This report evaluates the landfilling of wastewater treatment plant sludge for purposes of describing current practices, determining environmental and public health impacts, describing available control technology, and evaluating management options. The potential environmental/public health impacts and operational problems associated with current sludge landfilling practices are described. Potential public health risks from sludge landfilling are associated with contaminants entering ground or surface water. Environmental and public health risks associated with ludge landfilling can be significantly reduced by utilizing current available control technology. Stabilization of sludge may or may not be necessary, depending on the landfill site and design, but sludge dewatering is considered imperative for all landfilling operations to avoid problems in landfill operations and leachate generation.