Draft Environmental Impact Report (EOEA File Number 8695)
and
Draft Environmental Impact Statement
Volume 1 of 2
Boston Harbor, Massachusetts
Navigation Improvement Project and Berth Dredging Project
April 1994
US Army Corps
of Engineers
New England Division
Massachusetts
Port Authority
Maritime Department
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DRAFT
ENVIRONMENTAL IMPACT REPORT/ENVIRONMENTAL IMPACT STATEMENT
(DEIR/S)
Volume 1 of 2
APRIL 1994
BOSTON HARBOR NAVIGATION IMPROVEMENT DREDGING
BERTH DREDGING PROJECT
RESPONSIBLE LEAD AGENCIES ARE:
U.S. Army Corps of Engineers Massachusetts Port Authority
Impact Analysis Division Maritime Department
424 Trapelo Road Boston Fish Pier U
Waltham, Massachusetts 02254 Boston, Massachusetts 02210
FEDERAL COOPERATING AGENCIES:
National Marine Fisheries Service, U.S. Fish and Wildlife Service, and the U.S. Environmental
Protection Agency
DOCUMENT WAS PREPARED BY:
Normandeau Associates Inc. U.S. Army Corps of Engineers
25 Nashua Road 424 Trapelo Road
Bedford, New Hampshire 03310-5500 Waltham, Massachusetts 02254
for the
Massachusetts Port Authority
This joint Federal and State document addresses the impacts associated with the
Congressionally authorized navigation improvement dredging and disposal of material from the
Federal navigation channel and associated berthing areas in Boston Harbor, Massachusetts. The
Reserved Channel and Mystic River would be deepened from 35 feet mean low water (MLW) to
40 feet MLW. The Chelsea Creek would be deepened from 35 feet MLW to 38 feet MLW.
Disposal of the underlying parent material is proposed at the Massachusetts Bay Disposal Site.
Disposal alternatives for the silt material (maintenance material) overtopping the parent material are
assessed in this DEIR/S.
Comments should be sent to Colonel Miller at the U.S Army Corps of Engineers and Ms.
Trudy Coxe, Secretary, Executive Office of Environmental Affairs, Commonwealth of
Massachusetts by the date indicated in the transmittal letter. If you would like further information
on this document, Mr. Peter Jackson of the U.S. Army Corps of Engineers can be reached at (617)
647-8861 or contact Ms. Janeen Hansen, Massport, at (617) 973-5355.
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TABLE OF CONTENTS
Volume 1 of 2
PAGE
1.0 INTRODUCTION 1-1
1.1 GENERAL DESCRIPTION OF PROJECT AREA 1-2
1.2 PURPOSE AND NEED FOR ACTION 1-2
1.3 PROJECT SPONSORS 1-5
1.4 PUBLIC PARTICIPATION PROCESS 1-6
x , "
1.4.1 Advisory Committee 1-7
1.4.2 Technical Working Groups 1-8
1.4.3 Federal Scoping Meeting 1-9
1.5 COMPLIANCE WITH MEPA AND NEPA REQUIREMENTS 1-9
1.6 LIST OF PREPARERS 1-10
2.0 PROJECT DESIGN ALTERNATIVES ANALYSIS . . . 2-1
2.1 PROJECT DESIGN ALTERNATIVES . 2-1
2.1.1 No Action, No Maintenance Dredging 2-1
2.1.2 No Action, with Maintenance Dredging 2-2
2.1.3 Full Project - Three Channels, All Berths .... 2-3
2.1.4 Reduced Project 2-5
2.1.5 Delayed Action . . 2-6
2.1.6 Comparison of Project Design Alternatives .... 2-7
2.2 SEDIMENT CHARACTERIZATION . . . 2-7
2.2.1 Sediment Characterization 2-8
2.2.2 Federal Channel Sediment Testing Program 2-9
2.2.2.1 Tier I - Review of Existing Data .... 2-9
2.2.2.2 Tier II - Chemical Evaluation of the
Dredged Material 2-9
2.2.2.3 Tier III - Biological Evaluation of the
Dredged Material 2-10
2.2.3 Massport Sponsored Sediment Testing Program . . . 2-11
2.2.3.1 Tier 1 - Review of Existing Data .... 2-12
2.2.3.2 Tier II - Results of Bulk Sediment Chemi-
cal Analyses 2-12
2.2.3.3 Tier III - Bioassay/Bioaccumulation . . . 2-12
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PAGE
2.2.4 Summary of Findings 2~13
3.0 DISPOSAL SITE ALTERNATIVES ANALYSIS • 3~1
3.1 THE EVALUATION PROCESS 3"2
3.2 SEDIMENT/SITE MATCHING 3~5
3.3 SUITABILITY OF GENERIC TYPES OF DISPOSAL ALTERNATIVES FOR
DREDGED SILT 3
3.3.1 Land-Based Alternatives 3~6
3.3.2 Aquatic Alternatives
3.4 DEVELOPMENT OF DISPOSAL OPTIONS 3-11
3.4.1 Land-Based Options (A) 3~^2
3.4.2 Aquatic Options (B) 3"^
3.4.3 Land-Based Aquatic Combinations t~,&
3.4.4 Previously Used Aquatic Disposal Sites 3-16
3.5 ALTERNATIVE TREATMENTS AND BENEFICIAL USES 3-17
3.5.1 Treatment Technologies 3~^
3.5.2 Beneficial Uses 3"Z1
3.6 PREFERRED DISPOSAL OPTION 3"23
3.6.1 Practicable Alternatives 3"2^
3.6.2 Descriptions of Practicable Disposal Sites .... J-^B
3.6.2.1 Boston Lightship 3~2^
3.6.2.2 Massachusetts Bay Disposal Site ..... 3-29
3.6.2.3 Meisburger 2 3"33
3.6.2.4 Meisburger 7 f~«
3.6.2.5 Spectacle Island (CAD) 3~3?
3.6.2.6 In-Channel Sites 3'^°
3.6.2.7 Little Mystic Channel 3-«l
3.6.2.8 Reserved Channel f'T'3
3.6.2.9 Amstar 3"^
3.6.2.10 Mystic Piers *~**
3.6.2.11 Revere Sugar J'J*
3.6.2.12 Treatment Technologies ^'^
3.7 CUMULATIVE IMPACTS 3"54
3.8 SECONDARY IMPACTS/SUSTAINABLE DEVELOPMENT 3-54
3.9 IRREVERSIBLE AND IRRETRIEVABLE RESOURCES 3-55
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PAGE
3.10 MITIGATION ..... 3-55
4.0 DREDGING MANAGEMENT PLAN 4-1
4.1 SELECTION OF DREDGING METHOD 4-1
4.1.1 Mechanical Dredge Plant 4-2
4.1.2 Rock Blasting Plant 4-2
4.2 SEQUENCE OF DREDGING OPERATIONS 4-2
4.2.1 Pre-Dredge Sequence 4-2
4.2.2 Dredging Sequence 4-3
4.2.3 Structural Impacts of Dredging 4-5
4.2.4 Traffic Considerations 4-5
4.3 DISPOSAL OPERATIONS 4-5
4.3.1 Shoreline Disposal 4-5
4.3.2 Subaqueous Depressions and Borrow Pits 4-6
4.3.4 In-Channel Disposal 4-7
4.3.5 Open Water - Existing Disposal Sites 4-8
4.4 OVERALL SEQUENCE OF OPERATIONS 4-8
4.5 ENVIRONMENTAL IMPACTS EXPECTED FROM DREDGING OPERATIONS . 4-9
4.5.1 Water Quality/Sediment Quality 4-9
4.5.2 Biological Resources 4-11
4.5.3 Threatened and Endangered Species 4-13
4.5.4 Historical and Archeological Resources 4-13
4.5.5 Socio-Economic Environment 4-13
5.0 COMPLIANCE REQUIREMENTS 5-1
5.1 REGULATORY COMPLIANCE 5-1
5.2 COMPLIANCE WITH FEDERAL STATUTES AND EXECUTIVE ORDERS . . 5-2
5.2.1 Federal Statutes 5-2
5.2.2 Executive Orders 5-4
5.2.3 Executive Memorandum 5-4
5.3 EVALUATION OF SECTION 404(B)(1) GUIDELINES FOR BHNIP . . 5-4
5.4 PROJECT FEASIBILITY STUDY AND ENVIRONMENTAL ASSESSMENTS . 5-15
iii
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5.4.1 Federal EIS Scoping .*'.''
5.4.2 Berth Dredging Project Environmental Notification
Form
PAGE
5-16
5-16
5.4.3 Boston Harbor Dredging Project Advisory Committee 5-16
6 0 LIST OF AGENCIES, ORGANIZATIONS AND PERSONS TO WHOM THE BOSTON
HARBOR DREDGING PROJECT DEIS/R WAS SENT
7.0 LITERATURE CITED .
8.0 GLOSSARY OF TERMS
9.0 INDEX
7-1
8-1
9-1
ATTACHMENT 1- AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES
- £VALUATION FOR POTENTIAL DREDGING AND DISPOSAL SITES
IV
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TABLE OF CONTENTS
Volume 2 of 2
APPENDICES:
A. SCOPING DOCUMENTATION
A-l Federal Register Notice
A-2 NEPA Scoping Session
A-3 Scoping Letters
A-4 Biological Assessment for Threatened and Endangered Species
and Massachusetts Natural Heritage and Endangered Species
Program
A-5 MEPA Scope
B. ADVISORY COMMITTEE AND TECHNICAL WORKING GROUP REPORTS/MEMBERSHIP
C. SEDIMENT CHARACTERIZATION
C-l Sediment Sampling and Laboratory Analysis Plan
C-2 Federal Project (ACOE)
C-3 Berth Projects (Massport)
D. SHIP SIMULATION STUDY
E. ALTERNATIVES ANALYSIS - DISPOSAL SITES
F. ADDAM's MODEL
G. DISPOSAL ISSUES - MASSACHUSETTS BAY DISPOSAL SITE (MBDS)
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LIST OF FIGURES
ES-1. Boston Harbor Navigation Improvement Project.
ES-2. Locations of potential disposal sites extensively evaluated.
ES-2a. Locations of practicable disposal sites.
ES-2b. Locations of potentially practicable disposal sites.
ES-2c. Locations of short-listed sites found not practicable.
ES-3. Boston Harbor Navigation Improvement Project, Relative Costs and
Capacities of Disposal Options for Silty Dredged Material.
1-la. Boston Harbor Locus Map. Limits of Federal Channel.
1-lb. Boston Harbor Locus Map. Limits of Federal Channel.
2-la. Boston Harbor Navigation Improvement Project General Plan
2-lb. Boston Harbor Navigation Improvement Project General Plan
2-2. Navigation Improvement Project, Reserved Channel
2-3. Navigation Improvement Project, Mystic River
2-4. Navigation Improvement Project, Chelsea Creek Downstream of
Chelsea St. Bridge
2-5. Navigation Improvement Project, Chelsea Creek Upstream of
Chelsea St. Bridge
2-6. Location of Federal Channel and Berth Area Dredging
2-7. Tiered Testing & Decision Protocol for Open Water Disposal of
Dredged Material
3-1. Locations of potential disposal sites extensively
evaluated.
3-la. Locations of practicable disposal sites.
3-lb. Locations of potentially practicable disposal sites.
3-lc. Locations of short-listed sites found not practicable.
3-2. Screening of final-listed sites to determine preferred
alternative for disposal of present and future
(maintenance) dredged material. Boston Harbor
Navigation Improvement Project.
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3-3. Site map for Boston Lightship and MBDS sites
3-4. Site map for Meisburger 2 site
3-5. Site map for Meisburger 7 site
3-6. Site map for Spectacle Island CAD site
3-7. Site map for Little Mystic Channel site
3-8. Site map for Reserved Channel site
3-9. Site map for Amstar site
3-10. Site map for Mystic Piers site
3-11. Site map for Revere Sugar site
4-1. Example Schedule Disposal at Massachusetts Bay Disposal
Site
Al-1. General locations of short-listed disposal site
alternatives
Al-2. Site map for potential disposal site, Quincy-03
(Squantum Point)
Al-3. Site map for potential disposal site, Everett
Al-4. Site map for potential disposal site, Woburn-11
Al-5. Site map for potential disposal site, Wrentham-495
Al-6. Site map for the Plainville Landfill site
Al-7. Site map for the Fitchburg/Westrainster Landfill site
Al-8. Site map for BFI Northern Disposal Inc. (E. Bridgewater)
Landfill site
Al-9. Site map for Mystic Piers site
Al-10. Site map for Revere Sugar site
Al-11. Site map for Amstar site
Al-12. Site map for Cabot Paint site
Al-13. Site map for Little Mystic Channel site
Al-14. Site map for Reserved Channel site
Al-15. Site map for Spectacle Island CAD site
vii
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Al-16. Site map for Meisburger 2 site
Al-17. Site map for Meisburger 7 site
Al-18. Site map for potential disposal site, Subaqueous-B
Al-19. Site map for potential disposal site, Subaqueous-E
Al-20. Site map for potential disposal site, Winthrop Harbor
Al-21. Site map for Boston Lightship and MBDS sites
Al-22. Prohibited and restricted clam beds in Boston Harbor
Vlll
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LIST OF TABLES
ES-la. PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY) FOR
THE BOSTON HARBOR NAVIGATION IMPROVEMENT PROJECT
ES-lb. POTENTIALLY PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY)
BUT LIMITED BY CAPACITY AND COST
ES-lc. ALTERNATIVES (LISTED ALPHABETICALLY) EVALUATED BUT FOUND NOT
PRACTICABLE DUE TO ENVIRONMENTAL FACTORS OR COST
1-1. COST SHARING FOR BHNIP: NON-FEDERAL SHARE PERCENTAGES
1-2. LIST OF PREPARERS
2-1. MAINTENANCE DREDGING PROJECTIONS FOR THE TRIBUTARY CHANNELS AND
THE MAIN SHIP CHANNEL
2-2. VOLUME OF MATERIAL PROPOSED FOR DREDGING FROM CHANNELS AND
ASSOCIATED PROJECT BERTHS FOR THE BOSTON HARBOR NAVIGATION
IMPROVEMENT PROJECT
2-3. SUMMARY OF ALTERNATIVE PROJECT DESIGNS AND THEIR ENVIRONMENTAL
CONSEQUENCE
2-4. SEDIMENT METAL CONCENTRATIONS (ppra), MYSTIC RIVER
2-5. MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION BULK
SEDIMENT CHARACTERIZATION LEVELS FOR BOSTON HARBOR DREDGE
MATERIAL
2-6. POLYCYCLIC AROMATIC HYDROCARBONS
2-7. PERCENT SURVIVAL OF AMPHIPOD, CLAMS AND WORMS IN THE TOXIC ITY
TEST - FEDERAL PROJECT
2-8. AVERAGE METALS CONCENTRATIONS BY SITE AND MASSACHUSETTS DEP
CLASSIFICATION LEVELS FOR MASSPORT DREDGING PROJECT
2-9. POLYCYCLIC AROMATIC HYDROCARBONS AVERAGE CONCENTRATIONS BY SITE
AND MASSACHUSETTS DEP CLASSIFICATION LEVELS FOR MASSPORT
DREDGING PROJECT
2-10. PCBs(TOTAL) AVERAGE CONCENTRATIONS BY SITE AND MASSACHUSETTS
DEP CLASSIFICATION LEVELS FOR MASSPORT DREDGING PROJECT
2-11. PERCENT AMPHIPOD SURVIVAL FOR JULY - AUGUST 4, 1992 AND
SEPTEMBER 5-15, 1992 - MASSPORT DREDGING PROJECT
2-12. PERCENT SURVIVAL OF CLAMS AND WORMS, SEPTEMBER 5-15, 1992.
MASSPORT DREDGING PROJECT
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2-13. MEAN CONCENTRATION (ppm WET WEIGHT) OF PARAMETERS SIGNIFICANT
AT THE p>0.05 CONFIDENCE LEVEL FROM BIOACCUMULATION TESTING FOR
MASSPORT DREDGING PROJECT
3-1. POTENTIAL DISPOSAL SITE LISTS BY CATEGORY PRODUCED AT
THE END OF EACH SCREENING PHASE
3-2. CHARACTERISTICS OF GENERIC DISPOSAL ALTERNATIVES
3-3. MASSACHUSETTS REGULATORY GUIDELINE LEVELS OF DREDGED
MATERIALS FOR VARIOUS DISPOSAL ALTERNATIVES
3-4. EVALUATION OF SUITABILITY OF BOSTON HARBOR NAVIGATION
IMPROVEMENT PROJECT SEDIMENTS FOR VARIOUS DISPOSAL
ALTERNATIVES
3-5. SUMMARY OF POTENTIAL SITE PREPARATION, MANAGEMENT
REQUIREMENTS FOR USE OF GENERIC DISPOSAL ALTERNATIVES
3-6. POTENTIAL' IMPACTS FROM SILT DISPOSAL AT GENERIC
ALTERNATIVE DISPOSAL SITES
3-7. IMPACTS CAUSED BY USING SPECIFIC UPLAND SITE FOR
BOSTON HARBOR DREDGED MATERIAL DISPOSAL
3-8. POTENTIAL BENEFITS OF DREDGED MATERIAL DISPOSAL
ALTERNATIVES
3-9. IMPACTS CAUSED BY USING SPECIFIC AQUATIC SHORELINE
SITES FOR BOSTON HARBOR DREDGED MATERIAL DISPOSAL
3-10. POTENTIAL IMPACTS CAUSED BY USING SPECIFIC SUBAQUEOUS,
BORROW PIT AND IN-CHANNEL SITES FOR BOSTON HARBOR
DREDGED MATERIAL DISPOSAL
3-11. IMPACTS CAUSED BY USING EXISTING OPEN WATER DISPOSAL
SITES FOR BOSTON HARBOR DREDGED MATERIAL DISPOSAL
3-12. ALTERNATIVE DISPOSAL OPTIONS FOR DISPOSAL OF SILT
SEDIMENTS, BOSTON HARBOR NAVIGATION IMPROVEMENT
PROJECT
3-13. COST ESTIMATES FOR LANDFILL SITES FOR DISPOSAL OS
SILTS FROM BHNIP
3-14. COST ESTIMATES FOR LAND-BASED SITES FOR DISPOSAL OF
SILTS FROM BHNIP
3-15. COST ESTIMATES FOR AQUATIC SHORELINE OPTION B-l FOR
DISPOSAL OF SILTS FROM BHNIP
3-16. COST ESTIMATES FOR SUBAQUEOUS DEPRESSION OPTION B-2
FOR DISPOSAL OF SILTS FROM BHNIP
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3-17. COST ESTIMATES FOR IN-CHANNEL DISPOSAL OPTION B-3 FOR
SILTS FROM BHNIP
3-18. COST ESTIMATES FOR AQUATIC BORROW PIT OPTION B-4 FOR
DISPOSAL OF SILTS FROM BHNIP
3-19. ALTERNATIVES SCREENING OF TREATMENT TECHNOLOGIES FOR
DREDGE MATERIAL DISPOSAL
3-20. COST ESTIMATES FOR USING EXISTING DISPOSAL SITES FOR
DISPOSAL OF SILTS FROM BHNIP
3-21. SCREENING MATRIX FOR DETERMINING THE LEAST ENVIRON-
MENTALLY DAMAGING PRACTICABLE ALTERNATIVE FOR DISPOSAL
OF SILT FROM THE BHNIP
3-22a. PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY) FOR
THE BOSTON HARBOR NAVIGATION IMPROVEMENT PROJECT
3-22b. POTENTIALLY PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY)
BUT LIMITED BY CAPACITY AND COST
3.22c. ALTERNATIVES (LISTED ALPHABETICALLY) EVALUATED BUT FOUND NOT
PRACTICABLE DUE TO ENVIRONMENTAL FACTORS OR COST
Al-1. LANDFILL CHARACTERISTICS
Al-2. ESTIMATED ABUNDANCE (NO./m2) OF BENTHIC INFAUNA
(RETAINED ON A 0.5 mm MESH SIEVE) COLLECTED BY 0.023 m2
PONAR GRAB FROM PROPOSED DISPOSAL SITES IN BOSTON
HARBOR, APRIL 28-29, 1993
Al-3. SEDIMENT CHARACTERISTICS IN THE VICINITY OF POTENTIAL
DISPOSAL SITE EAST OF SPECTACLE ISLAND, 1988a
Al-4. COPPER CONCENTRATIONS AT A POSITION WHEN COPPER IS
DILUTED BELOW WATER QUALITY CRITERIA AT THE SPECTACLE
ISLAND CAD DURING FLOOD AND EBB TIDES OF DIFFERENT
VELOCITIES
Al-5. DOMINANT FISH SPECIES3 AND LOBSTERS IN TRAWLS CONDUCTED
IN AN AREA JUST WESTb OF THE MWRA PROPOSED OUTFALL BY
MASSACHUSETTS DIVISION OF MARINE FISHERIES, 1991-92
Al-6. MAXIMUM CONCENTRATION (mg/1) OF COPPER AND SILT/CLAY
IN THE WATER COLUMN AT THE MEISBURGER 7 DISPOSAL SITE
UNDER STRATIFIED CONDITIONS ESTIMATED BY THE ADDAM'S
MODEL FOUR HOURS AFTER A SINGLE DUMP OF 2,000 CU. YDS
Al-7. SEDIMENT CHARACTERISTICS IN VICINITY OF PROPOSED
SUBAQUEOUS CONTAINMENT SITES B AND E AND WINTHROP
HARBOR CONTAINMENT SITE
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Al-8. MAXIMUM CONCENTRATION (mg/1) OF COPPER AND SILT/CLAY
IN THE WATER COLUMN AT THE SUBAQUEOUS E SITE DURING
MAXIMUM EBB AND FLOOD TIDES UNDER UNSTRATIFIED CONDI-
TIONS ESTIMATED BY THE ADDAM'S MODEL FOUR HOURS AFTER
A SINGLE DUMP OF 1,000 CU. YDS
Al-9. PHYSICAL AND BULK CHEMICAL ANALYSIS OF WINTHROP HARBOR
SEDIMENTS3
Al-10. WINTHROP HARBOR BENTHIC INVERTEBRATES, FALL 1989
Al-11. MAXIMUM CONCENTRATION (mg/1) OF COPPER AND SILT/CLAY IN
THE WATER STRATIFIED COLUMN AT THE BOSTON LIGHT SHIP
DISPOSAL SITE UNDER SUMMER CONDITIONS ESTIMATED BY THE
ADDAM'S MODEL FOUR HOURS AFTER A SINGLE DUMP OF 2,000
CU. YDS
Al-12. WATER QUALITY DATA, BOSTON HARBOR
Al-13. AVERAGE CONCENTRATION OF TOTAL ORGANIC CARBON AND TOTAL
PETROLEUM HYDROCARBONS. MASSPORT DREDGING PROJECT
Al-14. COMPARISON OF AVERAGE LEAD AND CHROMIUM CONCENTRATIONS
(MG/L) WITH MASSACHUSETTS DEP BULK SOIL CONCENTRATIONS
(MG/L) FOR TCLP ANALYSIS. MASSPORT DREDGING PROJECT
Al-15. CONCENTRATION OF SODIUM AND CHLORIDE FOR MASSPORT DREDG-
ING PROJECT
Al-16. FINFISH SAMPLING IN BOSTON HARBOR - JULY 1986
Al-17. DOMINANT SPECIES BY TRIBUTARY
xii
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BOSTON HARBOR NAVIGATION
IMPROVEMENT PROJECT
DRAFT ENVIRONMENTAL IMPACT REPORT/STATEMENT
EXECUTIVE SUMMARY
Project Description
The Boston Harbor Navigation Improvement and
Berth Dredging Projects (BHNIP) encompass the
deepening of three tributary channels (Reserved
Channel, Mystic River Channel and Chelsea Creek
hannel) and two areas in the Main Ship Channel
Inner Confluence and the mouth of Reserved Chan-
nel) to provide sufficient ship maneuvering areas for
He deepened channels; six berth areas that would
benefit directly from the channel deepening (Conley
11-13, Prolerized, Distrigas, Moran, Eastern Minerals
and Gulf Oil); and six berth areas and one intake
structure that would not_benefrt directly from (i.e., be
connected to) the channel deepening (Boston Army,
Boston Edison Intake, Boston Edison Barge, Conley
14-15, Revere Sugar, Mystic Piers 1, 2, 49 and 50).
The President Roads Anchorage Area and adjacent
channels would be re-marked to enlarge the deep water
anchorage without additional dredging. Deepening of
the channels to -40 ft MLW (except Chelsea Channel
to -38ft MLW) would allow greater use of the hither-
to underutilized -40 ft MLW Entrance Channel and
Main Ship Channel (see Figure ES-1).
The improvements to the three Federal channels
were proposed as a result of a Feasibility Study
Completed by the Corps of Engineers. The three-
channel project was selected as the economically and
environmentally preferred project alternative. It was
authorized by Congress in the Water Resources
Development Act of 1990 (P.L. 101-640). The autho-
rized project would allow the Port of Boston to
maintain its competitiveness in the highly competitive
national and international marine trade business by
tgducing the cost of transporting goods and thus
improving efficiency.
Massachusetts Port Authority (Massport), as local
sponsor of the project, submitted an Environmental
Notification Form (ENF) to Massachusetts Executive
Office of Environmental Affairs in April 1991. The
Secretary's Certificate on the ENF required the prepa-
ration of an Environmental Impact Report (EIR) with
three major areas of focus:
^sediment characterization,
Devaluation of disposal
and
»-a dredging management plan.
alternatives
The Corps of Engineers, New England Division, com-
mitted to preparing an EIS in 1992 due to the cumula-
tive impacts of Federal actions (maintenance dredging,
navigation improvement dredging, and permitting of
the associated berthing areas) and the significant public
concern over disposal of dredged material. Because
the channel improvement and berth dredging projects
are intricately linked and interdependent and would be
reviewed by the same regulatory audience, it was
determined that preparation of a joint Environmental
Impact Report/Statement (EIR/S) would be most effi-
cient.
Public Participation
Massport, the project's local sponsor, and the Corps
of Engineers recognized the need to involve key
agencies and groups in the planning process through
consultation, information exchange and presentation of
diverse viewpoints. In March 1992, Massport formally
invited thirty-five federal, state and local agencies and
public and private interest groups to participate in a
project Advisory Committee. The Committee's
function was to advise Massport and the Corps of
ES-1
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V
£
lingincers in the overall design and planning of envi-
ronmental studies which would form the basis of the
environmental review. The Committee met seven
times over the course of the studies leading to the
preparation of this RIR/S.
Early in the public participation process two specific
technical issues were identified as those which would
benefit from a more focused analysis and review than
that which could be provided by the Advisory Com-
mittee. As a result, two Working Groups were formed
as subsets of the Advisory Committee to provide
guidance and expertise in : 1) sediment characteriza-
tion; and 2) disposal site identification and screening.
Through the course of the project these Working
Groups, and the larger Advisory Committee, provided
valuable commentary on sampling and testing proto-
cols and information on identifying and characterizing
disposal sites. The Working Group process contribut-
ed in creating a dynamic and responsive work product
by increasing the scope of the sediment sampling and
testing and expanding the types of disposal options
and specific disposal sites to be screened for the
project.
material) was composed of clay and sand/gravel which
generally has low levels of metals and organics. For
the purposes of providing sufficient capacity among
disposal alternatives it was assumed that all the silt
material would not be suitable for unconfmed open
water disposal^nd that only confined open water
disposal or confined land-based alternatives would be
evaluated as potential disposal options.
The underlying parent material, composed primarily
of Boston Blue Clay with gravel pockets, has been
shown on this and other projects to be uncontaminat-
ed and suitable for unconfined open water disposal.
The total volume of approximately 2 million cy of
jjgrcnt material (including the expansion factor) can be
disposed at an unconfined open water site if no
beneficial use (e.g., landfill and/or sediment capping)
arc identified. The final component of the dredged
material is rock that would be removed from Mystic
River Channel and two areas of the Main Ship Chan-
nel. Beneficial uses considered for the 132,000 cy
(post-dredging volume) of rock included habitat
enhancement.
Sediment Characterization
The BIINIP will result in approximately^ 1.3 million
cubic yards (cy) of silt requiring disposal. This
quantity includes approximately 0:5 ft of underlying
parent material and a (post-dredging) estimated
expansion factor of 20%. An extensive sediment
sampling and testing program, developed interactively
with the Sediment Characterization Working Group,
was undertaken to characterize the dredged material.
The surfictal silt layer (or "maintenance^ material) was
! fount! to contain varying concentrations of metals,
polynuclear aromatic hydrocarbons (PAHs),
pah/chlorinated biphenyls (PCBs), other organics.
j The sediment bulk chemistry data, in combination
with test organism toxicity and bioaccumulation
testing, indicated that the silt was generally not suitable
for unconfined open water disposal. It was further
determined that the underlying sediment (parse!
In addition to addressing the dredged material
<--ft^disposaUTCetfs--for-4be BHNIP itself, disposition of the
futureVmaintenance..oT the deepened channels over the
50 year pfojcct'life was addressed. The estimated 4.4
million cy of future maintenance material would be
composed primarily of sjjt. For the purpose of the
disposal alternatives analysis, it has been assumed that
this material could contain elevated levels of contami-
nants. Under this assumption (which may or may not
be the case), the material would have to be deposited
in a confined disposal site.
Disposal Alternatives Analysis
A Disposal Options Working Group was convened
to develop criteria for evaluation of the universe of
potential disposal sites and beneficial uses of parent
material, rock, silt and future maintenance dredging
material. The group participated in the disposal site
selection process at regular intervals, reviewing argu-
ES-2
-------
nents for retaining or eliminating specific sites. The
:iort list of potential disposal alternatives included
ites in two major categories, land-based and aquatic
itcs, and eight suhcategories: landfills, land-based
nland, land-based coastal, aquatic shoreline, aquatic
ubaqucous, aquatic borrow pit, existing aquatic
Hsposal sites, in-channel disposal and one treatment
echnology. All disposal alternatives would provide
:ontainmcnt of the silt: the upland sites through
lilution with other soil material or burial; the shoreline
iites through bulkheading and capping; and the other
iquatic sites through capping.
The disposal alternatives analysis screening process
vas comprised of three phases. In the first phase,
:omparisons were made using evaluation criteria
unong sites within each alternative category (i.e.,
andfills were evaluated together but not compared to
iquatic shoreline sites). A subsequent evaluation
bcussed on regulatory and other limiting criteria to
select the sites which provided the least environmental
mpact with the greatest project benefit. Finally, sites.
verescresncdJhr practicability issues of cost, logistics
md technology in relatigrrto project needs and goals.
From an init^=Kst^f \$76 jites and eight treatment
echnologics,\24 sites' and one treatment technology
•emaincd under^eetisideration as disposal alternatives
ifter the screening process (Figure ES-2).
The development of disposal options next focused
?n combining sites to meet the capacity requirements
jf the project. This evaluation emphasized the fact
;hat few sites are large enough to accommodate the
iisposal needs of the BIINIP by themselves. Finally,
m evaluation of options led to the development of a
short-list of six practicable alternatives (see Table ES-
la). Of these six sites, five sites (Meisburger 2 and 7,
Boston Lightship, Spectacle Island CAD and the
Massachusetts Bay Disposal site (with capping) have
the necessary capacity, individually, for the disposal of
ill the silt material. The sixth alternative consists
zapping the contaminated silts in-place in trenches
within the tributary channels to be dredged.
Although not necessarily the controlling issue, cost
is a factor in site screening under the definitkm of
practicability.. To put cost in perspective, a relative
cost (per cy) for disposal for the silt material was
developed for the various alternatives (Figure ES-3).
These costs were compared against the historical
method of unconfincd disposal of dredged material at
MBDS ($7.10/cy for silt) in accordance with MEPA
directives. These costs show that the relative costs per
cubic yard for the aquatic sites range from 1 to 5 times
the costs for unconfincd ocean disposal while the
upland sites range from 5 to 14 times higher than this
base. I lowevcr, land acquisition costs are not included
in the upland options so relative costs would be even
higher. These relative costs were used in the assess-
ment of practicability described below.
f^.
The cost of disposal of silt material at one of the
full capacity sites (Meisburger 2 or 7, Boston Light-
ship, Spectacle Island CAD and the Massachusetts
Bay Disposal site) would range from about $24 million
to about $33 million. The limited capacity sites, when
combined to accommodate the total volume, would
cost at least $10 million more than the most expensive^
full capacity site.
Through the screening process, this alternatives
assessment identified practicable alternatives for the
three categories of dredged material: parent material
(including rock), silt material and future maintenance
material. Once public comment is received on this
Draft EIR/S, a preferred alternative will be selected
and identified in the Final EIR/S. It is possible that
a single site or combination of sites could be included
in the preferred disposal alternative.
While the selection of a preferred disposal alterna-
tive is not required by the Massachusetts Environmen-
tal Policy Act (MEPA), it is required under the
National Environmental Policy Act (NEPA). Federal
agencies (e.g., the Corps of Engineers) are required to
"identify the agency's preferred alternative or alterna-
tives, if one or more exists, in the draft statement...".
In addition, the Final Rule for Operation and Mainte-
-------
nance of Army Corps of Engineers Civil Works
Projects Involving the Discharge of Dredged Material
into Waters of the U.S. or Ocean Waters (33 CFR
209, 335-338), slates that dredged material disposal
alternative or alternatives identified by the Corps
which represent the least costly alternatives consistent
with sound engineering practices and meeting the
environmental standards established by the 404 (b)(l)
evaluation process or ocean dumping criteria, will be
designated the Federal standard for the proposed
project. In compliance with the above regulations, the
Massport and the Corps select the Massachusetts Bay
Disposal Site (MBDS), the Boston Lightship, Meis-
burgcr sites 2 or 7, and Spectacle Island CAD as the
preferred disposal alternatives. These sites are selected
based on a totality of factors including least
environmental impact, logistics, capacity and cost.
The DEIR/S is to be used also as a disposal site
selection process for maintenance dredging if the
proposed navigation improvement project is delayed or
not implemented. Maintenance dredging of accumu-
lated silt material will be needed to allow ships to
transit the harbor safely. Unlike the navigation
improvement project, maintenance dredging would not
produce clean parent material which could be used for
capping. Therefore, disposal options which provide
cap material such as the Meisburger sites, Spectacle
Island CAD and in-channel disposal are preferable.
Disposal could occur at other sites if suitable cap
material can be found from other projects.
Effects of the Project
The BHNIP would have several important benefits
'to the Port of Boston. Vessel passage would be less
dependent on tidal navigation or lightering and would
enable Boston to keep pace with the changing charac-
ter (i.e., larger vessels) of the world fleet. Goods
would then be transported through Boston economi-
cally and would help maintain the port's competitive
status in the national and world marketplace. Al-
though the volume of cargo would not be projected to
increase due to this project, improvement of the
channels and berthing facilities are necessary to allow
the region to remain competitive in a global market-
place. Ship passage would be less tidally restricted,
thus a smooth flow and timely movement of ship
traffic could be maintained. In addition, reduction in
the need to lighter would reduce the potential for cargo
spills and related environmental impacts.
The BHNIP should contribute to the improvement
of Boston Harbor water quality by removing and
[ isolating silts in the channels and berths that contain
contaminants that are continually resuspended during
storm and vessel activity. MWRA is making major
strides in reducing inputs of contaminants into Boston
Harbor, primarily by removing solids starting in 1992.
Further improvements to Boston Harbor will occur
when the secondary treatment with offshore discharge
replaces the Deer Island outfall. Removing and
isolating the existing silts should hasten this clean-up
process.
y&
V/'The parent material and rock could be used benefi-
cially for such activities as closing landfills, lining
disposal sites, capping disposal sites, and enhancing or
creating habitat. Demand for the material and timing
with other construction projects will determine the fate
of appropriate portions of the parent material. Materi-
al not used beneficially will be disposed at MBDS.
Certain adverse effects of the project would be
unavoidable. Some benthic organisms and demersal
fish would be killed during dredging and blasting.
Substrate in the areas dredged would be temporarily
devoid of benthic organisms but would be recolonized
in approximately one year, reforming habitat with prey
suitable for finfish. Turbidity would increase in the
area of the dredge. Use of an environmental (closed)
bucket would help minimize contaminant elution.
Other turbidity controls, such as silt curtains, will be
assessed in terms of suitability depending on the
location of the dredging operation. Close monitoring
of the dredging operations to identify problems and
quickly seek corrective measures would be undertaken.
I5S-4
li
-------
The anticipated dredging rate would generate
approximately two to four barges per day, depending
on whether one or two dredges were operating and the
size of the barges. Thus barge traffic should not
noticeably impede normal ship traffic; interferences
with navigation would be minimized by coordination
from the Coast Guard.
.7
Impacts due to disposal of dredged materials would
vary depending on the alternative selected. The
alternatives evaluation indicated that the least environ-
mentally damaging practicable alternative would be use
of one or more aquatic sites. Practicability is defined
as providing a reasonable combination of logistics,
technology and cost. All potential practicable sites
would be managed to provide final containment of the
project silt through burial or capping. Use of these
sites would involve temporary alteration of existing
substrate although aquatic habitat would ultimately be
maintained.
During'the V/z year dredging process^benthic organ-
isms utilizmg-the-disposat-arcas would be buried, and
the frequency of disposal would prevent colonization
of the dredged material. Finfish should generally be
displaced from the area, tending to avoid the area
during disposal due to noise and turbidity disturbances.
Both of these biologic disruptions would be temporary
and ultimately would help reduce the potential for
transfer of contaminants through the food chain in the
disposal area. The benthos and fish would eventually
jEcolonize the dredge site and will benefit from the
removal of contaminated silts.
The water column in the vicinity of the disposal site
would experience increased turbidity following each
disposal event. Approximately three to five percent of
the silt/clay fraction would be lost to the environment
during the disposal descent phase. Disposal simulation
model evaluations indicated that disposal at the open
water sites should not cause adverse exposure (i.e.,
exceedances of water quality criteria) 'from the most
conservative element (copper) to sensitive resources
outside the disposal site after four hours.- Use of
mitigation measures to contain suspended solids and
associated chemicals may be necessary to protect
resources surrounding some aquatic disposal sites
within the harbor.
Some of the potential sites support commercial
fishing operations. Disposal would interfere with
fishing but only in a very localized area compared to !
the fishing ground available; appropriate site restric- j
tions and/or mitigation steps during project construc-
tion may be necessary.
Dredge Management Plan
The DEIR/S has addressed the requirement for a
Dredge Management Plan, as requested in the MEPA
Scope, on two levels. The first level evaluated alterna-
tive dredging projects, including No Action with and
without Maintenance Dredging, Full Project, Reduced
Project, and Delayed Project. The FuUProject was
found to achieve the greatest benefits for the port and
is the preferred option. The second level addressed
implementation of the dredging and disposal activities.
Until the preferred disposal alternative has been identi-
fied, the Dredge Management Plan provides general
protocols for handling disposal for each generic dispos-
al type. Methods for isolating the silt from the sur-
rounding environment (liners, caps, bulkheads) are
described. Procedures will be developed in greater
detail for the preferred disposal alternative once the
type and location of the preferred site(s) is identified.
Other Actions
Two other large projects are currently under con-
struction in Boston - the Deer Island wastewater
treatment facilities upgrade and the Central Artery/
Third I larbor Tunnel (CA/T). The level of ship traffic
generated by the BIINIP, its location relative to the
Deer Island and CA/T projects and the anticipated
schedules for the three projects should result in mini-
mal conflicts among the projects. The Massachusetts
ES-5
-------
\
Highway Department expects that the Third Harbor
Tunnel excavate at Spectacle Island will be complete
in 1995. As with other harbor infrastructure, coordi-
nation with the construction of the Third Harbor
Tunnel would have to be carefully orchestrated. The
BIINIP is expected to commence in 1996 and be
completed in 1998. Coordination of ship traffic from
each project by the U.S. Coast Guard will provide
further safeguards. The Massachusetts Water Resourc-
es Authority (MWRA) anticipates substantial comple-
tion of the Deer Island plant upgrades by late 1995.
Water quality (and ultimately sediment quality) would
continue to improve with the operation of the second-
ary treatment and offshore disposal facilities. The
BHNIP and future maintenance dredging would
continue to reduce the mass of contaminants in
, Boston Harbor even further. The EPA's Biological
Assessment for the MWRA outfall also has examined
the interaction among these three projects and found
that there are no cumulative impacts which would
pose a threat to threatened and endangered aquatic
species in the area.
Federal and StateRevicw
This DEIR/S will be reviewed by regulatory and
resource agencies on the federal, state and local levels,
as well as other interested parties for adherence to
MEPA and NEPA guidelines. Comments on the draft
document will be addressed in the final document.
Federal and state permits and consistency reviews
ultimately required potentially include:
-USACOE
- Section 10
- Section 404
- Section 103
••National Marine Fisheries Service
- Endangered Species Act/
Section 7 consultation
••local Conservation Commission(s)
- Order of Conditions
"Massachusetts DEP
- Water Quality Certificate
- Chapter 91 License
- Division of Solid Waste
Coordination
••Massachusetts CZM
- Coastal Zone Consistency
Once comments on this DEIR/S are received and
reviewed, a preferred disposal option would be selected
by the USACOE and the project sponsor. This and
remaining issues and concerns raised in the review of
the Draft EIR/S will be addressed in a Final EIR/S.
Summary of Findings
The remaining pages of this Executive Summary
consist of a figure, chart and table which highlight
several key issues raised in the Draft EIR/S. As
described in Figure I, the BHNIP preferred project
alternative consists of a combination of improvement
dredging (deepening) of three tributary channels and
two areas of the Main Ship Channel; maintenance
dredging of silt from berthing and all other project
areas; and non-dredging improvements to the President
Roads Anchorage Area.
This project design will generate approximately 3.5
million cy of material requiring disposal. This quanti-
ty is comprised of over 2 million cy of uncontaminated
parent material from the improvement dredging;
132,000 cy of rock from channel improvements, and
over 1.3 million cy of silt from the maintenance
dredging portion of the project.
Environmental considerations regarding disposal of
the silt material, based on sediment characterization
and site evaluation, resulted in the identification and
screening of numerous aquatic and land-based disposal
ES-6
-------
ptions. Practicability considerations of each option,
egarding logistics, technology and costs, relative to the
apacity available at each environmentally screened
otential disposal site, indicated that land based
ptions are, overall, more costly than aquatic options
nd can exceed, by 14 times, the cost of disposal at the
BDS. This cost/quantity comparison is depicted in
I chart represented in Figure ES-3.
The combination of environmental and practicabili-
y considerations resulted in the identification of six
lisposal options as listed in Table ES- la and depicted
>n Figure ES-2&. This list of potential disposal sites
ncludes those which could provide the capacity
iceded for the BHNIP as well as potential future
lisposal needs for maintenance material expected over
he 50-year design life of the project. Table ES- Ib lists
potentially practicable sites that were evaluated against
he screening criteria but which failed to meet a
ninimum of 200,000 cy of capacity and/or exceeded 4
imes the cost per cubic yard as compared to ocean
lisposal (see Figure ES-2b). While not considered
practicable for the BIINIP project, these sites may
provide disposal capacity for future maintenance
jrojects.
fable ES-lc (Figure BS-2c) lists the remaining sites of
he 24 that survived the screening evaluation but under
urther analysis are neither practicable nor potentially
nacticable for the BIINIP project sincethey are not
he least environmentally damaging alternatives anc
or at least some of them, are cost prohibitve.
Passport and the Corps select the Massachusetts Bay
disposal Site (MBDS), Boston Lightship, Meisburger
lites 2 or 7, and Spectacle Island CAD as the preferred
lisposal alternatives. These sites are selected based on
t totality of factors including least environmental
mpact, logistics, capacity and cost.
7inal selection of a preferred disposal option(s) will be
nade based upon public comments received on this
3KIR/S.
KS-7
-------
-------
EVERETT
CHELSEA
McArdla c/1(J,se9
35' Channel
EAST BOSTON
***.. \ V.'fPl
BOSTON
Deepen
To-40'MLW
To -38' MLW
-:- ^"V ^^^n^7^;-i -i r: - ; ^/*";?-. ;'^^^^S«p^ 1<": - ^ i ^
--- Existing Channel
......... Realigned Channel
(President Roads)
SOUTH BOSTON
SotolnFort
0 2000* 40W
US Army Corps ol Engineers
Naw England Division
Boston Harbor,
Navigation Improvement Project
Figure ES-1
January 1994
-------
Boston Harbor Dredging Project EIR/S
©
Scale: 0 10
Apprax. Scale in Miles
Figure ES-2
Locations of potential disposal sites
extensively evaluated.
Source:
USGS Quadrangles
Revised by NAI to reflect pertinent site conditions.
-------
s-
!
t
31
I
S,
-------
|WESTMVFtTCHBURGi
FITCHBURG
"^
E.BRIDQEWATER BFI
r^»««"—«M——•—•
• ~ ;:,-*uv K^*-
^ ^ «',& * -
-------
Boston Harbor Dredging Project EIR/S
©
Scofe: 0 70
Appraz. Scale in Miles
figure ES-2c. Locations of short-listed sites found
not practicable.
Source:
USGS Quadrangles
Revised by NAI to reflect pertinent site conditions.
-------
I'l't'
_ .^ jBbsfon Hairbli
lavfjjation (mpmi
=•5 E-P
W
, Relative Costs and Capacities
)t»jKMMtl Option* for SIHy DnKltftdl fttettri*t
ftff
die name
,o%i
«>tt)««3
Aquatic
;•
w~*.
t*,! , r / v „ f
~> tS° e -tft ff -.1 f Af < ' ^
|4|»U> :•,:• ^^l^^u/ ( t"ut^il— „ .•- ,
^
.../;.. i >. s
^
'. ••'•;l :, ^.K
Land-Based
Ui
• 4'XA;
Spectacle Is.
