Groundwater protection with single component sealing systems
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® protection nonwovens should be used above and below the Carbofol® geomembrane.
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® 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® geotextile protection system, Carbofol® geomembranes 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.
