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Estuarine Habitat Restoration on an
Intertidal/Submerged Cap
J. Shisler, M. Adkins, J. Beckner,
& T. Iannuzzi
Estuarine Habitat Restoration on
an Intertidal/Submerged Cap
EMCC 8-31-11
Agenda
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
•Problem
•Solution
•Objectives
•Goals
•Implementation
•Evaluation
Problem - Pascagoula River – PAH Distribution
3
Accepted Solution
•Cap sediments in the River & Bayou
•Cap soils of the upland
•Vertical slurry wall to contain
subsurface liquid wood treating
compounds
•Recover liquid wood treating
compounds
4
Accepted Solution Implementation
•Submerged Aquatic Vegetation
•Threatened & Endangered Species
•Wetlands
•Mitigation of Impacts
5
6
SAV Survey Results
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
SAV survey conducted by ARCADIS scientific dive team
on June 22-24, 2009
Surveyed 13 transects in River and 13 transects in
Bayou
No SAV encountered at any of the transects surveyed
Based on survey results, no mitigation required for
subaquatic habitat
7
Submerged Aquatic Vegetation Survey
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
One Year Later– Fall 2008
8
Threatened and Endangered Species
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
Federally Listed Alabama Redbelly Turtle (Pseudemys alabamensis) - Endangered
Gulf Sturgeon (Acipenser oxyrinchus desotoi) - Threatened
Gopher Tortoise (Gopherus polyphemus) – Threatened
State ListedMississippi Diamondback Terripan (Malaclemys terrapin pileata)
Gulf Salt Marsh Snake (Nerodia clarkii clarkii)
Southern Red Cedar (Juniperus virginiana siliciola)
Tall Prairie-gentain (Eustoma exaltatum)
Georgia Tickseed (Corepsis nudata)
Twig Rush (Cladium marscoides)
9
T&E HABITAT STATUS/MITIGATION
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
No Habitats on Site• Gopher Tortoise - Upland sandhill forest
• Tall Prairie-Gentain – Upland fields
• Georgia Tickseed - Wet longleaf pine savannahs
• Twig Rush – Freshwater marshes
• Alabama Redbelly Turtle – Northern Mobile Bay
• Southern Red Cedar – Not identified on Site
Potentially on Site• Mississippi Diamondback & Gulf Salt Marsh Snake – fringe tidal
marshes
1. Silt curtains during construction
2. Increase fringing tidal marshes and habitat
• Gulf Sturgeon
1. Silt curtains during construction
10
Tidal Fringe Wetland Delineation
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
11
Tidal Fringe Wetland Area Impacts
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
LOCATION
AREA
(SQUARE FEET)
AREA
(ACRES)
West Pascagoula River
North of railroad 4,500 0.1
South of Railroad 15,000 0.3
Bayou Pierre
Bayou east (of Graveline) 3,450 0.1
Bayou oxbow (west of Graveline) 5,800 0.1
New navigation channel (#2) 2,400 0.1
TOTAL IMPACTS 31,775 0.7
12
Wetland Mitigation Evaluation
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
Hydrogeomorphic (HGM) Approach will be incorporated
Tidal fringing wetlands will be compared to reference
wetlands in the USACE Regional Guidebook for
Applying the Hydrogeomorphic Approach to Assessing
the Functions of Tidal Fringe Wetlands Along the MS
and AL Gulf Coast
Pre-construction monitoring
Objectives
•Remediate the impacts
•Restore/create wetlands
•Increase habitat diversity
•Increase wildlife utilization
13
14
Wetland Mitigation Plan
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
Restore/Mitigate tidal fringe wetlands
Pre and post monitoring (5 years)
Adaptive management program
Monitoring of restored/constructed wetlands until
objectives are met
Pre-remedial Conditions
15
16
Pre-remedial Conditions
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
MHW (1.27)
MLW (-0.09)
Placement of Silt Curtains
17
Removal of Plants for Transplanting
18
Capping Design
19
MHW (1.27)
MLW (-0.09)
Capping Activities
20
Planting the Wetland
21
Past and Present
22
23
Post Remedial Conditions
Creek
Liner
Extent of
Observed
DNAPL
Near Completion – Fall 2007
One Year Later– Fall 2008
MHW (1.27)
MLW (-0.09)
Conclusions
•Effective control of contamination
•Alternative to bare riprap
• Increase of wetland habitat
• Increase in habitat diversity
•Threatened and endangered species
utilization
24
Adjacent Model Wetland
25
Questions?