United States
Environmental Protection
Agency
Great Lakes National Program Office
77 West Jackson Boulevard
Chicago, Illinois 60604
EPA-905-R-99-007
September 1999
&EPA Assessment of Contaminated
Sediments in Slip C
Duluth Harbor, Minnesota
Judy L. Crane
Environmental Outcomes Division
Minnesota Pollution Control Agency
520 Lafayette Road
St. Paul, Minnesota 55155-4194
Email: Judy.Cmne@pca.state.mn.us
-------
ASSESSMENT OF CONTAMINATED SEDIMENTS IN SLIP C,
DULUTH HARBOR, MINNESOTA
Submitted to
Scott Cieniawski, Project Officer
Great Lakes National Program Office
U.S. Environmental Protection Agency
77 West Jackson Boulevard
Chicago, Illinois 60604-3590
Cieniawski.Scott@epamail.epa.gov
Judy L. Crane
Environmental Outcomes Division
Minnesota Pollution Control Agency
520 Lafayette Road
St. Paul, Minnesota 55155-4194
Judy.Crane@pca.state.mn.us
-------
DISCLAIMER
The information in this document has been funded by the U.S. Environmental Protection
Agency's (EPA) Great Lakes National Program Office. It has been subject to the Agency's peer
and administrative review, and it has been approved for publication as an EPA document.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for use by the U.S. Environmental Protection Agency.
11
-------
TABLE OF CONTENTS
'-•age
DISCLAIMER ii
LIST OF TABLES v
LIST OF FIGURES vi
LIST OF ACRONYMS AND ABBREVIATIONS vii
ABSTRACT 1
INTRODUCTION 1
DESCRIPTION OF STUDY SITE 3
PREVIOUS SEDIMENT INVESTIGATIONS AT SLIP C 5
METHODS 6
Field Sampling 6
Laboratory Analytical Procedures 7
Quality Assurance/Quality Control 7
Data Analysis 8
Data Archival 9
RESULTS AND DISCUSSION 9
Field Sampling Information 9
Particle Size 9
TOC 10
General Contaminant Results 10
Distribution of PAH Compounds 11
Distribution of PCB Congeners 12
Chemical-Physical Relationships 13
Sediment Kriging Graphics 15
Volume of Contaminated Sediments 16
Preliminary Remediation Options 17
Sediment Management Plan 18
RECOMMENDATIONS 18
ACKNOWLEDGMENTS 19
REFERENCES 20
in
-------
TABLE OF CONTENTS
TABLES 25
FIGURES 47
APPENDIX A: Regression Analyses of Total PCBs with other Variables
APPENDIX B: Regression Analyses of PAHs, Mercury, and TOC with Particle Size Classes
IV
-------
LIST OF TABLES
Table
1 Description of field results 26
2 Particle size distribution of sediment samples 30
3 Comparison of contaminant data with low/threshold effect level and
probable effect concentration sediment quality guidelines (SQGs) 31
4 Summary of relative contamination factors (RCFs) for contaminant
concentrations normalized to low level effect sediment quality guidelines 33
5 Summary of relative contamination factors (RCFs) for contaminant
concentrations normalized to probable effect level sediment quality
guidelines 35
6 Summary of PAH concentrations for selected sediment samples 37
7 Percentage composition of PAH compounds in sediment samples 40
8 Distribution of PCB congeners in selected samples from Slip C 42
9 Nomenclature of predominant PCB congeners in Slip C 45
10 Results of regression analyses of chemical parameters with particle
size classes 46
-------
LIST OF FIGURES
1 Map of the St. Louis River AOC showing locations of contaminated
areas plus a reference area atKimball's Bay 48
2 Historical map of Slip C showing Slip numbers 5-8 49
3 Map of the Georgia-Pacific plant in Duluth, MN circa 1993 50
4 Map of the 1993 sediment sampling sites in Slip C 51
5 Map of the 1994 sediment sampling sites in Slip C 52
6 Map of the 1995 sediment sampling sites in Slip C as part of the
R-EMAP project 53
7 Location of the 1997 sediment sampling sites in Slip C and the slip
southeast of it 54
8 Close-up map of the 1997 sediment sampling sites in Slip C 55
9 Linear regression analysis of total PAHs versus lead 56
10 Linear regression analysis of total PAHs versus mercury 57
11 Linear regression analysis of mercury versus lead 58
12 Linear regression analysis of total PAHs versus TOC values less than 10% 59
13 Linear regression analysis of total PAHs versus the logarithm of TOC 60
14 Linear regression analysis of lead versus the logarithm of TOC 61
15 Linear regression analysis of mercury versus the logarithm of TOC 62
16 Linear regression analysis of lead versus percentage of sand and gravel
(>53nm) 63
17 Linear regression analysis of lead versus percentage of silt (52 - 2 |im) 64
18 Linear regression analysis of lead versus percentage of coarse silt
(53 -20|im) 65
19 Linear regression analysis of lead versus percentage of medium silt
(20-5|im) 66
20 Linear regression analysis of lead versus percentage of fine silt
(5-2|im) 67
21 Linear regression analysis of lead versus percentage of coarse clay
(2-0.2|im) 68
22 Sediment kriging graphs for selected depth intervals of lead
contamination in Slip C 69
23 Sediment kriging graphs for selected depth intervals of mercury
contamination in Slip C 70
24 Sediment kriging graphs for selected depth intervals of PAH
contamination in Slip C 71
25 Sediment kriging graphs for selected depth intervals of PCB
contamination in Slip C 72
26 Sediment kriging graphs for selected depth intervals of TOC in Slip C 73
VI
-------
LIST OF ACRONYMS AND ABBREVIATIONS
2Metnap 2-Methylnaphthalene
Acene Acenaphthene
Aceny Acenaphthylene
Anth Anthracene
AOC Area of Concern
ARCS Assessment and Remediation of Contaminated Sediments
ATSDR Agency for Toxic Substances and Disease Registry
AVS Acid Volatile Sulfide
bo Intercept of a Linear Regression Analysis Line
bi Slope of a Linear Regression Analysis Line
Bena Benzo[a]anthracene
Benap Benzo[a]pyrene
Benb Benzo[b&j]fluoranthene
Bene Benzo[e]pyrene
Beng Benzo[g,h,i]perylene
Benk Benzo[k]fluoranthene
BOD Biochemical Oxygen Demand
CAC Citizen's Action Committee
Chry Chrysene
cm Centimeter
Co. Company
Corp. Corporation
Cs Cesium
Diben Dibenzo[a,h]anthracene
DROs Diesel Range Organics
DSH Duluth/Superior Harbor (code name for sediment samples collected in 1993)
ECso Median Effective Concentration at which an effect occurred to 50% of the test
organisms within a given length of time
EPA Environmental Protection Agency
Fig. Figure
Fluo Fluorene
Flut Fluoranthene
GC/ECD Gas Chromatography/Electron Capture Detection
GC/MS SIM Gas Chromatography/Mass Spectrometry Selected Ion Monitoring
GLNPO Great Lakes National Program Office
GPS Global Positioning System
Indp Indeno[l,2,3-cd]pyrene
IT Corp. International Technology Corporation
IUPAC International Union of Pure and Applied Chemistry
kg Kilogram
LEL Lowest Effect Level
LUST Leaking Underground Storage Tank
vn
-------
LIST OF ACRONYMS AND ABBREVIATIONS (continued)
m Meter
MDH Minnesota Department of Health
mg Milligram
MPCA Minnesota Pollution Control Agency
Naph Naphthalene
PAH Polycyclic Aromatic Hydrocarbon
PCB Polychlorinated Biphenyl
PEC Probable Effect Concentration
Phen Phenanthrene
PRP Potentially Responsible Party
Pyrn Pyrene
QA/QC Quality Assurance/Quality Control
QAPP Quality Assurance Proj ect Plan
QC Quality Control
r2 Coefficient of Determination
R/V Research Vessel
RAP Remedial Action Plan
RCF Relative Contamination Factor
R-EMAP Regional Environmental Monitoring and Assessment Program
RPD Relative Percent Difference
SEM Simultaneously Extractable Metals
SLPC Slip C code name for 1997 sediment samples
SOP Standard Operating Procedure
SQG Sediment Quality Guideline
SUS Slip C code name for 1994 sediment samples
TEL Threshold Effect Level
TMA Thermo Analytical
TMDL Total Maximum Daily Load
TOC Total Organic Carbon
|lg Microgram
UMD University of Minnesota—Duluth
USEPA United States Environmental Protection Agency
VIC Voluntary Investigative Clean-up
WDNR Wisconsin Department of Natural Resources
WLSSD Western Lake Superior Sanitary District
wt. Weight
WWI World War I
Vlll
-------
ABSTRACT
A sediment remediation scoping project was conducted in a contaminated boat slip in the
Duluth, MN Harbor. Previous sediment investigations of this boat slip, Slip C, showed elevated
levels ofpolycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), DDT
metabolites, toxaphene, mercury, cadmium, copper, lead, and zinc. A sediment survey was
conducted in June 1997 to collect additional sediment samples to further delineate the spatial
extent of PAH, PCB, lead, and mercury contamination, as well as the distribution of total
organic carbon (TOC) and particle size classes. Total PAHs, lead, and mercury were foundto
co-vary, with the strongest linear relationship between total PAHs and lead (r2 = 0.877). The
percentage composition of PAH compounds throughout the samples were fairly uniform, which
may be indicative of a common source material of PAHs, such as from the combustion of fossil
fuels. High levels of TOC (up to 30%) were found in the sediments in front of a compressed
wood product plant that historically discharged industrial effluent into the slip until 1978. Lead,
mercury, and total PAHs displayed a logarithmic correlation to TOC. Particle size proved to be
an important indicator because the finer-grained sediments were more contaminated than the
sandy, coarser-grained sediments. Lead had the best correlation with the different particle size
classes, followed by total PAHs, mercury, and TOC. PCBs did not correlate well with any of the
other parameters, possibly due to the small number of samples analyzed for PCBs, narrow range
of corresponding TOC values, and highly elevated PCB concentrations in the core sections from
one sample. Contaminant data were compared to several sediment quality assessment
values/guidelines from other jurisdictions. The greatest exceedances of the guideline values
occurred in the inner portion of the slip, which had more historical sources of contamination.
The outer slip is more sandy and a portion of it is periodically dredged. Contaminant data were
pooled with data collected in 1994 in order to produce contaminant isoplethsfor the 0-15, 15-
30, and 30-45 cm depth intervals. These figures provided an effective visual picture of the
distribution of contaminants. No potentially responsible parties were identified due to the
historical nature of much of the contamination and current nonpoint sources, although this will
be investigated further with the identification of historical business operations. Decisions on
whether to remediate this site will be postponed until sediment quality objectives are developed
for the St. Louis River Area of Concern (AOC) in late 1999, a sediment bioaccumulation study is
completed in this slip in late 1999, and further work is done to assess groundwater and soil
contamination adjacent to the slip. A sediment management plan for Slip C will be incorporated
into an environmental management plan for the Duluth waterfront.
INDEX WORDS: Sediment assessment, sediment chemistry, remediation, Duluth Harbor, Area
of Concern.
INTRODUCTION
Contaminated sediments contribute to many impaired uses at Great Lakes Areas of Concern
(AOCs) including: fish advisories, habitat impairments, and restrictions on dredging. All of the
current 42 AOCs are impacted by sediment contamination based on the application of sediment
quality guidelines (Zarull et al. in press). In many cases, contaminated sediments represent a
-------
nonpoint source of pollutants to these AOCs, and may pose an unacceptable risk to aquatic
organisms, aquatic-dependent wildlife, and human health. Successful remediation of
contaminated sediments is essential for restoring impaired uses and contributing to the de-listing
of AOCs.
The EPA's Assessment and Remediation of Contaminated Sediments (ARCS) Program provided
a set of sediment assessment, risk assessment, modeling, and remediation tools for contaminated
sediment investigations (USEPA 1993, 1994 a,b). The sediment assessment techniques
recommended by the ARCS program promoted using a weight-of-evidence approach to conduct
sediment chemistry analyses, sediment toxicity tests, and benthological community surveys on
synoptic, surficially-collected sediment samples (USEPA 1994a). In particular, the sediment
quality triad approach (Long and Chapman 1985; Long 1989; Chapman 1992) provided both a
qualitative and quantitative means by which these data could be integrated together. The ARCS
program also provided guidance on field sampling and chemical analysis procedures for deeper
core segments (USEPA 1994a).
The work products and recommendations of the ARCS program have been implemented in the
St. Louis River AOC, located in northeastern Minnesota. The Minnesota Pollution Control
Agency (MPCA), and its collaborators, as well as the Wisconsin Department of Natural
Resources (WDNR), U.S Army Corps of Engineers, and some potentially responsible parties
have conducted a number of sediment assessment investigations in this transboundary waterway
between Minnesota and Wisconsin (Fig. 1). For the most part, these studies have followed an
ecosystem-based management approach, involving citizens and other stakeholders in the
decision-making process (MacDonald and Crane in review). These studies have shown that the
AOC includes relatively clean areas, in addition to several areas contaminated with a variety of
toxic and bioaccumulative substances. Mercury and polycyclic aromatic hydrocarbons (PAHs)
are widespread contaminants of concern in deposit!onal areas of the lower St. Louis River
estuary, whereas metals, polychlorinated biphenyls (PCBs), dioxins and furans, organochlorine
pesticides, tributyltin, and diesel range organics (DROs) tend to be more localized contaminants
of concern (MPCA and WDNR 1992, 1995; Redman and Janisch 1995; Schubauer-Berigan and
Crane 1996, 1997; Normandeau Associates 1996; TMA 1996; Crane etal. 1997; IT Corporation
1997; Breneman et al. in review). Several hot spot areas of elevated contamination occur in the
Duluth/Superior Harbor, including two Superfund sites (i.e., the Interlake/Duluth Tar and USX
sites), Hog Island Inlet/Newton Creek, several boat slips (e.g., Minnesota Slip, Slip C, Howard's
Bay), in the vicinity of historical and current wastewater treatment plants, and other areas with
historical sources of contamination (e.g., Grassy Point) (Fig. 1) (Schubauer-Berigan and Crane
1997; Crane et al. 1997). Additional background information on the extent of sediment
contamination in the St. Louis River AOC is given in the Stage I Remedial Action Plan (RAP)
(MPCA and WDNR 1992, 1995) and in MacDonald and Crane (in review).
During 1996, the MPCA solicited input from the Sediment Contamination Work Group of the St.
Louis River Citizen's Action Committee (CAC) to assist them in selecting an appropriate site for
a sediment remediation scoping project. The group selected Slip C, in the Duluth Harbor, as the
best candidate site because: the contamination was well-contained within the slip; several
surficial contaminants exceeded benchmark sediment quality guidelines (Persaud etal. 1993);
-------
the sediments contained bioaccumulative contaminants (e.g., PCBs, mercury) in the surficial and
deeper sediment layers; significant acute sediment toxicity had been observed at the site in the
past; and the benthological community was composed of organisms associated with degraded
environments (Schubauer-Berigan and Crane 1997; Crane etal. 1997). In addition, the site was
manageable for the budget available for this study. The group felt this site had a high potential
for being effectively remediated in the future.
The purpose of this sediment remediation scoping project was to further delineate the extent and
depth of contamination in the inner half of Slip C. The primary contaminants of concern were
eighteen PAH compounds, congener-specific PCBs, mercury, and lead. Total organic carbon
(TOC) and particle size classes were also measured. If possible, the volume of contaminated
sediments was to be estimated, and preliminary remediation options assessed. In addition, a
sediment management plan was to be developed for this site.
DESCRIPTION OF STUDY SITE
Slip C is located in the northern section of the Duluth Harbor basin in Duluth, MN (Fig. 1).
Historically, swampy areas were dredged in the late 1800s to form many of the existing boat slips
in the Duluth/Superior Harbor, including Slip C (Walker and Hall 1976). Four smaller slips (i.e.,
Slip numbers 5-8) used to extend out from the western side of Slip C (Fig. 2); these slips have
now all been filled in for upland development, except for a small remnant of Slip #7. The fill
material was usually of unknown origin. In the case of Slip #7, at least a portion of the fill
consisted of material from the demolition of a hospital building and a creamery (Barr
Engineering Company 1994). It is now known that the fill material in Slip #7 was contaminated
with PAHs, mercury, and metals.
Several commercial operations have been located along either Slip C, or its adjoining slips,
during the past hundred years (Walker and Hall 1976). These companies included: Duluth
Universal Milling Co. (1900 - 1940s), Marine Iron & Shipbuilding Co. (1905 - 1961), Great
Lakes Dredging and Dock Co. (1908 - c.1940), Standard Oil Co. storage facility (1890 - 1910),
Cutler-Magner salt dock (1902 - present), Great Lakes Towing Co. (1907 - early 1990s),
Superwood Corp. (now owned by Georgia-Pacific Corp.) (1940s - present), and Duluth Timber
Co. (1990s to present). Earlier this century, approximately thirty ships were built by Zenith Co.
in the vicinity of Slip C and its side slips (Keith Yetter, Marine Tech, personal communication,
1998). A gas station used to be located along Railroad Street in front of the Superwood plant; it
closed in the late 1970s. In addition, a city incinerator used to be located in the vicinity of the
Superwood plant. Additional information about this incinerator is being sought as to the time
period of its operation. A coal gasification plant once existed at Dakota Pier on the north end of
nearby Rice's Point. This plant could have been a source of airborne contamination to Slip C, as
well as through the disposal of waste material along the waterfront (Tim Musick, MPCA Duluth
Regional Office, personal communication, 1999).
