EPA-440/5-77-015B
EVALUATION OF
THE PROBLEM POSED BY
IN-PLACE POLLUTANTS
IN BALTIMORE HARBOR
AND RECOMMEDATION
OF CORRECTIVE ACTION
United States
Environmental Protection Agency
Office of Water Planning and Standards
Washington, B.C. 20460
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EPA Review Notice
This report has been reviewed by the Environmental
Protection Agency and approved for publication.
Approval does not signify that the contents neces-
sarily reflect the view and policies of the
Environmental Protection Agency, nor does mention
of trade names or commercial products constitute
endorsement or recommendation for use.
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EPA 440/5-77-015B
Evaluation of the Problem Posed by
jln-Place Pollutants in Baltimore Harbor
and Recommendation of Corrective Action
United States
Environmental Protection Agency
Office of Water Planning and Standards
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TABLE OF CONTENTS
Page
1.0 EXECUTIVE SUMMARY . . . 1
2 .0 INTRODUCTION AND PURPOSE OF STUDY 3
2. 1 THE AREA INVESTIGATED 5
3. 0 APPROACH. 8
3. 1 GEOCHEMISTRY 9
3. 2 BIOASSAY 11
3.3 POTENTIAL, CORRECTIVE ACTIONS 12
4. 0 DESCRIPTION OF IN-PLACE POLLUTANTS 13
4. 1 SOURCES AND QUALITY OF DATA AVAILABLE 13
4. 2 POLLUTANT CONCENTRATIONS AND THEIR
HORIZONTAL AND VERTICAL DISTRIBUTION 17
4. 3 ESTIMATED QUANTITIES 35
5. 0 THE EFFECTS OF IN-PLACE POLLUTANTS 40
5. 1 SEDIMENT AND INTERSTITIAL CHEMISTRY 41
5. 2 BENTHOS 43
5. 3 PELAGIC FISH AND PLANKTONIC ORGANISMS 49
6. 0 EFFECTIVENESS AND PERMANENCE
OF POTENTIAL CORRECTIVE ACTIONS 51
6. 1 BLANKETING AS A CORRECTIVE ACTION 53
6.2 INACTIVATION AS A CORRECTIVE ACTION 55
6. 3 REMOVAL AS A CORRECTIVE ACTION 56
6. 4 LEAVING UNDISTURBED 64
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TABLE OF CONTENTS
Pace
7. 0 FEASIBILITY AND COSTS OF
POTENTIAL CORRECTIVE ACTIONS 65
7. 1 BLANKETING 66
7. 2 INACTIVATING 67
7. 3 REMOVING 68
7.4 LEAVING UNDISTURBED 71
8. 0 CONCLUSIONS AND RECOMMENDATIONS 73
8. 1 CONCLUSIONS 73
8. 2 RECOMMENDATIONS 77
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LIST OF TABLES
Table Page
4-1 Averages of Sediment Analyses Concentrations 18
4-2 Averages of PCB Concentrations. 19
4-3 Averages of Interstitial Water Metal Concentrations 21
4-4 Averages of Elutriate Test Metal Concentrations 23
4-5 Average Concentrations of
Sediment Analyses for Core Samples 25-31
4-6 Elutriate Test Analyses for Sampling Sites 33
4-7 Metal Concentrations of Filtered Water 34
4-8 Sources of Heavy Metals
Entering Baltimore Harbor (Helz, 1976) 36
4.9 Percent Retention of Trace Elements
in Estuarine or Coastal Sediments (Helz, 1976) 37
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LIST OF FIGURES
Figure Page
2-1 Baltimore Harbor and Vicinity 6
2-2 Baltimore Harbor Sampling Sites 7
5-1 Toxic Zones 44
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1. 0 EXECUTIVE SUMMARY
This study: (1) describes the in-place pollutants within Baltimore Harbor,
(2) analyzes the pollutants for their effect upon the environment, (3) investi-
gates potential corrective actions for feasibility and cost, (4) examines the
effectiveness and permanence of potential corrective actions, (5) derives
conclusions and makes recommendations, and (6) recommends the course
of action which is most realistic given the conditions of the Harbor's require-
ments and use.
Following a comprehensive review of prior related work, a field program
was developed and carried out to confirm and extend the results of earlier
investigators. In the field program, core borings were taken from twenty
sites. Each core was divided into sections to test the levels of concentra-
tions of selected pollutants to depths of 10 feet below the sediment/water
interface. The individual samples were analyzed for nine heavy metals,
total hydrocarbons by hexane extract, PCB's, and interstitial water metals.
In addition, elutriate tests were made, and surface sediments from nine of
the twenty sites were used in a bioassay of two finfish and one clam species.
0 The analytical techniques used to determine the existence and
degree of pollution, such as the bulk sediment analyses, the
elutriate tests, interstitial water metal analyses, PCB con-
centration analyses, and the bioassay did not correlate one
with another to indicate pollutants or toxic elements consistently
or predictably. The two analytical techniques that did corre-
late were the bioassay and the sediment analyses for heavy
metal, hexane extract, and PCB concentrations. The elutriate
test showed that the entire Harbor is classified as polluted,
the elutriate being greater than 1.5 times the overlying filtered
water metal concentration. Neither the elutriate test nor the
interstitial water metal concentration analyses indicated con-
sistent zones of intensity or correlated with the areas known
to contain very high levels of toxic materials.
0 The biota within the Harbor are being stressed by the in-place
pollutants. The benthic organisms suffer the greatest amount
of damage, intensity varying according to locatipn within the
highly, moderately, low, or slightly toxic zones. The pelagic
species are damaged to a much lesser extent. The cause of
damage, whether from in-place pollutants or from those pres-
ently being discharged, is unknown.
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In-place pollutants are a direct result of waste discharges that are
incorporated into the sediments. Although the exact quantities and
chemical composition of the present discharges are not known, NPDES
permit authorizations indicate that significant quantities of heavy metals
and total suspended solids are being added to the Harbor each day. The
last total inventory of heavy metals and toxic chemicals, published in
1973, showed a daily Harbor influx of 86 tons. Until the goals of P. L.
92-500 are achieved and discharges of toxic materials are greatly reduced
or eliminated, any action such as removal of the in-place pollutants would
result in but a temporary solution.
0 Of the potential corrective actions, "leaving the pollutants in
place" is recommended as the preferred choice, at least until
the influx of pollutant loads is greatly reduced or eliminated.
0 Removal of the in-place pollutants by dredging may be an
effective and feasible action to be taken in the future, after the
discharge of pollutants has been eliminated. Dredging should
be contemplated only after an appropriate amount of time has
passed after the elimination of incoming pollutants; natural
recovery to the biota of the Harbor may be possible and may
well take place through blanketing of the in-place pollutants
with clean sediment and natural loss of heavy metals to the
water column.
* Placement in a diked disposal area such as the Hart-Miller
Island disposal site is feasible and is acceptable under Mary-
land State law. Costs to dredge and place 79 million cubic
yards are estimated at 74 million dollars. To construct a
diked disposal site for that quantity of material would cost 54. 5
million dollars --a total estimated expenditure of 128. 5 million
dollars.
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2.0 INTRODUCTION AND PURPOSE OF STUDY
The purpose of this study, authorized by EPA Contract Number 68-01-1965,
was to perform an "Evaluation of the Problem Posed by In-place Pollution
in Baltimore Harbor and Recommendation of Corrective Action Responsive
to the Mandate of Section 115 PL 92-500". EPA's statement of work
required that:
The Contractor shall furnish the necessary personnel,
materials, services, facilities ..., and otherwise do
all things necessary for or incident to the performance
of the work set forth below:
A. The Contractor shall collect and/or generate by
measurement, sampling, and analysis, the infor-
mation necessary to describe the problem area
and provide the basis for a viable program of
dredging and disposal or other corrective action
for Baltimore Harbor, Baltimore, Maryland.
The following minimum requirements should be
addressed in the study and included in the report:
1. Describe the harbor sediment for its pol-
lutional characteristics, including vertical
and horizontal distribution, and the volume
of polluted sediment involved in the problem
area...
2. Give an analysis of the environmental effect
of the polluted sediment and/or why it is a
problem (i. e., can it be left alone, is it part
of an area to be dredged, is it adversely affect-
ing water quality and water use?).
3. Determine the probable effectiveness and per-
manence of any corrective action. Will the
pollutant sources continue to affect the harbor
sediments?
4. Investigate the various alternative corrective
actions and detail their feasibility and cost.
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5. Recommend a course of action that is realistic
with regards to harbor requirements and use.
Six months were allowed for field work, taking of samples, laboratory work
and the preparation of a draft report. To encompass the maximum area of
Baltimore Harbor within the allotted time, the field work and the sampling
process were designed to build on and supplement prior work which has been
performed on the sediments and water column of the Harbor by the authors
and by others. Correlation between the findings of the current work and
prior work was made wherever possible.
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2. 1 THE AREA INVESTIGATED
In order to evaluate the problem posed by in-place pollutants in Baltimore
Harbor, sampling and other work was concentrated in the Harbor area
proper. Figure 2-1 shows the general location of Baltimore Harbor and
the Chesapeake Bay. Figure 2-2 shows the location of sampling sites used
in this investigation along with major sub-divisions of the Harbor and their
commonly used names. Since various sources use differing delineations
when referring to the segments of Baltimore Harbor, this report follows
the map and section names outlined in Villa and Johnson's report for EPA
dated January 1974.
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BALTIMORE HARBOR
AND
VICINITY
STUDY AREA
ANNAPOLIS.
WASHINGTON D'"7
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WARBOE-
If c spaee.ovfs:fr.
SAMPLE; SITE*
BIOA55AY SAMPLE. S/7E5
-7-
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3.0 APPROACH
The initial step was to review and consider for applicability all available
published and unpublished work relating to in-place pollutants in Baltimore
Harbor. A bottom-sampling field program was then devised and carred
out to both confirm and extend the results of prior work. Chemical
analyses were made to determine the nature of the pollutants in the core
samples and their concentrations. A bioassay was performed to deter-
mine the gross toxicity of the in-place sediments. From the work done
in this sampling and analysis program, correlated with previous studies,
the extent of the vertical and horizontal distribution of the polluted sedi-
ments in the Harbor was derived. The technical, economic, and other
implications of each potential corrective action were then evaluated, and
conclusions and recommendations were derived and a realistic course of
action proposed.
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3. 1 GEOCHEMISTRY
To measure the concentrations and distribution of heavy metal and other
pollutants present in Baltimore Harbor sediments, twenty sites were chosen
for sampling and chemical analysis. Core borings were taken between
June 9- 15, 1976, using the R. V. AQUARIUS, a 65-foot motor vessel
belonging to the University of Maryland Center for Environmental and
Estuarine Studies. The vessel is fully equipped with modern scientific
equipment for conducting research and studies within the Chesapeake
Bay and its tributaries. The sampling sites were selected with regard to
the location of the main shipping channels and to locations where previous
work had been performed. The sites sampled in this study cover the same
general areas as those used in the Villa and Johnson study (1974). The
sampling and analysis program included the same heavy metals analyzed
in the 1974 study. In addition, the investigation added arsenic, hexane
extract, PCB's, and an analysis of interstitial water metal concentrations.
Also, the standard elutriate test for metal was conducted.
A 15-foot gravity piston corer was used to obtain sediment samples at
each of the twenty sampling sites (See Figure 2-2 for locations. ). These
samples were fractioned into eight layers of individual samples, from
0, 16 to 10 feet; and the following analyses were performed:
0 Sediment Analyses
Analyses were made for percent moisture content; total hydro-
carbons by hexane extract; and nine heavy metals: arsenic (As),
mercury (Hg), cadmium (Cd), chromium (Cr), copper (Cu),
manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn). These
were done at each of the eight layers obtained. The individual
sample analyses and the procedure used are contained in
Appendix C.
Interstitial Water
Samples for interstitial water analyses were obtained from two
levels, or depths, of sediment; 5-10 cm and 40-45 cm. The
individual analyses and the procedure used to obtain the samples
are contained in Appendix C.
Elutriate Test
Samples for the elutriate test were taken from the same eight
sediment layers, or depths, of the core as for the sediment
analysis and were analyzed for the same nine heavy metals.
The individual sample analyses and the procedure used to
obtain the samples are contained in Appendix C.
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0 PCB Analyses
Samples for PCB analyses were obtained from the first four
depths of sample material, 0. 16, 0. 5, 1. 0, and 2. 0 feet.
The results of the PCB analyses and individual sample data
are contained in Appendix D.
0 Particle Size and Surface Area Analyses
Sediment samples were taken from the top layer at a depth of
0, 16 feet and from the bottom layer, 10. 0 1 2 feet. Samples
were analyzed for average particle size and specific surface
area. The analyses for individual samples is contained in
Appendix C.
0 Filtered Water
Water samples were obtained at each of the twenty sampling
sites. Samples were obtained in three fractions taken from
the lower, middle, and upper third of the water depth. The
water was then mixed, filtered and analyzed for the nine heavy
metals to provide a basis for the chemical analyses of the over-
lying water fraction in the elutriate test. The analyses for the
individual samples and procedure used to obtain the samples
are contained in Appendix C.
The results of these chemical analyses and tests provided the basis for
describing the in-place pollutants in Baltimore Harbor in terms of their
concentration and for their horizontal and vertical distribution as presented
in Section 4. 2. It also provided a basis for interpretative work in describing
the effects of the in-place pollutants contained in Section 5. 0. The overall
results of interpretative analyses for corrective actions are contained in
Sections 6 and 7 and in the Conclusions and Recommendations of this report.
Appendix C contains the detailed analyses and individual results of chemical
and physical analyses of the samples obtained in the field.
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3.2 BIOASSAY
At nine pre-selected sites (See Figure 2-2 for locations. ) a grab sampler
was used to obtain approximately 30 gallons of sediment from the upper-
most one foot of bottom material to be used in the bioassay. The proce-
dure used in preparing these samples for the bioassay is contained in
Appendix E.
A bioassay was performed using two species of finfish, mummichog,
Fundulus heteroclitus, and spot, Leiostomus xanthurus, and one species
of clam, Mya arenaria. The purpose of the bioassay was to determine the
gross toxicity of the sediments that were taken from several different areas
within the Harbor. Previous studies had classified portions of the Harbor
as "high, " "moderate," "slight," and "low" in toxic effects on the basis of
the distribution and abundance of benthic macro-invertebrates. The bioassay,
therefore, was designed to indicate relative gross toxicity from one sampling
site location to another. The interpretation of the bioassay results are con-
tained in Sections 5. 2 and 5. 3, and in the Conclusions and Recommendations
of this report. The method used for performing the bioassay and specific
findings are contained in Appendix E.
