The Florida Everglades is a mysterious place. Gold-tinged sunsets are a background for a land decorated in sawgrass prairies and mangrove and cypress swamps. Home to roseate spoonbills and great blue herons, the Everglades is the only place in the world where alligators and crocodiles exist side by side.
San Francisco-based URS Corporation is rebuilding nature in the Everglades that had been turned into farmland on one of the nation’s most precious wildlife reserves.
The United States Army Corp of Engineers, Jacksonville District, awarded URS Corporation a contract for the construction of a segment of a storm water treatment area outside the village of Wellington, FL. This storm water treatment area encompasses approximately 10 sq. mi. (25.8 sq km) and is located just northeast of the Loxahatchee National Wildlife Refuge. The multi-phase project involves site clearing, cell grading, and the construction of a canal, levee and water control structures.
The scope of the project, the largest ecosystem restoration project in Florida’s history, is so complex that it has been broken up into three phases and will take more than six years to complete. The reconstructed wetlands will use biological processes, which create a treatment area for storm water runoff, to reduce the level of phosphorous entering the Everglades. The result is cleaner water and a greater ability to preserve the many natural resources in the area.
“URS Corporation is part of an ongoing effort to restore the Florida Everglades tributary system,” said Sam Freeman, assistant superintendent of URS. “As an integral part of the process, we conducted environmental audits and developed storm water treatment strategies to reduce the impacts from agricultural runoffs.”
The Everglades began deteriorating many years ago when the swamp area was drained and canalled for farming, resulting in devastating consequences. “Basically the area was converted to farmland for orange groves, sugar cane and sod,” Freeman said. “The swamp was drained and the natural habitat that once existed was damaged. Now its our job to help rebuild it.”
Working on a site like the Everglades presented many challenges for URS Corporation, because the land is a mix of sand, mud and rock. “There are people dedicated to monitoring equipment emissions as well as the discharge of water into the Everglades,” said Freeman. South Florida Water Management monitors its canal so that no dirty water enters it.
Wildlife in the Everglades area also is a large concern for workers. It is critical that all wildlife must be strictly protected. “A person must closely monitor the working area for wildlife,” Freeman continued. “The box tortoise, indigo snakes and even manatee are closely protected in this area. If anyone spots a certain kind of wildlife, work has to stop immediately until the situation can be assessed.”
With the environmental concerns factored in, much of the project still involved moving dirt. “Basically we are loading material out of the borrowed canal, which is 100 feet wide at the top, 40 feet long and 10 feet deep,” said Freeman. “Then we are using that material to build a levee. And off of that levee, every 500 feet, a pad is being built. And those pads are for where power line equipment is being transferred over.”
The combination of sand, mud, rock and an unusually wet rainy season were cause for more than enough sleepless nights for Freeman and the rest of the crew involved with the restoration. “One major obstacle on this project has been the soft working conditions due to the rain,” Freeman said.
During one three-week stretch, they were only able to haul dirt on four days. And if it’s not the rain, then the thick sand in the area also can cause headaches, according to Freeman. “In the drop areas, we have thick sand everywhere,” Freeman said. “And in some instances we are running equipment on excavated rock. Basically, we faced many different materials and working conditions on this project. Alone they were not unusual to us, but having them all on the same job was. So we had to have equipment that worked in anything and at any time.”
The work schedule of the restoration required 10-hour days, six days a week with 40 equipment operators on the job. Those operators ran a variety of excavators, crawler dozers and haul trucks to move the various materials where they needed to go.
Among the machines URS operators ran were four new 444-hp Komatsu HM400-1 articulated haul trucks that when paired with a variety of machines, made easy work of the sometimes-messy conditions. “We are hauling a lot of muck and these trucks have to run through it. It’s a wet heavy organic material,” said Freeman.
Load counts are extremely important to URS’ success and with quick cycle times URS was able to keep its load counts high. Part of that, according to Freeman, comes from the trucks’ ability to get out of any situation they were subjected to on the project. “The rainfall we saw on this site was unbelievable,” Freeman noted. “It seemed like it was raining for weeks at a time but during any break in that pattern, we got the trucks rolling.”
At the Everglades site the longest haul for the HM400-1’s was approximately 1,000 ft. (304.8 m). “Primarily, we are loading the trucks with excavators outfitted with four-and-a-quarter cubic-yard buckets. On this project we are loading the HM400-1 in about one minute 40 seconds and the total cycle time from start to finish was about eight minutes.”
URS Corporation’s completion of the project is scheduled for August 2003, which is, despite the poor weather, right on time. The second and third phases of the project are not yet under way.