Landfill side and base drainage

The EnkaDrain Wide product portfolio encompasses a wide range of drainage geocomposites for use in landfill applications. Their core consists of highly durable, v-shaped monofilaments providing superior resistance to compressive stress. Filter nonwovens are stitched to the core longitudinally at closely spaced intervals. Its tight structure limits filter creep into the flow section of the drainage core – the so-called “intrusion phenomenon”. Depending on the level of compressive stress applied on the geocomposite and the in-plane flow capacity required for the specific landfill project, the core may be four or six millimeters thick. The mass per unit area can be adjusted.

While drainage mats with thermally bonded nonwovens are also available, when used for side and base drainage in landfills, EnkaDrain Wide is manufactured using needle-punched nonwovens. For maximum speed of installation, all Enkadrain Wide product variants are manufactured with a width of five meters.

Conventional designs include a thick protecting nonwoven geotextile on top of the geomembrane at the side and base of the landfill. A gravel layer measuring at least 50 cm thick is added as a protecting interface between waste and geosynthetics and to provide the required leachate drainage. Installation of EnkaDrain Wide is an approach which is not only as technically reliable, but also more economical. In addition to protecting the geomembrane, EnkaDrain Wide fulfills the drainage function, ensuring that leachate accumulation is kept to a minimum. In this application, the geocomposite’s discharge capacity has to be equal to that of the 20-30 centimeter of gravel for which it is a substitute. Hence, substantial volumes of granular material can be saved and the number of truck movements significantly reduced. At the same time, EnkaDrain Wide helps achieve a significant gain in available storage volume. In addition to acting as a drainage layer inside the slopes and at the base of the landfill, EnkaDrain Wide can also be applied as a leakage-detection layer underneath the landfill base.