The third contract of a $200 million project to deepen and widen the Port Jersey Channel is now under way, according to Kris Kolluri, commissioner of the New Jersey Department of Transportation (NJDOT).
NJDOT, the Port Authority of New York and New Jersey and the U.S. Army Corps of Engineers have all contributed to the funding of this project, Kolluri added.
“The Port Jersey deepening project will serve as a regional economic engine by improving the accessibility of the Port Jersey Channel for large ships,” Kolluri said.
He added that NJDOT’s $100 million share of the project’s funding was provided by the Dredging and Harbor Revitalization Bond Act of 1996.
According to Bryce W. Wisemiller, project manager of the U.S. Army Corps of Engineers of the New York District in New York City, the Port Jersey Channel Navigation Project Construction Contract No. 3 deepens and widens the non-federal channel from depths as shallow as minus 12 ft. mean low water (MLW) to a navigable depth of minus 50 ft. MLW.
“It is approximately 10,000 feet from its confluence with the main Anchorage Channel in the east to the Global Terminal and Container Services LLC at the western end,” Wisemiller explained.
“Construction of Contract No. 3 will create approximately 3.37 million cubic yards of dredged material, all of which is expected to be used beneficially, either at an approved and permitted upland remediation site, as remediation material at the Historic Area Remediation Site [HARES], or to create artificial fish reefs with the dredged rock material.”
He explained that the first two contracts deepened the previous non-federal channel area to a navigable depth of minus 41 ft. MLW. Concurrent to implementation and completion of these two contracts, “the Corps executed a Project Cooperation Agreement [PCA] with the Port Authority of New York and New Jersey to further deepen several federal channels within the Port [including the Port Jersey Channel] to a navigable depth of minus 50 ft. MLW. Through an innovative and unique regulatory and PCA arrangement, construction of the first two contracts, the first of which began in 2002, was consolidated, reducing combined construction costs by more than $30 million. Combining the two contracts also reduced the overall impact to the environment,” he added.
Contract No. 3 was awarded to Great Lakes Dredge and Dock Co. of Chicago on Oct. 19, 2007, Wisemiller said, adding that this $89.8 million portion of the project “is by far the largest and most complex Port Jersey Channel construction.”
According to Wisemiller, it is expected to take about two years to dredge the 3.37 cu. yd. of silt, sand, clay, till and rock material required under this contract.
“To give this volume of dredged material some scale, it would fill the ’bowl’ of the existing Giants stadium over two-and-a-half times, or cover all of Central Park in New York City to a depth of 28 inches,” he pointed out.
The Port Jersey Channel Navigation Project, Contract No. 3, is located between Port Jersey in Jersey City, N.J., and the Peninsula at Bayonne Harbor in Bayonne, N.J.
Great Lakes Dredge and Dock Co. will employ several types of dredges to perform the work called for under this contract. Most notable of these will be the use of one or more clamshell dredges as well as the contractor’s excavator dredge, the “New York.” In fact, the contractor, Wisemiller said, has proposed using three different clamshell dredges: the Dredge No. 51, the Dredge No. 54, and the Dredge No. 55.
Dredge No. 51, according to the Great Lakes Dredge and Dock Co. Web site (www.gldd.com) is for use with open channel excavations and for new work in harbors and routine maintenance dredging. This dredge operates with a variety of buckets, and in conjunction with the company’s 2,000- and 3,000-cu.-yd. (1,529 and 2,293 cu m) bottom dump barges in projects involving off-shore disposal.
The “New York” dredge is a backhoe dredge with a digging depth range of 60 to 83 ft. (18 to 25 m) and a bucket capacity ranging from 7 to 25 cu. yd. (5.3 to 19 cu m).
Dredge No. 54 has a digging depth of 74 ft. (22.5 m) on spuds and 150 ft. (45.7 m) on anchors and a bucket size capacity ranging from 12 to 30 cu. yd. (9 to 23 cu m). This dredge works in conjunction with the contractor’s fleet of 3,000 to 7,200 cu. yd. (2,293 to 5,505 cu m) dump barges on projects involving off-shore bottom-dump disposal.
The company also has specialized hydraulic unloaders that can pump material to upland disposal sites.
According to Wisemiller, one of the project’s “most significant” challenges is dredging the channel over an 80-year-old underlying utility tunnel.
The tunnel, constructed and owned by the Passaic Valley Sewerage Commissioners (PVSC), a New Jersey state agency, has a 12-ft. (3.6 m) inner diameter and was hand dug at the beginning of the 20th century to allow direct release of treated effluent from the PVSC treatment facility in Newark, N.J., to the Upper Bay of New York Harbor. When the tunnel was dug, the former Military Ocean Terminal, Bayonne (MOTBY) and Port Jersey did not exist. As a result, there was no contemplation of a navigation channel being constructed over the tunnel. It was lined with 18-in. (45.7 cm) thick unreinforced concrete that had been cold-cast in semi-circular halves.
The tunnel, which typically discharges approximately 330 million gal. (1.2 billion L) of treated effluent per day, is under pressure from the flow.
“As the channel is deepened,” Wisemiller said, “and the overburden material is removed, great care by the dredging equipment must be employed to protect this critical and historical utility tunnel.”
While much of the dredging near the PVSC tunnel will be performed in Contract No. 4, Contract No. 3’s contractor will still be dredging fairly close to the tunnel under Contract No. 3, he noted, adding that “in such locations, the ability of excavator dredges, such as the ’New York,’ to precisely and accurately control the bucket location and applied power are critical.”
Other challenges include dredging selected areas of the contract prior to the expiration of sediment testing permits; working around other constraints, such as maintaining safe channel navigation; environmental “no dredging windows;” and constructing a new habitat enhancement site in the unused channel south of MOTBY with the suitable clean material dredged from the contract.
In terms of challenges in an upland environment, much of the surface silt material is being used upland to remediate existing landfills and brownfields in the region. To do this, material is mixed with stabilizing agents, such as Portland cement, to solidify the material so that it can readily be applied at the sites.
Wisemiller noted that with the cost of dredging equipment and the demand for dredging nationwide, dredging, such as on this contractor, is typically a 24/7 operation. However, weather, maintaining navigation and maintenance do cause the contractor to stop work occasionally.
Given these factors, he observed, “downtime on a large excavator dredge, such as the ’New York,’ is typically measured in minutes. And, given the amount of material to be removed under this contract, completion will take upwards of two years. Should the contractor require additional time beyond what is allowed under this contract’s specifications, the contractor will be charged for the liquidated damages due to the costs that result from the delay.”
However, since it benefits the contractor to complete the job in a timely manner, so his dredge equipment can move to the next job, the Corps expects Contract No. 3 will be completed on schedule, Wisemiller added.
Furthermore, he said, since it has taken nearly five years of in-depth preparation before this contract started construction, everyone involved is dedicated to safely completing the project on budget and on schedule.
Contract No. 4 will deepen the remaining portion of the 50-ft. (15 m) Port Jersey Channel over an underlying utility tunnel as well as apply any necessary tunnel reinforcements.
Contract No. 4 is expected to be constructed in the summer of 2008 or 2009, depending on the completion schedule of the required design documents. CEG