(September 10, 2015, 7:16 AM EDT) -- SEATTLE — A regional office of the U.S. Environmental Protection Agency announced Sept. 3 that Repsol U.S.A. Exploration & Production Inc. (Repsol E&P USA) will pay $30,500 as a penalty for violating the Clean Water Act (CWA) when nearly 500 gallons of well testing fluids leaked onto an acre of frozen tundra in April 2013....