Chicago-area contractor moves 1.5 million yards of soil to merge wetlands and retail space.
Many people harbor the misconception that all development projects are alike—that is, simply level it, clear it, and build it. For those who do, a look at the area that will soon be home to the North Aurora Town Centre should convince them otherwise. The 330-acre site contains 100 acres of wetlands that have to be relocated before construction can begin. However, doing so in accordance with environmental mandates set forth by the US Army Corps of Engineers has proven to be one of the most challenging—but rewarding—aspects of any project undertaken by Rubloff Excavation LLC.Unique Development
Located about 45 miles west of Chicago on Interstate 88, North Aurora is the next logical extension of a metropolitan area that continues to expand outward in every possible direction. As people relocate, sites like the North Aurora Town Centre with its nearly 600,000 square feet of available retail space will provide for their needs. According to Bob Marsh, president of Rubloff Excavation, the firm charged with making the site construction ready, getting to that point has been anything but routine.
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PHOTO: TEREX |
| One of 14 Terex trucks at the North Aurora site |
“Not only is this the largest excavation project we have ever undertaken; it has also been the most complex, because of the 100 acres of core wetlands that have to be created. And it has to be created in a planned, sequential order which will ensure the least possible amount of environmental impact, with regular inspections by Army Corps, Soil and Water, and conservation officials along the way.”
The need to create the wetlands area stems from past construction of an auto mall located adjacent to the site. That location was initially designed to retain an area as wetlands. By the time it was completed, however, the wetlands concept had become little more than a pond. Marsh says when Rubloff Development Group negotiated to buy the property, a clause in the agreement said that, in exchange for relocating the streams that ran through the center of the property, the firm would create 100 acres of new viable wetlands.
Slow Beginnings
It’s hard to say if any contractor is really equipped to tackle a project with the constraints and demands present at the North Aurora site, but Rubloff’s resources and willingness to work with the Corps of Engineers kept the project moving along, even during some taxing early periods.
“The early part of the project was held up for about two-and-a-half months, again mostly due to sequencing constraints. With the right equipment on a job like this, we can easily move 1.5 million yards of dirt in 30 to 60 days; having the entire site available to you makes that possible. But this is not like any other job. Here we had to first dig diversion channels, stabilize them, plant them, and then reroute the creeks onsite.”
With that done, Marsh says they created a number of wetlands areas, mindful of strict adherence to elevation, outfall elevations, and so on, to maintain appropriate water levels. Different plant communities have been designed into each of the levels of wetland elevation. A 40-acre basin, for example, might have five different plant communities designed into it. Sculpted mounds can have 6 inches of water covering one part, and then be tapered down and terraced to a depth of 1 foot, then 18 inches, and then back up to just damp and again to dry, with a different plant species and community on each of those levels.
“We even had to put dead trees into several areas, making us one of the few projects with line items in their budgets to buy dead trees to be strategically placed in the bottoms of ponds.”
Bringing in the Iron
To handle issues related to wetland plantings and the like, Rubloff hired a wetland consultant and a landscaping firm, both of whom specialize in that area. To do the actual earthmoving and development, the company called upon its own strengths: an impressive fleet of Terex equipment, utilizing everything from an HR-18 mini excavator to a TXC-470 excavator and almost everything in between.
“We are fortunate in that we are in the process of becoming the Terex dealer for this part of the state. But that move, in itself, stems from the fact that we were a huge user of Terex equipment before deciding on a dealership position. When we first got into the excavation business, we had a tendency to purchase the least expensive equipment—mostly older machines sorely in need of repair. We quickly learned that it made far more sense to buy good equipment, make sure it is well maintained, trade it out on a regular basis to upgrade, and so on.”
Marsh says that while there is a certain amount of blind loyalty among many equipment users, such is really not the case with Rubloff. “For us it is simply a cost/benefit study. If I can buy Terex, factor in the operating costs—including fuel, upkeep, repair, et cetera—and move a yard of dirt from Point A to Point B less expensively than a competitive piece of equipment, I will request Terex forever. And that has been the case. We’ve found that our Terex fleet is not only productive; it is a good value-added investment for us.”
Removing the Spoils
Rubloff got to utilize the largest piece of equipment in its fleet—the TXC-470—in the early stages of the project when a berm left over from the auto mall’s construction had to be removed.
“This mound was probably in excess of 200,000 yards of dirt that had to be hauled out before work could proceed on that area,” says Steve Full, Rubloff’s project superintendent. “We had a steady stream of 18-yard TA-40 haul trucks being fed by the 470 with a 4.5-yard bucket, and they were staging and leaving every minute or so. The 470 really set the pace; it had that berm down, and the dirt redistributed to low areas throughout the site, in no time.”
Marsh says they initially mobilized more equipment than was necessary during the early stages of the project, but he knew that once the creek diversion channels were cut, stabilized, and inspected, things would open up.
“Once we got to that point, it opened up nearly two-thirds of the site for us,” he says. “Things were also complicated by the wide range of material we’ve encountered—everything from a gumbo-like clay to sand and cobbles—and the area’s high water. So creating several basins onsite, some of which have 200,00 to 300,000 yards of fill excavated and used to build beds in areas in the creek bottom, took a wide variety of equipment based on what layer of soil we were in. Tractors pulling Ashland scraper pans worked great in the topsoil and in the clay where it was dry. However, as soon as they got into the sand and wetter material, they bogged down and we had to switch to the Terex 14G scrapers. We ran those until we got to a point where traction became impossible, and then set the TXC-470 out there feeding the 40-ton off-road trucks.”
Additional Benefits
Rubloff has 14 trucks committed to the North Aurora project. Should they still need additional capacity, however, or if haul distances get too long, they are prepared to top-load the scraper pans and the 14G scrapers for additional volume.
“Again, that’s all a byproduct of the sequential approach,” says Marsh. “We can’t always take the fill from one basin and move it to the closest area in need of fill. It may be that we are not allowed to fill in that area until another step in the sequence has occurred. So we take it elsewhere. Of course there is always the possibility that we will then have to bring it back at a later point in the sequencing, but that’s just something we’ve learned to deal with.”
As challenging as the project has been, Marsh is quick to add that it has also proven beneficial from a number of standpoints. “A project like this tends to scare some contractors,” he says. “During the course of the job, we monitored the design, did the entire permitting process, handled the budgeting, and did all the earthmoving, site utilities, and wetlands before turning it over for construction to begin. So it really has been a turnkey full-service operation, and that, coupled with the equipment we can bring to bear, allows us to compete in areas in which many others simply aren’t equipped to operate. The development arm of our company has projects ready to go throughout Illinois and elsewhere in the country; North Aurora has us better prepared for anything those projects have to offer.”