Aug 5 (Reuters) - A U.S. appeals court on Wednesday said that the Dakota Access Pipeline does not have to be shut and drained per a lower court order.

However, U.S. regulatory officials may still have to issue another environmental assessment before deciding if the 570,000-barrel-per-day pipeline can continue to operate, the U.S. Court of Appeals for the District of Columbia said. (Reporting by David Gaffen; Editing by Sandra Maler)