The Charleston Harbor Federal Navigation Channel covers an area of approximately 14 square miles and is formed by the confluence of the Ashley, Cooper, and Wando rivers. Maritime interests want the harbor channel deepened beyond 45 feet so the Port of Charleston can handle the larger container ships. In response to this need, a feasibility study was conducted to examine the economic benefits and environmental impacts of the deepening project. ANAMAR was contracted to conduct sediment evaluations to determine if the proposed dredge material is suitable for disposal in the Charleston Harbor ODMDS.
ANAMAR managed all sampling operations and worked closely with subcontractors to coordinate logistics. The sampling plan included collection of vibracore samples at 105 sites, grab samples at the reference station, and site water samples at three locations for elutriate preparation. Due to the size of the project, the sampling effort took nearly 4 weeks to complete and presented some unique challenges. Inclement weather caused by Tropical Storm Sandy followed 2 days later by a winter storm resulted in minor delays in sampling operations. This area also experiences 6-foot tidal fluctuations resulting in very strong currents during incoming and outgoing tides; therefore, the sampling team had to plan daily sampling operations during workable currents (i.e., slack tides). Since sampling was taking place within the shipping channel and berthing areas, the captain maintained regular communication with the ships so sampling would not interfere with shipping traffic. The physical composition of the sediment itself also proved to be challenging. Most of the sediment was highly consolidated Cooper Marl, which was difficult to penetrate and to remove from the core barrel. A method was developed in the field to pressurize the core barrel using compressed air to extrude sample material from the barrel. This “on-the-fly” innovation helped the field effort stay on schedule.
Coordinating sample delivery with the chemistry and bioassay laboratories to meet holding times while field operations were ongoing required multiple sample shipments due to holding times and the amount of time required to collect all the samples. It was necessary to run the bioaccumulation tests in two batches due to holding times and the field time required to collect such a large number of samples. Close coordination with the laboratories and couriers was critical.
ANAMAR succeeded in collecting all the required sample material and processed and shipped the material to the laboratories within holding times. All sample material was analyzed within holding times and with no significant quality control issues. ANAMAR reviewed and compiled all the laboratory data and produced a report summarizing the results of the physical, chemical, and toxicological analysis of sediment, elutriate, water, and tissue samples of the proposed dredged material collected from the project area.
“ANAMAR is my contractor of choice for sediment testing (especially for compliance with ocean dumping of dredged material regulations). This type of sediment testing is complex, and invariably always results in some unforeseen problems/difficulties; they are proactive in responding to these problems. I would absolutely hire them again for this type of work.” Alan Shirey, 2/17/2015
Below is a quotation concerning this project from Dredging Today (July 2, 2015) "Post 45 Project Gets Funding"
"The Charleston Harbor Post 45 Deepening Project is the first project in the U.S. Army Corps of Engineers to go through the Corps’ new Civil Works Planning Process from start to finish.
This has enabled the Charleston District to reduce the initial study timeline of five to eight years down to less than four years, and reduce the initial study budget from $20 million to less than $12 million dollars. This project will serve as a model for Corps civil works projects around the world."