Laserfiche WebLink
Section 816.46 (u) Continued. <br />At a minimum, the top width of each pond will not be less than <br />20 percent of the sum of the height in feet of the embankment <br />measured at the upstream toe plus 35 fee[. The cross sections in <br />the plans show the dimensions of the top width and show that all <br />will be sized according to Section 816.46 (1). <br />The criteria presented in the plans show that the combined upstream <br />and downstream side slopes of the settled embankment will not be <br />less than 1v:5h, with neither slope steeper than lv:2h. Slopes <br />have been designed to be stable in all cases, even if flatter side <br />slopes are required. <br />One of the initial phases in construction of all sedimentation pond <br />embankments will be to clear all organic material, especially top- <br />soil for stockpiling or other use, to clear all unstable material, to <br />slope all surfaces to no steeper than 1:1, and to scarifty the <br />entire surface. <br />In many cases, dense clay will be used as fill material in sedimen- <br />tation pond embankments (See discussion under Section 816.46 (b)(2)(k)); <br />in no instances will coal processing waste be used. No coal pro- <br />cessing waste is produced at the site and therefore, none is avail- <br />able. See the discussion under Section 780.25 (d). All fill <br />material will be selected to exclude the presence of sod, large <br />roots, or other large vegetative matter and frozen material. An <br />exception to this procedure would be when sedimentation ponds are <br />retopsoiled, when necessary, with a veneer of topsoil and revegeta- <br />ted to control erosion and enhance embankment stability. Primary <br />strength of the embankment, however, will not depend upon the <br />topsoil; in other words, topsoil will not substitute for fill. <br />The placing and spreading of fill will be started at the lowest <br />part of the foundation and will be brought up in lifts of ten <br />inches to facilitate compaction and meet the design requirements of <br />Section 816.46. Each lift will be compacted so that the density of <br />the material is adequate to meet the design criteria of Section <br />816.46. <br />Exhibit Sp 816-47 12/13/99 <br />