Geomembranes are widely efficient across a plethora of industries; from affordable, easy to install PVC, all the way to industrial reinforced geomembranes used to contain chemical run-off. Geomembranes are some of the best options even for a backyard pond project. The impermeable material prevents seepage, and pollution into the groundwater or from within the soil.
Other options for pond liners, such as clay, or concrete, are incredibly porous, and lack in the same abilities of containment and protection where geomembranes exceed.