Sewage Sludge (Biosolids) Incinerators (SSIs) Percentage Contributionto each of the 30 urban HAPs regulated under Section 112 of the CAAA. 1,1,2,2-TetrachloroethaneEPA SSI Emission Estimate - 6% of totalConcentrations of 1,1,2,2 - Tetrachloroethane in analyzed biosolids were below the detection limit of 0.52 mg/dry kg.Give the high exhaust gas temperatures for SSIs (1200 -1400°F for Multiple Hearth Incinerators and 1500 -1600°F for Fluidized Bed Incinerators)and very low Total Hydrocarbon emissions (0 - 50 ppm), emissions of 1,1,2,2 -Tetrachloroethane from SSI are negligible.B. AcrylonitrileEPA SSI Emission Estimate - 3% of totalConcentrations of Acrylonitrile in analyzed biosolids were below the detection limit of 0.011 mg/dry kg.Give the high exhaust gas temperatures for SSIs (1200 -1400°F for Multiple Hearth Incinerators and 1500 -1600°F for Fluidized Bed Incinerators)and very low Total Hydrocarbon emissions (0 - 50 ppm), emissions of Acrylonitrile from SSIs are negligible.C. Arsenic CompoundsEPA SSI Emission Estimate - 2% of TotalEmissions of Arsenic from SSIs are regulated under 40 CFR Part 503 (Use or Disposal of Sewage Sludge).Through the use of venturi/impingement tray scrubbing systems and controlling burning zone temperatures, arsenic emissionsare normally less than 1% of the arsenic concentrations in the sewage sludge. A survey of 20 NACWA member POTWsthat practice incineration revealed average emissions of 0.0019 tons/year in 2002.D. Cadmium CompoundsEPA SSI Emission Estimate - 11% of totalEmissions of Cadmium from SSIs are regulated under 40 CFR Part 503 (Use or Disposal of Sewage Sludge).Through the use of venturi/impingement tray scrubbing systems and controlling burning zone temperatures, cadmium emissionsare normally less than 1% of the cadmium concentrations in the sewage sludge. A survey of 16 NACWA member POTWsrevealed total cadmium emissions in 2000 of 0.28 tons, while EPA had estimated cadmium emissions from these 16 POTWs tobe 4.08 tons per year. The reduction in cadmium emissions are also due to EPA's Pretreatment Program.E. ChloroformEPA SSI Emission Estimate - 0%NACWA agrees with EPA's SSI emission estimate for chloroform.F. Chromium CompoundsEPA SSI Emission Estimate - 1%Emissions of Chromium from SSIs are regulated under 40 CFR Part 503 (Use or Disposal of Sewage Sludge).Through the use of venturi/impingement tray scrubbing systems and controlling burning zone temperatures, chromium emissionsare normally less than 1% of the chromium concentrations in the sewage sludge. A survey of 20 NACWA member POTWsrevealed average cadmium emissions in 2002 of 0.0033 tons per POTW. The negligible chromium emissions are also due toEPA's Pretreatment Program.G. Dioxins (2,3,7,8 - TCDD)EPA SSI Emission Estimate - 5%In a 1994 report, U.S. EPA estimated that the SSIs in the U.S. emitted a total of 23 grams TEQ (Dioxin) to the atmosphere eachyear.This was approximately 0.25% of total Dioxin emissions. A study conducted by NACWA/Cambridge Environmental revealed that thatactualtotal emissions was 8 grams per year and that SSIs were a negligible source of dioxins.H. Lead CompoundsEPA SSI Emission Estimate - 7%Emissions of Lead from SSIs are regulated under 40 CFR Part 503 (Use or Disposal of Sewage Sludge).Through the use of venturi/impingement tray scrubbing systems and controlling burning zone temperatures, lead emissionsare normally less than 1% of the lead concentrations in the sewage sludge. A survey of 20 NACWA member POTWsrevealed average cadmium emissions in 2002 of 0.0222 tons per POTW. The negligible lead emissions are also due tothe use of unleaded gasoline.I. Manganese CompoundsEPA SSI Emission Estimate - 0%NACWA agrees with EPA's SSI emission estimate for manganese.J. Mercury CompoundsEPA SSI Emission Estimate - 3%The 230 biosolids incinerators located in the United States are a very minor source of mercury. For example.conservative (high) estimates show these units collectively emit less than 0.9 metric tons (1 U.S. ton) of mercury to the atmosphere each year,which is roughly 0.5% of the total amount of mercury annually emitted to the atmosphere in North America.POTWs that practice incineration are subject to the National Emission Standards for Hazardous Pollutants (NESHAPs) standard of3,200 grams mercper 24-hours as a plant-wide ceiling. Actual mercury emissions from each of these POTWs are less than 200 grams in 24-hours. This is primarily duethe fact that mercury concentrations in biosolids are typically less than 1 mg mercury /dry kg. Applying these results to available emission inventoryestmiates would reduce the stated impact of biosolids incinerators even more.K. Nickel CompoundsEPA SSI Emission Estimate - 1%Emissions of Nickel from SSIs are regulated under 40 CFR Part 503 (Use or Disposal of Sewage Sludge).Through the use of venturi/impingement tray scrubbing systems and controlling burning zone temperatures, nickel emissionsare normally less than 1% of the chromium concentrations in the sewage sludge. The negligible nickel emissions are also due toEPA's Pretreatment Program.L. Polychlorinated BiphenylsEPA SSI Emissions Estimate - 18%Testing of sewage sludge for PCBs revealed concentrations below the detection limits. This is due to the banning the manufacturer and useof PCBs in the 1970s. In addition, due to the high temperatures within an incinerators (1400 -1600°F), any PCBs that could possibly end upin sewage sludge would be destroyed during the incineration process.M. Vinyl ChlorideEPA SSI Emissions Estimate - 1%Testing of sewage sludge for vinyl chloride revealed concentrations below the detection limits.RPD6-1-09curyeto