Helping to shore up the infrastructure at the site of what was once one of America’s busiest naval bases is the task at hand for Landmark Construction of North Charleston, S.C.
A full-service construction firm, Landmark is currently in the middle of a more than $5 million project to install 2,600-ft. (790 m) of 9-by-5-ft. (2.7-by-1.5 m) box culvert at the site of the old Charleston Naval Shipyard. The Pentagon closed the shipyard in 1996 as part of a nationwide downsizing of military bases.
Since the closure, the shipyard has been under the control of the Charleston Naval Complex Redevelopment Authority (RDA), an agency of the state of South Carolina. The RDA contracted Landmark to rehabilitate the worn-out drainage line that runs from the Cooper River to nearby Spruill Avenue. The site is about 5 mi. (8 km) north of Charleston along the river.
“We are redesigning the drainage there because the existing line has been in the ground for years and years,” said Rick Mixson, Landmark’s president and son of the company’s founder, Fred Mixson. “What we are doing is redesigning the water runoff. It will tie into the Cooper River with a retention pond. It will have regular concrete pipes and ties and there will be several locations where there will be a box with concrete pipe runs that run off from the box culvert.”
Mixson said the site is on a marsh adjacent to the river and when there are heavy rains, the lack of adequate storm drainage has been a problem.
Currently, Landmark has a crew of five people at the site installing the box culverts, according to Chris Hawker, Landmark’s project manager at the shipyard. By the end of June, he anticipates adding another crew to tie in some sewer lines to the storm box.
Hawker said the work began several months ago and will continue to the end of the year, barring any unforeseen problems. Progress has been slowed by having to tie in so many of the different drainage lines that crisscross the old base, he said. In addition, the line of box culverts had to be realigned around a high-voltage power line that was in a different location from what was indicated on the base’s drawings.
Dealing With Contaminants
Another problem faced by Hawker and his crew was the high probability that ground contaminants would be found and have to be removed.
“The initial scope of work called for that possibility, since the work we were doing was on an old naval base,” Hawker explained. “We were going to excavate the material, place it in a stockpile and have it tested for contaminants. If it were contaminated, it would have to be hauled offsite to a special landfill. If it wasn’t contaminated it could go to a regular dumpsite.”
In order to save time and money, as well as the health of its crew, Landmark recommended that a testing firm be brought to the site to test the soil before digging commenced. Borings were taken at the site and, as everyone feared, contaminants were found, with arsenic being the most prevalent substance. While wearing protective suits, Landmark’s crew used a Volvo EC460 to excavate the toxic soil and had it hauled off. Landmark had used the EC460 in the project’s early days to dig the trenches and put the box culverts in place, but Hawker said that his crew has since switched to using the much larger EC700 model.
In addition to rehabilitating the storm drainage system that runs through that part of the old shipyard, Landmark’s work also will replenish the water for the tidal marsh that is located between Spruill Avenue and the Cooper River, according to Gene Knisley, RDA operations director. As a result of the project, he said, the tide will better move water through that basin twice daily.
The storm drainage project runs adjacent to and partially across property that is currently occupied by the Clemson University Restoration Institute. It is at that site that the old CSS Hunley, the world’s first successful submarine, dating back to the Civil War, is being restored. The Confederate submarine was raised off the floor of the Atlantic Ocean just off nearby Sullivan’s Island in August 2000 and moved by barge to the site of the institute. Since then, the Hunley has been in a 90,000-gal. conservation tank where it has undergone painstaking restoration work by Clemson scientists.
Plans call for the construction of a museum to house the Hunley, possibly at the site of the current restoration, sometime in the next several years, according to Kellen Correia of Friends of the Hunley, a nonprofit group that raises funds for the conservation and eventual exhibition of the historic vessel.
Other than the possible Hunley museum, no other buildings are planned for the area adjacent to the storm drainage project, Knisley said.
Besides the old warehouses and other abandoned buildings in the area near Landmark’s project, the federal government owns approximately 85 acres (35 ha), where it trains Homeland Security personnel, according to Knisley.
Back to the Shipyard
The Charleston Naval Shipyard covers more than 1,600 acres (647 ha) and once employed thousands of sailors and civilians. It is part of the much larger Charleston Naval Complex, which also included the Naval Station, the Naval Fleet and Industrial Supply Center, the Fleet and Mine Warfare Training Center and the Naval Reserve Center (which remains open).
The RDA has been able to entice more than 100 private, local, state and federal entities to locate facilities at the shipyard, including Detyens Shipyards, Charleston Marine Manufacturing Corp., the U.S. Postal Service, the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Coast Guard.
To the north of the shipyard, a private development company, the Noisette Co., is developing approximately 350 acres (142 ha) of the naval complex as part of a larger, sustainable urban redevelopment effort. South of the Naval Shipyard, the South Carolina Port Authority has been granted a 30-year lease to build a major marine cargo handling facility. Knisley said the Port Authority is currently in the process of demolishing some of the old buildings on the site and preparing the area for construction. CEG