United States
Environmental Protection
Agency
Environmental Research
Laboratory
Corvallis OR 97330
EPA-600/9-80-044
September 1980
Research and Development
Management of
Bottom Sediments
Containing Toxic
Substances
Proceedings of the
5th U.S.-Japan
Experts Meeting
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/9-80-044
September 1980
MANAGEMENT OF BOTTOM SEDIMENTS CONTAINING TOXIC SUBSTANCES
Proceedings of the Fifth United States-Japan Experts' Meeting
November 1979 — New Orleans, Louisiana
edited by
Spencer A. Peterson and Karen K. Randolph
Corvallis Environmental Research Laboratory
Corvallis, Oregon 97330
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
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DISCLAIMER
This report has been reviewed by the Corvallis Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publica-
tion. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
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ABSTRACT
The United States-Japan Ministerial Agreement of May 1974 provided for
the exchange of environmental information in several areas of mutual concern.
This report is the compilation of papers presented at the Fifth United States-
Japan Experts' Meeting on the Management of Bottom Sediments Containing Toxic
Substances, one of the 10 identified problem areas.
The first meeting was held in Corvallis, Oregon in November 1975 and the
second was hosted by the Japanese Government in October 1976. The third
session was convened in November 1977 in Easton, Maryland and the 1978 session
was conducted in Tokyo. The fifth meeting (at which these papers were pre-
sented) was held in New Orleans, Louisiana in 1979.
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CONTENTS
Page
Dredging on a Competitive Basis 1
W. R. Murden, Jr.
Sea Bottom Management in Japan 19
R. Takata
Control of Toxics in the United States 37
J. McCarty
Availability and Plant Uptake of Heavy Metals from
Contaminated Dredged Material Placed in Flooded
and Upland Disposal Environments 45
C. R. Lee, B. L. Folsom, Jr. and R. M. Engler
Distribution and Concentration of PCB in the Hudson
River and Associated Management Problems 61
I. G. Carcich and T. J. Tofflemire
The Section 404 Dredge and Fill Program 87
J. P. Crowder
Sediment Problems and Lake Restoration in Wisconsin 103
R. C. Dunst
Release of Phosphorus from Lake Sediments 115
M. Hosomi, M. Okada and R. Sudo
Release, Distribution, and Impacts of Polychlorinated
Biphenyls (PCB) Induced by Dredged Material Disposal
Activities at a Deepwater Estuarine Site 129
S. P. Pavlou, R. N. Dexter, D. E. Anderson,
E. A. Quinlan and W. Horn
Contaminant Mobility in Diked Containment Areas 175
R. E. Hoeppel
Mathematical Model of Phosphorus Release from Lake Sediment 209
T. Yoshida and T. Fukushima
Containment Area Design for Sedimentation of Fine-Grained
Dredged Material 229
R. L. Montgomery
Sampling, Preservation and Analysis of Sediment Samples:
State-of-the-Art Limitations 259
R. H. Plumb, Jr.
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DREDGING ON A COMPETITIVE BASIS
W. R. Murden, Jr., Chief
Dredging Division, Water Resources Support Center
Civil Works Directorate, U.S. Army Corps of Engineers
Fort Belvoir, Virginia 22060
ABSTRACT
This paper describes the dredging mission of the
U.S. Army Corps of Engineers to construct and maintain
adequate dimensions in navigation projects to accom-
modate maritime traffic and the scope of the national
dredging program required to accomplish this mission.
A decline in the workload or dredging yardage levels
during the period of 1963 through 1978 and the adverse
effects of this decline are discussed. The paper
outlines the factors relating to the evolution of
Public Law 95-269 and the major provisions of this
legislation which was enacted April 26, 1978. The
Industry Capability Program, which was initiated by
the U.S. Army Corps of Engineers in December 1976, is
described. This program, which provides an oppor-
tunity for industry dredges to compete with Corps
dredges, was implemented to encourage the industry to
make the large capital outlays required to construct
new dredges, particularly seagoing hopper dredges.
The statistics accumulated from the Industry Capa-
bility Progam (ICP) are presented and summarized. In
addition, the industry construction program which has
evolved due to the ICP is discussed. Also, the paper
describes the "minimum fleet" of the U.S. Army Corps
of Engineers as provided for in Public Law 95-269 and
the factors considered in developing a recommendation
to the Congress as to the number and class of hopper
dredges which would comprise the "minimum fleet."
INTRODUCTION
Public Law 95-269 directs the Chief of Engineers, U.S. Army, to undertake
a study to be submitted to the Congress for the purpose of determining the
minimum Federally-owned fleet of dredges required to perform emergency and
national defense work. This law also provides that as the industry demon-
strates its capability to perform the dredging work currently performed by the
1
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existing Federally-owned fleet, at reasonable prices and in a timely manner,
the existing Federally-owned fleet of dredges shall be reduced by the orderly
retirement of plant until the minimum fleet prescribed by the Congress is
reached. The legislation also indicates that the minimum fleet of the Corps
of Engineers shall be maintained to technologically modern and efficient
standards and be kept in a fully operational status. This paper presents the
background factors relative to the evolution of Public Law 95-269 and a status
report on the Corps and industry efforts to implement the provisions of the
legislation. The paper is relative to only the seagoing hopper dredge program
of the Corps of Engineers because this is a program in which the industry was
not active until 1977. In addition, a study of this program has been
completed and the Chief of Engineers recommendation as to the number and class
of hopper dredges which would comprise the Federally-owned minimum fleet has
been presented to the Secretary of the Army and the Office of Management and
Budget. A study of the non-hopper dredge elements of the minimum fleet is
nearing completion and is scheduled for presentation to the Chief of Engineers
in the next month or so.
NAVIGATION MISSION
In 1824 Congress assigned the U.S. Army Corps of Engineers the responsi-
bility for improving and maintaining the navigation channels of the nation's
ports, harbors and inland waterways. Since that time, the Corps of Engineers
has taken part in the construction, maintenance and improvement of over 25,000
miles of navigable waterways.
These waterways serve 130 of the nation's 150 largest cities and are
utilized to transport one-fourth of the nation's ton-miles of domestic cargo.
Thus, they are essential to the economic well-being of the nation. Nearly 60
percent of our waterways are also vital to our ability to meet the energy
needs of the country.
There are 107 commercial ports and 416 small boat harbors that include
Federally-authorized channels. The ports and harbors of the nation handle
nearly two billion tons of cargo annually and serve over seven million recrea-
tion craft.
The maintenance and improvement of the waterways to make them suitable
for waterborne commerce is one of the major responsibilities of the Civil
Works program of the Corps of Engineers. During the past three years an
average of 308 million cubic yards were dredged at an average annual cost of
about $228 million. The major part of the annual dredging work (about 95%) is
accomplished using cutterhead, dustpan and seagoing hopper dredges. The
remaining 5% of the annual dredging workload is accomplished by the use of
bucket, dipper and sidecasting dredges. In the case of the lower and mid
sections of the Mississippi River and tributaries the work is performed
primarily with the hydraulic dustpan type of equipment since these dredges
were designed especially to operate under conditions unique to these
waterways.
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The Corps of Engineers accomplishes the majority of the annual workload
by utilizing industry equipment under competitive bidding procedures and
performs the remaining work (about 35%) with Corps-owned dredges. Presently,
the Corps operates a fleet of 36 dredges which remove about 128 million cubic
yards of material annually at a cost of $86 million. The industry owns about
476 dredges and performs about 180 million cubic yards of dredging annually at
a cost of $151 mil lion.
LEGISLATIVE BACKGROUND
Prior to the enactment of Public Law 95-269 the dredging program of the
Corps of Engineers was accomplished under the provisions of 33 USC 622 and 33
USC 624. These laws required that the dredging workload be performed in the
most economical or advantageous manner by use of either Corps dredging plant
or by industry plant. Public Law 95-269, which replaced the above cited
statutes, includes similar language indicating that the Corps of Engineers
will utilize contractor equipment when industry reasonably demonstrates its
capability to perform the work done by the existing Federally-owned fleet at
reasonable prices and in a timely manner. This legislation also includes the
following provisions:
— That a study be undertaken by the Corps of Engineers to determine the
minimum Federally-owned fleet required to perform emergency and national
defense work. The legislation indicates that the study is to be submitted to
the Congress within two years after the April 26, 1978 enactment of Public Law
95-269.
-- That no river and harbor improvement work shall be done by private
contract if Federally-owned plant is reasonably available to perform the work
and the contract price is more than 25 per centufn in excess of the estimated
comparable cost of doing the work with Corps plant.
-- That when Corps plant is not reasonably available no river and harbor
improvement work shall be done by private contract if the contract price is
more than 25 per centum in excess of a fair and reasonable cost of a well-
equipped contractor doing the work.
— That the Corps of Engineers may retain as much of the existing
Federally-owned fleet as long as necessary to insure the capability of the
Corps of Engineers and industry to carry out projects for improvement of
rivers and harbors.
— That the Corps of Engineers shall retain a technologically modern
minimum fleet of dredges to carry out emergency and national defense work and
that this fleet shall be kept in a fully operational status.
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FACTORS LEADING TO ENACTMENT OF PUBLIC LAW 95-269
Reduced Scope of Capital Improvement Projects Since World War II
Since World War II there have been few instances in which the channels of
the ports and inland waterways of the country have been widened and deepened
to any significant extent. While there have been many deep draft channels and
harbors constructed for large supertankers and bulk cargo ships in many parts
of the world, there have been no such facilities constructed in the United
States since World War II. Thus, the dredging industry of the United States
has not had an opportunity to engage in large and lucrative dredging opera-
tions such as those at Rotterdam, The Netherlands; Zeebrugge, Belgium;
Dunkirk, Le Havre and Gulf de Fos, France; and Botany Bay, Australia. Due to
the decline in the scope of the annual workload since World War II, the finan-
cial condition of many of the United States dredging, firms has deteriorated
and some of the large firms have gone out of business.
Annual Improvement Dredging Workload and Expenditures
For the extended period of 1963 through 1978 industry dredges have
performed, on an average, 86% of all the improvement or new work workload
dredging and by 1978 the industry performed 97% of the new work dredging. The
annual improvement dredging decreased significantly from 263 million cubic
yards in 1963 to only 70 million cubic yards in 1978. This dramatic reduction
in the improvement dredging workload constituted the bulk of the overall
decrease in the total dredging workload for this period. Annual expenditures
for improvement dredging for this period also decreased from $107 million in
1963 to $93 million in 1978. The unit cost, which is probably the best factor
to consider in evaluating cost trends over extended periods, was $0.41/cubic
yard in 1963 and $1.33/cubic yard in 1978. The cost/cubic yard for 1978
compares favorably with the* 1963 unit cost because it reflects a reasonable
average annual escalation of 8%.
Annual Maintenance Dredging Workload and Expenditures
During the 1963 to 1978 period the annual maintenance dredging workload
experienced an upward trend with several significant peaks occurring.
However, the net result was a slight decrease of 3% when comparing the 1963
maintenance dredging workload of 217 million cubic yards to 210 million cubic
yards in 1978. It should be noted, however, that the industry workload during
this period averaged 48% of the total maintenance workload. Moreover, the
industry workload actually increased from 80 million cubic yards in 1963 to
118 million in 1978. Maintenance dredging expenditures increased substan-
tially to $210 million in 1978 from $59 million in 1963. However, if these
expenditures are calculated in terms of constant 1963 dollars and annual
escalation of 8%, the unit rate is found to have remained relatively stable.
Total Annual Dredging Workload and Expenditures
The total annual workload or cubic yardage decreased dramatically from
480 million cubic yards in 1963 to 280 million cubic yards in 1978. Most of
this decrease occurred from 1963 to 1967 and with the exception of some
periodic peaks there was a continuing downward trend to the current level.
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Expenditures dipped from $160 million in 1963 to $92 million in 1967 and then
climbed to a 1978 total cost of $280 million. Once again, on the basis of
unit cost, this increase merely reflects an annual escalation of about 8% over
the 15-year period.
Corps/Industry Distribution of the Annual Dredging Workload and Expenditures
The Corps of Engineers has performed the majority of the total annual
dredging workload with industry equipment for many years. The Corps/industry
percentage distribution of the total annual workload yardage during the period
of 1963 to 1978 was 41/59% even though the industry did not have any dustpans
during this period and entered the hopper dredge field in 1977. During this
period, the Corps/industry percentage distribution of the total annual expend-
itures was 34/66%. On an outlay basis, the percentage distribution of the
expenditures for 1963-1978 has been within the 25-35% Corps and 65-75%
industry range cited in a 1974 management/consulting firm report as the most
economical and optimum allocation of the dredging program between the Corps
and the industry.
Summary—Dredging Workload and Expenditures
In the perspective of a rapid and significant decrease in workload and
the relative constancy of unit cost from 1963 through 1978 it is not
surprising that the industry in the face of such a financial dilemma was
reluctant to invest in new equipment or major improvements to existing equip-
ment without some encouragement from the Corps of Engineers and the Congress,
even though the industry enjoyed a substantial and increasing share of the
total declining workload.
INDUSTRY CAPABILITY PROGRAM
Background
Based upon information contained in a comprehensive study of the national
dredging program completed by a management/consulting firm in 1974, the Chief
of Engineers concluded there was a need for a comprehensive program to deter-
mine, in a structured manner, the capability of the industry to accomplish
dredging work at reasonable prices and in a timely manner. A program to meet
this objective was initiated on December 13, 1976 with the issuance of Corps
of Engineers Circular EC 1125-2-358. This program, known first as the
Testing of the Market program and currently known as the Industry Capability
Program, was initiated to accumulate detailed operational and cost information
to reflect the relative efficiency of existing Corps dredges as related to the
performance of industry dredges.
Opportunity for Industry to Compete with Corps Dredges
The Industry Capability Program provides an opportunity for the industry
to bid competitively with all types of Corps of Engineers dredges over a broad
spectrum of.dredging work. Included in this competitive bidding program are
the types of projects traditionally accomplished with specialized Corps plants
such as dustpan, hopper and sidecasting dredges. The comprehensive statis-
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tical data developed by this program will be used by the Congress to determine
the relative relationship of the Corps/industry roles in carrying out the
Federal dredging requirements.
Program Results
By the end of August 1979 the "Industry Capability Program" yielded the
following statistics:
— 84 projects, with an estimated value of $86.0 million, have been
advertised to the industry since the beginning of the program in.
December 1976.
— 42 projects have been awarded to the industry at a total contract
cost of $52.6 million. This figure was $733,000 below the total
cost estimated by the Corps of Engineers to perform the work with
Corps dredges.
— 41 projects have been awarded to the Corps dredges at a total cost
of $32.9 million. The industry did not offer any bids on 12 of
these projects. The Corps estimate for the 29 projects on which the
industry competed was $20.5 million. This was $15.4 million less
than the industry bids to accomplish the work.
-- 1 project, with an estimated cost of $483,443, is being protested by
the industry. Therefore, the award of this work has been delayed.
— Discounting the 12 projects which were awarded to the Corps when the
industry did not offer any bids, there has been a saving of about
$16.1 million to the taxpayers.
To date, the industry equipment has performed reasonably well. Gener-
ally, the work has been done satisfactorily, although there have been some
isolated problems with the industry hopper dredges and the industry pipeline
dredges while working in exposed and ocean waters. After the dredging
industry modernizes its fleet and has more experience with hopper dredges, we
expect that the industry performance will improve.
A preliminary evaluation of the results of the Industry Capability
Program indicates that the industry has risen to the opportunity provided by
this program with five hopper type vessels in operation and four hopper
dredges under construction. In addition, the industry has constructed one
dustpan dredge. Thus, the industry will soon have an increased capability and
will be able to compete in a wider range of projects in the future.
Extension of the Program
The program was initially scheduled for completion in December 1980.
However, it has been extended to September 1981 to be consistent with the
language contained in the Conference Report on the fiscal year 1979 Appropri-
ations Act. This report indicates that a reassessment of the dredging program
is to be made by the Corps of Engineers in fiscal year 1982 to determine
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whether industry's response warrants an increase or decrease in the 30 million
cubic yard industry annual hopper dredge workload target contained in the
Conference Report.
CONSTRUCTION OF HOPPER DREDGES BY THE INDUSTRY
Background
As a result of the encouragement provided by the Industry Capability
Program initiated by the Corps of Engineers and Public Law 95-269, enacted by
the Congress on April 26, 1978, the industry has embarked on a program'to
construct seagoing hopper dredges.
Existing Industry Hopper Dredges
The existing industry hopper fleet of five dredges, as of October 1979,
was as follows:
Large Class
One large class hopper dredge, the Long Island, is available. This
vessel was built by the Construction Aggregates Corporation in 1971 and
acquired by the Great Lakes Dredge and Dock Company in 1978. The Long Island
is a barge with a volumetric hopper capacity of 16,000 cubic yards. It is
propelled by a tug fitted into a notch in the stern of the barge and is
equipped with dual pumps and dragarms. This vessel was initially equipped for
only direct pumpout operations. However, it was modified in fiscal year 1978
to include a bottom gate dumping capability which will improve its versa-
tility. The Coast Guard is currently assessing the condition of all types of
dredges to determine whether they meet the design standards of the Seagoing
Barge Act (USC 395). It is possible that the Coast Guard review will result
in a decision that the current load line assigned to the Long Island must be
revised. If this is the case, it could reduce the load carrying capability of
the vessel from 16,000 cubic yards to a much lesser figure while the vessel is
operating in the offshore zone.
Medium Class
Three medium class hopper dredges are available as follows:
Manhattan Island: This vessel, which has dual dredge pumps and dragarms,
is owned by the North American Trailing Company (a consortium consisting of
the Great Lakes Dredge and Dock Company and Ballast-Needham, a Dutch firm).
The dredge was commissioned in June 1977. It is a new and modern hopper
dredge with a split hull. It has a volumetric hopper capacity of 3,600 cubic
yards and has performed well on the navigation projects on which it has worked
for the Corps of Engineers. This vessel is not equipped for direct pumpout
operations. However, we are informed by representatives of the firm that it
will probably be converted to include this capability.
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Esperance: This vessel, acquired from a Dutch firm by the Roger J. Au
Company, Mansfield, Ohio, is a converted LSI which has only one pump and one
dragarm. It was placed in service in May 1978 and has worked on two naviga-
tional projects in the Great Lakes area. The vessel has a volumetric hopper
capacity of 3,600 cubic yards and is equipped for only direct pumpout opera-
tions. The production of this dredge was poor and it is currently for sale.
It appears doubtful that the dredge will be reactivated for work in the United
States in view of its low production record and the potential conflict of its
operation with the provisions of the Coastwise Shipping Act.
Sugar Island: This vessel, which has a volumetric hopper capacity of
3,600 cubic yards, is a sister ship to the Manhattan Island and is equipped
for direct pumpout operations. The vessel was placed in service in May 1979
and is expected to perform well.
Small Class
Only one small class hopper dredge, the Manson, is available. This
vessel, owned by the Manson/Osberg Company, Seattle, Washington, is a barge
with a volumetric hopper capacity of 1,600 cubic yards. It is propelled by a
tug coupled to the stern of the barge with articulating hydraulic arms and is
equipped with only one pump and one dragarm. This vessel was placed in
service in July 1978 so the experience base for this vessel is very limited.
Thus far it has worked only inside estuaries and has performed well. However,
there is some doubt as to its ability to perform well on the entrance or bar
channels exposed to the wave action of the Pacific Ocean.
Industry Hopper Dredges Under Construction
The four hopper dredges under construction by the industry are as
follows:
Large Class
One large class hopper dredge (about 8,800 cubic yards) is under
construction at the Avondale Shipyard in New Orleans, Louisiana. Details on
the construction schedule and delivery date are not available at this time.
It is understood that the owners of the vessel will be the National Dredging
Company (a consortium consisting of Zapata Marine of Houston, Texas, and Bos
Kalis, a Dutch firm).
Medium Class
Two medium class hopper dredges are under construction by the industry as
follows:
Eagle I: A contract was awarded for the construction of this vessel
during September 1978 by the Eagle Dredging Company (a consortium consisting
of the C. F. Bean Company of New Orleans and Volker-Stevin, a Dutch firm). We
are informed by the owners that this vessel is scheduled for delivery in
October 1980. It will have a volumetric hopper capacity of about 4,750 cubic
yards, dual pumps and dragarms and a split hull. It is expected to be an
efficient dredge representative of current design technology.
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Dodge Island: A contract was awarded to Southern Shipbuilding, Slidell,
Louisiana for the construction of this vessel during March 1979 by the Great
Lakes Dredge and Dock Company, Chicago, Illinois. We are informed by the
owners of this vessel, which will be a sister ship to the Manhattan Island and
the Sugar Island, that this vessel is scheduled for delivery in the summer of
1980. ' It will have a volumetric hopper capacity of 3,600 cubic yards, dual
pumps and dragarms, a split hull, and is expected to be an efficient dredge
representative of current design technology.
Small Class
One small class hopper dredge (about 1,300 cubic yards) is under
construction by the Twin City Barge Corporation in St. Paul, Minnesota. It is
understood that the owners of the vessel will be a consortium consisting of
the T. L. James Company of New Orleans and HAM Holland, a Dutch firm.
Delivery of this vessel, which has not been given a name, is scheduled for
May/June 1980. We are not aware of the physical and equipment features of
this dredge.
Hopper Dredge Construction Planned by the Industry
Large Class
We are not aware of any industry plans to construct additional large
class hopper dredges. Our assessment of the national dredging program indi-
cates that there are a limited number of navigation projects which will
require large class hopper dredges. Therefore, it seems doubtful that many of
these vessels will be constructed.
Medium Class
The T. L. James/HAM Holland consortium has announced plans to award a
contract in the near future for the construction of a medium class hopper
dredge. It is understood this vessel will have a volumetric hopper capacity
of about 3,500 cubic yards. We are not aware of the physical and equipment
features of this dredge.
Small Class
The C. F. Bean/Volker-Stevin consortium has announced plans to award a
contract in the near future for the construction of a small class hopper
dredge, the Eagle II. We are not aware of the volumetric hopper capacity or
the physical and equipment features of this dredge.
Summary
Existing Industry Fleet of Hopper Dredges: Consists of five vessels, one
large class, three medium class and one small class.
Hopper Dredges Under Construction: There are four hopper dredges under
construction by the industry including one large class, two medium class, and
one small class.
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Hopper Dredge Construction Planned: The construction plans of the
industry, as of October 1979 included two vessels, one medium class and one
small class.
Total Industry Fleet of Hopper Dredges: As of October 1979, includes
eleven vessels, two large class, six medium class and three small class hopper
dredges.
CORPS OF ENGINEERS HOPPER DREDGE FLEET
Background
During the period of 1871 to 1906 the industry and the Corps of Engineers
operated the first hopper dredges in the world. During 1899 to 1906 the
industry experienced a series of problems in the deepening of the Ambrose
Channel leading to New York Harbor. Based on these problems, the Congress
directed the Corps of Engineers to assign two Corps hopper dredges, the
Atlantic and Manhattan in 1902 to the project to expedite the deepening of the
channel. Later in 1902 the Congress authorized the Corps of Engineers to
design, construct and operate twelve additional hopper dredges. In 1906, the
only remaining industry firm operating hopper dredges, Metropolitan Dredging
Company, went out of business. From 1906 until 1977 when the industry reacted
to the Industry Capability Program, the only hopper dredges available to work
on navigation projects in the United States were those operated by the Corps
of Engineers.
Existing Fleet
Number and Type
The active Corps of Engineers fleet consists of 14 hopper dredges. Two
of these dredges are in the large class (6,000 cubic yards or greater hopper
capacity), seven are in the medium class (2,000 to 6,000 cubic yards), and
five are in the small class (under 2,000 cubic yards).
Age and Condition
The 14 existing Corps of Engineers hopper dredges have an average age of
32.1 years. The existing fleet is generally obsolete with three of the
dredges having an average age of 41 years as compared with a reasonable econ-
omic life cycle of 20 to 25 years. Older dredges require extensive mainten-
ance and repair work to keep them operational. The repair of old equipment is
expensive and it also results in considerable lost time.
Construction of New Hopper Dredges
The Congress has authorized the construction of the following three new
hopper dredges by the Corps of Engineers.
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West Coast Shallow Draft Hopper Dredge
This vessel, with a volumetric hopper capacity of 825 cubic yards, is
under construction by the Norfolk Shipbuilding and Drydock Company, Norfolk,
Virginia. Completion is scheduled for June 1980.
Large Class Hopper Dredge
This vessel, with a volumetric hopper capacity of 8,400 cubic yards, is
under construction by the Avondale Shipyard, New Orleans, Louisiana. Comple-
tion of construction is scheduled for March 1981.
Medium Class Hopper Dredge
This vessel, with a volumetric hopper capacity of 6,000 cubic yards, is
under construction by the Sun Shipbuilding and Drydock Corporation, Chester,
Pennsylvania. Completion of construction is scheduled for January 1982.
Summary
These three new dredges will constitute the nucleus of the minimum
Federally-owned hopper dredge fleet required to meet the emergency and
national defense requirements as provided for in Public Law 95-269.
MINIMUM HOPPER DREDGE FLEET OF THE CORPS OF ENGINEERS
Background
In developing the methodology for determining the hopper dredge require-
ments of the minimum fleet, paramount consideration was given to the national
defense mission cited in Public Law 95-269. A study of the national defense
needs was prepared by the Engineer Studies Center (ESC). This study focused
on determining the number the dredges needed to support military operations in
the continental United States and overseas. The study findings were predi-
cated on an evaluation of the Department of Defense planning guidance, current
war and contingency operational plans and a wide range of operational and
logistical contingencies. The ESC study concluded that seven hopper dredges
were necessary to support the military operations of the nation, including
three medium and four small class vessels. After reviewing the hopper dredge
fleet required to provide for the military mission, the emergency dredging
needs of the nation were evaluated by the staff of the Civil Works Direct-
orate. This evaluation indicated that a fleet of eight hopper dredges was
needed and that a change in the mix of the types of dredges was also required.
The assessment of the Civil Works staff indicated that eight hopper dredges,
consisting of one large class, four medium class and three small class
vessels, could meet both the military and emergency dredging needs of the
nation. However, this assessment also indicated that this fleet of eight
hopper dredges could not meet both of these needs on a simultaneous basis.
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Factors Considered In Determining the Minimum Hopper Dredge Fleet
The major factors considered in the review of the hopper dredge require-
ments of the minimum fleet were as follows:
-- Geographical distribution of the navigation projects in the United
States and the overseas deployment areas indicated in the Engineer Studies
Center report.
— Project dimensions and operational conditions as related to the sizes
and types of hopper dredges needed. Large and medium class hopper dredges
cannot gain access to shallow draft navigation projects. Conversely, small
class hopper dredges are either ineffective or very inefficient while oper-
ating in deep draft channels.
— The frequency of the dredging cycle required at each project, i.e,
biannual, annual or multi-year cycles. The frequency of the dredging cycle is
a major factor in evaluating the capability of immediate response.
— The level of maintenance required on each of the projects. In those
cases where the level of maintenance is minimal, i.e., when the depth provided
is only marginally greater than the depth required for marine traffic, it is
often necessary to dredge the channel more than once each year.
— Projects which have a rapid and extreme shoaling rate. In the lower
Mississippi River and other major delta regions, it is not unusual for the
shoaling rate during the runoff season to reduce the flotation depths by
several feet in a matter of a few days. An immediate response capability is
required in these situations to restore normal navigation.
— The haul distances from the navigation projects to the disposal areas.
During the past ten years there has been an increase in the distances from the
dredging areas to the disposal areas. This leads to an increase in the dredge
production time required per project and relates to the number and size of
hopper dredges required. This factor also leads to an increase in the annual
funding requirement and in the unit cost per cubic yard.
— The dredging depths at the various projects. This factor must be
considered in determining the number and size of dredges required. The small
class dredges are not equipped with dragarms long enough to dredge the deep
draft projects. Large class and medium class dredges cannot function effic-
iently in shallow draft areas.
— The type of material at the various projects. A variety of materials
must be dredged ranging from light silts to heavy sands and gravel. The type
of material affects the productive capability of hopper dredges. For example,
the excavation of gravel is difficult and time consuming which results in an
increase in the dredge production time required at the projects. On the other
hand, light materials can also extend the requirement for dredge production
time when the materials do not settle in the bins of the hopper dredges and
reduce the efficiency of the operations.
12
-------
-- The requirement for direct pumpout operations. In certain situations
it is necessary that the material excavated by hopper dredges be unloaded in
diked disposal areas. This type of operation is known as the direct pumpout
dredging mode. This operation results in a large increase in the dredge
production time required due to two factors. First, the hopper dredge must
travel to a designated location and be coupled to a mooring facility. Then
the material must be pumped through a discharge line into the diked area.
Based on the type of mooring facility, the exposure to wave action, the
distance from the dredging area to the mooring facility and the length of the
discharge pipeline, the total cycle time required ranges from two to four
times greater than the cycle time required for open dumping operations. There
has been a great increase in the use of the direct pumpout mode in the past
twenty years due to environmental considerations and beach nourishment
requirements. It is expected that there will be a further increase in this
trend.
— Limitations in the periods when dredging operations can be conducted.
There are two factors which lead to this situation. First, there are areas in
which dredging operations can be conducted only during given months due to
environmental considerations such as the spawning seasons for marine life
species. Secondly, there are areas in which the wave conditions are so severe
that dredging operations cannot be conducted during certain months of the
year. These conditions, which lead to a concentration of dredge production
time during a limited period, have a bearing on the number and size of hopper
dredges required to meet the emergency dredging requirements.
— Restrictions on overflow dredging. In several areas there are envir-
onmental considerations, such as spawning seasons and the presence of polluted
materials, which eliminate the use of the overflow method of dredging. In
many cases, the excavated materials are pumped into the bins of the hopper
dredges past the capacity of the hoppers of the dredge. This technique
increases the volume of material that can be carried during each dredging
cycle and improves the efficiency of the operations. Restrictions on the use
of this dredging mode result in an increase in the production time required
and has a bearing on the number and size of dredges required to meet emergency
conditions.
— The operating schedule of hopper dredges. Corps of Engineers hopper
dredges are operated on a twenty-four hours per day, seven days per week
schedule for eleven months per year. The twelfth month is reserved for major
repairs and overhauls. By staggering the repair schedules the majority of the
fleet of dredges are in operation at any given time. It is planned that this
type of schedule will be followed when the minimum fleet is available in order
to provide for the optimum use of the available hopper dredges.
— The transit time required to move from one location to another. The
distances in each of the three coastal regions and the Great Lakes are in the
range of 1,000 to 1,500 miles. Therefore, the frequency of the dredging
cycles and the proximity of one emergency situation to another can result in
an extended transit period. This factor must be considered in determining the
number and size of dredges required to meet emergency conditions. If the
regional assignment of dredges were not provided the transit times between
various regions would be in the range of three to four weeks.
13
-------
— The effective time rate of the hopper dredges. Effective time is that
spent during the actual dredging operations, including the pumping, loading,
hauling and disposal cycles. The time spent transiting between project loca-
tions, taking on fuel and supplies, repairs, delays due to weather and all
other non-productive operations is non-effective time. Therefore, the lesser
the number of dredges available, the greater the percentage of time that must
be spent in traveling between project locations and the greater the non-
productive time.
— The collision and sinking of hopper dredges. The Corps of Engineers
records indicate that a hopper dredge is lost through sinking once every ten
years. In addition, on the average, the number of collisions with other ships
and groundings is in the range of two to three per year. In most cases the
damages sustained are not major. However, lost time for repairs occurs in
each case.
— A. proposed minimum net bottom clearance. On 5 May 1976, the Coast
Guard published in the Federal Register a proposed policy that there be a
stated minimum net clearance between the hulls of vessels and the bottoms of
the waterways. If a policy for a mininum net clearance is implemented by the
Coast Guard it could result in a significant increase in the total annual
dredging workload for hopper dredges. Such a program would cause an increase
in the dredging frequency cycles as well as an increase in the volume of
material to be removed from the waterways. As a result, additional hopper
dredges beyond those currently envisioned could be required.
— An increasing trend in the usage of hopper dredges on beach nourish-
ment and hurricane protection projects. Since 1966 there has been a contin-
uing increase in the use of hopper dredges on these types of projects. This
trend is expected to increase in the future due to the need to obtain the
materials for beach nourishment and hurricane protection projects from borrow
areas located in the offshore zone rather than from sources located within the
estuaries. This change in the source of dredged materials results from envir-
onmental restrictions and constraints on the excavation of materials from the
estuaries. The use of hopper dredges for beach nourishment and hurricane
protection projects involves operations in exposed waters and frequently
involves the discharge of the excavated materials through long discharge
pipelines. This new and extensive requirement which involves a need for an
emergency response capability requires a large percentage of dredge production
time that would otherwise be available to provide for emergencies on naviga-
tion projects.
— It is impossible to predict the effects of industry strikes and
contractural commitments, including domestic and overseas requirements, on the
availability of industry dredges. However, it has been assumed that-industry
strikes and contractural commitments to other than Corps of Engineers projects
will be regional in nature and limited in scope.
— The Federal Water Pollution Control Act (PL 92-500, 18 October 1972)
known as the Clean Water Act and the Marine Protection, Research, Sanctuaries
Act (PL 92-532, 23 October 1972) known as the Ocean Dumping Act, have in
recent years caused an increase in the dredge production time required on
navigation projects. Under the provisions of these laws dredged materials are
14
-------
now classified as polluted or unpolluted by the Environmental Protection
Agency. These laws have caused the hopper dredge production time at the
various projects to increase due to two factors. First, it is necessary in
most cases to haul the dredged materials a greater distance to open water
disposal sites than in the past. Secondly, the requirement in some cases to
place the dredged materials in diked disposal areas increases the normal cycle
time by a factor of two to four. The recent delegation of the responsibility
for the issuance of permits for disposal areas to the states is expected to
lead to further increases in haul distances and in the usage of diked disposal
areas.
-- Conference Report No. 95-1490, dated August 14, 1978, on the fiscal
year 1979 Appropriation Act indicates that the Congress is concerned over the
adverse impact that the implementation of the Seagoing Barge Act provisions
would have if they are applied to the dredging operations of the nation. It
is estimated that the vast majority of the industry cutterhead dredges which
have operated in the offshore zone on beach nourishment and hurricane protec-
tion projects will not qualify for operations in the offshore zone under a
strict interpretation of the provisions of the Seagoing Barge Act (46 USC
395). If the Coast Guard proceeds with an immediate and strict implementation
of the provisions of the Act, and it seems very likely that this will be the
case, it will result in the need for additional seagoing hopper dredges to
perform the substantial volume of work previously performed with cutterhead
dredges. The impact of this action could result in a drastic change in the
requirement for hopper dredges.
Status of the Study
The U.S. Army Corps of Engineers study on the minimum hopper dredge fleet
requirements was forwarded to the Secretary of the Army by the Chief of
Engineers on 1 February 1979. The Secretary of the Army approved the Chief of
Engineers recommendation that the minimum hopper dredge fleet should include
eight hopper dredges and forwarded the study to the Office of Management and
Budget (OMB) on 6 February 1979. The study is under review by the OMB staff
and is expected to be forwarded to the Congress well in advance of the April
26, 1980 deadline established by the Congress in Public Law 95-269.
Risk Factors Included in the Study
The Civil Works Directorate assessment that eight hopper dredges are
needed in the minimum fleet of the Corps of Engineers accepts the following
risk factors:
— That eight hopper dredges will provide the necessary production
capability to meet either the overseas or the continental U.S.
defense requirements, but is not sufficient to provide for both
requirements at the same time.
— That emergency dredging requirements will not occur on a broad scale
or in more than one region at a time.
-- That vessel losses due to sinkings will not occur.
15
-------
That the requirements for overseas commitments will be limited in
scope and will not occur frequently.
That industry strikes will occur infrequently and only on a regional
basis.
That the usage of industry hopper dredges outside the United States
and/or their usage under contractural commitments within the contin-
ental United States would be limited and for short duration.
That extended delays due to groundings, weather and sea conditions
will not occur.
That vessel losses or extended lost time due to enemy action will
not occur.
That damages and lost time as a result of collisions and other
hazards of dredging operations will not occur.
That extended delays due to major mechanical problems will not
occur.
That emergency and national defense requirements will not occur
during a period when several dredges are incapacitated simultane-
ously by scheduled and unscheduled shipyard repairs.
That repairs of a vessel deployed to address a national defense
requirement would not be required for at least six months from the
date of deployment.
CONCLUSIONS
-- That the level of annual funding since 1963 has decreased signifi-
cantly and led to the industry experiencing financial problems.
— That Public Law 95-269 provides for the Corps of Engineers to main-
tain a minimum fleet of technologically modern dredges in a fully
operational status to respond immediately to emergency conditions,
national defense and national interest requirements both in the
United States and abroad.
— That the industry is responding to the opportunity to compete with
Corps plant for additional dredging work under the Industry
Capability Program.
— That the industry will construct additional modern hopper dredges.
— That the majority of the existing Corps of Engineers hopper dredges
are obsolete and must be retired.
16
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That the retirement of the existing obsolete Corps hopper dredges
must be carefully analyzed and equated to a clear indication that
the industry hopper dredges are capable of extended efficient
performance.
That eight hopper dredges are needed in the minimum Federally-owned
fleet: one large class, four medium class and three small class
hopper dredges.
That a request for funds to construct additional hopper dredges will
not be made until fiscal year 1983 to allow the industry additional
time to compete with Corps dredges.
17
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SEA BOTTOM MANAGEMENT IN JAPAN
Rikuro Takata, Director
Environmental Protection Division
Bureau of Ports and Harbors, Ministry of Transport
2-1-3 Kasumigaseki
Tokyo, Japan
INTRODUCTION
Japan is surrounded by the sea and most of her people live in coastal
areas. "Cleaning of the sea" is one of the urgent tasks facing the government
and the people of Japan. Although we had highly accelerated economic growth
in the 1960s, the environmental problems did not attract concern. However, in
the 1970s, environmental pollution progressed to the point of adversely
affecting our way of life. Now, the need for environmental preservation of
the sea and ports and harbors has attracted the attention of the nation. To
cope with the need for environmental improvement of ports and harbors,
extensive administrative measures have been taken. Projects that have been
implemented to upgrade the environment of ports and harbors under central
government authority are shown in Table 1. There are two types of projects
involving disposal and treatment of polluted bottom sediments. One is to take
preventive measures against water pollution in the ports and harbors. This
work is directed primarily toward the removal of polluted bottom sediments.
The other aspect includes studies on the feasibility of purification of
organic sediments that have accumulated and are widely distributed in the bays
and inland seas.
This paper will discuss some of the projects, now underway or planned as
Improvement Works for ports facilities.
SEA BOTTOM CLEAN UP PROJECTS IN PORTS AND HARBORS
Preventive Measures
The Federal Law relating to Special Measures on Finance for Pollution
Prevention was enacted in May 1971. Under this law, the Japanese government
subsidizes dredging or water-intake projects authorized in the Pollution
Control Program. This public waters Pollution Control Program has been estab-
lished in 50 areas, including Yokkaichi, Tokyo and Kitakyushu. Where the
program is not -established, projects must receive special designation by the
Minister of Home Affairs in order to obtain central government funding.
19
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TABLE 1. ENVIRONMENT IMPROVEMENT PROJECTS FOR PORTS AND HARBORS
Projects
Law Applicable
Ratio of
Burden of
Subsidy
Components to be Subsidized
Outline of the Systems
Construction of facilities to
protect water from oil pollution
The Law relating to Prevention
of Marine Pollution and Maritime
Disaster
5:10 Construction of waste oil
plant or its improvement
Construction or improvement of
the ship dumping oil disposal
facilities
Pollution prevention measures in
ports and harbors
The Law relating to Special
Measures on Finance by Central
Government concerned with
Projects for Pollution
1:2 Dredging, water intaking, etc.
Polluted bottom deposit dredging
operation or water intaking
works designated in the pollu-
tion control program or desig-
nated by the Minister of Home
Affairs
ro
o
Construction of waste disposal
facilities, etc.
Construction of revetments to
contain dredged materials
Construction of the marine waste
disposal facilities (receiver,
incinerator, crasher)
Construction of a port cleaning
ship
Disposal of wrecked ship
Stockpiling materials and
supplies to protect ports and
harbors from pollution
Building the green zone
Marine environment improvement
Port and Harbor Law
Port and Harbor Law, The Law
relating to Special Measures on
Finance by Central Government
concerned with Projects for
Pollution Prevention
Subsidization on Finance
Subsidization on Finance
Subsidization on Finance
Port and Harbor Law
Financial Measure
2.5:10
2.5:10
(5:10)
2.5:10
3:10
2.5:10
1:2
(for
facilities)
1:3
(for
reclaimed
land, etc.)
10:10
Construction or improvement of
the revetments for disposal
area
Construction of the marine waste
disposal facilities
Construction of port cleaning
ship
Disposal of abandoned ship
Stockpiling of oil fence
Building the green zone
Sea cleanup operation
Construction or improvement of
the revetments for disposal area
Construction of these facilities
designed to treat marine wastes
discharged from the ship or the
facilities at sea
Construction of the ship
designed for port cleaning
Disposal of abandoned ship
Stockpiling of the oil fence for
environmental conservation in
the ports and harbors
Building or improving the sea-
shore green zone, the park and
rest house, etc.
Collection of the floating oil
or garbage
Survey for the project
Financial Measure
10:10 Survey
The survey for execution of the
project
-------
When there are businesses or industries that create pollution, those
companies must share the pollution control or clean-up costs in proportion to
their contribution to the problem. Table 2 outlines pollution prevention
measures in ports and harbors now underway or planned.
Effects of Project Implementation
Clean-up procedures for polluted bottom sediments can be divided into two
categories according to the nature of the pollutant—one is used for bottom
deposits containing organic substances and the other process is to contain
toxic substances. The effectiveness of the latter can be checked by measuring
amounts of toxic substances contained in the sediments after the process is
complete. Accumulation of toxic substances in marine animals is measured
also.
When bottom sediments are contaminated by organic substances, sediment
removal is effective. Effectiveness can be evaluated in terms of improvement
in water quality near the dredging site and the reduction in odor.
In this paper, two bottom sediment clean-up projects are discussed. One
is the dredging operation in Tokuyama-Kudamatsu port and the results of envir-
onment surveys before and after the operation. The other is the project at
Hachinohe port.
Project involving sediment contaminated by toxic substances
Tokuyama-Kudamatsu port in Tokuyama Bay, in the western part of the Seto
Inland Sea, was heavily polluted by mercury (see Figure 1). The Japanese
tentative standard for mercury is set at 15 ppm; therefore the area to be
cleaned was confined to that where the mercury in the sediments exceeded the
standard. Dredging had occurred at the eastern site from June, 1975 to
November, 1976 and, at the western site from September, 1975 to March, 1977.
Two kinds of operations were used. One was the dredging of polluted sediments
and the other involved containing the polluted dredged materials. The
disposal site foundation was improved with the sand drain and sand compaction
pile method. After the foundation was reinforced, two rows of sheet pile and
sheet pile cellular cofferdam were installed. During the filling with dredged
materials and treatment of effluent water, precautions were taken to avoid
secondary pollution. No abnormal values of environmental parameters were
found during the project. After completion, the bottom sediment, water
quality and fish were examined (see Figure 2, Table 3).
Examination of bottom sediment. To assure removal of the sediments
containing excessive amounts of mercury, analyses were made of samples taken
around the project site. Results (Table 4) indicate the project effective-
ness; no bottom sediments containing over 15 ppm mercury were found. No
dispersion of the dredged materials occurred in the area.
Examination of the fish. Five species of fish that had been affected by
mercury poisoning have been checked annually since 1974. As can be seen in
Table 5, mercury in fish tissues was reduced to a permissible limit after the
dredging operation.
21
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TABLE 2. OVERVIEW OF PROJECTS INVOLVING REMOVAL OF BOTTOM SEDIMENT AT PORTS AND HARBORS (as of March
1979)
Name of Port
Tokyo
Yokohama
Nagoya
Yokkaichi
Osaka
Himeji
Wakayama
Shi mots u
Kita-Kyushu
Shiogama
Tagonoura
Mizushima
Ml namata
Hachinohe
Amagasaki ,
Nishinomiya,
Ashiya
Higashi-
Hirama
Kure
Takamatsu
Toyo
Iwakuni
Mitajiri-
Nakanoseki
Ube
Saeki
Work
Period
1972-1981
1973-1979
1972-1981
1974-1979
1973-1981
1974-1980
1979-1980
1972-1981
1972-1977
1972-1980
1972-1980
1975-1984
1979-1980
1977-1981
1978-1980
1980
1980
1977
1980
1976-1978
1980
1980-1981
Pollutant
organics
organ ics
mercury,
organics
mercury,
oils
organics
organics
organics
mercury
organics
organics
PCB,
organics
oil
mercury
organics
organics
organics
organics
PDB,
organics
organics
organics
organics
organics
organics
Spoil x
1000 m3
2,400
691
729
2,200
1,645
460
100
3,300
47
1,720
813
1,675
257
200
50
200
397
20
372
445
492
805
Removal Standard
6 points or more in the over-
all, ignition loss, COD, and
sul fides
same as Tokyo
Hg, 25 ppm; ignition loss,
15%
Hg, 6 ppm; oils, 4,000 ppm
ignition loss, 15%
ignition loss, 15%
pending decision on either
COD 20 mg/g or sul fides
1 mg/g
Hg, 30 ppm
ignition loss, 15%
PCB 10 ppm
1 ,500 ppm
Hg, 25 ppm; COD, 30 mg/g
sulfide, 1 mg/g; ignition
loss, 10%
ignition loss, 15%; COD,
20 mg/g or sul fides, 1 mg/g
undecided
undecided
undecided
odor no. , 2.5
undecided
ignition loss, 15%
undecided
undecided
Reclamation Method
Reclamation by sealed grab
bucket and special pumps
Reclamation by ordinary grab
buckets
Reclamation by ordinary grab
buckets
Reclamation by special pumps
Reclamation by special pumps
Dredging by ordinary pump,
solidification and
reclamation
Reclamation by sealed grab
buckets
Reclamation by sealed grab
buckets
(1) Reclamation by pump, (2)
Dredging by ordinary grab
buckets, solidification, and
reclamation
Reclamation by pump
Dredging by ordinary grab
buckets, solidification,
reclamation
Reclamation by sealed grab
buckets
Reclamation by special pumps
(continued)
22
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TABLE 2. (continued)
Work
Name of Port Period
Spoil x
Pollutant 1000 m3
Removal Standard
Reclamation Method
Otake
1980
orgamcs
890 undecided
Omuta
1973-1979 cadmium,
mercury
536 Hg, 25 ppm; Cd, 200 ppm
(1) Reclamation by special
pumps; (2) Earth covering
Nakatsu
1980
organics 1,008 undecided
Earth covering
Rumoi
1980
orgamcs
15 undecided
Matsuyama
1973-1974 organics
62 odor no., 2.5
Reclamation by sealed grab
buckets
Mi kawa
1973-1975 organics
50 COD, 16 mg/g; ignition loss,
10%; sulfides, 1 mg/g
Reclamation by sealed grab
buckets
Sakata
1974-1975 mercury
71 Hg, 28 ppm
Reclamation by special pumps
Aburatsu
1974 organics
18 ignition loss, 20%
Reclamation by ordinary grab
buckets
23
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TABLE 3. OUTLINE OF BOTTOM CLEAN-UP PROJECT AT PORT OF TOKUYAMA-KUDAMATSU
Work Period
Disposal Site
Dredging
PoKluted
Start
End
Area (m2)
Capacity (m3)
Area (m2)
Volume (m3)
Area (m2)
Eastern Site
July 7, 1975
November 11, 1976
29,00.0
365,000
239,000
148,000
145,000
Western Site
September 4, 1975
March 15, 1977
451,000
5,479,000
294,000
214,000
451 ,000
TABLE 4. RESULTS OF THE BOTTOM SEDIMENT ANALYSES
Site
T -
T -
T -
Eastern Site ...
T -
1
2
3
4
5
6
Total
N -
N -
N -
Western Site N -
N -
1
2
3
4
5
Number of
Points
6
5
9
20
9
7
56
14
12
12
12
12
Total Mercury (mg/kg)
Average
2.2
1.7
1.2
2.3
2.9
3.1
2.3
1.9
2.6
2.4
3.3
2.9
Range
0.26 -
0.03 -
0.14 -
0.08 -
0.95 -
0.71 -
0.03 -
0.03 -
0.14 -
0.13 -
0.56 -
0.19 -
3.8
2.7
4.0
7.6
5.2
8.4
8.4
7.7
8.5
5.0
6.5
7.5
Total
62
2.6
0.03 - 8.5
24
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TABLE 5. CONCENTRATION OF ACCUMULATED MERCURY IN FISH FROM TOKUYAMA BAY
Sept 1973 June Nov-Dec Jun-Jul Oct-Nov June Oct-Nov Jun-Jul
-Oct 1975 1976 1976 1977 1977 1978 1978 1979
Rock Trout
Japanese
Sea Perch
Sea Bass
Rock Fish
Black
Porgy
Average
(165)*
0.629t
(195)
0.428
(H5)
0.416
(110)
0.529
(115)
0.639
(730)
0.528
(30)
0.322
(30)
0.315
(10)
0.487
(25)
0.460
(20)
0.601
(115)
0.437
(10)
0.303
(20)
0.178
(25)
0.130
(30)
0.217
(20)
0.425
(105)
0.250
(10)
0.273
(20)
0.199
(20)
0.215
(30)
0.246
(25)
0.545
(105)
0.295
(15)
0.206
(30)
0.199
(15)
0.249
(15)
0.264
(30)
0.398
(105)
0.263
(20)
0.176
(25)
0.210
(25)
0.203
(25)
0.257
(30)
0.423
(125)
0.253
(25)
0.208
(20)
0.240
(20)
0.216
(20)
0.260
(25)
0.357
(110)
0.256
(25)
0.179
(30)
0.183
(20)
0.204
(30)
0.158
(25)
0.349
(130)
0.214
TOTAI* Number of samples (n). t Total mercury (mg/kg).
MERCURY
0.8
0.6
0.4
0.2
0
- —-DREDGING-
AVERAGE
BLACK PORGY
I i
TABLE 6. .PROPERTIES OF BOTTOM SEDIMENT IN PORT OF HACHINOHE*
COD
Sulfide
Ignition
Loss T-N
T-P
Cd
Surface Layer
Total
Pb Mercury
Property
39.5
mg/g
5.5
mg/g
12.5%
3.2
mg/g
2.7
mg/g
5.3
ug/g
311
12.0
* Average of 1973-1978.
25
-------
"2.8.
3.6
4.5
7.3
4.3
1.4
2.0
2.3
2.4
'3.6
.4.6
.34
.4.5
5.0
2.3
3.3;
16
rr-
737/'
V3.5
6-l>
.2.5
4.7
4.0
>6.6
.1-0
1.5
23 3-5
09
\zjr-
3.5
I 3-° «AI
5.0 / 5.8 \0.4 * 117 4-'
« ,, 4Vfp>jr
typ.?.'.
ippm
5PP™*
7.8
4.1«
10.1
15.1
8.7
.13.5
1.2
'7.3
7.2
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Figure 1. Mercury distribution
map of
-°6 -'6 •" /OSHIMA PENINSULA
bottom sediment in Tokuyama Bay (mg/g).
-------
TOM/7/1 RIVER
AL SITE
* ^
1st WASTE WAY
DREDGED AREA
ENCLOSED AREA
NISHI ISLAND
NAKA ISLAND N.
TOKUYAMA BAY
1st WASTE WAY
'2nd WASTE WAY
DUMPING SITE
POLLUTED AREA
WASTE WAY •
500 IOOO M
Figure 2. Dredged or enclosed area in Port of Tokuyama-Kudamatsu.
-------
Project involving sediment contaminated by organic substances
This project took place in the Hachinohe Port in Aomori prefecture. Deep
within the port is an industrial site where the water is always stagnant. In
1978 COD measured 7 mg/1, indicating extensive water pollution. Organic
deposits (see Table 6) are apparent sources of water pollution and offensive
odors. To eliminate these pollution sources, certain standards for removal of
organic deposits (Table 7) were set, providing the basis for the "clean water"
project of Hachinohe Port. The project duration is scheduled from 1979 to
1980. During the operation, as much as 256,800 m3 of bottom deposits will be
dredged and reclaimed as land fill material for the green area project (refer
to Figure 3).
The example of Hachinohe Port is appropriate to assess the effects of
clean-up since the project period is relatively short and the topography is
suitable for this purpose. Site surveys before and after the project will
measure the degree of pollution and, at the same time, provide data for an
analytical study of the mechanism and function of the pollutants contained in
bottom sediments. Main items of the surveys are listed in Table 8. Plans
include studies to determine the critical mass of organic substances causing
environmental pollution and increase the understanding of mechanisms by which
organic substances are released into the water and the causes of offensive
odors.
BOTTOM SEDIMENT CLEANUP IN BAYS AND INLAND SEAS
Countermeasures for Pollution of Bottom Sediment
Tokyo Bay, Ise Bay and the Seto Inland Sea are confined water bodies.
There are many sources of pollution and the water exchange dynamics are poor,
resulting in extensive pollution problems. Thus, it is essential to take
measures to improve water quality in these areas. Pollutants contained in
domestic and industrial liquid wastes have settled to the seabed and, over
many years, formed the highly polluted deposits. These deposits have contam-
inated the marine waters through release of organic substances and nutrient
salts; offensive odors and oxygen deficiency are associated with the release
of organic substances from bottom sediment.
