I call these infiltration berms. They aren’t berms like the others in this presentation but they function the same way-they contain water, divert water, or both.
The first two photos show created berms and the last is a utility trench that has not been paved yet. The first two were installed to contain the dirty runoff from muddy shoreline rip rap that we had to remove to install piling.
The berm surrounds about two acres of paved surface. The asphalt was removed to expose the subgrade to allow runoff to infiltrate. These can be designed but we didn’t have time.
To do this correctly, you should figure out how much runoff you will have, how much storage volume to create (this determines how long and how wide the trench is) and the actual infiltration rate of the subgrade.
The last photo shows how you can use your site to your advantage.
Presentation: David Jenkins-Sheetflow Erosion ControlPresentation: David Jenkins-Sheetflow Erosion ControlPresentation: David Jenkins-Sheetflow Erosion Control
Such a large containment for such a small container. Let’s see, one quart is 32 ounces. The containment needs to hold 110% of the largest container. So, the containment for a quart of oil needs to contain 32 plus 10%, or 3.2 ounces, which equals 35.2 ounces total containment. I think a small trash can would be big enough.
Comments Off on Large Containment, Small Container
I can’t get away from it. It doesn’t matter where I go, I always see some type of construction erosion issue. I went to visit relatives in Portland, Maine, flying in and out of Boston Logan International. In the terminal, waiting for my flight back home, I saw a construction project on the ramp; it had rained a few says before, hard. Obviously, the stockpile had not been covered before the storm and sediment washed off the pile into the drain.
I work at an airport that operates under strict turbidity
effluent limits; here is how we do this kind of work:
(1) rarely do we allow stockpiles on the ramp because we rarely
reuse the excavated material (it is either contaminated, unsuitable or doesn’t
meet current FAA requirements); it is direct loaded into trucks and hauled off.
When we do stockpile, we place dirt on plastic and cover it with plastic, using
lots of sand bags to secure it from jet blast and wind.
(2) work areas are always isolated so there is no runoff from
the site. Normally, we use four-inch extruded asphalt curbing along the base of
the jersey barriers. Rolled hot mix asphalt (HMA) is used at the entrance point
so water is contained but vehicles can access the site. Water that builds up inside the curbing is
pumped back into the excavation if clean, or a tank if contaminated.
I should have
mentioned that we also have strict sediment trackout requirements: no visible
sediment leaves the site at any time.
This is both because of the effluent limits and for safety reasons; dirt
and debris that gets sucked up into a jet engine is damaging and possibly
deadly.
Lastly, I am
not casting aspersions on the folks at Logan; I don’t know their situation,
permits, drainage system, or tolerance for risk. Because of my situation, I have low risk tolerance
for potential non-compliance with our permit and I notice when something would
cause me grief at my airport.