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3. 3 POTENTIAL CORRECTIVE ACTIONS
From the geochemical and bioassay findings and from engineering studies
and reports, all corrective actions having reasonable potential for appli-
cation were evaluated. These included blanketing, the deposition of layers
of plastic material over the polluted bottom sediments to preclude the trans-
fer of the pollutants from the sediments to the water column; inactivation of
the polluted sediments by chemical means; and removal of the polluted sedi-
ments by dredging. In addition, while not in a sense a corrective action, the
effect of leaving the sediments undisturbed also was evaluated. See Sections
6. 0 and 7. 0 for further discussion.
Each potential corrective action was evaluated with respect to the environ-
ment of Baltimore Harbor, which is an active shipping port in a highly
industrialized center. The Conclusions and Recommendations of this report
reflect a course of action that is considered to be the most realistic with
regard to harbor requirements and use and the current and projected future
discharges of industrial and community pollutants into the Harbor waters.
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4.0 DESCRIPTION OF IN-PLACE POLLUTANTS
4. 1 SOURCES AND QUALITY OF DATA AVAILABLE
An extensive literature review was made early in the investigation to both
ascertain the extent of current knowledge about pollutants in Baltimore
Harbor; and to assist in the design of the field sampling program. In
addition, certain proprietary reports and unpublished works were made
available to this study, which were helpful. The following is a list of
published material reviewed, together with summary comments, perti-
nent to this study. The reader is cautioned that data formats and data
values will be found to differ in these publications. Differing methods for
sample preparation, differing analytical methods, differing collection and
storage procedures, etc. , all combine to modify the final values by factors
of 2 to 100 and more (Sommer, 1974, and Bricker, 1975). It will noted
also that no literature could be found which contained information pertain-
ing to heavy metals in interstitial waters or elutriate tests on samples
from Baltimore Harbor.
Sediment Geochemistry
Villa and Johnson, 1974, EPA, Region HI
The most comprehensive source of sediment geochemical data
is by Villa and Johnson. Most of their samples were taken near
the surface (5 - 15 cm), 24 of the 176 sites were sampled at 30 -
40 cm depth. These cored samples were analyzed for Pb, Cd,
Cr, Cu, Mn, Ni, Zn, and Hg. This study served as the basis
for the design of the present report; i. e., techniques and site
selection are comparable so that the reports can be compared
equitably. The values for the horizontal distribution of the
heavy metals from this most recent study (1976) agree in almost
every case with the high and low concentrations of the same
metals from the same site locations from the Villa and Johnson
study.
Cronin, et al, 1974, Chesapeake Bay Institute
and Chesapeake Biological Laboratory
Analyses of Zn, Mn, Cd, Cu, Ni, and Fe, made at 23 sites in
the Harbor found large local spatial variations in the metal con-
centrations. This report found Zn, Cu, and Cd levels to be much
higher in the Harbor than in the Bay, 4 to 14 times the maximum
levels found in the Upper Bay. The maximum concentrations of
Mn, Fe, and Ni were found to be less in the Harbor than in the
Bay.
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Biggs, 1968, Chesapeake Biological Laboratory
Biggs analyzed for Cu, Pb, Zn, Cd, and Cr in sediment samples
taken from the Harbor in the vicinity of Dundalk Marine Terminal.
He found all of these metals to be of higher concentrations than
metals in sediments off Poplar Island, a potential dumping area.
Cr varied, at Dundalk, from 94 - 423 ppm, Cu from 65 185 ppm,
Cd from 2. 84 - 15. 58 ppm, and Zn from 303 - 2390 ppm for sur-
face samples. Biggs attributed the metal levels to industrial
activity and suggested that the metals are concentrated as metal
sulfides in the sediment.
Sommer and Diachenko, 1974, Geological Society of America
This study contains the only data on heavy metals in interstitial
water in the Chesapeake Bay.
Koo, 1975, Center for Environmental and Estuarine Studies
Contains a physical analysis of sediments in the Harbor obtained
from a sieve analysis for percentages of sand, clay, and silt for
28 stations. These data indicate a majority of the sediment to
be of silt size with the sand fraction becoming important at the
mouth of the Harbor.
Per Hall, Pulleritz - Zollman, 1974, Interstate Division
of Baltimore City
This report on construction in Baltimore Harbor contains the
only known information on sediment composition to depths of
80 feet and includes 16 components, many of which are not
covered in any other available report. Sediment samples taken
from very deep corings and analyzed for heavy metals may indi-
cate possible natural background levels which would be of interest
in establishing standards for pollution levels.
Green Associates and Trident Engineering Associates, 1970,
Maryland Department of General Services
This report contains abundant information on comparative
chemical extraction techniques applied to sediments and a com-
prehensive study of the dredged spoil disposal problem. Poten-
tial disposal areas from the mouth of the Susquehanna River to
Tangier Island were investigated. The chemical and physical
characteristics of the channel bottom sediments were examined
as were the pertinent characteristics of the movement of the
waters in Chesapeake Bay. Preliminary designs were made for
containments at the five sites having the greatest overall poten-
tial as diked disposal areas.
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Biota
H. T. Pfitzenmeyer under Koo, 1975, Center
for Environmental and Estuarine Studies
H. T. Pfitzenmeyer briefly reviewed literature pertaining to the
biology of Baltimore Harbor prior to 1971. He stated that natural
resources of the Harbor rapidly declined before the turn of the
century. In 1884 there were 3,800, 000 square yards of oyster
bars within the Harbor, northwest of a line from Old Road Bay
to Sellers Point. In 1907 the northern limit of all oyster grounds
was Rock Point at the entrance to the Harbor. Bottom grounds
above Bodkin Point were not recommended for oyster culture.
Yates, 1913, U. S. Coast and Geological Survey
Yates made a study of oyster bars in Chesapeake Bay in 1906-1912.
No oyster bars were shown for Baltimore Harbor.
Davis, 1948, Chesapeake Biological Laboratory
Davis also studied this copperas-polluted area of Curtis Bay and
confirmed the Olson, et al, findings, but he found more diatoms
present per liter in the polluted area than in the relatively unpol-
luted area.
Garland, 1952, Chesapeake Biological Laboratory
Garland made the first extensive water quality survey of Baltimore
Harbor and the Patapsco estuary. He stated that in some seasons
of the year fishing was good at the entrance to the Harbor, but
within the Harbor fishing and crabbing had diminished during the
previous quarter of a century and had virtually stopped. This,
he concluded, resulted from waste discharges.
Hohn and Hellerman, 1966, Transactions of American Micro. Soc.
Hohn and Hellerman studied diatoms in Lewes-Rehoboth Canal,
Delaware, and Chesapeake Bay area of Baltimore. They described
four new species from Curtis Bay, a major tributary of the Harbor,
in the vicinity of Sledds Point. These were Diploneis hormopunctata,
Navicula agmastriata, N. cumvibia and N. taraxa.
Koo, 1975, Center for Environmental and Estuarine Studies
Chesapeake Biological Laboratory conducted a comprehensive
biological study of Baltimore Harbor in 1970-1971. Four major
biological groups were studied: fish eggs and larvae by W. L.
Dovel; invertebrate benthos by H. T. Pfitzenmeyer; adult fish
by M. L. Wiley; and blue crabs by R. L. Lippson and R. E.
Miller. The results were summarized and edited by T. S. Y. Koo.
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Villa and Johnson, 1974, EPA, Region HI
Villa and Johnson studied the heavy metal contamination of Balti-
more Harbor sediments. They indicated that heavy metal con-
tamination might be a major contributing factor to the biological
deterioration of benthic communities of the Harbor.
Water Column Chemistry
Garland, 1952, Chesapeake Biological Laboratory
Garland evaluated the water quality in terms of -waste disposal,
past and present, and projected future usage.
Stroupe, 1961, Chesapeake Bay Institute
Stroupe studied the flushing mechanism of the Harbor and its
effect on waste discharge and biological conditions..
[These two studies are the standard references to water quality in Baltimore
Harbort However, neither report is truly applicable to this study. ]
Ryan, 1953, Maryland Department of Geology, Mines,
and Water Resources
This major study of the Bay sediments included only three sites
that could be considered in the Harbor. These samples were
analyzed by conventional sieve and wet techniques for size frac-
tionization. The samples were all over 98 percent silt and clay.
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4. 2 POLLUTANT CONCENTRATIONS AND THEIR
HORIZONTAL AND VERTICAL DISTRIBUTION
4. 2. 1 Horizontal Distribution
4. 2. 1. 1 Horizontal Distribution - Sediment Analysis
The pollutants identified and analyzed in this study consisted of nine heavy
metals, hexane extract, and PCB's. For ease of reference, the average
concentrations of the nine heavy metals and the hexane extract observed
at the twenty sampling sites have been summarized in Table 4-1. At each
site, the core sample was divided into eight layers of sediment by depth,
0.16, 0.5, 1.0, 2.0, 3.0, 5.0, 7.0, and 10. 0 feet to portray the vertical
•distribution of metal concentrations. The concentration of each metal
for each of the eight sample depths was then totaled and averaged. Although
an average figure for the eight samples does not represent a precise
description of the representative sample, it displays conveniently the
variable concentrations from one site location to another and offers an
overall view of the horizontal distribution. The individual analysis of the
concentration of each metal by depth and site location may be found in the
tables in Appendix C.
Table 4-1 shows that most of the highest concentrations of heavy metals
and hexane extract occur in Sites 1, 2, and 3, all three of which are located
in the Northwest Branch of Baltimore Harbor. (See Figure 2-2 for site
locations. ) Site 4, located in Colgate Creek, and Site 5, located in Bear
Creek, also have high concentrations of heavy metals and hexane extract.
All of these sites, containing very high concentrations of pollutants in
sediment metal distribution, PCB's, and hexane extract, also contain the
highest toxic materials as determined by the bioassay.
Site 9, located in Curtis Bay, and Site 13, in Old Road Bay, also contain
relatively high concentrations of heavy metals. The sites located in the
upper portions of the Harbor, Northwest Branch, and Middle Branch, and
the sites located within the creeks have the majority of high heavy metal,
hexane extract, and PCB concentration. (See Table 4-2 for PCB average
concentrations. )
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TABLE 4-1
AVERAGES* OF SEDIMENT ANALYSES
CONCENTRATIONS IN mg/kg
Site
1
2
3
4
5
6
71
8
9
10
II2
12
13
14
15
16
17
18
19
20
Total
Hydro-
Carbons
Extract
7,539
26, 295
25.922
11.889
12.292
1. 173
980
6,572
9.506
4,233
253
363
313
2, 155
8,463
2,011
4.233
1,918
4,791
10,606
Metals mg/kg
As
45
75
124
187
57
15
26
100
248
62
9
16
15
26
31
31
44
65
47
68
Hg
3.20
2.70
2.60
1.40
0.25
0.20
0. 19
0.78
1^30
0.66
0.04
0. 11
0.80
0.52
0.65
0.48
0.45
0.73
0.74
1.48
Cd
5
11
_8_
111
11
1
2
2
3
3
2
1
4
2
6
2
2
3
3
3
Cr
1, 115
1,848
1.037
621
926
76
183
300
342
298
23
28
137
147
596
178
270
348
288
362
Cu
426
1,235
j_. 66 1
427
164
44
61
164
291
196
14
25
74
80
186
104
117
226
228
408
Mn
294
331
333
419
693
906
810
949
767
325
910
1,390
511
1, 180
558
L423
917
1. 341
796
417
Ni
54
88
87
53
56
40
49
48
59
57
42
40
29
46
45
52
48
54
65
64
Pb
99
800
941
681
455
93
113
148
467
147
17
14
406
118
233
162
164
196
164
272
Zn
651
971
921
724
1.712
340
428
676
545
380
91
197
L458
466
961
466
477
726
661
478
*No bottom sample taken
*No middle or bottom samples taken
*A11 figures represent the average of the
concentrations for all samples per sita.
Highest concentration
Second highest concentration
Third highest concentration
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TABLE 4-2
AVERAGES1 OF PCB CONCENTRATIONS
Site
12
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Average PCB
Concentrations (mg/kg)
>22.58
1.26
1.75
1.36
2.17*
0.21***
0.27***
0.25**
0.48
0.59
<0.05
0.18***
0.49
0.15**
1.16
0.12*
0.45
0.52
0.37
0.43*
All figures represent the average of the
concentrations for all samples per site.
2 Aroclor 1260 was masking 1248 values so that
total values may be substantially higher for
this one sample set.
•ss^s Highest concentration
=*= Second highest concentration
Third highest concentration
*Average of three out of four samples.
One sample below detection limits.
**Average of two out of four samples.
Two samples below detection limits.
***One sample only.
Three samples below detection limits.
-19-
-------
The results of the sediment metal analyses correlate well with those of
the bioassay. Generally those areas containing high concentrations of
heavy metals, PCB's, and hexane extract are also those areas determined
as highly toxic from the bioassay. Pollutant concentrations, except for
Mn, decrease gradually toward the mouth of the Harbor and the entrance
to the Bay. The values for the horizontal distribution of the heavy metals
agree in almost every case -- Hg is one exception -- with the high and
low concentrations of eight of the same metals reported by Villa and
Johnson (1974). This correlation is remarkable considering that dredging,
storms, and ship traffic would have left their imprint during the three years
between sampling programs. This lack of dispersion may indicate the
stability of the metal within the sediment or that industrial output is suf-
ficient to replace quickly any metal concentrations removed or transferred.
4. 2. 1. 2 Horizontal Distribution - Interstitial Water Metal Levels
The analysis of interstitial water was considered vital to this study
because of its impact on the evaluation of alternative methods of action.
The interstitial water may be the major source of the releasable metals
during dredging, and no data existed prior to this study on these fluids in
Baltimore Harbor. Interstitial water data are very dependent on the manner
in which the sample is collected (Bricker, 1975; Sommer and Diachenko,
1974); great care must be taken in preventing oxidation of anoxic sediments,
as iron may precipitate and scavenge or adsorb trace metals out of solution.
Sample preparation and analytical techniques are contained in Appendix C.
The distribution of interstitial water concentrations for the nine heavy
metals is displayed in Table 4-3 which is an average of the two samples
taken from 5-10 cm and 40-45 cm depths of the core. Individual sample
analyses for each station are given in Appendix C. The distribution pattern
of the first, second, and third highest concentrations depicted in Table 4-3
shows that the horizontal distribution of interstitial water is quite hetero-
geneous and that it does not correlate with the sediment analyses or the
bioassay to define areas or sites of high pollutant concentrations. The con-
centration of metals in the interstitial water, unlike that in the sediment,
does not generally decrease toward the Outer Harbor and the Bay.
-20-
-------
TABLE 4-3
AVERAGES* OF INTERSTITIAL WATER-METAL
CONCENTRATIONS IN Ug/1
Site
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
As
34*
<50
71
91_
<25
<100
<100
152
56
59
<50
<100
<50
<50
<50
<100
50*
200*
78
67
Hg
2
5
2
<1
<1
9
6.
