R 299.4914 Landfill construction; bentonite geocomposite liners.

Rule 914. (1) A bentonite geocomposite liner may be used in place of a compacted clay liner if the combination of its thickness and hydraulic conductivity results in liquid migration through the liner that does not exceed the rate of liquid migration through 2 feet of clay that has a saturated vertical hydraulic conductivity equal to 1.0 x 10-7 centimeters per second. (2) A bentonite geocomposite liner shall consist of sodium bentonite that is contained on each side by a fabric, geotextile, or flexible membrane liner. (3) A bentonite geocomposite liner shall be seamed in accordance with the manufacturer's specifications so as to prevent leakage at the seams. (4) A bentonite geocomposite liner shall not be laid during precipitation events and shall be covered immediately by a flexible membrane liner or other protective cover. (5) A bentonite geocomposite liner shall be installed in accordance with the manufacturer's specifications and quality assurance quality control plans that are approved by the director.