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When did construction start, and how long did it take?___________________________ |
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 Site
preparation began in the summer of 2000. Actual construction on the bridge
began in September of 2000.
The bridge opened to traffic on August 22, 2003.
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How
was the bridge location selected?
Wouldn't it have made more sense to locate this section of US 20 further
north?___
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 The
selected location required the least amount of Greenbelt land, 10 acres,
compared with up to 29 acres for the other alternatives considered.
As a result, impact on the Greenbelt was held to a minimum.
New US 20 had to
cross the Iowa River Greenbelt at some point. The new alignment
of US 20 reduces the drive between I-35 and Waterloo
by 15 miles -- from 55 miles to 40.
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Will
runoff of salt or road treatment chemicals from the bridge and approach
roadways affect the Iowa River?__________________________________________
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This
is not seen as a problem, based on experience with other bridges in Iowa.
The current policy
of Iowa DOT is aimed at reducing the amount of salt usage. This is being
done by equipping snow removal vehicles with underbody ice blades, using
sand wherever possible, and prewetting road salt with liquid calcium chloride.
Runoff from the new US 20 bridge and portions of the approach roadways
travel through pipes embedded in the bridge structure, and
are diverted to silt basins off each side of the bridge. The basins
are located away from the river channel.
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What
about the intrusion of traffic noise into the Greenbelt?___________________
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 Noise
effects within sensitive portions of the Greenbelt are expected to be
confined to the river crossing, where summertime truck noise is predicted
to be generally perceptible (45-50 dba) at a distance of approximately
1500 feet up and downstream from the bridge. Local topography and the
high profile of the bridge is expected to limit traffic noise intrusion
into other wooded areas.
It is felt the traffic
noise from relocated US 20 will not substantially impair the continued
public use of the Greenbelt for the enjoyment of its natural qualities,
or deter recreation on the river.
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How
was the Iowa River impacted during construction?_______________________
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 Construction
plans included mitigation measures that held impacts on
the land and the river to a minimum. A biologist was present throughout
construction to monitor impacts that could affect water quality or the
well-being of protected species. Aggressive erosion control measures
were put in place to minimize the potential for the entrance of soil
and silt into the river.
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How
much did this project cost?__________________________________________
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 The
construction cost of the bridge was approximately $20.5 million dollars.
While the design
of the bridge is fairly typical, engineers had to devise a construction
method that would minimize impacts to the surrounding environment.
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