- Buyer's guide
Erosion Control Increasingly Important For Utility Construction
Oklahoma Erosion Control, Stillwater, OK, is a specialty contracting firm established in 2006 when owner Raygn Alexander recognized a niche market that wasn’t being adequately filled. The company installs silt fences and offers a service contract to maintain them during the course of a project.
“Equipment to install silt fences is highly specialized and not something a general contractor routinely has,” says Alexander. “For many general contractors, it makes sense to sub the silt fencing. And when a contractor has a big project far away from its home base, having the fence contractor maintain the fence may be the easier and most economical way to be sure fencing is in good repair for the life of the project.”
Hard to maintain
Maintenance of a silt fence is a problem that is obvious to even casual observers. Stakes and geotextile fabric laying on the ground, torn or loose fabric, gaps between the bottom of the fence material and ground make it evident the fence is not performing its intended function. Often the reason for failure can be attributed directly to improper fence installation.
The key to proper fence installation is securing the geotextile fencing material securely in the ground. There are two basic methods for doing that: trenching and static plowing or “slicing.” Recently vibratory plow silt fence attachments offer a third option.
Trenching is labor intensive and fabric not properly placed in the ground can result in failure of the fence, and it is rarely used for large fencing projects. Since the mid ’90s, slicing has been the primary method of installing silt fence fabric.
“We’ve never put in a fence by trenching,” says Alexander. “It’s too slow and costly with potential problems from failing to get fabric properly secured in the ground.”
Until recently, Oklahoma Erosion Control used a McCormick silt fence plow attachment pulled by a tractor. The attachment accommodates 3,000 foot rolls of 36-inch fence fabric and has a special blade with a chute through which the fabric passes. The blade is designed to keep fabric tight during burial in order to provide a fence without sags. An installation is made by lowering the blade/plow into the ground and moving the host vehicle forward with the plow attachment.
Fabric is placed into the ground to a depth of about 10 inches, leaving sufficient fabric for a 26-inch fence when fabric is attached to stakes, Alexander says. Wire mesh fencing also can be installed by the slicing process for projects that specify stronger fences because of fence length or stricter regulations.