Revere Sugar
' y?\W'*>' rtx*'-^V* ^\ f ^^.^.^.j^.^.g..-^.^^ *MysnoHtver •, *, UBh>,^88c • x, \ -; ; x -^^ ^ ,^ \, — -* ;,«.v s ,; ,-
> ;t: 1^::{:^^:ir"^j^li^^ if^A^T^^;:" ^V^;' ;Vi V.i v: ^
- tjpl :jMBDSfor |i ^11^y>'p :;^-.; ^ ;V,,V^'VrS^r>:^-i , "':f'l\vv i^ll^t-^^;
^, * ^;" in -1 Parent Mat f ^winmropnDr^ ^ ^ , %, ^« ^ ^ ^ ^ ^^, -^ ^ ^ Unconflned Ocean Disposal of Silt- $7.10/CY i* , , ^ *\
' »*% *;''*',' °' %''••'/ ,''*',"''' ^.'% - •. ^ ^ <-. ^ \ 5. * -, s, , %. „ r , -•• ^ •." ,
-------
TABLE ES-la. PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY) FOR THE
BOSTON HARBOR NAVIGATION IMPROVEMENT PROJECT
SITE NAME
CAPACITY (cy)
COST
PERCY
PARENT
MATERIAL
AND ROCK
BHNIP
SILT1
FUTURE
HARBOR
MAIN-
TENANCE2
HIGH CAPACITY SITES
Boston Lightship
(with capping)
Combined In-Channel Locations
MBDS
Meisburger 2
Meisburger 7
Spectacle Island CAD
Exceeds BHNIP
project and 50-year maintenance needs. Total
capacity unknown,
740,000
Exceeds BHNIP
project and 50-year maintenance
needs. Total capacity unknown.
4,660,000
6,125,000 +
1,450,000
$18
$25
$18
$20
$22
$25
X
X
X
X*
(with
capping)
X
X
X
X
X
X*
(with
capping)
X
X
*Disposal-and-capping (or unsuitable material) is prohibited at MBDS until its efficacy can be effectively demonstrated (40 CFR 228.12 [Amended]).
1BHNIP silt material consists of approximately 1.3 million cubic yards. Additional material from the BHNIP includes approximately 130,000 cy of rock and 2.0 million
cubic yards of parent material.
2Future harbor maintenance consists of maintenance dredging approximately 4.4 million cubic yards of material from the Main Ship Channel and 1.8 million cubic yards
of material from the tributary channels. These volumes are estimated as the aggregate accumulation over the 50-year life of the project (as calculated beginning in 1997).
These volumes are expected to be dredged intermittently over the life of the project as needed. Maintenance dredging of the tributary channels is not likley.to be needed for
at least 10-years after the BHNIP project, or not until the year 2007. Minor, spot dredging may be required in the President Roads Anchorage Area and Main Ship
Channel, Outer Harbor, beginning in the year 2002 if shoaling conditions warrant. More extensive maintenance dredging of the outer channels is not expected to be needed
until at least the year 2007.
-------
TABLE ES-lb. POTENTIALLY PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY)
BUT LIMITED BY CAPACITY AND COST
SITE NAME
Amstar
Little Mystic Channel
Mystic Piers
Reserved Channel
Revere Sugar
Lined Landfills
Treatment Technologies*
CAPACITY (cy)
128,000
303,000
98,000
18S.OOO
85,000
102.000
Unknown
COST
PER CY
$37
$33
$35
$255
S35
$56-$101
$55
PARENT
MATERIAL
AND ROCK
N/A*
N/A
N/A
N/A
N/A
N/A
N/A
BHNIP SILT1
X
X
FUTURE HARBOR
MAINTENANCE2
X
X
X
X
X
X
X
*N/A - Not Applicable
'BHNIP silt material consists of approximately 1.3 million cubic yards. Additional material from the BHNIP includes approximately 130,000 cy of rock and 2.0 million
cubic yards of parent material.
'Future harbor maintenance consists of maintenance dredging approximately 4.4 million cubic yards of material from the Main Ship Channel and 1.8 million cubic yards
of material from the tributary channels. These volumes are estimated as the aggregate accumulation over the 50-year life of the project (as calculated beginning in 1997).
These volumes are expected to be dredged intermittently over the life of the project as needed. Maintenance dredging of the tributary channels is not likley to be needed for
at least 10-years after the BHNIP project, or not until the year 2007. Minor, spot dredging may be required in the President Roads Anchorage Area and Main Ship
Channel, Outer Harbor, beginning in the year 2002 if shoaling conditions warrant. More extensive maintenance dredging of the outer channels is not expected to be needed
until at least the year 2007.
*Screening and evaluation of treatment technologies resulted in solidification as being the only practicable alternative for the BHNIP project Other technologies were
eliminated based on availability, quantity of material to be dredged, throughput requirements and costs which, for some of the technolgoies screened, could run as high as
S3SO per cy.
-------
TABLE ES-le. ALTERNATIVES (LISTED ALPHABETICALLY) EVALUATED BUT FOUND NOT PRACTICABLE
DUE TO ENVIRONMENTAL FACTORS OR COST
V
SITE NAME
Cabot Paint
Everett
Squantum Point
Subaqueous B
Subaqueous E
Winthrop Harbor
Woburn
Wrentham
CAPACITY (cy)
18,000 to MLW
99,000 to MHW
55,000
210,000
600,000
614,000
167,000
158,600
785,500
COST PER
CY
$278
$76
$37449
$17
$16
$12
S61
$50
PARENT
MATERIAL
AND ROCK
N/A*
N/A
N/A
N/A
N/A
N/A
N/A
N/A
BHNIP SILT1
N/A
N/A
N/A
N/
N/A
N/A
N/A
N/A
FUTURE HARBOR
MAINTENANCE*
X
X
X
X
X
X
X
X
IN/A - (Not appucaoie
silt material consists of approximately 1.3 million cubic yards. Additional material from the BHNIP includes approximately 130,000 cy of rock and 2.0 million
cubic yards of parent material.
2Future harbor maintenance consists of maintenance dredging approximately 4.4 million cubic yards of material from the Main Ship Channel and 1.8 million cubic yards
of material from the tributary channels. These volumes are estimated as the aggregate accumulation over the 50-year life of the project (as calculated beginning in 1997).
These volumes are expected to be dredged intermittently over the life of the project as needed. Maintenance dredging of the tributary channels is not likley to be needed for
at least 10-years after the BHNIP project, or not until the year 2007. Minor, spot dredging may be required in the President Roads Anchorage Area and Main Ship
Channel, Outer Harbor, beginning in the year 2002 if shoaling conditions warrant. More extensive maintenance dredging of the outer channels is not expected to be needed
until at least the year 2007.
-------
-------
-------
nil in Mini
i III 111 i III ill IIP 111 I 111 111 Mi 1 111 P1 Illllll I I 1 II
11 ii
Illlllllll llllIlllllllll Illllll Mil
III Illllll I 11 Illllll III
••I
Illllll IIIII 111 Illllll I Illlllllll
nil II
III III Illllll I
Illllll Illlllllll
in iiiiiii
nil iiiiiii
-------
1.0 INTRODUCTION
Boston Harbor is one of New England's most
important ports in terms of the movement of goods
and the region's economic vitality. While Boston
Harbor's principal entrance and main access channels
are -40 feet mean low water (MLW) the three major
tributaries, which include the Reserved Channel ?•
Mystic River and Chelsea River, arc only -35 feet
MLW. (The Chelsea River is locally known as
Chelsea Creek and will be referred to as such in this
BIR/S). These shallower depths can place substan-
tial restrictions on shippers by limiting vessel size and
loading (Eldridge, 1994). These conditions can
translate to increased safety hazards as well as envi-
ronmental (e.g. spill) and economic risks to the
harbor.
Congressional and local interests felt that modifi-
cations to Boston Harbor channels were needed due
to the increase in traffic of bulk commodities flowing
through the port and the delay time being experi-
encedEyincreasinElv larger vessels requiring a high
tide to negotiate the existing restricted ship channels
into the pojt. Local navigation interests, via two
Congressional Resolutions (March 1, 1968 and
September 11, 1969), requested the Army Corps of
Engineers to review the present and projected naviga-
tion needs in Boston Harbor. The Army Corps of
Engineers is given the authority to conduct General
Investigations into improving the navigability of the
waters of the U.S. under the Rivers and Harbors Act
of 1899.
A Feasibility Report and Environmental Assess-
ment was completed in 1988 by the U.S. Army
Corps of Engineers for the navigation improvement
project. The economically and environmentally
favored alternative selected in the report was autho-
rized by Congress in the Water Resources Develop-
ment Act of 1990 (P.L. 101-640). The navigation
improvement project involves the deepening of the
Mystic and Reserved Channel from -35 feet to -40
feet MLW and the Chelsea Creek from -35 feet to -
38 feet MLW. In addition to deepening, modifica-
tions are required in the Mystic River, the Inner
Confluence and at the entrance to Reserved Channel
to provide safe maneuvering areas. In the President
Roads area, channels will be re-marked and designat-
ed along the southern reach of the roads connecting
the outer confluence of the three entrance channels
with the inner harbor Main Ship Channel. This will
enlarge the anchorage area from about 375 acres to
about 420 acres.
To realize the economic benefits from deepening
the channels, six berth areas adjacent to these chan-
nels (Conley 11-13, Prolerized, Distrigas, Moran,
Eastern Minerals and Gulf Oil) must also be deep-
ened to the same depth as the channel. In addition
to these berthing areas, other berthing areas within
the project but not adjacent to the channel (Boston
Army, Boston Edison Intake, Boston Edison Barge,
Conley 14-15, Revere Sugar, Mystic Piers 1, 2, 49
and 50) would also be deepened at the same time as
part of Massport's Berth Dredging Project. The
Corps and Massport dredging projects are collectively
termed the Boston Harbor Navigation Improvement
Project (BIINIP) and will be treated as one project
throughout this document except where otherwise
noted.
This report is prepared as a joint Commonwealth
of Massachusetts Environmental Impact Report and
Federal Environmental Impact Statement (EIR/S) by
the Massachusetts Port Authority (Massport) and the
U.S. Army Corps of Engineers (Corps). A project is
subject to review under the regulations of the Massa-
chusetts Environmental Policy Act (MEPA) (301
CMR 11.00) if the project requires any state agency
action, financial assistance, or permit. It was deter-
mined by the Secretary of Environmental Affairs on
June 7, 1991 that an Environmental Impact Report
(EIR) is required for the dredging of the berths. The
U.S. Army Corps of Engineers determined that an
EIS was required under the National Environmental
Policy Act (NEPA) (42 USC 4321 el. seq.) due to
the cumulative impacts of Federal actions (mainte-
1-1
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nance dredging, navigation improvement dredging,
and permitting of the associated berthing areas) and
the significant public concern over disposal of the
dredged material. The MEPA certificate and the
NEPA scoping documentation are provided in
Appendix A.
This EIR/S is designed to assess the anticipated
environmental impacts associated with the Federal
navigation improvement and maintenance project
authorized by the Congress and associated dredging
by Massport and others in Boston, Massachusetts.
This document updates and expands on the 1988
Environmental Assessment and Feasibility Report for
the subject project.
An additional element provided in the EIR/S is a
discussion on potential long-term disposal options
that may be appropriate for future projects and
maintenance dredging of this project. These options
require additional analysis and development. This
additional aspect is provided in response to the
MEPA certificate's acknowledgement that "Massport,
as the lead agency for this dredging project, will
develop a considerable data base and expertise.
Thus, the agency may be able to contribute signifi-
cantly to the success of the longer range dredging and
disposal program."
1.1 GENERAL DESCRIPTION OF
PROJECT AREA
The Port of Boston, Massachusetts, as shown in
Figures 1-la and 1-lb (Note: referenced figures and
tables arc at the end of each section), is located on
the western side of Massachusetts Bay, approximately
50 miles from the lip of Cape Cod. Its outer and
inner harbors include all the tidal waters bounded by
a line drawn roughly from Point AUerton in Hull,
northward to Point Shirley in Winthrop. The harbor
comprises a water area of approximately 47 square
miles.
Boston Harbor is home to one of the United
States' oldest and most historic international trading
centers, the Port of Boston. A source of jobs and
commerce for the 13 million residents of the six-state
New England region, the Port handles more than 25
|| million tons of cargo, worth more than seven billion
|( dollars annually.
Deep water access to the harbor is provided by
three entrance channels constructed by the Army
Corps of Engineers. These channels are: the Broad
Sound North Channel, in two lanes at depths of -35
and -40 feet; the Broad Sound South Channel at a
-30 foot depth; and the Narrows Channel at a -27
foot depth all referenced to MLW. The main deep
water harbor consists of the Main Ship Channel,
Reserved Channel, Chelsea Creek and the Mystic
River. The tributary channels have all been im-
proved in the past by the Army Corps of Engineers
to a depth of -35 feet MLW. These depths limit
deeper draft traffic to tidal passage and therefore, the
40-foot improvements to the Broad Sound North
Channel and Main Ship Channel are not being used
efficiently. The three tributaries are surrounded by a
dense urban and industrial environment. Reserved
Channel supports the Black Falcon Terminal used by
cruise lines, Boston Edison, the Conley Terminal,
and other marine activities. The lower Mystic River
provides access to the port's widest variety of termi-
nal facilities. Chelsea Creek also supports marine
piers and terminals. Nine of the port's eleven petro-
leum terminals arc located along the Chelsea Creek
channel.
1.2 PURPOSE AND NEED FOR ACTION
'Hie purpose of the BIINIP project is to increase
the navigational efficiency jnd_safety of Boston
I larbor for present types of deep drafted vessel traffic
that arc currently transiting thejgoject area. The
need for this dredging is evidenced by an economic
analysis compiled by the New England Division
(NED) Corps of Engineers that found that the
1-2
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project has regional benefits that exceed project costs.
The Port of Boston is one of New England's most
important economic assets. More than 6,000 people
have jobs directly related to the cargo industry and
3,000 jobs in the industrial service sector support
cargo activity. As a result of its cargo handling
activities, Massport was responsible for generating
nearly $1.86 billion in economic benefits for the
region in 1992. As one of America's oldest and most
experienced ports, the Port of Boston is an important
gateway for the international trade and commerce. It
is also the energy lifeline of the region.
The existing Federal navigation project was
originally constructed to serve the port's commercial
terminals located along the main ship channel water-
front. Changing waterfront land use patterns have
resulted in most of the port's active terminal facilities
shifting from the Main Channel to the -35 foot
MLW tributary channels. Changes in the world wide
shipping fleet have resulted in vessels that are larger
in length, beam, and draft.
A depth of-40 feet MLW is needed to accommoV
date the container ships and tankers that are a maiml
stay of the present day shipping business. Projectn
benefits for deep draft navigation projects result from
reductions in the cost of transporting goods for ship-
pers. Factors influencing shipping costs are vessel
characteristics such as size, speed, immersion factor,
draft, cargo capacity and crew requirements; origin or
destination of shipments, flag of vessels, and vessel
operating costs. These are all elements of supplying
goods to the New England region.
Larger vessels have higher operating cost, but their
cost per ton shipped is lower. This results in the use
of larger vessels by shippers to reduce transportation
costs. Shippers can, and do, utilize vessels with
drafts in excess of the channel depths. However, the
vessels either incur tidal delay, have to be lightered or
are light loaded. The cost of these practices reduce
the benefits of using larger vessels and can result in
higher product costs.
Vessel operating costs reflect double hull require-
ments for oil tankers. Double hull construction has
increased vessel operating costs by approximately
nine percent for small tankers and seventeen percent
for the largest. Double hull tankers still carry the
same cargo, but draw about a foot more in draft.
Thus use of double hull tankers may decrease effi-
ciency of transporting oil if the amount of tidal delay
and lightloading is increased.
The economic analysis compiled by the Army
Corps of Engineers, and contained in the September
1988 Feasibility Report, reviewed the modem port
activity described above, and found that the project
is justified economically by increasing navigation
efficiency. The Project will also meet the port's
needs. Project benefits are derived from utilization of
more efficient, larger vessels which will transit the
harbor during a wider range of tidal stages. The
economic analysis was conducted using the policy
established by the Army Corps of Engineers, Wash-
ington Headquarters. The economic analysis was
also used to determine the most cost effective design
(National Economic Development Plan). Based on
the recommendations of the Feasibility Report and
reports from the Board of Engineers for Rivers and
Harbors and the Chief of Engineers, the project was
Congressionally authorized in the Water Resources
Development Act of 1990 (WRDA 1990).
Although the project was economically justified by
comparing the "with project" and "without project"
conditions, other benefits may accrue for the Port of
Boston and the New England region from deepening
the navigation channels, not included in the Army
Corps of Engineers report. These benefits, described
below, are basedon the experience of Massport and
£he projected future of shipping in the region^ New
legislation (Oil Pollution Act of 1990; 101 Public
L,aw 330) and the increase in the number and size of
container ships have had an effect on ship use in
Boston Harbor.
1-3
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Delays and light loading increase the container
jf ships' operating costs and discourage many ships
11 from calling directly on the Port of Boston. At the
*' present time, "Atlantic" and "Oceanus" class contain-
crships schedule arrivals into Boston around the tide.
The "Atlantic" class vessels do not call on Boston
loaded to the maximum capacity. If they did, they
would have to sojourn at the anchorage area to wait
for a favorable tide. The increased operating costs
arising from potential tidal delay not only discourages
other shipping lines from using the port, but could
possibly lead to the loss of existing services which J
/l
support the carriers.
In addition to losing the existing services, not
' dredging the Port may mean not being able to attract
new shipping business. The ability to bring in addi-
tional shipping lines with large container ships and
frequent schedules is important for the future growth
of the Port. Although many factors, such as a cargo
base, an efficient over-land distribution system,
frequent ship schedules, and the size of service area,
influence the number of containers that a port can
attract, deep water channels and berths are a pre-
requisite for the smooth flow of the cargo.
Petroleum shipping is affected similarly by silting
of the harbor. Smaller tankers generally wait at the
anchorage for the high tide. Larger tankers, drawing
more than 34 feet, nowjJccasionaHy off-load some or
all of their cargo to barges (lightering"), which then
deliver the oil to the Port's terminals. The need to
lighter increases shipping time, adds to the tankers'
operating costs (which may be passed onto the
consumer), and increases the risk of oil spills. Prob-
lems associated with lightering can be illustrated with
the current conditions in Providence Harbor, Rhode
Island. Dredging at Providence Harbor has been
stalled for lack of a disposal site. This delay has
resulted in shoaling which has reached a critical level.
As a result, final deliveries require regular lightering
and are subject to increasingly long tidal delays. The
double handling of fuel has increased the cost of
gasoline coming through the harbor by about 4Vz
cents per gallon (Interagency Task Force 1993). As
with all lightering operations, the risks of oil spills
increase with the increasing need to lighter. Al-
though the Port of Boston has never experienced a
major oil spill, the danger of such an occurrence is
real, if lightering is not reduced, eliminated, or needs
to continue indefinitely.
The vessel draft problem will be aggravated by the
introduction of double-hull tankers between the years
1995 and 2015. These tankers, which will have the
•'same carrying capacity as the old tankers, but with
larger exterior dimensions, will replace the present
tanker fleet serving the Port of Boston. Unless the
depth of the shipping channels and berths is in-
creased, more lightering will be required in the Port.
Improving the channel and berth depths in Boston
Harbor will, be the port's first major dredging project
sinceTl 982/198^^^^*1 867,000 cubic yards of dredged
material-was removed from the Mystic River, Chelsea
Creek and Presidents Roads. The only additional
dredging completed since that time have been small
quantity, individual maintenance of berths. Some
examples include:
•• Mobil Oil Corp. terminal berth in the Chelsea
Creek approximately 1,500 cubic yards in
1991.
•• Coastal Oil Corp. terminal berths in the Chel-
sea Creek and Reserved Channel, approxi-
mately 3,000 cubic yards in 1992.
»• Moran Terminal in the Mystic River, approxi-
mately 10,000 cubic yards in 1993. Dredging
a 1,000 foot berth at Moran Terminal, result-
ing in 16,600 cy of material, was originally
included in the full BIINIP project. The
reduced project performed in 1993 was de-
signed to improve an 800 foot berth to
accommodate a new cargo shipping line that
was ready to add the Port of Boston to its
service area. The 1993 reduced project was
1-4
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subjected to independent environmental
review and permitting. The 10,000 cy from
the reduced project was disposed at ar^gxist^
ingjandjai. The BIINIP full project now
includes only the remaining 200 feet of berth-
ing area and approximately 6,600 cy of mate-
rial requiring disposal.
The proposed dredging is critical, particularly in
Chelsea Creek for the petroleum shipping, and in the
Vlystic River for the container shipping. Safe and
fficient flow of cargo into and out of the harbor is a
prerequisite for the growth and success of the Port of
Boston, and to efficiently meet the heating and
fueling needs of the major metropolitan area of New
England.
In summary, the BIINIP is designed to serve a
variety of interests associated with efficient port
operations. These interests are:
1.
Maintenance dredging of the Federal chan-
nels to accommodate the current container
ships and tankers to keep the Port of Boston
<=^ """
in the same port categorofs
Improve navigation by deepening certain
Federal channels and associated berths and
providing future maintenance of the improve-
ments. Improvements in navigation will
accommodate the future larger container
ships and double-hull tankers with minimal
tidal delays, vessel lightering and economic
benefits occurring from the efficient flow of
cargo.
3. Identify potential disposal options to serve
future long-term maintenance requirements
to meet regional needs including Boston
liarEor.
1.3 PROJECT SPONSORS
Prior to the passage of the Water Resources Devel-
opment Act of 1986 (WRDA 1986) (Pub. Law 99-
662), commercial navigation improvements were
constructed, operated and maintained with 100
percent Federal funding (except for land and reloca-
tion requirements). Now, a non-Federal cost sharing
partner is needed to finance deep draft navigation
improvement projects. The non-Federal cost sharing
partner for the Boston Harbor Navigation Improve-
ment Project is the Massachusetts Port Authority
(Massport). Massport is also responsible for prepar-
ing the Environmental Impact Report (EIR) for the
project berthing areas. Cost sharing for the BHNIP
is dependent on two stages required to complete it:
dredging of maintenance material and improvement
dredging.
The tributary channels to be deepened in the
project are existing channels which have been main-
tained to the authorized 35 foot depth. Silt has
accumulated in these tributaries since the channels
were last deepened and includes material which has
filled in the over-depth areas (about -37 feet MLW).
This silt, or maintenance material, must be removed
prior to improvement (deepening), of the tributary
channels. The cost of dredging the maintenance
material will be 100% Federally funded.
In addition to the maintenance dredging, the
authorized project would also deepen the navigation
channels in the Mystic River, Chelsea Creek, and the
Reserved Channel. In order to realize the benefit of
this navigation improvement project in the Federal
channels, "beneficiaries" of the project must also
dredge berths to the same depth as the parent chan-
nels. The beneficiaries are the owners/operators or
users of those berths that benefit directly from the
channel deepening. These include shipping lines
using Moran Terminal, Exxon USA, Inc., Distrigas
of New England, Prolcrized of New England and
Boston Edison in the Mystic River channel. In
Chelsea Creek, beneficiaries include Eastern Minerals,
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Northeast Petroleum, Gulf Oil Co. and Coastal Oil
of New England, Inc. In the Reserved Channel,
beneficiaries are Coastal Oil of New England, Inc.,
and the shipping lines using Conley Terminal.
Section 101 of WRDA 1986, which describes cost
sharing, requires that the local (non-Federal) sponsor
bear a percentage of the harbor improvement con-
struction costs for project components that are cost-
shared (channel deepening, mitigation, etc.). This
varies according to the range of water depths where
the work is done (20 feet or less, greater than 20 feet
but not in excess of 45 feet, and greater than 45 feet).
For the BIINIP, 25% of the cost for channel deep-
ening is paid during construction and includes the
costs of planning, engineering and design, and con-
struction management.
The non-Federal participants must assume an
additional 10% of the channel deepening costs
payable over a period of up to 30 years. The remain-
ing costs of dredging, including dredging berths and
utility relocation must also be assumed by non-
Federal interests for this project. Utility relocations
to be undertaken by Massport will be credited against
the additional 10% share.
In addition to the cost sharing responsibilities, the
local non-Federal sponsor (Massport) will be re-
quired to obtain appropriate Corps (and all other)
permits for all berth areas.
Relocation and addition of navigation aids, for
example at the President Roads Anchorage Area, is
a Federal expense borne by the United States Coast
Guard. Table l-l summari7.es the percentage the
local sponsor must finance for the BHNIP.
The requirements of non-Federal participation will
be governed by the Project Cooperation Agreement
(PCA) which is a legally binding document signed by
the Federal government and the non-Federal sponsor
prior to construction. Once the project has been
constructed, the Federal government, through the
U.S. Army Corps of Engineers, is responsible for
maintaining Federal navigation channels. Berthing
areas are maintained by the respective owners.
1.4 PUBLIC PARTICIPATION PROCESS
Prior to initiating environmental studies in support
of the project, Massport recognized that large pro-
jects which may impact the public can no longer be
accomplished unilaterally. There was a consensus
that the success of the project depended on involving
key groups effectively. This general principle had a
number of important implications. Key parties
needed to be identified which either had a stake in
the outcome (regulatory agencies, environmental
groups, and harbor users), or could provide useful
information to Massport, its consultants and the
Corps. Effective involvement of these parties re-
quired that they be consulted early, that they be
provided timely information on the progress of the
project, and that they have the opportunity to
present diverse points of view. It was also recognized
that meetings of these parties would be assisted by a
professional facilitator whose objectives would be to
ensure that all parties were heard and to help the
parties resolve their differences where possible.
To that end, Massport and its consultant developed
a public participation process which consisted of a
broad-based Advisory Committee which was active
throughout the project preceding distribution of the
lilR/S. This Advisory Committee was supplemented
by targeted, focus groups to assist project planners in
particular technical areas. The following paragraphs
explain the process and its operation and affect on
the production of this EIR/S. Massport and the
Corps appreciate the valuable expertise and insight,
and most particularly, the generous contribution of
time from these agency personnel and other private
and public groups.
1-6
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1.4.1 Advisory Committee
To initiate the public participation process Mass-
port sent letters in March 1992, notifying the recipi-
ents of its plans for the Boston Harbor Dredging
Project and inviting them to participate in an Adviso-
ry Committee composed of concerned agencies,
interest groups, and political leaders. An initial
meeting of the Advisory Committee was held on
April 6, 1992. As described at that meeting, the
function of the Committee would be to advise
Massport and the Corps of Engineers in the conduct
of its environmental studies and the preparation of
the Environmental Impact Report/Statement. The
Committee would be a forum in which participants
would be encouraged to voice their concerns so that
Massport, to the best of its ability, could attempt to
resolve them. Suggestions were sought from atten-
dees for other groups which should be invited or
aicouraged to participate.
Invitations to participate were sent to the
following:
Bay State Cruise Company*
Boston Harbor Docking Pilots
Boston Line & Service Co., Inc.*
Boston Pilots
Boston Redevelopment Authority
City of Boston: Environment Dept.,
Public Works Dept.
Conservation Law Foundation
Mass. Audubon Society
Mass. Bay Transportation Authority
Mass. Bays Program
Mass. Coastal Zone Management
Mass. Dept. of Environmental
Management-Waterways
Mass. Division of Marine Fisheries
Mass. Division of Solid Waste Management
Mass. Division of Water Pollution Control
Mass. Division of Wetlands and Waterways
Mass. Exec. Office of Environmental
Affairs (MEPA Unit)
Mass. Highway Department
Mass. Water Resources Authority
Metropolitan Area Planning Council
Move MA 2000
National Marine Fisheries Service
New England Aquarium*
New England Fisheries Management
Council*
Office of Senator Edward Kennedy*
Office of Senator John Kerry*
Patterson, Wylde & Co., Inc.
Save the Harbor/Save the Bay
The Boston Harbor Association
The Boston Shipping Association
The Gillette Company
The Sierra Club
U.S. Coast Guard
U.S. Environmental Protection Agency
U.S. Fish and Wildlife Service
* Invited but did not participate.
The Advisory Committee met seven times over the
course of the studies and preparation of the EIR/S.
To assist with particular detailed technical issues, the
Committee formed two Technical Working Groups,
as described below, from which it received periodic
reports, enabling the Committee to focus on the large
policy questions. Minutes of meetings were distribut-
ed to all persons on the mailing list for their review
and approval (see Appendix B). Occasional new
members joined the Committee over its period of
operation.
Input from the Advisory Committee as well as the
two Technical Working Groups provided significant
direction to the project. As discussed below in
further detail, the many recommendations of the
Technical Working Groups were incorporated into
the ultimate testing design and alternatives analyses.
This process was flexible and dynamic, evolving as
information became available.
1-7
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Advisory Committee meetings typically were very
interactive. The facilitator sought reactions and
advice from all participants. Through group discus-
sion, Massport and other participants were able to
evaluate the advice and to decide on an appropriate
course of action. The EIR/S reflects the dynamic
nature of the project concept and development and
the expert advice of the Advisory Committee.
1.4.2 Technical Working Groups
Two Technical Working Groups were formed by
the Advisory Committee to provide it with support
on certain highly technical matters associated with
the project. While there was often much overlap
with the membership of the Advisory Committee, the
Working Groups drew technical personnel as appro-
priate from state and federal agencies. All members
of the Advisory Committee were invited to partici-
pate in either or both Technical Working Groups.
The Sediment Characterization Technical Working
Group met eight times to carry out a variety of
complex tasks. Early meetings dealt with the design
of a sediment sampling plan for berths to determine
impacts from dredging, impacts from material dispos-
al and post-construction impacts. Issues addressed
during development of the sampling plan included
selection of sampling locations to achieve statistical
validity, substances to be tested for, appropriate
laboratory testing procedures and detection limits,
and a reliable Quality Assurance/Quality Control
program. All these components were incorporated in
a Sediment Sampling and laboratory Analysis Plan
approved by the Working Group. Later meetings
reviewed the bulk chemical analyses and made
recommendations for conducting amphipod toxicity
tests. Final meetings were dedicated to making
recommendations on testing clams and marine
worms for bioaccumulation of selected contaminants
and reviewing those results. The plan and results are
presented in Appendix C.
Throughout its period of operation, the Sediment
Characterization Technical Working Group consis-
tently provided constructive guidance to Massport
and the Advisory Committee for the studies which
would be most useful to regulators and the interested
public. In numerous instances, one or more mem-
bers of this Working Group pressed for an expansion
of sediment sampling and analysis beyond the re-
quirements of the MEPA scope. Massport accepted
most of these recommendations, including a large
increase in the number of sediment samples taken,
testing for additional chemical constituents, and
conducting additional bioaccumulation tests. In
general, these modifications contributed to the
reliability of the sediment characterization results.
Determinations of suitability for ocean disposal
focusscd on bulk sediment chemical levels and
amphipod tests in addition to the bioaccumulation of
contaminants in the tissue of clams and marine
worms.
A second working group was convened to ensure
that the EIR/S would be based on the full range of
project, disposal and treatment alternatives, and that
appropriate criteria would be used in the evaluation
of those alternatives. Early meetings of the Disposal
Options Technical Working Group focussed on
identifying the generic disposal and treatment options
that should be considered, site requirements for each
of the options, and thedevclopmentjrfffcclusionary
critcna~~to screen out clearly inappropriate_sjtes.
I-atcr, this Working Group reviewed a list of poten-
tial disposal sites for its completeness. After the
exclusionary criteria had been applied, the Working
Group then reviewed the resulting subset of sites and
treatment technologies to see if any options had been
dropped prematurely or if any of the remaining
options should have failed the initial screening.
Group members were asked for any information
which might be useful in evaluating any of the sites
remaining on the short list. The Group's input
resulted in modifying, somewhat, the typical "funnel-
ing" approach of site selection; that is, some sites
1-8
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vere identified and added/evaluated subsequent to a
>revious screening stage, if so directed by the Group.
This Working Group also made numerous recom-
nendations, some of which went beyond the expect-
,d requirements of the M13PA scope. In the interest
>f accommodating these recommendations, Massport
Complied with requests to address options with
aspect to specific sites instead of generic characteris-
ics and also to carry the evaluation of options nearly
o the point at which a preferred alternative could be
elected in the draft EIR/S phase. In contrast, the
VIEPA certificate only required that the Draft EIR
bcus on "... sediment testing, an assessment of
ediment compatibility with the universe of alterna-
ives, and a generic evaluation of alternative feasibili-
y-"
.4.3 Federal Scoping Meeting
Shortly after Massport's formation of the Advisory
Committee, the Corps issued its formal Federal
Register Notice of Intent to prepare an EIS for its
>ortion of the project. Consistent with the require-
nents of the National Environmental Policy Act
NEPA), the Corps advertised and conducted a
>ublic scoping meeting to solicit comments about the
ypes of issues which should be included in the EIS.
issues were raised which had not previously been
dentified in the Corps' Environmental Assessment
md/or in the Secretary of Environmental Affairs'
Certificate in response to the Environmental Notifica-
ion Form (ENF). A transcript of these scoping
neetings is contained in Appendix A. Section 5.0 of
he EIR/S more fully details the Federal coordination
md scoping process.
1.5 COMPLIANCE WITH MEPA AND
NEPA REQUIREMENTS
As discussed earlier, this combined EIR/S must
neet the requirements of MEPA and NEPA in terms
of scope and format. The MEPA certificate (see
Appendix A) sets out five major issues in its scope
for the EIR. These consist of a project description,
sediment characterization, dredging methodology and
dredging impacts, feasibility of disposal alternatives
and mitigation measures. Central to the NEPA
requirements are considerations of alternatives to the!
project presented so that a clear basis for choice!
among options is provided.
Further, 40 CFR 1502.10 provides guidance on a
recommended format for NEPA documents. Similar
guidance for MEPA submittals is provided in 301
CMR 11.07. Format guidance provided in these
sections are largely compatible but combining them
required minor modifications from the individual
recommended formats. All required substantive
material is included and arranged as follows:
»• A summary, as required by NEPA, (herein
provided in the Executive Summary at the
beginning of this document) of the project
description, major environmental effects of the
project and its alternatives and major conclu-
sions.
»• A project description (MEPA requirement)
including purpose, need and objectives of the
project (NEPA requirement), and a descrip-
tion of the physical characteristics of the
project. This information has been provided
in the preceding paragraphs of Section 1.
•• Both MEPA and NEPA require an alterna-
tives analysis of the proposed project and a
description of alternatives to the proposed
project and a clear explanation of the selection
and screening process for the evaluation. This
requirement is contained in Section 2.0 and
Section 3.0 of this EIR/S. Section 2.0 pres-
ents a complete discussion of alternatives to
the project design, including No Build op-
tions, and identifies a preferred dredge (OT
build) alternative. The second half of Section
2.0 consists of a description of the design, pro-
1-9
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cess and results of the sediment characteriza-
tion studies specifically required by the
MEPA scope which, in addition to the pro-
ject design alternatives, forms the basis for
determining potential disposal options.
Section 3.0 provides a complete description
of the process of disposal alternatives identifi-
cation and the product of screening the alter-
natives in a multi-phase approach.
Attachment 1, Volume 1 of this EIR/S con-
tains an evaluation of the affected environ-
ment for the dredging and disposal sites.
This section also includes the environmental
consequences of the disposal activities.
Section 4.5 provides the environmental im-
pacts expected from dredging operations.
»• The MEPA scope called out specifically for
a Dredging Management Plan separate from
the preceding NEPA requirement for a dis-
cussion of the affected environment. Section
4.0 of this EIS/R consists of a draft plan
incorporating concerns as to type of dredging
technology likely to be employed, project
phasing and mitigation of impacts during
dredging and disposal operations.
The remaining sections of this EIR/S consist of
NEPA required information including regulatory
compliance in Section 5.0, a list of preparers (which
follows), and the distribution list for this document
in Section 6.0. References (Section 7.0), a glossary of
terms used in this report (Section 8.0) and an index
(Section 9.0) complete this volume. Much of the
substantive discussion presented in the technical
chapters is supported by data and analysis provided
in Attachment 1 to Volume I or in Appendices
appearing in Volume 2, as identified and referenced
throughout the document as appropriate.
1.6 LIST OF PREPARERS
This EIR/S is the product of a joint effort by the
local project sponsor, Massport, and the Corps of
Engineers, New England Division. The Corps, as the
lead federal agency, took primary responsibility for
ensuring that the document complies with the re-
quirements for EISs as set forth in the National
Environmental Policy Act and associated federal
regulations. Massport and its consultants, concen-
trated their efforts on compliance with the EIR as
required by the Massachusetts Environmental Policy
Act.
Key preparers of the document and their qualifica-
tions are summarized in Table 1-2.
1-10
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Ml
CHELSEA
35* Channel
Inner Confluence
35' Channel
CHARLESTO
umner and Callahan Tunnels
MBTA Tunnel
•Third Harbor Tunnel (under const)
"!>*.^
SOUTH BOSTON
Boston Harbor Dredging Project EIR/S
®
Scafc: ^.^ ____........___,
0 2000' 4000'
Scale in Feet
Figure 1-la.
Boston Harbor Locus Map
= = = = Umits of Federal Channel
Source:
New England Division, Corps of Engineers
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-------
V-\Cjfe-:
•-.-•-.-•v- ;,.„{&.§K- '
-. — 1. -Mta* A g*t + -yw %
Boston Harbor Dredging Project EIR/S
Figure 1-lb
Boston Harbor Locus Map
= == = = Limits of Federal Channel
Scale:
Source:
0 2000' 4000'
Scale in Feet
New England Division, Corps of Engineers
-------
-------
TABLE 1-1. COST SHARING FOR BHNIP: NON-FEDKRAL SHARE PERCENTAGES
Improvement Dredging
Channel Deepening
Aids to Navigation
Berthing Area Dredging
LERRD**
35%*
-0-
100%
100%
Operation and Maintenance Actions
Channel Dredging -0-
Aids to Navigation -0-
Berthing Area Maintenance 100%
*Consisting of 25% paid during construction and the remaining 10% paid out over a maximum of
30 years. The 10% share may be reduced by credits given for utility relocation undertaken by
Massport.
**LERRD - lands, Easements, Rights-of-way, Relocations and Dredged Material Disposal areas.
1-13
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TABLE 1-2. LIST OF PREPARERS
PERSONNEL
TITLE
QUALIFICATIONS
MASSPORT
Ms. Janeen Hansen
Dr. Norm Faramelli
Project Manager
Director,
Transportation &
Environmental
Planning
U.S. ARMY CORPS OF ENGINEERS
Mr. Peter Jackson Project Manager
Ms. Catherine Demos
Marine Ecologist
Mr. Robert Meader
Engineering Manager
Dr. Thomas Fredette
Marine Scientist
M.C.R.P. in City and Regional Planning from Harvard Univer-
sity. 13 years experience in transportation analysis and
policy planning.
B.S. in Chemical Engineering from Bucknell University and
Ph.D. from Temple University. 10 years consulting experi-
ence and 16 years at Massport in transportation and environ-
mental planning.
M.S. in Civil Engineering from Stanford University. 25
years of experience with the Corps of Engineers in San
Francisco District and New England Division in engineering
and managing water resources projects.
M.S. in Coastal Zone Management/Biology from University of
West Florida. 7 years experience with the Corps. Has
written several environmental assessments and EIS for coast-
al and marine projects.
B.S.C.E. from Worcester Polytechnic Institute, M.C.R.P. from
Rutgers. Over 18 years experience with Corps of Engineers
in study management of inland and coastal navigation pro-
jects.
Ph.D. in Marine Science from the Virginia Institute of
Marine Science at The College of William and Mary. 10 years
of experience in the area of environmental impact research,
assessment, and monitoring. Program Manager of New England
Division's Disposal Area Monitoring System (DAMOS).
-------
PERSONNEL
TITLE
QUALIFICATIONS
NORMANDEAU ASSOCIATES INC.
Ms. Virginia Treworgy
Ms. Ann Pembroke
Mr. John Shipman
Ms. Sarah Allen
Ms. Mary Small
Mr. James Bajek
Ms. Patty Marajh-
Whittemore
Project Manager
Chief Editor and
Marine Ecologist
Managing Corporate
Officer, Senior
Marine Ecologist
Wetland & Wildlife
Ecologist
Wildlife Biologist
Dredged Material
Specialist
Marine Ecologist
M.A. in Government and Public Policy from Harvard Universi-
ty. 16 years experience in environmental impact assessment,
permitting, and management of Remedial Investigation and
Feasibility Studies at state and federal hazardous waste
sites.
M.S. in Marine Biology from University of Delaware. 12
years experience with the firm. Project manager and senior
report author for numerous assessment projects dealing with
marine issues.
M.A. in Marine Biology from University of South Florida. 19
years experience with firm. Manages Marine Sciences Group
and NAl's Biology Laboratory. Has managed numerous large
marine and estuarine environmental studies.
M.S. in Wetland Ecology from University of Rhode Island.
Over 11 years in natural resource research and consulting.
Specializes in wetland delineation and junctional assess-
ments, and botanical and wildlife surveys.
M.S. in Wildlife Management form University of Maine with
emphasis in bird and small mammal ecology. 9 years expe-
rience life sciences.
B.A. in Biology from University of North Florida. 17 years
experience in the planning, material evaluation, and permit-
ting of dredging projects.
M.A. in Marine Affairs from University of Rhode Island. 7
years experience in evaluating the impacts of contaminants
on marine and coastal environments.
(continued)
-------
TABLE 1-2. (CONTINUED)
PERSONNEL
TITLE
QUALIFICATIONS
Mr. Jeff King
Water Resources
Specialist
M.S. in Water Resources from University of Vermont. 5 years
experience in assessing water quality impacts, especially
from non-point pollution sources.
BOELTER & ASSOCIATES
Ms. Alice Boelter
THE BSC GROUP
Ms. Ingeborg Hegemann
COMMONWEALTH RESOURCES
MANAGEMENT CORPORATION
Mr. Thomas Yeransian
WADE RESEARCH, INC.
Dr. Michael J. Wade
Principal
Port Planner
Environmental
Planner
Principal
Solid Waste
Management
Principal Scientist,
Marine Organic Geo-
chemist
Master in Public Policy Studies from the University of
Michigan. Over 20 years experience in urban planning and
project permitting.
M.R.P. in Regional Planning from University of Pennsylvania.
14 years experience in project impact analysis, wetland
science and permitting.
B.S. Chemical Engineering and B.A. Economics from Tufts
University. 11 years experience in the solid waste manage-
ment and environmental engineering/permitting fields.
Specializes in evaluating alternative environmental treat-
ment technologies for numerous applications.
Ph.D. in Marine Geochemistry from University of Rhode Is-
land. Dr. Wade provides chemical oceanographic consulting
services to government and industrial clients. He is an
organic geochemist with over 20 years technical and manage-
ment experience in a variety of research programs, with
special emphasis on pollutant fluxes in the environment.
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1111
Illilll 111
11111
II I I Illilll
11II 11 II 111 II I
II 11 IIIII I I II I I I II
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2.0 PROJECT DESIGN ALTERNATIVES
ANALYSIS
This section of the EIR/S focuses on the project
design alternatives and the likely environmental
consequences of each. The second half of this
section presents the results of the sediment character-
ization effort undertaken to determine the physical,
chemical and biological nature of the material to be
dredged in the BIINIP. The project design alterna-
tives and the sediment characterization study form
the basis for the selection and design of appropriate
disposal options for the project described in Section
3.0. It is the combination of these two factors that
result in the identification of the most practicable
alternatives for present disposal needs of silt and
parent material as well as for future maintenance
material needs.
Settling on a preferred disposal alternative is
fraught with the difficulty of weighing the relative
potential impacts to various environments. The
public, and their regulatory and congressional repre-
sentatives, have potentially conflicting goals. Federal
and state regulations, and the agencies that oversee
these regulations, can easily be in conflict as the
maximum protection for each resource is sought.
The potential for "gridlock" seems high. It is the
project sponsor's objective to show, through the
information developed throughout the following two
sections, what compromises mav be necessary to
complete this project in an environmentally and
socially responsible manner.
2.1
PROJECT DESIGN ALTERNATIVES
The project design alternatives evaluated for the
BIINIP include taking no action, completing thcfull
p_roject to the proposed depths, reducinpJhe project.
and postponing thejjroject. Both the.MEPA certifi-
cate ancTKITP A guidance require that the EIR/S
provide a discussion of the consequences of not
carrying out the project, often referred to as the "No
Action" alternative. The BIINIP has been evaluated
in terms of two scenarios under the "No Action"
alternative. The first considers no improvement or
maintenance dredging. The second considers no
improvement dredging but with maintenance dredg-
ing to maintain current conditions.
2.1.1 No Action, No Maintenance Dredging
This alternative assumes that no dredging activity,
including no maintenance dredging, would take place.
Silty material is continually deposited in the naviga-
tion channels and berthing areas by rivers and tidal
action. Organic material is deposited from combined
sewer outfalls (CSO's) and the outfall pipe at Deer
Island. Sediment deposited in the channels and
berthing areas since they were last dredged will be
referred to as "silt" in this report, to differentiate it
from underlying material, rock and parent material
(blue clay, gravel, etc.), proposed to be dredged in the
BIINIP.
Boston Harbor was last maintained in 1983 when
dredged material was disposed at the Massachusetts
Bay Disposal Site. On average the Reserved Channel
and turning areas, Mystic River and the Inner Con-
fluence, and Chelsea Creek have a siltation rate of
less than 0.2 inches, 0.2, and 0.8 inches per year,
respectively. This average rate, however, does not
account for specific areas that shoal much faster and
which require dredging more frequently. Areas
within the tributaries that tend to shoal at substan-
tially higher rates than the average eventually control
navigation through the tributaries. Not maintaining IV (V
the channels to the authorized depths would reduce ikjA'
If
Boston I larbor to a minor port unable to accommo-
datc deeper draft container ships and petroleum
tankers. ITicsc vessels draw at least 36 feet to 37 feet
if" loaded for a minimally economical operation.
Some transits, particularly in the Chelsea Creek, must
be made in daylight hours. There are limited oppor-
tunities for such transits at high tide, especially during
the winter months. Limited tidal operations are not
2-1
-------
consistent with efficient shipping, cargo handling or
scheduling.
Ultimately, more material would have to be
shipped into Boston via barges, necessitating more
trips, higher costs, and greater exposure to risks of
accidental spills. Impacts associated with this alterna-
tive are discussed in more detail in Section 2.1.6.
Maintaining, at least, existing constructed dimen-
sions of the channels and related berths will reduce
congestion at higher tide stages and enable the port
to remain viable for deeper draft, and safer, more
efficient shipping operations.
Leaving the top layer of silt material in place
continues to expose marine organisms that live in or
use the area, to contaminants. This material is also
subject to continual resuspension in the water col-
umn during vessel transits in shallower areas. Re-
moving the material to a more confined area, in
either open water or upland, reduces this risk of
• exposure. The environmental or economic benefits
accrued by leaving the material in place are few.
