CHARLESTON, S.C. (AP) — Environmental groups suing over the $650 million deepening of the Savannah River shipping channel want a federal judge to rule the project is subject to South Carolina environmental law, saying that will allow a fairer review by state officials.

Environmental groups in two states originally sued saying the deepening work needed a permit under the state’s Pollution Control Act. But in papers filed Monday seeking to amend the suit, attorneys noted the U.S. Army Corps of Engineers has said repeatedly the project could proceed without approvals from South Carolina.