Tittabawassee River Floodplain

Transcription

1 Tittabawassee River, Saginaw River & Bay Site Tittabawassee River Floodplain Mary P. Logan U.S. EPA CAG Meeting July 21, 2014

2 Agenda Recap of floodplain conditions Recap of 2013 outreach summary Remedy options Implementation approach What s next?

3 FLOODPLAIN CONDITIONS

4 Tittabawassee River 8-Year Floodplain Frequently flooded area along the lower 21 miles About 4,500 acres in the 8-year floodplain Dioxins, primarily furans are the contaminants of concern Distribution is not uniform Not all areas will need cleanup

5 TR 8-Year Floodplain Land Types Pond 1% Maintained 5% Hard surface > 1% Emergent wetland 2% Forested/ shrub wetland 14% Active agriculture 18% Unforested upland 11% Forest 48%

6 TR 8-Year Floodplain Land Types Segment 3

7 Green Corridor ~ 76% of the floodplain is natural land types Tittabawassee River Green Corridor Includes ecologically important areas Provides unique and varied habitat Promotes wildlife diversity Helps dissipate energy from floods, stabilize soil erosion and protect property Tan includes maintained, agricultural and hard surface land types

8 TR 8-Year Floodplain Land Uses Commercial 4% Public recreation 3% Residential maintained 5% Active agriculture 18% Shiawassee NWR 16% Undeveloped/ low use/ natural 54%

9 TR 8-Year Floodplain Land Uses Segment 3

10 Why is land type/use important? Land type helps us understand: Potential ecosystem impacts from remedies May be used to help target where to do cleanup Land use helps us understand: The potential exposures that people may have The appropriateness of each cleanup option

11 Floodplain Assessment Transect-based sampling Geomorphic units used to help locate samples Step out samples Segment 3

12 Floodplain Assessment (cont.) Samples primarily from Dioxin samples > 1,800 locations > 10,000 samples Furans dominate the TEQ More than 220 other chemicals assessed ~ 200 locations ~ 625 samples Biased sampling Dioxin floodplain sample locations

13 Floodplain Assessment (cont.) Evaluating the range of TEQ surface concentrations Evaluating depth, geomorphic type, etc. Additional data to support design and implementation Segment 2

14 2013 OUTREACH SUMMARY

15 Goals of 2013 outreach 2013 Outreach Understand community values about the current state of the floodplain & desires for future conditions and uses Obtain feedback on the possible tradeoffs that come with the cleanup options Identify what other information may be needed by the community Meetings: 1 st tier; 21 meetings held March September nd tier; 4 meetings held April July 2013

16 Views on Future Land Use of the Tittabawassee River Floodplain Increase Same Decrease No Opinion Undeveloped/ natural ecosystem 52% 44% 3% 1% Public Parks 52% 41% 5% 2% Shiawassee NWR 49% 40% 4% 7% Active Agriculture 26% 49% 23% 2% Residential 17% 56% 23% 4% Commercial 5% 36% 44% 14%

17 2013 Outreach Summary - Tradeoffs Split opinions about flexibility for future land use vs. limiting development in the floodplain Preserve, protect or improve the ecosystem; concentrate work in the most contaminated areas Work as quickly as possible; priority to residential or recreational areas; more time OK if cleanup is what community wants

18 2013 Outreach Summary Tradeoffs Split opinions about effectiveness of monitoring/ maintenance; most contaminated or highly used areas should rely least on monitoring/ maintenance Community and workers must be protected; short-term impacts like noise and truck traffic might be acceptable Cost should not be a limiting factor, especially in areas where there is more contamination

19 Why is the 2013 feedback important? EPA must choose cleanups that are protective and that comply with laws and regulations Helps us evaluate EPA s other selection criteria Provides insight into potential future land use Helps us understand the community priorities Highly used and more contaminated areas Maintain or improve natural ecosystem Helps us understand the strength of the preference split opinions vs. consistent results

20 REMEDY OPTIONS

21 Overview of Floodplain Cleanup Goals Overarching goal: to protect everyone who lives, works or plays in the floodplain by limiting people s exposure to dioxins in floodplain soil How to meet the goal: Conduct cleanups that reduce surface soil dioxin levels to below site-specific soil cleanup numbers Establish or maintain land uses that result in lower human exposures

