Great Basin Gas Transmission Company Seeks Variance for HDD Bore Method in Silver Springs Segment

Strategic Insights -

The Great Basin Gas Transmission Company has submitted a request to the Federal Energy Regulatory Commission (FERC) to allow the use of a horizontal directional drilling (HDD) bore method for a portion of the Silver Springs Segment of their 2024 Expansion Project. The company has already received a certificate of public convenience and necessity from FERC to construct, abandon, and operate the project, which involves the installation of approximately 3.41 miles of upsized or looped pipeline and associated appurtenant facilities in three segments along the 65 miles of Great Basin's Carson and South Tahoe Laterals in Nevada. The project will provide 5,674 dekatherms per day of incremental firm transportation service, and the incremental capacity has been fully subscribed.

Key Takeaways:

  • The Great Basin Gas Transmission Company is seeking a variance from the certificated installation method to permit the use of the HDD bore method for a 0.20-mile portion of the Silver Springs Segment between Project Milepost CA-17.15 and CA-17.35.
  • The HDD method will eliminate the need to support and expose existing utilities during open trench installation at a depth of 15 feet below grade and will safeguard those utilities and minimize the risk of damage.
  • Great Basin believes that the soil conditions are favorable for a bore, with a pilot bore being the recommended approach, and that the nearest noise-sensitive area (NSA) is located approximately 880 feet from the bore location.
  • The company's contractor is committed to only performing boring activities during daytime hours and will employ open trenching as a contingency if subsurface conditions prove unsuitable for boring.
  • Great Basin is submitting an inadvertent return response plan, safety data sheets, and a bore profile to support their request, and requests that the attachments be accorded the protections provided by the Commission under 18 C.F.R SSSS 388.112 and 388.113.
  • The company aims to complete the segment by August 15, 2025.

Statistics:

  • The project involves the installation of approximately 3.41 miles of upsized or looped pipeline and associated appurtenant facilities in three segments along the 65 miles of Great Basin's Carson and South Tahoe Laterals in Nevada.
  • The project will provide 5,674 dekatherms per day of incremental firm transportation service, and the incremental capacity has been fully subscribed.
  • The HDD bore method is estimated to reduce the environmental impact of digging the deep trench by minimizing surface disturbance and avoiding the need for deep excavation and its associated impacts.

Sources:

  • Debbie-Anne A. Reese, Esq., Secretary Federal Energy Regulatory Commission 888 First Street, N.E. Washington D.C. 20426 RE: Great Basin Gas Transmission Company Docket No. CP23-466-000 Request for Variance: Silver Springs Segment - Use of an HDD Bore pipeline installation between Project Milepost CA 17.15 and CA 17.35
  • USGS research indicates that groundwater levels in the area are approximately 40 to 45 feet deep.