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When did construction start, and how long did it take?
___________________________
 


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.



How was the bridge location selected?
Wouldn't it have made more sense to locate this section of US 20 further north?___
 


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.



Will runoff of salt or road treatment chemicals from the bridge and approach roadways affect the Iowa River?__________________________________________

 
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.


What about the intrusion of traffic noise into the Greenbelt?___________________ 
 


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.



How was the Iowa River impacted during construction?_______________________
 


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.



How much did this project cost?__________________________________________
 


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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