New Rule Proposed for Emissions from Sewage Sludge Incinerators
The EPA has proposed new rules directed at emissions from sewage sludge incinerator (SSI) units. SSI units are typically found at wastewater treatment facilities and, according to the EPA, are the sixth-largest source of mercury air emissions in the US. The proposal not only limits mercury emissions, but also sets standard and emission guidelines for eight other pollutants, including lead, cadmium, hydrogen chloride, particulate matter, carbon monoxide, dioxins and furans, nitrogen oxide, and sulfur dioxide. However, mercury is of particular interest because the proposed emission standard is more stringent than the mandates that were set under the Clean Air Act.
It has been estimated that the new rule would remove about 75% of the current levels of mercury that are emitted from SSI units. The standards and guidelines are scheduled to be finalized in 2011 and to become effective in 2015.
The new mercury emission limits will mean that many facilities that operate SSI units will have to install one or more air pollution controls. These controls may be one or a combination of the following: high-efficiency scrubbers, fabric filters, or activated carbon injection. It was estimated that larger facilities will probably opt to adopt these solutions, while smaller companies may decide to switch other disposal alternatives rather than to continue to use SSI units. Currently, there are 218 sewage sludge incinerator units in the U.S. and Puerto Rico. It has been estimated that 90% of these units will need the additional air pollution controls, at a cost of approximately $105 million annually after an estimated capital outlay of $89 million. The health benefits could be anywhere from $130 to $320 million by 2015. Any new SSI units installed at facilities in the US or Puerto Rico would also be subject to these requirements. Operators of all SSI units will have to prove initial and ongoing compliance with the new standards and emissions guidelines.
The environmental and health effects of these mercury and the other eight pollutants covered under these proposed performance standards and emission guidelines are well documented. Additional information about this proposal can be found on the EPA’s website at http://www.epa.gov/ttn/oarpg/t3pfpr.html.