DENVER (Denver Business Journal) – Colorado’s Tri-State Generation and Transmission Association has filed suit in federal appeals court to challenge the U.S. Environmental Protection Agency’s new mercury and air-toxics emissions standards for coal-fired power plants.

The Westminster-based power wholesaler is Colorado’s second-largest power utility after Xcel Energy. It operates coal-fired plants to generate electricity for rural and suburban power cooperatives with some 1.5 million customers in Colorado, New Mexico, Wyoming and Nebraska.

Read more on the website of CBS4 partner the Denver Business Journal.