Actions to Reduce Mercury Air Emissions and Related Exposure Risks in the United States

1. Actions to Reduce Mercury Air Emissions and Related Exposure Risks in the United States Ben Gibson Office of Air Quality and Planning and Standards U.S. EPA Presentation at C-MERC Workshop September 8, 2010

2. Mercury Air Emissions Estimates for 1990 and 2005 in U.S.A. Source Category (with 2005 emissions) Tons per year Reference: U.S. EPA, National Emissions Inventory, for 1990 and 2005

3. Upcoming or Revised National Emission Standards for Hazardous Air Pollutants (NESHAP) for Sources of Mercury

4. NESHAPs Require Maximum Achievable Control Technology (MACT) Standards for Major Sources of Hazardous Air Pollutants • MACT defined as the maximum degree of emissions reduction achievable taking into consideration cost, any non-air quality health and environmental impacts and energy requirements. The minimum level of control is known as the MACT “floor” • For existing facilities the MACT floor must be: • No less stringent than “the average emission limitation achieved by the best performing 12% of the existing sources” • For new facilities the MACT floor must be: • No less stringent than “the emissions control that is achieved in practice by the best controlled similar source” • EPA also must assess possible options to set standards that are beyond the MACT “floor” (i.e., more stringent), and determine if any of those options are achievable • EPA has some discretion and flexibility for various aspects of NESHAP development

5. NESHAP and Multi-pollutant Emissions and Controls NESHAPs regulate section 112(b) air toxics: mercury other metals (e.g., selenium, lead, arsenic) acid gases (e.g., HCl, HF) organic pollutants (e.g., dioxins/furans, formaldehyde) Some NESHAP are coordinated with sector wide strategies – where multiple regulatory actions apply to one industry

6. Benefits Analysis Required for Significant Rules • Executive Order 12866 • Agencies should assess all costs and benefits of available regulatory alternatives, including the alternative of not regulating. • Costs and benefits include both quantifiable measures and qualitative measures of costs and benefits that are difficult to quantify. • Agencies should select those approaches that maximize net benefits (including potential economic, environmental, public health and safety, and other advantages; distributive impacts; and equity), unless a statute requires another regulatory approach.

7. Benefits Analysis of Mercury Reductionsfor the Upcoming Utility NESHAP • Quantify human health benefits due to Hg reductions, with focus on IQ loss through fetal exposure • National-scale analysis for recreational freshwater anglers • Distributional (equity) analysis of high-risk sub-populations (e.g., subsistence fishers and Tribes) • Qualitative discussion of ecological benefits of mercury reductions • Unlikely to include marine or commercial fish in estimate

8. Key Areas for Enhancing Benefits Analyses for Mercury Reductions • Neurological and cognitive impacts • Possible positive effects from fish consumption may lead to underestimates of IQ loss • Quantifying and valuing discrete non-IQ impacts • Cardiovascular impacts • Data to develop a dose-response function for U.S. populations • Confounding effects of fatty acids • Relationship between modeled mercury deposition and fish tissue concentrations • Consideration of watershed loading, waterbody characteristics, fish migration, etc. • Methods to estimate Hg concentrations where we do not have observations • Near-coastal and marine environment • Subsistence populations and behavior • Consumption rates • Fishing patterns • Ecosystem benefits • Methodologies for valuing impacts on plants and wildlife

9. EPA Must also Conduct a Residual Risk Review CAA Section 112(f)(2) Residual Risk Assess remaining risk within 8 years after promulgation of MACT standards Set standards to provide an ample margin of safety to protect public health based on the Benzene Decision Framework 8

10. How Do We Make Risk Review Decisions? Use data on emissions, processes, and facilities, etc… and apply models, to estimate: Cancer and non-cancer inhalation risks Environmental risks Multi-pathway risks (where appropriate) Gather and review other relevant data and information (e.g., ambient monitoring data) Evaluate risks, costs, and other impacts of risk reduction measures and technologies Evaluate the potential for health effects other than cancer (neurological, developmental effects, etc…) Consider revising the MACT standard, if appropriate, based on all the analyses 9

11. Other Priorities for EPA-OAR Regarding Mercury • Improve emissions testing, monitoring and data collection for rulemakings and compliance demonstrations • Improve National Emissions Inventories • Achieve more comprehensive reporting of mercury emissions by States, Locals, and Tribes to the EPA’s Emissions Inventory System (EIS) • Obtain more data on mercury speciation • Evaluate new and improved mercury control technologies • Atmospheric Mercury Monitoring: • Continue to collaborate with States and other partners in the National Atmospheric Deposition Program to operate the Atmospheric Mercury Network (AMNet): • AMNet monitors speciated mercury concentrations at 20 sites in U.S. & Canada

12. Summary of Scientific Considerations forDeveloping Mercury Regulations • Data and Modeling to Support Expanded and More Refined Benefits Analyses • Non-IQ neurological and cognitive impacts • Cardiovascular impacts • Deposition / fish tissue relationship • Subsistence fisher populations and behaviors • Ecosystem valuations • Enhanced inventories and monitoring capabilities

13. Thank you for your time.Questions?Ben Gibsongibson.ben@epa.gov