The paper describes part of the Environmental Protection Agency's efforts in collecting data during incineration of various RCRA wastes to determine the quality of the residuals being generated. Ash and effluent streams were sampled and analyzed after rotary kiln incineration of three different wastes at an EPA facility in Jefferson, Arkansas. These wastes were RCRA Waste Code K024 (distillation bottoms from the production of phthalic anhydride), K001-PCP (wastewater treatment sludge from wood preserving processes using pentachlorophenol), and K037 (wastewater treatment sludge from the production of the pesticide disulfoton). The data on waste feed, ash and scrubber water composition (not stack gas) are discussed in the paper. Rotary kiln incineration appears to be an acceptable treatment process for the three RCRA wastes that were tested.