The present state of bottom sediment contamination in Tokyo Bay, Ise Bay
and the Seto Inland Sea is illustrated in Figure 4. It is apparent that
eutrophication and deterioration of the self-purification capacity of the
waters can be attributed to the polluted deposits. In this situation
extensive bottom cleanup projects are planned to improve the marine environ-
ment. Basic surveys have been conducted on a wide scale for Tokyo Bay, Ise
Bay and the Seto Inland Sea. Through the survey results, the benefits of the
bottom cleanup projects became apparent. However, such a cleanup operation
encompassing this vast area is no easy task. Before the project can be imple-
mented it is necessary:
1) To identify priority programs for the project.
2) To perfect sediment removal methods.
3) To make preliminary studies of potential impacts on the environment,
28
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TABLE 7. PROVISIONAL REMOVAL STANDARD OF BOTTOM SEDIMENTS, HACHINOHE
Removal Standard
COD
Sulfide
Ignition Loss
30 mg/g
1 mg/g
TABLE 8. MAJOR PARAMETERS SURVEYED IN HACHINOHE PORT
Parameter
Number of
Sampli ng
Sites
Items
Remarks
Current
24 Hours
Observation
Water Quality
pH, Cl , COD, DO,
TOC, T-P, P04-P, T-N,
NH4-N, SS, chloro-
phyll a, water color,
n-hexane extraction
substance, etc.
Content
ignition loss, COD,
sulfide, T-N, T-P,
TOC, Eh, n-hexane
extraction substance,
Fe2+, Mn2+, etc.
Bottom Sediments Void Water
COD, T-P, P04-P, T-N,
NH4-N, Eh, Fe2+,
Mn2+, etc.
Release
COD, TOC, T-N, NH4-N,
T-P, P04-P, etc.
Oxygen Demand
DO, S2-, etc.
Organism
benthos, plankton,
adnate organisms,
bacterium, etc.
Odor
H2S, CH4, CH3SH, etc.
29
-------
DREDGE V: 102700m* (1979)
154,100m3 (1980)
>^AX^ V: 154,100m3
&'•' • 'jr \
Figure 3. Sediment cleanup project in Port of Hachinohe.
-------
(mg/g)
ARA
DRIVER
EDO RIVER
TOKYO ..•
JAMA RIVER.'fy
YOKOHAMA..-:;
Figure 4a. Horizontal distribution of COD (sediment) in Tokyo Bay, September 1977 (mg/g).
-------
0 5 10 KM
co
ro
SHIMA PENINSULA
:.- NA60YA
\ATSUMI PENINSULA
Figure 4b. Horizontal distribution of COD (sediment) in Ise Bay, 1975 (mg/gj
-------
(mg/g)
NISHIHARIMA
oo
CO
SHIMONOSEKI
BEPPU
HIROSHIMA BAY MIZU'SHIMA
HIROSHIMA
OSAKA
Figure 4c. Horizontal distribution of COD (sediment) in Seto Inland Sea, August 1972 (mg/g)
-------
Therefore, before initiating the main operation, a pilot project should
be designed. The pilot project will serve as the model for most contaminated
sea bottom operations. The survey began in 1979 in the Seto Inland Sea with
the following objectives:
1) To study the mechanics of sea sediment pollution.
2) To analyze sediment pollution and the effects of removal.
3) To implement the experiments.
4) To study the impact of the project on the environment.
Effects of Bottom Cleanup in Bays and Inland Seas
One of the most important objectives of the pilot project is the analysis
of sea water pollution mechanisms and the effects of bottom cleanup. Because
of cost and time limits, cleanup in large areas such as the Seto Inland Sea
must be efficient. Therefore it is essential to the overall project that
there is an understanding of the pollution mechanisms and the ways polluted
deposits can affect their aquatic environments.
The plan calls for the development of a model of the mechanisms which
cause pollution and for analytical studies on the effects of the cleanup. The
model is being designed with data from related research projects, site surveys
and experimental demonstrations.
Concept of the circulating system of organic substances
It seems that water pollution progresses through a circulating system
(generation-dissolution-transfer-dispersion) in the Seto Inland Sea. There-
fore the model is being developed based on the concept of the circulating
system of organic substances (Figure 5).
Assessments of the model
Assessments of the improved water quality after cleanup should be made on
the primary (direct) effect and secondary (indirect) effect, taking into
consideration the time (season) and space (place) factors. The primary effect
is that attributed to removal of substances which would be released from
bottom sediments; secondary effects are those influencing oxygen demand and
the release of inorganic nutrient salts (phosphorus). The suppression of
inorganic nutrient salt (phosphorus) release will retard the development of
eutrophic conditions in surface waters.
Functions of the model
(1) To model the cyclic circulation mechanisms of the pollutants between
water and bottom sediments.
(2) To provide a fit for seasonal variation and yet be reliable for long term
observations.
(3) To provide a model that can predict the probable effects on water quality
and simulate the effects of bottom cleanup.
34
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CO
HORIZONTAL*
TRANSPORTATION
MIXING
HORIZONTAL
TRANSPORTATION
HORIZONTAL "*
MIXING
photic
aphotic
DISSOLVED
OXYGEN N
i
f
mixing
diffusion \
vertical
transporta
DISSOLVED
OXYGEN N
bottom
\ consumption
"of DO
N
INORGANIC
UTRIENT SALTS
'
ORGANIC
SUBSTANCE
decomposition
*
mixing
diffusion \
vertical
tion transportation <
INORGANIC
UTRIENT SALTS
I I >
release <
INORGANIC
UTRIENT SALTS
consumption of DO
> decomposition
t
I
mixing
diffusion
sedimentation
•«
i
ORGANIC
SUBSTANCE
disturbance
sedimentation
\
decomposition
\
(
release
lt
dk
iurbonce
ORGANIC
SUBSTANCE
HORIZONTAL
TRANSPORTATION
HORIZONTAL
MIXING
HORIZONTAL
TRANSPORTATION
HORIZONTAL
MIXING
Figure 5. Concept of the circulating system of the organic substances.
-------
(4) To model the substances' cycling mechanisms (generation, dissolution,
sedimentation and release) and the relationship between dissolved oxygen
and releasing speed.
FUTURE PROSPECTS
Federal government subsidized cleanup operations in the ports and harbors
beginning in 1972. Since then, some of the technical problems have been
solved through the actual projects or by conducting research studies and
surveys. Today's most critical problem is to establish a realistic standard
for sea bottom sediment cleanup and to adopt more effective cleanup methods.
Full scale surveys of the organically polluted bottom deposits in bays
and inland seas have just begun. Therefore, based on the relevant available
data, a comprehensive program of research and implementation must be estab-
lished.
Currently there is the problem of eutrophication in these waters. The
national projects of sea bottom cleanup combined with pollutant-loaded
effluent control programs are attracting considerable attention. The objec-
tives of this project lie not only in the removal of years' accumulation of
pollutants, but also in the creation of a better environment and ultimate
improvement of the coastal waters.
REFERENCES
1. The Association for the Seto Inland Sea Environmental Conservation; Data
Book for Environmental Conservation of Seto Inland Sea, 1978.
2. The Second District Port Construction Bureau, Ministry of Transport;
Environment in Tokyo Bay, 1979.
3. The Fifth District Port Construction Bureau, Ministry of Transport;
Environment in Ise Bay, 1979.
4. The Third District Port Construction Bureau, Ministry of Transport;
Material of the Pilot Project for Marine Environment Improvement, 1979.
5. Yamaguchi Prefecture; Environmental White Paper, 1978.
6. Yamaguchi Prefecture; Material of Yamaguchi Prefecture Council for
Control of Water Quality, 1979.
36
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CONTROL OF TOXICS IN THE UNITED STATES
James C. McCarty, Deputy Director
Environmental Research Laboratory
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
INTRODUCTION
The problems associated with disposal of toxic substances in the United
States have been spotlighted in the past few years for two primary reasons.
First, the Toxic Substances Control Act of 1976 (TSCA) gave the government
broad new authority to gather information on the potential of chemicals to
damage human health and the environment and authority to control these sub-
stances where necessary. Second, an even greater awareness of chemical
dangers has resulted from a recent series of unrelated toxic disposal episodes
in the United States.
The control of toxic substances is extremely complex as indicated by the
number of different chemicals produced, the number of manufacturers, and the
amounts of chemicals produced. In November 1977, the registry of chemicals
maintained by the American Chemical Society listed 4,039,907 distinct chemical
compounds—and the registry includes only chemicals reported in the literature
since 1965. The list has been growing at a rate of 6,000 per week (1).
Chemicals currently in commercial production in the U.S. may number as high as
70,000; 50 are produced in quantities greater than 1.3 billion pounds per year
(2). From 115,000 companies involved in the production and distribution of
chemicals, the business is worth $113 billion per year, or about 7 percent of
the nation's GNP (3). The majority of these chemicals probably are innocuous
and beneficial, yet our knowledge of them is limited.
TYPES OF PROBLEMS
Increasingly, the hazards of toxic substances—real or suspected—in the
home, marketplace and workplace are being reported in the popular as well as
the technical literature. These substances reputedly permeate the air we
breathe, the water we drink and the food we eat. Examples of these problem
types are:
- PCB (polychlorinated biphenyl) contamination of food is appearing across
the nation. At least nine states have restricted the consumption of fish
caught in local waters because concentrations of PCBs exceed the U.S.
Food and Drug Administration allowable limits (4). Accidental contamina-
tion of turkey feed with PCBs in the northwestern U.S. has resulted in
37
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withdrawal of thousands of birds from the marketplace. Public concern
has resulted in a precipitous decline in the sale of uncontaminated
turkeys with the secondary effect of seriously damaging the turkey
industry. (PCBs are now banned from sale in the U.S. but large amounts
are already in the environment or contained in electric capacitors and
transformers which present a serious disposal problem).
- Recent findings have shown people living near roadways may face up to
nine times the normal chance of contracting cancer due to their exposure
to polycyclic aromatic hydrocarbons found in automobile exhaust (5).
- Evidence shows that florists and others working with large quantities of
cut flowers are exposed to dangerous levels of toxics from the pesticide
or chemical residues on the plants (6).
- Benzene is found in many consumer products such as paint strippers,
carburetor cleaners, denatured alcohol, rubber cement and art and craft
supplies. Studies show that levels in households frequently exceed
standards allowed for occupational exposure. Excessive benzene exposure
is suspected of inducing leukemia (7).
- Across the nation old industrial waste disposal sites are being viewed
with alarm due to the recent discovery of highly toxic materials in New
Jersey, New York and Kentucky. In the Love Canal area of Niagara Falls,
New York where homes and a school were built over an old chemical waste
disposal site containing rusting barrels of more than 82 chemicals, 11 of
them suspected carcinogens, there has been an unusually high incidence of
birth defects and miscarriages. The seriousness of the disposal site
problem was reinforced by a recent Congressional report which concludes
"even an extraordinary effort commenced immediately, cannot achieve
adequate protection for the American public for years to come" (8).
- According to a survey of 4,636 U.S. industrial plants employing a total
of 985,000, one of four citizens is exposed in the workplace to some
substance capable of causing death or disease (9).
FEDERAL LEGISLATION
It is obvious that the possibilities for involuntary exposure to toxic
substances are almost endless. Government and industry, together, are re-
sponsible for protecting workers, the public and the environment. A series of
federal laws have been enacted to protect the public health and the environ-
ment from toxic substances (see Table 1). The focus of these laws parallels
the routes of involuntary exposure, e.g. air, water, food, drugs, etc. Toxic
laws are primarily extensions of public health and environmental protection
efforts. The scope of these laws and control philosophies has changed over
time.
In the early 1970s environmental legislation focused on controlling
pollution in specific media (air, water, land) after the pollutant had been
generated. The methods included setting "ambient" air standards or "receiving
water" standards and specific emission or discharge standards to limit the
38
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amount of a pollutant allowed into the environment. More recent legislation
supports a preventive philosophy. For example, the Toxic Substances Control
.Act and recent amendments to the Federal Insecticide, Fungicide and Rodenti-
cide Act require chemicals to be tested before they can be manufactured for
commercial use. The evolving toxics control philosophy in the United States
emphasizes the need to protect total ecological systems and to integrate the
regulation of industrial discharges to insure that the requirements for air,
water and solid waste discharges are compatible.
The diversity of toxics-related laws is illustrated in Table 1. The most
comprehensive of these are administrated by the Environmental Protection
Agency (EPA). The Toxic Substances Control Act (TSCA) and the Resource Con-
servation and Recovery Act (RCRA) are the most significant in terms of control
authority. TSCA requires premarket toxicological testing of all new chemi-
cals. All existing chemicals in commerce—excluding pesticides—must be
identified and testing can also be required. EPA has been given broad author-
ity to ban, limit, or modify the use, manufacture, or processing of any sub-
stance which could pose an unreasonable risk to human health or the environ-
ment. (Details of TCSA were presented by E. Wall en at the Third U.S.-Japan
Experts' Meeting in 1978.) RCRA establishes a comprehensive government regu-
latory system for control of hazardous wastes from generation to ultimate
disposal. It prohibits open dumps and the disposal of hazardous wastes in
sanitary land fills. RCRA also requires criteria to be established for con-
struction of proper disposal facilities and encourages recovery and recycling
activities.
Following is a summary of other important federal laws dealing with the
regulation of toxics:
- Clean Air Act (as amended 1970, 1977) regulates emissions from both
mobile and stationary sources and sets ambient standards for major
classes of pollution based primarily on public health considerations. It
also controls point source emissions of "hazardous air pollutants."
- Federal Water Pollution Control Act (as amended 1972, 1977) sets forth
procedures for establishing and enforcing water quality standards for
receiving waters and effluent standards for point source discharges of
pollutants. Provides for control of toxic pollutants in effluents and
enforcement in toxic spill events. Requires that, by 1984, best avail-
able treatment technology be applied to 65 classes of toxic chemicals for
21 industries and provides for cleanup action against other potentially
toxic chemicals by 1987.
- Occupational Safety and Health Act (1970) sets exposure standards for
toxic and hazardous materials in the workplace so that "no employee will
suffer material impairment of health or functional capacity."
- Both the Consumer Protection and Safety Act (1972) and the Federal
Hazardous Substances Act (as amended 1960, 1969) give broad power to
limit or prevent public exposure to toxic or hazardous materials in
consumer products (excluding tobacco, foods, drugs and cosmetics).
39
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TABLE 1. FEDERAL LAWS AND AGENCIES AFFECTING TOXIC SUBSTANCES CONTROL*
Statute
Responsible
Year Enacted Agency
Sources Covered
Toxic Substances Control Act
1976
EPA
Clean Air Act
Federal Water Pollution Control
Act
Safe Drinking Water Act
Federal Insecticide, Fungicide,
and Rodenticide Act
Act of July 22, 1954 (codified as
§346(a) of the Food, Drug and
Cosmetic Act
Resource Conservation and Recovery
Act
Marine Protection, Research and
Sanctuaries Act
Food, Drug and Cosmetic Act
Food additives amendment
Color additive amendments
New drug amendments
New animal drug amendments
Medical device amendments
Wholesome Meat Act
Wholesome Poultry Products Act
Occupational Safety and Health Act
Federal Hazardous Substances Act
1970, amended
1977
1972, amended
1977
1974, amended
1977
1948, amended
1972, 1975,
1978
1954, amended
1972
Consumer Product Safety Act
Poison Prevention Packaging Act
Lead Based Paint Poison
Prevention Act
Hazardous Materials Transport!on
Act
Federal Railroad Safety Act
Ports and Waterways Safety Act
Dangerous Cargo Act
1976
1972
1938
1958
1960
1962
1968
1976
1967
1968
1970
1966
1972
1970
1973, amended
1976
1970
1970
1972
1952
EPA
EPA
EPA
EPA
EPA
EPA
EPA
FDA
FDA
FDA
FDA
FDA
FDA
USDA
OSHA
CPSC
CPSC
CPSC
CPSC
DOT (Mater-
ials Trans-
portation
Bureau)
DOT (Fed-
eral Rail-
road Admin)
DOT (Coast
Guard)
Requires premarket evaluation of all new
chemicals (other than food additives, drugs,
pesticides, alcohol, tobacco); allows EPA
to regulate existing chemical hazards not
covered by other laws related to toxic
substances
Hazardous air pollutants
Toxic water pollutants
Drinking water contaminants
Pesticides
Tolerances for pesticide residues in food
Hazardous wastes
Ocean dumping
Basic coverage of food, drugs and cosmetics
Food additives
Color additives
Drugs
Animal drugs and feed additives
Medical devices
Food, feed and color additives and pesti-
cide residues in meat and poultry
Workplace toxic chemicals
"Toxic" household products (equivalent to
consumer products)
Dangerous consumer products
Packing of dangerous children's products
Use of lead paint in federally assisted
housing
Transportation of toxic substances
generally
Railroad safety
Shipment of toxic materials by water
CPSC = Consumers Product Safety Commission
DOT = U.S. Department of Transportation
EPA = U.S. Environmental Protection Agency
FDA = Federal Drug Administration
OSHA = Occupational Safety and Health Administration
USDA = U.S. Department of Agriculture
* From "Environmental Quality," the Ninth Annual Report of the Council on Environmental Quality, December
1978.
40
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- Federal Food, Drug and Cosmetic Act (as amended 1958, 1960, 1962, 1968,
1976) requires safety and performance testing of all new foods, drugs,
food additives and cosmetics. Any substance which shows carcinogenic
potential in test animals is barred from the marketplace.
- Federal Insecticide, Fungicide and Rodenticide Act (as amended 1972,
1975, 1978) requires registration of all pesticides, controls their uses
and requires certification of applications. Registration of pesticide
may be suspended immediately and the product taken off the market if
there is an imminent threat to human health or the environment.
- Safe Drinking Water Act (as amended 1977) regulates public drinking water
systems and sets standards on finished drinking water to protect the
public health from contaminants, including toxic substances. Regulates
underground injection of wastes to protect groundwater.
- Marine Protection, Research and Sanctuaries Act (1972) regulates the
dumping of any material transported from the United States into ocean
waters and any material from outside the U.S. into ocean waters under the
jurisdiction of the U.S.
Coordination
The need for coordination of these diverse laws to achieve a unified
toxic substances control program is evident. In 1977 the President of the
United States instructed the Council on Environmental Quality (the body in the
U.S. which has responsibility for developing national environmental policy) to
design a coordinated interagency program "(1) to eliminate overlaps and fill
gaps in the collection of data on toxic chemicals, and (2) to coordinate
federal research and regulatory activities affecting them." In response to
this directive, CEQ formed a 17-agency Toxic Substances Strategy Committee of
members from federal agencies with major responsibilities for toxic chemicals
(10). The committee's work relates to all the laws on toxic chemical controls
as shown in Table 1. Examples of issues addressed by the committee include:
- Coordination of regulatory and other approaches to prevent and/or control
toxic chemical problems.
- Usefulness of federal research in support of toxics regulation and
policy.
- Policies for handling trade secrets and maintaining confidentiality of
data.
- Analyses of case histories of past federal actions.
- Coordinated collection and exchange of toxics data among federal
agencies.
- Development of a standard procedure or basis for identifying carcinogens
throughout the federal government.
41
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- Development of a comprehensive action plan for handling toxic spills and
other emergencies, including definitions of state and local government
roles.
Closely related to the Strategy Committee is the Interagency Regulatory
Liaison Group which was formed by the Environmental Protection Agency, the
Food and Drug Administration, the Consumer Product Safety Commission and the
Occupational Safety and Health Administration. In 1977 the group published an
interagency agreement related to toxic substances control which sets forth a
common and consistent approach to:
- Testing protocols, criteria for interpretations, and quality assurance
procedures.
Epidemiological practices and procedures.
- Assessment of risks and estimation of benefits.
- Methods of handling data of mutual interest.
Research and development policies.
- Regulations and regulatory development activities such as joint public
hearings or rulemaking actions.
Compliance procedures and policies.
Public information.
Another important coordinating body is the Interagency Toxic Substances
Data Committee which is a permanent, independent group co-chaired by CEQ and
EPA. This committee has the task of evaluating data needs and coordinating
the data systems of all federal agencies generating toxics data into one
comprehensive program responsive to nonfederal as well as federal users. This
work is being done in support of the Strategy Committee and to fulfill other
responsibilities required of EPA and CEQ under the TSCA.
Problems
Based on the variety of programs and breadth of interagency involvement,
it is evident that the United States approach to controlling toxic substances
is diversified and complex. However, in spite of the many laws, agencies and
coordinating efforts there are still many difficult problems to be resolved.
Regulatory actions against toxic and hazardous substances have, for the
most part, proceeded on a chemical-by-chemical basis. With the thousands of
chemicals involved this is a slow, tedious process which will take years to
accomplish. EPA and other agencies are exploring a "generic" approach to
toxics regulation. Such an approach would group substances with similar toxic
properties—for example, carcinogens or suspected carcinogens—and any current
or new substance having these properties would be processed by some common
testing and regulatory scheme. A related approach, especially for new chemi-
cals, assumes substances with similar chemical structure have similar effects
42
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and control would be focused on groups or classes of chemicals rather than
single chemicals. However, the generic regulatory approach is still evolving
and to date no single procedural scheme has received strong support.
Most of the data available today has to do with acute effects of specific
toxics. There is little knowledge of synergistic or antagonistic effects,
environmental transport and fate, biological pathways, and chronic (long-term)
effects. A shortage of adequate laboratory facilities and professionals
trained in toxicology, industrial hygiene, pathology and related disciplines
makes the task of developing adequate toxicological data a very slow, perhaps
impossible, process. This problem has yet to be adequately addressed.
The primary purpose of the federal government's toxics program is to
bring hazardous wastes of all types under safe management and control. How-
ever, a major disposal problem exists, and is getting more critical each day.
How do we decide where to destroy, neutralize or contain hazardous wastes? The
public demands that these wastes be managed so there is no threat to health
and well being, but nobody wants it done in their neighborhood (11). A recent
report by the General Accounting Office states that the major roadblock to the
building (or even continued operation) of hazardous waste disposal sites is
public opposition—not economics, technical feasibility, government bureauc-
racy, or industrial recalcitrance. Ironically, properly run disposal sites
are desperately needed in every state; the lack of adequate sites and guide-
lines is forcing illegal uncontrolled disposal which has much greater poten-
tial for harm to health and the environment.
CONCLUSION
The problems of controlling toxic substances in a democratic, industrial-
ized society are complex, highly diversified and difficult to resolve. How-
ever, the problems caused by inadequate control are far greater and the conse-
quences much more severe. The United States has made great strides in devel-
oping protective legislation. Now, environmental planning for the decade of
the 80s dictates the need for sensitive interaction, communication and cooper-
ation among all levels of government, science and industry. We must develop
the data base for making rational decisions and devise reasonable adminis-
trative procedures that will protect human health and maintain environmental
quality, while preserving economic incentives. And we must have the foresight
and confidence to know that the challenge can be met.
REFERENCES
1. Maugh, Thomas H. Chemicals: how many are there? Science 199 (4325):
162 (1978).
2. Storck, William J. C&EN's top fifty chemical products and producers.
Chemical and Engineering News 56 (18):33 (1978).
3. U.S. Department of Commerce. Survey of current business 58(5):5-l, 5-6,
p. 56.
43
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4. Council on Environmental Quality. Environmental quality, the ninth
annual report. December, 1978, p. 179.
5. Blumer, Max, Walter Blumer, and Theodore Reich. Polycyclic aromatic
hydrocarbons in soils of a mountain valley: correlation with highway
traffic and cancer incidence. Environmental Science and Technology 11
(12):1082-84 (1977).
6. U.S. Department of Health, Education and Welfare, Public Health Service,
Center for Disease Control. Morbidity and mortality, weekly report. 26
(17):143 (1977).
7. Young, Ronald J. et al. Litter: benzene in consumer products. Science
199 (4326):248 (1978).
8. U.S. House of Representatives, Commerce Oversight and Investigations
Subcommittee. Hazardous waste disposal (96-IFC31), October, 1979.
9. U.S. Department of Health, Education and Welfare, National Institute for
Occupational Safety and Health. The right to know: practical problems
and policy issues arising from exposure to hazardous chemical and physi-
cal agents in the workplace. Prepared at request of the Subcommittee on
Labor of the Senate Committee on Human Resources, 1977, p. 50.
10. Members of the Toxic Substances Strategy Committee include representa-
tives from the Council on Environmental Quality; the Departments of
Agriculture, Commerce, Energy, Interior, Transportation, and State; HEW
and several of its components, the Food and Drug Administration, National
Cancer Institute, National Institute of Environmental Health Sciences,
and National Institute of Occupational Safety and Health; Consumer
Products Safety Commission; Environmental Protection Agency; National
Science Foundation; Occupational Safety and Health Administration (Dept.
of Labor); and Nuclear Regulatory Commission. In addition, there are
official observers from the Council of Economic Advisors, the Domestic
Policy Staff, the Office of Management and Budget, the President's
Reorganization Project, and the Office of Science and Technology Policy.
11. Costle, Douglas M. Statement on hazardous waste management. USEPA press
release dated October 12, 1979.
44
-------
AVAILABILITY AND PLANT UPTAKE OF HEAVY METALS FROM CONTAMINATED
DREDGED MATERIAL PLACED IN FLOODED AND UPLAND
DISPOSAL ENVIRONMENTS
C.R. Lee, B.L. Folsom, Jr., and R.M. Engler
Environmental Laboratory
U.S. Army Engineer Waterways Experiment Station
Vicksburg, Mississippi 39180
ABSTRACT
The availability and plant uptake of heavy metals
was evaluated from contaminated dredged material
placed in flooded and upland disposal environments
using a solid-phase plant bioassay. The objective of
the study was to verify previous dredged material
research results and to develop a plant bioassay
procedure that could indicate phytotoxicity and bio-
accumulation of heavy metals in contaminated dredged
material. The plant bioassay indicated more uptake
and bioaccumulations of cadmium and to a lesser extent
zinc when contaminated dredged material was placed in
an upland environment where the sediment was allowed
to air dry. Placing the contaminated dredged material
in a flooded (reduced) environment lowered the avail-
ability and plant uptake of cadmium and to a lesser
extent zinc. Factors that influenced the availability
and plant upake of heavy metals from contaminated
sediments included sediment oxidation-reduction
potential, organic matter content, total sulfur
content, and pH. The plant bioassay showed phyto-
toxicity and bioaccumulation of arsenic under a
flooded environment. Placing the arsenic-contaminated
sediment in a upland environment reduced both the
phytotoxicity and bioaccumulation of arsenic in the
freshwater marsh plant Cyperus esculentus.
INTRODUCTION
Each year the U.S. Army Corps of Engineers (CE) is required to remove in
excess of 129 million cubic meters of sediment to maintain navigable waterways
in the United States. Increased public concern over the environmental impact
of dredging and dredged material disposal led to the establishment of the
45
-------
Dredged Material Research Program (DMRP) conducted by the U.S. Army Engineer
Waterways Experiment Station (WES). The DMRP was initiated in 1973 and was
conducted for five years at a cost of $32.8 million. Significant information
was obtained on the nature of contaminants in dredged material and the trans-
formations that would occur when dredged material was placed in various
disposal environments. The following discussion will attempt to bring the
more significant findings together from the DMRP (1) and relate them to the
most recent results obtained from ongoing WES research.
Results from laboratory simulations of the effects of redox potential and
pH indicated that the availability of heavy metals in sediments was controlled
to a large extent by the degree of oxidation of a sediment in combination with
the pH of the sediment (2). The metal regulatory processes involved included
precipitation with sulfide, adsorption or coprecipitation with colloidal
hydrous oxides, and complex formation with soluble and insoluble organics.
Cadmium release to soluble and exchangeable forms was shown to be favored by
oxidizing conditions, particularly at pH 5.0 and 6.5. As oxidation intensity
increased, this cadmium was apparently released from large molecular weight
organics.
The Center for Wetland Resources (3) in follow-up research reported that
the trace and toxic metal uptake by marsh plants was affected by Eh, pH, and
salinity. Plant cadmium content responded more to a change in the physico-
chemical environment of the rooting medium than did the other metals studied.
Plant cadmium content was increased with an increase in oxidation conditions.
The highest plant cadmium contents occurred under acid oxidizing conditions.
Plant zinc content was also found to increase with increasing oxidation
conditions.
While these studies indicate transformations that are most likely to
occur under certain redox and pH conditions when heavy metal radioisotopes
were added to a sediment, there was a need to develop a technique that could
verify the results of laboratory simulations and that could indicate phyto-
toxicity and bioaccumulation of heavy metals in plants from an inherent
contaminated dredged or fill material. This technique could then give CE
District personnel a good indication of potential contaminant mobility
problems associated with a specific dredged or fill material.
Ongoing WES research is developing techniques to assist CE Districts in
estimating the potential bioavailability of contaminants in sediments that
require dredging presently or in the near future. One technique being
evaluated is essentially a solid-phase plant bioassay to test a sediment for
contaminants that are potentially phytotoxic and/or are potentially bio-
accumulated in plants. The sediment is tested under both flooded and upland
environmental conditions.
METHODOLOGY
The solid-phase plant bioassay was conducted in an experimental unit
shown schematically in Figure 1 (4). The sediment to be tested was placed in
46
-------
the inner container. The outer container was used as the water reservoir for
the test. Sediments tested under flooded conditions had water of appropriate
salinity in the outer container to a height of 5 cm above the sediment
surface. Water was added throughout the test period to maintain the sediment
under water in a flooded condition. Sediments to be tested under an upland
environment were first dried and then placed in the inner container.
Deionized water was added to the sediment initially to moisten the sediment
and to germinate tubers or to promote seedling growth. Additional water was
added only to meet the needs for plant growth. In this way, the sediment
remained in an aerobic or upland condition throughout the test period.
-DISTICHLIS SPICATA
\Cmarsh plant)
PLATINUM
ELECTRODE
WATER
22.7
LITRE
BAIN
MARIE
7.6
LITRE
BAIN
MARIE
2.54
CM PVC PIPE-7
TO VACUUM
TYGON TUBING
tSS TUBING
PLASTIC SAMPLE
ij
TIC HOLDER
PORO/S PLASTIC
FILTER CANDLE
WASHED QUARTZ SAND
POLYETHYLENE SPONGE
INTERS/ITIAL WATER
Figure 1. Schematic diagram of the experimental
phase plant bioassay.
unit used for the solid-
Sediments to be evaluated were collected from five freshwater locations
in the Great Lakes and five saltwater locations along the coastline of the
United States (Figure 2). These sediments were collected because they were
highly contaminated with one or more contaminants. Sediments were analyzed
for texture, organic matter, calcium carbonate equivalent, pH, total
phosphorus, total nitrogen, oil and grease, sulfur, and heavy metals (total
amounts and DTPA extractable).
47
-------
Plant species used as indicators of phytotoxicity and the bioaccumulation
of contaminants were Cyperus esculentus in the freshwater sediment tests and
Spartina alterni flora and Distichlis spicata in the saltwater sediment tests.
These species have been shown to take up and accumulate heavy metals in
previous DMRP research (5). In addition, these species were used in marsh
creation projects with dredged material (1). Plants were observed for phyto-
toxic effects and harvested for yield after the growth period. Plant material
was analyzed for heavy metals.
W
CE DISTRICT BOUNDARY
Figure 2. Sediment sample locations for the solid-phase plant bioassay.
RESULTS AND DISCUSSION
Discussion will be limited to the results of the freshwater sediment
tests. Occasionally, similar results from saltwater sediment tests will be
mentioned.
The texture of both the freshwater and saltwater contaminated sediments
was predominantly silt loam (Table 1). This is not surprising since heavy
metal contaminants tend to adsbrb more readily to finer particles of higher
exchange capacity than to coarser sand particles of lesser adsorptive
capacity. Most sediments contained organic matter in excess of 5 percent with
the exception of DE 3 and ME 1 (Table 1). The saltwater sediments contained a
similar range of organic matter. Organic matter has been suggested as having
major influence on the availability and translocation of heavy metals through
the environment (6,7).
48
-------
TABLE 1. SELECTED PHYSICAL AND CHEMICAL PARAMETERS OF THE FRESHWATER
SEDIMENTS
Location/
Site
DE+1
2
3
MC 1
2
3
IN 1
2
3
MW 1
2
3
ME 1
2
3
Texture
Silt 1 oam
Silt loam
Clay loam
Loam
Silt loam
Loam
Sandy loam
Silt loam
Loam
Silt loam
Silt loam
Silt loam
Sand
Sandy loam
Silt loam
Organic
Matter
%
10.7
10.7
3.1
5.7
14.2
13.0
6.6
7.3
21.9
13.1
8.8
8.8
2.7
27.3
19.5
CaCO3
Equivalent
%
32.1
23.2
22.3
19.5
13.5
21.1
18.2
13.6
16.7
34.5
51.7
56.3
7.6
6.5
35.4
pH*
Flooded
7.50
7.50
7.27
NDt
7.23
7.07
7.40
7.37
7.50
7.40
7.20
7.40
7.33
7.45
7.27
Upland
8.50
7.59
8.07
7.37
7.08
7.24
7.25
7.58
6.72
7.64
7.69
7.74
7.02
6.38
7.02
C.V.f
5.9
4.5
0.78
0.38
* Flooded pH is pH of the initial interstitial water. Upland pH is pH of a
1:2 sediment-to-solution suspension using air-dried sediment.
DE = Detroit; MC = Michigan City; IN = Indiana Harbor; MW = Milwaukee;
ME = Menominee River (see Figure 2).
t ND = not determined.
t C.V. = coefficient of variation (%).
All of the freshwater sediments contained large amounts of calcium
carbonate and had pH values approximating neutrality (pH 7.0). Under upland
(air dried) conditions, the sediments containing the most organic matter
showed a reduction in pH from near neutrality to pH 6.38 (Table 1). A similar
but more pronounced effect was observed for the saltwater sediments, in that
the pH under upland conditions decreased as low as 5.0 in a sediment contain-
ing 26.7 percent organic matter, 28.1 mg/g sulfur, and only 0.3 percent
calcium carbonate equivalent. In this case there was not sufficient calcium
carbonate to buffer the decrease in pH when both the organic matter and sulfur
49
-------
were oxidized under upland conditions. The solubility and availability of
some heavy metals such as zinc, copper, iron, manganese, and lead have been
shown to decrease with increased soil pH and increased amounts of calcium
carbonate (8-13).
The fertility of the sediment can be inferred from the amount of phos-
phorus (P) and nitrogen (TKN) present (Table 2). All plants grown in the
freshwater sediments were nitrogen limited (14). No additional fertilizer was
applied to the sediments during the tests. Consequently plants were dependent
on whatever was present in the sediment.
Oil and grease ranged from 0.2 to 12.2 mg/g (Table 2). Some of the
saltwater sediments tested contained up to 97.5 mg/g of oil and grease. These
elevated amounts of oil and grease did not appear to be phytotoxic to plant
growth. However, one difficulty was observed when the freshwater sediments
were dried and rewet in preparation for planting. The dried sediment repelled
TABLE 2. OTHER SELECTED CHEMICAL PARAMETERS OF THE FRESHWATER SEDIMENTS
Concentration (mg/g)
Location/
Site
DE+1
2
3
MC 1
2
3
IN 1
2
3
MW 1
2
3
ME 1
2
3
C.V.*
Total P
1.11
2.38
0.44
0.70
2.56
2.11
0.74
0.73
5.60
1.55
0.49
0.55
0.22
0.39
1.34
10.5
TKN
0.68
2.32
0.68
1.01
3.77
3.74
0.94
0.63
3.05
2.93
3.07
6.33
0.47
2.08
2.79
4.8
Oil and
Grease
7.8
9.2
0.2
0.5
5.8
4.6
4.4
12.2
6.8
4.8
0.2
0.2
0.22
1.5
2.2
54
Total
Sulfur
1.7
1.9
3.5
1.6
4.1
3.8
1.6
6.0
7.2
2.1
3.7
1.3
0.3
2.0
2.3
27
DE = Detroit; MC = Michigan City; IN
ME = Menominee River (see Figure 2).
C.V. = Coefficient of variation
50
= Indiana Harbor; MW = Milwaukee;
-------
the applied water and was extremely difficult to rewet. The presence of the
oil and grease appeared to inhibit the rewetting process.
The sulfur content of the freshwater sediments ranged from 0.3 to 7.2
mg/g (Table 2). The saltwater sediments contained much more sulfur, ranging
from 2.3 to 28.1 mg/g. Upon air drying, the pH of the saltwater sediments
decreased below neutrality whenever the sulfur content was greater than 13
mg/g and the calcium carbonate equivalent was less than 0.4 percent. Salt-
water sediments may be prone to show reduction in pH upon drying if placed in
an upland environment.
The redox potential of one of the freshwater sediments under flooded and
upland conditions during the tests is shown in Figure 3. Similar conditions
were observed for the other freshwater sediments. Flooded conditions resulted
in a stable negative redox potential throughout the study. The redox pot-
ential under upland conditions oscillated up and down due to the application
of water to meet the needs for plant growth. However, for the majority of the
growth period the redox potentials of the upland sediments were always higher
than those of the flooded sediments.
The concentrations of heavy metals found in the freshwater sediments are
shown in Table 3. The saltwater sediments contained similar ranges. Total
nitric acid digests of the sediments indicated how much heavy metals were
present but did not indicate the bioavailability of the heavy metals.
In order to get an indication of the bioavai lability of sediment heavy
metals under both flooded and upland conditions, a DTPA extraction procedure
was used. The DTPA extraction described by Lee et aJL (15) has been "shown to
estimate plant-available zinc, copper, manganese, and iron for agronomic
plants (16) and to correlate well to plant content of zinc, cadmium, and
copper and to a lesser extent with lead and chromium in saltwater marsh plants
(15).
While the DTPA extraction data for copper, mercury, nickel, chromium, and
lead did not show consistent differences, DTPA-extractable zinc, cadmium,
manganese, iron, and arsenic showed consistent results. Table 4 shows the
concentrations of zinc, cadmium, and arsenic in the DTPA extracts of the
freshwater sediments. Concentrations of zinc and cadmium in DTPA extracts of
saltwater sediments are shown . in Table 5. While DTPA-extractable zinc
appeared to be higher under upland conditions in 10 out of 15 freshwater
sediments (Table 4), all of the saltwater sediments showed pronounced
increases in DTPA-extractable zinc under upland conditions (Table 5). A
similar observation can be made for DTPA-extractable cadmium.
More cadmium was extracted under upland conditions than under flooded
conditions, expecially in the saltwater sediments (Table 5). These results
verify previous DMRP research that showed placing dredged sediment under
oxidized environments potentially increased the amount of available zinc and
cadmium in the sediment.
The opposite effect was observed with regard to DTPA-extractable arsenic
(Table 4). More arsenic was extracted under flooded conditions than upland
conditions.
51
-------
400 i-
200
S
0.
g -200
u
o:
-400
-600
MENOMINEE RIVER
10
20
30
40 SO
DAYS AFTER PLANTING
60
70
80
Figure 3. Redox potential during growth period of Cyperus esculentus in
flooded and upland disposal environments.
While the DTPA showed important results, plant content of zinc, cadmium,
and arsenic were even more important (Table 6). While certain freshwater
sediments such as MC and IN showed higher plant leaf zinc content under upland
conditions, all of the sediments showed higher plant leaf cadmium content
52
-------
TABLE 3. TOTAL* CONCENTRATIONS OF HEAVY METALS IN FRESHWATER SEDIMENTS
Ol
CO
.
Location/
Site
DE+1
2
3
MC 1
2
3
IN 1
2
3
MW 1
2
3
ME 1
2
3
C.V.
Zinc
2423
2048
233
796
1857
978
660
1433
8867
921
31458
711
124
3992
230
t 61
Concentration(ug/q)
Cadmium Copper Nickel Chromium
29.5
21.5
7.7
6.2
39.8
35.9
7.6
16.0
45.6
14.8
7.8
5.8
0.1
0.1
9.3
25
199
202 1
22
21
115
121 1
35
65
340 1
82
16
12
10
24
37
17
62.5
52.8
--
20.0
—
05.3
22.0
37.3
07.2
48.7
19.4
14.2
8.2
10.5
19.9
11
94.
327.
--
9.
--
135.
96.
117.
1974.
231.
23.
10.
10.
8.
23.
53
8
5
5
5
3
3
3
3
5
0
5
2
7
Lead
226.1
326.0
--
30.0
—
656.5
99.4
214.7
1521.0
385.0
25.5
26.8
143.0
315.3
60.0
40
Mercury
0.36
0.56
0.13
0.06
1.02
0.18
0.08
0.29
1.50
0.60
0.01
0.00
0.05
0.27
0.44
77
Iront Manganese Arsenic
74.31
56.97
17.10
11.56
19.73
29.81
40.17
89.81
291.31
23.91
12.67
9.86
7.02
8.56
27.41
6.9
1203
536
401
258
518
523
638
1461
2503
541
523
469
164
267
1213
9.8
11.4
7.5
3.3
2.5
4.7
2.3
18.8
27.0
37.5
7.9
1.1
0.0
4.1
6.4
316.5
26
*
+
t
t
Nitric acid
DE = Detroit
Figure 2).
digest for
total heavy
metal content
; MC = Michigan City; IN =
Concentration of iron
C.V. = coefficient of
is in mg/g
variation (%)
.
(4).
Indiana Harbor;
MW = Mi
Iwaukee;
ME = Menominee
River
(see
-------
TABLE 4. DTPA EXTRACTABLE HEAVY METALS FROM FLOODED AND UPLAND FRESHWATER
SEDIMENTS
Concentration
Location/
Site
DE+1
2
3
MC 1
2
3
IN 1
2
3
MW 1
2
3
ME 1
2
3
c.v.t
Zinc
Flooded Upland
48.1
276.6
1.8
179.9
180.1
5.4
205.8
48.3
10.6
144.6
21.1
14.5
5.3
5.3
6.3
10.4
173.1
255.1
13.6
130.0
811.6
743.1
227.0
512.9
1339.2
265.6
14.9
14.4
6.1
27.1
33.5
14.2
(nfl/g)
Cadmi urn
Flooded
<0.0005
4.89
0.30
3.33
0.83
<0.0005
0.53
<0.0005
<0.0005
3.39
0.82
0.50
0.40
<0.0005
<0.0005
34.1
Upland
6.30
4.15
0.03
2.92
25.26
31.25
1.10
3.11
5.44
6.08
0.73
0.53
0.19
0.64
2.72
18.1
Arsenic
Flooded
<0.005
0.169
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
0.122
<0.005
<0.005
<0.005
0.278
131.000
56.7
Upland
CI*
CI
CI
CI
CI
CI
CI
CI
'CI
CI
CI
CI
CI
CI
37.200
6.2
*? =
Chemical i
nterference
T Kl T
DE = Detroit; MC = Michigan City; IN
ME = Menominee River (see Figure 2).
t C.V. = Coefficient of variation (%).
= Indiana Harbor; MW = Milwaukee;
under upland conditions than under flooded conditions. Even though plant leaf
cadmium content reached 20.84 |jg/g in the MC 2 sediment, no phytotoxic
symptoms were observed.
These results indicate that sediments containing elevated amounts of zinc
and cadmium would have the availability of zinc and cadmium lowered if these
sediments were placed in a flooded (reduced) environment. Placing these
sediments in an upland environment would result in these metals becoming more
available for plant uptake as well as for migration into the surrounding
environment.
Phytotoxic symptoms were observed (Figure 4) in freshwater plants
containing 10.7 ug/g arsenic (Table 6). Plant growth was better when the same
54
-------
TABLE 5. DTPA EXTRACTABLE HEAVY METALS FROM FLOODED AND UPLAND SALTWATER
SEDIMENTS
Location/
Site
BA 1
2
3
CC 1
2
3
OH 1
2
3
SE 1
2
3
C.V.*
Zinc
Concentration (|jg/g)
Flooded
Upland
0.3
0.1
0.6
10.8
54.1
5.6
4.5
1.0
70.07
5.6
3.1
0.1
455.3
954.0
134.2
93.9
305.5
1511.8
125.4
166.9
168.4
67.5
128.5
111.6
Cadmiurn
Flooded
Upland
BR+1
2
0.3
0.9
408.3
803.2
<0.0005
<0.0005
0.42
28.54
<0.0005
<0.0005
<0.0005
<0.0005
0.22
<0.0005
0.86
<0.0005
0.38
0.18
<0.0005
<0.0005
32.34
15.94
2.06
1.16
3.27
19.02
2.08
1.96
0.75
1.01
2.30
2.03
40.3
22.0
75.8
42.4
BR = Bridgeport; BA = Baltimore; CC = Corpus Christi; OH = Oakland; SE =
Seattle (see Figure 2).
* C.V. = Coefficient of variation (%).
sediment was placed in the upland environment (Figure 4). Plant leaf arsenic
content was reduced to 1.45 ug/g under upland conditions. Availability of
arsenic was similar to that of phosphorus in that arsenic was more available
under flooded (reduced) conditions and became precipitated and adsorbed to
soil particles as the sediment or soil dried out (17). Sediments containing
elevated amounts of arsenic would have the availability of arsenic reduced if
placed in an upland environment.
Sediment parameters that appeared to be influencing the availability of
heavy metals in contaminated sediments were redox potential, organic matter
content, total sulfur content, manganese and iron content, calcium carbonate
content, and pH. Extraction of heavy metals from sediments with DTPA was also
directly related to plant content of heavy metals.
The results of the solid-phase plant bioassay verified the findings from
the DMRP. The test is easy to conduct and gives a good indication of phyto-
55
-------
TABLE 6. HEAVY METAL CONTENT OF CYPERUS ESCULENTUS LEAVES AFTER PLANT
GROWTH IN FRESHWATER SEDIMENTS UNDER FLOODED AND UPLAND
ENVIRONMENTS
Concentration (MQ/Q)
Location/
Site
DE+1
2
3
MC 1
2
3
IN 1
2
3
MW 1
2
3
ME 1
2
3
Flooded
75.5
96.8
151.5
63.3
70.04
56.7
34.8
51.8
63.5
48.8
87.8
84.9
29.6
76.5
0.2
Zinc
Upland
75.8
122.8
150.8
259.6
168.3
84.5
112.8
154.0
172.9
256.4
83.3
58.0
23.8
80.8
17.3
Cadmi
Flooded
0.77
0.79
0.23
1.31
2.81
2.50
0.19
0.51
0.25
1.24
0.41
0.32
0.82
0.36
0.47
urn
Upland
2.81
6.49
1.17
17.64
20.84
7.80
1.95
6.34
1.27
12.60
1.84
0.87
1.45
1.44
9.57
Flooded
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
10.700
Arsenic
Upland
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
<0.025
1.450
c.v.
26.6
24.5
40.2
26.8
50.2
88.4
DE = Detroit; MC = Michigan City; IN
ME = Menominee River (see Figure 2).
C.V. = coefficient of variation (%).
= Indiana Harbor; MW = Milwaukee;
toxicity and bioaccumulation of contaminants in sediments placed in flooded
and upland disposal environments. The plant bioassay procedure is presently
being refined and will be verified with field tests in the future.
56
-------
MENOMINEE RIVER
SITE 1
NENOMWEE RIVER
•."• SITE 3 •'"
MENOMINEE RIVER
SITE!
MENOMINEE RIVER
\SITE2
MENOMINEE RIVER
SITE 3
Figure 4. Growth of Cyperus esculentus under flooded and upland disposal
environments in sediments from three sites on the Menominee
River.
57
-------
REFERENCES
1. Saucier, R.T. et al_. Executive overview and detailed summary of the
dredged material research program. Technical Report DS-78-22, Environ-
mental Laboratory, U.S. Army Engineer Waterways Experiment Station,
Vicksburg, Mississippi (December 1978).
2. Gambrell, R.P. et aj^. Transformations of heavy metals and plant nutrients
in dredged sediments as affected by oxidation reduction potential and pH.
Contract Report D-77-4, Vol. II, U.S. Army Engineer Waterways Experiment
Station, Vicksburg, Mississippi (May 1977).
3. Center for Wetland Resources. Trace and toxic metal uptake by marsh
plants as affected by Eh, pH and salinity. Contract Report D-77-40, U.S.
Army Engineer Waterways Experiment Station, Vicksburg, Mississippi
(December 1977).
4. Folsom, Jr., B.L. et a^L Influence of disposal environment on avail-
ability and plant uptake of heavy metals in dredged material. Technical
Report, U.S. Army Engineer Waterways Experiment Station, Vicksburg,
Mississippi (In press).
5. Lee, C.R. et al. A hydroponic study of heavy metal uptake by selected
marsh species. Technical Report D-76-5, Environmental Laboratory, U.S.
Army Engineer Waterways Experiment Station, Vicksburg, Mississippi (June
1976).
6. Nissenbaum, A. and Swaine, D.J. Organic matter metal interactions in
recent sediments: the role of humic substances. Geochim. Cosmochim.
Acta 40:809 (1976).
7. Zunino, H. and Martin, J.P. Metal-binding organic macro-molecules in
soil I: hypothesis interpreting the role of soil organic matter in the
translocation of metal ions from rocks to biological systems. Soil Sci.
123:65 (1977).
8. Saeed, M. and Fox, R. L. Relations between suspension pH and zinc
solubility in acid and calcareous soils. Soil Sci. 124:199 (1977).
9. Singh, B. and Sekhon, G.S. The effects of soil properties on adsorption
and desorption of zinc by alkaline soils. Soil Sci. 124:366 (1977).
10. Udo, E.J. et al. Zinc adsorption by calcareous soils. Soil Sci. Soc.
Amer. Proc. 34:405 (1970).
11. Mclntosh, A.W. et al_. Some aspects of sediment distribution and
macrophyte cycling of heavy metals in a contaminated lake. J. Environ.
Qual. 7:301 (1978).
12. Sinha, M.K. et al_. Solubility relationships of iron, manganese, copper
and zinc in alkaline and calcareous soils. Aust. J. Res. 16:19 (1978).
58
-------
13. Zimdahl, R.L. and Skogerboe, R.K. Behavior of lead in soil. Environ.
Sci. Tech. 11:1202 (1977).
*
14. Barko, J.W. and Smart, R.M. The nutritional ecology of Cyperus
esculentus, as an emergent aquatic plant, grown on different sediments.
Aquat. Bot. 6:13 (1979).
15. Lee, C.R. et al_. Prediction of heavy metal uptake by marsh plants based
on chemical extraction of heavy metals from dredged material. Technical
Report D-78-6, Environmental Laboratory, U.S. Army Engineer Waterways
Experiment Station, Vicksburg, Mississippi (February 1978).
16. Lindsey, W. L. and Norvell, W.A. Development of a DTPA soil test for
zinc, iron, manganese and copper. Soil Sci. Soc. Amer. J. 42:421 (1978).
17. Hess, R.E. and Blanchar, R.W. Arsenic stability on contaminated soil.
Soil Sci. Soc. Amer. J. 40:847 (1976).
59
-------
DISTRIBUTION AND CONCENTRATION OF PCB IN THE HUDSON RIVER
AND ASSOCIATED MANAGEMENT PROBLEMS
I. G. Carcich and T. J. Tofflemire
New York State Department of Environmental Conservation
Bureau of Water Research
50 Wolf Road
Albany, New York 12233
ABSTRACT
The Hudson River is contaminated with PCBs and a
remedial program has been formulated by New York State
to cope with this toxic pollutant. Over $3 million
has been spent to fully document the extent of the PCB
contamination in the Upper Hudson River. It appears
that over 60 percent of the PCBs in the riverbed are
contained within 40 so-called "hot spot" areas, that
is, those areas that have PCB concentrations greater
than 50 ppm. After evaluating all alternatives the
PCB Reclamation Project was formulated which consists
of mechanically or hydraulically dredging the 40 "hot
spot" areas and placing the contaminated sediments in
an uncapsulated land burial facility. Such a facility
would meet all Federal and State criteria for PCBs
disposal. New York is seeking to finance this reme-
dial project through the use of Federal funds, that
could be obtained either through the Clean Water Act
or through special Congressional legislation or
through the Superfund Bill, once it is enacted. The
PCB Reclamation Project, if funded this spring as is
presently anticipated, could be completed by 1982.
INTRODUCTION
The Hudson River is contaminated with polychlorinated biphenyls (PCBs).
The toxicity of PCBs has been a topic of much research and experiments have
shown that PCBs at high doses can cause death and liver tumors have also been
induced in mice and rats. Much of the information on the toxicity of PCBs can
be found in the Criteria Document for PCBs (1976) published by the Environ-
mental Protection Agency (1) and a report published by the United States
Department of Health, Education and Welfare (2).
61
-------
It is currently estimated'that 640,000 pounds of PCBs are contaminating
the sediments of the Hudson River, from New York City to the Fort Edward Dam
site at Fort Edward, New York. PCB contamination of the Hudson River poses a
potential threat to the health of thousands of New Yorkers, especially those
who obtain their drinking water directly from the river.
Also, the United States Food and Drug Administration has set allowable
limits for PCBs in food, including fish. As a result of the high PCB con-
centration in fish, the New York State Department of Environmental Conser-
vation has banned commercial fishing for certain species in the lower Hudson,
from Troy to New York City and both commercial and recreational fishing for
all species from Troy to Fort Edward.
If remedial action is not taken, it is likely that the Hudson River will
remain contaminated with PCBs for a century or more.
BACKGROUND
Polychlorinated biphenyls (PCBs) were first manufactured in 1929 and were
soon found to be ideal for a number of industrial uses. They are very stable
chemically and biologically, have a low electrical conductivity and are nearly
insoluble in water. Because of these properties, PCB usage by General
Electric had been extensive and long standing at their capacitor manufacturing
facilities at Fort Edward and Hudson Falls.
Over 78 million pounds (3) of PCBs were purchased by these two facilities
between 1966 and 1974. Although records do not exist for years prior to 1966,
PCBs were used at the Fort Edward and Hudson Falls plants for more than 25
years.
High levels of PCBs in the Hudson River biota were first reported in
1969, but the seriousness of the situation was not recognized for several
years. Extensive sampling of the river in 1975 implicated the General
Electric plants as the major source of PCBs in the Upper Hudson River.