MWRA (1993) has reported that with the reduction
of toxics and solids in their discharge, cleaner sedi-
ments will settle over the older, more contaminated
sediment, making dredging an unnecessary mitigation
step in their clean-up program. Non-point source
pollution, such as urban runoff, does contribute to
the contaminant load. Also, several years would be
needed to cover the existing sediments with the
cleaner material. However biological processes and
weather events can still turn these sediments over.
Therefore benefits are provided by dredging the silt
before new deposition occurs.
2.1.2 No Action, with Maintenance Dredging
The No Action, with Maintenance Dredging (to -
35 feel MLW) alternative, would allow the Boston
Harbor Federal Channels and the project berths to
remain in their existing configurations. Table 2-1
0\
lists dates and volumes of material last removed from
each tributary (not including berths) as well as
projections of annual and project life (50 yrs.) accu-
mulation. As in Section 1, tables and figures refer-
enced throughout the following text are located at the
end of each section. The No Action, with Mainte-
nance Dredging alternative would be analogous to
maintaining the currently authorized depths, as
shown on Figure 2-la and 2-lb. This consists of
three main entrance channels, -27, -30 and -35/40 feet
MLW converging at the Outer Confluence in Presi-
dent Roads. A -40 foot MLW anchorage is located
adjacent to the channel at President Roads. From
President Roads to East Boston the Main Ship
Channel has two 600 foot lanes. The inbound lane
is -35 feet MLW and the outbound lane is -40 feet
MLW. The 40 foot depth continues upstream at an
average width of 700 feet to the -35 feet MLW Inner
Confluence Area at the mouths of the Mystic River
and Chelsea Creek. Three active deep draft tributary
channels, the Reserved Channel, Mystic River and
Chelsea Creek are^providecLwith 35jfoot depths^
,^J
£. ^^ ^g^CA"
lis alternative however, precludes the regional
economic benefits of the authorized, improvement
project. Environmental impacts associated with the
maintenance alternative include temporary distur-
bance from dredging and disposal activities. Mainte-
nance dredging would remove primarily silty materi-
als that have been transported into the channels since
they were last dredged (Table 2-1). Dredging impacts
include temporary and localized water quality degra-
dation from turbidity and release of contaminants
into the water column.
Disposal impacts would be dependent on the site
selected. Water-based sites would have a temporary
increase in turbidity and release of contaminants.
Since the uncontaminated parent material to be
dredged for the improvement project would be
unavailable in this option, cap material from some
alternative source would need to be identified before
disposal can occur in the water. Land based sites
'/Ti
^ f
2-2
-------
may need to be lined or the material treated to be
acceptable for disposal.
2.1.3 Full Project - Three Channels. All Berths
Over the past decade various dredging alternatives,
which fulfill the project purpose and need, have been
investigated to identify their economic and environ-
mental implications. The results of these investi-
gations are contained in the 1988 Feasibility Report.
The recommended plan, authorized in 1990, include
the following features: deepen Reserved Channel and
Mystic River from -35 feet to -40 feet MLW and
Chelsea Creek from -35 feet to -38 feet MLW. Also
included are non-structural modifications in the
Presidents Roads area. Project berths located in
these three tributaries would also deepen their areas
to the same depths as the adjacent channel to accom-
modate deeper draft ships (see Figures 2-la and 2-
Ib).
Deepening Boston Harbor will involve the remov-
al of approximately 2.9 million cubic yards of jilt,
day, and rock (Table 2-2). Short-term impacts from
dredging will include localized turbidity, and when
silty material is dredged, a temporary release of
contaminants to the water column. Rock blasting
will also have an impact on the biota in the area
immediately surrounding the blast site. The long-
term benefit from the project is the removal and
sequester of silty material from biological resources.
As the water in Boston I larbor becomes cleaner from
additional sewage treatment, the removal of contami-
nated sediment will also enhance the biological health
of this harbor. Potential disposal impacts associated
with water based sites include turbidity, potential
release of contaminants (depending on the material
disposed), and benthic impacts. Upland disposal
impacts could include habitat degradation, if the site
is not a landfill.
Engineering design of the project must consider
safety factors. For this reason a ship handling
simulation study was conducted and evaluated to
determine the impact of channel improvements on
the docking masters perception of safety. The
summary report is included in Appendix D. The
objectives of the simulation were to provide an "as-
ncar-to-reality-as-possible"real-time simulation of the
proposed changes and to record the actions and
opinions of docking masters currently working in the
harbor. Existing channel conditions and vessel
operations were tested and compared with the project
channels and vessel operations of the same vessels
loaded to greater drafts. Environmental and physical
conditions were held constant except for forces acting
on the more heavily laden ships. The results of the
ship simulation study ensured the safety of the
improved Harbor and minimized the area to be
dredged.
Based on the ship simulation study and the eco-
nomic analyses, the preferred navigation improve-
ment project, as authorized, consists of the following
components:
1. RESERVED CHANNEL - The existing
430-foot wide Reserved Channel will be
deepened to -40 feet MLW from its existing -
35 foot MLW with the exception of its upper
1,340 feet which will remain at -35 feet
MLW (Figure 2-2). The width of the project
channel will vary. The northern limit will be
relocated inward by 15 feet for the entire
length of the deepened channel, the southern -
channel limit will be relocated inward by 32
feet from the confluence with the main ship
channel, along the Conley Terminal (Berths
11, 12 and 13) to the upstream limit of
Conley Berth 11 resulting in a width of 383
feet for a distance of approximately 2,950
feet. Upstream from Berth 11 the existing
southern channel line will be relocated 15
feet inward to the upstream limit of the
deepened channel resulting in a width of 400
feet. The 32-foot wide reduction in the
width of the existing channel along the
2-3
-------
Conley Terminal Berths 11, 12 and 13 will
be deauthorizcd and become berth area. The
channel will be widened to provide maneu-
vering area at the confluence of the Reserved
Channel, Main Ship Channel and Drydock
Channel, and deepened to -40 feet MLW,
relocatingthe established harbor lines accord-
ingly. A trapezoidal area of the -35 foot
main ship channel, opposite the Reserved
Channel, will be deepened to -40 feet to pro-
vide required maneuvering area.
Approximately 159,700 cubic yards (cy) of
silty (maintenance) material and 438,800 cy
of parent (new) material will be removed
from the channel. Approximately 34,100 cy
of rock will be blasted and removed in the
maneuvering areas at the mouth of the Main
Ship Channel. Approximately 45,900 cy of
material will be removed from the Conley
Terminal berthing area 11-13 to deepen it to
-40 feet MLW. The Coastal Oil berth has
been deepened recently and does not require
dredging. Boston Edison Intake and Barge
Berth, Conley (Berths 14-15), and Boston
Army will remove about 152,800 cy of total
material. Dredging of the North Jetty berth
on the Main Ship Channel will generate
about 16,200 cy of material. The total
amount of dredged material to be removed
from Reserved Channel and associated work
in the Main Ship Channel, including rock, is
about 847,500 cy. The volumes arc detailed
in Table 2-2.
MYSTIC RIVER CHANNEL - About
5,670 feet of the existing 6,570-foot long -35
foot MLW Mystic River Channel would be
deepened to -40 feet MLW (Figure 2-3).
The Mystic River Channel is 580 feet wide
through the Tobin Bridge, 740 to 700 feet
wide from the bridge upstream to the Island
End River, widening to 930 feet at the Island
End River, widening further to 960 feet at
the Exxon Terminal then narrowing to 440
feet at the Distrigas pier continuing upstream
to the Prolerized Wharf to a depth of-40 feet
MLW. Areas of the channel not requiring
deepening would remain at their authorized
depth of -35 feet MLW.
Also included with the Mystic River channel
design is the Inner Confluence area. The
existing 35-foot deep Inner Confluence Area
would be deepened to -40 feet MLW as well
as about 2,500 feet of the -35 foot Main Ship
channel downstream of the Inner Conflu-
ence. This will improve the maneuverability
of larger vessels as part of the modification to
improve the approach to the Mystic River
Channel.
In the Inner Confluence and Mystic River
approximately 471,900 cy of silt, 791,800 cy
of parent material and 54,000 cy of rock will
be removed from the Channel. This includes
deepening a part of the -35 MLW Main Ship
Channel just south of the Inner Confluence.
Three of the berth areas will be deepened to
-40 feet MLW with the following approxi-
mate amounts of material removed: Distri-
gas, 13,800 cy; Prolerized, 7,600 cy; and
Moran Terminal, 6,600 cy. The Revere
Sugar berth will also be deepened to -40 feet
removing 12,800 cy as will the Mystic Piers
Berths (1,2,49, 50) with 62,800 cy removed.
3. CHELSEA CREEK CHANNEL - The
existing -35 foot MLW Chelsea Creek Chan-
nel will be deepened to -38 feet MLW, 200
to 225 feet wide downstream of the Chelsea
Street Bridge, 250 to 430 feet wide upstream
of the bridge and widened to the fenders at
the bridge openings. Chelsea Creek was
investigated for deepening to -40 feet MLW
but this depth was found to be unjustified
economically. The incremental cost of
2-4
-------
deepening the channel from -38 feet to -40
feet was not offset by the additional benefit
a deeper channel would provide. The signifi-
cant cost was the relocation or protection of
the subsurface utility crossings, primarily the
Boston Gas siphon (see Figures 2-4 and 2-5).
Utilities in the Chelsea Creek Channel will
be modified to accommodate the deepened
channel. These include: Boston Edison
Cables (moved), MWRA Water Tunnel
(removed), MBTA Cables (moved), and the
Boston Gas Siphon (protected).
Approximately 230,000 cy of silt and 320,100
cy of parent material will be removed from
the Channel. The Gulf Oil berthing area will
be deepened to -38 feet MLW resulting in
the removal of 12,300 cy of material. East-
ern Minerals will deepen their berthing area
to -38 feet MLW and remove approximately
39,900 cy of material.
4. MAIN SHIP CHANNEL - In addition to
the project tributaries, three berthing areas
along the main ship channel will also mainte-
nance dredge their berths. They include:
Boston Army Base (1-3) which will remove
about 40,000 cy of dredged material (of the
128,500 total for Boston Army 1-9), about
16,200 cy of dredged material will be re-
moved from North Jetty, and 17,600 cy of
dredge material will be removed from Mystic
Pier 1 (see Figure 2-6).
5. NON-STRUCTURAL IMPROVEMENTS
AT PRESIDENTS ROADS - Specific
Federal channel limits will be designated
through President Roads to connect the
Entrance Channels at the Outer Confluence
with the Main Ship Channel limits. This
will increase the size of the President Roads
Anchorage from 350 to 420 acres. The area
will be surveyed and several navigation buoys
\
relocated to ensure a safe navigation channel.
No dredging is required.
All told, the full project (including channels,
beneficiary berths, other berths, and related areas)
will remove about 1,100,000 cy of silt, 1,680,000 cy
of parent material, and 88,000 cy of rock, all mea-
sured in place. Because of expansion during removal
and handling, the corresponding volumes required for
disposal are approximately 1,320,000 cy of silt,
2,020,000 cy of parent material, and 132,000 cy of
rock.
( Future maintenance dredging of the tributaries in
the Full Project is anticipated to yield 95,000 cy for \
the Reserved Channel, 1,300,000 cy for the Mystic \
River, and 365,000 cy for the Chelsea Creek over a
50-year economic project life. Approximately
1,760,000 cy of silty material from the tributaries will
require removal and disposal at various times over I
the next 50 years. j
In addition to the tributary channels, maintenance
of the Main Ship Channel and the anchorages is
required to maximize the benefits of all the interde-
pendent projects that support the Port of Boston.
This maintenance would require removal of about
4,365,000 cy of material over the 50-year design life.
Maintenance volumes are listed in Table 2-1.
2.1.4 Reduced Project
The Navigation Improvement Project is made up
of improvements to three tributary channels. The
economic feasibility analysis prepared for the feasibili-
ty report and subsequently updated, viewed each
tributary channel and its berth areas as individually
justified. Each tributary channel can therefore be
treated as a separate project or in any combination
with other project tributaries.
A reduced project could result from economic
justification failing for one or more of the tributaries
2-5
-------
as a result of increased cost or reduced benefits to the
project. Economic justification is reviewed peripdi-
cally up to the time of construction. Corps project
evaluation procedures require that a project have
benefits at least as great as project costs, or expressed
differently, have a ratio of benefits to cost that is
greater or equal 1o one.
Another reduction in the project, a temporary
reduction, could occur if there is a delay in one or
two of the tributaries due to changes in the project
area that might require reformulation of the autho-
rized plan. An example would be the replacement of
the Chelsea Street Bridge by the City of Boston.
There is interest in reviewing the navigation channel
to consider widening and deepening to accommodate
larger vessels. Changes of this magnitude would
require reformulation of a plan because the benefits
would change and may require authorization by
Congress to implement. Such a delay in the Chelsea
Creek portion of the project would not impact the
Mystic and Reserved portions of the project which
could move ahead independently. Once reformulat-
ed, the Chelsea Creek improvement could proceed.
Minor changes to channel lines and berths would not
delay the project.
A reduced project may also result from reductions
in the dimensions of the project such as minor
realignment of channel lines, berth areas etc. Unless
these changes have substantial impact on the eco-
nomic justification of the project or require reformu-
lation and reauthorization they should not delay or
reduce the project to any great degree. It is anticipat-
ed that a number of these minor reductions and
possible enlargements to the project will occur as the
design is finalized.
2.15 Delayed Action
The present timetable is for the Boston Harbor
Dredging Project to begin early in 1996. Any sub-
stantial delays (>4 years) in this schedule could
noticeably impact shipping interests in the Port of
Boston. Continued siltation will steadily reduce the
useable channel and ship berth depths and could
eventually create unusable and, in some instances
hazardous, conditions for the larger vessels.
Reductions in the useable draft for the project
channels and berths could limit usage by more vessels
to high tide and increase the need for lightering.
Also, this may result in a reduction in the size of
vessels transiting Boston Harbor, increasing the
overall number of vessels needed for handling the
same quantity of goods. Vessel maneuverability
could also be impaired for larger vessels such as the
I,NO (Liquified Natural Gas) tankers that turn in the
inner confluence. Constraints on the size of vessels
that could utilize the harbor may reduce cargo
volumes and overall port employment.
A reduction in flexibility of ship schedules could
ultimately result in the diversion of cargo to other
ports. This loss in the cargo market would have a
negative impact on the Port of Boston.
The authorized depths in the port of Boston are
difficult to maintain since it is the upper "mainte-
nance" silty material that contains the higher contam-
inant concentrations that would cause the delay. The
harbor was last dredged in 1983 and maintenance
dredging of this and other channels is now already
overdue. Delaying the project another 5-10 years
could have substantial impacts, by increasing the
quantity of material that will eventually require
dredging. A greater quantity of material coupled with
inflation will increase the cost of dredging. The in-
creased quantity will also lengthen the duration of
dredging once it finally begins and could affect the
project schedule further if the increase in time con-
flicts with environmental dredging windows.
A delayed project will also result in a continuation
of having a large area of silt and associated contami-
nants on the bottom of Boston Harbor in direct
contact with marine biota. Storms and prop wash
2-6
-------
regularly resuspcnd silts. Once dredged, clean parent
material will be exposed for benthic recruitment.
2.1.6 Comparison of Project Design Alternatives
The project alternatives and their environmental
consequences are summarized on Table 2-3. Dispos-
al alternatives are discussed in later sections and are
not included in this analysis.
Three major factors differentiate the project
alternatives: quantities to be dredged, areas to be
maintained or improved, and the timing. The
quantities of sediment to be dredged affects:
»• duration of dredging
>• duration of turbidity plume
> amount of habitat affected
>• duration of interference with navigation.
The No Action without Maintenance alternative
would, of course, result in no dredging and therefore
would have none of these effects. In turn, the
alternative would have other environmental and
economic impacts. The No Action with Mainte-
nance alternative would remove only unconsolidated
silt and leave the cohesive parent material in place,
resulting in virtually the same turbidity, plume and
footprint, but reduced duration of dredging compared
to the Full Project or the Delayed Project. Because
the Delayed Project would encompass dredging a
larger component of silt, dredging would take longer
and result in a prolonged period of increased turbidity
compared to the Full Project.
The physical limits (both horizontal and vertical)
of the dredging alternatives affect:
•• socioeconomic benefits
»• navigation safety.
»• potential improvements to bottom sediment
quality
r
The changing world fleet requires deeper ports to
minimize double-hauling of cargos. The two No
Action alternatives would allow shipping to continue
in Boston Harbor but would eventually lead to
greater and greater reliance on partially loaded
vessels, lightering or feeder barges. The No Action
with Maintenance dredging alternative has all the
potential impacts of the Full Project but without the
economic benefits of the full project. Deepening of
any of the channels would improve this outlook for
specific components of the Port's activities. Petro-
leum shipping would be affected by dredging in
Chelsea Creek, Mystic River and Reserved Channel.
LNG shipment would be affected by activities in the
Mystic River. Container shipping would be affected
by deepening the Mystic River or Reserved Channel.
Thus the Full Project has the greatest potential to
benefit shipping in Boston Harbor. These benefits
would be reduced for the Delayed Project. Delaying
the project could reduce the economic benefits if port
costs or navigation conditions cause current port
users to use other ports.
The Full Project is the preferred, and congressio-
nally-authorizcd, alternative for the dredging project.
In addition to the removal of all unconsolidated silts
required for maintenance, parent material would be
dredged to project depths. The purpose and need for
the Full Project has been documented (ACOE 1988;
and Section 1.2). It offers the greatest benefits to the
port of Boston; the impacts associated with the
dredging are, as with the other alternatives, tempo-
rary. The preferred project alternative can reduce the
cost of product shipped through Boston, reduce
associated shipping costs, and maintain a workforce
engaged in maritime support services.
2.2 SEDIMENT CHARACTERIZATION
Boston Harbor is bordered by a group of outlying
islands and the peninsula areas of Winthrop and
Hull. /The harbor is the largest^ port in the New
England region, covering approximately 47 square
-------
miles. It supports shipping, commercial, industrial,
fishing and recreational interests.
In general, much of the environmental quality of
Boston Harbor can be characterized by its water and
sediment quality which improve from the Inner
Harbor seaward. The Harbor areas that are planned
to be dredged are all classified as "SC" waters (314
CMR 4.05, (4)(a) and (4)(b) and (4)(c). Such waters
are designated as habitat for fish, other aquatic life
and wildlife, for secondary contact recreation, aesthet-
ic enjoyment, and industrial cooling and process use.
Boston Harbor water is used for several of these
purposes. Recreational vessels however, are limited
due to the restricted number of berthing areas for
these types of boats.
Boston Harbor is an urbanized working port. It
is surrounded by several port activities along the
three previously described tributaries and the main
ship channel. Downtown Boston is also located in
the Inner Harbor area along the south shore just
below the Inner Confluence. The Reserved Channel
supports a cruise terminal, Boston Edison and dock-
ing facilities. Berthing areas for oil terminals and
liquid natural gas storage tanks occur along the
Chelsea Creek and several types of port activities
occur along the Mystic River. There arc limited resi-
dential establishments around the Harbor. The resi-
dential development generally occurs away from the
shoreline in condominium complexes and compact
two or three family houses.
The Outer Harbor areas, except for Broad Sound
Channels, are classified SB waters. The classification
of SB implies acceptability for aesthetic enjoyment,
habitat for indigenous wildlife and forage and game
fish, and the harvesting of shellfish with depuration.
The waters in the Broad Sound areas are classified as
SA. These waters are designated as excellent habitat
for fish, other aquatic life and wildlife and for prima-
ry and secondary contact recreation. In approved
areas these waters can be suitable for shellfish har-
vesting without depuration.
In all dredging projects, the issue of greatest
concern is the sediment quality of the dredged materi-
al and how it will affect the surrounding water
quality, briefly described above, during dredging and
at the proposed disposal site(s). Therefore, as direct-
ed by the MEPA certificate, an intensive study was
undertaken to assess sediment quality under existing
conditions using a testing protocol developed as part
of the Sediment Characterization Working Group
and Advisory Committee process described in Section
1.4 (sec Appendix C-l).
2.2.1 Sediment Characterization; Overview
and Approach
Parent material which is expected to be dredged
was tested and found suitable under Section 103
exclusionary criteria of the Marine Protection Re-
search and Sanctuaries Act. Sediment Characteriza-
tion described in the following sections refer to the
silt material only.
The sediment sampling and testing program for
the BHNIP silt was actually comprised of two
separate characterization effects: one for the Federal
project and the second for the Massport sponsored
berth area dredging. Both programs however, were
designed to be consistent with the three tiered evalua-
tion approach outlined in the national "Green Book"
1991 guidelines, and U.S. EPA Region I/U.S. Army
Corps of Engineers (ACOE) regional protocol
entitled "Guidance for Performing Tests on Dredged
Material to be Disposed in Open Waters," May,
1990. The three tier analytical approach that has
been developed for marine sediment characterization
is graphically represented in Figure 2-7. As depicted,
the focus of this approach is on evaluating the
suitability of dredged material from Boston Harbor
for ocean disposal. However, the test results can also
be utilised to evaluate disposal at other open water
disposal sites as well as upland disposal.
2-8
-------
Tier I of this process consists of a review of
existing literature, environmental data and the physi-
cal characteristics of the area to determine the poten-
tial for contamination and the need for chemical
testing (Tier II). In Tier II, bulk chemical analysis of
the material is performed to determine whether
contaminants are present at concentrations that have
the potential for environmental impacts. Tier III
uses biological testing (acute toxicity and bioaccum-
ulation) to determine the potential impacts of
dredged material disposal on marine organisms. The
results of these analyses are used to determine if the
material is suitable for unconfined ocean disposal.
The feasibility of capping dredged material not
meeting the requirements for unconfined disposal can
also be evaluated from the results.
2.2.2 Federal Channel Sediment Testing Program
During preparation of the 1988 Environmental
Assessment and Feasibility Report for the Federal
project, 18 sediment samples were collected for bulk
chemical analysis in 1986 from Mystic River, Chelsea
Creek and Reserved Channel. Using the 1986 test
results as a basis, two statiojis from each of the three
areas were resampled in 1990 for additional chemical
and biological testing. Analyses were performed for
all chemicals listed in the regional protocol (see
Appendix C-2). In addition to metals and PCBs,
sediments were analyzed for pesticides, volatile and
semi-volatile organics, dioxin and furan homologs.
Further details of the Corps sampling and testing
program are presented in Appendix C-2.
The following is a summary of the results of the
three tier analytical approach that was used for the
Federal project marine sediment characterization.
2.2.2.1 Tier I - Review of Existing Data
The Tier I evaluation began by performing a
literature review of the sediment quality within
Boston Harbor. Results showed that sediments in
Boston Harbor are predominantly glacial materials
with the organic fraction of the sediments resulting
from industrial and sewage discharges, and transport
of contaminants into the Harbor by rivers. The most
prevalent harbor sediment is a plastic clay of glacial
origin, know locally as the Boston blue clay. This
layer has been identified throughout the harbor in
various seismic investigations (Edgerton, 1963 and
1965). The clay is often overlain by more recent
sediments, including silts and sands that serve as
repositories for contaminant associated particulates.
In several areas, finer grained recent sediments con-
tain considerable quantities of gas, predominantly
C02, CH4, and H2S. Sasaki Associates (1983)
summarizes the chemical characteristics of the harbor
sediments based on studies by the Corps of Engi-
neers, Massachusetts Division of Water Pollution
Control, the New England Aquarium and other pri-
vate groups.
2.2.2.2 Tier II - Chemical Evaluation of the Dredged
Material
The literature review, together with the Corps data,
indicated that certain types and concentrations of
contaminants with the potential for biological im-
pacts were present in the sediment. In 1986, eighteen
sediment samples were collected from three areas to
be dredged as part of the Federal project (the Mystic
River, Chelsea Creek and Reserved Channel). The
Mystic River had elevated levels of arsenic, lead, and
zinc. The Chelsea Creek and Reserved Channel had
elevated concentrations of lead. Elevated levels of
PCBs were found in one sample from the Mystic
River and moderate concentrations in one sample
from the Reserved Channel. It was determined that
these results adequately characterized the chemical
nature of the sediments to be dredged for the Federal
2-9
-------
project. However, further chemical and biological
testing was required to determine the suitability of
the dredged material for unconfmed ocean disposal.
The 1986 Corps sediment test results were used as
a basis for conducting the 1990 bulk chemistry
testing. Two stations each from the Mystic River,
Chelsea Creek and Reserved Channel were resampled
in 1990. Table 2-4 shows the metal concentrations
in the Mystic River, Chelsea Creek and Reserved
Channel for 1986 and 1990. Tor both sampling
periods arsenic, chromium, lead, and zinc were
detected at Level III in the Mystic River and Chelsea
Creek. Level III is defined as a concentration similar
to the Massachusetts DEP Category III (Table 2-5).
In the Reserved Channel arsenic, chromium, and zinc
were detected at high levels in 1986 and 1990. In the
1986 samples elevated concentration of PCBs found
in one sample from the Mystic River and moderate
concentration from one sample in the Reserved
Channel. PCBs were not detected in any of the 1990
samples. In general, there is good agreement for
metal concentrations for samples collected in 1990
and 1986.
Polycyclic aromatic hydrocarbon (PAH) concen-
trations in the Reserved Channel, Chelsea Creek and
Mystic Channel are listed in Table 2-6. The total
PAII concentrations in the lower Chelsea Creek
(Station B) was detected at level III, and in the
Mystic River (Station B) it was detected at Level II
for the 1990 samples.
The semi-volatile compound Bis(2-ethtylhexyl)-
phthalate was detected in all of the samples. Phtha-
lates are used in the manufacture of plastics. Elevat-
ed sediment phthalate concentrations are commonly
the result of sample contamination. The plastics
operation in the upper Mystic River could also
explain the more elevated levels found in this reach.
Pour volatile organic compounds were detected in
several of the samples. Most of these were at low
concentrations. Acetone was found in all samples at
a relatively high level. The source of acetone to these
samples is unknown. Acetone is a natural by-prod-
uct of microbial respiration in sediments. It is also a
commonly used laboratory solvent and therefore
laboratory contamination cannot be ruled out as a
source. Vblatiles would most likely be lost during
the dredging process and are not a major concern.
Sediment samples were tested for dioxin and furan
compounds in 1990. All the compounds tested were
below detection limits except total Hepta-chloro-
dibcnzo dioxins (IIpCDD) and total Octa-chloro-
dibcnzo dioxins (OCDD). One sample (Mystic A)
showed test results below detection limits for total
IIpCDD. HpCDD and OCDD are not considered
as toxic as the other compounds such as Tetra-
chlorodibenzo dioxins (TCDD) (McFarland, pers.
comm. 1993).
The only pesticide which was detected in all of the
samples was endrin aldehyde. This compound was
also present in the blank, suggesting lab contamina-
tion as the source. The remaining pesticides were
either not detectable or present only at low levels.
The semi-volatile, volatile, and pesticides data are
presented in Appendix C-2.
2.2.2.3 Tier 111 - Biological Evaluation of the
Dredged Material
Bioassay: Solid phase bioassays were performed in
1990 on sediments from six locations in Boston
Harbor. This involved a 10-day static toxicity testing
for the amphipod (Ampellsca abdita) and a 28-day
flow through bioassay for a deposit-feeding clam
(Macoma nasuta) and the sandworm (Nereis virens).
The amphipod tests were flawed and run again using
one sediment sample from each reach. The results of
these analyses are summarized in Table 2-7.
The clams exposed to the test samples had good
survival ranging from 84% to 95%, except for Mystic
A, where the survival average was 44%. The refer-
2-10
-------
encc and control sediment had 93% and 99% surviv-
al respectively. The test worms had a high survival
ranging from 93% to 98%. Survival in the reference
and control were 93% and 95% respectively. Ninety
percent survival or greater is considered satisfactory
for control sediments.
The regional protocol for assessing acute toxicity
potential requires a comparison of the mean values
for survival rates of test animals exposed to the test
and reference sediments. Test animals exposed to
test sediments that show a statistically significant
reduction in survival, and a difference in mean values
of greater than 20% for the amphipods and 10% for
the clams and worms, are considered to exhibit acute
toxic response. Conversely, those means that are
either not statistically different or less than the 20%
and 10% difference thresholds may be considered to
have low toxic response to the prospective dredged
material. The test sediments for this project showed"
statistically significant mortality effects (defined by a
probability of more than 95%, expressed as the
inverse of probability (p sO.05)) and exceedance of
the 20% threshold for amphipods at_ajl proposed
dredging locations. The lest sediments also showed
significant mortality effects and exceedance of the
10% threshold for clams exposed to the Mystic A
test sediments. -—
Bioaccumulation:- The purpose of the bioaccumu-
lation studies was to determine the potential for
uptake of contaminants of concern in representative
benthic marine organisms. Bioaccumulation tests
were performed on clams and worms surviving the
acute toxicity bioassay to determine the potential
uptake of contaminants by the organisms. The
parameters measured for bioaccumulation were based
on the results of the bulk chemical analysis of sedi-
ments. The test results are presented in Appendix C-
2. The data were statistically analyzed using the
Corps, New England Division SAL (Statistical
Analysis of Dredged Material) program. No statis-
tically significant differences were found for uptake of
heavy metals by the worms. The bioaccumulation
tcsting..showed substantial ugtake by the clams .for ..
/cadmium from Mystic A sediment and/cchromium \
\ ancTlcadfrom the Chelsea Creek and the Reserved
Channel No statistically significant uptake of PCBs,
pesticides, or PAIIs was observed for any of the clam
or worm tests exposed to Boston Harbor sediment
from any of the six stations when compared to the
reference results.
2.2.3 Massport Sponsored Sediment Testing
Program
The Sediment Characterization Technical Working
Group for the Massport sponsored portion of the
Project met on a number of occasions to assist in
developing the sampling and testing strategy for the
berths. A stratified random sediment sampling design
was established that allocated three samples at each
of the fifteen dredging sites. Sampling locations at
each dredging site was randomly selected using a 40-
foot grid and random number table. One terminal,
Boston Army Base, was divided into two sites (for
sampling) because of its size and configuration (it
extends from the Reserved Channel into the Main
Ship Channel over a length of 4870 feet).
The chemical parameters for Tier II (bulk chemical)
testing followed EPA analytical methods and detec-
tion limits for heavy metals, PCBs, pesticides, PAHs,
TOC, and grain size (Table 2-5). These procedures
and detection limits meet the regional testing proto-
col established by the U.S. EPA and Army Corps of
Engineers. The samples for the Tier II bulk chemical
analysis were collected in June-July, 1992. Tier III
analysis began with amphipod acute toxicity tests on
sediment from the sites that had elevated sediment
contaminant levels (Levels II and III). Due to the
length of time needed to conduct sampling at all
sites, two separate amphipod toxicity test series were
conducted in July and September 1992. The solid
phase bioassay with clams and worms was conducted
in November 1992. Details of the sampling and
2-11
-------
testing protocols and results are discussed in Appen-
dix C-3.
The following is a summary of the results of the
three tier analytical approach that was used for the
proposed Massport-sponsored berth dredging in
Boston Harbor.
Table 2-9 and Table 2-10 are summaries of the
bulk chemical test results for total PAHs and total
PCBs. Total PAHs and total PCBs were found to
high levels at Prolerized, Distrigas, Revere Sugar,
Boston Edison intake, Moran, North Jetty, Eastern
Minerals, and Conley. Mystic Piers showed high
levels for total PAHs and I^vel II for total PCBs.
2.2.3.1 Tier 1 - Review of Existing Data
In this first screening step all existing site related
information, including dredged material volumes for
each area, results from previous physical, chemical
and biological testing, known physical and hydrody-
namic characteristics of the sites, spill histories, and
prior dredging history were reviewed. There was little
existing sediment chemistry information of value in
characterizing the sites. Less than half of the 15 sites
had historical information collected within the last 10
years on sediment chemistry (Appendix C-3). In
general, there were insufficient historical data relating
to heavy metals, PAIIs and PCB concentrations for
evaluation of the prospective dredging sites. There-
fore, further chemical and biological testing was
required to determine the suitability of the dredged
material for upland or ocean disposal.
2.2.3.2 Tier II - Results of Bulk Sediment Chemical
Analyses
Table 2-8 is a summary of the bulk chemical test
results for metal concentrations by site. Arsenic,
lead, and zinc all were found to be at Level III at P-
rolerized, Distrigas, and Revere Sugar. Mystic Piers
and North Jetty showed Level III for lead and zinc
only, and Moran had Level III for arsenic and lead
only. Eastern Minerals had Level III for lead only.
Mercury was found to be only as high as Level II at
Prolerized, Distrigas, Mystic Piers, Moran, North
Jetty, Eastern Minerals, Army Base and Conley.
Cadmium was at Level II at Prolerized, Boston
Edison Intake and Boston Edison Barge berth.
2.2.3.3 Her III - Bioassay/Bioaccumulation
Amphipod Test Results
Two sets of amphipod tests were conducted, each
with its own reference test results.
The July 24-August 3, 1992 amphipod tests: This
series involved nine test sediments with five replicates
each. As shown in Table 2-11, the survival after 10
days ranged from 3% to 63% hi the test sediments.
The reference and control sediments had 82% and
93%, survival respectively. The Conley test sediment
showed a survival rate of 63% and a reference-test
difference of 19%. All other sites tested in this series
showed a reference-test mortality difference greater
than 20%.
The September 5-15. 1992 amphipod tests: This
testing was conducted in the same manner as the first
series. Of the five sites tested, two sites (Gulf Oil and
Edison Barge Berth) showed survival of 55% and
63%, respectively (Table 2-11). The other sites had
survival that ranged from 21 to 47%. The control
had 92% survival and the reference site had 74%
survival. The mortality difference (reference-test) for
the Gulf Oil and Boston Edison Barge berth sites
were 19% and 11% respectively. All other sites
tested in this series showed a reference-test morality
difference greater than 20%.
2-12
-------
Results for Solid Phase Bioassay
The bioassay results showed that clam and marine
worm survival were high for all sites tested (most >
95 %, none < 90 %). Survival data for the eight
sites produced by solid phase bioassays with clams
and worms are presented in Table 2-12. Survival of
the worms was 90 to 97%. Clam survival for all sites
was 94 to 99%. This is considered very good surviv-
al and does not indicate any acute toxicity to the
organisms tested. Ninety percent survival or greater
is considered satisfactory for control sediments. The
test sediments did not cause any statistically signifi-
cant mortality compared to the reference sediments
which was 93% survival for worms and 97% for
clams. The control tests had mean survival of 95%
for worms and 98% for clams, indicating healthy
organisms and a proper test system were used in the
assay.
Bioaccumulation
The bioaccumulation tests were performed on
clams and marine worms surviving the bioassay to
determine the potential uptake of contaminants by
organisms. The parameters measured for bioaccumu-
lation were based on the results of the bulk chemical
analysis of sediments; metals, PAIIs, and PCBs were
measured. Appendix C-3 includes the bioaccumula-
tion test results for all parameters and all sites tested.
The chemical means of the bioaccumulation
testing were first compared to the corresponding
means established for the reference exposures.
Results for each chemical parameter analyzed for
bioaccumulation where the test mean exceeded the
reference mean were first subjected to Levene's test
for homogeneity of variances. Those with homoge-
nous variances were tested with analysis of variance
(ANOVA), comparing each site's replicate values
with the corresponding reference site values. Dun-
nett's test was used to evaluate significant results in
order to determine which sile(s) showed a significant
difference from the reference site. A logarithmic
transformation was utilized to reduce heterogeneity of
variance. An ANOVA on log,0 transformed data
was performed in cases where log transformation led
to homogeneous variances as revealed by Levene's
tests. A nonparametric analysis of variance
(Kruskall-Wallis test) was performed on those param-
eters that did not have a homogeneous variance
structure even with transformation. If this test
revealed significant differences between reference and
project sites, a nonparametric analogue of the t-test
(Wilcoxon's summed rank test) was performed
comparing each site with the reference site.
Determinations of significance were made at the
0.05, 0.01, and 0.001 levels, although it is recognized
that the EPA and Corps regulatory decisions are
based on the 0.05 confidence level. It should be
noted that many of the significant results occurred
near the detection limits of a particular chemical, and
those findings of significance could be an artifact of
the nonvariability of the reference replicate results
which were found to be below detection limits. In
those cases, the detection limit was used for the
statistical evaluation. Table 2-13 is a summary of the
mean concentration of parameters significant at the
p sO.05 confidence level at each site tested for bioac-
cumulation.
2.2.4 Summary of Findings
Based on the above results, the 2.9 million cubic
yards of dredged material from the navigation im-
provement dredging will consist of approximately 1.7
million cubic yards of "clean" parent material includ-
ing rock. The remaining 1.1 million cubic yards of
silty material will have the general chemical charac-
teristics as summarized above and in Appendices C-2
and C-3.
Based on these results, the U.S. Army Corps of
2-13
-------
Engineers has determined that all the maintenance
material (silt), except 160,000 cy from Reserved
Channel, and 200,000 cy from the berth areas of Gulf
Oil, Army Base,_Conley Terminal, and the Edison
Barge berth, ^unsuitable for unconfined open water
disposal. Conversely, all of the silt material is con-
sidered to befunsuitable for unconfined open water
disposal by the U.S. Environmental Protection
Agency.
The implication of these results in developing
options for the dredged material disposal are dis-
cussed in Section 3.0. Due to the divergence of
opinion regarding the suitability of the silt for ocean
disposal Section 3.0 details options for assuming no
ocean disposal of silt as well as alternatives which
consider ocean disposal of 360,000 cy of material
deemed suitable by the U.S. Army Corps.
2-14
-------
CHELSEA
Inner Confluence
35' Channel
CHARLESTOWN
umner and Callahan Tunnels
MBTA Tunnel
Logan
Airport
•Third Harbor Tunnel (under const)
•~-*^
Deepen
Mystic River to 40'
Inner Confluence to 40'
Reserved Channel to 40'
Chelsea River to 38'
SOUTH BOSTON
Boston Harbor Dredging Project EIB/S
® Scale: =
°
•••••••• |
2000' 4000'
Scale in Feet
Figure 2-ia Boston Harbor
Navigation improvement Project
General Plan
Source:
New England Division, Corps of Engineers
-------
-------
' *"'*
^,,--"'-' '- " ^ I,
^ "^' ^V/%' *% ;^r
- » -
i/^ -•.- - ~~^ "•".rv -, ,N xr>%v- - -'"' t
V4 ***T* *~* "^*"'""™" *** C^WU* JJiJ S^> Jwl **^^ . ^ •.-. "" j**"' t ^ X % v--' i. *?" -^ %%^ ^Xs /
r ;;.?i^^; . fteaJjgTH^C&eBTnef f c , -% \s, % , W
fi'u:";x*.^>^>;s -?-":V_ IA^'S %-, '\ 7^\
r-."-. ^-" %% ' •>' ' ^" "• ' ^\ \ ' %%'' , 1
Boston Harbor Dredging Project EIR/S
©
.?/./>;«• P i
0 2000' 4000'
Scale in Feet
Figure 2-ib Boston Harbor
Navigation Improvement Project
General Plan
Source:
New England Division, Corps of Engineers
-------
Boston Harbor Dredging Project EIS/R
Figure 2-2
Navigation Improvement Project
Reserved Channel
Source:
Scale in Yards
Boston Inner Harbor Navigation Chart
-------
Boston Harbor Dredging Project EIR/S
€)
» *X> SCO
Scale in Yards
Figure 2-3
Navigation Improvement Project
Mystic River
Source:
Boston Inner Harbor Navigation Chan
v»
-------
Boston Harbor Dredging Project EIR/S
^T*V Scale:
^X
•I^^__~___.g»
Scale in Yards
Figure 2-4 Navigation improvement Project
Chelsea Creek
Downstream of Chelsea St. Bridge
Source:
Boston Inner Harbor Navigation Chart
-------
CHELSEA
Northeast Petroleum
Coastal Oil
Glbbs
Global
See Sheet a
of this figure for.
details downstream of
Chelsea St Bridge
EAST BOSTON
Existing Channel Units
Dredge to -38 MLW
Intertidal
Project Beneficiary
Boston Harbor Dredging Project EIR/S
&
Scale in Yards
Figure 2-5 Navigation Improvement Project
Chelsea Creek
Upstream of Chelsea St. Bridge
Source:
Boston Inner Harbor Navigation Chart
-1T
-------
I MYSTIC PIERS
CHARLESTOWN
BOSTON EDISON
INTAKE
Proposed Dredging - (Non-Federal)
Terminal/Berth Areas
BOSTON EDISON
BARGE BERTH
Deepen • (Federal)
Boston Harbor Dredging Project EIR/S
®
Scale:
0 ^^ 4W J*9
Scale in Yards
Figure 2-6 Location of Federal Channel
and berth area dredging
Source:
Boston Inner Harbor Navigation Chart
-------
Project Proposed
Alternative
Analysis
Dispose Within
Appropriate Env.
Laws & Regs.
Yes —
Non-Open Water
Disposal Option
Available or Feasible?
Tier I
Data Review
Tier II
Chemical Evaluation
(Bulk Chemistry)
Tier III
lologlcal Evaluation
issay/Bloaccumulatlon)
No
I
Is there Reason To Believe The
Sediment is Contaminated Or
Doesn't Satisfy Exclusion Criteria?
Yes
Yes
Is There potential For
Toxicity/Bioaccumulation of
Sediment Contaminants?
Yes
(Option)
Yes
i
Do Tests Show
Potential Impacts
To Marine Ecosystem
Yes
No
i i
Yes
Unconfined
Open Water
Open Water Disposal
With Capping
No Open Water
Disposal
Rgure 2-7. Tiered testing & decision protocol for open water disposal of dredged material.
-------
TABLE 2-1. MAINTENANCE DREDGING PROJECTIONS FOR THE TRIBUTARY
CHANNELS AND THE MAIN SHIP CHANNEL.
CHANNEL
TRIBUTARIES
Reserved Channel
Mystic River
Chelsea Creek
TOTAL for
Tributaries
MAIN SHIP CHANNEL
40 -foot Main Ship
Channel
35 -foot Main Ship
Channel
President Roads An-
chorage
TOTAL for Main
Ship Channel
DATE LAST
MAINTAINED
None since
deepened in
1966
1983
1983
1974
1968
1983
ESTIMATED ANNUAL
RATE OF
ACCUMULATION
(cy/year)
1,900
26,000
7,300
43,900
14,300
29,100
ESTIMATED
50 YEAR1
TOTAL (cy)
95,000
1,300,000
365.000
1,760,000
2,195,000
715,000
1.455.000
4,365,000
JLA fifty (50) year project life is used for economic evaluation and
starts at the timing of completion of the project. This table does not
include future maintenance requirements of the berths.
-------
TABLE 2-2. VOLUME OF MATERIAL PROPOSED FOR DREDGING FROM CHANNELS AND ASSOCIATED PROJECT
BERTHS FOR THE BOSTON HARBOR NAVIGATION IMPROVEMENT PROJECT.
DREDGE VOLUMES (Cubic Yards)
CHANNEL
Main Ship Channel/
Reserved Channel
Inner Confluence/
Mystic River
Chelsea River
Subtotal
TOTAL0
AREA
Federal Channel
Conley 11-13
North Jetty '
Boston Army 1-9
Boston Edison Intake
Boston Barge Berth
Conley 14-15
Federal Channel
Prolerized
Distrigas
Moran
Revere Sugar
Mystic Piers 2, 49, 50
Mystic Pier 1
Federal Channel
Eastern Minerals
Gulf Oil
Federal
Berths
In-situ
After retnovalb
TOTAL
632,600
45,900
16,200
128,500
1,100
16,100
7,100
1,317,700
7,600
13,800
6,600
12,800
45,200
17,600
550,100
39,900
12,300
2,500,400
370,700
2,871,000
3,471,000
ROCK
34,100
0
0
0
0
0
0
54,000
0
0
0
0
0
0
0
0
0
88,100
0
88,000
132,000
PARENT
438,800
18,000
7,800
0
0
10,800
2,800
791,800
5,500
10,000
0
3,100
28,700
8,400
320,100
32,700
5,400
1,550,700
133,200
1,684,000
2,021,000
SILT"
159,700
27,900
8,400
128,500
1,100
5,300
4,300
471,900
2,000
3,800
16,600d
9,700
16,500
9,200
230,000
7,200
6,900
861,600
237,500
1,099,000
1,319,000
Projected through 1996:
aSilt volumes assume 0.5 foot of overdredge to ensure all silt is removed.
Expansion factor (20% for silts and parent materials, 50% for blasted rock) added for use in
computing disposal site requirements for aquatic disposal sites. Material would be dewatered to
in-situ volume for disposal in upland sites.
°Rounded to nearest 1,000 cy.
dlncludes 10,000 cubic yards already removed in 1993 under a reduced project design at Moran.
See Section 1.2.
-------
2-3. SUHHARY OF ALTERNATIVE PROJECT DESICNS AKD THEIR ENVIRONMENTAL CONSEQUENCES.
RESOURCE
Navigation
Sediment
Characteris-
tics
• material
to be
dredgedb
• material
to be
exposed
Duration of
Dredging0
NO ACTION
H/0 MAINTENANCE OF
CHANNELS
No removal of silt;
no improvement.
No sediments removed.
Exposed material is
silt and associated
contaminants .
0 days
NO ACTION
W/ MAINTENANCE OF
CHANNELS
Removal of silt;
no increase in
depth.
Removal of up to
861,600 cy silt
over burden.
Maintenance dredg-
ing would occur
only when problems
developed.
Parent material. •
5.5 months
FULL PROJECT*
Reserved Channel to -40 ft
MLW, 1B/5NB berths; Mystic
Channel to -40 ft MLW,
3B/3NB berths; Chelsea
Channel to -38 ft MLW, 2B
berths
RC: 335,200 cy silt;
478,200 cy parent; 34,100
cy rock.
MC: 513,200 cy silt;
847,500 cy parent; 54,000
cy rock.
CC: 244,100 cy silt;
358,200 cy parent (in-
cludes channels and all
berths).
Parent material.
REDUCED PROJECT"
RESERVED MYSTIC CHELSEA
Removal of silt and increase in depth for one or two
channels and associated berths.
Non-beneficiary (MB) berths might not be dredged un-
less Federal Project takes place.
As under full project.
Parent material.
Reserved Channel: 6 months
Mystic Channel: 8 months (but may use 2 dredges)
Chelsea Channel: 4 months
DELAYED PROJECT
Same as full
project but de-
layed 5 to 10
years after pro-
posed project.
As in full pro-
ject but volume
of silt in chan-
nels expected to
increase by
28,000 cy/year.
