Document LgxZddwBO4RxNbk5JxKpq7RQq

Tittabawassee River and Floodplain Cleanup: JUNE 1 5,201? Sierra Club v. EPA 18cv3472 NDCA Tier 3/4 ES VATION & SUSTAINABL 'oductioi Background Dioxins and furans were formed in the early days of Dow's manufacturing processes. In the early 1900s, Dow used an electrolysis process to produce bleaching powders and bromides. Before waste management ponds were built around 1920, some solids were washed into the Tittabawassee River. Dioxin and furan compounds were not well understood until the 1960s. D Dow electrolytic bromine cell, 1910-1916 period. Historic photo of Michigan Operations showing early waste management ponds. Herbert H. Dow founded The Dow Chemical Company in 1897. D Historic photo of Michigan Operations showing cell buildings used in the electrolysis process. Sierra Club v. EPA 18cv3472 NDCA Tier 3/4 'Oduci Site Overview The site is defined as the lower Tittabawassee River and its floodplain, the Saginaw River and its floodplain, and and portions of the Saginaw Bay. Tittabawassee River and banks: 24 miles Tittabawassee River floodplain: about 4,500 acres Saginaw River: 22 miles ED 002061 00173016-00003 Extensive Investigation Activities Dow, in partnership with DEQ and EPA, has extensively studied floodplain and bank soils and in channel sediments since 2006, gathering tens of thousands of samples. Since 2010 alone, Dow has collected more than 1,000 samples to help inform remedial design, cleanup and monitoring activities. 'Oduci m Site map showing soil and sediment sample locations Tier 3/4 ED 002061 00173016-00004 Jcal Elemei or Success Early Cleanup While following the Superfund Alternative Process under CERCLA, Dow's efforts have focused rapid implementation, with residual risk assessment at a later time. Sierra Club v. EPA 18cv3472 NDCA Installation of a Cellular Containment System (CCS) cal Elemer jr Success :kl Eemei or Success Early Cleanup - continued Bank management area after construction and early vegetation g ro w th Bank management area showing established vegetation Sierra Club v. EPA 18cv3472 NDCA Floodplain removal area being seeded following the completion of removal activities Critical Elements for Success Collaboration with EPA and MDEQ Working in partnership with EPA and MDEQ, Dow teams have taken a pragmatic yet flexible approach to project management. This involved monthly meetings, work in real-time and commitment to an aggressive timeline. ED 002061 00173016-00006 Adaptive Management Approach and Innovative, Sustainable Technologies With the adaptive management approach, lessons learned in one phase of cleanup inform the next. Promoting continuous improvement and innovative technologies, this approach results in faster and more effective cleanups tailored to the specific characteristics of the Tittabawassee River. Critical Elements: for Success ^ The piloted cap technology became a final remedy selected by th e EPA. Picture of cap installed at Sediment Management Area 1-4. Sierra Club v. EPA 18cv3472 NDCA Critical Elements for Success W The piloted bank technologies that performed well became final cleanup technologies at bank management areas. Pictures depicts stabilized bank at Bank Management Area 2-4. ED 002061 00173016-00007 Aggressive Timeline sua :* ikiAumti senoym ficai Efemer :or Success km nemovO UsfeOD: tfe atn tp i complete! wtUtin the iit k b is w im e e ftwar and sk ifsoslplift from M tdlam l lo the toofyomre of Ute Shwwsme 8 t . Endy Acnou Am m \o W 2010 & 2011 2012 W 1 1 2012 * ; 1 2014 I 1 201$ O See vtan* Ciocsnup Area*, Q Bank Csemurp Amas |j|||||f T.1"< '>':>. R:>.Ci .$ : j :.i d p ! Liemujp Areas O tiyctiom 2030 f'oodpiwn Am? Sierra Club v. EPA 18cv3472 NDCA cal Eiemer jr Success -sy.