The proposed Atlantic Coast (ACP) and Mountain Valley (MVP) pipelines have secured FERC certificates but continue to encounter pushback at the state level, with opposition groups looking to regulators in West Virginia, Virginia and North Carolina to put a halt to the projects.

In a pair of recent letters to state regulators, project opponents have also keyed in on Commissioner Cheryl LaFleur’s dissenting opinion in the certificate orders the Federal Energy Regulatory Commission handed down earlier this month for ACP and MVP.

The Southern Environmental Law Center, the Chesapeake Bay Foundation and Appalachian Mountain Advocates told Virginia’s State Water Control Board in a letter last week that there is insufficient information to approve draft Clean Water Act (CWA) section 401 water quality certifications pending for the two projects.

“The board must be certain that it has ‘reasonable assurance’ that the Atlantic Coast and Mountain Valley pipelines will not violate Virginia’s water quality standards,” the groups wrote. “The draft 401 certifications before the board suffer from critical deficiencies that render it impossible for the Board to make the determination that the Clean Water Act requires.”

In West Virginia, where the state recently moved to scrap its water quality certification for MVP, a coalition of environmental groups is urging Gov. Jim Justice to “apply ample resources” to the state Department of Environmental Protection’s (DEP) 401 certification reviews for the natural gas pipelines.

“Both of these pipelines are proposed to be build over delicate caves, karst terrain and groundwater systems,” they wrote in letter to Justice, which was published by the Charleston Gazette-Mail in West Virginia.

“Combined, the two projects will impact over 1,000 streams in West Virginia. The routes of both pipelines will require extensive construction on steep slopes in highly erodible soils that are likely to cause severe runoff and siltation into streams affecting aquatic life.”

Both letters highlight LaFleur’s dissenting opinion, referring to her vote against approving the projects as an “extraordinary step.” In her dissent, LaFleur raised concerns about the cumulative environmental impacts of the two projects and suggested they should be combined or collocated given their similar routes and supply/demand areas.

“Though the two newly-appointed commissioners…approved the certificates” for ACP and MVP “states still have the authority and critical role under the Clean Water Act to ensure that these projects will not violate water quality standards,” the West Virginia coalition told Justice. “The dissent by Commissioner LaFleur shows an awareness of the need to balance these projects’ collective environmental impact with business interests to keep our water safe for human consumption and future economic development.”

Meanwhile, in North Carolina, the state’s Department of Environmental Quality (DEQ) has now issued three information requests to ACP as it reviews the pipeline’s section 401 water quality certification permit. In the most recent request,issued last week, the DEQ, among other things, asked ACP to change its proposed stream crossing method for the project and provide additional details on 16 planned stream crossings in the state.

The state CWA 401 permitting process has gained traction as an avenue for opposing pipeline projects since New York state’s denial of a water permit for the Constitution Pipeline in 2016 effectively stalled that project, even though it had already secured FERC approval.

Both ACP and MVP plan to cross the West Virginia/Virginia border to connect Marcellus and Utica shale gas to markets in the southeast and mid-Atlantic. Both projects expect to begin construction this year, with MVP targeting a late 2018 start-up and ACP planning to enter service in the second half of 2019.

The 303-mile, 2 million Dth/d MVP is a joint venture between EQT Midstream Partners LP, NextEra US Gas Assets LLC, Con Edison Transmission Inc., WGL Midstream and RGC Midstream LLC. ACP, which would extend roughly 600-miles and carry 1.5 Bcf/d, is a joint venture backed by Dominion Energy Inc., Duke Energy, Piedmont Natural Gas and Southern Company Gas.

Dominion CEO Thomas Farrell said during a conference call Monday the Richmond, VA-based company expects to have all state-level approvals in place for ACP by mid-December.