Slip C is currently bordered on the southwest side by the Duluth Timber Company, a firm that
removes lumber from historic structures. On the northwest side, Georgia-Pacific Corporation
-------
and Cutler-Magner Company border the slip. Georgia-Pacific manufactures SuperwoodR that is
made from the compression of fine wood fibers with phenolic resin and moisture inhibitors.
Most of the Superwood® made at the Duluth plant is used to manufacture dash boards for
automobiles (Tom Lochner, Georgia-Pacific Corp., personal communication, 1997). Cutler-
Magner imports salt which is stored on their property.
A portion of the land northwest of the Georgia-Pacific plant is included in the MPCA's
Voluntary Investigative Clean-up (VICs) program. Historically, this site was Slip #7, which was
filled in during either 1973 or 1974 (Tom Lochner, Georgia-Pacific Corp., personal
communication, 1998). The groundwater beneath this site has been found to be contaminated
with PAHs, mercury, and metals. Land on the southeast side of the plant is included in the
MPCA's Leaking Underground Storage Tank (LUST) program because of two ruptures that
occurred in their underground oil line during September 1990 and September 1991. The LUST
site has now been included under the VICs program so that a comprehensive evaluation of soil
and groundwater contamination can be made before implementing clean-up measures. As a next
step, monitoring wells will be installed to assess groundwater contamination in the surrounding
area (Jonathan Smith, MPCA Duluth Regional Office, personal communication, 1998).
Navigational dredging in Slip C is maintained by commercial operations, as needed. Dredging
last occurred in 1986 in front of Cutler-Magner's dock, and they only dredged the spots that
soundings indicated would interfere with boat draft (Mark LaLiberte, Cutler-Magner Co.,
personal communication, 1999). The inner end of the slip has not been dredged for some time as
Georgia-Pacific relies on rail and truck traffic to transport their compressed wood products.
Marine Tech (formerly known as Zenith Dredge) moors two dredging scows along Duluth
Timber's dock for long-term storage. Thus, most water uses of the slip are limited to the outer
half of it.
There are no current wastewater effluent discharges into Slip C. Effluent and sanitary discharges
from all of the neighboring businesses have been routed to WLSSD since approximately 1978.
Historically, Superwood Corp. was the major discharger to Slip C (MPCA/WDNR 1992). A
MPCA report, published in 1969, noted that both industrial and sanitary waste treatment was
inadequate at Superwood Corp. The sanitary sewage of approximately 200 persons was treated by
septic tank, and the industrial wastes were treated by settling ponds (MPCA 1969). At that time,
the total discharge of effluents was approximately 450 gallons per minute with a high 5-day
biochemical oxygen demand (BOD) of about 2,000 mg/L (MPCA 1969).
Stormwater runoff from the Georgia-Pacific wood yard currently drains through a weir into an
outfall at the southern (most inland) end of the slip (outfall 001) (Fig. 3). Buckingham Creek,
which provides Stormwater drainage of a section of Duluth, flows along the northern side of the
Georgia-Pacific plant into the remnant of Slip #7 (Fig. 3). Outfalls 002 and 003 discharge into
the creek, whereas outfall 010 discharges cooling water directly into Slip C (Fig. 3).
Buckingham Creek was recently enclosed in a culvert along Georgia-Pacific's property, and two
extra sand traps were added to promote the deposition of particulate matter (Tom Lochner,
Georgia-Pacific Corp., personal communication, 1998).
-------
Several nonpoint sources could have contributed contamination to Slip C. These sources
potentially include the runoff of contaminated fill material from former Slips #7 and 8; other land
runoff (e.g., coal piles); groundwater transportation of contaminants from the surrounding
property; ship, rail, and motor vehicle traffic; transport and deposition of sediment-derived
contaminants from elsewhere in the harbor; and atmospheric transport and deposition of
contaminants.
PREVIOUS SEDIMENT INVESTIGATIONS AT SLIP C
The MPCA, and its collaborators, have conducted three previous sediment investigations in the
Duluth/Superior Harbor in which sediment samples were collected from Slip C. During 1993, a
sediment investigation was conducted at 40 depositional sites in the Duluth/Superior Harbor;
four of these sites were sampled within Slip C (Schubauer-Berigan and Crane 1997) (Fig. 4).
This study indicated that overall contamination decreased from the inland end of the slip to the
outer end of the slip. Contaminants of concern at the inland end of the slip included: PAHs,
PCBs, DDT metabolites, toxaphene, mercury, cadmium, copper, lead, and zinc. Bacterial and
acute sediment toxicity tests were run on the sediments. The two most inner samples were toxic
in the initial 90% screen of the Microtox® test, but not in the ECso run. The inner three samples
caused genotoxicity of samples in the Mutatox® test. The sediments were not acutely toxic to the
midge, Chironomus tentans, and the results were inconclusive for 10-day toxicity tests with the
amphipod, Hyalella azteca, due to control failure.
A follow-up investigation was conducted during 1994 to further utilize a weight-of-evidence
approach to assess contaminated sediments in Slip C (Crane et al. 1997). Eight sites were
sampled in a transect of this slip (Fig. 5). Selected core sections were analyzed for a suite of
contaminants at various 15 cm depth intervals. Four surficial sites were sampled for 10-day
sediment toxicity testing with C. tentans and H. azteca. The results indicated significant acute
toxicity to C. tentans at site SUS 3. The specific cause of toxicity could not be determined. The
control for the C. tentans toxicity test of SUS 7 sediments barely failed the acceptable control
survival requirements by 2%. Although the results were not analyzed statistically, the mean
percent survival in SUS 7 (i.e., 0%) was highly depressed relative to the control (i.e., 68%).
Similarly, the control survival for the H. azteca test on SUS 7 sediments barely failed the
acceptable control survival by 2%; although the results were not analyzed statistically, the mean
percent survival in SUS 7 (i.e., 45%) appeared to be highly depressed relative to the control (i.e.,
78%). All of the surficial sites were sampled for benthological community structure. The
benthological survey showed that oligochaetes were the dominant group in the inner half of the
slip (sites SUS 1-6), comprising 70-90% of the fauna; tubificids made up 62-85% of the
oligochaete community. Chironomids accounted for 53% of the fauna at SUS 7; this site was
within the area dredged for Cutler-Magner Co. in 1986.
Two sites were sampled in Slip C during June 1995 as part of a Regional Environmental
Monitoring and Assessment Program (R-EMAP) project. One site (#51) was located directly in
front of Georgia-Pacific's plant, whereas the other site (#24) was located in front of the remnant
of Slip #5 in the outer slip (Fig. 6). Sediment chemistry and toxicity tests were run on synoptic
-------
0-5 cm composite sediment samples. In addition, benthological samples were collected at the
same time. Neither sample was acutely toxic to 10-day exposures ofH. azteca and C. tentans.
Oligochaetes dominated site #51, whereas both chironomids and oligochaetes dominated site
#24. Mercury was elevated at site #51, and simultaneously extractable metals (SEM) also
exceeded acid volatile sulfides (AVS) at this site. Total PAHs were elevated at both sites,
particularly at site #51 (i.e., 56 mg/kg dry wt).
METHODS
Field Sampling
Sediment samples were collected during June 16-18, 1997 according to the procedures specified
in the quality assurance project plan (QAPP) (Crane 1997), the GLNPO Health, Safety, and
Environmental Compliance Manual (GLNPO 1997), and Smith and Rood (1994). The field crew
consisted of staff provided by the Great Lakes National Program Office (GLNPO), Seward
Services, the MFC A, and volunteer members of the St. Louis River CAC Sediment
Contamination Work Group. GLNPO's specially designed research vessel, the R/V Mudpuppy,
was used to sample the sediments.
A total of 19 sampling sites were selected, three of which were located in the slip southeast of
Slip C, two of which were located in the slip north of Slip C, and fourteen of which were located
in Slip C itself. The slips, other than Slip C, were sampled because no sediment contaminant
data were available for these sites. The sampling design in Slip C was best represented by a
rectangular grid pattern for an elliptical-shaped hot spot (Lubin et. al. 1995).
A sediment sounding was taken at each site to determine the approximate depth of the soft
sediment layer. This was done using a long metal rod of known length, in which the pole was
lowered into the sediment and pushed in until the point of refusal (WDNR 1995). A real-time,
differential global positioning system (GPS) unit was used to determine station positions by
receiving digital codes from three or more satellite systems, computing time and distance, and then
calculating an earth-based position. The positional accuracy of the GPS measurements was
between 0.5-5 m. GPS measurements were converted from degree/minute format to decimal
format for preparation of the site maps.
The R/V Mudpuppy was anchored in place at each site by the use of specialized "spuds." A new
Vibrocorer system, composed of lexan plastic, was used to collect sediment cores down to 1.6 m.
Cores were processed on board the R/V Mudpuppy immediately after collection. Each core was
sectioned at 15 cm intervals down to 60 cm. A physical description of each core section was made,
including sections below 60 cm. Each section was homogenized and split for specific chemical
analyses. The samples were stored on ice in a cooler while on board the R/V Mudpuppy. At the
end of each day, the sediment samples were stored under refrigeration (in the dark) at the Duluth
MPCA Regional office. Samples were delivered to the contract laboratories for chemical
analyses within one week of collection. Selected sediment core sections were analyzed for either
-------
all or a portion of the following chemical/physical measurements: eighteen PAH compounds, 107
PCB congeners, mercury, lead, TOC, and particle size classes.
Laboratory Analytical Procedures
Sediment samples were analyzed by three different analytical laboratories. PCB congeners were
analyzed by En Chem, whereas particle size was analyzed by the University of Minnesota-Duluth
(UMD). PAH compounds, lead, mercury, and TOC were analyzed by the Minnesota Department
of Health (MDH).
A subset of 107 PCB congeners were analyzed by capillary column GC/ECD according to En
Chem's standard operating procedures (SOPs) (En Chem 1995). Eighteen target PAH compounds
were measured by capillary column GC/MS SIM using MDH Method 513 (MDH 1997). Mercury
was measured using flow injection atomic absorption spectrometry—cold vapor technique according
to EPA Method 245.1 A (USEPA 1983). Total lead was determined by digesting the samples with
concentrated nitric acid and analyzing them with stabilized temperature graphite furnace atomic
absorption spectroscopy (MDH 1993a,b; USEPA 1991). TOC was measured on a Dohrmann DC-
80 TOC analyzer (Rosemount Analytical 1990a,b; 1991). Percent moisture of samples run by
MDH was done according to MDH Method 261 (MDH 1995). Particle size was measured using an
Horiba LA-900 analyzer (Lodge 1996). The particle size results were reported as percentages of the
following classes: sand and gravel (>53 |im), coarse silt (53 - 20 |im), medium silt (20 - 5 |im), fine
silt (5-2 |im), coarse clay (2 - 0.2 |im), medium clay (0.2 - 0.08 |im), and fine clay (<0.08 |im).
Quality Assurance/Quality Control
The Quality Assurance/Quality Control (QA/QC) procedures followed in this study adhered to the
site-specific QAPP (Crane 1997) which was based on guidance given in U.S. EPA (1995). Two
field replicate samples were collected to assess field precision. Analytical data quality objectives
were made to assess analytical precision, accuracy, and completeness. The sampling strategy was
designed to generate representative data for Slip C. The analytical methods utilized in this study
were similar to methods used in previous investigations so that the data would be directly
comparable to them. All samples were extracted within the holding time period specified in the
QAPP (Crane 1997)
Two field replicates were collected in Slip C at the SLPC 08 and SLPC 15 sites. In both cases, the
R/V Mudpuppy was repositioned to collect the replicate sample. Due to the heterogeneity of the
sediments, the replicate core lengths were quite different for both sites. At SLPC 08, the replicate
sample was 2.3 times longer than the field sample; thus, only the chemical data from the 0-15 cm
segment was averaged with the field sample. The physical description of both 0-15 cm core
sections were similar (Tables 1 and 2). At SLPC 15, the replicate sample was nearly half the length
of the field sample (Table 1). In addition, the R/V Mudpuppy moved more than when the SLPC 08
replicate core was collected. The SLPC 15 replicate sample was treated as a separate sample from
the field sample because the physical descriptions of the sediments varied greatly [as shown in the
particle size (Table 2) and TOC (Table 3) data].
-------
The analysis of PAHs included several quality control (QC) measurements. The results of three
reagent blank samples were all less than the reporting limits for individual PAH compounds. The
recoveries for three fortified blank samples, in which each blank was spiked with the suite of PAH
compounds at a concentration of 100 |ig, ranged from 72-116%; this was within the QC limit of
50 - 120%. The initial and continuing instrument calibrations were within the QC criteria. Three
surrogate compounds of 2-fluorobiphenyl, pyrene-dlO, and benzo[a]anthracene-d!2 were added to
each sample; the recoveries ranged from 48 - 128%, which were nearly all within the QC limits of
40 -120%. The following samples were selected for the matrix spikes: SLPC 01 (0-15 cm), SLPC
11 (0-15 cm), and SLPC 16 (15-30 cm). Each sample was spiked with 100 |ig of each PAH
compound; the recoveries ranged from 36 - 201%, which deviated from the QC limits of 50 -
120%. For SLPC 01 (0-15 cm), only naphthalene was below the acceptable QC limit. For SLPC
11 (0-15 cm), four PAH compounds slightly exceeded the QC limit. For SLPC 16 (15-30 cm), six
PAH compounds exceeded the QC limit with phenanthrene having the highest exceedance. This
indicates that the sample matrix may bias the surrogate results for these two samples. Analytical
duplicates were run on SLPC 03 (0-15 cm), SLPC 10 (0-15 cm), and SLPC 15R (30-45 cm). For
SLPC 03 (0-15 cm), the Selective Ion Monitoring (SUV!) part of the analysis was lost; the full scan
analysis had several compounds below the full scan reporting limit of the working calibration
curve. Thus, the results of this analytical duplicate were not compared to the corresponding sample.
For the other two analytical duplicates, the relative percent difference (RPD) for individual PAH
compounds ranged from 5 - 40% for SLPC 10 (0-15 cm) and 1 - 54% for SLPC 15R (30-45 cm),
with one exceedance for fluorene. The RPDs for the field replicate of SLPC 08 ranged from 2 -
40%; this was within the QC limit of <50% RPD.
Similar types of QC samples were run with the PCB congener samples. The method blank that was
extracted and analyzed with the samples had two small hits for congeners #1 (1.2 |ig/kg) and #4
(2.0 |lg/kg). The initial and continuing instrument calibrations were within the QC criteria.
Congeners #14, 65, and 166 were used as surrogate compounds for each sample. All surrogate
recoveries were between 62 - 89%, which were within the QC limits of 40 - 120%. Sample SLPC
17 (0-15 cm) was chosen for the matrix spike. Eleven congeners of interest were added to the
matrix spike at a concentration of 10 |lg/kg, wet weight. The matrix spike recoveries ranged from
47.3 - 85.5%, which were nearly all within the QC limits of 50 - 120%. Sample SLPC 17 (0-15
cm) was also chosen for the analytical duplicate. All congener relative percent differences (RPD)
between the sample and duplicate results were between 0 - 44.5%, which were below the QC limit
of 50% RPD. The control spike, consisting of blank sand fortified with eleven congeners of
interest (at 10 |ig/kg, wet weight), was extracted and analyzed with the samples; the recoveries
ranged from 68.0 - 89%, which were within the QC limits of 50 - 120%.
Data Analysis
The analytical data were obtained electronically from each laboratory as Excel spreadsheets. The
results of analytical duplicates were averaged with the field sample results, providing all data
quality objectives had been met. As described in the previous section, only the field replicate for
SLPC 08 was averaged together with the sample for the 0-15 cm segment. All manipulations of the
data sets were double-checked to ensure that no errors had occurred. The relationships between
-------
different chemical and physical parameters were analyzed statistically by linear regression analysis.
Any data points that were on or outside the 95% prediction intervals were designated as outliers and
were removed from the regression analysis. The intercept (bo), slope (bi), and coefficient of
determination (r2) were reported for each regression analysis.