Acting on information supplied by the Environmental Protection Agency and
the Fish and Wildlife Service, and on additional evidence collected by the
Department of Environmental Conservation, the General Electric Company (GE)
was charged with polluting the river with the toxic substance known as PCB.
Administrative proceedings between the Environmental Conservation Department
and GE began on September 8, 1975.
On February 9, 1976, after weeks of testimony, reports, studies and other
exhibits, Professor Abraham D. Sofaer (4), the Hearing Officer, found GE was
responsible for the high concentrations of PCBs in the Upper Hudson's waters,
sediments, organisms and fish. A settlement agreeable to all parties was
negotiated and signed on September 8, 1976.
Under the terms of the settlement, a comprehensive program of at least $7
million was to be enacted in order to deal with PCBs in the Hudson River and
with related environmental concerns. GE was to gradually eliminate all PCB
62
-------
discharges from the two plants by July 1977. In addition, GE agreed to con-
tribute $3 million to the Environmental Conservation Department as its share
of a program to monitor the presence and levels of PCBs in the Hudson; to
further investigate the need for remedial action concerning PCBs in the river;
and aid in developing a program to regulate the storage and discharge of
environmentally hazardous substances.
New York State agreed under the terms of the settlement, to contribute an
additional $3 million for the above mentioned work. Also, GE was required to
perform $1 million of research related to PCBs, including a study of the
environmental compatability of a PCB substitute.
PROBLEM
Studies (Table 1) directed by NYS Environmental Conservation Department
have reinforced the early evidence of PCB contamination of the Hudson River.
Of the more than 600,000 pounds of PCBs existing in the river, approximately
two thirds of this amount are still located in the bed sediments north of
Troy. It has also been calculated that more than 5,000 pounds of PCBs move
over the Federal Dam at Troy, New York and into the estuarine portion of the
river.
Analysis of edible portions of fish has exceeded many times the FDA
tolerance level of 5 ppm. Water column concentrations of PCBs measure around
1 ppb and organisms have been shown to accumulate PCBs rapidly from the river
water. Volatilization of the various PCBs aroclors occurs more readily than
was originally predicted and air pollution from PCBs was found to be a real-
ity. The settlement funded studies paint a bleak picture of the total envi-
ronment for the Hudson River Basin (Table 2).
Large amounts of PCBs were caught in the sediments built up behind dams
near the capacitor plants at Fort Edward and Hudson Falls (Figure 1). The
first dam, located at Fort Edward, was removed in 1973, allowing large amounts
of contaminated sediments to move downstream.
The scientific and engineering studies have pinpointed 40 riverbed sedi-
ment areas containing more than 50 parts per million of PCBs. These 40 areas,
known as the "hot spots", (Figure 2) and the remnant deposits, constitute only
8 percent of the total upper riverbed, but contain approximately 60 percent of
all of the PCBs located in the Upper Hudson Riverbed sediments.
The remaining dam sediments behind the Fort Edward Dam, containing an
additional 28 percent of the upper river's PCBs, now form part of the river-
bank south of Fort Edward.
A summary of distribution of residual PCBs in the Hudson River Basin is
provided by Table 3.
63
-------
TABLE 1. HUDSON RIVER PCB SETTLEMENT STUDIES (4, 5)
(1976 to present)
1. Aquatic Studies
A. Physical
1. Monitoring of river flow and sediment and PCB transport -
USGS
2. PCB mapping, upper river - Normandeau Associates
3. Bedload sediment transport - Rensselaer Polytechnic Institute
4. Screening survey of lower river PCB concentrations - EPA
5. PCB concentrations of esturary sediments - Lament Doherty
6. Groundwater - Weston
7. Wastewater - Pure Waters, O'Brien and Gere
8. Use of high volume centrifuge to better define PCB-particulate/
water interchange - DEC Bureau of Water Research
9. Additional bed sediment sampling - DEC Bureau of Water Research
B. Biological
1. Fish monitoring - fish collections and data evaluation - Dec,
PCB analysis by O'Brien and Gere
2. Macroinvertebrates monitoring - DOH
3. Aquatic food chain dynamics and lower trophic level studies -
NYU Medical Center, SUNY Stony Brook and Fordham University
II. Land
A. Physical
1. Air monitoring - DEC Divsion of Air Resources
B. Biological
1. Plant and Farm Product uptake - Sample collection and data
evaluation by DEC Bureau of Water Research and Boyce Thompson
Institute, PCB analysis by Raltech
III. Engineering related to remedial measures
A. Hot spot dredging project - Malcolm Pirnie, Inc.
B. Landfills and Dumps - Weston
C. Alternatives: "No action", Lawler, Matusky and Skelly
Effects of remedial action - Hydroscience
D. Removal and Treatment - GE,
E. Public Water Supply - Treatability Study - NYS Dept of Health
and O'Brien and Gere
IV. Project Management
A. Study Management and data storage - DEC Bureau of Water Research
B. Laboratory intercomparison and quality control - NYS Department
Health - Division of Laboratories and Research
C. Modeling
1. Up river sediment transport modeling - Lawler, Matusky and
Skelly
2. Biological modeling - Hydroscience
D. Study Interpretation and Report Preparation - DEC Bureau of
Water Research
64
-------
TABLE 2. HUDSON RIVER SYSTEM TYPICAL PCB VALUES
Upper Hudson River
Bed Sediment 20-150 PPM
Water Column 0.1-1 PPB
Fish 10-130 PPM
Macroinvertebrates 3-10 PPM
Dredge Spoil Areas
Spoil 5-50 PPM
Leachate 0.5 PPB
GE Industrial Landfills
Waste Material 500-5000 PPM
Leachate 50-500 PPB
Ambient Air
(Fort Edward) 100-3000 Nanograms/m3
Dust (Fort Edward) 17 PPM
Plants
Near GE Landfill 10-500 PPM
Near Dredge Spoil Area 0.2-1.3 PPM
Lower Hudson River
Bed Sediment 1-15 PPM
Water Column ND-0.8 PPB
Fish
Resident 5-10 PPM
Migratory 0.5-15 PPM
Macroinvertebrates 1-3 PPM
Turtles
Muscle 5 PPM
Eggs 25 PPM
65
-------
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NORMAL POOL
ELEVATION
CANDIDATE
DISPOSAL SITE
10
CANDIDATE
DISPOSAL SITE
12
-N-
HOT SPOT AREA
NUMBER
$M AREA TO BE DREDGED
2000 1000 0 2000
SCALE IN FEET
Figure 2. Dredging of PCB-contaminated "hot spots",Thompson Island Dam Pool
67
-------
TABLE 3. SUMMARY DISTRIBUTION OF RESIDUAL PCBs IN THE HUDSON RIVER BASIN (5)
EstimatedEstimatedCalculated
total PCBs Scourable PCBs loss rate*
Area Ibs Ibs (Ibs/yr)
River sediments
Remnant deposits 140,000 45,000 8,600
Upper Hudson Riverbed
(Ft. Edward Dam Site to Troy) 300,000 98,000 5,700
Lower Hudson Riverbed
(Estuary-Troy to New York Harbor) 200,000 ? ?
Dredge spoil areas
(Upper Hudson) 160,000 - 170
Landfi11s and dumps
(Upper Hudson) 530,000 - 800
Biota
Lower River 200-2,000 - 0
Total 1,330,000
*Does not include volatilization.(Based on April 1978 Data).
DISTRIBUTION AND CONCENTRATIONS OF PCB
Methods
Between 1974-1979, a large number of bed sediment samples have been taken
from the Hudson River and analyzed for PCBs. Normandeau Associates, Inc.
(NAI) did the primary bed sampling and mapping in the summer of 1977, taking
670 grab and 200 core samples. In addition, DEC staff has collected over 200
grab samples of bed sediments in the Upper Hudson.
NAI collected their grab samples on transects across the river, while the
cores were taken in the finer textured sediments near the banks. Because of
the known sources of PCB contamination, sampling was more frequent near Fort
Edward and less frequent down the river.
NAI used a Motorola mini ranger and transponder system to provide quick
and accurate sample locations and a precision Rayethon DE-719B fathometer to
provide accurate bottom transects. The pulsed radar signals are timed and
interpolated automatically and printed out on a tape in the boat. For sam-
pling, NAI used a shipek grab sampler and manually forced core tubes.
68
-------
DEC personnel used a Leitz range finder with accuracy comparable to a
transit and stadia system for horizontal locations. DEC also used a ponar grab
sampler, manually forced core tubes and a 7 m long copper probing pipe 1.5 cm in
diameter. The probing pipe proved to be a very quick and reliable tool in
determining the depth and nature of the sediments. Cores were typically cut
into 5-15 cm (2-6 in.) sections. All sediment samples were given a visual
texture code on a scale ranging from 0 for clay to 9 for coarse sand.
Sediment analysis included PCB, total solids, volatile solids and texture.
PCB was reported to a 1 [jg/g detection limit as three aroclors - 1016, 1221 and
1254 and their total, and a rigorous quality control program was maintained at
all times (6). It appeared that the shaker extraction used for PCB gave about 85
percent recovery compared to the soxhlet method. The data including exact
locations, depths, and texture were entered on computers (7, 8).
Results
PCB concentration in the Upper Hudson River sediments appear to be log
normally distributed (Figure 3). Thus, for statistical analysis, log PCB values
were used, while for total mass tabulations, a duel area averaging system for
hot areas greater than 50 |jg/g and cold areas less than 50 H9/9 was used.
Analysis of the data for each of the two groups, that is, hot areas and cold
areas, tends to be more normally distributed than the entire data group.
The areas and arithmetic mean of PCB concentration for each of the hot and
cold spots are given in Table 4.
TABLE 4. THE AREA AND AVERAGE PCB CONCENTRATION BY REACH OF HOT SPOTS
(concentration > 50 ppm) AND COLD AREAS (concentration < 50 ppm)
IN SEDIMENTS OF THE UPPER HUDSON RIVER
Total 8 7
Reaches*
654 32
1
PCB Levels**
Hot spots — 151 103 163 70 108 159
Cold areas — 19 20 20 13 13 23 13.9 9.7
Overall — 67.6 86.2 43.6 11.6 41.9 52.3 13.9 9.7
Area
*
**
(x!06ft2)
Hot spots
Cold areas
Total
10.86
120.79
131.65
Reaches are identified
Average concentrations
4.27 0.
10.73 7.
15.00 8.
6
4
0
in Figure 1
for sediment
2.59
5.91
8.5
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1.75
41.2
42.95
sampl es
1.
9.
11.
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5 0.
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15
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20
20
69
-------
80
70
60
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50
40
30
20
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CD
10
5 50 100 200 300 400
PCB CONCENTRATION (ppm)
500+
I
I .
-1.0 0 1.0 2.0 3.0
LOG|QPCB CONCENTRATION
Figure 3. Frequency distribution of sediment PCB levels in the Upper Hudson River.
-------
PCB in |jg/g was typically higher in the finer textured sediments near the
banks and lower in the coarse sediments in the main channel. The downriver
variation of PCB values was much less than the cross river variation as noted in
Figure 4 which shows the log mean PCB values for the grab samples by river
reaches. Much of the variation indicated by the 95 percent confidence interval
lines are due to across river variations.
It should be noted that Reaches 8, 7, 6 were significantly higher in PCB
than Reaches 5, 2, 1 and 0. The drop in PCB in Reach 5 appeared partially due to
the nature of the reach which was typically narrower and higher in velocity.
Reaches 3 and 4 were wider and lower in velocity than Reach 5.
Additional analysis of the river sediment samples indicated that muck and
wood chips had PCB levels typically greater than 50 ppm and very seldom less
than 25 ppm. On the other hand, samples consisting of primarily gravel were low
in PCB concentrations but would immediately increase if wood chips were present
in the gravel.
For the lower river reaches, the sediment did not generally contain wood
chips. Three size fractions for 11 samples were compared for PCB and volatile
solids. The coarsest size fraction contained a significantly higher percent of
volatile solids due to wood chips and also the highest average PCB content. PCB
was typically skip graded in sieved samples, that is, concentrations were high
in the coarse sand size, low in the fine sand size, and high again in the silt
size. The coarse fractions with over 90 percent volatile solids were mostly
wood chips. Sieve analysis and texture codes on about 670 NAI grabs were
entered on the consultants' computers. The mean D50 for these grabs was .3 mm
(7). The D50 is the sieve size that passes 50 percent of the sample. In
addition, 20 percent of the grabs had a D50 of greater than 2 mm, while 10
percent of the grabs had a D50 of less than .06 mm (the silt size division). The
adsorption ability for PCB of various materials, such as activated sludge,
Hudson River sediments, top soil, silt, saw dust, celite, etc. was compared, and
it was noted that silty soil, wood chips and river sediment adsorbed well
compared to such materials as Ottawa sand.
While the grabs were used to assess the spread of PCB across river areas,
the cores were used to assess the depth of penetration of PCB. Most core samples
were taken in silt and sand near the banks. However, probings were made in both
center of channel and near bank regions to determine the depths of sediment
present over rock and clay. The PCB typically peaked between an 8 and 30 cm
depth in the cores taken in the hot spots or near bank contaminated areas
(Figure 5). In the core sampling it was noted that compression of the sediment
in the core tube commonly occurred. It is possible that the actual depth of PCB
penetration is up to 30 percent greater than the stated depth. The results on
the depth of PCB in the main channel were not yet available but probing data
indicated that there was on the average less than .52 m (1.7 ft.) of sediment
present and it was coarser textured. From limited data, the mass of PCB in cold
areas was estimated to be located at the .3 m (1.0 ft.) depth.
One set of 12 cores, the NAI winter cores, were sectioned every inch and
selected ones analyzed for PCB, Cs 137, heavy metals and size analysis. The Cs
137 came from fallout from atomic bomb testing and can be used for roughly
dating the sediment layers. It appeared that these near-bank areas received
71
-------
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Figure 4. Average PCB concentration in sediments of Hudson River>log mean and 95% confidence interval
(number of samples)
-------
REACHES 8,9
REACHES 6,7
REACHES 1-5
3
5 6
LU
5
Z 12
LU
8 '"
Z
- 24
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36
FREQUENCY OF MEAN
PCB>50 ppm PCB (ppm)
.39
58
.36
.33
25
.22
0
93
112
120
133
75
69
4.7
N
87
57
103
63
27
9
7
FREQUENCY OF MEAN
PCB > 50 ppm PCB (ppm)
.40
.57
.29
.18
0
0
102
153
130
48
6.3
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47
23
51
22
II
1
FREQUENCY OF MEAN
PCB > 50 ppm PCB (ppm)
.08
.20
.29
.05
0
0
22
47
49
14
5
3
N
48
25
62
22
6
1
Figure 5. PCB penetration in cores by reach from areas where PCB > 5 ppm.
-------
1.5 to 2.5 cm of sediment deposition per year on the average, and this placed
the peak PCB deposition period in the 1960s. Cs 137 followed a log normal
distribution in the sediments, so log Cs 137 and log PCB were related for all
12 winter cores with a resulting correlation coefficient of 0.82. Certain
heavy metals concentrations and percent silt were also positively correlated
with PCB (9).
As a result of the data analysis, the Upper Hudson Riverbed sediments
were divided into two areas, the so called "hot spots" (PCB concentration > 50
ppm) and "cold areas" (PCB concentration < 50 ppm). The total mass of PCBs in
each of these general areas was calculated and is presented in Table 5.
TABLE 5. ESTIMATED MASS OF PCB IN SEDIMENTS OF UPPER HUDSON RIVER
PCB mass (thousands of Ibs)
Reach Total Hot Spot Cold Area Scourable*
9
8
7
6
5
4
3
2
1
3
118
16
49
45
20
18
14
13
**
98
6
41
n
12
2
0
0
3
20
10
8
34
8
16
14
13
2
47
4
9
9
7
11
3
6
All 296 170 126 98
Sources: Tofflemire and Quinn (10).
* Estimated from relative scour velocities determined from sediment
transport model.
** The average concentration for this reach is 20 ppm, but sampling is
inadequate to define hot spots and cold areas. It should probably be
considered a cold area.
MANAGEMENT ALTERNATIVES
During the initial stages of formulating the plan of study for the PCB
Hudson River Project, a number of potential methods for managing the PCB
contaminated sediments were reviewed. Some of these methods consisted of:
degradation by ultra-violet ozonation, biodegration, chemical treatment,
adsorption, chemical fixation, covering PCB contaminated sediments, dredging,
bioharvesting, etc. Most of these alternatives could not be applied to the
Hudson River problem because of the high cost and/or impracticability. Others
were judged not to be sufficiently technically developed for possible use in
the Hudson River Project.
The development could require a 5 to 10 year period before a full evalua-
tion could be made. In the meantime, contaminated sediments would continue to
74
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move into the estuarine portion of the river and possible major flood condi-
tions could further disperse the known areas of high contamination. Because
of the urgency in the nature of the project, the major management alternative
that was studied in detail was dredging.
Four alternatives which appear feasible are summarized in Table 6. The
following is a brief description of the four alternatives and the effective-
ness of each in removing PCBs from the river.
No Management Action (Maintenance dredging)
If no action takes place in the river, New York State Department of
Transportation, empowered by the State's constitution, has the task of main-
taining the State canal system. Based on past requirements to maintain a
navigable, 12 foot deep channel in the Upper Hudson River, it has been esti-
mated that DOT will be required to remove over 900,000 yd3 of sediments over
the next ten years.
This maintenance program will in fact remove approximately 50,000 pounds
of PCBs from the river. This estimate was made on the assumption that the
removal sediments would contain about 35 ppm of PCB and that a 90 percent
removal efficiency could be achieved under a carefully controlled dredging
program.
Remnant Deposits
The remnant deposits are those formed by the sediments that settled
behind the former Fort Edward Dam. These deposits can erode easily, especi-
ally during high river flows. They cover five distinct areas in a 2 mile
stretch of river. Three of the areas contain a low PCB concentration of 1-20
ppm, and no structural action was planned. The remaining two areas, although
high in PCBs (25-200 ppm), were stabilized and could be removed later if
necessary. An additional area which contained an average PCB contamination of
1000 ppm, was removed and placed in a secured, encapsulated facility. The
excavation of two highly contaminated areas would eliminate about 140,000 Ibs
of PCBs.
Hot Spot Dredging
The greatest amount of PCBs can be removed economically by dredging the
hot spot areas. The main reason for considering the hot spot dredging was the
fact that the unit costs ($/pound PCB) of removal was the lowest, yet the
least environmental disruption would occur. It has been estimated that an
efficient, well operated and modernized dredging operation can remove effec-
tively over 94 percent (11) of the PCBs contained in the hot spot areas.
While disturbing only 8 percent of the riverbed area in the Upper Hudson,
the hot spot program can remove 160,000 pounds of PCB. Careful evaluation of
the various physical conditions in each of the areas will provide the neces-
sary information so that the best equipment for each of the areas can be se-
75
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TABLE 6. SUMMARY DESCRIPTION AND EVALUATION OF POSSIBLE MANAGEMENT STRATEGIES FOR THE HUDSON RIVER
Possible
Management
Action
Yd3 Dredged
from River
(1978-1988)
Lbs. PCBs
Removed from
River System
(1978-1988)
Types of Technology
Status
1.
Further study -
No management action
Stabilize and/or
remove remnant
deposits.
Remove remnant
deposits and remove
all river sediments
with PCB concentrations
greater than 50 ppm
(hot spot dredging).
Removal of all river
deposits greater than
1 ppm (>5 ppm in rem-
nant deposit areas).
916,000
1,082,000*
(888,000)**
1,660,000
15,000,000
50,800
165,000*
(97,500)**
313,000
410,000
Continuous DOT main-
tenance dredging
necessary for Barge
Canal operation.
Modified DOT maintenance
dredging program to
assure permanent removal
of >90% of PCBs dredged
from river as part of
maintenance program.
Bank stabilization and/or Environmental assess-
remove remnant deposits ment prepared; 2-year
and modified DOT main-
tenance dredging program
Removal of remnant de-
posits and hot spot
dredging technology to
vary from small special-
ized hydraulic dredges
to large clamshell
dredges. Maximum prac-
tical PCB containment
technology would be used.
Massive clamshell dredg-
ing effort. Maximum
practical PCB contain-
ment technology would be
used.
program anticipated
as outlined above
(1978-1979).
Remnant deposit envir-
ronmental assessment
prepared; 2-year pro-
gram anticipated; hot
spot environmental
assessment under
preparation; 3-year
program anticipated
(1980-1982).
Environmental assess-
ment not as yet
authorized; 10-year
program anticipated
(1980-1990)
Source: calculated from Malcolm Pirnie (7, 14) and Tofflemire and Quinn (10).
* Assumes area 3, 3A and 5 are removed from the basin.
** Assumes area 3A and 5 are removed and area 3 is stabilized.
-------
lected. Much more sampling and related geological and engineering work must
be done in order to fully delineate the hot spot areas, which could be fully
dredged within a 2 to 3 year period.
Complete Dredging
The most expensive and extensive dredging program could be undertaken if
funds were available for dredging the entire shore-to-shore 40 mile section of
the Upper Hudson River. The dredging yardage involved in this program would
be an order of magnitude greater than the hot spot dredging, but it would
allow well over 94 percent of the total PCBs to be removed from the riverbed
between Fort Edward and Troy, New York.
This removal project, because of its extensive scope of work, would
require approximately 10 years to complete.
DISPOSAL
A number of methods for final disposal were evaluated. Among these were
incineration, biodegradation and total encapsulation.
Incineration
The technical, economic and environmental feasibility of destroying PCBs
in river sediments was investigated by GE (12). As long as temperatures
exceeded 1800°F (982°C) and 0.5 seconds contact time, most PCBs were
destroyed.
The incineration process is expensive, however, it may become attractive
if a co-disposal or tri-disposal system could be designed. That is, the
incineration system could provide ultimate disposal for both the solid waste
and wastewater sludge stream as well as toxic waste, such as PCBs in river
sediments. Disposal schemes, such as the one being developed by Wright-Malta
Corporation (13), that is, a gasifier-gas turbine system, could generate
electric power to off-set the yearly operation and maintenance costs.
Biodegradation
Biodegradation is a possibility but sufficient information does not now
exist to design such a system. Environmentally and economically, it is a very
attractive and desirable option that has not yet been technically developed.
Total Encapsulation
This process involves the total containment and isolation of contaminated
material within a land burial facility. The Federal and State governments
have issued very extensive regulations regarding the design and operation of
toxic chemical landfills, especially with regards to PCBs. These criteria
77
-------
relate to site selection, lining and leachate prevention, and operation and
maintenance.
Detailed information (7) was developed for each of the criteria. Over
100,000 acres of land, along a 2 mile corridor on both sides of the river
between Fort Edward and Troy, were evaluated (14). Forty potential sites were
selected during the preliminary period and now six remaining candidate sites
are being fully evaluated before a decision is made. Detailed field studies
are now in progress in order to select the best possible site and one that
lends to the dredging program.
Potential for environmental losses will be minimized by placing an imper-
meable barrier beneath the contaminated sediments and a similar impermeable
cap above it to prevent water from infiltrating into the dredged material.
Long term operation and maintenance provisions must be made in order to
guarantee the impermeability of the cap, the collection and disposal of leach-
ate, if any, and a complete environmental monitoring program.
New York State as well as the rest of the country has little experience
in many of these areas, especially in the design, construction, operation and
maintenance of an encapsulated toxic substance facility. Pilot projects and
other dredging operations presently on-going in New York State will facilitate
the final design of PCB dredging and disposal program.
ENVIRONMENTAL IMPACTS
The public health impact of the PCBs in the sediments of the Hudson River
is a primary reason for pursuing the removal project. Secondly, the fishery
resource for most of the river is unavailable to New York residents and visi-
tors.
Whether one is concerned with public health or ecological benefits, the
remedial project for the Hudson River will have a definite impact on the PCB
contamination of fish. Any action that can economically remove and isolate a
toxic material from the environment should be given high priority.
A summary of both short and long terms effects of the alternatives that
were considered are presented in Tables 7 and 8.
78
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TABLE 7. SUMMARY OF SHORT TERM ENVIRONMENTAL IMPACT OF VARIOUS MANAGEMENT ALTERNATIVES
Aesthetic
Biota
Water Supply
Land
4.
Further study,
No management action
Stabilize/remove
remnant deposits
Remove remnant
deposits plus hot spot
dredgi ng
Removal of all river
deposits with PCBs
greater than 1 ppm
(5 ppm in remnant
deposits)
Minimal disturbance in
sections of river dredged
as part of DOT maintenance
dredging program.
Extremely localized.
Local water quality stand-
and for turbidity will be
violated during dredging
operation (2-3 yrs).
Potentially extensive. Con-
tinued local disturbance
in the areas under active
dredging will cause aesthe-
tic problems for 8-10 yrs.
Localized elimination of
benthic fauna in main-
tenance dredging areas.
Temporary increase of PCB
levels in macroinvertebrates
immediately downstream of
dredging.
Temporary (1-2 years) loss
of benthic fauna in dredged
hot spot areas. Short term
rise in PCB concentration
in biota immediately down-
stream from dredging area.
Temporary increase of PCB
levels in macroinvertebrates
immediately downstream of
dredging. Loss of wetlands.
Temporary elimination of
benthic fauna in dredged
areas for period of up to
3 yrs after dredging.
Temporary increase of PCB
levels in macroinvertebrates
immediately downstream of
dredging.
Minimal increase in PCBs in
vicinity of Waterford water
supply intake when areas
adjacent to water intake
are dredged.
No short term impact other
than as stated above for
maintenance dredging.
Land areas involved are
small and land based
operation will be local
and of minimal environ-
mental significance.
2 - 8 ha of land may be
completely disrupted.
Since there are no hot spots 30 - 70 ha of land will
in vicinity of Waterford
intake, no water supply
impacts are expected other
than the maintenance dredg-
ing impact stated above.
Temporary increase in PCB
concentrations in vicinity
of Waterford water supply
intake when that segment of
the river is dredged.
be completely disrupted.
Up to 400 ha of land
will be disrupted.
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TABLE 8. SUMMARY OF LONG TERM ENVIRONMENTAL IMPACT OF VARIOUS MANAGEMENT ALTERNATIVES
PCB Containment
Biota (11)
Water Supply
Land
Air
00
o
1. Further study -
No Management
action
2. Stabilize/remove
remnant deposits
3. Remove remnant
deposits and re-
move all river
sediments with
PCB concentra-
tions >50 ppm.
(hot spot dredg-
ing).
Approximately 23,000 kg
of the PCBs will be
recovered from the
riverbed by mainten-
ance dredging, leaving
175,000 kg (or 88% of
the inplace upper river
PCBs) to disperse and
probably recycle through
the environment.
PCB levels in fish and
other biota in the upper
and lower river will not
change in the foreseeable
future (upper river >10,
lower river >20); lower
river concentrations may
rise as highly contami-
nated PCB sediments move
from the upper river into
the estuary.
As much as 75,000 kg of
of PCBs will be per-
manently removed from
the riverbed leaving
122,000 kg (or 63% of
the upper river inplace
PCBs) to disperse and
continually recycle
through the environment.
Stabilization of the
remnant deposits will
substantially eliminate
a known active source
of PCBs to the upper river
system; will reduce size
and PCB complexities of
of DOT maintenance dredging
program.
Will reduce by an unknown
amount the time required
for PCB levels in the
upper river biota to fall.
Minimal effects on the
lower river biota are
anticipated.
Approximately 142,000
kg of PCB will be per-
manently removed from
the riverbed leaving
56,000 kg (or 28% of
the upper river inplace
PCBs) to disperse and
continually recycle
through the environment.
This option will elimi-
nate all high concentra-
tion sediments (>50 ppm)
from the river system.
Water column PCB concen-
trations will continue to
cause public health con-
cerns for people using
the river as a source of
drinking water. Any plans
to use the Hudson for
for drinking water in the
future will have to accomo-
date this contamination.
May reduce water column
PCB concentrations in
in vicinity of Waterford
water intake by reducing
an active source to the
upper river. Will have
only a minimal effect on
any lower river water
supplies, and planned
and planned flood skim-
ming for NYC water supply
in the foreseeable future.
No long term land
impact is fore-
seen.
Can reduce PCB biota
concentrations in upper
river by 50% to fish flesh
levels of 20-40 ppm. In
the lower river, fish
burdens may drop by
about 20% to about
8-12 ppm.
Should substantially re-
duce water column PCB con-
centrations in vicinity of
Waterford water supply
intake. Will have a mar-
ginal effect on lower
river water supplies,
existing and planned in
the foreseeable future.
Continued probable vola-
tilization from the
river and dredge spoil
from maintenance dredg-
ing.
2 - 8 ha of land
will be required
for spoil dispo-
sal . Permanent
restrictions on
use of the land
will be required.
Restrictions may be
mitigated by using
land as a nature pre-
serve or ecological
study area. (Permanent
restrictions could be
changed by technological
advancement in PCB bac-
terial, biodegradation
research).
Reduction of volatiliza-
tion from river probably
slight.
30 - 70 ha of land
will be required
for contaminated
spoils disposal.
Permanent restric-
tions on use of land
will be required.
Restrictions may be
mitigated by using
land as a nature pre-
serve or ecological
study area. (Permanent
restrictions could be
Should substantially
reduce PCB volatiliza-
tion from the upper
river.
-------
TABLE 8. (continued)
changed by technological
advancement in PCB bac-
terial, biodegradation
research).
4. Remove all upper
river deposits
>1 ppm (>5 ppm
in remnant de-
posit areas).
00
It will substantially re-
duce the size of PCB com-
plexity of DOT maintenance
dredging operations. The
sediments to be recovered
are also generally contami-
nated with organic pollu-
tants and other toxic mater-
ials. This project would re-
move these materials from the
river environment.
About 186,000 kg (-v 94%) Can reduce PCB biota
of the PCBs in the upper concentrations in the
river will be perma-
nently removed from the
riverbed and the en-
vironment. Substantial
reductions in the size
and PCB complexities of
future DOT maintenance
dredging programs will
occur. Most of the
sediments to be removed
are also contaminated
with other organic pollu-
tants and other toxic
materials. This project
will remove these materials
from the river environment.
upper river to fish flesh
levels of 10-20 ppm.
By significantly reduc-
ing PCB input into the
lower river, it may re-
duce the body burden of }
larger fish by about 30-
50% to levels close to
5 ppm.
Will substantially elimi-
nate the problem of PCBs in
the village of Waterford
water supply intake. Will
also lower level of other
toxic contaminants in the
Waterford water supply. Can
measurably reduce PCB
water column problems in
vicinity of estuary water
supply intakes by stopping
active sources of PCBs to
the lower river. May re-
duce PCB problems associ-
ated with flood skimming
project.
About 400 ha of
of land will be
required for con-
taminated spoil
disposal. Perma-
nent restrictions
on use of land
will be required.
Restrictions may be
mitigated by using
land as a nature pre-
serve or ecological
study area. (Perma-
nent restrictions
could be changed by
technological advance-
ment in PCB bacterial,
biodegradation research).
Will eliminate the
river as a source of
PCBs to atmosphere.
Odors associated with
extensive sludge beds
should also be essen-
tially eliminated.
-------
FUNDING
A number of funding methods have been considered in order to complete the
Hudson River remedial program. These included:
1. State/local funding.
2. Funding as a Corps of Engineers (COE) public works project.
3. Funding by special Congressional legislation.
4. Funding under the Water Pollution Control Act. (Clean Waters Act).
New York State is not able to finance the cost of this remedial program.
The Federal government together with New York State should bear the burden of
financing the large remedial program, since the entire nation has benefited by
the capacitor manufacturing process at GE's Fort Edward and Hudson Falls
plants.
Funding both as a Corps of Engineers public works project or through
special legislation would require a long period of time and unacceptable
delays. Contamination of the lower Hudson continues at a rate of over 5,000
Ibs per year and the cost of the project also continues to rise.
New York State has seized the opportunity to fund the remedial project
under the Federal Water Pollution Control Act. Two portions of the Act that
appeared relevant were a research and development grant under Title I and a
treatment works construction grant under Title II.
Two grants requests were submitted to EPA under Title I, Section 115 and
under Title II, Section 201. Innovative and alternative wastewater treatment
techniques are specifically encouraged by Section 201(g)(5) of the Water
Pollution Control Act for the purpose of confining disposal of pollutants, so
that pollutants will not migrate and cause water or other environmental pollu-
tion.
To this day, New York State has not received eligibility ruling for
either of these grant applications. EPA in Washington is presently reviewing
the project under Section 201 and insufficient funds exist in Section 115.
Two additional areas of funding are being pursued: a) a special Congres-
sional action on Clean Waters Act amendment to authorize the PCB project
(proposed New Section 116), and b) the Superfund Bill that is now in Congress.
Both of these areas could produce funds by spring of 1980. New York State is
fully committed to this project and is continuing to obtain additional scien-
tific and engineering data so that it can be in a position to start the PCB
remedial project in 1980.
82
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STATUS
The New York State Department of Environmental Conservation through a
small but highly technical staff is continuing to finance the on-going scien-
tific research and has begun to formulate, in detail, the management schedule
for the implementation of the PCB Reclamation Project. It is a difficult task
and there are many steps that could delay the project (Figure 6). However,
the commitment to eliminate the spreading contamination of the Hudson River by
PCB has long been made by the State of New York. Some initial phases of this
project were already taken in the summer of 1978 (15). New York state Depart-
ment of Transportation, as part of the maintenance dredging, has removed an
additional 7,000 Ibs of PCBs in the summer and fall of 1979. And, if the
funding becomes a reality by spring of 1980, it is possible that the PCB Hot
Spot Dredging Project for the Hudson River could be completed by 1982.
83
-------
00
PROJECT ACTIVITY
PROJECT MANAGEMENT
SITE APPROVAL PROCESS
SITE ACQUISITION PROCESS
FEDERAL PERMIT PROCESS"
STATE PERMIT PROCESS
FEDERAL EAS/EIS PROCESS" .
STATE EAS/EIS PROCESS _
SITE FIELD ENGINEERING
SITE PLANS/SPECS
SITE CONTRACT PROCESS
CONSTRUCTION SUPERVISOR
SITE CONSTRUCTION
DREDGING FIELD ENGINEERING
DREDGING PLANS/ SPECS
DREDGING CONTRACT PROCESS
DREDGING CONSTRUCTION
DREDGING PREQUAL. BIDDERS
MONITORING PROCESS
PUBLIC INFORMATION PROCESS
1979
OND
—
I960
J FMAMJ JASOND
1981
J FMAMJ JASOND
\t-formal public hearing
\
— h
endofsiteaf.
K"
Ct
SI
+
m
proval process
tmplete c
te work / u
••••••»
begin dredging
upper pools
1982
JFMAM J JASOND
omplete site
ork lower pools
begin dredging
lower pools
1983
JFMAMJ
Figure 6. Hudson River PCB reclamation project - accelerated schedule.
-------
REFERENCES
1. Nisbet, Ian C. T. (1976), Criteria Document for PCBs, EPA 440/76-021.
2. Subcommittee on the Health Effects of PCBs and PBBs (1976), Final Report,
Department of Health, Education and Welfare, Washington, D.C.
3. Sofaer, A. February 1976. Interim Opinion and Order, unpublished opinion
in the matter of violations of ECL by GE Company. New York State Depart-
ment of Environmental Conservation, File #2833. 77 pp.
4. New York State Department of Environmental Conservation, "Hudson River PCB
Study Description and Detailed Work Plan, Implementation of PCB
Settlement", Technical Report No. 58, NYS Dept. of Environmental
Conservation, Albany, NY 12233 (Jan. 1979).
5. Hetling, L. J. , E. Horn and T. J. Tofflemire, "Summary of Hudson River PCB
Study Results", Technical Paper #51, Bureau of Water Research, NYS Dept. of
Environmental Conservation, Albany, NY 12233 (July 1978).
6. Daly, C. J., "An assessment of the performance of laboratories providing
PCB data for the PCB Settlement", NYS Department of Health, Environmental
Health Center, Division of Laboratories and Research (September 1979).
7. Malcolm Pirnie, Inc., "Dredging of PCB Contaminated River Bed Materials -
Upper Hudson River, NY, Feasibility Report, Volume 1, 2, 3 and Data Base",
White Plains, NY (Jan. 1978).
8. Lawler, Matusky and Skelly Engineers, "Upper Hudson River PCB No Action
Alternative Study: Final Report", Pearl River, NY (March 1978).
9. Matusik, J. J., "Unpublished Data on Heavy Metals in Hudson River Sedi-
ments." NYS Department of Health, Radiological Sciences Laboratory,
Albany, NY (Sept. 1978).
10. Tofflemire, T. J. and S. 0. Quinn, "PCB in the Upper Hudson River: Mapping
and Sediment Relationships", NYS Department of Environmental Conservation,
Technical Report No. 56, Albany, NY (April 1979).
11. Tofflemire, T. J., L. J. Hetling and S. 0. Quinn, "PCB in the Upper Hudson
River: Sediment Distributions, Water Interactions/and Dredging", NYS
Department of Environmental Conservation, Bureau of Water Research,
Technical Report No. 55, Albany, NY (Jan. 1979).
85
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12. Griffen, P. M. , C. M. McFarland and A. R. Sears, "Research and Removal or
Treatment of PCB in Liquid or Sediments Dredged from the Hudson River:
Semi-annual Progress Report. "General Electric Company, Corporate
Research and Development, Schenectady, NY (Feb. 1978).
13. Coffman, J. A. - Personal Communication - Wright-Malta Corporation,
Ballston Spa, NY (Feb. 1978).
14. Malcolm Pirnie, Inc. "Phase I Engineering Report, Dredging of PCB Con-
taminated Hot Spot Upper Hudson River, New York". White Plains, New York
(Dec. 1978).
15. Thomas, R. F., R. C. MtPleasant, and S. P. Maslansky, "Removal and Disposal
of PCB - Contaminated Riverbed Materials", Proceedings of 1979 National
Conference on Hazardous Material Risk Assessment, Disposal and Management,
April 25-27, 1979, Miami Beach, Florida, pp 167-172.
86
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THE SECTION 404 DREDGE AND FILL PROGRAM
J. P. Crowder
Chief, Aquatic Protection Branch (WH-585)
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
ABSTRACT
Dredging and filling in the navigable-in-fact waters
of the United States have been regulated for 80 years
under provisions of section 10 of the River and Harbor Act
of 1899. Since 1968, major federal environmental legisla-
tion has expanded the criteria for decision on section 10
permit applications to include numerous public interest
factors in addition to navigation. With enactment of the
Federal Water Pollution Control Amendments of 1972, sec-
tion 13 of the 1899 Act was amended and expanded to create
a water pollution control program regulating discharges of
all classes of pollutants into the Nation's waters. The
new statute established the section 404 program to
regulate discharges of dredged or fill material, with
responsibilities for administration divided between the
department of the Army and the Administrator of the Envi-
ronmental Protection Agency. The geographic scope of the
section 404 program is substantially broader than that
available in the 1899 Act, but the classes of activity
regulated are to some degree similar.
Environmental criteria for the Section 404 program
are based on objectives that encourage minimization of
impact principally through careful evaluation of material
proposed for discharge and through rigorous evaluation of
alternative disposal sites and methodologies.
INTRODUCTION
The section 404 permit program for the regulation of discharges of
dredged and fill materials in waters of the United States under an authority
directed specifically and exclusively to that purpose is of relatively recent
origin. A closely-related regulatory program has been carried out for 80
years under section 10 of the River and Harbor Act of 1899. The interrela-
tionships between these programs are so strong that a discussion of the one is
87
-------
incomplete without due reference to the other. The purpose of this paper is
to describe briefly the legislative origins of the section 404 program; the
geographic scope and range of activities regulated by the program; and the
environmental review criteria used to review applications for section 404
permits.
HISTORY OF FEDERAL LEGAL AUTHORITIES AFFECTING
DREDGING AND DREDGED MATERIAL DISPOSAL
River and Harbor Act of 1899
The principal authorities for the regulation of dredging and the dis-
charge of dredged material in waters of the United States are section 10 of
the River and Harbor Act of 1899 (33 U.S.C. 401 et seq.) and section 404 of
the Clean Water Act (13 U.S.C. 1344). The first of these authorities essen-
tially constitutes an assertion of police power to protect from damage or
obstruction those waters which are in use for the transportation of interstate
or foreign commerce, which have been used for such purposes in the past, or
which, with reasonable improvement, could be made usable for that purpose.
Section 10 prohibits the construction or placement of any structure in
navigable waters of the United States unless authorized by a Department of the
Army permit. This includes docks, piers, wharves, bulkheads, weirs, booms,
breakwaters, jetties, pilings, power transmission lines, cables, aids to
navigation, and similar structures. Section 10 also requires a permit for
such work in navigable waters as dredging, disposal of dredged material,
filling, and the connection of artificial canals and ditches to existing
navigable waters in any manner which might affect their navigable capacity.
For about the first 69 years of its implementation, the 1899 Act was
interpreted and implemented exclusively in terms of navigational concerns,
that is, the sole criterion for issuance or denial of a permit was the extent
to which proposed structures or work would affect navigation. In 1968, the
Department of the Army revised the regulations implementing section 10 (and
other authorities under the 1899 Act) to expand the scope of permit review to
include the effect of proposed work or structures "... on navigation, fish and
wildlife, conservation, pollution, aesthetics, ecology, and the general public
interest ..." (33 CFR 209.120(d), 1968). In the following decade, a number of
new environmental laws were enacted, the effect of which was to increasingly
expand the environmental factors taken into account in the review of section
10 permit applications. Among the major laws enacted in this period were:
The National Environmental Policy Act of 1969 (PL
91-90, 42 U.S.C.4331et seq.), which requires Federal
agencies to evaluate the environmental consequences of
their actions. For major actions that significantly
affect the environment, agencies are required to develop
detailed "environmental impact statements" and to submit
these to interagency and public review before malking a
final decision of whether to carry out a proposed agency
action.
88
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The National Historic Preservation Act of 1966 (80
Stat. 915, 16 U.S.G. 470), which established a National
Advisory Council on Historic Preservation to advise the
President and the Congress on matters of historic preser-
vation and to review and comment on activities licensed or
permitted by the Federal government which will have an
affect on major historical properties.
The Coastal Zone Management Act of 1972 (PL 92-583,
86 stat. 1280), which establishes procedures for States to
follow in development and operation of Federally-approved
coastal zone management programs. These programs involve
the development of comprehensive plans for the long-term
protection and development of coastal land and water
resources. The Act requires any applicant for a Federal
permit or license to conduct any activity affecting coas-
tal land or water uses to furnish the permitting or li-
censing agency with a certification that the proposed
activity complies with the State's coastal zone management
program. Generally, no Federal permit or license will be
issued for such an activity until the State concurs with
the applicant's certification.
I have cited these particular authorities because they are major environ-
mental laws which, in combination with the River and Harbor Act of 1899, have
substantially improved the degree to which environmental values are protected
through the Department of the Army's section 10 permit program. These stat-
utes, together with a number of other environmental and other laws, have led
the Department of the Army, acting through the U.S. Army Corps of Engineers,
to expand the public interest review of permit applications to embrace, cur-
rently, a total of 17 specifically named factors. These are, "conservation,
economics, aesthetics, general environmental concerns, historic values, fish
and wildlife values, flood damage prevention, land use, navigation, recrea-
tion, water supply, water quality, energy needs, safety, food production and
in general the needs and welfare of the people" (33 C.F.R. 325.3(b)(l)).
Federal Water Pollution Control Act Amendments of 1972
By the year 1972, the scope of the public interest review of permit
applications under the 1899 River and Harbor Act was commendably broad.
Although that Act itself was not designed or implemented primarily for envi-
ronmental protection, it was evolving into an effective tool for that purpose
when applied in combination with other laws. In 1972, widespread public
concern about the degraded condition of the Nation's waters prompted the
Congress to consolidate, revise, and expand upon the existing body of Federal
law controlling water pollution. The product of these Congressional labors
was a comprehensive water pollution control act, entitled the Federal Water
Pollution Control Act of 1972 (FWPCA) (33 U.S.C. 1344), which embodies a
national goal "to restore and maintain the chemical, physical, and biological
integrity of the Nation's waters".
The 1972 Act did not change section 10 of the River and Harbor Act of
1899. It did, however, amend another Section of that Act, namely section 13.
89
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Section 13, referred to as the "Refuse Act," prohibited the discharge of
refuse mater (except liquid sewage) into any navigable water of the United
States or any tributary thereof unless authorized by a permit from the Secre-
tary of the Army and the Chief of Engineers. For many years, Section 13 lay
in almost total disuse until, in the mid-1960's, it reemerged as the primary
Federal enforcement tool for control of pollution discharges into the Nation's
navigable waters. Section 402 of the FWPCA essentially superseded section 13
by transferring to the Administrator of the Environmental Protection Agency
the permitting authority for discharge of most classes of point source pollut-
ants.
The early drafts of the FWPCA envisioned a single permit program for the
regulation of point source discharges of all pollutants into the navigable
waters, with authority to administer this program to be vested with the Admin-
istration of the Environmental Protection Agency. As the 1972 legislation
evolved within the Congress, several considerations emerged which impelled the
Congress to the eventual establishment of a separate permit program to control
the discharge of dredged or fill material. First, the Congress recognized
that management of dredged material was a responsibility that had long been
vested in the Secreatry of the Army through section 10 of the River and Harbor
Act of 1899 and that for this reason an established administrative system was
already in place, within the U.S. Army Corps of Engineers, for the processing
of dredge and fill permit applications. For this reason, the Congress "did
not wish to create a burdensome bureaucracy in light of the fact that a system
to issue permits already existed."(1) It was also argued, by certain elements
of the Senate, that a regulatory program so vitally tied to the economics of
navigation should not be entrusted to a newly-established regulatory agency
such as EPA, which, at the time, had been in existence for only about two
years. The outcome of the Congressional deliberations on this issue was to
establish separate permit programs for the regulation of point-source pollut-
ants. Section 402 of the FWPCA provides a permit program, characterized as
the National Pollutant Discharge Elimination System, to regulate point souce
discharges of municipal and industrial point source discharges of water pol-
lutants. The Administrator of the Environmental Protection Agency is respon-
sible for the administration of this program. Section 404 of the 1972 Act,
and as subsequently amended, provides a permit program exclusively for regula-
tion of discharges of dredged and fill material. The Secretary of the Army,
acting through the Chief of Engineers, carries out the permit program under
this section. (A 1977 Amendment provides that individual States may operate
their own section 404 programs under standards prescribed by law, after ap-
proval by the Administrator. State programs, however, cannot regulate dis-
charges into waters actually used for transportation of waterborne commerce or
capable of being put to such use.) The Administrator of the Environmental
Protection Agency, however, is provided a very substantial role in the section
404 program in that he is required to develop guidelines to be used, by the
Corps and by States, in the evaluation of all proposed discharges of dredged
or fill material. The Administrator is also required to monitor the operation
of approved State programs and can revoke State programs where he finds that
they are not being carried out as required by law. Moreover, the Administra-
tor is provided (at section 404(c)) with the authority (frequently alluded to
as a "veto power") to restrict or deny the use of any site as a site for the
discharge of dredged or fill material. This means that even in cases where
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the Chief of Engineers or a State official has issued or would issue a permit,
the Administrator can, for sufficient cause, use his authority to prevent the
discharge from being made. In explaining the basis for this unusual balance
of powers in Section 404, the Conference Committee stated that, it:
"... did not believe that there could be any justification
for permitting the Secretary of the Army to make deter-
minations as to the environmental implications of either
the site to be selected or the specific spoil to be dis-
posed of in a site. Thus, the conferees agreed that the
Administrator of EPA should have the veto over the selec-
tion of any site for dredged spoil disposal and over any
specific spoil to be disposed of in any selected site"
(D-
In summary, then, in the Federal Water Pollution Control Act Amendments
of 1972, the Congress formally recognized dredged material (as well as fill
material) as a pollutant; acknowledged the substantial experience of the Corps
of Engineers in managing these materials via the section 10 permit program and
assigned administration of the section 404 permit program to the Corps; and
provided the Administrator of EPA with substantial authorities designed to
assure that this new program would focus effectively upon its primary purpose
of controlling water pollution.
SCOPE OF THE CURRENT SECTION 404 PROGRAM
Geographic Scope
As explained above, the 1899 River and Harbor Act is applicable only to
those waters that are, have been, or could be used for the actual transporta-
tion of interstate commerce. For the first several years of its administra-
tion, the Corps of Engineers administered the section 404 program only within
these same waters. A number of private environmental organizations opposed
the Corps' interpretation of this point. They agreed that the Congress in-
tended, in section 404 and in the rest of the 1972 Act, to control pollution
in all of the waters of the United States where discharges of pollutants could
affect the quality and value of those waters for any purpose of interstate
commerce, not merely for navigation. In 1974, the Natural Resources Defense
Counsel and the National Wildlife Federation filed suit against the Secretary
of the Army, the Corps of Engineers, and the Environmental Protection Agency*
(NRDC v. Callaway, 392 F. Supp. 685 D.D.C. 1975). These plaintiffs asked the
court to compel the Department of the Army to extend its section 404 jurisdic-
tion to all waters, the pollution of which could affect interstate commerce.
This litigation was successful, and on March 27, 1975, the District Court for
In addition to seeking an expansion of geographical jurisdiction for the
section 404 program, the plaintiffs sought to compel EPA and the Corps to
publish the section 404(b)(l) guidelines which, although required by
statute, had not been published at the time the suit was filed.
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the District of Columbia ordered the Department of the Army to revoke and
rescind that part of its regulation which limits jurisdiction of the Corps by
definition or otherwise to other than the waters of the United States." On
March 27, 1975, the court directed that the Department revise its regulation
to extend the geographical jurisdiction of the section 404 program to the
maximum extend permissible consistent with the commerce clause of the United
State Constitution. The current Corps of Engineers permit regulation responds
to this mandate. Accordingly, the jurisdiction of section 404 extends into
all waters subject to use for navigation; recreational use; production of fish
and shellfish; production of agricultural products; industrial water supply;
or for any other purpose which involves the use of the waters for interstate
or foreign commerce purposes.
This broad jurisdiction means that section 404 regulates activities in
many waters of the United States that never were subject to regulation under
the section 10 permit program. Section 10, for the most part, extended only
to coastal waters and the inland waters that did or could actually support
navigation. There are many thousands of miles of streams within the United
States and millions of acres of standing water bodies that are incapable of
supporting navigation, but that are of extremely high importance for fish and
shellfish production; wildlife habitat; municipal and industrial water supply;
timber production; recreation; and other purposes having connection with
interstate commerce. Most notably among these are wetlands, which are typi-
cally flooded for only a portion of the year, but which perform a number of
ecologically and socially valuable functions, including fish and wildlife
production; erosion control; filtration and purification of runoff waters;
temperature stabilization; and flood storage. It is estimated that there may
be as many as 37 million hectares of wetlands within the United States, ex-
cluding Alaska and Hawaii (2). Prior to the decision in NRDC v. Callaway, the
only wetlands regulated under section 404 were coastal wetlands subject to the
regular ebb and flow of the tide and freshwater wetlands lying below the
ordinary high water mark of navigable-in-fact freshwater bodies. The exten-
sion of section 404 jurisdiction to most of the wetlands was widely applauded
by environmental interests who had long been concerned about the widespread
and indiscriminate filling of wetlands and the very substantial public values
lost through such actions.
Also of great significance is the extension of section 404 jurisdiction
to small streams, including those streams that support runs of anadromous
fishes such as salmon, steel head, striped bass and other fish species of major
importance to domestic and international sport and commercial fisheries.
Workload Implications
This manyfold expansion of jurisdiction could easily have created burden-
some administrative problems in the processing of the numerous additional
permit applications that resulted, and in the task of enforcement against
unpermitted discharges of dredged or fill material into the newly-regulated
waters. These problems were largely avoided by several means, including: (1)
a nationwide publicity campaign, including public hearings and public meet-
ings, to inform the public of the extended jurisdiction; (2) the develop-
ment of a "general permit" program. General permits authorize minor dis-
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charges of dredged or fill materials, to be undertaken under the terms of an
already-issued permit. A general permit specifies the conditions that must be
met by a discharger in order to be in compliance with the permit. Once a
permit has been issued, anyone desiring to perform work authorized by the
general permit may proceed to do so, without being required to make an indi-
vidual application and without having to wait for a permit application to be
processed. This is a major savings of time, since the minimum period for
obtaining individual section 404 permit application is about 45 days from the
date an application is submitted.
To date, over 200 general permits have been issued by District Engineers
of the U.S. Army Corps of Engineers. In addition, two nationwide general
permits were issued in the Corps of Engineers' most recent permit regulation
(33 C.R.F. 323.4). The general permit program has probably authorized tens of
thousands of individual minor discharges of dredged or fill material into the
waters of the United States. (3) increased Department of the Army staff to
process permit applications. The Congress, recognizing the need for addi-
tional personnel to operate the expanded section 404 program, increased the
staff in the Corps of Engineers regulatory program to over 1,000 persons.
The Environmental Protection Agency has also increased the number of
personnel assigned to carry out its responsibilities in the section 404 pro-
gram. EPA had fewer than 30 positions assigned to the program in 1975. Total
EPA personnel now numbers 62.
Scope of Activities Regulated
Dredging not regulated
The section 404 program is frequently characterized, both coloquially and
formally, as a "dredge-and-fill" program. The term was widely used to des-
cribe activities regulated under the section 10 permit program. That program
did, in fact, regulate the act of dredging, or excavation, of material from
ports, harbors, channels, and other navigable-in-fact waters. By contrast,
section 404 is intended only to regulate actual discharges of dredged or fill
materials and therefore does not regulate the act of dredging itself.
