Topas Ukraine

Graf Drain Tunnels

By installing a biological wastewater treatment plant Topas Automatic, you solve the problem of sewage disposal in your area. Thanks to the technological processes at the exit from the station, we get purified water, which also needs to go somewhere. One of several options for the removal of treated water after the station is the arrangement of an underground drainage field in your area. Especially for such purposes, we made the Graf drainage tunnel.  For the possibility of arrival by passenger cars, the minimum layer of soil filling should be at least 500 mm. If the area above the drainage is pedestrian, the soil layer may be at least 250 mm. Drainage fields work well with TOPAS Automatic stations.

Price for drainage tunnels:

Tunnel – 75 Є / pcs

Caps – 30 Є / set (set of 2pcs)

The heavy-duty and unique design of the Graf drainage tunnel makes it possible to get to 300 liters of water instantly, which replaces about 10 meters of the drainage pipe. The presence of side holes in the drainage tunnels allows to drainage-purified water in three planes. The tunnels it interconnects easily, depending on the configuration and features of the site’s relief, they can lay in one or several rows without the use of special equipment, due to the relatively low weight, (weight of one Graf tunnel is 11 kg). Number of drainage tunnels in a row is virtually unlimited and depends on the volume of incoming drains as well as type of the soil into which it will drain the water. At the beginning and at the end of the row, it installs the special stubs for connecting pipes DN 100/150/200/300. In the last tunnel, in each of the installed rows, it mounted a ventilation pipe. In the last tunnel, in each of the installed rows, it mounts a ventilation pipe. The bottom of the pit, in which the tunnels are mounted, it covers necessarily with a layer of rubble, for more efficiently drainage of purified water into the ground. Above the drainage field shelters with geotextile and covers with soil.

Price for drainage tunnels:


  • good ventilation can significantly increase the length of the drainage with a large amount of waste;
  • simple installation; tunnels are easily interconnected, plugs are installed at the ends; 
  • economy (minimum earth work, good balance “price-quality”);
  • high capacity (3 times more water than a regular gravel trench);
  • withstands vehicle weight (3.5 t / m2)

Quite often, our company, along with the installation of biological wastewater treatment plants, Topas Automatic provides installation services for Graf drainage tunnels. The experience gained over a long period of work in this area allows us to assert confidently that the combination of the Topas Automatic autonomous wastewater treatment system with Graf drainage tunnels – is an excellent way to clean sewage and discharge treated water from your site.  You can specify prices and buy Graf drainage tunnels by contacting our manager. We will be happy to answer all your questions.

Examples of installation of drainage tunnels by specialists of our company:

Any questions?