Respecting the environment
Air, water and land quality are of paramount importance as we undertake this project.
While emission control technology has significantly improved over the past decades, the environmental and health effects of coal combustion continue to be an issue of public concern. We all want to breathe clean air and live in a safe environment. Utility company employees are no exception. Our goal is to minimize the environmental impact of Big Stone II while ensuring that we provide reliable and cost-effective energy to serve the growing needs of our customers.
Air quality: Two plants will be as clean as—or cleaner than—one.
- Big Stone Plant and Big Stone II will share a new wet scrubber that not only will clean emissions from the new plant but also will reduce emissions at the existing plant. Commercially proven technology (supercritical coal-fired
boiler and advanced wet scrubber technology) will minimize coal
consumption and achieve greater efficiency with fewer emissions.
Big Stone II will meet or out perform all federal and state air emission regulations. While more than doubling the generation capacity, the Big Stone site will see emissions of sulfur dioxide, nitrogen oxides and mercury from the two plants be less than or equal to the historical emissions from the existing Big Stone Plant. - Carbon dioxide emissions will be 20% lower than existing regional power plants, and participants will offset 100% of Big Stone II’s carbon emissions attributable to Minnesota customers.
- Participants will install technology that is most likely to remove 90% of the mercury emissions from the Big Stone site, including both the existing plant and Big Stone II.
- Big Stone II is designed to be carbon capture retrofit-ready, with the capacity to incorporate carbon capture technology when it becomes available and cost effective.
- The fly ash and gypsum collected with the wet scrubber technology can be used in place of cement in concrete production, reducing by one ton the CO2 that otherwise would be emitted.
Water quality: We will minimize water impact, just as we have for 30 years.
- Big Stone II is designed as a zero discharge plant, meaning that water recirculates and is reused until it evaporates, eliminating any potential for thermal or other impact on the surrounding surface water supplies and wildlife.
- Our studies and permits show that area water resources are sufficient to allow us to use water in the same responsible way that area people have experience for more than 30 years with Big Stone Plant.
- The existing Big Stone Plant and Big Stone II will use water from Big Stone Lake in accordance with conditions set forth in their permits. Only limited pumping can occur when the lake’s level falls below 967 feet elevation. At a point when withdrawal from Big Stone Lake is curtailed, we would use water pumped from the Veblen Aquifer. Using groundwater will provide drought protection for both plants. This should not impact other water users.
Land use: Expanded power plant will bring new efficiencies.
- Building on an existing power plant site means minimal changes to habitat or the environment.
- Using an existing site will capitalize on existing infrastructure for rail, coal handling, water storage and treatment, and landfill and also minimize changes to other areas.
- Ash and gypsum, byproducts of the combustion process, will be marketed to other industries, reducing the amount of material that goes into the landfill.
Committed to an energy-balanced future, including renewable resources.
For project participants, Big Stone II represents just one part of a diverse and balanced power supply, which includes renewable resources. In fact, Big Stone II participants plan large additional quantities of wind energy. But wind cannot replace the need for baseload power, nor can any one source alone meet the growing demand as our nation works to achieve energy independence.
The Big Stone II project will provide baseload generation and transmission capacity and support the use of renewable resources.
For more information, contact:
Dan Sharp, Manager, Communications . 701-426-3650
Steve Schultz, Manager, External Affairs . 218-770-9111
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