A silt fence installer is a machine that can automatically install silt fences by trenching the earth and inserting the silt fence in one motion. Silt fences are often used to control sediment runoff from construction sites or other areas where large volumes of earth are disturbed. They are typically installed uphill from potentially vulnerable streams or other ecosystems that could be damaged by a large influx of silt. These fences were traditionally installed by digging a trench, staking the fence material, and then backfilling it. After installation, the fence material can then be staked by hand as necessary.
Typical silt fence installers are motorized and consist, at a minimum, of a cutting or digging device and a spool capable of dispensing fence material. In certain configurations, the cutting wheel will dig a trench in the dirt and press the fence material into the channel at the same time. As the silt fence installer moves forward, more fence material is released from the spool device and is subsequently pressed into the channel. This can create a significant time savings over manual installation, especially when large stretches of silt fence are required in big construction projects.
Whether installed in a traditional method or with a silt fence installer, a sediment barrier can be an important part of any site management plan. The material that silt fences are typically made of can allow water to pass through freely and also restricts sediment of a particular grain size. This captured sediment can then be trapped in the trench, preventing it from contaminating nearby streams, lakes, or other bodies of water.
Especially silty soil can make a silt fence installer all the more important. Certain sites can contain a large amount of rock flour or stone dust, which may be potential water contaminants. Rock flour is a type of soil that consists of tiny particles of bedrock that were ground away by previous glacial motion. If these sediment sized particles are allowed to wash away into a body of water, they can be held in a suspension and turn the water an opaque, milky color.
Since construction activities can disturb large volumes of earth, they may result in rock flour and other sediments entering water runoff. Silt fences typically aren't designed to channel storm water in any way, as they are meant primarily to capture sediment. The design and placement of silt fences is usually determined ahead of time and the fence will be installed before the ground is disturbed in ways other than to cut or dig the necessary trenches.