Mercury Emissions

Mercury occurs naturally in coal and a portion of it is released into the air when coal is burned to fuel power plants. Mercury emissions are a concern because biological processes convert some of the mercury into a toxic form that can enter soil, lakes, rivers and streams and accumulate in fish tissue. Mercury can present a health risk to wildlife and humans when there is exposure to high enough levels.

Mercury emissions down 13%

In 2004, our company-wide mercury emissions were 610 kilograms, a 13 per cent decrease from 2003 levels. This decrease was largely the result of the Wabamun unit 3 shutdown in 2002.

As a large point source emitter of mercury, we recognize the need to manage these emissions and to contribute to science-based solutions. Addressing this issue, however, presents significant scientific and environmental challenges for our company and our industry. There remain uncertainties related to the transportation of mercury into the environment. Also, there are no proven, commercially available mercury control technologies for utility boilers.

In 2004, we continued to partner with other utilities and organizations to support the development and testing of mercury control technology. Through the Canadian Electricity Association (CEA) and U.S. Electric Power Research Institute (EPRI), we monitored research from government and university laboratories. We also collaborated with other power companies in the Canadian Clean Power Coalition to research new technologies to control mercury and other emissions from coal-fired boilers.

Since 2002, we have been an active participant in the CEA’s mercury monitoring program, a national initiative involving the sampling, analysis and reporting of coal and ash for mercury content and testing for mercury in flue gas. In 2004, we tested and measured mercury emissions levels from Sundance units 5 and 6. We are now reviewing the results of our tests and evaluating methodologies to better estimate TransAlta’s mercury emissions. These and other studies will provide critical information to help TransAlta find cost-effective and efficient options for managing mercury emissions over the long term.