Jug Handle Ecology
Officials go to great lengths to bridge the gap between ecology and economy.
CAMA. USCG. NPS. USFWS. NCDEQ. USACE. NOAA. NCDOT.
Dealing with the alphabet soup of government agencies when building an Outer Banks bridge might lead some to use NSFW language as every last “i” is dotted and “t” crossed. But minimizing the environmental impact of the Rodanthe Jug Handle Bridge was a team effort from the start.
Flatiron Construction is just a few months away from completing the $145 million project designed to divert traffic over the Pamlico Sound and away from the ocean-side stretch of Highway 12 prone to flooding. Flatiron project manager Adrian Price has been involved from the very beginning.
“Flatiron has been in North Carolina for the last 20-plus years working on high-profile projects,” Price says. “North Carolina prides itself on their environmental stewardship, so there’s a lot of oversight, and if you work in North Carolina, you have to understand what you’re doing. Flatiron’s pretty good about that at this point.”
The Washington bypass bridge near Greenville is one example of Flatiron’s recent experience building over water. (The Bonner Bridge and #OBXBlackout, for the record, was NOT a Flatiron project.) From the moment the jug handle bridge plans moved forward in 2016, environmental concerns were raised – and addressed.
“A lot of the environmental stuff we do is on the front end to make sure we minimize the impacts,” Price explains. “It’s how small can you make your footprint on the bridge.”
That’s where the North Carolina Department of Transportation comes in. Resident Engineer Pablo Hernandez has worked out of the Manteo office for the past 23 years. So he has a wealth of experience when it comes to local projects.
Hernandez explains that when the DOT starts planning projects, it holds merger team meetings with several agencies: Coastal Area Management Act officials, the U.S. Army Corps of Engineers, N.C. Department of Environmental Quality, even the State Historic Preservation Office. Those meetings can include upwards of 20 different agencies.
“That whole process is designed to give everybody a heads up 1) what the department would like to do and 2) for the various stakeholders to bring forth the items they want us to look into as we move forward,” Hernandez says. “Through that process, we come up with the list of things we want to minimize but don’t tell the contractor how to minimize it.”
To put it another way, Hernandez says with a laugh, on design-build project bids like this one, “We tell them we want a cake, but we don’t tell them how to make the cake.”
One of the main ingredients of concern for the Rodanthe bridge involved another fun acronym: SAV.
“This entire corridor, the water’s one to four feet deep, so it’s the perfect environment for sub-aquatic vegetation,” Price says. “There’s special seaweed that grows out there. SAV is perfect for microorganisms and small fish and birds to come in, so they’re really protective about it.”
So much so that the DOT hired a firm to transplant the seaweed from wherever bridge pilings would be placed to another location in an attempt to save it. And a monitoring program will be in place for the next five to 10 years to gauge whether or not the shadows cast by the new bridge are killing the SAV around the structure.
Other quirks to building a bridge over protected waters abound. For instance, night work was scarce for this project. Still, when Flatiron did go late – such as waiting for temperatures to cool enough during the summer when forming the concrete road surfaces – amber lights were used. That satisfied a requirement from the folks with the U.S. Fish and Wildlife Service on sea turtles.
“During the turtle breeding season, you have to have special lights that don’t attract baby sea turtles to our project,” Price says. “They’re attracted by the moonlight, so the last thing they want is a turtle to hatch and come towards our project instead of towards the ocean. So our lights have to be a red tint.”
In another nod to one of the Outer Banks’ most beloved sea creatures, the USFWS and North Carolina Division of Marine Fisheries requested that barrier railings on the shorter Rodanthe bridge be a little taller than those on the high-rise Bonner Bridge so that future turtle nests on the beach will be shielded from vehicle headlights.
Another challenge with this project is that the bridge spans the Pappy’s Lane shipwreck. The repurposed World War II landing craft was checked out by the State Historical Office, with plans made to ensure that construction did not impact the barge’s final resting place in any way.