<1
1*
<1
3
<2
3
3
3
11
2
2
3
2
Cd
<2
<25
<25
<2
<2
=H*
=41
<2
12
<2
<25
2
<25
<25
<25
IL*
<25
<25
25*
25.
Cr
186
94
44
21
256
i.
<38
38*
36
59
45
<100
60
<38
<38
38*
<38
<38
<38
38*
<38
Cu
16*
50*
<50
12*
10*
750*
50
7*
<17
7
84*
27
<50
<50
<50
<50
<50
<50
<50
<50
Mn
1,755
1,700
2,700
1, 120
310*
6.650
2,340
1,275
220
1,835
3.000
2, 115
855
385
420
1,030
1,015
325
565
900
Ni
<5
<75
100*
5*
<5
100*
<75
<5
915
<5
1,500
70
<75
<75
175*
150*
75*
88
<75
<75
Pb
88
570*
<290
41
157
2,550
360*
4. 535
<170
193
<500
1,650
<290
1, 100*
360*
580
1,470
<290
290*
290*
Zn
1,055
1,800
'"
370
165
87
3,850
1,000
210
115
580
260
435
305
865
255
1. 150
550
180
180
165
* Single sample, not an average.
All others below detection limits.
+ All figures represent the average of
the concentrations for all samples per site.
-21-
Highest concentration
Second highest concentration
Third highest concentration
-------
4. 2. 1. 3 Horizontal Distribution - Elutriate Test
The elutriate test (Lee and Plumb, 1974), developed by the Army Corps
of Engineers, is used to indicate probable metal release as a result of
dredging and disposal operations. This test attempts to determine the
amount of toxic metals released into the water column from --or removed
from the water column by -- the sediment. Metals are presumed to have
been released from the sediment when their concentrations are higher in
the elutriate than in the reference water; conversely, they are presumed
to have been removed by the sediment when their concentrations are
higher in the original reference water than in the elutriate. The Army
Corps of Engineers suggests that concentration of each dissolved metal
not exceed 1, 5 times its original concentration in the filtered water column
(Bricker, 1975).
Table 4-4 shows that the horizontal distribution of heavy metals is hetero-
geneous with little or no correlation to the metal concentrations found in
the sediment and interstitial water analyses, or by the bioassay. Addi-
tional discussion on this relationship is contained in Section 5. 0, "Effects
of In-Place Pollutants. "
4.2. 1.4 Horizontal Distribution - Bioassay
The bioassay was conducted with sediments from eight sampling sites out
of a total of nine. (Site 9 was not completed for all bioassay work due to
an extreme change in pH of the sediment. See Appendix E for further dis-
cussion. ) The bioassay and previous work with the community structure
and diversity of benthic macro-invertebrates show a definite division of
the horizontal distribution of toxic zones or sites. Generally, the same
sampling sites that have high concentrations of heavy metals, PCB's, and
hexane extract, as shown in Tables 4-1 and 4-2, are also the sites within
the zones of high toxicity determined by the bioassay.
Site 5 in Bear Creek was the most toxic for both the finfish and the clam
species of the bioassay. Site 4 in Colgate Creek was the second most
toxic for finfish and Site 10, in Middle Branch, the third most toxic.
Site 2 in the Northwest Branch was the second most toxic for the clam
and Site 1, also in the Northwest Branch, the fourth most toxic. There is
a general decrease in toxicity toward the mouth of the Harbor, next to
the Bay.
-22-
-------
TABLE 4-4
AVERAGES"*" OF ELUTRIATE
TEST-METAL CONCENTRATIONS IN yg/1
Site
1
2
3
4
5
6
71
8
9
10
II2
12
13
14
15
16
17
18
19
20
As
<25
44**
41**
26
<25
32*
33**
<25
50*
44*
tt
<25
30*
32*
<25
<25
<25
25*
<25
25*
Hg
<1
<1
<1
<1
<1
1*
1*
<1
JL
-------
4.2.2 Vertical Distribution
4.2.2. 1 Vertical Distribution-Sediment Analysis
It would be difficult to graphically display pollutant concentrations from
twenty sites, each containing a core sample divided into eight levels and
analyzed for nine heavy metals and hexane extract at each of the eight
depths. Thus, the eight samples per site were averaged into three layers:
the top layer consisting of the three samples from 0. 16, 0. 5, and 1. 0
feet; middle layer of 2. 0, 3. 5, and 5. 0 feet; and the bottom layer of 7. 0
and 10. 0 feet ( see Table 4-5). This reduces the vertical distribution to
three columns of figures instead of eight and also nearly represents the
homogeneous concentrations of the top, middle, and bottom layers that
would be of interest if removal by dredging were contemplated for depths
of 1.0, 5. 0, or 10 feet.
Table 4-5 shows a general major decrease in most metals, hydrocarbons,
and moisture content at the sub-surface depth of about 5 ft. t 2 ft.
[5 ft. t 2 ft. (corrected core depths utilizing Piggot's (1941) correction
factors, due to compaction, would change core depths by approximately
+0. 30 - 0. 9 ft. from 1 to 10 ft; 5 1 2 ft. would then read 5. 5 t 2 ft.)]
There are some exceptions where the bottom layer contains concentrations
higher than found in the upper two layers, e. g., Site 3 in the Northwest
Branch for Hg and Pb; Site 4, 5, and 8 for Mn; Site 9 in Curtis Bay for As,
Hg, Cu, and Pb; Site 10 in Middle Branch for As and Mn; and Sites 15, 16,
and 18 for Mn. The vertical distribution of concentrations shows the same
general trend as horizontal distribution --a decreasing concentration of
heavy metals except for Mn toward the mouth of the Harbor.
4. 2. 2. 2 Vertical Distribution - Interstitial Water Metal Levels
Because the sampling for interstitial water was taken from depths of only
5-10 cm and 40-45 cm, vertical distribution is limited to interpretation for
variations or consistencies within a narrow range. The individual sample
results are contained in the tables of Appendix C for the twenty sampling
sites. These data indicate that maximum concentrations are very often
found at the lowest core interval, probably indicating a gradient increasing
with depth. The sites with the highest levels are on the western side of
the Harbor. Pb and Cu are highest near the Bay mouth; Ni, Cd, and As
-24-
-------
TABLE 4-5
AVERAGE CONCENTRATIONS OF
SEDIMENT ANALYSES FOR CORE SAMPLES
Trident
No.
Site 1
Top layer
Site 1
Middle layer
* Site 1
Bottom layer
Site 2
Top layer
Site 2
Middle layer
* Site 2
Bottom layer
Site 3
Top layer
Site 3
Middle layer
Site 3
Bottom laver
Sample
Type
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
Moisture
63.07
51.35
43.70
71.71
61.05
60.92
58.28
63.81
58. 22
Total
Hydro-
Carbons
Hexane
Extract
nig /kg
13,800
8,067
750
43,333
35,233
320
29,966
19,600
28,200
Mean Values of Top, Middle, and Bottom
Core Sample Chemical Analysis
Metals mg/kg
As
71
59
5
115
100
10
109
146
118
Hg
4.37
5.01
0.23
4. 16
3.91
0. 11
1.40
2.75
3.67
Cd
8
5
1**
20
12
1**
6
9
8
Cr
2,177
1,037
130
3,400
2,023
120
923
1,467
720
Cu
757
497
23
2,300
1,373
31
2, 133
1,500
1,350
Mn
320
343
220
497
207
290
320
343
335
Ni
67
56
39
147
79
37
121
70
71
Pb
172
98
26
1,143
1,243
13
653
910
1,260
Zn
1,240
657
56
1,800
1,043
71
780
1,228
755
co
w
i
Core Depths
Top layer - 0. 16, 0. 5, 1. 0 feet
Middle layer - 2.0, 3.0, 5. 0 feet
Bottom layer - 7. 0, 10. 0 feet
* Single sample
** Average figure contains one or more sample
analyses where detection limit has been used
as the concentration.
Continued . . .
-------
TABLE 4-5 (Continued)
Trident
No.
Site 4
Top layer
Site 4
Middle layer
* Site 4
Bottom layer
Site 5
Top layer
Sitp 5
Middle layer
* Site 5
Bottom layer
Site 6
Top layer
cif-f, A
Middle layer
* life* A
Bottom layer
Sample
Type
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
Moisture
%
70.60
65. 01
46.34
78.08
60.25
56.91
57.42
58.25
49.49
Total
Hydro-
Carbons
Hexane
Extract
mg/kg
16,267
16,900
2,500
33,066
3,410
400
2,913
260**
345
Mean Values of Top, Middle, and Bottom
Core Sample Chemical Analysis
Metals mg/kg
As
111
419
30
111
40
21
27
9
10
Hg
1. 11
2. 74
0.28
0.56
0. 18*=
0. 02**
0.47
0.06
0. 07
Cd
84
229
20
29
3**
I **
2
1**
1**
Cr
813
910
140
2,467
217
95
130
54
43
Cu
580
640
61
403
78
12
104
14
14
Mn
333
383
540
380
600
1, 100
840
1, 003
875
Ni
64
62
32
82
48
37
70
21
30
Pb
620
963
460
1, 107
238
19
251
14
13**
Zn
1,510
283
380
4,333
716
86
847
84
87
Core Depths
Top layer - 0. 16, 0. 5, 1. 0 feet
Middle layer - 2.0, 3.0, 5.0 feet
Bottom layer - 7. 0, 10. 0 feet
* Single sample
** Average figure contains one or more sample
analyses where detection limit has been used
as the concentration.
Continued . . .
-------
TABLE 4-5 (Continued)
Trident
No.
Site 7
Top layer
Site 7
Middle layer
Site 8
Top layer
Site 8
Middle layer
* Site 8
Bottom layer
Site 9
Top layer
Site 9
Middle layer
* Site 9
Bottom layer
Sample
Type
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
Moisture
%
61.85
42. 58
67.99
65.30
54.23
77.49
69.27
65. 19
Total
Hydro-
Carbons
Hexane
Extract
mg/kg
1,800
160**
11,600
6,167
1,950
5,467
12,500
10,550
Mean Values of Top, Middle, and Bottom
Core Sample Chemical Analysis
Metals mg/kg
As
40
11
121
158
20
68
110
566
Hg
0.34
0.04
0.71
1.37
0.25
0.73
2.54
6.64
Cd
2
1**
4
2
1
3
3
2
Cr
313
52
653
207
39
357
333
336
Cu
108
13
200
242
51
283
270
321
Mn
900
720
680
647
1,520
1,573
323
405
Ni
74
24
55
55
35
80
44
52
Pb
215
1 1 **
330
81
32**
192**
393
815**
Zn
787
68
1. 147
760
120
697
453
486
CorejDepths
Top layer - 0. 16, 0. 5, 1.0 feet
Middle layer - 2. 0, 3. 0, 5. 0 feet
Bottom layer - 7. 0, 10. 0 feet
* Single sample
** Average figure contains one or more sample
analyses where detection limit has been used
as the concentration.
Continued . . .
-------
TABLE 4-5 (Continued)
Trident
No.
Site 10
Top laver
Site 10
Middle layer
* Site 10
Bottom layer
Site 11
TOD layer
Site 12
Top layer
Site 12
Middle layer
Site 12
Bottom layer
Sample
Type
sediment
sediment
sediment
sediment
sediment
sediment
sediment
Moisture
%
56.83
50.83
46.36
49.53
58. 13
58.72
59.01
Total
Hydro-
Carbons
Hexane
Extract
mg/kg
5,600
4,000
3, 100
253**
750**
290**
50**
Mean Values of Top, Middle, and Bottom
Core Sample Chemical Analysis
Metals mg/kg
As
42
50
93
9
18
17
12
Hg
0.57
0. 75
0.66
0. 04
0. 16
0. 13*
0. 05*
Cd
4
3
1
2
1
1
1
Cr
467
227
200
23
44
29
12
Cu
207
220
160
14
40
25
9
Mn
317
287
370
910
1,610
1,230
1,330
Ni
73
51
48
42
44
44
32
Pb
173
139
130
17**
19**
12**
10**
Zn
583
337
220
91
333
170
88
CD
Core Depths
Top layer - 0. 16, 0. 5, 1.0 feet
Middle layer - 2. 0, 3.0, 5. 0 feet
Bottom layer - 7. 0, 10. 0 feet
* Single sample
** Average figure contains one or more sample
analyses where detection limit has been used
as the concentration.
Continued . . .
-------
TABLE 4-5 (Continued)
Trident
No.
Site 13
Top layer
Site 13
Middle layer
Site 13
Bottom layei
Site 14
Top layer
Site 14
Middle layer
Site 14
Bottom layer
Site 15
Top layer
Site 15
Middle layer
Site 15
Bottom laye
Sample
Type
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
Moisture
%
59.09
43.57
40.80
58.69
58.96
54.35
63.81
53.54
53.88
Total
Hydro-
Carbons
Hexane
Extract
mg/kg
713
127**
100**
2,767
3,467**
230
21,333
3,617
440
Mean Values of Top, Middle and Bottom
Core Sample Chemical Analysis
Metals mg/kg
As
35
7
4
27
40
11
63
23
7
Hg
2. 32
0.05
0. 04
0.65
0.57
0. 33
1.27
0.46
0.23
Cd
9
1**
1#*
2
3
1**
13
4
1
Cr
333
44
34
190
203
48
1,400
330
58
Cu
200
12
10
99
125
16
447
104
8
Mn
1,166
193
175
1,340
950
1,250
610
203
860
Ni
54
17
16
53
52
32
66
36
33
Pb
1,197
12**
10**
97
237
20
553
123
22
Zn
4,267
58
48
467
833
97
2, 300
483
99
to
Core Depths
Top layer - 0. 16, 0. 5, 1,0 feet
Middle layer - 2.0, 3.0, 5.0 feet
Bottom layer - 7. 0, 10. 0 feet
* Single sample
** Average figure contains one or more sample
analyses where detection limit has been used
as the concentration.
Continued . . .
-------
TABLE 4-5 (Continued)
Trident
No.
Site 16
Top layer
Site 16
Middle layer
Site 16
Bottom layer
Site 17
Top layer
Site 17
Middle layer
Site 17
Bottom layer
Site 18
Top layer
Site 18
Middle layer
Site 18
Bottom layer
Sample
Type
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
sediment
Moisture
%
61.47
60.58
58. 19
59.32
61.04
54.55
65.97
60.21
54.51
Total
Hydro-
Carbons
Hexane
Extract
mg/kg
3,900
2,033**
100**
4,800
7,800
100**
1,323
3,430
1,000
Mean Values of Top, Middle, and Bottom
Core Sample Chemical Analysis
Metals mg/kg
As
38
46
8
39
81
13
109
79
8
Hg
0.51
0.64
0.30
0.52
0.75
0.07
i
1.08
1.02
0.09
Cd
2
2
2
2
4**
1**
5
2**
1**
Cr
275
209
51
353
420
37
707
266
70
Cu
143
152
17
157
172
21
430
221
26
Mn
1,423
1,297
1,550
1,073
717
960
493
980
2,550
Ni
60
59
37
54
48
43
60
53
48
Pb
170
307
10**
187
277
28
323
236
29
Zn
657
647
93
540
790
100
1,567
514
96
OJ
o
I
Core Depths
Top layer - 0. 16, 0. 5, 1.0 feet
Middle layer - 2.0, 3.0, 5.0 feet
Bottom layer - 7. 0, 10. 0 feet
* Single sample
** Average figure contains one or more sample
analyses where detection limit has been used
as the concentration.
