Coal-Fired Power Plants Produce Insignificant Mercury

Back in December, I wrote about the absurdity of the EPA claim that coal-fired power plants produced significant mercury which necessitated drastic reductions at any cost.  I was then puzzled that the EPA did not produce maps of the mercury concentrations that would show the mercury was found in higher concentrations downwind of coal-fired power plants.  It turns out that maps of the concentrations of mercury do exist and can be examined.  The National Atmospheric Deposition Program produces annual maps of the mercury concentrations across the USA here.  Note that the mercury high concentration areas changed somewhat between 2009 and 2010, but coal-fired power plants do not have giant chicken legs to rise up and walk to a new location.  But, the highest mercury concentrations are in the Southern Rocky Mountains and in the plains states just to the west of those southern Rocky Mountains.

The hottest areas for mercury are the states of Nevada, Arizona, New Mexico, Utah, Colorado, Kansas, Nebraska, South Dakota and other states near them.  Florida is a bit warm also.  So one would conclude that most of our coal-fired power plants are in southern California and the Southwest in general.  I do not know how one would explain the high concentrations in Florida.  But let us look at where the coal-fired power plants are then.

Of course, as you already knew, most of them are in the eastern half of the United States.  There are only a few dinky coal-fired power plants in southern California and most of those in Arizona are in northeastern Arizona.  There is a large concentration of coal-fired power plants in the Ohio River Valley and no lack of them in Mississippi, Georgia, South Carolina, North Carolina, Virginia, Maryland, and Pennsylvania.  Despite this huge concentration of coal-fired power plants, the East Coast Mid-Atlantic states are relatively green, which means they have lower mercury concentrations than the western part of the USA.  Being downwind of a coal-fired power plant does not appear to be anything like as important a factor as natural geographic sources of mercury are.  The mercury concentration maps give no hint of a mercury plume to the east of a power plant or even to the east of a concentration of large coal-fired power plants.  We should see such a plume due to the prevailing wind direction.

Update: I noted in my earlier post referred to above that coal-fired power plants produce about 41 to 48 tons of mercury a year. That post observed that forest fires in the US were estimated to release about 48 tons of mercury a year. Most of the big forest fires occur in the West, especially in many areas consistent with high concentrations in this map due to dry climates and low population densities drawing fewer fire-fighters. If these were the only sources of mercury, then the distribution of mercury across the US would still not differ much East to West since the forest fires of the West would be balanced by the higher concentration of coal-fired power plants in the East.

So what is the likely cause of the high mercury concentrations that are observed in the Southern Rockies and in the plains states to the west, especially the northwest, of them?  In comparison to these puny sources of mercury, volcanoes, subsea vents, and geysers are thought to produce 9 to 10K tons of mercury a year. The areas of high mercury concentrations do not correlate very well with the newer and more active volcanoes of the Pacific Northwest in the US, however. But, it turns out that they correlate well with the old volcanoes of the Rocky Mountains shown in white in the map here and shown below:

It is well-known to geologists that the southern Rocky Mountains are much richer in minerals and precious metals than the northern Rockies because volcanoes and rising magma played a much greater role in their formation.  I expect the high mercury concentration areas are due to the erosion of mercury mineral deposits, commonly cinnabar, in these old volcanoes and from their environs. The mercury released by forest fires is clear evidence that there is substantial mercury in the ground in the West already distributed about. The Rockies have been eroding for a very long time now and mercury is distributed over long distances from these old volcanoes by winds and eastward flowing rivers. The rivers flow into the Mississippi, so none of the mercury they transport goes east of the Mississippi River.  This is my best guess about the source in any case. Update End.

Once again we see that the EPA does not use rational science to govern its actions, even when those actions will have drastic negative consequences for the economy and put many people out of jobs.  Hauling coal by train to power plants, operating the power plants, and extracting coal from the ground all provide many hard-working Americans with jobs.  We also have huge coal reserves, which it makes more sense to burn to create electricity than it does to use natural gas which is better for making plastics and other products.  Of course, now natural gas is inexpensive and it is being used to generate electricity.  I am happy to leave how it will be used to the free market, but I do not want the EPA under the guidance of the ever-foolish Obama pushing and shoving the free market to influence such decisions.