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.
On-Scene Coordinator (OSC) Jim Augustyn is providing oversight with assistance from U.S. EPA’s START Contractor, Weston Solutions, Inc.
The following tasks are currently on going:
• Collection of turbidity measurements from meters in the Tittabawassee River in order to compare downstream turbidity measurements with background turbidity.
• Continued dewatering of the RMU 3 / 4 excavation areas.
• Preparation for the removal of sheet piling from the RMU 1 / 2 areas.
• The treatment, sampling, and discharge of water generated from the impacted sediment dewatering operations.
• The transportation and off site disposal of excavated sediments from Reach O.
To view a map that depicts current site progress, please visit the Document Section of this website and open the document titled "Site features map".
The following tasks have been completed by Dow’s contractor during the period from September 13 – September 19, 2007:
Thursday, Sept. 13th: Dow’s contractor continued the dewatering of Removal Management Unit (RMU) 1/2 and RMU 3. Began installation of sheet piling around the perimeter of the RMU 4 area.
Friday, Sept. 14th: Excavation and staging of impacted sediment from the RMU 3 area began. Dow’s contractor began the treatment, sampling and discharge of wastewater generated from the dewatering of the excavated sediments. Dewatering activities at the RMU 1/2 area were terminated. Laboratory analytical results from post excavation samples indicated concentrations of dioxin below 15 ppt.
Saturday, Sept. 15th: Dow’s contractor continued excavation of sediment from the RMU 3. Other site activities included; the transportation of contaminated sediment to the Salzburg Landfill for disposal, the continued installation of the sheet piling around the perimeter of the RMU 4 area, and treatment and discharge of wastewater to the Tittabawassee River.
Sunday, Sept 16th: Continued excavation of sediment from the RMU 3. Other site activities included transportation of contaminated sediment to the Salzburg Landfill for disposal. Dow’s contractor completed the installation of the sheet piling around the perimeter of the RMU 4 and began dewatering operations.
Monday, Sept. 17th: Excavation of impacted sediment within RMU 3 was completed. Impacted sediment within the RMU 3 area adjacent to the sheet piling along the southern perimeter, and the impacted sediment below the gravel access ramp in the southeast corner of the RMU 3 area will be removed as part of the RMU 4 excavation activities. Dewatering operations continued in the RMU 3 and RMU 4 excavation areas.
Tuesday, Sept. 18th: The US EPA START contractor and Dow’s contractor collected four (4) post excavation baseline samples from the RMU 3 area. All four (4) samples were submitted to the laboratory for analysis. Four (4) post excavation sediment samples were also collected from the RMU 3 area for visual characterization. Dewatering operations continued in the RMU 3 and RMU 4 area. All impacted sediment from the RMU 3 area was transported off site for disposal at the Salzburg Landfill. Barges have been mobilized on site in order to remove the sheet piling at RMU 1 / 2 areas.
Wednesday, Sept. 19th: Dow’s contractor continued mobilizing materials and equipment for the removal of sheet piling at the RMU 1 / 2 areas. Heavy equipment will be placed on barges in order to remove the sheet piling. Other site activities included the removal of equipment and materials from the RMU 4 area in preparation for the upcoming excavation activity.
• The preparation for creating access to the RMU 5 area.
• The excavation of the impacted sediment from the RMU 5 area.
• The removal of the sheet piling from the RMU 1 / 2 areas.
|
As of 9/19/07, Dow has removed and transported to the Salzburg Landfill approximately 10,944 in-place cubic yards of impacted sediment from the Reach O site. A total of 608 loads, estimated at 18 in-place cubic yards per load, have been transported for disposal.
8/31/2007 6 loads 150 in-place cubic yards
9/7/2007 84 loads 1,512 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 1,278 in-place cubic yards
9/16/2007 76 loads 1,368 in-place cubic yards
9/18/2007 164 loads 2,952 in-place cubic yards
As of 9/19/07, Dow has treated and discharged 18,311 gallons of water. The wastewater treatment process includes settling and filtration using 10 micron filters. Samples are collected continuously during the discharging process and tested for Total Suspended Solids (TSS) and Total Equivalent (TEQ) concentrations of dioxin and furans.
9/14/2007 – 9/15/07 Batch 1 18,311 gallons
|
