Firestone PondGard EPDM geomembrane utilizes EPDM (ethylene propylene diene terpolymer) synthetic rubber, which provides a highly flexible and stable waterproofing membrane. It can be shaped to fit the complex contours of any size pond or landscape feature, and requires little maintenance. PondGard is highly resistant to ultraviolet radiation, ozone, and other potentially harmful environmental conditions, and so has a long life. Fish, plant and wildlife friendly, it is ideal for applications ranging from backyard decorative ponds to potable water reservoirs and constructed wetlands.