Continued . . .
-------
TABLE 4-5 (Continued)
Trident
No.
Site 19
Top layer
Site 19
Middle layer
* Site 19
Bottom layei
Site 20
Top layer
Site 20
Middle layer
Site 20
Bottom laye
Sample
Type
sediment
sediment
sediment
sediment
sediment
sediment
Moisture
%
59.87
58. 14
53.32
63.59
55.86
53.46
Total
Hydro-
Carbons
Hexane
Extract
mg/kg
6,600
4,473
3,300
10,667
13,300
7,850
Mean Values of Top, Middle, and Bottom
Core Sample Chemical Analysis
Metals mg/kg
As
70
58
14
59
96
48
Hg
0.83
0.80
0.58
1.20
2.10
1. 13
Cd
4
4
1
4
3
2**
Cr
393
310
160
503
400
182
Cu
350
239
96
380
440
403
Mn
817
840
730
430
417
405
Ni
72
77
45
70
68
55
Pb
233
176
'84
243
393
179
Zn
937
877
170
627
693
115
I
OJ
Core Depths
Top layer - 0. 16, 0. 5, 1. 0 feet
Middle layer - 2. 0, 3.0, 5. 0 feet
Bottom layer - 7. 0, 10. 0 feet
* Single sample
** Average figure contains one or more sample
analyses where detection limit has been used
as the concentration.
-------
are highest in the center; Cr is high at the head and mouth of the Harbor;
and Mn, Zn, and Hg seem to be dispersed throughout the area.
There is little to no correlation in the samples between concentrations of
the interstitial metal levels and those found in the sediment analysis and
the elutriate test. In general, unlike the sediment analysis and elutriate
test, the interstitial water analysis indicates no reduction of concentrations
for the sites in the mouth of the Harbor. The relationship between inter-
stitial water and the elutriate test is further discussed in Section 5.0,
"Effects of In-Place Pollutants."
4. 2. 2. 3 Vertical Distribution - Elutriate Test
As noted above, the Corps of Engineers' elutriate test standard for con-
sideration of dredging/disposal is that the concentration of a dissolved
metal not exceed 1. 5 times its original concentration in the filtered water.
At all depths of every site sampled, the entire Harbor exceeds this standard
for one or more of the heavy metals. Table 4-6 indicates that every heavy
metal analyzed (except Pb that was below detection limits) exceeds 1. 5 x
filtered water in the bottom layer of 7 to 10 feet almost as often as in the top
or middle layers. The individual sample concentrations contained in
Appendix C show that several of the metals, particularly Mn, increase in
concentration with depth of sample.
At no depth of any site sampled is there any correlation in concentrations
of heavy metals between those measured by the elutriate test and those
found in the bulk sediment analysis. Review of the individual elutriate
sample analyses in Appendix C shows that the elutriate exceeds the ref-
erence water by as much as 5 and 6 times, e. g. , Zn exceeds the filtered
water by 5. 53 times at Site 13-4 and by 6. 66 times at Site 13-3. As seen
in Table 4-7, the filtered water concentrations vary only slightly from one
site to another. The wide variations of the elutriate could thus not be attrib-
uted to variations of the background water. Based on the standard of
1. 5 x the filtered water, the results of the elutriate test indicate that the
entire 10 feet of sediment sample for every site would be classified as
polluted.
-32-
-------
TABLE 4-6
ELUTRIATE TEST ANALYSES
FOR SAMPLING SITES
1,5 to 3.5 - Range where the elutriate test
exceeded 1.5 times the filtered
water to 3.5 times or more.
Core Depths
T - Top Layer - 0.16, 0.50, 1.0 feet
M - Middle Layer - 2.0, 3.0, 5.0 feet
B - Bottom Layer - 7.0, 10.0 feet
-33-
* Entire site contained samples
below detection limits of atomic
absorption analyses.
+ Individual samples within a site
that contained samples below detec-
tion limits of flameless atomic
absorption analyses.
-------
TABLE 4-7
METAL, CONCENTRATIONS OF
FILTERED WATER* IN yg/1
Site
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
As
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
Hg
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Cd
8
8
10
8
7
7
9
9
9
9
6
7
6
8
8
8
8
9
10
12
Cr
19
17
<5
<5
<5
<5
<5
<5
17
<5
38
<5
<5
<5
<5
<5
<5
<5
<5
<5
Cu
14
13
17
14
12
14
15
12
11
14
19
12
12
15
15
18
16
17
17
14
Mn
380
320
450
410
420
270
410
450
390
360
330
300
90
380
380
450
410
420
540
450
Ni
43
36
50
36
47
43
36
36
85
36
94
29
32
36
36
43
36
39
50
50
Pb
<50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Zn
20
19
24
39
73
78
32
31
31
24
84
32
15
22
48
23
26
24
30
68
* All figures represent a single sample.
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4. 3 ESTIMATED QUANTITIES
There are three known sources of data that estimate or list quantities of
pollutants discharged into Baltimore Harbor: Helz (1976) surveyed data
and estimated quantities of heavy metals that flow into and out of the Harbor;
Quirk, Lawler, and Matusky (1973) estimated total tonnages of pollutants
being discharged to the Harbor; The National Pollutant Discharge Elim-
ination System (NPDES) permits maintained by the State of Maryland
authorize quantities of material for community and industrial discharges.
- 3. 1 Helz (1976)
Helz tabulated the metric tons/year of heavy metals entering the
northern Chesapeake Bay and the Patapsco Estuary (Baltimore Harbor)
(See Table 4-8). He states, "For each metal, the percentage of the
total input ascribable to human activities is presented in the bottom line
of Table 2 [our Table 4-8]. The figures are for the entire northern
Bay system, including the Patapsco. Only industrial discharge, waste-
water, storm drainage and the high inputs to the Patapsco from rain and
dust have been considered as due to human activities; one exception is
Pb for which the rain and dust input to the main stem was also included
because most of this is believed to derive from gasoline combustion. "
An important result of this data inventory was that relatively small
percentages of some metals entering Baltimore Harbor remain in Bal-
timore Harbor. Of the totals entering the Harbor, only the following
percentages remain: 76% of Cr, 30% of Mn, 32% of Fe, 10% of Ni, 24%
of Cu, 30% of Zn, 21% of Cd, and 35% of Pb (See Table 4-9.) (Helz,
1976).
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TABLE 4-8
SOURCES OF HEAVY METALS
ENTERING BALTIMORE HARBOR
IN METRIC TONS PER YEAR
(From Helz 1976 Survey)
Northern Chesapeake Bay
Excluding the Patapsco
Estuary
Rivers
Salt Water Advection
Shore Erosion
Municipal Wastewater
Rain
Atmospheric Fallout
Subtotal
Patapsco Estuary
(Baltimore Harbor)
Rivers and Storm
Drainage
Excess Sediment
Municipal Wastewater
Rain
Atmospheric Fallout
Direct Industrial
Discharge
Subtotal
Total
Minimum Percent
Anthropogenic
Cr Mn Fe
70 7000 70000
3 20 70
23 70 27000
20 10 100
20 20
—
116 7120 97190
0.5 50 500
4 13 4200
40 20 200
— 27
—
100 440 20000
145 525 24007
261 7645 122097
63 6 20
Co Ni Cu Zn Cd Pb
150 300 150 1000 3 100
30 100 50 130 5 4
4 9 8 36 0.7 10
0.5 5 30 40 2 10
10 90 200 — - 100
200
184.5 424 328 1406 10.7 424
1 6 10 70 0.02 50
0.7 1 2 4 0.07 0.9
1 10 60 80 5 20
2 6 30 — 20
50
58 240 470 1.6 76
2.7 77 318 654 6.7 217
187 501 646 2060 17.4 641
1 15 51 29 50 74
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TABLE 4-9
PERCENT RETENTION OF TRACE ELEMENTS
IN ESTUARINE OR COASTAL SEDIMENTS
(From Helz 1976 Survey)
Pa taps co Estuary
Chesapeake Bay System
Southeastern U. S. Estuaries-*
World2
Windoat (in press)
2Horn and Adams (1966)
Cr Mn Fe Ni Cu Zn Cd Pb
76 30 32 10 24 30 21 35
68 26 89 16 20 26 22 23
66
64 >100
22
17
29 8 13 44 24
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4.3.2 Quirk, Lawler and Matusky (1973)
A second source of data, Quirk, Lawler and Matusky, lists the following
substances as being discharged into the Harbor from all sources.
Substance Tons/Day (Short Tons)
Iron 55.5
Sulfates 13.5
Antimony 4. 1
Chlorides 3.0
Tin 3.0
Phenols 2.5
Zinc 1.7
Sulfides 0.89
Arsenic 0.82
Chromium 0.78
Copper 0.75
Total 86. 4 tons/day
4. 3. 3 National Pollutant Discharge Elimination System Permits
An effort was made during the study to determine the pollutant loads that
presently are being discharged into the Harbor. The Maryland State
Department of Natural Resources and the EPA regional office in Phila-
delphia both maintain the same NPDES permit file that lists the individual
authorized loadings for both commercial and industrial dischargers and
the periodic chemical analyses performed by the industrial dischargers.
Unfortunately, the manner in which both the authorized loadings and the
periodic chemical analyses files are maintained in the computer system
does not include a program that can be called to summarize or total all
factors, or even one column of figures. The file is maintained on a state-
wide basis, and to find the discharge authorizations for Baltimore Harbor
alone, one would have to manually sort through a computer listing of 423
industries by name under the counties whose watersheds flow into the
Harbor and obtain the permit number of those industries.
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Once the permit numbers were obtained for those industries located in the
Baltimore Harbor watershed, one would have to go to another computer
listing that maintains the authorized discharge parameters numerically.
To obtain valid data, the permit would also have to be screened to determine
whether it was an initial or final authorization. The discharge permitted
under a final authorization could be quite different from the initial author-
ization. Both classifications are printed out on the same computer listing.
In another report format, the actual chemical analyses of the discharges,
as recorded by the industry, are reported on an individual basis.
Determination of the loadings authorized by NPDES permit or of the actual
loading being discharged into Baltimore Harbor from community and indus-
trial sources was not a task of this project. Since an excessive amount of
time would be required to obtain total loadings, and the information, once
summarized, would be of questionable value inasmuch as total metal
loadings only are reported and these are broken down to individual heavy
metals for only a very few industries, further effort in this direction was
discontinued.
From the NPDES computer listings, a few of the larger commercial and
industrial permit authorizations were totaled to show, as a sample, part
of the loadings being, or authorized to be, discharged into Baltimore
Harbor. These partial summaries for the month of January 1977 are as
follows:
Domestic -- Total suspended solids of 276, 816 Ibs/day as a
weekly average from 47 major sources out of 690 total.
Industrial - Total suspended solids of 879, 372 Ibs/day maximum
from 65 industries out of a total of 184.
Total metals of 238, 378 Ibs/day maximum from 9
major industries out of a total of 184.
Although these discharges permitted in 1977 may be considered to be
typical at present, the EPA objective is "zero discharge" by 1985.
Achievement of the goals of P. L. 92-500 -- "Wherever obtainable. ..
water quality by 1983 will be improved enough to allow for the propagation
of fish and for recreation in and on the nation's water... and... by 1985
elimination of all discharges of pollution into navigable waters" -- will
eventually eliminate most or all of the pollutants presently being discharged
into the Harbor.
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5.0 THE EFFECTS OF IN-PLACE POLLUTANTS
The in-place pollutants were evaluated with respect to their effect on the
benthos, the pelagic, and planktonic biota of the water column within the
Harbor and the biota further afield in the Chesapeake Bay. This division
is necessary as it has been found from this study and others that the in- ,
place pollutants in Baltimore Harbor affect these three biological structures
in different degrees of intensity and in different manners.
Within this study, the effects upon the benthic and pelagic biota within the
Harbor were evaluated from the findings of former studies of the community
structure and diversity of benthic macro-invertebrates and from this study's
bioassay on finfish and clam species. The bioassay was conducted with
sediments from the sampling sites where chemical analyses were con-
ducted for nine heavy metals, hexane extract, PCB's, interstitial water,
and the elutriate test. The sections which follow describe the effects of
the pollutants on the biota within the limits of the analytical techniques
employed and for the toxic elements analyzed.
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5. 1 SEDIMENT AND INTERSTITIAL CHEMISTRY
The commonly used procedure that approximates the sediment-releasable
metal level is the elutriate test. The elutriate test results indicate that
the sediment has a significant effect on the overlying water column when
the sediment is mixed with the water. Every site tested by the elutriate
procedure released metals to the water at all core depths in excess of the
Corps of Engineers' suggested limit, i.e., 1. 5 times the ambient concen-
tration.
The release of metals appears to be very complex and is not explainable
by a simple relationship between high sediment-metal concentrations and
high elutriate-metal concentrations. Many samples of high metal-pollutant
concentrations in the sediment released less metals than those sediment
samples of a lower metal content. The pollutant may be partitioned between
various mineral components, the interstitial water, and the organic portions
in such a way that the effect on the water column by sediment disruption
cannot be predicted from bulk chemistry or even from the elutriate test.
Within the limits of this study, one conclusion seems warranted: release
of metals contained in the sediment will occur on mixing with the over-
lying water. Neither the residence time of these metals in the water column
nor the per cent of removal from the sediment is known. The release of
metals may well be a continuous process. As measured by the elutriate
test, the release of metals is approximately 2-4 orders of magnitude less
than the metal concentration of the sediment levels. This suggests that
a sufficient source of metals in the sediment moves to the water over long
periods of time (with physical mixing) and returns to the sediment in a new,
less-soluble form. This new form of metal pollutant may again be solu-
bilized in the interstitial water or in the sediment at some later date.
Interstitial water-metal concentration analyses often indicate that the con-
centrations of the metals in the interstitial water are higher than those in
the elutriate solutions from which they get their metals. The high levels
are much higher than can be accounted for by dilution during the elutriate
test (4:1 dilution ratio). Many of these metals are thought to be released
from the sediment during the elutriate procedure; the high interstitial (or
low elutriate) values may be indicative of oxidation and precipitation during
the elutriate analysis, with subsequent loss of dissolved metals for analyses.
This interpretation would indicate that the elutriate test, for anoxic sediments,
would tent to underestimate the concentrations of those elements that tend
to be scavenged or precipitated with hydrous Fe and Mn oxides.