The distinction is not unimportant, for it is entirely possible for a
dredging operation to be carried out in a manner which does not involve the
discharge of dredged material into the waters of the United States. No sec-
tion 404 permit is required to authorize the discharge of dredged material
that is conveyed to, and deposited upon a dry-land disposal site, but the
environmental standards by which section 10 applications are evaluated are not
as strict as those under section 404. If the dredging is carried out in
waters not subject to section 10, and the discharge is confined entirely to
dry land, the dredger avoids regulation under either authority. For these
reasons, neither section 10, nor section 404, nor the two laws working in
concert can be considered to be comprehensive in their regulation of dredging
and filling in all waters of the United States. These relationships are shown
graphically in Table 1.
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TABLE 1. COMPARISON OF THE GEOGRAPHICAL REACH OF TWO FEDERAL
REGULATORY PROGRAMS AND THEIR EXTENT OF REGULATION
OF THE ACTS OF DREDGING AND FILLING
Type and Location of Activity
Statutory
Authority
Section 404 of
Clean Water Act
Dredging in
navi gab le-in-
fact waters*
not
regulated
Dredging in
other than
navi gable- in-
fact waterst
not
regulated
Discharge of
dredged/f i 1 1
material in
nav i gable- in-
fact waters
regulated
Discharge of
dredged/f i 1 1
material in
other than
nav i gable- in-
fact waters
regulated
Section 10 of
River and , . ,
Harbor Act of regulated
1899
regulated re9ulated
not
regulated
* "navigable-in-fact waters" means coastal waters that are subject to ebb and
flow of the tide shoreward to the mean high water mark (mean higher high
water mark on the Pacific coast), and/or are presently used or have been
used in the past, or may be susceptible to use to transport interstate or
foreign commerce.
t "other than navigable-in-fact" includes waters other than "navigable-in-fact
waters" the degradation or destruction of which could affect interstate
commerce.
Refuse Discharges Not Regulated
Except for dredged material, section 404, as currently implemented does
not regulate the discharge of any form of waste or refuse. Fill material, the
second category of pollutant regulated under section 404, is defined, for
regulatory purposes, as "any material used for the primary purpose of replac-
ing any water of the United States with dry land or of changing bottom eleva-
tion of a waterbody". "Dredged material" is defined as "material that is
excavated or dredged from waters of the United States". Considering these two
regulatory definitions together, it is interesting to contemplate a situation
in which soil, clay, sand, rock, or some other earthern substance is excavated
from an area outside the waters of the United States, but is then discharged
into waters of the United States for the purpose of getting rid of it. The
material handled can not be defined as "dredged material", since its origin is
outside the waters. Nor would it meet the definition of "fill material",
since it is not discharged for either of the two purposes which that defini-
tion requires. It may be possible to close this unfortunate loophole in the
coverage of section 404 by revising the definition of fill material to expand
the purposes associated with that term. Unless and until that is done, such
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discharges can be regulated under section 402 of the Act. The section 402
program, however, has not been administratively designed to handle these kinds
of discharges, and thus is ill-equipped to do so.
Range of Activities Regulated
Two district classes of activity are regulated by the section 404 pro-
gram. Discharges of dredged material, for the most part, are undertaken in
conjunction with navigation. In the United States, annual quantities of
materials dredged by or in behalf of the Corps of Engineers average about
290,000,000 cubic yards for maintenance dredging and 78,000,000 cubic yards
for new work dredging (3). Additional navigation dredging is performed by
other interests, both public and private, but the vast majority of all dredg-
ing for navigation in United States waters is carried out by the Corps.
Typical activities of the Corps are construction and maintenance dredging of
channels, canals, turning basins, small boat harbors, and ocean inlets.
Private industry dredging, and associated disposal, typically includes
the dredging of ship berths; marinas; residential canals; canals and slips for
movement of equipment used in exploration and extraction of oil, gas, sulfur
and other minerals; and dredging of shell, gravel and sand for manufacture of
construction materials or roadway construction.
As discussed above, it is possible to discharge dredged material on dry
land sites and to thereby avoid regulation under section 404. In actual
practice, however, a large proportion of the material dredged from the waters
of the United States is also discharged into those waters, at other locali-
ties. Therefore, in most instances involving major dredging for navigation, a
section 404 permit is required for the discharge, as well as a permit under
section 10 of the 1899 River and Harbor Act.
Unlike the discharge of dredged material, the discharge of fill material
is not dominantly associated with a single agency or activity. Common uses of
fill material are the restoration of eroded sand beaches; stabilization of
shorelines with riprap; construction of sites for commercial industrial facil-
ities, including power generation plants; construction of wharves, jetties,
groins, breakwaters, bulkheads, causeways, roads, bridge abutments, dikes,
dams and levees, and burial of utility lines. Much less commonly, discharges
of fill material are made for the purpose of constructing residential sites,
solid waste containment facilities, raw materials storage sites, and for other
purposes that may not intrinsically require proximity to water, but which can
not, in particular situations practicably be sited elsewhere.
Volume of Permits Processed
In 1978, the most recent year for which complete records are available, a
total of 10,150 permit applications were reviewed under the section 404 pro-
gram. Of these, some 6,972 involved activities in the navigable-in-fact
waters that were also subject to section 10 of the River and Harbor Act of
1899. In such cases, the permit processing procedures currently in use pro-
vide for the simultaneous public notice and review of both permit applica-
tions. About 9,000 additional permit applications were reviewed in 1978 for
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activities that were regulated only under authority of section 10 of the River
and Harbor Act of 1899.
ENVIRONMENTAL CRITERIA FOR REVIEW OF SECTION 404 PERMIT APPLICATIONS
Relationship to National Environmental Policy Act
As pointed out above, all Federal actions, regulatory or otherwise, are
subject to the requirements of the National Environmental Policy Act of 1969.
Neither time nor the purpose of this paper warrant a detailed review of the
requirements of that Act, except to take note that those requirements are much
broader and more general than are the environmental evaluation criteria man-
dated in the section 404(b)(l) guidelines (40 CFR 230). The guidelines, as
published September 5, 1975, define the procedures to be used in determining
the extent to which given discharge of dredged or fill material will adversely
impact the quality of the waters of the United States and the living systems
and beneficial natural uses which such waters support.
Objectives of Guidelines
The guidelines require that, in the review of all section 404 permit
applications, a number of objectives be considered in determining whether to
permit a proposed discharge. These objectives are to:
"(1) Avoid discharge activities that significantly disrupt the chemical,
physical, and biological integrity of the aquatic ecosystem, of
which aquatic biota, the substrate, and the normal fluctuations of
the water level are integral components;
(2) Avoid discharge activities that significantly disrupt the food chain
including alterations or decrease in diversity of plant and animal
species;
(3) Avoid discharge activities that inhibit the movement of fauna,
especially their movement into and out of feeding, spawning, breed-
ing and nursery areas;
(4) Avoid discharge activities that will destroy wetland areas having
significant functions in maintenance of water quality;
(5) Recognize that discharge activities might destroy or isolate areas
that serve the function of retaining natural high waters or flood
waters;
(6) Minimize, where practicable, adverse turbidity levels resulting from
the discharge;
(7) Minimize discharge activities that will degrade aesthetic, recrea-
tional, and economic values;
(8) Avoid degradation of water quality as determined through application
of §§230.4, 230.5 (b), (c), and (d)."
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The Sections of the guidelines referenced in item (8) above deal with (1)
evaluation of physical and chemical-biological interactive effects; (2) the
comparison of concentrations of pollutants present in material with the per-
missible concentrations established in the water quality standards prescribed
under section 303 of the Act; (3) consideration to determine the size of a
disposal site and the conditions of disposal to minimize the possibility of
harmful effects; and (4) the prohibition of discharge of fill material having
unacceptable quantities, concentrations, or forms of contaminants deemed
"critical" by EPA or the Corps of Engineers, except where adequately confined.
In attempting to achieve the eight objectives listed above, the guide-
lines require that consideration be given to the need for the proposed dis-
charge and the availability of alternative sites and methods of disposal that
are less damaging to the environment. The alteratives analysis lies at the
very heart of the section 404 permit evaluation, and it is in this analysis
that the section 404 program differs most significantly from the section 402
(NPDES) program. In the latter program, a discharger must meet the require-
ments of "effluent guidelines", which establish the types and concentrations
of defined pollutants that he may lawfully discharge. In the section 404
program, by contrast, the material proposed to be discharged may be completely
uncontaminated, but its discharge may nevertheless be prohibited because of
the acutely destructive impact of discharging the material upon a biologically
productive site, especially when there are other, feasible, alternative sites
where the discharge can be made at much less expense to the environment. The
section 404(b) guidelines explicitly recognize that, "From a national perspec-
tive, the degradation or destruction of aquatic resources by filling opera-
tions in wetlands is considered to be the most severe impact covered by these
guidelines." (40 CFR 230)
Water Dependency
Proposals for filling wetland areas are submitted to the most rigorous
scrutiny of any activity evaluated by the guidelines. In order to obtain a
permit for filling of wetlands, the applicant must demonstrate that either (a)
the activity is "water-dependent," that is, that it requires direct access or
proximity to, or location directly within the water in order to carry out its
basic purpose; or (b) other site or construction alternatives are not practic-
able. He must also show that the proposed fill will not cause a "permanent
unacceptable disruption to the beneficial uses of the affected aquatic sys-
tem." These burdens of proof are sometimes difficult to bear, as indicated in
recent years by the denial, or radical reduction in scope, of permit applica-
tions involving proposed fill material discharges in wetlands. In one especi-
ally noteworthy case, the Corps of Engineers denied two permits to a major
real estate developer in Florida, whose proposed projects would have resulted
in dredging and filling of about 3,000 acres of coastal wetlands and shallows
to create canal and residential homesites (4). The permit was denied even
though the applicant had already sold most of the property to hundreds of
purchasers of individual homesites and had already obtained all required local
and state permits. The principal basis for denial was the finding that the
proposed development would "constitute an unacceptable adverse impact upon
this aquatic resource" and that destruction of environmentally important
wetland areas was "contrary to the public interest" (5). The Corps, in this
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case, concluded that housing, the basic purpose of the project, was clearly
not dependent upon a water location. This landmark case has undoubtedly had a
major chilling effect upon the plans of other would-be real-estate developers
coveting coastal and freshwater wetland locations as sites for waterfront
residential property development.
Proposals for discharge of dredged material as a waste disposal activity
(as contrasted with discharge of fill material to create fast land sites) are
somewhat less rigorously evaluated in terms of impacts on wetlands. The
guidelines recognized that dredging, by definition, is an activity intrinsic-
ally arising from use of the waters and that the activity of dredging may
entail a need for disposal that cannot be practicably met, in a given case,
unless a wetlands site is used. The guidelines require, however, that the
applicant demonstrate that the site selected is the least environmentally
damaging of the practicable alternatives that are available. Even where this
is the case, the permit to discharge may still be denied if the sheer magni-
tude of the enviornmental impact is unacceptably adverse.
Testing and Evaluation
The guidelines provide general guidance as to the chemical and biological
testing and evaluation to be required for dredged or fill materials proposed
to be discharged into waters of the United States. Standards are specified,
in addition, for the exclusion of material from these testing requirements.
No testing is required when:
(1) Dredged or fill material is composed predominantly of sand, gravel,
or any other naturally occurring sedimentary material with particle
sizes larger than silt, characteristic of and generally found in
areas of high current or wave energy such as streams with large bed
loads or coastal areas with shifting bars and channels;
(2) Dredged or fill material is for beach nourishment or restoration and
is composed predominantly of sand, gravel or shell with particle
sizes compatible with material on receiving shores.
(3) When:
(a) The material proposed for discharge is substantially the same
as the substrate at the proposed disposal site; and
(b) The site from which the material proposed for discharge is to
be taken is sufficiently removed from sources of pollution to
provide reasonable assurance that such material has not been
contaminated by such pollution; and
(c) Adequate terms and conditions are imposed on the discharge of
dredged or fill material to provide reasonable assurance that
the material proposed for discharge will not be moved by cur-
rents or otherwise in a manner that is damaging to the environ-
ment outside the disposal site.
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A revision to the guidelines has been formally proposed (6), which sub-
stantially expands upon the factors that should be considered in demonstrating
reasonable assurance of the lack of toxic contamination in materials proposed
to be dredged. Once such assurance is obtained, there is no requirement for
chemical and biological testing. The factors to be consulted include:
(1) known potential routes of pollution or polluted sediments to the
extraction site;
(2) pertinent results of previous tests on the material at the extrac-
tion site;
(3) potential for pesticide contamination from land runoff;
(4) information of record on spills or petroleum products or hazardous
substances;
(5) information of record indicative of introduction of pollution from
industries along potential routes of contamination to the extraction
site; and
(6) possibility of presence of natural mineral deposits (e.g., phos-
phate) which could be exposed by dredging and released into the
aquatic environment.
The rationale for preliminary screening via these factors is to avoid
costly, routine, and repetitive testing in those numerous cases where there is
no significant reason to believe that dredged or fill materials contain toxic
contaminants. Where such a finding cannot be reached, testing is required,
with the type and extent of testing for each specific case generally being
determined by the judgment of the District Engineer. The Regional Administra-
tor of EPA may require specific testing approaches and procedures on a case-
by-case basis by specifying to the District Engineer the type of information
needed and stating how the results of the analysis will be of value in evalu-
ating environmental impacts. The types of tests generally employed upon
dredged material are:
(1) an elutriate procedure, involving the aqueous extraction of soluble
chemical species through vigorous shaking of a water-sediment mix-
ture, followed by settling and filtration of the supernatant. The
elutriate (i.e., filtered supernatant) is chemically analyzed for
constituents deemed important by the District Engineer, after con-
sultation with the Regional Administrator;
(2) a benthic bioassay of the material proposed for discharge, whereby
appropriately sensitive and representative organisms are exposed to
this material, and acute toxic effects, if any are measured;
(3) inventory of total concentration of chemical constitutents. This
whole sediment analysis may be used to compare sediment at the
dredging site with sediment at the disposal site;
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(4) analysis of biological community structure. This procedure is
essentially an inventory and comparison of biological communities
colonizing the substrates at extraction and disposal sites, and may
be used in defining the existing degree of environmental stress at
both sites.
The testing guidance and the range of tests available in the current
guidelines are now widely considered to be in need of improvement. EPA and
the Corps are developing a much-expanded testing package that will provide a
greater variety of tests; much more structured rationale for the determination
of which tests to use in particular situations; and improved guidance in the
interpretation of test results. The agencies have also agreed to publish a
testing methods manual for use by field personnel and contractor personnel
retained by the Corp or by applicants to carry out required tests.
SUMMARY
The section 404 "dredge and fill" program is a relatively new water
pollution control program having historic roots in the River and Harbor Act of
1899. The adminstrative structure of the program is unusual in that its sub-
stantive responsibilities are divided between two agencies, EPA and the Corps
of Engineers. The program is extremely broad in its geographical reach,
extending into all waters of the Nation having a nexus with interstate or
foreign commerce, but is relatively narrow in terms of the specific activities
that it regulates. The program employs stringent evaluation criteria, with
particular emphasis upon alternative siting and operational means of reducing
or avoiding adverse environmental impacts. In appropriate cases, chemical
and/or biological testing of material proposed for discharge is required in
order to assess the impacts that would result from release of the material at
a proposed disposal site. As the section 404 program matures, its essential
technical and regulatory literature are also evolving in the attempt to in-
crease the overall quality and efficiency of program operation.
REFERENCES
(1) U.S. Senate, "Consideration of the Report of the Conference Committee,
October 4, 1972, Amendment of the Federal Water Pollution Control Act"
(1972).
(2) Shaw, S. P. and C. G. Fredine, "Wetlands of the United States, Their
Extent and Their Value to Waterfowl and Other Wildlife." U.S. Fish and
Wildlife Service (1956).
(3) Boyd, M. B., et aJL "Disposal of Dredge Spoil; Problem Identification
and Assessment and Research Program Development." Technical Report
H-72-8 (U.S. Army Engineers Waterways Experiment Station, CE, Vicksburg,
Mississippi, 1972).
(4) Horowitz, E. L., "Our Nation's Wetlands; An Interagency Task Force
Report." President's Council on Environmental Quality (1978).
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(5) Gribble, W. C., Jr., "Report on Application for Department of the Army
Permits to Dredge and Fill at Marco Island, Florida." Office of the
Chief of Engineers, Washington, D.C. (1976).
(6) Environmental Protection Agency, "Guidelines for Specification of Dispo-
sal Sites for Dredged or Fill Material." Proposed in: Federal Register,
Vo. 44, No. 182 (September 18, 1978).
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SEDIMENT PROBLEMS AND LAKE RESTORATION IN WISCONSIN
R. C. Dunst
Wisconsin Department of Natural Resources
Office of Inland Lake Renewal
Box 7921
Madison, Wisconsin 53707
ABSTRACT
Twelve dredging projects are underway or will begin
soon. These include both natural and man-made lakes, with
lake size and sediment removal up to 205 hectares and
1,720,250 cubic meters, respectively. Solids content of
the sediments ranges from 70-80 to 1-5 percent. The
projects were designed using a mixture of onsite data
collection, predictive models, and professional judgement.
Sediment disposal has limited project implementation,
with arsenic being a special problem. Theoretically,
sediment concentrations below 4 ug/g could still produce
unacceptable contamination of groundwater at the disposal
site. One project is being held up, pending completion of
laboratory testing.
>
Organic sediments from Lilly Lake were deposited in
an inactive gravel pit and within diked areas on agricul-
tural land. Passage through a spray irrigation system
proved impractical. Rapid infiltration of water into the
bottom and sides of the settling basins was short-lived
due to the self-sealing characteristics of these sedi-
ments. Studies are now underway to determine the effect
of lake sediment application to upland soils on corn
production.
INTRODUCTION
The Office of Inland Lake Renewal (OILR) was created within the Depart-
ment of Natural Resources in 1974, to protect and rehabilitate Wisconsin's
inland lakes. Water quality had been declining on many lakes and there was
general concern for the future well-being of all lakes. There are nearly
15,000 lakes in the State, with a combined area of over 400,000 hectares.
They form the foundation of the tourism/recreation economy, the third largest
industry. Citizen demand for better environmental protection of these lakes
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prompted the State Legislature to authorize the 01LR program through Chapter
33, Wisconsin Statutes. Lake protection/rehabilitation projects are generated
and progress through local initiative with technical and financial support
from the OILR. Additional assistance is provided by the University of
Wisconsin-Extension.
At present, there are 120 projects in some stage of development—data
collection/planning/implementation. Rehabilitation projects have utilized
various techniques such as aeration, dredging, drawdown, storm sewer diver-
sion, inlake aluminum sulfate treatment, aquatic macrophyte harvesting, im-
proved animal manure handling, streambank erosion control, and several upland
conservation methods. However, dredging has been the most often used tech-
nique. This paper will describe: 1) the dredging program now underway, 2)
the design methodology in usage, 3) the arsenic problem, and 4) the Lilly Lake
project.
TEXT
Dredging Program
There are now 12 dredging projects planned or underway in the program
(Table 1). Most of these lakes were originally created by dam construction.
Two are natural lake basins, although the water level in Little Muskego Lake
was raised an additional 2.5 meters in 1938. The lakes range from 4 to 205
hectares. The amount of sediment removal varies from 26,760 to 1,720,250
cubic meters. Hydraulic equipment will normally be used, but in a few cases
drawdown has permitted usage of dryland excavation techniques.
TABLE 1. OFFICE OF INLAND LAKE RENEWAL DREDGING PROJECTS
Lake Size Watershed Impoundment Sediment
Name (ha) Size (km2) or Lake Removal (m3)
Marinuka 40 404 I 420,500
Upper Willow 96 422 I 150,600
Perch 13 329 I 191,100
Angelo 21 313 I 152,900
Emery 14 28 I 109,300
Martha 5 88 I 38,200
Chi 1 ton 4 52 I 26,800
Bugle 14 285 I 160,600
Henry 18 466 I 152,900
Decorah 42 1,425 I 229,400
Little Muskego 205 30 L 1,720,250
Lilly 37 1.6 L 665,200
104
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The sediment characteristics have been diverse. In some cases the mater-
ials are dense, primarily inorganic sand, with a solids content of 70-80
percent. This is the usual situation when the lake is located on a major
river system. At the other extreme, natural lake sediments are primarily
lightweight and organic. The solids content may be as low as 1-5 percent.
Chemical composition has also been variable, dependent on previous lake and
watershed usage. Analyses are typically performed for at least nitrogen,
phosphorus, select heavy metals, and arsenic. Disposal sites have included:
1) lakeside settling lagoons, 2) an inactive gravel pit, 3) diked areas on a
golf course and on agricultural lands, and 4) landspreading on cropland.
Design Methodology
There have been two primary objectives in most projects: 1) deepen the
lake for improved recreational usage, and 2) control the aquatic macrophyte
growth. Before embarking on any inlake dredging project, certain types of
information are necessary. Not all of the following are collected on each
project; however, there must be a reasonable assurance of environmental im-
provement and permanency.
1. Radiometric dating. Sediment cores are taken at 1 to 5 sites in the
lake basin. These are segmented into depth intervals and analyzed
for cesium 137 and/or lead 210 content (Lerman, ed.; 1978). Results
have been useful in determining the present and historical rate of
infilling, the relative source of the sediment (e.g., streambank
versus upland), and the need for improved land usage in the water-
shed.
2. Sediment delivery. The watershed is examined for streambank and
upland erosion. Channel erosion sites are identified by stream
survey. The soil loss from each site is quantified on a per year
basis, and 50 percent is assumed to enter and be retained in the
lake. Soil loss from the uplands is determined by application of
the Universal Soils Loss Equation (Wischmeier and Smith, 1965). A
number of quarter sections in the watershed are randomly selected
for collection of the necessary parameters (Figure 1). The results
are then extrapolated to the entire watershed. The actual soil
yield to the lake is dependent on the watershed size (Figure 2).
3. Sediment retention. The quantity of sediment trapped in the lake
each year is determined by usage of Figure 3. In addition to sedi-
ment delivery, it is necessary to determine the annual inflow and
the lake's storage capacity in order to use the curve.
This information, coupled with professional judgment, is used
to determine the life span of the lake under existing conditions,
the life expectancy of a particular dredging plan, and the need for
erosion control in the watershed. In terms of achieving various
inlake benefits, several additional considerations are necessary.
4. Habitat preservation. Areas with existing high value for fish
and/or wildlife are identified and eliminated from the dredging
105
-------
70
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DRAINAGE AREA (SQUARE MILES)
Figure 2. Sediment delivery ratio vs. size of drainage area (SCS, 1971).
106
-------
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CAPACITY INFLOW RATIO
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"P
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Figure 3. Reservoir trap efficiency as a function of
the capacity-inflow ratio (Brune, 1953).
plan. These might be spawning or nursery areas for fish, feeding
areas for waterfowl, etc. Emergent and floating leaf plant communi-
ties are usually included in this category.
Depth of soft sediment. The lake bottom is normally probed to
determine the depth of soft sediment. This information is useful in
establishing the maximum bottom slope permissible ^fter dredging.
If hard bottom (e.g., sand/gravel) is exposed by sediment removal,
the slope may be 4 to 1 — horizontal to vertical distance. Light-
weight, organic sediments represent the other end of the range of
possibilities at 10 to 1.
Algae/macrophyte control. In projects where macrophyte control is a
major objective, the average summer water clarity is determined
through periodic measurement by Secchi disc. The maximum depth of
weed growth is then estimated by:
Y = 0.83 + 1.22X
where Y = maximum depth of growth in meters
and X = average summer water clarity in meters
(derived from Belonger, 1969 and Modi en,
1970)
107
-------
and the dredging project is designed to produce greater lake depth,
thereby preventing growth in that area.
One concern is the potential increase in planktonic algae. It is theo-
retically possible to produce excessive algae through dredging. Macrophyte
control will result in greater availability of incoming nutrients for algal
growth. Also, according to Vollenweider (as described in Uttormark and
Hutchins, 1978) and Sakamoto (1966) an increase in hydraulic residence time
will promote higher algal densities even though the level of nutrient loading
remains constant.
Wherever possible, nutrient control measures are applied in the water-
shed, but when the watershed to lake size ratio greatly exceeds 10 to 1,
significant nutrient reductions are generally unattainable (Uttormark et al.,
1974).
These are the primary information and predictive tools utilized at pre-
sent in the decision-making process. They provide the technical framework and
financial justification for designing and implementing (or not implementing)
dredging projects.
Arsenic
The major impediment to dredging—other than cost—has been the avail-
ability of disposal sites. This problem is especially acute for lakes with
contaminated sediments. Arsenic is proving to be the single most troublesome
element, at least from the standpoint of a potential health hazard.
Prior to 1970, application of sodium arsenite was an acceptable method of
controlling the growth of macrophytes. Between 1950 and 1970 about one mil-
lion kilograms were added to the waters of 167 lakes (Lueschow, 1972). One
lake received 142,000 kilograms during that period. Concentrations of arsenic
up to 659 ug/g dry weight have since been measured in the surface sediments
(Kobayashi and Lee, 1978). Some of these lakes have recently entered the 01LR
program. In most cases it has been possible to find sites with appropriate
characteristics to allow sediment disposal. However, one lake is located in a
populous area and the only potential disposal sites are in close proximity to
numerous private wells used for drinking water supply. Groundwater contamina-
tion is a serious concern.
According to Anderson (1979), arsenic can exist in several different
oxidation states and in inorganic or organic configuration. Transformations
occur readily, dependent on oxidation potential and pH. Based on theoretical
computations, it was determined that even though the average arsenic concen-
tration would be only 4 ug/g in the disposal site, significant groundwater
pollution was possible if the element was in a mobile form. Therefore, a
three-tiered series of experiments was established to allow prediction of
mobility under anaerobesis in the disposal site.
First, sediments were collected from the lake. The concentration of
arsenic was determined per species in both the sediments and pore waters.
These tests are now underway (Anderson, personal communication). The second
108
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level of testing will involve thorough mixing of the sediments with terres-
trial soils under aquaeous, anoxic conditions. This will be performed with
representative sandy, silty, and clayey soils from each disposal area. If the
results at this point are still questionable, undisturbed cores will be taken
from a number of sites in the disposal area. Under anoxic conditions in the
laboratory, lake sediments will be placed above the core. Measurements will
determine the degree of arsenic mobility through the core. Experimentation
can be terminated at any point in this process if findings are favorable. If
the results do not allay the present environmental concerns, it will be neces-
sary to line the disposal sites with a layer of clay.
Details of arsenic transformation and laboratory experimentation are
available from Prof. Anderson. On this project as well as others involving
potentially hazardous materials in the sediments, long-term monitoring plans
will be established at the disposal sites.
Lilly Lake Project
Lilly Lake is located in southeastern Wisconsin. The drainage basin is
155 hectares in size, and there are no surface inlets or outlets. The lake
covers 37 hectares and has a mean depth of 1.4 meters. Maximum depth was only
1.8 meters with greater than 10.7 meters of underlying organic sediments
(e.g., 62 percent). The water content of the sediments ranged from 90-98
percent (Table 2). The bottom was covered by dense rooted macrophytic growth.
Inlake production and deposition was causing an infilling rate of 0.5 centi-
meter per year (e.g., radiometric dating using the PB 210 method).
TABLE 2. SOLIDS CONTENT OF THE SEDIMENT (September 20, 1977; 4 locations)
Depth Into Sediments Percent Dry Solids Percent Water
1.5
3.7
6.1
meters
meters
meters
(5
(12
(20
ft.)
ft.)
ft.)
2.
3.
4.
4 -
1 -
8 -
8.
4.
9.
6
3
4
96.
95.
90.
4
7
6
- 97.
- 96.
- 95.
6
9
2
The dredging operation was designed to remove about 600,000 cubic meters
of sediment, increasing the maximum depth to 6.1 meters. Dredging was initi-
ated in July, 1978 and continued until November. It commenced again in May,
1979 and was completed by September. During 1978, a hydraulic dredge was used
to pump the sediments through a 30 centimeter polyethylene pipe almost 3
kilometers to a settling basin. In 1979 the sediment was also applied to 15
hectares of agricultural land. The effect of dredging on the lake and dispo-
sal sites are being monitored through a grant from the U.S. EPA. Investiga-
tions began in 1976, and will continue into 1982. Selective findings relating
to sediment disposal are presented herein.
109
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The settling basin was originally an inactive gravel pit cut into a
hillside resulting in slopes approximately 10 meters high on one side. Top
soil had been removed from the 18 hectare area. Two earthen dikes were con-
structed—one across the open side of the pit and another through the middle
of the area, thereby creating 2 sub-basins. The dikes and bottom of the
basins were composed primarily of clay, whereas the side slopes were mostly
sand/gravel/rocky material. Nine observation wells, including three piezom-
eter nests, were established around the area to monitor for changes in water
level. In addition, nine domestic wells were periodically sampled for water
quality.
It was initially anticipated that the materials would be removed from the
lake without requiring entrainment of carriage waters. Therefore, the capac-
ity of the site was designed to hold sediments only, with eventual drying
primarily through evaporation. However, because the inlake sediments did not
flow as expected—vertical walls were reportedly created by dredging—and the
dredge was relatively slow-moving, the pumped slurry consisted of 55 percent
carriage water in 1978. As the mixture was deposited in the basin, the sedi-
ments settled to the bottom and were overlain with carriage water. At first
this water was able to infiltrate rapidly into the highly porous side slopes.
The influence of water infiltration was greatest near the basin and
decreased with distance away (Figure 4). At 18 meters the water level even-
tually exhibited a 3 meter increase versus wells further away. At 75 and 150
meters the change was less than at 350 meters, suggesting that the effect of
infiltration became negligible somewhere between 18 and 75 meters.
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Figure 4. Change in water levels at various distances from the settling basin.
110
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About one month before dredging ended in 1978, the water level at 18
meters began to recede, dropping over 3 meters by late November. The basin
was essentially filled from mid-October through November and the change in
sediment/water elevation was slight. Apparently the basin's side slopes were
sealed soon after the sediment/water reached a particular elevation. Rapid
infiltration was possible only during the filling process. In 1978 the water
levels in the observation wells were not significantly influenced by the
disposal operation and dropped in response to dry climatic conditions despite
the near-full settling basin.
Although substances with long-term toxicity had not been used historic-
ally in the lake or watershed, there initially was some concern, especially
regarding nitrogen transport away from the disposal area. However, examina-
tion of the sediment pore waters at the disposal site revealed no problem, nor
is it likely that one will develop in the future (Table 3). The water quality
of the domestic wells has not changed to date. These wells range in distance
from the settling basin - 75 to 360 meters - and in depth to the well point -
10 to 90 meters. In addition, a review of the borings and well logs in the
area suggests that all of the wells may be hydraulically separated by clay
layers from any materials put into the settling basin.
TABLE 3. COMPOSITION OF THE SEDIMENT AND PORE WATERS
Parameter* Sediments (ug/g) Pore Water (ug/1)
Aluminum
Barium
Iron
Copper
Zinc
Chromium
Phosphorus
Ammoni a- ni trogen
Ni tri te/ni trate- ni trogen
Total nitrogen
219,400
3,040
136,000
270
3,790
540
6,600
—
—
27,000
250
Less than 400
3,200
3
40
Less than 3
1,300
9,700
Less than 20
--
* pH of 7-8
In 1979 agricultural land was also used for sediment disposal. Dikes
were erected on 15 hectares of land, creating 6 individual basins capable of
holding up to 2 meters of material. Spray irrigation equipment was addition-
ally installed on 10 hectares. Unfortunately the fibrous organic sediments
consistently clogged the nozzles (5 centimeter orifice) within 30 minutes
operation. The technique should be useful for disposal of carriage waters
from settling basins in future projects; however, dispersal of the sediment/
water slurry will be infeasible without major system modifications.
Ill
-------
Six observation wells were installed around the perimeter of the 15
hectare site and monitored periodically for changes in water level and qual-
ity. The well borings revealed an extreme variability in the stratigraphy of
the area, with some borings passing through only sand/gravel while others went
through clay. Nevertheless, following a temporary rise the water levels
dropped throughout the summer, and little change has been detected in water
quality. Apparently the organic nature of the sediment causes it to form a
nearly-impermeable seal over the bottom and sides of the settling basins,
thereby greatly inhibiting infiltration into, and water quality effects on,
the groundwater system.
After sufficient drying has taken place, next spring the dikes will be
removed; the organic sediments will be plowed into the terrestrial soils; and
the area will be returned to agricultural production. Planned studies on this
area will determine residual effects on soil chemical and physical properties
including nitrate accumulation in the soil profile. The following will be
investigated concurrently: 1) nutrient mineralization rate for sediments from
10 diverse lake types; 2) effect of sediments on corn production in greenhouse
experiments (4 sediment types selected on the basis of their ranges in C/N and
N/P ratios will each be added to a sand and a silt loam soil at 4 different
application rates); and 3) field tests using corn will be performed with a
representative silt loam soil from the area and the Lilly Lake sediments at 4
rates of application.
Preliminary work has been promising (Corey and Peterson, personal commun-
ication). These studies are particularly important to the OILR program,
because if lake sediments significantly increase crop production and the
benefits have been clearly demonstrated, agricultural lands will become more
available for future dredging projects. Also, a market might ultimately be
developed for the sediments, thereby reducing the total cost for a project.
ACKNOWLEDGEMENTS
Financial support for the Lilly Lake investigation is being provided
through a grant from the U.S. Environmental Protection Agency's research
laboratory in Corvallis Oregon; Spencer Peterson, project officer. Rick
Beauheim (hydrogeologist) assisted in analyses of monitoring data from the
Lilly Lake sediment disposal sites.
REFERENCES
Anderson, Marc. Personal communication. Assoc. Prof. , Water Chemistry pro-
gram, University of Wisconsin, Madison.
Anderson, Marc. 1979. Arsenic contamination in Little Muskego Lake - A
position paper. Unpublished report. Wisconsin Department of Natural
Resources, Madison. 14 p.
Belonger, B. J. 1969. Aquatic plant survey of major lakes in the Fox River
(Illinois) watershed. Research Report #39, Wisconsin Department of
Natural Resources, Madison. 50 p.
112
-------
Brune, G. M. 1953. Trap efficiency of reservoirs. Trans. American Geophysi-
cal Union, 34(3):407-418.
Cory, R. and A. Peterson. Personal communication. Professor, Soils Depart-
ment, University of Wisconsin, Madison.
Kobayashi, S. and G. F. Lee. 1978. Accumulation of arsenic in sediments of
lakes treated with sodium arsenite. Environmental Science and Technol-
ogy, 12(10):1195-1200.
Lerman, A. (editor) 1978. Lakes: Chemistry, geology, and physics.
Springer-Verlag Publ. New York. 353 p.
Lueschow, L. A. 1972. Biology and control of selected aquatic nuisances in
recreational waters. Technical Bulletin #57. Wisconsin Department of
Natural Resources, Madison. 36 p.
Modi in, R. F. 1970. Aquatic plant survey of Milwaukee River watershed lakes.
Research Report #52. Wisconsin Department of Natural Resources, Madison.
45 p.
Sakamoto, M. 1966. Primary production by phytoplankton community in some
Japanese lakes and its dependence on lake depth. Archiv. f. Hydrobiolo-
gie, Bd. 62(1):1-28.
Soil Conservation Service, U.S.D.A. 1971. National Engineering Handbook,
Section 3: Sedimentation, Chapter 6. Sediment sources, yields, and
delivery ratios. Washington, D.C.
Soil Conservation Service, U.S.D.A. 1974. Unpublished data. Madison, Wis.
Uttormark, P. D. and M. L. Hutchins. 1978. Input/output models as decision
criteria for lake restoration. Technical Report, Wisconsin WRC 79-03,
Water Resources Center, University of Wisconsin, Madison. 61 p.
Uttormark, P. D., J. D. Chapin, and K. M. Green. 1974. Estimating nutrient
loadings of lakes from non-point sources. EPA-660/3-74-020. U.S Envi-
ronmental Protection Agency, Washington, D.C. 112 p.
Wischmeier, W. H. and D. D. Smith. 1965. Predicting rainfall-erosion losses
from cropland east of the Rocky Mountains. Agricultural Handbook #282.
Agricultural Research Service, U.S.D.A. Washington, D.C. 47 p.
113
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RELEASE OF PHOSPHORUS FROM LAKE SEDIMENTS
Masaaki Hosomi, Mitsumasa Okada, and Ryuichi Sudo
Laboratory of Freshwater Environment
National Institute for Environmental Studies
P.O. Yatabe, Ibaraki
300-21, Japan
ABSTRACT
The relationship between the content of various
forms of phosphorus in lake sediments and the amount
of phosphorus released under aerobic and anaerobic
conditions was studied. Total phosphorus content in
the sediment of Lake Kasumigaura was highest at the
0-5 cm surface layer and decreased with depth. The
constant value below 15 cm was consistent with the
decrease of iron-bound phosphorus content (Fe-P). The
amount of phosphorus released from the sediments was
proportional to the decrease of Fe-P under both
aerobic and anaerobic conditions. Under anaerobic
conditions, 90% of the Fe-P initially held in the
sediments was released in 55 days. Using dialysis
apparatus, maximum growth yield of algae was shown to
be linearly dependent on the amount of phosphorus
released under aerobic conditions.
INTRODUCTION
Bottom sediment is known to play an important role in the eutrophication
process. Particularly in a lake restoration program, we cannot ignore the
effects of the sediments on the phosphorus budget. In restoration programs
that have been completed, there are examples where water quality did not
improve to the desired levels because of phosphorus release from the sediments
(1).
Many studies have reported on the rates of phosphorus release from the
sediment. These studies were conducted under defined environmental condi-
tions, aerobic and/or anaerobic, using specific lake sediments (2-4). The
results, however, differ greatly from case to case, even among sediment
samples from the same lake, depending on the experimental conditions and/or
characteristics of the sediment. Thus, because of this lack of basic knowl-
edge, it is doubtful if we can estimate the real rate of phosphorus release.
115
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The purpose of this study was to clarify the relationship between the
amount of released phosphorus and the amount of various fractions of phos-
phorus contained in the sediment. Phosphorus in the sediments was fraction-
ated before and after phosphorus release experiments and the fractions which
contribute the phosphorus release were determined.
MATERIALS AND METHODS
Sediment Sampling
Sediment samples were taken with a coring device to minimize sample
disturbance. Immediately after sampling, the core was divided at 2- to 5-cm
intervals and taken to the laboratory. Samples for phosphorus analyses were
freeze-dried; those for phosphous release experiments were refrigerated at
5°C.
Phosphorus Analysis of the Sediments
Total phosphorus content (T-P) was determined by the ignition method of
Anderson (5,6). To determine total inorganic phosphorus (I-P), it was
extracted by 1 N HC1 (or 1 N H2S04) for 16 hours at room temperature and then
the concentration of orthophosphate in the extract was analyzed. Total
organic phosphorus (0-P) was determined by subtracting the value of I-P from
that of T-P (7).
Several procedures to fractionate I-P in sediments and/or soils have been
reported (8-10). Many are based on the procedure proposed by Chang and
Jackson (11) as is the procedure used in this study (Figure 1). Three frac-
tions of phosphorus extracted by NH4-F, NaOH, and H2S04 were defined as
aluminum-bound phosphorus (Al-P), iron-bound phosphorus (Fe-P), and calcium-
bound phosphorus (Ca-P), respectively. Phosphorus concentrations extracted by
these methods were determined by the Ascorbic Acid Reduction Method (12) as a
concentration of P04-P.
Phosphorus Release Experiment
The sediments were suspended homogeneously in a lake water medium and the
rate of phosphorus release was measured under both aerobic and anaerobic
conditions. The apparatus shown in Figure 2 was designed to study the effect
of aerobic sediments on algal growth (13). This apparatus is composed of two
L-type vessels with a volume of approximately 300 ml. A Millipore membrane
filter (pore diameter = 1.2 microns) between the vessels is supported by
porous glass discs.
Phosphorus-free AAP (algal assay procedure) medium (14) was used in this
study. The working volume was 250 ml for both vessels. Sediment was
suspended (sediment vessel) in one vessel and Selenastrum capricornutum
(green alga) was located in the other (algal vessel).Both vessels were
stoppered with cotton plugs, and mounted on a rotary shaker illuminated by
fluorescent light at 25 ± 2°C. The light intensity at the medium surface was
about 4,000 lux. In this system, the only phosphorus supply to the algae was
that contained in the sediment and it had to pass through the membrane filter.
116
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sediment sample 0.3-0.5 g
1-
< 1 M NH4C1 20 ml
shaking 30 min. at room temperature
centrifuge 8000 rpm
precipitate supernatant
L o.5 M NH4F (pH = 8.2) 20 ml
shaking 60 min. at room temperature
centrifuge 8000 rpm
~ ^~^^*B*^^
precipitate supernatant >• ( Al-P )
v
washing twice by NaCl solution
I-
0.1 M. NaOH 20 ml
shaking 17 hours at room temperature
centrifuge 8000 rpm
precipitate supernatant >( Fe-P )
.
washing twice by NaCl solution
i-
0.25 M H2S04 20 ml
shaking 60 min. at room temperature
centrifuge 8000 rpm
precipitate supernatant > ( Ca-P )
Figure 1. Inorganic phosphorus fractionation in lake sediments.
117
-------
GLASS FILTER
HOLDER
MILIPORE
FILTER
BINDER
SUSPENSION OF
SEDIMENTS IN
P FREE MEDIUM
P FREE MEDIUM
S. capricornutum
Figure 2. A dialysis apparatus used to study the effect of aerobic phosphorus
release on the growth of algae.
Algal biomass was monitored by cell counting and by mean cell volume
measurement with a Coulter Counter, Model ZF equipped with Mean Cell Volume
Computer (Coulter Electronics, Inc., Hialeah, Florida). The data on cell
number and mean cell volume were converted to dry weight of algal cells,
referring to a calibration prepared separately, i.e., a sample of the algal
suspension was filtered through a Millipore filter (Type HA, pore diameter =
0.45 microns), and dried at 90°C for 24 hours before weighing.
At the stationary phase of algal growth, total phosphorus concentration
in the medium was determined by the Ascorbic Acid Reduction Methods after
digesting cells with potassium persulfate. Both before and after incubation
of the sediments, the phosphorus fractions in the sediments were determined as
described previously.
The phosphorus release experiments under anaerobic conditions were
conducted as follows. A sediment sample of 1 g (as dry weight) was suspended
in lake water which had been filtered through a Millipore filter and poured
into a 1,000-ml Erlenmeyer flask. This sediment-lake water mixture was mixed
homogeneously by a magnetic stirrer and the anaerobic condition was maintained
by passing nitrogen gas through at 20 ± 2°C. The P04-P concentration in the
water phase was determined by sampling the sediment-water mixture. The
suspended sediments were removed by centrifugation followed by filtering
118
-------
supernatant through a Millipore filter. Phosphorus fractions in aerobic and
anaerobic sediment were determined by using the same procedure (Chang and
Jackson fractionation followed by Ascorbic Acid Reduction Method).
RESULTS AND DISCUSSION
Fractionation of Sediment Phosphorus
Figures 3 and 4 show the vertical distribution of phosphorus fractions in
the sediment core samples from Lake Kasumigaura. As shown in Figure 3, T-P
decreased with depth and showed a constant value below 8 cm. The ratio of I-P
to T-P was 70% at the surface layer and decreased with depth. Thus the amount
of T-P decrease seems consistent with the decrease of I-P. Similar results
were obtained with the other sediment samples from Lake Kasumigaura, Lake
Hinuma (eutrophic), and also from Lake Shoji-ko (eutrophic). These results
correspond to those reported by Wildung et al. (5) where they concluded that
most of the 0-P was highly resistant to mTcrobial activity. Thus, when phos-
phorus release from sediments is to be studied, detailed analyses of I-P are
required rather than T-P or 0-P.
Figure 4 shows the vertical distribution of phosphorus fractions in the
sediment core samples from the center of Lake Kasumigaura. T-P decreased from
1.06 mg P/g in the 0-5 cm surface layer to 0.78 mg P/g in the 10-15 cm layer.
Below 15 cm, T-P content was consistent around 0.7 mg P/g. I-P in this case
was the sum of Al-P, Fe-P, and Ca-P, and was almost the same as that deter-
mined by 1 N HC1 extraction (15). Although Al-P did not change significantly
with depth, Fe-P and Ca-P decreased with depth but were relatively constant
below 15 cm. The highest values for all three fractions were observed at the
0-5 cm surface layer. The most notable decreases in phosphorus content of
sediments with depth were those for the Fe-P fraction from the surface to 15
cm.
Phosphorus Release Under Aerobic Conditions
Sediment samples for this study came from Lake Kasumigaura (Tsuchiurairi
Bay, depth = 2.5 m). Only the surface layer of the core, from 0 to 3 cm, was
used. Figure 5 shows the relationship between the maximum growth yield of S.
capricornutum and the amount of total phosphorus released from the container-
ized sediment and diffused into the algal vessel. Both the maximum growth
yield and the amount of phosphorus released increased linearly with the
increase in the amount of suspended sediment. Dissolved oxygen concentration
in the sediment vessel was around 7 mg/1 throughout the experiment.
Table 1 shows the variations of phosphorus fractions in the sediment
before and after aerobic incubation. The amount of sediment suspended in this
case was 0.72 g per 250 ml of medium. T-P of 0.18 mg P/g decreased from 1.14
mg P/g to 0.96 mg P/g by the release of phosphorus. Among three fractions of
I-P, Fe-P of 0.17 mg P/g decreased from 0.3 to 0.13 mg P/g, whereas neither
Al-P nor Ca-P decreased. Thus the amount of T-P decrease appears to corres-
pond with that of Fe-P.
119
-------
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O
Vertical distribution of phosphorus content in the sediment of Lake
Kasumigaura (11/25/77).
0-Pn
-I-P-
-T-P
Figure 4.
0 10 20 30 40 50 60 70
DEPTH (cm)
Vertical distribution of phosphorus fractions in the sediment of
Lake Kasumigaura.
120
-------
I 2 3
WET SEDIMENT (g/250 ml PAAP-P MEDIUM)
I
0
O.I 0.3 0.5 0.7
DRY SEDIMENT (g/250 ml PAAP-P MEDIUM)
Figure 5. Maximum growth yield of .S. capricornutum and the amount of
phosphorus released under aerobic conditions in the algal
vessel as affected by the amount of the sediments of Lake
Kasumigaura suspended in the sediment vessel.
121
-------
TABLE 1. VARIATION OF PHOSPHORUS FRACTIONS IN THE SEDIMENT
OF LAKE KASUMIGAURA UNDER AEROBIC CONDITIONS
Phosphorus
Fraction
Total Phosphorus
Inorganic-P
Al-P
Fe-P
Ca-P
Organic- P
Initial Content
mg P/g
1.14
0.67
0.11
0.30
0.26
0.47
Content After
Incubation
mg P/g
0.96
0.50
0.10
0.13
0.27
0.46
Difference
mg P/g
-0.18
-0.17
-0.01
-0.17
+0.01
-0.01
In the cases where the sediment taken from Lake Towada (oligotrophic),
Lake Shikotsu (oligotrophic.), and Lake Yunoko (eutrophic) were incubated, the
same result was obtained, i.e., T-P decrease corresponded to Fe-P decrease
(data not shown). Figure 6 shows a positive linear relationship between the
amount of phosphorus released and Fe-P fraction in the sediments.
PHOSPHORUS RELEASE UNDER ANAEROBIC CONDITIONS
Sediment samples for this study came from two sites, Akanoi-wan
(polluted, depth = 1.8 m) and Kusatsuyamada-oki (unpolluted, depth = 3.0 m),
in the South Basin of Lake Biwa. The surface layer and the deeper layer of
the sediment core were suspended in the surface water at the sediment sampling
point.
Figure 7 shows the release of phosphorus into lake water under anaerobic
conditions. After the 25th day of incubation, the phosphorus concentration
did not change. Oxidation-reduction potential during incubation was main-
tained between -58 mV and -123 mV. Table 2 shows the variation of phosphorus
fractions in the sediments before and after anaerobic incubation. Although
the Al-P and Ca-P fractions from Akanoi-wan sediment increased after incuba-
tion for unknown reasons, a remarkable decrease of the Fe-P fraction was
observed. The relationship between the amount of phosphorus released and the
Fe-P fraction in the sediments is shown in Figure 8. Approximately 90% of
Fe-P fraction was released from the sediment under anaerobic conditions.
122
-------
Ill
5
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200
100
I T
LAKE TOWADA
(0-3cm)
LAKE
KASUMIGAURA
(0-3 cm)
LAKE YUNOKO
tO-3 cm)
LAKESHIKOTSU (3-6 cm)
I
I
0 0.2 0.4 0.6 0.8
Fe-P IN THE SEDIMENTS (mg P/g SED.)
Figure 6. A relationship between Fe-P fraction in the lake sediment and
the amount of phosphorus released under aerobic conditions.
123
-------
2.0
1.5
o>
E
Q- 1.0
l
0.5
AKANOIWAN
(0-4 cm)
AKANOIWAN
( f4- 24 cm)
KUSATSUYAMADAOK1 (0-2.5cm)
(75H2.5cm)
0
10
20 30 40
TIME (DAYS)
50 60
Figure 7. Release of phosphorus (as phosphate) during the incubation of
the sediments of Lake Biwa under anaerobic conditions.
124
-------
1
LU
s
20
a:
UJ
QQ
UJlM
2CO
UJn.
K O>
CO^
QC
O
0.
CO
O
I
Q.
1.5
1.0
0.5
AKANOIWAN
(0-4cm)
AKANOIWAN
(14-24 cm)
r(0-2.5 cm)
KUSATSUYAMADAOKI (75-IZ5cm)
I I I |_
0 0.5 1.0 1.5 2.0
Fe -P IN SEDIMENTS (mgP/g SEDIMENT)
Figure 8. Relationship between Fe-P fraction in the sediment and the
amount of phosphorus released under anaerobic conditions.
125
-------
TABLE 2. VARIATION OF PHOSPHORUS FRACTIONS IN THE SEDIMENT
OF LAKE BIWA UNDER ANAEROBIC CONDITIONS
Samp 1 e
Akanoi-wan (0-4 cm)
Akanoi-wan (14-24 cm)
Kusatsuyamada-oki (0-2.5 cm)
Kusatsuyamada-oki (7.5-12.5 cm)
T-P
mg P/g
2.70
1.11
0.72
0.47
Al-P
mg P/g
0.09
0.47*
0.02
0.14*
0.04
0.05*
0.03
0.03*
Fe-P
mg P/g
1.98
0.42*
0.75
0.07*
0.25
0.04*
0.08
0.02*
Ca-P
mg P/g
0.28
0.43*
0.12
0.20*
0.20
0.18*
0.08
0.08*
* Contents after incubation.
CONCLUSIONS
Fractionation of sediment phosphorus and the measurement of phosphorus
release were conducted to establish the relationship between the distribution
of phosphorus fractions and the amount of phosphorus released. The results
were as follows:
(1) T-P in the sediment of Lake Kasumigaura was highest at the surface
layer, decreased with depth, and was constant below 15 cm. This
variation was consistent with the change of Fe-P.
(2) Both the amount of aerobically released phosphorus and the maximum
growth yield of algae were proportional to Fe-P fraction in the
sediments.
(3) The amount of anaerobically released phosphorus was about 90% of the
Fe-P fraction in the sediments.
REFERENCES
1. Welch, E. B. 1977. Nutrient Diversion: Resulting Lake Trophic State
and Phosphorus Dynamics. EPA-600/3-77-003. Environmental Protection
Agency, Con/all is, OR.
2. Fillos, J. and W. R. Swanson. 1975. The release rate of nutrients from
river and lake sediments. Jour. Wat. Poll. Cont. Fed. 47:1032-1042.
126
-------
3. Freedman, P. L. and R. P. Canale. 1977. Nutrient release from anaerobic
sediments. Jour. Env. Eng. Div., ASCE, 103(EE2):233-244.
4. Okada, M. and R. Sudo. 1978. The effects of sediment on lake eutrophi-
cation: The application of algal assay procedure. The 4th U.S./Japan
Experts Meeting on Management of Bottom Sediments Containing Toxic
Substances. EPA-600/3-78-084. Environmental Protection Agency,
Corvallis, OR.
5. Wildung, R. E. and R. L. Schmidt. 1973. Phosphorus Release from Lake
Sediments. EPA-R3-73-024. Environmental Protection Agency, Corvallis,
OR.
6. Andersen, J. M. 1976. An ignition method for determination of total
phosphorus in lakes. Water Res. 10:329-331.
7. Aspila, K. I., H. Agemian and A. S. Y. Chau. 1976. A semi-automated
method for the determination of inorganic, organic and total phosphate in
sediments. Analyst 101:187-197.
8. Sekiya, K. 1975. Methods for Soil Nutrient Analysis (in Japanese).
Yokendo, Tokyo. 225-227.
9. Williams, J. D. H., J. K. Syers, R. F. Harris and D. E. Armstrong. 1971.
Fractionation of inorganic phosphorus in calcareous lake sediments. Soil
Sci. Soc. Amer. Proc. 35:250-255.
10. Williams, J. D. H., S. K. Syers, D. E. Armstrong and R. F. Harris. 1971.
Characterization of inorganic phosphate in noncalcareous lake sediments.
Soil Sci. Soc. Amer. Proc. 35:556-561.
11. Chang, S. C. and M. L. Jackson. 1957. Fractionation of soil phosphorus.
Soil Sci. 84:133-144.
12. U.S. Environmental Protection Agency. 1976. Methods for Chemical Anal-
ysis of Water and Wastes. EPA-125/6-74-003a, 249-265.
13. Hosomi, M., 0. Yagi and R. Sudo. 1978. Effect of bottom sediments on
algal growth. Conf. of the Society of Fermentation Technology, Japan,
219.
14. Joint Industry/Government Task Force on Eutrophication. 1969. Provis-
ional Algal Assay Procedure. P.O. Box 3011, Grant Central Station, New
York 10017, p. 62.