Parent material
but not until
2000+.
Increase 7 days
for each year
delay after
2000.
50
(Continued)
-------
TABLE 2-3. (CONTINUED)
RESOURCE
Water
Quality
Marine
Resources/
Habitats
Wetland
Threatened/
Endangered
Species
NO ACTION
W/0 MAINTENANCE OF
CHANNELS
Continued resuspen-
sion of silt in berth
areas from prop wash
and siltation into
channels .
Benthic resources
will continue to be
dominated by pioneer
species; no change in
present substrate.
Continued exposure of
demersal fish and
epibenthos to contam-
inants in sediments.
No change to Land
Under Ocean/Tidal
Waters
NO ACTION
«/ MAINTENANCE OF
CHANNELS
FULL PROJECT"
REDUCED PROJECT"
RESERVED MYSTIC CHELSEA
Resuspension of silt during dredging but minimized by use of closed bucket; reduction of turbidity to
normal harbor conditions after dredging of silt complete; dredging of parent material expected to
induce little turbidity.
DELAYED PROJECT
Continued resus-
pension of silt
in berth areas
until dredging
complete; resus-
pension of silt
during dredging
minimized by use ',
of closed '
bucket; reduc- j
tion of turbidi-
ty after
dredging. '
Temporary defaunation of dredged areas until newly exposed sediments are colonized.
Temporary increase in suspended sediments would deter some finfish from dredging area and increase exposure of those who
remain until dredging of silt is complete; then significantly reduce risk of exposure to contaminants.
Mortality of finfish during blasting.
Alteration in substrate and depth to
No
Land Under the Ocean/Tidal Waters. No loss of wetland habitat.
impact .
(Continued)
-------
TABLE 2-3. (CONTINUED)
5b
r
V
v
RESOURCE
Historical/
Archeologi-
cal Resourc-
Socio-
economics/
Land Use
Traffic/
Navigation
NO ACTION
W/0 MAINTENANCE OF
CHANNELS
No impact.
NO ACTION
W/ MAINTENANCE OF
CHANNELS
Rapid decline in
ability of port to
service world fleet;
increased port-of-
call costs; reduced
loads or increased
lightering; increased
risk of accidents.
Increased cost of
consumer goods.
Increased, risk of
collisions; increased
vessel traffic if
cargo volume is main-
tained, smaller ves-
sels; eventually re-
duced traffic.
Gradual decline in
ability of port to
service world
fleet; increasing
costs; reduced
loads and in-
creased lighter-
ing; increased
risk of accidents.
No significant
change in vessel
traffic.
FOIL PROJECT*
Chelsea St. bridge is only
structure of historic sig-
nificance in project. No
impact anticipated.
Economic benefit of full
navigation improvement
project demonstrated. In-
creased competitiveness
with Eastern Seaboard
ports; will enable one
area of cost control for
regional petroleum, LNG
industry .
Improved navigation safe-
ty; larger ships; total
number of ships may not
change.
REDDCED PROJECT"
RESERVED MYSTIC
No impacts.
Reserved Channel
is Boston's Port
of the Future; no
dredging in Mystic
or Chelsea would
lead to higher
costs • for heating
and fuel indus-
tries.
Economic bene-
fits to contain-
er and LNG
berths; no bene-
fit for petro-
leum industry.
CHELSEA
DELAYED PROJECT
Chelsea St. bridge is only struc-
ture of historic significance in
project. No impact anticipated.
Economic bene-
fits for fuel
industry; no
benefits to con-
tainer shipping.
Improvement in navigation safety restricted to the
areas deepened. Little change in total number of
ships
Delay of entire
project could
have same ef-
fects as No Ac-
tion without
Maintenance; in-
creased project
costs due to
higher volume of
silt for dispos-
al
Eventually, same
effects as full
project.
•Main Ship Channel modification included with Reserved Channel; Inner Confluence included with Mystic River.
•"Chemical and physical characteristics summarized in Section 2.2; quantities do not include bulking factor.
°Assumes round-the-clock dredging, one dredge.
B = Beneficiary berths
NB = Non-beneficiary berths
-------
TABLE 2-4.
(CONTINUED)
CHELSEA RIVER
1966 Samples
(Environmental Assessment:)
G
1990 Sanples MASS
(Bloassay/accunulation) REGS
A E REF I -III
An
As
Ha
Cd
Cr
Cu
Pb
,|g
Ki
Be
Ag
Th
Zn
Cy
V
5.1
900
<4
1602
71
1582
0.612
<642
<8
197
<720
5.9
1500
<3
1382
41
80
0.40
45
-------
TABU 2-4. SEDIMENT METAL CONCENTRATIONS (ppm) MYSTIC RIVER
HYSTIC RIVER
1986 Samples 1990 Samples
(Environmental Assess»ent) (Bioascay/Bioaccumulatlon)
An
As
Da
Cd
Cr
cu
Pb
llg
Hi
Se
Ag
Th
Zn
cy
V
A B D C D A B
120 110
21, 73 11. 72 28. 43 4.8 - 243 273
840 1200 1200 940 500 110 110
<3 4 <4 <3 <3 2.6 2.9
77 1B02 1022 42 37 1402 1702
112 21B2 124 35 39 140 180
2133 3423 2893 23 94 2103 1902
0.692 1.352 1.172 0.14 oi532 l.l2 l.O2
29 752 522 37 <2 39 38
0.69 0.88
<7 <8 <8 <7 <7 <10 <10
0.50 <0.5
2422 4353 3B12 102 81 4203 3802
0.025 <0.005
<6GO <710 <700 <610 <5BO
REP
120
122
74
0.17
95
20
45
<0.06
29
0.64
<10
<0.5
120
-------
TABLE 2-4. lUUNiJ-NUfci^
1986 Sanples
(Environmental Assessment)
A B C
An
As
Ba
Cd
cr
CU
0
Pb
^ Hg
?
Ni
Se
Ag
Hi
In
cy
V
8.8
810
<3
1862
161
2213
1.482
5B2
<7
2642
<700
5.4
1200
<4
93
73
84
0.55
S62
8
178
<700
6.9
600
<3
82
100
105
1.54
37
<7
137
<620
RESERVE CHANNEL
1990 Sanples
(Dloasaay/Dloaccumulatlon)
D B D REP
7.2
720
<3
1092
67
1092
0.41
37
-------
TABLE 2-5. MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION
BULK SEDIMENT CHARACTERIZATION LEVELS FOR BOSTON
HARBOR DREDGE MATERIAL.
LEVELS
II
III
Arsenic (ppm)
Cadmium (ppm)
Chromium (ppm)
Copper (ppm)
Lead (ppra)
Mercury (ppm)
Nickel (ppm)
Zinc (ppm)
PCBs (Total) (ppm)
Silt/Clay (%)
PAHs (ppm)
<5
<100
<200
<100
<0.5
<50
<200
<0.5
<60
<5
10-20
5-10
100-300
200-400
100-200
0.5-1.5
50-100
200-400
0.5-1.0
60-90
5-10
>20
>300
>400
>200
>1.
>100
>400
>1.
>90
-------
TAJBLE
AKUMAT1U HlLJRUUARBONS
Boston Harbor, HA
PMI. ppb. by GC/MS
Mapthalene
Acenaphthylene
Acenapthena
riuorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Bnnzo(a)anthracene
Chryeene
neneo(b)fluoranthene
rumEo(k)fluoranthene
Ben«o(a)pyrene
Indeno(l,2,3-cd)pyr«ne
Dlbenz(a,h)anthracene
Oenzo(g,h,i)perylene
Total PAMs
Reserve Reserve Chelsea Chelsea Mystic Mystic HDDS
"B" "D" "A" "E" "A" "B" Reference
J130 J130
J360 J270
J270 J2SO
J140 J160
JlOO J220
J310 J310
JlOO
1390 1440
790
J200
J120
J180
800
J470
J30Q 1700
J290 2000
J150 1200
J220 1700
1500
,7360
J140 1100
J570
J120
J560
1460 13090
J300
J170
J210
J260
J210
J580
770
J340
J260
3260
3440
J430
J170
J330
J280
1100
1200
J630
690
1400
670
7100
*Estimate value less than detection limit but a definite peak.
-------
TABLE 2-7. PERCENT SURVIVAL OF AMPHIPOD, CLAMS AND WORMS IN THE
TOXICITY TEST - Federal Project
1990
LOCATION
Reserved Channel B
Reserved Channel D
Mystic A
Mystic B
Chelsea A
Chelsea B
Reference
Control
AMPHIPOD % **
SURVIVAL
21
41
14
24
24
18
85
92
CLAMS %
SURVIVAL
95
87
44
84
86
89
93
99
WORMS %
SURVIVAL
97
97
98
92
93
97
93
95
** Data unreliable due to test procedures used.
PERCENT SURVIVAL OF AMPHIPOD IN THE TOXICITY TEST - Federal Project -
1991
Location
AMPHIPOD %
SURVIVAL
Reserved Channel
Mystic Channel
Chelsea Creek
Reference
Control
90
63
17
94
94
-------
TABLE 2-8. AVERAGE METALS CONCENTRATIONS BY SITE AND MASSACHUSETTS DEP CLASSIFICATION LEVELS FOR HASSPORT DREDGING PROJECT.
Army Base
Conley
Distrigas
Eastern
Minerals
Edison Barge
Berth
Edison Intake
Gulf Oil
Koran
Mystic
North Jetty
Prolerized
Revere Sugar
Arsenic 1 Cadmium !
Mean 1 Level 1 Mean I Level
lO.ll1!!!2 i 2.731 I
9.03 ! I i 3.47! I
27.73 1III ! 3.59! I
1 II
1 1 1
10.86 III ! 3.20! I
1 1 1
1 1 1
13.09 ill ! 6.291II
5.38 II ! 4.46! I
8.18 1 I ! 3.101 I
24.23 IIII i 2.53! I
19.13 ill ! 4.02! I
12.10 III I 3.59! I
! 28.93 IIII ! 6,42111
23.30 !III 1 3.68! I
Chromium ! Copper ! Iron
Mean ! Level! Mean I Level! Mean ! Level
146.83111 ! 125.27! I 133533.331
188.50111 1 169.50! I !32850.00!
149.33! II ! 225.33111 1106066.71
1 i 11 !
241.67111 1 179.33! I 124133.33!
! ! 1 ! !
173.33! II 1 230.00! II !23866.67i
185.13111 i 158.67! I ',38800.001
134.67!II ! 90.331 I 119100.00!
99.97! I ! 159.00! I 137866.67!
163.71111 1 212.43!II !23171.43!
189.33111 1 164.27! I 136033.33!
151.33111 1 234.33111 1123833.3!
177.67!I1 ! 244.67111 153900.00!
Lead
•_ •• *• J
Mean I Level
111.18111
140.53111
657.33IIII
1
1
220.671III
1
1
175.67!II
108.00111
155.67111
349.67! Ill
299.291III
321.33!III
476.00!III
! 501.33iIII
Mercury
hw — •• «. «, J
Mean i Level
0.99!II
0.52SII
0.781II
1
t
0.561II
0.21! I
1.01III
0.361 I
0.581II
0.65SII
0.68111
0.73III
1 0.47! I
Nickel
Mean ! Level
38.58! I
39.38! I
40.47! I
1
1
33.40! I
68.53111
90.43!II
19.871 I
25.33! I
35.33! I
44.23! I
66.47SII
50.27!II
Zinc
Mean 1 Level
212.831II
258.17111
568.331III
1
1
376.00SII
,
239.00111
236.00111
223.33111
255,33111
402.861III
579.331III
676.33SIII
451.00SII1
(1) Concentrations expressed in ppm. dry wt.
(2) Bulk sedinent characterization levels as described in Sediment Sampling and
Laboratory Analysis Plan for Boston Harbor Improvement Dredging Project
prepared for Massport by Normandeau Associates Incorporated, June, 1992.
-------
TAilB 2-9. FOHCICLIC AROMTIC HTOROCAilOHS AVERAGE CWCHHTRATIOiS II SITi A» HASSACWSmS DE? CLASSIEICATIOH UVBLS
FOR HASSPORT DREOGIHG PROJECT.
I
I
!
1
Benzo(a) 1
i Benzo(b) 1 Benzo(ghi) 1
1 Acenaphthene lAcenaphythylenel Anthracene ! anthracene !Benzo(a) pyrene! fluoranthene !
"*""
1
1
Arny Base !
Conley !
Distrigas !
Eastern !
Minerals 1
Edison Barge !
Berth I
Edison Intake!
Gulf Oil
Horan
Mystic
North Jetty
Prolerized
Revere Sugar
Mean !
0.02!
0.291
0.81!
!
0.03!
I
0.03!
0.37!
0.04!
0.71!
0.02!
0.13!
0.88!
0.98!
Mean !
0.13!
0.281
0.61!
!
0.07!
i
0.08!
0.07!
0.02!
0.63!
0.10!
0.34!
0.80!
0.90!
Mean 1
0.17!
0.41!
3.40!
I
0.31!
!
0.16!
0.16!
0.38!
2.12!
0.30!
0.391
3.57!
2.62!
Mean !
0.32!
0.801
2.24!
!
0.641
!
0.15!
1.35!
0.20!
1.81!
0.94!
1.26!
3.32!
0.97!
Mean i
0.33!
1.66!
2.34!
i
i
0.47!
1
1
0.72!
1.04!
0.53! .
0.83!
1.65!
0.71!
2.87!
1.71!
Mean !
0.48!
1.24!
2.11!
!
2.18!
1
1
0.83!
1.02!
0.90!
2.46!
1.201
0.68!
3.64!
3.38!
Benzo(k)
perylene ! fluoranthene
Mean 1
0.44!
0.481
0.94!
1
t
1.36!
1
1
0.32!
0.45!
1.58!
0.95!
1.27!
0.031
0.51!
0.12!
Mean
0.47
1.19
2.13
0.95
0.85
1.01
0.57
2.57
1.08
0.69
3.50
3.32
(1) Concentrations expressed in ppst. dry vt.
(2) Bulk sedinent characterization levels as described in Sedirent Sampling and Laboratory Analysis Plan for Boston Harbor inprovenent
Dredging Project prepared for Massport by Nornandeau Associates Incorporated. June. 1992.
-------
TABLE 2-9. (COHTIHUBD).
Amy Base
Conley
Distrigas
Eastern
Minerals
Edison Barge
Berth
Edison Intake
Gulf Oil
Koran
Mystic
Horth Jetty
Prolerized
Revere Sugar
!
Chrysene i
Mean !
0.78!
0.84!
2.33!
I
1
1.07!
!
0.36!
1.79!
0.73!
3.39!
1.57!
0.93!
2.77!
3.62!
Dibenzo(a.h) !
anthracene I
Hean !
0.17!
0.10!
0.31!
1
1
0.38!
!
0.08!
0.21!
0.08!
0.57!
0.14!
0.16!
0.14!
0.25!
1
I
Fluoranthene !
«• 41
Mean !
0.77!
1.66!
5.77!
1
1.90!
I
1
1.28!
4.95!
3.27!
5.37!
3.47!
1.32!
4.53!
5.57!
!Ideno(l,2,:
Flurorene ! pyrene
« v <• •+ „-.*.-.——*.——
Mean ! Mean
0.29!
0.34!
4.42!
!
0.10!
1
I
0.03!
0.12!
0.08!
1.22!
0.16!
0.75!
2.92!
1.81!
l-cd)!
!
!
i
0.18!
0.10!
0.28!
!
0.39!
1
0.08!
0.59!
0.11!
0.58!
0.21!
0.17!
0.13!
0.31!
i
i
Napthalene i
Mean i
0.20!
0.271
4.08!
1
0.04!
I
I
0.02!
0.03!
0.05!
1.38!
0.11!
0.22!
2.00!
1.04!
t
i
Phenanthrene !
Mean !
0.65!
0.63!
3.06!
1
1
0.67!
1
0.26!
0.67!
0.55!
3.36!
0.58!
0.56!
4.21!
4.07!
!
Pyrene !
_____ ____ _i _
————•—•- — - 1 —
Mean !
0.93!
1.76!
8.11!
1
i
1.76!
1
1
1.34!
5.06!
0.87!
6.78!
2.13!
1.86!
8.97!
5.85!
Total PAHs
Mean I Level
6.27!II
12.00!III
42.91SIII
1
I
12.29!III
1
1
6.51!II
18.85IIII
9.91III
34.69IIII
14.87IIII
10.18!III
44.77IIII
36.51!III
(1) Concentrations expressed in ppti, dry vt.
(2) Bulk sedinent characterization levels as described in Sedinent Sampling and Analysis Plan for Boston Harbor Inprovement Dredging Project for Hassport by
Nornandeau Associates Incorporated, June, 1992.
-------
TABLE 2-10. PCBs(TOTAL) AVERAGE CONCENTRATIONS BY SITE
AND MASSACHUSETTS DEP CLASSIFICATION LEVELS
JOR HASSPORT DREDGING PROJECT.
Amy Base
Conley
Distrigas
Eastern
Minerals
Edison Barge
Berth
Edison Intake
Gulf Oil
Horan
Mystic
North Jetty
Prolerized
Revere Sugar
PCBs (Total)
Mean ! Level
0.63III
1.051III
4.83JIII
t
1
1.65IIII
1
0.46! I
0.79III
0.431 I
1.79IIII
0.90SII
2.36IIII
7.64IIII
4.47! Ill
(1) Concentrations expressed in ppn, dry wt.
(2) Bulk sedinent characterization levels as described in Sediient
Sanpling and Laboratory Analysis Plan for Boston Harbor
iHprovenent Dredging Project prepared for Massport by
Nornandeau Associates Incorporated. June. 1992.
-------
TABLE 2-11. PERCENT AMPHIPOD SURVIVAL FOR JULY - AUGUST 4, 1932 AND
SEPTEMBER 5-15, 1992 - MASSPORT DREDGING PROJECT
LOCATION
Prolerized/
Distrigas
Revere Sugar
Moran
North Jetty
Army Base
Conley
Reference
Control
JULY -AUGUST 4, SEPTEMBER 5-15,
1992 1992
% SURVIVAL LOCATION % SURVIVAL
3
29
43
51
49
63
82
93
Mystic Pier
Eastern Minerals
Gulf oil
Boston Edison
Barge Berth
Boston Edison
Intake
Reference
Control
21
47
55
63
25
73.3
92
TABLE 2-12. PERCENT SURVIVAL OF CLAMS AND WORMS, SEPTEMBER 5-15,
1992. MASSPORT DREDGING PROJECT.
LOCATION
Conley
Army Base
Moran
North Jetty
Eastern Minerals
Mystic Piers
Boston Edison Barge
Berth
Gulf Oil
Reference
Control
% CLAM SURVIVAL
97
98
97
99
96
96
95
94
97
98
% WORM SURVIVAL
90
97
96
92
96
96
93
97
93
95
-------
TAB1E 2-13. HEAH CONCENTRATION (ppn WET WEIGHT) OF PARAMETERS SIGNIFICANT AT THE p>O.OS CONFIDENCE LEVEL FROM BIOACCOHULATION TESTING FOR
HASSPORT DREDGING PROJECT.
HBDS REFERENCE
BIOASSAY
CLAMS WORMS
MYSTIC PIERS MORAN
CLAHS WORMS CLAMS WORMS
EASTERN BOSTON EDISON
NORTH JETTY MINERALS GULF OIL ARMY BASE CONLEY BARGE BERTH
CLAMS WORMS CLAMS WORMS CLAHS WORMS CLAHS WORHS CLAHS WORMS CLAMS WORMS
Lead
Mercury
PCBs (Total)
Anthracene
Benzo(a) anthracene
Benzo(a) pyrene
Benzo(b) fluoranthene
Benzo(k) fluoranthene
Chrysene
Dibenzo(a,h) anthracene
Flour anthene
Ideno(l,2,3-ed) pyrene
Napthalene
Phenanthrene
Pyrene
0.800
0.015
<0.010
<0.020
<0.020
<0.020
<0.020
<0.020
<0.020
<0.020
<0.020
<0.020
<0.020
<0.020
<0.020
-------
-------
in ill I in ill ill 11 ill iiiiiii i nil
II I 1111 II III I IIIIIII
-------
3.0 DISPOSAL SITE ALTERNATIVES
ANALYSIS
The MEPA and NEPA scopes provide direction
for the analysis of dredged materials handling alterna-
tives. Dredged material handling and disposal are
vital issues in port and harbor planning since the lack
of suitable disposal alternatives have delayed port
improvements not only in New England but nation-
wide, ^t is anticipated that maintenance dredging of
the tributary channels alone, will generate 1.8 million
cy of silt in the 50 years following this project.
f the Main Ship Channel and Presi-
dent Roads Anchorages will add an additional 4.4
mffliojLcy_aLsat. Other dredging projects are also
anticipated. Thus- the MEPA scope required that
the BHNIP evaluate disposal alternatives suitable not
just for the current project but which could provide
a solution for future projects. The first priority of
the BHNIP evaluation is a disposal solution for its
own dredged materials. However, future mainte-
nance of the channels is closely linked to the
BHNIP; therefore, the disposal alternative analysis
also identified alternatives that could be useful for
nature dredging.
As stated in the previous section of this EIR/S,
the project will generate some 2.9 million cubic yards
of material (as measured in-situ) requiring disposal.
This quantity was shown to be comprised of a
combination of material characterized as suitable for
unconfined ocean disposal, potentially suitable for
confined ocean disposal, and unsuitable for ocean
disposal. The disposal alternatives analysis builds on
these requirements of quantity and material quality
and involved a stepwise progression from conceptual
alternatives to the selection of feasible disposal
options. The entire process is documented in Ap-
pendix E.
This section of the EIR/S begins with a summary
of the disposal alternative identification and screening
process. As stated in Section 1, the Disposal Options
Working Group (DOWG) was critically important in
the identification of potential sites, the selection and
interpretation of evaluation criteria and in providing
technical data used to characterize individual sites.
This section of the EIR/S also includes a summa-
ry of the dredged material treatment technologies
which may allow the use of material previously
deemed unsuitable for a particular disposal option.
In addition, beneficial uses of the rock, maintenance
material and parent material are considered.
Section 3.0 concludes with the identification of a
f short list of practicable alternatives, a description of
each and the environmental impacts associated with
their use. (Practicable alternatives are defined as those
that are "...^vaiiable and capable of being done after
taking into consideration cost, existingjtechnolggy,
and logistics in light of overall project purposes' (40
CFR230.10
The MEPA scope identified several generic types
of disposal options for consideration and screening.
These generic types are discussed herein as well as
additional subtypes identified during the screening
process. NEPA requires that all reasonable alterna-
tives are rigorously explored and objectively evaluat-
ed. For alternatives which were eliminated from
detailed study, reasons for their elimination should be
briefly discussed.
Disposal sites used for beach nourishment or fill
landward and within three miles seaward of the ter-
ritorial sea base line are evaluated under 404 (b)(l)
guidelines under the Clean Water Act. Other dispos-
al sites are evaluated under Section 103 of the Marine
Protection, Research and Sanctuaries Act which
states that ocean disposal is permitted after certain
factors are considered such as other feasible alterna-
tives (40 CFR 227.15 and 227.16). The material
which follows satisfies the requirements offered in the
MEPA and NEPA guidance.
This EIR/S goes beyond the requirements of the
MEPA scope for analysis of disposal alternatives.
3-1
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The MEPA scope placed the primary focus of the
EIR/S on the sediment testing and the assessment of
compatibility with the universe of alternatives.
Generic evaluation of disposal alternatives feasibility
was recommended, with presentation of specific sites
included in the FEIR/S. The Working Group
process enabled and encouraged the project to
accelerate this analysis so that specific sites could be
evaluated in the DEIR/S. Preliminary screening of
potential upland and aquatic sites was available from
several sources (Appendix E), so that, for most
alternative disposal types, specific sites were identifi-
T able. In addition, the concern existed that absence of
\ specific site analysis in the draft would not allow for
I sufficient public review and commentary under the
/regulatory process. As a result, the decision was
made to identify and evaluate specific sites for each
practicable alternative.
3.1 THE EVALUATION PROCESS
The process for identifying disposal sites and alter-
natives involves a complex mixture of data collection,
analysis, synthesis and judgment. As described in
Section 1.4, to assist in this process, and to develop
a satisfactory selection process, Massport established
a Disposal Options Working Group, whose members
represent federal, state, and local agencies and special
.A . interest groups. The working group assisted and
RjN/11 reviewed the methodology and findings of every stage
\ / If of the site selection process. In interacting with the
working group, several key interests which the
disposal site selection process needed to address were
identified, including:
1. Recognizing the need for responsible expen-
diture of public funds as reflected in the num-
ber of sites assessed, the level of detail re-
quired in data collection to assess the sites,
and the development of disposal options
which maintain a benefit-to-cost ratio greater
than or equal to one for parent material and
the least costly, environmentally acceptable
practicable alternative for silt.
2. Meeting federal, state, regional and local envi-
ronmental laws and regulations.
3. Meeting the objectives set forth in the Massa-
chusetts Environmental Policy Act (MEPA)
and National Environmental Policy Act
(NEPA) scoping guidance.
4. Providing disposal alternatives flexible enough
to allow for changes in the project stemming
from public comments, differences in dredging
quantities, alterations in project limits, consid-
erations regarding project requirements for
phasing of dredging, and the length of time for
handling the marine sediments.
5. Satisfying project requirements in terms of site
availability, volume (for BHNIP) and dura-
tion.
6. Attempting to contribute benefits to long-
term regional dredged material disposal needs.
The Commonwealth of Massachusetts and
various federal and state entities have estab-
lished a goal of developing a long-term
dredged materials management plan to simpli-
fy the process for disposing of sediments that
are not suitable for unconfined ocean disposal.
This plan is in the developmental stages,
however, and will not be implementable for
the Boston Harbor dredging project. The
BHNIP can support the overall goals of the
long-range plan by providing a screening
process for site selection, by providing base-
line information on sites potentially suitable
' for marine sediment disposal and by providing
excess capacity for future projects, such as
future maintenance dredging in Boston Har-
bor.
3-2
-------
7.
Demonstrating a wise use of over 2 million
„ yards of clean marine sediments by identifying
/ benefits for both the short term needs of Bos-
'ton Harbor clean-up and long term dredged
material management disposal needs.
The Boston Harbor Navigation Improvement
Project (BIINIP) will generate up to 3.5 million cy
of marine sediment and rock (as measured after
removal) under the preferred development option.
The materials assessment and characterization (Ap-
pendix C) indicated that the parent material and rock
are acceptable for unconfined ocean disposal while
the silt may require other options. To ensure that
disposal alternatives evaluated would provide suffi-
cient capacity, it has been assumed, for sizing purpos-
es only, that all silt would not be suitable for uncon-
fined ocean disposal.
The determination of sediment quality relative to
guidelines for unconfined open water disposal is a
typical first step in evaluating disposal options for
marine or estuarine dredged materials. The MEPA
scope identified ocean disposal at MBDS as the
preferred disposal option for marine sediments of
acceptable quality from dredging projects and the
alternative against which other alternatives would be
judged. Because of the large quantity of material to_
be dredged, it is assumed that parent material not
earmarked for beneficial uses would be disposed at
the MBDS. The disposal options evaluation fo-
cussed primarily on the silty maintenance and berth
sediments. The remainder of this section describes
the process for identifying alternative disposal sites
and disposal options for the approximate 1.3 million
cubic yards of this silt material.
The MEPA Scope (Appendix A) identified, in
general terms, three disposal alternatives: upland,
nearshore and open water. Where possible, specific
sites in each of these categories were to be identified
and evaluated for their suitability for dredged material
disposal. For disposal alternatives where no sites
were identifiable, an evaluation of the generic concept
was to be presented.
As a starting point for identifying disposal alterna-
tives, a wide range of sites were developed from a
number of sources to create a 'universe* of sites from
which potential disposal areas could be extracted.
The sources for the universe of sites included poten-
tial disposal sites from the Central Artery/Tunnel
Project, the MWRA Residuals Management Facili-
ties Plan (Black and Veatch 1987), Massachusetts
Bay Disposal Site Designation, an EPA study on
nearshore disposal faculties (Metcalf and Eddy 1992)
and conversations with local, state and federal agen-
cies. The process through which these conceptual
disposal alternatives were evaluated and by which
specific sites were identified and evaluated is detailed
in Appendix E. A summary of the process is provid-
ed herein.
The BHNIP disposal site evaluation process con-
sisted of three phases. The Phase I screening process
was limited to identifying fatal flaws of particular sites
(see Tables E-l through E-9). These fatal flaws
included water supply wells located on a site, sites
within a sole source aquifer, sites within the estimat-
ed habitat of rare and endangered species^ sites in or
abutting state parksTsites within Areasof Critical
Environmental Concern (ACECs), sites containing a
21E hazardous waste property, and (for upland sites)
sites with less than 15 acres of developable land.
Landfills were first screened against requirements for
accepting dredged material and for being permitted
for use until at least 1996. Disposal and stockpiling i •
capacity and distance from the dredging locations I
were also used as screening criteria on these landfills \ \
which met the first two criteria.
Sites were categorized into land-based and aquatic
sites. Land-based sites included inland and coastal
sites and landfills. Aquatic sites included shoreline
facilities, subaqueous depressions, borrow pits, in-
channcl trenches and existing open water disposal
sites. The universe of sites in all categories that made
3-3
-------
up the first phase screening process consisted of the
following:
>• 312 land-based inland and coastal sites;
>• 21 landfills; and
•• 21 aquatic sites
An additional 22 sites within the various categories
were identified in consultation with the DOWG and
agency personnel (see Table E-4, Appendix E). This
consultation also resulted in limiting disposal site
selection to sites within the Commonwealth. It was
deemed important to use the information gained in
this project to help resolve the regional long-term
dredging disposal needs. As such, out-of-state, long
distance sites were not evaluated as disposal options.
The Phase 1 screening resulted in the elimination
of sites with the following number of sites remaining
as potentially suitable for disposal purposes:
>• Land-based inland - 14 (Table E-5)
> Land-based coastal - 12 (Table E-6)
•• Landfills - 4 (Table E-8)
•• Aquatic shoreline - 10 (Table E-4)
>• Subaqueous depressions - 6 (Table E-4)
»• Borrow pits - 4 (Table E-9)
»• In-channel trenches - Not identified or
screened in Phase 1
»• Existing open water sites - 2 (Table E-9)
The list of sites remaining after the first phase site
screening (Table 3-1) were presented at a meeting of
the DOWG on January 25, 1993.
Phase II consisted of evaluating potentially accept-
able disposal sites against objective criteria relevant to
the environment and physiography of the site.
Criteria were used that reflected regulatory guidelines
(e.g., 404(b)(l) dredge and fill guidelines; Clean
Water Act, Massachusetts Coastal Zone Management
regulations) and requirements, (especially Massachu-
setts^ Wetlands Protection Act and Site Suitability
Criteria for Solid Waste Site Assignments). Criteria
recommended by Disposal Options Working Group
participants or identified in other dredged material
disposal site screening documents (e.g., Metcalf and
Eddy 1992) were also included. (See Tables E-10
through E-12).
While each criterion is important, certain criteria
stand out from the list as having the potential to be
a deciding factor in the site screening process. Each
criterion was assigned a T" (priority) or an "S" (stan-
dard) classification. "Priority" criteria are those that
require compliance (e.g. based on regulatory criteria).
Inability to meet priority criteria could become a fatal
flaw. "Standard" criteria are important to the overall
evaluation of a site's suitability but do not rise to the
level of the most stringent standard or, conversely, a
potentially fatal flaw. Categorizing the criteria into P
and S groupings enabled a semi-quantitative screen-
ing in addition to the standard qualitative analysis.
Phase II criteria were applied to all sites identified
as potentially feasible after Phase I, as well as several
sites identified after Phase I was complete (see Table
3-1). Quantitative evaluation of sites was performed
for each disposal site category. Within each disposal
site category, site "scores" were compared (see Ap-
pendix E for details) to focus attention on the most
promising sites. Criteria that were not met were
examined carefully to evaluate whether the concern
could be avoided or reduced through site planning
and management or readily mitigated. Data for all
sites were examined both quantitatively and qualita-
tively before determining whether a site should be
short-listed.
The results of the Phase II screening are presented
in Appendix E and were presented to the Disposal
Options Working Group on April 15, 1993. Discus-
sion at this meeting and subsequent investigations
revealed additional information and issues regarding
many sites that resulted in further modification of the
short-list (Table 3-1).
3-4
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The evaluation of Rowes Quarry as an additional
site raised considerable comment in Working Group
meetings because this site had been short-listed by
MWRA for landfilling of sludge from the Deer Island
wastewater treatment facility. Issues that MWRA
felt constrained use of this site included its proximity
to Rumney Marsh ACEC and the tendency for
leachate to flow towards the marsh, the need for
extensive filling to bring the quarry floor five feet
above the normal water table (as required by State
landfill site location regulations) before constructing
a liner and the proximity of residences to the quarry
(M. Virda, MWRA, pers. comm.)- Rowe's Quarry
is an ongoing business. The owner has consistently
expressed his unwillingness to sell the property.
While the leachate and fill/liner issues could be dealt
with through site design, Massport prefers to avoid
disrupting active businesses. It would be very diffi-
cult to relocate an active quarry operation and costly
to take it by eminent domain. Rowes Quarry was
therefore not carried onto the short list of potential
disposal sites.
Phase III involved the development of additional
site-specific information for the short-listed sites
through site visits, aerial photographs, and discus-
sions with appropriate resource agencies. The short-
listed sites were re-evaluated against Phase II criteria
in light of the additional information resulting in a
revised short list (see Table 3-1).
This draft document provides a forum for present-
ing the public with the proposed list of disposal sites
so input can be received and evaluated. Combining
sites into disposal options to acquire sufficient
capacity for disposal of the silty dredged material
yields hundreds of potential combinations. The
existing conditions and potential impacts of using
representative options are discussed in the following
sections. A single preferred disposal option has not
been selected at this stage since it was felt that it was
most appropriate to open the process to public
review before completing the option analysis.
3.2 SEDIMENT/SITE MATCHING
As stated in the MEPA scope, ocean disposal
(Massachusetts Bay Disposal Site) is the preferred
disposal option for uncontaminated marine sediments
of acceptable quality and is the option against which
other alternatives should be judged. A substantial
component of this project has focussed on the issue
of quantifying the levels of metals and organics in
project sediments. Review of these results has
indicated a wide range of chemical concentrations in
sediments throughout the project area (Section 2.2
and Appendix C). Characterization of sediments for
disposal options relies on interpretation of the results
of bioassessment in terms of ecological significance,
and is, therefore, not a clearcut decision. The
USEPA and USACOE have joint responsibility for
making this determination. The silt from the Re-
served Channel area was the only material for which
a consistent opinion was not reached. To ensure that
the disposal option alternatives analysis would
identify sufficient space, it was assumed that alterna- ;
tives to unconfined ocean disposal would have to be |
sought for all silt materials from the project. |
Potential impacts arising from use of different
disposal alternatives vary among the generic alterna-
tives. These differences are reflected in testing re-
quirements and required control measures (Table 3-
2). All disposal types evaluated require bulk chemi-
cal analysis of most parameters identified in the
"Green Book" (U.S. EPA and U.S. ACOE, 1991).
Unconfined open water disposal, lined and unlined
landfills each have identified thresholds for a suite of
parameters that must be met for disposal to be
permitted (Table 3-3). Thresholds for non-landfill
upland disposal are not currently established; howev-
er, site suitability was evaluated assuming that such
a facility would be lined and that the Category A
(lined) landfill criteria would be appropriate. Similar-
ly, regulatory thresholds for in-harbor or coastal
containment have not been defined. Both alterna-
tives would provide isolation of the disposed material
from the surrounding environment once disposal is
3-5
-------
complete. The in-harbor containment alternative
provides the opportunity for isolation during dispos-
al. It was assumed that there were no sediment
quality thresholds necessary for in-harbor contain-
ment or open-water containment, but that either
alternative would be dependent on achieving accept-
able water quality conditions as demonstrated by
acceptable water quality modelling results or moni-
toring. Stability of the disposed material after em-
placement on the bottom would also have to be
addressed.
Site-specific sediment data (see Section 2.2 and
Appendix C) were compared to thresholds for each
disposal alternative (Table 3-4). Clay and rock from
all dredging areas were acceptable for any type of
disposal, provided capacity was available. Silt from
most areas of the harbor was viewed as appropriate
for disposal at any type of site being evaluated except
unconfined open water. The following section
discusses how silt material could be managed for each
of the generic disposal options, including special
handling or design features required for disposal, with
the least environmental impact.
33 SUITABILITY OF GENERIC TYPES OF
DISPOSAL ALTERNATIVES FOR
DREDGED SILT
The types of impacts associated with disposal of
dredged materials can be categorized generally as
habitat loss or alteration, water quality degradation,
emigration (physically or biologically) of contami-
nants from the disposal site, and socioeconomic
concerns (primarily land use and traffic) and are
related to site preparation and management activities.
The following paragraphs summarize the site prepara-
tion and management requirements needed for each
generic disposal alternative to minimize these im-
pacts. The findings are summarized on Table 3-5.
3.3.1
Land-Based Alternatives
Inland and Coastal Sites
In general, upland sites would have to be cleared
and graded before construction of a silt containment
facility. The containment facility would include a
liner, diked disposal cells constructed in sequence,
runoff and leachate controls, and access roads (Table
3-5). Closure of the site would include capping and
landscaping. Configuration of the containment
facility would be designed to minimize impacts to
critical environmental features.
Locations of upland sites are shown in Figure 3-1.
Access to inland sites is restricted to truck or rail
transportation. Coastal sites could be accessible by
barge, although this could require dredging of access
channels.
Potential impacts associated with developing an
upland (either inland or coastal) disposal facility are,
in contrast to landfills, relatively severe (Table 3-6).
While it would be desirable to focus on previously
degraded sites, areas that have received other waste
materials are not always suitable for disposal facility
development without remediation first. While chemi-
cally-degraded sites may be suitable for a long-term
future regional facility after remediation, sites that
have experienced habitat alteration (clearing,excava-
tion and mining) are themost likely candidates
available for the BHNIP. Development of a disposal
facility on such a site could result, in loss and/or
alteration of terrestrial habitat (particularly Wrentham
(W-495) and Woburn (WOB-11)), possibly including
wetlands. Loss of vegetated wetland habitat (Table
3-7) would occur with development of the Wrentham
(9 acres), Woburn (I acre) and Squantum Point
(QUI-03) (0.3 acres) sites. Everett (EVR-04), Squan-
tum Point and Wrcntham all provide habitat for
state-listed species of special concern (Table 3-7).
Development of the coastal sites (Everett and
Squantum Point) would affect marine resources due
to dredging. Prevention of water quality impacts
3-6
-------
would depend on site design features including design
criteria to minimize the risk of exposure of freshwater
resources to elevated chloride levels (inland sites
only) or contaminants. Marine waters could experi-
ence locally-elevated turbidity and contaminant
concentrations at the dewatering site (Mystic Pier or
North Jetty) for inland sites, but this would be
limited by proper design and monitoring. Depending
on site access, use of coastal sites could affect marine
water quality during site preparation (dredging for
barge access) or dewatering (for truck transportation).
Both inland and coastal sites offer some risk of
contaminant emigration due to the prolonged period
required for drying the sediments before capping.
Although the disposed materials would remain azoic,
the containment area would appear pondlike and
may be attractive to birds.
Both types of sites could have socioeconomic
impacts - displacement or alteration of land use and
high truck traffic volumes. None of the shortlisted
sites are currently in use except Wobum which has a
closed, but uncontained, municipal landfill onsite.
Due to its large capacity, Wrentham would experi-
ence the highest truck volume but its proximity to
major highways would minimise the neighborhood
effects of this traffic. Rail access could become avail-
able for Woburn. Barge transport would be likely for
Everett and Squantum Point.
Disposal of silty sediments from Boston Harbor in
an upland area would remove this associated chemi-
cal load from the harbor environment (Table 3-8).
A regional facility might be able to use a chemically-
degraded area, but the remedial actions necessary to
develop such a site would be greater than a single
project (even a large one) could bear. Thus, such
sites were not shortlisted although any upland site
that demonstrated merit for potential development
would require a preliminary assessment, as a mini-
mum, for hazardous materials. Parent material (clay)
could be used in construction of the site, although
the silt would then have to be stockpiled during
construction. There would be potential for enhance-
ment of terrestrial habitats once the facility was
closed. Any landscaping would have to preserve the
integrity of the cap, probably eliminating the planting
of trees.
Landfills
Existing landfills can provide disposal space for
marine dredged materials under two scenarios - use
for daily cover or burial. In the case of the BHNIP,
the suriicial silts would have to be mixed with clean
materials to- meet the regulatory thresholds for daily
cover.
No special site modifications would be required
for landfills, although all the short-listed landfills have
odor limitations. Three existing landfills (Figure 3-1),
Plainville/Laidlaw, East Bridgewater and Fitchburg/-
Westminister, were identified as having the ability to
accept marine sediments in the approximate time
frame for the BHNIP.
From a qualitative perspective, use of lined
landfills for disposal of dredged materials provides the
least environmentally damaging alternative (Table 3-
6) because the natural environment has already been
disturbed to develop the landfill. However, competi-
tion for space at landfills is a key issue. Landfill
space is fast approaching capacity, and while various
landfills are capable of handling marine sediments,
this type of use could displace other, higher-priority
uses. Of the 122 landfills currently permitted to
accept municipal solid waste in Massachusetts, 114
are scheduled for closure by 1996 (MADEP, January
1993 active MSW landfill list). The three sites short-
listed have limited capacity for burial of dredged
material (Table 3-7). The exception is that there
continues to be a need for daily cover and final
closure material. Dredged material can be suitable
for these purposes under some circumstances. To be
used for daily cover, sediment must have contami-
nant levels within a range that, after mixing with a
"reasonable" amount of clean material, would meet
3-7
-------
TCLP regulatory levels (Table 3-3). Maximum need
for daily cover that could be provided by BHNIP
dredged materials ranges from 50 cy/day (Plainville/
Laidlaw) to 250 cy/day (Fitchburg/Westminister)
(Table 3-7). Only clean material that would contrib-
ute to construction of an impermeable layer could be
used for a cap. Marine clay can be suitable for this
purpose (S. Lipman, MADEP, 1993, pers. comm.)-
The limited available capacity for dredged materials
at these landfills would minimize the traffic burden
associated with the BHNIP.
The benefits (Table 3-8) of using landfills for
disposal of marine sediments are relatively high,
primarily because this alternative utilizes existing
facilities. Again, however, this apparent benefit must
be weighted against the constraint of competing uses
for a limited resource.
333 Aouatic Alternatives
Shoreline Facilities
There are two fill alternatives proposed for the
Mystic Pier sites, Revere Sugar, Amstar and Cabot
Paint (see site locations Figure 3-1). The first alter-
native is for partial fill which would result in a final
elevation (including cap) of mean low water. The
total fill alternative elevation would be mean high
water (or higher where adjacent land elevations
would allow it). For both alternatives, a bulkhead
would be constructed to isolate the site from the
harbor during disposal. The bulkhead would remain
in place after disposal in the total fill alternative but
be cut off at MLW after the cap was secured for the
partial fill alternative.
Two fill alternatives were considered for these sites
since the cost of disposal site development can only
be offset by maximizing the disposal site capacity.
However, the total fill option creates an irretrievable
loss of subtidal habitat by replacing it with fast land.
The partial fill option is designed to allow for the
establishment of intertidal habitat.
Little Mystic Channel and Reserved Channel
(Figure 3-1) would require maintenance of aquatic
habitat. Little Mystic Channel would be filled to a
final elevation (including cap) of -6 to -3 ft MLW.
Fill in the Reserved Channel would encompass either
the entire area west of Summer Street or only the
western end of that area. The western end would, in
either case, be filled to a final grade (including cap) of
+ 9 ft MLW, a suitable elevation for establishing salt
marsh vegetation. The eastern portion would be
filled to a final elevation of -6 ft MLW. Both sites
would be bulkheaded during disposal.
Both shoreline fill scenarios would result in loss of
marine habitat, although in the partial fill scenario
loss would be temporary (Table 3-6). Permanent
habitat losses would be highest at Cabot Paint (total
fill). Temporary habitat losses would be highest at
Reserved Channel (if entire area used) or Little
Mystic Channel (Table 3-9). There were no marked
differences in benthic infauna among the six potential
disposal sites, but the pier areas (Amstar, Cabot
Paint, Mystic Piers and Revere Sugar) may provide
slightly better finfish refuge potential than the chan-
nels (Little Mystic, Reserved) because of the pilings.
Ultimately, in the partial fill alternative, marine
habitat could be altered from fine-grained substrate to
vegetated or rocky substrate of potentially higher
productivity (Reserved Channel, Little Mystic Chan-
nel).
Temporary localized water quality impacts could
be minimized by appropriate site management (e g.,
dredging and disposal methodology, disposal behind
bulkheads, use of silt curtains, disposal timing) for
both total and partial fill alternatives. In both scenari-
os, the disposal site would be essentially isolated from
the rest of the harbor. The partial fill scenario could
pose a slightly higher risk of emigration of silty
sediments in the long term than the total fill. Since
the shortlisted shoreline sites are in relatively quies-
3-8
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cent parts of the harbor, and thus relatively safe from
erosiona! currents, other forces (e.g.; boats, biological
activity) are unlikely to disrupt the cap of the partial
fill.
I and use impacts would be site dependent. Any
fastlands created would have to be used for a water-
dependent activity. Alterations in current use would
be greatest at Amstar because of MWRA's newly
constructed floating dock (for transport of Deer
Island workers). Other pier areas arc not presently in
use. Filling in the eastern portion of Reserved
Channel could interfere with the existing marina
operations. Traffic impacts would be minimal at pier
sites since sediments would be transported by barge.
It could be necessary to use a barge and truck combi-
nation for Little Mystic Channel and Reserved
Channel because of low clearance bridges across the
entrance of each site.
Each of these fill alternatives could result in envi-
ronmental or socioeconomic benefits (Table 3-8).
All of the shoreline sites are likely to have or have
been demonstrated currently to contain, contaminat-
ed sediments with elevated chemical constituents.
Either the total or partial fill alternative would isolate
these contaminants from the Boston Harbor environ-
ment. The partial fill scenario has the potential to
enhance the environmental quality of the site by
providing clean substrate for benthic organisms (all
sites), or plantings to increase primary productivity
(especially Reserved Channel and Little Mystic
Channel). Totally filled sites could be developed for
port-related activities. Clay from the improvement
dredging could be used in capping these sites, reduc-
ing the need to transport material to MBDS.
