A wildlife pond should be lined with a durable, non-toxic material with good resistance to tears, punctures, and UV damage. RPE liners that are certified for potable water storage are guaranteed not to leach harmful chemicals over time, making them safe for sensitive aquatic life and plants. ANSI/NSF 61 is the highest level of safety, making them an excellent choice for wildlife ponds.
A wildlife pond may be designed for a natural appearance, which often involves irregular pond shapes. A liner with excellent flexibility, such as EPDM, RPE, or to a lesser degree PVC, can easily conform to curves and corners. Another consideration is the liner's resistance to mechanical damage, such as punctures and tears from sharp claws, hooves, and beaks. A reinforced liner, such as RPE, is the most durable for these challenges. In the end, when choosing a liner for your wildlife pond, consider factors such as the pond's size and depth, the types of expected residents and visitors, and material's safety for sensitive wildlife.