-41-
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The determination of the effects of in-place pollutants on the biota based
on interpretation of sediment and interstitial chemistry is complex and
equivocal when one analytical technique is employed as a standard or
criteria for quantifications and qualifications of biota toxicity. As reviewed
in the preceding sections, the results of the sediment analyses and the
elutriate test indicate that, based on the standards established for each
analytical technique, the sediments in Baltimore Harbor are polluted.
Quantification of toxicity is difficult to establish when evaluated by an
analytical technique that may not be measuring the pollutant available
to the organism. In addition, unknown factors such as time relationships
of exposure, temperature, pH, salinity, etc. may change or alter the
availability of toxic substances to biota in a field condition. While these
factors may be measured and controlled in a laboratory experiment, it
is extremely difficult to duplicate the conditions to be found in the field.
The effects of the in-place pollutants on the benthic and pelagic biota are
discussed in the following sections separately.
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5.2 BENTHOS
Based on the results of former studies of the community structure and
diversity of benthic macro-invertebrates and on the results of the bioassay
from this study, it is concluded that toxicity may be correlated to a signif-
icant degree with the high levels of pollutants contained in the sediments of
Baltimore Harbor. The present benthic community structure and diversity
reflect the toxicity of in-place pollutants in the sediments. Using gross
toxicity as the principal criterion, the sediments in Baltimore Harbor were
divided into four toxic zones: highly toxic, moderately toxic, low toxic,
and slightly toxic (see Figure 5-1). The criteria and detailed division of
these four toxic zones and their relationship to the benthic macro-inverte-
brates in the Harbor are contained in Appendix E.
Highly Toxic Zone
The highly toxic zone includes the middle section of the Northwest Branch,
Site 2} Colgate Creek, Site 4; Bear Creek, Site 5; Curtis Bay, Site 9*. and
a part of Inner Harbor (no sample site at this location). In this zone Site 5
was the most toxic, and Sites 2 and 4 were the next most toxic for both fin-
fish and the clam species of the bioassay. (See Figure 2-2 for the location
of sampling sites.) In this zone the surface layer of sediments contained
high concentrations of PCB (0. 64 - 5. 60 mg/kg) and hexane extracts (oil and
grease) (15, 500 - 48, 500 mg/kg, except for Curtis Bay where the hexane
extracts were 4, 200 mg/kg). The bulk concentrations of heavy metals in
the sediments were also high, as can be seen in Table 4-1. In this zone
the species diversity indexes of benthic organisms were less than 0. 69.
Only pollution-tolerant Annelida, such as LimnodTilus sp., Heteromastus
filiformis, Scolecolepides viridis, and Streblospio benedicti were common
in this zone. Insecta and Arthropoda were absent or nearly absent.
Moderately Toxic Zon.e
The moderately toxic zone includes most of Inner Harbor, Site 10; the
upper and lower reaches of Northwest Branch, Sites 1 and 3; and the
Patapsco River portion of the Harbor, Sites 16, 17, and 20. In this zone
the surface layer PCB and hexane extracts were moderately high,
<0. 05 - 2. 27 mg/kg1 for the former and from 3, 900 to 58, 400 mg/kg for
the latter.
iThe PCB concentration for Site 1 is not included in this rage of concen-
trations as the sensitivity of detection limit was exceeded by a background
masking. Therefore, the quantity indicated is probably incorrect.
-43-
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TOXBC ZONE
"INUCR
SaW*
gJg^S? ..
"C-v>; .•:•;- .;. • tA
' >*•.
wixii
:;:*;:;'
•:«•:•:/•
Figure 5-1 Distribution of toxic zones and mummichog 24-hour TLm values for
suspended solids in Baltimore Harbor (numbers in squares, real values
obtained from the bioassay; numbers not in square obtained from con-
version of species diversity inde||s of benthic invertebrates).
-------
Site 1 was the third most toxic for the clam, and Site 10 was the fifth
most toxic for clam and the fourth most toxic for finfish. In this zone
the species diversity indexes of the benthic macro-invertebrates were
between 0. 70 - 1. 09. The community structure was still dominated by
pollution-tolerant Annelida, but a few species of Arthropoda, Insecta,
and Mollusca were occasionally present. In addition to those species
of Annelida commonly found in the highly toxic zone, one species of Mol-
lusca, Macoma balthica, was fairly abundant in this zone.
Low Toxic Zone
The low toxic zone is located in the middle portion of the Harbor, Sites 6,
8, 14, 15, 16, and 19. In this zone, the concentrations of in-place pol-
lutants ranged from 0. 11 - 2. 32 mg/kg for surface PCB's and from'2400
to 21,000 mg/ g for surface hexane extracts. The heavy metal concen-
trations were generally low except for Mn at Site 16, which was the highest
average for all samples. In this zone, Annelida were still a dominant
group of the benthic macro-invertebrates, but some species of Insecta,
Mollusca, Arthropoda, Coelenterata, and Nemertea were also commonly
present. They were represented by Macoma balthica of Mollusca,
Rithropanopeus harrisi of Arthropoda, and Micrura leidyi of Nemertea.
Slightly Toxic Zone
The slightly toxic zone includes Outer Harbor, Stony Creek, and Old Road
Bay, Sites 7, 11, and 12. In this zone the surface concentrations for PCB's
and hexane extracts were lowest in the Harbor, less than 0. 05 - 0. 07 mg/kg
for the former and 400 - 2, 900 mg/kg for the latter. The average heavy
metal concentrations were relatively low, except for Mn at Site 12 where
it was the second highest for all sites. The species diversity indexes of
the benthic macro-invertebrates were higher than 1. 50. Mollusca, Arthro-
poda and others were as common or as abundant as those pollution-tolerant
species of Annelida. . In this zone Macoma balthica, Macoma phenax and
Rangia cuneata of Mollusca; Leptochierus plumulosus, Cymadusa compta,
Corophium lacustre, and Cyathura polita of Arthropoda; and Micrurus leidyi
of Nemertea are either as common or as abundant as those pollution-tolerant
species of Annelida found in the highly and moderately toxic zones.
-45-
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The bottom-dwelling and bottom-feeding species of fish which depend on
benthic macro-invertebrates as their foods are virtually absent from the
entire Harbor. These include winter flounder, Atlantic croaker, and
hogchoker which are normally very common in Chesapeake Bay estuaries.
These species of fish are affected strongly by in-place pollutants directly
and/or indirectly.
In-place pollutants in sediments occur primarily in two forms, particle-
associated and dissolved. Their concentrations vary vertically and hori-
zontally in Baltimore Harbor as outlined in Section 4. 0. The in-place
pollutants in the deep layer of the sediments, which are anaerobic and
abiotic, do not seem to directly affect the water quality and biotic life in
the Harbor. However, this layer becomes a reservoir for the pollutant
which, if sufficiently disturbed, may become available to the biota. The
greatest concern in terms of the ecosystem of the Harbor is with the in-place
pollutants in the present upper layer of sediments where the benthic organ-
isms live and where these pollutants may be released into the water column.
5.2. 1 Interstitial Water Metal Concentrations
Pollutants dissolved in the interstitial water are mobile and chemically
active, and it was assumed that the pollutants in this form had a more sig-
nificant effect on aquatic life than the particle-related forms that are fairly
stable. Benthic organisms that live in and on the sediments are in contin-
uous contact with the interstitial water, and they are the organisms to be
directly affected by this dissolved form of in-place pollutants in the sediments.
On the basis of this consideration, the toxicity level of interstitial water in
the Harbor was assessed in accordance with the hazard levels of heavy
metals in water for marine organisms suggested by EPA (1973): 0. 1 mg/1
for Cr, Mn, Ni, and Zn; 0. 05 mg/1 for As, Cu, and Pb; 0, 01 mg/1 for Cd;
and 0.0001 mg/1 for Hg. The concentrations at or exceeding the hazard
limits are: As at Site 9; Hg at Sites 1, 2, 6, and 7; Cd at Site 9; Cr at
Sites 2, 4, and 5; Cu at Sites 2 and 7; Ni at Sites 6 and 9; and Mn, Pb, and
Zn at all sites studied. On the basis of these standards set for hazard
levels, the interstitial water in the Harbor sediments-at all bioassay sites
is hazardous to aquatic life.
-46-
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Species diversity indexes for benthic macro-invertebrates significantly
correlate with the gross toxicity of sediments as determined from the
24-hour TLm value of the Mummichog in the bioassay. (See Appendix E
for specific correlation and determinations. ) However, the high concen-
trations of Pb, Cr, Zn, and Mn in interstitial waters from the same sites
showed no correlation with the results of the bioassay. Therefore, these
heavy metals dissolved in interstitial waters, assumed to be an important
factor in biota toxicity, apparently are not the decisive factors determining
direct toxicity or, probably, species diversity.
5.2.2 Sediment-Metal Concentration
The bulk concentrations of heavy metals in the Harbor sediments mentioned
previously in the toxic zones are much higher than those present in the
interstitial water. The average bulk concentrations of. heavy metals in the
surface layer at the nine bioassay sampling sites are more than those in
the interstitial water by the following: 27,481 times for Cu, 4,481 times
for Cr, 2, 100 times for Zn, 871 times for Pb, 631 times for Ni, and 503
times for Mn. Almost all of the heavy metals in the Harbor sediments are
in the particle-related form. Benthic macro-invertebrates live in and on
the sediments and may take in these particle-related heavy metals through
ingestion or sorptive mechanisms.
Correlation analyses between the gross toxicity of the Harbor sediments
and the bulk concentrations of heavy metals in the sediments show that the
correlation coefficients are -0.42 for Pb, -0. 39 for Cr, -0.21 for Zn,
-0.51 for Cd, -0.41 for Hg, -0. 18 for Ni, -0.43 for Cu, -0.22 for As, and
0. 46 for Mn. All are at insignificant levels, but higher than those for the
interstitial water. The heavy metals associated with particles are much
more important in causing damaging effects on benthic organisms than
those dissolved in water.
5. 2. 3 PCB's and Hexane Extract Concentrations
PCB's are soluble in oil but only slightly soluble in water. Bulk concen-
trations in the Harbor sediments at twenty widely distributed sites were
all considerably higher than the hazard limit of 0. 002 yg/1 for freshwater
-47-
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suggested by EPA (L973). (Marine organisms are much more sensitive
to PCB's than freshwater organisms.) Because the PCB analysis for
this study was performed from sediment samples only, the concentrations
of PCB's in the interstitial water are unknown. Therefore, it is not known
if concentraions of PCB's in this medium are hazardous to aquatic life in
the water column.
PCB concentrations in the Harbor sediments correlate significantly with
hexane extracts, tending to be higher in the surface layer than in the deep
layer. Because PCB's are associated mainly with oil and grease, extremely
high concentrations of hexane extracts in the Baltimore Harbor sediments
suggest correspondingly high concentrations of oil and grease. The benthic
organisms living in such sediments will be affected by the oil and grease
and the in-place pollutants, PCB's, which they contain. Hexane extracts
and PCB's are moderately correlated with the gross toxicity of the Harbor
sediments.
Therefore, it appears that those in-place pollutants associated with particles
and those pollutants associated with grease and oil in the Harbor sediments
are major factors causing damaging effects on the benthic macro-invertebrates
and the bottom-dwelling and -feeding fish. These, perhaps in combination
with other toxic conditions, adversely affect benthic populations throughout
the Harbor to a varying but serious degree.
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5. 3 PELAGIC FISH AND PLANKTONIC ORGANISMS
The community structure, diversity, and distribution of pelagic fish and
phytoplankton are much less related to the sediment toxicity than are the
benthic macro-invertebrates and bottom-dwelling fish. (See Appendix E
for distribution charts. )
The species diversity of fish, particularly those living in shallow shore
water, tended to decrease going from the slightly toxic zone to the highly
toxic zone; but this trend was not so obvious as that in the benthic inver-
tebrates. Certain species of fish, such as silversides in water near shores,
and white perch, rock fish, and alewife in the off-shore water in the Harbor,
were common and abundant over all toxic benthic zones. However, some
fish had lesions on their skins and fins, indicating the presence of a degree
of environmental stress. Planktonic larva and juvenile fishes were fairly
evenly distributed in the Harbor regardless of toxic zones. As they feed
mainly on planktonic foods, they demonstrate no gross effect from the in-
place pollutants in the sediments. It is possible that the in-place pollutants
in the sediments are being released into the water column and thus are
affecting the water quality and aquatic life since both emigration from the
sediments and the effects of resuspension can introduce such pollutants.
It appears that the present community structure, diversity, and distri-
bution of pelagic fish and planktonic organisms may be affected by the
pollutants present in the water column as a result of domestic and indus-
trial waste discharges and by those released from the in-place sediments.
It is not possible to estimate the relative importance of these two sources.
The highly and moderately toxic zones within Baltimore Harbor depicted
in this study are those where in-place pollutants have caused or may poten-
tially cause significant damage to the Harbor ecosystem. The chemical
compositions of the in-place pollutants in the Harbor sediments are extremely
complicated. There is no single chemical parameter among those examined
in this study that can be used to indicate sediment toxicity. There is no way,
from the few chemical parameters studied, to know all of the pollutants in
the sediments, to predict their toxicity, or to assess their impact on the
Harbor ecosystem.
The gross toxicity of the Harbor sediments determined by the bioassay
and the biological indicator represented by the species diversity index of
the Harbor's benthic macro-invertebrates provides useful information
-49-
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regarding the total toxicity of the in-place pollutants and their biological
effects in Baltimore Harbor. These analytical techniques are considered
to be the most accurate in describing areas that may be considered in the
future for removal of the sediments that are considered to be highly toxic
and where the benthic macro-invertebrates have already been severely
damaged. These areas are located in Northwest Branch, Colgate Creek,
Bear Creek, Curtis Bay, and a part of Inner Harbor. The moderately
toxic zone undoubtedly is also a problem area but less so than the highly
toxic.
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6. 0 EFFECTIVENESS AND PERMANENCE OF POTENTIAL
CORRECTIVE ACTIONS
It is clear from the results of the tests made in this study and from the
information derived from previous work that the sediments at the major-
ity of the sites in Baltimore Harbor exceed relevant established criteria
for pollutant levels. Given this condition and given the provisions of
Section 115, P. L. 92-5001, it becomes pertinent to examine the correc-
tive actions which have potential for solving the problem. These, essen-
tially, are four in number, and they are reviewed in Sections 6. 1 through
6. 4 which follow.
The results of any corrective action applied to in-place pollutants which
were deposited over a period of time measured in decades will be But
temporary if similar or other pollutants are permitted to be discharged
into the Harbor or the tributaries which flow into it. Thus, to fully grasp
the effectiveness and permanence of any proposed action, one must first
consider the question of the current influx of pollutants to the Harbor and
the projected changes and trends in these influxes.
