Reservoirs indentified as mercury ‘hot spots’

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(Host) New research has identified five “hot spots” of mercury contamination in New England and Canada.

One area of concern includes reservoirs along the upper Connecticut River, where changing water levels have aggravated mercury levels.

VPR’s John Dillon reports:

(Dillon) Mercury is released by coal-burning power plants and falls onto the landscape with rain and snow. It becomes a problem when it’s converted by bacteria into methyl mercury, a form that’s readily absorbed by plants and animals.

What happens next is called bio-accumulation. Small fish get eaten by bigger fish, and the mercury can build up to dangerous levels.

Reservoirs can make the problem worse. Neil Kamman is a scientist with the Vermont Department of Environmental Conservation.

(Kamman) “The action of moving that water up and down across what I’ll call the bath tub ring that surrounds the reservoir behind the dam. The action of moving that water level up and down creates a geo-chemical condition whereby the conversion of mercury to methyl mercury is favored.”

(Dillon) The reservoirs on the upper Connecticut River are among five mercury hotspots in eastern North America. Fish found in those reservoirs contain mercury substantially above federal safety levels.

Kamman says that other hot spots are likely found in the Deerfield River Basin in southern Vermont, but more research is needed. He’s also concerned about areas of the Northeast Kingdom. The region, like parts of the Adirondacks, is susceptible to damage from acid rain as well as mercury pollution.

(Kamman) “And the Northeast Kingdom, particularly the Nulhegan Basin area, is one part of the state that makes me a little bit nervous if you will. I know what the water chemistry is, and the water chemistry variables are in line. But we just don’t have a lot of fish mercury information.”

(Dillon) The scientists say that the U.S. Environmental Protection Agency has underestimated the impact of pollution from the power plants.

Kathy Fallon Lambert is a spokeswoman for the Hubbard Brook Research Foundation, which coordinated much of the research. She spoke at a news conference in Washington.

(Fallon) “EPA is underestimating the deposition to begin with. So if you try to project into the future about the impact of the clean air mercury rule, starting with a map that underestimates the deposition then of course you are projecting a future based on incomplete information to start with.”

(Dillon) The EPA wants to allow a “cap and trade” system to control mercury pollution. The idea is that overall mercury levels would be capped, while utilities use the market to get credit for cutting pollution in other parts of the country.

Charles Driscoll, a scientist from Syracuse University, has concerns about the EPA plan.

(Driscoll) “Given the vagaries of the emissions trading program there’s the possibility that there could be sources adjacent to sensitive areas that could continue or have limited reductions and that would allow these highly sensitive areas, these hot spots, to persist.”

(Dillon) In Vermont, Environmental Commissioner Jeffrey Wennberg said that the state has done everything it can to reduce mercury pollution. He said the studies show the need for more meaningful reductions from outside the Northeast.

For Vermont Public Radio, I’m John Dillon in Montpelier.

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