The dry weight analytical data for lead, mercury, PAHs, PCBs, and TOC were combined with
previously collected data sets from 1993, 1994, and 1995 (Schubauer-Berigan and Crane 1997;
Crane et al. 1997; Breneman et al. in review). This was done in order to evaluate graphical
techniques by which the data could be plotted in either two-dimensional or three-dimensional
space. The most appropriate use of this data set was to generate two-dimensional contaminant
isopleths for similar depth intervals (i.e., 0-15, 15-30, and 30-45 cm). Only data from the 1994
study (Crane et al. 1997), and this study, qualified for use in the graphics due to their similar depth
intervals. Surfer software was used to make the isopleth figures, and AutoCad Release 14 was used
to finalize the figures with sample site labels.
Data Archival
The field and laboratory sediment data from this study will be submitted electronically to GLNPO's
regional contaminated sediment database. The MPCA used this study to participate in a pilot
project with GLNPO to test out their new field and laboratory data fields for the sediment database.
The database will be available for public use when it is completed.
RESULTS AND DISCUSSION
Field Sampling Information
The field sampling information for the sediment cores is given in Table 1. Sites SLPC 01 through
SLPC 03 corresponded to the surficial samples collected in the slip southeast of Slip C, whereas
sites SLPC 06 through SLPC 19 were sampled in Slip C (Figs. 7-8). Sediment samples could not
be obtained in the slip north of Slip C (i.e., SLPC 04 and SLPC 05) due to the gravely nature of
the sediments and presence of logs. Nearly all of the Slip C sites were sampled as planned. The
positions of SLPC 09 and SLPC 10 were adjusted westward because two dredging scows were
docked in the area that was initially going to be sampled. A cohesive sediment core could not be
collected at SLPC 18 the first time it was sampled, necessitating movement of the boat closer to
SLPC 17.
Particle Size
Particle size analyses were conducted on all samples in which PAHs and/or PCBs were measured.
Due to cost constraints, particle size was not done on samples in which only lead and mercury were
measured. In general, the sediments in the inner portion of Slip C had a higher percentage of silt
and coarse clay than the outer sites, which were more sandy (Table 2). In comparison, the surficial
sediments in the slip southeast of Slip C were predominately sand (i.e., > 96% sand); the incidence
of sediment scouring is probably higher in this slip due to active ship traffic. Thus, silty material
-------
may be transported out of this slip due to resuspension caused by ship propellers. None of the
sediment samples, from either slip, contained a fine or medium clay fraction.
TOC
TOC ranged from 0.34 - 1.1% in the slip southeast of Slip C and from 0.81 - 30% in Slip C (Table
3). The sediments in the inland portion of Slip C contained a large amount of detrital material (i.e.,
wood fibers and wood chips), resulting mostly from historical operations of the Superwood plant.
The manufacturing performed by Superwood Corp. and Georgia-Pacific Corp. has remained
consistent, since operations began around 1948; this process includes mechanically refining wood
into fiber, adding phenolic resin and wax, and pressing it in a hot press (James Holmes UJ, Georgia-
Pacific Corp., memorandum, 1999). Thus, the release of wood-derived material in Superwood's
effluent was a major contributor to elevated TOC levels in Slip C sediments. Correspondingly,
TOC was highest (up to 30%) in the core sections collected at SLPC 14 and SLPC 15, in front of
the former Superwood plant (Table 3).
General Contaminant Results
As with previous sediment investigations in Slip C, elevated concentrations of lead, mercury, total
PAHs, and total PCBs were found in both surficial sediments and deeper core sections (Table 3).
Lead and mercury concentrations that were less than the detection limit were reported in Table 3 at
one-half the detection limit for SLPC 08 (15-26 cm) and SLPC 08R (30-45 cm), respectively.
The contaminant concentrations in Table 3 were compared to two classes of empirically-derived
sediment quality guidelines: a threshold level, or lowest effect level, and a probable effect
concentration (Table 3). Threshold effect level (TEL) values are intended to estimate the
concentration of a chemical below which adverse biological effects only rarely occur (Smith et al.
1996). Lowest effect level (LEL) values indicate the level of sediment contamination that can be
tolerated by the majority of benthic organisms (Persaud et al. 1993). Probable effect concentrations
(PECs) are intended to estimate the concentration of a chemical above which adverse biological
effects frequently occur (Ingersoll and MacDonald 1998). TEL values for lead, mercury, and total
PCBs were used in Table 3; since a TEL value for total PAHs was not available, the LEL value was
used. PEC values were available for each of the contaminants of concern.
Low levels of contamination were found in the slip southeast of Slip C, whereas multiple
exceedances of the TEL and LEL values were common at most of the Slip C sites and depth
intervals. Total PAHs and lead were the predominant contaminants of concern due to the number
of exceedances of the PEC values. Thus, at sites SLPC 11-14, SLPC 15R, and SLPC 17, the
surficial sediments were sufficiently contaminated to present a greater probability of risk to the
benthic community. However, other site-specific factors in the sediment matrix (e.g., type of
contaminant source such as fly ash or oil, TOC, particle size) may affect the bioavailability of these
contaminants to aquatic organisms. In addition, PCBs and mercury remained as contaminants of
concern due to their potential to bioaccumulate in organisms.
10
-------
Relative contamination factors (RCFs) were calculated by dividing the contaminant concentration
by its associated sediment quality guideline value. This was done based on using the
threshold/lowest effect level guidelines (Table 4) and the PEC guidelines (Table 5). A cumulative
mean low level or probable effect level RCF value was calculated for each core section. Since
PAHs and PCBs were not measured at every site, the mean values were skewed towards those
chemicals in which data were available. Mean RCF values greater than one implied a higher
probability of either low level or adverse effects impacting the benthological community. From this
data set, there were no instances in which a high individual chemical RCF was diluted by low
chemical RCFs to result in a mean RCF less than one.
Nearly all of the inland Slip C sites, throughout the core profiles, had mean low level RCFs
exceeding one. Of these sites, SLPC 13 had the most contaminated sediments in the 0-15 and 15-
30 cm depth intervals. SLPC 15 had the most contaminated sediments in the 30-45 cm core
segment. SLPC 13 was located by the outfall for Georgia-Pacific's yard runoff, whereas SLPC 15
was located in front of the Georgia-Pacific plant. These sites also had a mean probable effect
concentration RCF greater or equal to one. Most of the other samples had mean probable effect
concentration RCFs of less than one. Thus, there appeared to be intermediate levels of
contamination at most of the Slip C sample sites.
Distribution of PAH Compounds
The distribution of eighteen PAH compounds was determined in this study (Table 6). Sediment
samples were selected for PAH analyses based on either physical observations of the sample (e.g.,
presence of an oil sheen) or to fill data gaps (e.g., sites SLPC 01 through SLPC 03).
Individual PAH concentrations were converted to a percentage of the total concentration for each
sample (Table 7). Fluoranthene (18.1%), pyrene (13.5%), phenanthrene (12.1%), and chrysene
(7.9%) made up the greatest proportion of total PAHs. Fluoranthene is a constituent of coal tar and
petroleum-derived asphalt; it is a universal product of the combustion of organic matter and is
present in fossil fuel products. Pyrene and chrysene are ubiquitous products of incomplete
combustion, whereas phenanthrene most likely results from the incomplete combustion of a variety
of organic compounds, including wood and fossil fuels. All four compounds are strongly adsorbed
to sediments and to paniculate matter when released into the water column (U.S. Library of
Medicine, Health, and Safety Database 1999).
All other PAH compounds, on average, constituted less than 6.8% each of the total PAHs.
Dibenzo[a,h]anthracene (0.9%) and acenaphthylene (0.4%) made up the lowest percentage of total
PAHs. Dibenzo[a,h]anthracene is a ubiquitous product of incomplete combustion. Acenapthylene
is a component of crude oil and coal tar, as well as being a product of combustion which may be
produced and released to the environment during natural fires. The other PAH compounds
generally result from the incomplete combustion of fossil fuels (U.S. Library of Medicine, Health,
and Safety Database 1999).
The low molecular weight PAHs generally constituted less than 2.8% each of total PAHs, except
for phenanthrene that made up 12.1% of PAHs. The other low molecular weight PAHs were: 2-
11
-------
methylnapthalene, acenapthene, acenapthylene, anthracene, fluorene, and naphthalene. The
remaining PAH compounds made up the high molecular weight fraction; most of them constituted
over 5.5% each of total PAHs, except for benzo[k]fluoranthene (2.5%) and dibenzo[a,h]anthracene
(0.9%).
The percentage of PAH compounds appeared fairly uniform between depth intervals, between
spatial locations in Slip C, and between Slip C and the slip southeast of it. This uniform
distribution would suggest that photolysis and microbial degradation are not active degradation
pathways for the sorbed PAH compounds. In addition, this may be indicative of a common type of
source material, such as coal combustion products, for contributing most of the PAH contamination
in these slips. The Duluth/Superior Harbor area had a high historical use of coal during the past
100 years through the storage and transport of coal along the waterfront, the presence of several
coal gasification plants (including one a half-mile from Slip C), and the manufacture of coal-
powered ships, especially during WWI. The release of some PAH compounds may also have
resulted at the Superwood plant from the combustion of the wood fines, oversized chips, and chip
wash residue as boiler fuel.
The individual PAH concentrations were compared to available sediment quality guidelines that
represented either a lower level or probable level of effects (Table 6). No sediment quality
guidelines were available for benzo[b&j]fluoranthene or benzo[e]pyrene. No probable effect level
guidelines were available for benzo[g,h,i]perylene, benzo[k]fluoranthene, or indeno[l,2,3-
cd]pyrene. For the other PAH compounds, the greatest probable effect level exceedances occurred
for phenanthrene, pyrene, fluoranthene, benzo[a]anthracene, chrysene, and benzo[a]pyrene (Table
6). These last three compounds, in addition to benzo[b]fluoranthene, benzo[k]fluoranthene,
dibenz[a,h]anthracene, and indeno[l,2,3-cd]pyrene, have caused tumors in laboratory animals
through ingestion, dermal, and inhalation exposure pathways (ATSDR 1990). Human exposure to
these compounds in Slip C is minimal because swimming and wading do not occur in this slip, and
fishing probably occurs infrequently there. In addition, fish metabolize PAHs so they would not
bioaccumulate in their tissues as readily as for benthic invertebrates. Inhalation would not be an
important human exposure pathway because most of the PAH compounds are strongly sorbed to
the sediments and would not be partitioning much to the water column, with subsequent
volatilization to the air. An exposure assessment, combined with a toxicity assessment, would need
to be done to quantitate human health risks at this site. A similar process could be used to assess
ecological risks to aquatic receptors.
Distribution of PCB Congeners
The distribution of PCB congeners at six Slip C sites is given in Table 8. The highest congener
concentrations for the SLPC 17 and SLPC 18 samples were the coeluting congener pair of IUPAC
numbers 77/110. For the SLPC 09 samples, this was the second most prevalent congener group,
with congener #4 being the most predominant. However, the small hits for congeners #1 and 4,
found in the method blanks, were not subtracted from the sample results. Considering this, #77/110
would be the most prevalent congeners in the SLPC 09 samples. Other prevalent congeners in all
samples were IUPAC numbers: 95, 101/90, 118, 132/168/105, and 163/138 (see Table 9 for
associated congener nomenclature). In general, these compounds were mostly highly chlorinated
12
-------
penta- and hexachlorobiphenyls. These compounds would be more resistant to degradation in the
environment than lower chlorinated congeners, and would be more likely to be associated with
higher PCB Aroclor mixtures such as Aroclor 1260.
Chemical-Physical Relationships
The contaminant data were examined for trends with other contaminant and physical parameters.
The data set included the Slip C sites, as well as three sites in the slip southeast of Slip C. The non-
Slip C sites provided lower bound contaminant values for use in the regression analyses. Total
PAHs were strongly correlated to lead (r2 = 0.877) (Fig. 9) and moderately correlated to mercury
(r2 = 0.770) (Fig. 10). Thus, lead could be used as a good indicator of PAH contamination in Slip
C. Mercury and lead were more moderately correlated to each other (r2 = 0.744) (Fig. 11).
Mercury and lead are both components of coal, and PAHs result from the incomplete combustion
of fossil fuels, like coal. Thus, some of the contamination in Slip C may result from fossil fuel
sources, such as fly ash and petroleum products. Some of the sediment samples had a visible oil
sheen and were oily; it is not known whether two fuel oil leaks at Georgia-Pacific's plant in the
early 1990s contributed to this sediment contamination. A gas station was located in the area
historically, and it is not known if used oil could have been dumped in the slip by it, or other
historical businesses.
For the outlier data that were removed from Figs. 9-11, these data were either clustered in Slip C at
SLPC 13 (0-15, 15-30 cm), SLPC 15 (15-30 cm), and/or SLPC 19 (0-15 cm). The SLPC 13 and 15
outliers had elevated PAH concentrations, whereas mercury was elevated in the SLPC 19 (0-15 cm
outlier. Of the sites sampled in Slip C, SLPC 13 was located at the most shallow water depth (i.e.,
4.5 m). Both this site and SLPC 15 had deep soft sediment layers (i.e., 1.4-1.8 m), whereas the soft
sediment layer in SLPC 19 was much less (i.e., 0.5 m) (Table 1). SLPC 13 was located at the most
inland section of Slip C by the yard runoff outflow for the south section of Georgia-Pacific's
property. The particle size distribution in the surficial sediments from SLPC 13 contained a much
higher coarse grain fraction (>53 |im) than SLPC 12 or 14. These results are consistent with
general observations of outfalls that the coarser material settles out closer to the outfall and finer
material settles out further away from the outfall. There may also be more resuspension of material
below the outfall that would promote the mixing of the upper sediment layers. The lead, mercury,
PAH, and TOC levels were highest in the surficial sediments of SLPC 13, but the 15-30 cm section
was also elevated for these parameters (Table 3). Radioisotope dating of a sediment core with
910
lead could provide more information about the extent of sediment mixing at this site.
The coarse grain fraction in the upper two sections of SLPC 15 was also high, but it is not known if
any historical discharges occurred in this area. SLPC 19 was located in the area dredged for Cutler-
Magner Co. in 1986. This site was also located in front of former Slip #6 which was filled in
around 1993 (Mark LaLiberte, Cutler-Magner Co., personal communication, 1998)]. The elevated
mercury levels in these surficial sediments may have resulted from the exposure of deeper, more
contaminated sediments during the 1986 dredging, from the displacement of contaminated
sediments from the edge of Slip #6 when it was filled, and/or from the runoff of fill material from
Slip #6 into Slip C.
13
-------
Total PCBs did not correlate to total PAHs (r2 = 0.0194), lead (r2 = 0.0351), or mercury (r2 =
0.0875) (Figs. A-l through A-3, Appendix A). This lack of correlation may have been partly
attributable to the small sample size of PCBs used in the regression analyses (i.e., n = 5 for PAHs;
n = 6 for lead and mercury). Therefore, the combined 1993 (Schubauer-Berigan and Crane 1997)
and 1994 (Crane etal. 1997) data sets for Slip C were also examined for relationships between total
PCBs and total PAHs, as well as total PCBs and mercury. There were insufficient lead data to
compare to total PCBs. The results of these regression analyses also demonstrated a lack of
correlation with total PAHs (r2 = 0.428, n = 18, Fig. A-4) and mercury (r2 = 0.230, n = 42, Fig. A-5)
(Appendix A). Since total PCBs did not correlate to the other three contaminants, they must have
entered Slip C through a different source material. In particular, a high pocket of PCB
contamination was found between sites SLPC 17 and SLPC 18. This area encompassed a 1994
sample site, SUS 5 (15-23 cm), which had the highest PCB concentration of 1140 |lg/kg reported in
Slip C (Crane et al. 1997).
Hydrophobic organic contaminants, such as PAHs and PCBs, preferentially partition to organic rich
sedimentary particles in lakes and rivers (Chevreuil etal. 1987). For example, the concentration of
PCBs correlated well with percent organic carbon (r2 = 0.86) and the percent silt-clay fraction (r2 =
0.96) in surficial sediments from northeast Lake Michigan (Simmons etal. 1980). However, PCBs
were not associated with TOC in Slip C (r2 = 0.0169) based on the 1997 data set (Fig. A-6,
Appendix A). Likewise, no correlation was observed between sediment PCB concentrations and
the percentage of clay or organic matter in sediments from the upper Great Lakes (Glooschenko et
al. 1976). A more detailed examination of the correlation between total PCBs and TOC, based on
r\
the 1993 and 1994 data sets for Slip C, showed a stronger correlation of r = 0.707, n = 42 (Fig. A-
7, Appendix A). The 1993 and 1994 data sets spanned a wider range of TOC values (i.e., 0.09 -
19%) than for the 1997 TOC values (i.e., 2.2 - 5.4%). Thus, the lack of a correlation in the 1997
data set may have been attributable to the small number of samples, narrow range of TOC values,
and highly elevated PCB concentrations in the SLPC 18 core sections (i.e., 0-15, 15-30 cm).
