The U.S. Forest Service (USFS) told FERC that a proposal to use horizontal directional drilling (HDD) to construct the Atlantic Coast Pipeline (ACP) — to avoid impacts to the Appalachian Trail and the Blue Ridge Parkway — is feasible, and it would not object to concurrent construction through other forest lands before the crossing is completed.

Meanwhile, the U.S. Environmental Protection Agency (EPA) recommended that FERC conduct further analysis before releasing its final environmental impact statement (EIS) for the project [CP15-554]. The Department of Interior (DOI) also voiced several concerns, including potential disturbance to its stream gauges along the proposed pipeline’s route.

The comments by the federal agencies were among nearly 800 filed at the Federal Energy Regulatory Commission on Thursday — the official last day for public comments on its draft environmental impact statement (DEIS) for the project — and through mid-day on Friday.

In a letter dated last Tuesday, USFS said it had reviewed Atlantic Coast Pipeline LLC’s proposal to use HDD as the primary method to cross the Appalachian Trail and Blue Ridge Parkway, as well as the company’s contingency method to use direct pipe installation (DPI) for the crossing.

“ACP’s filings contain sufficient information to assess the feasibility of the proposals. Based on the USFS’ review, the HDD would be feasible at the proposed location and the DPI would be a feasible contingency option,” wrote USFS Forest Supervisor Clyde Thompson. He added that USFS had no further questions or requests regarding the crossing.

In January 2016, USFS denied ACP a special use permit (SUP) to cross the Monongahela and George Washington national forests in West Virginia and Virginia. Thompson said USFS told FERC at the time that since ACP had not yet submitted any detailed proposals, any SUP issued to ACP may be conditioned to require successful completion of HDD at the crossing — essentially halting any concurrent construction across forest lands elsewhere.

But Thompson said USFS has since decided to drop that condition.

“Because ACP subsequently filed adequate documentation for the USFS to assess the feasibility of the primary and contingency proposals, and based on our independent assessment that the proposals are feasible, such a condition in the SUP would no longer be necessary,” Thompson said. “Thus, the USFS would not prohibit concurrent construction at other spread on [National Forest System] lands before the completion of the [Appalachian Trail and Blue Ridge Parkway] crossing.”

EPA, DOI voice concerns

In a separate letter, EPA Region 3, based in Philadelphia, told FERC that its final EIS for the project would be strengthened if it conducted additional testing and analysis on geology and soils, streams and wetlands, and groundwater and drinking water protection.

Specifically, EPA said the project will likely encounter “challenging geologic conditions,” and that blasting — coupled with steep slopes, karst topography, and active and abandoned mines and quarries along the project’s route — pose additional challenges to protecting local residents and their sources for drinking water.

“EPA appreciates the special consideration that crossing karst streams and terrain has received in the DEIS,” the EPA said. “In light of the DEIS, which indicates over 50% of karst hazards throughout the 71 miles of karst terrain crossed are identified as ‘high risk,’ we recommend the final EIS consider ecological risks to karst systems, and risk mitigation that includes avoidance measures.”

EPA also recommended that the final EIS complete ongoing wetland and stream surveys, and offered to assist in that endeavor. Other recommendations included considering alternative crossings for the Neuse River; the inclusion of various studies on the impacts to watersheds and ecosystems; and additional analysis of cumulative impacts, especially on groundwater, stream crossings and water withdrawals.

DOI also voiced concerns in another letter to FERC. Its “greatest concern” is that the ACP will cross the South River upstream of Waynesboro, VA, at a point less than five miles from a former textile plant that discharged high levels of mercury waste between 1929 and 1950. DOI said mercury in the streambed could be disturbed when a trench for the pipeline crossing is built.

“If the pipeline route were altered again to where it crossed the South River downstream of this site, or disturbed contaminated areas, the high potential for mercury release could become a critical environmental issue,” DOI said. “Total mercury should be quantified upstream and downstream of the crossing point as an essential element of the water quality monitoring conducted before and after installation of the pipeline.”

DOI added that it was concerned over potential impacts to eight stream gauges operated by its U.S. Geological Survey (USGS) located within one mile of the pipeline route or access roads. The USGS uses the gauges to measure water quantity and quality for a variety of purposes.

Other concerns raised by DOI include alerting towns along the pipeline route of construction activities upstream of their public water supply intakes; impacts to drinking water wells; potential damage to nearby pipelines and other structures from blasting; the potential for landslides from construction in steep-sloped areas; and potential impacts to aquatic species.

Backed by a joint venture between Dominion, Duke Energy and Southern Company Gas, ACP aims to transport 1.5 Bcf/d of natural gas from the Marcellus and Utica shales to satisfy heating and electric generation demand in the Southeast. The project is around 96% subscribed under long-term commitments.

ACP filed with FERC for a Natural Gas Act certificate in 2015. Originally it was targeting a 2018 start-up, but the denial of an SUP by USFS caused Dominion to push the in-service date to 2019.

Earlier this month, a bipartisan group of lawmakers from all three states the pipeline will traverse sent a letter to FERC, urging the agency to approve the project. Separately, a labor union also hand-delivered nearly 1,600 letters of support to the offices of Virginia’s two senators, both Democrats, Tim Kaine and Mark Warner.