5 40 leveling bed inst alla tion 1 OP TIONAL A lay er o f geo textile f abric is rec ommended around the exc a v a tion to prev ent ma terial migr a tion a G e o t extile f abric shall be plac ed per geo textile f abric manuf ac t u rer s rec ommenda tions b A n impermeable liner may be inc orpor a t ed to prev ent in ltr a tion If speci ed the liner must be inst alled per liner manuf ac t u rer rec ommenda tions 2 P lac e a L e v eling B ed per engineer plans a Ma terial should meet A ppendix C A c c e p t able F ill Ma terial b Ma terial should be free o f v oids lumps debris sharp objec t s and c ompac ted