Total PAHs were linearly related to TOC up to about 10% TOC (r2 = 0.876) (Fig. 12) after which
point the data became more scattered. Thus, with this data set, normalization of PAH
concentrations by TOC should only be done when TOC is less than 10%. This also corresponds to
the use of some organic carbon normalized sediment quality guidelines for PAHs which limit their
use to sites with TOC less than 10% (Persaud et al. 1993). For the whole data set, the logarithm of
the corresponding TOC values accounted for over 76% of the variance in total PAHs (r2 = 0.766)
(Fig. 13). Lead and mercury also displayed a logarithmic relationship with TOC (r2 = 0.793 and
0.773, respectively) (Figs. 14-15).
Lead, mercury, total PAHs, total PCBs, and TOC were compared to their corresponding particle
size classes. Particle size proved to be an important indicator because the finer-grained sediments
were more contaminated than the sandy, coarser-grained sediments. Lead had the best correlation
with the different particle size classes (Figs. 16-21), followed by total PAHs, mercury, and TOC
(Table 10, Figs. B-l through B-9 in Appendix B). For lead, the correlations were stronger for the
sand and gravel (>53 |im) and silt (52 - 2 |im) fractions than they were for individual silt fractions
and coarse clay fraction (2 - 0.2 |im) (Figs. 16-21).
14
-------
Sediment Kriging Graphics
The contaminant data were merged with the results of a 1994 hot spot study in Slip C (Crane et al.
1997) in order to examine spatial trends in the data. Contaminant isopleths, for selected depth
intervals, were done for lead (Fig. 22), mercury (Fig. 23), total PAHs (Fig. 24), total PCBs (Fig.
25), and TOC (Fig. 26) through a sediment kriging technique. The figures provided an effective
way to visualize a large quantity of data in three different depth segments. For all chemical
parameters, the bulk of the chemical contamination was concentrated in the inner half of the slip.
This demonstrates that these sediments are fairly stable and are not being transported very much,
through advective transport, out of the slip.
The 137Cs dating of a sediment core (DSH 38) taken from the middle of Slip C in 1993 showed a
classic 137Cs profile with easily distinguishable peaks and edges; this suggests that not much mixing
has occurred in the sediments from this site in recent years (Schubauer-Berigan and Crane 1997).
The sedimentation rates for this particular core, which was located near SLPC 08, were as follows:
1954-1964, 2.03 ± 0.51 cm/year; 1964-1993, 0.56 ±0.15 cm/year; 1954-1993, 0.94 ± 0.1 cm/year
(Schubauer-Berigan and Crane 1997). The diversion of Superwood's effluent to WLSSD in 1978
probably resulted in the greatest decrease in sedimentation rates in the slip caused by the reduction
of wood particle waste entering the slip. This reduction in organic matter entering the slip is
reflected in the lower TOC concentrations in the surficial sediments (Fig. 26). The wide range of
surficial TOC concentrations (i.e., 0.91 - 15%) observed in Slip C is still greater than the surficial
TOC ranges observed in some nearby hot spot areas such as Minnesota Slip (i.e., 1.6 - 4.8%),
Howard's Bay (i.e., 0.9 - 5.2%), and around the embayment encompassing WLSSD, Miller Creek,
and Coffee Creek (i.e., 1.7 - 5.6%) (Schubauer-Berigan and Crane 1997).
Assuming the 1964-1993 sedimentation rate could be extrapolated to 1997, the upper 18.5 ± 5 cm
sediment section would correspond to the period from 1964-1997. The next 20.3 ±5.1 cm core
section would correspond to the period from 1954-1964; this could encompass the 18.5 - 38.8 cm
core section. Since these sedimentation rates were based on a core taken near the middle of Slip C,
the sedimentation rate would probably be much greater in the inland end of the slip due to more
910
point source discharges. Radioisotope dating of some inland sediment cores, using lead, would
provide useful information about whether the sediments are being redistributed based on smearing
910
in the lead profile.
All of the data used for the lead isopleth figures were based on this investigation since total lead
was not measured in the 1994 hot spot survey (Schubauer-Berigan and Crane 1997). For all three
core sections, the highest concentrations of lead occurred in the area bordered by SLPC 11, SLPC
12, SLPC 13, SLPC 14, SLPC 15, and SLPC 15R (Fig. 22). This corresponded to the most inland
section of Slip C. At SLPC 13, the concentration of lead increased 64.4% from the 30-45 cm
segment to the 15-30 cm segment; similarly, the concentration of lead increased 58.3% from the 15-
30 cm segment to the 0-15 cm segment. This pattern implies there was a more recent source of lead
to the surficial sediments, such as from outfall 001. In addition, the surficial sediments at SLPC 17
were higher in lead and PAHs than the historical sediments, implying a current source of material to
these sediments, such as from the filling of former Slip #7 or discharge of cooling water and
storm water runoff at the Buckingham Creek outlet.
15
-------
For the mercury plots, the highest concentration of mercury (i.e., 0.97 mg/kg) observed in this slip
occurred in the 30-45 cm segment of SUS 2 (Schubauer-Berigan and Crane 1997). This area
became progressively cleaner in the 15-30 cm (i.e., 0.47 mg/kg) and 0-15 cm (i.e., 0.19 mg/kg)
segments. However, other areas became more contaminated with mercury in the surficial
sediments compared to the deeper layers. In particular, there appears to be a more recent source of
mercury contamination at SLPC 19 (Fig. 23); the surficial concentration of mercury at this site was
0.6 mg/kg compared to 0.18 mg/kg in the 15-30 cm core segment and 0.16 mg/kg in the 30-45 cm
core segment (Table 3).
For the PAH graphics given in Fig. 24, not as much data were available for the 15-30 cm and 30-45
cm plots due to the high cost of analyzing sediment samples for PAHs. Thus, more detail in the
distribution of PAHs is given in the 0-15 cm graphic. Due to the triangulation pattern used in the
sediment kriging process, single data points of high contamination surrounded by much lower
contaminated data points may not be designated by its corresponding color on the concentration
scale. Such was the case with SLPC 15 and SLPC 15R that were located next to each other, but
had total PAH concentrations that varied by 4,283 - 22,350 |lg/kg from each other. From Fig. 24, a
larger area of PAH contaminated sediments appeared in the 15-30 cm core segment versus the 30-
45 cm core segment, and higher levels of contamination occurred in the surficial sections of SUS 3
and SLPC 17. In addition, total PAH contamination at SLPC 13 increased 125.5% in the 15-30 cm
core section compared to the 30-45 cm core section; PAHs increased 10% in the 0-15 cm core
segment compared to the 15-30 cm core section at this site. The level of PAH contamination at
SLPC 13 (0-15 cm) is of concern because it is more than double the probable effect concentration
for PAHs.
The data for PCBs (Fig. 25) were more sparse due to the incompatibility of adding the 1993 field
data (which were collected in 30 cm increments) to the graphics data set. Since PCBs were not
associated with the other contaminants, no extrapolations can be made about their presence in other
parts of the slip. PCBs were generally highest in the 15-30 cm segment in front of the former
Superwood plant. In addition, a high pocket of PCB contamination occurred near SLPC 18. The
transect of PCB samples collected from Slip C in 1993 also showed higher historical levels of
PCBs in the sediments in front of the former Superwood plant (Schubauer-Berigan and Crane
1997). This spatial distribution of PCB contamination does not necessarily imply that the
contamination was due to the former Superwood plant (now owned by Georgia-Pacific Corp.).
Volume of Contaminated Sediments
Determination of the volume of contaminated sediments is dependent on setting contaminant clean-
up goals for Slip C. By doing this, volume estimates can be generated for those sediments
exceeding the clean-up goals. From the available data, the inner slip is clearly the most
contaminated section warranting additional evaluation of remediation options. The MFC A, and its
collaborators, are in the process of developing sediment quality objectives that will be one piece of
information, in addition to toxicology, bioaccumulation, and benthological data that will be
considered for setting clean-up goals. The distribution of contaminants down to 45 cm has been
well determined in Slip C. For this study, physical observations of unsampled core sections down
16
-------
to as much as 90 cm revealed physical indications of contamination (e.g., oil sheen, odor, detrital
material) (Table 1).
Previous sediment investigations at Slip C have demonstrated deeper areas of contamination. Of
four sediment cores collected in Slip C during 1993, the most inland core (DSH 29) was
contaminated with mercury and PCBs down to 157 cm (Fig. 4) (Schubauer-Berigan and Crane
1997). In addition, mercury was found to be contaminated down to 74 cm at the second most
inland core (DSH 37) (Schubauer-Berigan and Crane 1997). For the 1994 hot spot investigation,
the sediments were contaminated with mercury and PCBs down to 126 cm at SUS 2 and to 115 cm
at SUS 4; PCBs were also elevated down to 54 cm at SUS 5 (Fig. 5) (Crane etal. 1997). The
sediment contamination in Slip C is very heterogeneous and may require a more sophisticated
integration of contaminant volume estimates than just multiplying the area by a single depth
interval.
Preliminary Remediation Options
Decisions on whether to remediate contaminated sediments in Slip C will be postponed until
sediment quality objectives are developed for the St. Louis River AOC in late 1999, a sediment
bioaccumulation study is completed in this slip in late 1999, and further work is done to assess
groundwater and soil contamination adjacent to the slip. In addition, future land and water uses
around Slip C need to be assessed. Lastly, a determination of potentially responsible parties needs
to be made, if possible.
The MPCA will use the weight-of-evidence data available for this site, with input from community
stakeholders, to decide on the course of actions to be taken at this site. If it is decided the slip
warrants remediation, the following remediation options should be considered further through a
feasibility study:
• natural recovery (i.e., no action alternative)
• dredging and removing the contaminated sediments to an upland landfill appropriate to
the level of sediment contamination or to a confined disposal facility (e.g., Erie Pier)
• capping the contaminated sediments
• in situ treatment of contaminated sediments
• in situ containment of contaminated sediments
• filling in the most contaminated area of Slip C and developing it for upland uses
• some combination of the above remediation options.
The development and implementation of any remediation options will be highly dependent on
whether any potentially responsible parties (PRPs) can be held legally responsible for
contamination in Slip C. If no PRPs can be named for this site, then local, state, and federal sources
of money will need to be competitively sought to remediate this site if options, other than natural
recovery, are selected.
17
-------
Sediment Management Plan
A sediment management plan for Slip C will be developed within the context of an environmental
management plan for the entire Duluth waterfront. The waterfront has many historical sources of
contamination resulting from the filling in of former wetlands with unknown fill material to expand
the waterfront; from former industry, business, and municipal sources of contamination; and from
nonpoint sources. Thus, a multimedia approach is warranted to address contamination along the
waterfront and to prioritize where clean-up actions should take place. The MPCA's Duluth
Regional Office will lead the effort to develop an environmental management plan for the
waterfront, which may be expanded to eventually include the entire St. Louis River AOC.
Stakeholder involvement will be sought to develop shared goals and situational alliances that will
ultimately result in a consistent and effective management plan for reducing multimedia sources of
contamination in this section of the watershed. In addition, this plan will play an important role in
developing total maximum daily loads (TMDLs) for mercury and other contaminants in the St.
Louis River.
RECOMMENDATIONS
Based on the results of this investigation, the following recommendations can be made for
managing contaminated sediments in Slip C.
• Compare existing sediment chemistry data for Slip C with sediment quality objectives
that will be developed for the St. Louis River AOC by the fall of 1999.
• Assess the bioaccumulation of Hg, PAH compounds, and PCB congeners in
Lumbriculus variegatus organisms exposed to Slip C sediments. This project will be
completed by the fall of 1999.
• Assess the need for remediating soil and groundwater contamination on Georgia-
Pacific's property by Slip C.
• Implement source control measures to reduce contaminant inflows into Slip C through
point and nonpoint sources.
• Monitor the loading of contaminants entering Slip C from the Buckingham Creek
outfall and Georgia-Pacific's yard runoff outfall to ensure existing source control
measures are working.
• Conduct 210Lead dating on at least two sediment cores from Slip C in order to determine
historical time periods in the cores; the distribution of an indicator chemical like
mercury would be measured in the same core segments. This information would be
used to assess the level of mixing in the cores, as well as to determine the sediment
depth at which major changes occurred in the immediate watershed (e.g., depth at which
nearby commercial business operations started, changed, and ended).
• Analyze some sediments for the presence of phenolic resins, phenols, and formaldehyde
as an indicator of waste products released by the former Superwood Corp. Phenols
would also be present due to coal tar contamination as well.
• Discuss present and future water and land uses around Slip C with current business
owners, the City of Duluth, the Metropolitan Interstate Commission's Harbor Technical
18
-------
Advisory Committee, the St. Louis River CAC Sediment Contamination Work Group,
and other interested stakeholders. This would have implications for determining what
kinds of remediation options would be feasible for maintaining existing and future
water uses in Slip C.
• Develop contaminant clean-up goals based on integrating sediment quality objectives
with the weight-of-evidence information available for sediment chemistry, sediment
toxicity, benthological, and bioaccumulation data for this site.
• Conduct a feasibility study of viable remediation options for Slip C.
• Determine the extent of sediment contamination at the former coal gasification plant at
Dakota Pier, and examine the data for any similar trends in the distribution of PAHs,
lead, and mercury with the Slip C sediments.
• Determine if any current, or historical companies, can be designated as potentially
responsible parties for sediment contamination in Slip C.
• Develop an overall environmental management plan for the Duluth waterfront that ties
together known air, soil, sediment, and groundwater contamination sources with setting
priorities for the remediation of known sediment hot spots.
Implementation of the above recommendations will depend on the availability of funding and staff,
as well as cooperative ventures developed with potentially responsible parties or other interested
stakeholders.
ACKNOWLEDGMENTS
Field support was provided by H. Wiegner and J. Beaumaster (MPCA); C. Bolattino (GLNPO); J.
Bonem and C. Ferris (Seward Services); and J. Taffe and G. Peterson (St. Louis River CAC
Sediment Contamination Work Group). J. Kahilainen (MDH) coordinated the overall use of their
laboratory for a number of analyses. P. Swedenborg (MDH) coordinated the analyses of PAHs,
whereas K. Peacock (MDH) coordinated the analyses of TOC, mercury, lead, and percent moisture.
D. Turgeon (MDH) was instrumental in providing electronic copies of MDH's data in a format
compatible with GLNPO's data reporting requirements. Particle size analyses were conducted
through a contract with K. Lodge (UMD). PCB congeners were analyzed through a contract with
En Chem (project manager: T. Noltemeyer). Input from the St. Louis River Citizens Action
Committee's Sediment Contamination Work Group was helpful in carrying out this project.
Preparation of site maps was done by J. Beaumaster (MPCA). Sediment kriging graphics were
prepared through a contract with Short Elliott Hendrickson Inc. (J. Thornton and J. Eberhardt).
Word processing support was provided by J. Eckart (MPCA). The draft report was reviewed by S.
Cieniawski (Great Lakes National Program Office), T. Janisch (Wisconsin Department of Natural
Resources), and J. Holmes m (Georgia-Pacific Corporation). Financial support for this project was
provided by the U.S. Environmental Protection Agency's Great Lakes National Program Office
(GLNPO), Chicago, IL through grant number GL985131-01. C. Bolattino and S. Cieniawski were
the successive GLNPO project officers for this study.
19
-------
REFERENCES
ATSDR. 1990. ATSDRpublic health statement: Polycydie aromatic hydrocarbons. Agency for
Toxic Substances and Disease Registry, Atlanta, GA.
Barr Engineering Company. 1994. Phase I/Phase II investigation report Slip 7. Barr Engineering
Company, Minneapolis, MN.
Breneman, D., Richards, C., and Lozano, S. (in review). Environmental influences on benthic
community structure in a Great Lakes embayment. Submitted to J. Great Lakes Res.
Chapman, P. 1992. Sediment quality triad approach. In: Sediment classification methods
compendium, pp. 10-1 to 10-18. Office of Water, U.S. Environmental Protection Agency,
Washington, DC. EPA 823-R-92-006.
Chevreuil, M., Chesterikoff, A., and Letolle, R. 1987. PCB pollution behavior in the River Seine.
Water Res. 21:427-434.
Crane, J. L. 1997. Quality assurance project plan (QAPP): Slip C sediment remediation scoping
project. Revision: 0. Minnesota Pollution Control Agency, Water Quality Division, St. Paul,
MN.
Crane, J. L., Schubauer-Berigan, M., and Schmude, K. 1997. Sediment assessment ofhotspot
areas in the Duluth/Superior Harbor. U.S. Environmental Protection Agency, Great Lakes
National Program Office, Chicago, IL. EPA-905-R97-020.
En Chem. 1995. Congener specific determination ofpolychlorinatedbiphenyls (PCBs) in soils by
capillary column gas chromatography. Standard Operating Procedure (July 5, 1995). En
Chem, Inc., Madison, WI.
Glooschenko, W. A., Strachan, W. M. J., and Sampson, R. C. J. 1976. Residues in water.
Distribution of pesticides and polychlorinated biphenyls in water, sediments, and seston of the
upper Great Lakes—1974. Pesticide Monitoring J. 10:61-67.
Great Lakes National Program Office (GLNPO). 1997. Health and safety and environmental
compliance manual. U.S. Environmental Protection Agency, Great Lakes National Program
Office, Chicago, IL.
