FERGUS FALLS -- Extensive studies and analysis by the South Dakota Department of Environment and Natural Resources show that Big Stone II's use of water from Big Stone Lake will not have an adverse impact on the Minnesota River, according to Dan Sharp, communications director with the Big Stone II project.
He said the impact would be "insignificant'' or so small as to be "almost imperceptible.
"It's slight, very slight,'' he said.
Permits would allow Big Stone II to appropriate up to 18,000 acre-feet of water annually from the lake, equivalent to 20 percent of the lake's volume. The power plant would tap the Veblen aquifer in South Dakota as a backup source when lake levels are down.
Sharp said the 20 percent figure is easily misunderstood. The water would be taken from the lake through the course of the year as other sources of water also reach it.
Overall, the lake would be drawn down by an average of 1¾ inch due to the power plant, according to Sharp.
He also charged that concerns about mercury do not acknowledge that Big Stone II will reduce the amount of mercury being emitted. Currently, the existing Big Stone plant emits up to 189 pounds of mercury per year. The new technology to be included as part of the Big Stone II project will reduce the overall mercury emissions from both Big Stone I and Big Stone II to 80 to 90 pounds per year.
Big Stone II is needed to meet growing power needs in the area, he said. Sharp called it "totally foolish'' to believe that wind and other renewable energy sources could meet the growing demand by 2011, when Big Stone II would begin producing electricity.