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Mercury Emissions: Regulations and Impacts. Mercury in NC Water & Fish: Science & Regulation Kathy Stecker, NC DENR Division of Water Quality Mercury Regulations, Emissions, & Deposition Modeling in NC Steve Schliesser, NC DENR Division of Air Quality
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Mercury Emissions:Regulations and Impacts Mercury in NC Water & Fish: Science & Regulation Kathy Stecker, NC DENR Division of Water Quality Mercury Regulations, Emissions, & Deposition Modeling in NC Steve Schliesser, NC DENR Division of Air Quality Overview: Mercury Deposition Network in NC Jim Bowyer, PhD, NC DENR Division of Air Quality
Kathy Stecker Division of Water Quality, NC DENR Mercury IN NC WATER & FISH: Science & regulation June 2012
Content • The Mercury Problem • NC Impacts and Sources • Reducing Mercury in NC Water & Fish
The Mercury Problem • Mercury Cycling • Natural element • Human activity increased mercury release
The Mercury Problem- Mercury Forms • Air • Soil • Water: Methylation
Mercury in Fish • National Concern • Northeast • Minnesota • New Jersey • Florida • Michigan • Mercury in NC fish • NC DHHS Statewide Fish Consumption Advisory • Clean Water Act 303(d) List • NC Statewide Mercury “Total Maximum Daily Load”
Mercury in NC • NC DHHS Statewide Fish Consumption Advisory http://epi.publichealth.nc.gov/fish/current.html
Mercury Sources • Air Quality modeling • Total Hg air deposition within NC • Relative contributions in-state & out-of-state • Sources of mercury in NC fish(2002 estimate) • Wastewater discharges (~2%) • Atmospheric deposition (~98%)
Federal Clean Water Act (1972) §303(d) • Total Maximum Daily Load (TMDL) • amount of pollutant waters can receive and still meet standard • TMDL = WLA + LA + MOS • WLA (waste load allocation): Allowable load from point sources (like wastewater) • LA (load allocation): Allowable load from nonpoint sources (like atmospheric deposition) • MOS: margin of safety
Wasteload Allocation • Statewide aggregate load for wastewater • Per-facility maximum in permitting strategy • No reductions from NPDES stormwater
Nonpoint Source Impacts • Atmospheric deposition accounts for ~98% of mercury in waters • Based on Air Quality Modeling • NC sources contribute ~16% • Nearby states contribute ~14% • Global pool contributes ~70% • US Mercury Air Emissions • 49% Electric generating facilities • 44% Other industrial sources • 5% Area sources • 2% Mobile sources
Trend of Estimated US Mercury Emissions to the Atmosphere(Source: Husar and Husar, 2002; slide borrowed from state of FL)
Documents • Draft NC Mercury Total Maximum Daily Load (TMDL) • Draft Wastewater Permitting Strategy • Reduction Options for Nonpoint Sources • http://portal.ncdenr.org/web/wq/ps/mtu/tmdl/tmdls/mercury • Or Google NC mercury TMDL
Comments • Submit written comments on TMDL and wastewater permitting strategy by June 18, 2012 • Response to comments on TMDL will be included in package for EPA approval • Informal comments on nonpoint source reductions are welcomed
Thank You • Submit your written comments to Jing.Lin@ncdenr.gov by June 18, 2012 • Questions? Kathy.Stecker@ncdenr.gov