Nov 10 2014 If cost of river sand is equal to cost of manufactured sand following points have to be considered-a 25 bulk age is to be considered for wet sand. Sieving. Wastage of 25 is to be considered for oversize material. b If organic impurities are more than 6 sand should be washed. Washing cost is not less than Rs. 300.00 for 100 CFT.