EPA-905-FO-9001
Remediation of the Black Lagoon
Trenton, Michigan
Great Lakes Legacy Program
March 2009
&EPA
U.S. Environmental Protection Agency
Great Lakes National Program Office
77 West Jackson Boulevard
Chicago, IL 60604-3511
& Michigan Department of Environmental Quality
'f 525 West Allegan Street
— P.O. Box 30473
Lansing, Ml 48909-7973
-------
U.S. Environmental Protection Agency
Great Lakes National Program Office
77 West Jackson Boulevard
Chicago, IL 60604-3511
Michigan Department of Environmental Quality
Water Division
Constitution Hall
South Tower, 2nd Floor
525 West Allegan Street
Lansing, Ml 48933
-------
ACKNOWLEDGEMENTS
ACKNOWLEDGEMENTS
This document was prepared under the direction of Marc Tuchman, Project Lead, U.S.
EPA Great Lakes National Program Office and Mike Alexander, Project Manager,
Michigan Department of Environmental Quality; Susan Boehme, Coastal Sediment
Specialist, IL/IN Sea Grant College Program; and Louis Blume, Work Assignment and
Quality Manager, U.S. EPA Great Lakes National Program Office. The report was
prepared by Judith Schofield, Reina Downing, Lynn Walters, Harry McCarty, and Ryan
Hansen of Computer Sciences Corporation (CSC), under U.S. EPA Contract Number 68-
C-01-091. Significant portions of the text in this report are based on the information in
the project report by Environmental Quality Management Incorporated titled,
Remediation of the Black Lagoon, Trenton Channel, Detroit River, Trenton, Michigan,
Final Project Report, October 2006. We gratefully acknowledge this assistance from
Environmental Quality Management.
The Black Lagoon Sediment Remediation project was accomplished through the efforts
of many project partners. Marc Tuchman, Project Lead, U.S. EPA Great Lakes National
Program Office and Michael Alexander, Project Manager, Michigan Department of
Environmental Quality wish to acknowledge the assistance of David Bowman, William
Merte, and James Schulz, U.S. Army Corps of Engineers-Detroit District; John Hartig,
formerly Detroit River Navigator-American Heritage Rivers Program; Michelle Jaster,
U.S. EPA, Region 5 Superfund; Rosanne Ellison, U.S. EPA, Great Lakes National
Program Office; Dr. Russell Kreis, Jr., U.S. EPA, Office of Research and Development;
and Mayor Gerald Brown, City of Trenton.
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
JANUARY 2008
-------
TABLE OF CONTENTS
TABLE OF CONTENTS
Acknowledgements i
Executive Summary vii
1.0 Project Description 1
1.1 General Site Description 2
1.2 Site History 3
1.3 Project Objectives 6
1.4 Project Funding 7
1.5 Project Management 7
1.5.1 Project Planning, Permits and Notifications 7
1.5.2 Project Communication, Roles and Responsibilities 8
1.5.3 Public Outreach and Community Involvement 11
1.6 Data Management 11
1.6.1 Data Management 12
1.6.2 Database 14
1.6.3 Public Access 14
2.0 Monitoring Impacts of Dredging Operations 15
2.1 Air Monitoring 15
2.2 Water Quality Monitoring 18
3.0 Site Preparation and Set Up 20
3.1 Site Survey 20
3.2 Site Security 20
3.3 CDF Site Construction and Placement 21
3.3.1 CDF Preparation 21
3.3.2 Construction of Transfer Station/Offloading Area 22
4.0 Dredging Operations and Dredge Material Disposal 26
4.1 Containment of The Dredge Area 26
4.2 Mechanical Dredging 27
4.2.1 Initial Dredging Operations (Phase I) 28
4.2.2 Modified Dredging Operations (Phase II) 31
4.3 Disposal of Dredged Material 34
4.3.1 Loading of Transport Barges During Phase I Dredging Operations 34
4.3.2 Transporting Dredged Materials to the CDF 35
4.3.3 Stabilizing Barged Dredge Materials at the CDF 35
4.3.4 Offloading and Conveying Barged Dredge Materials 36
4.3.5 Trucking and Contingency Plan Operations During Phases I and II 36
4.3.6 Placement of Dredged Material 39
4.3.7 Capping the CDF Cell 39
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
5.0 Sediment Confirmation Sampling and Analysis 40
5.1 Sediment Confirmation Sampling Design 40
5.2 Sampling And Analysis 43
5.2.1 Sampling Methods 44
5.2.2 Analytical Methods 46
5.3 Quality of Sediment Confirmation Data 46
6.0 Project Results 48
6.1 Post-Dredging Sediment Confirmation Sample Results 48
6.2 Volume of Contaminated Sediments Removed 54
6.3 Final Sediment Confirmation Results 58
7.0 Residual Cover Placement, Demobilization, and Site Restoration 63
7.1 Placement of the Residual Cover 63
7.2 Demobilization and Site Restoration 64
8.0 Conclusions and Project Accomplishments 65
9.0 Future of the Site 68
References 69
Appendix A Summary Sediment Confirmation Data 71
Appendix B Summary Sediment Concentration Data, 1999 74
LIST OF TABLES
Table 1-1 Site Sediment Concentrations From 1999 Sediment Survey 4
Table 1-2 Project Team Roles and Responsibilities 9
Table 2-1 Air Monitoring/Sampling Activity, Parameters, and Frequency 17
Table 6-1 Results From Sediment Confirmation Samples Collected After
the First Dredge 49
Table 6-2 Results From Sediment Confirmation Samples Collected After the
Second Dredge 50
Table 6-3 Results From Sediment Confirmation Samples After Placement of
Residual Cover 59
JANUARY 2008
-------
TABLE OF CONTENTS
LIST OF FIGURES
Figure 1-1 Black Lagoon Remediation Site Location Map 3
Figure 1-2 Pre-remediation Sediment Mercury Concentrations at Depth in Black
Lagoon 5
Figure 3-1 Schematic Drawing of Black Lagoon Remediation Site 21
Figure 3-2 Map of Detroit Area with Barge Route from Black Lagoon to the CDF .... 22
Figure 4-1 Map Showing Side Slope Stabilization Areas (SSSA) 29
Figure 4-2 Schematic Drawing of Contingency Trucking Operations 38
Figure 5-1 Black Lagoon Sediment Confirmation Sampling Design 42
Figure 5-2 Actual Black Lagoon Sampling Locations for May, August, and
September 2005 44
Figure 6-1 Black Lagoon Sediment Thickness After Completion of Phase I
Dredging (based on data collected in May 2005) 50
Figure 6-2 Black Lagoon Sediment Thickness After Completion of Phase II
Dredging (based on data collected in August and September 2005) 51
Figure 6-3 Estimated Oil and Grease Concentrations Prior to Phase II Dredge 52
Figure 6-4 Estimated Oil and Grease Concentrations After Phase II Dredge 52
Figure 6-5 Estimated PCB Concentrations Prior to Phase II Dredge 53
Figure 6-6 Estimated PCB Concentrations After Phase II Dredge 53
Figure 6-7 Cumulative Summary of Sediment Quantities Dredged from the
Black Lagoon 55
Figure 6-8 Three-dimensional View of Estimated Sediment Surfaces,
Before Phase II Dredging (May 2005) and After Phase II
Dredging (September 2005) 56
Figure 6-9 Three-dimensional View of the Estimated Volume of Sediment
Removed During Phase II 57
Figure 6-10 Oil and Grease Concentrations in Black Lagoon Sediment Floor
After Remediation 59
Figure 6-11 Total PCB Concentrations in Black Lagoon Sediment Floor
After Remediation 60
Figure 6-12 Mercury Concentrations in Black Lagoon Sediment Floor
After Remediation 61
Figure 6-13 Black Lagoon Sediment Surfaces Overlain with Total PCB
Concentrations through the Remediation Project 62
Figure 8-1 Black Lagoon Sediment Volume and Contaminant Mass Removed,
with Residual Layer of Sediment and Residual Cover Overlain with
Total PCB Concentrations 67
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
JANUARY 2008
-------
EXECUTIVE SUMMARY
EXECUTIVE SUMMARY
This report describes a joint effort between the U.S. Environmental Protection Agency
(EPA) Great Lakes National Program Office (GLNPO) and the Michigan Department of
Environmental Quality (MDEQ) to remediate contaminated sediments in the Black
Lagoon. The Black Lagoon lies in the Trenton Channel of the Detroit River, outside the
City of Trenton, Michigan. The Detroit River is a 32-mile international connecting
channel linking Lake St. Clair and the upper Great Lakes to Lake Erie. The lagoon is
within the Detroit River International Wildlife Refuge, the first international refuge so
designated in North America. The lagoon also is adjacent to a public park that contains
picnic and playground areas.
The Detroit River Area of Concern (AOC) is a binational AOC which drains
approximately 700 square miles of land in Michigan and Ontario, including the city of
Detroit. Eleven beneficial use impairments have been identified in the Detroit River (see:
http://www.epa.gov/glnpo/aoc/detroit.html). The known causes of impairments include
bacteria, polychlorinated biphenyls (PCBs), polynuclear aromatic hydrocarbons (PAHs),
metals, and oil and grease from urban and industrial development in the watershed.
Combined sewer overflows (CSOs) and municipal and industrial discharges are major
sources of contaminants within the AOC. Stormwater runoff and tributaries in Michigan
are also major sources of contaminants. Additional environmental concerns include
invasive species, changes in the fish community structure, and reductions in fish and
wildlife habitat.
The Black Lagoon proposal was the first project to be accepted and funded under the
Great Lakes Legacy Act (GLLA) of 2002. This legislation was specifically developed to
address the contaminated sediment problem in Great Lakes AOCs. The primary objective
of the project was to remove the polluted sediments in the lagoon, and improve the
environment by mitigating beneficial use impairments (BUIs) that impacted the lagoon,
its inhabitants, and the surrounding community.
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
Two specific goals were targeted with this objective:
1) Reduce relative risk to humans, wildlife, and aquatic life, and
2) Restore the aquatic habitat within the Black Lagoon.
GLLA Project activities at the site began in late September 2004 and continued through
November 2005. Prior to dredging, a silt curtain was installed to enclose the entire
lagoon and protect the adjacent river from releases of suspended sediments during
dredging operations. Water quality and air monitoring strategies also were employed
throughout the project to ensure that the remediation activities were not adversely
affecting the health of the ecosystem, surrounding environment, or the remediation staff.
Dredging operations were undertaken with the goal to dredge to hardpan across the
lagoon. Using a clamshell dredge device, approximately 103,500 cubic yards of
contaminated sediments were removed. After completion of this first round of dredging,
the remaining residual sediments were sampled and analyzed to verify that the dredging
activities reduced contamination to acceptable levels. Results of these analyses suggested
that high concentrations of the contaminants of concern still remained in some areas, so a
second phase of dredging was conducted to remove an additional one to three feet of
sediment. Sampling after Phase II of dredging indicated that, although contaminants
were still present in some areas above originally targeted levels, the second round of
dredging successfully reduced both the overall concentration and the distribution of those
contaminants. In all, approximately 115,000 cubic yards of contaminated sediments
containing approximately 478,000 pounds of PCBs, mercury, oil and grease, lead, and
zinc were removed from the lagoon.
After removing the contaminated sediments, a sand and stone cover was installed. The
cover consisted of at least 6 inches of clean sand that was further covered by 4 to 6 inches
of stone. The primary purpose of the cover was to provide a barrier between the benthic
community and any residual contaminated sediment. This cover will enhance natural
attenuation, add habitat for regrowth of healthy organisms on the lagoon floor, and reduce
exposure offish to contamination through consumption of bottom dwelling organisms.
JANUARY 2008
-------
EXECUTIVE SUMMARY
Following dredging and the placement of a sand cover in the lagoon, the City of Trenton
was awarded $151,000 from the Great Lakes Basin Program for Soil Erosion and
Sediment Control for shoreline habitat restoration (2006). In June 2007, the City of
Trenton received a $582,000 boating/infrastructure grant from the U.S. Fish and Wildlife
Service for marina construction/boating access and is matching that grant with $200,000
to construct floating docks and boat access at the site, as well as move forward on
redevelopment of its downtown area. The lagoon was informally named the Black
Lagoon after aerial surveys depicted the lagoon as literally black from oil and grease
contamination. On Monday June 18, 2007, the City of Trenton and its many partners
celebrated the restoration and revitalization of the Black Lagoon in a ceremony renaming
Black Lagoon as "Ellias Cove" in honor of the family who donated the adjacent land to
the City of Trenton that became Meyer-Ellias Park.
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
JANUARY 2008
-------
PROJECT DESCRIPTION
1.0 PROJECT DESCRIPTION
This report describes remediation of the Black Lagoon, located in the Trenton Channel of
the Detroit River, near Trenton, Michigan. The Black Lagoon is part of the Detroit River
Area of Concern (AOC). The Detroit River is a 32-mile international connecting channel
linking Lake St. Clair and the upper Great Lakes to Lake Erie. The Detroit River AOC is
a binational AOC which drains approximately 700 square miles of land in Michigan and
Ontario, as well as the 107 square mile City of Detroit "sewershed." Approximately 75
percent of the total land area of the watershed is in Michigan (607.7 square miles).
Eleven beneficial use impairments (BUIs) have been identified in the Detroit River and
most of these are impairing the Black Lagoon. The known causes of impairments include
urban and industrial development in the watershed, bacteria, polychlorinated biphenyls
(PCBs), polynuclear aromatic hydrocarbons (PAHs), metals, and oils and greases.
Combined sewer overflows (CSOs) and municipal and industrial discharges are major
sources of contaminants within the AOC. Stormwater runoff and tributaries in Michigan
are also major sources of contaminants. Additional environmental concerns include
invasive species, changes in the fish community structure, and reductions in fish and
wildlife habitat. Detroit River priorities include: control of combined sewer overflows
(CSOs), control of sanitary sewer overflows (SSOs), point/nonpoint source pollution
controls, remediation of contaminated sediments, habitat restoration, and pollution
prevention.
The Black Lagoon had been severely impacted by historical contamination from
upstream industries. These impacts included the lagoon's reduced capacity to support
recreational activities such as swimming, fishing, and boating, as well as impairment of
lagoon aesthetics by oil floating on the water surface. The health of the aquatic life in the
water and sediments of the Black Lagoon, as well as wildlife along the shoreline, also
were adversely affected by the pollution.
One of the greatest pollution concerns was contaminants in the sediment underlying the
lagoon. Contaminated sediments are ingested by bottom-dwelling benthic organisms as
they feed and can be toxic to many of the invertebrates inhabiting the sediment.
Additionally, the chemical toxins can be concentrated up the food chain as larger
JANUARY 2008 1
-------
REMEDIATION OF THE BLACK LAGOON
organisms eat the smaller organisms. Contaminated sediments also have the potential to
be resuspended by storms and ship propellers, potentially contaminating other areas
downstream. Removal of the contaminated sediments was deemed necessary to lessen or
eliminate these pollution-associated risks.
The remediation of the Black Lagoon was a joint effort between the U.S. Environmental
Protection Agency (EPA) Great Lakes National Program Office (GLNPO) and the
Michigan Department of Environmental Quality (MDEQ). This project was performed
under the authority of the Great Lakes Legacy Act of 2002, with support from the Clean
Michigan Initiative (CMI) of 1998. Additional support for the project was provided by
the Detroit District of the U.S. Army Corps of Engineers (USAGE), the City of Trenton,
the American Heritage Rivers program, and several private firms operating under contract
to U.S. EPA and MDEQ.
