Not all geomembrane applications require a ballast, however it may assist in stabilizing and anchoring the material. Liners that are sensitive to UV radiation need to be buried several feet under the soil in order to prevent degradation. Other geomembranes are resistant to UV radiation, and can be directly exposed to the sun. When the geomembrane is above the ground, an anchor trench is typically used to hold the liner in place.
In ponds, or other bodies of water intended for aquatic life, a geomembrane is often covered with a soil pond-bottom. This provides a place for plants to grow and fish to lay their eggs.