^ i hi-.'t-i'i J- tfdik-v u<i lilllliiilllllililiiillilll illliillliillliill ... ..................... iili ii* iiia i',, -i V. ih..:! -K "*> Tier 3/4 ED 002061 00173016-00008 Community Engagement Dow and EPA continue to partner on extensive outreach to affected property owners and the community at large. The robust community involvement program includes EPA Information Sessions, public meetings and a Community Advisory Group (CAG), as well as frequent communications to keep property owners updated on project stages and activities. tical Elemer :or Success Sierra Club v. EPA 18cv3472 NDCA Educational brochures cal Elemer jr Success TITTABAWASSEE RIVER CONSERVATION PROGRAM Dow created this voluntary program to preserve the natural features of the river and floodplain and ensure the long-term effectiveness ofthe cleanup. The Tittabawassee River Conservation program is available to qualifying land owners who have property within the eight-year floodplain and whose land will be evaluated for cleanup. The current use ofthe floodplain consists of 5% residential maintained, 18% active agriculture, and 76% forest, wetland, meadows or ponds. FIGURE: Eight-Year Floodplain Along the Tittabawassee River Fast Facts Preserves the natural features ofthe river and floodplain. Provides access to the property for sampling and implementing the cleanup, and for periodic monitoring, if needed. Allows property owners to continue using the property as they do today (unless they currently raise poultry or livestock on the floodplain, which the Covenant prohibits). Signing the Conservation Covenant means the owner is confirming property ownership, and agrees to the conditions ofthe Covenant. ED 002061 00173016-00009 The adaptive management approach and use of innovative sustainable technologies - along with collaboration and early cleanup actions - resulted in faster and more effective cleanups. Remedy options were tailored to the specific characteristics of the Tittabwassee River. Installing armor stone over the Sediment managment area in S M A 1-5. % ' Floodplain removal activities along the Tittabawassee River. Sierra Club v. EPA 18cv3472 NDCA A fte r establishing access, installation of cellular containment system (CCS) cap. Installation of armor stone around the outer edge of the CCS cap using a pontoon boat with a conveyor system. CCS cap filling with clean river sediment which naturally moved down the river system. Tier 3/4 ED 002061 00173016-00010 li'"diianne! Ilernawai Installation of sheetpile walls around the sediment management area to allow the area to be dewatered, removal of sediment in the dry. Removal of river sediment with direct loading into trucks for transportation and disposal. Sierra Club v. EPA 18cv3472 NDCA Tier 3/4 Bank Stabilization Before Banksthat are unstable and contain contaminated soil are being stabilized to stop bank erosion. During p i. JI M an Step 1: Trees are trimmed or removed to allow sun light to the bank so deep rooting vegetation can stabilizethe banks. Step 2: In some cases the bank angle is reduced to help create stable conditions. Step 3: Special materials are often used to help stabilize the banks and allow the native vegetation to be established. I 'mkm.A S ill . 1 After Monitoring and maintenance activities will ensure that the remedy continues to maintain bank stability over time. ED 002061 00173016-00011 Extensive site-specific human exposure and ecological risk studies funded by unrestricted grants from Dow, along with other scientific studies, will be factored into final risk assessment. University of Michigan Dioxin Exposure Study fUMDES) !The Study found no direct exposure pathway by which dioxins in soils and sediments have accumulated in bodies of residents inhabiting fVlidiand and Saginaw." Principal Investigator Or. David Garabrant The Univeisit' of Michigan Dioxin Exposure Study Michigan State University Wildlife Study SiDesp$te more than 20,000 person-hours in the field and the conscription of more than 6,350 animals, we were unable to identify the presence of any adverse effects associated with exposure to the contaminants of concern" Principal Investigator Or. Matt Zwiernik Sierra Club v. EPA 18cv3472 NDCA The final step of a risk assessment will be a collaborative effort between Dow, EPA, and MDEQ, and will require a realistic, pragmatic approach in order forthis project to be successful. i I E <t* <<fl SS ED 002061 00173016-00012 Sierra Club v. EPA 18cv3472 NDCA Tier 3/4 ED 002061 00173016-00013