This question is one of overriding importance in understanding the problem
in Baltimore Harbor since the Harbor receives effluent from numerous
industrial sites and drainage from more than 600 square miles of land area,
discharging a mean of 550 cfs of water into the Harbor. It has been esti-
mated that more than 86 tons of contaminants enter the Harbor each day
(Quirk, Lawler, and Matusky; 1973). Therefore, any corrective action
would soon be made ineffective by the addition of new pollutants replacing
those previously removed or otherwise disposed of. The present daily
input of pollution must be eliminated or drastically reduced in order to
achieve a clean Harbor; else any corrective treatment of the sediments
would soon be negated.
The physical circulation pattern in the Harbor is dependent upon phenomena
occurring in the adjacent Chesapeake Bay. According to Stroupe, et al,
1961, the primary factor contributing to the renewal of water in Baltimore
1P.L, 92-500, "In-Place Toxic Pollutants", "Sec. 115. The Adminis-
trator (EPA) is directed to identify the location of in-place pollutants
with emphasis on toxic pollutants in harbors and navigable waterways
and is authorized, acting through the Secretary of the Army, to make
contracts for the removal and appropriate disposal of such materials
from critical port and harbor areas,.. ",
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Harbor is a density-induced, three-layered flow pattern. This circula-
tion pattern of the Harbor's water must be taken into consideration when
evaluating corrective actions such as dredging and disposal and what
effect this action might have on both the Harbor and the Chesapeake Bay
waters as a result of the dispersion of polluted sediments into the water
column.
Pollutants in the sediments are highly heterogeneous in distribution and
concentration, although all twenty sites of the materials sampled are
contaminated by criteria of the elutriate test standard of 1. 5 times the
concentration of the overlying water. Previous observations by EPA and
others and the chemical sampling conducted under this program all
demonstrate that subsections of the Harbor vary greatly in pollution
burden and suggest that highly localized deposits may also exist. It is
also clear that wind, tidal action, vessel traffic, and the effects of
dredging have dispersed extensively some of the surface sediments and
associated chemicals within the Harbor.
In addressing possible corrective actions, the size of the area to be
treated or quantities of material to be removed are important consider-
ations. The Harbor is a shallow embayment consisting of approximately
34 square miles of the lower portion of the Patapsco River and ends at a
line between North Point and Rock Point. With a mean depth of 15. 8 feet,
the Harbor contains 15 billion cubic feet of water (Quirk, Lawler, and
Matusky; 1973).
Using the elutriate test results to determine which sampling sites contain
contaminated material and to what depths, it can be seen from Table 4-6
that all twenty sampling sites contain contaminated sediments. The num-
ber of heavy metal contaminants per site varies from two to seven of the
nine metals analyzed, and they are distributed at all depths taken in the
core samples, from 0. 15 to 10. 0 feet. These findings indicate that con-
taminants in the form of one or more of the heavy metals analyzed are
present throughout the Harbor at all vertical levels.
If only the areas of higher pollutant concentrations are to be considered
for correction, the proper analytic technique to identify these areas must
be determined. As mentioned in Section 5.0, the chemical and bioassay
analyses performed for the sediments, the interstitial water, and the
elutriate test do not correlate to show clear evidence of a definite zonal
distribution of pollutants. Within this study, the results of the elutriate
test and of the bioassay have been used to define kinds and degrees of
contaminated material since these techniques are the only two presently
accepted by Federal and State agencies for dredging and disposal con-
siderations.
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6.1 BLANKETING AS A CORRECTIVE ACTION
A recent development in reducing turbidity during diving and similar
operations may prove significant as a corrective action to water pol-
lution. This development, known as blanketing, involves depositing
plastic in thin layers over material that might be easily disturbed.
The United States Naval Civil Engineering Laboratory in Port Hueneme,
California, has experimented with forcing chemicals through a shaped
nozzle to form a layer of flexible, nontoxic plastic to seal sediments to
the bottom in a working area. Because of the possible advantages of
sealing contaminated sediments in place by this method, it was analyzed
further to determine its applicability to Baltimore Harbor. Additional
information on the process and technique can be found in Appendix F.
d. 1. 1 Effectiveness and Permanence
The success of an effort to seal the contaminated sediments in Baltimore
Harbor in place with a plastic layer would depend upon the feasibility of
locating the film permanently and avoiding damage by external forces.
In considering these problems, the following difficulties emerge:
0 Ship channel maintenance and improvement dredging would
remove the plastic strips from alongside piers, channels,
and vicinity of channels;
0 The screw currents of ship traffic would disrupt the strips
of plastic, expecially in and near channels. Evidence of the
tendency for screw currents to disrupt the bottom can be
seen wherever ships' passages leave a trail of increased
turbidity. On occasion, ship traffic to certain terminals
in Baltimore Harbor may have only a few feet clearance
below the hull or may even make contact with bottom muds
as an accepted procedure;
* Anchoring by vessels of any size, ranging from small
pleasure craft up to and including commerical vessels,
would defeat the purpose of the plastic layer. Since the
effectiveness of an anchor depends upon its ability to dig
into the bottom and obtain a purchase, almost every
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conceivable anchor would penetrate the plastic layer.
Anchors in use on the Harbor range from a few pounds
in weight up,to 30, 000 pounds:
0 The debris brought into the Harbor by storms can range
from the tree stumps and branches brought in by spring
freshets to the heavy debris brought downstream by
heavier storms like Hurricane Agnes. Much of this
debris has the potential to tear and otherwise disrupt
a plastic sealant layer on the bottom of the Harbor;
0 In addition to the disruptive agents cited above, currents
in parts of the Harbor would also contribute to disturb-
ing the plastic strips laid on the Harbor bottom. Each of
the boundaries of the strips, in addition to any tears or
other openings in the plastic, would offer an opportunity
for Harbor currents to get under the strip and further
disturb its position;
0 Many modern vessels rely on taking in water through hull
openings for the operation of the ship. These openings
can be as small as two or three inches or as large as five
or six feet in diameter. Blocking such openings with
plastic sheeting can put the ship out of operation and cause
serious damage to machinery.
In the light of these difficulties, it is concluded that blanketing could be
effective only in isolated areas for special applications, out of the normal
Harbor traffic patterns and not subject to heavy storm runoff. Of the
sites sampled, only one (Site 10), located in the Middle Branch area and
in relatively shallow water off to the side of the sand bars of the Patapsco
River, meets these criteria. However, this site would experience heavy
current flows with accompanying debris in the event of another storm
comparable to Hurricane Agnes; so, even here, the use of plastic blan-
keting is questionable.
In view of these considerations, blanketing with a plastic layer is not con-
sidered an effective method to correct the problem of contaminated sedi-
ments in Baltimore Harbor.
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6. 2 INACTIVATION AS A CORRECTIVE ACTION
Inactivating or neutralizing the toxic materials contained in sediments
has not, according to available data, been accomplished in a field situ-
ation where millions of square feet of bottom area and multiple chemi-
cal compounds are involved. Probably the best known examples of
neutralization or inactivation of toxic substances in field conditions are
to be found in the treatment of mine drainage spoils. In mine drainage
spoil material or acid mine drainage water, various processes or treat-
ments have been used to neutralize or reduce chemical parameters such
as pH, acidity, alkalinity, and sulfates and have reduced to acceptable
effluent levels compounds of iron, calcium, magnesium, manganese,
and aluminum. The processes or treatments are usually specific for
individual or specifically known compounds and are applied to the efflu-
ent rather than the spoil material. Typically, mine spoil is simply
treated with lime to neutralize the acidity and the mine drainage water
is then further treated, if necessary, for aquatic life or for potable water
uses.
6.2. 1 Effectiveness and Permanence
Within this study, chemical analyses were performed on samples from
sediments, water column, and interstitial water, and for the elutriate
test. The analyses show that the sediment samples from all twenty sites
and from one or more core depths contain at least two heavy metals that
exceed the elutriate test level of 1, 5 x the overlying filtered water con-
centrations. It is highly likely that they contain significant quantities of
additional chemical contaminants whose compositions are unknown because
they were not analyzed.
Only four sampling sites, numbers 1, 2, 3, and 7 (see Table 4-6) do not
contain heavy metal concentrations that exceed the elutriate test in the
bottom strata of seven to ten feet of sediment. The depth of containment
of the heavy metals analyzed in all the other sites is such that any treat-
ment or inactivation attempted on surface sediments would be relatively
ineffective on those contained in lower depths. Due to the volumes and
depths of contaminants in the Harbor sediment and improbability of an
effective treatment, inactivation of the toxic materials is not considered
an effective or permanent corrective method.
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6. 3 REMOVAL AS A CORRECTIVE ACTION
The removal of all or part of the sediments considered to be either highly
or moderately polluted in Baltimore Harbor is physically possible, although
the depths of the contaminants beyond 10 feet are unknown. There are
several alternative methods of dredging and a number of theoretically pos-
sible alternative receiving sites for disposal of the dredged materials
which are contained in detail in the following sections.
6. 3. 1 Volumes to be Removed
The depth to which Baltimore Harbor would have to be dredged to be able
to reach an "uncontaminated" stratum is unknown. In this study, the
elutriate test was used to determine when heavy metal concentrations
exceeded the established criteria and could be called "contaminated."
At every sampling site, several of the heavy metal concentrations exceeded
the elutriate test criteria to a depth of at least 5 feet. In 15 of the 20 sites,
the elutriate test was exceeded to a depth of 10 feet.
Per Hall, Pullerits, Zollman, 1974, found concentrations of heavy metals,
particularly lead and zinc, in quantities exceeding former criteria for
open water disposal (0. 005 by per cent of dry weight for lead and zinc) to
depths of 70 to 80 feet below the sediment surface level. It is not known
whether the natural background levels for these two metals could become
available to organisms in the water column. The importance of this
example is that it points out that some heavy metals may occur in natural
background levels in certain geographic locations in quantities that
exceed one or more standards established for toxicity criteria.
In general, this study has found that the upper five feet of sediment contain
higher concentrations of heavy metal in the sediment analysis but do not
always show the highest quantities of the same metal in the elutriate test.
For example, at Site 1, Cu exceeds the elutriate test in only one core sample,
No. 1-5 (see Appendix C, sediment sample tables). In the sediment samples
for Site 1, the mg/kg ratio for Cu is greater at five of the other core samples;
yet these test lower than Sample No. 1-5 in the elutriate test. A discussion
of the probable cause of this inconsistency in correlation is contained in
Section 5. 1. The results of these analyses are significant, and any criteria
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established for dredging to remove pollutants should be carefully evaluated
in terms of the type of chemical analysis performed and the meanings of
the analysis for biological considerations.
Baltimore Harbor has a surface area of approximately 34 square miles,
or 950 million square feet. It is estimated that approximately one-half
the Harbor's sediment surface area, some 475 million square feet, con-
tains material that is either highly or moderately polluted. Dredging
this area to a depth of ten feet would require the removal of about 176
million cubic yards of material. Even dredging to a depth of five feet
would require the removal of 88 million cubic yards of material. This
estimate of the volume that may be termed significantly polluted is based
on the "Distribution of Toxic Zones" map, Figure 5-1, that indicates that
approximately one-half of the Harbor's surface area is classified in the
highly and moderately toxic zones.
The sample sites in this study were distributed fairly evenly throughout
the entire Harbor, and as previously stated, material termed contami-
nated according to the elutriate test criteria was found at all sites and
at various depths of the core samples. If the elutriate test results alone
were used to determine contaminated sediments, then, the entire Harbor
would be classified as contaminated because it exceeds the 1. 5 times the
overlying water concentration of the metals analyzed. Because dredging
to this volume may well be not feasible, new standards for classifying
degrees of pollution are needed. At present a recommendation would be
to design a dredging program to remove effectively only the mosi highly
contaminated sediment. Such new standards should identify the concen-
trations of heavy metals, hydrocarbons, PCB's, or other contaminants
that exceed the established limits, classifying the material in question as
"significantly or highly contaminated" as compared to samples containing
lesser quantities of contaminants and classified as "low or slightly con-
taminated. "
To determine the exact location and distribution of the zones of high con-
centrations of pollutants, additional sampling would be required in areas
where sampling sites within this study did not extend, such as up into the
creek areas and between the sampling sites within the Harbor. A deter-
mination could then be made of the specific areas of the Harbor containing
sediments classified as "highly toxic" and that may be considered for
dredging and removal. The classification of material would depend upon
the establishment of a definition and standard that outlines the analysis
techniques to be used and the levels or concentrations of measured con-
taminants to be considered as "high" or "low" toxicity.
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6.3.2 Dredging Techniques
From studies conducted by the Corps of Engineers and others (see
Appendix F), there is evidence that dredging can be accomplished with
certain improved techniques and equipment that will greatly reduce exten-
sive plumes or disturbance to the sediments and the release of contaminated
materials into the water column. Newly developed dredging equipment, such
as the PneumarDredge, is reported to cause less disturbance to bottom sedi-
ments than other equipment traditionally employed in dredging. Modifica-
tions to older equipment, such as the use of silt curtains, have also been
reported effective in reducing turbidity or sediment dispersal into the
water column.
Assuming a dredging technique was used that reduced turbidity to an
acceptable level, the problem of placement and site location must then be
considered. There are basically four different methods of disposing of
dredged spoils: open water disposal, creation of artificial habitat such as
marshland, upland disposal, and diked disposal.
6. 3. 3 Open Water Disposal
Placement of the contaminated dredged spoils from Baltimore Harbor,
defined by Maryland law as "the tidal portions of Patapsco River and its
tributaries lying westward of a line extending from Rock Point in Anne
Arundel County to North Point in Baltimore County, " into open waters of
the Chesapeake Bay is prohibited under the Annotated Code of Maryland,
Article - Natural Resources Title 8, Subsection 16, 1975. The only other
alternative for open water disposal of the Harbor sediments would be to
place them in the ocean. Federal regulations and criteria, including those
contained in Section 163 of the Marine Protection, Research, and Sanc-
tuaries Act of 1972, and Section 404 of the Federal Water Pollution Control
Act Amendments (P. L. 92-500), must be met for any disposal of material in
navigable waters.
Ocean dumping of the Harbor dredged spoils would be subject to review by
Federal agencies under the previously cited public laws and regulations,
as well as State laws for whatever states' borders might be affected by
off-shore ocean disposal. Because the purpose of the Marine Protection,
Research, and Sanctuaries Act is to find means of disposal that will end
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all ocean dumping, releasing the Harbor spoils at sea is not considered
to be an effective or feasible solution to the problem.
Reinforcing this conclusion is the distance the material from Baltimore
Harbor would have to be transported. It is 130 nautical miles from the
Harbor mouth to the entrance to Chesapeake Bay; and, of course, any
ocean dumping would necessarily take place a considerable distance off-
shore. The logistics, hazards, economics, and political obstacles to
such a means of disposal would be formidable.
