Minnesota Water Resources Conference - Water Resources Center ...

BOOK OF ABSTRACTS
Tuesday, October 28
Concurrent Sessions VI 3:00–4:30
Track B: I-35W Bridge, continued
Developing, Implementing, and Monitoring Pollution Discharge Prevention During the 35W St. Anthony
Bridge Removal Under the Clean Water Act NPDES Permit Program
Dwayne Stenlund, Minnesota Department of Transportation, dwayne.stenlund@dot.state.mn.us
1. Prior to collapse, active concrete rehabilitation of the roadway and bridge deck was performed under
requirements of the NPDES permit. As this was the largest discharge of construction debris and private
property under the Clean Water Act NPDES permit program, rapid response to control further discharge
seemed obvious. The objectives of this portion of the project were to rapidly develop a Storm Water
Pollution Prevention Plan under circumstances of sensitive recovery efforts, no soils nor surface runoff
data, no original grading plan, and limited or restricted site access.
2. The methodologies used in the development of the Storm Water Pollution Prevention Plan included aerial
photo reviews, uniform aerial photo grid of collapse area, ground reconnaissance, and guesses of direction
of flow and locations of storm drains. Using concepts of Desktop Publishing, aerial and ground photos were
inserted into Microsoft Publisher, overlaid with colored doodles representing best management practices
and materials, and narrative descriptions to form rapid and active management plans. Due to rapid
changes during human and equipment recovery, demolition removals, and environmental discoveries, the
same methods were used for daily program updates and addendums to the pollution prevention plan.
3. As a result of the process developed during this crisis, several new and innovative practices and materials
were developed. The presentation will discuss methods of oil and debris capture in the Mississippi River,
access into the river for structure and debris removals, heavy metal trapping in storm water conveyance
locations, groundwater dewatering methods, rapid erosion control, and dust control. The main conclusion
was the development of a communication tool for implementation of pollution prevention plan under
constant change due to construction operations, at multiple locations.
This is part of a program discussing the 35W Bridge Response Team: Andrea Hendrickson, Petra DeWall, Aaron
Buesing, Peter Leete, and Keri Aufdencamp.
79 Minnesota Water Resources Conference, October 27–28, 2008