Ingersoll, C. G. and MacDonald, D. D. 1998. Unpublished sediment quality guidelines for
freshwater ecosystems. MacDonald Environmental Sciences Ltd., Ladysmith, BC.
IT Corporation. 1997. Remedial investigation data report, sediment operable unit, St. Louis
River/Interlake/Duluth Tar site, Duluth, Minnesota. Volume I of V. IT Corporation, St. Paul,
MN.
20
-------
Lodge, K. B. 1996. A method for the particle-size analysis of freshwater sediments using the
Horiba LA-900 analyzer. Department of Chemical Engineering, University of Minnesota,
Duluth, MN.
Long, E. R. 1989. Use of the sediment quality triad in classification of sediment contamination.
In: Contaminated marine sediments-assessment and remediation. Marine Board. National
Research Council. Washington, DC.
Long, E. R. and Chapman, P. 1985. A sediment quality triad: Measurements of sediment
contamination, toxicity, and infaunal community composition in Puget Sound. Mar. Poll.
Bull. 16:405-415.
Long, E. R. and Morgan, L. G. 1990. The potential for biological effects of sediment sorbed
contaminants tested in the National Status and Trends Program. NOAA tech. memo. NO A
OMA 52. National Oceanic and Atmospheric Administration, Seattle, WA.
Lubin, A. N, Williams, M. H. and Lin, J. C. 1995. Statistical techniques applied to sediment
sampling (STATSS). U.S. Environmental Protection Agency Region 5, Chicago, IL. Draft #3.
MacDonald, D. D. 1993. Development of an approach to the assessment of sediment quality in
Florida coastal waters. Prepared for Florida Department of Environmental Regulation,
Tallahassee, FL by MacDonald Environmental Sciences Ltd., Ladysmith, BC.
MacDonald, D. D. 1994. Approach to the assessment of sediment quality in Florida coastal
waters, Vol. 1. Development and evaluation of sediment quality assessment guidelines.
Prepared for Florida Department of Environmental Protection, Office of Water Policy,
Tallahassee, FL by MacDonald Environmental Sciences Ltd., Ladysmith, BC.
MacDonald, D. D. and Crane, J. L. (in review). Development of an ecosystem-based approach to
the assessment and management of contaminated sediments in the St. Louis River Area of
Concern. Submitted to J. Great Lakes Res.
MDH. 1993 a. Procedure for the determination of: Metals by inductively coupled plasma (ICP)
atomic emission spectroscopy (AES) in water, waste, and sediment. MDH Method
Metals-ICP-Water/Waste/Sed, Revision B (April 22, 1993). Minnesota Department of
Health, Minneapolis, MN.
MDH. 1993b. General method for metals determination by stabilized temperature graphite
furnace atomic absorption spectroscopy. MDH Method GEN-STGFAA (September 1,
1993). Minnesota Department of Health, Minneapolis, MN.
MDH. 1995. Percent moisture sed/soil. MDH Method 261. Minnesota Department of Health,
Minneapolis, MN.
21
-------
MDH. 1997. Procedure for the determination ofpolyaromatic hydrocarbons in solid matrices
by gas chromatography/selected ion monitoring-mass spectrometry. MDH Method 513
(June 3, 1997). Minnesota Department of Health, Minneapolis, MN.
MFC A. 1969. Lake Superior study. Minnesota Pollution Control Agency, Division of Water
Quality, St. Paul, MN.
MFC A and WDNR. 1992. The St. Louis River system remedial action plan. Minnesota
Pollution Control Agency, St. Paul, MN and Wisconsin Department of Natural
Resources, Madison, WI.
MFC A and WDNR. 1995. The St. Louis River system remedial action plan. Progress report.
Minnesota Pollution Control Agency, St. Paul, MN and Wisconsin Department of Natural
Resources, Madison, WI.
Normandeau Associates. 1996. Results of elutriate, whole sediment, and bioaccumulation
dredged material evaluations ofUSACOE: Duluth-Superior Management Units.
Normandeau Associates, Spring City, PA.
Persaud, D., Jaagumagi, R., and Hayton, A. 1993. Guidelines for the protection and management
of aquatic sediment quality in Ontario. Ontario Ministry of Environment and Energy,
Ottawa, ON. Report No. ISBN 0-7729-9248-7.
Redman, S. and Janisch, T. 1995. Newton Creek system sediment contamination site
characterization report. Wisconsin Department of Natural Resources, Sediment
Management and Remediation Techniques Program, Madison, WI.
Rosemount Analytical. 1990a. Analysis of sludges and solids for carbon. Application Note
TOC-011. Rosemount Analytical, Dohrmann Division, Cincinnati, OH.
Rosemount Analytical. 1990b. Extending the carbon concentration range of the boat sampler.
Application Note TOC-012. Rosemount Analytical, Dohrmann Division, Cincinnati,
OH.
Rosemount Analytical. 1991. DC-80 total organic carbon analyzer systems manual. Revision
N. Rosemount Analytical, Dohrmann Division, Cincinnati, OH.
Schubauer-Berigan, M. and Crane, J. L. 1996. Preliminary contaminant assessment of the
Thomson, Forbay, and Fond du Lac Reservoirs. Minnesota Pollution Control Agency, Water
Quality Division, St. Paul, MN.
Schubauer-Berigan, M. and Crane, J. L. 1997. Survey of sediment quality in the Duluth/Superior
Harbor: 1993 sample results. U.S. Environmental Protection Agency, Great Lakes National
Program Office, Chicago, IL. EPA 905-R97-005.
22
-------
Simmons, M. S., Bialosky, D. L, and Rossmann, R. 1980. Polychlorinated biphenyl contamination
in surficial sediments of northeastern Lake Michigan. J. Great Lakes Res. 6:167-171.
Smith, S. L., MacDonald, D. D., Keenleyside, K. A., Ingersoll, C. G., and Field, L. J. 1996. A
preliminary evaluation of sediment quality assessment values for freshwater ecosystems. J.
Great Lakes Res. 22:624-63 8.
Smith, V. E. and Rood, S. G. 1994. Sediment sampling surveys. In: ARCS Assessment Guidance
Document., pp. 33-56. U.S. Environmental Protection Agency, Great Lakes National Program
Office, Chicago, IL. EPA 905-B94-002.
TMA. 1996. Sampling and analysis of sediments from the Duluth-Superior Harbor, September
1995 -April 1996. Thermo Analytical, Ypsilanti, MI.
U.S. EPA. 1983. Methods for chemical analysis of'water and wastes. U.S. Environmental
Protection Agency, Office of Research and Development, Cincinnati, OH. EPA-600/4-79-
020.
U.S. EPA. 1991. EPA methods for the determination of'metals in environmental samples. U.S.
Environmental Protection Agency, Office of Research and Development, Washington, DC.
EPA/600/4-91/010.
U. S. EPA. 1993. Assessment and Remediation of Contaminated Sediments (ARCS) Program:
Risk assessment and modeling overview document. U.S. Environmental Protection Agency,
Great Lakes National Program Office, Chicago, IL. EPA 905-R93-007.
U.S. EPA. 1994a. Assessment and Remediation of Contaminated Sediments (ARCS) Program:
Assessment guidance document. U.S. Environmental Protection Agency, Great Lakes
National Program Office, Chicago, IL. EPA 905-B94-002.
U.S. EPA. 1994b. Assessment and Remediation of Contaminated Sediments (ARCS) Program:
Remediation guidance document. U.S. Environmental Protection Agency, Great Lakes
National Program Office, Chicago, IL. EPA 905-R94-003.
U.S. EPA. 1995. QA/QC guidance for sampling and analysis of sediments, water, and tissues for
dredged material evaluations: Chemical evaluations. U.S. Environmental Protection
Agency, Office of Water, Washington, DC. EPA 823-B-95-001.
U.S. Library of Medicine, Health, and Safety Database. 1999. Retrieval for PAH compounds.
Walker, D. A. and Hall, S. P. 1976. Duluth-Superior Harbor cultural resources study.
Archeology Department, Minnesota Historical Society, St. Paul, MN.
WDNR. 1995. Guidance for sediment assessment in the state of Wisconsin. Wisconsin
Department of Natural Resources, Bureau of Water Resources, Madison, WI.
23
-------
Zarull, M. A., Hartig, J. H., Krantzberg, G., Burch, K., Cowgill, D., Hill, G., Miller, I, and
Sherbin, G. 1999. Contaminated sediment management in the Great Lakes ecosystem. J.
Great Lakes Res. (in press).
24
-------
TABLES
25
-------
TABLE 1. Description of field results.
Site
Location
SLPC 01
SLPC 02
SLPC 03
SLPC 06
SLPC 07
SLPC 08
SLPC 08R
SLPC 09
Sampling Soft
Date Water Sediment Core Core
(mo/d/yr) Latitude Longitude Depth (m) Depth (m) Length (cm) Section (cm)
6/16/97 46.77057 -92.10852 9.3 0.3 45 0-15
15-55
6/16/97 46.77090 -92.10582 2.3 0 50 0-15
15-60
6/16/97 46.76871 -92.11148 2.6 0.1 75 0-15
15-85
6/16/97 46.77356 -92.10617 6.3 1 72 0-15
15-30
30-45
45-60
6/16/97 46.77322 -92.10674 6.5 0.8 36 0-15
15-30
30-36
6/16/97 46.77282 -92.10776 7.1 0.3 26 0-15
15-26
6/16/97 46.77282 -92.10776 7.4 0.3 61 0-15
15-30
30-45
45-60
6/17/97 46.77234 -92.10810 7.1 0.5 87 0-15
15-30
30-45
45-60
Core Section Description
small amount of fibrous material and fine grained sand on
top, rest of core is brown sand
uniform brown sand w/ rocks and shells present
brown sand
uniform brown sand w/ bottom 15 cm more hard packed
brown sand
uniform brown sand
brown sand w/ some fines, thin layer of wood chips on
top
brown sand with some detrital material
brown sand with some detrital material and 5 cm layer of
silty material
brown sand with detrital material throughout, lower layer
contained clay
brown sand/silt
brown sand/silt, more organic material than upper section
brown sand/silt w/ some fibrous material
dark brown sand/silt, fibrous material, wood chips
coarse brown sand w/ some gravel and detritus, tar streaks
dark brown sand/silt, large wood chips
brown sand, piece of shingle in sample (discarded)
uniform brown sand
uniform brown sand
grey-brown, pudding-like consistency, fine silt/sand,
some wood chips and detritus
firm brown silt/clay w/ detrital material throughout and
large chunks of wood
brown sand w/ some detrital material (wood)
brown sand w/ small amount of detrital material
R = Field replicate
26
-------
TABLE 1. Continued.
Sampling Soft
Site Date Water Sediment Core Core
Location (mo/d/yr) Latitude Longitude Depth (m) Depth (m) Length (cm) Section (cm)
SLPC 10 6/17/97 46.77208 -92.10935 5.9 1.5 63 0-15
15-30
30-45
45-60
SLPC 11 6/17/97 46.77128 -92.11111 6.4 1.5 75 0-15
15-30
30-45
45-60
SLPC 12 6/17/97 46.77075 -92.11054 5.9 0.8 118 0-15
15-30
30-45
45-60
60-75
SLPC 13 6/17/97 46.77050 -92.11125 4.5 1.4 86 0-15
15-30
30-45
45-60
60-75
Core Section Description
grey-brown, pudding-like consistency, silty, oil sheen,
some detrital material
brown sand/silt, firmer texture than upper section, detrital
material
uniform brown sand w/ some detrital material
homogeneous clay/sand w/ lots of detrital material
grey-brown, pudding-like consistency, silty, slight oil
sheen, some detrital material
brown sand w/ lots of detrital material, wood chunks
brown silt w/ lots of detrital material
brown silt, increased clay content w/ depth, odor, small
amount of detrital material
grey-brown, pudding-like consistency, silty, fine detritus
brown silt, pudding-like consistency, some detritus
brown silt, firm, pudding-like consistency, some detritus,
odor
brown clay/sand w/ wood particles, odor, one rock
brown, more clay than 45-60 cm section, wood fibers,
odor
grey-brown, pudding-like consistency, silty, some
detritus, oil sheen
grey-brown, firm pudding-like texture, silty/sand, oil
sheen, lots of detrital material
brown silt w/ lots of detrital material
dark brown sand/silt/clay, detritus, odor
dark silt and detritus
27
-------
TABLE 1. Continued.
Site
Location
SLPC 14
Sampling
Date
(mo/d/yr)
6/18/97
Latitude Longitude
46.77084 -92.10675
Water
Depth (m)
5.9
Soft
Sediment
Depth (m)
0.9
Core
Length (cm)
55
Core
Section (cm)
0-15
15-30
Core Section Description
brown silt, pudding-like consistency, some detritus
brown silt, firm pudding-like texture, lots of detrital
SLPC 15
6/18/97
46.77157
-92.11048 5.9
SLPC15R 6/18/97 46.77157 -92.11048 6.4
1.5
SLPC 16 6/18/97 46.77195
-92.10976 5.2
SLPC 17 6/18/97 46.77254 -92.10886 6
0.6
1.4
material
30-45 brown silt/sand, firm texture, lots of detrital material
45-55 dark brown sand/silt, some gravel, lots of woody detrital
material, oil sheen
90 0-15 brown sand/silt, detritus, oil sheen
15-30 brown silt, lots of detrital material, some wood chunks
30-45 brown silt, mostly detrital material, some twigs
45-60 brown silt/clay, detrital material
60-75 brown, mostly sand, some silt/clay, odor, sawdust
75-90 brown sand/gravel, clay layer on bottom, small amount of
detrital material, odor
47 0-15 brown silt, pudding-like consistency, lots of detrital
material
15-30 brown silt, firm, lots of detrital material
30-45 brown sand/silt, firm, lots of detrital material, odor
45-47 brown sand/silt, firm, mostly detrital material
33 0-15 brown silt, oil sheen, lots of detrital material
15-30 brown sand w/ some detrital material
30-33 brown sand, small amount of detrital material
79 0-15 brown silt, oil sheen, lots of detrital material, pudding-
like consistency
15-30 firm brown silt/sand with lots of detrital material
30-45 firm brown sand/silt with detrital material
45-60 brown sand/silt with detrital material, some pebbles
60-75 mostly brown sand w/some detrital material
R = Field replicate
28
-------
TABLE 1. Continued.
Site
Location
Sampling
Date
(mo/d/yr)
Latitude Longitude
Water
Depth (m)
Soft
Sediment
Depth (m)
Core Core
Length (cm) Section (cm)
Core Section Description
SLPC 18
SLPC 19
6/18/97
6/18/97
46.77259
46.77320
-92.10864
-92.10774
6.2
7.7
0.5
46 0-15 brown, silty, soupy, oil sheen, twigs, small amount of
detrital material
15-30 brown, silty, odor, lots of detrital material, some sand
30-45 brown sand, some silt, detrital material
52 0-15 brown, soupy, silty, twigs, detrital material, oil sheen
15-30 brown silt/sand, detrital material
30-45 brown, sand/silt, detrital material
45-52 brown sand, gravel, wood chunks, odor
29
-------
TABLE 2. Particle size distribution of sediment samples.
Percent Composition of Different Size Ranges
Site Location
SLPCOl
SLPC 02
SLPC 03
SLPC 06
SLPC 07
SLPC 08 (mean; SD)
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
Estimated
Core Median Sand
Section Diameter & Gravel
(cm) (|im) >53 |im
0-15
0-15
0-15
0-15
0-15
0-15*
0-15
15-30
0-15
15-30**
0-15
15-30
0-15
15-30
0-15
15-30
30-45
0-15
15-30
30-45***
0-15**
15-30
30-45
0-15
15-30
30-45
0-15
15-30
0-15
15-30
30-45
45-60**
0_15***
15-30
0-15**
>53
>53
>53
>53
>53
>53
>53
>53
>53
>53
37
>53
18
28
>53
>53
>53
32
33
>53
>53
>53
33
>53
33
>53
>53
>53
>53
>53
>53
>53
>53
>53
>53
96.2
97.6
96.2
93.5
86.5
95.0 (2.2)
62.7
78.3
68.9
89.1
41.7
56.4
26.8
33.8
50.3
56.2
66.7
36.9
36.3
63.2
71.7
61.8
37.9
50.6
39.3
70.7
74.8
96.0
56.7
82.9
91.9
83.9
69.5
90.9
62.6
Coarse
Silt
53-20 |im
1.8
0.8
1.1
1.5
4.5
1.7(1.1)
11.8
6.7
11.4
3.5
17.0
13.4
19.2
21.2
17.2
24.6
14.5
20.9
22.5
12.6
7.8
11.2
19.8
14.4
18.0
9.4
7.0
0.9
19.9
5.6
2.9
5.7
10.3
2.1
11.9
Medium
Silt
20-5 |im
0.9
0.7
1.4
2.3
4.6
1.8 (0.7)
14.3
8.0
10.6
4.0
23.7
17.4
30.8
25.0
18.3
11.0
11.5
24.8
25.1
14.4
11.5
15.6
26.0
19.2
25.0
11.4
10.1
1.8
13.4
6.2
2.9
5.9
11.2
4.0
14.1
Fine
Silt
5-2 |im
0.4
0.3
0.4
0.9
1.5
0.5(0.1)
3.8
2.3
3.1
1.1
6.0
4.4
7.9
7.0
5.0
2.9
2.9
6.2
6.3
3.8
3.1
4.3
6.5
3.8
7.1
3.2
2.8
0.5
2.1
1.8
0.9
1.6
3.2
1.1
3.7
Coarse
Clay
2-0.2 |im
0.7
0.6
0.9
1.8
2.9
1.0 (0.2)
7.4
4.6
5.9
2.2
11.6
8.4
15.3
12.9
9.2
5.3
4.4
11.2
9.8
6.1
5.8
7.0
9.8
12.0
10.7
5.3
5.2
0.8
7.9
3.5
1.5
2.9
5.8
1.9
7.7
SD = Standard deviation
R = Field replicate
* Mean of field replicates
** Mean of analytical duplicates, based on full preparation
*** Mean of analytical duplicates, based on elutriate
30
-------
TABLE 3. Comparison of contaminant data with low/threshold effect level and probable effect
concentration sediment quality guidelines (SQGs). Values in bold exceed the low level SQGs,
whereas values in bold shading exceed the probable effect concentration SQGs.
