Today, the Senate Committee on Environment and Public Works convenes a hearing to discuss the EPA's proposal to reduce mercury, lead, and other toxic air pollution from power plants. One of the witnesses will be Cathy S. Woollums, senior vice president of MidAmerican Energy. She will threaten rate hikes and job losses if the proposed safeguards become final. MidAmerican is owned by Warren Buffett's Berkshire Hathaway Inc.