1.1 GENERAL SITE DESCRIPTION
The Black Lagoon lies within the U.S. Fish and Wildlife Service's Detroit River
International Wildlife Refuge, the first international refuge so designated in North
America. The lagoon is a 3.5-acre cove of relatively still water in the Trenton Channel of
the Detroit River at the end of Helen Street in the City of Trenton, Michigan (see Figure
1-1).
The city's Meyer Ellias Memorial Park, which contains picnic and playground areas, is
immediately adjacent to the west side of the lagoon. Residential homes, private boat
slips, and a sea wall are located immediately to the south and southwest of the lagoon.
An open, flat area of private property (the E. C. Levy property) is located immediately
north of the lagoon area, and the defunct McLouth steel mill is approximately 0.5 miles
to the north. The mill closed in 1995 and is considered the primary source of sediment
contamination in the Black Lagoon.
The shoreline consisted of exposed sand and gravel, with broken concrete placed below
the water level to provide erosion and ice flow protection (prior to remedial activities).
Water depths vary from approximately 1 to 6 feet below Low Water Depth (LWD). The
JANUARY 2008
-------
PROJECT DESCRIPTION
lagoon is partially separated from the Trenton Channel by a sand/silt bar, which has water
depths of 0.2 to 1.8 feet below LWD.
Black Lagoon Location Map
Figure 1-1 Black Lagoon Remediation Site Location Map
1.2 SITE HISTORY
Numerous environmental studies were conducted from 1993 to 2003 by U.S. EPA,
MDEQ, and the USACE-Detroit District to investigate the extent of contamination in
Black Lagoon waters and sediments. (Floating oil and grease and the effects of pollution
on the Black Lagoon wildlife were readily observable by the neighborhood residents and
by the City of Trenton.) Results from these studies indicated elevated levels of several
contaminants, including concentrations of up to 11 mg/kg of mercury, 6.5 mg/kg of
PCBs, and 30,000 mg/kg (dry weight) of oil and grease. Such levels exceed the
Consensus-based Sediment Quality Guidelines (CBSQG) probable effect concentrations
(PEC) found in MacDonald et al. (2000). Table 1-1 provides a comparison of CBSQGs
to average concentrations of contaminants reported in the lagoon (see Appendix B for
surficial sediment concentrations for these and additional contaminants). Based on these
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
data and consideration of the most likely impacts to the AOC, mercury, PCBs, and oil and
grease were identified as the contaminants of concern (COC) for this site.
Table 1-1 Site Sediment Concentrations From 1999 Sediment Survey
Average Sediment Sediment Quality Ratio of Average
Concentration'1' Guideline Sediment
Contaminant (mg/kg, dw) (mg/kg, dw) Concentration to SQG
Mercury'2'
Oil & Grease(3)
Total PCBs(2)
4.24
6,039
2.6
1.06
2,000
0.68
4.0
3.01
3.85
Notes:
(1) Site mean determined as the mean of the weighted mean concentrations for each sediment core
(2) SQGs are based on the Probable Effects Concentrations found in MacDonald, et al. (2000), "Development and Evaluation of
Sediment Quality Guidelines for Freshwater Ecosystems"
(3) SQG is based on the "heavily polluted" designation found in U.S. EPA (1977), "Guidelines for the Pollutional Classification of
Great Lakes Harbor Sediments"
PCBs - Polychlorinated biphenyls (as Aroclors)
dw - Dry weight
Contamination of the sediments was observed at depths of 0.5 to 12 feet below the
surface of the sediment. Mercury concentrations were found to increase with depth in
some locations within the lagoon (Figure 1-2).
To address these challenges, U.S. EPA's Great Lakes National Program Office (GLNPO)
facilitated a workgroup comprised of MDEQ, U.S. EPA, the USAGE, the City of Trenton,
and American Heritage Rivers, that would undertake dredging of the Black Lagoon. This
project was identified in the 1996 Detroit River Remedial Action Plan as one of the
priority contaminated sediment cleanup sites in the river.
JANUARY 2008
-------
PROJECT DESCRIPTION
Black Lagoon
Mercury Concentrations
Pre- remediation (1990 study)
Top Core
0-73"
X
extitHier.illcn inlhe I dlreaion 'or v>w allzatun
Figure 1-2 Pre-remediation Sediment Mercury Concentrations at Depth in Black Lagoon
In March 2004, MDEQ submitted a proposal to GLNPO for GLLA funding to remediate
the Black Lagoon. USACE-Detroit District developed the remediation specifications and
related drawings with input from MDEQ and GLNPO.
Briefly, the project design consisted of four major components:
1) Dredge the contaminated sediments.
2) Convey the removed sediments by barge down the Detroit River to the Pointe
Mouillee Confined Disposal Facility (the facility is operated by the USAGE).
3) Cover the remaining sediment with clean sand and gravel.
4) Monitor the dredging process with appropriate testing protocols to ensure that
remediation activities did not cause further environmental contamination, and
sample the remaining sediments to verify that contaminants were removed as
planned before placing the clean sand and gravel cover over the dredged area.
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
1.3 PROJECT OBJECTIVES
The primary objective of this project was to remove the polluted sediments in the lagoon,
and improve the environment by mitigating impacts that affected the lagoon, its
inhabitants, and the surrounding community. The remediation of Black Lagoon
sediments was identified in the Remedial Action Plan (RAP) as one of many necessary
actions to move toward the de-listing of this AOC.
Two specific objectives were targeted with the following strategies:
1. Reduce relative risk to humans, wildlife, and aquatic life - Dredging and removal
of the contaminated sediments were planned to permanently reduce the amount of heavy
metals, PCBs, and oil and grease entering the lagoon food web. To further protect the
lagoon ecosystem from any remaining contaminants, the dredged areas were to be
covered with sand and gravel.
2. Restore the aquatic habitat within the Black Lagoon - Once contaminated
sediments are removed and covered with the protective cover, the food web and the entire
aquatic ecosystem will have a stable, non-toxic environment. Benthic organisms, in
particular, will benefit, along with the native fish and wildlife that feed on them. In
conjunction with the remediation project, the City of Trenton planned to use a grant for
habitat restoration to further encourage the return of native fish and wildlife species.
This remediation project along with many other actions recommended in the RAP has the
potential to directly impact the following Beneficial Use Impairments (BUIs):
Restrictions on fish and wildlife consumption, degradation of benthos, restriction on
dredging activities, and loss offish and wildlife habitat
A side benefit of this project was the revitalization of the economic and recreational
resources. Removal of the contaminated sediment would improve the aesthetic value of
the area and allow development projects to proceed safely. In order to meet these project
objectives, the Project Team established target levels for post-dredging sediment
concentrations for the three COCs as: 1 mg/kg for total PCBs (as Aroclors), 1 mg/kg for
mercury, and 2,000 mg/kg for oil and grease. The technical approach used to accomplish
these activities is discussed in detail in Sections 2-7 of this report.
6 JANUARY 2008
-------
PROJECT DESCRIPTION
1.4 PROJECT FUNDING
The Black Lagoon proposal was the first project to be accepted and funded under the
Great Lakes Legacy Act of 2002. This legislation was specifically developed to address
the contaminated sediment problem in Great Lakes AOCs. Together, the Great Lakes
make up one fifth of the fresh water on the earth's surface, providing water, food,
recreation, and transportation to more than 35 million Americans. The quality of this
resource is of great importance and, although the discharge of toxic and persistent
chemicals from industrial and municipal wastes into the Great Lakes has been
substantially reduced over the past 20 years, contaminated sediments remain at certain
sites, affecting water quality. Among other things, the Act provides for the remediation
of contaminated sediment in 31 U.S. Great Lakes Areas of Concern (AOCs).
The Act is divided into three components: projects; research and development; and public
information. Projects may be classified as either remediation (cleanup of sediments) or
non-remediation (monitoring or prevention of further contamination).
The $8.7 million Black Lagoon remediation project was funded with $5.6 million from
GLNPO under the GLLA and $3.1 million in non-federal matching funds from the
MDEQ.
1.5 PROJECT MANAGEMENT
Because the Black Lagoon project was a collaborative effort involving multiple partners,
a project management team was established to ensure effective communication, clear
understanding of responsibilities, and adherence to project requirements by all parties.
These project management strategies are summarized below.
1.5.1 Project Planning, Permits and Notifications
The U.S. EPA and MDEQ entered into a written Project Agreement for the Black Lagoon
remediation project. This Project Agreement documented the financial, technical, and
logistical obligations and responsibilities of the U.S. EPA and the non-Federal sponsor,
MDEQ, and included the financial coordination process that would be used to jointly
fund the project. Through this agreement, GLNPO and MDEQ developed a formal
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
strategy of commitment and communication to facilitate successful completion of the
project.
Project participants also reviewed all specifications and drawings developed by the
USACE-Detroit District. Project planning meetings were held at offices in Chicago and
at the project site to discuss and finalize key project activities (e.g., plans, permits,
technical methods, quality control requirements and procedures).
The prime contractor, Environmental Quality Management (EQ), developed a written
Project Work Plan (EQ, 2004) that documented the project goals, strategies, and
implementation plans. This work plan was approved by U.S. EPA and was supplemented
by a Quality Assurance Project Plan (QAPP) that documented the management and
quality systems implemented to achieve the objectives for the project. Together, these
documents provided a mechanism for ensuring that all project objectives and strategies
were clearly understood by all involved parties and that these strategies included a project
design and quality control procedures that would ensure that data collected during the
project would be reliable and of sufficient quantity and quality to support U.S. EPA
decisions regarding project.
EQ was responsible for securing all required permits, licenses, access agreements, and
making all notifications (e.g., the dredging permit, the MDEQ Environmental permit, and
access agreements with the City of Trenton and Meyer Ellias Park). Copies of all
permits, licenses, access agreements, and notifications were maintained at the project site
at all times.
1.5.2 Project Communication, Roles and Responsibilities
Communication procedures were defined in the QAPP (available as part of the Project
Record), and included regularly scheduled conference calls, progress meetings, daily
activity reports, and project management teams. GLNPO also assembled a Project Team
comprised of representatives from all parties involved in major project activities. The
role of the Project Team was to ensure communication among all staff involved in the
project, address technical and logistical issues as they arose, and communicate problem
resolution to all involved parties. Although GLNPO was responsible for serving as U.S.
JANUARY 2008
-------
PROJECT DESCRIPTION
EPA's lead office on the project, EQ's support to GLNPO was provided through an
existing U.S. EPA Region 5 contract. Therefore, representatives from both EPA offices
(GLNPO and Region 5 Superfund) participated in project management and project team
activities. The roles and responsibilities of key project management personnel are
identified in Table 1.2. All of the individuals shown in Table 1.2 served on the Project
Team.
\ao\e\-z. rrojeci i earn rcoies ana rcesponsimimes
Organization/
Key Person Role Responsibility
Marc Tuchman
Michael
Alexander
Michelle Jaster
Rosanne
Ellison
Louis Blume
David Bowman
Susan Boehme
Jack Greber
U.S. EPA GLNPO
Project Lead
MDEQ
Project Manager
U.S. EPA Region 5
Federal On-scene
Coordinator (FOSC)
U.S. EPA GLNPO
Remedial Action Plan
(RAP) Liaison for the
Detroit River AOC
U.S. EPA GLNPO
QA Manager
U.S. Army Corps of
Engineers (U.S.
ACE) point of contact
Illinois/Indiana Sea
Grant Liaison to U.S.
EPA
EQ
Project Director
• Primary GLNPO contact
• Financial and contractual monitoring
• Ensure that decision objectives are met at project
completion
• Primary MDEQ contact for EQ
• Coordinate with GLNPO on project requirements
• Financial and contractual monitoring
• Ensure that decision objectives are met at project
completion
• Primary U.S. EPA FOSC contact for GLNPO, MDEQ,
and EQ Project Team
• Oversee site activities
• Approve modifications to project plans relating to site
activities
• Point of contact for local issues
• Area of Concern (AOC) liaison
• Assist in the development of quality documentation
and identification of project quality objectives
• Ensure that all environmental collection activities
achieve appropriate quality documentation
• U.S. ACE point of contact
• Coordinate activities associated with confined
disposal facility (CDF) and other technical issues
• Outreach to community
• Prepare fact sheets and provide updated content for
U.S. EPA website
• EQ primary point of contact with the U.S. EPA FOSC,
GLNPO, U.S. ACE, and MDEQ
JANUARY 2008
-------
REMEDIATION OF THE BLACK LAGOON
Table 1-2 Project Team Roles and Responsibilities
Key Person
John Mullane
Organization/
Role
EQ
Project Manager
Responsibility
EQ point of contact with the U.S. EPA FOSC
Identify resource requirements and assign staff to
project teams
Develop and monitor project budgets and costs
Develop and implement field-related work plans;
ensure compliance with schedules and project
requirements
Participate in preparation of EQ's final project report
Robert
Armstrong
EQ
Site Manager
• Report to the EQ Project Manager and perform on-
site, daily communications with EPA, and
subcontractor foremen and supervisors
• Coordinate on-site work and inspections
Weekly conference calls were conducted during the course of the project to provide
progress updates and status reports to all involved parties. These meetings also were
used as a forum to communicate new issues and challenges that required resolution or
decisions. Urgent issues and challenges were communicated through ad-hoc conference
calls, meetings, or on-site discussions. Decisions resulting from on-site discussions were
documented by EQ in Daily Activity Reports. These reports were used to log all
decisions made in the field and are available in EQ's project files. Decisions resulting
from meetings and conference calls were documented through meetings minutes and
group emails.
Use of these carefully considered communication strategies and pre-arranged roles and
responsibilities enabled U.S. EPA to keep the project on track, despite the logistical
challenges at the remediation site. For example, after the project started, it was
discovered that the original pre-hydrographic survey of the lagoon had some errors that
were propagated through to the calculations of the sediment volume that needed to be
removed. The project managers held several on-site meetings to find an equitable
method of using the valid survey data and calculating sediment quantities to ensure that
this unforeseen problem would not delay remediation activities. Final resolutions of this
and other challenges were documented in the Daily Activity Reports and updates to the
work plan.
10
JANUARY 2008
-------
PROJECT DESCRIPTION
1.5.3 Public Outreach and Community Involvement
A variety of outreach activities were used to communicate information concerning this
remediation project to the community surrounding the Black Lagoon. These included
community meetings, public announcements, and ceremonies. One such ceremony in
September 2005 was jointly hosted by U.S. EPA Administrator Mike Leavitt and Larry
Arreguin, representing Governor Jennifer Granholm, to announce the initiation of the
Black Lagoon remediation project as the first project funded by the GLLA. Two public
meetings regarding the Black Lagoon project were held in 2004 to present detailed
information to the public and provide them with an opportunity to voice concerns.
EPA also maintains a Web site with links to Black Lagoon remediation information topics
and press releases. The site,
http://www.epa.gov/greatlakes/sediment/legacy/blklagoon.index.html, includes:
• Information about Black Lagoon cleanup site visits,
• Fact Sheets about the Black Lagoon project,
• New releases,
• Maps and aerial photographs of the Black Lagoon project region,
• This project report: Remediation of the Black Lagoon Trenton, Michigan, Great
Lakes Legacy Program, January 2008, and
• A Black Lagoon photo gallery with pictures of the different stages of the remediation
process, such as site preparation, installation of silt curtains, and transportation of
contaminated sediments on barges down the Detroit Channel.
Additionally, as a part of the outreach program, U.S. EPA maintains a Great Lakes
Legacy Act Web site with links to various topics, located at:
http://www.epa.gov/greatlakes/sediment/legacy/index.html.
