Land Division RCRA Facilities Management Office • March 2015 75 Hawthorne Street, San Francisco, CA 94105 866-EPA-WEST • www.epa.gov/region9 v»EPA U.S. Environmental Protection Agency Pacific Southwest/Region 9 Saving Arizona, California, Hcafaii, Nevada, the Pacific Islands and 148 Tribes Steps to Risk Assessment <33 Measure Emissions EPA conducted a trial burn at the facility to find out amounts of chemicals coming out of the Evoqua facility's smokestack. ~~~ Identify Possible Exposure Routes EPA considered exposures via: • Breathing in of chemicals from the smokestack; • Eating food or touching soils that have absorbed chemicals; and • Eating fish potentially affected by chemicals in wastewater. Determine Chemical Concentrations EPA determined the concen- trations of chemicals through those exposure pathways which could reach human and animal populations. Calculate Potential Impacts Ji Based on information from existing scientific studies with these chemicals, EPA calculates the potential impacts to humans and animals. LOAEL NOAEL Evoqua Quick Facts What does the facility do? The: Evoqua facility treats spent carbon — a filtration material — by putting it in a furnace to remove con- tamination. Where is the facility? The facility is approximately a mile southeast of Parker, AZ. How long has the Evoqua facility been around? The Evoqua facility has been operating since 1992. But it has had different names throughout its lifetime including Siemens, US Filter, and Westates Carbon. Why did EPA do a Risk Assessment? The: Evoqua facility is regulated by EPA under the Resource Conservation and Recovery Act (RCRA) because it handles hazardous waste. A Risk Assess- ment is one way to make sure that the facility is operating safely What is EPA doing now? EPA will also be making a decision about whether or not to issue a RCRA permit to allow the facility to continue managing hazardous waste. Such a permit would create additional requirements for operations at the facility. Risk Considerations In conducting the risk assessment, EPA considered the following populations: • Elderly • Pregnant • Children • Facility Workers • Farmers, Fishermen, and Hunters 15 20 25 Dose (mg/kg) ------- 1 in 100,000 is EPA's risk threshold. This means that in a town of 100,000 people, at most 1 additional person might develop cancer over a lifetime (70 years) of exposure to chemicals emitted from the Evoqua facility. With regard to this threshold, EPA has deter- mined that impacts from long-term exposure to the Evoqua facility emissions are insignificant. What Typically Comes Out of the Smokestack? Nitrogen ,42.2% Oxygen Carbon Dioxide 3.9% Other 0.006% Water (steam) 49.2% Nitrogen Oxides 0.005% Hydrogen Chloride and Chlorine 0.00023% Carbon Monoxide 0.0002% Ash 0.00007% Metals 0.0000004% Organics (estimated) 0.0000005% Dioxin 0.0000000000001% Contacts Please contact the following with questions or comments: "Mike" Mahfouz Zabaneh, Project Manager Phone: (415) 972-3348 zabaneh.mahfouz@epa.gov Dr. Patrick Wilson, Senior Regional Toxicologist Phone: (415) 972-3354 wilson.patrick@epa.gov Mailing Address: U.S. EPA Region 9 (WST-4) 75 Hawthorne Street San Francisco, CA 94105 For media inquiries, please contact: Margot Perez-Sullivan Phone: (415) 947-4149 perezsullivan.margot@epa.gov The complete text of the risk assessment is available online at: http://www.epa.gov/region09/waste/siemens/pdf/ RiskAssessment/siemens-riskassess-report.pdf ------- |