The developer of the $10 billion Jordan Cove LNG export project failed to fully describe potential impacts on water quality when applying for a permit, an Oregon agency told federal regulators.

In a letter to the Federal Energy Regulatory Commission, the Oregon Department of Environmental Quality said the developer must revise its application to reflect the full scope of the possible impact to water quality. The Oregon agency said that after reviewing Jordan Cove's application for a clean water permit, it determined "the activities described in that application are merely a subset of the larger array of activities that may affect water quality that would be governed by any subsequent" FERC authorization.

A water permit issued in the meantime should not be considered the comprehensive certificate required by FERC to grant overall authorization for the project, the state agency said.

The Pembina Pipeline Corp.-led Jordan Cove project has faced hurdles at the federal, state and local levels. FERC denied the liquefaction and export terminal in March 2016 because of what regulators said was a lack of commercial need for the associated Pacific Connector gas pipeline. The developer is again seeking approval for a slightly modified version of the 0.9-Bcf/d LNG export facility and the roughly 230-mile pipeline that connects to it.

Jordan Cove is just one on a long list of proposed LNG export projects seeking a spot in the global market. The venture has nonbinding agreements with Japan's Itochu Corp. and Jera Co. Inc. and has an advantage in its relative proximity to key Asian markets. As the only West Coast LNG terminal planned for the U.S., the project faces heightened environmental and landowner opposition, industry observers have said.

A spokesman for the project did not immediately respond to a request for comment.