Fans - and foes - of suction dredge mining will have to wait a little bit longer to find out whether a ban instituted in 2009 will remain in effect.But the findings in two studies the U.S. Geological Survey recently released provide a hint of the possible contents of a draft Environmental Impact Report being prepared by the state Department of Fish and Game.That's the report mandated by the state when then-Gov. Schwarzenegger signed a bill in August 2009 temporarily banning miners from using gasoline-powered dredges to glean flecks of gold from river bottoms. The environmental review was requested to …