When it came time for day-to-day operations on the new span, Flatiron employed a number of methods to protect the natural area. For example, while a standard piece of equipment at any job site, spill kits could be found with every piece of equipment rather than at a centralized location. That way, if a crane or other piece of machinery happened to spring an oil leak, for example, a boom and absorbent could be deployed immediately to capture it.
Furthermore, each employee took part in an orientation session about all the environmental concerns and what to be watching for with wildlife. Flatiron works with Three Oaks Engineering out of Durham to help with the permitting process, with Three Oaks condensing the endless stream of documents into something more manageable for the several hundred workers involved throughout the project.
“This is a very high-profile project, so the guys know that this is something we have to take seriously,” Price says. “They found a dead pelican next to the job one day. That’s the biggest thing we’ve had our guys call about.”
Taking such measures is seriously essential.
“Making them aware of environmental conditions, that’s always a challenge, and it doesn’t matter who the contractor is,” Hernandez says. “They all have different struggles with that learning curve, and we eventually get there. The fact that Flatiron brought in many people who had worked in many other environmentally sensitive areas was a bonus. They understand where the department’s passion is coming from.”
Perhaps the most significant effort to minimize the construction project’s footprint involved the rail system designed to build the two-and-a-half-mile span.
Typically, barges are used to build over the water, but that wasn’t an option in the shallow sound. The next best bet is to create a temporary work bridge to hold all the equipment, but that also didn’t work in this case because of the length of the bridge and the size of the 54-inch diameter concrete pilings.
Instead, rail systems of 1,600 feet on each side of the bridge – only 3,200 feet of a temporary structure rather than some 13,000 feet – were built on 24-inch diameter steel piles. Each temporary section was in place about three months before the rail crane and car would remove everything from the back and bring it forward for the next construction phase: a fun game of leapfrog.
“When we remove those after a few months, stuff will grow back in, so we have a very minimal environmental impact, which is different than some other systems,” Price explains of the smaller, temporary piles.
Details like this make building on the coast incredibly challenging. As Hernandez put it, a five-mile road project near Rocky Mount might have “a dozen areas the size of a basketball court that are environmentally sensitive.” OBX projects, on the other hand, might have just a handful of spots that aren’t sensitive.
“There are lots of little and major things that are done, and a lot of things that go unnoticed by the general public to address the concerns those stakeholders may have,” Hernandez adds.
The bridge was supposed to be finished by May of 2021, but delays in permitting pushed the start date back by nearly a year. There were also construction delays related to environmental impacts, most notably when the massive pilings supporting the new structure weren’t going in as planned.
The initial plan was to “jet” the 54-inch diameter pilings into the surface of the sound, similar to how home builders do it on land – using a high-pressure air/water mix to move the sand out of the way and let the pile drive in. That method, however, sends dirt and sand everywhere, even outside the turbidity curtain that was supposed to contain it.
Since that silt would settle over the SAV and potentially impact that special seaweed, Flatiron had to pause and figure out a new way of getting those massive pilings in.
“Instead of jetting, we drive the piles in, but eventually the ground got to be too hard,” Price explains. “Now what we do is we drive the pile into the ground a little bit, and then we drill out the center and drill out all the sand that’s in the center, because it’ll plug, and then we can drive it the rest of the way, which is pretty innovative. No one’s really done that before, but we had to figure out a way to get the piles down.”
There’s certainly plenty to be proud of as Price looks out across the new bridge. The fact he’s been involved from the design phase in 2016 through four years of building is rare in the construction industry. It won’t be long before he and his family head back to Flatiron’s main office in the Triangle.
Soon, there will be other projects to design and build, other challenges to address and overcome. But the Rodanthe jug handle bridge will always be a special project, both for what it did for the OBX – and what it didn’t do.
“Everyone wants to know when it’s going to be done, how we’re building it. They just want to understand – they like to understand what’s happening in their own backyard,” Price says of questions he always got from locals. “There’s just something about the Outer Banks. The people that live out here, they take pride in what they have.”