1.6 DATA MANAGEMENT
Data collected during the Black Lagoon project were managed using procedures outlined
in the project planning documents. These procedures included using standard protocols
for recording field data and remedial activities, defined electronic data deliverables
JANUARY 2008 11
-------
REMEDIATION OF THE BLACK LAGOON
(EDDs) for laboratory data, chain-of-custody forms for transferred samples, and a data
logging system to track all field and laboratory data submitted for independent data
verification.
1.6.1 Data Management
EQ was assigned responsibility for managing most of the field data, laboratory data, and
other project information gathered during preparation and implementation of the project.
This included:
• Original planning documents developed for the project.
• Laboratory data generated during analysis of excavated material stockpile samples
(used to determine disposal specifications).
• Field records and a Daily Activity Quality Control (QC) Report that described
dredging work performed, areas dredged, estimated volume of material removed and
conveyed to the confined disposal facility (CDF), activities planned for the next day,
and environmental monitoring results. These environmental monitoring results
included the water quality and air monitoring data generated by on-site direct read
instruments and by Clayton Laboratory Services to confirm that the remediation
activities were not adversely affecting the health of the ecosystem, surrounding
environment, or the remediation staff.
• A Construction Documentation Report developed by EQ upon completion of the
project that includes an overview of the remediation.
To ensure effective handling of such data, EQ developed and implemented field-related
work plans and QC procedures for technical data generated by field staff.
GLNPO's QA contractor, CSC, was responsible for managing data associated with the
sediment confirmation sampling conducted after completion of each phase of dredging.
This sampling was conducted by MacTech, who reported the data to MDEQ and
GLNPO. GLNPO, in turn, forwarded their copy of the data to CSC. Data management
strategies for these activities are described below.
12 JANUARY 2008
-------
PROJECT DESCRIPTION
Sediment Confirmation Sampling Records. Logbooks and chain-of-custody forms were
used to document sediment confirmation sampling activities. Daily logbooks were used
to record field information, including weather conditions, personnel present, field
measurements and observations, and any deviations from original sampling plan.
Calibrations of any field equipment, including any calibration results, also were
documented in the logbooks. Instrument readings taken during the remediation were
documented in boring logs, in the field logbook, or both. Daily logbooks were stored at
the project site and were turned over to GLNPO for inclusion in the project file at the
completion of field activities. Upon collection, each sediment sample location, sediment
thickness and physical properties were recorded. Once samples were collected, a chain-
of-custody record was created for each sample. This record then accompanied the sample
until the analytical data had been accepted. After data quality was deemed acceptable, all
chain-of-custody forms were archived in the project file maintained by EQ.
Laboratory Records for Sediment Confirmation Samples. Sediment confirmation
samples collected by MacTech were analyzed by TriMatrix Laboratories. Because results
from these samples would be used to decide whether or not dredging activities must be
resumed, activities at the site were delayed pending receipt of the laboratory data. In
order to minimize costs associated with the delay of field activities, TriMatrix was
required to provide summary level data on a quick-turnaround basis and supplement the
data with a full data package. These summary level data included a subset of data
qualifiers for the sediment confirmation results. Following submission of these quick
turnaround summary level results, all laboratory data and records associated with the
sediment confirmation sampling were included in final analytical reports submitted to the
MDEQ Project Manager. Final data were delivered in the form of EDDs (electronic data
deliverables), as well as hard-copy data packages that included the analytical results,
quality control sample results, data narratives from the analytical laboratory, and the
chain-of-custody forms.
Results of the Independent Data Verification. GLNPO forwarded the TriMatrix data to
CSC for independent data verification. CSC followed standard procedures to receive and
manage all incoming sediment confirmation data. Data quality assessments were used to
JANUARY 2008 13
-------
REMEDIATION OF THE BLACK LAGOON
evaluate the quality of the Black Lagoon sediment confirmation data. CSC followed
standard procedures for verifying the sediment data (see the Black Lagoon Project
Record for CSC's data verification SOP). The purpose of the data quality assessment
was to verify that the data were of a sufficient quality to support their intended use. The
data verification process focused on evaluating the sediment confirmation data relative to
pre-determined measurement quality objectives (MQOs) specified in the QAPP to ensure
that only data of acceptable quality would be used for decision making. A data review
narrative was drafted to document results of the review (see the Black Lagoon Project
Record for the data review narratives). The narratives also included quantitative data
quality assessments which are an evaluation of the sensitivity, precision, and bias
associated with the data. No sediment confirmation sample results generated during this
project were invalidated for use based on the data verification.
1.6.2 Database
GLNPO developed a sediment confirmation database used to maintain and archive GLLA
project sediment contamination data from various projects. This database is referred to as
the Great Lakes Sediment Database (GLSED). This database contains sediment
confirmation data for project contaminants of concern and their respective location
information. Field observations and all relevant collection information also are stored in
the database. The database is compatible with the Query Manager Data Management
System administered by the National Oceanic and Atmospheric Administration.
1.6.3 Public Access
Upon request, GLNPO provides data generated for the Black Lagoon remediation project
to stakeholders and other interested parties. To facilitate distribution, a comprehensive
Project Record has been compiled and components are available to requestors. The
record contains all relevant documentation concerning the project, including project
planning and operational documents, fact sheets, analytical data, and all project reports.
Interested parties may contact GLNPO's Sediment Assessment and Remediation Team to
submit a request. In addition, and as discussed in the previous section, GLNPO expects
to provide public access through written request.
14 JANUARY 2008
-------
MONITORING IMPACTS OF DREDGING OPERATIONS
2.0 MONITORING IMPACTS OF DREDGING OPERATIONS
As part of the project design, an environmental monitoring program was conducted to
ensure that the remediation activities themselves were not adversely affecting the health
of the ecosystem, the surrounding environment, or the remediation staff, and were not
causing exceedances of applicable federal, state, and local standards. Air quality was
monitored prior to and throughout the project, as described in Section 2.1. Water quality
was monitored during the project as described in Section 2.2.
2.1 AIR MONITORING
A two-stage approach to air monitoring was implemented to ensure that release of
airborne contaminants was minimized and that air emissions from project construction
activities did not adversely affect air quality in the surrounding community. The first
stage involved assessment of background contaminant levels prior to project construction
activities. Collection of these pre-construction data provided a baseline for comparing
the emissions produced during the dredging process, as well as information on the quality
of the air entering the work zone. The second stage consisted of daily air quality
monitoring once dredging started and throughout the project duration.
Fixed sampling sites were established around the perimeter of the lagoon area. The
locations were established so that at least one sampling location would be downwind of
site operations, and at least one other station would be upwind and represent background
conditions (see Figure 3-1). Global positioning system (GPS) units were used to
physically locate each site, and personal sampling pumps were used to collect the air
samples. Samples were taken at each of these three perimeter locations on two separate
occasions prior to dredging operations to establish background levels of PCBs, lead, and
mercury. These samples are collected as 8-hour composites. Air concentrations were
determined using methods published by the National Institute for Occupational Health
and Safety (NIOSH), as shown in Table 2.1. All air samples collected during the project
were picked up from the site by a local laboratory (Clayton Laboratory Services) and
results were received within 48 hours. EQ evaluated the data and verified the usability of
the results by reviewing the associated method QC reported by the laboratory.
JANUARY 2008 15
-------
REMEDIATION OF THE BLACK LAGOON
Once the project began, air samples were collected from the same three perimeter
locations on each of the first six days of dredging and then biweekly thereafter, until the
end of dredging operations. As with the background samples, these air samples were
analyzed for PCBs, lead, and mercury using NIOSH Methods 5503, 7300, and 6009.
Any results at or above the reporting limit were evaluated against background results and
applicable permissible exposure limits (PELs). During a single day, PCBs were not to
exceed of 0.5 mg/m3 air, lead was not to exceed 0.05 mg/m3 air, and mercury was not to
exceed 0.5 mg/m3 air. Monitoring results indicated that there were no adverse effects on
air quality resulting from the construction activities, and all results recorded were less
than the applicable PEL.
During dredging, real-time air monitoring for volatile organic compounds (VOCs) and
particulate emissions also was conducted using direct-read instruments at each of the
perimeter locations. All air monitoring equipment was calibrated daily, and calibration
data were noted on the Daily Activity Report. These real-time samples were collected
and analyzed at the beginning and end of each shift and every two hours throughout the
work day on each day that dredging operations were conducted and recorded on the Daily
Activity Report. For total VOCs, the action level was considered to be 5 ppm sustained
for 15 minutes, and no exceedances of these levels occurred during the project. For
particulate emissions, a visible dust plume was an action level requiring notification and
corrective action. Additional air monitoring (beyond the fixed perimeter locations) was
performed at various locations at the request of the Federal on-scene coordinator (FOSC)
or designated representative. The locations and results of this additional air monitoring
were reported on each day's report. Any results above background also were accounted
for and noted on the daily report.
16 JANUARY 2008
-------
MONITORING IMPACTS OF DREDGING OPERATIONS
Table 2-1 Air Monitoring/Sampling Activity, Parameters, and Frequency
Air
Monitoring/
Sampling
Activity
Parameter/
Method
Number of
Locations/
Identified
Task
Frequency
Results
Perimeter
Air
Sampling -
Background
Perimeter
Air
Sampling -
Definitive
Perimeter
Air
Monitoring -
Real Time
Personnel
Air
Monitoring
PCBs/NIOSH
5503
Pb/NIOSH 7300
Hg/NIOSH 6009
PCBs/NIOSH
5503
Pb/NIOSH 7300
Hg/NIOSH 6009
VOCs and
Particulates via
direct read
instruments
Lagoon:
PCBs/NIOSH
5503
Pb/NIOSH 7300
Hg/NIOSH 6009
CDF:
PCBs/NIOSH
5503
Pb & Cr/NIOSH
7300
Hg/NIOSH 6009
3 locations -
lagoon
3 locations -
lagoon
3 locations -
lagoon
1 location -
lagoon
(dredge
operator)
3 locations -
CDF (truck
driver,
excavator
operator,
bulldozer)
All locations were
sampled in 2 separate
events prior to any
dredging operations.
All locations were
sampled the first 6
days of dredging
operations and
biweekly thereafter.
All locations were
monitored every 2
hours throughout the
workday on any day
that dredging
operations were
conducted.
Each task was sampled
the first 6 days of
dredging operations
and biweekly
thereafter.
PCBs: All results
non-detect
Pb: All detected
results < PEL
Hg: All detected
results < PEL
PCBs: All results
non-detect
Pb: All detected
results < PEL
Hg: All detected
results < PEL
VOCs: All results
non-detect
Particulates: All
results < project
action levels
PCBs: All results
non-detect
Pb: All detected
results < PEL
Hg: All detected
results < PEL
Finally, air samples were collected in the proximity of personnel associated with different
tasks at both the lagoon and the confined disposal facility (CDF). At the lagoon, air
samples were collected in the cab of the dredging excavator. At the CDF, air samples
were collected in the excavator, bulldozer, and dump truck. As with the perimeter
samples, these samples were collected as 8-hour composites once per day for each of the
first six days of dredging operations and biweekly thereafter, and were analyzed for
PCBs, lead, and mercury using the same NIOSH methods used to analyze the perimeter
samples.
JANUARY 2008
17
-------
REMEDIATION OF THE BLACK LAGOON
All sampling and analysis activities were conducted in accordance with the approved
Quality Assurance Project Plan (QAPP). Data were formatted to facilitate QC review by
EQ's Corporate QC Director or her designee. During this QC check, the reviewer
identified any out-of-control data points and omissions and interacted with the laboratory
to correct data deficiencies. QC reviews were reported in the Daily Activity Reports on
the same day that results were received, along with any results above the reporting limit.
In addition to the QC review of all data reported, a complete data validation was
performed on 10% of the data collected, as described in the project QAPP.
2.2 WATER QUALITY MONITORING
Water quality monitoring was conducted on a daily basis during dredging activities to
ensure that contaminants from the dredged sediments were contained. Turbidity was
used for evaluating the water quality.
Water quality samples were collected at three locations
relative to the silt curtain: 300 feet upstream; 300 feet
downstream; and 600 feet downstream. The criteria for
evaluating turbidity for the project were established as
follows: if turbidity measurements taken at the sample
point 300 feet and/or 600 feet downstream are greater
than 150% of the measurement taken 300 feet upstream
during dredging activities, dredging was discontinued,
results were evaluated with the regulators, and potential
engineering controls were implemented.
Turbidity measurements were taken at mid-depth within the water column every 2 hours
when dredging operations were underway. Turbidity was initially monitored using in-situ
monitoring stations capable of taking turbidity measurements at any time, and the data
were transmitted via radio telemetry to a data logging receiver onshore. These data were
recorded on a laptop for evaluation purposes and reported in the Daily Activity Report.
During the winter months, the monitoring stations were removed to avoid potential
damage from ice flows. The 6-inch pilings used to support the telemetry equipment were
left in the river to mark the turbidity monitoring locations, and a 2-person crew working
18
JANUARY 2008
-------
MONITORING IMPACTS OF DREDGING OPERATIONS
from a small boat collected turbidity measurements from these locations every 2 hours
using a hand-held in-situ turbidity meter.
Turbidity samples were always collected at the upstream location prior to the downstream
location, and downstream results were evaluated against upstream results. In addition to
these pre-planned upstream and downstream locations, turbidity readings also were taken
along the silt curtain, both inside and outside the dredge area, to verify that there was no
release of suspended sediment into the river system. The locations of these additional
sampling sites were coordinated by EQ and the FOSC or designated representative; these
locations and associated turbidity readings were documented in the Daily Activity Report.
Twice-daily visual observations were made of the silt curtain and the area downstream
from the lagoon. If a water quality problem was observed, such as an oil sheen on the
water, additional inspections were performed. As with other exceedances, the
information was immediately provided to the on-site government representative and
documented in the Daily Activity Report. In all situations, the exceedances were
confirmed to be either weather-related, or the result of physical activity in the proximity
of the monitoring stations (i.e., boat traffic).
Early in the project, all turbidity exceedances could be correlated with tugboat and barge
movement near the remote turbidity stations. On several occasions, as the project
progressed and the turbidity curtain began to show signs of wear, however, there were
visual observations of turbidity outside of the project area. In these instances, all work
was ceased and hand-held turbidity readings were taken in the visually turbid area.
Although there were no exceedances of the limits in the dredging permit, work was not
resumed until the apparent cause of the turbidity was located and corrected.
JANUARY 2008 19
-------
REMEDIATION OF THE BLACK LAGOON
3.0 SITE PREPARATION AND SET UP
Before remediation activities began, several site preparation and set up activities were
necessary at both the Black Lagoon and at the Pointe Mouillee confined disposal facility
(CDF). The CDF is a 700-acre crescent-shaped dike designed to contain contaminated
dredged materials from the Detroit and Rouge Rivers. It is located in Lake Erie at Pointe
Mouillee, Michigan, and is operated by the USAGE. As part of the project design,
contaminated sediments removed from the Black Lagoon were transported to the Pointe
Mouillee CDF. Site preparation and set up activities at the Black Lagoon and the CDF
included establishing work zones, conducting site surveys, establishing site security
controls, and preparing the CDF for receipt of Black Lagoon sediments. Site setup began
on Monday, September 27, 2004. These activities are described in Sections 3.1 - 3.4,
below.
3.1 SITE SURVEY
Both the lagoon and CDF work areas were surveyed prior to mobilizing activities at these
sites. The lagoon area was surveyed to delineate property lines and to provide proper
placement of the perimeter security fence. The CDF was surveyed to define the limits of
the sub-cell disposal area in Cell 5, prior to placement of dredged materials, and for
positioning of a cross-dike that was to be constructed along the southern end of the sub-
cell between existing perimeter dikes.
