“What’s old is new again” can describe Poplar Island when the reclamation project there is completed.
Poplar Island, located in the upper middle of the Chesapeake Bay, southeast of Annapolis in Talbot County, MD, was formed during the last “Ice Age” more than 10,000 years ago. It was named Popeley’s Island by explorer William Claiborne in 1627. The island was first settled in 1630.
Through the centuries, Poplar Island has supported an abundance of life in its waters and on the land. However, hurricane winds and rising water levels have taken their toll. The island that once covered an estimated 1,100 acres has dwindled to a mere 5 acres on four islands. Today, that is in the process of changing.
In 1994, an interagency group, including the U.S. Army Corps of Engineers (USACE), the Maryland Port Administration, and federal and state environmental agencies studied the feasibility of using Poplar Island as a beneficial use project for dredged material from the Chesapeake Bay navigation channels leading to the Port of Baltimore.
It was determined that rebuilding Poplar Island and restoration of more than 1,000 acres of diverse habitat was a viable, beneficial use of dredged material. In September 1996, the project was approved for construction.
In 1998, the USACE, Baltimore District, started to rebuild the island by placing, shaping and planting up to 38 million cu. yds. of uncontaminated dredged material from the Baltimore Harbor and Channels Federal Navigation Project. The island reconstruction will take place over a period of 24 years through placement of up to 2 million cu. yds. of dredged material per year.
VSA Construction Services LLC (VSA), of Jessup, MD, was hired to put in a lower bench in the dike. A bench is a terrace along the bank of a body of water, often marking the former shoreline. Next, the company was to raise the dike three more feet to elevate it to 23 ft. and eventually to the final 45 ft. above sea level.
After barges carried the equipment to the island, oak mats were used under the machinery to protect the ground over which it traveled. When crews and machinery were in place, the work of excavating and placing thousands of tons of material began.
“The first task was to create a borrow area for the material that we needed to build the bench and dikes. The borrow area was below water, so development of the borrow area required major pumping and excavation of rim ditches,” said David Krebs, field manager of VSA.
Project conditions required extremely careful work and constant attention to the water level in the area. Although the dewatering effort was under separate contract to another contractor, VSA operations were directly affected by water control within the dike area.
“We began to ditch all over the place, using Komatsu equipment of all kinds. The very cold, wet weather was challenging, but digging the ditches to drain this [borrow area] out was easy with these kinds of machines,” Krebs said.
In addition to the weather, the soils on the island provided a challenge for men and machine. “In Phase one, the soils have been touchy. We’ve been dealing with dredge mud, which is very difficult to get the bench into. We are now pushing the dredge mud out and placing sand into its place to get a solid foundation for the dike,” Krebs explained.
Because the sand for the foundation is coarse and wetter, it’s also very hard to work in.
“Excavators have literally sunk into the bay, but these Komatsus are completely tough cookies. They are quick and can pick up dirt at an alarming rate. We have two sites out here to dump the dirt and we’re averaging 4,000 to 5,000 yards a day to get this done on time. During this job, we have placed, in certain areas, a very gentle and tricky material. You must stay on top of this job or possible disaster can take place. We have been using a lot of crane mats, which have been a must,” said Krebs.
The VSA team also has developed several wetland cells for wildlife habitat on Poplar Island. The wetland cells were created by moving more than 450,000 cu. yds. of materials from the center of the diked area and construction of an additional 10-ft. high sand/soil dike approximately 5 mi. in length.
A cross dike was added in the wet cell of the island. The scope of the work expanded to include the installation of two spillways through the dike to aid in drainage for dewatering of dredge cuttings and establishment of ground cover on all earthen dikes. Erosion control was a constant issue. VSA subcontracted to have erosion-control matting and seeding installed as soon as a section of dike was completed.
The Baltimore District Corps of Engineers is managing six primary cells on Poplar Island. The 540 acres on the eastern half of the island includes four primary cells, some of which are being managed as wetland habitats, with perimeter dike wall crest elevations. Cells 4 and 5 are being used as a source of borrow material for the continued construction of perimeter dike walls for other cells that are used to contain dredge. Cell 2, located on the western, upland, side of the island, was the primary cell used to receive dredge materials from the Chesapeake Bay Channel maintenance.
In September 2003, Hurricane Isabel came through the area and washed away approximately 500 ft. of sand/stone along the island perimeter on the southern portion of Cell 5. VSA was subcontracted to repair this breach and close the open access of the bay into the Cell by reconstructing approximately 700 ft. of gravel roadway and to repair an additional 8,400 sq. yds. of eroded roadway.
The repairs were accomplished by removing approximately 1,800 tons of 250-lb. rip rap and 900 tons of 3,000-lb. armor stone from the failed dike wall. The dike construction also included placement of approximately 8,000 cu. yds. of sand and 3,000 tons of bedding stone. The larger rip rap was then positioned along the dike exterior slope to protect the dike wall. Geotextile was placed on top of the dike and a 20-ft. gravel roadway, which is part of the Poplar Island perimeter road system, was then constructed on top of the new dike. The contract value for this project was more than $600,000 and was recently completed.
When the entire Poplar Island project is completed, dikes will cover approximately 1,700 acres of land. The island will, once again, provide a haven for wildlife, which includes bird sanctuaries The habitat area is at the halfway mark and to date, 1 million tons of dirt have been moved. “We still have to undercut, in phase one, about a foot and a half, and dozers are helping us a lot by clearing things away after we squeeze material out of the dregs,” said Krebs.
To meet its schedule on a $7-million contract, VSA has relied on Komatsu equipment with Midlantic Machinery, formerly Furnival, providing 99 percent of the equipment.
“We purchased 11 articulated dump trucks and have found them to be easy riding machines. We got them because our guys keep all trucks moving for 12 hours straight every day. I have used many other brands of dump trucks, but the driving ability and transmission of the HM3003s are truly a new innovation and the cylinder system and chassis is unsurpassed,” Krebs said.
“Komatsu equipment is the longest running equipment that we have without a lot of breakdowns and Midlantic Machinery has a full-time mechanic out here to minimize downtime. That is another great feature of working with these guys. Midlantic did a great job getting millions of dollars of equipment to do the work in a timely fashion. Chuck Scott is our sales representative and [he] has done a great job. He has made a lot of boat rides out here to watch out for our best interest,” he said.
Midlantic Machinery is headquartered in Hatfield, PA, with branches in Harrisburg and Wilkes-Barre, PA; Delmar, DE; and Baltimore, MD.
Today's top stories