15. Hosomi, M. and R. Sudo. Unpublished data.
127
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RELEASE, DISTRIBUTION, AND IMPACTS OF POLYCHLORINATED BIPHENYLS (PCB)
INDUCED BY DREDGED MATERIAL DISPOSAL ACTIVITIES AT A DEEPWATER ESTUARINE SITE
S. P. Pavlou, R. N. Dexter,
D. E. Anderson, E. A. Quinlan and W. Horn1
Advanced Environmental Studies and Technology Program
URS Company
Fourth and Vine Building
Seattle, Washington 98121
ABSTRACT
The aquatic disposal field investigation initiated in
Elliott Bay, Puget Sound, Washington, in February 1976,
was designed to evaluate the ecological effects of open-
water disposal of dredged material. The experimental
disposal site was located at a depth of 60 m in a marine
estuary with generally weak circulation. Approximately
114,000 m3 of dredged material contaminated with poly-
chlorinated biphenyls (PCBs) were dumped at the site from
split-hull barges. The material presented in this paper
is limited to a discussion of PCB impacts. It includes:
(a) a summary of results from the studies conducted
between 1976 and 1977 to assess short-term impacts during
and after the disposal of PCB contaminated sediments at
the Elliott Bay disposal site;
(b) a presentation of preliminary results from the
continuation studies initiated in February 1979 to deter-
mine long-term impacts of the disposal operations.
The preliminary data indicate that both dredged-
material deposit and the associated PCBs appear to be
stable. No major long-term impact on benthic organisms is
apparent from this analysis.
Supported by the U.S. Army Corps of Engineers, Waterways Experiment
Station, Contract No. DACW39-79-C-0038.
129
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INTRODUCTION
The aquatic disposal field investigation (ADFI) in Elliott Bay, Seattle,
Washington, was initiated in February 1976 as part of the Environmental
Impacts and Criteria Development Project of the U.S. Army Corps of Engineers,
Waterways Experiment Station, Vicksburg, Mississippi. This study was one of
four major research projects within the Dredge Material Research Program
designed to evaluate the ecological effects of open-water disposal of dredged
material.
Among the four coastal area disposal sites selected for the ADFI (Lake
Erie, off Ashtabula, Ohio; the mouth of the Columbia River; Gulf of Mexico off
Galveston, Texas; Elliott Bay, Puget Sound, Washington), Elliott Bay was the
only deepwater estuarine location where dredged material disposal by barges
was investigated and where maintenance dredging of the Duwamish River (dis-
charging into the bay) involved the disposal of sediments highly contaminated
with polychlorinated biphenyls (PCBs). Therefore, the potential adverse
biological consequences that could result from the release of PCBs induced by
these dredging and disposal activities made this site particularly interest-
ing.
The material presented in this paper is limited to a discussion of PCB
impacts and includes:
(a) a summary of results from the studies conducted between 1976 and
1977 to assess short-term impacts during and after the disposal of
PCB contaminated sediments at the Elliott Bay disposal site;
(b) a presentation of preliminary results from the continuation studies
initiated in February 1979 to determine long-term impacts of the
disposal operations.
In this paper, only the PCB distributions, sediment physical characteri-
zation, and the impacts on benthic macrofauna will be considered. These and
other aspects of the short-term studies have been discussed in detail else-
where (U.S. Army Engineers, 1978).
DESCRIPTION OF THE STUDY AREA
Elliott Bay is situated midway on the eastern shore of the central basin
of Puget Sound (Figure 1). The surface area of the bay is approximately 14.4
km2 and is defined by Magnolia Bluff as its northwest boundary and on the
southwest by Duwamish Head. The volume of the bay comprises approximately 1
percent of the volume in the main basin (McClellan, 1954) and 0.5 percent of
the total Puget Sound volume. Bottom topography is characterized by steep
marginal shore slopes around an internal basin of about 130 m in depth. This
basin slopes gently to the northwest until it merges with the central Puget
Sound basin.
The southern portion of the bay is divided into two smaller basins by a
bottom ridge that slopes northwesterly from the northern end of Harbor Island
130
-------
g Bellingham
u
Figure 1. Puget Sound and Elliott Bay
131
-------
and extends to the center of the bay. This ridge may represent a delta built
by the Duwamish River, which discharges into the southern portion of the bay.
The circulation in Elliott Bay is predominantly induced by tides. Tide
fluctuations (3.2 m mean tide range) generate a weak, generally counter-
clockwise flow in the upper layers (<50 m) of the bay, with water from the
main basin entering around Duwamish Head. While deepwater exchange between
the bay and the main basin has no topographic restrictions, circulation in the
deep layers is probably limited except during periods of deep water renewal
within the entire Puget Sound system.
The Duwamish River provides freshwater input to Elliott Bay at an average
annual rate of about 1,300 cfs (U.S. Environmental Protection Agency, 1974).
The flow is highly seasonal, reflecting variations in precipitation and snow-
melt. The river discharge normally increases in late fall and again in late
spring. The lower Duwamish forms a vertically stratified salt-wedge estuary
with net outflow of fresh to brackish water at the surface and net inflow
(upriver) of saline Elliott Bay water at depth. The highly variable flow of
freshwater is nearly always seaward. However, the instantaneous movement in
both layers may be either upstream or downstream. At its mouth, the river is
split and discharges into Elliott Bay around both sides of Harbor Island.
Dredging of the western channel and a shallow sill at the south end of the
eastern channel result in the majority of the water exchange taking place via
the West Waterway. The freshwater discharge forms a low salinity surface
plume (1-15 m) in the southern portion of the bay. The behavior of this plume
reflects a response to both tidal currents and wind stress. In the absence of
strong southerly winds, the plume is "compressed" into the southern bay around
the river mouth by flood tides. During ebb tides, the plume normally drifts
northward, spreading along the northeastern waterfront and following the
shoreline until its identity is lost by mixing with Puget Sound surface water.
As a result, the influence of the river discharge is felt primarily in the
southern and southeastern portions of Elliott Bay and along the Seattle water-
front.
The presence of PCBs in Puget Sound has been known since 1972. In gen-
eral, PCB concentrations were found to correlate with sites of increased
industrial and municipal activity with no apparent temporal trends. The
highly industrialized Duwamish Estuary contained the highest PCB concentra-
tions observed in the sound. Elliott Bay, which receives the Duwamish River
discharge, also was found to contain elevated PCB levels showing a spatial
distribution in surface sediments that decreased with distance from the mouth
of the river. A recent examination of PCB levels in the sediments of Elliott
Bay and the Duwamish River suggests that the history of PCB input into this
area has been sporadic over a fairly long period of time. Sediment cores
often show marked differences in both the PCB types and their total concentra-
tions as a function of the core depth. A detailed discussion on these aspects
has been presented elsewhere (Pavlou and Dexter, 1979; Horn, 1979).
132
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SAMPLING SCHEME
Short-Term Studies
The dredging and disposal operations were initiated in February 1976 and
completed in March 1976. A clamshell bucket dredge and two split-hull barges
of approximately 1100 m3 combined capacity were used in the operation. The
total volume of material disposed in Elliott Bay was approximately 114,000 m3.
The source of these sediments was a 1.88 km stretch of the upper Duwamish
Estuary between river km 6.3 and 8.2. The disposal site was located over the
60 m depth isoline due north of the mouth of the West Waterway (47°37'41" N;
122°21'42" W). The sixteen-station sampling grid comprised an area of 0.13
km2, as shown in Figure 2. The two reference sites were also located in 60 m
of water and positioned east and west of the disposal site. The west refer-
ence site historically has received the least impact from the municipal,
commercial, and industrial activities of the Seattle area. Water flow over
this location originates primarily from the main basin of Puget Sound rather
than from the interior of Elliott Bay. The east reference site has received
effluents from the Duwamish River and unknown contributions of contaminants
from shipping, nearby shore-based activities, and from a number of sewage
overflow discharges along the Seattle waterfront.
During the short-term studies, effects of the disposal operations were
examined by monitoring three barge dumping episodes on each of two separate
days. Rapid time series of whole water and suspended particulate matter
samples for PCB analysis were collected at the center of the disposal grid.
Reference values were measured each day before and after the monitoring period
at each of the east and west reference areas and at the mouth of the Duwamish
River. Samples were collected at the surface (0-1 m), 10 m off the bottom and
1 m off the bottom at each station.
Replicate water and suspended particulate matter samples were collected
at intervals of two days, 10 days, one month, three months, six months, and
nine months after the cessation of all dumping at two stations.near the center
of the disposal grid and at the same three reference stations mentioned above.
The same sampling depths also were used.
Replicate sediment cores from the river, disposal grid, and east and west
reference stations were collected 10 days before initiation of dredging.
Additional cores were collected at 20 Elliott Bay stations (Figure 2) during
the nine-month post-disposal sampling period discussed above.
Benthic macrofauna were collected in replicate or triplicate using a 0.1
m2 van Veen grab sampler at the same stations and schedule as was used for the
sediment samples. The macrofauna were sieved using 1 mm screens on board
ship.
Long-Term Studies
Since the baseline study results indicated that the disposed material
extended beyond the boundaries of the original station grid (see below), the
spatial coverage for the long-term studies was expanded. In this manner also,
133
-------
EAST
REFERENCE
SITE
EXPERIMENTAL
DISPOSAL SITE
WEST
REFERENCE
SITE
n
MOUTH OF
DUWAMISH
DUWAMISH
RIVER
STATIONS
(DREDGING LOCATIONS)
Figure 2. Original Station Grid
134
-------
a better comparison could be made between impacted and non-impacted zones,
specifically with respect to estimating patterns and variability in the sur-
rounding biotopes for evaluating recovery from perturbation. A new sampling
scheme was therefore developed and is briefly summarized below.
Of the original grid of sixteen stations in a four-by-four square pattern
(Figure 2), the four corner stations were retained; the original side sta-
tions, together with the reference stations, were eliminated. Four new side
stations within the grid were chosen at intermediate locations. Eighteen
stations were chosen outside the grid at points located at 35 m increments of
distance from the center of the grid at random angles. For each subsequent
cruise, stations outside the grid were re-randomized. A schematic diagram of
the station randomization scheme is shown in Figure 3. The new configuration
for the first sampling cruise is shown in Figure 4. This method was used to
establish an unbiased selection of reference stations, while still maintaining
temporal continuity for some of the original grid stations.
Essentially the same sampling schemes were employed in the long-term
studies, with the major exception that the sediment cores were split into a
greater number of horizons (up to 5), usually at visual or textural disconti-
nuities.
All analytical procedures used during these studies have been described
in detail elsewhere (U.S. Army Engineers, 1978).
SPATIAL CONFIGURATION OF THE DISPOSAL MOUND
Detailed bathymetric maps of the disposal areas are shown in Figures 5
and 6, with contour intervals of one foot and five feet, respectively. These
maps were generated from data collected in December 1978 by the U.S. Army
Engineers, Seattle District, but they are essentially the same as the previous
post-disposal surveys.
The most prominent feature is the dredged material "mound" of approxi-
mately 3 meters depth defined by the 190-foot contour near the center of the
grid. Detailed comparisons of pre- and post-disposal surveys indicated that
dredged material is present throughout most of the grid area, predominantly in
the northern section.
Only minor changes were detected when comparisons were made between the
previous post-disposal bathymetric surveys and the more recent data. These
changes are illustrated in Figure 7, which compares bottom-depth profiles
along east-west transects through the grid center and at 100 foot intervals
north and south of the centerline.
STABILITY OF THE DREDGED MATERIAL DEPOSIT
In order to determine the physical stability of the disposal mound,
measurements of current velocity, salinity, temperature, transmissivity, and
pressure were taken. In May 1979 one array of Aanderaa current meters and the
135
-------
West
270°
114
East
90°
Figure 3. Station Location Randomization Procedure
136
-------
CM
CM
CM
47°36'
CM
*,
CM
129 ELLIOTTBAY
130
125
124
J19
116 113
120
109
108
110 i
105
114
101
104* *103
J06
I
112
126
•
L:
107
'«j
115
117
121
127
•
128
at
I
I
122
J18
123
0 100 200 300 400 500
Figure 4. Station Locations - Reconnaisance Cruise February 1979
137
-------
Figure 5. Bathymetric Map of Disposal Site (1 foot contours)
Dashed Lines Define the Area of the Original Sampling Grid
138
-------
CO
VD
Figure 6. Bathymetric Map of Disposal Area (5 foot contours)
Dashed Lines Define the Area of the Original Sampling Grid
-------
190
West
a.
0)
O
E
2
+••
o
03
— 230
500
700
900 East
•••**• •***•*•*••
— Pre-Disposal
1976
1978
Distance from Survey Centerline , Feet
Note: Vertical Distance Expanded When Compared
to Horizontal Distance
Figure 7. East-West Transects Through the Disposal Site
-------
Sediment Dynamics Sphere (SDS) tripod system, from the Department of Oceanog-
raphy at the University of Washington, were deployed for 40 days in the study
area. The current meter array and tripod were placed about 30 m apart in a
relatively flat area just north of the original grid. The data for the SDS
system and current meter records are now being processed and will include
tables of velocity components, current speed and direction, temperature,
conductivity, pressure and transmissivity measured at 15 minute intervals
during the deployment.
Sediment Transport Calculations
Based on the data obtained, some preliminary sediment transport calcula-
tions have been made. The critical boundary shear stress (T ) is dependent on
grain size and can be estimated for a range of phi sizes. A critical shear
velocity (u* ) was calculated for each T from the relation
c c
Tc = pu*c2
A range of critical Reynolds numbers (R* ) was then calculated from
X*
R —
K*c ~ v
where D = grain size diameter and v = water viscosity.
Using Nikuradze's diagram a Z was determined for each R* .
The Karman-Prandle equation
relates the velocity u, at depth Z above the bottom to the shear velocity u*
and the natural log of j-. Knowing the critical values of u* and ZQ, a criti-
o
cal value of u can be calculated. If the actual values of u exceed the criti-
cal value, sediment may be moved.
The results of these calculations are summarized in Table 1. It should
be noted that these calculations are based on cohesionless sediments, whereas
the sediments in the study area are cohesive. Therefore, the values calcu-
lated (Table 1) for the critical velocities (u ) which would be required to
move the various sediment classes probably represent minimum velocities.
As can be seen in Table 1, current speeds actually observed at 2 m above
the bottom exceeded 15 cm/sec 0.5 percent of the time during the deployment
period. Currents exceeded 20 cm/sec for a total of 0.25 percent of the time.
The maximum velocity (one 15 minute reading) during the 40-day deployment was
23.3 cm/sec. Velocities were predominantly 10-12 cm/sec and appeared to
change direction in response to the tides.
141
-------
phi Size
TABLE 1. SEDIMENT TRANSPORT CALCULATIONS
D(cm)
u*c (cm/sec)
"o (cm) uc (cm/sec at 2 m)
2
3
4
5
6
7
2.5 x 10-2
1.25 x 10-2
6.25 x TO-3
3.12 x 10-3
1.56 x 10-3
7.81 x 10-4
1.43
1.33
0.96
0.81
0.71
0.62
1.0 x 10-3
1.1 x 10-3
1.5 x 10-3
1.8 x 10-3
2.0 x 10-3
2.3 x TO-3
43.6
40.3
28.3
23.5
20.4
17.6
currents exceeded 15 cm/sec
currents exceeded 20 cm/sec
maximum value: 23.3 cm/sec.
Observed Values
0.5% of deployment period
0.25% of deployment period
Based on' these calculations, sediments of phi size 7 or greater could
have been resuspended a maximum of 0.5 percent of the time during the deploy-
ment. Sediments of phi size 6 could have moved a maximum of 0.25 percent of
the time. Sediments of 5 phi or less should not have moved. In comparison
with the observed sediment texture (see below), these calculations suggest
that some fine sediments could have moved during a small percentage of the
deployment period. However, the effect of the sediment cohesion probably
prevented significant resuspension. This conclusion is supported by transmis-
someter readings which indicated that the suspended sediment concentrations
never exceeded 1 mg/1. No significant peaks were recorded.
Sediment Texture Analysis
Sediments were analyzed for percent water, percent organic matter and
grain size distribution. Standard sieve and pipette techniques were used to
measure grain size. Sands were measured in 1/4 phi intervals, silts in 1/2
phi intervals and clays in 1 phi intervals. The relationship between phi (0)
size and grain diameter is given by 0 = -log2D where D = grain diameter in
millimeters. The basic statistical analysis included calculations of the
percents of gravel, sand, silt and clay; sand-to-mud ratio; sorting; skewness;
Kurtosis; and mean and median phi. The following discussion is applicable to
samples collected during the reconnaissance cruise (February 1979). Analysis
of all samples collected in May 1979 is not yet complete.
There was significant variability in grain size between some samples
taken at the same station. For example, differences of 36 percent in sand
content among three replicate surface samples were measured. This variability
must be kept in mind when reviewing the general results presented below.
142
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Plots of percent sand and mean phi size samples for the February data are
presented in Figures 8 and 9, respectively. Where more than one replicate was
analyzed per station, the average percent sand and average mean phi were used.
A north-south orientation is apparent in the. percent sand distribution. There
was a middle band of coarse sediment bordered by less coarse bands. Most of
the surface sediments are between 30 percent and 60 percent sand. A somewhat
similar pattern is seen in the mean phi size distribution although it is not
as distinct as in percent sand. Most samples had mean phi in the silt size
class.
All of the samples analyzed had large standard deviations indicating poor
sorting. As a result, it is difficult to characterize the sediments since the
distributions of various parameters tend to produce different spatial pat-
terns.
Part of the shipboard processing of the gravity cores included recording
a physical description of each core. This description included overall
length, color and texture variations, odor, layering, and any other notable
characteristics. In and near the grid area, a layer of black sediment under-
lain and/or overlain by greenish gray sediment was observed in many samples.
Considering the location of the samples and the known characteristics of the
dredge material, this black layer was most probably dredge material. In
outlying areas cores were frequently fairly uniform with depth and were
generally greenish-gray or grayish-brown in color. Since the usual character-
istics noted in the cores corresponded poorly with the usual sediment textured
paramters, patterns in individual phi sizes were examined. The phi size
classes were ranked for each sample in order of abundance. Similarities in
the six most abundant phi sizes were apparent and the majority of the sedi-
ments could be classified into five subjectively defined sediment groups based
on these recurring patterns. The criteria defining each sediment type are
presented in Table 2.
TABLE 2. DEFINITION OF SEDIMENT TYPES
Type Criteria
a 4.50 and 3.250 in 6 most abundant, without 2.750
b 4.50, 3.250 and 2.750 in 5 most abundant
c 4.50 not present in 6 most abundant
f 120 most abundant, 4.50 2nd, no 90
g 120 most abundant, 4.50 2nd, and 90 3rd-5th most abundant
Misc. Does not fit any other sediment type.
143
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0 100 200 300 400 500
Figures. Percent Sand, February 1979
144
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0 100 200 300 400 BOO
Figure 9. Mean Phi Size,February 1979
145
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By comparing the sediment types with the physical descriptions of the
cores, some interesting relationships were established. Types a and b sedi-
ment are almost always associated with the black sediment found in and around
the grid area, while type f was usually a gray-green sediment from the same
area. Type g sediment was usually associated with greenish gray or dark brown
sediments and was never associated with black sediments. Type c sediments are
mainly associated with samples that were a mixture of greenish gray and black
or with other colors not frequently seen. No major association was observed
between other sediment types and core descriptions.
PCB RESULTS
Short-Term Study
Water Column
Time plots of the total PCB concentrations during two monitoring events
are shown in Figure 10. In general the data indicate rather rapid pulses of
high concentrations associated with each of the barge-dumping events. The
highest values (up to three orders of magnitude from background levels) were
observed at the bottom depths and were associated with particulate matter.
After each pulse, the ambient concentrations rapidly returned to near pre-dump
conditions, but with a slight increase in PCB levels shown by the end of each
daily monitoring period.
Since the water column within Elliott Bay is normally stratified, it was
deemed appropriate to:
(1) examine the vertical profile of PCB concentrations in terms of the
hydrographic characteristics of the sampling site;
(2) determine whether residues originated from the disposal operation
were maintained and distributed primarily at specific depth layers.
The data indicated that within the depth strata sampled, the highest PCB
levels were observed at the surface. This gradient suggests that the low
salinity water discharged by the Duwamish River is a major source of contami-
nation within the bay. However, this depth dependence was not statistically
significant, which was consistent with the near vertical uniformity observed
in the salinity, temperature, and density profiles. These observations agree
with the trends observed in earlier studies (Pavlou and Dexter, 1979; Clayton
et al., 1977). Plots of the average concentrations of PCBs versus time for
whole water samples over the post-disposal monitoring period are shown in
Figure 11. Similar behavior was also exhibited for the suspended particulate
matter samples.
The data from all depths at each station were treated statistically to
determine the existence of spatial and temporal patterns. Although it appears
that there is a general temporal trend toward decreasing PCB concentrations in
the water at each station with time, only levels measured two days after
cessation of dumping were significantly different from all subsequent post-
146
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100
50-
CD
03
0.
100
50-
QQ
O
en
CN
b
x 0
g 100
50-
0
CRUISE 55
O Surface
D Mid-Depth
A Bottom
CRUISE 57
• Surface
• Mid-Depth
A Bottom
400
ITT
0800
Tl
1000 1200
Time, Hours
1400
1600
Arrows indicate approximate
times of dump episodes.
Figure 10. Plots of Whole Water Total PCB (TCB) Concentrations at
Buoy Site (Sta. 6) Versus Local Time
147
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TCB
O Sta-6
D Sta-10
• Sta-17
Sta-19
~l
Q_
co
5
CO
I
CD
Q.
O
f—
0
o
CD
CO
§
13.0
12.0
11.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0
• Sta-44
A
• D
•
O
H
n
2 a o
• • • fi
O J A A
i
i i i J_ i
1.0 2.0 3.0 4.0 5.0 6.0 7.0
Cruise Number
Figure 11. Plots of Mean Habitat TCB Concentrations Versus
Time for Whole Water (Post Disposal Cruise Series)
148
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disposal measurements. The mean PCB value for all stations measured two days
after dumping ceased was approximately 7 ppt and was higher than had been
observed in the past. Comparisons between stations within each cruise did not
yield significant differences, although the levels at the east side and
Duwamish River (19 and 44) were often higher than the other three stations,
probably reflecting the input from the industrialized Duwamish River and
Seattle waterfront.
Sediments
s,
The concentrations of PCBs observed in the river sediments, providing the
source of material for the disposal project, ranged between 0.01 and 7.0 ug
PCB/g dry sediment (ppm). A profile of these values over the stations sampled
is presented in Figure 12. Considerable spatial variability was observed with
high levels associated with a rather narrow band of highly contaminated sedi-
ments towards the northern part of the dredged channel. Both up and down-
stream, the levels decreased fairly regularly. The mean PCB concentration
throughout the section of the river sampled was 2.0 ppm.
PCB concentrations within the sediments of the disposal site and refer-
ence areas before dumping showed a pronounced gradient of significantly higher
levels in the east (mean about 0.3 ppm) and central portions (mean approxi-
mately 0.2 ppm) of the bay and decreasing to the west (mean about 0.03 ppm).
Although in general this is consistent with the .deposition pattern of contami-
nated sediments discharged from the Duwamish River as observed in previous
studies (Pavlou and Dexter, 1979), very pronounced spatial inhomogeneity was
observed, with values in the disposal grid ranging from about 0.1 ppm to as
high as 1.7 ppm.
As has been discussed previously (Hafferty et a^L , 1977), characterizing
environmental distributions of PCBs through measurements of the relative mass
fractions, FN, of the individual PCB components provides a useful technique
for assessing the dispersal of these chemicals and tracing their source. The
characteristic F.. distribution, or "fingerprint," of the river sediments is
shown in Figure T3 as a plot of FN versus the chlorine number, N. The values
were generated by determining the relative concentrations of the CB components
grouped according to the number of chlorine atoms, the N-CB, averaged over all
the river stations. While the pentachlorobiphenyl (5-CB) residues predomi-
nated, significant quantities of lower chlorinated biphenyls were observed.
In particular, the trichlorobiphenyls (3-CB) averaged about 20 percent of the
total.
Although there was little spatial variability in the FN distributions of
the river samples, substantial differences were noted in the FN profiles for
stations within the disposal grid prior to disposal. In spite of the vari-
ability in the FN profiles, all river samples were enriched in lower PCB com-
ponents, specifically the 3-chlorobiphenyls compared to the background grid
sediments. This pattern provided an effective discriminator between the
background sediments at the disposal sites and the dredged material from the
river.
149
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c
CD
E
CD
CO
_
Q
CO
CD
O
i
CO
CD
i
O
X
DO
O
C
CD
ID
a
2 -
0
25
30
35
Station Number
Figure 12.Plots of the Total PCB (TCB) Concentrations in
Sediments Versus Relative Distance (Station Number)
Within the Duwamish Site
150
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D Dredge Site
O Disposal Site: All Stations (average value)
0.5 i-
0.4
0.3
0.2
0.1
0
I X
N
Figure 13. Plots of Relative Mass Fraction, F^,Versus Chlorine Number, N
151
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To facilitate visualization of the general spatial and temporal trends of
PCB residues in the disposal and reference zones during the pre- post-disposal
monitoring, three-dimensional histograms of PCB concentrations were con-
structed (Figures 14 and 15). Inspection of these histograms indicates that
after disposal the highest concentrations were encountered at the central
section of the station grid with values diminishing roughly radially away from
the center. Based on this feature, the grid stations were sorted into three
groups consisting of the corner, side, and central stations. The mean values
for each group, including the reference stations, plotted as a function of
time (sequential cruise number), are shown in Figure 16.
By examining these data, it is clear that there was a significant in-
crease in the PCB concentrations within the upper horizon (upper 10 cm) at all
grid station groups as a result of the disposal. No significant change was
noted during post-disposal monitoring at the reference stations. Although
there is an apparent trend toward increasing concentrations at the grid site
during the later cruises (especially at the side and corner groups), these
increases were not statistically significant.
PCB concentrations in the lower horizon (sediment depth >10 cm in the
core) of the grid during the post-disposal period showed the same general
behavior. The statistical analyses of temporal and spatial trends were based
on the trichlorobiphenyl concentrations to provide the most sensitive discrim-
ination between the background sediments and those deposited during the dispo-
sal operation. Similar to the residue levels in the upper horizon, the lower
horizon of the central station group showed a significant increase in CB con-
centrations immediately after no changes were noted in subsequent samplings.
In contrast, the lower horizon of neither the side nor corner groups increased
significantly immediately after disposal, indicating that the depth of the
original dredged materials deposit was less than 10 centimeters thick around
the periphery of the disposal zone. However, the data from later field col-
lections showed a trend toward increasing chlorobiphenyl concentrations within
the lower horizon sediments at the side and corner groups. After six months,
the lower horizon at the side stations had reached concentrations signifi-
cantly higher than those observed in the background (surface) sediments.
Similar trends were seen at the corner stations, but a significant increase in
lower horizon concentrations did not occur until the ninth month.
Comparisons of the mean 3-chlorobiphenyl concentrations for each station
group within cruises correlate with these temporal trends. For the first
month after disposal, the lower horizon of the central group had significantly
higher residue levels than the corresponding horizon at either the side or
corner groups. By three months, however, the side and central groups were no
longer significantly different. At nine months, none of the three station
groups were significantly different from each other. These trends are appar-
ent in the "leveling" of the histograms with succeeding cruises as shown in
Figure 15.
In summary, the overall spatial and temporal features of the PCB concen-
trations suggest that the sediments deposited at the disposal site were not
stabilized during the monitoring period. They were slumping from the center
of the grid to the periphery. The absence of significant reduction in PCB
152
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Cruise
Number
342
265
168
99
76
17
18'
Scale
Parts per million
10
Figure 14. Three Dimensional Histogram of the TCB Concentrations in Sediments
for the Upper Horizon
153
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Cruise
Number
342
265
168
99
76
Scale
Parts per million
10
5
1
Figure 15. Three Dimensional Histograms of the TCB Concentrations
for the Lower Horizon
154
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A. Corner.
D Middle o East Reference
• Sides • West Reference
CD 4-°-|
CD
+-*
CD
•*-•
'-Q .
I 3.0-
-------
levels in the grid site indicated that no major resuspension or bed-load
transport of bottom material had occurred during the monitoring period. This
is not unreasonable if one considers the weak and variable velocity field
along the bottom of Elliott Bay.
Mass Input Computations
The total amount of PCB deposited in Elliott Bay as a result of the
disposal operation was estimated as follows. An average value of 2.0 x 10-6 g
PCB/g dry sediment was determined from the PCB data obtained in the river
sediments before dredging. The total volume of the sediments dredged was
about 1.1 x 10s m3. Assuming a wet density of 1.3 g/cm3 and 50 percent water
content by weight, a value of 1.4 x 105 g PCB was calculated to have been
deposited in the sediments at the disposal site in Elliott Bay.
Long-Term Studies
Sediments
At the present time, data for the PCB concentrations in the sediments
from the February and May 1979 samplings are available.
A contour plot of the concentrations of total chlorobiphenyl (t-CB)
residues in the surface sediments, combining both sets of data, is shown in
Figure 17. Although replicate samples were collected at a few stations, only
the highest observed PCB value was used in generating these contours to pro-
vide a "worst case" comparison. The general distribution of PCBs agrees with
that observed in the previous study. High PCB levels are noted in the vicin-
ity of the disposal site, corresponding to the dredged material deposit, while
away from the disposal site, the distribution indicates a similar trend of
decreasing PCB concentrations from east to west. Interestingly, the samples
do not indicate a major increase in PCB levels associated with the mouth of
the West Waterway, a feature noted in previous studies (Pavlou and Dexter,
1979). This latter observation, however, may result simply from the high
variability of the sediment levels and the low sampling intensity near the
river mouth.
Similarly, a contour plot (Figure 18) of the highest t-CB levels observed
in any core from each sampling station, irrespective of depth in the core,
shows essentially the same distribution, but extends eastward—the apparent
influence of the dredge material.
Comparisons of these t-CB values alone, however, were insufficient to
precisely delineate the dredged material deposit, particularly toward the east
where high levels were observed in many of the samples.
As discussed earlier, the PCBs in the dredged material were noted to be
relatively enriched in the lower chlorinated CBs. Therefore, the concentra-
tions of the trichlorobiphenyl (3-CB) residues in the sediments were compared.
As expected, the 3-CB distribution (Figures 19 and 20, for surface and highest
values, respectively) shows a spatial extent of the dredged material in close
agreement with that anticipated from the results of the previous study and the
recent bathymetric survey.
156
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E LLIOTT BAY
0 100 200 300 400 500
Figure 17. Contour Plot of the Concentrations of TCB Observed
in the Surface Sediment Horizon ( In Units of ng t-CB/g dry sediment)
157
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E LLIOTT BAY
0 100 200 300 400 500
Figure 18. Contour Plot of the Highest Concentration of TCB Observed
in the Sediments, Irrespective of Depth in the Core
(In Units of ng t - CB/g dry sediment)
158
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E LLIOTT BAY
0 100 200 300 400 500
Figure 19. Contour Plot of the Concentrations of 3 - CB in the Surface Sediment Horizon
(In Units of ng 3-CB/g dry sediment)
159
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E LLIOTT BAY
0 100 200 300 400 500
Figure 20.Contour Plot of the Highest Concentration of 3-CB Observed in the Sediments,
Irrespective of Depth in the Core (In Units of ng 3-CB/g dry sediment)
160
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Tracing the Distribution of Dredged Material
As noted above, a number of values from stations outside of the original
disposal monitoring grid also had both high 3-CB and high t-CB residue concen-
trations. In addition a number of samples from both inside and outside the
grid area had intermediate 3- and t-CB levels. Both factors preclude a clear
distinction between dredged material deposits and native sediments based on
differences in their PCB content only. It was noted, however, that the dis-
tributions of certain sediment types, and the high -3-CB levels closely cor-
responded. Therefore, a histogram was constructed (Figure 21) to relate the
levels of 3-CB in each sample to the corresponding sediment type. On the
basis of this histogram, two dominant groups of sediments can be delineated;
one group characterized as sediment types c and g with low 3-CB concentra-
tions, the other by f, b and f/b sediment types and higher 3-CB levels. The
latter group is considered to be representative of at least the majority of
the dredged material deposit. The remaining sediment samples fell in inter-
mediate ranges with no clear discriminator available at this time.
Those stations having sediments that clearly met the criteria for dredged
material are indicated in Figure 22, which also shows the approximate depths
of the dredge-material deposit at each location as determined by the length of
the core from the surface to the bottom of the lowest horizon consisting of
dredge material.
While differences in the sampling plan preclude direct point-to-point
comparison of the PCB levels at each location, a comparison of the overall
levels is possible. The mean t-CB concentration from the average of all
samples of dredge-material observed in the original study was about 1.7 ppm,
while the corresponding mean 3-CB concentration was 0.29 ppm. A similar
averaging of all of the available 1979 data for dredged-material samples
yielded 1.9 ppm and 0.4 ppm for the t-CB and 3-CB concentrations, respec-
tively. Considering the variability observed in both the old and newer data
sets, these means are undoubtedly statistically indistinguishable.
The distribution of the dredged-material deposit delineated by these
results is in general agreement with the supposition that little movement of
the deposit or change in the associated PCB levels has occurred since the
original disposal operation. There are indications, both in the position of
the observed dredged-material sediments and in the bathymetry (see above),
that some shifting of the disposal mound to the east or northeast may have
occurred over the last few years. The highest PCB values were observed at
station 114, just east of the grid, while the west and south grid corner
stations (109, 111, and 112) had no dredged-material.
Interestingly, the distribution generally agrees with what would be
expected from fluid flow of the dredged material along bathymetric contours,
which would have occurred with the slumping and settling noted above. How-
ever, it must be recognized that detailed delineation of the spatial extent of
the deposit is not possible considering the level of sampling intensity em-
ployed and the limitations in the precision of the bathymetric surveys. In
addition, since no sampling was performed outside the grid during the initial
study, it is difficult to determine when the eastern deposits originated.
161
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I
Sample Values
Values with Questionable
Grain Size Analyses
500
400
. 300
O>
CQ
O
A 200
100
g Misc. a f
Sediment Type
Figure 21. Histogram Relating the Concentrations of 3-CB
in the Sediments to the Sediment Type
162
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CM
CM
%*
CM
47°36'
CM
E LLIOTT BAY
-10 L
Q)
i
I
CO
in
^h
Yards BNorth
0 100 200 300 400 500
Figure 22. Contour Plot of the Approximate Depth of
the Dredge - Material Deposit (In cm )
163
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Considering the general stability of the major deposit, it seems most likely
that the major features of these distributions were generated by the initial
disposal operation.
IMPACTS TO BENTHIC MACROFAUNA
Baseline Study
The rationale for conducting a biological study was to determine whether
or not the benthic macrofauna at the disposal site responded to the effects of
dredged material disposal on a long-term basis. The baseline biological
investigations (U.S. Army Engineers, Appendix G, 1978; Harman and Serwold,
1978) documented the short-term effects of the disposal on the benthic macro-
fauna. The impact of dredged material disposal was evident through reductions
in fauna! abundance and biomass immediately after disposal. Burial of the
fauna was hypothesized as the primary cause. Although the total spatial
extent of the disposal impact was not discernible due to limited sampling, it
is known that at least an area of 0.13 km2 experienced a 21 percent reduction
in mean faunal abundance and a 25 percent reduction in biomass compared to
predisposal values (Harman and Serwold, 1978).
Recolonization phases of benthic macrofauna at the dredged material
disposal site were reported as follows:
(1) summer recruitment of opportunistic benthic macrofaunal species and
annuals (three months after disposal), followed by
(2) an increase in predatory polychaetes and a decline in opportunistic
species (Harmon and Serwold, 1978).
These authors stressed that the composition of the biological community
had not returned to predisposal conditions nine months after the disposal
occurred.
U.S. Army Engineers, Appendix G, 1978, provided additional numerical
analyses to the data reported by Harman and Serwold (1978). The impact of the
dredged material disposal was greatest at the central disposal stations, with
mean faunal density and biomass remaining low through nine months. In con-
trast, many stations at the margins showed greater values for mean abundances,
biomass, and number of species than the reference stations.
U.S. Army Engineers (1978) summarized the overall dredged material dispo-
sal project for Elliott Bay. Discussion pertaining to the benthic macrofauna
suggested that the major effect of the disposal was physical rather than
chemical. The authors suggested that the most obviously impacted central
stations suffered no permanent damage since the mean number of species present
climbed from a low of three to twenty-five nine months after disposal.
Present Biological Characteristics
Some difficulties with appropriate selection of reference stations in the
short-term studies, as cited by U.S. Army Engineers (1978), were overcome by
164
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using a different sampling design for the long-term studies, as described
earlier in this paper.
Biological data analyses in the present study were different in many
respects to earlier works. Harman and Serwold (1978) analyzed the data pri-
marily by calculation of mean values and production of geometric contour plots
of the disposal site and reference station to show spatial and temporal data
trends.
U.S. Army Engineers, Appendix G (1978) used numerical analyses, emphasiz-
ing statistical methodologies, including ANOVA and the nonparametric Kruskall-
Wallis test. In this study, statistical treatment of the data includes map-
ping, cluster analysis, Wilcoxon's two-sample test, spatial autocorrelation,
Kendall's coefficient of rank correlation, and multiple regression analysis.
Preliminary analyses of fauna! abundances have been conducted on data
from both the February and May 1979 cruises. Discussion is limited here to
analyses of abundance from the May 1979 cruise and is based on mapping, clus-
ter analysis, and Wilcoxon's two-sample test.
Mapping
Mapping of the biological data was conducted to provide a preliminary
evaluation of the spatial trends in taxa abundances. Two approaches to map-
ping the individual taxa abundances were used:
(1) calculating mean values for each station's three replicates and
manually producing geometric contour maps;
(2) dividing the range of abundances for each taxa into discrete subsets
and plotting individual replicates.
For purposes of visual representation of biological data, the authors
feel that contour mapping may oversimplify spatial patterns due to unknown
variability in abundance values and may present a biased picture of abun-
dances. Therefore, the second method of mapping was selected for display
since it does not rely on mean values, and does not necessitate interpolation
of abundance values between samples. Figure 23 shows the spatial abundance of
the polychaete family Capitellidae. The plot suggests that higher abundances
occur within and in the immediate proximity of the original sampling grid.
Similar tendencies were also found for Axinopsida sericata, the most abundant
bivalve; several of the Maldanidae, including Praxiella affinis, £. gracilis,
Maldane glebifex, and Euclymeninae; and Paronella spinifera and Eteone sp.,
polychaetes from the families Paraonidae and Phyllodocidae, respectively.
These hypotheses are tested explicitly (below).
Cluster Analysis
Cluster or numerical classification analysis was conducted to combine
station replicates (samples) into groups based on similarities in taxa abun-
dances. The purpose of grouping the samples was to form testable hypotheses
concerning spatial patterns in taxa abundances relative to the disposal site.
165
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47°36'
CM
CM
°CM
CN
A*
140
CM
?M
CM
E LLIOTT BAY
136
137
Key
Symbol
(no./0.1nrr)
0= 0-14
A = 15-44
* = 45 - 73
• =74- 103
= 104- 118
135
1 no
109
! 105
***
108
102
HlPL
** ** 106
A 103 *
111
131
J
i*
133
* •
132
**
*
134
0>
S
139
i
141
0 100 200 300 400 500
Figure 23. Spatial Distribution of Polychaete Family Capitellidae
166
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Cluster analysis was performed using the CLUSTAN (1C) computer program
developed by Wishart (1975). All abundance values were species-total stand-
ardized (e.g., Boesch, 1977) prior to calculating similarity indices. The
Bray-Curtis Index was used to calculate the "distance" between samples. The
Lance-Williams flexible beta combinatorial method was used to calculate dis-
tances between groups of samples (Boesch, 1977). These computations were
initially run using the seventeen most abundant taxa sampled in the May cruise
and considering each station replicate as a separate entity (60 x 17 matrix).
These taxa are listed in Table 3. Cluster analysis was also run using these
same taxa and their mean abundances from the three replicates at each station
(20 x 17 matrix). The results are shown in the dendrogram plots in Figures 24
and 25 for the individual sample abundances and mean sample abundances, res-
pectively. Three distinct station groupings within each of these plots are
evident. Figure 26 shows the spatial relationship of these groups of sta-
tions/samples relative to each other and the original sampling grid.
TABLE 3. RANKING OF TAXA FROM MAY CRUISE BY ABUNDANCE
Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Abundance
Taxa
Axinopsida sericata
Capitellidae spp.
Euclymeninae spp.
Paraonella spinifera
Macoma carlottensis
Aricidae cf. lopezi
Cossuridae sp.
Lumbrineris luti
Amphipoda spp.
Nuculana minuta
Prionospio cirrifera
Chaetozone setosa
Glycera capitata
Nephtys ferruginea
Ostracoda spp.
Organism
Type3
C
MW
MW
MW
C
MW
MW
MW
CR
C
MW
MW
MW
MW
CR
Mean Density1
(Abundance 0.1 m2)
270
58
51
36
25
17
16
10
9
9
8
7
4
4
3
Percent2
Relative
Abundance
100
21
19
13
9
6
6
4
3
3
3
3
1
1
1
1 Total number of particular taxa abundance for all replicates divided by 60.
2 Percent relative abundance to Axinopsida sericata.
3 MW-marine worm; C-clam; CR-crustacean.
167
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1-574
1.424
1.274
1.124
0.974
•*-»
C
J 0-824
•s
<3
—i _nj
CTi •=
00 §
£
b
.675 4-
0-
0.375 4-
0.
Gifoupl
^
^
Groui
Gro6p2
Samples (Station and Replicate^- May Cruise
Figure 24. Cluster Analysis of Biological Organism Abundances for May Cruise/Matrix Equals 60 Replicates by 17 taxa
-------
0>
jo
0)
6
£
J2
1
8
5
f J - 962
D-87U
0.790
0.703
fc
0-617
0.531
0-445 -f
0 • 359
0.272
0 .106 4-
Group 1
I
_T
Group 2
Group 3
OJ CO 03 rr- CD
O CJ CV) O O
in
o
rn
en
o
en
OJ
oo
on
CO
en
en
CD
on
r-
on
o
ro
-^ -—i
Samples (Station Means), May Cruise
Figure 25. Cluster Analysis of Biological Organisms Mean Abundances for May Cruise/ Matrix
Equals 20 Samples by 17 Taxa
-------
ELLIOTT BAY
0 100 200 300 400 500
Figure 26. Samples(Station and Replicate)Locations for Biological Sampling May Cruise
(as grouped by cluster analysis) ] 70
-------
The cluster analysis results suggest that taxa abundances for samples in
and immediately around the original sampling grid (group 1) appear to be more
to each other than to samples more distant from the grid (groups 2 and 3).
This analysis suggests that the disposal site contains a unique assemblage of
macrofauna. This hypothesis is tested explicitly (below). Two obvious excep-
tions to this generalization are stations 139 and 141, which were clustered in
group 1.
Wilcoxon Two-Sample Test
The nonparametric Wilcoxon two-sample test was conducted to determine
whether or not particular taxa, suggested from mapping and cluster analysis,
had statistically significant differences in abundances within and around
versus more distant from the disposal area. A nonparametric test was used
because it requires no assumptions of normally distributed populations. The
Wilcoxon two-sample test was run using a subroutine of the Statistical Analy-
sis System Institute, Inc., 1979, data base management system.
The test was run for seventeen taxa using two different station group-
ings. The first run used a station grouping which combined groups 2 and 3
from the cluster analysis and compared it to group 1. The second run used an
identical grouping except stations 139 and 141 were excluded from group 1 and
put into the combined groups 2 and 3 (see Figure 26). This approach compared
all stations within and immediately around the disposal site to all distant
stations.
The results of the analyses for station groupings are summarized in Table
4. Results were nearly identical for both test groupings. The abundances of
nine of the seventeen taxa were different between groups (statistically sig-
nificant at the 1 percent level). All of these taxa had greater abundances
within the grid and in its immediate proximity.
Relationships of Biological Results to Physical/Chemical Results
As previously indicated, the scope of the discussion was to describe
results of the mapping, cluster analysis and Wilcoxon two-sample tests.
Spatial autocorrelation is presently being conducted with preliminary results
supporting the trends shown by the Wilcoxon two-sample tests. The analyses
planned for the immediate future will attempt to relate the biological results
to the physical/chemical results. These analyses include multiple regression
analysis and Kendall's coefficient of rank correlation. Those independent
variables considered relevant to the multiple regression analysis include
depth, distance from the disposal grid center, PCB concentrations in the
sediment and interstitial water, mean sediment size, and percent organic
carbon in the sediment.
The physical and chemical data analyses have shown that the sediments at
stations in and near the disposal grid consist of dredge material containing
unsorted sediments and elevated PCB concentrations. The biological analyses
have also demonstrated that taxa abundances are different in the same area as
compared to more distant stations. This similarity in results may indicate a
long-term physical and/or chemical impact on the biological community. Possi-
ble relationships will be investigated as a part of this research project.
171
-------
TABLE 4. RESULTS OF WILCOXON TWO-SAMPLE TESTS FOR SELECT TAXA FROM GROUPS OF STATIONS1
ro
Group 1 Compared to
Groups 2 and 3 Combined2
Difference Does Exist
between Groups3
Axinopsida sericata
Capitellidae spp.
Euclymeninae spp.
Paraonella spim'fera
Macoma carlottensis
Cossuridae sp.
Chaetozone setosa
Nephtys ferruginea
Amphicteis scaphobranchiata
Probability
0.0001
0.0001
0.0001
0.0005
0.0001
0.0000
0.0001
0.0073
0.0008
Taxa Abundance
Lower or Higher
on Original
Sampling Grid
Higher
Higher
Higher
Higher
Higher
Higher
Higher
Higher
Higher
No Difference Exists
between Groups
Nuculana minuta
Prinospio cirrifera
Glycera capitata
Ostracoda spp.
Laonice cirrata
Nucula tenuis
Aricidae cf. lopezi4
Lumbrineris luti
Probability
0.2143
0.2488
0.0444
0.9234
0.0919
0.1373
0.0237
0.0101
1 Taxa are the same as those used for cluster analysis of May cruise biological data.
2 See Figure 26 for better understanding. Group 1 includes Stations 102, 103, 104, 105, 106, 108, 109,
111, 112, and 131. Group 2 includes Stations 132, 133, 134, 135, 136, 137, 138, 139, 140, and 141.
3 Statistically significant at the <1% level, when each test (taxa) considered separately.
4 When Wilcoxon run on this taxon with Stations 139 and 141 included in Group 1, the difference was
significant at the 1% level.
-------
Summary of Biological Results
The following points may be summarized from the biological analyses:
1. Mapping of particular taxa suggests that they may have higher abun-
dances in close proximity to and within the original sampling grid
(i.e., the dredge material disposal site).
2. Cluster analysis using the abundances for the individual station
samples and for mean station abundances both suggest that stations
in close proximity to the grid are more similar to each other than
to more distant stations.
3. Nonparametric Wilcoxon two-sample tests revealed significant differ-
ences in abundances for nine taxa that were grouped as stations
within the grid site versus more distant stations. All but one of
the taxa tested exhibited greater abundances at the disposal site.
4. Mapping of physical and chemical parameters showed a similar central
tendency and therefore may be interrelated.
REFERENCES
Boesch, D. F. "Application of Numerical Classification in Ecological Investi-
gations of Water Pollution." Report No. EPA-600/3-77-033, Corvallis
Environmental Research Laboratory, U.S. EPA, Corvallis, Oregon (1977).
Clayton, J. R., S. P. Pavlou, and N. F. Breither. "Polychlorinated Biphenyls
in Coastal Marine Zooplankton: Bioaccumulation by Equilibrium Partition-
ing." Environ. Sci. Technol. 11:676 (1977).
Harmon, R. A. and J. C. Serwold. "Recolonization of Benthic Macrofauna over a
Deepwater Disposal Site." Technical Report D-772-24, Appendix F, Aquatic
Disposal Field Investigations, Duwamish Waterway Disposal Site, Puget
Sound, Washington (1978).
Horn, W. "Distribution of Polychlorinated Biphenyls in Northern Puget Sound
Sediment." Department of Oceanography, University of Washington (1979).
McClellan, P. M. "An Area and Volume Study of Puget Sound, Washington."
Technical Report No. 21, Department of Oceaography, University of
Washington, Seattle, Washington (1954).
Pavlou, S. P., and R. N. Dexter. "Distribution of Polychlorinated Biphenyls
(PCB) in Estuarine Ecosystems. Testing the Concept of Equilibrium Parti-
tioning in the Marine Environment. Environ. Sci. Technol. 13:65 (1979).
U.S. Army Engineers. "Aquatic Disposal Field Investigations, Duwamish Water-
way Disposal Site, Puget Sound, Washington." Technical Report D-77-24
and Appendixes A-G. Environmental Laboratory, U.S. Army Engineers Water-
way Experiment Station, Vicksburg, Mississippi (1978).
173
-------
U.S. Environmental Protection Agency. "Puget Sound 305-A Report." Report No.
EPA-910/7-74-001. Surveillance and Analytical Division, U.S. EPA Region
X, Seattle, Washington (1974).
Wishart, D. CLUSTAN 1C User Manual Computer Centre, University College
London, London, England (1975).
174
-------
CONTAMINANT MOBILITY IN DIKED CONTAINMENT AREAS
R. E. Hoeppel
USAE Waterways Experiment Station
Environmental Laboratory
P. 0. Box 631
Vicksburg, MS 39180
ABSTRACT
Nine dredged material land containment areas,
located at upland, lowland, and island sites, were
monitored during hydraulic dredging operations in
fresh and brackish-water riverine, lake, and estuarine
environments. Influent-effluent sampling at the diked
disposal areas showed that, with proper retention of
suspended solids, most chemical constituents could be
removed to near background water levels. Most heavy
metals, oil and grease, chlorinated pesticides, and
PCBs were almost totally associated with solids in
both the influent and effluent samples. The para-
meters which appear to have the greatest potential
impact as a result of land disposal of dredged
material are ammonia, soluble manganese, total mer-
cury, and dissolved oxygen; occasionally soluble iron,
zinc, and copper may exceed criteria or background
levels. However, none of these should present serious
problems after dilution of the effluent discharge in
the receiving waters. Actively growing vegetation in
disposal areas appeared to be efficient in removing
ammonium nitrogen to low levels and also for filtering
out suspended solids. Dissolved oxygen in effluents
ranged from 0.6 to 12.5 ppm. Geochemical phase parti-
tioning of influent and effluent solids indicated that
carbonate solids of several heavy metals tended to
form during dredged slurry containment, promoted by
high alkalinity and pH in site waters. Metal adsorp-
tion onto suspended particles (exchangeable phase)
also increased slightly, along with a significant in-
crease in cation exchange capacity of effluent solids.
175
-------
INTRODUCTION
Recent legislation has given the Corps of Engineers greater regulatory
jurisdiction over lands adjacent to navigable waterways, including wetlands
and drainage systems from upland areas. Since upland areas along navigable
waterways are becoming scarce, there is also increasing economic pressure to
create new upland areas by disposing dredged materials on wetlands and marsh-
lands. Additionally, there is increasing emphasis on the land containment of
highly contaminated or toxic dredged material, instigated by growing concern
about the pollution potential of open-water or near-shore disposal operations.
Irrespective of any potential environmental impact created by the disposal of
dredged material in aquatic systems, one must keep in mind that land disposal
produces effluent and leachate discharges, which can irreversibly impact
sensitive wetland or upland habitats.
There have been only limited studies concerning the pollution potential
and physicochemical changes which are induced by the disposal of dredged
material in land containment areas. Some research has suggested that the
mobility or availability of many harmful chemical constituents in dredged
material can be accentuated by changing environmental conditions (19,20). The
placement of reduced subaqueous sediments on aerobic upland soils certainly
should not create stable environmental conditions. However, other studies
(1,2,13,17) have failed to demonstrate significant releases of contaminants in
disposal area effluent discharges, with the noted exceptions of ammonia
(2,7,19,20) and orthophosphate (2,17,19). Due to the paucity of information
available and conflicting findings, a comprehensive field study concerning the
impact of land disposal was warranted.*
SITE SELECTION
Nine different confined land disposal areas were monitored in different
geographic settings, including three freshwater and six brackish water dredg-
ing locations. Descriptions of each site are given in Table 1. These sites
were chosen on the basis of dredge site sediment and water variability, in-
cluding suspected high concentrations of contaminants such as oil and grease,
chlorinated pesticides, PCBs, nutrients, and heavy metals. Investigated
dredged material characteristics that could greatly influence the mobility of
contaminants include the sediment texture, oxidation-reduction status (Eh),
pH, sulfide and organic matter contents, water salinity and alkalinity, and
solids to water ratio of the dredged slurries. Disposal area characteristics
were also considered, including the geographic location, effective size,
*This paper summarizes data and findings presented in Technical Report D-78-24
(June 1978), U.S. Army Engineer Waterways Experiment Station, Environmental
Laboratory, Vicksburg, Mississippi 39180.
176
-------
TABLE 1. DESCRIPTION OF THE DREDGING AND CONFINED LAND DISPOSAL AREAS AND OPERATIONS
Description of Treatment
Description of Disposal Area
Site
No.
1
2
3
4
5
6
7
8
9
Location of Dredging Site
Sayreville, N. J.
South channel of Raritan
River, km 8 (brackish
water)
Houston, Tex.
Houston Ship Channel at
sta 1040+00 and in ship
turning basin at
sta 1080+ (brackish
water)
Grand Haven, Mich.
Grand River, main chan-
nel at sta 120+00
(freshwater)
Wilmington, N. C.
Anchorage Basin, Cape
Fear River (fresh to
brackish water)
Richmond, Va.
James River, main chan-
nel and dock area at
Deepwater Terminal
(freshwater)
Lake Charles , La .
Calcasieu River, main
channel near northwest
end of Lake Calcasieu
(brackish water)
Seattle, Wash.
