This would not have been my choice as a berm for quarry spalls; straw wattles are too light to use on asphalt and they allow water to flow under them. A compost sock, being heavy, would work better, though, they are prone to tearing. An asphalt berm might be best here.
The bulk of the work will take place to the right of the silt fence. The grass will be removed and the area re-graded. The grass to the right of the construction fence will remain undisturbed. Some work will occur on the taxiway to the left of the tractor. Rather than use silt fence in this low risk area, compost berm will suffice. When done, the construction fence and stakes will be removed and re-used elsewhere and the compost will be spread out on the grass.
Cold mix asphalt berm works too. Used along the base of “jersey” barriers, high pH water from a concrete breaking operation is contained for later disposal off site.
Extruded asphalt berm at project entrance with center section “rolled” to allow trucks to enter and exit.
Another example of an extruded asphalt berm used to keep off site water from entering the work area.
We use extruded asphalt berms extensively to contain and direct site water to grass infield areas and to keep clean offsite water from entering the project. When the project is completed, the asphalt is removed and hauled to a batch plant for recycle.
The work area is the left. All runoff is diverted by silt fence and this hot mix asphalt berm to a sump, where it is pumped to a chitosan-enhanced sand filtration treatment system. This system prevented all turbid site water from entering the roadside ditch-outside of the silt fence-from draining to a creek. Note the mud on the left side of the berm and the clean asphalt on the right.
Since this is summer work and perimeter BMPs are containing all site runoff, we are not covering bare soil.
Upon completion and soil stabilization, the asphalt berm will be removed and hauled to an asphalt batch plant for recycle.
Whenever I see something like this, it makes me think that the site owner/contractor either didn’t know what they were doing or bit off more project than they could chew, or both. These guys cleared, grubbed and graded something over 80 acres starting in late summer, failed to phase the work, failed to use soil cover practices, failed to listen to the experts and got nailed by the fall rains.
Erosion control is really about water control: reducing volume, preventing it from becoming turbid, and controlling where it goes. By the time the rains hit this project, there was too much water, it was too dirty, and there were too few options for controlling where it went.
In addition, they refused to set up a chitosan-enhanced sand filtration system to treat and discharge water; this left them no options and too much turbid water that had nowhere to go. As a result, they hammered a wetland, were fined heavily, and were shut down for months.
Silt fences are not meant to control water, convey water, filter water; they are designed to control eroded sediment. Ditches, berms (rock, gravel, triangular silt dikes, etc.) would have been better choices at this location. Not opening up so much area so late in the season would have been the best option. Their means and methods did not save them time or money.
I was just minding my own business last Friday, driving from Fred Meyer to the UPS store and passed this project. I told my wife I have to get a photo; she says okay since she knows me and my habit of stopping to take TESC photos.
I made a u -turn at the Wal Mart, drove back a block and stopped in the middle of the street to get this shot.
There is so much wrong here, where do I start? Clearly, dirt is tracked off of the project in the background, as you can see the sediment build up in the curb line. Someone told someone to put something in the swale to keep dirt out, then someone else installed this silt fence.
First off, silt fence needs to be trenched in and this just has a few rocks placed on the flap.
Second, they probably couldn’t trench this in anyway without tearing up the drainage swale.
Third, only two of the three curb cuts are backed by the silt fence.
Fourth, silt fence is a barrier, not a filter, and with the volume of water draining off the asphalt during a rain event, dirty water would just blow around and under the silt fence.
Conclusion, silt fence is never used in a water flow situation; it is only to contain eroded sediment from a sloped area. A better BMP here is a compost berm or something similar that would allow some water to pass but filter some sediment. Sand bags would work to keep everything out of the swale but then the dirty water would bypass to the next catch basin, which probably has a catch basin insert, which would collect sand and such but would not do anything for turbidity. So, what is the best BMP? Stop the !@#$ ing trackout in the first place!
This eroded stockpile is well within the project boundaries and there is nothing leaving the project. I consider this a problem for the contractor, not for water quality compliance. By allowing this to occur, the contractor has made the eroded stockpile soil unsuitable for use in embankment fill and has to haul it offsite at their expense. This could have been avoided by berming the top of the stockpile to direct water to pipe slope drain pipe that prevents water from flowing over the side of the fill.
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