Lake Champlain PV-20 Submarine Cable Replacement

Beneath the tranquil surface of Lake Champlain were 50-year-old oil-filled transmission cables threatening energy reliability and the environment, so their replacement became essential. CHA guided the project management, engineering, and construction administration to replace these aged cables that connect the New York Power Authority and Vermont Electric Power Company. To minimize environmental impacts, four installation methods were used. Cables on land were installed through direct burial, and trenchless installation methods were selected to avoid disturbing the lakeshore. Underwater methods, such as horizontal directional drilling (HDD), a trenchless drilling technique, were implemented to transition the cable from the land to the lake.

Through careful execution, the old cables were replaced without significant power service interruption or environmental harm. New cables were successfully laid across the lake bottom, reaching depths of up to 100 feet, ensuring the essential long-term reliability for the vital electrical interconnection.