Opponents of a proposed $10 billion oil refinery that would be built in southeastern South Dakota have asked a judge to strike down a state permit for the project.
The state Board of Minerals and Environment recently issued a revised air quality permit for Hyperion Resources that also extended the deadline for starting construction until March 2013.
A lawyer for groups opposing the refinery argued in court Thursday that the permit should be overturned because no full-blown environmental study was done and environmental controls should be strengthened.
But lawyers for Hyperion and the state board say the permit should be upheld. Circuit Judge Mark Barnett of Pierre says he will issue a decision soon because he knows the case will be appealed to the South Dakota Supreme Court.