Methods of making ground containment liners

A method of making a containment liner comprising:

• providing first and second felt geotextile layers comprising polypropylene fibers, polyester fibers, or a combination thereof;
• and
• extruding a first molten polymeric barrier layer material adjacent to the first felt geotextile layer and applying pressure between the first molten polymeric barrier layer material and the first felt geotextile layer to thereby embed at least a portion of the first polymeric barrier layer material into the first felt geotextile layer, wherein the first polymeric barrier layer extends into the first felt geotextile layer at least 5 percent of a thickness of the first felt geotextile layer and a distance of from 3 to 30 mil, and wherein a second polymeric barrier layer is embedded in the second felt geotextile layer, and an intermediate layer comprising a continuous, liquid impermeable polymeric layer is placed between the first and second polymeric barrier layers.