Mitigations

  • Seawater Intake Impacts to Marine Life – The seawater intakes of these “pinpoint” facilities will draw no more than 5.4 MGD (based on 3,000 AFY) per plant. All seawater intakes will be filtered through proven rotating wedge wire screens.
  • Brine Discharge Impacts to Marine Life – Brine will be discharged at each facility using diffuser piping mounted near the water surface to provide exceptional diffusion.
  • Visual Impacts – The barge-based facility will extend above the waterline no more than approximately six feet and will be difficult to see one mile offshore when standing on the nearest shoreline. The seafloor-based monopile will measure approximately 25 feet or less in diameter and will extend above the waterline no more than approximately 30 feet. It will have less visual vertical square footage than a fully sailed 25-foot sailboat located the same distance offshore.
  • Seafloor Impacts – The permeate pipeline transporting the reverse osmosis water from the offshore facility to the shore tie-in to the onshore conveyance will consist of a high-density polyethylene (HDPE) pipeline installed in a hole bored approximately 80 to 100 feet under the seafloor from a location onshore, thereby eliminating any impacts to the seafloor except where the pipeline exits the seafloor at the offshore facility. The barge-based facility will utilize a four-point mooring system offshore and its four anchor legs are estimated to impact less than 7,900 total square feet of the seafloor.  All anchor placements will avoid impacts to hard bottom features using hydrographic surficial features surveys to identify and facilitate placement of anchors in soft bottom strata only.  The approximately 75-foot diameter reinforced concrete base of the monopile will impact less than 4,500 square feet of seafloor.
  • Sea Level Rise – The barge-based system cannot be affected by sea level rise because it floats, and its mooring system will adjust infinitely. The seafloor-based monopile system will be designed with adequate freeboard to account for anticipated sea level rise during the life of the facility.
  • Power – Desalination of seawater from an OceanSpring offshore facility uses no more electrical power per gallon of recovered freshwater than reverse osmosis filtering at onshore facilities recycling wastewater, brine water from onshore wells, and the similar water enterprises.
  • Hazardous Materials Impacts – The offshore facilities will be electrically powered via a submarine power cable pulled through the same horizontal directionally drilled bore as the permeate pipeline and there will be no need for any fuels or hazardous materials to present at the barge-based plant or monopile plant.
  • Catastrophic Event Impacts – Seismic events, tsunamis, and storm events will be accounted for in the marine facility designs. Seismic events will have minimal impacts on the barge-based system because it is floating, and its mooring system is highly flexible and redundant.  The seafloor monopile facility will be designed to survive maximum anticipated seismic events.  In the 60 to 70 feet of seawater where the facilities will be located 5,000 to 7,000 feet offshore, tsunami wave energy will pass around the column structures.  Annual storms are possibly the largest threat to either of the facilities, and the facility designs, including the barged-based facility mooring system and the reinforced concrete base of the seafloor-based monopile facility, will be designed to survive a 100-year significant wave height.  Facility designs will be based on metocean data specific to each geographical location.
  • Navigational and Public Safety – The facilities will be located well shoreward of commercial navigation channels and in shallow waters not frequented by shipping. The facilities will be visible to recreational and commercial traffic that may travel along the shoreline, and the facilities will be equipped with day/night navigational lighting to warn boaters of their locations.