A device/apparatus for using a multilayer fabric of varying deniers for the processing and treatment of fluids which must be treated to remove materials so that the resultant treated fluid may be reused and/or returned to the earth and particularly to the water table. More particularly the multilayer fabric, each layer being of selected denier, is used in combination with conduit in a drainage field or leaching system usually associated with a septic tank or septic system. Most particularly the multilayer fabric of varying deniers is wrapped around corrugated plastic pipe of the type well known in the field of drainage or leaching fields. At least one of the multilayer fabric layers is formed from an unstructured assemblage of fibers. The unstructured assemblage of fibers are supported by an outer sheeting. Oils, greases and chemicals contained in the fluids to be treated and entering within the fluid conducting conduit structure are entrapped within at least one of the first layers and at least one additional layer of fabric and particularly on the unstructured assemblage of fibers. The unstructured assemblage of fibers provides a large surface area whereon consequent biodegradation of said oils, greases and chemicals takes place permitting treated fluid to pass omnidirectionally through the unstructured assemblage of fibers and subsequently leach into the ground. The particular objectives, features and advantages of the device are: 1) Multiple layers of fabric; 2) Fabric layers of varying deniers; 3) Useful in wrapping corrugated plastic pipe; 4) With the selection of fabric and fabric denier, specific fluid treatment objective can be met; 5) The multilayer fabric provides boundaries/interfaces and regions within which specifically chosen bacteria, chemicals, microbes and the like may be introduced to facilitate the biodegradation of specifically chosen undesirable materials; and 6) Improve performance over the currently known leach fields.