The staff of the Federal Energy Regulatory Commission (FERC or Commission) has prepared an environmental assessment (EA) for the Mountain Valley Pipeline Amendment Project (Amendment Project) proposed by Mountain Valley Pipeline, LLC (Mountain Valley).      

On February 19, 2021, Mountain Valley, pursuant to section 7(c) of the Natural Gas Act (NGA), in FERC Docket No. CP21-57-000, filed an application seeking to amend the Certificate of Public Convenience and Necessity (Certificate) granted in Docket No. CP16-10-000 for its Mountain Valley Pipeline Project.  Mountain Valley proposes to change the crossing method of specific waterbodies and wetlands from open-cut dry crossings (as authorized by the Certificate) to trenchless methods (conventional bore, guided conventional bore, or Direct Pipe®).  Specifically, Mountain Valley proposes to use trenchless methods at 120 locations to cross 136 streams and 47 wetlands that the Commission originally authorized as open-cut crossings.  The Amendment Project also includes a small route adjustment at milepost (MP) 230.8 and alignment shift at MP 0.7 to avoid wetlands, and a requested modification to allow nighttime noise activities at 8 locations where trenchless crossings are proposed.

The EA has been prepared in compliance with the requirements of the National Environmental Policy Act (NEPA), the Council on Environmental Quality regulations for implementing NEPA (40 Code of Federal Regulations [CFR] 1500–1508), and FERC regulations implementing NEPA (18 CFR 380).  The conclusions and recommendations presented in the EA are those of the FERC environmental staff. 

The FERC staff concludes that if Mountain Valley completes the waterbody and wetland crossings via trenchless crossing methods in accordance with its application and supplements, and the staff’s recommended mitigation measures in the EA, approval of the Amendment Project would not constitute a major federal action significantly affecting the quality of the human environment.  Overall, the EA concludes that impacts associated with the waterbody and wetland crossings would be reduced as compared to the impacts analyzed for these crossings in the Final Environmental Impact Statement for Certificated Mountain Valley Pipeline Project (FEIS).  However, the EA concludes that the Amendment Project would lead to an increase in construction emissions and construction noise.  While the EA concludes that impacts from the Amendment Project on emissions and noise would exceed those analyzed in the FEIS, it concludes that these temporary and short-term increases would not be significant.    

The conclusions in the EA are based on our independent review of the Amendment Project, information provided by Mountain Valley and concerned citizens, and our consultations with federal regulatory and resource agencies.  Although many factors were considered during our environmental review, the principal reasons for these conclusions are:

  • the proposed trenchless crossings would avoid and/or minimize impacts on wetlands and waterbodies as compared to the open-cut crossings originally authorized for the Mountain Valley Pipeline Project;
  • the FERC Staff is recommending a condition for Mountain Valley to monitor nighttime construction noise for compliance with our noise criteria;
  • Mountain Valley would minimize impacts on natural and cultural resources during the proposed trenchless crossings by implementing Mountain Valley’s Erosion and Sediment Control Plan; FERC Upland Erosion Control, Revegetation, and Maintenance Plan; and Mountain Valley’s Wetland and Waterbody Construction and Mitigation Procedures; as well as other project-specific mitigation plans as listed in appendix C of the EA; 
  • Mountain Valley would comply with all applicable federal requirements;
  • the FERC staff would complete the process of complying with section 7 of the Endangered Species Act prior to approving construction of the proposed trenchless crossings;
  • the Amendment Project complies with Section 106 of the National Historic Preservation Act and implementing regulations at 36 CFR 800; and
  • Mountain Valley’s environmental inspection program and FERC staff’s third-party monitoring oversight program would be implemented to ensure compliance with the mitigation measures that become conditions of the FERC authorization.

Comments on the EA must be received on or before September 13, 2021.  The FERC Commissioners will take into consideration EA comments and FERC staff’s recommendations when they make a decision on the Amendment Project.

This page was last updated on August 13, 2021