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.
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 August 31 – September 12, 2007:
Friday, August 31st: Dow’s contractor began installation of sheet piling around Removal Management Unit (RMU) 1 and 2 areas in the Tittabawasse River. Turbidity and spill control countermeasures were installed in the river prior to the start of work activities. Continuation of construction activities on the dewatering and wastewater treatment pad. Sediment dredged on August 29th was loaded into trucks and transported off-site for disposal at the Salzburg Landfill.
Saturday, Sept 1st: Dow’s contractor continued the installation of sheet piling around RMU 1 and 2. Work continued on the ramp for access the RMU 3 and 4 areas in the river. Continued work on the dewatering /wastewater treatment pad.
Sunday, Sept 2nd and Monday, Sept 3rd: Installation of sheet piling around the perimeter of the RMU 1 and RMU 2 continued.
Tuesday, Sept 4th: Dow’s contractor completed the installation of sheet piling around RMU 1 and 2. Began dewatering, filtration, and discharge of river water from the enclosed RMU 1 and 2 area. Work continued on the ramp being constructed in order to access RMU 3 and RMU 4 areas in the river. Continued construction work on the dewatering /wastewater treatment pad.
Wednesday, Sept 5th: Dow’s contractor continued the dewatering of RMU 1 and 2 areas to be dredged. A dewatering trench was excavated within the enclosed RMU 1 and 2 areas in order to facilitate the dewatering of the sediments within the sheet piling enclosure. Work continued on the ramp being constructed in order to access the RMU 3 / 4 areas in the river. Dow’s contractor began the installation of sheet piling around the perimeter of the RMU 3 and 4. Turbid water was observed downstream of the dewatering filtration operations. A review of the downstream turbidity measurements indicated no exceedences. Dow’s contractor implemented additional countermeasures to eliminate the downstream turbid discharge.
Thursday, Sept 6th: Dow’s contractor began the excavation of impacted sediment from RMU 1 and 2. Excavated sediment was transported to the dewatering pad for staging. Installation of sheet piling around the perimeter of the RMU 3 and 4 areas in preparation of the dredging activities continued.
Friday, Sept 7th: Dow’s contractor continued excavation of impacted sediment from RMU 1 and 2 areas. Transportation and disposal of dewatered sediment to the Salzburg Landfill began. Three of six post-removal samples were collected from the northern portion of the RMU 1 / 2 areas and submitted for laboratory analysis. Installation of sheet piling around the perimeter of the RMU 3 and 4 areas continued.
Saturday, Sept 8th: Dow’s contractor completed the excavation of impacted sediment in RMU 1 and 2 areas. Collection of the last three post-removal samples from RMU 1 / 2 areas were collected and submitted to the laboratory for analysis. Nine (9) post excavation sediment cores were collected from the RMU 1 / 2 areas for visual characterization. Installation of sheet piling around the perimeter of RMU 3 and 4 areas in preparation of the dredging activities continued.
Sunday, Sept 9th: Site activities included the continued dewatering of the RMU 1 / 2 dredge area cell, and the modification of the haul road access ramp leading to the RMU 3 / 4 dredge area.
Monday, Sept 10th: Dewatering of RMU 1 / 2 areas continued. Post-removal GPS coordinates and elevations of RMU 1 / 2 excavation areas were collected. Installation of sheet piling around the perimeter of the RMU 3 and 4 areas continued.
Tuesday, Sept 11th: Dow’s contractor has completed the installation of the sheet piling around the RMU 3 excavation area. The dewatering process of RMU 3 area started during the night shift operation.
Wednesday, Sept 12th: Dewatering operations continued at the RMU 3 excavation area in preparation for sediment excavation activities. Dow’s contractor started the installation of sheet piling around the perimeter of the RMU 4 area.
The following tasks are currently on going:
• The 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 area.
• The review of laboratory analysis from the post excavation samples collected from the RMU 1 / 2 areas.
• The installation of sheet piling around the perimeter of the RMU 4 area.
• Pumping and storage of wastewater from the dewatering pad into Baker tanks.
The following tasks will be implemented:
• The excavation of impacted sediments from RMU 3.
• Transportation and disposal of the impacted sediment to Salzburg Landfill.
• Treatment and discharge of water generated from the impacted sediment dewatering operations.
• The removal of the sheet piling from the RMU 1 / 2 areas.
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As of 9/12/07, Dow has removed and transported to the landfill approximately 6,837 in-place cubic yards of impacted sediment from the Reach O site. A total of 297 loads, estimated at 25 cubic yards per load, have been transported to the Salzburg Landfill for disposal.
8/31/2007 6 loads 150 in-place cubic yards
9/07/2007 84 loads 1,512 in-place cubic yards
9/08/2007 174 loads 4,350 in-place cubic yards
9/10/2007 33 loads 825 in-place cubic yards
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