On July 9, 2007, Dow’s contractor began positioning equipment on a work barge to begin the preparation of driving temporary sheet piling in the river to delineate the area of highest dioxin contamination. Dow’s contractor has completed construction on the HDPE sediment transport pipeline and has conducted hydrostatic testing of the line. The sediment transport line is approximately 9,000 feet long and will transport sediment slurry from the dredge area in the river to the Geo-Tube dewatering cell.
On-Scene Coordinators (OSC) Jim Augustyn and Brian Schlieger are providing oversight with assistance from U.S. EPA’s START Contractor, Weston Solutions, Inc.
The following tasks have been completed by Dow’s contractors during the period of July 28 to August 3, 2007:
Saturday July 28th, Dow’s contractor completed installing a sheet pile turbidity barrier up stream of the pipe bridge in preparation for excavation of rip rap along the RGIS system. Air monitoring throughout the project area continued. Work activities at the containment cell included: site grading and restoration, survey and grade control, HDPE pipe welding, installation of odor control piping, installation of electrical infrastructure for each containment cell, dust and track-out control, and miscellaneous house-keeping activities.
Monday July 30th, Installation and driving of the temporary sheet piling turbidity barrier continued in the river. Excavation and transportation of rip rap materials along the RGIS system to Dow’s Salzburg Landfill began. Air monitoring throughout the project area continued. A second crew began preparation for sheet piling installation under the bridge. Dow’s contractor began collecting background turbidity data from a temporary monitor located upstream from the project area. Work activities at the containment cell continued.
Tuesday July 31st, Installation and driving of the temporary sheet piling turbidity barrier under the bridge continued. Excavation, transportation, and disposal of rip rap materials continued. Dow’s contractor continued collecting background turbidity data from a temporary monitor located upstream of the project area and began data collection downstream of the Reach D work area. Work activities at the containment cell continued.
Wednesday August 1st, Installation and driving of the temporary sheet piling turbidity barrier under the bridge continued in the river and excavation and transportation of rip rap materials to Dow’s Salzburg Landfill continued. Dow’s contractor continued collecting background turbidity data from temporary turbidity monitors located upstream and downstream of the project area. Work activities at the containment cell continued.
Thursday August 2nd, Dow’s contractor installed temporary sheet piling underneath the piping bridge. Excavation and transportation of rip rap materials to Dow’s Salzburg Landfill continued. Air monitoring throughout the project area continued as well as turbidity data collection. Work activities at the containment cell continued.
Friday August 3rd, Installation and driving of the temporary sheet piling turbidity barrier continued in the river and excavation and disposal of rip rap to Dow’s Salzburg Landfill continued. Air monitoring throughout the project area continued. Dow’s contractor continued collecting background turbidity data from turbidity monitors located upstream and downstream of the project area. Work activities at the containment cell continued.
Sheet piling will be driven down to established elevations to complete the installation of the turbidity barrier above the Dow bridge. Permanent Turbidity monitors will be placed in the river to monitory potential increases in turbidity that may result from excavation and dredging operations.
Rip rap and large debris will continue to be mechanically excavated from the existing RGIS sheet piling within the turbidity barrier area. The excavated material will be placed over the RGIS system and allowed to drain. Once sufficiently free of water, the excavated material will be transported to Dow’s Salzburg Road Landfill for disposal.
Construction on the containment cell will continue. Geo-Tubes and associated connections to the sediment transport line will be completed in preparation for dredging operations to start.
Installation of the temporary turbidity barrier under the Dow bridge to the Dow Dam will continue.
Once all rip rap and large debris is removed from the work area, installation of new permanent sheet piling for the RGIS system will begin. Dredging of contaminated sediment cannot begin until the permanent sheet piling is in place.
The second sheet piling crew will continue to install temporary sheet piling and will place another section under Dow's 'Railroad' bridge. The temporary sheet piling will be installed along the entire length of the project area and will end adjacent to the Dow Dam.
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