Cost estimates are made for ultimate disposal of the concentrated contaminants resulting from complete renovation of a municipal waste water. The processes investigated are wet oxidation (Zimmerman Process) and incineration. For wet oxidation, plant costs vary from $4 to $80 per gallon of concentrate per day capacity (10,000,000 to 1,000 gallons per day). Operating costs vary from $1.40 to $35 per thousand gallons of feed. Pre-evaporation could reduce costs. Fixed costs constitute a large proportion (8 figures, 19 references). For incineration, estimates of the cost of pre-evaporation to 30 percent solids and hauling of the ash were included. A flash dryer-Nichols Herreshoff furnace combination was selected. Costs per 1,000 gallons of concentrate varied from $0.57 (10,000,000 gallons per day, 300 ppm) to $68 (1,000 gallons per day, 3000,000 ppm). Corresponding unit investment costs were $1.53 and $108 per gallon per day capacity (11 figures, 30 references). (Author)