22 Site-Specific Soil Cleanup Numbers Site-specific means that there are exposure factors that are unique to the TR floodplain EPA and MDEQ worked together on these Cleanup goals for two land uses: Maintained residential areas Other land use areas EPA s criteria are designed so that people will be safe when they come in contact with floodplain soil

23 Other Land Use Other Land Use River

24 Floodplain Cleanup Options In areas that need cleanup: Soil Removal & Disposal Dig up contaminated soil Backfill with clean soil, if needed Transport & dispose contaminated soil Soil Cover Place a cover of clean material over contaminated soil Monitoring required, and maintenance if needed Combination of these two

25 Land Management Soil removal and/or cover would be combined with land management ( institutional controls or ICs ), where needed Legal and administrative tools Often an important part of the overall cleanup Designed to lower the potential for people to be exposed to contamination Can keep areas in natural condition ICs already in place in the floodplain

26 IMPLEMENTATION APPROACH

27 Implementation Approach Floodplain work will be upstream-todownstream, segment-by-segment Work to start adjacent to Segment 2 Each floodplain segment cleanup expected to take 1 2 years In-channel and bank work done concurrently

28 Segment 2 Planning 2015 Work Start 2015 Tittabawassee River Floodplain Work Schedule Segment 3 Planning 2015 Work Start 2016 Segment 4 Planning 2016 Work Start 2017 or 2018 Segments 5, 6 and 7 Planning and Work Start after 2016

29 Projected Schedule Segment 1 Remobilize to finish field work Segment 2 Propose cleanup plan to public Finalize cleanup plan First season of in-channel and bank work (anticipate two field seasons) Remobilize to finish in-channel and bank work Tittabawassee River Floodplain Engage floodplain stakeholders regarding cleanup options & tradeoffs Develop cleanup plan Propose cleanup plan to public Finalize cleanup plan First season of field work (Along Segment 2) Second season of field work (Along Segment 3) Segment 3 Develop cleanup plan Propose cleanup plan to public In-channel and bank work Finalize cleanup plan

30 Implementation Approach (cont.) Property-by-property evaluations will be done to determine if cleanup is needed Focus on the 8-year floodplain Dioxin levels compared to cleanup goal Only a portion of the property may need work If cleanup is needed, owners will have input on property-specific plans and schedules

31 Implementation Approach (cont.) Generally, construction on each property should be completed within a few weeks People can stay in their house during the work No services are expected to be disrupted Some parts of the yard likely to be restricted during construction Most plants and trees will need to be removed Properties will be replanted after construction is complete The project team will work with homeowners to see if specific trees could left in place

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33 Implementation Approach (cont.) There will be no expense to the property owner Cleanups are voluntary however, EPA will try hard to persuade owners to accept the cleanup Once the cleanup is done (or if no cleanup is needed), the owner will receive a confirmation letter from EPA

34 What to expect when cleanup starts in your river segment EPA notifies you that work is starting in your segment Project team meets with you to discuss propertyspecific details Project team takes samples (if needed) EPA determines if work on property is needed If work is needed Project team develops work plans and schedules work Project team conducts cleanup on property EPA sends you a letter stating cleanup is complete = Owner input If no work is needed

35 Green Remediation Will try to incorporate green and sustainable remediation practices into floodplain cleanup Core elements Material and waste Energy Air and atmosphere Water Land and ecosystem May use site footprint analysis, net results analysis and/or best management practices (BMPs)

36 WHAT S NEXT?

37 Process and Timing EPA, working with MDEQ, issues a proposed cleanup plan for public comment August 60 day public comment period target 8/15 through 10/14 Informal information sessions with floodplain owners late August to mid-september Formal public meeting expected to be on Wednesday, September 24

38 Materials available for the public Fact sheet describing EPA s proposed cleanup plan and rationale Frequently Asked Questions Short fact sheet describing how the cleanup numbers were developed Long technical document describing how the cleanup numbers were developed Floodplain Response Proposal a very long technical document describing floodplain conditions and assessing cleanup options

39 Process and Timing (cont.) EPA, working with MDEQ, considers and responds to comments and selects the cleanup option(s) Fall 2014 Dow begins Segment 2 designs and planning Fall 2014 into spring/summer 2015 Construction start planned for 2015 Will start adjacent to Segment 2

40 QUESTIONS?