Site
Location
SLPC01
SLPC 02
SLPC 03
SLPC 06
SLPC 07
SLPC 08 (mean)
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 07
SLPC 08
SLPC 08R
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 07
SLPC 08R
SLPC 09
SLPC 10
SLPC 11
SLPC 12
Core
Depth (cm)
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
15-30
15-26
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
30-36
30-45
30-45
30-45
30-45
30-45
Lead
(mg/kg)
12
7.6
9.4
10
25
0.36
75
75
130
140
190
150
68
130
81
100
83
96
0.2
0.05
0.94
77
70
120
150
120
140
110
120
43
65
81
43
0.15
1.5
47
69
150
160
Mercury
(mg/kg)
0.04
0.02
0.02
0.03
0.12
0.08
0.24
0.22
0.31
0.34
0.27
0.37
0.19
0.4
0.24
0.26
0.3
0.6
0.17
0.09
0.08
0.22
0.17
0.26
0.36
0.18
0.39
0.35
0.33
0.07
0.34
0.15
0.18
0.22
0.0025
0.09
0.2
0.34
0.45
Total PAHs Total PCBs
(Hg/kg) (Hg/kg)
4726
2238
2925
3450
6623
3486
14285 99
15996
28229
25625
48996
32036
19717
24000
12441
27855 111
14933 258
14314
9534 66.9
9196
22562
29450
44537
28200
35841
25428
4988
8823 96.8
269
TOC
(%)
1.1
0.34
0.79
0.91
1.9
1.4
4
3.4
7.6
8.4
10
9.5
4.3
15
1.8
5.4
4.3
5.1
2.9
1.8
7.2
13
8
30
11
21
1.9
2.6
2.2
31
-------
TABLES. Continued.
Site
Location
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 15
SLPC 15R
SLPC 17
Core
Depth (cm)
30-45
30-45
30-45
30-45
30-33
30-45
30-45
30-45
45-60
45-47
45-60
Lead
(mg/kg)
73
92
170
89
38
56
44
69
150
200
88
Mercury
(mg/kg)
0.25
0.36
0.49
0.3
0.1
0.14
0.06
0.16
0.4
0.5
0.16
Total PAHs Total PCBs
(Hg/kg) (Hg/kg)
19753
22597
43639
21289
7980
14032
TOC
(%)
14
13
19
9.9
1.9
2.5
Sediment Quality Guidelines:
LEL
TEL
PEC
35
128
0.174
1.06
4000
22800
34.1
676
R = Field replicate
LEL = Lowest effect level (Persaud et al. 1993)
TEL = Threshold effect level (Smith et al. 1996)
PEC = Probable effect concentration (Ingersoll and MacDonald 1998)
32
-------
TABLE 4. Summary of relative contamination factors (RCFs)for contaminant concentrations
normalized to low level effect sediment quality guidelines. Bold values exceed an RCF of 1.
Site Location
SLPC01
SLPC 02
SLPC 03
SLPC 06
SLPC 07
SLPC 08 (mean)
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 07
SLPC 08
SLPC 08R
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 07
SLPC 08R
SLPC 09
SLPC 10
SLPC 11
SLPC 12
Core
Section
(cm)
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
15-30
15-26
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
30-36
30-45
30-45
30-45
30-45
30-45
Lead TEL
RCF
0.3
0.2
0.3
0.3
0.7
0.01
2.1
2.1
3.7
4.0
5.4
4.3
1.9
3.7
2.3
2.9
2.4
2.7
0.01
0.001
0.03
2.2
2.0
3.4
4.3
3.4
4.0
3.1
3.4
1.2
1.9
2.3
1.2
0.004
0.04
1.3
2.0
4.3
4.6
Mercury
TEL
RCF
0.2
0.1
0.1
0.2
0.7
0.5
1.4
1.3
1.8
2.0
1.6
2.1
1.1
2.3
1.4
1.5
1.7
3.4
1.0
0.5
0.5
1.3
1.0
1.5
2.1
1.0
2.2
2.0
1.9
0.4
2.0
0.9
1.0
1.3
0.01
0.5
1.1
2.0
2.6
PAH LEL PCB TEL
RCF RCF
1.2
0.6
0.7
0.9
1.7
0.9
3.6 2.9
4.0
7.1
6.4
12.2
8.0
4.9
6.0
3.1
7.0 3.3
3.7 7.6
3.6
2.4 2.0
2.3
5.6
7.4
11.1
7.1
9.0
6.4
1.2
2.2 2.8
7.9
Mean
Low Level
RCF
0.6
0.3
0.4
0.4
1.0
0.4
2.5
2.5
4.2
4.1
6.4
4.8
2.7
4.0
2.3
3.6
3.8
3.3
0.5
0.3
0.2
2.0
1.8
3.5
4.6
5.2
4.4
4.7
3.9
1.0
2.2
3.7
1.1
0.6
0.03
0.9
1.6
3.1
3.6
33
-------
TABLE 4. Continued.
Site Location
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 15
SLPC 15R
SLPC 17
Core
Section
(cm)
30-45
30-45
30-45
30-45
30-33
30-45
30-45
30-45
45-60
45-47
45-60
Lead TEL
RCF
2.1
2.6
4.9
2.5
1.1
1.6
1.3
2.0
4.3
5.7
2.5
Mercury
TEL
RCF
1.4
2.1
2.8
1.7
0.6
0.8
0.3
0.9
2.3
2.9
0.9
PAH LEL PCB TEL
RCF RCF
4.9
5.6
10.9
5.3
2.0
3.5
Mean
Low Level
RCF
2.8
3.4
6.2
3.2
0.8
1.5
0.8
1.4
3.3
4.3
2.3
R = Field replicate
LEL = Lowest effect level (Persaud et al. 1993)
RCF = Relative contamination factor
TEL = Threshold effect level (Smith et al. 1996)
34
-------
TABLE 5. Summary of relative contamination factors (RCFs)for contaminant concentrations
normalized to probable effect level sediment quality guidelines. Bold values exceed an RCF of 1.
Site Location
SLPC01
SLPC 02
SLPC 03
SLPC 06
SLPC 07
SLPC 08 (mean)
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 07
SLPC 08
SLPC 08R
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 07
SLPC 08R
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
Core
Section
(cm)
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
15-30
15-26
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
30-36
30-45
30-45
30-45
30-45
30-45
30-45
Lead PEC
RCF
0.09
0.06
0.07
0.08
0.2
0.003
0.6
0.6
1.0
1.1
1.5
1.2
0.5
1.0
0.6
0.8
0.6
0.8
0.002
0.0004
0.01
0.6
0.5
0.9
1.2
0.9
1.1
0.9
0.9
0.3
0.5
0.6
0.3
0.001
0.01
0.4
0.5
1.2
1.3
0.6
Mercury
PEC
RCF
0.04
0.02
0.02
0.03
0.1
0.08
0.2
0.2
0.3
0.3
0.3
0.3
0.2
0.4
0.2
0.2
0.3
0.6
0.2
0.08
0.08
0.2
0.2
0.2
0.3
0.2
0.4
0.3
0.3
0.07
0.3
0.1
0.2
0.2
0.002
0.08
0.2
0.3
0.4
0.2
PAH PEC PCB PEC
RCF RCF
0.2
0.1
0.1
0.2
0.3
0.2
0.6 0.1
0.7
1.2
1.1
2.1
1.4
0.9
1.1
0.5
1.2 0.2
0.7 0.4
0.6
0.4 0.1
0.4
1.0
1.3
2.0
1.2
1.6
1.1
0.2
0.4 0.1
0.4
0.9
Mean PEC
RCF
0.1
0.1
0.1
0.1
0.2
0.1
0.4
0.5
0.8
0.8
1.3
1.0
0.5
0.8
0.5
0.6
0.5
0.6
0.1
0.04
0.04
0.3
0.4
0.7
0.9
1.0
0.9
0.9
0.8
0.2
0.3
0.4
0.3
0.1
0.007
0.2
0.4
0.7
0.8
0.6
35
-------
TABLES. Continued.
Site Location
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 15
SLPC 15R
SLPC 17
Core
Section
(cm)
30-45
30-45
30-45
30-33
30-45
30-45
30-45
45-60
45-47
45-60
Lead PEC
RCF
0.7
1.3
0.7
0.3
0.4
0.3
0.5
1.2
1.6
0.7
Mercury
PEC
RCF
0.3
0.5
0.3
0.09
0.1
0.06
0.2
0.4
0.5
0.2
PAH PEC PCB PEC
RCF RCF
1.0
1.9
0.9
0.4
0.6
Mean PEC
RCF
0.7
1.2
0.6
0.2
0.3
0.2
0.3
0.8
1.0
0.5
R = Field replicate
PEC = Probable effect concentration (Ingersoll and MacDonald 1998)
RCF = Relative contamination factor
36
-------
TABLE 6. Summary of PAH concentrations for selected sediment samples. PAH concentrations in bold itallics exceeded a low level
sediment quality guideline (SQG) value, whereas shaded values exceeded a higher level SQG number.
Site
Location
Core
Section
(cm)
PAHs (wi/kg dry weight)
2Metnap
Acene
Aceny
Anth
Bena
Benap
Benb
Bene
Beng
Benk
Chry
Diben
Flut
Fluo
Indp
Naph
Phen
Pyrn
Total
SLPC 01
SLPC 02
SLPC 03
SLPC 06
SLPC 07
SLPC 08*
mean
SD
SLPC 09
SLPC 10**
mean
SD
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
69
25
25
25
52
54
6.3
149
112
20
421
198
438
270
109
347
98
249
182
218
63
29
48
57
59
58
0.85
110
139
12
294
168
660
390
292
357
131
421
143
230
18
4.5
4.5
4.5
25
11
3.2
66
49
1.7
92
99
129
96
49
128
69
101
67
64
143
58
129
104
181
99
9.3
310
349
46
530
435
1372
719
647
843
270
795
325
472
407
172
232
280
557
279
53
1086
1162
142
7555
1581
2623
1750
1277
1324
774
2044
1126
768
307
166
169
191
520
203
42
1055
1139
179
1821
1939
3250
2185
1309
1579
938
1673
1069
923
208
111
106
136
465
145
31
863
985
96
1607
1691
2533
1864
1070
1456
785
1368
945
817
214
114
110
125
282
139
33
962
1043
129
1627
1747
2634
1801
1068
1572
825
1427
933
796
195
115
103
123
277
151
38
1128
963
145
1720
1851
3001
1975
1142
1574
921
1489
933
898
157
82
81
103
233
112
28
396
478
133
902
539
1308
855
545
346
252
775
351
298
572
161
199
247
525
233
50
1086
1239
77
2459
2487
4115
2836
1616
1691
1034
2264
1190
1103
43
27
25
34
59
33
5.6
130
138
5.9
257
239
969
320
183
170
125
272
128
116
944
449
602
779
1258
655
71
2358
2906
382
5229
4452
8632
5666
3600
4084
2148
5043
2588
2444
86
42
65
65
111
82
5.7
178
215
7.4
455
263
1083
520
409
427
188
737
221
398
272
138
112
137
308
161
39
1187
1090
172
1895
2032
3355
2230
1277
1764
898
1658
973
829
58
15
31
51
72
51
8.6
148
115
20
377
216
430
257
115
349
138
245
179
192
627
222
425
528
777
454
11
1372
1791
381
3109
2280
5808
3909
2391
2960
1175
3419
1623
2111
SLPC 09
SLPC 10
15-30
15-30
102
72
78
84
36
21
190
215
727
824
732
657
636
558
658
567
567
481
228
172
764
845
74
62
1669
1637
116
119
660
586
102
70
944
1034
602
307
459
458
868
566
51
7705
2082
248
3885
3412
6656
4394
2616
3031
1672
3874
1958
1636
4720
2240
2920
3450
6623
3490
490
14280
16000
2120
28230
25620
49000
32040
19720
24000
12440
27850
14930
14310
1252
1192
9534
9196
37
-------
TABLE 6. Continued.
Site
Location
Core
Section
(cm)
PAHs (jig/kg dry weight)
2Metnap
Acene
Aceny
Anth
Bena
Benap
Benb
Bene
Beng
Benk
Chry
Diben
Flut
Fluo
Indp
Naph
Phen
Pyrn
Total
SLPC 1 1
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
203
384
271
274
382
573
139
138
266
313
680
779
798
530
79
112
81
140
125
99
ISO
211
32
35
657
692
1471
688
1225
556
127
195
1276
1113
2705
1309
1796
1232
482
579
1616
2137
2654
1766
2182
1454
274
657
1345
1840
1851
1823
1763
1320
239
595
1356
1900
2044
1668
1818
1368
203
598
1443
2191
2286
911
1936
1364
165
505
667
941
1358
362
1026
431
105
174
1942
1838
3865
1898
2721
2168
441
649
275
278
726
222
318
190
55
75
5975
5205
8166
4692
6510
4660
987
1540
545
431
956
992
962
555
104
159
7577
2340
2478
1830
2037
1486
172
597
181
357
248
187
465
497
99
130
2360
3232
5943
4871
4730
3264
627
959
3083
4117
6711
3829
4991
3570
657
1146
22560
29450
44540
28200
35840
25430
4990
8823
SLPC 13
SLPC 14
SLPC 15
SLPC 15R**
mean
SD
SLPC 17
30-45
30-45
30-45
30-45
30-45
30-45
304
442
832
227
14
64
342
795
609
388
55
72
66
76
305
103
0
26
445
957
1336
682
100
170
1002
920
1700
992
100
559
1272
1358
2707
1337
147
592
1151
1179
2194
1136
131
532
1184
1220
2468
1154
155
540
1097
1135
2842
1224
202
470
289
467
1305
394
76
176
1696
1135
2958
1898
75
627
142
183
345
189
23
69
3309
3751
7752
3778
304
1470
414
1015
1091
512
197
105
7557
1418
2985
1376
240
568
152
265
667
277
9.4
51
2947
3493
5346
2670
456
796
2610
2790
6202
2953
111
1070
19750
22600
43640
21290
2110
7980
SLPC 17
45-60
239
116
55
255
999
994
839
866
995
557
1179
779
2408
183
938
153
1448
1907
14030
Sediment Quality Guidelines (jog/kg):
LEL
PEC
ERL
PEL
(MacDonald 1993)
PEL
(MacDonald 1994)
70
450
650
16
44
128
220
845
320
1050
370
1450
170
240
340
1290
60
320
750
2230
190
536
200
561
160
560
1170
490
1520
4000
22800
38
-------
TABLE 6. Continued.
* Mean of fie'.d replicates
** Mean of analytical duplicates
SD = Standard deviation
R = Field replicate
LEL = Lowest effect level (Persaud and Jaagumagi 1993)
PEC = Probable effect concentration (Ingersoll and MacDor.ald 1998)
ERL = Effects range low (Long and Morgan 1990)
PEL = Probable effect level (MacDonald 1993, 19S4)
PAH Codes:
2Metnap = 2-Methylnaphthalene Bena = Benzo [a] anthracene Beng = Benzo[g,h,i]perylene Flut = Fluoranthene Phen = Phenanthrsne
Acene = Acenaphthene Benap = Benzo[a]pyrene Benk = Benzo [kjfluorantrene Fluo = Fluorene Pyrn = Pyrene
Aceny = Acenaphthylene Benb == Benzo [b&j]fluoranthene Chry = Chrysene Indp = Indeno[l,2,3-cd]pyrene
Anth = Anthracene Bene = Benzo[e]pyrene Diben = Dibenzo[a,h]anthracene Naph = Naphthalene
39
-------
TABLE 7. Percentage composition of PAH compounds in sediment samples.
