On April 26, the three companies that own Big Stone Plant – Otter Tail Power Company, Montana-Dakota Utilities Co., and NorthWestern Energy – held a groundbreaking ceremony for the plant’s air-quality control system (AQCS). Graycor Industrial Constructors is the general contractor for this major AQCS project. “We commemorate this $405-million project that will help us balance our commitment to environmental stewardship with cost-effective service for our customers,” Mark Rolfes, project manager, said in his welcoming remarks.

Chuck MacFarlane, president and CEO of Otter Tail Power Company, which operates Big Stone Plant on behalf of the other owners, noted that the plant began commercial operations 38 years ago, on May 1, 1975. “It was built for a cost of $150 million. And it was built to comply in every way with the environmental standards of the day. Since 1975, it has kept pace with increasingly stringent regulations,” said MacFarlane, “and with regularly upgraded technologies it is more efficient now than it was when it was built.”

MacFarlane said that today’s ceremony marked the launch of a three-year construction project to install new air-quality control equipment that will reduce emissions even further to comply with new Environmental Protection Agency and state requirements. “The primary components of the AQCS are the selective catalytic reduction system, a dry scrubber and baghouse,” he said, adding that this equipment “will reduce emissions of nitrogen oxides, sulfur dioxide and mercury by 80 to 90 percent at a cost more than 30 percent less than alternatives.” MacFarlane concluded his remarks by thanking plant employees, supportive communities and policymakers, and the state of South Dakota, among others. He acknowledged distinguished guests including South Dakota Governor Dennis Daugaard and the mayors of neighboring Milbank, Big Stone City and Ortonville.

“Installing an air-quality control system is just another step in providing a responsible power source for our customers,” said Frank Morehouse, president and CEO of Montana-Dakota Utilities Co. “I am excited to kick off this project that not only will give the local economy a huge boost over the next few years but serve our customers for many years to come.” Bob Rowe, president and CEO of NorthWestern Energy echoed Morehouse’s comments. “This project is possible because of our excellent operating partnership with Montana-Dakota and Otter Tail. It demonstrates the commitment that we all have to this facility, the community, the environment and especially our customers,” he said. “Big Stone has served our customers for almost 40 years and, with this upgrade in technology, it will be ready to serve for many more years.”