Hoping to pass the muck

The discovery of an unexpected patch of muck during digging has Collier County officials and a contractor scurrying to keep the Golden Gate Parkway overpass project on schedule.

The situation has the potential to cause a late opening for the much-anticipated overpass that is elevating Golden Gate Parkway over Airport-Pulling Road.

A goal to finish the project by the end of this year may not be met if a steel shipment fails to come in on time for a wall that is being built to handle the soft soil conditions.

The county’s schedule shows the steel for that wall arriving in late fall, said Jay Ahmad, the county’s director of transportation engineering.

“If that steel comes as scheduled, we’re good for (the overpass opening) the end of the year, or just shortly after the beginning of the year,” he said. “If it doesn’t come, then we will have issues and delays after that.”

Ahmad remains optimistic that drivers will be traveling the overpass by the end of this year or early next year.

“At this time it is all looking good to open on time, but steel is a commodity,” he said.

On Tuesday, the Collier County Commission approved a change order that adds $2.5 million to the project to deal with the muck problem, which brings the total contract amount to more than $40 million.

Photo by Garrett Hubbard, Daily News // Buy this photo

Melitan Ortiz of MCM Corp. climbs down the unfinished overpass Tuesday at the southeast corner of Airport-Pulling Road and Golden Gate Parkway. Collier County commissioners are being asked to approve an additional $2.5 million to complete the project due to unforeseen difficulties with soil and water.

Based on soil information available at the time of the bid, county officials expected hard subsurface rock to be a potential problem during construction.

But as it turned out, soft soil turned out to be a major issue.

The county’s examination of the site had missed the fact that organic soils and loose silt existed below rock in a canal skirting the overpass site.

Gary R. Putaansuu, the principal project manager, explained in a letter to commissioners that there are several reasons why the soft soil went undetected.

“Borings really only represent the materials at one location. Many natural and manmade obstructions to construction lurk below the ground that will not be picked up by the borings,” he wrote in a letter to commissioners.

He states that one soil boring was taken in the area of muck removal, but for whatever reason, the boring didn’t encounter muck.

“Additional borings should have been added to the project when it was expanded to the west. However, much of the muck removal was done under the existing pavement,” he wrote. “Providing this additional investigation would have required lane closures on Golden Gate Parkway.”

The existing roadway was in good condition and didn’t show signs of settling or pavement breakup that would have tipped staff off that there was muck below, he said.

Taking more boring samples would have consumed too much time.

“Time has always been of the essence on this project,” he wrote, adding that the county’s goal was to finish the overpass project before the Florida Department of Transportation’s new Interstate 75 interchange opens at Golden Gate Parkway.

The interchange is slated to open late spring or early summer of next year.

County officials desperately want the overpass to open before the interchange, which is expected to pour thousands of additional cars on the parkway.

The soft-soil problem has resulted in a need to redesign an overpass “S-wall” and a support for the city of Naples’ main water main that extends alongside Golden Gate Parkway.

The overpass project could be described as one of the most controversial in the county’s history.

The Naples City Council unsuccessfully tried to stop the project, arguing that it violated the city’s comprehensive land-use plan.

And neighboring residents were livid about the fact that the overpass was being built near the entrance to the community. They argued it would be a waste of tax money and simply move traffic faster to other congested city intersections.

But county traffic officials say people will have a much kinder view of the project once they see how well it moves traffic through that crowded intersection.