Percentage (%) Composition of PAH Compounds in Sample Sediments
Site Code
SLPC 01
SLPC 02
SLPC 03
SLPC 06
SLPC 07
SLPC 08*
SLPC 09
SLPC 10**
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
SLPC 18
SLPC 19
SLPC 09
SLPC 10
SLPC 11
SLPC 12
SLPC 13
SLPC 14
SLPC 15
SLPC 15R
SLPC 16
SLPC 17
Core
Section
(cm)
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
0-15
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
15-30
2Metnap
(%)
1.5
1.1
0.9
0.7
0.8
1.6
1.0
0.7
1.5
0.8
0.9
0.8
0.6
1.4
0.8
0.9
1.2
1.5
1.1
0.8
0.9
1.3
0.6
1.0
1.1
2.3
2.8
1.6
Acene
(%)
1.3
1.3
1.6
1.7
0.9
1.7
0.8
0.9
1.0
0.7
1.3
1.2
1.5
1.5
1.1
1.5
1.0
1.6
0.8
0.9
1.2
1.1
1.5
2.8
2.2
2.1
1.6
1.3
Aceny
(%)
0.4
0.2
0.2
0.1
0.4
0.3
0.5
0.3
0.3
0.4
0.3
0.3
0.2
0.5
0.6
0.4
0.5
0.4
0.4
0.2
0.4
0.5
0.3
0.4
0.5
0.8
0.6
0.4
Anth
(%)
3.0
2.6
4.4
3.0
2.7
2.8
2.2
2.2
1.9
1.7
2.8
2.2
3.3
3.5
2.2
2.9
2.2
3.3
2.0
2.3
2.8
2.3
3.3
2.4
3.4
2.2
2.6
2.2
Bena
(%)
8.6
7.7
7.9
8.1
8.3
8.0
7.6
7.3
5.5
6.2
5.4
5.5
6.5
5.5
6.2
7.3
7.5
5.4
7.6
9.0
5.7
3.8
6.1
4.6
5.0
4.8
9.7
6.6
Benap
(%)
6.5
7.4
5.8
5.5
7.9
5.8
7.4
7.1
6.5
7.6
6.6
6.8
6.6
6.6
7.5
6.0
7.2
6.4
7.7
7.1
7.2
7.3
6.0
6.3
6.1
5.7
5.5
7.2
Benb
(%)
4.4
5.0
3.6
3.9
7.0
4.2
6.0
6.2
5.7
6.6
5.2
5.8
5.4
6.1
6.3
4.9
6.3
5.7
6.7
6.1
6.0
6.2
4.2
6.5
4.9
5.2
4.8
6.7
Bene
(%)
4.5
5.1
3.8
3.6
4.3
4.0
6.7
6.5
5.8
6.8
5.4
5.6
5.4
6.5
6.6
5.1
6.2
5.6
6.9
6.2
6.0
6.5
4.6
5.9
5.1
5.4
4.1
6.8
Beng
(%)
4.1
5.1
3.5
3.6
4.2
4.3
7.9
6.0
6.1
7.2
6.1
6.2
5.8
6.6
7.4
5.3
6.2
6.3
5.9
5.2
6.4
7.4
5.1
3.2
5.4
5.4
3.3
5.7
Benk
(%)
3.3
3.7
2.8
3.0
3.5
3.2
2.8
3.0
3.2
2.1
2.7
2.7
2.8
1.4
2.0
2.8
2.3
2.1
2.4
1.9
3.0
3.2
3.0
1.3
2.9
1.7
2.1
2.0
Chry
(%)
7.9
7.2
6.8
7.2
7.9
6.7
7.6
7.7
8.7
9.7
8.4
8.9
8.2
7.0
8.3
8.1
8.0
7.7
8.0
9.2
8.6
6.2
8.7
6.7
7.6
8.5
8.8
7.4
Diben
(%)
0.9
1.2
0.9
1.0
0.9
0.9
0.9
0.9
0.9
0.9
2.0
1.0
0.9
0.7
1.0
1.0
0.9
0.8
0.8
0.7
1.0
0.9
1.6
0.8
0.9
0.7
1.1
0.8
Flut
(%)
20.0
20.1
20.6
22.6
19.0
18.8
16.5
18.2
18.5
17.4
17.6
17.7
18.3
17.0
17.3
18.1
17.3
17.1
17.5
17.8
17.6
17.7
18.3
16.6
18.2
18.3
19.8
17.5
Fluo
(%)
1.8
1.9
2.2
1.9
1.7
2.4
1.2
1.3
1.6
1.0
2.2
1.6
2.1
1.8
1.5
2.6
1.5
2.8
1.2
1.3
1.5
1.5
2.1
3.5
2.7
2.2
2.1
1.8
Indp
(%)
4.5
6.2
3.8
4.0
4.7
4.6
8.3
6.8
6.7
7.9
6.8
7.0
6.5
7.4
7.2
6.0
6.5
5.8
6.9
6.4
7.0
7.9
5.6
6.5
5.7
5.8
3.4
6.8
Naph
(%)
1.2
0.7
1.1
1.5
1.1
1.5
1.0
0.7
1.3
0.8
0.9
0.8
0.6
1.5
1.1
0.9
1.2
1.3
1.1
0.8
0.8
1.2
0.6
0.7
1.3
2.0
2.0
1.5
Phen
(%)
13.3
9.9
14.5
15.3
11.7
13.0
9.6
11.2
11.0
8.9
11.9
12.2
12.1
12.3
9.4
12.3
10.9
14.7
9.9
11.2
10.5
11.0
13.3
17.3
13.2
12.8
12.6
10.9
Pyrn
(%)
12.7
13.7
15.7
13.3
13.1
16.2
11.9
13.0
13.8
13.3
13.6
13.7
13.3
12.6
13.4
13.9
13.1
11.4
13.1
13.0
13.7
14.0
15.1
13.6
13.9
14.0
13.2
13.0
T. PAHs
(%)
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
40
-------
TABLE?. Continued.
Percentage (%)
Core
Section
Site Code (cm)
SLPC 13 30-45
SLPC 14 30-45
SLPC 15 30-45
SLPC 30-45
15R**
SLPC 17 30-45
SLPC 17 45-60
Mean
SD
CV
Range: Low
Range: High
2Metnap
(%)
1.5
2.0
1.9
1.1
0.8
1.7
1.2
0.5
42
0.6
2.8
Acene
(%)
1.7
3.5
1.4
1.8
0.9
0.8
1.4
0.6
42
0.7
3.5
Aceny
(%)
0.3
0.3
0.7
0.5
0.3
0.4
0.4
0.1
38
0.1
0.8
Anth
(%)
2.3
4.2
3.1
3.2
2.1
1.8
2.7
0.6
24
1.7
4.4
Bena
(%)
5.1
4.1
3.9
4.7
7.4
7.1
6.5
1.5
24
3.8
9.7
Benap
(%)
6.4
6.0
6.2
6.3
7.4
7.1
6.7
0.7
10
5.5
7.9
Benb
(%)
5.8
5.2
5.0
5.3
6.7
6.0
5.6
0.9
16
3.6
7.0
Composition of PAH Compounds in Sample Sediments
Bene
(%)
6.0
5.4
5.7
5.4
6.8
6.2
5.6
0.9
17
3.6
6.9
Beng
(%)
5.6
5.0
6.5
5.7
5.9
7.1
5.6
1.2
21
3.2
7.9
Benk
(%)
1.5
2.1
3.0
1.8
2.2
2.4
2.5
0.6
25
1.3
3.7
Chry
(%)
8.6
5.0
6.8
8.9
7.8
8.4
7.9
1.0
12
5.0
9.7
Diben
(%)
0.7
0.8
0.8
0.9
0.9
0.8
0.9
0.2
26
0.7
2.0
Flut
(%)
16.8
16.6
17.8
17.7
18.4
17.2
18.1
1.3
7.0
16.5
22.6
Fluo
(%)
2.1
4.5
2.5
2.4
1.3
1.3
2.0
0.7
35
1.0
4.5
Indp
(%)
6.7
6.3
6.8
6.5
7.1
6.7
6.3
1.2
19
3.4
8.3
Naph
(%)
0.8
1.2
1.5
1.3
0.6
1.1
1.1
0.4
33
0.6
2.0
Phen
(%)
14.9
15.5
12.3
12.5
10.0
10.3
12.1
2.0
16
8.9
17.3
Pyrn
(%)
13.2
12.3
14.2
13.9
13.4
13.6
13.5
0.9
6.8
11.4
16.2
T. PAHs
(%)
100
100
100
100
100
100
* Mean of field replicates
** Mean of analytical duplicates
R = Field replicate
Standard deviation
C V = Coefficient of variation
PAH Codes:
2Metnap = 2-Methylnaphthalene
Acene = Acenaphthene
Aceny = Acenaphthylene
Anth = Anthracene
Bena = Benzo [a] anthracene
Benap = Benzo[a]pyrene
Benb = Benzo [b&j]fluoranthene
Bene = Benzo[e]pyrene
Beng = Benzo[g,h,i]perylene
Benk = Benzo[k]fluoranthene
Chry = Chrysene
Diben = Dibenzo[a,h] anthracene
Flut = Fluoranthene
Fluo = Fluorene
Indp = Indeno[l,2,3-cd]pyrene
Naph = Naphthalene
Phen = Phenanthrene
Pym = Pyrene
41
-------
TABLE 8. Distribution ofPCB congeners in selected samples from Slip C.
PCB Congener Concentrations
(|ig/kg)
PCB IUPAC
Number
1
4
7
6
8
5
19
18
17
27/24
32/16
26
25
31
28
33
53
22
45
46
52
49
47
48
44
59
37/42
71
64/41
40
63
74
70
SLPC 09
0-15 cm
4.5
7.4
0.2
1.3
0.22
1.9
0.91
0.17
0.18
0.32
0.90
0.91
0.15
0.94
0.86
0.33
0.50
0.16
0.18
0.51
2.2
2.4
0.64
0.14
1.6
0.14
0.6
0.35
0.63
0.32
0.15
0.85
1.6
SLPC 09
15-30 cm
2.7
4.9
0.17
0.87
0.19
1.1
0.55
0.14
0.15
0.27
0.29
0.71
0.13
0.92
0.59
0.28
0.44
0.26
0.15
0.12
1.7
1.7
0.54
0.12
1.3
0.12
0.5
0.13
0.25
0.13
0.13
0.62
1.1
SLPC 17*
0-15 cm
2.7
7.1
0.22
0.82
0.24
1.9
0.68
0.28
0.20
0.34
0.58
0.91
0.16
1.1
0.87
0.36
0.55
0.17
0.37
0.43
3.4
3.1
0.91
0.15
2.3
0.15
0.65
0.52
0.75
0.27
0.16
0.89
2.0
SLPC 17
15-30 cm
3.0
5.3
0.17
0.92
0.18
1.3
0.56
0.14
0.15
0.26
0.67
0.80
0.13
0.99
0.73
0.28
0.43
0.27
0.15
0.37
3.1
2.8
1.1
0.12
1.7
0.12
0.50
0.49
0.70
0.36
0.12
0.70
1.7
SLPC 18
0-15 cm
4.6
7.1
0.22
1.3
0.24
1.8
0.82
0.51
0.19
0.33
0.92
3.3
0.42
1.4
1.2
0.35
1.5
0.41
0.19
0.59
11
7.4
2.7
0.15
6.1
0.15
2.3
1.1
1.5
0.74
0.33
1.7
5.8
SLPC 18
15-30 cm
2.5
4.3
0.15
0.83
0.17
1.2
0.53
0.58
0.14
0.24
0.58
5.2
0.66
1.4
0.85
1.3
0.39
0.33
0.46
0.33
15
8.6
2.4
0.11
7.9
0.11
2.0
0.67
1.8
0.83
0.31
1.9
6.2
* Mean of field sample and analytical duplicate
42
-------
TABLES. Continued.
PCB Congener Concentrations
(|ig/kg)
PCB IUPAC
Number
76
66
95
91
56/60
92
84
101/90
99
119
97
81/87
85
136
77/110
82
151
135/144
107
123/149
118
114
146
153/184
132/168/105
141
137
176
163/138
158
126/178
182/187
183
SLPC 09
0-15 cm
0.14
0.19
3.9
0.78
0.30
0.74
1.3
3.5
1.8
0.42
1.4
2.9
1
0.82
5.9
0.44
0.89
0.28
0.6
0.28
3.4
0.27
0.9
3.6
3.1
0.89
0.3
0.77
4.6
0.51
0.38
1.5
1.2
SLPC 09
15-30 cm
0.12
0.16
2.9
0.51
0.25
0.54
0.96
2.5
1.3
0.14
0.92
1.9
0.64
0.6
4.1
0.28
0.58
0.66
0.46
0.24
2.3
0.12
0.67
2.3
2
0.55
0.12
0.46
2.8
0.3
0.24
0.97
0.77
SLPC 17*
0-15 cm
0.15
0.21
5.1
1.1
0.78
1.1
1.9
4.6
2.3
0.60
1.8
3.6
1.3
1.0
7.7
0.55
0.99
0.30
0.72
0.30
4.4
0.34
1.1
4.1
3.8
0.96
0.32
1.1
5.3
0.61
0.4
1.6
1.1
SLPC 17
15-30 cm
0.12
0.16
4.7
0.92
0.50
1.0
1.6
4.4
2.1
0.38
1.7
3.2
1.0
0.89
7.2
0.49
0.91
0.23
0.66
0.23
4.1
0.11
0.96
3.9
3.5
0.91
0.32
0.72
5.1
0.57
0.29
1.1
0.88
SLPC 18
0-15 cm
0.15
0.20
16
3.1
1.3
3.6
6.0
15
8.2
0.79
6.0
12
3.1
2.6
26
1.8
2.1
0.29
2.0
0.30
14
0.57
2.2
9.3
11
2.2
0.87
0.11
14
1.6
0.42
1.7
1.5
SLPC 18
15-30 cm
0.11
0.14
16
2.5
1.0
3.9
5.8
15
7.9
0.76
5.7
11
2.5
2.3
28
1.6
2.0
0.21
2.1
0.21
15
0.51
2.4
9.9
12
2.3
0.87
0.075
15
1.7
0.52
2.2
1.6
* Mean of field sample and analytical duplicate
43
-------
TABLES. Continued.
PCB Congener Concentrations
(|ig/kg)
PCB IUPAC
Number
128
167
185
174
177
202/171
156
157
172
197
180
199
169
170
190
201
196/203
189
208
195
194
206
209
SUM
SLPC 09
0-15 cm
1.1
0.39
0.28
1.3
0.76
1.5
0.15
0.15
0.28
0.30
2.6
0.13
-------
TABLE 9. Nomenclature of predominant PCB congeners in Slip C.
IUPAC Number
PCB Congener Name
77/110
95
101/90
118
132/168/105
163/138
3,3'4,4'-Tetrachlorobiphenyl
2,3,3',4',6-Pentachlorobiphenyl
2,2',3,5',6-Pentachlorobiphenyl
2,2',4,5,5'-Pentachlorobiphenyl
2,2',3,4',5-Pentachlorobiphenyl
2,3',4,4',5-Pentachlorobiphenyl
2,2',3,3',4,6'-Hexachlorobiphenyl
2,3',4,4',5',6-Hexachlorobiphenyl
2,3,3',4,4'-Pentachlorobiphenyl
2,3,3',4',5,6-Hexachlorobiphenyl
2,2',3,4,4',5'-Hexachlorobiphenyl
45
-------
TABLE 10. Results of regression analyses of chemical parameters with particle size classes. Regression relationships are in the
form ofy = bo + bj(x), with variables defined below.
Chemical Parameter
(y variable)
Total PAHs
Total PAHs
Total PAHs
Mercury
Mercury
Mercury
TOC
TOC
TOC
Total PCBs
Total PCBs
Total PCBs
Intercept
(bo)
47
3.3
4.2
0.56
0.083
0.086
20
-0.068
0.66
-22
210
230
Slope
(bi)
-0.44
0.54
2.2
-0.0048
0.0058
0.025
-0.20
0.25
0.97
2.4
-2.7
-15
Particle Size Class
(x variable)
Sand and Gravel (>53 |im)
Silt (53-2 |im)
Coarse Clay (2 - 0.2 |im)
Sand and Gravel (>53 |im)
Silt (53-2 |im)
Coarse Clay (2 - 0.2 |im)
Sand and Gravel (>53 |im)
Silt (53-2 |im)
Coarse Clay (2 - 0.2 |im)
Sand and Gravel (>53 |im)
Silt (53-2 |im)
Coarse Clay (2 - 0.2 |im)
r2 value
0.787
0.802
0.678
0.715
0.711
0.676
0.612
0.630
0.500
0.115
0.104
0.155
N
32
32
32
34
34
34
34
34
34
6
6
6
Outlier(s) at
95% Prediction Intervals
SLPC 13 (0-15, 15-30 cm)
SLPC 13 (0-15, 15-30 cm)
SLPC 13 (0-15, 15-30 cm)
SLPC 19 (0-15 cm)
SLPC 19 (0-15 cm)
SLPC 19 (0-15 cm)
SLPC 14 (15-30 cm)
SLPC 14 (15-30 cm)
SLPC 14 (15-30 cm)
none
none
none
N = Number of samples used in the regression analysis.
