Risk assessment methods have been developed which can be used to calculate criteria for controlling toxic pollutants in municipal wastewater sludges. These methods consist of algorithms, ranging from simple to complex, which allow calculation of exposure and risk from various sludge disposal practices. These calculations may show a need for management practice controls or for numerical limits on specific pollutants. Criteria for land-applied or distributed and marketed sludge may take the form of application rate limits (kg/ha) or concentration limits, calculated to control pollutant levels in the food chain or off-site movement in air or water. Criteria for landfilled sludge are defined in terms of acceptable leachate concentrations, as determined by an appropriate leachate characterization test, to prevent excessive groundwater contamination of vapor emission.