Filtrexx Siltsoxx proved to be the solution to a compounding problem plaguing my project in late 2014. The issue began as a design problem on a sediment and erosion control plan. About six hundred feet of the western side of the project abutted a wetlands buffer. The buffer was also an overgrown, briar filled thicket. Along this stretch, the designer had the clearing limits, silt fence, and tree protection fence all occupying the same line. In addition, two feet east of that line the plan showed the permanent chain link fence. Directly east of the permanent fence was shown the access road into the project. Finally, immediately east of the road began the construction of the solar array that comprised the project.
Permanent fence installation was scheduled before silt fence and that is what happened. The tight quarters between the permanent fence and the wetlands buffer prevented silt fence installation. Rather than silt fence, we settled for straw wattles along the road side of the fence to provide the wetlands protection. I knew straw wattles were not approved substitutes for silt fence.
With this problem still on my mind, I traveled to Hickory, NC to attend an Erosion and Sediment Control Planning and Design workshop offered by the Water Resources Research Institute (WRRI) of the University of North Carolina. By chance and good luck, I found JR Stewart of Filtrexx International at a workshop display booth. Filtrexx has a wide variety of interesting and innovative products but his explanation of the SiltSoxx product hit home. I knew SiltSoxx was the solution to my existing problem. I knew SiltSoxx also had great potential for new work, repair, and maintenance at other projects.
Some Filtrexx Siltsoxx Specifications
The SiltSoxx flyer describes the product as the only compost filter sock approved by US EPA, USDA NRCS, AASHTO and state agencies.
SiltSoxx stops pollutants in two ways: 1. Deposition-sediment settles out as water ponds behind the barrier and 2. Filtration-sediment is trapped as water passes through the barrier.
SiltSoxx comes in a variety of diameters. None of them are light. I have seen 5”, 8” and 12” delivered on pallets. Larger sizes are filled on site with a blower truck.
How we used Filtrexx Siltsoxx
Over the next couple of years, we used the 8” product extensively as designed for perimeter protection and slope interruption but we also found the product to be the “duct tape” of sediment and erosion control maintenance and repair. Although heavy, the product is lighter than a comparable volume of stone. It also requires lighter equipment in order to deploy to the field.
We used the product to repair silt fence and stone silt fence outlets. Silt fence undermining repair is as easy as it gets with SiltSoxx. Silt fence “knock down” is also a problem. Wind, deadfalls, ultraviolet degradation, equipment operators, wild and domestic animals can all render sections of silt fence ineffective. Silt fence installers are often long gone before silt fence damage occurs. Access to the damage is often difficult. Willingness to remobilize trenching manpower and equipment is often lacking. As a result, I found it much easier to get someone to put a length of SiltSoxx in a cart, drive it to the repair and stake in place.
Access to silt fence outlets can also be difficult. A truckload of #57 stone delivered to repair an outlet or two is cost ineffective. Storage of the balance of the stone can also be a problem depending on the job layout and schedule. Clearing fouled #57 outlets is an unpleasant chore. The availability of repair labor and equipment is another problem. Problem outlets are usually those at the lowest elevations of a project creating access problems for larger and heavier equipment. Filtrexx SiltSoxx stacked on top of the fouled or buried stone is usually an effective fix.
We stacked 8’ or 12” product to repair or replace outlets. If these repair outlets fouled it was easy enough to cut the mesh and scatter compost before installing fresh SiltSoxx.
Other Filtrexx Siltsoxx Uses
We used SiltSoxx to repair or replace stone check dams in diversion ditches. Easier and more cost effective resulted compared to rebuilding with stone.
Misplaced or improperly graded diversion ditches could often be salvaged by installing SiltSoxx. Bank elevations were raised along areas subject to spill with various sizes of Siltsoxx or by stacking product.
We used the compost filter sock to protect curb and yard inlets.
Erosion repairs often required the installation of SiltSoxx as slope interruption to slow and control runoff. I found that using the product to fill rills and ruts of similar size was a good fix. Filling these erosions prevented further damage to existing slopes. Note that erosion is progressive. Deeper and wider rills erode faster as they grow larger. Eventually, vegetation grew over these repairs.
Siltsoxx demolishes easier than silt fence. Ease of demolition is an advantage to consider. Photodegradable or biodegradable mesh cover the Siltsoxx compostable material. Hence, this product may not need demolition at all. The other option is to cut the mesh from the product and leave the compost in place. Removing the wooden stakes used to anchor the product is far easier than removing metal silt fence posts. One caution, fire ants will nest in this product as well as in wattles. Beware.