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Neal Bolton
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By
Neal Bolton
In an ideal
world, landfill managers would have plenty of time and
money to prepare for the wet season. But of course it
doesn't always work that way. Things happen, schedules
slide, and before you know it, the rain is falling
and your erosion control plans never got off the drafting
table.
Obviously
it's best to prepare your erosion control systems
before it rains. It's cheaper too. But if the wet
season catches you unprepared, don't just throw
in the towel. Even after the rain starts, it might be
possible to implement some reasonably effective erosion
control measures, but you will have to change your strategy.
Instead of fitting it into the summer's work schedule,
you'll have to squeeze in projects between storms.
Also, if the soil is saturated or unstable, your options
for moving dirt might be limited. In that case, your
effort might be related to manual labor.
Let's
look at some of the available options for the rainy
season.
Tractor
Work
Immediately
after the first rain can be a great time to move dirtgreat,
that is, as long as the soil did not become saturated.
If it didn't, there will be less dust. The soil might
be compacted more easily. And then there's the big benefit:
After that first big rain, you'll know where the ponding
problems are!
When it comes
to working during the wet season, the first rule is:
Don't make things worse. If you are trying to use
a machine but are succeeding only in making big ruts,
getting stuck, or risking an accident, it's probably
best to do nothing. Your time might be better spent
ordering bales of straw, lining up a low-ground-pressure
dozer, or just waiting for a break in the weather.
For work
that just can't wait, consider bringing in a low-ground-pressure
dozer. "Mudcats," as they're called,
are equipped with extra-wide track grousers for traction
and flotation. Also, depending on the amount of material
to be moved, remember that smaller machines are lighter
andeven if the ground pressure is similar to that
of a large machinesmaller machines are easier
to extricate if there's a chance they will get
stuck.
If the ground
is too wet to drive on, you might consider using an
excavator. Some models are equipped with a very long
boom or stick, which provides tremendous reach and might
be able to "work in the mud while standing on solid
ground." These machines are well suited for cleaning
and constructing ditches or sedimentation basins.
When things
are just too wet and muddy for any machine to work,
you might have to import material and bridge it across
the wet spots. Of course, that material could be stone
or gravel, which can be expensive. Consider using a
few loads of shredded wood or greenwaste instead. This
material will provide a good temporary base across the
muddiest of areas. It also can be used to stabilize
a soil slope. Just spread a few inches on the slope
to help reduce soil erosion. In a pinch, use brush or
tree trimmings.
Where loaders
or motor graders are used in muddy conditions, traction
often is a problem. If that's the case at your
landfill, consider equipping your rubber-tired machines
with snow chains. When ordering snow chains, don't
forget you'll need to chain the "steering"
tires to the "drivers."
Hand Work
Sometimes
it's just too wet to get a machine in a work area. Or
perhaps the problems are too minor to warrant a big
tractor. In those cases, manual labor might be the bestand
onlyoption.
Some of the
most common areas requiring manual labor are soil slopes.
These could be landfill, stockpile, or excavation slopesanywhere
erosion can occur and machines can't easily go
when it's wet.
If the slopes
are short and the erosion is limited to small rills,
simply placing straw or matting on the slope might solve
the problem. If you can't get onto the slope, find
a contractor who does hydroseeding. He should have the
equipment to blow straw or other mulch onto the slope.
If the slopes
are long or there is serious erosion, straw or matting
alone probably won't solve the problem. You'll
have to find a way of getting the water quickly off
the slope. If you can get a dozer or a motor grader
on the site to make a drainage berm or ditch, do it.
If it's too wet for a tractor, get some laborers.
Give each one some sandbags and a shovel or a McCleod
(rake and grubbing tool). These simple hand tools can
be used to quickly construct small drainage ditches
that can control runoff and minimize erosion. Even a
few carefully placed temporary downdrains can help control
runoff and the erosion that goes with it.
Also, don't
overlook the option of seeding the slopes while you're
blowing that straw. Just because it says on a permit
or a plan that you should have seeded the slopes by
a certain calendar date doesn't mean the seeds
won't grow. Germination is based on moisture and
temperature, not a calendar date. If the conditions
are right, the seeds will grow. And even if there isn't
enough time for them to grow to maturity, when it comes
to stabilization, a little root structure is better
than none.
If you find
yourself fighting the rain to control erosion, don't
beat yourself up. Just look around and figure out how
to deal with the problem. Maybe better planning would
have prevented the problem
maybe not. Even the
most proactive landfills can encounter unexpected problems
and leave you working in the mud.
Having a
good erosion control plan is smart. But it is also smart
to know your options if things don't go exactly
as planned. In other words, plan wisely
but keep
your rubber boots handy.
Neal Bolton
is a consultant specializing in landfill operations
and management. He is principal of Blue Ridge Services
in Atascadero, CA.
MSW
- March/April 2003
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