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Fact Sheet on Mercury Pollution from Coal-Fired Power Plants in Kansas
Prepared by Kansas Chapter, Sierra Club - 10-06-06
Summary. Coal fired power plants are currently the largest single source of airborne mercury emissions in the United States. Airborne mercury emissions travel tens to hundreds of miles before depositing, primarily in rainfall, into lakes and streams where it accumulates in fish that may be eaten by people. This adds to uptake via seafood consumption. The EPA recently announced that 1 in 6 women of childbearing age in the US have blood mercury levels that could be harmful to a fetus. Fish mercury levels in Kansas lakes have been increasing.
The USEPA recently promulgated a new Mercury Rule for coal fired power plants that calls for nationwide reduction of mercury emissions in two stages. The first stage calls for about a 25% reduction by 2010 as a co-benefit of an existing rule calling for new for scrubbers to reduce acid rain. Additional reductions are not required until 2018. USEPA, under a "cap and trade program," will allow utilities to avoid installing state-of-the-art mercury removal equipment by buying emission credits from other utilities.
In effect the USEPA has created a loophole where Sunflower and other Kansas utilities can choose to emit most of their mercury by buying emission credits.
In the draft permit issued on Sept 21, 2006, the Kansas Department of Health and Environment is attempting to establish a state-level mercury emission limit for Sunflower's 1980 MW Holcomb expansion. This draft is currently undergoing the mandated comment period. Unfortunately the text is unclear and may not hold up if challenged.
The Details. In June of 2006 USEPA finalized its new mercury rule for coal fired power plants. It has two main parts.
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EPA established mercury emission limits consistent with the incidental capture of mercury by conventional stack gas scrubbers which are already required under another rule to reduce acid gases. In other words they are allowing many utilities to avoid installing dedicated mercury removal equipment which involves the injection of powdered carbon into the flue gas. |
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Eastern coals have a relatively high chlorine content that causes mercury emissions to be water soluble. Power plants burning eastern coals can get 80 - 90% mercury capture in their scrubbers without doing anything special. |
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Wyoming coal has a low chlorine content that causes mercury emissions to exist in an insoluble, elemental form. Power plants in Kansas, which almost always burn Wyoming coal, can obtain only 25% or less capture of mercury in their scrubbers. |
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EPA also established a "cap and trade' system which sets caps for overall national mercury emissions effective in the year 2010 at 38 tons and in 2018 at 15 tons. EPA allows utilities to trade among themselves for the right to emit mercury within these caps. That is, one utility whose power plant captures 90% of the mercury can sell unused "credits" to another utility whose plant captures little or no mercury. |
The attorneys general of several states have challenged this rule in court on the basis that it will lead to mercury "hot spots." If power plants choosing to buy credits to avoid buying and operating mercury removal equipment are concentrated in one region of the country, then so will be the mercury contamination.
Some 3100 megawatts of coal plants are planned for Kansas. These are Sunflower Electric's 1980 MW addition to their existing coal-burning plant in Holcomb, Westar's proposed 850 MW plant whose site has not yet been announced, and BPU's proposed 300 MW addition to its Nearman unit in Kansas City, Kansas.
There is some controversy about what happens to mercury after it leaves the stack; but there is general agreement that most of it eventually falls out in rainfall especially in urban regions where smog is a problem. That's because ozone smog has the ability to convert the insoluble form of mercury to a soluble form that dissolves in cloud water.
Given the west-to-east movement of weather in Kansas it is reasonable to assume that mercury emitted in western or central Kansas will find its way to eastern, especially northeastern Kansas which has much higher rainfall and smog levels. Thus the strong potential exits for a mercury pollution hot spot in northeastern Kansas.
Sunflower Electric has already filed for a permit, and its huge coal burning complex at Holcomb will be the largest west of the Mississippi River. They have proposed a mercury emission limit in the draft permit that requires only about 25% removal. The final version of EPA's mercury rule allows essentially zero removal in counties with 25 inches of rainfall or less which would apply to Finney County; so Sunflower could choose to use an even weaker limit. Such a limit would allow an 80% increase in the emission of mercury compared to existing Kansas coal plants, from the Holcomb project alone.
On the other hand Sunflower says they are going to go ahead and install the carbon storage tank and ducts that would allow them to blow carbon sorbent into the flue gas if they choose to do so when the plant starts up after 2010. Sunflower has conducted mercury removal tests, co-sponsored by Westar and BPU, at their existing 360 MW Holcomb coal plant. They achieved 90% mercury removal with activated carbon injection.
However they have not yet committed to actually operate this system and could, instead, choose to wait many years and buy pollution credits. If such a commitment is not made in the form of an emission limit in the permit document, then it cannot be enforced. The catch is that the vast majority of cost associated with carbon injection is in buying the powdered activated carbon and operating the system, not in buying and installing the storage silo.
Subject to the disposition of a state level mercury emission limit proposed by KDHE (discussed below), Sunflower Electric could wait and see what the price of mercury credits are when their new boilers start up after 2010. EPA estimates seven tons of mercury emission credits will be available in 2010 from utilities that burn eastern coal. These will be sold to utilities that burn western coal. What utilities in our region choose to do may entirely depend on the price of these mercury pollution credits in 2010 and beyond. Westar and BPU have not announced what they intend to do about mercury emissions.
On the Sunflower Holcomb expansion, KDHE is attempting to set a state-only emission limit for mercury that would result in about a 20% increase in mercury emissions compared to existing Kansas coal plants. KDHE believes the Secretary of the agency has the authority to set such a state limit. While Sunflower appears to have accepted the idea of a state level mercury limit there was no agreement on the specifics as of the time the draft permit was issued.
Unfortunately KDHE wrote the draft permit and emission limit in a way that appears to be unenforceable. It could be interpreted to allow the highest emission limit, one that would allow up to an 80% increase in emissions compared to existing Kansas coal plants. While KDHE should be commended for seeking the lower mercury emission limit, it remains to be seen what we end up with. The language could be clarified after the comment period.
If this state level administrative limit does not pan out, the only way to prevent Kansas utilities from choosing to emit mercury, instead of capturing it, is for the state legislature to mandate a certain level of removal, such as 90%. A couple of states have already done so. An amendment to require 80% mercury removal was voted down by the Kansas House in the 2006 session.
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