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Ground Control
Erosion prevention is a major issue for all attractions
by Dan Rafter
THE VIRGINIA AQUARIUM & MARINE SCIENCE CENTER in Virginia Beach will open its $25 million Restless Planet expansion in late 2009, offering four new habitats and 110,000 gallons of new aquariums. But one thing the expansion’s visitors won’t notice is the erosion-control work that took place behind the scenes.
All amusement parks, aquariums, zoos, and family entertainment centers have to be aware of erosion when undertaking large-scale expansions. When soil erodes during construction work, it can work its way into nearby streams and waterways, polluting the water.
The fines for this, spelled out under the United States government’s National Pollutant Discharge Elimination System— better known as the NPDES—can be steep. That’s why construction plans for any expansion include several steps to control on-site soil erosion.
“Our building juts over a creek,” says Maylon White, director of exhibits and animal husbandry at the Virginia Aquarium & Marine Science Center. “So it was important that we not have any soil getting into the creek. We needed to do whatever we could to keep the soil from leaving the site.”
Good for the Pocketbook
Limiting erosion is good for the environment, but it’s also good for a facility’s bottom line: Federal government fines for not controlling erosion can eat into a company’s profits for the year. At the same time, amusement attractions are extremely visible to the public; any bad publicity parks get for receiving federal fines can ultimately hurt attendance and a facility’s revenue numbers.
For Ellen Crane Mullen, owner of Crane Environmental Services in Evansville, Indiana, this attention to erosion-control measures is no surprise. Her company regularly performs engineering work for Holiday World in Santa Claus, Indiana, drafting plans to keep soil from leaving construction sites during expansion projects.
“Holiday World is such a high-profile business in the area that all eyes, including the regulators, look to them to be a leader in erosion control,” Mullen says. “They have their personnel trained to conduct regular inspections of temporary and permanent erosion-control measures, and to be able to spot trouble areas.”
Very Big Tanks
At the Virginia Aquarium, engineers faced a significant challenge when it came to erosion control: The Restless Planet project called for construction crews to punch a hole in the building’s floor. Once crews did that, they could look straight through the hole and down into the creek below the building. It would have been easy for soil to erode and fall into the creek, a serious violation of government regulations.
 Punching through the floor, though, was a necessary step. At 1 million pounds, the 110,000 gallons of aquariums in the Restless Planet exhibit would have been too heavy for the existing floor. To keep any soil from getting into the creek, which eventually leads to the Atlantic Ocean through the Rudee Inlet, construction crews erected an underwater silt fence. White says the structure, kept in place for about a year, was similar to what engineers devised to contain water-based oil spills: “The fence was like a curtain, basically.”
This extensive project was followed by additional invasive measures, including installing sediment traps and the removal of rocks and other material to ensure new pilings could support the large tanks.
Good for the Earth
“It’s important for us to be protective of our surroundings,” White says. “Part of our mission here is to be good stewards of the environment. Controlling erosion and keeping soil from washing off our construction site is all part of that.”
Chris Marr agrees. He’s the owner of ESI Resource Services in Rancho Cordova, California, a company that specializes in erosion issues. The California Exposition and State Fair in Sacramento recently hired ESI to prepare a soil-containment plan for the event’s horse-racing track. When trainers washed the mud and dirt off the horses at the track, it consistently ran into the track’s drainage system. The exposition faced significant fines if its officials didn’t fix the problem.
State fair authorities were looking for someone to redesign the track’s entryway so it would include some mechanism to contain the sediment from the horses or tracked by the animal’s hooves as they entered and left the track. Marr eventually recommended a high-draining sand entrance whereby the racetrack’s entryway would feature a large screen with a catch basin under it, six inches below a layer of sand. This would hide the screen from public view, but when trainers would wash dirt from the horses, it would travel through the sand-based mixture, into the catch basin, and eventually through a meadow that would filter out sediment.
Before Opening Day
Holiday World will open its newest attraction, the “Wildebeest” water coaster, on opening day, May 14, 2010. The coaster is no small attraction: At one-third of a mile, it will rank as the longest water coaster in existence.
Mike Kamp, general manager at Holiday World, oversees all new construction projects and says he and his coworkers began working with Crane Environmental Services a full year and a half before the ride’s scheduled opening. Before the first bit of earth is moved on any construction project, park officials need to determine whether their construction plans will impact any nearby waterways or wetlands.
“We place a great emphasis on erosion control and other environmental issues whenever we take on a construction project,” says Kamp. “We’ve developed a good rapport with the local agencies. That way, if we do come up with a problem, we can resolve it in an expeditious manner and to the satisfaction of everyone.”
Before beginning actual construction work, the engineers from Crane Environmental Services will prepare a construction plan. Holiday World, though, takes pains to keep its new attractions as secret as possible, even from the engineers at Crane. For instance, when Crane engineers began working on their construction plan for “Wildebeest,” they only knew that they were working on a project that Holiday World was simply calling “2010 new attraction.”
Holiday World officials then review the firm’s recommendations. “We’ll look over what we need,” Kamp says. “We’ll study the area that will be disturbed. We’ll look over the project site layout, the soils report, the permits that are required, and the type of erosioncontrol measures the engineers are recommending. Do they want silt fences, rock dams, vegetative filter strips, sediment barriers? There are many ways to halt erosion.”
Mullen says Holiday World is innovative in its erosion-control efforts with “Wildebeest.” For instance, the it is being constructed on grade; the coaster’s path will require chopping down the smallest number of trees possible and the slope itself will be disturbed as little as possible, Mullen says. Also, any trees removed will be chipped into mulch and used for a permanent erosion-control feature.
Dan Rafter is a journalist with 15 years’ experience. He has written for the Washington Post, the Chicago Tribune, Business- Week Online, Phoenix Magazine, and several trade magazines. He can be reached at danrafter@sbcglobal.net.
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