6. 3.4 Creation of Artificial Habitat
There have been several projects and studies conducted in the use of
dredged spoils to create new marsh areas or to fill in adjacent-to-land
shallow water to create new upland sites (see Appendix F). While this
method of using dredged material may be a worthwhile concept under
certain circumstances and in particular geographic areas, it is not con-
sidered feasible as a disposal method for the contaminated Baltimore
Harbor spoils.
Both artificial marsh and low-lying land created from dredged spoils are
subject to runoff, tidal wash, and seepage that could transport the sedi-
ment fines and dissolved toxic materials from the deposited spoil into the
surrounding water. There is, in short, probability of substantial environ-
mental damage to the adjacent water column, to benthic communities, and
to ground water. Before taking such action in the Chesapeake Bay, a
specific site would have to be pre-selected and thoroughly evaluated for
the possible environmental impact on aquatic habitat such as spawning sites,
nursery grounds, shellfish beds, etc. Further, Maryland State law quoted
previously specifically states that Baltimore Harbor spoil may be deposited
only in "contained areas approved by the Department. " Any proposed arti-
ficial habitat would have to be thoroughly studied to determine whether it
qualified as a contained area.
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6. 3. 5 Upland Disposal
The location, feasibility, and cost of upland disposal sites for contaminated
dredged spoils has been studied by the Maryland Department of Transpor-
tation for a number of years. In the Environmental Impact Statement for
the proposed 1-95 Fort McHenry Tunnel in Baltimore Harbor, potential
upland disposal sites for dredged material were identified. These sites
consisted mainly of abandoned sand and gravel quarries. The largest
site identified could contain 8 million cubic yards of material. The average
site was 3 million cubic yards. In all, 12 potential sites were located within
a 52-mile radius of Baltimore that could possibly contain a maximum of
41 million cubic yards of dredged material.
Some additional studies were completed to look for abandoned strip or
deep mines in Western Maryland and West Virginia. The mines were con-
sidered as possible disposal sites, but the cost of hauling material from
Baltimore Harbor to Western Maryland or West Virginia was considerable.
It was estimated that it would cost approximately $11. 00 (1972 dollars)
per cubic yard to remove the material from the Harbor, transport it by
rail or truck, and place it in an abandoned mine. This did not include the
cost of the land or any land reclamation costs.
In addition to the high cost associated with a long-distance haul for upland
disposal, all land disposal sites have one potential common environmental
impact. It is that the contaminated materials can leach out and enter nearby
streams or be transferred into ground water supplies or aquifers. There-
fore, a potential land disposal site must be thoroughly investigated for its
location in a watershed and the danger of contamination of a stream, lake,
or groundwater.
Material that is contaminated and cannot be disposed of in open water can
be placed in land sites if the particular site is determined to be safe from
the leaching or groundwater contamination potentials discussed above.
However, upland site placement of the Baltimore Harbor material is not
considered a feasible solution due to the large quantities involved. It will
be recalled that removing one-half of the square footage of highly and mod-
erately toxic material in the Harbor to a depth of 10 feet would involve some
176 million cubic yards of material. If all of the potential upland disposal
sites within a 52-mile radius of Baltimore could be used, they could hold
only 41 million cubic yards or 23% of the total quantity. Removal of only
the highly toxic material to a depth of 10 feet involves 79 million cubic
yards. Additional sites such as abandoned strip or deep mines where
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environmental acceptability are unknown would have to be utilized. The
only potential use of upland sites appears to be for relatively small quan-
tities of spoil. If the spoil is highly contaminated, such as that in certain
locations in the Harbor, exceptional effort would be required to prevent
environmental damage.
6.3.6 Diked Disposal
The use of a diked disposal area to contain material dredged from Baltimore
Harbor and its approaches has been approved by the State of Maryland and
the appropriate Federal agencies. Following application for the use of the
Hart-Miller Islands site by the State in 1972, and following the filing of the
appropriate environmental impact statement and numerous hearings, con-
struction of this containment site is scheduled to begin in the near future.
This method of spoil placement is the only feasible one at present in Mary-
land given both the practical limitations connected with upland disposal,
creation of an artificial habitat, etc. , and the legal limitations which pro-
hibit open water disposal.
6. 3. 6. 1 Effectiveness of Diked Disposal
The effectiveness of diked disposal sites has been evaluated by a small
number of investigators, all within the past few years and only for indi-
vidual sites. Appendix M of the Dredge Disposal Study - San Francisco
Bay and Estuary (see Appendix F) indicates that in diked disposal sites:
"Regulations set by The California Regional Water
Quality Control Board on turbidity and settleable
matter from dredged material containment areas
can generally be met by providing adequate resi-
dence time in holding ponds. The possible release
of heavy metals in the diked area effluent depends
on many factors which make effluent quality predic-
tions difficult, but it appears that a well-designed
settling area will produce an effluent meeting real-
istic water quality requirements. However, in
cases where specific effluent requirements are not
being met, then a coagulation treatment system could
be readily and inexpensively installed to upgrade the
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" effluent to meet the requirements. A brief study of
the Mare Island disposal site for dredged material
indicated that metals were not being leached from
the disposal area. "
The Arthur D. Little, Incorporated study for the Army Engineer Waterways
Experiment Station states: "Toxic pollutants can be released from confined
disposal areas through seepage and through incorporation into food chains.
An initial effort should be made to determine whether release of toxic pol-
lutants is a problem. "
The study also states:
"Most districts d'o not test for possible release of
toxic pollutants from confined disposal areas,
although testing of material to be dredged will be
performed in the future according to regulatory
practices. In the New Orleans District, no testing
of possible release of toxic pollutants is performed
unless a known toxic pollutant exists, as determined
by previous testing of the material at the dredged
site. In areas where mercury is known to be pres-
ent, tests are performed continuously to determine
the mercury concentration at the dredged site, dis-
posal site, the spillway, and in the receiving waters
near the disposal area. No detrimental impacts
have been registered. "
6. 3. 7 Permanence of Removal
The overriding factor in considering the permanence of any potential cor-
rective action is the reduction or elimination of the contaminants now being
discharged into the Harbor. In-place pollutants could be physically removed,
but any effectiveness achieved by this action would soon be negated by new
pollutant loadings from community and industrial discharge sources.
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Section 4. 3 of this report discusses former studies which report quantities
of pollutants discharged into Baltimore Harbor in addition to the NPDES
permit authorizations. The present rate of discharge of pollutants to
Baltimore Harbor is unknown for the quantities of heavy metals and other
pollutants measured in this study; but from the data reviewed, it is known
that significant quantities of metals and total suspended solids are presently
being discharged each day. Helz (1976), for example, reports that approx-
imately 27 thousand metric tons of heavy metals are entering the Harbor
each year from all sources; Quirk, Lawler, and Matusky (1973) list approx-
imately 86 tons per day of all pollutants, 72% of which are metals. A
partial summary of NPDES permit authorizations for January 1977 indicates:
Domestic -- Total suspended solids of 276,816 Ibs/day as a
weekly average from 47 major sources out of 690
total reported.
Industrial - Total suspended solids of 879, 372 Ibs/day maximum
from 65 industries out of a total of 184 reported.
- Total metals of 238, 378 Ibs/day maximum from 9
major industries out of a total of 184 reported.
The areas considered to be the most highly contaminated are also the areas
receiving both community and industrial discharges at the present time,
e.g. , Northwest Branch from the Jones Falls Discharge and adjacent plants;
and Colgate Creek, Bear Creek, Curtis Bay, and the Inner Harbor from
their individual watershed stream flows, industrial sites, and sewage treat-
ment plants located on these creek and harbor areas.
Only after these discharge loadings have been eliminated could removal of
the in-place pollutants be considered a permanent action.
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6.4 LEAVING UNDISTURBED
To leave the Baltimore Harbor sediments undisturbed would not be a cor-
rective action in the same sense as blanket, inactivate, or remove, but it
is a viable alternative to be considered under the terms of this study --
"give an analysis of the environmental effect of the polluted sediment and/
or why it is a problem (i. e. , can it be left alone; is it part of an area to be
dredged; is it adversely affecting water quality and water use?)."
The findings of this study and others have shown that the benthos within the
Harbor are adversely affected by the in-place pollutants. The pelagic and
planktonic biota are also stressed but to a lesser degree. Leaving the pol-
lutants in place, undisturbed, will not aleviate the present damage to the
biota, nor will it help future improvement while the pollutants remain in
their present concentrations and distribution. However, any other potential
action that could be taken, such as removal of the polluted sediments by
dredging, will likewise be ineffective as long as new pollutant loads are being
discharged into the Harbor.
The alternative action of leaving the polluted sediment undisturbed is, there-
fore, the only practical action that can be considered at this time under the
present conditions. The feasibility of this action is discussed in Section 7.4
which follows.
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7.0 FEASIBILITY AND COSTS OF POTENTIAL
CORRECTIVE ACTIONS
All potential corrective actions contain within them elements of trade-offs
which need to be weighed carefully before a realistic course can be recom-
mended. In particular, any preferred corrective action to be applied to
Baltimore Harbor must be selected with due regard to the fact that the
Harbor is a major U. S. port. In 1975, there were more than 4,000 ship
arrivals and departures: being a shallow body of water, many vessels
maneuver in the Harbor with little or no bottom clearance. Within the
Harbor, many industrial facilities, ranging from steel mills and electric
generating power plants to small manufacturing firms, use the waters for
intake cooling, discharges and transport of equipment, fuel and goods.
Wharves and other facilities contribute significantly to the oils, greases,
and detritus to be found floating in the Harbor eventually to be lodged in
the sediments. It is in this environment that the possible corrective
actions which follow have been evaluated for feasibility.
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7. 1 BLANKETING
Blanketing the polluted sediments in the Harbor is not considered to be a
practical method for overcoming the problems associated with in-place
pollutants in Baltimore Harbor. The constant volume of ship and barge
traffic -- including anchoring and maneuvering of large vessels -- and
related water activities would soon tear or displace any plastic film
extruded over the surface of the bottom of the Harbor. The process of
blanketing with a chemical composition that forms a plastic film in place
under water is relatively new, and, to our knowledge, has only been used
on sediments to decrease turbidity for underwater ship repair and other
marine work. Its applicability to large or extensive areas and its dura-
bility for long periods of time are unknown.
The cost of the blanketing pilot tests performed in 1970 by the U. S. Navy
was approximately $1. 00 per square foot. The Navy did not carry this
project beyond the experimental phase to see if the blanket was effective
in reducing turbidity for divers working on the ocean floor. The duration
of time that this blanket will stay in place and its overall effectiveness
is unknown. Accordingly, due to the complexities of attempting to main-
tain a plastic film intact in a working harbor and the lack of sufficient data
on the effectivenss of the blanket for an extended period of time, this
approach is not considered feasible.
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7.2 INACTIVATING
The potential for inactivating the pollutants within the sediments of Balti-
more Harbor is not considered a feasible action due to the complexities
of dealing with multiple chemical compounds in various forms and under
variable toxic conditions. As there are no known methods or pilot pro-
grams that have attempted this type of inactivation of polluted sediment
by chemical neutralization or reactive treatment, this method must be
considered infeasible at the present time.
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7. 3 REMOVING
Removing contaminated sediments by dredging is a proven method that
has been successfully accomplished in many harbors and waterways for
many years. In dredging operations, however, there is necessarily some
disturbance to the sediments that creates turbidity in the adjacent area of
the dredge equipment, even under the best of conditions. Although there
have been objections raised to dredging because of the danger of releasing
contaminants into the water column, dredging is an accepted method for
removing unwanted spoil. It is an ongoing activity in Baltimore Harbor
and approaches for purposes of maintenance of channels, approaches, slips
and berths. Thus, removal of the polluted sediments in Baltimore Harbor
should, if properly done, be slightly, if any more, disturbing to the water
column than present activities. In addition, large ships' passage, storms,
and tidal action also cause disturbances and increased turbidity in shallow
areas, such as in Baltimore Harbor, whose bottom is composed of fine-
grained particles that make up the sediment layers. The contaminants
released to the water column through these actions seem to remain within
the Harbor itself and do not appear to affect adversely the health of the
Harbor's water or the health of the biota in the Chesapeake Bay (see dis-
cussion in Section 5.3).
Therefore, it is concluded that removal of the in-place pollutants by dredg-
ing can effectively be accomplished without extensive or permanent damage
to the waters of the Harbor or Bay.
7. 3. 1 Feasibility
Although dredging can remove polluted sediments, the feasibility of applying
this approach to the problem studied here can be seriously questioned because
of the huge volumes involved, costs, and the need to provide a suitable repos-
itory for the spoil. If the results of the bioassay and previous findings on
the community structure and diversity of benthic macro-invertebrates are
used to determine the zones of toxicity within the Harbor, it will be seen
from Figure 5-1 that approximately one-half (17 square miles) of the Harbor
is classified as highly and moderately toxic. Dredging an area of this size
to a depth of ten feet would require the removal of about 176 million cubic
yards of material. While this can be done with dredging equipment available
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today, placement of this huge volume of contaminated material in a suitable
location is not possible under present laws and available site locations.
As a final note to the approaches reviewed above, but with particular import
to dredging, the overriding consideration in all three instances is that unless
the pollutant loads now being discharged into the Harbor are eliminated or
reduced drastically, no approach will have lasting effect. In addition, the
question of costs aside, dredging is feasible only when an environmentally
suitable disposal site can be made available.
7.3.2 Costs of Removal
The costs of dredging and the placement of the spoil vary from one location
to another and for different sized jobs. Normally, the larger the quantity
to be dredged, the less the cost per cubic yard will be because the contractor
must mobilize his equipment regardless of the size of the operation. The
direct cost for dredging alone is not the sole consideration, however, because
with the prohibition of open water disposal of Baltimore Harbor materials
in the Chesapeake Bay, dredged material must be disposed of either within
the Harbor itself or be placed in a diked disposal or upland site. Transport
costs and costs of site acquisition, preparation, and construction must be
included.
The most recent contract (1977) let by the Corps of Engineers for dredging
the Craighill-Cutoff Channel Angle was for $0. 91 per cubic yard based on a
quantity of 685, 300 cubic yards and a cost of $12, 000 to mobilize and demo-
bilize the dredging equipment. It was specified that the material be placed
in the open water of the Harbor at the disposal site off Rock Point in the
mouth of the Patapsco River. This type of dredge and placement is the most
inexpensive since the material is placed in open water not far from the dredge
site.
Unit costs for dredging and placement based on the ratio of the Engineering
News Record Construction Cost Index (December 1976) for utilization of a
hopper dredge are as follows:
Total Unit Cost = cutting and offloading costs (,44/cu yd)
4- transportation costs (0.0497/cu yd/mi).
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Utilizing this formula, it would cost over 74 million dollars to remove,
transport, and place 79 million cubic yards of highly toxic material into
a diked disposal site ten miles from the dredging site. The cost incurred
in the construction of a diked disposal site such as Hart-Miller Island is
estimated to be $0. 69 per cubic yard of placed storage or a total of approx-
imately 54. 5 million dollars for holding the 79 million cubic yards.
