White Stallion Energy Center LLC, Sunflower Electric Power Corporation, Tri-State Generation and Transmissions Association Inc., Power4Georgians LLC, Deseret Power Electric Cooperative, and Tenaska Trailblazer Partners filed a motion April 27 in the U.S. Court of Appeals for the District of Columbia Circuit contending that they are unable to begin construction on their plants because the new Environmental Protection Agency mercury limits are unattainable, but that they must begin construction by next April to avoid being subject to unattainable greenhouse gas standards. The group asked the court to sever new source issues from the issuer issues being raised in consolidated cases challenging the agencyʼs Mercury and Air Toxics Standards and asked the court to expedite the briefing schedule. The Institute of Clean Air Companies asked the Environmental Protection Agency to reconsider the mercury standards last week, saying that they are so stringent that the could prevent new coal-fired power plants from being built.