the pump that directs the conditioned sludge to the dewatering station however it should be pointed out that it has been found to be effective to divide the infeed of the polymer to the sludge to where approximately 50 percent of the polymer is added prior to the pump and 50 percent of the polymer is added downstream from the pump table ii appearing below shows the data and conditioning parameters for three separate wastewater treatment facilities that utilized the dewatering process of the present invention all three facilities are designed to digest and dewater sludge as seen in table ii facility 1 includes three atad reactors and a post digestion aerobic holding tank this particular facility utilizes alum coagulant along with a cationic polymer the equivalent iron feed rate for the alum is 0 04 lbs fe lb solid as seen in table ii the total dewatering cost based on the alum and polymer cost is 59 25 per dry ton of solids facility 2 utilizes a single atad reactor and a following anaerobic holding tank the coagulant feed for the metal salt in this case is ferrous chloride note that the feed rate of the ferrous chloride is 0 02 lbs fe lb solid this resulted in a total coagulant and polymer cost of 45 40 per dry ton of solids facility utilizes two atad reactors and a.