Landfill liner utilizes efficient geotextile solution instead of gravel

Naue enables more economical and more efficient construction in Galați county (Romania)

Conventional landfill lining systems require thick gravel-soil layers. Problems occur when the appropriate material is not available in the area, as is the case in Galaţi, in eastern Romania. Modern geotextile liner systems are more than just another alternative: They are more cost-effective, efficient and, sustainable.

With the accession to the European Union in 2007, Romania had to adjust to EU standards and, for example, make numerous changes regarding environmental protection. Landfills not meeting the EU standards had to be closed, and new landfills had to be built in accordance with these requirements. In the early 2000s – not only in Romania, but in all ten Central and Eastern European candidate countries – this led to a wave of environmental remediation and numerous measures, as well as measures to safeguard transport corridors. To ensure that this was also affordable, the EU created an Instrument for structural Policies for Pre-Accession (ISPA).

ISPA funds are awarded only for transport and environmental projects, such as the Tirighina landfill in the county of Galaţi. Galaţi is a large industrial city and port on the River Danube – the last port before the Danube Delta. The Tirighina Landfill is located just 5km outside of Galaţi and is the largest landfill in the county of Galaţi. ISPA financing was the impetus for the construction of a new landfill cell with an area of approximately 80,000m². During construction from 2008 to 2011 the old landfill cell remained in operation.

Pioneer in Romania
Once Tirighina, as one of the first landfills in Romania, was able to close its old incinerator, work was started on the liner.

The original design foresaw a surface lining system consisting of the following layers (from top to bottom):

  • Soil layer: 1.0m
  • Drainage layer for rainwater: 0.5m
  • Sand protection layer for geosynthetic clay liner (GCL): 0.05m
  • GCL
  • Sand protection layer for GCL: 0.05m
  • Levelling / gas-drainage layer: 0.5m

This would have required gravel or recycled rubble for the levelling / gas-drainage layer and 16/32mm gravel for the drainage layer for precipitation. However, no appropriate high-quality aggregate was available locally, and transport costs for suitable fill material would have been immense.

The contractor therefore asked NAUE to propose a technical solution for the surface sealing using geosynthetic materials. Together with BBG Bauberatung Geokunststoffe (Germany), Naue proposed a more economical lining system with the following layers (from top to bottom):

  • Soil layer: 1.0m
  • Secudrain® 401 C WD 601 to drain off rainwater
  • Bentofix® NSP 4000 GCL barrier layer
  • Secudrain® 201 WD 601 201 for gas evacuation
  • Levelling layer of recycled rubble: 0.2m
  • The gas-evacuation capacity of Secudrain® 201 WD 601 201 is at least equivalent to the originally planned 0.5m-thick gravel layer.

The County Council of Galaţi was pleased that the project team had found a more economical solution, with which the landfill could meet the EU requirements even faster and in a more environmentally friendly manner. It was decided to use Secudrain® drainage composites for gas evacuation and flood control. Approximately 60,000m² of geosynthetic drainage materials were installed.

Total project costs were significantly reduced. Moreover, the use of a geosynthetic liner system instead of a conventional gravel layer saved over a month construction time on site.