Subaqueous Depressions
Use of the outer harbor subaqueous sites B and E
(Figure 3-1) would rely on existing bathymetric
conditions to keep disposed sediments in place.
Sediments would be transported by bottom-dumping
scow. After disposal of silt is complete, the area
would be capped by depositing dredged parent
material over the sediments.
Use of the subaqueous depressions would result in
temporary habitat losses until capping was complete
(Table 3-6). The disposal site footprint would be
smallest at the Winthrop Harbor site (8 acres).
Subtidal habitat would be altered by changes in
substrate texture and depth. Some fine-grained sedi-
ments and associated contaminants would remain in
suspension and be transported away from the dispos-
al site. ADDAM'S model results indicate that the
plume could extend a distance of approximately
4,500 ft from the disposal site and on a flood tide
potentially carry contaminants (which may exceed
water quality criteria by 2x) outside the disposal site.
Commercially harvested clam beds on the Snake
Island flats and the Basin could be sensitive to
sediments with elevated contaminants dispersed from
a Winthrop Harbor disposal site. Disposed
sediments would be exposed to currents for the
duration of disposal activities, presenting a risk for
further emigration and bioaccumulation. The model
results imply that water quality exceedences should
not extend up-channel beyond Chelsea Point in Win-
throp, so the Belle Isle Main ACEC should not be at
risk (Table 3-10). Subaqueous B and E are exposed
to higher current velocities than Winthrop Harbor;
areas of potential exposure include the Governor's
Island flats and Deer Island flats. There would be no
land-based traffic impacts to any of these sites,
although some impacts to navigation would occur.
Restrictions would be temporary in Winthrop Har-
bor and Subaqueous B. Seasonal recreational boat-
ing could restrict disposal operations in Winthrop
I larbor. Small boat use of the channel passing across
Subaqueous E could also cause seasonal restrictions
on use of the site.
Using subaqueous depressions for material dispos-
al would isolate dredged contaminants from the
harbor ecosystem. Another benefit associated with
3-9
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the subaqueous disposal alternatives is the ability to
use project parent material for the cap (Table 3-8).
In-Channels and Borrow Pits
Both In-Channel and Borrow Pit alternatives
would require additional dredging of m-situ parent
material plus the quantity needed to cap the silty
sediments. Sufficient surficial material dredged from
each disposal site would be stockpiled to use as final
capping material to restore the site to pre-existing
substrate conditions. Native clay from channel deep-
ening would be used for the initial cap.
In-Channel alternatives would include Chelsea
Creek, Inner Confluence and Mystic River naviga-
tional channels. Borrow pit alternatives include
Mcisburgcr 2 and 7 and Spectacle Island CAD (see
Figure 3-1). This latter site is located in the shallow
(-10' MLW) subtidal area east of the Island and is
totally disassociated from the Island itself and the
CA/T project work in progress.
Both the In-Channel and the borrow pit alterna-
tives would temporarily remove marine subtidal
habitat from production. There would be a greater
impact at the previously undisturbed Meisburgcr sites
than the In-Channel alternatives. Surface substrates
at borrow pit sites could be altered somewhat but
substrate in the In-Channel sites would not be
noticeably different from the planned post-dredging
conditions. Containment of sediments during dispos-
al for inshore alternatives is an issue requiring mitiga-
tion to lessen the resulting turbidity plume.
ADDAM'S model results indicate that water quality
criteria exceedences would not occur at the offshore
(Meisburgcr) sites while mitigation measures may be
necessary to contain sediment dispersion at the
Spectacle Island CAD site. Sediments would be
exposed for the duration of the disposal operation,
resulting in some potential for emigration through
current transport or biological activity. The smaller
capacities of the In-Channel alternatives would result
in shorter periods of exposure than the borrow pits.
I lowcvcr, ADDAM's model results, for the Subaque-
ous E site, indicate that there could be water quality
criteria cxccedenccs during flood tide after four hours;
and silt/clay plumes were predicted to extend as
much as 4,500 ft upstream of this in-harbor disposal
site. Because of shallower water near the Spectacle
Island CAD site, dilution to below water quality
criteria was predicted at greater distances, but reached
that distribution level in less than four hours.
Biological impacts could vary among the In-
Channel alternatives primarily because of the Mystic
River's value to anadromous fish although seasonal
restrictions on disposal in the Mystic River Channel
could avoid these impacts. The offshore borrow pit
if; sites, Meisburgcr 2 and 7, support high benthic
!j productivity and fisheries resources are relatively
^ abundant. The outer harbor Spectacle Island CAD
appears to support substantially lower benthic
production. Its location in the general vicinity of the
proposed Central Artery/Tunnel fish reef mitigation
project, however, would mean that disposal methods
and/or mitigation efforts would need to account for
the protection to this resource if it is in place by the
time the Harbor is dredged. Additionally, special
plans to avoid or mitigate for fishing gear losses
(lobster, pots, etc.) from barge traffic or construction
activities may be necessary at the Meisburger and
Spectacle Island sites.
The In-Channel alternative could utilize dredged
clay for capping material (Table 3-8). Clay could be
incorporated into the borrow pit cap. Sediments
(sand and gravel) dredged from the borrow pit sites
during site preparation could be used for beach nour-
ishment or construction, if the need exists. Other-
wise, this sediment would have to be disposed at
MBDS. The In-Channel alternative has the advan-
tage of being located in an already impacted area (i.e.,
the navigational channels).
3-10
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Existing Disposal Sites
Previously-used dredged material disposal sites,
MBDS and Boston Lightship (Figure 3-1), could be
utilized for the project for silt disposal, with capping.
At MBDS disposal of contaminated material with
capping is prohibited unless such a demonstration is
made; with respect to the BLDS, the Corps has
successfully demonstrated effective capping at sites
with similar depths elsewhere in New England. A
containment area would be prepared by configuring
parent material in a specific area. Silt would be
point-deposited by accurate positioning of the barge.
Once disposal was complete, additional parent
material would be deposited over the silt to form the
final cap.
Disposal of silty dredged materials at a previously-
used disposal site would have impacts generally
similar to use of a borrow pit (Table 3-6). Since
disposal of the silty sediments at the Massachusetts
•. Bay Disposal Site is currently prohibited by EPA
without further testing, a field program to demon-
strate the effectiveness of capping, if it is needed,
would likely push this site out of a reasonable time
frame for use on the current project. Agency con-
cerns associated with capped disposal at MBDS have
largely focussed on emigration of contam-
inants/sediments during disposal and long-term
integrity of the cap (see Appendix G). In a recent
study by EPA (1993) ADDAM'S models were run
for the MBDS using this project's data and no water
quality exceedences were predicted outside the site
during the disposal phase (Table 3-11). These results
were used to conclude that disposal activities from
this project (BHNIP) would not add to impacts from
the MWRA ocean outfall at a level to cause a risk to
threatened and endangered species in the area.
ADDAM'S model results for the Boston Lightship
also indicate that water quality criteria would not be
exceeded outside that disposal site which is half as
deep and twice as close to Boston as MBDS. In the
foreseeable future BHNIP is the only project that
could provide its own capping material, perhaps
representing the only opportunity to cap silty sedi-
ments of this volume and provide a demonstration of
this option's effectiveness. This scenario would
provide beneficial use of all parent material dredged
from the project. Capping at the MBDS may
represent a practicable alternative for the future
maintenance material as it is not considered imple-
mentable at this time due to the EPA and CZM
requirement for a demonstration of its efficacy. Its
use for future maintenance material would hinge on
such a demonstration, if those sediments are found
unsuitable for unconfined ocean disposal.
3.4 DEVELOPMENT OF DISPOSAL
OPTIONS
As discussed previously, there are few alternative
disposal sites that have the capacity to handle all the
dredged material, parent, silt and rock, for this
project. In addition, disposal considerations must
include the requirement of future disposal of mainte-
nance (silt) material. In order to address both the
present and future capacity needs individual disposal
sites have been combined into disposal options which
attempt to balance environmental consequences with
practicability concerns.
The volume of material requiring disposal from
the proposed BHNIP was conservatively estimated to
ensure sufficient capacity will be provided at disposal
options. Table 2-2 presented the estimated volumes
of rock, parent and silt material requiring disposal.
The volumes shown assume a 0.5 foot overdredge to
ensure all silt material is removed. The volumes also
factor in a 20% expansion of silt and parent material
over in-situ volumes to account for the water en-
trained in the dredging process. Rock was assumed
to expand by 50% over in-situ conditions due to the
blasting fractures. Based on the measured in-situ
volumes and expansion factors the BHNIP will /
generate approximately 132,000 cy of rock, 2 million
cy of parent material and 1.3 million cy of silt.
These quantities represent one consideration used in
3-11
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developing potential disposal options. As discussed
in Section 3.2 and summarized on Table 3-4, sedi-
ment quality must also be taken into account in
considering disposal sites. Environmental impacts of
using undeveloped sites for disposal, presented in
Section 3.3, are also a factor in developing disposal
options, particularly related to contaminated dredged
material. Finally, practicability considerations of
costs, technology and logistics which are reasonably
related to project needs must be factored into the
development of disposal options.
These four factors: volume, sediment quality,
environmental impact and practicability, were used to
formulate several disposal options by combining
ic sites. jThefollowihg sections
described options in four categories developed
through the process defined above. Each option
assumes that dredged parent material and rock will be
''used for beneficial uses to the maximum extent
2o ^^TP°ssibIe and that th656 uses wm ke identified and
V^, _ ^expanded throughout the EIR/S process. The
remaining quantity of this material after beneficial
are accomplished will be disposed at the MBDS.
Options for disposal of silt material considered
potentially unsuitable for unconfined ocean disposal
(Table 3-12) are the primary focus of the next sec-
tion. Options defined as group "A" include combin-
ing land-based sites for silt disposal. The "B" group
options focus on combining aquatic sites while "C"
group options include combinations of land-based
sites and aquatic options. The *D" group options
consider aquatic sites previously used for offshore
disposal and which have the capacity to receive all
the project material.
Tables 3-13 through 3-18 and 3-20 are provided
for use in determining the relative costs of alternative
disposal options described in the following para-
graphs. The objective of preparing these tables was
to determine relative unit costs by estimating the
total cost to dredge the silts, process the dredged
material, transport the material to the disposal site,
construct any required features at the disposal site
and any other costs associated with the dredging and
disposal of silts. The costs are based on October
1993 price levels.
The unit costs should not be used to estimate a
project cost. Project costs, once a disposal site -is
selected, will be computed based on optimal use of
equipment, distribution of silts to other disposal sites
if applicable, and other factors that can not be
estimated until a final disposal plan is selected and
the cost of disposal of the parent material is deter-
mined. Also cost for mobilization would have to be
added as well as associated design and construction
management costs required for the selected plan.
Assumptions used are listed on each table. Exist-
ing information was used when available. Experience
from other projects was used when specific site data
was unavailable. These assumptions should be
carefully reviewed since, in some cases, significant
cost items are not included (i.e., real estate acquisi-
tion costs for upland and shoreline sites).
3.4.1 Land-Based Options (A) ty
Use of any of the upland sites for silt disposal
would require that the material be dewatered prior to
disposal. Dewatering would occur at Boston Harbor
shoreline sites to facilitate trucking efficiency and
minimize potential chloride impacts to freshwater
systems. For calculations of disposal needs it was
assumed that dewatering and compaction would
reduce the silt volume nearly to its in-situ estimate of
approximately 1.1 million cy.
Option A1. Option Al would involve disposal of
all silt at landfills. The three landfills_which survived,
the screening process (see Table 3-1) are expected to
have a combined maximum need of 1,000 cy/day of
cover material. TCLP results indicated that most of
the harbor silts would have to be mixed with equal
quantities of clean materials to be suitable for daily
3-12
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cover, reducing the total potential daily use of project
material to 500 cy/day, or 7-13% of the anticipated
dredging rate. Over the anticipated 100 days of silt
dredging (assuming two dredges, yielding 8,000
cy/day each), the total daily cover needs at the
landfills of 50,000 cy over the 100 days would fall far
short of project disposal needs. In order for landfills
to provide the necessary capacity, project sediments
would have to be buried, not simply used as daily
cover. Using all three landfills, a total of 525 cy/day
of silt material, or 52,500 cy over the 100 day dredg-
ing period could be buried. The maximum disposal
capacity for project silts combining daily cover and
burial is, therefore, 102,500 cy.
As pointed out in preceding sections, there are
definite environmental advantages to using landfills
since they are engineered and permitted designated
disposal areas. The major drawbacks to using land-
fills are daily limitations on quantities that the
landfills can handle and competing public uses for
landfill capacity. It would take more than 4 years to
accommodate the 1.1 million cy generated by the
; BHNIP using Option Al. Costs would range from
; $56 - $101/cy to dispose of material at the landfills
not including the cost of land needed to stockpile silt
for four years (see Table 3-13).
Option A2. Option A2 would involve a combina-
tion of one or more landfills and one or more inland
sites. Meeting the capacity requirements of the
BHNIP would, at a minimum, involve using Wren-
tham (W-495), Squantum Point (QUI-03), and all
three landfills. To reduce the volume of dredged
materials to be buried at the landfills (52,500 cy), a
third upland site, Everett (EVR-04), would have to
be included. Any other combination of inland and
landfill sites would fail to provide adequate capacity.
Distribution of dredged material to four or five differ-
ent locations would be difficult logistically and each
town would feel the maximum potential effects of
disposal. In addition, all dredged material would
have to be dewatered at either Mystic Pier or North
Jetty. Once dewatering started, dredged materials
would have to be removed at the, rate of 4,000-8,000
cy/day (200-400 truckloads) ..while silt was being
dredged, x^
This option also assumes that a lined disposal
facility would need to be designed and constructed at
two or more inland or coastal sites and that silt
overburden in excess of landfill capacity would have
to be stored until access to sufficient quantities of
clay become available for the facility's liner. Costs j
for Option A2 would be approximately $50/cy (see
Table 3-14).
Option A3. Option A3 would rely entirely on
developing land-based disposal sites for the silty
material. Individually none of the four upland sites
could provide the total capacity needed for the
BHNIP, but the combination of the Wrentham (W-
495), Wbburn (WOB-1I) and Squantum Point
(QUI-03) sites meet the capacity needs. This option
also provides some excess capacity beyond the
current project needs. The benefits of Option A3
include reserving landfills for other public uses,
minimi/ring the area and time needed for stockpiling
and minimizing impact to the marine environment.
Significant drawbacks include long-term management
of three sites along with attendant costs, the minor
capacity available for future dredging projects andon-
site and neighborhood impacts from constructing the
facilities and transporting up to 55,000 truckloads of
silt to the sites. Costs for implementation of the
above scenario of the Wrentham, Woburn and
Squantum sites would be $50/cy (see Table 3-14).
3.4.2 Aouatic Options (B)
Aquatic options must be able to accommodate an
estimated 1.3 million cy silt material which includes
the 20% expansion factor over in-situ volumes.
Option Bl. Option Bl relies on placing all the
silt material in shoreline containment areas. Use of
all the sites short-listed could not provide all the
3-13
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disposal capacity needed for the BHNIP, but use of
some or all of the sites could provide a variety of
disposal configurations in combination with other
types of sites. Filling these sites (Amstar, Cabot
Paint, Mystic Piers, Revere Sugar to fastland; Little
Mystic Channel to -3 ft MLW; and Reserved Chan-
nel to MHW in its western end and -6 ft MLW near
the Summer St. bridge) would result in a temporary
or permanent loss of marine habitat. However, this
option would benefit the Boston Harbor aquatic
environment by covering the silty sediments that
V presently exist at these sites, would enhance sediment
^quality for benthic organisms and could enhance
primary productivity by creation of low salt marsh in
(Reserved Channel or subtidal productivity in parts of
the Little Mystic Channel. Impacts to harbor traffic
are also rninimized by providing disposal within the
vicinity of the proposed dredging. This option would
not have capacity remaining for future use unless an
additional site were included in the development
plans.
Costs for maximum capacity at all six sites range
from S33 - $278 cy depending upon the amount of
engineering and site preparation required (Table 3-
15). Costs include construction of a bulkhead across
the face of each site and transfer of sediments from
barge to truck by crane.
Option B2. Option B2 involves filling existing
outer harbor subaqueous sites. No site by itself
would provide the capacity necessary for the BHNIP.
Combination of the maximum fill scenarios at
Subaqueous B and Subaqueous E and Winthrop
Harbor would provide sufficient project capacity.
Because development of the subaqueous sites would
not include construction of a physical containment
structure, future use (if any capacity remained) would
be dependent on having sufficient capping material.
This option would result in temporary water quality
impacts, and loss of marine subtidal habitat during
the disposal and capping process. The habitat would
be altered in depth, microtopography, and potential-
ly, sediment grain size characteristics. The logistical
benefits to this option are substantial as it would
mean disposal sites would be near the dredge sites,
minimizing conflicts with ship traffic and greatly
reducing transportation costs and impacts.
\ I \ Costs for this option would be approximately $ 15
/ per cubic yard (see Table 3-16). No site preparation
i> I costs would be incurred.
\
A
/ Option B3. ..Option B3 would require overdredg-
ing in at .least three navigational channel areas, filling
the dredged trench with silt and capping it with
dredged parent material. Because this scenario would
be confined to the footprint of the federal portion of
the BHNIP, no additional habitat would be impact-
ed. This option would prolong the dredging process
by 3-6 months and require temporary barge storage
of dredged silt until the initial cell was dredged. The
three channel areas where it would be feasible to
overdredge, Mystic, Chelsea and Inner Confluence,
would be unable to provide the capacity needed for
BHNIP; some parent material would have to be
disposed elsewhere (probably MBDS). Overdredging
would be impracticable in the Reserved Channel
because it is the only tributary of Boston Harbor that
has no physical restrictions to future deepening. This
option might generate some tidal-dependent water
quality problems. The ability to localize any impacts
makes this an attractive option for the BHNIP, it
would also offer a potential solution to hold aside for
future maintenance dredging. Again, transportation
disturbances and costs would be minimized by this
option. —x
This option would cost approximately $25 per cy
for disposal of 664,000 cy of silt which includes the
costs of additional dredging and disposal of parent
material (see Table 3-17).
Option B4. Option B4 would require dredging
and capping a borrow pit for containment of BHNIP
silts. A beneficial use would be sought for the
material dredged from the pit. Meisburger 7 could
provide capacity for all the silt dredged during the
3-14
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BHNIP. Meisburger 2 also has the capacity if the
sand and gravel deposits are proved to average more
than 10 feet thick. The Spectacle Island CAD with
a 45-acrc footprint could also provide the necessary
capacity. Each of these sites could be constructed to
provide capacity for other projects if they occur
during the time frame of the BHNIP. The Meis-
burger sites could provide sufficient additional capaci-
ty for future maintenance dredging of Boston Harbor,
assuming disposal was confined to discrete cells.
Impacts associated with this option would be
temporary but would include .disturbance to areas
utilized by commercial fish and fishing activities. In-
harbor sites may experience some water quality
exceedences while the offshore sites would noi.
Costs would range betweenV$20 and $25 per cy.)
depending on the site selected/^Reuse-ef-sedinieht
dredged at the disposal site could reduce the costs.
Option B5. Option B5 assumes a combination of
aquatic shoreline sites and any of the other aquatic
sites. This option would require use of at least two
sites - an aquatic shoreline site and a subaqueous, in-
channel or borrow pit site. An advantage over
Option B1 would be the avoidance or minimization
of permanent habitat loss, depending on the aquatic
shoreline site selected. For example, this option
could provide the capacity needed for the BHNIP by
filling Revere Sugar to fastland and constructing an
intermediate footprint at the Spectacle Island CAD.
Any aquatic shoreline site could similarly be com-
bined with the Spectacle Island CAD or with reduced
disposal scenarios at the Meisburger sites to meet
project capacity needs. Mitigation for water quality
impacts would need to be addressed. Other possible
combinations within this option would require the
use of four or more sites (e.g. Little Mystic Channel,
Subaqueous E, Inner Confluence In-Channel and
Mystic River In-channel). Any sites not used could
potentially be available for future disposal of Boston
Harbor dredged materials.
3.4.3 Land-Based Aquatic Combinations (C)
Option Cl. Option Cl would utilize a combina-
tion of landfills and aquatic shoreline sites. The
combination of all six shoreline sites (to full capacity)
and three landfills (50,000 cy of daily cover plus
burial of 52,500 cy) would provide disposal capacity
for a total of 1.18 million cubic yards. This option
does not provide any future maintenance disposal
and is logistically quite complex in terms of requiring
dewatering locations, barge and truck loading at
various sites around the dredging location and in-
creased truck traffic in shoreline and landfill commu-
nities. In addition the option removes landfill capaci-
ty from other public users. The costs for this option
range from $33 to $278/cy depending upon the site.
Option C2. Option C2 would combine non-
landfill upland and aquatic shoreline sites. It could
be implemented by using as few as three sites; a
combination of Wrentham (W-495) and Everett
(EVR-04) with Reserved Channel or Little Mystic
Channel (to -6 ft MLW). That option would yield
excess capacity. Alternatively, Squantum Point
(QUI-03), Wrentham, and Mystic Piers (at maximum
capacities) would meet needs but provide very little
excess capacity. The costs for these scenarios would
range between $50 and $255/cy depending on the site
selected.
Not using Wrentham would require a minimum
of eight sites: Squantum Point, Everett and the six
aquatic shoreline sites except Little Mystic Channel,
to their maximum capacities. Truck traffic impacts
would be reduced in this scenario but construction of
shoreline facilities would keep the cost range high,
between $35 and $278 depending on the site.
Option C3. Option C3 would utilize a combina-
tion of landfills and aquatic disposal sites. Use of
any of the borrow pits to full capacity would make
landfill disposal essentially superfluous; however,
landfills could be used in part if there were strong
public pressure for landfill use. Without the landfills,
3-15
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this option becomes similar to Options B4 or B5,
discussed earlier. The Spectacle Island CAD, Meis-
burger 2 or Meisburger 7 (borrow pits) could provide
the 1.3 million cy capacity and would be the simplest
way to minimize use of landfill space and completely
confine the dredged materials. No habitat would be
permanently lost although capping the aquatic site
would likely result in some alteration of substrate
character. Spectacle Island CAD is located in shal-
low enough water to enable use of control structures
to isolate the site during disposal. At other sites,
because no physical structure other than lateral con-
straints provided by bathymetric conditions (existing
or created) would be in place during disposal, some
emigration of sediments and contaminants might
occur from the aquatic disposal site during place-
ment, potentially affecting nearby fisheries and other
aquatic resources. If borrow pits were not used for
this option, a minimum of two subaqueous depres-
sions would be required.
Since no structures would be needed, costs for
disposal under Option C3 would be less than Cl or
C2. Assuming use of Spectacle Island CAD and East
Bridgewater landfill, Option C3 costs range from $25
to $56/cy.
Option C4. Option C4 would combine develop-
ment of a new land-based disposal facility with a
non-shoreline aquatic site. Many possible combina-
tions of two or three sites could meet current needs
and potentially provide excess capacity for future
dredging. Most efficient implementation of this
option would likely focus on aquatic disposal first;
development of the upland facility would start when
clay dredged from the improvement portion of the
BHNIP could be provided for the liner of the upland
facility. The selection of both the upland and aquatic
sites would determine whether excess capacity would
remain for future dredged material disposal. Presum-
ably, any excess capacity would be provided at the
upland site, provoking the question of costs and
responsibility for long-term management of the
facility. Possible combinations of sites include
Wrentham (W-495) and Subaqueous E; Wrentham,
Everett (EVR-04), and Mystic River; and Squantum
Point (QUI-03), Woburn (WOB-11), Subaqueous E,
Mystic River and Inner Confluence.
Providing a constructed facility with substantial
excess capacity would drive the costs of the BHNIP
up substantially and would render this option im-
practicable. A regional use facility could be con-
structed and maintained by a separate authority.
Costs for the suggested combinations of sites would
range from $25 - $76 per cy, assuming that upland
site preparation costs would be offset by future users
of the excess capacity provided.
3.4.4 Previously Used Aquatic Disposal Sites
Option Dl. Option Dl would rely on solidifica-
tion of silty sediments prior to disposal at either
MBDS or Boston Lightship. Solidification processes
have been demonstrated to stabilize metals, PAHs
and PCBs (Breslin, et al. 1988; IWT Co. 1993, pers.
comm.) and have been considered to provide perma-
nent removal of these contaminants from the ecosys-
tem when applied in the terrestrial environment (see
Section 3.5 and Table 3-19). There would be no
short-term water quality impacts associated with
offshore options, as demonstrated by the ADDAM'S
model results. This option would also address
concerns about resuspension and/or transport of silt
sediments offsite, as well as further reducing on-site
risks. However, this option would require special
handling of the dredged material, and this, along with
the cost of the treatment material, would make this
option more costly. Disposal of hard material at an
offshore site could increase habitat complexity or
make habitat reestablishment more difficult.
Costs for solidification with offshore disposal
would be approximately $55 per cy (see Table 3-19).
Option D2. Option D2 would rely on disposal of
the silty sediments at either MBDS or Boston Light-
3-16
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ship and subsequent capping with parent material
(primarily clay) from the channel deepening. As
discussed in prior sections, resuspension of contami-
nants during disposal and from the boundaries of the
designated disposal site has been the major concern
associated with the capping option. However,
modelling done in this study and by the EPA indi-
cates that short-term water quality criteria exceeden-
ces should not be a problem with these sites. This
project overcomes a major stumbling block faced in
the past by proposals for capping at MBDS: avail-
ability (or lack thereof) of suitable capping material.
The BIINIP will produce over 2 million cy of parent
material, 1.5 times the quantity of silt to be dredged.
Further, due to the physical constraints created by
the transportation tunnels under the Main Ship
Channel, it is likely that the Inner Confluence,
Mystic Channel and Chelsea Channel will never be
deepened below the authorized 40 feet. Thus, the
supply of potential capping material is unlikely to be
available for this purpose again without relying on an
outside source. However, in its final site designation,
EPA has found that disposal-and-capping (of
unsuitable material) is prohibited at MBDS until its
efficacy can be effectively demonstrated (40 ,€FR
228.12 [Amended)).
Cost for this option would be approximately $ 18
per cy for disposal of project silt (see TablcNJ^O).
3.5 ALTERNATIVE TREATMENTS AND
BENEFICIAL USES
The silt portion of material to be dredged from
Boston Harbor could undergo certain treatment
processes that may either immobilize or reduce
chemical concentrations to a level that may be
acceptable for open water or other disposal options.
Various commercial treatment processes exist that
have been successfully utilized elsewhere in the
country on sediment and on other material that may
be applicable to dredged material. These treatment
technologies were evaluated and potentially viable
alternatives considered during the site screening
process. Of the potentially viable alternatives consid-
ered, costs for treatment ranged from $50 per cy to
$350 per cy, the most expensive being thermal
treatment options (Table 3-19).
The parent material planned to be dredged for the
full project has certain potential beneficial uses which
deserve consideration within the alternatives analysis
process. Some of these benefits occur one-time only,
due to the proposed channel deepening, and therefore
they should be considered carefully before the oppor-
tunity is permanently lost.
3.5.1 Treatment Technologies
Several general categories of treatment technolo-
gies were reviewed in the development of disposal
options. The following paragraphs summarize each
technology and its potential applicability to the
BHNIP.
•• Physical/Mechanical. These are largely de-
watering and separation technologies often
used to prepare materials for additional treat-
ment. Dewatering processes include passive
settling and drainage systems, as well as active
mechanical systems such as belt filter presses
and centrifugation. Mechanical separation
and particle classification processes employ
equipment such as grizzlies, hydroclones, and
hydraulic classifiers to separate fine-grained
clays and organic matter from coarser dredged
material. This process may be desirable for
the Boston Harbor material not only to facili-
tate handling, but because contaminants tend
to sorb primarily onto the finer-grained mate-
rial, thereby reducing the volume of material
which would require treatment. These me-
chanical technologies are generally widely
available, and many have been fully demon-
strated in the treatment of sludges as well as
in mining and other materials-handling indus-
3-17
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tries. Factors limiting the effectiveness of
these technologies can include the moisture
content, flow rates, particle size distribution of
the subject materials, and practicability of
handling the large volumes and high daily
production (dredging) rates. In addition,
debris typically found in the harbor would
have to be carefully removed prior to process-
ing.
Biological. These technologies, which include
such processes as aerobic and anaerobic bio-
reclamation and digestion, treat contaminated
sediment through the biodegrading action of
microorganisms or enzymes produced by mi-
cfbbes. However, biodegradation is effective
dnlyto materials high in organic content, and
is generally ineffective for treatment of heavy
metals. In addition, biodegradation generally
works best under operating conditions which
permit a high degree of control of critical pro-
cess parameters such as temperature, moisture,
and nutrient content. These conditions may
not be readily achievable for a large volume of
material where climatic conditions vary widely
or in instances when the treated materials are
highly heterogeneous. Furthermore, biodegra-
dation processes are complicated by the possi-
ble toxic effects of one contaminant in the
treated matrix on the microorganisms used to
treat another contaminant.
Chemical. These technologies use chemical
agents and processes to destroy, modify,
remove (extract) or chemically immobilize
toxic materials, or to alter them in a way that
affects their solubility, stability, separability
and other properties affecting handling and
disposal. Averelt et al. (1990) identify avail-
able chemical treatment processes, including
chelation and nuclcophilic substitution (de-
chlorination), as well as 22 extraction technol-
ogies, most of which can be viewed as essen-
tially chemical in nature. Variations of these
technologies are potentially effective in treat-
ing PCBs, non-halogenated semivolatiles such
as PAHs, and metals. However, according to
the literature, many chemical processes may
be difficult to implement because of materials
handling and process control requirements
that have not been fully demonstrated for
application to dredged material. Heterogene-
ity of grain size and density can limit the
effectiveness of the extraction processes. For
those processes, there may also be problems
associated with recovery and disposal of the
extraction solvents.
.
Immobilization. These technologies typically
isolate and limit mobility of contaminants
:rrrottgh"'solidification and/or stabilization
(SIS), and are usually applied to sediments
that are ultimately placed in a confined site or
disposal area. Averett et al. (1990) cite 12
such processes, including lime-based and
Portland cement-based solidification process-
es, as well as encapsulation. S/S facilitates
materials handling, decreases the surface area
of the sediment mass across which contami-
nant loss or transfer can occur, and can limit
contaminant solubility through Ph adjustment
or sorption phenomena. According to the
literature, S/S processes can be effective for
both organics and metals. The most common
of these technologies have been demonstrated
on a pilot or full-scale basis for treatment of
soils and solid residues from other treatment
processes. In addition, the immobilization
processes are generally not as sensitive to
process control conditions as the biological
and chemical-extractive processes. However,
the effectiveness of cement-based solidification
processes may be impeded by organics in the
treated materials which reduce the binding
capacity of the fixative, resulting in premature
structural degradation. Another limiting
factor in the use of immobilization technolo-
gies is the availability of a suitable confined
3-18
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disposal area or beneficial use for the solidified
material. Marine applications may be avail-
able, however. Artificial reefs constructed of
stabilized incinerator residues have been
placed in Ijong Island Sound. Studies on
mobility from these reefs of dioxins and furans
(Wente and Roethal 1993) and various metals
(Breshlin, et al. 1988) have indicated that
these constituents have neither leached nor
been accumulated by organisms attached to
the reef. Other proprietary stabilizing agents
have been demonstrated to immobilize PCBs
and PAHs (IWT 1993, pers. comm.). Blocks
constructed of solidified dredged material may
also be useful for shoreline protection and
reinforcement.
>• Thermal. This category includes incineration
processes, pyrolytic processes, vitrification
processes, wet air oxidation, and other pro-
cesses that involve heating the sediment hun-
dreds or thousands of degrees above the ambi-
ent temperature. A number of these processes
have been widely demonstrated, and are con-
sidered effective for destroying organic con-
taminants. However, they are often more
expensive than other options. For example,
the low fuel value and high water content of
sediments results in high additional energy
input requirements during incineration. In
addition, volatilized metals and other incinera-
tion by-products must be removed from flue
gases, ash or other residues for treatment and
disposal. Incineration processes may also be
difficult to implement because of siting prob-
lems related to complex permitting require-
ments and generally poor community accep-
tance. On the other hand, few of the non-
incineration thermal processes have been dem-
onstrated on other than a bench-scale or pilot
basis.
Many of the specific processes which fall within
each of the technology categories identified above
have been reviewed in published literature, either
genetically or in connection with specific dredging or
sediment remediation projects. From this review it
was apparent that different investigators have used
varying approaches to process nomenclature and
categorization of specific processes (e.g., some review-
ers classify chelation as a chemical process, others as
a physical process; some place extraction within the
chemical treatment category, others regard extractive
processes as a treatment category by itself.) Averett
et. al. (1990) have organized over 70 treatment
process options within six technology categories. It
is important to note that while many of these tech-
nologies have been widely demonstrated in non-
marine applications, only a few have been used for
bench scale and pilot scale tests on marine dredged
materials, and few are considered commercially
demonstrated and available for this purpose. The
total volume of material being handled on this
project and its rate of production are also serious (,. (
impediments to the use of these technologies.
New Technologies
The U.S. Environmental Protection Agency has
established the ARCS Program in the Great Lakes
Region with the interest of developing appropriate
assessment and contaminant removal technologies in
five areas of the Great lakes. The Program includes
a Technological Working Group on Engineering and
Treatment Technologies, which assessed nine avail-
able treatment technologies. Four were selected for
use in a pilot program: thermal adsorption, sediment
washing, solvent extraction and bioremediation. The
pilot studies were completed in 1993, with the results
currently undergoing analysis and assessment. Final
reports on the four technologies tested may be
available in early 1994. This information, as avail-
able, will be included and further evaluated, as
appropriate, in the FEIR/S.
'Hie Corps of Engineers' Waterways Experiment
Station (WES) in Vicksburg, Miss, has been investi-
3-19
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gating a new technology, geotextile containers.
Pilling gcotextile containers with sandy dredged
material has been successfully used for construction
of groins for several years but filling the containers
with fine grained dredged material has been very
limited. This technology as applied to the BHNIP
would consist of mechanical or hydraulic dredging,
filling the container positioned in a bottom dump
scow, scaling the container, and disposing at an open
water site. WES has just begun investigation into
gcotextile containers for deep open water disposal.
Some of the advantages over traditional disposal
includes: 1) no loss of contaminated material during
the descent phase, 2) more control over the location
size and shape of the deposition pile, and 3) long
term containment of contaminated material. Cap-
ping of the containers, if required, would further seal
contaminants from the environment. The cost of
this technique has not been determined. Information
on this technology, as it may be applied to the
BIINIP, will be assessed as it becomes available.
Technology Screening Criteria
A wide range of treatment technologies from the
above described processes have been assessed with
respect to effectiveness in treating the specific param-
eters of interest in the BIINIP (PCBs, PAIIs, metals)
as well as the implementability of each process
considering the volume and through-put expected
from the project. A subset of the most feasible
technologies was further evaluated with respect to
technical, environmental, economic and regulatory
compatibility (Table 3-19). This subset was further
narrowed to the selection of three treatment technol-
^ .ja^"^— — i^—^^m , f
ogies (thermal, immobilization and chemical) that
showed the most promise and applicability__io_the
Boston Harbor sediments to be dredged. These
technologies were evaluated for various effectiveness
and implementability and are summarized on Table
3-19.
Dredging and Potential Treatment Technology
Relationships
The critical characteristics of the Boston Harbor
Dredging Project that impact the selection of the
alternative technologies include the following:
>• The types of contaminants that are of con-
cern, based upon contaminant concentrations
found during the sampling and testing pro-
gram, are polychlorinated biphenyls (PCBs),
polynuclear aromatic hydrocarbons (PAHs),
petroleum hydrocarbons and trace metals.
The ability of each technology to treat these
contaminants in the medium of dredged
material is an important qualifier on effective-
ness.
»• A maximum of approximately 1.3 million
cubic yards of dredged material may be un-
suitable for unconfined ocean disposal and
therefore could require treatment. Depending
on the disposal option selected, production
rates could range from 4,000 to 9,000 cy per
day. This quantity and rate of dredged mate-
rial would require a large scale facility for any
of the applicable treatment technologies to be
used. It is therefore, important to select
demonstrated technologies that have operated
on similar types of dredged materials at the
scale required by the project schedule. This
imposes a substantial constraint because there
is very limited experience with operating
treatment technologies at the scale of the
proposed project for marine dredged materials.
Implementation of any alternative treatment
technology will result in residue streams to the
environment. The ability of each technology to
control these residue streams, and thus to mitigate
environmental impacts is another important consider-
ation for effectiveness.
3-20
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The projected quantities of dredged material will
require relatively large sites (at least 4-6 acres) for any
of the applicable treatment technologies except the
solidification process which could utilize a barge
mounted processing plant. Each treatment technolo-
gy will be required to have similar receiving, storage,
handling, and transport areas and relatively large fixed
industrial facilities. To limit handling/transfer costs,
the site would necessarily be located on the coast
with barge access.
The time frame for permitting a relatively large
and new industrial operation in the Boston area is
estimated to take between 12 to 24 months. The
design, construction/installation, start-up and testing
of the selected treatment technologies could take an
additional 12 to 24 months. Of the five basic treat-
ment options, four show limited promise for use with
the BHNIP dredged materials. Mechanical sepa-
ration would do little to reduce the volume of materi-
al for disposal since contaminants are primarily
associated with the silt. Biological digestion has not
been shown to be effective with heavy metals.
Chemical reclamation would require a multi-step
process, including dewatering and disposal of sol-
vents. Thermal treatmBrtfwouK^JHost^Fective on
organic compounds/ Solidification oE^uie other
hand, has been demo
fwou
Solidification,
riobilize a variety
of organic and inorganic constituents effectively. It
is the only treatment technology carried forward into
the disposal options analysis^
3.5.2 Beneficial Uses
There is a strong potential a portion of the Boston
Harbor dredged material to be used for one or more
beneficial uses. The types and volumes of parent
material may never be available again from Boston
Harbor and therefore provide some unique mitigation
opportunities for dealing with the silt. The parent
material, specifically the rock and Boston Blue Clay
could have a variety beneficial uses.
It is also possible that the silt portion of the
dredged material containing elevated levels of organ-
ics (PCBs, PAHs and petroleum hydrocarbons) and
heavy metals could be utilized for daily cover at
Massachusetts Category A lined landfills, provided
the material is mixed with a sufficient amount of
cleaner material prior to use. However, the concen-
tration of certain contaminants in the mixed material
must meet the DEP criteria for this type of use. One
drawback to utilization of the dredged material for
landfill cover is that each landfill is limited to receiv-
ing small quantities (50-250 cubic yards at the short-
listed sites) of material for daily cover use. Stockpil-
ing at landfills is limited due to the confined space
available. Consequently, only a small portion of the
Full Project quantity of dredged silt material (approx-
imately 1.1 million cubic yards total) could be used
in this manner.
Beneficial uses for rock and parent material could
include the following:
Use of Rock Material
Fish Habitat Enhancement
There will be a large quantity (132,000 cubic
yards) of rock removed from this project which could
be utilized for constructing or improving a fishery
habitat. For a perspective on the overall volume of
material available, a containment structure with an
approximate height of 15 feet would encompass an
area of over 5 acres. A structure of this magnitude
could be located in an in-harbor or offshore area
considered to be in need of fisheries improvement but
away from heavily utilized locations and high energy
areas. A drawback to the rock to be removed for the
BHNIP is that it will be mostly small in size ( < 10")
and mixed with some clay which would not provide
large interstitial space for fisheries habitat. It would
however, provide hard substrate for benthic organ-
3-21
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isms and some interstitial space which could increase
the diversity and productivity of habitat niches.
Shoreline Protection
It was investigated to determine if some of the
rock material could be utilized for shoreline protec-
tion along certain areas in and around Boston Har-
bor. Specifically, there are waterfront areas in Chel-
sea and Mystic Rivers and along the Main Ship
Channel that may be structurally unstable due to
erosion from inadequate protection. As an example,
an area that may benefit from increased shoreline
protection is a city property located along the south
shore of the Chelsea Creek near Condor Street.
Additionally, there may be shoreline areas outside of
Boston Harbor proper that could benefit from in-
creased protection. Massport does not have any
waterfront areas that could readily use the rock
material for protection. However, due to the size of
the rock material after blasting (10' diameter) its use
as shoreline protection will be limited.
Containment Site Development/Armoring
The rock removed from dredging could be useful
for developing a containment site for the unconsoli-
dated (silty) dredged material. One such use could be
for the construction of subaqueous berms that could
assist in retaining the finer material during disposal
operations at some types of sites. Likely sites for this
use would include the subaqueous sites in the outer
harbor and Spectacle Island CAD. The rock could
particularly be useful in providing armor aggregate
for a portion of the containment berms. However, it
is expected that a substantial quantity of other larger
size rock may be needed to completely protect the
exposed faces of the containment berms.
Upland Fill/Commercial Reuse
The dredged rock mixed with clay could be useful
for various upland filling applications where clean fill
is needed (highway construction, etc.). It would be
relatively easy to handle and transport, and could
provide a suitable foundation for certain light com-
mercial or industrial uses. Additionally, the rock
could have some commercial reuse potential as
construction aggregate. Its clay content may decrease
its utility.
Use of Parent Material
Open Water Disposal Cap
There will be approximately 2 million cubic yards
of parent material (primarily clay and sand/gravel)
available from the Boston Harbor Dredging Project.
This material is highly cohesive and could be useful
as capping material at an open water disposal site.
Open water sites still under consideration which
could utilize this method of containment include the
Massachusetts Bay Disposal site, Boston Lightship,
and the Meisburger 2 and 7 sites. Capping would be
initiated soon after the disposal of silt material was
completed. The operation would be conducted using
traditional barge scows with bottom operating doors.
The material would be point dumped within specific
radii from the center of the silt material to form a
continuous mound deposit of approximately 1 meter
thick on top of the silt. This would effectively
provide a clay cap which would seal off the silt from
the environment.
Ncarshorc Containment Cap
The parent material could also be used in a
similar fashion for capping any of the nearshore
containment sites currently under consideration.
However, because of limited barge access to some of
I ID
3-22
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these sites, it may be necessary to utilize landbased
equipment or a barge mounted crane for offloading
the sediments from barges for cap placement.
Subtidal/Intertidai Habitat
The Reserved Channel and Little Mystic Channel
containment options will require surface material that
would be suitable for establishment of subtidal and
intertidal habitat. The parent material to be dredged
would be suitable as base material that could be
placed directly onto the silty dredged material in the
containment site. A surface layer of clean sand/silt
mixture placed over the clay would provide substrate
favorable for benthic recruitment and establishment
of vegetation.
Landfill Liner/Cap/CIosure Material
The parent material could also be useful for lining
landfills or other upland sites that may require liner
material. Since the parent material is primarily clay,
it is highly impermeable and could be suitable for
this purpose. This material could also be useful for
capping or covering some of the silt to be dredged
from this project that may require burial. The pre-
dominately clay parent material may also be useful as
final closure material at certain landfills. Massachu-
setts DEP, Division of Solid Waste Management
identified anticipated closure dates for municipal solid
waste landfills in Massachusetts (January 6, 1993).
The information indicates that 56 landfills are to
close in 1993, 52 in 1994, 2 in 1995, 4 in 1996 and 1
in 1997. Excavated soils from the Central Artery
project will be used to cap many of these landfills.
Should CA/T material not be used in this manner,
by the time BHNIP begins, the 108 landfills closing
prior to 1995 could potentially utilize a proportion of
the parent material provided practicability problems
(primarily logistics and cost) can be overcome.
However, the potential future use of synthetic liners
for landfill application may substantially reduce or
eliminate the need for clay at many landfills that
currently use this material.
hi summary, beneficial uses of rock and parent
material may include a variety of enhancement and
containment purposes as follows:
ROCK
(Amount available: approximately 132,000 cubic
yards)
Fish habitat enhancement
Shoreline protection
Containment site development/armoring
Upland fill
Commercial reuse (construction aggregate)
PARENT MATERIAL
(Amount available: approximately 2 million cubic
yards)
Open water disposal cap
Nearshore containment site cap
Landfill liner/cap
Landfill final closure material
Other upland site liner/cap
3.6 PREFERRED DISPOSAL OPTION
The single preferred disposal option is not identi-
fied in this Draft EIR/S. Public comment on the
alternatives presented herein must be factored into
that decision. The preceding discussions have dem-
onstrated the complexity of identifying and combin-
ing sites to form disposal options. This section will
assess the issues involved in critically evaluating the
merits of the disposal options to select the preferred
option.
Selection of the Preferred Disposal Alternative will
be based on screening the options through a series of
key criteria (Figure 3-2) which include:
3-23
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»• ability of disposal sites/methods to meet
regulatory criteria for receiving material
>• reasonable capacity for this project
>• minimization of negative environmental im-
pacts
> maximization of environmental benefits
»• reasonable in light of logistics, technology and
cost.
Determining the suitability of each site for the
different types of dredged material is an initial screen-
ing criteria and this "matching' process was discussed
earlier (Section 3.2). A second important factor is
having enough capacity within the site(s) to offset its
development cost. Sites with less than 200,000 cy of
capacity W£rejdeem€aTajpEacticable for this project.
X. Environmental impact was a third criterion.
Lancbbassd (landfill ,and>development of new inland
or coastal sites) and aquatic (nearshore and various
open water alternatives) disposal sites would inher-
ently involve different types of impacts (Table 3-6)
since different resource types would be involved in
each case. Thus, while comparisons among land-
based alternatives and among aquatic alternatives are
fairly straight forward, comparisons between upland
and aquatic alternatives are more complex. The
types of environmental impacts that would weigh
most heavily against a site being included in the
preferred alternative (based on sensitive resources
identified in this study) would include unmitigatable
risks to:
marine and/or upland habitat
wetlands
anadromous fish passage
important resident fish and shellfish
water quality
threatened and endangered species
traffic (marine and/or roadway)
> neighborhood impacts
Distinctions can be made among disposal alterna-
tives based on their ability to provide environmental
benefits (Table 3-8), although, again, it is difficult to
weigh benefits against each other, particularly on the
generic level. However, benefits that would weigh
most heavily toward including a particular alternative
would include:
> maximizing use of parent material
> use of any available sand or gravel v •
" providing capacity for future dredging needs
»• providing clean bottom habitat within Boston
Harbor
»• providing alternatives which are practicable
and achievable
Identifiable future disposal estimates (i.e., 50-year
maintenance for Boston Harbor) point out the
necessity to evaluate disposal options on both the
generic and specific levels. As indicated in Section
3.4, identifying capacity for the BHNIP is the first
challenge. Adding future dredging projections to the
equation makes the evaluation more complex but is
critical to the process and was identified as such in
the MEPA scope. The preferred disposal option
should include a site or sites and methods to accom-
modate future dredging as well as the current need.