Duwamish Waterway, Slip
No. 1 (brackish to
ma r ine )
Vicksburg, Miss.
Brown Lake, upper end of
9.5 ha lake (freshwater)
Southport, N. C.
Elizabeth River, in open
channel at confluence
with the Cape Fear estu-
ary and near the Coast
Guard Boat Harbor
(brackish to marine)
Location of
Disposal Area
National Lead Industries
Disposal Area No. 4,
adjacent to river
East half of Clinton
disposal area, about
1.5 km inland from
channel
Verplank's Coal & Dock
Ferrysburg, Mich.,
Eagle Island disposal
area, between Cape
Waterways
Disposal area on east
bank of James River
Disposal area No. 22,
16 river km south of
Lake Charles, on
dredged material
islands between the
ship channel and lake
Old wastewater treatment
plant sludge lagoon
site, 60 m from
waterway
Adjacent to upper end of
lake
East end of Oak Island,
with dikes adjacent to
Intracoastal Waterway
Predominant
Dredged Sediment
Dark grey silt
Fine reddish sand
and silt, often
heavily impreg-
the red oil
Fine sand with
Dark grey silt
and clay
Coarse sand and
gravel, some
light brown to
dark grey silt
Dark grey to
reddish-brown
mixed silt,
clay, and fine
sand; some oily
sediments
Black silt-clay
Light grey silt
with light
brown crust
Black silt-clay
(both sampling
trips)
Effluent
Discharge Site
Raritan River (sur-
face brackish
water)
Hunting Sayou-Houston
Ship Channel, 3 km
east of dredging
to brackish water)
Grand River (surface
Brunswick Waterway
(surface fresh to
brackish)
James River (surface
freshwater)
Calcasieu River (sur-
face fresh to
brackish)
Duwamish Waterway
(surface brackish
water)
Durden Creek -Brown
freshwater)
Atlantic Intracoastal
Waterway (surface
brackish water)
Size of
Size of Treatment
Diked Area Area
acres (ha) acres (ha)
44 40
(17.8) (16)
280 225
(113) (91)
6 6
(2.4) (2.4)
525 400
(212) (162)
70 35
(28) (14)
185 150
(75) (61)
1.9 1.9
(0.77) (0.77)
5 5
(2.0) (2.0)
48 45
(19.4) (18)
Configuration
Roughly circular; divided
into three equal rectangu-
lar compartments; sluice
box discharge; vegetated
Rectangular; large sluice
box discharge
Roughly rectangular; sluice
box discharge
Discharge by one sluice box
and two D-shaped weirs;
circular; heavily
vegetated
Long and narrow; divided
into three equal square
discharge
Roughly rectangular; pipe
discharge,* and discharge
over large rectangular
weir**
Rectangular; divided into
two equal rectangular com-
partments, each 46 by 85
by 4.7 m, effluent pumped
from second compartment
Rectangular; divided into
two equal compartments;
sluice box discharge
Elongated; D-shaped weir
discharge; heavily
vegetated
Effective
Length of Overland
Treatment Flow
Area Distance
yd (m) yd (ro)
1400 * 700
(1280) (640)
1300 «200
(1190) (185)
250
2000 «=1800
(1830) (1650)
1100 *700
(1010) (640)
300** =»300
(275) (275)
1300**
(1190)
200
(185)
440
(400)
1500 *=700t
(1370) (640)
(370)
Size of
Ponded Area
acres (ha) Site Veaetation
**35 70 percent cover of
(14) half of site by com-
mon reed grass
(Phragmites communis)
=200 Sparse
(81)
**6 None
**75 Approximately 80 per-
(30) cent cover by dead or
dormant grasses and
brush; Phragmites
communis predominates
*»20 Approximately 20 per-
(8) cent low density
cover by forest and
dormant undergrowth
=125 Sparse; less than
(51) 10 percent cover by
large bushes and dead
grasses
1 . 9 None
(0,77)
5 None
(2.0)
«5t 6 ha of thick stand of
(2) trees and bushes in
(8) of tall grass; 4 ha
vegetation
* Day 1.
** Days 2 and 3.
t Collection trip 1 (6-7 May).
tt Collection trip 2 (17-20 May).
-------
potential slurry residence time, degree of ponding, extent of vegetation
cover, and past history of each site.
TEST PROGRAM
The relationship between slurry residence time and effluent quality was
evaluated by considering all of the sites but in particular the comparisons
between cross-dike and final effluent samples collected concurrently at the
Sayreville, New Jersey and Seattle, Washington disposal areas. The effect of
increased residence time on ammonium and phosphate release, in conjunction
with pH changes, was evaluated by continuous monitoring of effluents from the
Vicksburg, Mississippi disposal area during and after completion of the dis-
posal operations. The heavily vegetated containment area at Southport, North
Carolina was monitored primarily to assess what influence actively growing
vegetation might have on effluent quality; the influence of dormant winter
vegetation in disposal areas on contaminant release was evaluated by monitor-
ing the heavily vegetated Wilmington, North Carolina site. Salinity effects
were evaluated by comparing trends at all of the disposal areas because of the
wide range of salinities encountered. However, other physicochemical vari-
ables, such as those prevalent in freshwater versus marine environments (e.g.,
variance in sulfide levels) were always considered in context with the salin-
ity comparisons.
The mobility and toxicity of trace metal contaminants are regulated by
the chemical compounds with which they become associated. Although the number
of discrete compounds is immense, the association of a contaminant with a
general group of chemical complexes can be determined by subjecting the sedi-
ment to different specific chemical extractions or treatments. These will be
referred to as "geochemical phase partitioning". The association of metals
with "geochemical phases" such as soluble, exchangeable, acetic acid extract-
able (carbonate), and manganese and amorphous iron oxide (easily reducible)
sediment components was determined for influent and effluent solid phase
samples from Wilmington, North Carolina; Richmond, Virginia; Lake Charles,
Louisiana; and Seattle, Washington. The hydrogen peroxide-oxidizable
(organic-sulfide) component was also determined in the Seattle samples. The
metals, which are mainly bound in very stable crystalline matrices, were
included in the analysis of final total acid digests (residual phase) of
samples from the four sites.
FIELD AND LABORATORY METHODS
More than 50 different physical and chemical parameters were determined
in total samples, 0.45-um filtrates, and greater than 0.45-um suspended solids
of disposal area influents and effluents, and surface background water
samples. Influents were generally collected beneath the end of the dredge
discharge pipe in the turbulent mixing pool; effluents were obtained either at
the outfall pipe beneath the sluice or from the back side of a weir structure;
surface background water samples were collected from the water body receiving
the effluent discharge. Compositing of at least three subsamples was per-
formed in most cases to obtain more representative samples. Three to four
daily samples were collected from the monitoring stations at each site either
178
-------
consecutively or during separate trips; six samples were obtained at the
vegetated Southport disposal area but these were equally divided into an
initial and final set to evaluate what effects different densities of vege-
tation in land containment areas might have on effluent water quality.
Collapsible 4£ polyethylene containers were employed for collection of
samples used for heavy metal, nutrient, and oil and grease analyses, after
being prewashed with 0.1 M hydrochloric acid and rinsed twice with deionized-
distilled water. Usually, four of these containers were used; 50 ml of chlor-
oform was added to one container as a preservative for nutrients. Samples for
chlorinated hydrocarbon analyses (pesticides, PCBs) were collected in 2$. glass
wide-mouth jars. The containers were prewashed with hexane, rinsed twice with
deionized-distil led water, and combusted at 350°C for 30 minutes in a muffle
furnace. All containers were completely filled with sample to exclude air,
and the polyethylene containers were collapsed as aliquots were removed.
All samples were packed in ice immediately after collection and shipped
by air freight to an analytical laboratory. Samples from sites 1-3 (see Table
1) were sent to the Environmental Engineering Laboratory at the University of
Southern California in Los Angeles, while the samples from sites 4-6, 8, and 9
were shipped to the Environmental Laboratory at WES. Sample collection and
preparation for site 7 were performed by the personnel of the Environmental
Protection Agency (EPA) Region X Laboratory in Seattle, Washington. Samples
were stored in environmental chambers maintained at 4°C.
Salinity, conductivity, dissolved oxygen (DO), slurry pH, and water
temperature were measured in the field concurrently with influent, effluent
and background water subsampling. Disposal area sediment pH and oxidation-
reduction potential (Eh) were obtained in fresh sediments in the disposal
areas; depending on site conditions, 6 to 40 measurements were made at each
site.
Upon arrival at the analytical laboratory, the field-collected samples
were processed as soon as possible to separate the solid from the liquid phase
and to prepare each phase for different chemical analysis. Sample phase
separation (centrifugation and filtration), total and filterable sulfides, and
geochemical phase partitioning extractions were performed in a glove bag that
was purged continuously with nitrogen gas to preserve the anaerobic integrity
of the samples. The sequential preparation scheme for influent samples is
shown in Figure 1, while the slightly different scheme used for effluent and
background water samples is shown in Figure 2. The modified preparatory
procedures were necessary because of the often extreme variations in solids
content between respective influent, effluent, and background water samples.
Generally, if an influent sample was low in suspended solids, the total sample
was subjected to total acid digestions for metals, phosphorus, and total
Kjeldahl nitrogen (TKN).
The parameters analyzed in the less than 0.45-mm (soluble phase) frac-
tions of samples are listed in Figures 1 and 2. The soluble phase separations
for chlorinated pesticide, PCB, and oil and grease determinations involved
only highspeed centrifugation in stainless steel centrifuge tubes to approxi-
mate 0.45-um filtration. The remaining parameters, listed in Figures 1 and 2
179
-------
1
SHAKE ON M
SHAKER (30
i
ECHANICAL
MIN)
CE
TOTAL
SAMPLE
(4°C)
TOTAL
SAMPLE
SLURRY
NTRIFUGE
POUR INTO POLYCARBONATE
CENTRIFUGE TUBES
(UNDER N2)
CENTRIFUGE AT 11,000 RPM
FOR 40 MIN (TO APPROXIMATE
0.45-jj.m FILTRATION) AT
AMBIENT FIELD TEMPERATURE*
FILTER SUPERNATANT
THROUGH 0.45-Min
MEMBRANE FILTER
(UNDER N2)
GLASS TUBES
FOR 30 MIN.
CENTRIFUGATE
TOTAL ACID DIGEST FOR TOTAL -P,
Ca, Mg, K, Na, Fe, Mn, Zn, Cd, Cu,
Ni, Pb, Hg, Cr, V, Ti, As **
70°C TEMPERATURE ACID DIGEST
FOR MERCURY (SITES 3, 7)
CHLORINATED PESTICIDES, PCB'S
OIL AND GREASE (SITES 1, 2, 3)
TOTAL KJELDAHL NITROGEN **
(ORGANIC-N, AMMONIUM-N)
NONFILTERABLE SOLIDS
SETTLEABLE SOLIDS
OIL AND GREASE (SITES 8, 9)
• TOTAL ACID DIGEST FOR TOTAL -P,
Ca, Mg, K, Na, Fe, Mn, Zn, Cd, Cu,
Ni, Pb, Hg, (SITES 4, 5, 6, 7, 8, 9)
— CHLORINATED PESTICIDES, PCB's (SITE 7)
•— OIL AND GREASE (SITE 7)
-*• TOTAL ORGANIC CARBON
-»• TOTAL KJELDAHL NITROGEN
(ORGANIC-N, AMMONIUM -N)
-»• TOTAL SULFIDES
-*• CATION EXCHANGE CAPACITY AND
EXCHANGEABLE AMMONIUM -N
r*- PARTICLE SIZE DISTRIBUTION t
• TOTAL SOLIDS
• VOLATILE SOLIDS (SITE 7)
-» CHEMICAL OXYGEN DEMAND (SITE 7)
L*- ELEMENTAL PARTITIONING OF METALS
-JrFMTBiFiir&TFU~" CHLORINATED PESTICIDES, PCB'S
H»| CENTRIFUGATE^
FILTRATE
OIL AND GREASE (SITE 7)
SOLUBLE METALS (Ca, Mg, K, Na, Fe, Mn,
Zn, Cd, Cu, Ni, Pb, Hg, Cr, V, Ti, As)
•* SOLUBLE OIL AND GREASE
SOLUBLE TOTAL CARBON (SITE 3)
-* SOLUBLE ORGANIC CARBON
-*• SOLUBLE KJELDAHL NITROGEN
(ORGANIC-N, AMMONIUM-N)
-*• AMMONIUM-N
— NITRATE + NITRITE-N
-» SOLUBLE TOTAL-P
-*• ORTHOPHOSPHATE -P
TOTAL SULFIDE (SITES 2, 7)
•*• SULFATE (SITES 3, 7)
•*• CHLORIDE
L» ALKALINITY
* SITE 7: 12,500 RPM FOR 20 MINUTES AT 4*C; ALL CENTRIFUGATIONS
WERE MADE IN A SORVALL GSA ROTOR.
** TOTAL SAMPLE WAS DIGESTED ONLY WHEN THE SOLIDS WERE LOW.
t THE
-------
SHAKE ON M
SHAKER (30
ECHANICAL
MIN)
POUR INTO POLYCARBONATE
CENTRIFUGE TUBES
(UNDER N2>
TOTAL
CAUPI F
dMIHr LC.
(4°C)
TOTAL
SLURRY
1
CENTRIFUGE
AT 1900 RPM IN
GLASS TUBES
FOR 30 MIN.
i
CENTRIFUGATE
• TOTAL ACID DIGEST FOR TOTAL -P,
Ca, Mg, K, Na, Fe, Mn, Zn, Cd, Cu,
Ni, Pb, Hg, Cr, V, Ti, As
• LOW TEMPERATURE DIGESTION
FOR MERCURY (SITES 3,-7)
• CHLORINATED PESTICIDES, PCB'S
• OIL AND GREASE
• TOTAL ORGANIC CARBON
• TOTAL KJELDAHL NITROGEN
(ORGANIC -N, AMMONIUM -N>
• TOTAL SULFIDES
• NONFILTERABLE SOLIDS
• SETTLEABLE SOLIDS
•COULTER COUNTER PARTICLE
SIZE ANALYSIS
OIL AND GREASE
CENTRIFUGE AT 11,000 RPM
FOR 40 MIN (TO APPROXIMATE
0.45 fj.m FILTRATION) AT
AMBIENT FIELD TEMPERATURE*
^rFlUTBlFlirATF
- CENTRIFUGATE
FILTER SUPERNATANT
THROUGH 0.45 ^m
MEMBRANE FILTER
(UNDER N2)
»\ FILTRATE]
> PCB'S (SITE 7)
•CATION EXCHANGE CAPACITY AND
EXCHANGEABLE AMMONIUM -N
• PARTICLE SIZE DISTRIBUTION
• TOTAL SOLIDS
• ELEMENTAL PARTITIONING *
OF METALS
CHLORINATED PESTICIDES, PCB'S
OIL AND GREASE (SITE 7)
•SOLUBLE METALS (Ca, Mg, K, Na, Fe, Mn,
Zn, Cd, Cu, Ni, Pb, Hg, Cr, V, Ti, As)
•SOLUBLE OIL AND GREASE
•SOLUBLE TOTAL CARBON (SITE 3)
•SOLUBLE ORGANIC CARBON
•SOLUBLE KJELDAHL NITROGEN
(ORGANIC -N, AMMONIUM -N)
• AMMONIUM -N
• NITRATE + NITRITE-N
•SOLUBLE TOTAL -P
-ORTHO PHOSPHATE-P
• TOTAL SULFIDE (SITES 2, 7)
•SULFATE(SITES2,3, 7)
•CHLORIDE
•ALKALINITY
* SITE 7: 12,500 RPM FOR 20 MINUTES AT 4'C; ALL CENTRIFUGATIONS
WERE MADE IN A SORVALL GSA ROTOR.
Figure 2. Effluent and background water sample preparation.
181
-------
as filtrates, were determined in liquid which was both centrifuged (in poly-
carbonate centrifuge tubes) and then filtered through 0.45-um nitrocellulose
membrane filters. The filters were previously washed twice with 1 M hydro-
chloric acid and deionized-distil led water to ensure the removal of acid-
leachable chemical constituents present or in the filters. Meticulous clean-
ing of all labware was routinely practiced, following precautions described
elsewhere (6,7). All centrifugation and filtration steps were performed in a
nitrogen gas atmosphere.
Following the separation of the solid and soluble phases, different
aliquots were preserved according to standard procedures (10,11). The solid
phase material was placed in small plastic specimen cups under a nitrogen gas
atmosphere and tightly sealed. Soluble phase samples were placed in tightly
capped polyethylene bottles. All of the prepared samples were stored at 4°C
until further processing and analysis. Detailed descriptions of the analy-
tical methods and instrumentation used in the study are cited elsewhere
(5,12,15). Most parameters were measured according to Standard Methods (3,4)
or procedures recommended by the EPA (11).
Quality control within and between laboratories consisted of multiple
digestions and analyses, standard addition, and inter!aboratory correlation of
select samples. About half of the samples were subjected to these control
measures.
Geochemical Phase Partitioning Analysis
The geochemical phase partitioning analyses were performed for influent
and effluent slurry solids from sites 4-7, according to the methods outlined
by Chen et al. (7). They include sequential extractions with chemicals which
selectively remove metal contaminants associated with certain major geochemi-
cal complexes or phases. A detailed description of the procedures is cited
elsewhere (12) but a generalized pairing of the extracted phases with the
extractants, in sequential order, is as follows:
a. Exchangeable phase: 1.0 M ammonium acetate.
b. Acetic acid extractable (carbonate) phase: 1.0 M acetic acid.
c. Easily reducible (manganese-amorphous iron oxide) phase: 0.1 M
hydroxylamine hydrochloride in 0.01 M in nitric acid.
d. Organic and sulfide phase: 30% acidified hydrogen peroxide.
e. Remaining (residual) metals): total hot acid digest.
Extractions were conducted by shaking the extractant with wet solids for 30
minutes on a mechanical shaker, followed by centrifugation and 0.45-um mem-
brane filtration under nitrogen gas.
182
-------
RESULTS
Site Variability
The monitoring of nine different land containment areas during dredged
material disposal operations was intended to aid in an assessment of the
environmental impact of this mode of disposal. The general site descriptions
are given in Table 1. The values for many physicochemical parameters measured
in waters and sediments at each site are listed in Table 2. Many of these
parameters govern the mobility of contaminants in sediment-water systems as
well as being contaminants in their own right. Data on each measured para-
meter, including the total number of samples, ranges, means, standard devia-
tions, and analysis of variance F values for surface background water, influ-
ent, and effluent, are presented in Table 3. The F values show whether varia-
tions between data sets are significantly different from variations within
each tripartite set. The nature of the variances can be roughly assessed by
consulting the means, ranges, and standard deviations given for each sample
source. However, wherever variations between two means within a data set
appeared to be significant, a Student's t-test was used to determine their
significance.
Generally, 77 to 98% by weight of the hydraulically dredged disposal area
influents consisted of sediment pore and bottom water from the dredged channel
(Table 2), and at least 80% of this total water should be bottom water. Site
salinities ranged from fresh to over 20 /oo, particle size distributions from
5 to 65% sand and 11 to 65% clay-sized particles, and cation exchange capacity
from 10 to 80 meq/lOOg of dry weight dredged sediment. Although DO was
usually near zero when measured directly at the influent discharge pipe, it
averaged 3.8 ppm when monitored in the mixing pool beneath the pipe discharge
(Table 3).
In order to determine dredged material contaminant mobility and fate in
land disposal areas, contaminant levels in influent and effluent samples were
compared. Comparisons were also made between effluents and background water
to roughly assess the potential impact of the effluents on water quality near
the discharge site. The information in Table 3 presents a general idea of the
changes in contaminant levels which were encountered during influent, efflu-
ent, and background water monitoring.
Influent-Effluent Comparisons
Comparisons between total influent and effluent digests showed prominent
net decreases for all nutrients, oil and grease, PCBs, DDT, the DDT transfor-
mation product - ODD, and most major elements and trace metals during land
containment as shown in Figures 3 and 4. However, site variability was great
for most contaminant levels in effluents, as shown in Figure 5. Despite the
often very great variance in the solids content of the influent samples, most
total contaminants showed highly significant differences between influent,
effluent, and background water concentrations (Table 3). The statistical
non-significance shown for solid phase sulfide, DDT, ODD, and possibly total
mercury is due mainly to influent solids variability, which in reality has a
minimal impact on the effluents because of attenuation of the rapidly fluctu-
183
-------
TABLE 2. AVERAGE VALUES FOR PHYSICOCHEMICAL PARAMETERS OF INFLUENTS, EFFLUENTS,
AND BACKGROUND WATER FROM THE SAMPLED CONFINED LAND DISPOSAL AREAS
Location
Sayreville, N. J.
Influent
Effluent
Background
Houston, Tex.
Influent
Effluent
Background
Grand Haven, Mich.
Influent
Effluent
Background
Wilmington, N. C.
Influent
Effluent
Background
. Richmond , Va .
QQ Influent
_pa Effluent
Background
Lake Charles, La.
Influent
Effluent
Background
Seattle, Wash.
Influent
Effluent, Pond 1
Effluent, Pond 2
Background
Vicksburg, Miss.
Influent
Effluent
Background
Southport, N. C. (1)
Influent
Effluent
Background
Southport, N. C. (2)
Influent
Effluent
Background
Water
Temperature
°C
17.5
—
21.0
19.5
• —
1.5
0.75
3.5
8.5
9.9
—
10.6
9.8
—
14.0
17.3
—
—
•7.1
11.2
7.8
18.5
26.1
—
21.2
24.0
—
22.4
30.4
—
Salinity
o/oo
12.0
14.0
9.0
7.95
8.9
1.7
0.7
0.6
—
2.8
2.6
—
0.25
1.25
0
15.9
18.6
4.2
—
18.5
23.0
8.0
0.15
0.1
—
20.0
21.3
21.0
15.2
20.9
—
Conductivity
mmho/cm
15.3
17.6
10.5
—
—
3.25
0.52
0.41
0.39
3.2
4.05
—
0.29
1.61
0.18
20.8
25.3
6.8
—
30.1
36.2
14.1
0.65
0.70
—
30.0
32.0
31.5
23.7
38.05
—
Dissolved
02, mg/£
6.3
—
—
7.85
—
—
12.5
11.5
2.3
2.2
—
7.75
8.6
—
4.9
3.7
—
—
5.4
6.5
8.3
3.0
2.4
—
2.75
3.3
—
2.8
6.1
—
Mechanical Particle
Size, percent Coulter
Clay Silt
pH (<2 um) (2-50 um)
- — — —
—
—
7.1
7.7
6.9
— — —
7.5
7.6
6.6 60 31
7.4 61 35
5.5
6.7 11 24
7.2
6.7
7.15 64.5 29.5
7.25 58 30
6.3
—
5.8
7.7
7.3
7.0 22.5 72.5
7.7
—
7.9 49 26
7.65
—
7.55 41.5 50
7.9
—
Sand Particle
(>50 um) >50 percent
— —
—
—
—
— —
—
—
—
—
9 1.05
4 2.0
—
65 1.15
3.75
7.6
6 0.91
12 3.1
5.4
—
—
—
—
5 0.89
8.9
5.5
25
—
—
8.5
—
—
Nonfilterable
Counter Solids
Size, um percent
>80 percent
—
—
—
—
—
—
—
—
—
0.6
1.2
—
0.63
1.9
3.8
0.56
1.65
2.82
—
—
—
—
0.56
3.4
2.85
—
—
—
—
—
—
Weight
—
—
—
—
—
—
—
—
—
7.19
0.901
0.00448
1.66
0.0464
0.0010
6.26
1.218
0.0036
—
0.02
<0.01
—
23.30
0.248
0.00204
18.50
0.0152
0.0094
17.10
0.1715
0.02697
Cation
Settleable Exchange
Solids Capacity
ml/Jl meq/100 g
— —
—
—
—
—
—
—
—
— —
467 80.6
417 120.6
<0.1
85 26.2
0.7 65.9
<0.1
367 56.8
120 66.2
<0.1
350 70.0
0.6
0.25 88.0
—
950 10.3
13.5
<0.1
500 55.0
<0.1
<0. 1
693 57.9
1.9
<0.1
Alkalinity
; va/i.
680
840
500
524
517
92
240
218
140
345.1
480.3
17.3
82.3
60.5
40.8
320.8
199.2
29.9
348
183
199
—
285.5
237.3
290.0
512
178
101
1024
631
112
-------
Table 3
Statistical Character of Background Water. Influent, and Effluent
Samples From the Confined Disposal Areas
Number of Samples
Parameter
Water Temp, C
Salinity, 0/00
Conductivity,
mmhos/cm
Dissolved 0., mg/S.
Slurry pH
Particle size,
Silt, %
Sand, %
Coulter Counter
>50%, pm
>80%, urn
Total solids, % wt.
Back-
ground
Water
1
4
5
I
5
0
0
0
3
3
3
Influent
24
23
21
17
16
17
17
16
9
9
12
Effluent
26
23
22
23
16
2
2
2
10
10
17
Background
Water
3.5-3.5
0.0-21.0
0.39-31.5
11.5-11.5
5.5-7.6
5.4-7.6
2.82-3.8
0.009-0.043
Range
Influent
1.0-23.7
0.0-21.5
0. 0-32.1
0.25-9.3
6.25-8.3
4 -6R
17 -78
0.0-79.0
0.77-1.2
0.5-0.65
1.94-32.0
Effluent
0.0-34.0
0.0-22.0
0.0-39.2
0.6-12.5
6.9-8.1
58 -61
30 -35
4.0-12.0
0.2-10.5
0.56-3.8
0.005-2.85
Back-
ground
Water
3.5
6.7
8.4
11.5
6.6
6.2
3.15
0.022
Mean
Influent
14.9
8.2
11.3
3.8
7.16
43.2
38.1
19.9
0.97
0.58
8.64
Standard Deviation
Effluent
16.8
9.6
14.0
5.3
7.51
59.5'
32.5
8.0
4.75
2.22
0.345.
Back-
ground
Water
0.0
10.50
14.25
0.0
0.775
1.242
0.557
0.018
Influent
7.299
7.800
12.39
2.885
0.516
20.15
16.68
22.50
0.131
0.043
8.416
Effluent
10.16
9.202
15.62
3.402
0.316
2.121
3.536
5.657
3.545
1.171
0.785
Probability
F Value
Exceeded
0.308
0.862
0.788
0.048*
0.0025**
0.280
0.649
0.479
0.0035**
0.0001**
0.0006**
(Continued)
* Influent, effluent, and background water values are significantly different at p £ 0,05.
** Influent, effluent, and background water values are significantly different at p <_0.01.
(Sheet. 1 of 8)
-------
Table 3 (Continued)
00
Number of Samples
Parameter
Konfilterable
solids, % wt.
Settleable solids
mi/fc
Total C, <0.45 pm
mg/1
Organic C,
Total, mg/£
Solid, mg/kg
<0.45 pm, mg/H
Oil & Grease,
Total, rng/l
Solid, mg/kg
<0.45 pm, mg/fc
Total Chlorinated
Pesticides
op'DDE, mg/i
pp'DDE, mg/J.
Back-
ground
Water
8
7
1
13
1
10
11
0
2
5
5
Influent
17
22
3
16
20
29
12
5
11
14
14
Effluent
24
24
3
13
7
35
18
0
9
13
13
Background
Water
0.001-0.027
0.1-0.1
58 -58
2 -14
10 -10
4 -43
0.1-47.2
1.1-1.1
<0. 01-0. 28
<0. 01-1. 57
Range
Influent
0.58-32.0
45 -999
30 -85
35.0-11500
974 -53400
3 -185
25.0-1497
2928 -8492
1.8-48.0
<0. 01-0. 53
<0. 01-1. 72
Effluent
0.004-3.27
0.1-950
60 -70
4 -1060
11 -53200
3 - 120
2.4-196
0.32-13.0
<0. 01-0. 50
<0. 01-2. 87
Back-
ground
Water
0.007
0.1
58
6.5
10
15
6.5
1.1
0.08
0.37
Mean
Influent
11.70
452
57
3880
25100
27
458
6060.
11.2
0.13
0.47
Standard Deviation
Effluent
0.329
69
65
151
20800
19
27.5
3.1
0.07,
0.37
Back-
ground
Water
0.009.
0.0
0.0
4.521
0.0
12.89
14.32
0.0
0.117
0.679
Influent
10.61
288.8
27.54
3405
16026
43.32
433.0
2121
16.88
0.139
0.527
Effluent
0.760
205.6
5.000
303.1
23677
22.31
50.99
3.997
0.136
0.773
Probability
F Value
Exceeded
0.0000**
0.0000**
0.872
0.0000**
0.385
0.456
0.0000**
0.300
0.555
0.915
* Influent, effluent and background water values are significantly different at p £0.05.
** Influent, effluent and background water values are significantly different at p < 0.01.
(Sheet 2 of 8)
-------
Table 3 (Continued)
Number of Samples
Parameter
op'DDD, mg/j>
pp'DDD, mg/jj,
op 'DDT, mg/j>
pp'DDT, mg/j,
Total PCB, mg/J.
Organic N,
Total, mg/Jl
Solid, mg/kg
<0.45 ym, mg/Jl
NH.-N, Total, mg/Jl
Exch, mg/kg
<0.45 urn, mg/Jl
N03-N02-N, mg/Jl
Total P,
Total, mg/Jl
Solid, mg/kg
Back-
ground
Hater
1
0
1
1
1
17
0
10
16
0
10
16
17
0
Influent
14
14
14
14'
20
28
21
28
7
18
29
26
28
21
Effluent
13
13
13
13
23
26
3
34
21
7
35
32
34
3
Background
Water
<0.01-<0.01
<0.01-<0.01
"O.Ol^O.O
<0.01-0.3
<0. 01-2. 35
0.1-1.35
0.01-1.54
0.01-0.82
0.01-1.98
0.07-0.86
Range
Influent
<0. 01-1. 28
<0. 01-1.04
<0.01-5.4
<0. 01-5. 94
<0.1-21
3.6-839
532 -3870
0.1-27.6
7.3-86.0
2.4-339
0.66-71.7
0.01-0.82
12.8-496
639 -4400
Effluent
<0.01-<0.01
<0.01-<0.01
<0. 01-0. 23
<0. 01-0. 96
<0.1-7.66
0.1-74.5
906 -3042
0.1-6.7
0.82-80.3
58.5-458
0.74-70.9
0.01-1.83
0.11-82.1
1400 -4000
Back-
ground
Water
<0.01
<0.01
<0.01
0.058
0.376
0.55
0.53
0.27
0.46
0.26
- -
Mean
Influent
0.19
0.21
1.1
0.68
5.81
168
1820
4.3
45.6
110
20.8
0.18
155
1850
Standard Deviation
Effluent
<0.01
<0.01
0.02
0.07
0.50
9.7
2220
1.6
19.6
196
13.6
0.35
11.7
3070
Back-
ground
Water
0.0
0.0
O.Q
0.090
0.556
0.397
0.459
0.270
0.523
0.236
_ _
Influent
0.368
0.368
1.993
1.627
5.451
205.8
1087
5.871
28.46
94.12
19.03
0.234
133.6
1179
Effluent
0.0
0.0
0.061
0.263
1.60.7
18.017
1150
1.627
22.93
167.8
15.73
0.396
21.85
1447
Probability
F Value
Exceeded
0.183
0.050*
0.152
0.416
0.0000**
0.0000**
0.562
0.0083**
0,0000**
0.115
0.0034**
0.066
0.0000**
0.117
(Continued)
* Influent, effluent and background water values are significantly different at p ^0.05.
** Influent, effluent and background water values are significantly different at p <^ 0.01.
(Sheet 3 of 8)
-------
Table 3 (Continued)
Number of Samples
Back-
ground
Parameter Water
<0.45 Mm, mg/i
Orthophosphate P,
<0.45 ym, mg/fc
Alkalinity, mg/fc
as CaC03
Chloride, mg/&
Total Sulfide,
Solids, rag/kg
Cation Exch. Cap,
__, tneq./lOOg
CO
CO Calcium,
Total, mg/J,
Solids, mg/kg
<0.45 ym, mg/i
Magnesium,
Total, mg/J.
Solids, rag/kg
<0.45 urn, mg/i
* Influent, effluent
** Influent, effluent
10
8
10
10
0
0
10
0
10
10
0
10
, and
, and
Influent
29
22
29
29
21
19
24
22
24
24
22
24
background
background
Range
Back-
Background ground
Effluent Water Influent Effluent Water
32 0.
28 0.
35 16
34
3
6
25 4.
7
25 4.
25 2.
8
25 1.
water values
water values
02-0.5
03-0.16
.27-290
-20600
8-390
1-390
5-1300
5-1300
0.03-9.47 0.01-1.53 0.18
0.04-5.89 0.01-1.04 0.08
51.38-1520 29.75-670 88.10
5.0-19200 5.0-16400 4150
17.8-3090 94.1-327
2.37-88.2 65.9-120.6 - -
45.7-11500 16.8-560 98.7
1150 -37900 1190-26100
8.0-416 13.0-532 95.4
26.5-1320 3.15-1200 279.0
933 -37800 4700-16300
2.6-1300 2.6-1200 265
(Continued)
Mean
Influent
0.86
0.79
412
8290
493
50.9
2450
16300
181.1
1270
11200
415
Standard Deviation
Back-
ground
Effluent Water
0.33 0.175
0.18 0.051
287 83.08
7810 7909
208
82.5
250 142.3
9930
204.8 141.6
464 514.4
10200
398 497.1
Influent
2.047
1.585
217.4
7326
679.5
25.16
3420
13722
140.7
1057
8239
432.8
Effluent
0.499
0.294
184.5
6365
116.6
21.55
163.6
10844
166.3
416.8
4853
447.9
Probability
F Value
Exceeded
0.221
0.074
0.0015**
0.261
0.484
0.011*
0.0013**
0.274
0.165
0.0003*
0.746
0.661
are significantly different at p £0.05.
are significantly different at p £0.01.
(Sheet 4 of 8)
-------
Table 3 (Continued)
Number of Samples
Parameter
Potassium,
Total, rng/J,
Solids, mg/kg
<0.45 pm, mg/Z,
Sodium,
Total, mg/fc
Solids, mg/kg
J§ <0.45 urn, mg/J.
Iron,
Total, mg/Jl
Solids, mg/kg
<0.45 vim, mg/S,
Manganese,
Total, mg/8.
Solids, mg/kg
<0.45 urn, mg/Z
* Influent, effluent
** Influent, effluent
Back-
ground
Water
10
0
1C
8
0
9
17
0
10
17
0
10
, and
, and
Influent
24
20
24
19
11
24
29
22
29
29
22
29
background
background
Effluent
25 2
8
25 1
23 6
5
25 6
34 0
8
35 0
35 0
8
35 0
water values
water values
Background
Water
.2-338
.2-380
.5-9800
.1-9700
.38-63.6
.001-1.43
.04-0.40
.002-0.184
Range
Influent Effluent
128 -6360 4.6-1145
3100 -43500 8330-18200
1.6-450 1.5-440
85.0-9900 6.5-11300
2394 -13100 240-43200
6.2-9500 6.0-9400
46.1-12600 1.14-1290
24300-81600 24100-48300
0.043-15.9 0.01-10.1
0.8-310 0.21-48.5
250-2110 683-2170
0.004-14.4 0.002-7.95
(Continued)
are significantly different at p £
are significantly different at p ^_
Back-
ground
Water
121
98.6
2470
2183
5.19
0.378
0.107
0.059
0.05.
0,01.
Mean
Influent
1770
13200
163
3900
9430
3620
3400
42300
3.52
63.1
682
2.35
Standard Deviation
Back-
ground
Effluent Water
390 148.3
142.00
166 151.6
3540 4026
23600
3450 3737
193 15.13
38300
0.814 0.457
7.9 0.095
1160
1.45 0.057
Influent
1644
8655
137.0
3422
3583
3806
3565.
13117
5.009
73.00
383.9
3.485
1
Effluent
362.3
3647
144.9
3963
18176
3798
343.0
7068
1.816
13.61
470.9
2.090
SVlppl- S r\f
Probability
F Value
Exceeded
0.0000**
0.762
0.418
0.772
0.021*
0.607
0.0000**
0.421
0.0037**
0.0000**
0.0081**
0.057*
R1
-------
Table 3 (Continued)
Number of Samples
Parameter
Zinc,
Total, mg/n
Solids, mg/kg
<0.45 pm, mg/i
Cadmium,
Total, mg/Jl
Solid, mg/kg
<0.45 ym, mg/fc
Copper,
Total, mg/fc
Solid, mg/kg
<0.45 iam, mg/fc
Nickel ,
Total, mg/4
Solid, mg/kg
<0.45 pm, mg/i
Back-
ground
Water
17
0
10
13
0
9
15
0
10
14
0
10
Influent
25
22
25
26
17
29
29
22
29
29
22
29
Background
Effluent Water
30 0.006-1.28
8
30 0.001-0.121
32 <0. 0002-0. 01
4
35 <0. 002-0. 012
35 0.003-0.16
8
35 0.001-0.028
30 <0.01-1.5
8
30 0.003-0.036
Range
Influent
0.6-206
55.8-1960
Back-
ground
Effluent Water
0.026-5.49 0.238
31.7-3660
0.001-0,496 0.002-0.228 0.028
0.002-7.17
0.048-45.3
0.0002-
0.015
0.1-18.2
6.0-165
0.001-
0.106
0.21-18.2
15.4-124
0.003-
0.047
0.001-0.37 0.003
0.045-4.87
0.001- 0.003
0.011
0.02-1.59 0.038
26.0-131
0.001-0.1 0.009
<0. 01-1. 70 0.120
25.3-74.6
0.002- 0.011
0.043
Mean
Influent
27.5
323
0.055
1.39
7.1
0.004
6.09
52.2
0.019
5.8
47.3
0.014
Standard Deviation
Back-
ground
Effluent Water
1.03 0.422
621
0.064 0.042
0.051 0.003
1.62
0.003 0.004
0.28 ' 0.042
46.3
0.021 0.010
0.30 0.397
47.1
0.012 0.013
Influent
40.28
435
0.10
2.036
10.44
0.004
5.327
48.43
0.026
4.555
26.06
0.013
Effluent
1.481
1232
0.069
0.102
2.216
0.003
0.414
35.00
0.022
0.414
15.18
0.013
Probability
F Value
Exceeded
0.0003**
0.325
0.472
0.0002**
0.319
0.824
0.0000**
0.753
0.323
0.0000**
0.982
0.820
(Continued)
** Influent, effluent, and background water values are significantly different at p
0.01.
(Sheet 6 of 8)
-------
Table 3 (Continued)
Number of Samples
Parameter
Lead,
Total, mg/Jl
Solid, mg/kg
•=0.45 vm, mg/Jl
Mercury,
Total, ng/Jl
Solid, mg/kg
<0.45 urn, mg/H
Chromium,
Total, mg/£
<0.45 Mm, mg/1
Titanium,
Total, mg/Jl
<0.45 urn, mg/d
Back-
ground
Water
9
0
10
14
0
8
8
1
1
1
Influent
28
21
24
18
18
19
3
3
4
4
Effluent
23
8
25
24
6
28
8
8
4
4
Background
Water
0.001-0.049
<0. 001-0. 005
<0.0002-
0.009
<0.0002-
0.004
0.009-
0.026
0.003-
0.003
0.01-0.01
0.0001-
0.0001
Range
Influent
0.24-86.5
5.7-327
<0.001-
0.012
0.001-
0.243
0.07-1.66
0.0002-
0.008
56.7-76.6
0.003-
0.005
2.1-4.35
0.025-
0.038
Effluent
0.001-7.57
1.0-142
<0.001-
0.007
<0.0002-
0.367
0.08-3.2
<0.0002-
0.006
0.024-0.58
0.004-
0.033t
0.255-0.50
0.020-
0.036
Back-
ground
Water
0.011
0.002
0.001
0.001
0.018
0.003
0.010
0.0001
Mean
Influent
16.2
81.5
0.002
0.044
0.46
0.001
63.8
0.004
3.31
0.029
Standard Deviation
Effluent
1.38
43,7
0.002
0.024
0-.79
0.001
0.12
0.017t
0.36
0.028
Back-
ground
Water
0.015
0.002
0.002
0.001
0.005
0.0
0.0
0.0
Influent
23.88
88.65
0.003
0.059
0.438
0.002
11.11
0.001
0.956
0.006
Effluent
2.437
43.58
0.002
0.080
1.234
0.002
0.190
0.011
0.117
0.009
Probability
F Value
Exceeded
0.0033**
0.262
0.725
0.161
0.334
0.895
0.0000**
0.132
0.0017**
0.030*
(Continued)
* Influent, effluent and background water values are significantly different at p £
** Influent, effluent and background water values are significantly different at p f_
t High effluent concentrations resulted from inclusion of high effluent values from
influent data.
0.05.
0.01.
the Seattle, Washington site, which lacked comparable
(Sheet 7 of 8)
-------
Table 3 (Concluded;
Number of Samples
Back-
ground Background
Parameter Water Influent Effluent Water
Vanadium
Total, mg/Jl 277 0.029-0.32
<0.45 (jm, mg/fc 277 0.004-
0.004
Arsenic,
Total, rag/* 9 12 17 0.001-
0.013
<0.45 urn, mg/J. 2 12 17 0.0003-
— i 0.001
VD
ro
Range Mean Standard Deviation
Back- Back-
ground ' ground
Influent Effluent Water Influent Effluent Water Influent Effluent
2.29-5.23 0.076-0.47 0.175 3.52 0.26 0.206 1.321 0.134
0.004- 0.003- 0.004 0.018 0.015 0.0 0.013 0.010
0.039 0.027
0.181- 0.003- 0.004 1.73 0.096 0.004 1.979 0.126
6.02 0.41
0.0001- 0.0001- 0.001 0.027 0.004 0.000 0.043 0.006
0.117 0.021
Probability
F Value
Exceeded
0.0000**
0.317
0.0006**
0.077
** Influent, effluent and background water values are significantly differnt at p < 0.01.
(Sheet 8 of 8)
-------
100 90
% DECREASE
60 50 40
30
20
20
% INCREASE
40 50 SO
90
100
•
F
1
mm
CALC
OTASS
C
Zl
mm
•M
NOj-l-NOj-N
•"•f™
UM, <0
UM, <0
MC, <0
45 nm
•
45 urn
—
45 nrr-
~^=
COPPI
HROMI
R, <0.
•
JM, <0
mi
15 (im
I^HI
45 IUTI
m
—
-
SETTL
TOTAL
ORGAI"
ORGAI>
OIL &
OIL &
Op' DO
pp'DD
Op'OD
pp' DD
op1 DD
pp'DD
TOTAL
ORGAf
ORGA^
NH,-r
NH3-
ORTHC
TOTAL
TOTAL
TOTAL
—
CALCI
MAGNE
MAGN
•
POTAS
5ODIU
5ODIU
IRON,
IRON,
MANG
MANG
ZINC,
CADMI
CAOMI
COPPI
NICKE
NICKE
XEAD,
LEAD,
:MERCI.
MERC
i^M
CHROU
TITAN
TITAN
VAN A
VANA[
ARSEC
ARSE^
ALKA
CHLOF
IABLE
.TERAE
SOLID
IC-C, <
IC-.C.T
GREAS
jREASE
:
-.
)
D
T
T
PCB
JIC-N,
JIC-N,
<,<0.4!
1, TOT/
-PO4-
-P, <0.
-P, TO
SULFI
•
JM, TO'
:SIUM,
:SIUM,
SIUM, '
M, <0.4
M, TOT>
<0.45 (i
TOTAL
iNESE,
ANESE,
1^
TOTAL
UM,
-------
EFFLUENT AQUEOUS PHASE
DECREASE
EFFLUENT AQUEOUS PHASE
INCREASE
EFFLUENT AQUEOUS PHASE
DECREASE
EFFLUENT AQUEOUS PHASE
INCREASE
LOCATION -14 -12 -10 -8 -b -4 -2 0 2 4 i, 8 LOCATION
1 1 1 1 1 1 1
WILMINGTON, NC (F-B)
HOUSTON, TX (B, 1
LAKE CHARLES, LA (B-M, C
SOUTHPORT, NC (B-M,
SEATTLE, VIA (B-M)
RICHMOND, VA (F) E
VICKSBURG, MS (F) B
GRAND HAVEN, Ml (F)
WILMINGTON, NC (F-B,
LAKE CHARLES, LA (B-M)
SOUTHPORT, NC IB-HI) 1
SEATTLE, WA IR-II, 1
RICHMOND, VA (H D
VICKSBURG, MS (F)
fcPvAND HAVEN, Mf (F) '
WILMINGTON, NC GT
HOUSTON, TX (B) CZ
LAKE CHARLES LA (B M) L
SOUTHPOfiT, NC (B-M) 1 1 1
SEATTLE, WA (B-M) 1
VICKSBURG, MS (Fl 1 i I
WILMINGTON, NC
SOUTHPORT, NC (B-H) NITRATE NITROGEN rag T(x 10 ')
SEATTLE, WA (B-M)
RICHMOND, VA (F) 1
VICKSBURG, MS (F)
GRAND HAVEN, Ml If}
WILMINGTON, NC (F-B) 1 ~
HOUSTON, TX (B)
LAKE CHARLES, LA (B-ll) C
RICHMOND, VA IF)
VICKSBURG, MS (Fl
GRAND HAVEN, Ml IF) C
HOUSTON, TX IB)
SOUTHPORT, NC (B-M) C
SEATTLE, WA (B-M)
RICHMOND, VA (F) CT
GRAND HAVEN, Ml (F)
WILMINGTON, NC (F-B)
HOUSTON, TX (B)
I AKFr.NHRIFS 1 A 1 |
SOUTHPORT, NC (B-M) CT
SEATTLE, WA (B-M)
RICHMOND, VA (F) C
VICKSBURG, MS (F) '
GRAND HAVEN, Ml (F) !
1 1 1 1
WILMINGTON, NC
LAKE CHARLES, LA
SOUTHPORT, NC
ORGANIC CARBON, „,/» „ 10', j^^
VICKSBURG, MS
GRAND HAVEN, Ml
WILMINGTON, NC
HOUSTON, TX
1 SOUTHPORT, NC
ORGANIC NITROGEN, -,T Sot^A
VICKSBURG, MS
13 GRAND HAVEN, Ml
WILMINGTON, NC
HOUSTON, TX
LAKE CHARLES, LA
SOUTHPORT, NC
AMMONIUM NITROGEN, ng-T RICHMOND VA
GRAND HAVEN, Ml
WILMINGTON, NC
1 HOUSTON, TX
3 LAKE CHARLES, LA
] SOUTHPORT, NC
3 SEATTLE, WA
;3 RICHMOND. VA
VICKSBURG, MS
1 GRAND HAVEN, Ml
WILMINGTON, NC
HOUSTON, TX
1 LAKE CHARLES LA
SOUTHPORT, NC
RICHMOND, VA
TOTAL PHOSPHORUS, mg/f(* 10 ') VICKSBURG MS
1 GRAND HAVEN. Ml
'VILMINGTON, NC
LAKE CHARLES, LA
SOUTHPORT, NC
SEATTLE, WA
RICHMOND, VA
VICKSBURG, MS
IRON, mg T
GRAND HAVEN, Ml
HOUSTON, TX
HOUSTON, TX
GRAND HAVEN, Ml
HOUSTON, TX
P -GANESE-T =A^,M,
• U -12 10 -8 -6 -4 -2 0 2 4 fc 8 10 12
1 1 1 1 1 1
IF-B)
(B-M)
ffl-H" 1
[*,""' ZINC, mg1'(xlO'!)
(F)
(F-B, 1
(Bl 1
[|""jj CADIIIUII, mgTIxlO"3)
(F) C
(F)
(F) I
IF-B)
(B) C
(B-M)
m-u> 1
(F,
(F)
(F)
(F-B,
(B, C^
(B-M, c:
(B-M, CZ
IB-M,
(F)
(F)
II-. HI 1
IB) C
(B-M)
(B-M) LEAD, mgl'lxlO ')
(F) C=
(F)
(F,
(F B, C^
(B-M,
IB-M, 1
(B-M)
(F)
(F,
(F) CHROMIUM, mg T(x 1C'3)
(B) 1" 1
IF)
IB) 1
IF) i
1 1 1 1 1 1
1
- - " — 1
rra
3
3
ra
NICKEL, mg^(«10 J)
MERCURY, mgl'fxlO'3)
CD
TITANIUM, tngT.(>10'3>
VANADIUM. maTI»10 3,
ARSENIC, mg r (« 10 ')
(F) = FRESH WATER: INFLUENTS WITH < 0.:.X SALINITY
(F-B) = FRESH -BRACKISH: INFLUENTS WITH 0.1 TO 0.5X SALINITY
(B) = BRACKISH WATER: INFLUENTS WITH 0.5 TO 1.5% SALINITY
(BM) = BRACKISH MARINE: INFLUENTS WITH > 1.5% SALINITY
NOTE: DISPOSAL AREA LOCATIONS ARE LISTED IN THE ORDER OF THEIR DECREASING DETENTION TIMES
BASED ON SEE, INFLUENT- EFFLUENT FLOW RATES, AND TORTUOSITY.
Figure 4. Changes in the nutrient and heavy metal concentrations in the aqueous phase of
effluents from confined disposal areas.
-------
IO
CJ1
LOCATION
WILMINGTON, NC (F-B)
HOUSTON, TX (B)
LAKE CHARLES, LA (B-M)
SOUTHPORT, NC CB-M)
SEATTLE, WA (B-M)
RICHMOND, VA (F)
VICKSBURG, MS (F)
WILMINGTON, NC (F-B)
HOUSTON, TX (8)
LAKE CHARLES, LA (B-M)
SOUTHPORT, NC
SEATTLE, WA (B-H)
RICHMOND, VA (F)
VICKSBURG, NS (F)
GRAND HAVEN, HI (F)
SAYREVILLE, NJ (B)
LAKE CHARLES, LA 1.5X SALINITY
EFFLUENT AQUEOUS PHASE
r* \
»
a
_3
" COPPER, •fttuur')
n
Z3
—.J
.j LEAD, me/I (x ID"1)
=='
3
LJ A CHROMIUH, ntd/I
5 VANADIUM, rng/1 (x 10"*)
3 1
1
NOTE: DISPOSAL AREA LOCATIONS ARE LISTED IN THE ORDER OF THEIR DECREASING DETENTION TIMES,
BASED ON SIZE, INFLUENT-EFFLUENT FLOW RATES, AND TORTUOSITY.
Figure 5. Concentrations of nutrients and heavy metals in the aqueous phase of effluents
from the confined disposal areas.
-------
ating influents. Sodium, mercury, and the DDT transformation product - DDE
were the only parameters which did not seem to be greatly reduced in the total
effluents. For most elements, the percent decrease in total concentration was
very close to the respective decrease in suspended (nonfilterable) solids
during containment, which averaged 97.2% for all sites (Figure 3). However,
some variances in elemental versus solids removal efficiency seemed to be
greater than analytical error. Despite overall significant decreases in total
samples, organic nitrogen, phosphorus, potassium, sodium, manganese, zinc, and
mercury showed major increases in the effluent solid phase (Table 3). These
contaminants were probably mainly associated with very small or low density
(e.g., organic) particles. Other studies have shown similar relationships in
dredged material from land containment areas (15), marine sediments (10), and
in ocean discharges of wastewater effluents (8).
The only measured parameters which exhibited removal efficiencies of less
than 90% in total sample preparations include: titanium (89%); manganese
(88%); settleable solids (85%); potassium (78%); magnesium (64%); ammonium
nitrogen (57%); mercury (46%); op' DDE (46%); and pp' DDE (21%). The two
chlorinated pesticide analogs of DDE were at similar concentrations in both
the effluent and background water samples.
Nitrate-nitrite nitrogen was the only soluble phase parameter which
showed a significant increase during land containment of dredged material
(Figure 3). The concentration increased almost twofold, from 0.18 to 0.35
mg/£. However, this increase should have minimal impact since the discharge
concentration was below the surface background water average (Table 3) and
well below accepted water quality standards (9). The greater than threefold
increase in soluble chromium indicated by Table 3 is the result of high levels
of chromium in effluents from the Seattle disposal area; chromium was not
measured in the influent samples from Seattle. Excluding the Seattle data,
chromium showed only a very small increase, as shown in Figure 3. High con-
centrations of soluble ammonium nitrogen and manganese occurred in some influ-
ent and effluent filtrates. Soluble ammonium nitrogen in the influents
averaged 20.8 mg/£, with an upper range of over 70 mg/£; effluent samples
averaged 13.6 mg/£, with maximum concentrations also around 70 mg/£. Soluble
manganese showed a comparable decrease during residence in the land contain-
ment areas; the influent and effluent means were 2.35 and 1.45 mg/£, while
maximum values were 14.4 and 8.0 mg/£, respectively. Soluble iron was also
high in influents but it showed a high removal efficiency of 70%,. Average
soluble phase concentrations of zinc and copper were slightly higher in efflu-
ents. However, as indicated in Figure 4, their increased mobility was site-
specific and their levels (Figure 5) were below the present drinking water
standard and criteria for aquatic life (9).
Some total alkalinity values (as calcium carbonate) were also very high,
giving average influent and effluent values of 412 and 287 mg/£ in comparison
to a background water average concentration of 88 mg/£ (Figure 3 and Tables 2
and 3). Dissolved oxygen in effluents, based on multiple surface water mea-
surements made inside of the discharge weirs, fluctuated greatly. Ranges were
from 0.6 to 12.5 mg/£, with an average of 5.3 rng/A. Thus low effluent DO can
occasionally be a problem. '
196
-------
Geochenrical Partitioning of Influent and Effluent Solids
The potential mobility or toxicity of an element is highly dependent on
the geochemical phases with which it is associated in the solids fraction.
The exchangeable ions are considered to be readily available to aquatic or-
ganisms as they are mainly weakly adsorbed on the surfaces of fine solids.
