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?