Opponents of a 145-mile transmission line project through western Maine are planning to rally Friday outside a Department of Environmental Protection building in Augusta as the review process intensifies for the New England Clean Energy Connect.

“This is still part of the process where we want to build awareness and create a consensus,” said Sandra Howard, an organizer of the rally and an administrator for the Facebook group “Say NO to 145-mile transmission line through Maine.” “This proposal was kept quiet for a long time, and I think the rally will shed light on some of the issues. It also comes as the public comment period is still open, and it’s a critical time for us to bring awareness.”

On Friday, Howard and others will gather to voice their opposition to Central Maine Power Co.’s NECEC project, a power line that would run from Beattie Township on the Quebec border to Lewiston to bring hydro-power from Canada to Massachusetts.

The rally comes as officials from the DEP and Land Use Planning Commission are gathering to plan the steps for public hearings and other considerations in the permitting process.

“This is the point where people are bringing these types of objections forward in the process,” said John Carroll, a spokesman for CMP. “The regulators will weigh whether those are relevant to their decisions or not. We believe the project has been sited well, we selected a good corridor and we believe strongly in the benefits the project offers Maine.”

Howard, a resident of New Hampshire who has spent the past 22 summers working as a white-water rafting guide at Northern Outdoors in the West Forks, said opponents to the project in Somerset County have cited a variety of reasons — environmental concerns, wildlife, wetlands, natural resources, the scenic character of the area and tourism.

“This is our first public event,” she said. “A lot of us have been engaged in writing letters to the editor and state officials, but this is the first time we’re coming together in a more formal setting.”

Previously, CMP had received letters of support from 37 of 38 communities in the project’s corridor, which includes about 145 miles of new line to be built between Beattie Township and Lewiston, as well as about 50 miles of line to be rebuilt from Lewiston to Pownal.

The town of Caratunk recently rescinded its letter, saying in a letter to the DEP in July it had no representation in mitigation proceedings, the town is concerned the project would harm the development of renewable energy projects in Maine, and it has concerns the project would be a detriment to white-water rafting and fishing tourism.

Others who have expressed concern about the project include the Old Canada Road National Scenic Byway; the Appalachian Mountain Club; NextEra, a renewable energy company; the Sierra Club of Maine; and Trout Unlimited.

Those who have expressed support include the city of Lewiston, which anticipates about $6 million in annual revenue from the construction of a converter station and new transmission lines within the city; and the International Brotherhood of Electrical Workers, which has said it expects the project to pay about $436 million in compensation to construction workers.

In addition to state and local permits, the project also requires approval from the U.S. Department of Energy, U.S. Army Corps of Engineers and the Federal Aviation Administration before construction can begin.

CMP has estimated the permitting process will be complete by 2019 and construction could be completed by 2022.