EPA is issuing a proposed rule that would limit emissions of mercury, particulate pollution and other harmful pollutants from sewage sludge incinerators (SSIs). The proposed rule would establish opacity limits and emission limits for nine pollutants emitted from SSIs, including mercury, lead, cadmium, hydrogen chloride, particulate matter, carbon monoxide, dioxins/furans, nitrogen oxides, and sulfur dioxide. It would require approximately 196 of 218 existing SSI units in the United States to install one or more air pollution-control devices, including activated carbon injection, fabric filters or high-efficiency scrubbers. It would also require SSIs to test, monitor, keep records, report, and provide operator training. EPA will accept comments on the proposal for 30 days after it is published in the Federal Register.