Many people associate mercury with the silver liquid found in thermometers. This is the elemental form of mercury and exists naturally in our air, water and land.

Another form of mercury, and the one we've heard so much about lately as a result of human activity, is called methylmercury, and is formed when mercury comes into contact with bacteria in low-oxygen environments, like lake bottoms.

Mercury comes from a variety of sources. Approximately one-third of emitted mercury comes from natural sources such as the ocean, volcanoes and forest fires. Another third comes from activities like erosion due to land clearing and the burning of timberland or crops.

The remaining one-third of mercury emitted comes from man-made, industrial sources such as manufacturing, waste incineration and power plants. Of this, the contribution of all U.S. power plants to the global mercury pool is very small: about one percent, according to the EPA.

While it is certainly important to control and minimize mercury emissions to the greatest possible extent, it is also important to keep its dangers in perspective. Only four environmental cases of mercury poisoning events have ever been recorded worldwide. All are linked to unusual occurrences of extended, direct exposure or consumption. None were in the United States.

More than 50 percent of the world's emissions are generated in Asian power plants, the majority of which lack the environmental control technology now required in the U.S. and at Santee Cooper facilities.

Only about one percent of the world's mercury emissions are produced by U.S. power plants.

Yes. Mercury emissions travel great distances – even thousands of miles – from their sources of origin. Since mercury emissions travel so far, the measured levels of mercury in the U.S. far exceed the amount of mercury produced here. In fact, the Environmental Protection Agency (EPA) reports that only eight percent of the mercury that lands in the U.S. actually comes from U.S. power plants.

The U.S. and the State of South Carolina both strictly regulate mercury emissions. The EPA has conducted extensive studies on mercury deposited in our national waterways as it relates to sources of mercury emissions. These studies were then used to develop regulations governing mercury emissions at the federal level.

As strict as the federal regulations are, in South Carolina, the Department of Health and Environmental Control (DHEC) has set restrictions in the draft permit for the Pee Dee Energy Campus that are up to 40 percent more strict than what was required by the EPA. As regulations continue to tighten, Santee Cooper will continue to comply with these changing regulations, protecting human health and the environment.

The EPA provides guidelines on how much fish any of us should eat. To prevent the possibility that individuals could consume too much mercury by eating too much fish, the EPA has set consumption guidelines that are one-tenth the level at which anyone has shown harmful mercury effects.

Yes. South Carolina's waterways, as well as the fish in them, are tested for potential pollutants, including mercury. Although South Carolina is smaller than our neighbors, DHEC samples as much or more ? 1,800 fish per year from 150 sites ? than the state governments of neighboring states in the region. In addition, our fish advisory guidelines are generally more conservative.

Our state's lakes and rivers, and the fish they support, are extensively tested – as much and more than our larger neighbors of North Carolina, Georgia and Florida – for mercury levels and other potential pollutants. South Carolina measures up very well compared to our neighboring states as well as nationally. For example, South Carolina accounts for just 0.21 percent of the nation's mercury impacted waterways.

Producing power from coal-fired power plants does involve minute levels of mercury emissions. Responsible producers, like Santee Cooper, are using the highest and best available environmental control technology to minimize those emissions, to ensure South Carolinians that they are safe and that reliable, affordable power can be produced while protecting our environment at the same time. According to EPA standards, the Pee Dee Energy Campus will have among the highest controls of any facility currently in operation.

U.S. EPA, Clean Air Mercury Rule, http://www.epa.gov/air/mercuryrule/pdfs/slide2rev1.pdf

The process Santee Cooper elected to pursue with DHEC will evaluate permit limits nationwide and ensure that the Pee Dee Energy Campus is performing at a very high level relative to other plants.