The EPA has discovered that a number of old, coal-fired power plants, “grandfathered” under the Clean Air Act, seem to have flouted the law by making major renovations to produce more power without installing required pollution controls. The EPA is still investigating and no action has yet been taken against the power companies, but the agency could levy millions of dollars in fines and require plants to install pollution-control equipment. Demand for coal-fired power has risen in recent years as deregulation has let electric companies sell cheap power from old coal plants across state lines. Sens. Joseph Lieberman (D-Conn.) and Jim Jeffords (R-Vt.) have proposed a bill that would end Clean Air Act exemptions for old plants and require electricity producers to purchase increasing percentages of renewable power.