New York state now boasts the nation’s strictest pollution controls on power plants, thanks to measures approved yesterday by Gov. George Pataki (R). The announcement was met with joy by environmentalists, who had been pushing for the tougher rules for upwards of three years, but the electricity industry said the move would cost custumers while doing little to reduce smog and acid rain. Under the new rules, New York power plants have until 2008 to cut their sulfur-dioxide smokestack emissions by an additional 50 percent below those reductions already required by the federal Clean Air Act. Beginning in the fall of 2004, the rules will also extend controls on nitrogen oxide emissions from the summer season to the entire year. Enviros said the rules would improve air quality and mitigate health problems such as asthma. They also expressed the hope that other states would follow suit, because much of the power-plant pollution that plagues New York drifts in from beyond the state’s borders.