COLUMBIA, S.C. — Savannah River Maritime Commissioners said Monday that South Carolina’s environmental agency improperly approved a water quality permit for dredging the Savannah River.

The unanimous vote to declare the Department of Health and Environmental Control’s decision invalid likely sends the issue to court. The commission, created in 2007 to represent South Carolina’s interests in the river channel shared with Georgia, also asked Attorney General Alan Wilson to handle the case on its behalf.

The move comes four days after the board approved a compromise on a permit application from the U.S. Army Corps of Engineers to deepen about 35 miles of the Savannah River, allowing supersize ships to reach the Savannah port. Staff rejected the application in September, citing unacceptable harm to endangered sturgeon and fragile marshes. The compromise was worked out with Georgia officials shortly before the board was set to hear the Corps’ appeal.

“We now have two state agencies: One says there is a water quality permit. This state agency says it has not been properly issued, so I imagine we are headed to court,” said Senate Transportation Chairman Larry Grooms (R-Bonneau) also a commission member.

Grooms said the commission’s responsibilities include river dredging and navigability.

“DHEC overstepped their boundaries when issuing the permit,” Grooms said.