On June 27, 2007, U.S. EPA ordered The Dow Chemical Company (Dow) to negotiate an Administrative Order on Consent, to address removal of extremely elevated levels of dioxin-contaminated sediment from within Reach O of the Tittabawassee River near Midland, Michigan. Dow agreed to the terms of the Order and on July 12, 2007, the Order was signed by the Regional Administrator and Dow. For additional background information please see the site profile. Dow completed all site work on November 27, 2007. Dow submitted its Final Report on February 28, 2008. U.S. EPA reviewed and approved the Final Report on April 10, 2008.
On-Scene Coordinator (OSC) Jim Augustyn provided oversight with assistance from U.S. EPA’s START Contractor, Weston Solutions, Inc.
The following tasks were completed by Dow during the period from November 1–27, 2007:
• Treatment, sampling and discharging of the remaining wastewater generated from the sediment dewatering and equipment decontamination activities.
• Decontamination and demobilization of Baker tanks and associated filtration equipment.
• Decontamination and demobilization of all heavy equipment and construction materials.
• Demobilization of all office trailers, generators and equipment storage trailers.
• The dewatering pad will be left in-place for potential future corrective action use. The northwest corner of the containment berm of the dewatering pad was breeched to prohibit the accumulation of water inside the dewatering pad.
• Completion of restoration activities included; the three (3) river access ramps along the east embankment of the river, the access haul road along the top of the river embankment, disturbed areas which were used to stage construction equipment and materials, and sand borrow pit and accompanying access roads.
• The temporary access haul road from Saginaw Road to the dewatering pad will be left in-place for potential future use.
• All equipment and materials were demobilized from the site on November 27, 2007.
No further removal activities are planned for Reach O under the Administrative Order Issued on July 12, 2007.
Dow will evaluate and correct any restoration issues that occur until vegetation has been established at the site.
Dow reported the estimated final costs for completing the work required by the Order to be $4,300,000
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Dow has removed and transported to the landfill a total of approximately 22,775 in-place cubic yards of impacted sediment from the Reach O site. A total of 911 loads, estimated at 25 in-place cubic yards per load, have been transported to the Salzburg Landfill for disposal. The following disposed waste dredged and disposed from the Reach O area includes:
8/31/2007 6 loads 150 in-place cubic yards
9/7/2007 84 loads 2,100 in-place cubic yards
9/8/2007 174 loads 4,350 in-place cubic yards
9/10/2007 33 loads 825 in-place cubic yards
9/15/2007 71 loads 1,775 in-place cubic yards
9/16/2007 76 loads 1,900 in-place cubic yards
9/18/2007 164 loads 4,100 in-place cubic yards
9/24/2007 162 loads 4,050 in-place cubic yards
10/5/2007 77 loads 1,925 in-place cubic yards
10/29/07 64 loads 1,600 in-place cubic yards
Dow has treated and discharged a total of approximately 96,935 gallons of water. The wastewater treatment process includes settling and filtration using 25 and 10 micron filters. Samples were collected continuously during the discharging process and tested for Total Suspended Solids (TSS) and Total Equivalent (TEQ) concentrations of dioxin and furans. The following quantity of water discharged from the Reach O treatment operations include:
9/152007 Batch 1 18,311 gallons discharged
9/24/2007 Batch 2 7,953 gallons discharged
10/5/2007 Batch 3 22,678 gallons discharged
10/24/2007 Batch 4 15,134 gallons discharged
11/6/2007 Batch 5 12,319 gallons discharged
11/7/2007 Batch 6 20,540 gallons discharged
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