NAC444.6891. Requirements for design and construction of system for final cover.

     1. The owner or operator of a Class I site shall install a system for a final cover which is designed to minimize infiltration and erosion. Except as otherwise provided in subsection 2, the system must be designed and constructed to:

     (a) Have a permeability that is less than or equal to the permeability of any system for a bottom liner or natural subsoils present, or have a permeability no greater than 1 x 10^-5 centimeters per second, whichever is less;

     (b) Minimize infiltration through the closed municipal solid waste landfill unit by the use of an infiltration layer which contains at least 18 inches of earthen material; and

     (c) Minimize erosion of the final cover by the use of an erosion layer which contains at least 6 inches of earthen material which is capable of sustaining the growth of native plants.

     2. The solid waste management authority may approve an alternative design for a final cover which includes:

     (a) An infiltration layer which achieves an equivalent reduction in infiltration as the infiltration layer specified in paragraphs (a) and (b) of subsection 1; and

     (b) An erosion layer which provides equivalent protection from wind and water erosion as the erosion layer specified in paragraph (c) of subsection 1.

     3. The final cover must be graded to drain surface water from the cover. The top slope must have a grade of not less than 3 percent. The design of the final cover must be sufficient to control erosion and maintain the stability of the slope.

     (Added to NAC by Environmental Comm’n, eff. 11-8-93)