Atlantic Coast Pipeline LLC (ACP) said Tuesday it would avoid construction work along 100 miles of the planned 600-mile route until the U.S. Fish and Wildlife Service (FWS) revises a key permit that was invalidated last week by the U.S. Court of Appeals for the Fourth Circuit.

According to an analysis completed by the company, the work stoppage involves 21 miles in West Virginia and 79 miles in Virginia with no impact in North Carolina. The court agreed with environmental groups that had argued the project’s incidental take permit failed to set clear limits for affected species. Issued by the FWS under the Endangered Species Act, the permit is required for activities that could result in the take of, or a negative impact to, threatened wildlife.

FERC instructed ACP last week to file documents that specifically identify by milepost the habitat areas of the affected species that will be avoided and to confirm the company’s commitment to avoid construction in those areas. The deadline to file that documentation passed on Monday, and ACP was forced to hand deliver the documents Tuesday because of problems with the Federal Energy Regulatory Commission’s website and online applications.

ACP, however, did not disclose the exact locations where work would be avoided because both FERC and FWS customarily treat such areas that are home to sensitive species as privileged and confidential, the company said. The company added that only 10 miles that are being avoided are included in 2018 construction spreads.

“…The court’s action only affects those areas of pipeline construction where endangered species or their habitats may be present,” spokeswoman Jen Kostyniuk said. “The incidental take statement has no direct effect on the route or other required permits. It simply removes the shield that protects against an otherwise unlawful take, and for that reason, we will avoid any activities in any areas identified by FWS that would be likely to adversely affect any of the listed species.”

ACP said it would now turn to coordinating with the FWS, which it expects will revise the incidental take permit to provide more specific limits for the affected species. It’s unclear when the agency might issue a revised permit.

ACP would originate in West Virginia, pass through Virginia and into North Carolina to move 1.5 Bcf/d of natural gas to the Southeast. The project’s backers are still targeting a 2019 in-service date.

Also on Tuesday, a coalition of environmental groups filed a motion in the Fourth Circuit to stay construction of the Mountain Valley Pipeline, which has a similar route as ACP and is scheduled to enter service later this year. The groups want work stopped on the 2 Bcf/d project while they challenge the Section 404 permit issued by the U.S. Army Corps of Engineers under the federal Clean Water Act.

The Army Corps issues such permits for stream crossings. The environmental groups claim MVP cannot meet the conditions of the permit.