The plaintiffs suing over the $650 million deepening of the Savannah River shipping channel want a federal judge to rule the project is subject to all South Carolina environmental laws.
Their lawsuit originally contended the project needed a permit under the state's Pollution Control Act. But on Monday, environmental groups in two states asked to amend the complaint, seeking a declaration the project is subject to all applicable laws.
The plaintiffs noted the Army Corps of Engineers has said the project can continue regardless of state law and that's resulted in an unfair evaluation of the project by state regulators who may think that opposing the deepening is futile.
The plaintiffs say that the court ruling in their favor would allow a fair review.