HDPE/LDPE Geomembrane Liners

HDPE Geomembrane is utilized for a variety of containment applications. HDPE resin is formulated for Ultraviolet and Ozone resistance and is an excellent geomembrane to use in an exposed environment. Covering the geomembrane with geotextile, and then covering the lined area with an appropriate backfill material will extend performance life. An HDPE geomembrane is also resistant to a wide range of chemicals. This particular geomembrane is typically deployed in very large projects and is widely used for leachate containment in landfill and mining operations. Pond liners incorporate HDPE as a very cost effective way of lining earthen basins for containment purposes.

The HDPE geomembrane is produced in a 22.5′ roll width for the smooth surface material and 23.0′ wide for the textured surface material and is available in thicknesses ranging from 40 to 100 mil. Considering the wide roll width this geomembrane may be deployed over large areas in a relatively short period of time. The installation of an HDPE Geomembrane must be accomplished with specialized seam welding equipment in the hands of trained technicians. Testing of seams also requires various testing apparatuses that are designed to perform different tests such as peel, shear, vacuum, and spark testing. The actual test to be performed is determined by the seam type. Seams are made with wedge welders on long and straight field seams and extrusion welders are utilized for detail seams, pipe boots, etc. It is very important that an HDPE membrane be installed by experienced technicians that are familiar with inherent factors to this particular geomembrane such as expansion / contraction influences, welding parameters, quality control procedure, documentation, etc. Design engineers should consider previously installed square footage as a factor when qualifying an installer. This may be a reasonable indicator of the installers experience but it should also be considered that a company does not necessarily maintain identical capabilities from year to year. Previously installed square footage also does not reflect the quality of the work performed by said company. We believe that the most important criteria is likely reflected by project references, which should be provided by an installer for comparable projects, regarding complexity and scope-of-work.

The typical pond liner and landfill impoundment is surrounded by an earthen berm with the geomembrane extending into an anchor trench that is excavated along the upper edge of its slopes. A typical anchor trench is 12″ wide and 24″ deep, although for steep or long slopes the trench dimensions may be greater. The geomembrane may be attached to existing concrete with steel battens and to new concrete with an embedded HDPE channel. Pipe boots are fabricated to provide for an HDPE sleeve that is banded in order to compression seal the geomembrane to the pipe, or may be extrusion welded to an HDPE pipe.