Prior to initiating the project, access agreements were established with the City of
Trenton and private property owners. Existing limits of all property to be accessed and
utilized under the project were located and properly identified. This property included
the areas to be remediated as well as the supporting areas used for staging operations and
access. Property for which rights had been obtained was surveyed and property lines
identified with semi-permanent markers, except where there were existing approved
markers. Prior to beginning the removal operation, a pre-dredge hydrographic survey
was conducted to establish baseline conditions. This survey is discussed in Section 4.2.1.
3.2 SITE SECURITY
A perimeter fence was erected that encompassed the land utilized under access
agreements with the City of Trenton and private property owners. This fence provided
20 JANUARY 2008
-------
SITE PREPARATION AND SET UP
security for equipment and materials, and restricted access by the general public. To
further enhance security and ensure the safety of site personnel and the public, a
uniformed security guard was stationed at the lagoon area during non-working hours, and
around the clock at the CDF. Figure 3-1 provides general schematic drawing of the
lagoon work area.
AIR MONITORING
TURBIDITY SAMPLE POINTS
LAYDOWNAREA
FENCE
TRAILERS
SHORELIHE
ROA.D
NEW ROAD
HARBOR BOOM
SILT CURTAIN
SECOND SILT CURTAIN
RMUGflID
BARGE
f*rte. Lagoon s tr&de Bw silt curtams
and shoralin*
Figure 3-1 Schematic Drawing of Black Lagoon Remediation Site
3.3 CDF SITE CONSTRUCTION AND PLACEMENT
3.3.1 CDF Preparation
Setup, preparation, and construction work was necessary to prepare Cell 5 of the facility
for acceptance of the excavated sediments. Figure 3-2 provides a map of the barge route
from the Black Lagoon to the Pointe Mouillee CDF. Cell 5 is located in the northwest
corner of the CDF. These CDF preparation activities involved:
JANUARY 2008
21
-------
REMEDIATION OF THE BLACK LAGOON
1) Making required enhancements at the transfer station and offloading area for
transferring the dredged material from barges to haul trucks and/or to the temporary
storage area;
2) Constructing a temporary sediment storage cell near the transfer station;
3) Clearing and grubbing (removing vegetation from the roots) Cell 5;
4) Construction and enhancement of haul roads; and
5) Construction of the sub-cell area within Cell 5 that received the dredged contaminated
sediment.
Figure 3-2 Map of Detroit Area with Barge Route from Black Lagoon to the Pointe Mouillee CDF
3.3.2 Construction of Transfer Station/Offloading Area
A temporary transfer facility was constructed in the south interior channel of the CDF,
next to the existing pump-out platform. The existing structures in this area were removed
and replaced upon completion of offloading activities. Six large H-piles were installed to
provide moorings for the working deck barge and sediment transfer barges during
offloading operations. The storage pad area and roadway north of the transfer site were
22
JANUARY 2008
-------
SITE PREPARATION AND SET UP
cleared, grubbed, and leveled to accommodate equipment and offloading operations.
Additional gravel/stone was added to improve the stability of the area and enhance work
operations. This work and storage area was used as the general construction support site
and consisted of a small office trailer, tool shed, and portable toilets; heavy equipment
fueling and parking; and material lay down.
A shallow depression was constructed in the storage pad area to accommodate temporary
storage of sediment. This structure was 6 feet deep and approximately 75 feet x 100 feet,
and was lined with 30-mil PVC with 24 inches of overlap at every chemically welded
seam. A dike was constructed around the storage area to prevent releases into the
channel.
Soundings were taken across the full width and length of the transfer site prior to start-up
and immediately after completion of all transfer operations. Accumulated material that
fed into the channel around the transfer facility during off-loading operations was
removed after the final soundings were taken, and all data were provided to USAGE.
Clearing and Grubbing. The cell and borrow pit areas were cleared and grubbed of
existing vegetation (e.g., Phragmites) and small trees (cottonwood, willows, etc.). The
interior slopes and floor of the cell were cleared using a dozer and excavator. All
vegetation refuse was disposed of within Cell 5.
Haul/Dump Road Construction. A temporary haul road was constructed within the
containment cell to facilitate offloading of dredged material. This road bisected the cell
from east to west and included a temporary ramp at both ends. Due to extreme moisture
conditions of the cell floor and heavy rains early in the project, it became necessary to
deviate from the original work plan and utilize the cross dike as a road. Sediment was
dumped from the cross dike and from other strategic locations around the perimeter of the
cell. These sediment piles were spread from the outer edges of the cell toward the center
and compacted in 2-foot lifts. Eventually, the entire cell was graded to drain to the center
of the cross dike, where a weir was installed to prevent stagnant water from
accumulating. (See Section 4.3.6 for additional details concerning placement of the
dredged materials.)
JANUARY 2008 23
-------
REMEDIATION OF THE BLACK LAGOON
Cross Dike Construction. A new interior cross
dike was installed along the southern end of the
sub-cell between the existing perimeter dikes.
The interior dike segregated and confined the
dredge materials from existing and future
materials in Cell 5. The dike was constructed in
accordance with USAGE drawings and
specifications.
Dike construction material was originally to be obtained from within Cell 5, in the
borrow area shown on the USAGE drawings. This material was inappropriate, due to its
water content and composition, therefore, material was conveyed from the offloading
area to the cross dike location via 35-ton off-road articulated dump trucks.
Placed borrow materials were shaped, graded, and compacted using a D6 LPG dozer.
Soil material was placed in layers not more than 12 inches in loose thickness. Each layer
was compacted by a minimum of 3 passes of the D6 LPG. Dike construction tolerances
adhered to the required engineering specification of plus 0 and minus 6 inches.
Existing Dike Liner. A 2-foot soil layer was
placed over the interior of the existing dike to
cover the riprap and to prepare the surface for
placement of the synthetic liner. The soil
materials were obtained from areas directly
adjacent to the interior of the existing dike (i.e.,
the soil/dredge spoil material that is in the floor
of Cell 5).
The soil was placed in layers not more than 12 inches in loose thickness, and each layer
was compacted by a minimum of 3 passes of the D6 LPG dozer. Woven fabric liner of
polyethylene geotextile was installed along the interior slope of the existing perimeter
dike to confine the solidified dredged material and to prevent any seepage through the
dike wall into Lake Erie or the Pointe Mouillee Wildlife Refuge. Inspections were made
24
JANUARY 2008
-------
SITE PREPARATION AND SET UP
prior to liner placement to ensure no protruding objects existed that could cause damage
to the liner. The geotextile was placed with the long dimension parallel to the existing
dike and laid smooth and free of tension, stress, folds, wrinkles, or creases. The strips
were placed to provide a minimum 24 inches of overlap for each joint and each joint was
sealed per the manufacturer's specifications. Geotextile installation did not exceed the
placement of dredged material by more than 100 linear feet, per the USAGE
specifications.
Overflow Weir Construction. An overflow weir was installed in the interior dike in
accordance with USAGE drawings and specifications. The weir helped properly manage
and control free water in the sub-cell, and mitigate any oil sheen formation.
JANUARY 2008 25
-------
REMEDIATION OF THE BLACK LAGOON
4.0 DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
4.1 CONTAINMENT OF THE DREDGE AREA
A silt curtain was installed to enclose the entire lagoon and protect the adjacent river from
releases of suspended sediment during dredging operations. Dredging was not allowed
within 10 feet of the silt curtain. The curtain measured 1,500 feet long by 25 feet deep
and consisted of an 18-ounce laminated vinyl polyester fabric; heat-sealed seams; 5/8-
inch polypropylene twisted rope edge reinforcement; 8-inch by 8-inch by 8-inch EPS
foam blocks for buoyancy; aluminum stress plates at the corners; 5/16-inch galvanized
ballast chain; and 5/16-inch galvanized steel top-load cable.
The original work plan called for
anchoring the turbidity curtain every 50
feet to a pipe piling at the water surface
and to the river bottom using H-beams
attached to the ballast chain. Due to strong
and erratic currents, the initial placement
failed. The project team explored several
options with USAGE and decided to
decrease the spacing between anchor
pilings to 10 feet.
This method proved to be successful for a short period of time (approximately 60 days).
However, sporadic tears in the fabric eventually appeared. The tears were addressed by
adding additional layers of turbidity curtain at the tear locations. This method eventually
failed when the river current scoured a hole under the turbidity curtain. Ultimately, an
inner curtain made from a permeable material was deployed along the entire length of the
project. This curtain performed very well and proved successful for the remainder of the
project (Figure 3-1).
To reduce the need for mechanically handling ice inside of the turbidity curtain, eight to
ten bubblers were strategically placed within the lagoon to circulate the water and prevent
ice formation. As described in Section 2.2, ice flows in the river made it necessary to
26
JANUARY 2008
-------
DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
remove the existing fixed turbidity stations from within the Trenton Channel; the
turbidity readings continued as per the permit requirements utilizing a handheld turbidity
monitor and work boat or harbor tugboat. These readings were documented and reported
in the same manner as previously required.
A 12-inch harbor boom was placed along the
inner perimeter of the turbidity curtain to
provide added containment of any potential
oil sheen. Sorbent boom was also maintained
directly inside the harbor boom to provide a
secondary level of containment for potential
oil sheen. Emergency oil spill containment
equipment and materials were maintained
on-site at all times in the event of oil releases during dredging operations.
All turbidity curtain and boom containment structures were kept in place during active
dredging operations within the contaminated lagoon areas, and these safeguards remained
in place until the water quality within the dredge area met the water quality standards
specified by MDEQ and USAGE. At a minimum, the curtain and boom were inspected
daily to ensure that they were intact and in good working condition. Any damage or
performance problems discovered with these structures were documented and
immediately reported to on-site government representatives. Necessary repairs or
adjustment were made immediately, and dredging did not proceed until these
modifications were completed.
4.2 MECHANICAL DREDGING
Dredging occurred in two phases. Phase I of the dredging operations was accomplished
using a long-reach excavator and a CAT excavator with an environmental clamshell. The
excavators were mounted on two deck barges, and dredged material was placed into a
steel hopper on the back of the barge. The sediments were allowed to drain through weep
holes in the hopper that were equipped with filters to prevent resuspension of sediment in
the lagoon. The CAT excavator was used to remove the lighter density material first and
the long-reach excavator was used subsequently to remove the remaining sediment to a
JANUARY 2008 27
-------
REMEDIATION OF THE BLACK LAGOON
depth of between 13 and 15 feet below LWD, or until hardpan or clay was reached.
These activities are detailed below in Section 4.2.1.
After completing the first phase of dredging, the remaining sediments were sampled and
analyzed to verify that the dredging activities reduced contamination to acceptable levels.
However, results of these analyses indicated that high concentrations of the contaminants
of concern still remained, so a second phase of dredging was conducted to remove an
additional 1 to 3 feet of sediment. Unlike the sediments removed during the first phase,
the layer of sediments targeted during Phase II consisted of fine-grained material that was
difficult to remove using the excavation methods implemented in Phase I. The
management team looked for an alternative method that could remove the light sediments
and decided to use a mechanical dredge plant equipped with an environmental clamshell.
New technology was employed to carefully track the excavation process; survey
equipment and software (Hypack's Dredgepack® system) allowed the location data to be
recorded during the process. Material from the excavator was offloaded directly into the
hopper barges on the dredge plant. In addition to the change in dredging operations for
Phase II, additional environmental controls were implemented. A second turbidity
curtain was installed perpendicular to the inner permeable curtain to completely enclose
the dredge area. Four additional curtains were installed to create 5 separate cells. Single
cells ranged from 150 to 200 feet wide. Three to seven pieces of pipe were used to
prevent sediment migration along the bottom. Phase II dredging procedures are detailed
in Section 4.2.2.
4.2.1 Initial Dredging Operations (Phase I)
Prior to beginning the removal operation, a pre-dredge hydrographic survey was
conducted to establish baseline conditions. These soundings were performed with
hydrographic sounding equipment and software. The original intent was to conduct the
survey jointly with USAGE, but due to scheduling conflicts, EQ's marine subcontractor
and a technician from the software manufacturer conducted the survey. The pre-dredge
survey results were presented to the on-site USAGE representative, who approved the
survey prior to dredging. As the actual dredging effort progressed, it was discovered that
several measurement errors in the pre-dredge survey had gone unnoticed. These errors
28 JANUARY 2008
-------
DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
caused the calculation of material dredged to be incorrect, and as progress surveys were
conducted, the error in quantities increased in frequency. When the problem was
discovered, the survey data were reviewed by USAGE and EQ engineers to determine an
equitable way to effectively utilize the large amount of valid survey data that was
available. This resulted in several on-site meetings during which parameters were agreed
upon for using the pre-dredge survey data and for making sediment quantity calculations
(see Daily Activity Report dated 2/9/05). Mechanical dredging began with the side slope
stabilization area (SSSA), specifically the sandbar, at the far northeast portion of the
project area (Figure 4-1).
Black Lagoon Side Slope
Stabilization Areas
» too 200
AM
Legend
Side Slop* Stabilization Areas
— Sid* Slope Contours above w«1
Shoreline
Figure 4-1 Map Showing Side Slope Stabilization Areas (SSSA)
Upon completion of removal of the sandbar, a survey was conducted and EQ was
informed by the USAGE on-site representative that the area was over-dredged and not in
accordance with the specifications set forth in the engineer's drawings. This resulted in a
meeting with all involved parties, during which it was determined that the available
drawings were inadequate and the intent not clear. All parties agreed that the existing
JANUARY 2008
29
-------
REMEDIATION OF THE BLACK LAGOON
material would be shaped to conform as best as possible to the intent of the riprap
structure that was to be placed in this area. Once the SSSA was shaped to the new
specifications issued by the USAGE, a lead line was used for sounding measurements for
this area. Riprap was laid over the entire SSSA to the depths specified by the USAGE.
Following removal of the sandbar, dredging progressed from the northeastern end
(upstream) of the lagoon toward the southern end of the project limits (downstream).
Dredging continued from the channel area towards the shoreline. This pattern was
maintained throughout the first phase of dredging.
Phase I dredging was accomplished by
mechanical means with a 320L long-reach
excavator and a CAT 23 SDL excavator
equipped with an environmental clam-
shell. The excavators were mounted on
two deck barges, 28'xlll' (#744) and
33'xl38' (#102), equipped with spuds.
Dredged material was placed into a steel
hopper located on the back of each dredge
barge (dredge plant). The hoppers contained weep holes, which allowed necessary bulk
dewatering of the sediment. Absorbent pads or sausage boom were placed on and around
the hoppers to contain any oil. A silt fence and filter fabric panels were attached on the
inside of the hoppers in front of the weep holes. This allowed the material to shed water,
yet prevented as much re-suspension of the sediments as possible.
Dredging began by removing the top "light weight sediment" utilizing a closed hydraulic
clamshell bucket on the CAT 23 SDL excavator to reduce the amount of sediment re-
suspension. After the light layer of sediment was removed and a stiffer silty clay layer
was reached, the CAT 330 long-reach excavator followed behind and removed the
remaining contaminated sediments. Sediment was removed to a minimum depth of 13 to
15 feet from LWD, based on IGLD 85 Datum, or until hardpan was reached anywhere in
30
JANUARY 2008
-------
DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
between these depths. After the hoppers on the dredge plants were loaded to capacity, the
operation transit!oned to the loading of the transport barges.
Check soundings were conducted during dredging operations using a lead line and
hydrographic survey equipment.