The carbonate phase may also be readily affected by changes in the environ-
ment, especially as a result of interactions with or uptake by the biota.
Also the carbonates of a given metal are generally more soluble than many
other solid phase chemical precipitates, and thus a major shift of a metal to
a carbonate complex may result in a similar increase in its soluble phase
concentration. The easily reducible phase variations reflect the oxidized or
reduced status of a containment area during disposal operations. An increase
in this phase would suggest an overall increase in the oxidation of the
dredged material slurry, and vice versa. If reducing conditions occur,
increased mobility of ions from the easily reducible phase (iron-manganese
oxide precipitates) is favored, thus presenting a potential water quality
problem. In retrospect, greater mobility may occur from sulfide complexes
(organic-sulfide phase) under oxidizing conditions since most metal sulfides
are much less soluble than their more oxidized substituents. Thus with chang-
ing environmental conditions many contaminants change their mobility and form,
and likewise their bioavailability (18).
Figure 6 gives the amounts and percentages of each of 14 nutrient and
trace metals that were solubilized during sequential chemical extractions of
five influent and effluent solids. Some metals exhibited noticeable phase
changes during migration of suspended solids in the dredged slurry across land
containment areas, while other metals showed little change. About a third of
the solids-bound calcium and sodium were removed from the influent solids
during extraction of the exchangeable phase, with measurable increases in
exchangeable calcium, sodium, copper, and arsenic noted in effluent solids.
Exchangeable phasfe manganese, magnesium, and cadmium were similarly high
(^10%) in both influent and effluent solids. Most metals showed increases in
carbonate phase concentrations as a result of confined disposal. Influent
solids generally showed high carbonate phase values for cadmium and manganese,
while zinc, cadmium, manganese, lead, copper, and sodium showed major
increases in effluent solids. Carbonate phase cadmium, zinc, and manganese
composed 57, 33, and 20% of the effluent solids, respectively. Iron, manga-
nese, cadmium, and copper increased in the easily reducible phase of the
effluent solids, although only manganese showed a major increase of 20%. Upon
total digestion of the remaining influent and effluent solids, most metals
(except for iron, nickel, and chromium) showed noticeable decreases in the
effluent digests. A limited amount of data on the organic-sulfide phase
(Seattle site) suggests that the concentration decreases were mainly associ-
ated with reductions in solid phase organic and/or sulfide complexes during
disposal area detention under oxidizing conditions.
Metals showing major geochemical phase changes included manganese (easily
reducible phase), cadmium (carbonate and easily reducible phases), zinc
(carbonate phase), lead (carbonate phase), copper (carbonate phase), sodium
(exchangeable phase), and calcium (exchangeable phase). Metals showing little
change in phase during the solids detention times included chromium, nickel,
mercury, potassium, and magnesium. Iron could not be properly evaluated because
197
-------
ELEMENT
NO. OF
SAMPLES
ANALYZED
PARTITIONING PHASE, PERCENT ••
40 SO 60
80
90
-r
CALCIUM
EXCH
MAGNESIUM
E.R.
A.D.
POTASSIUM
SODIUM
CO
IRON*
100
—I
LEGEND
INFLUENT SOLIDS
EFFLUENT SOLIDS
EXCHANGEABLE = AM.MONIUM ACETATE
EXTRACTABLE PHASE
CARB CARBONATE = 1 M ACETIC ACID
EXTRACTABLE PHASE
EASILY REDUCIBLE = 0.1 M HYDROXYLAMINE
HYDROCHLORIDE IN 0.01 M NITRIC ACID
EXTRACTABLE PHASE
ACID DIGEST = NITRIC-HYDROFLUORIC-FUMING
NITRIC ACID DIGEST
• PARTITIONING PHASES ARE SIGNIFICANTLY
DIFFERENT, p 0.05 FOR AVERAGE PERCENT
OR AVERAGE CONCENTRATION VALUES
•• DETERMINED FROM TOTALLING THE AVERAGE
PERCENT VALUES FOR EACH SAMPLE DIVIDED
BY THE NUMBER OF SAMPLES
(2,120) AVERAGE CONCENTRATION MEASURED IN mgAg
DETERMINED FROM TOTAL CONCENTRATION
DIVIDED BY THE NUMBER OF SAMPLES
(13,630)
1(14,120)
MANGANESE
ZINC*
3(225)
3 (203)
(167)
J(246)
"j 1102)
3(261)
-1(486)
(370)
(10.0)
-1(21.6)
iCI99!
3 (23.3)
3(43.1)
all 91)
3(172)
Figure 6. Geochemical phase partitioning of metals in influent and effluent solids from four
confined land disposal areas (sheet 1 of 2).
-------
NO. OF
SAMPLES
PARTITIONING PHASE, PERCENT •*
ELEMENT ANALYZED 0 10 20 30
.
/ EXCH
1 CARB
COPPER 5 <
IE.R,
( i
V A.D.
EXCH
CARB
CADMIUM' 5
E.R.
A.D.
/ EXCH
1 CARB
LEAD 5 <
J E.R.
( !
V A.D.
/ EXCH
1 CARB
NICKEL 5 /
E.R.
\ A.D.
/ EXCH
1 CARB
CHROMIUM 1 /
\ A.D.
EXCH
CARB
MERCURY 4
E.R.
A.D.
EXCH
CARB
ARSENIC 1
E.R.
A.D.
1 1
1(0.13)
™3(i.i)
J (0.44)
} fn,Q^)
It2.11
J {2.5)
T (0.34)
' ' | 112.71
' (1 1-51
1 K0.05)
1 (0.2)
1 (4.4)
Jd.O)
1(0.001)
J (0.005)
1 KO.OOt)
KO.OOD
1(0.001)
- - 1 (0.055)
1(0.15)
) 17.11
K0.15I
K0.15)
«o!l5)
40 50 60 70 80 90 100
11 1 1 "1 1 ~1
) (52.6)
-;• - :::::: -,..:".. " .:. . — '"" ! — "" .. v . • ~™ : . . • i (75.0)
l(yu.b)
1(11 .0)
.. , _ | (41,4)
Figure 6. (sheet 2 of 2)
-------
of its high total concentration. Arsenic showed a large increase in an ex-
changeable phase extract of an effluent sample from the Seattle site.
Effluent-Surface Background Water Comparisons
Suspended (nonfilterable) solids were 47 times higher in effluents than
in adjacent surface background water (Table 3). Therefore, it is not sur-
prising that most total sample contaminant levels were also correspondingly
higher, as depicted in Figure 7. The only contaminants which were signifi-
cantly higher in the effluents than in the background water were total lead
(125X) and total manganese (74X). Contaminants which had appreciably lower
levels in total effluent samples than the respective suspended solids contri-
bution included: PCBs, DDT, ODD, DDE, copper, chromium, sulfide, zinc,
nickel, vanadium, calcium, magnesium, potassium, and sodium (Table 3). The
major source for the total manganese, DDE, and major ions (Ca, Mg, Na, K) was
the soluble phase.
The only measured soluble phase parameters which were appreciably higher
than the background water levels include: ammonium nitrogen (SOX), manganese
(25X), alkalinity (3X), zinc (2.5X), copper (2.5X), and iron (2.5X) (Figure
7). Titanium and vanadium were significantly higher in effluents in the
Houston site, but were at background levels at two other monitored sites.
Despite the data given in Figure 7, chromium and arsenic were not shown to be
higher in effluents since high effluent values for each at the Seattle site
could not be matched with missing background water data. More information is
required for those trace contaminants which are not commonly monitored.
The primary source for the DDE and nitrate levels in effluents seemed to
be water incorporated with the dredged sediments since higher levels for each
were present in surface background water samples (Table 3). The soluble phase
concentrations of the major ions (Ca, Mg, Na, K, Cl) were significantly higher
in effluents than in background water because of salinity stratification in
most brackish dredge site waters.
The association of trace contaminants with very fine particles was ob-
served. This was particularly evident for mercury and potassium at most
sites. Combined geochemical phase partitioning and particle-size fractiona-
tion of effluent solids show the association of potassium with very fine
silicate mineral particles, e.g., illite clay. Fine clays, as well as man-
ganese and iron oxide precipitates and low density organic detritus, may be
important media for the transport of adsorbed contaminants. This is supported
by high exchange capacity (Table 3) and increased levels of exchangeable
cations (Figures 3 and 6) associated with effluent suspended solids.
DISCUSSION
The removal efficiency for most heavy metals closely paralleled the
removal of the solids during dredged slurry containment in land disposal
areas. However, different metals seemed to have varying affinities for dif-
ferent geochemical phases and particle sizes of suspended solids. Total
mercury in effluent samples decreased by only 46%, which indicates that it was
200
-------
ro
o
35,
30 I
25
20
IS
10
o
O
u
u
2.1
u
u
QL
O
o
oa
UJ
a:
O
_J
O
g
D-
_j
o
a:
o
1.5
1.2
0.9
0.6
0.3
§.
o
z
i
0.07
0.06
0.05
0.04
0.03
0.02
0.01
LEGEND
EJ EFFLUENT
• BACKGROUND WATER
NOTE: ASTERISK DENOTES AMOUNT <0.45flm.
o
a:
Z
N
Q_
CL
O
O
ID
U
o:
I
u
Figure 7. Average concentrations of nutrients, organic contaminants, and soluble phase heavy
metals in effluents and surface background water samples representing the confined
disposal areas.
-------
often associated with a fine particulate fraction and/or one of low specific
gravity (e.g., organic suspended solids). Soluble phase titanium in the
Sayreville samples mainly originated from the settling of very fine titanium
oxide aerosol particles into the water near the dredging site. Most of the
DDE also.seemed to be associated with very fine particles present in dredged
site waters. Thus, the filter size and the instrument employed for analyses
are of great importance in determining "soluble phase" concentrations. The
impact that fine parti cul ate matter has on aquatic life is not well docu-
mented, but the findings of this study suggest that perhaps suspended solids
should be included in any predictive test or effluent analysis; the methods
used to separate solids and analyze samples should be well documented. How-
ever, bulk analyses (acid digests) of bottom sediments or total influents are
not recommended as a predictive tool as they generally show a poor relation-
ship to contaminant mobility or availability.
Most of the chlorinated hydrocarbons (pesticides, PCBs) with the excep-
tion of DDE, showed very efficient removal when proper solids retention was
maintained in confined disposal areas. The source for the DDE was probably
not the dredged sediments since comparable DDE concentrations were observed in
surface background water samples. Oil and grease were generally removed
efficiently during dredged slurry containment. However, sediments containing
high levels of petroleum residues seemed to settle more slowly, often creating
highly fluid oi1-water-sediment suspensions near the bottom of ponded areas.
Poor site management may effect the release of these suspensions, resulting in
a poor effluent quality.
Analytical data for influent and effluent sample filtrates showed that
soluble phase ammonium nitrogen was released in high concentrations from some
bottom sediments. Ammonium release was most frequently directly related to
organic nitrogen and TKN concentrations in the bottom sediments. Soluble
phase ammonium nitrogen concentrations in disposal area influent samples
averaged-20.8 mg/S, with maximum levels of 70 mg/£. Generally, an equivalent
amount of ammonium nitrogen was exchangeable from the influent solids. A very
rapid initial decrease in soluble phase ammonium was noted in most sites
displaying a short slurry detention. This was attributed to sorption by
disposal area solids in contact with the slurry and was most pronounced in the
presence of fine-grained sediments. Although ammonium nitrogen was removed
from the dredged slurry by 57% during residency, the observed effluent con-
centrations could warrant concern, especially if high pH conditions exist in
the disposal area or discharge zone, promoting the formation of highly toxic
un-ionized ammonia.
Soluble manganese and iron were the only heavy metals consistently re-
leased at above ambient background water concentrations in effluent filtrates.
Soluble manganese removal in the disposal areas was generally good, averaging
38%. Soluble iron was readily removed during slurry residency. However, both
iron and manganese frequently greatly exceeded present standards and criteria.
Although copper and zinc concentrations were higher in the soluble phase of
many effluents, the levels encountered suggest that only rarely should these
contaminants exceed present standards and criteria. The increased mobility of
zinc and copper during containment could be promoted by their release from and
complexation by organic compounds as well as the formation of moderately
202
-------
soluble carbonate minerals indicated by their notable increases in the acetic
acid extractable solids phase. Generally, the soluble phase concentrations of
other heavy metals closely reflected the concentrations in comparable back-
ground water samples. Soluble phase cadmium showed no major change in con-
centration during confinement, but there was a major shift of cadmium into the
carbonate phase of effluent solids. This suggests that cadmium associated
with effluent suspended solids may have greater potential for bioavailability
or mobility in receiving waters. However, solid phase cadmium seemed to be
readily removed during short-term residency in land disposal areas.
There was a 60% increase in the cation exchange capacity of effluent
solids. This increase was reflected by general increases of exchangeable
ammonium and metals associated with the effluent solids. The dominance of
fine particulate matter in effluents was probably responsible for this.
Manganese and other metal increases in the easily reducible geochemical phase
also suggest the importance of manganese and iron hydroxide precipitates in
sorption phenomena. However, effluents having low solids contents should be
negligibly affected by the increase in exchange capacity. Thus dredged slurry
retention must be sufficient to allow for efficient suspended solids removal.
Although a direct relationship between carbonate phase shifts and
influent-effluent alkalinity values was not consistently noted, high alka-
linity undoubtedly played an important role. Alkalinity showed an overall
decrease during containment, although the trends were site specific. Major
shifts in alkalinity during dredged slurry containment seemed to be promoted
by biological activity. The highest influent alkalinity values were noted
when the dredged sediments contained a high total organic carbon concentra-
tion.
There was a small but significant increase in pH during the dredging and
land disposal cycle (Table 3). Algal photosynthesis appeared to be an impor-
tant source for the increase, with pH values in excess of 9 observed in efflu-
ents from a nonvegetated disposal area with a retention time of greater than a
week. High nutrient levels can increase algal growth in site waters, result-
ing in alkaline pH. The combination of high nutrient and pH levels may have
both positive and negative effects; ammonia volatilization may lead to nitro-
gen depletion of site waters and increased ammonia toxicity could impact both
the microbial pathogens in the dredged material and aquatic organisms in the
receiving waters. High turbidity and vegetation in the disposal areas should
prevent excessively high pH.
Dissolved oxygen averaged 5.3 mg/S, in effluents, and generally effluents
containing higher solids contents were lower in DO. Some very clear effluents
which contained high concentrations of soluble nutrients were also low in DO.
Subsurface effluent discharge had lower DO than surface discharge. Low DO
values were also observed in vegetated overland flow disposal areas; this may
be prompted by the turbulent mixing and greater contact of reduced sediments
with the water in overland flow systems. Influents entering the vegetated
overland flow areas were also unusually high in nutrients, which may have
prompted the low levels of DO by accentuating microbial growth.
In summary, trace contaminants are mainly associated with suspended
particles, and turbid water will impact sensitive aquatic life. Recently
203
-------
disturbed bottom sediments, resulting from dredging, will also suppress DO
levels in the immediate discharge waters. Therefore good disposal area manage-
ment requires removal of suspended solids. However, long-term retention of
the dredged material supernatant in disposal areas could produce a high pH
problem. ' Although slightly alkaline pH generally favors the removal of sol-
uble contaminants (14,18), very high values are not desirable. If organic
matter and TKN values are high, ammonia released with high pH effluent dis-
charges may be toxic to sensitive organisms in the immediate receiving waters.
Since the main source for the high pH is probably algal photosynthesis in
disposal area water, algal blooms should be watched for and prevented. Such
biological blooms could also create unstable physicochemical conditions during
the rapid death phase, resulting perhaps in rapid decreases in DO, Eh, and pH.
In turn, biochemical and geochemical phases of contaminants may shift, which
could increase their mobility.
The increases of nutrient trace metals in soluble phase effluent samples
from the Wilmington disposal area, where site water was subjected to long
residency in dead vegetation, indicate that the mobility of especially zinc
and copper may be favored under conditions of extensive retention time and
presence of abundant organic debris (Figure 4). Other studies have shown
similar trends (19,20). However, the Southport disposal area, which contained
actively growing thick vegetation, elicited the best removal of nutrients
(ammonium and soluble phosphate) and suspended solids of any of the sites
monitored, and no significant increases in soluble trace metals were found.
Thus, there seems to be a seasonal pattern for best treatment. The presence
of vegetation in disposal areas can accentuate slurry solids removal, but it
is recommended that such dredging be scheduled for the spring or summer period
for best effluent quality. In retrospect, disposal into nonvegetated areas
may be best during cooler weather, to avoid algal blooms.
Proper planning and management of land disposal area operations should be
a goal of dredging concerns and regulatory agencies. Based on present trends
in criteria and standards, the main goal for achieving acceptable effluent
water quality should be the removal of suspended solids, even at the expense
of increasing the concentrations of certain soluble phase trace contaminants.
Most soluble phase trace contaminant levels in effluents were found to be
within present water quality guidelines, except for ammonia, manganese, and
iron, and longer residency under oxidizing conditions should favor their
removal. However, it must be kept in mind that there are seldom close rela-
tionships between total contaminant levels and toxicity or biological accumu-
lation (16,18-20). Certainly much more research must be performed on such
relationships before a clear understanding of impact of confined land disposal
of dredged material can be formulated.
CONCLUSIONS AND RECOMMENDATIONS
1. Most contaminants (chlorinated hydrocarbons, oil and grease, nutri-
ents, and trace metals) are primarily associated with the solid phase of
dredged material. Ammonium, manganese, and possibly iron, copper, and zinc
are the only contaminants which might occasionally exceed both background
water levels and present water quality standards and criteria following effi-
204
-------
clent suspended solids removal Other soluble phase contaminants in effluents
were either below presently prescribed criteria or comparable to background
water concentrations. Thus proper retention or treatment of site waters to
limit 'suspended solids levels seems necessary to meet the present regulatory
guidelines. However, background water levels should also be considered in
properly evaluating and regulating excessive effluent levels.
2. Major shifts of several trace metals from organic-sulfide and resi-
dual to carbonate and exchangeable geochemical phases were noted during resi-
dency of dredged material solids in land containment areas. Despite a poten-
tial increase in mobility of most metal carbonate complexes, increased adsorp-
tion onto and coprecipitation with fine effluent solids probably prevented
notable soluble phase increases. Only zinc and copper were noted to increase
in effluent filtrates at several sites, but levels were below present regula-
tory guidelines.
3. Actively growing vegetation in land disposal areas elicited excel-
lent removal of nutrients (ammonium and soluble phosphate) and suspended
solids. However, seasonal use of such sites during active plant growth is
suggested for best effluent quality.
4. Effluent monitoring and predictive testing methodologies should
include suspended solids. Chemical data for total settleable solids or bulk
sediments should not be used to indicate environmental impact.
5. Confined land disposal of dredged material, under proper management,
seems to be a viable method for the containment and treatment of most contami-
nated sediments. However, sites located adjacent to sensitive wetlands in
confined water bodies are not recommended without extensive predictive
testing.
205
-------
REFERENCES
1. Adams, D. D. and Young, R. J. , "Water Quality Monitoring of the Craney
Island Dredge Material Disposal Area, Port of Hampton Roads, Virginia--
Dec. 1973 to Feb. 1975," Institute of Oceanography, Old Dominion Univer-
sity, Norfolk, VA, Technical Report No. 23, Jul. 1975.
2. Adams, D. D. and Park, M. T. , "Water Quality Monitoring of the Craney
Island Dredge Material Disposal Area, Port of Hampton Roads, Virginia-
Apr. 1975 to Mar. 1976," Institute of Oceanography, Old Dominion Univer-
sity, Norfolk, VA, Technical Report No. 29, May 1976.
3. American Public Health Association, Standard Methods for the Examination
of Water and Wastewater. 13th Ed., Washington, DC, 1971.
4. American Public Health Association, Standard Methods for the Examination
of Water and Wastewater, 14th Ed., Washington, DC, 1975.
5. Blazevich, J. N. ; Gahler, A. R.; Vasconcelos, G. J.; Rieck, R. H.; and
Pope, S. V. W. , "Monitoring of Trace Constituents During PCB Recovery
Dredging Operations, Duwamish Waterway," U.S. Environmental Protection
Agency, Surveillance and Analysis Division, 1200 Sixth Avenue, Seattle,
Wash., Aug. 1977, EPA 910-9-77-039.
6. Brannon, J. M.; Engler, R. M.; Rose, J. R.; Hunt, P. G.; and Smith, I.,
"Selective Analytical Partitioning of Sediments to Evaluate Potential
Mobility of Chemical Constituents During Dredging and Disposal Opera-
tions," Technical Report D-76-7, U.S. Army Engineer Waterways Experiment
Station, CE, Vicksburg, Miss., Dec. 1976.
7. Chen, K. Y. ; Gupta, S. K.; Sycip, A. Z.; Lu, J. C. S. ; Knezevic, M.; and
Choi, W-W., "Research Study on the Effect of Dispersion, Settling, and
Resedimentation on Migration of Chemical Constituents During Open-Water
Disposal of Dredged Materials," Contract Report D-76-1, U.S. Army
Engineer Waterways Experiment Station, CE, Vicksburg, Miss. , Feb. 1976.
8. Chen, K. Y. and Lockwood, R. A., "Evaluation Strategies of Metal Pollu-
tion in Oceans,"Journal of the Environmental Engineering Division, Pro-
ceedings o_f the American Society o_f Civil Engineers, Vol 102, No. EE2,
Apr. 1976, pp 347-359.
9. Chen, K. Y. ; Mang, J. L.; Eichenberger, B.; and Hoeppel, R. E. , "Confined
Disposal Area Effluent and Leachate Control (Laboratory and Field Investi-
gations)," Technical Report DS-78-7, U.S. Army Engineer Waterways Experi-
ment Station, CE, Vicksburg, Miss., Oct. 1978.
206
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10. Choi, W-W. and Chen, K. Y., "Associations of Chlorinated Hydrocarbons
with Fine Particles and Humic Substances in Nearshore Surficial Sedi-
ments," Environmental Science and Technology, Vol 10, No. 8, Aug. 1976,
pp 782-786.
11. Environmental Protection Agency, Methods for Chemical Analysis of Water
and Wastes, Washington, DC, 1974.
12. Hoeppel, R. E.; Myers, T. E.; and Engler, R. M., "Physical and Chemical
Characterization of Dredged Material Influents and Effluents in Confined
Land Disposal Areas," Technical Report D-78-24, U.S. Army Engineer Water-
ways Experiment Station, CE, Vicksburg, Miss., Jun. 1978.
13. Krizek, R. J.; Gallagher, B. J.; and Karadi, G. M., "Water Quality
Effects of a Dredging Disposal Area," Journal of the Environmental Engi-
neering Division, Proceedings of the American Society of Civil Engineers,
Vol 102, No. EE2, Apr. 1976, pp 389-409.
14. Leckie, J. 0. and James, R. 0., "Control Mechanisms for Trace Metals in
Natural Waters," in Aqueous-Environmental Chemistry of Metals, ed. by A.
J. Rubin, Ann Arbor Science Publishers, Inc., Ann Arbor, Mich., 1976, pp
1-76.
15. Lu, J. C. S.; Eichenberger, B.; and Chen, K. Y., "Characterization of
Confined Disposal Area Influent and Effluent Particulate and Petroleum
Fractions," Technical Report D-78-16, U.S. Army Engineer Waterways
Experiment Station, CE, Vicksburg, Miss., May 1978.
16. May, E. B., "Environmental Effects of Hydraulic Dredging in Estuaries,"
Alabama Marine Resources Bulletin, Vol 9, 1973, pp 1-85.
17. May, E. B., "Effects on Water Quality When Dredging a Polluted Harbor
Using Confined Spoil Disposal," Alabama Marine Resources Bulletin, Vol
10, 1974, pp 1-8.
18. Price, N. B., "Chemical Diagenesis in Sediments," prepared for National
Science Foundation, June 1973, National Technical Information Service,
5285 Port Royal Rd., Springfield, VA 22151, NTIS/PB-226-882.
19. Skidaway Institute of Oceanography, "Research to Determine the Environ-
mental Response to the Deposition of Spoil on Salt Marshes Using Dikes
and Undiked Techniques," National Technical Information Service, 5285
Port Royal Rd., Springfield, VA 22151, NTIS/AD-763-920.
*
20. Windom, H. L., "Environmental Aspects of Dredging in Estuaries," Journal
of the Waterways, Harbors, and Coastal Engineering Division, Proceedings
American Society of Civil Engineers, Vol 98, Nov. 1972, pp 475-487.
207
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MATHEMATICAL MODEL OF PHOSPHORUS RELEASE FROM LAKE SEDIMENT
T. Yoshida, Chairman, Technical Committee
T. Fukushima, Chief Engineer
Japan Bottom Sediments Management Association
Chuoko, Tokyo 104, Japan
ABSTRACT
This paper reports the results of a study on the
phosphorus release mechanism of lake sediment, primarily
by examining the relationship between release rates and
sediment depth. Sediment samples from Lake Nakanoumi were
used to examine the relationship between phosphorus con-
tent and sediment depth and to measure the released quan-
tities of nutrients, specifically phosphorus. From these
data, a model of phosphorus release rates was conceived
and evaluated. This study concludes that phosphorus
release rates from sediment depend primarily on phosphorus
content of the sediment.
INTRODUCTION
Lake Nakanoumi is situated in the western district of mainland Japan,
which faces the Nippon Sea (Figure 1). The lake has a surface area of 96.9
km2, a water volume of 521 x 10s m3, a length of 81 km and a mean depth of 5.4
m. It joins Lake Shinjiko at its inlet and flows into the Nippon Sea. Two
major cities, Matsue and Yonago, face the lake and others, Izumo and Sakai are
located nearby (Figure 2). Most of the lakes adjacent to urban areas in Japan
are extensively polluted because of industrial development and recreational
pressures. This lake is no exception and the back portion of Yonago Bay is
highly eutrophic.
The Izumo Construction Bureau, a branch of Japan's Construction Ministry,
began dealing with this pollution problem several years ago; recently a plan
was formed for lake restoration by sediment removal. As part of the project,
the Bureau requested the Japan Bottom Sediments Management Association to
perform tests on sites proposed for dredging and spill water treatment, and
develop predictions for lake water quality after restoration. In this manner,
we were able to conduct release experiments on the sediment, and then examine
the effects of dredging and reduction of internal phosphorus loading. Sampl-
ing stations are shown in Figure 3. In Yonago Bay, which has a surface area
of about 15 km2, dredging had been routine to maintain shipping routes. But
this is the first time dredging will be done as part of the lake restoration
process.
209
-------
NIPPON SEA
LAKE NAKANOUMI
Figure 1. Location of Lake Nakanoumi.
NIHONKAI SEA
Figure 2. The river basin of Lakes Shinjiko and Nakanoumi
210
-------
o
• SOIL SURVEY
O SEDIMENT ANALYSIS
D RELEASE TESTS
Figure 3. Sampling sites in Yonago Bay.
To prepare for the restoration plan, the following tests were performed:
87 sites were observed for soil classification and soil color.
16 sites provided samples for sediment analysis.
5 sites were checked for phosphorus release and AAP (Algal Assay
Procedure) tests.
DISTRIBUTION OF PHOSPHORUS CONTENT IN SEDIMENT
The phosphorus concentration of Nakanoumi's sediment is distributed ac-
cording to sediment depth, as shown in Figure 4.
The phosphorus concentration is highest at the surface, and decreases
rapidly to a depth of approximately 50 cm. Beyond a depth of 50 cm the con-
centration is relatively uniform. It may be assumed that the upper portion of
the curve represents an accumulation of polluted sediment, and the lower
portion of the curve, a background value representing an unpolluted state.
As Figure 4 shows, the sediment phosphorus distribution curve for Lake
Nakanoumi is parabolic. Data from other lakes confirm this pattern, for
example, the distribution curve for Lake Koyamaike is shown in Figure 5.
211
-------
~ 0
E
u
- 20
x
a. 40
w
h- 60
LJ
1 80
o
UJ
w 100
CONCENTRATION OF T-P ( mg/kg )
0 400 800 f200 1600
Figure 4. Distribution of phosphorus concentration with
depth in Yonago Bay, Lake Nakanoumi, Japan.
T-P (mg/g)
0.2 0.4 0.6 0.8 1.0 1.2
1.4
20
I
ej 40
Q
£60
UJ
UJ
10
100
120
Figure 5. Distribution of T-P concentrations in Lake Koyamaike sediment.
212
-------
Assume that the phosphorus concentration is represented by the following
equation:
(ZR - Z)2
p = p + —E
s K3 2f
where:
P = Phosphorus in sediment (mg/Kg)
P = Background value of phosphorus concentration
Z0 = Sediment depth at Pn
P p
f • = Figure index of parabolic curve (see Figures 6 and 7)
Z = Sediment depth
0
B
Z I
Figure 6. Illustration of parabolic curve for Equation (1) variables.
Figure 7. Figure index f of parabola for Equation (1).
213
-------
The more horizontal the parabola., the smaller the value of f , and the more
vertical the parabola, the larger the value; f = » is represented by a verti-
cal line. The mean concentration at sediment depth Z (mg/kg) becomes:
Z3 - (Z0 - Z)3
_ , J. ( (Zft - Z)2/
Ps = i / PR + -fe; dZ = PR + H /
s 2J0 i P 2fp ) ^ 6fpZ
The dry weight (kg) of the sediment layer for thickness Z is
1+eo
where:
F = area of column, cm2
e = void ratio of sediment
o
y = unit weight of dry sediment (usually 0.0026 kg/cm3)
Thus, in the following equation we derive the total amount of phosphorus
contained in the sediment at depth Z (mg):
zi -
-------
dZ=4
CONCENTRATION OF T-P
PORE WATER
Figure 8. Concentration of pore water.
WATER CONTENT (PERCENT)
200
300
400
BLACK
Figure 9. Relationship between water content and
sediment depth in Lake Nakanoumi.
215
-------
liquid viscosity, the diffusipn coefficient is Targer at the surface and
smaller in the deeper layers. It can be assumed from this, that a reduced
molecular diffusion rate in sediment indicates the sediments are from deeper
strata.
Therefore, it is possible to assume that
where:
D
h =
2f
Diffusion coefficient at the surface
Sediment depth, where D approaches uniformity
Figure index of parabola
(5)
0
-DO-
As previously mentioned, the Index fQ can be applied to all sediment pore
conditions. If fD is equal to °°, the diffusion c
stant against depth. Here Equation (4) is rewritten as
water conditions. If fD is equal to °°, the diffusion coefficient D is con-
= 0
(6)
If we assume a solution of Equation (6) in the following series form:
(7)
and substitute:
*1
Cp" = (m - 1) mAoZm" + m(m + 1) kf + (m + l)(m + 2) A2Zm + ...
(8)
216
-------
In the given equation, we obtain
m-2
(m-l)m
m(m + 1) AjD^ - (m - l)m Ar
,m
-i
(m + l)(m + 2) A2DQ - m(m + 1) Aj j- + (m - l)m pf
(m+2)(m+3) A3Do - (rrn-D(m+2) A2 j- + m(m+l) At ^f
,m
... = 0 (9)
To satisfy this relationship identically, it is necessary to do the following:
(m - 1) m AQDo = 0
m(m + 1) AiDo - (m - 1) m AQ j- = 0
(m + l)(m + 2) A2Dn - m(m + 1) Ax $~ + (m - 1) m -5]- = 0
0 TD ^TD
(m + 2)(m + 3) A3D - (m + 1 )(m + 2) A2 - + m(m + 1)
0 TD
= 0
Hence, we get:
m "
A = -— A
1 m + 1 fDDo
A, =
(m - l)m (2h2 - fDDQ)
2(m +
2) fD
(m - l)m (h2 - fDDQ) h
(m + 2)(m + 3) f
Thus we have:
CP = V
m ^ (m - 1) h . 7m+1
(m + l)fnDo V
217
-------
That is, the concentration of overlying water is constant against the column
height (Figure 10).
Figure 10. Concentration of overlying water.
THEORETICAL RELEASE RATES
As mentioned previously, the amount of phosphorus (mg) contained in the
sediment depth Z has been determined.
V -
6f
(3)
We now assume that the phosphorus concentration on the sediment surface in-
creases by dc during the short time dt. The increased quantities of phos-
phorus in the pore water and overlying water are equal to the quantities of
phosphorus particulates partitioned from the solid phase to the pore water
phase. Then we have:
4 W (Z) dt = dC (H + Z) F x 10-3
(14)
where:
4 = partition coefficient of phosphorus particles
Obviously, the partitioning of phosphorus in the sediment is influenced by a
variety of factors; e.g., biological, chemical and hydrostatic. Therefore,
the partition coefficient involves all of them (Figure 11).
218
-------
+2
AZ
2(m + l)(m+2) fD* o
•(m - 1) m h (h2 - fnDn) m+3
Do A -,01+
A -,
(m -H 2)(m * 3) f
Since (m - 1) m = 0, provided m = 1 or m = 0
m = 1 ; Cpl = AQ Z
m = ° ' Cp2 = Ao - fB Ao Z
The complete solution where A = 1, is then:
C = AZ -H B(l - ^r- Z) = B + (A - ?\-) Z (11)
p TDUo TDUo
This is the distribution curve of phosphorus concentration in pore water, which
is a straight line.
DISTRIBUTION OF PHOSPHORUS CONCENTRATION IN OVERLYING WATER
The distribution of phosphorus concentration in overlying water is derived
from the following equation:
->. Si • o
The solution is:
C = -CZ H- D
The boundary conditions are:
Z = 0 ; C = Cp (0) = B /. D = B
Z = H ; Do|f=0 ,'. C = 0
Hence we have:
C = C (0) = B (13)
219
-------
WATER
SEDIMENT
0
Figure 11. Partitioning of phosphorus particulates.
From equation (14), we have:
v 3 _
dt
(1 + eo)(H + Z)
as, (mg/l/day)
Hence:
= C +
o
2.6 4
.fell
6f
(1 + eQ)(H + Z)
t as, (mg/1)
(15)
In release tests this concentration is measured with time. Since the expres-
sion for the phosphor-US quantities which are released to the overlying water
is(C-C)FHx 10-3 mg, we have the theoretical release rates as follows:
Pr =
(C - C ) F H x 10-3
Ft
Z 3 - (I - Z)3
B ^ B ;
6f '
(1
eo)(l + g)
as, mg/m2/day
(16)
220
-------
RELEASE TEST RESULTS
The release tests were conducted using a columnar system with the device
shown in Figure 12. Sediment samplers are made of 15 cm x 70 cm acrylic
pipes. Samples were taken from undisturbed sediments in thicknesses of 7.5
cm, 11.5 cm and 30 cm.
The overlying water was collected with the sediment samples. The samples
were taken so that the overlying water was protected from the air by a paraf-
fin film when small quantities were removed for analysis. The test results
are summarized in Figure 13. From these tests and analyses we can identify a
relationship between phosphorus release rates and depth of sediment (Figure
14). The curve in Figure 14 indicates that the phosphorus release rates
increase significantly in proportion to sediment depth for shallow cores, but
levels off rapidly as core depth increases.
PARAFFIN FILM
WATER
SAMPLE
Figure 12. Apparatus for release test procedures.
PARTITION COEFFICIENT
If the relationship between phosphorus release rates and sediment depth
is known by measurement, we can derive the values of the partition coefficient
4, which are calculated back by Equation (16):
p ~
r
26
«h
r -\
,, v
... \ /• T
- (zp - ;
6f
L Z,
o3
as, mg/m2/day
(16)
221
-------
600 r-
400 -
200
_ 0
I. = 7.5 cm
Pr=2.0 mg/m/day
10 15 20 25
TIME (DAYS)
30
35
40
Q.
\-
600
u_
O
400
z
O
< 200
QL
\-
O
O
Z= 11.5 cm
Pr = 2.75 mg/m /day
°c
1
) 5
I
10
I
15
i
20
I
25
1
30
I
35
I
40
TIME (DAYS)
600
400
200
Z = 30 cm
J_
= 3.7 mg/m/day
I
10
15 20 25
TIME (DAYS)
Figure 13. Release test results.
30
35
40
222
-------
0 5 10 15 20 25
SEDIMENT DEPTH (cm)
Figure 14. Relationship between phosphorus release rates and sediment depth.
Using the following data:
PQ = 1600 mg/kg
PB = 500 mg/kg
In = 80 cm
f =
V
802
p 2 (PQ- P ) 2 x 1100
= 2.909 cmVmg-Vkg
H =31.15 cm
Prx =2.0 mg/m2/day, for Z = 7.5 cm
Pr2 = 2.75 mg/m2/day, for 2 = 11.5 cm
Pr3 = 3.70 mg/m2/day, for Z = 30.0 cm
we have:
d = 4.21 x 10-5
|2 = 4.34 x 10-5 (day)-1
£3 = 3.76 x 10-5
223
-------
From data shown in Figure 14, ijt appears that the release rate curve becomes
flat at a certain sediment depth.
Pr
Thus, the following may be assumed:
Differentiating the given equation:
Pr =
26 4 Pp Z
Vl
6f_
(1 + e0)(l + g
(16)
we have:
[
f
££
az
zft3-(z -z)3)
+ _E _ _§ _ U
2f
(1 +
Then we obtain:
7 3-f7 -Z}3
+ JJ °
6f
= 0
Z=h
ff+ «4-
(17)
where:
- 6f
a =
ZLi
V
(Z3 "
- 3(H + h)(Z0 - h)2
6
(1 +n^
6f
(18)
224
-------
The solution for Equation (16) is
4 = Ce"aZ (19)
This demonstrates that the partition coefficient | behaves exponentially
against sediment depth.
Since it seems from Figure 14, that h lies at about 30 cm, we have the
value of a for h = 30 cm. In Figure 15 the theoretical values of | are com-
pared to actual measurements. We can see they are in close agreement, with
little deviation.
The theoretical values of phosphorus release (Pr), which are calculated
le
follows
by the function | = Ce-°"00866 based on the point Z = 30 cm, becomes as
Sediment Depth Calculated Measured
cm mg/m2/day mg/m2/day
Z = 7.5 Pr = 2.17 Pr = 2.0
Z = 11.5 Pr = 2.79 Pr = 2.75
Z = 30.0 Pr = 3.75 Pr = 3.75
The comparison in terms of release rates gives an impression of better agree-
ment (Figure 16).
As mentioned above, the close agreement of the calculated and measured
values of | verifies our theory. So we could establish the following two
points in regard to |:
1) The partition coefficient | lies in the order of 10-5 I/day under
anoxic conditions.
2) It behaves as an exponential function in terms of sediment depth.
4 = Ce a That is, its value is greater at the surface and smaller
at deeper depths. This means that partitioning of phosphorus is
more active in the surface than in the deeper layer.
DETERMINATION OF h
If the release rates are measured, the values of | can be calculated by
the following equation.
Pr (1 + eo) (1 + §)
26
Z3 - (Z - Z)3
p 7 + _J_ B
6f
225
-------
o
-5 5
IO
23
2
I
0
- 0.00866 Z
I
I
10 15 20 25
SEDIMENT DEPTH (cm)
30
35
Figure 15. | curve.
CJ
o»
CALCULATED _^^=>
I
0 5 10 15 20 25 30 35
SEDIMENT DEPTH (cm)
Figure 16. Comparison of calculated and measured phosphorus release.
226
-------
These are independent of h, but the theoretical values of £ obtained by
-aZ
4 = Ce are dependent on h, because a is a function of h. Therefore, the
good agreement of them determines the value of h. As noted previously, it is
30 cm in this case. Figures 17 and 18 indicate that improper assumptions of h
will result in significant deviations from the measured values of |.
CONCLUSIONS
This paper supports several conclusions regarding phosphorus dynamics:
1) Release rates depend primarily upon the phosphorus content in the
sediment.
2) The relationship between release rate and sediment depth is appar-
ently parabolic.
3) Partition coefficients of phosphorus in sediment are on the order of
10-5 I/day in an anoxic condition.
4) Partitioning of phosphorus particulates is more active at the sedi-
ment surface than at deeper depths.
5) The sediment depth h, where the release rate curves become flat, is
about 20 cm in this case, and perhaps near this in other sediments.
In this study we found that the various indexes and curves obtained showed
considerable similarity and order. This implies that we must pay more atten-
tion to hydrostatic factors among the various aspects affecting phosphorus
release mechanisms.
227
-------
0
GOOD AGREEMENT OF
CALCULATED AND
MEASURED VALUES OF
10 20 30 40
SEDIMENT DEPTH (cm)
Figure 17. Function of ot.
h=20 cm
0 5 10 15 20 25 30
SEDIMENT DEPTH Z (cm)
Figure 18. Behavior of | against Z.
228
-------
CONTAINMENT AREA DESIGN FOR SEDIMENTATION
OF FINE-GRAINED DREDGED MATERIAL
R. L. Montgomery
Chief, Water Resources Engineering Group
Environmental Laboratory
USAE Waterways Experiment Station
Vicksburg, Mississippi 39180
ABSTRACT
Procedures are given for containment area design for
retention of suspended solids based on solids removal
through gravity sedimentation. Separate design proce-
dures for freshwater and saltwater sediments provide for
determination of the respective surface area or detention
time required to accommodate continuous dredged material
disposal. Procedures are also given for estimation of
the storage volume required for a single disposal
activity and the corresponding ponding depths, freeboard
requirements, and dike heights. Laboratory testing
procedures required to obtain data for sediment charac-
terization, containment area design, and estimates of
long term storage capacity are given. Sediment charac-
terization tests include salinity determination of near
bottom water and natural water content, Atterberg limits,
organic content, specific gravity, and grain size
analysis of the sediments. Sedimentation tests performed
in an 8 inch diameter column are used to define settling
behavior. Procedures for both flocculent settling tests,
generally applicable to freshwater sediments, and zone
settling tests, generally applicable to saltwater sedi-
ments, are described.
INTRODUCTION
Confinement of dredged material on land has been a disposal alternative
used by the Corps of Engineers for a number of years. In more recent years
this practice has increased, and added requirements have been placed on the
solids retention capability of confined disposal areas. The confined disposal
(containment) areas used for both retention and disposal of dredged material
are simply sedimentation basins.
229
-------
Dredged material sedimentation basins are slightly different from those
used in water and wastewater treatment in that the dredged material basins
must provide for sedimentation to achieve acceptable effluent quality while
providing storage volume for several years of material dredged from local
waterways. In most cases, the amount of dredged material storage required is
probably the controlling factor in sizing a conventional disposal area.
Nevertheless, effluents from the large areas now in existence often have
problems meeting the effluent requirements for suspended solids. This short-
coming can be attributed to the non-uniform lateral distribution of flows and
short-circuiting currents that occur in most dredged material containment
areas. As a result of short-circuiting currents, one section of flow is
subjected to a different velocity from another. Since sufficient detention
time is not provided in this section, the effluent has a higher solids level.
This can be seen in aerial photographs of containment areas in operation. An
example of a poorly designed containment area is shown in Figure 1. The flow
in this containment area is essentially overland flow resulting in significant
short-circuiting. In addition, the effective settling area appears to be
reduced to above one half the diked area because of a build-up of the coarse-
grained dredged material. These factors result in poor suspended solids
removal as indicated by the turbidity plume from the weir.
Figure 1. Turbidity from dredged material containment area.
230
-------
The major problem Is that very little is known about the actual sedimen-
tation process in dredged material containment areas. The hydrodynamic
problem of one particle falling through a fluid has been solved (Stoke's Law),
and formulas have been developed by researchers to determine the fall speed
when the density of a particle is very small and their distance apart is much
greater than their size. In practice, dredged material is discharged into the
sedimentation basin at concentrations averaging about 145 g/1. Because of
this high concentration, it is believed that sedimentation occurs under either
flocculent or zone settling processes.
High density slurries have been observed near the surface of dredged
material sedimentation basins indicating that hindered settling occurs in a
significant portion of the water column. The velocity for hindered settling
is less than that predicted by theories based on discrete settling because of
the upward velocity of water displaced by the highly concentrated slurry. A
review of present practices indicates that many dredging disposal operations
cannot be undertaken on a continuous basin and still maintain acceptable
suspended solids removal levels. Where strict effluent suspended solids
limits are enforced, periods of interrupted dredging are common to reduce the
loading rate and provide time for particle settling. These interrupted
dredging operations usually result in increased overall operational costs.
This paper provides procedures for designing fine grained dredged
material sedimentation basins to provide adequate retention of suspended
solids so that required effluent suspended solids levels can be met. The
procedures described herein were developed by the author with funds from the
Dredged Material Research Program, Environmental Laboratory, U.S. Army
Engineers Waterways Experiment Station, Vicksburg, Mississippi.
CONCEPTS OF CONTAINMENT AREA OPERATION
Diked containment areas are used to retain dredged material solids while
allowing the carrier water to be released from the containment area. The two
objectives inherent in the design and operation of a containment area are:
(a) to provide adequate storage capacity to meet dredging requirements; and
(b) to attain the highest possible efficiency in retaining solids during the
dredging operation in order to meet effluent suspended solids requirements.
These conditions are basically interrelated and depend upon effective design,
operation, and management of the containment area.
The major components of a dredged material containment area are shown
schematically in Figure 2. A tract of land is surrounded by dikes to form a
confined surface area, and the dredged channel sediments are then pumped into
this area hydraulically. The influent dredged material slurry can be charac-
terized by suspended solids concentration, particle gradation, type of carrier
water (fresh or saline), and rate of inflow.
In some dredging operations, especially in the case of new work dredging,
sand, clay balls, and/or gravel may be present. This coarse material (more
than half > No. 200 sieve) rapidly falls out of suspension near the dredge
inlet pipe forming a mound. The fine grained material (more than half < No.
231
-------
,MOUNDED COARSE-GRAINED
DREDGED MATERIAL
AREA FOR SEDIMENTATION
'DEAD ZONE
PONDING DEPTH—) r—FREEBOARD
COARSE-GRAINED X
DREDGED MATERIAL^
FOR FINE-GRAINED
DREDGED MATERIAL STORAGE
CROSS SECTION
Figure 2. Example of dredged material containment area.
200 sieve) continues to flow through the containment area with most of the
solids settling out of suspension, thereby occupying a given storage volume.
The fine grained dredged material is usually rather homogeneous and is easily
characterized.
The clarified water is discharged from the containment area over a weir.
This effluent may be characterized by its suspended solids concentration and
rate of outflow. Effluent flow rate is approximately equal to influent flow
rate for continuously operating disposal areas. Flow over the weir is con-
trolled by the static head and the effective weir length provided. To promote
effective sedimentation, ponded water is maintained in the area; the depth of
water is controlled by the elevation of the weir crest. The thickness of the
dredged material layer increases with time until the dredging operation is
completed. Minimum freeboard requirements and mounding of coarse grained
material result in a ponded surface area smaller than the total surface area
enclosed by the dikes. Dead spots in corners and other hydraulically inactive
zones reduce the effective surface area, where sedimentation takes place, to
considerably less than the ponded surface area (1).
232
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FIELD INVESTIGATIONS
Field investigations are necessary to provide data for containment area
design. The channel must be surveyed to determine the volume of material to
be dredged, and channel sediments must be sampled to obtain material for
laboratory tests. This part of the paper describes field investigations
required to obtain the necessary samples for laboratory testing. The methods
in common use for determining volumes of channel sediment to be dredged are
well known and do not warrant discussion here.
The level of effort required for channel sediment sampling is highly
project dependent. In the case of routine maintenance work, data from prior
samplings and dredging activities can provide a basis for developing the scope
of field investigations. Grab samples are considered adequate for sampling
fine grained sediments from maintenance dredging locations (2). Such samples
are adequate for sediment characterization purposes and are relatively easy
and inexpensive to obtain. An evaluation of dredged material after being
removed by the hydraulic dredge indicated that grab samples were adequate to
characterize the sediment properties (3).
Research by Bartos (4) summarized equipment available for sampling
channel sediments. He concluded that there are two general classes of
sampling equipment available for use in sampling channel sediments—grab
samplers and tube samplers.
Petersen Dredge
The Petersen dredge was found to be adequate for most sampling needs. An
example of this type of grab sampler being used is shown in Figure 3. The
Petersen dredge is a versatile sampler; it will sample a wide range of bottom
texture, from fine grained clays to sands. The Petersen dredge samples 144
square inches to a depth of about 12 inches, depending on the texture of the
sediment. It can be seen in Figure 3 that the sampler closes tightly, mini-
mizing the loss of sediment and water upon retrieval. The fine grained sedi-
ment samples obtained with this type grab sampler are considered to be repre-
sentative of i_n situ moisture contents.
Water Samples
Water samples should be taken at the same time as channel sediment
samples. The water samples should be taken near the water-sediment interface
and used to determine the salinity of the sediment environment. As will be
discussed later, salinity levels play an important role in the way sediments
settle.
Quantity of Sediment Samples
The quantity of sediment required is based on the amount needed for the
laboratory tests. Enough sediment to perform the necessary characterization
tests and provide material for the column settling tests should be collected
from each established sampling station. Five gallon containers can be used to
hold the sediment samples. These containers are about the largest that can be
233
-------
Figure 3. Petersen dredge being used to sample channel sediments,
handled efficiently. Small samples of sediment should be collected and placed
in 8-ounce watertight jars for water content and specific gravity tests. Care
must be taken to collect the small sediment samples that appear to be most
representative of the entire sample.
After the characterization tests are performed on grab samples from each
sampling station, the samples collected in the 5-gallon containers can be
combined to obtain sufficient material for the column settling tests.
Sample Preservation
Samples should be placed in air- and watertight containers and then in a
cold room (6 to 8°C) within 24 hours after sampling. The organic content
should be determined for each sample and, if less than about 10 percent, it is
not considered necessary to have the samples remain in the cold room. Below
this organic content level, it is assumed that little biological activity
could occur that would affect subsequent testing.
LABORATORY TESTING
Laboratory tests are required primarily to provide data for sediment
characterization and containment area design. A flow chart illustrating the
complete laboratory testing program for sediment samples is shown in Figure 4.
234
-------
SEDIMENT
SAMPLE*
1
VISUAL
CLASSIFICATION
CLEAN SANDS
FINE-GRAINED
(<40SIEVE)
SEPARATION
(40 SI EVE)
COARSE-GRAINED
(>40 SIEVE)
SPECIFIC
GRAVITY
PLASTICITY
ANALYSES
GRAIN-SIZE
ANALYSES
ORGANIC
CONTENT
CLASSIFICATION
(<40SIEVE)
YES
FLOCCULENT
SETTLING
TESTSt
FRESHWATER
SEDIMENTS**
NO
ZONE
SETTLING
TESTSt
SEDIMENTATION
PROPERTIES
DATA
NOTES:
ANALYZE DATA AND
DESIGN SEDIMENTATION
BASIN
NATURAL WATER CONTENTS
SHOULD BE DETERMINED ON
FINE-GRAINED SEDIMENTS.
IN AN ESTUARINE SYSTEM
WATER SAMPLES TAKEN
FROM THE BOTTOM OF THE
CHANNEL SHOULD BE TESTED
TO DETERMINE SALINITY.
MAY BE PERFORMED ON
COMPOSITE SAMPLES.
Figure 4. Flow chart of recommended laboratory testing program.
235
-------
Sediment character and requirements for sedimentation data estimates will
dictate which laboratory tests are required. Not all laboratory tests indi-
cated in Figure 4 are required for every application. The required magnitude
of the laboratory testing program is highly project dependent. Fewer tests
are usually required when dealing with a relatively homogeneous material
and/or when data are available from previous tests and experience, as is
frequently the case in maintenance work. For unusual maintenance projects
where considerable variation in sediment properties is apparent from samples
or for new work projects, more extensive laboratory testing programs are
required. Laboratory tests should always be performed on representative
samples selected using sound engineering judgment.
Sediment Characterization Tests
A number of sediment characterization tests are required before settling
tests can be performed. Visual classification will establish whether the
sediment sample is predominantly fine grained. Tests required on fine grained
sediments include natural water content, Atterberg limits, organic content,
and specific gravity. The coarse grained sediments require only grain size
analyses. Water samples taken from the channel should be tested for salinity
to provide information for use in performing the column settling tests.
Sedimentation Tests
Sedimentation, as applied to dredged material disposal activities, refers
to those operations in which the dredged material slurry is separated into
more clarified water and a more concentrated slurry. Laboratory sedimentation
tests must provide data for designing the containment area to meet effluent
suspended solids criteria and to provide adequate storage capacity for the
dredged solids. These tests are based on the gravity separation of solid
particles from the transporting water.
The sedimentation process can be categorized according to three basic
classifications: (a) discrete settling where the particle maintains its
individuality and does not change in size, shape, or density during the
settling process; (b) flocculent settling where particles agglomerate during
the settling period with a change in physical properties and settling rate;
(c) zone settling where the flocculent suspension forms a lattice structure
and settles as a mass, exhibiting a distinct interface during the settling
process.
The important factors governing the sedimentation of dredged material
solids are initial concentration of the slurry and flocculating properties of
the solid particles. Because of the high influent solids concentration and
the tendency of dredged material fine grained particles to flocculate, either
flocculent or zone settling behavior governs sedimentation in containment
areas (3). Discrete settling describes the sedimentation of sand particles
and fine grained sediments at concentrations much lower than those found in
dredged material containment areas.
236
-------
Laboratory tests are necessary to characterize the sediment and to
provide data for containment area design. A flow chart of the laboratory
testing program recommended for providing design data is shown in Figure 4.
The recommended laboratory procedures discussed here are for characterization
of the dredged material sedimentation process. They are based on results from
the extensive laboratory testing program (3, 5).
The objective of running settling tests on sediments to be dredged is to
define, on a batch basis, settling behavior in a large scale, continuous flow
dredged material containment area. Results of tests must allow determination
of numerical values for the design parameters which can be projected to the
size and design of the containment area.
