Section 840.124  Final Slope and Stabilization

a)         All final slopes must be designed and constructed to a grade capable of supporting vegetation and minimizing erosion.

b)         All slopes must be designed to drain runoff away from the cover and to prevent ponding.

c)         Ash Pond D must meet the stability criteria of 35 Ill. Adm. Code 811.304.

d)         The owner or operator may use coal combustion waste generated at the site in establishing the final grade and slope as provided below:

1)       The earthen berms surrounding Ash Pond D must be regraded to eliminate any freeboard between the top of the berm and the adjacent surface of the coal combustion waste;

2)       Additional coal combustion waste may be placed only directly on top of coal combustion waste that is already in place;

3)       The maximum final slope must be no greater than 5 percent;

4)       Any additional coal combustion waste used to establish the final grade and slope is considered coal combustion by-product, and its use does not require any independent approval pursuant to Section 3.135 of the Act [415 ILCS 5/3.135].