4.2.2 Modified Dredging Operations (Phase II)
Alternative dredging methods were necessary to remove the 1 to 3 feet of fine grained,
unconsolidated sediments targeted during the second round of dredging. These sediments
were difficult to remove due to the material density, which was only slightly above that of
the water, allowing the sediment to shift along the bottom of the lagoon. It was the
opinion of all parties involved that even the simple action of moving a barge or
penetrating the sediment with an open bucket or clamshell was sufficient to cause
sediment shifting. To overcome this problem, several bench-top experiments were
conducted to evaluate the efficiency of alternative operational procedures and methods,
including increasing the density of the sediment. Methods tested included: the use of
mulch and bentonite to compress the sediment, thereby increasing its density; a slow rate
of descent and ascent of a clamshell; and the addition of a polymer to control re-
suspension. Upon completion of these investigations and lengthy discussions with all
involved parties, the following changes in operational procedures were implemented.
Dredging Equipment. One mechanical dredge plant equipped with an 8-ton crane and a
4-cubic yard environmental clamshell replaced the two dredge plants equipped with
hydraulic excavators. This dredge plant was also outfitted with real-time positioning
software, which monitored the horizontal position of the dredge plant as well as the
horizontal and vertical position of the clamshell. The dredge plant offloaded directly into
the hopper barges, which were shuttled to the solidification and offloading area on the
northern shore of the lagoon, using the 35-ft harbor tug. There were no changes in
solidification or transportation procedures other than the amount of solidification agent
used. A 15% increase was required because bulk shedding of water was eliminated from
the operation.
JANUARY 2008 31
-------
REMEDIATION OF THE BLACK LAGOON
Additional Environmental Controls. An
additional turbidity curtain was
strategically placed perpendicular to the
inner permeable curtain (i.e., east to
west). The curtains were bolted together
from surface to sediment and prevented
recontamination as each cell was
completed. In addition to the turbidity
curtains, a barrier consisting of 3 to 7
pieces of 4-foot by 50-foot HDPE pipe was also used to prevent sediment migration
along the bottom of the lagoon. Each section of barrier pipe was floated into position
prior to dredging a cell and located approximately 25 feet beyond each curtain placement
location. The pipe was flooded and weighted with pipe saddles to overcome neutral
buoyancy and each end was marked with buoys.
Operational Procedures. Phase II dredging began in the far south end of the lagoon and
proceeded to the north. The lagoon was divided into isolated cells by installing turbidity
curtains that ran from the main curtain to the shore. The isolation curtains extended from
the surface of the water to the bottom of the lagoon. The curtains were held in place by
steel pipe pilings and weights attached to the bottom of the curtain. Individual cells
ranged from 150 to 200 feet wide (north to south). Length of the isolation turbidity
curtains varied depending on location in the lagoon, but generally ranged between 250
and 350 feet.
Four isolation curtains were installed,
creating five cells. All isolation curtains
were attached to a new inner perimeter
curtain before any dredging began, but
isolation curtains were not positioned or
pulled into place until a cell had been
dredged. Dredging along the northern
edge of each cell extended approximately 25 feet beyond the limits of the cell, up to the
32
JANUARY 2008
-------
DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
barrier pipe, and then the isolation curtain was pulled into place. Survey data for the
entire lagoon were updated and recorded throughout the dredging process by the onboard
equipment and software prior to designating an area as completed and before placing the
isolation curtain. After the isolation curtain for an individual cell was placed, the barrier
pipe was pumped out, floated into its next position, flooded again, weighted, and sunk
into place. This allowed the operator to overlap dredging areas to ensure that the best
possible coverage was achieved. In conjunction with the above procedures, careful
operation of the clamshell was crucial to the overall success of the project. For this
reason, Hypack's Dredgepack® system was employed and individual training conducted
on-site, prior to, and during, dredging activities. Training was provided directly by
Hypack. In addition to technology and training, clamshell descent and ascent through the
water column was restricted to a maximum of 1 foot per second, minimizing
resuspension in the water column.
Procedural Steps/Order for Silt Curtain and Barrier Pipe Placement. Placement of the
segregation structures and dredging progressed from south to north (Cell 1 to Cell 5).
Specific work activity proceeded as follows:
1. Barrier pipe was placed from east to west, approximately 25 feet north of the location
of the curtain to be placed perpendicular to the shoreline.
2. Dredging proceeded up to the barrier pipe.
3. After dredging was completed up to the barrier pipe, the curtain was placed inside,
isolating that cell from the remainder of the lagoon.
4. Barrier pipe was evacuated and floated into position approximately 25 feet north of
the next cell to be dredged and flooded again.
This process was repeated until the project was completed, at which time, the pipe and
curtains were removed from the lagoon and disposed of appropriately.
Daily Activity Quality Control (QC) Report. A Daily Activity QC Report addressing
dredging activities was presented to the on-scene coordinator or their designee. This
report described dredging work performed, areas dredged, and environmental monitoring
JANUARY 2008 33
-------
REMEDIATION OF THE BLACK LAGOON
results (e.g., water quality and air monitoring). The estimated amount of material
removed daily and conveyed to the CDF was documented, and planned work for the next
day was described. Other remarks or clarifications pertinent to the dredging operation
were documented, as needed, in the appropriate section of the report. When trucking
became the primary mode for the transport of dredge material to the CDF, these activities
were described in the daily report in a similar manner. Corporate QC (CQC) inspection
data and photo-documentation records were maintained throughout the sediment removal,
transfer, and placement operations. CQC inspection procedures and reports were
attached to the daily activity reports when applicable and maintained on-site throughout
the duration of the project.
4.3 DISPOSAL OF DREDGED MATERIAL
During Phase I of the dredging operations, transport barges were used to transport the
sediment to the CDF until January 2005, when ice in the river prevented travel up the
channel. A contingency in the work plan allowed for trucking the sediment, so this
method was implemented for the remainder of Phase I and for Phase II. These activities
are detailed below in Sections 4.3.1 through 4.3.7.
4.3.1 Loading of Transport Barges During Phase I Dredging Operations
Transport barges were loaded outside of the
silt curtain. This was accomplished by
locating the transport barges immediately
adjacent to the outside perimeter of the
curtain, and then loading them by extending
the excavator boom over the curtain from the
dredge plant and dumping the material into
the transport barges. Various engineering
controls and careful operator practices were used to prevent removed sediment from
being released into the river channel. The primary control was a "spill prevention plate,"
which consisted of a steel plate that overlapped the transport barge and the silt curtain and
lead back to the dredge plant. This plate was welded to 6 of the steel pipe pilings that
34
JANUARY 2008
-------
DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
anchored the turbidity curtain and was hinged to allow it to adjust to the varying height of
the transport barge as it was loaded.
4.3.2 Transporting Dredged Materials to the CDF
Three transport barges were used to convey the
dredged materials to the government-provided
CDF on Pointe Mouillee. The barges were moved
using the Robin Lynn, a 90-foot, 1,800-
horsepower tugboat, up the Trenton Channel to
the north, under the Grosse He toll bridge, and
into the Detroit River Channel.
4.3.3 Stabilizing Barged Dredge Materials at the CDF
Dredged material was mixed with Calciment to solidify the material. Solidification
greatly reduced the risk of releasing sediment back into the environment during handling
and conveyance operations. The Calciment was stored at the CDF offloading site
described in Section 3.4.1. The stabilizing agent was mixed with dredge material in the
transport barges prior to offloading at the CDF. The temporary storage pit was intended
to be used in the case of a rain event to prevent shutdown of dredging activities. Due to
the composition of dredge material and the amount of water separation that occurred
during transportation to the CDF, material was solidified on the barge and transferred to
the storage pit for further solidification prior to placement in the cell.
Given the inherent nature of the mixing and transfer operations, some sediment re-
entered the adjacent water surrounding the offloading area. Engineering controls were
employed to isolate the spillage to that area and consisted of surf ace-to-bottom
impermeable curtains and harbor and absorbent booms. Upon completion of offloading
operations, the adjacent waters were dredged and the engineering controls were removed.
With the onset of winter, ice in the channel prevented barge transportation to the CDF.
Beginning in January 2005, transportation via truck to the CDF was implemented with
much success, as described in Section 4.3.5 of this report.
JANUARY 2008
35
-------
REMEDIATION OF THE BLACK LAGOON
4.3.4 Offloading and Conveying Barged Dredge Materials
Dredged sediment from the Black Lagoon was
received at the transfer/offloading area of the
CDF. The tug and barges entered the CDF
through the Southeast Interior Channel, where a
smaller harbor tugboat (e.g., 35-foot, 300-
horsepower) was used to maneuver the barges
and place them at the transfer site. The barges
were moored next to the H piles and the working deck barge at the temporary, contractor-
installed, transfer site.
After the full barges were moored, the previously unloaded barges were transported back
to the lagoon by the 90-foot tugboat, Robin Lynn. Sediments were removed from the
barges with a CAT 330 long-reach excavator positioned on shore and an 85-ton
Manitowoc crane positioned on the adjacent working deck barge. The sediments were
offloaded from the barges directly into the storage/solidification pit and then into 35-ton
off-road articulated dump trucks. Sediment was transported from the offloading area to
the Cell 5 placement area using four articulated dump trucks.
4.3.5 Trucking and Contingency Plan Operations During Phases I and II
In late December 2004, severe winter
weather and hard freezing occurred. The
river channel became clogged with ice and
impassable at the toll bridge and at the
entrance to the CDF. These weather
conditions required implementation of the
trucking contingency plan. Implementing
the trucking contingency plan included
moving the GTB2 barge into the lagoon
and positioning it along the north shore.
""'"if Jifjil
This barge was used to solidify the sediment, which was then directly loaded into trucks.
To accomplish this, a small area of the shoreline (i.e., the bank of the lagoon) was
36
JANUARY 2008
-------
DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
excavated to bring the barge as close to the shore as possible. The excavated material
was solidified with Calciment and transported to the CDF. The area that was excavated
along the north shoreline was approximately 150 feet x 40 feet x 4 feet. The amount of
Calciment required to solidify the excavated material averaged approximately 17% over
the course of the project.
A loading platform was constructed to offload the barge into trucks, using approximately
60 linear feet of sheet piling to create a wall at the shoreline. Limestone aggregate was
used to raise the grade behind the sheet piling wall from the existing grade of 576.5 feet
to an elevation of 583.5 feet. Placement of the GTB2 barge immediately adjacent to the
shoreline/sheet piling prevented inadvertent spillage of dredged material into the lagoon
during the offloading process. Once all dredging operations were complete, the sheet
piling was removed and the area restored.
The solidification agent (Calciment) was staged directly west of, and adjacent to, the
raised aggregate landing. Calciment was added into the barge and mixed in place prior to
direct loading into trucks. Mixing operations were closely monitored to ensure that no
free liquid existed prior to loading the dredged material into trucks for transportation over
the road. Calciment was stored in a secure area surrounded on 3 sides, to protect it from
prevailing winds and minimize dust migration (see Figure 4-2). This same equipment
also was used to load the transport trucks. The existing air/dust monitoring methods and
frequency proved to be adequate to ensure compliance with the original work plan.
However, 2 to 3 additional monitoring points were added to encompass the area of new
operations.
Any solids dropped while loading trucks were collected and placed back into the barge,
using a CAT 966 loader. Vehicle decontamination pads were constructed at the lagoon
and at the CDF. All trucks were washed prior to leaving both the lagoon and the areas of
operation in the CDF. All water generated from the vehicle washes at the lagoon was
collected in a sump at the southwest end of the wash pad and pumped back into the barge
GTB2 and solidified.
JANUARY 2008 37
-------
REMEDIATION OF THE BLACK LAGOON
DECG NAM I NATION
PAD
TRUCK
ROUTE
PERCH FOR
EXCAVATOR
LAGOON
BARGE SET
INTO BANK
CONEX BOXES FOR
CALCIMENT STORAGE
JEFFERSON AVE.
Figure 4-2 Schematic Drawing of Contingency Trucking Operations
Transport trucks were scheduled to facilitate truck traffic, and typically traveled in groups
of two or three. Several groups of trucks were utilized concurrently to maintain
production rates. A bill of lading was prepared for each load, and a copy was retained in
the site file. Trucks were covered prior to leaving the lagoon area. Upon arriving at the
CDF, trucks backed up to the temporary storage pit and offloaded. All transport trucks
were washed prior to leaving the CDF area. Water collected at the CDF wash pad was
pumped into the temporary storage pit. Off-road dump trucks were used within the
confines of the CDF to convey the dredged material to the placement area in Cell 5.
38
JANUARY 2008
-------
DREDGING OPERATIONS AND DREDGE MATERIAL DISPOSAL
4.3.6 Placement of Dredged Material
Dredge material was placed in the CDF at an elevation of 579.0 feet. Sediment was
dumped off the cross dike and other strategic locations around the perimeter of the cell.
These sediment piles were then spread from the outer edges of the cell toward the center
and compacted in 2-foot lifts, using an excavator and D6 LGP wide-track bulldozer. The
material was distributed evenly throughout the cell and to a consistent depth to eventually
form a relatively flat surface with a gradual slope that allowed drainage to be directed to
the weir. The placed materials were compacted in 12-inch layers by making a minimum
of 3 passes with the dozer.
4.3.7 Capping the CDF Cell
A minimum of a 2-foot cap was placed on top of the dredged materials. Cap material was
obtained from areas adjacent to the offloading site within Cell 5. The material was
excavated with a CAT 330 excavator and spread in 1-foot lifts, then compacted with a D6
LGP dozer. At least 3 passes were made with the D6 LGP dozer over all placed cap
material. The top of the cap did not exceed an elevation of 581.0 feet.
JANUARY 2008
39
-------
REMEDIATION OF THE BLACK LAGOON
5.0 SEDIMENT CONFIRMATION SAMPLING AND ANALYSIS
After each of the dredging phases, the remaining sediments were sampled at pre-
determined locations and analyzed to confirm that the remediation activities achieved the
project objectives. The locations for these post-dredging sediment samples were
randomly selected according to a statistical plan designed to provide a specified level of
power and confidence in achievement of project objectives. The basis of the design is
described below in Section 5.1. Additional details concerning its execution, including the
location of sampling points, sample collection procedures, analytical procedures, and
quality control strategies are provided in Sections 5.2 and 5.3.
5.1 SEDIMENT CONFIRMATION SAMPLING DESIGN
The sampling design and residuals analysis were developed in accordance with U.S.
EPAs seven-step, systematic planning process known as the Data Quality Objective
(DQO) process. The technical approach detailing development of the sampling design is
documented in Appendix D of the project QAPP and is summarized below.
In order to determine if concentrations in the remediated area were lower than target
levels, a 100 x 100-foot grid system was established within the Black Lagoon area
cordoned off behind the silt curtain. Each 100 x 100-foot grid was considered a remedial
management unit (RMU), for a total of 14 RMUs. The RMUs were identified by the
capital letters A through N and served as the basis for evaluating the achievement of
target levels.
As part of the DQO process, a decision statement was developed for the sediment
confirmation sampling in the lagoon. This statement was based on achieving study
obj ectives, namely: "Has the dredging removed the contaminated sediment sufficiently
to proceed with placement of the aggregate residual cover? " It was agreed that
additional excavation might be warranted in an RMU if the average concentrations of
contaminants of concern in that RMU exceeded certain target levels. These target levels
were 1 mg/kg for total PCBs (as Aroclors, hereafter total PCBs), 1 mg/kg for mercury,
and 2,000 mg/kg for oil and grease.
