open tap No. 3. In this case, excess sludge will flow into the second chamber.
2. Removal of deposits from the first septic tank. Biomass coming from the house settles in this chamber. This is not silt and it is better to remove it with a sewage machine. It should not be called more than once a year. In principle, you can get by with a fecal pump, but you need to pump the waste into a compost pit where they should “reach” for at least six months.
   

3. Replenishment of limestone filling is necessary every 2-3 years. Look into the penultimate compartment, if the lime has become noticeably less, it’s time to top up (a bag or two, depending on the size of the installation).
4. Ruff cleaning. If there is a noticeable plaque – once every 3-4 months – they should be washed with a stream of cold water. If there are badly damaged ruffs (rare), they can be replaced.
5. Capital cleaning of walls and partitions is needed every 2-3 years. To do this, the system is pumped out, the sediment is washed off with a strong pressure of water (from Karcher, for example).

Compressor maintenance is also required, but it is carried out separately, according to the activities indicated in its passport.

What can not be poured into a septic tank Tver

Since the processing of juices occurs due to the vital activity of bacteria, antibacterial drugs (antibiotics), preservatives (vinegar, salt in large quantities), and chlorine-containing drugs are harmful to them. The installation almost does not react to powders and detergents for dishes, but a large amount of bleach poured out at a time is harmful. If you just wash your plumbing with bleach once or twice a week, it’s not a big deal. But if you carry out such a procedure daily, problems may arise – the “living creatures” will die out.

It is impossible to drain fruit and vegetable peelings, hard paper, construction waste and large amounts of sand into the sewage treatment plant. All these substances either do not decompose by microorganisms at all or decompose insufficiently. They float on the surface or sink to the bottom. If we talk about sand and other heavy insoluble fragments, then they settle to the bottom of the first chamber, where they are compressed with the remnants of pollution, turning into a solid mass. This can become a problem when pumping. A sewage truck can handle this, but when manually pumping out with a fecal pump, you will have to somehow break this layer or climb inside with a shovel.

Read about one of the competitors – Topas septic tank here. 

The lineup

Tver septic tanks are of different volumes, for a different amount of drains. Each model has modifications that have a different letter designation:

• P – plastic case (without a letter, the case is metal).
• H – there is a pump compartment for forced pumping of purified water (a necessary option for high groundwater levels and a scheme with an intermediate well). If there are two letters H, then there are two pumps. The NPN marking indicates that there is a special compartment for installing the pump (in another case, it is suspended).
• M – increased insertion depth. As a standard, the inlet is located at a depth of 30 cm, in this modification it can be lowered to a level of 60 cm. In this modification, the position of the walls also changes, the height of the manholes of the manholes does not change.

The dimensions, volume and price of some models of Tver septic tanks are summarized in the table.

Model selection principle

This type of treatment plant is chosen according to the flow rate per day and the magnitude of the salvo discharge. The cost per day is calculated based on the number of residents and all the procedures that they take every day.

For example. Family of 3, there is a washing machine, dishwasher, shower / bath, toilet, kitchen sink. We count how many times a drain tank can go down on average per day, multiply by its capacity, we find how much water is drained when the toilet is placed. Next, we consider how much water is spent on washing, washing dishes, washing, how often family members take a shower, bath, etc. We summarize all the data and get the number of drains per day.

Now we calculate the magnitude of the volley discharge. This is the volume that an individual sewer installation can process within 2 hours. Most often, at least, this is the volume of two bathrooms or the amount of water that the family spends during the evening/morning shower + toilet flushes + water for washing + cooking + washing dishes. This is if all these processes are going on simultaneously.

Knowing these two numbers, select a model. In the selected model, both numbers should not be less. More – easily, less – the installation is unlikely to cope. As a rule, the main criterion is a volley discharge. Since if the installation cannot cope with such an amount of water, untreated water will leave the septic tank. As professionals say, there will be sludge removal, and, accordingly, there will be a smell and related “charms”.

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Installation of a septic tank Tver

First of all, you need to find a place where you will put the treatment plant. If you plan to use a sewage truck to pump out the first septic tank, you must take into account the possibility of its entrance. Otherwise, it is necessary to take into account the requirements of regulatory documents:

• at least 5 m from the road, houses and buildings;
• from garden trees – at least 3 m;
• from the reservoir – at least 10 m;
• from a well or well (own or neighbor’s) – at least 20 m.

The task is not easy. Having found a place for installation, it is necessary to determine the level of groundwater and the type of soil. You need to know the level during high water (spring after snowmelt or autumn during heavy rains) as well as how deep the water is during the rest of the year. This depends on the method of discharging purified water. After the Tver septic tank, it can be immediately dumped onto the ground without additional purification, but if you sometimes have water on the site, there is still no point in adding it. For such cases, they put a storage well into which drains merge in such situations. Then they are pumped out using a drainage pump.