46
-------
FIGURES
47
-------
Duluth/Superior Harbor
Minnesota Slip
Duluth, MN
SlipC
Lake Superior
WLSSD/Miller Creek/
Coffee Creek
DM&IR Stockpile
Erie Pier
Mroescb PoUuScn Control Agency
Jure 1996
USX Superfund Site
1012
Intertake/DulutriTar
Superfund Site
FIG. 1. Map of the St. Louis River AOC showing locations of contaminated areas plus a reference area at Kimball 's Bay.
48
-------
F/G. 2. Historical map of Slip C showing Slip numbers 5-8.
49
-------
C Caustic Line
A Acid Lin:
R Resin Line
O 01 Line
Aboveground
Belowground
Fence
Direction of Flow
Bone Yard/
Buckingham Creek
Outfall 002 with Gate
a
FaeMHyMap
Georflla-Pacffis Dulrth, Waaesota, Hardbeart Plant
F/G. 3. Mop o/^/ze Georgia-Pacific plant in Duluth, MN circa 1993. Note: boiler ash and sawdust are no longer stored by outfall 001.
50
-------
FIG. 4. Map of the 1993 sediment sampling sites in Slip C (Schubauer-Berigan and Crane 1997).
51
-------
Slip C (SUS Sites)
Duluth/Superior Harbor
JW18BB
FIG. 5. Map of the 1994 sediment sampling sites in Slip C (Crane et al 1997).
52
-------
Duluth, MN
N
A
Duluth
Ship
Canal
Lake
Superior
Hoarding
Island
Duluth Harbor Basin
St. Louis River Area of Concern
Habitat class 1, shallow areas
Habitat class 2, shipping channels
250 0 250 500 7501000
Meters
Minnesota Pollution Control Agency
July 1996
FIG. 6. Map of the 1995 sediment sampling sites in Slip C as part of the R-EMAP project.
53
-------
Duluth/Superior Harbor
• 1997 Samping Sites
^r 1997 Replicate Sites
• 1995 R-EMAP Sites
O 1994 Sample Sites
A 1993 Sample Sites
Slip C Sites
N
A
50 0 50 100 150
Meters
Duluth Harbor
Northern Section
FIG. 7. Location of the 1997 sediment sampling sites in Slip C and the dip southeast of it.
54
-------
Duluth/Supcrior Harbor
• 1997 Samping Sites
£• 1997 Replicate Sites
• 1995 R-EMAP Sites
O 1994 Sample Sites
A 1993 Sample Sites
N
A
50
50
Slip C Sites
Meters
FIG. 8. Close-up map of the 1997 sediment sampling sites in Slip C.
55
-------
Total PAHs vs. Lead (excluding SLPC 13: 15-30 cm; SLPC 15: 15-30 cm)
50
40 -
•a
M 30
a 20
0.
o
H
10 -
b0 = -1.
r2 = 0.877
I
50
100
I
150
Lead (mg/kg dry wt.)
FIG. 9. Linear regression analysis of total PAHs versus lead.
200
56
-------
Total PAHs vs. Mercury (excluding SLPC 13: 0-15,15-30; SLPC 19: 0-15 cm)
50
40 -
--
Is
5
"Sfc
30 -
a 20 A
o.
10 -
b0 = - 0.50
bj =76
r2 = 0.770
0.1 0.2 0.3 0.4
Mercury (mg/kg dry wt.)
0.5
0.6
FIG. 10. Linear regression analysis of total PAHs versus mercury.
57
-------
Mercury vs. Lead (excluding SLPC 13: 0-15 cm; SLPC 19: 0-15 cm)
0.6
bo = 0.054
bj=2.2
r2 = 0.787
0.4 -
50
100 150
Lead (mg/kg dry wt.)
200
250
FIG. 11. Linear regression analysis of mercury versus lead.
58
-------
Total PAHs vs. TOC (<10%) (excluding SLPC 13: 15-30 cm; SLPC 15R: 30-45 cm)
50
•5fc
E
a.
"3
•s
H
40 -
30 -
20 -
10 -
b0 = 0.64
b! = 3.7
r2 = 0.876
4 6
TOC (%)
10
F/G. 12. Linear regression analysis of total PAHs versus TOC values less than 10%.
59
-------
Total PAHs vs. log TOC (excluding SLPC 13: 0-15,15-30 cm)
50
40 -
30 -
a 20 J
0-
lo-l
b0 = 4.6
bi=20
r2 = 0.766
0.1
1 10
log TOC (%)
100
FIG. 13. Linear regression analysis of total PAHs versus the logarithm of TOC.
60
-------
Lead vs. log TOC (excluding SLPC 13: 0-15, 30-45 cm)
200
log TOC (%)
FIG. 14. Linear regression analysis of lead versus the logarithm of TOC.
61
-------
Mercury vs. log TOC (excluding SLPC 19: 0-15 cm)
0.6
0.5 -
-04-1
•s
Sf
"a" °-3 "
?
P 0.2 -I
0.1 -
0.0
b0 = 0.085
b!=0.23
r2 = 0.773
0.1
1 10
log TOC (%)
100
FIG. 15. Linear regression analysis of mercury versus the logarithm of TOC.
62
-------
Lead vs. Percentage of Sand & Gravel (excluding SLPC 13: 0-15 cm)
200
150 -
•a
W)
^
"Si
4*
100 -
50 -
= 216
r = 0.837
20
40 60 80
Percentage (%) of Sand & Gravel (>53 um)
100
FIG. 16. Linear regression analysis of lead versus percentage of sand and gravel (>53 jum).
63
-------
Lead vs. Percentage of Silt (excluding SLPC 13: 0-15 cm)
200
150 -
•o
jf
•o
3
100 -
50 -
• •
b0 = 23
r2 = 0.839
10 20 30 40 50
Percentage (%) of Silt (53 - 2 jim)
60
FIG. 17. Linear regression analysis of lead versus percentage of silt (52 - 2 /jm).
64
-------
Lead vs. Percentage of Coarse Silt (excluding SLPC 13: 0-15 cm)
200
150 -
•o
J20
"Si
•o
3
100 -
50 -
• •
b0 = 27
r = 0.761
0 5 10 15 20 25
Percentage (%) of Coarse Silt (53-20 jim)
FIG. 18. Linear regression analysis of lead versus percentage of coarse silt (53 - 20 jjm).
65
-------
Lead vs. Percentage of Medium Silt (excluding SLPC 13: 0-15 cm)
200
150 -
•o
OK
•o
e«
100 -
50 -
b0 = 27
bj =4.7
r2 = 0.814
5 10 15 20 25 30
Percentage (%) of Medium Silt (20 - 5
35
FIG. 19. Linear regression analysis of lead versus percentage of medium silt (20 - 5 jjm).
66
-------
Lead vs. Percentage of Fine Silt (excluding SLPC 13: 0-15 cm)
200
150 -
"Si
£
i
4*
100 -
50 -
b0 = 27
r = 0.764
0246
Percentage (%) of Fine Silt (5 - 2 um)
F/G. 20. Linear regression analysis of lead versus percentage of fine silt (5-2 jum).
67
-------
Lead vs. Percentage of Coarse Clay (excluding SLPC 13: 0-15 cm)
200
150 -
"Si
£
i
4*
100 -
50 -
r2 = 0.764
4 6 8 10 12 14 16
Percentage (%) of Coarse Clay (2 - 0.2 um)
18
FIG. 21. Linear regression analysis of lead versus percentage of coarse clay (2-0.2 jum).
68
-------
DEPTH 0-15 en
SLPC 14
SLPC
SLPC
DEPTH 15-30
SLPC
DEPTH 30-45 en
SLPC 14
SLPC 13
SLPC
SLPC 8
SLPC 9
SLPC 10
SLPC 11
SLPC 12
\
KEY
TOTAL LEAD Cng/kg)
150
120
90
METERS
0 25 30 100
30
SOL
FIG. 22. Sediment kriging graphs for selected depth intervals of lead contamination in Slip C.
69
-------
SLPC
DEPTH 0-15 en
SLPC
SUS
SUS
SLPC 14
SLPC 13
KEY
MERCURY (mo/kg)
SUS 4
SLPC 16
DEPTH 15-30 en SUS 3
SLPC 15
2
SUS 1
SLPC 14
SLPC 13
DEPTH 30-45 en SUS 3
SLPC 15
SUS
SLPC 14
<
SLPC 13
FIG. 23. Sediment kriging graphs for selected depth intervals of mercury contamination in Slip
C. * Depth intervals for the 1994 SUS code samples ranged from 0-15 cm to 0-21 cm.
70
-------
SLPC
SLPC
SLPC
SUS
SLPC
DEPTH 0-15 ciV
SUS
SLPC
SUS
SLPC
SLPC
DEPTH 15-30
SLPC
SLPC
DEPTH 30-45 en
SLPC U
SLPC 13
KEY
TOTAL PAHS
50
40
30
20
METERS
0 85 50 100
10
SOL
FIG. 24. Sediment kriging graphs for selected depth intervals of PAH contamination in Slip C.
*Depth intervals for the 1994 SUS code samples ranged from 0-15 cm to 0-21 cm,
71
-------
SLPC
SLPC
SUS
DEPTH 0-15 en
sus
SUS
DEPTH 15-30
DEPTH 30-45
METERS
0 85 30 ii»
300
250
200
150
100
BDL
FIG. 25. Sediment kriging graphs for selected depth intervals of PCS contamination in Slip C.
*Depth intervals for the 1994 SUS code samples ranged from 0-15 cm to 0-21 cm.
72
-------
SLPC 19
SUS
SLPC 16
DEPTH 0-15 en* SUS 3
SLPC 15
SUS 2
SUS 1
SLPC 14
SLPC 13
SUS 4
SLPC 16
DEPTH 15-30 en sus 3
SLPC 15
SLPC 14
SLPC 13
DEPTH 30-45 cm SUS 3
SLPC 15
SUS 1
SLPC 14
<
SLPC 13
KEY
TOTAL ORGANIC
CARBDN CO
20
14
METERS
o as so toe
BDL
FIG. 26. Sediment kriging graphs for selected depth intervals ofTOC in Slip C. *Depth
intervals for the 1994 SUS code samples ranged from 0-15 cm to 0-21 cm.
73
-------
APPENDIX A
Regression Analyses of Total PCBs with other Variables
-------
Total PCBs vs. Total PAHs (all data)
300
Sf
1
8
0.
"eS
-M
o
H
250 -
200 -
100 -
50
b0 = 106
r = 0.0194
10 15 20 25
Total PAHs (mg/kg dry wt.)
30
FIG. A-l. Linear regression analysis of total PCBs versus total PAHs.
A-l
-------
300
Sf
1
8
0.
o
250 -
200 -
100 -
50
b0 = 34
r = 0.0351
Total PCBs vs. Lead (all data)
60
70
80 90
Lead (mg/kg dry wt.)
100
110
FIG. A-2. Linear regression analysis of total PCBs versus lead.
A-2
-------
Total PCBs vs. Mercury (all data)
300
M
-i
"Si
Wl
S
a.
3
o
250 -
200 -
100 -
50
b0 = 251
r = 0.0875
0.10
0.15 0.20 0.25
Mercury (mg/kg dry wt.)
0.30
0.35
FIG. A-3. Linear regression analysis of total PCBs versus mercury.
A-3
-------
Total PCBs vs. Total PAHs ('93 - '94 data set)
400
300 -
Sf
PQ
u
0.
200 -
100 -
10 20 30 40
Total PAHs (mg/kg dry wt.)
bi = 4.8
r2 = 0.428
50
60
FIG. A-4. Linear regression analysis of total PCBs versus total PAHs for the 1993 and 1994
Slip C data sets.
A-4
-------
600
400 -
•o
Sf
~£i
oa
u
PH
O
200 -
Total PCBs vs. Mercury ('93 - '94 data set)
(excluding SUS 5: 15-23 cm)
0.2 0.4 0.6
Mercury (mg/kg dry wt.)
b0 = 60
bi = 310
r2 = 0.230
0.8
1.0
FIG. A-5. Linear regression analysis of total PCBs versus mercury for the 1993 and 1994 Slip C
data sets.
A-5
-------
300
Sf
1
8
0.
3
o
250 -
200 -
100 -
50
Total PCBs vs. TOC (all data)
b0 = 184
r = 0.0169
TOC (%)
FIG. A-6. Linear regression analysis of total PCBs versus TOC.
A-6
-------
600
400 -
•o
Sf
S
«i
oa
u
0.
o
200 -
T. PCBs vs. TOC ('93 - '94 data set)
(excluding SUS 5: 15-23 cm)
b0 = 43
b!=24
r2 = 0.707
10
TOC (%)
15
20
F/G. ^4-7. Linear regression analysis of total PCBs versus TOC for the 1993 and 1994 Slip C
data sets.
A-7
-------
APPENDIX B
Regression Analyses of PAHs, Mercury, and TOC with Particle Size Classes
-------
Total PAHs vs. Percentage of Sand & Gravel (excluding SLPC 13: 0-15,15-30 cm)
50
40 -
•o
M 30
>j>
•510
%
a 20
Q-
o
H
10 -
20
b0 = 47
b!=-0.44
r2 = 0.787
40 60 80
Percentage (%) of Sand & Gravel (>53 jim)
100
FIG. B-l. Linear regression analysis of PAHs versus percentage of sand and gravel (>53 jjm).
B-l
-------
Total PAHs vs. Percentage of Silt (excluding SLPC 13: 0-15,15-30 cm)
50
40 -
-
fr
•o
si
•^
O
20 -
10-1
b0 = 3.3
r2 = 0.802
10 20 30 40 50
Percentage (%) of Silt (53 - 2 jim)
60
F/G. 5-2. Linear regression analysis of PAHs versus percentage of silt (52 - 2 jum).
B-2
-------
Total PAHs vs. Percentage of Coarse Clay (excluding SLPC 13: 0-15,15-30 cm)
50
40 -
M 30 -
£
%
&3 20 -I
o
H
10 -
b0 = 4.2
r = 0.678
2 4 6 8 10 12 14
Percentage (%) of Coarse Clay (2 - 0.2 jim)
16
F/G. 5-3. Linear regression analysis of PAHs versus percentage of coarse clay (2-0.2 jjm).
B-3
-------
Mercury vs. Percentage of Sand & Gravel (excluding SLPC 19: 0-15 cm)
0.6
0.5 -
•o
OK
>->
S
53 ^m)
100
FIG. B-4. Linear regression analysis of mercury versus percentage of sand and gravel (>53
B-4
-------
Mercury vs. Percentage of Silt (excluding SLPC 19: 0-15 cm)
0.6
0.5 -
0.4 -
0.3 -
£
S
0.2 -
0.1 -
b0 = 0.083
bi = 0.0058
r2 = 0.711
10 20 30 40
Percentage (%) of Silt (53 - 2 jim)
50
60
FIG. B-5. Linear regression analysis of mercury versus percentage of silt (52 - 2 /jm).
B-5
-------
Mercury vs. Percentage of Coarse Clay (excluding SLPC 19: 0-15 cm)
0.5 -
•o
OK
-
"wi 0.3 -
S
0.1 -
b0 = 0.086
b!= 0.025
r2 = 0.676
4 6 8 10 12 14 16
Percentage (%) of Coarse Clay (2 - 0.2 jim)
18
F/G. B-6. Linear regression analysis of mercury versus percentage of coarse clay (2-0.2 /jm).
B-6
-------
TOC vs. Percentage of Sand & Gravel (excluding SLPC 14: 15-30 cm)
25
U
O
20 -
15 -
10 -
5 -
b0 = 20
b! = -0.20
r^ 0.612
20
40 60 80
Percentage (%) of Sand & Gravel (>53 um)
100
FIG. B-7. Linear regression analysis of TOC versus percentage of sand and gravel (>53 jum).
B-7
-------
TOC vs. Percentage of Silt (excluding SLPC 14: 15-30 cm)
25
U
o
20 -
15 -
10 -
5 -
b0 = - 0.068
bj =0.254
r2 = 0.630
10 20 30 40
Percentage (%) of Silt (53 - 2
50
60
FIG. B-8. Linear regression analysis of TOC versus percentage of silt (52 - 2 jum).
B-8
-------
TOC vs. Percentage of Coarse Clay (excluding SLPC 14: 15-30 cm)
25
U
o
20 -
15 -
10 -
5 -
b0 = 0.66
b!=0.97
r2 = 0.500
0 2 4 6 8 10 12 14 16
Percentage (%) of Coarse Clay (2 - 0.2 um)
FIG. B-9. Linear regression analysis of TOC versus percentage of coarse clay (2-0.2 jjm).
B-9
------- |