40 JANUARY 2008
-------
SEDIMENT CONFIRMATION SAMPLING AND ANALYSIS
U.S. EPA's Guidance for the Data Quality Objective Process (EPA G-4) was used to
develop a power curve for optimizing the sampling design. In developing the power
curve, existing sediment confirmation data were needed to estimate the variability that
might be expected in the sediment confirmation samples for this project. Therefore, case
study data from several sediment remediation projects were obtained and evaluated for
use in planning the remedial activities, sampling design, and residuals analysis for the
Black Lagoon project. A series of case studies were evaluated against the site criteria of
the Black Lagoon (U.S. EPA 2004). Of these, one project, the Fox River SMUs 56/57,
was found to be most similar to the Black Lagoon, based on pre-determined criteria, and
was used to develop parameters for the residuals analysis. Total PCBs were chosen as the
proxy contaminant for all of the COCs because the observed concentrations showed the
highest variability in the earlier studies. In addition, average total PCB concentrations in
the Black Lagoon prior to remediation were closest to the target level and would,
therefore, require the largest number of samples to demonstrate successful remediation.
Based on the power curve, four samples per RMU were determined to be necessary for
evaluating the post dredging site conditions against the project target levels with the
specified decision error. Therefore, each of the 14 RMUs was further sectioned into four
50 x 50-foot cells, for a total of 56 cells. Sampling stations were randomly located within
each of the 50 x 50-foot cells (Figure 5-1), in accordance with a stratified random
sampling design (i.e., a combination of grid and random sampling). Due to the shape of
the lagoon, a few small areas were outside the grid system. Adjacent RMU sediment
sample results were used to determine management of those areas.
As part of developing the power curve, the limits of the decision error also were
specified. A false positive (F+) decision (i.e., an incorrect determination that a COC was
still present above the target level) could result in unnecessary additional remediation and
dredging. A false negative (F-) decision (i.e., an incorrect determination that the COCs
were no longer present at the target levels) could result in unwanted increased risk to
human health and to the environment. The sediment confirmation sampling strategy used
in this study was designed to achieve a 95% power in detecting an exceedance of the
target level when the true concentration of total PCBs across the RMU was 5 mg/kg.
JANUARY 2008 41
-------
REMEDIATION OF THE BLACK LAGOON
This allowed for decisions to be made with false positives rates of 15% (confidence of
85%) and false negatives rates of less than 5% (power of 95%).
Legend
• R.FS Ssi moles
RML? Boundary
50x50 Gfds.
Coast
SM Curlam
N
-Jt^E
HOO 15:
Feet
Black Lagoon Sampling Design
Figure 5-1 Black Lagoon Sediment Confirmation Sampling Design
The sampling design called for one homogenized composite sample to be collected from
each 50 x 50-foot cell, yielding four routine field samples (RFS) per RMU, or a total of
56 routine field samples. Individual samples were collected and homogenized as
described in Section 5.2.1 and analyzed for each contaminant of concern as described in
Section 5.2.2. The thickness of the sediment was measured prior to collecting each
sample. These thickness measurements were taken within 3 to 5 feet of each sampling
location, but not so close that the sediment would be disturbed prior to sampling at the
pre-defined site.
Statistical tests were developed to evaluate whether remediation activities achieved
project goals. These tests were based on null hypotheses that total concentrations of the
contaminants of concern were less than the project-specified target levels. The project
42
JANUARY 2008
-------
SEDIMENT CONFIRMATION SAMPLING AND ANALYSIS
target levels were 1 mg/kg for total PCBs, 1 mg/kg for mercury, and 2000 mg/kg for oil
and grease.
The specific statistical tests were:
1. Total PCBs concentration less than the target level of 1 mg/kg
H0: Total PCBs <1 mg/kg
HI: Total PCBs> 1 mg/kg
2. Mercury concentration less than the target level of 1 mg/kg
HQ: Total Mercury < 1 mg/kg
HI : Total Mercury > 1 mg/kg
3. Oil and grease concentration less than target level of 2000 mg/kg
H0: Total Oil and Grease < 2000 mg/kg
Hi: Total Oil and Grease > 2000 mg/kg
The average concentration of each COC was calculated for each of the 100 x 100-foot
RMUs and compared to the respective target levels. If the statistical evaluation was
inconclusive, additional sampling could be considered. Results for this comparison are
presented and discussed in Section 6.
Additional information concerning the sediment confirmation sampling design can be
found in Appendix D, Post-dredging Sediment Sampling and Residuals Analysis, of the
project QAPP
5.2 SAMPLING AND ANALYSIS
Sediment confirmation sampling was conducted in the Black Lagoon following each
excavation phase. Samples were collected after Phase I according to the sampling design
set forth in the QAPP (Figure 5-2, Samples May 05). After the second phase of
excavation, a sampling design was developed to evaluate achievement of target levels
that specified collecting samples at the center of each RMU. In some cases, logistics in
the field, such as a stuck barge, prevented collecting all of the samples at the prescribed
locations. For these cases, samplers and project leads determined alternative locations
that provided sufficient coverage of the site to evaluate achievement of project objectives.
Final sample locations are provided in Figure 5-2. Analytical results from sediment
JANUARY 2008 43
-------
REMEDIATION OF THE BLACK LAGOON
confirmation samples collected after the first dredge and second dredge are provided in
Tables 6-1 and 6-2, respectively.
Legend
Samples Au&'S«pt 05
• A« COCs
Samples. May 05
a TotalArodws
• 04 and gr«as«
O Mercury
50*50 Grxte
Shoreline
0 L'5 SO H» ISO
FMI
Black Lagoon Sample Locations
Figure 5-2 Actual Black Lagoon Sampling Locations for May, August, and September 2005
(Note: Two samples are located so close together that they cannot be differentiated in this
figure)
5.2.1 Sampling Methods
As noted above, the sampling design called for one homogenized composite sample to be
collected from each 50 x 50-foot cell, yielding four routine field samples (RFS) per
RMU, or a total of 56 samples collected in May 2005. To maximize RFS
representativeness, three Ponar grab samples were collected at the randomly located
station within each 50x50-foot cell, homogenized separately, then combined, and
homogenized again. Figure 5-2 illustrates the Black Lagoon sampling locations for the
56 samples collected in May 2005 and the 15 samples collected in August/September
2005. These pre-selected sampling sites were located in the field using a GPS receiver.
44
JANUARY 2008
-------
SEDIMENT CONFIRMATION SAMPLING AND ANALYSIS
Samples were collected by MDEQ's contractor. Sampling methods are described in
detail in Appendix D, Attachment 2 of the project QAPP and are summarized briefly
here. Routine field samples were collected from 0 to 6-inches below the surface as a
composite of three grab samples for each sampling location shown in Figure 5-2. At each
station, a mini-Ponar dredge sampling device was used to collect three grab samples: one
off the bow of the sampling vessel, one off the stern, and one off the port site. These
three grab samples were composited in a clean stainless steel bowl and thoroughly
homogenized using clean stainless steel spoons and spatulas. Because thorough
homogenization of the samples prior to filling the sample containers was critical for
creation of representative composite samples, unrepresentative materials such as stones
and wood chips were removed, and the sample was mixed until uniform texture and color
were obtained. The Ponar sampler and mixing utensils were cleaned and decontaminated
with river water and a steam cleaner after collection of every three samples, or whenever
oil or grease was visible on the sampling equipment.
Samplers recorded sample location, sediment thickness, and sediment physical
observations in a field log book. Sediment depth measurements were determined to the
nearest half foot, at locations a minimum of three feet away from the sampling locations,
in order to avoid disturbing or contaminating the sediment to be sampled for chemical
analysis. Observations included the gross physical characteristics of the surficial
sediment, such as obvious odor, oily sheen, texture, color, and the presence of debris.
Due to the importance of the sediment confirmation samples in determining whether
dredging activities had achieved project objectives, they were supplemented by a suite of
samples gathered for quality control purposes. These QC samples included:
- Field Sample Splits (FSS): Field sample splits were prepared by using extra volume
from each composite created when preparing the RFSs. Six of these splits were
prepared (i.e., a 10% frequency) at randomly selected locations provided to the
sampling team along with the locations of the RFSs. These FSSs were placed in the
same type of jars that were used for the RFSs and were labeled so that they appeared
to be routine samples to the laboratory staff that received and analyzed them.
JANUARY 2008 45
-------
REMEDIATION OF THE BLACK LAGOON
- Matrix Spikes/Matrix Spike Duplicates (MS/MSD): Matrix spike and matrix spike
duplicate samples also were prepared by using extra volume of the final homogenized
composite obtained for six of the RFSs (i.e., a 10% frequency). Unlike the FSSs,
which were sent as "blind" QC samples (i.e., the laboratory did not know they were
splits), the MS/MSD samples were clearly designated as QC samples for the
laboratory. Locations of the MS/MSDs were selected at random by the samplers.
5.2.2 Analytical Methods
Sediment sample analyses were performed by TriMatrix Laboratories, under contract to
MacTec. EPA Method 8082 was used to determine Total PCBs (as Aroclors). EPA
Method 7471A was used to determine mercury. EPA Method 907 IB was used to
determine oil and grease. EPA Method 3550B was used to determine solids.
5.3 QUALITY OF SEDIMENT CONFIRMATION DATA
Due to the importance of the sediment confirmation samples in determining whether
dredging activities had achieved project objectives, all data were reviewed as described in
the project QAPP In addition, the data were evaluated to verify that they provided the
sensitivity, precision, accuracy, representativeness, completeness, and comparability
required to support these decisions. Details of that assessment are provided in Appendix
A of this report. Briefly, this assessment concluded that:
• Sensitivity: Reporting thresholds were sufficient to meet project objectives for this
study, but this was due, in part, to the relatively high concentrations of mercury and
oil and grease present in the samples. If the sample concentrations had been lower for
these analytes, it may not have been possible to verify that non-detects were due to
the true absence of contamination at the target level or to limitations of the analytical
procedure. This issue should be considered in future studies.
• Precision: Precision was examined in two ways: (1) by comparing results of RFSs
with their FSSs to assess precision of the entire sampling and laboratory system, and
(2) by comparing results from MS samples with their MSDs to determine laboratory
precision. As was expected, laboratory precision was better than system precision
(which includes laboratory variability plus sampling variability), and variability in the
sampling activities accounted for most of the system variability. Precision estimates
46 JANUARY 2008
-------
SEDIMENT CONFIRMATION SAMPLING AND ANALYSIS
were within acceptable ranges for mercury, oil and grease, and most PCB
components. However, the system precision for one of the PCB components (Aroclor
1260) exceeded the measurement quality objective of 50% RPD, with an observed
precision of 75% (still within what is typically observed with sediment sampling and
analysis).
• Bias: Although slight measurement bias was observed for each COC, these biases
were within acceptable ranges of measurement error.
• Comple teness and Representativeness: The sediment confirmation sampling strategy
reflected a stratified random design intended to generate a data set representative of
the entire lagoon. This strategy was followed completely after the first phase of
dredging (which accounted for approximately 90% of the total sediment removal
activities), thereby yielding a fully representative and complete data set for this stage
of the project. Sediment confirmation sampling after subsequent dredging passes was
to be conducted as deemed necessary and if resources allowed. A sampling design
was developed after Phase II dredging operations were completed (which accounted
for approximately 10% of the total sediment removal activities). Although the
confirmation sampling was not as extensive, the design was based on the same grid
pattern used for the Phase I sampling.
• Comparability: Comparability is the confidence with which one data set can be
compared to other data sets. Sediment confirmation data were generated using
standard analytical methods. All sampling and analytical procedures used in
evaluating sediment conditions in this project are well-documented and available in
the project QAPP, facilitating comparability of the sediment confirmation results.
These procedures should be reviewed and considered when evaluating these data for
other uses. In regards to the sediment volume data, as is discussed in Chapter 6 of
this report, the survey data originally used to design the project work plan reflected
the International Great Lakes Datum (IGLD) 55 instead of the newer IGLD 85
system. This difference in specification accounted for some of the unexpected
challenges encountered with respect to sediment depths and volumes. Physical
changes to the lagoon floor also may have accounted for some of these challenges.
JANUARY 2008 47
-------
REMEDIATION OF THE BLACK LAGOON
6.0 PROJECT RESULTS
Three sets of sediment confirmation samples were collected using the statistically based
sampling designs described in Section 5. The first set was collected immediately after the
first phase of dredging operations. Results from this set indicated that high levels of
contamination were still present in the remaining sediments across the lagoon. Based on
these results, a second round of dredging (Phase II) was performed to remove
approximately 12,000 cubic yards of additional sediments. After completing the second
round of dredging, a second round of sediment confirmation samples were collected. As
is typical for dredging projects, these data indicated that a residual layer of contaminated
sediment still existed, even though a significant reduction in contaminant levels in the
remaining sediments was observed. The remaining sediments were then covered with a
protective layer of clean sand and gravel to provide a clean substrate for the benthic
community. A third set of sediment confirmation samples was collected after application
of the clean sand and gravel to confirm the absence of contamination at levels of concern
in the new lagoon substrate.
Results from all three sets of sediment confirmation samples are discussed in Section 6.1.
Results of the final hydrographic survey and final calculations of the contaminated
sediment removed from the site are presented in Section 6.2. A discussion of the quality
of sediment confirmation data used to determine achievement of project objectives is
presented in Section 6.3. Chapter 7 of this report describes the process for installing the
clean sand and gravel cover over the dredged site, demobilizing equipment and staff, and
restoring the site to pre-existing conditions.
6.1 POST-DREDGING SEDIMENT CONFIRMATION SAMPLE RESULTS
Initial dredging activities were completed in May 2005. To determine if dredging had
restored the lagoon sediments to acceptable levels, 62 sediment confirmation samples
were collected as described in Sections 5.1 and 5.2.1 of this report (i.e., 56 RFS and 6
FSS samples). In addition, 19 sediment core samples also were collected to confirm the
depth of the sediment after the survey. Samples were analyzed by TriMatrix Laboratories
as described in Section 5.2.2, and results were reported to the Project Team. All 56 RFS
samples were analyzed for oil and grease, 24 of the samples were analyzed for mercury,
48 JANUARY 2008
-------
PROJECT RESULTS
and 27 were analyzed for PCBs. The 19 core samples were analyzed for oil and grease
only. Because all results exceeded the target levels of 2000 mg/kg for oil and grease, 1
mg/kg for mercury, and 1 mg/kg for total PCBs, the laboratory was instructed to
discontinue further analysis of the remaining samples. The minimum, maximum, and
mean COC concentrations for the samples that were analyzed are shown in Table 6-1. A
summary of all sediment confirmation data is provided in Appendix A.
Table 6-1 Results From Sediment Confirmation Samples Collected After the First Dredge
Concentrations Reported (mg/kg)
Target Level
for Project Standard Number of
(mg/kg) Minimum Maximum Mean Deviation samples
Contaminant
Oil and Grease
Mercury
Total PCBs
2,000
1
1
12,000
1.1
0.54
28,500
3.1
2.28
20,242
2.45
1.47
3612
0.42
0.45
56
24
27
The original plan was based on the assumption that dredging activities would remove all
or most of the sediments, and along with them, all or most of the contaminants of
concern. As shown in Table 6-1, however, the contaminants of concern were still present
at high levels after the first round of dredging operations. These higher than expected
concentrations, along with deeper than expected post-dredge sediment depth
measurements, confirmed suspicions that the original sediment depth estimates were
incorrect. In order to better understand the magnitude of additional work required to
reach hardpan and remove the contaminated sediments, a distribution map showing the
remaining sediment floor was created by kriging the post-dredge sediment depth
measurements. Kriging is a spatial and variance interpolation method used to predict
values across the site in areas where samples were not collected (Cressie, 1990). The
map, presented in Figure 6-1, indicated that two to six foot depths of sediment still
covered large areas of the lagoon.
JANUARY 2008
49
-------
REMEDIATION OF THE BLACK LAGOON
Legend
Sediment Thickness {ft.)
