The landfill at the 9th kilometre of Tyumen’s Velizhansky Tract accumulated waste for 11 years. Waste accumulated across an area of 41 ha near water intake facilities, lakes and dacha properties. During the survey work, lead concentrations exceeding the maximum permissible concentration by 1.31 and 5.91 times were identified at the landfill. Eight hundred thousand residents living near the landfill suffered from landfill gas emissions and chemical contamination of the area.
In 2022, reclamation of the site began under the national Ecology project. The work involved relocating 357 000 cubic metres of waste and degraded soil while forming the landfill body.
To prevent the spread of contamination (migration of landfill leachate) beyond the landfill, a vertical cut-off wall was installed around the entire site perimeter, with a total length of 21 855 linear metres. Specifically, 1819 soil-cement columns with a diameter of 1.4 m and a depth of up to 21 m were installed in the ground.
The choice to install a multifunctional protective cover using geosynthetics was justified by the reduced quantity of inert materials required and the increased speed of installation work. The design solutions, approved by the state expert review, provided for 11 layers in the landfill’s upper cover system:
- Geogrid Armoset-P for slope stabilisation;
- Geogrid three-dimensional to create a gas drainage layer;
- Geotextile to prevent the layers from mixing;
- Sand;
- Bentonite mat Bentotech ASL to provide additional gas and hydraulic insulation for the drainage layer;
- Sand;
- Geotextile to protect the geomembrane against puncture;
- Geomembrane Type 4/1 for gas and hydraulic insulation;
- Hydromat 3D provides surface runoff drainage;
- Peat-sand mixture;
- Biomat for rapid revegetation, formation of a turf layer, reinforcement and drainage of slopes during reclamation.
This multilayer cover will not only protect the environment from the negative impact of accumulated waste, but will also provide an aesthetically pleasing appearance once the work is completed.
In addition, the design documentation provides for a degassing system to clean landfill gas and remove unpleasant odours, as well as an emergency dewatering system to prevent the contamination of groundwater by landfill leachate.
Reclamation was completed in January 2024, and by this summer the site had become a green hill rising above the surrounding area.
