Cove Point LNG Pipeline Dredging

Cove Point Terminal is an offshore liquid natural gas (LNG) shipping terminal located near Lusby, MD on the western shore of the Chesapeake Bay. The shipping dock is located about 1.4 miles from the plant's storage tanks and is connected by pipes in an underwater tunnel. Cove Point LNG Terminal has a storage capacity of 14.6 billion cubic feet and a daily send-out capacity of 1.8 BCF. The terminal connects, via its own pipeline, to the major Mid-Atlantic gas transmission systems of Transcontinental Gas Pipeline, Columbia Gas Transmission, and Dominion Energy Transmission.

CASHMAN was contracted to mechanically remove ~110,000 yd³ of silt and sand material at the facility, as well as provide pier and revetment wall reinforcement. 


PROJECT HIGHLIGHTS 

• Mechanical removal of ~110,000 yd³ of silt and sand material utilizing the Tangier Sound, a Lima 2400 crane dredge. 
• Material was loaded into two 3,000-yd³ hopper scows and transported to the unloading barge located adjacent to the pier revetment at the Cove Point LNG facility for hydraulic unloading and placement evenly behind a revetment wall. 
• Material was unloaded from hopper scows utilizing an excavator-mounted DAMEN DOP hydraulic pump. 
• Material was transported through 1,000 feet of 12-inch HDPE pipe and discharged. Initial 2,000 yd³ of material were discharged in a geotube. The remaining material was discharged evenly behind the revetment wall, moving the pipeline as material filled in the areas. 
• Water from behind the revetment wall was pumped through a return pipeline and discharged to the waterbody, following Contract discharge water environmental controls.