Simulations of RGM air emissions from 30 power plants + 16 other large RGM sources in the 4-state region Simulations with HYSPLIT-Hg for Oct-2004 through Dec-2005, using NARR met data Oct-2004 through Dec-2004 used as model “spin-up” Results for Jan-2005 through Dec-2005 are presented, i.e., the entire year 2005 Unit emissions runs were carried out; then results multiplied by actual emissions Individual runs done for each plant; results added together in post-processing RGM emissions estimates from EPA’s 2005 National Emissions Inventory Emissions from plants have not been constant; this is a “snapshot” for one year Results were tabulated on a 0.5 o x 0.5 o grid (~50km) Pattern of deposition makes “sense” relative to plants modeled With just the 30 power plants, the maximum deposition grid cell is ~15 ug/m 2 -yr Adding in the other RGM sources, the maximum deposition grid cell is ~37 ug/m 2 -yr More than 100 cells have grid-cell fluxes of between 1-16 ug/m 2 -year All values are average deposition flux over a given grid cell, i.e., a 50km x 50km area Localized deposition can be significantly higher We have include the power plants + 16 other large RGM sources, but there are other mercury sources in the region Sources outside the region will also contribute to deposition So, this is only a “partial” picture of the mercury deposition pattern Methodology Results and Discussion

We explicitly modeled sources representing about 90% of the RGM emissions in the four-state area, according to the 2005 NEI

15 Location of modeled power plant Here’s what we had before, when we just included the power plants

Here’s what we get when we add in other large RGM sources in the region Location of modeled power plant Location of other large RGM source

Location of modeled power plant

Just in case its helpful, here’s something I did a few weeks earlier… These are illustrative overall and time-series results just for one plant (Big Cajun) First map is for the overall simulation, over 15 months The second set of slides shows the time-series of deposition, on a finer-grid close-in to the source, that demonstrates how things evolve… for a unit emissions of RGM from the plant, for 3-hr time steps… This “movie” might be interesting to show?

Movie showing illustrative simulation of deposition arising from 1 g/hr emissions of RGM from Big Cajun II power plant each frame represents 3 hours; four weeks shown actual plant emits ~9 g/hr RGM (according to 2005 National Emissions Inventory)