The Federal Energy Regulatory Commission issued a draft report in 2009 that project planner Downeast LNG said was favorable. The project would provide around 500 million cubic feet of imported natural gas to the New England market.
The project would connect to an existing pipeline that runs from Nova Scotia through Maine.
FERC said it found the preliminary engineering design would be acceptable "provided the mitigation measures relating to the reliability, operability and safety of the proposed design are addressed by Downeast."
The Bangor (Maine) Daily News reported in December that community groups were concerned about the environmental safety of energy projects near the St. Croix River.
FERC revisited the project after a 2012 report from the Energy Department expressed concerns about LNG spills into water.
The U.S. Coast Guard said the regional waterways could handle the expected marine traffic associated with the project.
FERC said it would accept public comment on the analysis through May 20. The review comes as members of Congress are calling for more LNG exports because of the increase in U.S. natural gas production.