The type of soil affects the choice of installation method. If the soil normally drains water (sand, arrogance, loam with a large amount of sand), the Tver septic tank is covered with sand. If clay prevails in the soil, and even the groundwater level is high, a concrete slab is laid / poured at the bottom, to which the septic tank body is tied. At the same time, the gap between the wall of the pit and the septic tank is filled with a cement-sand mixture (1 to 5).

Warm or not

When installing an autonomous sewage system in Tver, the question often arises: should it be insulated or not? If it will be operated all year round, if you do not leave the house in winter for longer than a couple of days, you can not insulate. The drains are warm, the reactions go with the release of heat, the compressor blows warm air from the house. In this mode, the treatment plant will not freeze. If you go on vacation in winter, or make sewers in a country house, which is visited occasionally in winter, then it is better to insulate the upper half of the body.

To insulate a septic tank, it is better to use not foam, but extruded polystyrene foam. It is, of course, more expensive, but with the same thickness it is much “warmer”, does not absorb water, does not color, and rodents and insects do not eat it, fungi and bacteria do not multiply on it. For the Middle Strip, it is enough to lay a 5 cm insulation, another thing is that it is better to make two layers – 2 + 3 cm, lay the plates so that the seams of the first row overlap with the second. It is fashionable to fix it on liquid nails, then it will close anyway, crushed by soil.

Order of work

Installation methods are different, but they have common rules. Particulars should be thought through / learned as questions arise, and preferably before installation. Here’s how to install a septic tank Tver:

• We dig a pit 25-30 cm larger than the dimensions of the hull. The depth depends on the type of installation: on well-draining soils, a sand cushion 10 cm thick is needed; on clay soils, a reinforced concrete slab is installed or poured. Depending on the thickness of the slab, an adjustment is made to the depth of the pit.
• To the pit, trenches are dug from the house to the inlet pipe, observing the slope of the sewer (when using a 100 mm pipe – 2 mm per meter). It also digs to the place where wastewater is discharged.
• A sewer pipe is laid immediately from the house (preferably red plastic for outdoor use) and an air duct from the compressor (at a depth of at least 70 cm). To prevent the septic tank from freezing in winter, the pipeline is insulated.
  

• The bottom of the pit is leveled and rammed.
• Sand is laid on a leveled and compacted bottom. The first layer – 5 cm, is leveled, spilled with water, rammed to a high density. The second layer is laid in the same way, only it must still be level.
• The surface of the slab must be level. It should be provided with reinforcement outlets, to which metal strips can be welded to hold the septic tank. If there are no releases, you can install anchors, you can already attach strands to them.
  

• Before fixing the body of the septic tank, it is necessary to check whether it is level. Permissible deviation – between the front and rear ends of the blocks – no more than 10 mm, vertical deviation – no more than 5 mm.
• Connect pipelines, hose from the compressor,
• The exposed body falls asleep:
  • sand, if the GWL is low and the soil drains water well;
  • sand with cement (5:1) if the GWL is high and / or clayey soils (clay and loam).
    

• Sand or a mixture is poured around the perimeter, in layers of 20 cm, compacted with hand tools, trying not to damage the body. Sand can be spilled, Mixture with cement – only rammed “dry”.
• If necessary, the top is insulated (penoplex or analogues).
• Continue backfilling with sand until the hull is backfilled. The top layer is road soil, in which grass or flowers can be planted.
•  The cover should be raised above the ground by 10 cm.

As you can see, the installation is not the most difficult, but requires accuracy. It is necessary to carefully lower the body without damaging it. No less carefully it is necessary to ram the sand or mixture.

Installation option at high GW

For such a case, you can bury half of the body, fill up the other half, making an artificial hill. Slopes can be reinforced with a special “Geodor” grating or something similar. Plant grass with strong roots in the ground. But this option is not always possible – pipes from the house must be laid with a slope.

What to do before starting

When transporting a septic tank, some of its parts may shift. Need to check:

• whether the loadings are in place – expanded clay and lime;
• pipelines (popping out of the clips);
• ruff nozzle;
• Chlorpatron.

When working, you must be careful not to damage the aerators, which are located under the backfill. Having set everything in place, seal the neck of the septic tank with rubber gaskets, you can coat it with bituminous mastic. Then install sludge pumps, if there is a pump, place its plug in the neck.

Do the input of electricity through a cabinet fixed on special racks, ground it. The bottom of the cabinet should be 70 cm above ground level. Lead the input from the shield to the terminal blocks, connect the control cable that goes to the control panel from the arc side. Install the float switch, connect its cable to the appropriate terminals in the cabinet.

Check functionality:

• for a few seconds by turning on the pumps in the socket in the cabinet (if pumps are included in the package);
• by lifting the float switch, simulate the filling of the septic tank and see if the pumps work.

Next, you can fill the system with water and check its performance. That’s all, the septic tank Tver is installed.