Single component sealing systems featuring Carbofol® geomembranes,
are used in industrial facilities for storage, filling and transferring
and for production, treatment and utilization – where there is a danger
of groundwater contamination by hazardous materials.

Sealing

When used in the construction of collection basins, Carbofol®
high-density polyethylene (HDPE) geomembranes effectively protect
groundwater and soil resources from pollution by potentially harmful
contaminants.

With a minimum thickness of 1.5 mm, Carbofol® HDPE geomembranes
fulfil a wide range of chemical resistance as well as physical
durability requirements. In addition to their long-term chemical
resistance, Carbofol® HDPE geomembranes have long-term UV resistance and
are resistant to rodents as well as root growth when manufactured with a
minimum thickness of 1.0 mm.

By virtue of Carbofol’s® high flexibility, more complicated
connections are feasible without sacrificing quality or performance. Due
to their advantageous melt index properties, Carbofol® geomembranes can
be welded under a wider range of conditions, producing gas and
watertight overlaps.

Quality control tests are conducted continuously on every project in
addition to the standard manufacturing quality control practices.

Protection

To ensure the performance and quality of a single component sealing
system, mechanically bonded Secutex® or Depotex® protection nonwovens
should be used above and below the Carbofol® geomembrane, the selection
of which should be based upon project specific conditions.

With a low gravel content sandy subsoil (< 30 % gravel portion), a
400 g/m² mechanically bonded polypropylene (PP) Secutex® protection
nonwoven is sufficient. However, with coarser grained soils,
mechanically bonded Secutex® protection nonwovens with a mass per unit
area of up to 1,200 g/m² should be considered. 

With Secutex® and Depotex® nonwoven geotextiles, the long-term
performance and integrity of the Carbofol® sealing element can be
preserved both during the installation as well as against subsequent
construction loads.

Performance Monitoring

After completion of the single component sealing system, an
independent expert must approve the quality of the installation. To
enable permanent monitoring and documentation of the sealing system
performance, a drain and control tube system or an electro-resistivity
leak detection system, may be installed directly below the Carbofol®
geomembrane. With a photo-ionization-detector (PID), leakage from the
liner can be observed as contamination in the control tube system and
measured via special soil air investigations. In principle, it is best
if the sealing system performance is measured twice a year during the
first two years. In the following years, the frequency of system checks
may be reduced to once a year unless the defined performance standards
are exceeded.

Conclusion

With a properly specified mechanically bonded polypropylene Secutex®
or high-density polyethylene Depotex® geotextile protection system,
Carbofol® geomembrane offer high quality long-term single component
sealing systems.

In chemical storage depots, petrol stations, collection basins,
liquid depots, container areas, chemical plants, scrap yards as well as
many other applications where measures for groundwater protection are
necessary, NAUE’s high quality, single component geosynthetic sealing
systems can be effectively and economically employed.