Watersolve’s experience and coast-to-coast agility keeps solutions rolling out including this latest partnership.
(Taken from Dredging Today.com)
Two large cranes worked together to lift a 23-ton dredge vessel up and over the Dick White Bridge on North Dogwood Trail in Southern Shores on Wednesday, Jan. 5. Now, the dredging of the canal under the bridge can resume.
A handful of officials were on hand to watch the lift including Mayor Hal Denny and Tom Bennett, the town’s project manager for the 2.5-mile dredging job with a $2.2 million price tag.
A portion of the project was paid for with an $800,000 grant from the N.C. Department of Environment and Natural Resources. The rest of the money came from the town’s capital resources, officials said.
Byrd Brothers Emergency Services out of Wilson serves as the main contractor for the project, which is scheduled to be completed in several months.
Town Manager Peter Rascoe stopped by the site briefly to have Mayor Denny sign several papers.
Rascoe said he was glad to see the dredge work being completed.
“The canals are an important asset to the town and its residents,” he said.
A small army of workers from Rose Welding and Crane Service of Columbia first positioned the two 100-ton cranes on the road that traverses the small bridge. After the cranes were set up, it took a while to rig up to the dredge.
The craft features two large pontoons in the front, and the cutter head protrudes in the center. A vacuum pump sucks up the mud and water and it exits from the stern through a large, black pipe that runs all the way to the spoil site.
Amidships there’s a small cabin for the operator. Three legs or spuds stabilize the craft when it’s engaged in dredging. It is not a sleek vessel by any means.
“That thing is all business,” Denny said.
Once the lift started, the dredge was raised up, across the bridge and set back into the canal with relative ease.
“This is an exciting moment here,” said Joe Anlauf an engineer with Quible & Associates of Southern Shores. “A little bit of history.”
From the comfort and warmth of his big red pick-up truck, Nate Dorman, the dredge operator, admitted it made him a little nervous to see his craft suspended from the crane cables. He works for Advanced Divers Inc., one of the subcontractors for the project.
Dorman has had a bit of bad luck while in town as he’s injured each foot. Dorman was getting around on crutches before he took refuge in his truck.
“Nate’s had a rough month here with a couple of foot accidents,” Bennett said.
The project manager said a second operator was on his way to help out but Dorman can still work, too.
“They’re bringing in a second operator today so they can dredge longer hours,” Bennett said.
So far, the company has dredged the canal north of the Dick White Bridge to a depth of four to six feet, Bennett said. Now, they’ll look to dredge about 3,500 feet to the south. It’s the second stage of Phase I of the project.
The final stage is the main channel that runs from the North Marina out and across the mouth of the Ginguite Creek and then into the Currituck Sound, Rascoe said.
The water was so low the morning of the lift, it almost looked as if the dredge could slip under the bridge, but the town officials said it was not possible. For one thing, the lower water level brings the rip rap rocks on each side into play and the dredge is just too wide.
For different reasons, the water has been low during the entire project, Denny said.
“There’s low water today,” he said. “It has hampered the project all along.
“This is a costly operation, this lift,” the mayor said.
During the hydraulic dredging process so far, all sorts of things have been recovered from the bottom of the canal — just about everything but treasure.
They’ve recovered binoculars, guywires, an anchor and chain, a car battery and plenty of natural things such as tree limbs and tree trunks.
All of the dredge materials, both the mud and the water, are pumped to a huge disposal or de-watering site along the canal just off of Hillcrest Drive.
There, two basins allow the silt to settle out of the water before the water is pumped back into the canal system. The larger basin contains 24,000 cubic yards of materials, Bennett said.
It’s a huge site with heavy machinery, large pumps and water treatment facilities. Due to government regulations, the water that’s returned to the canals has to meet certain criteria.
In a make-shift tent adjacent to the settlement basins, Mike Broering of Watersolve out of Grand Rapids, Mich. was busy testing the turbidity of the water. He adds coagulants and polymers to the water to speed up the clarification process.
In the larger basin, an excavator is used to dip soil out of the bottom and it is hauled to a staging area by a six-wheel-drive dump truck. Once the project is completed, all of the dark soil and the materials will be mixed together and graded back to a natural slope down to the water.
The three hilltop property owners that allowed the basins to be built in the back yards of their respective canal front properties were compensated for the use of the land and they also get to keep the fill materials.
The town plans to dredge another five miles of canals in the future. They’re considering using a different type of dredging such as mechanical dredging for that work. First, however, they need to come up with the money, town officials said.
BY DARYL LAW (womacknewspapers)