May 2005
Figure 6-1 Black Lagoon Sediment Thickness After Completion of Phase I Dredging (based on
data collected in May 2005)
After reviewing the new sediment depth and contaminant data, a second phase of
dredging was deemed necessary and samples were collected based on new criteria. The
area to be dredged and the sample frequency were reduced. The change in scope for the
project was documented in a revised DQO table. The Phase II criteria were to dredge to
the clay layer. The minimum, maximum, and mean concentrations of the sediment
samples collected after the second phase of dredging in August and September 2005 are
presented in Table 6-2.
Table 6-2 Results From Sediment Confirmation Samples Collected After the Second
Dredge
Contaminant
Target Level Concentrations Reported (mg/kg)
for Project I Standard I Number of
(mg/kg) Minimum Maximum Mean Deviation samples
Oil and Grease
Mercury
Total PCBs
2,000
1
1
2,050
0.24
0.13
16,500
4.7
1.91
10,724
2.78
1.12
4,154.00
1.42
0.56
15
15
15
50
JANUARY 2008
-------
PROJECT RESULTS
A new map of the sediment thickness after the second phase of dredging is presented in
Figure 6-2.
Legend
Sediment Thickness (tt.)
Sept. 2005
|^| 0.0 -0.2
^•03-0.4
^H 0.5-0-6
Q 2S M 100 ISO SOD
F-M1
Figure 6-2 Black Lagoon Sediment Thickness After Completion of Phase II Dredging (based on
data collected in August and September 2005)
Results suggest that, although the Phase II dredging activities did not completely reduce
contaminant concentrations to the levels targeted, the second round of dredging was
successful in reducing both the overall concentration and the distribution of those
contaminants. Figures 6-3 and 6-4 illustrate this by showing the estimated concentration
and distribution of oil and grease before and after contaminated sediments were removed
in Phase II. Figures 6-5 and 6-6 present similar information for total PCB distributions.
A similar pair of figures could not be presented for mercury due to the lack of
confirmation samples in the southern half of the lagoon because of the decision to halt the
sample analysis when results reported for oil and grease showed all samples exceeded the
target levels (see Table 6-1). As can be seen from these figures, dredging efforts in the
Black Lagoon dramatically reduced the levels of contamination across the site. See
Section 6.3 for final sediment confirmation results after placement of the residual cover.
JANUARY 2008
51
-------
REMEDIATION OF THE BLACK LAGOON
Slack Lagoon
Oil and Grease Concentration
Post Phase I Dredging
Figure 6-3 Estimated Oil and Grease Concentrations Prior to Phase II Dredging
sh Lagoon
Oil and Grease Concentration
Post Phase II Dredging
Oil and Gr.'.;i!,r: AIIT|,':>'|II OS
(mgflig)
| l?.oao-30oi>
|icdt .*oaO'
r :-: i . w LOG
10001.
n
o nt 9»
Qtl Hid Gre«i« Tjirg«t Uml ' 1.000 ntgrttg
Figure 6-4 Estimated Oil and Grease Concentrations After Phase II Dredging
52
JANUARY 2008
-------
PROJECT RESULTS
Black Lagoon
Total PCS Concentration (as Aroclors)
Post Phase I Dredging
Figure 6-5 Estimated Total PCB Concentrations Prior to Phase II Dredging
Black Lagoon
Total PCB Concentration (as Aroclors)
Post Phase II Dredging
Mi :
WMn
PC8» TVQOI Lncl > 1
Figure 6-6 Estimated Total PCB Concentrations After Phase II Dredging
JANUARY 2008
53
-------
REMEDIATION OF THE BLACK LAGOON
6.2 VOLUME OF CONTAMINATED SEDIMENTS REMOVED
Upon completion of all dredging activities, a final hydrographic survey was performed to
calculate the exact amount of dredge material removed from the lagoon. A hydrographic
survey was conducted by both EQ's survey crew and a crew from the USAGE Detroit
District. The data from both surveys were compared and deemed accurate.
Due to inherent problems with the pre-dredge survey discussed previously, certain data
and quantity adjustments were made to accurately calculate sediment volumes. These
adjustments or accommodations included: adding pole soundings taken by hand into a
surface model of the survey (water depth was too shallow for hydrographic equipment);
adjusting the surveys to International Great Lakes Datum (IGLD) 85 elevations (the
original specifications were in IGLD 55)1; and encompassing a greater survey area that
extended outside of the specified dredge limits to account for side slope failure. Once all
of these accommodations were made and individual calculations completed, the total
volume removed from the lagoon was determined. The total amount of sediment
removed from Black Lagoon was determined to be 115,671 cubic yards. Figure 6-7
presents cumulative dredge volume data by month, based on these calculations.
As can be seen from this figure, 103,549 cubic yards were removed during Phase I
(October 2004 through May 2005), and an additional 12,122 cubic yards were removed
in Phase II (September 2005).
1 The IGLD is an international elevation reference system. Because of movement of the earth's crust, the
"datum" must be adjusted every 25-35 years.
54 JANUARY 2008
-------
PROJECT RESULTS
140,000
120,000 -
100,000 -
§ 80,000
•o
> 60,000 -
o
O
40,000 -
20,000 -
0 -I
These cumulative quantities represent in-place measurements based on
hydrographic surveys conducted during each phase.
115,671
103,549
Oct 04 Nov 04 Dec 04 Jan 05 Feb 05 Mar 05 Apr 05 May 05 Sep 05
Figure 6-7 Cumulative Summary of Sediment Quantities Dredged from the Black Lagoon
The accuracy of the revised calculations was substantiated by the estimates obtained from
the kriging maps presented in Figures 6-1 and 6-2. A three-dimensional view of both
surfaces is provided in Figure 6-8 to show the difference in the estimated sediment
thickness before and after Phase II dredging activities.
JANUARY 2008
55
-------
REMEDIATION OF THE BLACK LAGOON
Black Lagoon
May 2005
Aug/Sept 2005
*
SO 100
Feel
200
Legend
Sediment Thickness (ft.)
Aug'Sept Samples
May Samples
^H05-06 I <26-3
I [13-14 H^I.R
[ I 15- 16 ^H61'es
| I 1.7-1.8 ^^6fl-6B
H'9-2 Shor**n»
10X Exaggeration In Ihe Z dlfeclion for visualization
Figure 6-8 Three-dimensional View of Estimated Sediment Surfaces, Before Phase II Dredging (May 2005) and After Phase II
Dredging (September 2005) (Sediment thickness in the Z dimension includes a 10X exaggeration factor for visualization.)
56
JANUARY 2008
-------
PROJECT RESULTS
Figure 6-9 provides a cut-and-fill report to show the three-dimensional surface of the
estimated sediment removed from the site during Phase II. The cut-and-fill surface,
calculated area, and volume were developed by subtracting the estimated sediment
thickness surface of August/September 2005 from the May 2005 surface (Figure 6.8).
Even though all estimates are based on sediment thickness ±0.5 feet, the cut-and-fill
report provides fairly accurate account of the sediment removed from the site
(approximately 11,000 cubic yards, which agrees within 10% with the calculated figure
of 12,122 cubic yards).
Black Lagoon
Cul & Fit) Report
Estimated Sediment Removed
AREA = 126940 sqft
VOLUME =-270,000 ft3
-11.000 cy
IOX E wogcraiion ii» iho Z direction tut vnuallzaIMn
Estimated Sediment Removed
F«»t
IB
j^B 1.1-2
^H2t-3
^B 3.1-4
H 41-5
^B 51-6
j^B 6.1 -7.3
SiK Curtam
Shorten*
Figure 6-9 Three-dimensional View of the Estimated Volume of Sediment Removed During
Phase II. (Calculated cut-and-fill report for volume and area of the three-dimensional surface
derived by subtracting September 2005 estimated surface from the May 2005 estimated
surface.)
JANUARY 2008
57
-------
REMEDIATION OF THE BLACK LAGOON
6.3 FINAL SEDIMENT CONFIRMATION RESULTS
Dredging efforts in the Black Lagoon dramatically reduced the levels of contamination
across the site. Approximately 95% of the contaminated sediment inventory was
successfully removed from the site (based on the
total sediment volume removed as presented in
Figure 6-1 and the estimated volume remaining
Total PCBs 160
Mercury 360
Oil & Grease 300,000
Lead 38,000
,, . . +u „ Arm . , . , , , +u Zinc 140,000
forth in the QAPP were not achievable under the
calculated from the post dredge sediment thickness
data). However, the target levels for the COCs set
Estimated Amount of Contaminants of
Concern Removed from the Black Lagoon
Contaminant Pounds Removed
project sediment volume constrictions, schedule, and budget.
Practical limits to the dredging attempts are based on both engineering and case study
findings. Two dredging attempts were made to remove the contaminated sediments from
Black Lagoon. The original plan specified that if additional dredging was deemed
necessary for a specific RMU, additional dredging would be limited to one additional
pass per RMU. This limit on the number of redredging attempts was due to project
resources, as well as the diminishing returns reported in environmental dredging case
studies. For example, at the GM Massena site, the greatest reduction of PCB residuals
concentrations was experienced through the second dredging attempt (U.S. EPA 2004).
Therefore, in the event that sediment removal operations are unsuccessful in achieving
the mean residual concentrations for the contaminants of concern, engineering
contingencies such as an isolation cover are implemented. The best professional
judgment of GLNPO, MDEQ, USAGE, and their supporting contractors concluded that
the correct course of action was to install the residual cover to isolate any remaining
contaminated sediments.
The residual cover consisted of at least 6 inches of sand and 6 inches of gravel installed
to trap the underlying sediment and provide a clean habitat for benthic communities.
After the deposition of the sand layer, 18 additional sediment confirmation samples were
collected. Sampling in the sand cover is an environmental verification technique that is
kept to a minimum, to maintain the residual cover's integrity and prevent mixing the
underlying sediment with the clean cover. Results of the residual cover sampling and
58 JANUARY 2008
-------
PROJECT RESULTS
analyses showed that the mean concentrations of oil and grease, mercury, and total PCBs
were all below target levels (Table 6-3).
Table 6-3 Results From Sediment Confirmation Samples After Placement of Residual
Cover
Contaminant
Target Level
for Project
(mg/kg)
Concentrations Reported (mg/kg)
Standard Number of
Minimum Maximum Mean Deviation samples
Oil and Grease
Mercury
Total PCBs
2,000
1
1
180
0.03
Not detected
1,830
2.1
0.27
457
0.19
0.14
456
0.48
0.1
18
18
18
Figures 6-10, 6-11, and 6-12 illustrate the distribution of contaminants of concern in the
new sediment floor. Note that two samples, BL-05-10 and BL-05-12, are located so close
together that they cannot be differentiated in Figures 6-10, 6-11, and 6-12.
Black Lagoon
Oil and Grease Concentration
Post residual cover
Oil and Grease, Nov 05
(nig'kg)
~1 0-750
751 • 1 000
1,001 - 1,827
O RFS Samstes
- 50x50 Gods
Shoreline
Silt Curtain
Oil and Gre w* Targal Lovol = 2,000 mo/kg
Figure 6-10 Oil and Grease Concentrations in Black Lagoon Sediment Floor After Remediation
JANUARY 2008
59
-------
REMEDIATION OF THE BLACK LAGOON
Black Lagoon
Total FCB Concentration (as Aroclors)
Post residual cover
PCBs NovOS
I. 1 0-01
[ _ | 0.11 - 0.2
21 OL21 - 0.27
O RFS Samples
SOxSOGnds
Show*™
— ^ SMCurtrin
JL
;'J 1Kl 1M MO J»
ntt
0 12.5 « SO IS ICQ
.WtiMl
PCBs Tat get Level» 1.0 uig*g
Figure 6-11 Total PCB Concentrations in Black Lagoon Sediment Floor After Remediation
60
JANUARY 2008
-------
PROJECT RESULTS
Black Lagoon
Mercury Concentration
Post residual cover
Morcury Target Level = t.O rng/Kg
Figure 6-12 Mercury Concentrations in Black Lagoon Sediment Floor After Remediation
Total PCB concentrations were significantly reduced throughout the lagoon, from a mean
of 2.6 mg/kg prior to remediation to 0.14 mg/kg post remediation and application of the
sand cover (Figure 6-13).
JANUARY 2008
61
-------
REMEDIATION OF THE BLACK LAGOON
Black Lagoon
Total PCB Concentration (as Aroclors)
Total PCB Conceritralion i.as Aroclorst
Pre-r«fnedialion surface 11999 & 2003 >
1st core intervals
L-0,5 ft
Post Phase I Dredge
surface shews sediment
depth overlaid -vitli
cone en (ration
c
2 ft.
0.1ft
1ft.
o.i ft.
Total PCBs (mg/kg)
I [0-0.5
I 10.51-10
[3 1.1-1.5
~] 1.51-2.0
^B 2.1-3.0
IH31 - 5-°
Shoreline
Post Phase II Dredge
surface shews sediment
depth overlaid wilh
concen (ration
Post residual cover
surface shews sand
depth overlaid with
concentration
Exaggeration in tJte Z direction for visualization
Figure 6-13 Black Lagoon Sediment Surfaces Overlain with Total PCB Concentrations through the Remediation Project
62
JANUARY 2008
-------
RESIDUAL COVER PLACEMENT, DEMOBILIZATION, AND SITE RESTORATION
7.0 RESIDUAL COVER PLACEMENT, DEMOBILIZATION, AND SITE
RESTORATION
7.1 PLACEMENT OF THE RESIDUAL COVER
Following completion and approval of all dredging operations, residual cover placement
began over the dredge area with the goal of enhancing natural attenuation and adding
habitat for aquatic life within the lagoon. The cover consisted of a minimum 6-inch
lower layer of clean sand and a 6-inch upper layer of stone covering the sand. The sand
and stone aggregate material characteristics complied with USACE-approved quarry and
gradation curves.
The sand cover was spread using an 8 5-ton
crane with a 3-cubic yard bucket, utilizing
Dredge Pack to log the exact GPS location
where each bucket was released. Each
bucket was released by progressively
opening the bucket wider as the material
was released. Materials were released from
a height of approximately 2 feet above the
surface of the water to achieve a greater rate of dispersion and to reduce mounding. The
cover materials were shuttled from the north end of the lagoon by hopper barge and
tugboat, and the progression of cover material was from south to north.
An additional 1,500 cubic yards of sand were approved for placement in the northern half
of the lagoon to increase cover thickness. Because of variables outside the control of the
operator, such as the topography of the bottom of the lagoon and the strength of the
current within the lagoon that could have affected the rate of descent and dispersion of
material, the sand layer of some areas varied in thickness by up to 20%. Prior to stone
placement, the sand layer thickness was tested and verified by taking a predetermined
number of core samples.
The stone cover was applied in the same manner as the sand layer and provided a cover
of approximately 4 to 6 inches over the sand. Again, the exact depth of this layer varied
JANUARY 2008
63
-------
REMEDIATION OF THE BLACK LAGOON
due to the bottom topography, but was less affected by any current within the lagoon
because of the weight of the stone.
7.2 DEMOBILIZATION AND SITE RESTORATION
Following completion and acceptance of all work (i.e., dredging, aggregate placement,
and CDF capping), site demobilization activities were conducted. This consisted of site
restoration at both the lagoon and the CDF; removal of all work-related facilities,
equipment, and materials; and final inspection of all restored areas.
Restoration at the lagoon work site consisted of removing boardwalks; grading work
areas; seeding of the Ellias Property; and removal of the field office, utilities, and
temporary security fence. All refuse or waste construction materials in the park area and
around the shoreline area were removed and properly disposed.
