Jay Cashman Revises Quincy Pier 1 Dredging Plans

Image source: Jay Cashman, Inc.

Jay M. Cashman of Quincy Shipyard, LLC, has revised plans in seeking a permit from USACE’s New England District to conduct work in waters of the U.S. to expand and modify the dredging footprint to Pier 1 in the Quincy Shipyard in Quincy, Mass.

This work is proposed in the Fore River at 549 South Street in Quincy. A notice was issued on May 16, 2017 for the proposed work at Quincy Shipyard but those plans have changed and a new notice is being distributed with the revised plans.

The proposed work involves the expansion and modification to the authorized dredging footprint at and adjacent to Pier 1 in the Quincy Shipyard in order to create a turning basin to accommodate the turning radius of larger vessels.

Image source: Jay Cashman, Inc.

The applicant originally proposed to dredge approximately 4,500 cubic yards of silty material from approximately 1.50 acres of subtidal habitat in the Fore River to a depth of -31 feet mean low water (MLW) from existing depths ranging from -27 feet MLW to -31 feet MLW.

The applicant is proposing to reduce the originally proposed footprint in the Fore River; however, they are adding a second dredge area to the project, USACE said in its release.

This new dredge area is located at the end of Pier 1 and increases the proximity of the turning basin to within 400 feet of the Fore River Bridge. The applicant is proposing to dredge approximately 2,300 cubic yards of silty material from a 32,200-square-foot area within the previously proposed dredge area.

Additionally, the applicant is proposing to dredge approximately 1,720 cubic yards of silty material from the newly proposed 10,100-square-foot area. Dredging will increase water depths from existing depths of -27 feet MLW to -31 feet MLW to approximately -31 feet MLW. The new dredging proposal reduces the project’s total footprint from approximately 1.5 acres to 0.97 acres.

As before, dredging will be completed by mechanical means using a clamshell bucket dredge with a 27 cable arm environmental bucket.

The dredged material will be loaded onto scows that will be moored within the dredging site where the material within the scows will be allowed to settle for a minimum of 24 hours to allow for the fine material to drop out of suspension. Once the material has settled, the excess standing water will be decanted and returned to the project waters.

The dredged material will be offloaded from the scows and placed at a stockpile within the Quincy Shipyard before being transported to the Peabody Landfill to be used as cover.

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