U.S. regulators this week temporarily suspended their review of pipeline operator Enbridge Inc.’s proposed crude export facility off the U.S. Gulf Coast, a government filing showed.

Enbridge and Oiltanking Partners LP in February sought federal permits to build a deepwater port about 30 miles (48 km) off Freeport, Texas, to export U.S. shale oil.

The U.S. Maritime Administration and the U.S. Coast Guard on June 26 issued a “stop clock” letter that pauses their evaluation of the pair’s Texas Crude Offshore Loading Terminal (COLT).

“Texas COLT remains confident in its application and the regulatory review timeline as it relates to our 2022 in-service date,” Enbridge spokesman Devin Hotzel said in a statement.

Regulators sought more information about an air pollution control system before permitting could resume, according to a federal filing. Enbridge has proposed a design change that would add a system to “control vapors generated during the offshore loading process,” according to the letter.