New Bedford Lower Harbor Remediation Dredging

New Bedford Harbor is a deepwater commercial port with easy access to the maritime corridor from the Massachusetts coast, located on the northwestern side of Buzzard’s Bay. Once the world’s largest whaling port and a cotton manufacturing center, the harbor is now a major fishing port. The Port of New Bedford also serves as a break-bulk handler of perishable items, including fruit and fish, and also handles other cargo.

CASHMAN was awarded a $21 million contract for mechanical dredging of the New Bedford lower harbor, with an estimated completion during the first half of 2018.


PROJECT HIGHLIGHTS

• Dredging is being performed in depths of up to 30 feet of water and as shallow as 3 feet.
• Sediments placed into the Lower Harbor Confined Aquatic Disposal Cell (LHCC) are being dredged using mechanical dredging equipment with a closed environmental bucket.
• Approximately 177,000 cubic yards of dredge materials exceeding the Lower Harbor Superfund cleanup level of 50 ppm was removed and placed in the LHCC. Most of the material underlies the State Channel on the New Bedford side of the Harbor.
• To minimize over-dredging, dredging accuracy was controlled by using a CASHMAN-refined and enhanced Dredgepack dredge bucket positioning system (DGPS).
• CASHMAN developed a precise technical approach that incorporates “lessons learned” from dredging PCB-impacted sediments and from precision dredging using state-of-the-art dredge monitoring & positioning systems.