Sedimentation of freshwater sediments at slurry concentrations as high as
175 g/1 can be characterized by flocculent settling properties (3). However,
as slurry concentrations are increased, the sedimentation process may be
characterized by zone settling properties. The settling column shown in
Figure 5 can be used with procedural modifications for both flocculent and
• VALVES FOa SAMPLE
EXTRACTION
SCTTLIN6 COLUMN
Figure 5. Schematic of flocculent settling test equipment.
237
-------
zone settling tests. Salinity, enhances the agglomeration of dredged material
particles (6). The settling properties of all saltwater dredged material
tested during the study by Montgomery (5) would be characterized by zone
settling tests.
Flocculent Settling Test
The flocculent settling test consists of measuring the concentration of
suspended solids at various depths and time intervals in a settling column.
If an interface forms near the top of the settling column during the first day
of the test, sedimentation is governed by zone settling and that test proce-
dure should be initiated. Information required to design a containment area
in which flocculent settling governs can be obtained using a procedure
described below.
1. A settling column such as that shown in Figure 5 is used. The test
column depth should approximate the effective settling depth of the
proposed containment area. A practical test depth is 6 feet. The
column should be at least 8 inches in diameter with sample ports at
1-foot intervals. The column should have provisions to bubble air
from the bottom to keep the slurry mixed during the column-filling
period.
2. Mix the sediment slurry to the desired suspended solids concentra-
tion in a container with sufficient volume to fill the test column.
At least two tests should be performed at the concentration selected
to represent the concentration of influent dredged material C-. Use
the average detention time computed from these tests for design.
Field studies indicate that for maintenance dredging in fine grained
material the disposal concentrations average about 145 g/1.
3. Pump or pour the slurry into the test column using air to maintain a
uniform concentration during the filling period.
4. While the column is completely mixed, draw off samples at each
sample port and determine the suspended solids concentration.
Average these values and use the results as the initial concentra-
tion at the start of the test. After the initial samples are taken,
stop the air bubbling and begin the test.
5. Allow the slurry to settle, then withdraw samples from each sampling
port at regular time intervals and determine suspended solids con-
centrations. Sampling intervals depend on the settling rate of the
solids—usually at 30-minute intervals for the first 3 hours and
then at 4-hour intervals until the end of the test. The sampling
times can be adjusted after the first complete test. Continue the
test until the interface of solids can be seen near the bottom of
the column and the suspended solids level in the fluid above the
interface is < 1 g/1.
238
-------
6. If an interface has not formed within the first day on any previous
tests, run one additional test with a suspended solids concentration
sufficiently high to induce zone settling behavior. This test
should be carried out according to the procedures outlined below for
zone settling tests. The exact concentration at which zone settling
behavior occurs depends upon the sediment being used to estimate the
volume required for dredged material storage.
Zone Settling Test
The zone settling test consists of placing a slurry in a sedimentation
column and recording the fall of the liquid-solids interface with time. Plot
the depth to the interface versus time as illustrated in Figure 6. The slope
of the constant settling zone of the curve is the zone settling velocity,
which is a function of the initial test slurry concentration. Information
required to design a containment area in which zone settling governs can be
obtained by using the procedure described below.
0.0
0.5
- 1.0
UJ
o
UJ
5 |.S
P.
X
a
Q2.0
2.5
-PERIOD OF AGGLOMERATION
CONSTANT SETTLING ZONE
SLOPE * ZONE SETTLING VELOCITY
L_
CONSOLIDATION ZONE
J.
0
20
40 60
TIME, hr
80
100
120
Figure 6. Typical batch settling curve for dredged material.
239
-------
1. Use a settling column such as that shown in Figure 5. It is impor-
tant that the column diameter be sufficient to reduce wall effects
and the test be performed at a slurry depth near that expected in
the field. Therefore, a one-liter graduated cylinder should never
be used to perform a zone settling test for sediment slurries repre-
senting dredged-disposal activities.
2. Mix the slurry to the desired concentration and pump or pour it into
the test column. Test concentrations should range from about 60 to
200 g/1. Air may not be necessary to keep the slurry mixed if the
filling time is less than 1 minute.
3. Record the depth to the solid-liquid interface with respect to time.
Observations must be made at regular intervals to gain data for
plotting the depth to interface versus time curve. It is important
to make enough observations to clearly define this curve for each
test.
4. Continue the readings until sufficient data are available to define
the maximum point of curvature of the depth to interface versus time
curve for each test. The tests may require from 1 to 5 days to
complete.
5. Perform a minimum of eight tests. Data from these tests are
required to develop the curve of zone settling velocity versus
concentration.
6. One of the above tests should be performed on sediment slurries at a
concentration of about 145 g/1. The test should be continued for a
period of at least 15 days to provide data for estimating volume
requirements.
DESIGN PROCEDURES
The flow chart shown in Figure 7 illustrates the design procedures recom-
mended in the following paragraphs. The design procedures were adapted from
procedures used in water and wastewater treatment and are based on field and
laboratory investigations on sediments and dredged material (3). Design
methods for saltwater and freshwater sediments are presented. Essentially the
method for saltwater sediments is based on zone settling properties, and the
method for freshwater sediments is based on flocculent settling properties.
The design procedures presented here are for gravity sedimentation of
dredged suspended solids. However, gravity sedimentation wi11 not completely
remove suspended solids from containment area effluent since wind and other
factors can resuspend solids and increase effluent solids concentration. The
sedimentation process, with proper design and operation, will normally provide
removal of fine grained sediments down to levels of 1 and 2 g/1 in the
effluent for saltwater and freshwater sediments, respectively. If the
required effluent standards are lower than this, the designer must provide for
additional treatment of the effluent, e.g., flocculation or filtration.
240
-------
DETERMINE DETENTION
TIME REQUIRED FOR
SUSPENDED SOLIDS REMOVAL
COMPUTE VOLUME
REQUIRED FOR
CONTAINMENT OF
SOLIDS
ADD PONDING DlrPTH
AND FREEBOARD
RECOMMEND CONTAINMENT
AREA DESIGN FOR
SUSPENDED SOLIDS RETENTION
Figure 7. Flow chart of recommended design
sediments.
procedures for fine-grained
241
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Data Requirements
The data required to use the design procedures are obtained from field
investigations, laboratory testing, dredging equipment designs, and past
experience in dredging and disposal activities.
Estimate In Situ Sediment Volume
The initial step in any dredging activity is to estimate the in situ
volume of sediment to be dredged. Sediment quantities are usually determined
from channel surveys on a routine basis.
Determine Physical Characteristics of Sediments
Field sampling and laboratory testing should be accomplished according to
the methods discussed by Palermo et aj_. (2). Adequate sample coverage is
required to provide representative samples of the sediment. In situ water
contents of the fine-grained sediments are also required. Care must be taken
in sampling to ensure that the water contents are representative of the ijn
situ conditions. The water content of representative samples, w, is used to
determine the iji situ void ratio e- as follows:
(w/100)Gs
ei = Sd/100 (1)
where
w = water content in percent
G = specific gravity of sediment solids
S. = degree of saturation (equal to 100 percent for sediment)
A representative value from in situ void ratios is used later to estimate
volume for the containment area.Grain-size analyses must be performed to
estimate the quantities of coarse and fine-grained material in the sediment to
be dredged.
Obtain and Analyze Proposed Dredging and Disposal Data
The designer must obtain and analyze data concerning the dredged material
disposal rate. For hydraulic pipeline dredges, the type and size of dredge(s)
to be used and the average solids concentration of the dredged material when
discharged into the containment area must be considered. If the size of the
dredge to be used is not known, the design must assume the largest dredge size
that might be expected to perform the dredging.
242
-------
Based on these data, the designer must estimate or determine containment
area influent rate, influent suspended solids concentration, effluent rate
(for weir sizing), effluent concentration allowed, and time required to
complete the disposal activity. If no other data are available for hydraulic
pipeline dredges, an influent suspended solids concentration of 145 g/1 (13
percent by weight) can be used for design purposes.
Perform Laboratory Sedimentation Tests
The procedures for sedimentation tests are given earlier in the section
on laboratory testing. A designer must evaluate the results of salinity tests
to determine whether the sediments to be dredged are freshwater or saltwater
sediments. If the salinity is about 3 ppt, the sediments are classified as
saltwater sediments for the purpose of selecting the laboratory sedimentation
test.
Design Method for Saltwater Sediments
The following design method is recommended for sedimentation of dredged
material from a saltwater environment. It can also be used for freshwater
dredged material if the laboratory settling tests indicate zone settling
properties. An example of this design method is presented by Montgomery (3).
Analyze Laboratory Data
A series of zone settling tests must be conducted as detailed earlier.
The results of the settling tests are analyzed to determine zone settling
velocities at the various suspended solids concentrations. The procedure is
as follows:
1. Develop a settling curve for each test. Plot depth to interface
versus time.
2. Calculate the zone settling velocity, v , as the slope of the
constant settling zone (straight line portion of the curve). The
velocity should be in feet per hour.
3. Plot v versus suspended solids concentrations on a semi-log plot.
4. Use the plot developed in step 3 to develop a solids loading versus
solids concentration curve as shown in Figure 8.
Compute Design Concentration
The design concentration, Cn, is defined as the average concentration of
the dredged material in the containment area at the end of the disposal
activity and is estimated from data obtained from the 15-day column settling
tests. The following steps can be used to estimate average containment area
concentrations for each 15-day column settling test. It may be desirable to
perform more than one 15-day test. If so, use an average of the values as the
design concentration.
243
-------
5r-
t-
U.
i
IT
I
m
j
o
z
o
J
J
O
SOLIDS CONCENTRATION C, UB/FTJ
Figure 8. Typical solids loading curve for dredged material.
1.
2.
3.
4.
5.
Compute concentration
Assume zero solids in
lify calculation.
versus time for the 15-day settling test.
the water above the solids interface to simp-
Plot concentrations versus time on log-log paper (see Figure 9).
Draw a straight line through the data points. This line should be
drawn through the points representing the consolidation zone.
Estimate the time of dredging by dividing the dredge production rate
into volume of sediment to be dredged.
Estimate the concentration at tj, (one-half the time required for the
disposal activity determined itf step 4) using the figure developed
in steps 2 and 3. This time is an approximation of the average time
of residence for the dredged material in the containment area.
Since concentration is a function of time, one-half the dredging
244
-------
lOOOr—
900-
800 -
9600 -
"500-
5*00-
>300
too
OeSIGN CONCfMTKA TIOH. Cd-340f/t
6 7
890
TIME,
20
30 40 90 60 708090100
Figure 9. Concentration versus time.
time would represent a period during which one-haIf of the dredged
material would have been in the area longer and the other half less
than a time equal to one-half the dredging time.
6. Use the value computed in step 5 as the design solids concentration,
CD.
Compute Area Required for Sedimentation
Containment areas designed according to the following steps should
provide removal of fine grained sediments well enough so that suspended solids
levels in the effluent do not exceed 1 to 2 g/1. The area required for the
zone settling process to concentrate the dredged material to the design
concentration is computed as follows, using the Yoshioka et a]_. (7) graphic
solution to the Coe and Clevenger procedure (8).
1. Use the design concentration and construct an operating line from
the design solids concentration tangent to the loading curve as
shown in Figure 10. The design loading is obtained on the y-axis as
S, .
245
-------
5X>r
«M
E 4.0
3X)
o
5
o
2.0
1.0
S = vsC
DESIGN SOLIDS
CONCENTRATION
0 5.0 10.0 15.0 20.0 25.0
SOLIDS CONCENTRATION, C , Ib/ft3
Figure 10. Solids loading curve showing design line.
30.0
2. Compute the required area as
(2)
where
A = containment area surface requirement, ft2
in
Qi = influent rate, ftVhr (Qi = A Vd; assume Vd = 15 ft/sec i
absence of data and convert Q. calculated in ftVsec to ftVhr)
A = cross sectional area of dredge pipeline, ft2
V, = velocity of dredge discharge, ft/sec
C. = influent solids concentration, Ib/ft3 (use M5 g/1 or 9.2 Ib/ft3
if no data are available)
S, = design solids loading, lb/hr-ft2
246
-------
3. Increase area by a factor of 2.25 to compensate for containment area
short-circuiting and dispersion.
Ad = 2.25 A (3)
where
Ad = design basin surface area, ft2
A = area determined from Equation 2, ft2
Design Method for Freshwater Sediments
Sediments in a dredged material sedimentation basin are comprised of a
broad range of particle floes of different sizes and surface characteristics.
In the sedimentation basin under flocculent settling conditions the large
particle floes settle at faster rates, thus overtaking finer floes in their
descent. This contact increases the floe sizes and enhances settling rates.
The greater the ponding depth in the containment area, the greater is the
opportunity for contact among sediments and floes. Therefore, sedimentation
of freshwater dredged sediments is dependent on the ponding depth as well as
the properties of the particles.
The results of one flocculent test are shown in Figure 11. The initial
concentration of the test slurry was 175 g/1 and the depth of slurry was 8
feet. Percent by dry weight of initial concentration was plotted versus depth
for various times. These times represent the period of settling for the
slurry. Settling data plotted in this manner can be used to evaluate the
dominant sedimentation process (9). The dashed lines in Figure 11 were gener-
ated by dividing the depth by time and plotting dashed lines of constant d/t
values. It is possible to tell directly from this plot that flocculation is
causing the particles to settle more rapidly (9). This is indicated by the
fact that the dashed lines, d/t, slope toward the d-axis. When neither zone
settling nor flocculation occurs, the dashed lines will be straight and
parallel to the d-axis. When zone settling slows the particles down more than
flocculation can speed them up, the dashed lines will slope away from the
d-axis.
Analyze Laboratory Data
Evaluation of the sedimentation characteristics of a freshwater sediment
slurry is accomplished as discussed earlier. The design steps are as follows
[refer to Montgomery (3} for example problem]:
1. Arrange data from laboratory tests illustrated in Table 1 into the
form shown in Table 2.
2. Plot these data as shown in Figure 11. The percent by weight of
initial concentration for each depth and time is given in Table 2.
The solid curved lines represent the concentration depth profile at
247
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TABLE 1. OBSERVED FLOCCULENT SETTLING CONCENTRATIONS WITH DEPTH
(in grams per liter)
Time
(min)
0
30
60
120
180
240
360
600
720
1020
1260
1500
1740
1
132
46
25
14
11
6.8
3.6
2.8
1.0
0.9
0.8
0.7
0.6
Depth
2
132
99
49
20
14
10.2
5.8
2.9
1.6
1.4
1.1
0.9
0.7
from top
3
132
115
72
22
16
12
7.5
3.9
1.9
1.7
1.2
1.0
0.8
of settling
4
132
125
96
55
29
18
10
4.4
3.1
2.4
1.4
1.1
0.9
column
5
132
128
115
78
75
64
37
14
4.5
3.2
1.7
1.2
1.0
(feet)
6
132
135
128
122
119
117
115
114
110
106
105
92
90
7
132
146
186
227
Note: Data from actual test on freshwater sediments. Although a 6-foot test
depth is recommended, an 8-foot depth was used in this test.
TABLE 2. PERCENT OF INITIAL CONCENTRATION WITH TIME
Time, T
(min)
0
30
60
120
180
240
360
600
720
Depth
1 ft
100
35
19
11
8
5
3
2.0
1.0
from top of settling
2 ft
100
75
37
15
11
8
4
2.2
1.2
column
3 ft
100
87
55
17
12
9
6
3.0
1.4
Note: Initial suspended solids concentration = 132 g/1.
248
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to 20 30
PERCENT BY DRY WEIGHT 4, OF INITIAL CONCENTRATION
Figure 11. Depth versus percent solids by weight of initial concentration.
various times during settling (refer to Figure 11 for more details).
Numbers appearing along the horizontal depth lines are used to
indicate area boundaries.
3. Compute a design concentration using data from the 15-day zone
settling test. Follow the procedure outlined in the design method
for saltwater sediments.
Compute Detention Time Required for Sedimentation
The detention time is computed as follows:
1. Calculate removal percentage at depths of 1, 2, and 3 feet for
various times using the plot illustrated in Figure 12. The removal
percentage for depth dx and t = 1 is computed as follows:
249
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PERCENT BY DRY WEIGHT Of INITIAL CONCENTRATION
Figure 12. Removal of flocculating dredged material particles.
D - Area 0, 10. 11, 1* v inn ,A,
R - Area 6, 2\ 11, 1 x 10° (4)
where
R = removal percentage
Determine these areas by either planimetering the plot or by direct
graphic measurements and calculations. This appproach is used to
calculate removal percentages for each depth as a function of time.
The depths used should cover the range of ponding depths expected in
the containment area. This report recommends at least 2 feet of
ponding depth at the end of the dredging project.
2. Plot the solids removal percentages versus time as shown in Figure
T *S
* These numbers correspond to the numbers used in Figure 12 to indicate the
area boundaries for the total area down to depth d (0, 2, 11 1) and the
to the right of the t = 1 time line (0, 10, 11, 1).
250
-------
ZOO
400 600
TIME , min
800
1000
Figure 13. Solids removal versus time as a function of depth.
Theoretical detention times can be selected from Figure 13 for
various solids removal percentages. Select the detention time, T,
that gives the desired removal percentage for the design ponding
depth.
The theoretical detention time, T, should be increased by a factor
of 2.25 to compensate for the fact that sedimentation basins,
because of short circuiting and dispersion, have average detention
times less than volumetric detention times:
Td = 2.25 T
(5)
where
= design detention time
251
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Volume Requirements for Containment of Solids
The procedures outlined in the above paragraphs are aimed at providing
sedimentation basins with sufficient areas and detention times to accommodate
continuous disposal activities while providing sufficient suspended solids
removal to meet effluent suspended solids requirements. Sedimentation basins
must also be designed to meet volume requirements for a particular disposal
activity. The total volume required of a sedimentation basin includes volume
for storage of dredged material, volume for sedimentation (ponding depths),
and freeboard volume (volume above water surface). Volume required for
storage of the coarse-grained material (> 200 sieve) must be determined separ-
ately, because this behaves independently of the fine-grained (< 200 sieve)
material.
Estimate Volume Occupied by Dredged Material in Sedimentation Basin •
The volume occupied by dredged material in the sedimentation basins after
the completion of a particular disposal activity is computed as follows. The
volume is not an estimate of the long-term needs for multiple-disposal activ-
ities. The procedures given below can be used to design for volume required
for one disposal activity, or used to evaluate the adequacy of the volume
provided by an existing sedimentation basin.
1. Compute the average void ratio of fine-grained dredged material in
the sedimentation basin at the completion of the dredging operation
using the design concentration determined in earlier steps as dry
density of solids. (Note that design concentration is determined
for both flocculent and the zone sedimentation design procedure.)
Use the following equations to determine void ratio:
Vw
% = — 'I
where
e = average void ratio of dredged material in the sedimentation
0 basin at the completion of the dredging operation
G = specific gravity
5
W
= density of water, g/1
y, = dry density of solids at design concentrations, (Cr. = Yd)
2. Compute the change in volume of fine-grained channel sediments after
disposal in the sedimentation basin from:
252
-------
AV = Vi
where
AV = change in volume of fine-grained channel sediments after
disposal in the sedimentation basin, ft3
e. = average void ratio of ijn situ channel sediments
V. = volume of fine-grained channel sediments, ft3
3. Compute the volume required by dredged material in the sedimentation
basin from:
V = V. + AV + Vsd (8)
where
V = volume of dredged material in the sedimentation basin at the
end of the dredging operation, ft3
V . = volume of sand (compute using 1:1 ratio), ft3
Estimate of Basin Depth
Previous calculations have provided a design area A. and design detention
time T. required for fine-grained dredged material sedimentation. Equations
6-8 are used to estimate the volume and corresponding depth requirements for
the storage of solids in the containment area. Throughout the design process,
the existing topography of the containment area must be considered, since it
can have a significant effect on the average depth of the containment area.
Saltwater Sediments (Zone Settling)
The following procedure should be used for saltwater sediments:
1. Estimate the thickness of dredged material at the end of the
disposal operation from:
253
-------
where
H . = thickness of the dredged material layer at the end of dredging
operation, ft
V = volume of dredged material in the basin, ft3 (from Equation 8)
A. = design area, ft2 (as determined from Equation 3 or known
surface area for existing sites)
2. Consult with soils design engineers to determine maximum height
allowed for confining dikes. Anticipated settlement of the dikes
should also be considered.
3. Add ponding depth and freeboard depth to H. to determine the
required containment area depth (dike height).
D = Hdra + Hpd + Hfb ™
where
D = dike height, ft
H . = average ponding depth over the area, ft (a minimum of 2 feet
P is recommended)
Hf. = freeboard above the basin water surface to prevent wave over-
topping and subsequent damage to confining earth dikes, ft (a
minimum of 2 feet is recommended to account for fetch and
wi nd).
4. Compare with allowable dike height.
Freshwater Sediments (Flocculent Settling)
The following procedure should be used for freshwater sediments:
1. Compute the volume required for sedimentation from:
254
-------
where
Vg = sedimentation basin volume required for meeting suspended
solids effluent requirements, ft3
T^ = required detention time from Equation 5
2. Consult with soils design engineers to determine maximum height
allowable for confining dikes D. In some cases, it might be desir-
able to use less than the maximum allowed dike height.
3. Compute the required design area as a minimum required surface area
for solids storage from:
A - V (12)
d Hdm(max)
where
Hdm(max) = D " Hpd " Hfb
or set the design area A. equal to the known surface area for
existing sites.
4. Evaluate volume available for sedimentation near the end of the
disposal operation from:
V* = HpdAd <13)
where
V* = volume available for sedimentation near the end of disposal
operation, ft3
5. Compare V* and Vn. If the volume required for sedimentation is
larger than V*, tne sedimentation basin will not meet the suspended
solids effluent requirements for the entire disposal operation. The
following three measures can be considered to ensure that effluent
requirements are met: (1) increase the design area, A.; (2) operate
the dredge on an intermittent basis when V* becomes less than VB or
use smaller size dredge; and (3) provide for post-treatmentr of
effluent to remove solids.
255
-------
6. Estimate the thickness of dredged material at the end of disposal
operation using Equation 9. A. is determined using step 3 above.
7. Determine the required sedimentation basin depth using Equation 10.
8. Compare with maximum allowable dike height (see paragraph below).
At most sedimentation basins, the foundation soils are soft. Such foun-
dations limit the heights of confining earth dikes that can be economically
constructed. Therefore, soils design engineers must be consulted to determine
the maximum dike height that can be constructed. If the maximum dike height
allowed by foundation conditions is less than the sedimentation basin depth
requirement, the design area A. must be increased until the depth requirement
can be accomodated by the allowable dike height; the thickness of the dredged
material layer must also be decreased.
SUMMARY
The field verification work performed by Montgomery (5) indicated that
conservative values could be estimated from laboratory tests for solids
concentrations expected in the dredged material sedimentation basin. The
laboratory tests data were reasonably close and should be adequate for design
purposes. The column sedimentation tests can be improved with further exper-
ience in dredged material sedimentation basin design and with more laboratory
testing.
The flocculent settling tests and design procedures recommended for
freshwater sediments were found to provide design estimates that agreed
closely with actual field values. However, additional cases should be eval-
uated before full substantiation of these procedures is proclaimed.
A significant amount of work is required on the hydraulic efficiency of
dredged material sedimentation basins before firm design correction factors
can be established to account for scale-up and flow-through problems. Five
dye tracer tests were evaluated by Montgomery (5). The correction factors
determined from these tests varied from 2.13 to 2.72. Based on the work
accomplished during this research, a correction factor of 2.25 appears reason-
able. This factor is higher than those recommended in the sanitary engin-
eering literature. However, the conditions experienced at a dredged material
sedimentation basin are more complex than those of wastewater treatment
facilities.
REFERENCES
Brian J. Gallagher and Company, "Investigation of Containment Area Design
to Maximize Hydraulic Efficiency," Technical Report D-78-12, U.S. Army
Engineer Waterways Experiment Station, CE, Vicksburg, Miss., 1978.
256
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2. Palermo, M. R., Montgomery, R. L., and Poindexter, M. E., "Guidelines for
Designing, Operating, and Managing Dredged Material Containmant Areas,"
Technical Report DS-78-10, U.S. Army Engineer Waterways Experiment
Station, CE, Vicksburg, Miss., 1978.
3. Montgomery, R. L., "Methodology for Design of Fine-Grained Dredged
Material Containment Areas for Solids Retention," Technical Report
D-78-56, U.S. Army Engineer Waterways Experiment Station, CE, Vicksburg,
Miss., 1978.
4. Bartos, M. J., "Classification and Engineering Properties of Dredged
Material," Technical Report D-77-18, U.S. Army Engineer Waterways Experi-
ment Station, CE, Vicksburg, Miss., 1977.
5. Montgomery, R. L. , "Development of a Methodology for Designing Fine-
Grained Dredged Material Sedimentation Basins," Ph.D. Dissertation,
Vanderbilt University, Nashville, Tenn., 1979.
6. Migniot, C., "A Study of the Physical Properties of Various Very Fine
Sediments and Their Behavior Under Hydrodynamic Action," La Houille
Blanche, Vol. 23, No. 7, 1968, pp. 59-620.
7. Yoshioka, N. et aj., "Continuous Thickening of Homogeneous Flocculated
Slurries," Chemical Engineering (Tokyo), Vol. 21, 1957, pp. 1-10.
8. Coe, H.S., and Clevenger, G. H. , "Methods for Determining the Capabil-
ities of Slime Settling Tanks," Transactions, American Institute of
Mining Engineers, Vol. 55, No. 9, 1916, pp. 356-384.
9. Mclaughlin, R. T. , "The Settling Properties of Suspensions," Journal of
the Hydraulics Division, American Society of Civil Engineers, Vol. 85,
No. 12, 1959, pp. 9-41.
257
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SAMPLING, PRESERVATION, AND ANALYSIS OF SEDIMENT SAMPLES:
STATE-OF-THE-ART LIMITATIONS
R. H. Plumb, Jr.
Great Lakes Laboratory
State University College at Buffalo
1300 Elmwood Avenue
Buffalo, New York 14222
ABSTRACT
The collection and analysis of sediment samples has
become a topic of increased regulatory concern. This
paper presents a procedure for preparing a sediment samp-
ling program based on an awareness of the interrelated
nature of the decisions to be made. The first step in the
approach is to explicitly state the purpose of the in-
tended study so that testing procedures can be selected
based on the sample property they measure. This provides
the most efficient use of available procedures and simpli-
fies the selection of sample handling and storage require-
ments. Selection of sample collection techniques and
locations is the most difficult area to provide definitive
guidance because of the importance of point sources, local
hydrology, study purposes, and financial resources.
Therefore, bias that can be introduced into the final data
as a consequence of collection technique and sample loca-
tion decisions are discussed. By being aware of the
present limitations of available sampling techniques and
analytical procedures, project managers can define the
best sampling program for their specific need.
INTRODUCTION
Sediments are an important reservoir in the aquatic cycling of chemical
contaminants that can respond to equilibrium stresses. Major point source
discharges can enrich the composition of sediments through the processes of
precipitation and sorption/settling. The mechanisms of mixing and diffusion
can also result in the transfer of sediment-associated constituents from the
sediments to the overlying water column. The dynamic, although ill-defined,
interaction between sediments and water and the tremendous quantities of
material involved in dredging activities has created increased regulatory
concern over the composition of sediments and the effects of sediments on
water quality. This concern has contributed to the implementation of Section
259
-------
404 of Public Law 92-500 (Clean Water Act) and Section 103 of Public Law
92-532 (Marine Protection, Research, and Sanctuary Act). These regulations
are requiring a more complete characterization of sediments to be dredged and
an evaluation of the potential environmental consequences of disposing of this
material.
Since the regulatory criteria will require an expanded sediment sampling,
it will be necessary to standardize the methods of sediment collection, sample
handling, and analysis to insure comparability of data for the regulatory
decision-making process. To achieve this objective, the Great Lakes Labora-
tory has been working with the Environmental Protection Agency/Corps of
Engineers Technical Committee on Criteria for Dredged and Fill Material to
develop state-of-the-art guidance for the collection, handling, and analysis
of sediment samples. This paper will discuss the present limitations on
providing the required guidance.
PLANNING A SEDIMENT COLLECTION PROGRAM
An individual responsible for implementing a sediment sampling study is
faced with numerous decisions. However, it is not possible to provide defini-
tive guidance for all these decisions because of site-specific influences.
This can best be illustrated by listing the decisions to be made and the
factors that can influence each decision, as in Table 1. This approach
clearly identifies those decisions related to sample collection as the most
subjective. The next most subjective decisions are related to the selection
of specific tests and analyses to be performed. While procedures and analyti-
cal techniques can be specified, the need and appropriateness is site- and
project-dependent. The least subjective of the decisions relates to sample
storage and handling as these procedures become mandatory once the tests and
analyses are specified.
The summation in Table 1 also points out the interaction between the
various decision points. For example, sampling locations, testing procedures,
and specific analyses all depend on the specific purpose of the study. In
addition, although testing procedures and analyses are chronologically last in
the processing of samples, a decision on which test and analyses to perform
must be made prior to sampling so that proper precautions can be taken for
sample handling and storage.
It should be apparent that an essential component of any field sampling
program is a pre-project meeting with all concerned personnel. The purpose of
this meeting should be to define the objective of the sampling program so that
the information needed can be matched with the specific tests that are avail-
able for use. This approach will have the effect of directing the sampling
program at a specific need and assist in deciding which tests to perform. A
second benefit of such a meeting is increased communication between partici-
pating groups so that field personnel are aware of potential sample handling
and contamination problems and laboratory personnel are available to analyze
collected samples within prescribed time limits.
260
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TABLE 1. REQUIRED DECISIONS IN PLANNING A SEDIMENT SAMPLE COLLECTION PROGRAM
Decision Point Influencing Factor
Where to sample Major point sources
Local hydrology
Purpose of study
How many samples Site variability
Required degree of definition
Resources (dollars and/or manpower) available
When to sample Are seasonal fluctuations expected?
Type of sample Purpose of study
Tests to be run
How to sample Site variability
Purpose of study
How to store samples Type of test to be run
Type of analysis to be run
What tests to be run Purpose of study
What analysis to perform Site-specific factors
Purpose of study
Any definition of a project should avoid generalized tasks such as "an
environmental assessment of a proposed dredged material disposal operation".
Although an environmental assessment may be the overall objective of the
study, this objective should be considered a cumulative effect. Therefore,
the objective of the sampling program should be subdivided into specific tasks
such as:
a. Compare two or more sites in a project area.
b. Quantitate the total amount of certain contaminants present.
c. Determine the mobility of contaminants in dredged material.
d. Determine the distribution of certain chemical contaminants in the
sediments of a project area.
e. Determine potential sediment toxicity.
f. Determine the biological suitability of project-site water.
261
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g. Determine whether a local discharge has altered the water and/or
sediments in the project area.
h. Determine the sediment-phase distribution of certain chemical con-
taminants in the sediments of a project area.
As will be stated shortly, the chemical tests available for sediment studies
measure specific characteristics of sediments. Thus, the more explicitly the
goals of a project can be stated, the easier it should be to select the tests
to be run and, subsequently, the required method of sample handling.
Sample Testing Procedures
The next step in the project-planning process should be the selection of
testing procedures to be used. Presently, the three types of tests available
for the analysis of sediments include (1):
a. Bulk Analysis
b. the Elutriate Test
c. fractionation/extraction procedures
The utility of any one sediment test for a particular project can only be
determined after the purpose of the study has been identified since each test
provides different information as indicated below:
a. Bulk Analysis provides an estimate of the total concentration of a
constituent in the sediment sample. The analytical result will
include the various sediment phases (interstitial water phase,
exchangeable phase, residual phase, etc.), but is poorly related to
the biological availability of the constituent. A beneficial aspect
of this test is that storage and preservation problems are minimized
since changes in the oxidation state generally do not affect total
concentrations. Bulk Analysis results are useful for calculating an
inventory of the total amount of a constituent involved in a dredg-
ing project. However, a major limitation of the test is that re-
sults are a poor indicator of potential environmental effects of
moving the sediments (2) (as in a dredging operation) because of the
poor relationships between total concentration of a constituent in
sediments and biological availability (3, 4) or water quality
changes (5).
. b. The Elutriate Test provides an estimate of the mobility of chemical
constituents from the sediment phase to the water phase. This test
has the advantage of being more environmentally interpretable since
it measures "water soluble" constituents which are the basis of most
water quality criteria. The disadvantages associated with the
Elutriate Test are the lack of understanding of the mixing process
that influences data interpretation (6), the fact that the test is
of short duration and may not estimate long-term changes following
disposal, and the fact that this test, like Bulk Analysis, does not
address possible impacts on benthic fauna. In addition, the test
requires a greater effort for storage and preservation of samples
since oxidation state changes may alter test results (7).
262
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c. The fractionation procedures provide more detailed information on
the distribution of chemical constituents within the sediments by
subjecting the sample to a series of increasingly harsh extractions
solutions (5, 8). It is possible there may be a crude inverse
relationship between the harshness of. the extraction solution and
the bioavailability of the constituents. However, the full meaning
of a given distribution is not understood. Further limitations of
this procedure are that the actual testing is more time consuming
and strict storage requirements are mandatory.
An important aspect of the description of each test procedure is that
each test measures a different property of the sample. The Bulk Analysis Test
measures the total concentration of a chemical constituent of sediments re-
gardless of chemical form and the Elemental Partitioning procedure measures
the distribution of the total amount of material among several operationally-
defined phases. The Elutriate Test measures chemical mobility under specified
conditions. It is these properties, chemical presence, chemical distribution,
and chemical mobility, that should be matched with the identified purpose(s)
to determine whether the test is appropriate for the study in question.
A major limitation of all three tests is the present inability to inter-
pret the results, particularly in terms of biological impact. For example,
Bulk Analysis tells one how much is present, but the literature in the water
field clearly demonstrates that total concentration is not the factor that
determines biological response (2). Thus, any total measurement will over-
estimate potential biological response. Similarly, the Elutriate Test has
some merit because the mobility phase is operationally equated with the sol-
uble phase and the soluble phase has been classically used in the establish-
ment of water quality criteria. However, water quality criteria have an
implied time factor of 96 hours to one year whereas the Elutriate Test concen-
tration represents end-of-the-pipe concentrations that are diluted by several
orders of magnitude in 10 to 60 minutes. Because the exposure time and expo-
sure concentrations are over exaggerated, the Elutriate Test is also a poor
estimator of biological response (6). The Elemental Partitioning procedure is
a relatively new test that has been used more as a research tool than a regu-
latory tool. Studies have indicated a time-dependent relationship between the
more labile Elemental Partitioning phases and water quality changes (5), but
no relationship between phase distribution and biological response (3). At
present, the meaning of an elemental distribution is unknown.
A second limitation of.all three tests is that each contains a degree of
subjectivity. The Elutriate Test (1) consists of shaking one volume of sedi-
ment with four volumes of water for 30 minutes. Both the ratio and time are
subjective. The Elemental Partitioning procedures described by Brannon et al_.
(5, 8) consist of the use of six extraction solutions. The number and rela-
tive strength of the extraction solutions are subjective. Finally, even Bulk
Analysis procedures can be less than objective. Numerous digestion procedures
have been described and the efficiency of any one digestion method can be
affected by (1) length of digestion time, (2) the specific chemical contami-
nant of interest, (3) the type of sample, and (4) particle size (9, 10).
263
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Any attempt to make the testing procedures more objective would be desir-
able from a scientific point of view, but would not necessarily be helpful
from a regulatory point of view. The reason for this situation is that alter-
ing the testing procedure will not improve the ability to interpret the re-
sults. Thus, the present emphasis should be to apply the available tests,
subjective though they may be, in a standardized manner.
Type of Samples
Once the tests to be used have been selected, the type of samples that
have to be collected has been determined. When the Elutriate Test is to be
run, both water and sediment must be collected. For the Bulk Analysis and
Elemental Partitioning procedures, only sediment samples are needed.
Specific Analyses
The next item on the planning meeting agenda should be the selection of
the specific chemical analysis to be completed. This is necessary to insure
that proper handling and sample storage techniques are available during the
collection period. It will also insure that sufficient sample is collected to
perform all scheduled analyses.
The preparation of a mandatory analysis list should be discouraged. The
analysis to be performed should be site specific and based on project pur-
poses, major point sources, and/or local activities. For example, if the
purpose is to clean up an industrial spill for PCBs, there is certainly reason
to analyze for PCBs, but additional analysis for a wide spectrum of metals
would not be useful in terms of the stated project purpose. This is not to
say that sediment data is not scientifically useful, but rather a distinction
between regulatory need and research must be made. Such a distinction will
make most efficient use of the analytical dollars for specific projects.
Sample Storage Procedures
Specific identification of project purposes will lead to the selection of
chemical tests to be used and chemical analyses to be performed. These deci-
sions will simplify the selection of sample storage procedures. The use of
the Elutriate Test and/or Elemental Partitioning will require samples to be
stored moist in an oxygen-free environment. Bulk Analysis samples may be
stored under a variety of conditions depending on the specific analyses to be
performed. Different storage techniques are required because each test mea-
sures a different property of the sediment sample.
The Elutriate Test measures chemical mobility under specified conditions.
Since mobility is a function of chemical speciation, any preservation tech-
nique must minimize changes in chemical speciation. Because oxidation will
change chemical form, exposure to the atmosphere is undesirable. Chemical
additives are also undesirable since they may alter solubility and chemical
form (and, hence, mobility). The recommended method of sample storage is to
approximate field conditions (refrigerate and seal in an oxygen-free environ-
ment) and process as soon as possible.
26-4
-------
A similar approach of sample refrigeration in an oxygen-free environment
is also recommended for Elemental Partitioning samples. Whereas the Elutriate
Test is concerned about the "concentration" of a chemical constituent in a
specific phase (water Teachable), Elemental Partitioning is concerned about
the distribution of a chemical constituent between several phases. Therefore,
changes in oxidation and solubility are equally undesirable. Since there is
no known preservative that preserves chemical distribution in sediments, the
best state-of-the-art approach is to refrigerate the sample to inhibit bacter-
ial growth and reduce Eh stress by isolating the sample from atmospheric
contact. Freezing and drying are not recommended because physical changes can
alter chemical form and, hence, distribution.
The third test procedure, Bulk Analysis, measures total concentration and
is, therefore, less sensitive to chemical speciation changes. Consequently,
greater flexibility in sample storage is acceptable for this procedure. The
procedure used for the Elutriate Test and Elemental Partitioning can be used
for Bulk Analysis samples, but freezing and drying can also be utilized for
sample storage as long as the constituent of interest is not altered or lost
by volatilization during the drying or thawing steps. A recommended list of
analysis that can be performed on moist, dried, and frozen samples is pre-
sented in Table 2. It is apparent that the largest number of analysis can be
run on moist samples since samples stored in this manner are least subject to
change.
Information on sample handling for each chemical parameter was summarized
in the format shown in Figure 1. The most extensive information was available
for handling and storage of water samples. The least information is available
for sediment sample handling. It was assumed that container requirements for
water samples were also valid for sediment samples. A major unknown is the
length of time that sediment samples can be stored prior to analysis.
SAMPLING CONSIDERATIONS
The remaining decision points in Table 1 relate to location, numbers, and
method of sample collection. Each component is important because the quality
of any sediment evaluation study is only as good as the information gained
through sampling. Thus, any errors incurred during sampling will manifest
themselves by limiting the accuracy and/or appropriateness of the study.
The objective of the sampling program should be to obtain representative
samples using appropriate sampling techniques (11, 12, 13). However, despite
the fundamental importance of these factors, it is difficult to provide spe-
cific guidance to achieve this objective because of site-specific factors such
as major point sources and project purposes. Therefore, the best state-of-
the-art guidance that can be provided is to be on guard against introducing a
bias during sample collection (11).
One potential bias can be introduced during the selection of sampling
locations. For example, it is a usual practice to collect samples in the
vicinity of major point sources and in quiescent areas that are conducive to
the settling of finer-sized material. The former sites would be expected to
have higher concentrations because of their proximity to the sources. The
265
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TABLE 2. ACCEPTABLE METHOD OF SAMPLE STORAGE AS A FUNCTION
OF BULK SEDIMENT ANALYSES TO BE PERFORMED
Wet
CEC
C12 Demand
BOD
COD
SOD
Carbamates
PH
SRP
Redox
Total Solids
Volatile Solids
Sul fides
Phenoxy Acids
Particle Size
Minerology
TOC
TIC
Pesticides
Phenol ics
Spec. Grav.
NH3
N02"
N03"
ORG-N
TKN
0 & G
PCB
ORG-P
Total -P
PAH
Hg
Al
As
Cd
Ca
Cr
Cu
Fe
Pb
Mg
Mn
Mo
Ni
Se
Zn
Dry
Particle Size*
Minerology
TOC
TIC
PCB
Pesticides
ORG-P
Total -P
PAH
Hg**
Al
As
Cd
Ca
Cr
Cu
Fe
Pb
Mg
Mn
Mo
Ni
Se
Zn
Freeze
Particle Size*
Minerology
TOC
TIC
0 & G
PCB
Pesticides
Phenol ics
ORG-P
Total-P
PAH
Hg
Al
As
Cd
Ca
Cr
Cu
Fe
Pb
Mg
Mn
Mo
Ni
Se
Zn
* Dispersed particle size probably not affected by drying or freezing.
Apparent particle size may be affected.
** Mercury may be lost if sample is dried at too high a temperature.
266
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| WATER SAMPLE |
ACIDIFY
I
STORE
I
DIGEST
1
ANALYZE
(Wl)
1
F 1 LTER | | NO TREATMENT ( W3) |
|
ACIDIFY
|
STORE
|
ANALYZE
(W2)
DREDGE SAMPLE]
STORE WET
1
ELUTRIATE
FRACTIONATE BIOAS
1
AMAI Y7F*
/Ql A \
ANALYZE
(SIB)
CORE SAMPLE
1 1
SAY (SIC) | DIGEST
1
ANALYZE
(SID)
1
[CORE SECTION |
1 I
DRY
|
STORE
1
DIGEST
I
ANALYZE
(S2)
FREEZE
1 ,
STORE
1 ,
DIGEST
1
ANALYZE
(S3)
SAMPLE DESIGNATION
PURPOSE
CONTAINER
SAMPLE TREATMENT
PRESERVATIVE
STORAGE TIME
DIGESTION SOLUTION
SAMPLE VOLUME OR WEIGHT
Wl W2 W3 | SIA
TOTAL WATER SOLUBLE USED IN MOBILE
CONCENTRATION WATER ELUTRIATE CONC.
CONC.
G,P G,P G,P G,P
NONE FILTER NONE NONE
SIB
CHEMICAL
DISTRIBUTION
G,P
NONE
SIC | SID
BIOAVAIL- TOTAL
ABILITY SEDIMENT
CONC.
G,P G,P
NONE NONE
HNOs HN03 NONE 4° C 4°C 4°C 4°C
pH«2 pH<2 (MINIMIZE AIR CONTACT KEEP FIELD MOIST.)
90d 90 d <1w <1w
STRONG ACID NONE - W3
100-500 ml 100-500 ml VARIABLE VARIABLE
<1W
VARIABLE
300- 500 g
<1w <1w
S2 [ S3
TOTAL TOTAL
SEDIMENT SEDIMENT
CONC. CONC.
G,P G,P
AIR DRY FREEZE
NONE • NONE
- " -
STRONG ACID STRONG ACID STRONG ACID
VARIABLE 2-5g
2-5g 2-5 g
cr>
Figure 1. Schematic diagram for processing samples scheduled for metal analysis.
-------
latter sites would also be expected to have a high concentration because the
smaller particles that accumulate in quiescent areas are known to concentrate
many chemical contaminants (14, 15). Thus, this approach would be expected to
produce a result that is biased high. While this result would be acceptable
if the purpose is to locate the maximum concentration in a project area, it
would produce non-representative results if the purpose is to define the dis-
tribution of chemicals within a project area. Suggestive guidance in the
latter case would be to divide the sampling locations between the anticipated
maximum concentration zones and the remainder of the project area. The im-
portant point is that both the project site and project purposes should be
included in the selection of sampling locations.
A project manager should also be aware of the fact that the selection of
sampling equipment can have a potential effect on resultant data. The choice
is restricted to dredges and corers and dredges are frequently used because of
ease of operation and larger sample recovery- However, since the depth of
sediment penetration by a dredge can be affected (16, 17) by the weight and
shape of a sampler, the height of free-fall, the angle of impact, and sediment
texture and density, the recovered sample is site-dependent. Because sedi-
ments are frequently stratified in the vertical dimension and the depth of
sediments sampled is variable, grab samplers may introduce analytical vari-
ability into the final data that is a function of dredge penetration rather
than being a property of the sample. This effect is summarized in Figure 2
for a hypothetical situation where the sediment concentration varies by a
factor of 10. In an extreme case, a differential dredge penetration could
produce more than a 300 percent variation in analytical results at the same
sampling location.
The need to consider this artifact of sampling may vary with project
purposes. However, when important, corers should be the method of choice in
areas that sediments are known to be stratified. Dredges should be used in
areas where sediments are known to be homogeneous and differential penetration
would not have an effect on sample composition.
The final point to be mentioned relates to the number of samples to be
collected. Again, it is not possible to provide specific guidance on this
point because of site-specific variability and project-specific needs. How-
ever, it should be pointed out that the number of samples will be proportional
to the financial resources available and inversely proportional to the ana-
lytical cost per sample:
Number of samples - Dolors for analysis
H Cost per sample
This relationship suggests that a judicious selection of parameters to be
analyzed is required. If a large number of analyses are to be completed on
each sample, the cost per sample increases and the number of samples, there-
fore, has to decrease. An awareness of this fact reinforces the position
stated earlier that a mandatory list of analyses should not be prepared.
268
-------
0
RELATIVE CON@ENTRATION
2 4 6 8 10
12
i I I I I I I
I I I I
e 4
o
0-
LJ
O
8
10
DEPTH OF SAMPLE
COLLECTED
1
2
3
4
5
6
7
8
9
10
CALCULATED AVERAGE
CONCENTRATION
10
7
5.6
4.7
4.0
3.5
3.1
2.9
2.7
2.5
Figure 2. Effect of vertical sediment profiles on grab sample
composition as a function of penetration.
269
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SUMMARY
Recent regulatory developments Uill require a more systematic testing of
sediments to be dredged. Based on this need, the Great Lakes Laboratory is
working with the U.S. Environmental Protection Agency and the U.S. Army Corps
of Engineers to develop a sediment collection and analysis manual. This
experience indicates that it is possible to provide guidance on how to perform
available testing procedures and specific analyses. However, the decisions on
where to sample and when to use the testing procedures is site-specific and
the responsibility of the project manager.
A procedure is described that allows a project manager to assess the
utility of available procedures for a specific study. This approach relies on
an awareness of the sediment properties b^ing characterized and the relation
between these properties and the purpose of the study. The selection of
specific chemical analysis to be performed should also be based on the purpose
of the study. Once the procedures and specific analysis have been selected,
the method of sample handling and storage will be defined. The least objec-
tive portion of the procedure is the selection of sampling locations because
of the importance of site-specific variability and project purposes. The best
general guidance that can be provided is to guard against the introduction of
a bias as a consequence of selecting the sampling locations.
Each test procedure considered measures a different property of the sam-
ple. The tests are complementary in that they measure the presence, distribu-
tion, and mobility of sediment-associated contaminants. Unfortunately, these
properties are not directly related to the potential environmental impact of
sediment-associated contaminants. Thus, the major state-of-the-art limitation
in conducting a sediment evaluation is the absence of valid criteria to evalu-
ate results in response to the regulatory mandate.
ACKNOWLEDGEMENTS
This project was supported by grant R805885010 from the U.S. Environmen-
tal Protection Agency and co-sponsored by the U.S. Army Corps of Engineers
Waterways Experiment Station. Project managers were Dr. Mike Mull in (EPA) and
Dr. Robert Engler (WES).
REFERENCES
1. Environmental Effects Laboratory. "Ecological Evaluation of Proposed
Discharge of Dredged or Fill Material into Navigable Waters". Interim
Guidance for Implementation of Section 404(b)(l) of Public Law 92-500
(Federal Water Pollution Control Act Amendments of 1972). Misc. Paper
D-76-17, U.S. Army Engineer Waterways Experiment Station, Vicksburg,
Miss. 33 p. + App. (1976).
2. Lee, G. F. and Plumb, R. H., Jr. "Literature Review on Research Study
for the Development of Dredged Material Disposal Criteria". Contract
Report D-74-1, U.S. Army Engineer Waterways Experiment Station,
Vicksburg, Miss. 145 p. (1974).
270
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3. Neff, J. W., Foster, R. S. and Slowey,. F. J. "Availability of Sediment-
Adsorbed Heavy Metals to Benthos with Particular Emphasis on Deposit-
Feeding Infauna". Contract Report D-78-22, U.S. Army Engineer Waterways
Experiment Station. 286 p. (1978).
4. Prater, B. L. and Hoke, R. A. "A Sediment Quality Evaluation of Five
Harbors of the Great Lakes Using 96-Hour Sediment Bioassay and Bulk
Chemistry". Water Quality Laboratory, Heidelberg College, Tiffin, Ohio.
Report prepared for U.S. Environmntal Protection Agency, Office of Re-
search and Development, Chicago, 111. 117 p. (1978).
5. Brannon, J. M., Plumb, R. H., Jr. ana Smith, I. "Long Term Release of
Contaminants from Dredged Material". Technical Report D-78-49, U.S. Army
Engineer Waterways Experiment Station, Vicksburg, Miss. 66 p. (1978).
6. Plumb Jr., R. H. "A Bioassay Dilution Technique to Assess the Signifi-
cance of Dredged Material Disposal". Waterways Experiment Station;
Vicksburg, Miss. Miscellaneous Paper 0^76-6. 16 p (1976).
7. Lee, G. F., Piwoni, M. D., Lopez, J. M., Mariani, G. M., Richardson, J.
S., Homer, D. H., and Saleh, F. "Research Study for the Development of
Dredged Material Disposal Criteria". Technical Report D-75-4, U.S. Army
Engineer Waterways Experiment Station, Vicksburg, Miss. (1975).
8. Brannon, J. M., Engler, R. M., Rose, J. R., Hunt, P. G. and Smith, I.
"Selective Analytical Partitioning of Sediments to Evaluate Potential
Mobility of Chemical Constituents During Dredging and Disposal Opera-
tions". Technical Report D-76-7, U.S. Army Engineer Waterways Experiment
Station, Vicksburg, Miss. 90 p. (1976).
9. Rosengrant, L. E., "A Method Study for the Digestion of Lacustrine Sedi-
ments for Subsequent Heavy Metal Analysis by Atomic Absorption Spectro-
• photometry". M.S. Thesis, State University College at Buffalo, Buffalo,
N.Y. 77 p. (1977).
10. Oliver, B. G. "Heavy Metal Levels of Ottawa and Rideau River Sediments".
Environmental Science and Technology 7:135-137. (1973).
11. Griffiths, J. C. Scientific Method in Analysis of Sediments. McGraw-Hill
Book Company, N.Y., N.Y. 508 p. (1967).
12. American Public Health Association. Standard Methods for the Examination
of Water and Waste Water including Bottom Sediments and Sludges. APHA,
N.Y. 1193 p. (1976).
13. Research and Education Association. Modern Pollution Control Technology.
Vol. 2. Water Pollution Control and Solid Waste Disposal. Research and
Education Association, N.Y. Unnumbered. (1978).
14. Helmke, P. A., Koons, R. D., Schomberg, P. J., and Iskandar, I. K.
"Determination of Trace Element Contamination of Sediments by Multiele-
ment Aanlysis of Clay-Size Fraction". Environmental Science and Technol-
ogy 11:984-989. (1977).
271
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15. Forstner, U. , Patchineelam, S. R., and Deurer, R. "Grain Size Distribu-
tion and Chemical Associations of Heavy Metals in Freshwater Sediments
(Examples from Bodensee and Rhine). Presented bfore ACS Environmental
Chemistry Division, 175th National Meeting; Anaheim, California. Unnum-
bered. (1978).
16. Hudson, P. L. "Quantitative Sampling with Three Benthos Dredges".
Trans. Amer. Fish. Soc. 99:603-607. (1970).
17. Christie, N. D. "Relationship Between Sediment Texture, Species Rich-
ness, and Volume of Sediment Sampled by a Grab". Marine Biology
30:89-96. (1975).
272
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/9-80-044
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Management of Bottom Sediments Containing Toxic
Substances —Proceedings of the Fifth U.S.-Japan Experts
Meeting November 1979--New Orleans, Louisiana
5. REPORT DATE
September 1980 issuing date
6. PERFORMING ORGANIZATION CODE
r. AUTHOR(S)
Spencer A. Peterson and Karen K. Randolph, editors
8. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Research Laboratory--Corvallis, OR
Office of Research and Development
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
same
13. TYPE OF REPORT AND PERIOD COVERED
conference proceedings
14. SPONSORING AGENCY CODE
EPA/600/02
is.SUPPLEMENTARY NOTES Proceedings of the Second, Third, and Fourth U.S.-Japan Experts
meeting on bottom sediments were published in EPA's Ecological Research Series as
EPA-600/3-77-083. EPA-600/3-78-084. and EPA-600/3-79-102. respectively.
16. ABSTRACT
The United States-Japan Ministerial Agreement of May 1974 provided for the exchange
of environmental information in several areas of mutual concern. This report is the
compilation of papers presented at the Fifth United States-Japan Experts Meeting on
the Management of Bottom Sediments Containing Toxic Substances, one of the 10 identifiec
areas.
The first meeting was held in Corvallis, Oregon in November 1975 and the second was
hosted by the Japanese Government in October 1976. The third session was convened in
November 1977 in Easton, Maryland and the fourth session in Tokyo. The fifth meeting
(at which these papers were presented) was held in New Orleans, Louisiana.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a.
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
?7d
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
* GPO 697-429 1980
273
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