The temporary transfer station at the CDF and all other temporary structures were
removed. Disturbed areas (such as the offloading storage pad, temporary storage pit, and
borrow areas) were graded and returned to their pre-existing conditions. Because of
excessive truck traffic during transportation activities, all dike roads were re-graded and
gravel added as necessary.
Upon completion of site restoration work, a final site inspection was conducted with
project partners and other interested parties (e.g., park and City officials) to ensure that all
work and restoration activities were satisfactorily completed.
64 JANUARY 2008
-------
CONCLUSIONS AND PROJECT ACCOMPLISHMENTS
8.0 CONCLUSIONS AND PROJECT ACCOMPLISHMENTS
The Black Lagoon remediation proposal was the first project to be accepted and
implemented as a result of the Great Lakes Legacy Act. As the initial undertaking in a
series of projected clean-up projects under the GLLA, the Black Lagoon project
experienced challenges that will provide valuable lessons for future projects. These
challenges included sediment volumes that were greater than anticipated based on
historical data, low sediment densities encountered in the second phase of the project, and
a barge that ran aground in the northern part of the lagoon (see Section 4.2.1 for details).
These issues illustrated the importance of establishing accurate baseline conditions
through comprehensive hydrographic surveys prior to initiation of the project.
Many of these challenges led to the development of new approaches or techniques that
may be applied to future remediation efforts. For example, a series of bench tests was
performed to identify operational procedures that ultimately allowed for successful
removal of the low-density sediments encountered in Phase II. These operational
procedures are discussed in Section 4.2.2 and may be of use should similar situations be
encountered elsewhere. Likewise, kriging techniques were employed by GLNPO and
MDEQ for the first time as a means of estimating sediment volumes and provided a
means for confirming the revised volume calculations that were necessary to account for
unforeseen problems with the original hydrographic survey data. Kriging also provided a
new way to estimate and visualize contaminant distributions in GLLA projects.
Despite these challenges, the Black Lagoon project also was a story with many successes,
including the environmentally safe removal of 115,000 cubic yards of contaminated
sediment from the small bay (Figure 8-1). Several techniques were effective in
preventing accidental contamination of the environment during the remediation process.
Oil spill booms put in place prevented surface contaminants such as oil and grease from
spreading to the surrounding water. A combination of various types of silt curtains kept
sediments resuspended by dredging from traveling outside of the dredging area. Careful
monitoring of turbidity and chemical measurements in the water and air around the
lagoon reassured the neighborhood residents that neither their health nor the environment
was endangered by the remediation project.
JANUARY 2008 65
-------
REMEDIATION OF THE BLACK LAGOON
Testing of the sediments barged to the Pointe Mouille CDF showed that large amounts of
oil and grease (300,000 pounds), mercury (360 pounds), and PCBs (160 pounds) were
successfully removed, along with lead (38,000 pounds) and zinc (140,000 pounds).
These are contaminants that will no longer endanger the aquatic and shoreline wildlife.
The addition of a sand and gravel cover will allow the regrowth of healthy organisms on
the lagoon bottom, and fish will no longer become contaminated from feeding on the
bottom dwellers.
Black Lagoon Remediation Project Accomplishments
> 115,000 cubic yards of contaminated sediments were removed
> Approximately 478,000 pounds of PCBs, mercury, oil and grease, lead, and zinc were
removed
160 pounds of PCBs
• 360 pounds of mercury
• 300,000 pounds of oil and grease
• 38,000 pounds of lead
• 140,000 pounds of zinc
> Contaminant concentrations measured in the sediment floor after removal of contaminated
sediments and placement of a new cover were all below target concentrations
• PCB concentrations in the lagoon sediment were reduced from an average of 1.12
mg/kg to 0.135 mg/kg in the new sediment floor—an 8-fold reduction
• Mercury concentrations in the lagoon sediment were reduced from an average of 1.40
mg/kg to 0.205 mg/kg in the new sediment floor—a nearly 7-fold reduction
• Oil and grease concentrations in the lagoon sediment were reduced from an average
of 6,280 mg/kg to 473.3 mg/kg in the new sediment floor—a 13-fold reduction
> First cleanup project under the Great Lakes Legacy Act, a special initiative designed to
clean up contaminated Great Lakes sediment hot spots
> First use of kriging techniques in a GLNPO or MDEQ sediment remediation project
66 JANUARY 2008
-------
CONCLUSIONS AND PROJECT ACCOMPLISHMENTS
Black Lagoon Sediment Volume and Contaminant
Mass Removed
115,671 cubic yards sediment removed
160 Founds PCB
3f)il Titunds Mercury
3IHI,INH) Pounds Oil & <,
14.0ft
16,0ft
Lagoon
Eoitoin
Post
Remediation
PCB concentration (as Aroclors)
(mg/kg)
I | 0.1-0.5
I I 0.51-1
1.01-125
1.51-1,61
Sand and Gravel Cover
Sediment Removed
Shoreline
—-— Hardpan
M
j>
*
10 X Exaggeration In the 2 direction for visuaftzation
Figure 8-1 Black Lagoon Sediment Volume and Contaminant Mass Removed, with Residual Layer of Sediment and Residual Cover Overlain
with Total PCB Concentrations
JANUARY 2008
67
-------
REMEDIATION OF THE BLACK LAGOON
9.0 FUTURE OF THE SITE
The remediation project is expected to serve as a catalyst for redeveloping not only the
lagoon, but also the city's entire 240-acre shoreline and waterfront district. Adjacent
areas of the city are also experiencing a rebirth as a result of the redevelopment. The City
of Trenton has completed a downtown streetscape with decorative streetlamps, new
landscaping and curbs just south of the lagoon. The adjacent site of the former McLouth
Steel plant is also undergoing redevelopment.
The lagoon was informally named the Black Lagoon after aerial surveys depicted it as
literally black from oil and grease contamination. Subsequent to the $8.7 million
remediation of the Black Lagoon's contaminated sediment in 2004-2005 through the U.S.
Great Lakes Legacy Act and the Clean Michigan Initiative, a $151,000 shoreline habitat
restoration was completed in 2006. In 2007, a $582,000 Boating Infrastructure Grant was
awarded from the U.S. Fish and Wildlife Service to build a marina and further economic
revitalization of downtown Trenton ($200,000 will also be provided as a local match
from Trenton). On Monday June 18, 2007, the City of Trenton and its many partners
celebrated the restoration and revitalization of the Black Lagoon in a ceremony renaming
of the Black Lagoon as "Ellias Cove," in honor of the family who donated the adjacent
land to Trenton that became Meyer-Ellias Park.
JANUARY 2008
-------
REFERENCES
REFERENCES
Cressie, N. A. C. , 1990, "The Origins of Kriging," Mathematical Geology, v. 22, p. 239-
252
Environmental Quality Management, Inc., October 2006, Remediation of the Black
Lagoon, Trenton Channel, Detroit River, Trenton, Michigan, Final Project Report,
Cincinnati, Ohio.
Environmental Quality Management, Inc., October 2004, Quality Assurance Project
Plan, Remediation of the Black Lagoon, Trenton Channel, Detroit River, Trenton
Michigan.
Environmental Quality Management, Inc., September 2004, Final Work Plan,
Remediation of the Black Lagoon Trenton Channel, Detroit River, Trenton, Michigan.
Cincinnati, Ohio.
MacDonald, Donald D., Christopher G. Ingersoll, and Tadd A. Berger, 2000,
"Development and Evaluation of Consensus-Based Sediment Quality Guidelines for
Freshwater Ecosystems," The Archives of Environmental Contamination and Toxicology,
Vol. 39, No. 1, pp. 20-31.
U.S. EPA, 2004, Hudson River PCBs Superfund Site, Engineering and Performance
Standards, Technical Basis and Implementation of the Residuals Standard, Volume 3 of 5.
U.S. EPA, 2000, Pre-remedial Investigation of Sediment Quality within The Black
Lagoon, Trenton Channel, Detroit River Michigan.
U.S. EPA, 1977, Guidelines for the Pollutional Classification of Great Lakes Harbor
Sediments.
JANUARY 2008
69
-------
REMEDIATION OF THE BLACK LAGOON
70 JANUARY 2008
-------
APPENDICES
APPENDIX A SUMMARY SEDIMENT CONFIRMATION DATA
Sample
BL05-01
BL05-05
BL05-02
BL05-04
BL05-07
BL05-14
BL05-06
BL05-08
BL05-09
BL05-10
BL05-13
BL05-11
BL05-15
BL05-18
BL05-22
BL05-20
BL05-27
BL05-24
BL05-25
BL05-26
BL05-19
BL05-17
BL05-16
BL05-21
BL05-30
BL05-28
BL05-29
BL05-33
BL05-34
BL05-40
BL05-38
BL05-37
BL05-39
BL05-35
BL05-36
BL05-31
BL05-32
BL05-41
BL05-42
BL05-46
BL05-47
BL05-48
BL05-56
Phase
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Lab
Sample
ID
389434
389436
389437
389438
389439
389440
389473
389474
389475
389476
389478
389479
389480
389481
389482
389483
389484
389485
389486
389487
389488
389490
389491
389492
389565
389566
389567
389568
389569
389570
389571
389572
389573
389574
389575
389576
389577
389578
389579
389580
389735
389736
389737
Results in mg/kg
Sampling Oil & Total
Date Grease PCBs Mercury
5/9/2005
5/9/2005
5/9/2005
5/9/2005
5/9/2005
5/9/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/10/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/11/2005
5/12/2005
5/12/2005
5/12/2005
22300
18100
18500
18900
19100
22900
18500
18700
21800
15800
14400
20700
17800
18900
17500
25800
26700
25900
22300
19100
21700
25500
27300
25300
20900
24200
26500
17100
16100
21200
28500
24500
25200
19200
20800
22400
22400
15500
16900
21300
22800
20900
12900
1.870
1.690
2.270
2.280
2.020
2.200
1.210
1.010
1.700
0.950
1.380
2.180
1.260
1.180
1.060
0.960
1.790
1.210
1.410
1.430
1.360
1.210
1.430
1.250
1.650
1.170
1.430
2.4
2.3
2.5
2.7
2.7
2.6
2.7
2.4
3.1
2.3
2
2.5
2.5
2.2
2.1
2.6
2.9
2.7
2.2
2.2
2.9
2.2
3.1
1.1
JANUARY 2008
71
-------
REMEDIATION OF THE BLACK LAGOON
Sample
BL05-55
BL05-45
BL05-54
BL05-57
BL05-60
BL05-59
BL05-58
BL05-43
BL05-44
BL05-51
BL05-53
BL05-49
BL05-50
BL05-R
BL05-61
BL05-04COR
BL05-04COR
BL05-59COR
BL05-59COR
BL05-39COR
BL05-39COR
BL05-39COR
BL05-28COR
BL05-28COR
BL05-41COR
BL05-41COR
BL05-53COR
BL05-53COR
BL05-07COR
BL05-07COR
BL05-07COR
BL05-01COR
BL05-01COR
BL05-04COR
BL-05-N
BL-05-M
BL-05-L
BL-05-K
BL-05-J
BL05-01
BL05-02
BL05-03
BL05-04
BL05-05
BL05-06
BL05-07
Phase
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 1° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Lab
Sample
ID
389738
389739
389740
389741
389742
389743
389744
389746
389747
389748
389750
389751
389752
389753
389754
390300
390301
390302
390303
390304
390305
390306
390307
390308
390309
390310
390311
390312
390313
390314
390315
390316
390317
390318
394379
394380
394381
394382
394383
395404
395405
395406
395407
395408
395409
395410
Results in mg/kg
Sampling Oil & Total
Date Grease PCBs Mercury
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/12/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
5/19/2005
8/18/2005
8/18/2005
8/18/2005
8/18/2005
8/18/2005
9/19/2005
9/19/2005
9/19/2005
9/19/2005
9/19/2005
9/19/2005
9/19/2005
16900
15800
16600
19600
16900
18800
21700
22400
20200
12000
19600
18300
20500
18000
25500
29400
18800
11500
24900
18400
14300
23500
27200
23900
19700
19000
19100
26000
24100
28300
27700
23100
26900
10300
10400
12600
8590
12800
8820
8450
13700
2050
3790
16500
9780
0.540
1.380
0.690
1.010
0.770
1.100
1.690
1.890
1.040
0.130
0.200
1.540
1.910
4.7
4.1
4.4
2.3
4
3.04
4.12
2.17
0.24
0.69
2.78
3.55
72
JANUARY 2008
-------
APPENDICES
Sample
BL05-08
BL05-09
BL05-10
BL-05N
BL-05-L
BL-05-M
BL-05-J
BL-05-K
BL-05-#6
BL05-11
BL05-12
BL05-10
BL05-8
BL05-9
BL05-7
BL05-6
BL05-5
BL05-4
BL05-3
BL05-2
BL05-1
Phase
Post 2° Dredge
Post 2° Dredge
Post 2° Dredge
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Post Sand Cover
Lab
Sample
ID
39541 1
395412
395413
396253
396254
396255
396256
396257
396258
396759
396760
396761
396762
396763
396764
396765
396766
396767
396768
396769
396770
Results in mg/kg
Sampling Oil & Total
Date Grease PCBs Mercury
9/19/2005
9/19/2005
9/19/2005
10/11/2005
10/11/2005
10/11/2005
10/11/2005
10/11/2005
10/11/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11/2/2005
11400
16500
15190
477 U
1830
460 U
465 U
471 U
500 U
572 U
520 U
488 U
507 U
520 U
507 U
493
709
732
579
663
1240
0.990
1.660
0.810
0.013
0.075
0.000
0.000
0.000
0.000
0.185
0.273
0.161
0.207
0.230
0.150
0.129
0.157
0.234
0.212
0.266
0.270
2.22
2.92
0.67
0.17
2.1
0.085
0.13
0.051
0.048
0.056
0.053
0.027
0.028
0.031
0.045
0.04
0.091
0.044
0.029
0.066
0.44
U = not detected at the reporting limit shown
Post 1° Dredge = Samples collected after the primary phase of dredging
Post 2° Dredge = Samples collected after the secondary phase of dredging
JANUARY 2008
73
-------
REMEDIATION OF THE BLACK LAGOON
APPENDIX B SUMMARY SEDIMENT CONCENTRATION DATA, 1999
Surficial Sediment Concentrations from 1999 Sediment Survey
Average Sediment Sediment Quality Ratio of Average
Concentration Guideline Sediment
Contaminant (mg/kg, dw) (mg/kg, dw) Concentration to SQG
Arsenic1
Cadmium1
Chromium1
Copper1
Mercury1
Nickel1
Lead1
Zinc1
Oil & Grease2
Total PAHs1
Total PCBs1
8
5.6
99
90
1.40
52
146
1380
6,280
10.5
1.12
33
4.98
111
149
1.06
48.6
128
459
2,000
22.8
0.68
0.25
1.12
0.89
0.60
1.32
1.07
1.14
3.01
3.14
0.46
1.66
SQGs for these contaminants are based on the Probable Effects Concentrations found in
MacDonald, etal. (2000), "Development and Evaluation of Sediment Quality Guidelines for
Freshwater Ecosystems."
2 SQG for this contaminant is based on the "heavily polluted" designation found in U.S. EPA
(1977), "Guidelines for the Pollutional Classification of Great Lakes Harbor Sediments."
PAHs - Polynuclear aromatic hydrocarbons
PCBs - Polychlorinated biphenyls
dw- Dry weight
Data taken from Environmental Quality Management, Inc., October 2004, Quality Assurance
Project Plan, Remediation of the Black Lagoon, Trenton Channel, Detroit River, Trenton
Michigan.
74
JANUARY 2008
------- |