Inspecting Soil stockpiles: they need to be covered when not being used. This helps both with keeping the soil dry in the case of reusing it for backfill and with preventing rain from washing soil into the storm drainage system.
In addition, fugitive dust is prevented from blowing off of the stockpile in windy areas. If the stockpile is to remain in place for longer than a few weeks, black plastic, (at least 6 mil thickness) should be used, as the black plastic is UV (ultraviolet light) stabilized and won’t break down as quickly in sunlight as will clear plastic, which is not UV stabilized.
The plastic needs to completely cover the soil. If soil is exposed at the base of the pile, clean rainwater will run off of the plastic and into the exposed soil causing erosion of the soil and will generate dirty water runoff that can flow into the storm drainage system. In order to keep the plastic in place and prevent it from blowing off in the wind, plenty of sandbags or some other heavy material needs to be used to hold it in place.
As with the plastic itself, sandbag fabric should be UV stabilized if they will be in place for longer than about a month. White sandbags will deteriorate fairly quickly in strong sunlight.
When inspecting plastic cover, make sure sheets are overlapped and secured from blowing wind. Also, collect the clean runoff and direct it away from bare soil so it doesn’t get dirty.
I told the contractor and the contract specifies that all chemicals and gas-powered tools remain in secondary containment when not in use. So, either they aren’t telling all of the workers and sub-contractors, they aren’t inspecting their site, or maybe they don’t care.
Catch Basin Open to the Rain – When inspecting a project, I always look closely at the storm drain system to verify whether any dirty water from the project will drain to an active system. In this example, the catch basin has been installed but the main line it is connected to is not active.
Inspecting a project during a rainstorm is sometimes the best way to determine how storm water will flow around the site. It was clear, during this inspection, that the flat area above the slope was graded toward the slope face , which allowed water to flow over and down the slope, causing it to erode. If it was not possible to grade the area above away from the slope, a sand bag berm and a pipe slope drain could have been used to collect the water and convey it to the base of the slope.
Video: David Jenkins
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