Former General Motor Assembly Site: Bulkhead, Dredging & Backfill

Consultant/Engineer: Arcadis US, Inc.

Dredging and Backfill:

Weeks Marine’s work was performed along the property of the Former General Motor Assembly Site in Sleepy Hollow, New York.

The work included the installation of 250 linear feet of sheet pile wall to protect the existing bulkhead during the dredging operation. A heavy turbidity curtain was installed along the shore side of the sediment removal area to protect any spill into the Hudson River.

The dredging operation consisted of removing 4,400 CY of contaminated material along the shore to a specific elevation of -17 feet using a 9 CY environmental bucket. Contaminated material was placed into a DOS barge for decantation. Thereafter the contaminated material was unloaded on site to be mixed with a stabilization agent and used as backfill on site.

The excavated area was replaced by clean material supplied by the client.

Weeks performed its own Quality Control Program to quantify the dredge volume and verify the final elevation of the excavation. The Crane Barge was equipped with a DGPS System and single beam sonar was used to corroborate the result.