Salem Lateral Pipeline Project
|Client:||Spectra Energy / Algonquin Gas|
|Project Date:||May, 2015 - November, 2016|
This project supported the construction of ~1.2 miles of a new lateral gas pipeline and a new metering and regulating station. The pipeline delivers natural gas supplies for the Footprint Power Salem Harbor Station facility, a 674-megawatt natural gas-fired, quick-start, combined-cycle electric generating facility. Salem Harbor Station was designed to produce low emission electrical power to New England and to support the introduction of new renewable resources to the energy grid.
This project created the pipeline capacity necessary to deliver affordable supplies of clean-burning natural gas from the existing Algonquin Gas Transmission pipeline system to the Salem Harbor Station facility. Work took place primarily within Beverly Harbor, Collins Cove and the City of Salem, and industrial properties. This effort is one of the latest examples of an industry migrating away from coal towards natural gas as a feedstock for making electricity.
- Cashman's work included the installation of temporary mooring piles and a cofferdam in Beverly Harbor; two horizontal directional drill (HDD) crossings across Beverly Harbor and Collins Cove; a meter station at the Salem Harbor Footprint Power Plant; and 900 feet of pipeline connecting the HDDs and meter station.
- Required hydraulic dredging of an 85' x 55' area of the seafloor to a depth of -8.5 feet in Beverly Harbor; ~1,500 cubic yards of sediment was excavated and placed in hopper barges for temporary storage / decanting. Decanted material was placed back into the cofferdam.
- An 8' x 10' permanent concrete vault was installed below the seafloor in order to conduct future internal inspections; upper elevation of this vault lies ~1 foot below the existing seafloor elevation.
- Included wetlands protection and strategies to deal with local Essential Fish Habitat (EFH) for various species and life stages.