Cost Summary:
Cutting and offloading --
79,000,000yd3 x $0.44/yd3 = $ 34,760,000
Transportation --
79,000,000yd3 x $0.0497/yd3/mi x 10 mi = $ 39,263,000
Construction of diked disposal area --
79,000,000yd3 x $0. 69/yd3 = $ 54,510,000
Total (est. ) $128,533,000
Total costs for this quantity (79 million cubic yards) would thus approximate
a total expenditure of 128.5 million dollars to dredge, transport, place, and
construct the diked disposal site for its placement. If, as is usual, the diked
area were located in shallow water, the cost of creating a channel to reach it
would need to be included.
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7.4 LEAVING UNDISTURBED
Before the feasibility of leaving the polluted sediments undisturbed can be
fully evaluated, consideration must be given to the present and future
effects of these sediments on benthic species and on the water column inso-
far as it affects pelagic species and other users of the Harbor waters.
Through the analyses of some of the known pollutants in the sediment and
water and from the bioassay, this study, like others, found that in-place
pollutants are causing damage to the benthic macro-invertebrates and the
bottom-dwelling and -feeding fish. The damage to the pelagic fish and
planktonic organisms is less but also measurable. It is not known if the
damage to the pelagic species is caused by pollutants from incoming dis-
charges, by the release of pollutants from the sediments, or by a com-
bination of both.
If the polluted sediments are left in place, undisturbed, we may expect that:
0 Some of the contaminants will continue to be released slowly
from sediments into the water column and, with high dilution,
into the Chesapeake Bay system.
0 There will be sporadic increases in the rate of release into the
water column as the result of storms, ship traffic, or other
transient events.
0 There will be continued stress to the benthos; but this stress
is expected to decrease with time as the sources of incoming
pollutants are reduced or eliminated.
0 The damage to water quality and the pelagic species will also
continue, but should decrease as incoming pollutants are
decreased.
0 Since there is less damage occurring to the pelagic species
than to the benthic and since it is possible that some of the
present damage may be caused from incoming pollutants
rather than the in-place pollutants, the recovery to the water
quality and pelagic species should be more rapid than for the
benthos.
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The in-place pollutants will, in time, be covered either par-
tially or completely with clean sediments as incoming pollutant
loads are reduced or eliminated
Leaving the sediment undisturbed is, therefore, a feasible alternative from
the standpoint that the damage the in-place pollutants have caused or will
cause to the benthos has already occurred and should not increase. The
effects of the in-place pollutants should be reduced by the slow accumula-
tion of cleaner sediments resulting from the elimination of incoming loads
of new pollutants to the point that, in time, the benthos and water quality
will slowly recover.
The cost of leaving the sediment undisturbed is difficult to measure as
there is an intrinsic value of clean water to users for both industrial and
recreational purposes. From the point of view of commercial fishing,
there is some cost associated with the reduction of spawning sites and
nursery grounds for finfish, crabs, clams and oysters, and the benthlc and
planktonic species that are in the food chain. However, Baltimore Harbor
has not served as an important spawning site for commercially important
species nor has it had good nursery ground habitat for many years, pos-
sibly since the early 1900's. Recovery of this habitat, while important,
is minor compared to the rest of the Chesapeake Bay, and will always be
of less significance due to the Harbor's normal activity of heavy industry,
related water uses by the industrial complex, and channel dredging.
No other cost factors that can be measured in dollars can be applied to this
alternative action, but the cost of this course of action will not increase but
rather should decrease in time as additional pollutant loads are eliminated.
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8.0 CONCLUSIONS AND RECOMMENDATIONS
8. 1 CONCLUSIONS
1. The in-place pollutants in Baltimore Harbor are distributed heter-
ogeneously throughout the Harbor sediments with a number of highly
localized concentrations occurring in certain areas. This conclu-
sion is based on the results of this study and others and is supported
by the community structure diversity and distribution of finfish and
benthic organisms.
2. The depths to which the pollutants extend is unknown, but core
samples have shown that all heavy metals examined are to be
found at depths up to 10 feet in quantities that exceed the elutriate
test standard of 1.5 times the overlying water. There is a general
tendency for the quantities of all pollutants to decrease with depth
below five feet, but several sample sites contain pollutants in equal
or greater quantity in the seven-to-ten-foot depths.
3. The results of the elutriate test, the bioassay, and the sediment and
interstitial water analyses do not correlate well enough with each
other to indicate the sites of highest pollution levels. The sites that
contain some of the highest quantities of heavy metals in the sediments
tested low in the elutriate test. Conversely, some of the samples test-
ing the highest in the elutriate test contain relatively low quantities of
the same metal in the sediment. The results of the bioassay correlate
to some degree with the bulk sediment and the PCB analyses but cor-
relate less with the results of the elutriate and the interstitial water
analyses.
4. The results of this study correlate very closely, for the same site
locations, with the high and low concentrations of heavy metals as
reported in the 1974 Region III EPA Study, "Distribution of Metals
in Baltimore Harbor Sediments" by Villa and Johnson.
5. The result of the bioassay and the observed community structure
and diversity of benthic macro-invertebrates correlate with the gross
toxicity of the sediments to reflect high, moderate, low, and slight
zones of toxicity within the Harbor. On this basis, approximately
one-half the area of the Harbor is classified in the high and moderate
toxic zones.
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6. The sites containing high levels of PCB's and hexane extracts cor-
relate moderately well with the sites considered as highly toxic for
benthic macro-in vertebrates and the bottom-dwelling and feeding
fish. It appears that these in-place pollutants are major factors
in causing stress to these species.
7. The results of the elutriate test indicate that the heavy metals con-
tained in the sediments may have a significant effect on the over-
lying water column when the sediments are mixed or dispersed in
the water. The residence time that these metals remain in the
water column and the percent removed from the sediment are
unknown.
8. The community structure, diversity, and distribution of pelagic fish
and phytoplankton bear no relation to the zones of toxicity such as
those of the benthic macro-invertebrates and bottom-dwelling fish.
9. The community structure, diversity, and distribution of pelagic fish
and planktonic organisms may be affected by the pollutants from
industrial and community discharges as well as from those released
from the in-place sediments. It was not possible to assess the
relative importance of these two sources of pollution.
10. It was not possible to determine the quantities of the same pollutants
examined in this study that are presently being discharged into the
Harbor, but it is known from the investigation of NPDES permit data
that industrial and community discharges contain significant quantities
of heavy metals and suspended solids. The last total inventory of
pollutants discharged to the Harbor (1973) indicates that some 86 tons
of heavy metals and toxic chemicals were being discharged into the
Harbor each day.
11. In a recent review, Helz (1976) estimated that a relatively small
percentage of the heavy metals entering the Harbor remain in the
Harbor. The rates and routes of removal and the form of the metals
leaving the Harbor and entering the Chesapeake Bay are unknown,
but the mechanism by which this occurs may be significant to the
upper estuary which is a nursery region.
1Z. Despite the reported high-removal rate of heavy metals from
Baltimore Harbor, the Harbor acts as a repository for pollutants
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as evidenced by the concentration of heavy metals found at all depths
of the core samples and the high concentrations of certain metals
to be found in localized deposits.
13. Of the three possible corrective measures requiring action-- blan-
keting, inactivating, removing -- only the last, dredging the Harbor
bottom and placing the polluted sediment elsewhere, is a practical
method if certain factors such as cost and the location and type of
disposal sites are not considered. This conclusion is dictated by
practical considerations of the uses of the Harbor and the state-of-
the-art in large scale blanketing and inactivation techniques.
14. All sites and all depths of sampling contained concentrations of
heavy metals that exceed the elutriate test standard indicating the
entire Harbor is contaminated to depths of at least 10 feet. Also
by 1973 EPA interstitial water standard for levels of heavy metals
hazardous to aquatic life, the entire Harbor would be classified
contaminated. A designation of those areas that are highly, mod-
erately, or slightly polluted is difficult to make by means of these
analytical techniques. If partial removal of the contaminated sedi-
ments is to be undertaken to dredge only those areas that contain the
highest concentrations of pollutants, new or additional criteria would
need to be established to describe the pollutional characteristics of
the sediments so that priority judgments could be made.
15. Maryland State law prohibits the placing of any material dredged from
Baltimore Harbor in the open waters of the Chesapeake Bay. The law
further requires that "the spoil maybe redeposited in contained areas
approved by the Department. " The only presently approved contained
area, other than upland disposal sites, is the Hart-Miller Diked
Disposal Site. Therefore, any dredged material from the Harbor
would have to be placed in an upland site, in the future Hart-Miller
Disposal Site, or in a similar site yet to be designated.
16. A review of potential upland disposal sites within a 52-mile radius
of Baltimore found that there is a maximum containment potential of
some 41 million cubic yards of material. Even partial removal of
the highly contaminated sediments and placement in upland disposal
sites would exceed the total potential capacities of these sites.
17. The influx of new pollutant loads, now being discharged into the
Harbor from industrial and community sources, would eventually
negate the benefit achieved by any corrective action. The pollutants
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now being discharged into the Harbor would soon begin to replace
those removed, blanketed, or inactivated. Therefore, a pre-
requisite to any permanent action is the implementation of the
provisions of P. L. 92-500 and a cessation or drastic reduction of
the current influx of pollutants to the Harbor waters.
18. Given conclusion number 17 and given the difficulties and obstacles
faced by any active solution to the problem of in-place pollutants,
we conclude that leaving the polluted sediments undisturbed is the
most realistic course to take at the present time. We conclude that
this course will continue to be the most realistic one until such a
date that the pollutant discharge loading into the Harbor is eliminated
or drastically reduced.
This date, according to the provisions of Sec. 101(a)(l), P. L. 92-500,
is 1985. During the interim, we can anticipate a gradual improve-
ment in the quality of the water column as the provisions of Sec. 402,
"National Pollutant Discharge Elimination System" (NPDES) are met;
and, through natural processes, a partial improvement in the surface
layer sediments as deposition of clean runoff sediments occur from
stream sources.
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8.2 RECOMMENDATIONS
1. The in-place polluted sediments in Baltimore Harbor be left undis-
turbed. (Note: This recommendation applies only to the nature of
the problem posed by this study. It is not intended to apply to any
present or planned activity such as channel or ship berth mainte-
nance and improvement dredging.)
2. These sediments be left undisturbed at least until such time as the
current influx of pollutants is eliminated or reduced sufficiently so
as to not negate any corrective action.
3. Removing the in-place pollutants by dredging is recommended only
following a determination that the natural recovery that might be
expected from the inflow of uncontaminated sediments from the river
and stream sources is not correcting the present problems. Once
the discharge of toxic material has been stopped, a slow recovery
of the benthos and of the water column should result from a partial,
if not full, blanketing effect of uncontaminated sediments from
natural sources covering the in-place pollutants.
4. A re-evaluation be made at the time the influx is reduced or elimin-
ated (i. e., 1985) to determine whether or not the deposition of clean
sediments is occurring at a rate commensurate with the objectives of
P. L. 92-500. If not, the preferred method for meeting the provisions
of Sec. 115 is the removal of the highly and moderately toxic polluted
areas by means of dredging and the placing of the dredged material
in approved diked disposal sites. This recommendation presumes
that no new, innovative means for otherwise dealing with the problem
is developed in the interim.
5. If removal of the in-place pollutants becomes a necessity, only the
areas classified as highly and moderately toxic be considered. If
a priority need be established and only partial removal can be accom-
plished for economic considerations, the areas of high toxicity should
be given first priority. Any dredging in the areas of high toxicity
should be done by dredging methods and equipment that create a min-
imum of disturbance to the sediments, thus reducing turbidity and
release of the materials into the water column.
6. A more thorough analysis and quantification of the pollutants presently
being discharged into the Harbor and determination of the pathways of
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transport, deposition, re-re lease, and movement into the biota
should be accomplished.
7. The scheduled channel improvement in Baltimore Harbor and the
scheduled Hart-Miller disposal site construction and activation
be carefully followed by means of a planned monitoring program to
determine the actual effect on the biota and other environmental
impacts. The dredging, due to begin shortly, offers a unique
opportunity to obtain, empirically, information on the actual stress
caused by large-scale dredging in the Harbor and, given the uncer-
tainties normally associated with deductive methods, appears to be
the one approach certain to yield positive answers quickly. While
this recommendation is not within the scope of this study, it is con-
sidered appropriate and particularly germane in light of the scheduled
large scale dredging program planned for the Harbor and its approaches.
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TECHNICAL REPORT DATA
(Pltax reed Inunctions on the reverse before completing}
2.
3. RECIPIENT'S ACCESSION*NO.
4. TITLE AND SUBTITLE
EVALUATION OF THE PROBLEM POSED BY IN-PLACE POLLUTANTS
IN BALTIMORE HARBOR AND RECOMMENDATION OF CORRECTIVE
ACTION
«. REPORT DATE
September 1977
6. PERFORMING ORGANIZATION CODE
'. AUTHORIS)
8. PERFORMING ORGANIZATION REPORT NO,
. PERFORMING ORGANIZATION NAME AND ADDRESS
Trident Engineering Associates,
48 Maryland Avenue
Annapolis, Maryland 21401
Inc.
10. PROGRAM ELEMENT NO.
2BH413
11. CONTRACT/GRANT NO.
68-01-1965
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Water Planning and Standards
U. S. Environmental Protection Agency
401 M Street, SW
Washington, D.C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA 700/01
IB. SUPPLEMENTARY NOTES
Prepared in cooperation with the Center for Environmental and Estuarine Studies.
University of Maryland, Horn Point, Cambridge, Maryland.
18. ABSTRACT
Previous studies had indicated that Baltimore harbor is heavily polluted. To assess
the impact of in-place pollutants on the harbor, the Contractor sampled and analyzed
bottom sediments, the water column, and the interstitial water, using bulk sediment
analyses, elutriate tests, and bioassays. On the basis of the results of this
investigation, it is possible to divide the harbor into four zones; highly toxic,
moderately toxic, low toxlcity, and slightly toxic. The biota are being stressed by
1n-place pollutants. Benthic organism's suffer the greatest damage, the Intensity
varying with the location in the zones of toxicity. Pelagic species are damaged to a
lesser extent. Although feasible corrective actions do exist, they would offer only
a temporary solution. A permanent solution involves the corrective action plus
elimination of pollutant discharges into the harbor,
A companion report, EPA 440/5-77-015a, contains the appendices and details of the
testing and anlaysis.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
» b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI FUd/CrOOp
Environmental Research
Sediments
Water Quality
Bioassay
Baltimore Harbor
Pollution
Dredging
13 B
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (TUt Report)
UNCLASSIFIED
21. NO. OF PAGES
20. SECURITY CLASS (TUtptgt)
UNCLASSIFIED
22. PRICE
EPA Form 2120-1 (1-73)
omci i mr 0-730-117/1014
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