/Cost, iiraddition to logistics and technology, is a
factor in-^determining practicability of the disposal
options. Final cost comparisons among disposal
options cannot be made without considering specific
sites. An acceptable benefit/cost ratio must be
reachedor the project will not go forward. Federal
participation in the BHNIP is governed by two cost-
related criteria. These criteria relate to the material
to be removed during construction of the project: 1)
silt or maintenance material that has accumulated
3-24
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since the channel was last deepened; and 2) the
parent material that must be removed to deepen the
channels to their new depth: Because the cost of
deepening the channels (removing parent material)
and removing silt and parent material from project
berths are direct project costs, the total must be
compared to the benefits that the deeper project will
provide. Therefore, the benefit-to-cost ratio for thet -.
project or each separable increment of the project \ 1
must be at least 1:1 for the project to qualify for \ \
Federal funding. Included in the benefit to cost ratio
is the incremental cost to maintain the project during
its economic life (SO years).
As described in Section 1.3, costs of construction
of disposal sites, or acquisition of lands for disposal,
are non-Federal costs. While a particular disposal
option may pass the Federal participation criteria, the
sponsor may find its cost contribution unacceptably |
high. The screening process of practicability^
considered costs in excess of 4 times that of ocean
disposal as prohibitive. The cost criterion that
applies to the project related berths is affordability
relative to the perceived benefits in site management.
The cost of disposal of silt material at one of the
full capacity sites (Meisburger 2 or 7, Boston Light-
ship, Spectacle Island CAD and the Massachusetts
Bay Disposal site) Would range from about $24
million to about $33 million. Limited capacity sites,
when combined to accommodate the total volume,
would cost at least $10 million more than the most
expensive full capacity site.
Identification of suitable disposal options for
BHNIP has been an open process involving valuable
collaboration with the project's working groups.
This DEIR/S is another step in that process. Mass-
port and the Army Corps of Engineers will incorpo-
rate comments received on the specific sites, disposal
types, practicable disposal options and the final
selection criteria into their determination of a Pre-
ferred DisoosaLQption which best meets the identi-
fied goals.
Table 3-21 provides a summary of the principal
impacts associated with the twenty-four disposal sites
and one treatment technology that remained poten-
tially suitable for BHNIP material disposal after site
screening. The existing conditions at each site and
principal environmental impacts associated with its
use are provided in Attachment 1 in Volume 1 of 2
of this Draft EIR/S. The twenty-four sites were
screened against the final practicability considerations
described above for selecting a preferred disposal
option. This analysis has resulted in a final short-list
of practicable alternatives from which a preferred
disposal option will be selected.
While the selection of a preferred disposal alterna-
tive is not required by the Massachusetts Environ-
mental Policy Act (MEPA), it is required under the
National Environmental Policy Act (NEPA).
Federal agencies (e.g., the Corps of Engineers) are
required to Identify the agency's preferred alternative
or alternatives, if one or more exists, in the draft
statement..." In addition, the Final Rule for Opera-
tion and Maintenance of Army Corps of Engineers
Civil Works Projects Involving the Discharge of
Dredged Material into Waters of the U.S. or Ocean
Waters (33 CFR 209, 335-338), states that dredged
material disposal alternative or alternatives identified
by the Corps which represent the least costly alterna-
tives consistent with sound engineering practices and
meeting the environmental standards established by
the 404 (b)(l) evaluation process or ocean dumping
criteria, will be designated the Federal standard for
the proposed project. In compliance with the above
regulations, Massport and the Corps select the
Massachusetts^ Bay Disposal Site fMBDS). the
Boston Lightship, Meisburger sites 2 or 7, and
Spectacle Island CAD as their preferred disposal
alternatives.
The DEIR/S is to be used also as a disposal site
selection process for maintenance dredging if the
proposed navigation improvement project is delayed
or not implemented. Maintenance dredging of
accumulated silt material will be needed to allow
3-25
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ships to transit the harbor safely. Unlike the naviga-
tion improvement project maintenance dredging
would not produce clean parent material which could
be used for capping. Therefore, disposal options
which provide cap material, such as the Meisburger
sites, Spectacle Island CAD and in-channel disposal,
are preferable. Disposal could occur at other sites if
suitable cap material can be found from other pro-
jects.
The following section describes the factors and
reasoning for selecting the final short list of practica-
ble alternatives.
3.6.1 Practicable Alternatives
The preferred disposal option will be made up of
one or a combination of several sites and options
described earlier.' The twenty four remaining disposal
sites have been further screened to yield several
practicable alternatives which meet the capacity,
environmental benefits and cost requirements of the
BHNIP.
As stated earlier 'practicable' is defined as 'avail-
able and capable of being done after taking into
consideration cost, existing technology, and logistics
in light of overall project purposes" (40 CFR
230.10(a)(2)). qAcr'feasiblealtematives'areevaluat-
ed under Section 103' of the Marine Protection,
Research and Sanctuaries Act.
,..
The twenty-four sites were evaluated according to
a five step practicability screening which proceeded as
follows:
1. Habitat loss at each disposal site was
examined first. Sites were retained if
habitat would not be lost or if it would be
altered in a way that continued to provide
resource function.
Sites meeting the first criterion were evalu-
ated for water quality impacts. Sites were
retained if disposal actions did not show
water quality exceedences or if adequate
mitigation measures could be implement-
ed.
Sites meeting criteria 1 and 2 were exam-
ined for socioeconomic impacts. Poten-
tially excessive exposure to neighbor-
hoods, traffic or sensitive natural resources
was used as an elimination criteria.
V '
Sites meeting criteria 1, 2 and 3 were
examined based on meeting a minimum
capacity of 200,000 cy.
While not a direct reason for ruling out a
site, sites with disposal costs greater than
4 times and higher, than capping at
MBDS, were considered excessive.
6. Sites meeting all the above criteria were
also evaluated as to their potential for
providing capacity for future maintenance
dredging projects.
These criteria were used to identify the least
environmentally damaging practicable alternatives for
the three areas .of need (parent material, silt material,
future maintenance material). Based on this analysis
I all land-based and aquatic shoreline sites were found
I to have severely limiting environmental socio-eco-
Inomic or capacity constraints. Cost, logistics, tech-
nology and capacity, measures of practicability, were
also found to be less favorable at land-based and
aquatic shoreline sites.
Table 3-22a lists the sites considered practicable
for the BHNIP project. These sites were found to be
the least environmentally damaging and the most
practicable in terms of disposal capacity, logistics and
costs. Among the listed sites Boston Lightship and
MBDS have unlimited capacity as long as there is
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sufficient capping material (and this mitigation
measure is proven to be feasible at MBDS). The
BHNIP can provide 2 million cy of parent material
for capping during the improvement dredging. This
capping material is a one-time opportunity for this
project. Because there are no site preparation costs
at Boston Lightship or MBDS, costs to implement
these alternatives would be lower than other sites.
The MBDS has been deemed acceptable for the
parent material.
Meisburger 7, and potentially Meisburger 2, could
accommodate all the silt dredged during the BHNIP
as well as provide capacity for future maintenance.
These sites would be excavated below grade, filled,
then capped with parent material and the excavated
material used to restore to existing grade and cover
type. Thus, these sites could provide their own
capping material. Costs for use of Meisburger 2 and |
7 would have to include site preparation - dredging of |
the borrow pit - but could be partially offset by 11
beneficial uses (e.g. beach nourishment projects) of
the on-site sediment deposits.
Spectacle Island CAD, though no more costly
than the Meisburger sites, could not provide the full
capacity needed for the future maintenance material
and, thus, has use only for silts from the present
project.
In-channel locations, while not having the capaci-
ty, even taken together, to accomodate all the
BHNIP silt material, do provide a total of about
740,000 cy and the environmental benefit of capping
the contaminated sediments in place.
Table 3-22b lists sites which survived the screening
process but on further review were found to provide
insufficient capacity and were cost prohibitive. These
sites are potentially practicable for future
maintenance dredging requirements where the
required capacity will not be as great. Among these
potentially practicable sites, both Little Mystic
Channel and Reserved Channel offer the potential for
resource enhancement assuming temporary water
quality impacts could be mitigated. Neither site, nor
a combination of the two, could provide the
necessary capacity for the BHNIP and are costly
options.
Amstar, Mystic Piers and Revere Sugar would
provide the benefits of capping contaminated sedi-
ments, but are of high cost relative to the amount of
maerial they could accomodate. All aquatic shoreline
sites, even if filled to capacity, would require bulk-
head construction which has the benefit of isolating
contaminated sediments in those areas. The trade-off
is that existing sub-tidal habitat is lost to fast land if
the sites are filled to capacity. Due to the permanent
loss of subtidal habitat in the total fill option only
the partial fill option, which provide for the establish-
ment of intertidal habitat, was selected as potentially
practicable.
Lined landfill sites do not provide sufficient
capacity relative to costs per cubic yard for disposal.
These sites may be suitable for future small quantity
maintenance dredging needs if the cost is reasonable
in relation to the amount of material to be disposed.
Solidification would also meet all the environmen-
tal criteria for the "least environmentally damaging"
alternatives. Although it could meet the capacity
requirements for the BHNIP, but not the dredge
material production rates, current costs would be up
to 8 times those for implementing the other alterna-
tives. Other technologies (particularly bioremedia-
lion) are continually being investigated and may
eventually prove to be practicable. Therefore, it may
be a potential option for future maintenance material.
The potentially practicable alternatives selected
through the foregoing process are listed in Table 3-
22b. Table 3-22c lists the remaining sites of the 24
that survived the evaluation process. Further review
of these sites, in terms of practicability, revealed that
they do not provide the least environmentally
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damaging alternatives and some are cost prohibitive.
Based on the final evaluation these sites have been
excluded from consideration as practicable
alternatives.
3.62 Descriptions of Practicable Disposal Sites
Section 3.6.1 and Table 3-22a identified six practi-
cable alternatives from which a preferred disposal
option will be selected. The information which
follows provides a description of each of these
options, existing environmental conditions and
proposed site conditions and impacts from material
disposal operations.
In addition to the six identified sites, an additional
five have been evaluated in the following sections.
These additonal sites, consisting of aquatic shoreline
facilities, are considered potentially practicable due to
their proximity to the dredging locations and poten-
tial for providing environmental benefits by removing
and capping contaminated sediments occuring at
these locations. However, their practicability is
limited due to the cost of site development relative to
the capacity they provide and, as such, are not the
preferred alternatives.
3.6.2.1 Boston Lightship
The Boston Lightship disposal site (BLDS) is a
historical disposal site approximately five miles across
and more or less centered on the Boston Lightship
(Figure 3-3). The site received hazardous and low
level radioactive waste containers, construction debris
and sunken vessels between 1940 and 1976. Three
million c.y. of Boston Harbor dredged material was
disposed there in the late 1960s and early 1970s.
Volumes disposal in earlier decades are unknown.
Existing Conditions
The sedimentary environment out to the 50 m
contour (which bisects this disposal site) has been
characterized as either depositional (see hatched area
in Figure 3-3) or sediment reworking (Knebel 1993)
The depositional area, within which the disposal site
is proposed, is depicted as an area with modern fine-
grained (muddy sands and mud) sediments that have
accumulated in areas of dominating weak bottom
currents.
A summary of the benthic species collected at
Boston Lightship in December of 1977 and May of
1978 indicate a smaller number of individuals and
species than at other disposal sites located in the Gulf
of Maine (DAMOS 1979b). Dominant benthic
species include the polychaetes Sternapsis scutata,
Nepthys incisa, Maldane sarsi, Lumbrineris fragilis,
Ninoe nigrippes, Goniada metadata, Ampharete
acutifrons, the nemertean worm Micntra sp., bur-
rowing anemone Edwardsia elegans, and the amphi-
pod Hippomedon serratus (DAMOS 1979b, Supp
D).
The Massachusetts Bay area is a productive
fishery habitat. Fish reported to occur in the area of
the disposal site include cod, dab and gray sole,
yellowtail flounder and whiting. Atlantic herring are
caught near the vicinity of the Boston Lightship and
the MBDS (DAMOS 1979b, Supp D). Lobster and
ocean quahogs are also reported in the area.
Proposed Use/Impacts
This site is an alternative for disposal of the 1.3
million cy (expanded volume) of silt material, assum-
ing the disposal would be capped with three feet of
parent material. There is a depositional area within
this site below the 50 m contour that is proposed as
the disposal site in order to maximize opportunities
for bottom stability (see Figure 3-3). Capping has
occurred at this depth at the Portland, ME disposal
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site. Knebel (1993) has estimated that fine sand and
silt at this depth can show frequent motion at least
1.2% of the time with occasional movement another
14% of the tune. He inferred that these movements
are not sufficient to leave a permanent imprint on the
bottom; this is consistent with studies by Rhoads et
al (1978) which showed that only a few millimeters
of mud deposits are moved by episodic strong bot-
tom currents (in Long Island Sound) and massive
erosion does not occur.
Sediment disposal simulations for the Boston
Lightship site conducted with COE's ADDAM's
model (Appendix F) showed that four hours after a
2,000 cy disposal event that water quality criteria for
copper were not exceeded outside the disposal site's
boundary. Since this was true for the summer (strati-
fied) condition, it would be safe to assume it would
hold for winter (unstratified) conditions as well.
Within the site, soluble copper concentrations in the
water column were also estimated to not exceed
water quality criteria. After a four hour period, total
volume of silt within the cloud was estimated to be
equivalent to about 3.3% of the initial disposal
volume. These results indicate that risks to marine
resources would be minimal, since water quality
criteria are met after two hours within the disposal
site.
Biological resources at the site would experience
some impacts as a result of the disposal activity. The
sessile benthic community within the footprint of the
disposal would be temporarily lost; it may take a year
or so for recolonization to occur from surrounding
populations after disposal activities cease. Motile
benthos and finfish feeding in the area would be dis-
placed and may not return to pre-disposal levels until
bottom secondary production is re-established.
Impacts to these populations would be similar to
those at other offshore alternative sites. However,
given that this disposal site is not known to be
biologically unique and recovery is expected within a
reasonable time-frame, long-term adverse impacts are
not anticipated. Consultation with the National
Marine Fisheries Service has been initiated to ensure
threatened or endangered species with this area would
not be adversely affected (see the Biological Assess-
ment, Appendix A). The EPA- (1993) has already
found that activities from this project and MWRA's
ocean outfall should not result in cumulative damag-
ing impacts to these species.
Boston Lightship is an inactive disposal site.
Extensive shipping, fishing, recreational activities, and
scientific investigations take place in Massachusetts
Bay in the vicinity of the site. Barge traffic to the
site would have to be coordinated by the U.S. Coast
Guard, which would involve up to 500 trips for the
parent material (including rock) and 170 barge trips
for the silt, assuming large (4,000 cy) barges are used.
There are no known or anticipated long-term inter-
ferences or damage to these activities from disposal
events at this site. However, Boston Lightship is an
area deemed 'sensitive' by the Board of Underwater
Archeological Resources because of the number of
shipwrecks that have occurred there over time or
because the historic disposal site may contain materi-
al of archaeological interest. Sensitivity of the site
will be confirmed by the staff upon review of the
Board's files. . « •
3.62.2 Massachusetts Bay Disposal Site
The closest U.S. Environmental Protection
Agency (EPA) designated dredged material open
water disposal site is the Massachusetts Bay Disposal
Site (MBDS). It is located approximately 22 nautical
miles east from Boston Harbor in Massachusetts Bay
(Figure 3-3) in 90 meters of water. MBDS has a
circular boundary with a 2 nautical mile diameter.
The general vicinity of MBDS has received
wrecks, dredged material, organic and inorganic
compounds, including low level radioactive waste,
and construction debris since the 1940s. Earlier
disposal was not at a specified point, but sufficiently
far from land to reduce the impacts of disposal.
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Most dredged material was disposed of at sites closer
inshore, especially the Boston Lightship Site (BLS).
Historically, some dredged material considered
'contaminated' or oil laden (without any testing) was
disposed at the offshore area which eventually was
termed the "Foul Area' and now is called the
MBDS. This site has received approximately three
million cubic yards of dredged material between 1975
and 1985 and about another million from 1986 to
1991. The majority of this material came from
Boston Harbor dredging projects. MBDS has also
received dredged material of varying composition
from many harbors.
From past disposal activities at MBDS, 62.1% of
all material was silt and clay (greater than 4 phi) and
37.3% was sand (-1 to 4 phi), the remaining 0.6%
was gravel (less than -1 phi). Much of the material
disposal was a mixture of sandy silt. MBDS has
retained this material because of the stable nature of
this deepwater onshore she. The majority of material
at MBDS has come from Boston Harbor (67%),
•with harbors south of Boston making up 20% of the
material historically disposed at MBDS. The remain-
ing 13% was generated from dredging projects in
harbors north of Boston to Gloucester, Massachu-
setts. Material from the CA/T project is currently
being disposed at MBDS.
The EPA's decision regarding the boundary for the
designation of an ocean dredged material disposal site
in Massachusetts Bay has been issued as a Final
Rulemaking published in the Federal Register. The
revised location of MBDS will overlap the existing
site but be offset slightly to the southwest. The
center of the site is 42°-25.1' north latitude and 70°-
35.0' west longitude. The Final Rulemaking, which
follows the Proposed Rulemaking and is also pub-
lished in the Federal Register, resulted in MBDS
becoming an actual site designation. The final rule
states that disposal and capping of unsuitable materi-
al is prohibited at MBDS until its efficacy can be
effectively demonstrated (40 CFR 228.12 as amend-
ed).
Existing Site Conditions
The physical properties of the substrate near the
disposal point is varying in composition, predomi-
nantly sandy silt, reflecting the various harbor dredg-
ing projects disposed here. The natural bottom
covering the majority of MBDS (i.e., areas of the silt
that have not received dredged material) is a fine
silt/clay substrate (NED unpublished data). The
composition of this natural material indicates the
basin is a depositional area capable of containing the
dredged material; it is this characteristic that could
render it suitable for capping, with the appropriate
capping management plan.
The EPA (1989) evaluated the sediment composi-
tion of the MBDS in their DEIS to evaluate the
continued use of this site. The results of the metals
analysis show that metal concentrations in the
MBDS are either Category I (low) or II (moderate)
(314 CMR 9.00) using the Massachusetts Depart-
ment of Environmental Protection (MADEP) guide-
lines for dredged material. In general, these results
were similar to levels found outside the disposal site
in Massachusetts Bay (EPA 1989). Petroleum
hydrocarbons were detected at a higher level within
the MBDS than outside. However, polyaromatic
hydrocarbons (PAHs), a measure of the aromatic
fraction of petroleum hydrocarbons, was more varied
inside than outside the disposal site. Polychlorinated
biphenyl (PCB) levels in the dredged material were
somewhat higher than ambient levels. PCB levels
detected from dredged material in the vicinity of the
MBDS are comparable to levels identified in other
Massachusetts Bay studies (EPA 1989).
i
The oceanography of MBDS is influenced, hi
part, by the circulation of the Gulf of Maine (SAIC
1993). The Gulf of Maine circulation patterns in the
vicinity of the MBDS are modified to a large extent
by the presence of Stellwagen Bank on the eastern
margin of the Massachusetts Bay. Results of MBDS
oceanographic studies indicate the site to be located
ill
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in a low energy, deep water environment, allowing
containment of dredged material within the site
(DAMOS 1979; Turman 1977; Gilbert 1975; SAIC
1987a, 1993).
The temperature/salinity cycle of Massachusetts
Bay is characterized by seasonal variability, with
maximum temperatures (18° C) typically occurring at
the surface in a stratified water column during August
and September, and minimum temperatures (5°C)
typically occurring in an essentially isothermal water
column in January and February (SAIC 1987a).
Salinity values range from 31-33 ppt in this area.
Recent sampling of the benthos at MBDS (SAIC
1986) determined three (3) distinct community
assemblages responding to the specific and varied
sediment regimes at the site. Coarse sands and gravel
in the northeastern section of MBDS support the
Syllidae polychaete Exogone vemgera profunda (907
individuals/m2); the Paraonidae polychaete Levinse-
nia gracilis (350/m2); and the Spionidae polychaete
Prionospio steenstnpi (3I3/m2).
The western portion of the MBDS has been im-
pacted by the approximately three million cy of
dredged material continuously disposed from the
greater Boston region. This continual disturbance of
the bottom has caused the community of benthic
organisms to be in dynamic equilibrium; the most
adaptable species proliferate. Those species that
reproduce rapidly and have high numbers of offspring
(i.e., larvae) colonize the newly disposed dredged
material and biogenically rework the substrate. This
assemblage was dominated by oligochaetes (6,293
individuals/m2); the Spionidae polychaete Spio
pettibonae (4,607/m2); the Cirratulidae polychaete
Chaetozone selosa (2,160/m2); and the Capitellidae
polychaete Mettomastus ambiseta (1,757/m ). The
undisturbed section of MBDS was dominated by the
Paraonitae polychaete Levinsenia gracz'fo(l,583/m2);
oligochaetes (1,050/m2); and the Capitellidae poly-
chaete Metiomastus ambiseta (693/m ).
Various finfish species have been collected during
sampling cruises (SAIC 1986) within the MBDS. In
the spring of 1985, the spiny dogfish (Squalus acan-
tfuas) was the dominant finfish recovered. Fall 1985
finfish collections were dominated by the witch floun-
der or grey sole (Glyptocephalus cynoglossus) and
the dab or American plaice (Hippoglossoides plaies-
soides).
MBDS is located just outside of the western
boundary of the Stellwagen Bank national marine
sanctuary. Endangered whale species are known to
congregate above the shallow (30 meter) Stellwagen
Bank when foraging for prey (e.g., sand lance Am-
montytes americanus) (U.R.I. 1981). These species
also have been observed within the 2 nautical mile
circular boundary of the MBDS. Endangered species
identified as transients of MBDS include the finback
whale, Balaenoptera physalur, the sei whale, Balaen-
optera borealir, the humpback whale, Megaptera
novaeangliae and possibly the northern right whale,
Eubalaena glacialis (Manomet Bird Observatory,
MBO 1987). The impact of the use of the MBDS
on endangered species is assessed in a Biological
Assessment by the ACOE, NED (Appendix A). Use
of the site to date has not indicated any impacts to
threatened and endangered species. The EPA (EPA
1993) has examined the potential for cumulative
impacts to threatened and endangered species from
the BHNIP and MWRA's ocean outfall and found
that such impacts are considered unlikely to occur.
Other marine mammals, not listed as threatened
or endangered species, may occur in the area of the
MBDS. The larger whales tend to select areas of
rapidly changing bathymetry (MBO 1987). Other
areas where large whales congregate are principally
along the shelf edge of Georges Bank. The greatest
concentrations of dolphins occur from Georges Bank
south to the mid-Atlantic regions, principally from
mid-shelf seaward to the shelf edge, independent of
season (MBO 1987).
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The harbor seal Phoca vltulina is the most abun-
dant pinniped species in the eastern United States
(Manomet Bird Observatory 1987). They prefer
sheltered and undisturbed rocky ledge haulout sites of
coastal bays and estuaries from Maine south to
Plymouth, Massachusetts. They are now only
seasonal residents in southern New England south of
Maine. The only active breeding population of the
gray seal Hallchoerus gryjnis in the eastern United
States is located southwest of Nantucket Island, away
from the proposed disposal sites.
Proposed Site Conditions/Impacts
MBDS has received approximately 300,000 cy of
dredge material annually; this material has been of
variable quality. As EPA (1993) has pointed out,
further deposition of clean parent material from the
Project would not cause any adverse effects to the
current sediment regimes, but in fact could result in
a 'cleaner* sediment environment. Only clean
materials can be disposed of at MBDS at this time,
unless capping can be proven to effectively isolate
unacceptable silt material at this depth. The parent
material was tested and found suitable under Section
103 of the Marine Research, Protection and
Sanctuaries Act for unconfined open water disposal.
A turbidity plume will be created by the disposal
of the dredged material. During descent, some of the"
fine-grained sediment separates from the plume and
remains in suspension. The amount of material that
is dispersed in the disposal plume is dependent upon
the physical characteristics of the sediment, the
volume of material disposed, and method of disposal,
and typically ranges from 3 to 5% (WES 1986).
Results from COE's ADDAMS model, which is used
to asses water quality exceedences at the perimeter of
a dump site, indicated that the BHNIP should not
cause water quality problems at MBDS (EPA 1993);
this was based on disposal of even the most contami-
nated sediments from this project.
Dredged material which settles on the bottom at
MBDS can be expected to remain in place. Near
bottom currents are low, averaging less than 7 cm/s;
the site is considered a depositional area. Resuspen-
sion from storm events is rare, typically resulting in
resuspension of only 4% of the surficial material.
This area has contained dredged material on site and
does not disperse sediment or chemicals to affect
ambient environments. In general, the proposed
disposal of an estimated 2.0 million cubic yards of
parent and rock material dredged from the project
area will not cause long term adverse impacts to the
disposal site given its physical, chemical and biologi-
cal characteristics and general history of use; in fact,
improvement to the sediment environment could
occur.
Disposal of dredged (parent) material will have a
temporary displacement impact on finfish at the site.
f. ! These impacts are not expected to be substantial
considering the mobile nature of fish. Temporary
impacts are expected to come from the temporary
loss of benthic species for foraging. Due to the
already disturbed nature of the site and the quick
recolonizing ability of benthic organisms, impacts
should not be substantial. Any changes to the
benthic community structure should be localized and
not reflected on fisheries resources on a baywide
basis.
No substantial impacts are anticipated to wildlife
or threatened or endangered species (EPA 1993);
these resources are transient under normal conditions.
No impacts are expected to site usage or commerce.
Also, since there are no regulated wetland resources
or historical and archeological resources at MBDS,
there will be no impacts relative to these issues.
Historically, disposal of sediments at the site has
buried organisms inhabiting the impact area. The
frequency of disposal events has maintained a con-
stant state of disturbance that provides suitable
habitat primarily for pioneer, opportunistic species.
These species tend to occupy and rework the surficial
3-32
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sediments. Disposal of additional sediments in the
same location would keep the benthic community in
a pioneering species stage, as long as it continues
with some frequency.
3.6.2.3 Meisbureer 2
Meisburger 2 is one of several potential sand and
gravel offshore borrow pit areas that, along with
Meisburger 7, has been identified by the EPA as a \
potential site for the disposal of contaminated
materials for the Metro-Boston area (Metcalf and
Eddy 1992). The largest part of the sand and gravel
represents approximately 140± acres of subtidal area
and could possibly contain all 1. 3 million cy of
expanded silt material, plus a 3-foot cap. The total
volume of sand estimated to be available from this
site ranges from 780,000 cy to 4.7 million cy,
providing an estimate of the disposal (including cap)
capacity. Further surveys may be necessary to locate
the specific borrow pit disposal area, as the sand
deposits are indicated as ranging from 5 to 30 feet
thick. An 86-acre, 13-foot deep disposal site was
assumed, providing capacity for silt material and cap.
Final design would depend on more detailed site
survey data.
This site, centered at 42° 24.7'N and 70° 50.2'W,
is located offshore of the proposed dredging sites, and
approximately 7.2± miles east of Deer Island (Figure
3-4). Both Meisburger sites are in the general
proximity of MWRA's proposed offshore ocean
outfall and arc within the nearfield monitoring zone
for that project. The existing sediment (sand and
gravel) would be removed to create a hole in which
the silt material from the Inner Harbor would be
disposed and capped with parent material. It is /
anticipated that the sediment removed could be used ;
beneficially for beach nourishment or construction. \
The sites would be restored to their original bathy-
metry and physical substrate conditions with native
materials from the site.
Existing Site Conditions
Based on the (Metcalf & Eddy 1992) report, Meis-
burger 2 lies in 98 feet of water and is about 4,100
feet long. Sand and gravel deposits at this site have
estimated depths of about 5.0± feet, possibly extend-
ing to 30± feet deep; a 1-foot silt layer covers the
coarse sand and gravel. A minimum of 780,000 cy of
deposits and possibly as much as 4.7 million cy were
estimated to be at this site, yielding at least the
needed capacity for all the silty dredged material if
this site is excavated; although there are a few peaks
at the edges of the site which rise to 70 feet below
MLW, the majority of the depths range from 80 Jo
105 feet.
The overlying waters at the site are classified as
SA by MADEP. These waters have an absence of
any well-defined mean current direction other than
from storm events. Any discernible currents are tidal.
The dominant and representative benthic species
for this site were typically an amphipod/polychaete
combination (i.e., Corophiwn crassicorne/Exogene
hebes) or a polychaete assemblage dominated by
Spio llmicola, Polydora socialis, and Mediomastius
californiensis. The former species group was charac-
teristic of the transition area between the soft bottom
area and the hard substrate of the Meisburger sites.
Target fish species in the offshore coastal waters
and Boston Harbor areas include forage species such
as Atlantic menhaden, Atlantic herring and rainbow
smelt, and predator species such as yellowtail floun-
der, winter flounder, striped bass, bluefish, pollock,
Atlantic cod, tautog and cunner. The site is used for
recreational boat and for commercial fishing. The
site is under federal jurisdiction through Section 404
of the Clean Water Act.
Waterfowl, including great cormorant (Phalacro-
corax carbo), herring gull (Larus argentatia), white
winged scoter (Melanitla deglandi), common golden-
eye (Ducephala clanguld), bufflehead (Bucephala
3-33
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albeola), mallard (Anas platyrhynchos), black duck
(Anas rubripes), merganser (Mergus spp.) and scaup
(Aythya spp.) are likely to intermittently utilize the
area for feeding and resting. Each of these species
feed on fish and invertebrates (Martin et al. 1951;
Whitlatch 1982; and DeGraff and Rudis 1986) that
occur in the area.
There are several threatened and endangered
species which are documented to occur in the western
North Atlantic and portions of Massachusetts Bay.
These are presented in Attachment 1, Volume 1 of
this EIR/S. There is nothing unique about the
Meisburger 2 site that should attract these species
beyond an occasional transient passage. There is no
evidence indicating any substantial sightings of these
species in this area. The ACOE, NED has addressed
potential impacts to these species in the Biological
Assessment (see Appendix A).
There are no listed historical or archeological
resources at Meisburger 2.
Proposed Site Conditions/Impacts
The area proposed for disposal is 155± acres. The
dredged sediments placed at the disposal site would
be stabilized by a 3-foot cap of clean 'parent' sedi-
ments. The borrow pit at Meisburger 2 could be
filled to pre-existing contour with 490,000 to
6,196,000 cy of dredged material and thus could
handle all 1.3 million cy of silt material from the
present project. The dredged material will be stabi-
lized by a 3-foot cap of clean sediment.
The cap and the dredged sediments would be
confined within the walls of the borrow pit below the
level of the sea floor. Therefore, a deposit in a
borrow pit would present a low probability for the
release of contaminants because it is not in direct
contact with the water column or storm energy. To
address concerns about the stability and/or grain size
of the cap in this area, some of the mined sand and
gravel could be saved and deposited as the final cap
layer.
There is no well-defined steady current direction
at Meisburger 2. Water and particle movements are
generated by a variety of actions, including tides,
winds, and river flow. During the construction of the
pit, it is anticipated that turbidity levels in the imme-
diate construction area will be increased by dredging
and materials disposal activities. Use of a mechanical
dredge would greatly reduce potential water, quality
impacts from this operation. The turbidity plume
generated would be restricted to a very limited 'area in
the vicinity of the dredge, with 95-99% of the sus-
pension material settling within a few yards (Schubel
et al. 1978). Because of the coarseness of the sand
removed, resuspension would be minimal.
During the open water disposal operation, sus-
pended solids would be released into the water
column. As a result, there would be localized and
temporary increases in suspended solids concentra-
tions (and turbidity) in the water column. During
this descent anywhere from 3% to 5% of the dredged
material may be lost to the water column (WES
1986).
Representative sediment disposal simulations for
the Meisburger 2 site, using the ADDAM's Model
(Appendix F), indicated only temporary water quality
impacts (i.e., below water quality criteria within 4
hours) on disposal activities; less than 5% of en-
closed material would remain suspended and be
transported outside of the site. Results indicate that
risks to marine organisms outside the disposal site
should be minimal; this is consistent with EPA's
(1993) finding at MBDS, although that site is about
twice as deep as the Meisburger site.
During construction and capping, the existing
benthic community (amphipod/polychaete combina-
tion) will be lost. Upon completion of site activities,
a recolonization to the previous benthic community
will occur. The nature of the community will depend
3-34
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on the final cap make-up and organism response to
the substrate.
Disposal operations would have only minor, short-
term effects on fish in the vicinity of the borrow
pit/disposal site (winter flounder, Atlantic cod and
yellowtail flounder). Some mortality of adult fish
may occur during construction of the pit and disposal
events due to burial or exposure to high suspended
sediment levels because they may be attracted to
food items suspended during this activity. There will
also be displacement of these species from the site
construction activities. Impacts would be limited to
the immediate vicinity of the site. Pit construction
and disposal of dredged material would also tempo-
rary reduce prey available to species that feed primar-
ily on benthic invertebrates.
Temporary displacement of Tidal Water resources
are expected. Natural recolonization of this resource
is expected. Construction of the borrow pit and
disposal of dredged material in the borrow pit should
have no significant impact on wildlife populations
(e.g., birds) occurring at or near the disposal site.
The proposed project should have no significant
impact on any species considered threatened or
endangered by the USFWS, NMFS or the Massa-
chusetts Natural Heritage and Endangered Species
Program (MANIIESP), nor on any historical or
archeological resources, since none have been record-
ed at Meisburger 2.
Assuming all of the silt material was disposed of at
Meisburger 2, the disposal operations could involve
660 barge trips to remove existing sediments, and 660
trips to transport Harbor sediments to the site. This
would result in some delays to commercial and recre-
ational boat traffic using the harbor. This activity
would be regulated by the U.S. Coast Guard. Con-
struction activities would have a minor adverse
aesthetic impact.
The filling operation at this location will have
some effect on fishing and recreational boating
interests for the duration of the filling activity. The
proximity of the sites to the MWRA's ocean outfall
ensures monitoring data available before, during and
after placement of material to evaluate any impacts
from the filling operation; no permanent impacts are
expected.
Use of this location will entail dredging of existing
sand and gravel which may be suitable for beach
nourishment projects provided it meets grain size,
availability and suitability criteria for the specific
beach nourishment project. In the alternative fhe
material may be used for other construction purpos-
es.
3.6.2.4 Meisburger 7
Meisburgcr 7 (Figure 3-5) is another of several
sand and gravel borrow pit areas that could be
developed for dredge material disposal. This site, as
well as Meisburger 2, has been identified by the EPA
as a potential site for the disposal of contaminated
materials for the Metro-Boston area (Metcalf and
Eddy 1992). This site, centered at 42° 20.7'N and
70°47.7'W, is located offshore of the proposed
dredging sites in approximately 80 to 100 feet of
water. It is approximately 8.2± miles east of Deer
Island and in the proximity of MWRA's proposed
offshore ocean outfall (Figure 3-5). The existing
sediment (sand and gravel) would be removed to
create a hole (up to 10 feet deep) in which the silt
material from the Inner Harbor would be disposed
and capped. The sediment removed would be used
beneficially for beach nourishment or construction.
The sites would be restored to their original
bathymetry and physical substrate conditions. The
sand and gravel borrow pit at Meisburger 7 could
range up to 403 acres and could yield the needed
capacity for all the silty material from this project.
The Metcalf and Eddy (1992) report indicates that up
to 19.5 million cy of sand and gravel may exist at this
3-35
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site, yielding capacity for future maintenance material
as well. The final design of the site would depend on
results of site-specific surveys to determine sand
depths and preferred locations. The dredged material
will be stabilized by a 3-foot cap of clean sediment
and a sand layer could be added to that to further
stabilize the cover and restore sediment characteristics
to existing conditions.
Existing Site Conditions
The overlying waters at the site are classified as SA
by the Massachusetts Department of Environmental
Protection (MADEP). These waters have an absence
of any well-defined mean current direction; other
than storm influence, most discernable currents arc
tidal.
The dominant and representative benthic species
for this site were typically an amphipod/polychaete
combination (i.e., C. crassicorne/E. hebes) or a
polychaete assemblage dominated by 5. limicola, P.
socialis, and M. californlensis. The former species
group was characteristic of the transition area be-
tween the soft bottom area and the hard substrate of
the Meisburger sites.
Target fish species in the offshore coastal waters
and Boston Harbor areas include forage species such
as Atlantic menhaden, Atlantic herring and rainbow
smelt, and predator species such as yellowtail floun-
der, winter flounder, striped bass, bluefish, pollock,
Atlantic cod, lautog and cunner. The site is used for
recreational boat and for commercial fishing.
Waterfowl, including great cormorant (P. carbo),
herring gull (L. argenlalits), white winged scoter (M.
deglandi), common goldeneye (B. clangula), buffle-
hcad (B. albeola), mallard (A. plalyrhynchos), black
duck (A. rubripes), merganser (Mergtts spp.) and
scaup (Aythya spp.) are likely to intermittently utilize
the area for feeding and resting. This site is under
federal jurisdiction through Section 404 of the Clean
Water Act.
There arc several threatened and endangered
species which arc documented to occur in the western
North Atlantic and portions of Massachusetts Bay;
these are discussed in Attachment 1. There is noth-
ing unique about the Meisburger 7 site that should
attract these species beyond an occasional transient
passage. There is no evidence indicating major use of
this area by these species. A Biological Assessment
by ACOE, NED in Appendix A addresses these
issues further.
V '
There are no listed historical or archeologjcal
resources at Meisburger 7.
Proposed Site Conditions/Impacts
The cap and the dredged sediments would be
confined within the walls of the borrow pit at or
below the existing contour level of the sea floor.
Therefore, a deposit in a borrow pit would be pro-
tected from releasing contaminants. To address
concerns about the stability and/or grain size of the
cap in this area, some of the mined sand and gravel
would be saved and deposited as the final cap layer.
There is no well-defined mean current direction at
Meisburger 7. Water and particle movement are
generated by a variety of actions, including tides,
winds, and river flow. During the construction of the
pit, it is anticipated that turbidity levels in the imme-
diate construction area will be increased by dredging
and materials disposal activities. Use of a mechanical
dredge would greatly reduce potential water quality
impacts from this operation. The turbidity plume
generated would be restricted to a very limited area in
the vicinity of the dredge, with 95-99% of the sus-
pension material settling within a few yards (Schubel
ct al. 1978). Because of the coarseness of the sand
removed, resuspension would be minimal.
3-36
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During the disposal operation in open water,
suspended solids would be released into the water
column. As a result, there would be localized and
temporary increases in suspended solids concentra-
tions (and turbidity) in the water column. During
this descent any where from 3 to 5% of the dredged
material may be lost to the water column (WES
1986). Sediment disposal simulations for the Meis-
burger 7 site using the ADDAM's Model (Appendix
F) indicated only temporary water quality impacts
( < 4 hours) during construction and disposal activi-
ties; only 5% of disposal material would remain
suspended and be transported outside of the site.
During construction and capping, the existing
benthic community (amphipod/polychaete combina-
tion) will be completely lost. Upon completion of
site activities, it is reasonable to assume that a
recolonization to the previous benthic community
will occur. The nature of the community will depend
on the final cap make-up and organism response to
the substrate.
Disposal operations would have only minor, short-
term effects on fish (winter flounder, Atlantic cod and
yellowtail flounder) in the vicinity of the borrow
pit/disposal site. Some mortality of adult fish may
occur during construction of the pit and disposal
events due to burial or exposure to high suspended
sediment levels. Therefore, there may be some dis-
placement of these species from construction activi-
ties. Impacts would be limited to the immediate
vicinity of the site. Pit construction and disposal of
dredged material would also temporary reduce prey
available to species that feed primarily on benthic
invertebrates.
Temporary displacement of Tidal Water resources
are expected. Natural recolonization of this resource
is expected. Construction of the borrow pit and
disposal of dredged material in the borrow pit should
have no significant impact on wildlife populations
(e.g., birds) occurring near the disposal site.
Water quality disturbances from the proposed
project should have no significant impact on any
species considered threatened or endangered by the
USFWS, NMFS and MANHESP (EPA 1993); the
Biological Assessment prepared by ACOE, NED
(Appendix A) addresses this further. Significant
historical or archeological resources were not identi-
fied at the Meisburger 7 site, so no impacts of this
nature are expected.
The disposal operations could involve approxi-
mately 660 barge trips to remove existing sediment
and 660 barge trips to transport Harbor sediments:
This would result in some delays to commercial and
recreational boat traffic using the harbor. Again, this
would be coordinated by the Coast Guard.
The filling operation at these locations will have
a minor effect on fishing and recreational boating
interests for the duration of the filling activity.
Rigorous turbidity controls will minimize these
impacts. The proximity of the sites to the MWRA's
ocean outfalls should address the question of moni-
toring before and during placement of material to
evaluate any impacts from the filling operation, since
the outfall's monitoring program is well in place.
After completion of the filling, there will be no
permanent impact.
Use of these locations will entail dredging of
existing sand and gravel which maybe suitable for
beach nourishment projects provided it meets grain
size, availability and suitability criteria for the specific
beach nourishment project. In the alternative, the
material may be used for other construction purpos-
es.'
3.6.2.5 Spectacle Island (CAD)
Spectacle Island is located on the western edge of
the Outer Boston Harbor (Figure 3-6). The nearest
neighboring islands are Thompson Island, located
3,000± feet to the west; Long Island, 5,000± feet to
3-37
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the cast; Moon Head, 8,000± feet to the south, and
Castle Island, 6,000± feet to the northwest. Approxi-
mately 700 feet north of the northern end of Specta-
cle Island is President Roads, the 45-foot-deep main
shipping channel that connects Boston to the open
ocean. The island is bounded by a 15-foot-deep
channel to the west called Western Way and by
Sculpin Ledge Channel (15 to 22 feet deep) to the
east and southeast.
An area of between 22 and 50 acres (most likely
about 45 acres) being considered for disposal of the
contaminated sediments from the Project is located
off the east side of the island in the nearshore sub-
tidal region (Figure 3-6). This area is east of that
previously affected by the historic landfill on Specta-
cle Island (CDM 1990). Water depths in this loca-
tion vary from 4 feet to 15 feet below mean low
water (MLW) with an average depth of about 9 feet.
The proposed site is located in an area defined by
earlier studies (Cortell 1990b) as having cleaner
sediments.
Existing Site Conditions
Bulk sediment analyses of sediment borings con-
ducted for CA/T indicate the sediments are made up
of fine sands, silts and some clays (Cortell 1990b).
Surface and near surface sediments were generally free
of contaminants (Category I) under MADEP criteria
for the classification of dredge and fill materials (314
CMR 9.00). However, arsenic levels in surficial and
deeper sediments were elevated to both Categories II
and III levels, respectively.
The waters in the vicinity of Spectacle Island have
been classified as Class SB waters. This classification
protects saline waters for the propagation of marine
life, primary and secondary contact recreation and
shellfish harvesting with depuration. Water quality in
the outer harbor area has historically been influenced
by raw sewage discharges, CSOs, various industrial
discharges, urban runoff and the pollutants flowing
from the inner harbor system. However, as upgrades
to treatment processes are completed, water quality
in the harbor should improve.
Circulation is dominated by tidal currents. Waves
in the vicinity of the site are primarily storm driven,
with breaker heights ranging from 0.09 to 2.6 feet
with wave powers of 0.1 to 412.9 ft.-lb/sec.
Benthic resources east of Spectacle Island were
dominated by the amphipod Ampelisia abdita, and
the gastropod Nassarhts trivittatus. In addition,
offshore areas support nereid worms, Pagarus sp.
(hermit crabs), Panopeus sp. (mud crabs) and Cancer
irroratits (rock crabs). Free-living and early benthic
phase lobsters and mussel beds were also very preva-
lent (Cortell 1990b).
Based on the on-going development of the artifi-
cial reef design, as required by the Individual Per-
mit—Landfill Closure and Maintenance at Spectacle
Island for CA/T (ACOE no. 199202207; 2/16/93),
target fish species in the Spectacle Island area include
forage species such as Atlantic menhaden, Atlantic
herring and rainbow smelt, and predator species such
as winter flounder, striped bass, bluefish, pollack,
Atlantic cod, tautog and cunner. The location is
currently used by fishermen and recreational boaters.
The Spectacle Island CAD location is considered
Land Under the Ocean under the Massachusetts
Wetlands Protection Act and Regulations (MGL
c.131, s.40, and 310 CMR 10.00) and Tidal Waters
under Section 404 of the Federal Clean Water Act.
Several species of waterfowl have been observed
feeding on fish and invertebrates in the vicinity of
Spectacle Island. No federally or state-listed threat-
ened or endangered species occur or are expected in
the vicinity of the site. This site does not contain
any listed historical or archeological resources.
Proposed Site Conditions/Impacts
3-38
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Construction of the Spectacle Island CAD would
require dredging a disposal pit in the shallow subtidal
flat east of the island (Figure 3-6). Silt material from
the Inner Harbor would be deposited in the pit and
capped with parent material. Sediments of suitable
quality dredged from the CAD area could be retained
for final capping. The rest of the material 'bor-
rowed* would be evaluated for beneficial uses or
disposal at MBDS. The site would be restored to its
original bathymetry and physical substrate condition.
All activities would be beyond the dike being con-
structed along Spectacle Island and removed enough
so as to not affect the integrity of this structure.
The placement and capping of the dredged sedi-
ments in the proposed pit will isolate these materials
from existing substrates. Construction of the pit, and
deposition of the dredged sediments should cause
only temporary impacts during the activity. Disposal
silt plume modeling (ADDAM's Model) indicates
that suspended solids concentrations should be low
(< 30 mg/1) and should quickly decline. The model
also predicts about 5% of the suspended material
may remain suspended and transported from the site
(Attachment 1). The model shows that copper
concentrations (the most conservative parameter) in
the dredged material should be below the water
quality criteria within about 3.8 hours from the time
of disposal; at the rate of water movement in Sculpin
ledge Channel (approximately 0.6 kn) this should be
reached within about 9,000-13,000 feet of the disposal
point on flood and ebb tides, respectively (see At-
tachment 1). The slower currents within the CAD
area as well as the structure of the pit itself should
help greatly reduce this distance. It is expected that
silt curtains, if properly designed, could be employed
to help control suspended solids and silt plumes in
current areas less than approximately 0.5 knots; such
designs might include more rigid controls of the
curtains and their extension to or near-bottom. This
mitigation approach should help reduce the size and
area of influence of the silt plume.
