Hydrokinetic Energy Decommissioning/Site Reclamation: Resource Requirements and Impact Sources
Decommissioning and site reclamation activities include facility removal from the sea, river, and the land.
Decommissioning of an ocean or river facility would include removal and disposal/salvage of hydrokinetic devices. Mooring cables would be removed but anchors and buried transmission cables may be abandoned in place to minimize disturbance. All onshore structures would be removed.
Decommissioning of a barrage facility would include removal of at least above-ground portions of the powerhouse and the excavation and removal of portions of the barrage and intake structure to restore a natural connection between the ocean and the embayment. Following removal of onshore components, site reclamation and revegetation would mitigate some impacts, such as soil erosion and visual impacts.
The following describes the factors that could affect whether an environmental impact could occur and whether it would be considered an adverse effect:
Acreage — Portions of the ocean or river bottom within the project area that are disturbed during decommissioning would be no larger than that disturbed during construction. If decisions are made to abandon some facilities in place, less disturbance would occur. Onshore transmission lines would probably remain in place as part of the transmission grid.
Emissions — Decommissioning and reclamation activities would generate engine emissions from the ship power plants, from on-board equipment such as cranes, and from heavy equipment and vehicles on shore. Onshore activities would produce fugitive dust emissions from vehicle traffic and removal of structures and stabilizing disturbed areas.
Waste Generation — Wastes generated would include solid and industrial wastes similar to those from construction, along with broken concrete, anchors, cables, wave and tidal energy device components that cannot be recycled, and lubricants and hydraulic fluids contained in the components of each wave energy device.
Water Needs — Water would be needed for dust suppression and potable supply for the workforce.
Workforce — Decommissioning and reclamation activities would require approximately the same number of workers as required for construction.