Superstorm Sandy's effect on many of the beaches of the East Coast was like a knife on burnt toast—scraping and scraping away, until, in some places, not much was left but rocks. But in a widespread and intensive effort that began last summer, the U.S. Army Corps of Engineers and its contractors began replenishing beaches and undoing years of erosion, work that is expected to continue through most of this year. The aim is to restore beaches to their original construction state.

"People who go to the beach will notice a big difference when they show up this year," says Manny Vianzon, a project manager for contractor Great Lakes Dredge & Dock Co. "There's going to be about 100 more feet of beach than there used to be," he says, referring to his firm's $18-million restoration project at Asbury Park, N.J., set for mid-June completion.

That is one of a checkerboard of Sandy-related projects that have taken place from North Carolina to New York during the past 18 months. While most have been completed, a few are expected to wrap up this fall.

At Asbury Park, the goal is to bring 2.5 miles of beach back to the level of a decade ago. To get there, the Oak Brook, Ill.-based Great Lakes is using a pair of hopper dredges. The long deep-hulled ships scoop up sand from the bottom of the Atlantic and haul it back to shore in an efficient, detailed process that starts with materials selection.

Not just any sand will do. The Corps selects areas with material that is a near-identical match to the sand that was lost; if it's too fine, waves will wash it away, officials say. Often, this material is not just a short boat ride offshore, but far out to sea. That's true in the case of Asbury Park, where sand must be quarried from a rectangular patch of ocean bottom 14 miles away.

Giant powerful vacuums suck up material from the bottom, including water and rocks that will be filtered out, and into the dredges, which each holds 2,500 cu yd. Once one fills up and heads for shore, the other takes its place to make for a seamless 24-hour-a-day operation, says Vianzon, who has worked in marine construction for 13 years.

When near shore, the dredges must tie up at a floating cargo transfer device, known as the Cube, that sits about 2,000 ft offshore. The massive dredges themselves can't be pulled too close to the beach as the water there is too shallow. The sand is pumped into pipes that rest on the bottom of the Atlantic and snake their way onto shore, where it is filtered again with an even tighter screen and bulldozed into place.

All told, the unloading process takes about an hour if the ocean isn't heaving, Vianzon says. On a good day, the crews can add 15,000 cu yd to the beach. Its replenishment will ultimately require more than 1 million cu yd, he says.

At Asbury Park, however, a series of brutal winter storms made it hard to keep the ship steady at sea, causing a week's delay. The possibility of severe winter weather delays, however, was baked into the schedule, and no lost time is expected for the overall project, which began Jan. 10, Vianzon says.

In some respects, restoration work at Jones Inlet on Long Island's Jones Beach was less complicated because the replacement sand was located close to shore instead of far out at sea. Steel pipes alone were used to carry the sand to its intended site, says Steve Chatry, who manages dredging at contractor Weeks Marine, Cranford, N.J. The contractor finished this $10-million job in mid-February.

At Jones Inlet, 600,000 cu yd of sand were dug from a next-door channel, which itself required dredging, Chatry says. Crews did not venture more than about two miles from shore and a single ship was used, known as a cutter-head dredge. The vessel acted as a relay station by scooping sand and sending it though 800-ft sections of 30-in.-wide pipes laid along the ocean floor. The process used three pumps that create a hefty 400 psi of pressure. The force of the pumps was so intense that it could propel the sand to shore without the use of boosters.

Weeks Marine's next Sandy-related job will zero in on six miles of beach in the Rockaways section of Queens. The $26-million contract kicks off in March.

For Seattle-based contractor Manson Construction Co., operations took on a different twist in the midst of a $40-million contract to restore 3.3 million cu yd of sand at Long Branch, N.J., near Sandy Hook. While rocks and wild weather may be typical hurdles, Manson Construction's crews found munitions, which might have been left over from the World War II era when target practice along the shore was common.

Fortunately, ordnance disposal teams that are often assigned to Northeast deep water projects near military bases were able to safely remove the debris, says Henry Schorr, a Manson Construction vice president.

The Long Branch job, which began in November, lost about 15 days due to below-freezing temperatures that could have frozen fluid lines, Schorr says. Like Great Lakes, the contractor had also built extra time into the schedule for such events, so the overall project will not be delayed, Schorr says.

Using dredges, Manson Construction is digging 3 miles out to sea and about 8 miles from the project site. The sand there, which sits about 60 ft down, is loaded into the Glenn Edwards dredge, which is one of the newest and largest in the country, Schorr says. It can carry 13,500 cu yd of material and has a crew of 20.

In many ways, moving the sand into place is the easiest part of the operation. What can be tricky is deciding how much sand should be delivered, contractors and local authorities say. The reasons vary but many coastal residents don't want the dunes to be so high that they block ocean views. Even before shore restoration work began last year, real-estate easement issues such as this were an issue but, for some towns in New York and New Jersey, the post-Sandy beach replenishment projects have intensified the debate.

"There is always controversy about where the beach level should be," says Chatry, noting that the Corps handles design work. In the end, he adds, "you try to get it as close to what it looked like before erosion occurred, as close to the natural condition as you can get, which will give you the most sustainable beach."