The project activity would cause a direct short-
term impact to 20-50± acres classified by the state as
Land Under the Ocean and Tidal Waters. Tempo-
rary impacts and displacement of the benthic com-
munity and area fishing resources would occur. After
completion of the disposal and capping, it is reason-
able to expect that recolonization and re-population
of the benthic and finfish resources should occur.
Construction of the borrow pit and disposal of
dredged material in the borrow pit would have no
significant impact on wildlife populations, or any
species considered threatened or endangered by the.
U.S. Fish and Wildlife Service (USFWS), National
Marine Fisheries Service (NMFS) or the Massachu-
setts Natural Heritage and Endangered Species Pro-
gram (MANHESP), occurring near the disposal site.
There are no listed historical or archeological sites at
or near the Spectacle Island CAD site.
The disposal operations would involve approxi-
mately 660 barge trips while the same number would
be required to remove the existing CAD site material
to MBDS. This could result in some delays to com-
mercial and recreational boat traffic using the harbor;
this traffic would be coordinated by the U.S. Coast
Guard. Close coordination with the Lobsterman's
Association would be necessary to help minimize
barge traffic conflicts with lobster gear in the adjacent
channel area. MWRA's Deer Island Project involves
the transport of four barges per day in the Harbor,
about the same rate expected from the dredging
project, and has not experienced problems with this
level (Steve Corbett, MWRA, 1993, pers. comm.).
Construction activities would have a minor adverse
aesthetic impact, and result in slightly elevated noise
levels.
Part of the Spectacle Island Landfill Closure Plan
for CA/T includes the installation of an artificial fish
reef. Due to plans to locate this structure (about one
acre footprint) in Sculpin Ledge Channel, special
mitigation plans may be necessary during disposal
site construction and use to protect this resource, as
3-39
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well as shellfish (lobster) resources to the north of the
Island.
3.6.2.6 In-Channel Sites
These sites include the Chelsea Creek, Inner
Confluence and Mystic River In-Channel disposal
scenarios. The In-Channel disposal scenario assumes
that the silt material will be dredged from each
channel and placed on a barge, while a deeper trench
will then be dug in the channel (parent material); the
silt would then be placed within the trench and
capped with some parent material. Excess parent
material removed from the trench would be disposed
at MBDS. Each channel/tributary would then
contain its own capped silt material. The environ-
mental resources impacted for this disposal alterna-
tive are the same as for the dredging site.
Benefits from this alternative include keeping the
silt material within the channel of origin, thus reduc-
ing the amount of silt exposed to biological resources
elsewhere and keeping transportation costs, vessel
traffic disturbances and socio-economic impact to a
minimum.
Proposed Conditions/Impacts
General site conditions would be the same as
described for each channel/tributary. Essentially,
once dredging is complete, the site will be left at the
proposed project depth.
The proposed disposal sites occur in tributaries
currently used by ship traffic. The U.S. Coast Guard
would need to coordinate between ships needing to
use the tributary and disposal activities. However,
since material would essentially be disposed in the
same place it is dredged, only barges for temporary
storage and those required to dispose of excess parent
material would have to be dealt with; major barge
movement within the harbor should not be neces-
sary.
The characteristics of the underlying sediments in
the channels have been described in Section 2.2 of
the DEIR/S as clean parent material. Bulk sediment
analysis indicated that no parameter exceeded Cate-
gory I limits. The channel would be filled with silt
and capped with parent material. The remaining
parent material would be disposed at the MBDS or
other suitable site. Since the channels are currently
covered with silt material, returning the silt to its
place of origin and capping it with parent material
would provide an environmental benefit.
The disposal site would end up, as proposed, 3.0
to 5.0 feet deeper than the channel's current autho-
rized depth. The area would of course remain
subtidal; the substrate would change from a silt
material to a clay or gravel material. The benthic
. community may change as a result of this sediment
change but should be *healthier" because the avail-
ability of contaminants for bioaccumulation will be
reduced, at least until future siltation occurs. No
federally or state-listed threatened or endangered
species are expected to be at risk from this activity in
the channel and tributaries.
Each of the channels falls within the Designated
Port Areas of Boston Harbor (e.g., Mystic River,
Chelsea Creek, East Boston and South Boston desig-
nations) under State jurisdiction (310 CMR 10.00)
and within Tidal Water jurisdiction under Section
404 of the Federal Clean Water Act. Since these
proposed disposal sites are part of the overall mainte-
nance dredging operation, their construction will not
impact these regulated resources beyond the impacts
of the dredging itself, other than from increased silt
plumes during disposal. ADDAM's model results
indicate that these plumes should not directly impact
economically important fish and shellfish resources.
Any impacts would be temporary and, upon capping
and project completion, the resources should restore
themselves to natural conditions. Newly-exposed
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substrate and clean capping materials will provide
better substrate conditions for benthic community
development in the near-term.
This disposal alternative should have no effect
upon any structure of historic or archeological
significance as defined by the Massachusetts Histori-
cal Commission (MHC) or the National Historic
Preservation Act of 1966, as amended.
3.6.2.7 Little Mvstic Channel
The Little Mystic Channel, which is a small inlet
off the Main Ship Channel in Charlestown (Figure
3-7), is proposed as a disposal site for silt materials.
The Little Mystic Channel could be filled to 3 to 6
feet below MLW with 233,000 to 303,000 cy of
dredged material. The dredged material would then
be stabilized by a 3Tfoot cap of clean sediment. The
site would be maintained as a shallow subtidal area,
providing suitable habitat for marine benthic organ-
isms and other biological resources that utilize this
habitat in Boston Harbor.
The Little Mystic Channel is 150 feet wide and
extends from the Main Ship Channel. This minor
tributary channel was originally a tidal channel
draining the Mystic flats at the mouth of the Mystic
River in Charlestown. The filling of the Mystic flats
by the Commonwealth in the 1860's closed off the
upper end of the Channel. The Mystic-Tobin Bridge
crosses the Little Mystic Channel. A number of
land-based terminals (overland shipping) and a
condominium complex were constructed on the filled
tidelands. Only the northern banks of the Little
Mystic Channel lie in the Mystic River Designated
Port Area (DPA). This site is approximately 15.0
acres. The water depth in the Mystic Channel ranges
from approximately 3 to 31 feet below lower MLW.
Existing Site Conditions
A vertical granite wall surrounds the north and
south side of the site. On the west side there is a
sloping rip-rap embankment for approximately 100
feet. A metal bulkhead approximately 50 feet in
length is located about 50 feet from the Mystic-Tobin
Bridge. Close to this is a pile of debris (bricks and
scrap metal). On the north side of the site, five
storm drainage pipes (possibly inactive) and one
active drainage pipe were observed. There is one
CSO, the Chelsea Street Extension outfall, which
discharges directly to the Little Mystic Channel along
the south shore. At the eastern end, the mouth of
the site is restricted by concrete bridge pilings. The
distance between the bridge and the water at high
tide, is small based upon the water mark on the
bridge piling. There are some submerged logs and a
submerged boat in the middle of the channel. There
is a sandy/gravel beach on the south side, and the
rock ledge beach on the north side of the site.
Observed representative sediment textures were
predominantly fine-grained silt-clay. Bulk sediment
analyses showed arsenic, cadmium, chromium,
copper, lead, mercury, and zinc at Category II and
III levels (314 CMR 9.00). Total PAHs, TPHs and
PCBs were present at elevated concentrations.
The water quality of the Little Mystic Channel is
influenced by tidal exchange and the six discharge
pipes that were observed on the north side of the site
and a CSO. These storm drainage pipes add an
unknown level of pollutants, along with their runoff
water, into the Channel. The Little Mystic Channel
is classified as SC water by the MADEP. The
currents in Little Mystic Channel are primarily tidally
driven.
Available dissolved oxygen levels diminish within
Boston Harbor and cause a corresponding depression
in biological activity at the sediment-water interface.
This is commonly referred to as the "August Effect"
and hereafter will be cited as such. Salinity data
3-41
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collected in April 1993 ranged from 16.8 to 28.9% at
low tide, indicating the influence of freshwater inputs.
Little Mystic Channel flows directly into the Main
Ship Channel, but the Mystic-Tobin Bridge pilings
slow and deflect currents and contribute to sedimen-
tation in the vicinity of the pilings.
The intertidal habitats within the Mystic Channel
vary and include: vertical granite walls on the north
and south sides, sloping rip-rap embankment on the
•west side, wooden bridge pilings on the east side,
submerged logs and boat on the north side, a metal
bulkhead approximately 50 feet from the bridge, a
sandy/gravel beach on the south side, and a rock
ledge beach on the north side. Fucus sp., green
algae, and some mussels are the dominant fouling
biota.
Composition of the benthic infauna (see Attach-
ment 1) generally includes oligochaetes as the domi-
nant taxa supported by Caidlereitta sp., Strebolospio
bcnedicti, and nematoda. Although there were no
data from this site, the dominant finfish species
recorded in the Main Ship Channel include flounder
(Pleuronectes americamts), rainbow smelt (Osmerus
mordax), and alewife (Alosa pseudoharengus)
(ACOE, NED 1988). There probably is movement
of at least some of these species in and out of the
Little Mystic Channel.
Little Mystic Channel is located within the Mystic
River DPA (310 CMR 10.00). The site is primarily
Land Under the Ocean, under Massachusetts Wet-
lands Protection regulations, and is considered to be
significant to marine fisheries, storm damage preven-
tion and flood control. The vertical granite wall on
the north and south side, together with the sloping
rip-rap embayment on the west of the site, were all
structures designed for storm damage prevention and
flood control. Anadromous fish are known to
traverse the Main Ship Channel; there may be some
movement into the Little Mystic Channel but it is
not a destination. The entire she is classified as Tidal
Waters under federal Section 404 regulations.
Little Mystic Channel may provide feeding habitat
for several waterfowl and diving feeders (e.g., mal-
lards, cormorants and tems). Abandoned piers also
provide roosting sites for gulls and terns. No federal-
ly or state-listed threatened or endangered species are
identified or expected to occur within the vicinity,
and there are no listed historical or archeological
resources at the Little Mystic Channel site.
This little-used channel in Charlestown is sur-
rounded by a mixture of land uses including residen-
tial, recreational and maritime-industrial. The
channel provides a visual buffer between the residenc-
es to the south and the marine terminal to the north.
A public boat ramp is located on the north side of
the channel. However, this ramp has not received
the use anticipated when it was installed in the early
1970s. Marine access to this site is constrained by
the 12 foot vertical clearance under the Little Mystic
Channel Crossing at the mouth of the channel.
Proposed Site Conditions/Impacts
Sediments in the Little Mystic Channel contain
moderate to high levels of certain chemicals. PCBs,
arsenic,lead and zinc were found at Category III
levels. The dredged sediments proposed for place-
ment at this disposal site would be stabilized by a 3
foot cap of clean sediment. Therefore, although this
alternative would decrease the water depth (and
volume) in the channel, it would have the beneficial
affect of providing 15 acres of new, clean sediment
habitat.
The Little Mystic Channel can be characterized as
a low energy environment suitable for dredged
material disposal and containment. The average
current velocity at this site is approximately 0.5
knots. During disposal operations, suspended solids
would be released into the Little Mystic Channel
waters. Because of these potential impacts, use of a
silt curtain at this site to trap most of the suspended
sediment would likely be necessary to maintain water
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quality standards during construction. Localized and
temporary impacts are anticipated from the suspend-
ed solids and chemical concentrations on the water
quality within the site. Most of the chemical constit-
uents are tied up with the sediment.
In the intertidal zone, there would be temporary
reduction in Fucus sp., green algae, and barnacle
production on the hard substrate and on the small
gravel/sandy beach present at the site. Benthic
invertebrates in the Little Mystic Channel would be
buried during disposal operations. There would be
a temporary loss of 15.0± acres of soft substrate.
Dredged material placed at the site would quickly be
re-colonized with resident taxa (i.e., likely to be 5.
benedicti, oligochaetes, and other common species)
occurring in the harbor sediments. The resulting
community is expected to be similar to that presently
existing in the Little Mystic Channel subtidal areas.
However, since the cap material would be clean, a
more diverse population should occur.
Siltation caused by disposal operations would
probably have some short-term adverse impacts on
invertebrates occurring in the immediate adjacent
areas. However long-term impact on invertebrate
communities in the shallow subtidal area of the Little
Mystic Channel are not expected to be measurable.
Disposal operations would have some impact on
fish utilizing the disposal site. Some mortality of fish
eggs, larvae, and adult fish would occur during
disposal events due to burial or exposure to high
suspended sediment levels. Impacts will be limited to
the immediate vicinity of the disposal site. Disposal
of dredged material would temporarily reduce prey
available to species that feed primarily on benthic
invertebrates, such as winter flounder.
There would be a short-term impact on 15.0±
acres classified as Tidal Waters and Land Under the
Ocean in a DPA at this site. The site would be
restored after construction and maintained as a
shallow subtidal area. Flowever, disposal of dredged
material in Little Mystic Channel should not adverse-
ly impact wildlife populations occurring near the
disposal site. No federally or state-listed threatened
or endangered species are identified or expected to
occur within the vicinity of Little Mystic Channel.
The proposed project would have no effect upon
any structure or site of historical, architectural or
archeological significance as defined by MHC the
National Historic Preservation Act of 1966, as
amended.
The disposal operations would involve approxi-
mately 170-220 barge trips to the Mystic Pier. This
would result in some minor delays to commercial and
recreational boat traffic using the harbor which would
be controlled by the U.S.C.G. Alternatively, approx-
imately 11,700-15,200 truck trips would be involved
in transporting the dredged material. There would be
some impact of noise and traffic from truck trips
between the Mystic Pier and Little Mystic Channel.
Construction activities would have some aesthetic
impact, and result in slightly elevated noise levels.
While the most direct effect of partial filling of the
channel would seem to be compromising the boat
dock facility, this dock has not been used for its
intended purpose so this is viewed as a minor impact.
3.6.2.8 Reserved Channel
Both project areas are depicted oh Figure 3-8, and
can be characterized as follows:
Area A—This area is located at the mouth of the
inlet on the inner side of the bridge (away from
open water). A floating dock and the yacht club
are located in this portion of the site. The pas-
sage under the Summer Street Bridge is 40 feet in
width. Northwest of the bridge is a vertical
granite wall approximately 50 feet in length.
Continuing west-northwest, the granite wall is
replaced by a metal bulkhead. On the far north-
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western end of the bulkhead are some abandoned
wood pilings and an old floating dock. On the
southwestern side of the site from the bridge is a
sloping rip-rap embankment for approximately 50
feet. From this rip-rap toward the neck are
discarded concrete slabs and trash material. West
of the trash material are wooden pilings and
behind the pilings is a vertical granite wall.
Area B—This portion of the site extends from the
neck on the northwest toward the tip of the penin-
sula. A steel bulkhead extends for approximately
75 feet. Continuing along the western tip and
along the southwestern side of the inlet is a slop-
ing rip-rap embankment. Between the bulkhead
and the rip-rap is a pile of rubble. On the south-
western side toward the neck the rip-rap is re-
placed by a granite wall, which is fronted by a
rocky beach. In front of the rocky beach are one
or two sunken boats and some abandoned pilings.
In the middle of the tidal area is a floating lobster
pot dock.
Both Areas A and B are not a part of the DPA.
Areas A and B are approximately 8.9 and 7.7 acres,
respectively. The water depth in Area A ranges from
6 to 12 feet, and in Area B from 0 to 16 feet below
mean lower low water.
Existing Site Conditions
Benthic samples collected at the Reserved Channel
contained odorless, gray-black clay/silt sediment. No
chemical analyses were performed on these sedi-
ments, but Station 3 of the Boston Edison Intake
was located approximately 1000 feet from the Re-
served Channel Area B. This station had a 66.2%
silt-clay component and indicated PCB at Category
III levels. Fluoranthene, ideno(l,2,3-cd)pyrene, and
pyrene contributed more than 50% to the total
elevated PAHs concentrations. Cadmium, Lead, and
Nickel were found at Category II at this station.
Total organic carbon was 13%, the second-highest
value of all the sites analyzed for TOC. This indi-
cates that the potential for bioaccumulation at the
Reserved Channel Area B may be lower than other
sites in the Boston Harbor. The total petroleum
hydrocarbon at this station was 4270 ppm.
The COE conducted chemical sampling during
1986 at four stations in the Reserved Channel. One
station (A) was located in the western end of the
Reserved Channel close to Area B where a 18-23 cm
core section was analyzed. It had a 18.2 cm layer of
black organic clay. This upper organic clay consisted
of 93% fine grain material with a moderate chemical
oxygen demand (79,000 ppm). Lead was the only
chemical constituent present at Category III concen-
trations (221 ppm). Mercury (1.48 ppm), zinc (264
ppm), chromium (186 ppm), and nickel (58 ppm)
were detected at Category II. PCB samples were also
collected at eight stations in November 1982, from
the Reserved Channel west of Summer Street Bridge
within Area A. PCB concentrations at all eight
stations occurred at Category III and, ranged from
1.0-34.5 ppm.
The water quality of the Reserved Channel is
influenced by the three combined sewerage overflows
(CSO) observed approximately 700 feet northwest of
Pappas Street, at Summer Street, and at I street.
These CSOs can add urban runoff pollutants (e.g.,
PAHs, nutrients, detergents, bacteria, etc.) into the
Channel. Boston Edison Intake has a NPDES dis-
charge pipe in the vicinity of Summer Street, which
may impact water quality by increasing temperature
in the Reserved Channel.
The Reserved Channel flows directly into the
Main Ship Channel. The Summer Street bridge
pilings slow and deflect currents and contribute to
some sedimentation in the vicinity of the pilings.
The Reserved Channel is classified as SC Water
by the MADEP. In both Areas A and B, dissolved
oxygen readings collected in April ranged from 8.4-
8.7 ppm and 6.8-8.9 ppm respectively. In August,
3-44
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available dissolved oxygen levels diminish and cause
a corresponding depression in biological activity at
the sediment water interface. Salinity data collected
in April 1993, ranged from 27.0-31.2 ppt at Area A
and 23.4-33.4 ppt at Area B during low tide, indicat-
ing the influence of freshwater inputs.
The intertidal habitats within the Reserved Chan-
nel include:
Area A:- The wooden bridge pilings and floating
dock at the yacht club were sparsely covered with
green algae. Vertical granite walls were covered
with approximately 20% of algae. Metal bulk-
heads were covered with green algae and barnacles.
A sloping rip-rap was covered with Fucus sp.,
barnacles, Littorina, and green algae. A concrete
slab and trash material had no visible growth.
Area B:- A steel bulkhead was approximately
90% covered with barnacles. The sloping rip-rap
embankments were moderately covered with
Fucus sp., Enteromorpha sp. and other green
algae. A granite wall had moderate growth of
Fucus sp., Uha sp., and barnacles. Rocky beach
areas in front of the granite wall were sparsely
covered with Littorina, Fucus sp., and green algae.
Benthic infauna in the Reserved Channel are
dominated by Oligochaeta, 5. benedicti, C. insidio-
sum and Nematoda. The dominant finfish species in
the Main Ship Channel (about one mile from Area
A) have been recorded as winter flounder (P. aaneri-
canus'), rainbow smelt (O. mordax), and alewife
(Alosa pseudoharengus). There may be movement
of these species into the Reserved Channel; the
Reserved Channel may provide spawning habitat for
winter flounder.
Areas A and B of the Reserved Channel are not
located within a DPA (310 CMR 10.00). The site is
primarily Land Under the Ocean under State regula-
tions (310 CMR 10.00), and is considered to be
significant to the protection of marine fisheries.
Nearshore areas of Land Under the Ocean such as
Areas A and B are likely to be significant to storm
damage prevention and flood control. The entire site
is classified as Tidal Waters under federal Section 404
regulations. The fined-grained sediment and contam-
inant levels of the samples analyzed indicate that this
site has the potential for sediment/toxicant affinity
and nutrient retention.
The Reserved Channel may provide feeding
habitat for several waterfowl and diving feeders (e.g.,
mallards, comorants and terns). Abandoned piers
and pilings also provide roosting sites for gulls and
terns. No federally or state-listed threatened or
endangered species are identified or expected to occur
within the vicinity of the Reserved Channel. Also,
there are no listed historical or archeological resourc-
es in the Reserved Channel site.
This channel is generally surrounded by industrial
and office uses in South Boston. There is a sewer
outfall at the southerly end of the Channel which
would require relocation if this area were to be filled.
There is a yacht club immediately adjacent to the
Summer Street Bridge, and a passive water viewing
area has been created for the general public to use on
the west side of the channel.
While the South Boston peninsula was settled
early in Boston's history, much of the land area
between the subject site and Boston Harbor was
created by filling the tidal flats. The filled land
supported maritime shipping and railroad terminal
uses. Marine access to this site is restricted by the
6.0± feet vertical clearance at high tide at the Summer
Street Bridge.
Proposed Site Conditions/Impacts
The silt sediments proposed to be placed at each
area would be stabilized by a 3-foot cap of clean
sediment. Since this site already has elevated
chemical levels, covering it with clean dredged materi-
3-45
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al would have a beneficial effect on the existing
sediment quality, reducing the likelihood of dissemi-
nating contaminants into the water column and
harmful bioaccumulation. Use of the Reserved
Channel areas for disposal will require construction
of a steel bulkhead fronting the water edge. The cost
for the bulkhead, in addition to other costs, requires
that disposal capacity at the site offsets the cost of
development. Area A does not provide substantial
capacity (only 14,000) cy to offset the cost.
Therefore, only Area B is potentially practicable.
Both areas of the Reserved Channel can be
characterized as a low energy environment suitable
for dredged material disposal and containment.
During disposal operations, suspended solids would
be released into the Reserved Channel waters. As a
result, there would be localized and temporary
increases in suspended solids and attendant chemical
concentrations in the water column. The use of a silt
curtain would help trap and contain most of these
suspended sediments.
There would likely be some temporary impacts on
intertidal resources, including reductions in green
algae, barnacles, Fucus sp., barnacles and Littorina
sp. production in both areas. The small rocky beach
in front of the granite wall on the southwestern side
of the site would be temporarily impacted.
Benthic invertebrates in Area A of the Reserved
Channel would be buried during disposal operations.
There would be a temporary loss of 8.9± acres of soft
substrate. Dredged material placed at the site should
quickly be colonized by local taxa, including 5.
benedicti, oligochaetes, and other common species
occurring in the harbor sediments. Benthic inverte-
brates in Area B of the Reserved Channel would be
buried during disposal operations. There would be
a permanent loss of 7.7± acres of soft substrate.
Siltation caused by disposal operations may have
some short-term adverse impacts on invertebrates
occurring in adjacent subtidal and intertidal areas.
Area A would recolonize to a similar or better
habitat. Area B will experience a change from
subtidal habitat to salt marsh.
Some displacement and/or mortality of adult fish
would occur during disposal events due to burial or
exposure to high suspended sediment levels. Impacts
should be limited to the immediate vicinity of the
disposal site. Disposal of dredged material in Area A
would temporarily reduce prey available to species
which feed primarily on benthic invertebrates, such as
winter flounder. In Area B there would be perma-
nent replacement of subtidal finfish refuge and
foraging habitat with intertidal.
There would be a short-term impact on the areas
classified as Tidal Waters and Land Under the Ocean
at Area A (8.9 acres). The site would be restored
after construction and maintained as a shallow
subtidal area. However, in Area B, there would be a
permanent loss of Land Under the Ocean and Tidal
Waters, but the 7.7 acres loss would be replaced with
intertidal habitat.
Disposal of dredged material in Areas A and B
should not adversely impact wildlife populations
occurring near the disposal site. Converting Area B
into a salt marsh would in fact provide new habitat
for various wildlife species. No federally or state-
listed threatened or endangered species are expected
to occur within the vicinity of either area.
The proposed project would have no effect upon
any structure or site of historic, architectural or
archeological significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
The disposal operations would involve approxi-
mately 140 barge trips to the North Jetty, resulting
in some minor delays to commercial and recreational
boat traffic using the harbor. There would also be
some impact of noise and traffic from the estimated
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9800 truck trips between North Jetty and the disposal
areas.
The impacts of disposal at this location should be
limited to water dependent uses in the Channel.
Depending on the extent of fill material placed in this
portion of the channel, the yacht club operation
could be affected. If there is only partial fill, odor
from this "backwater' could also be problematic for
yacht club patrons if disposal occurs during the prime
use period.
3.6.2.9 Amstar
Amstar is an industrial site containing approxi-
mately 20 acres in Charlestown (Figure 3-9). It is
currently available for sale, although there are several
industrial tenants. One tenant runs a sand and gravel
operation and uses the dock for material transfer.
The site is in the City's Maritime Economy Reserve
Zone which is geared to water dependent activities.
It is surrounded by industrial uses to the east and
west. Across Medford Street from the site are
residences and a park.
This site can be filled with 128,000 cy of dredged
material and capped to MLW. The silt sediments
placed at the disposal site would be stabilized by a
retaining wall and 3 foot cap of clean sediment. The
elevation after filling would be equal to the adjacent
land. Sediment samples collected in close proximity
to this site indicated that the sediments within the
site are likely to be moderately to highly contaminat-
ed. The existing poor sediment quality will be
isolated by capping and bulkheading, reducing the
potential of disseminating contaminants into the
water column and of bioaccumulation.
Existing Site Conditions
There are three types of intertidal habitat that
occur at the Amstar site. Pilings and vertical seawalls
along the eastern side provide hard substrate that has
been colonized by barnacles, mussels and green algae.
Beneath the ramp to the floating dock is a small,
gently sloping gravel-cobble beach. The cobble
support green algae. The rest of the south boundary
is a rip-rap slope comprised of boulders that are
heavily covered with Fucus sp. There is a little
Fucus sp. on the western rip-rap slope except at the
mouth of the site. Along the western boundary
barnacles and periwinkles (Littorina sp.) were numer-
ous; green algae was present above and below the
barnacle zone.
Amstar is located within the Mystic River Desig-
nated Port Area (DPA) (310 CMR 10.00). The site
is primarily Land Under the Ocean, under Massachu-
setts wetlands regulations, and is considered to be
significant to marine fisheries, storm damage preven-
tion and flood control. The Amstar site may provide
both refuge (from predators and currents) to many
fish species and feeding opportunities (primarily
demersal species). It is unlikely to provide important
spawning habitat.
Benthic samples collected at Amstar contained
odorless, grey silty sediments. No chemical analyses
were performed on sediments from the Amstar site,
but Station 3 from the Revere Sugar berth was
located approximately 300 feet from the mouth of the
site and is assumed to be representative of on-site
conditions (see EIR/S Section 2.2). That station had
a 73% silt-clay component (Category III). Chromi-
um, copper and nickel all occurred at Category II
levels; arsenic, lead, zinc and PCBs were Category HI
concentrations. Total PAIIs were among the highest
(46.41 ppm) observed during the 1992 berth area
sampling. Benzo(b)fluoranthene, benzo(k)fluoran-
thene, fluoranthene and pyrene each contributed
more than 5 ppm to the total concentration. Total
petroleum hydrocarbons were 3,540 ppm. Total
3-47
iV
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organic carbon was 6.6%, among the higher values
observed during the berth sampling, suggesting that
potential for bioaccumulation of contaminants is
lower at Amstar than other sites in Boston Harbor.
Zinc and PAH uptake may be exceptions to this
generalization, as these constituents were found at
higher levels at Revere Sugar Station 3 than at other
berths.
There are no listed historical and archeological
resources on or within 1,000 feet of the Amstar site.
Proposed Site Conditions/Impacts
Filling of the Amstar site would result in a
'' conversion of approximately 3.5 acres of wetland
« resources (Land Under the Ocean and Tidal Waters)
to intertidal habitat.
browsers. Most fish species could avoid the area of
disposal, but there would be permanent loss of finfish
refuge and foraging habitat.
The average current velocity at this site is less
than 0.5 knots. During disposal operations suspend-
ed solids could be released into the Mystic River
waters resulting in localized and temporary increases
in suspended solids concentrations in the water
column. Therefore, the use of a silt curtain at this
site would be appropriate to trap most of the sus-
pended sediment. Disposal activity will occur for a
6- to 9-month period; if properly controlled effects
from the suspended solids concentrations on the
water quality in the vicinity of the site should be
minimized. A sedimentation basin or a settling pond
may be necessary to mitigate water quality impacts.
There would be no degradation of the Class SC
waters.
In the present intertidal zone, there would be a
permanent loss in production from barnacles, mussels
and green algae on the hard substrate (pilings, vertical
seawalls and rip-rap) present at the site. The
construction of a retaining wall across the pier
opening would replace some of that habitat. The
small gravel-cobble beach beneath the ramp would
also be lost.
Benthic invertebrates at the Amstar site will be
permanently buried and displaced from disposal
operations. Nematodes, the polychaete P. cornuta
andoligochaetes were typically abundant harbor-wide
and were the abundant species at this site. The
dredged material placed at the site would fill the site
to the adjacent land elevation.
Disposal operations would impact fish utilization
of this site. Some displacement and/or mortality of
adult fish would occur during disposal events due to
burial or exposure to high suspended sediments
kvels. Anadromous river herring could no longer use
this area for refuge. Subtidal regions would not be
available to provide food resources for demersal
The disposal operations would involve approxi-
mately 130 barge trips to Amstar. The Coast Guard
.would have to coordinate any minor delays to
commercial and recreational boat traffic using the
harbor. Construction activities would have some
aesthetic impact, and result in slightly elevated noise
levels.
Adjacent to the Amstar site is Revere Sugar which
has an active water transportation facility. Any filling
at the Amstar property would require a bulkhead to
contain material so as to prevent any effect on the
dock at Revere Sugar. Partial filling of the property
would restrict ship to shore transfer of people or
freight including the current sand and gravel opera-
tion. However, it would not restrict marine-related
storage of material. Since placement of material
would occur from the water, there will be no impact
on adjacent streets caused by truck traffic delivering
material to the site.
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3.6.2.10 Mystic Piers
The inlet between the Mystic Pier No. 1 and Pier
49 is no longer used for cargo handling at Massport's
Moran Terminal in Charlestown. Charlestown is a
neighborhood within the City of Boston. Recre-
ational vessels docking here in the late 1970s were
removed to accommodate shipping activity. The
recreational docking has not been reinstated even
though the port-related shipping activity ceased to
operate in the inlet. There are no residential areas
abutting this property. The closest residential neigh-
bors are across the Little Mystic Channel in the
Charles Newtowne complex and in the former Navy
Yard.
This site could be filled with 98,000 cy of dredged
material and capped at MLW (Figure 3-10). The silt
sediments placed at the disposal site would be
stabilized by a retaining wall and a 3 foot cap of
clean sediment. Sediment samples collected in close
proximity to this site indicated that the sediments
within the pier are likely to have moderate to high
levels of metals and organics (see Section 2.2 of the
EIR/S). The existing poor sediment quality would
be covered by capping, eliminating the potential for
further dissemination of existing contaminants into
the water column and for further bioaccumulation.
Existing Site Conditions
Like all of Boston Inner Harbor, the Mystic Piers
site is a depositional environment (EG&G 1984),
accumulating fine grained sediments (silts and clays).
Sediment sampling along the harbor-face of Mass-
port's Mystic Piers 1 (Station 1), 49 and 50 (Stations
1 and 2), adjacent to the proposed disposal site,
revealed that the silt-clay component was 41-78%,
averaging 60% (see EIR/S Section 2.2). Benthic
grabs collected within the proposed disposal area
contained predominantly silty sediments, although
gravel was present in one sample.
No within-berth data were available for assessing
sediment quality. However, all stations sampled to
characterize berth-area dredged materials were within
approximately 400 feet of the mouth of the proposed \
Mystic Pier disposal site and may be indicative of
sediment quality. Assuming these data reflect condi-
tions within the Mystic Pier site, the sediments are
likely to contain moderate to high levels of metals
and organics. Arsenic, chromium, copper and
mercury likely occur in Category II levels; lead end
zinc likely occur in Category III levels. Total PAHs
concentrations are likely to be high ( > 10 ppm), with
fluoranthene and benzo(g,h,i)perylene contributing
the highest concentrations. Total organic carbon is
likely to be 2-3% of dry weight, indicating a relative-
ly high potential for bioaccumulation of contami-
nants.
The site was visited during low tide on April 28,
1993, to evaluate habitat conditions. The intertidal
zone is restricted to the tidal excursion vertically
along the •walls and pilings surrounding the Mystic
Piers site, except in the southwest corner where
rubble has accumulated in sufficient quantity to be
exposed at low tide. Intertidal portions of the
western and northern walls are covered extensively
with algae (primarily Fucus sp. with some Spongo-
morpha sp.). The pilings along the southern perime-
ter were heavily covered with barnacles, blue mussels
(Mytilus edulis) and green algae (Spongomorpha sp.)
with algal cover increasing with distance from the
mouth. Diatoms were present on the algae and
rubble. Mussels and macroalgae both provide
habitat for other organisms. These communities may
be exploited for food or shelter by crustaceans and
finfish.
Two areas were sampled (in April 1993) for ben-
thic infauna. One station, adjacent to the pilings,
was nearly azooic (two taxa totalling 86 individu-
als/m2. The second station, near the head of the site,
contained 17,759 individuals/m2 (11 taxa) of which
11,954/m2 were nematodes. The total abundance at
the second station was in the range observed by the
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Corps in the Chelsea Creek and Confluence Area in
1986. However, the channel stations were dominated
by polychaetes (> 70%) while the Mystic Pier station
was dominated by nematodes (67%). Capitella
capitata and oligochaetes comprised 85% of the
remaining organisms. These predominant taxa are
classified as pioneer taxa. Nematodes are early
settlers in organically enriched sediments whose
presence stimulates microbial degradation of organics
(Tietjen 1982). Oligochaetes and C. capilata are
typically associated with organically enriched, stressed
environmentsT Its reproductive strategy enables C.
capitata to colonize disturbed sediments rapidly. No
amphipods or live mollusks were collected. The
moderate abundance of infauna (17,759/m2 in at least
a portion of the site contributes to the productivity of
Boston Harbor and these near-surface dwelling
organisms are available as prey items for crabs and
demersally feeding fish. Winter flounder (Pieuronec-
tes amsricamts) have been documented as feeding on
C. capitata in Boston Harbor (Haedrich and Haed-
rich 1974; NAI 1985), although their preferred prey
includes amphipods and large worms.
Finfish were not sampled in this site. It is likely
that most species that reside in or migrate through
Boston Inner Harbor could enter this area. The
pilings and wharf, shading the area below, offer
shelter from predators. The orientation of the site
perpendicular to the main channel provides shelter
from currents. Both'subtidal and intertidal benthic
resources provide prey items. Soft substrate could
support feeding by demersal species (e.g., winter
flounder). Fish such as cunner (Taulogolabrus
adspersus), tomcod (Microgadtcs tomcod) and scul-
pins (Myoxocephalus spp.) could feed on the fouling
community on the walls and pilings (Edwards et al.
1982; Menge 1982; Ojeda and Dearborn 1990). Two
species of particular concern are alewife (Alosa
psuedoharengus) and winter flounder. The anadro-
mous alewife spawns above the head of tide of the
Mystic River so reproductive adults migrate upriver
past the Mystic Piers site between April and May
(Whitlatch 1982). Adults descend the river during
the summer, juveniles swim downriver past the site
from late summer-fall (Loesch 1987). Another
anadromous species, rainbow smelt, may also use this
portion of the Harbor. Winter flounder is one of the
most abundant species in Boston Harbor where it is
considered to be a resident. It prefers to spawn on
sand common in the outer harbor (Bigelow and
Schroeder 1953). Site-specific data for winter floun-
der were not available.
Under the jurisdiction of the Massachusetts Wet-
lands Protection Act (MGL c.131, s.40 and 310
CMR 10.00) the Mystic Piers site is a Designated
Port Area (DPA). DPAs are almost completely
developed areas where few or no natural land forms
or vegetation remain. They tend to be paved, bulk-
headed, and used for heavy industry so that they
have virtually no significance to the interests of the
Act, except for Land Under the Ocean. Land Under
the Ocean in DPAs are significant to flood control,
storm damage prevention, and the protection of
marine fisheries, as is Land Under the Ocean outside
of DPAs. The major addition is that Land Under
the Ocean in designated port areas also provides
support for coastal engineering structures, such as
bulkheads, seawalls, revetments, and solid fill piers.
As Land Under the Ocean, the site is potentially
important to marine fisheries, storm damage preven-
tion and flood control. Land Under the Ocean
within the Mystic Pier provides food resources and
shelter; however, the silty substrate is not preferred
spawning habitat for winter flounder, nor are the
saline conditions conducive to spawning of the
anadromous alewife. Storm damage protection and
flood control are provided by the vertical granite wall
surrounding the perimeter of the site.
Under federal wetlands guidelines, the entire
Mystic Piers site is defined as tidal water. The fine-
grained character of sediments at the site, as well as
proximity to identified contaminants, suggest that the
potential for retention of sediments, toxicants and
nutrients exists. Abundance and diversity of the
benthic fauna varied substantially in the site. Com-
3-50
-------
pared to other locations in the harbor, Mystic Piers
exhibited moderate potential for supporting higher
trophic levels. Construction activities could be more
sensitive at this site due to its proximity to an ana-
dromous fish run (in the Mystic River).
No federally or state-listed threatened or endan-
gered species are identified or anticipated to occur
within the boundaries of the Mystic Piers site (Lin-
coln 1993). Although common terns have been
observed nesting within Boston Harbor, no evidence
of nesting was present at the Mystic Piers site on
April 28, 1993.
There are no listed historical or archaeological
resources at the Mystic Piers site.
Proposed Site Conditions/Impacts
There would be a conversion of 2.7 acres of Land
Under the Ocean in a DPA and Tidal Waters at this
site to intertidal habitat.
In the present intertidal zone there would be a
permanent loss in macroalgae, barnacles, and blue
mussel production on the hard substrate (vertical
seawalls and pilings) present at the site. The
construction of a retaining wall across the pier
opening would replace some of that habitat.
Benthic invertebrates at the Mystic Piers site
would be buried during disposal operations. The
overall high abundance of infauna in at least a
portion of the site contributes to the productivity of
Boston Harbor and these near-surface dwelling
organisms are available as prey items for crab and
demersally feeding fish. The dredged material placed
at the site would fill the site to the adjacent land
elevation.
Disposal operations would have some impact on
fish at the disposal site. Some displacement and/or
mortality of fish eggs, larvae, and adult fish would
occur during disposal events due to burial or expo-
sure to high suspended sediment levels. Finfish are
likely to use the site for shelter from currents and
predators and for feeding. The anadromous alewife
spawns at the head of tide in the Mystic River, so
reproductive adults migrate upriver past the Mystic
Piers site between April and May. Adults descend
the river during summer. Winter flounder could
spawn in the close proximity to this site from March
to September but prefers to spawn on sand common
in the outer harbor. Seasonal disposal restrictions
would be enforced at this site during migration and
spawning of species of concern. Most fish species
would avoid the area during disposal and thus be
displaced; there would be permanent loss of finfish
refuge and foraging habitat.
The average current velocity at this site is less
than 0.5 knots. In general, water circulation at the
Mystic Pier site is driven by tidal cycles and influ-
enced by seasonal weather patterns. This should not
be affected by filling of a relatively limited area of
existing tideland. During disposal operations, sus-
pended solids would be released into the Boston
Harbor waters. As a result, there would be localized
and temporary increases in suspended solids concen-
trations in the water column as discussed below. The
use of a dragline at this site would also contribute to
a higher amount of suspended sediment at this site;
however, the use of a silt curtain would trap most of
the suspended sediment. Disposal activity would
occur for a 6- to 9-month period and if controlled
there would be only temporary impacts of the sus-
pended solids concentrations on the water quality in
the vicinity of the site.
The effects of disposal on the Boston Harbor
water column chemistry are likely to be minor;
mitigative measures (silt curtains, etc.) would mini-
mize release of sediment contaminants into the water
column. There would be no degradation of the Class
SC waters.
3-51
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3.6.2.11 Revere Sugar
Revere Sugar, a site containing 6.5 acres in
Charlestown, is currently under lease from Massport
by the MWRA which has constructed a water
transportation facility for the ferrying of construction
personnel to Deer Island (Figure 3-11).
This site could be filled with 85,000 cy of dredged
and capped to MLW. The silt sediments placed at
the disposal site would be stabilized by a retaining
wall and a 3 foot cap of clean sediment. Sediment
samples collected in close proximity to this site
indicated that the sediments are likely to contain high
concentrations of metals and organics (see Section 2.2
of the EIR/S). The existing poor sediment quality
would be isolated by capping and bulkheading,
eliminating the potential for further exposure of
contaminants to the water column and for
bioaccumulation.
Existing Site Conditions
Habitat conditions were examined at the Revere
Sugar site on April 28, 1993. The intertidal zone is
restricted primarily to vertical excursion on pilings
and walls. The wooden retaining wall along the
eastern boundary and the abandoned pier on the
southern side supported small quantities of macro-
algae (predominantly Fucus sp. with some green
algae). Barnacles and littorinid snails were present
but not numerous. The barnacle cover increased
along the western pilings towards the mouth. The
granite wall behind the pilings supported some algae
cover (Fucus sp. and green algae). Barnacle cover
was heaviest on the metal pilings at the mouth of the
site. Mussels were observed only at the northwest
corner of the site.
Breaching of the retaining wall along the southeast
portion of the site has allowed erosion into the
aquatic zone, creating a small intertidal zone of
rubble and fine-grained sediments.
Benthic infauna was sampled in three locations.
Nematodes accounted for > 80% of the abundance
at Stations RS-I and RS-2 (98% RS-1, 84% RS-2);
C. capitate and oligochaetes were also numerically
important components of the fauna. Abundances at
RS-3 were low, made up primarily of the cirratulid
polychaete Caullariella sp. and nematodes. Species
richness at RS-1, near the mouth of the site, indicates
that, at least seasonally, benthic infauna can be
relatively diverse in this site. The polychaetes present
are primarily surface deposit feeders, indicative of the
stressed sediment conditions. The tube dwelling
amphipod Microdeutopus gryllotalpa, is commonly
found associated with docks, algae and mussels
(Bousfield 1973). Its presence in the infauna suggests
it is present among the fouling organisms on the
pilings and bulkheads. The paucity of suspension
feeders (e.g., bivalves) indicate that suspended partic-
ulates or siltation rates are higher than suitable.
As with Mystic Piers, finfish are likely to utilize
the Revere Sugar site for shelter from currents and
predators, and for feeding. Species feeding indiscrim-
inantly on the bottom would encounter prey.
Species that prefer to browse on hard substrates
would find little food. While winter flounder could
spawn in this area, their preferred spawning habitat
(sand) may not occur at this site. Revere Sugar is
located well below the head-of-tide, so does not
provide suitable conditions for anadromous species to
spawn.
The Revere Sugar site is located within the Mystic
River Designated Port Area (DPA) (310 CMR
10.00). Under Massachusetts wetlands regulations,
most of the site would be designated as Land Under
the Ocean and have the potential to be significant to
marine fisheries, storm damage prevention and flood
control. This site could provide both refuge (from
currents and predators) and feeding opportunities
(primarily for demersal feeders). It is unlikely to
provide spawning habitat for either winter flounder,
as it appeared to lack sandy sediments, or anadro-
mous species (e.g., alewife), as it is located well below
3-52
-------
the head-of-tide. Storm damage prevention and flood
control are enhanced at this site by the man made
boundaries, although the seawall at the southern end
of the site is in disrepair and offers limited protection
against exceptionally high tides. The greatest poten-
tial for storm damage prevention and flood control
occurs during low tides.
Intertidal resources include a debris strewn beach
in the southeastern comer and the granite walls and
pilings surrounding the site. The beach could be
categorized as Coastal Beach but is not significant in
the DPA. No natural intertidal features exist at this
site.
No federally or state-listed threatened or endan-
gered species are identified or anticipated to occur
within the boundaries of the Revere Sugar site
(Lincoln 1993). Although the state-listed common
tern has been observed hi Boston Harbor, no evi-
dence of nesting activities of this species were seen
during a site visit on April 28, 1993.
There are no listed historical or archaeological
resources on or within 1,000 feet of the Revere Sugar
site.
Proposed Site Conditions/Impacts
There would be a conversion of 3.7 acres of Land
Under the Ocean in a DPA and Tidal Waters at this
site to intertidal habitat.
There will be a permanent loss of present intertidal
substrate and secondary production of marcroalgae,
barnacles, and littorinid snails on the hard substrate
(pilings and vertical seawalls). The construction of a
retaining wall across the pier opening would replace
some of that habitat on its outside wall.
Benthic invertebrates at the Revere Sugar site will
be permanently buried and displaced during disposal
operations. Nematodes accounted for > 80% of the
abundance, also, C. capitata and oligochaetes were
numerically important components of the fauna.
The dredged material placed at the site would fill the
site to the adjacent land elevation.
The average current velocity at this site is less
than 0.5 knots. Circulation within the Revere Sugar
site is governed by tidal flow and physical structures.
Disposal activities would occur for a 6- to 9-month
period with some potential for temporary impacts
from the suspended solids in the vicinity of the site.
As with other pier sites, silt curtains and other
mitigative measures (settling basin, etc.) would be
necessary to prevent unacceptable levels of suspended
sediments form entering the river and harbor. Partial
bulkheading during site construction and disposal
would help restrict openings to the river and provide
better opportunities for point-source controls.
The effects of disposal on the Mystic River water
column chemistry are likely to be minor. Release of
sediment-borne contaminants into the water column
are expected to be controlled so that there would be
no degradation of the Class SC waters.
3.6.2.12 Treatment Technologies
Pre-disposal treatment or alternative technological
use of silty sediments from Boston Harbor is being
kept as a potentially practicable alternative for
Boston Harbor sediments. For the current mainte-
nance dredging needs it is not practicable because
technically and logistically feasible treatments are not
cost effective for the large volume of material and the
rate it would be generated from this project. Howev-
er, research on these technologies is continuing and
by the time future maintenance dredging for this
project is needed, these options may become practi-
cable. When logistics and cost become reasonable,
treatment of silt material to render it a material suit-
able for unconfined open water disposal (or other
economically feasible use) would appear to be the
most practicable alternative at this point since a
3-53
-------
designated site is available (MBDS). Upland disposal
of treated sediments would still not appear practica-
ble because of disposal siting difficulties (permitting,
logistics, cost), unless it is in small enough quantities
such that it could be used as daily cover for landfills.
