Reclaiming Snow Hill

Reclaiming Snow Hill

♪ Music ♪ The priorities of this project, um, were to
address two coarse coal refuse piles on either side of Coal Creek. That had been placed here in 20s and 30s,
some into the 40s, along the side of the creek. And we had hired ATC Group Services over the
past several years to do surface water and ground water studies. And we determined there was quite a bit of
surface water infiltration through the piles as well as ground water infiltration which
then made its way into Coal Creek. And created an acid loading in Coal Creek
on its way to the Wabash River which is not very far downstream from here. There was a couple of structures left from
the mine that we hadn’t anticipated. One looked like a foundation from a shaft
and maybe a tunnel for transport of coal. At Kerns Excavating we use all the latest
machine controlled Topcon GPS technology that’s available. All of our grading equipment has machine controlled
GPS that allows us to hit all the elevations that are designed in the project. And with this project there’s a lot of critical
elevation points. The amount of cover, the amount of elevation
change and design elevations ditches are all very critical. So, having that technology in that GPS machine
control really allows our operators to make sure that they’re hitting the correct elevations
the first time. So, after many considerations of how to deal
with the surface and ground water flow through the piles. We considered possibly picking up the piles
and moving them elsewhere up away from the creek to limit the water moving through the
piles. That was quite cost prohibitive so in consultation
with ATC Group Services a decision was made on the design to place a geomembrane liner
over the top and limit the surface water infiltration. This was the first time that Indiana used
the geomembrane to address this kind of a problem. The geomembrane liner that we selected to
use is a plastic material that’s welded together to make sure that it’s water tight and doesn’t
allow any water to enter the gob pile. One of the decisions we made was to just cover
the flattest slopes on top of the piles where the infiltration would be the greatest. And then where the slopes were steeper along
the sides not cover them because the water would move off the pile well enough there. One of the construction difficulties with
this project was being able to manage the 40 acres of site that we have here with the
storm water runoff. From the south hill and the north hill there
is almost 100 feet of elevation change from the top of the hill to the creek. So being able to coordinate our work with
the berms and outfall structures to make sure we’re managing the storm water with best management
practices. The one unusual thing we used was the Flexamat
ditch to help get the water down off the pile without having to excavate too deep to place
heavy duty riprap in the ditches. We have a number of monitoring wells and they
have indicated that the level has begun to drop since the liner was installed. And, also the quality of the water leaving
the site has improved. We knew we would not be able to eliminate
all of the acid mine drainage coming into the creek. We have limited it to a significant level
though. We may be able to address the rest of the
problem with a wetland in the future.

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