Geomembranes

Geomembranes are engineered, impermeable polymer sheets used as barriers in civil, environmental, and mining applications. They are a key component of geosynthetic liners, designed to prevent fluid migration and protect soil and groundwater from contamination. Geomembranes are typically manufactured by extrusion or calendaring and delivered in large sheets that are joined at seams to form a continuous barrier.

The most common materials are high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE), chosen for chemical resistance and long-term durability. Other widely used options include polypropylene (PP), polyvinyl chloride (PVC), and EPDM rubber. The choice of material, thickness, and surface texture depends on the application, chemical exposure, temperature, and installation conditions.

Properties of geomembranes include very low permeability, chemical resistance to a wide range of substances, and suitability for long-term performance. They often incorporate stabilizers to improve UV resistance and additives to enhance flexibility. Thickness typically ranges from about 0.5 to 3 millimeters, with heavier grades used in aggressive or demanding environments. The integrity of seams is critical; joints are created by welding or fusion and are tested for watertightness and strength.

Applications span primary and secondary containment in landfills, containment for mining leachate and chemical facilities, potable and non-potable water reservoirs, wastewater treatment ponds, and environmental protection projects such as canal linings and aquaculture ponds.

Installation requires careful site preparation, controlled handling, and quality assurance. Field seams are tested using electrical methods, vacuum tests, or hydrostatic tests to ensure barrier integrity. Design considerations include chemical compatibility, temperature range, UV exposure, puncture resistance, and long-term aging.