North Carolina on Friday issued the Atlantic Coast Pipeline (ACP) a section 401 water quality certification (WQC) under the federal Clean Water Act, capping part of a prolonged regulatory process that brings the project one step closer to construction.

The North Carolina Department of Environmental Quality (DEQ) conducted what it said was an “exhaustive review” of the project plans in which it requested additional application information from the sponsors on five occasions. ACP applied for the WQC last May.

Leaving “no stone unturned,” DEQ Secretary Michael Regan said the WQC carries with it more stringent requirements, including stream and wetland monitoring; horizontal directional drilling in certain areas to better protect the environment; and private water well testing before and after construction within 150 feet of any disturbed area, or 500 feet from blasting areas.

The 600-mile ACP, a 1.5 Bcf/d project backed by Dominion Energy Inc., Duke Energy, Piedmont Natural Gas and Southern Company Gas, welcomed the news. “At every stage of the project, we’ve gone above and beyond regulatory requirements and adopted some of the most protective measures ever used by the industry,” said spokesperson Aaron Ruby. “Additionally, state and federal inspectors will closely monitor construction to ensure we meet all regulatory standards.”

Also on Friday, the West Virginia Department of Environmental Protection (WVDEP) approved the project’s erosion and sediment control permit. WVDEP waived the state’s WQC requirement for the project last month, and Virginia conditionally approved a WQC in December. FERC approved the project last October.

ACP would originate in West Virginia, run southeast through Virginia and into North Carolina. The project is designed to pair Appalachian shale gas with growing power generation and heating demand in the Southeast. Although it has cleared the major hurdles, the pipeline still needs regulatory approvals in all three states in addition to a Section 404 permit from the U.S. Army Corps of Engineers.

Upland tree felling and vegetation clearing is underway in West Virginia and is scheduled to continue through the end of March. After it receives the remaining state and federal approvals, ACP plans to request a notice to proceed with the Federal Energy Regulatory Commission. Ruby said the sponsors are still targeting a late 2019 in-service date, with construction slated to begin by early spring.

Like other Appalachian infrastructure projects, ACP has faced staunch opposition from environmental groups, which filed rehearing requests with FERC late last year challenging the certificate order. Despite the approvals on Friday, the Sierra Club, for example, said it would continue to fight the pipeline “at every turn.”