3.7 CUMULATIVE IMPACTS
Construction of the Boston Harbor navigation
improvement project will provide deeper access
channels for ships using the Port of Boston. During
construction of this project, additional barge traffic
will occur in the shipping channels and at the open
water disposal sites. Barge traffic from the Boston
Harbor navigation improvement project is not antici-
pated to interfere with barge traffic from the CA/T
project. Barge traffic to Spectacle Island is anticipat-
ed to be complete by the end of 1995.
The MBDS is not receiving any more material
from the CA/T project. Approximately 470,000
cubic yards of material from the CA/T project was
disposed at the MBDS. No material was disposed at
this disposal site from the MWRA project in Boston
Harbor (the other large project in Boston Harbor).
Other small dredging projects in the Massachusetts
Bay area (such as the Winthrop Harbor) may dispose
of materials at the MBDS. The draft and final EISs
for the MBDS site designation discuss the cumulative
impacts from disposal at the MBDS. However,
because of the current designation restrictions to the
MBDS, the likelihood of many projects being accept-
ed for disposal there is slight.
Disposal at any of the other preferred disposal sites
discussed in this report could increase as more
material is determined not to be acceptable for
disposal at the MBDS. The Commonwealth of
Massachusetts, with the Corps of Engineers, is
currently evaluating the regional need for a disposal
site(s). The data obtained in this report will also be
evaluated by a working group looking at this long-
term problem.
Beneficial cumulative impacts are expected with
the dredging of silt material from the navigation
improvement project. Silt material will be removed
from the navigation channel and disposed at a site
that will sequester the contaminants. This will
expose the "clean" parent material. At the same
time, the MWRA is controlling sludge and CSO's
disposal into the harbor, and will have a new sewage
treatment plant in operation. This will reduce the
amount of contaminants released to the harbor and
provide a cleaner substrate and water column for
aquatic organisms inhabiting Boston Harbor.
3.8 SECONDARY IMPACTS/SUSTAINABLE
DEVELOPMENT
Deepening the Federal navigation channels in
Boston Harbor will improve the access for deep draft
vessels. The benefits resulting from the project are
improved operating efficiency and navigational safety
which will help the Port of Boston maintain its
standing in the world market and to attract deeper
draft vessels, which will make up a larger percentage
of the world's fleet, in the future. The benefits are
not expected to require land-based infrastructure
improvements or a substantial increase in the work
force tied to Port operations since the Port is already
well served by an established support service industry.
The benefits accruing from the project are also
expected to sustain Port activities over the 50-year
life of the project. Maintenance dredging, which
would be required to maintain the Port over the next
50-years even without the project.would benefit from
the identification and creation of a disposal site(s) for
the current proposal which can maximize the benefi-
cial use of the uncontaminated parent material.
3-54
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3.9 IRREVERSIBLE AND IRRETRIEVABLE
RESOURCES
Construction of this project will result in the use
of diesel engines on dredges used to remove material
from the navigation channels and berthing areas, and
to dispose of the material. Diesel fuel, which is an
irreversible and irretrievable resource, will be used to
operate this equipment. A temporary increase in air
pollutants will occur as a result of this action.
3.10 MITIGATION
Dredging and disposal activities will have some
short-term impacts. The dredging and blasting
impacts on organisms associated with the substrate in
the project area include potentially interfering with
anadromousfisheries movements, increasing turbidity
levels, resuspending sediments with absorbed contam-
inants (e.g., lead and PCBs) and causing mortality to
finfish and shellfish in the vicinity of the blasting
Shockwave. Control of sediment resuspension will be
minimized by the use of an 'environmental bucket"
during the removal of the silt. Use of silt curtains,
where they can be effectively designed and imple-
mented, may be appropriate and or necessary at
certain in-harbor disposal sites.
The Boston Harbor Navigation Improvement
project proposes various measures and precautions to
minimize interference with the movement of anadro-
mous fish. Anadromous fish movements through the
project area are predominantly transiting spawning
runs that occur in the spring. Finfish that spawn in
freshwater respond to chemical signals in the water
column and transit the estuarine project areas travel-
ing upstream to freshwater spawning regions. The
Mystic River channel dredging has the potential to
impact this anadromous migration. The dredging
activity will increase ambient turbidity levels and
release sediment absorbed contaminants as the dredge
bucket moves through the water column. This
activity has the potential to degrade system produc-
tivity (primary and secondary). Restricting dredging
of this channel to the months of June through
February will avoid impacting these sensitive resourc-
es.
The blasting and removal of rock will destroy
associated finfish and benthos. Proper blasting
techniques (e.g. minimize blasting during fisheries
migrations) will minimize fish mortalities. The
potential exists for the use of the rock material for
environmental enhancement. This material can be
disposed in a location separate from parent material
at the Massachusetts Bay Disposal Site to increase
habitat niches there. Other rock disposal areas could
be identified to increase habitat diversity, but the size
of the rocks (< than 10*) precludes placement in a
nearshore area exposed to high storm waves.
The transport and disposal of dredged material
will be monitored by onboard disposal inspectors
under contract to the Corps. The inspectors will
record the position of the barge at the time of dispos-
al to ensure point discharges at selected disposed
sites. This type of disposal maintains a layering or
capping of material, since the most contaminated
materials will be disposed first and then capped with
pristine clays. The rock/cobble barge loads could be
disposed at an alternate buoy for habitat creation.
These mitigation measures are in accordance with
ongoing Corps management practices of the Massa-
chusetts Bay Disposal Site, isolation of contaminated
dredged material and Corps policy for beneficial use
of dredged material.
An operational timing sequence (approximately 17
months) would be to dredge the Mystic River and
Inner Confluence beginning in the fall and winter
(October through February), then proceed by spring
and through summer (March through October) to
the Reserved Channel. Upper Chelsea River regions
could be dredged at any time (e.g., once the Reserved
Channel is finished and heavy winter petroleum
shipments have lessened). Any remaining work on
the Mystic River and Inner confluence areas would
be finalized in October through February.
3-55
-------
Mitigation for loss of subtidal habitat associated
with inshore harbor filling could include saltmarsh or
eelgrass plantings in Boston Harbor. Some of the
inshore pier disposal sites could be filled to the mean
low water level increasing tidal habitat in Boston
Harbor. This area could be left to recolonize natu-
rally or planted with saltmarsh grass. As the waters
of Boston Harbor are improving in water clarity and
quality, eelgrass plantings could succeed in greater
depths and in more areas.
In summary, the dredging schedule could proceed
year round with the above mitigation practices to
minimize environmental impact on the dredging or
disposal site ecosystems. Loss of subtidal or intertid-
al habitat could be replaced with additional intertidal
habitat, saltmarsh or eelgrass plantings.
3-56
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Boston Harbor Dredging Project EIR/S
©
Scale: 0 w
Approx. Scale in Miles
Figure 3-1
Locations of potential disposal sites
extensively evaluated.
Source:
USGS Quadrangles
Revised by NAI to reflect pertinent site conditions.
-------
Boston Harbor Dredging Project EIR/S
Scafe: 0
Apprax. Scale in Miles
Figure 3-la. Locations of practicable disposal sites.
Source:
USGS Quadrangles
Revised by NAI to reflect pertinent site conditions.
3-5?
-------
Boston Harbor Dredging Project EIR/S
©
Scofe: 0 10
Apprax. Scale in Miles
Figure 3-lb. Locations of potentially practicable
disposal sites.
Source:
USGS Quadrangles
Revised by NAI to reflect pertinent site conditions.
-------
Boston Harbor Dredging Project EIR/S
©
Scale: 0 I0
Apprax. Scale in Miles
Rgure3-lc. Locations of short-listed sites found
not practicable.
Source:
USGS Quadrangles
Revised by NAI to reflect pertinent site conditions.
"ff
-------
ALTERNATIVES SCREENING PROCESS
Present
Parent
Material
Silt
Material
Logistics,
Technology
Cost
Sites Suitable
For Material
Reasonable
Capacity
for this Project
Acceptable or Mltigable
Environmental Impacts
Practicable Alternatives
Preferred Alternative
Parent
Material
Silt
Material
Future
Maintenance
Material
Benefits
Future
Maintenance
Material
Figure 3-2. Screening of final-listed sites to determine preferred alternative for disposal of present and
future (maintenance) dredged material. Boston Harbor Navigation Improvement Project.
-------
Co
i
w
o
I
H
£
s
W
w
•o'
%
W
/: ;F'- *&.
MASSACHUSETTS
BAY DISPOSAL SITE
Depositional substrates within the disposal sites.
* BIDS approximate proposed disposal location = 42° 19' 43" N
70° 37 30" W
-------
—*2°es'
EXPLANATION
Best Potential (or sand/gravel
i 157 Cori Location
2518
2519
•95-
NoYiqotion Fins
Contours in Ft«t
*,
\
Boston Harbor Dredging Project EIR/S
(ft
Scofe: , . _
Scolt in Tords
500 0 1000
Figure 3-4
Site map for Meisburger 2 site.
Source:
Metcalf & Eddy Inc., 1992
-------
Boston Harbor Dredging Project EIR/S
Figure 3-5 Site map for Meisbuiger 7 Site.
t""l * GENERAL AREA WITHIN WHICH DISPOSAL.
SITE WOULD BE LOCATED.
Scale:
Source:
Metcalf& Eddy Inc., 1992
-------
PROPOSED DISPOSAL AREA
BORING LOCATIONS
Boston Harbor Dredging Project EIR/S
®
Scale:
500
Scale in Yards
0
1000
Figure 3-6
Site map for Spectacle Island CAD site.
Source:
NOS Chart No. 13270
Sediment Classifications from CorteU 1990
-------
Boston Harbor Dredging Project EIR/S
Figure 3-7
Site map for Little Mystic Channel site.
Scale:
Source:
Boston Haibor Navigation Chart
-------
Boston Harbor Dredging Project EIR/S
Figure 3-8
Site map for Reserved Channel site.
300
Source:
Boston Harbor Navigation Chan
-------
Boston Harbor Dredging Project EIR/S
Figure 3-9
Site map for Amstar site
Scale:
100
Source:
Scale in Yards
Boston Harbor Navigation Chart
-------
Boston Harbor Dredging Project EIR/S
Figure 3-10
Site map for Mystic Piers site
Scale:
100
Source:
Boston Harbor Navigation Chart
3-6?
-------
i ' / / ' .' i
,' / / / / / /
Boston Harbor Dredging Project EIR/S
(B
Scale:
0 50 100
Scale in Yards
Figure 3-11
Site map for Revere Sugar site
Source:
Boston Harbor Navigation Chart
-------
TABLE 3-1. POTENTIAL DISPOSAL SITE LISTS BY CATEGORY PRODUCED
AT THE END OF EACH SCREENING PHASE.
PHASE 1
LAND-BASED OPTIONS:
Land-based Inland
BRN-06
CAN- 17
EBROOK
HLB-13
NAT-02
NOR-02
RAYNHAM
RED-03
SAG- 02
W-495
WHY- 13
WIL-06
WIL-07
WOB-11
Land-based Coastal
BOS-13
BOS-23
BOS -25
BOS-31
EVR-04
LOGAN
LYN-02
MAL-01
CHAR-01
PROV
QUI-03
QUI-09
PHASE 2
BRN-06
HLB-13
NAT-02
NOR-02
RED-03
SAG-02
BOS-13
BOS-23
BOS-31
•
LYN-02
CHAR-01
QUI-09
PHASE 3
(DEIR/S)
W-495
WOB-11
EVR-04
QUI-03
3-71
(Continued)
-------
TABLE 3-1. (CONTINUED)
PHASE 1
Landfills
Agawam
E. Bridgewater
Fall River
Plainville
Fitchburg/Westminister
AQUATIC OPTIONS:
Aquatic Shoreline Sites
Amstar
Cabot Paint
CHEL-01
FPC
LMC
Mystic Piers
Northend Park
ResChn
Revere Sugar
Spec CDF
Subaqueous Depressions
Subaq B
Subaq D
Subaq E
Subaq F
CHEL-02
Winthrop
PHASE 2
E. Bridgewater
Fall River
Plainville
Fitchburg/-
Westminister
6CR Peabody*
Amstar
Cabot Paint
CHEL-01
FPC
LMC
Mystic Piers
Northend Park
ResChn
Revere Sugar
Spec CDF
Hangman ' s 1 s 1 and*
Island End River*
Subaq B
Subaq E
CHEL-02
PHASE 3
(DEIR/S)
E. Bridgewater
Plainville
Fitchburg/-
Westminister
Amstar
Cabot Paint
LMC
Mystic Piers
ResChn
Revere Sugar
Sub B
Subaq E
Winthrop
(Continued)
-------
TABLE 3-1. (CONTINUED)
PHASE 1
PHASE 2
PHASE 3
(DEIR/S)
Borrow Pits
Willet I
Willet III
Meis 2
Meis 7
In-Channel Sites
Existing Disposal Sites
MBDS
Boston Lightship
Willet I
Willet III
Spec Is CAD
MBDS
Boston Lightship
Meis 2
Meis 7
Spec Is CAD
Chelsea Creek**
Mystic River**
Inner Confluence**
MBDS
Boston Lightship
*Added after DOWS meeting, 1/25/93
**Added after DOWG meeting, 4/15/93
3-73
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TABLE 3-2. CHARACTERISTICS OP GEHBRIC DISPOSAL ALTERNATIVES.
CHARACTERISTIC
Potential
Environmental
Problems
Major Testing
Requirements
Available Options
Design
Considerations
Available Control
Measures
LINED LANDEILL
(CATEGORY A)
• Leachate impacts
• (Minimal since
lined)
• Bulk analysis
• TCLPa
• Elutriate
• Daily cover
• Disposal with burial
• Existing site design
• Transportation
• Mix with cleaner
materials
• Dewatering
UNLIHED LANDEILL
(CATEGORY B)
• Leachate impacts
• Bulk analysis
• TCLP
• Elutriate
• Unconfined disposal
• Contouring/grading
material
• Daily cover
• Existing site design
• Transportation
• Diking
• Runoff, control
• Dewatering
(UAll T lUTtQTf T \
iw*l"lHulUklUlJ/
• Groundwater
contamination
• He t land impacts
• Bulk analysis
• TCLP
• Elutriate
• Unconfined disposal
• Confined disposal
• Reuse
• Capacity
• Containment
• Monitoring
• Transportation
• Diking
• Runoff control
• Leachate control
• Dewatering
AQUATIC SHORELINE
* CONTAINMENT
• Contaminant
migration
• Burial impacts
• Bulk analysis
• TCLP
• Elutriate
• Habitat creation
• Upland use
• Capacity
• Containment
• Monitoring
• Transportation
• Bulkheading
• Diking
• Subaqueous berm
• Capping
OPEN HATER
• Hater column impacts
• Benthic impacts
• Bioaccumulation
• Bulk analysis
• Benthic toxicity
• Bioaccumulation
• Unconfined disposal
• Capping
• Capacity
• Containment
• Monitoring
• Transportation
• Point dumping
• Capping
OPEN-HATER HITH
CONTAINMENT
• Contaminant
migration
• Burial impacts
• Bulk analysis
• Elutriate or water
quality modelling
• Benthic impacts
• Bioaccumulation
• Habitat enhancement
• Burial
• Capacity
• Containment
• Monitoring
• Transportation
• Subaqueous berm
• Borrow pit
• Capping
• Point dumping
"TCLP • toxic concentrations leaching potential
-------
TABLE 3-3. MASSACHUSETTS REGULATORY GUIDELINE LEVELS OF DREDGED MATERIALS FOR VARIOUS DISPOSAL ALTERNATIVES.
OPEN HATER DISPOSAL
MASSACHUSETTS SEDIMENT CLASSIFICATION
I» IIb III0 A B C
BULK ANALYSIS .(.ppa.1
Mercury
Lead
Zinc
Arsenic
Cadmium
Chromium
Copper
Nickel
Total PCBs
Total PAHs
Total VOCs
Total PHC
Volatile Solids (%)
Water Content (%)
Silt/Clay (%)
Oil & Grease (%)
ISLE
Arsenic
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
<0.5 0.5-1.5 >1.5
<100 100-200 >200
<200 200-400 >400
<10 10-20 >20
<5 5-10 >10
<100 100-300 >300
<200 200-400 >400
<50 50-100 >100
<0.5 0.5-1.0 >1.0
<5 5-10 >10
<40 40-60 >60
<60 60-90 >90
<0.5 0.5-1.0 >1.0
LANDFILL
(LIN|D)
10
500
40
25
500
2
100
10
1000
UPLAND DISPOSAL
CATEGORY
MIN. BULK SOIL
(UNLINED) CONG." FOR TCLP
B ANALYSIS (ppm)
2
500
40
14
100
2
100
4
500
xuu
20
100
1 fiA
1UU
4
2o
.
TCLP REGULATORY
LEVELS* (mg/1)
5
1
5 '
0.2
1
5
"= normally approved for unconfined open water disposal
b= the presence of several parameters in this category may require bioassay and bioaccumulation testing for evaluating open water disposal
<== the presence of one or more parameters in this category will most likely require bioassay and bioaccumulation testing for evaluating open water disposal
«"= dredged material which exceeds any of the limits may be mixed with cleaner material to bring the material into compliance with this classification
•= TCLP analysis would be needed for those parameters that exceed any listed threshold
f= material has non-hazardous characteristics if listed regulatory levels are not exceeded using the TCLP test methods
-------
TABU 3-i. HVAHIAnOH 0! SWIUILITI Of lOSTOH Wm MAYICAnOH IKTROYHXHI EROJZCI SBIHIHTS m YAUOtIS DISPOSAL ALTOHMIYES.
DREDGE SITE
Reserved Channel FP
Conley P
Arny Base P
Boston Edison (Barge Berth) P
Boston Edison (Intake) P
Hain Ship Channel FP
Horth Jetty P
Hystic Piers P
Chelsea River EP
Eastern Minerals P
Gulf Oil P
Hystic River FP
Koran P
Revere Sugar P
Distrigas P
Proleriied P
SILT PAREHT ROCK
U S S
U S NA
It S HA
U S HA
H HA HA
H S S
K S HA
H S HA
H S HA
H S HA
U S HA
H S S
H HA NA
H S HA
H S HA
H S HA
OPEH VATER AQUAT1I
UNRESTRICTED
SILT PAREHT ROCK
U S S
U S HA
U S HA
U S HA
H HA HA
H S S
H S HA
H S NA
N S HA
K S HA
U S HA
H S S
K HA HA
H S HA
H S HA
N S HA
CEKLUDIK! KIDS)
(CAPPING)
SILT PAREHT ROCK
S S S
S S HA
S S NA
S S HA
S HA HA
S S S
S S NA
S S HA
S S HA
S S NA
S S HA
S S S
S HA HA
S S HA
S S HA
S S HA
SILT PAREHT ROCK
S S S
S S HA
S S HA
S S HA
S HA HA
S S S
S S HA
S S HA
S S HA
S S HA
S S HA
S S S
S HA HA
S S HA
S S HA
S S HA
UPLAND COASTAL
SILT PARIHT ROCK
S S S
S S HA
S S HA
S S HA
S HA HA
S S S
S S HA
S S HA
S S HA
S S NA
S S HA
S S S
S NA NA
S S HA
S S NA
S S HA
UPLAHD1HIAHD
SILT PAREHT ROCK
S A.S S
S A.S HA
S A.S HA
S A.S HA
S HA HA
S S S
S A.S HA
S A.S HA
S A.S HA
S A.S HA
S A.S NA
S A.S S
S HA HA
S A.S HA
S A.S HA
S A.S HA
i
LINED LAKOEILL ;
SILT PARENT ROCK !
U A.B.C.S S
D.E A.B.C.S NA
D.E A.B.C.S HA '
D.E A.B.C.S HA
D.E NA NA
D.E A.B.C.S S
D,E A.B.C.S NA
D.E A.B.C.S HA
U A.B.C.S HA
D.E A.B.C.S HA
D.E A.B.C.S HA
U A.B.C.S S
D.E HA HA
D.E A.B.C.S NA
D.E A.B.C.S HA
D.E A.B.C.S HA
Keys: EP • Federal project! P • Hon-Federal project
A * suitable as liner
B - suitable as closure naterial
C * suitable as daily cover without nixing
D • suitable as solid vaste {or disposal
in a lined landfill
E - suitable as daily cover with nixing
H • unsuitable
HA - not applicable
S - suitable
U • unresolved; treated as unsuitable for disposal option alternatives analysis
-------
TABLE 3-5. SUMMARY OF POTENTIAL SITE PREPARATION, MANAGEMENT
REQUIREMENTS FOR USE OF GENERIC DISPOSAL
ALTERNATIVES.
SITE PREPARATION
•Baseline investigations
•Permitting
•Acquisition
•Dredging
•Containnent structure-dike
-berm
-bulkhead
•Access road/rail
•Alteration of navigational channel
•Liner
MATERIAL PREPARATION
•Dewatering
•Mixing
TRANSPORTATION
•Barge
•Truck
•Rail
SITE MANAGEMENT
•Runoff control
•Closure
-landscaping
-dredged clay
-soil
-structure
-larine organic
-marine nineral
-prior desronstration of success
-marine habitat
•Burial
•Daily Cover
UPLAND
LANDFILL
X
X
X
X
X
X
X
X
X
UPLAND
INLAND
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
UPLAND
COASTAL
X
X
X
X
X
X
X
X
X
X
- X
X
X
X
X
AQUATIC
NEARSHORE
X
X
X
X
X
X
X
X
X
X
X
BORROW
PITS
X
X
X
X
X
X
X
OPEN
MATER
X
X
X
X
X
X
X
EXISTING
DISPOSAL
SITES
X
X
X
X
X
- 3-97
-------
TABLE 3-6. POTENTIAL IMPACTS FROM SILT DISPOSAL AT GENERIC ALTERNATIVE DISPOSAL SITES.
IMPACT
Exceeds Sedinent Criteria
Loss ot Habitat
Terrestrial
Hetland (F.H.)
Marine subtidal
Marine intertidal
Uteration of Habitat
Terrestrial
Hetland (f.H.)
Marine subtidal
Marine intertidal
rfater Quality
Freshwater
Marine
Current Use (Displaceaent)
SocioeconoBic
traffic
Truck
Barge
Historic/
ircbeological
Baigration Potential for
Contaninants
During disposal
Prior to contaiuent
Volatization
long-tern
Bioaccun. potential
UHD-8ASH)
LANDFILL IKLAHD COASTAL
X
X
X
P
X
X
P
P
X
X
X
P
P
P
X
P
T
X
P
T
X
T
X
X
X
P
P
P
jptic
TOTAL PARTIAL
X
X
X
X
T
X
X
P
T
X
P
T
X
X
P
P
SUBAQUEOUS
OUTER HARBOR CHAHHEL
T
X
T
X
P
P
P
P
T
T
X
T
X
P
P
P
P
T
808ROHEIIS
H/CAP
T
T
T
P
P
P
P
P
T
EXISTIHQ SITES
H/ CAP H/0 CAP
T
T
T
P
P
P
P
T
X
T
T
T
P
P
X
X
SOLIDIFICATION
T
P
Key: X • Upactj P • Possible iepact: T • Tetporary iipact.
-------
TABLE 3-7. IMPACTS CAUSED BY USING SPECIFIC UPLAND SITES FOR BOSTON HARBOR DREDGED MATERIAL DISPOSAL.
RESOURCE
SITE DESIGN
WATER QUALITY
MARINE
INTERTIDAL
MARINE
SUBTIDAL
SHELLFISH
FINFISH
FRESHWATER
AQUATIC
RESOURCES
WETLAND
VEGETATION,
WILDLIFE
THREATENED &
ENDANGERED
SPECIES
HISTORIC &
ARCHEOLOGICAL
SOCIOECONOMIC
& LANDUSE
TRAFFIC
PLAINVIEW/
LAIDLAW WESTMINSTER
LANDFILL LANDFILL
•DewatetfnB facility at Mystic Pier or North Jetty -Dewatering facility at Mystic Pier or North Jetty
•No special site modlllcallons required -No special site modlllcallons required
•Available capacity: dally cover < 500 cy/day 'Available capacity: dally cover < 250 cy/day
•Waste < 1 50-200 cy/day 'Waste < 200 cy/day
EAST
BRIDGEWATER
LANDFILL
•Dewaterlng facility at Mystic Pier or North Jetty
•No special site modifications required
•Available capacity: dally cover < 400 cy/day
•Waste < 75 cy/day
None
WRENTHAM
•Dewaterlng facility at Mysllc Pier or North Jetty
•She modification from undeveloped
forest/shrub to lined tandllll
•Footprint approx. 60 acres
•Capacity approx. 785,500 cy
•No groundwater Impacts
•Possible temporary surface water Impacts
from sedimentation and contaminants
- None
None
None
None
None
None
Nona
•Permanent toss of 9 ac. wetland
•Permanent loss of habitat to resident
spedes and fragmentation of wooded land
Possible habtlaJ for northern halrstreak
and Philadelphia panic grass
None
No change In land use, taut use (or dredge
material disposal would preempt other uses
Increase In truck IraHIc for transporting
dredged material to landfill
Possible change from undeveloped forest
and shrubland to lined containment facility
•Increase In (ruck traffic during
construction and dredge disposal phase
•Heavy truck use already occurs from
adjacent gravel operation
-------
TABLE S-y.tCONTiNUED) IMPACTS CAUSED BY USING SPECIFIC UPLAND SITES FOB BOSTON HABBOR DREDGED MATERIAL DISPOSAL
RESOURCE
SITE DESIGN
WATER QUALITY
MARINE
IHTERTIDAL
MARINE
SUBTIDAL
SHELLFISH
FINFISH
FRESHWATER
AQUATIC
RESOURCES
WETLAND
VEGETATION,
WILDLIFE
THREATENED &
ENDANGERED
SPECIES
HISTORIC &
ARCHEOLOGICAL
SOCIOECONOMIC
& LANDUSE
TRAFFIC
WOBURN
•Dwa wing ladftym Mystic Pto or HofihJeny
•Capping dosed munWpaJ 1 ami fill
with lined Way
• Footprint-25 acres
• C«p«ity.158.eoOcy
•May Improve oroundwaler quality by
capping tandWI
•Possible temporary surface water Impacts
from sedimentation and contaminants
Nona
None
None
None
Possible temporary Impacts to tributary
to Hall's Brook
•Permanent loss of portion of 1 ac. wetland
•Permanent loss ol early succession^ field
and wooded habitat
None
None
Permanent capping of dosed municipal landfill
•Construction traffic
•Increase In truck end rail traffic due to
transport of dredged material to landfill
EVERETT
•Dredge bargu tang
•SBe modlod from abandoned
urban land to tandM
•Footprint .6 acres
• CopncJty-TO.OOOcy
SQUANTUM
POINT
•Dredge barge tano
•Construct Urwd containment twm and
fill with drsdg&d materials up to 1 0 foot deep
•Dewattr through Mention basin, cap when dry
• FootprinMBacrM • Capadry.210,000cy
•Temporary local Increase In suspended solids during dredging
•Temporary release ol contaminants during dredging
•Dredging of 2 acres ol Inlertldal habitat
•Potential slltatlon during dredging and barge manuevering
Dredging of approximately 0.03 ac, of fine-grained
sediment and disturbance during barge manuevering
will result In temporary loss ot benlhlc production
No harvestable shellfish beds In area
Temporary disturbance to llnllsh habitat.
Permanent loss ol approximately 0.3 ac, ol
fine-grained tidal flat and 0.03 ac. of salt marsh
Alteration ol approximately 1.4 ac. of
fine-grained habitat
Temporary Impact to mussel and soflshell dam habitat
Temporary disturbance to llnllsh habitat.
None
•No freshwater wetland Impacts
•Loss of open land In an urban setting
None
Jacknlfe drawbridge within 1 000 ft of site
Permanent change from abandoned urban land to landfill
•Construction traffic
•Dredged material transported by barge
•Permanent loss of approximately 0.33 ac. of wetland
•Permanent loss ol shrubland bird habitat and
disturbance ol salt marsh tidal flat habitat
Loss ot short-eared owl migratory/wintering habitat
None
None
•Construction traffic
•Dredged material transported by barge
-------
TABLE 3-8. POTENTIAL BENEFITS OF DREDGED MATERIAL DISPOSAL ALTERNATIVES.
BENEFIT
Remove/Isolate Contaminated
Sediment from Environment
Cover Existing Contaminated
Sediments
Enhance Resource/Habitat
Economic Benefits
Cap Existing Disposal Site
Beneficial Use of Parent
Material
Use of Existing On-site
Materials
Future Use of Impacted Area
UPLAND
LANDFILL INLAND COASTAL
XXX
P
P P
X
X X .X
X P P
AQUATIC
SHORELINE
TOTAL PARTIAL
X X
X X
X
P
X X
X X
SUBAQUEOUS
OUTER HARBOR CHANNEL
X X
X X
X
BORROW
PITS
H/ CAP
X
P
X
X
EXISTING DISPOSAL
SITES
W/ CAP H/0 CAP
X
P
P
X X
X
X X
SOLIDIFICATION
X
X
ft,*S'
P
Key: X = Benefit; P = Possible benefit
-------
TABLE 3-9. IMPACTS CAUSED BY USING SPECIFIC AQUATIC SHORELINE SITES FOR BOSTON HARBOR DREDGED MATERIAL DISPOSAL
RESOURCE
SJTE DESIGN
WATER QUALITY
MARINE
INTERTIDAL
MARINE
SUBTIDAL
SHELLFISH
FINFISH
FRESHWATER
AQUATIC
RESOURCES
WETLAND
VEGETATION,
WILDLIFE
THREATENED &
ENDANGERED
SPECIES
HISTORIC &
ARCHEOLOGICAL
SOCIOECONOMIC
& LANDUSE
TRAFFIC
MYSTIC PIERS
TOTAL FILL
Bulkhead h»rborl»c«illll behind
(BicurtaJrvwtlrto MHWorhlflrwr.
Draglne (a postilon udlminti.
Fowprlnt-2.7*c;
c» party. 135,000 cu. ydi.
•P«mantnl toss ol 31 mllon gal.
of Boston Harborca|j«c)!y, no
Impact on current vtbdty
•Dtmdiring controls r**d*d.
Permanent Iocs ol mscroalgao,
bwnacle, and blue mussel
production on hard substrate
Lou ol 2.7 acres llna-gralned
soft habitat
PARTIAL FILL
Btrikhtad haibo r l«c«; H I toihfnd
i« curttWiwtr to -3 ft MLW.op
v*h clay to MLW. Drtgitn* to
pottbn ledlmwtt. Footprint*
2.7 ic; e»pidly-e8,000 cu, y* .
•Pirmimnt tost ol 29 mlBon giL
ol Botton Hiitor aptdty, no
Impact on oumnt vebcty
•Dtwitirlng oontrob n*«did
No loss ol hard substrate
•Alteration of 2.7 ac. line-grained
soft substrate.
•Capping of existing contaminants
•Loss of piling and bulkhead
(hard substrate)
Loss ol Inlortldal mussels on pUlngs
•Mortality ol demersal (ton eggs;
larvae and adults
trapped behind bulkhead.
•Permanent loss ol (Irtish reluge
and foraging habitat
•Mortality ol demersaal fish eggs;
larvae and adults
trapped behind bulkhead.
•Temporary loss ol (Irtish refuge
and foraging habitat
REVERE SUGAR
TOTAL FILL
BulWwKl hut of lice; III bthfnd
inwMrvVMlrtoMHWorNgtnf
DrtgKne to petition Hdlminti.
Footprlnt.3,7«o,;
cap«ctty«1 08,000 cu. ydt.
•Ptmwwm toss ol 21 mllon gil.
ol Boston Hubof opacity, no
Impact on cunint vtloclty
•Otwitwlng contrail nw tfc d.
Permanent loss of macroalgtie,
barnacle, and llttorina snail
production on hard substrate
Loss ol 3.7 acres Una-grained
soft habitat
PARTIAL FILL
8uMnadtwborfic«;IIilb
-------
TABLE 3-9 (CONTINUED). IMPACTS CAUSED BY USING SPECIFIC AQUATIC SHORELINE SITES FOR BOSTON HARBOR DREDGED MATERIAL DISPOSAL.
RESOURCE
SITE DESIGN
WATER QUALITY
MARINE
INTERTIDAL
MARINE
SUBTIDAL
SHELLFISH
F1NFISH
FRESHWATER
AQUATIC
RESOURCES
WETLAND
VEGETATION,
WILDLIFE
THREATENED &
ENDANGERED
SPECIES
HISTORIC &
ARCHEOLOGICAL
SOCIOECONOMIC
& LANDUSE
TRAFFIC
CABOT PAINT
TOTAL FILL
Bulkhead harbor face;flll behind
silt cimalntolrto M-tW or higher.
Footpilnt«5.6ac,;
capaclly-99.000 cu. yds.
•Permanent loss of 33 minion
gallons ol Boston Haitaor capacity
•Oewuwlng controls meded.
•Perm, lose of Fucus & barnacle
production on hard substrate
•Permanent toes of gravel
beaches on northeast and
northwest
Permanent toes ol 5.6 acres
line-grained soft habitat
PARTIAL FILL
Bulkhead river face; (III behind
eUt curtaWwelrto -3 ft MLW.cap
wHnclaytoMLW. Footprint-
6.6 ae.; capacdy-18,000 eu. yds.
•Permanent toss of 12 mlMon
gallons of Boston Harbor capacity
•Oewattrlng controls needed.
Permanent loss of gravel
beaches on northeast and
northwest
•Alteration of 5.6 ac. ot soft
substrate.
•Improve sediment quality
None
•Mortality of demereal lleh eggs;
larvae and adults
trapped behind bulkhead.
•Permanent loes 04 (Irtish reluge
and (oraglng hablud
Permanent loes ot 6.6 acres ol
Intertldal and sublldal wetlands
•Mortality ol demersal Iteh eggs;
larvae and adults
trapped behind bulkhead.
•Temporary loss of flnHsh refuge
and foraging habitat
Alteration ol 5.6 acres of
kilortkJal and subtldal wetlands
1 ITTI C MVQTIP PUAMMCI
LI 1 1 LC n/i TO i i\j vrmnncL
Bulkhead rivertace; fill behind
sltt curtah/welr to -3 It MLW.cap 3 It
thick with clay to MLW. Footprirrt-1 6 ac.;
capacfty-303.000 cu. yds.
•One CSO and six discharge p^»s
may need to be dlv«n»d
•SIRatlon controls needed.
•Temporary reduction In Fucus, green algae and
bamada production on hard substrate
•Short-term Impact on small sandy -5 ravel beach
•Conversion to shallow sublldal habttat
•Improve sediment quality
•Temporary loss ol 1 5.0 acres ol soft substrate
Short-term Impacts on mussels and metal bulkhead
RESERVED CHANNEL
AREA A
Bulkhead near Summer St. Bridge,
west of marina. FID to -6ft MLW;
Cap; Cut bullhead,
Footprtm-8.9 ao
CapacKy-14,OOOcy
•P«nn. loss ol 48.5 million gallons
ot Boston Haibor Capacity, no
Impact on current velocity
•Station controls needed
Temporary reduction In Fucus,
green algae and bamaete
production on hard substrate
•Conversion to shallow subtldal
habitat
•Improve sediment quality
•Temporary loss ol 8.0 acres ol
soft substrate
AREA B (WEST END)
Bulkhead westernmost end;
FID to 46ft MLW, Cap to
MHW; Remove bulkhead; Sattmarsh
Foolpr!nl-7.7 ao
Capactty-185,000cy
•Perm, loss of 16 minion gallons
of Boston Hubor Capacity
•3 CSCXs would need to be relocated
•SIHatlon controls needed.
•Perm, loss ol barnacle, Fucus, green
algae and barnacle prod, on hard sub.
•Perni. loss of small rocky btach
•IncfMS* In IntMtldal habitat
>!nc.
Possible conflict with yacht club
•Sediment by barges (140) and trucks (9800): minor delays to
commercial/recreational boating traffic.
•Some roadway traffic delays and noise Impacts
I
-------
-A
JftBlE 3-10. POTENTIAL IMPACTS CAUSED BY USING SPECIFIC SUBAQUEOUS, BORBOW PIT AND IN^CHANNEL SITES FOR BOSTON KABBOR DREDGED MATERIAL DISPOSAL
RESOURCE
SITE DESIGN
WATER QUALITY
MARINE
INTERTIDAL
MARINE
SUBTIDAL
SHELLFISH
FINFISH
FRESHWATER
AQUATIC
RESOURCES
WETLAND
VEGETATION,
WILDLIFE
THREATENED &
ENDANGERED
SPECIES
HISTORIC &
ARCHEOLOGICAL
SOCIOECONOMIC
& LANDUSE
TRAFFIC
SUBAQUEOUS
B
Place sill end cap with day to
Boald«plhoM5flMLW.
Footprtnit-Wae.
Capadty«op to 609,000 cy
•Potential for water quality exeoedoncos
after 4 hrs up (o 4500 It from dump site
•Permanent toss ol up to 204 million
gel, ol Boston Harbor water capacity
SUBAQUEOUS
E
Pise* tilt and cap wfih day to
linaldoplhol-anMLW.
FootprW-79 acres
Capactty.up to 614,000 cy
•Potential for water quality excoodencos
alter 4 hrs up to 4500 It from dump site.
•Permanent loss ol up to 201 million
gal. ol Boston Harbor water capacity
WINTHBOP
HARBOR
ptaca sift and cap wllh day to
final depth of -12 ft MLW.
Footprint-^ acres
Capaetty-W.OOOcy
•PoMal [or water quality oxceedences
alter 4 hrs up to 4500 ft from dump site
•Permanent loss ol up to 64.B million
gal. ol Boston Harbor water capacity
CHELSEA
CREEK
IN-CHANNEL
•Over drodgo chwoJ to -47 It MLW
•Fill lo -42 ft MLW with contaminated
sediments
•Cap to -40 ft MLW with clay
•Capactty«207.000cy
•Potential lor watw quality exceedences
aftar 4 hrs up to 4500 ft from dump silo
•Negligible meet on current volodty
•No change In Harbor volume
Not applies We
Temporary loss ol up lo 63 ac. ol
soft substrate
Temporary loss ol up to 79 ac. ol
soil substrata
Short-tern Impact on softshell dam and lobster populations due to
Increased suspended sediments
s oft substrdo
•Improved habitat quality for bonlhta
fauna
Short-term Impact on soflsholl dam
population due to Increased
suspended sediments
INNER
CONFLUENCE
IN-CHANNEL
•Ovor dredge channel to -49 ft MLW
•Fill to -44 It MLW with contaminated
Mdtmtnis
•Cop to -42 It MLW with clay
• Capacfty.l40,000ey
•Polaroid (or water quaSty exce«d»now
attsr 4 hrt up to 4500 ft from dump tits
•Negf gbl« etloct on current vatodty
•No change In Harbor volume
No habitat loss beyond that caused by Improvement dredging project.
Potential short-term Impacts to nearby resources
due to Impacts to water quality,
although no commercial beds nearby.
• Short-tarn mortality ol fish eggs, larvae, and adults
• Temporary reduction ol prey available to species which lead primarily on Invertebrates
• Temporary Interference with commercial flshery
Not applicable
Temporary Impact on 83 ac.
olsubtldal wetland
Temporary Impact on 79 ac.
olsubtldal wetland
Temporary loss of 8.14 ac.
olsubtldal wetland
No Impacts beyond those Incurred due to dredging project
• None expected
• None
Minor temporary Impact on
boal traffic
•Transportation ol dredged material
bybarga
•Approx. 450 barge trips
•Temporary Interruptions In Dorchester
Channel
Interruption ol use ol small vessel
navigation channel
•Transportation ol dredged material
by barge
•Approx. 450 barge trips
•Relocation of small vessel channel
Temporary Impact on boat traffic
•Transportation of dredged material
by barge
•Approx. 120 barge trips
•temporary Interruptions In Wlnlhrop
Harbor Channel
Prolonged dredging In navigational channel resulting
In additional minor Interruption ol shipping traffic
•Addlt. dredging would require 60 days
•120 bargetrips required to remove
clay sediments
• 30 days of additional dredging
• 60 barge trips to remove day
-------
TABLE 3-10 (CONTINUED). POTENTIAL IMPACTS CAUSED BY USING SPECIFIC SUBAQUEOUS, BORROW PIT AND IN-CHANNEL SITES FOR BOSTON HARBOR DREDGED MATERIAL DISPOSAL
RESOURCE
SITE DESIGN
WATER QUALITY
MARINE
INTERTIDAL
MARINE
SUBTIDAL
SHELLFISH
RNFISH
FRESHWATER
AQUATIC
RESOURCES
WETLAND
VEGETATION,
WILDLIFE
THREATENED &
ENDANGERED
SPECIES
HISTORIC &
ARCHEOLOGICAL
SOCIOECONOMIC
& LANDUSE
TRAFFIC
MYSTIC
RIVER
IN-CHANNEL
•Over-dredge to -49 ft MLW
•Fill to -44 flMLW with B|»
•cap to -42 II MLW with day
Capacity 318,000 cy
•Potential tor water quality exceedenoes
after 4 hra up to 4500 ft from dump site
•Mo change In Harbor volumes
MEISBURGER
2
•Dredge pit $40 ft deep
•Fill wfth dredged silt
•Cap with day and sand to pre-existing contours
•Footprint 86 acres
•Capacity 780,oou-4,660,000 cy
Water quality criteria not exceeded
outside site 4 tire after dump.
MEISBURGER
7
•Dredge pit 10 ft deep
•Fill with dredged silt
•Cap with clay and sand to pre-existing contours
•Footprint 121 acres
•Capacity to 6.1+ million cy
Water quality criteria not exceeded
outside stle 4 hrs after dump.
SPECTACLE
ISLAND
CAD
•Fill with dredged silt
•Cap with day and sand to pre-existing contours
•Footprint 20-50 acres
•Capacity 600,000-1 ,450,000 cy
Potential for water quality exceedences;
Construction/mitigation steps would be planned
Not applicable
No habitat loss beyond that caused
by Improvement dredging project
Potential short-term Impacts to
nearby resources due to Impacts
to water quality
•Temporary loss of 1 50 ac. of soft substrate
•Beach Improvement from excavated material
•Temporary loss of 82-403 ac. of soft substrate
•Beach Improvement from excavated material
•Short-term Impact on lobster population
•Temporary Interference with commercial fishery
Temporary loss ot 20-70 ac. of soft substrate
Potential temporary slltatlon on nearby
mussel beds
•short-term mortality of fish eggs, larvae and adults
•Temporary reduction of prey available to species which feed primarily on Invertebrates
•Temporary Interference with commercial fishery
Not applicable
No Impacts beyond those Incurred due
to dredging project
None expected
•No state lurfsdlctlonal wetlands) >SOHMLW)
•Temporary Interference wHh commercial fishery
None expected, although some spedes of whales
and sea turtles could occur In area Incidentally
Temporary loss of 22 ac. of sublldal wetlands
Not applicable
None
Prolonged dredging In navigational channel
resulting In additional minor Interruption of
shipping traffic
•90 days of additional dredging
•1 85 barge trips to remove
parent material
Temporary Impact on fishing and recreational boallng
•Dredge will be on-stte for > 1 year
•660 barge trips required to remove sediments
•660 barge trips required to transport harbor
sediments to site
•Dredge will be on-stte for > 1 year
•660 barga.trips required to remove sediments
•660 barge'trips required to transport harbor
sediments to site
•Temporary Impact on recreational boating
•Possible conflict wtth construction of fish reef
•Dredge will be on-stte for> 3 months
•660 barge trips required to remove sediments
•660 barge trips required to transport harbor
sediments to site
-------
TABLE 3-11. IMPACTS CAUSED BY USING EXISTING OPEN WATER DISPOSAL SITES FOB BOSTON HARBOR DREDGED MATERIAL DISPOSAL
^
\
6s
RESOURCE
SITE DESIGN
WATER QUALITY
MARINE
INTERTIDAL
MARINE
SUBTIDAL
SHELLFISH
FINFISH
FRESHWATER
AQUATIC
RESOURCES
WETLAND
VEGETATION,
WILDLIFE
THREATENED &
ENDANGERED
SPECIES
HISTORIC &
ARCHEOLOGICAL
SOCIOECONOMIC
& LANDUSE
TRAFFIC
MASSACHUSETTS BAY DISPOSAL SITE
BOSTON LIGHTSHIP
Continuous point disposal of (Nt two WMta after elart ol df edging;
Capping vrtth pwmt material,
No water quality criteria oxcwxfoncos after lour hours outside the stto.
Not appllcablo
•Benlhlc resources maintained In pioneering stage due lo regular disposal
•No significant change from existing conditions
Possible mature benlhlc community now existing,
Disposal would temporarily convert lo a pioneering community.
Gills of any shellfish In Immediate vicinity ol disposal site could become clogged
•Some mortality ol demereel flsh due to burial
•Avoidance ol disposal operation
Not 'applicable
Designated disposal she
Alteration ol sublldal habitat conditions
In Tidal Waters
•Endangered whales and turtles are transients In area, and would likely avoid disposal activities
None
•Designated dredged material disposal site
•No change In current use
Needs further review
Former dredged material disposal site
•Disposal ol parent material and rock would require up to 500 barge trips (4000 cy capacity)
•Disposal ol silt would require up to 1 70 barge trips (4000 cy capacity)
•Average ol two barge trips per day
-------
TABLE 3-12. ALHWATIYB DISPOSAL OPTIONS FOE DISPOSAL OF SILT SEDIKEHTS. BOSIOH EAEBOR KAYIGATION IHPKOYHKffllT PROJECT.
UPLAH)
AQUATIC
\
•\
J
)
TREATMENT
TIPE
Landfill
Inland
Coastal
Shoreline
«
Subaqueous
in^el
Borrov pit
Existing
Disposal site
HINIHUH NO. SITES KBH
SITE
E. Bridgevater
Plainville
Fitchburg/Hest«inster
Hotnira
Hrentbac
Everett
Squantui Point
Anstar
Cabot Paint
Little Mystic Cbannel
Mystic Piers
Reserved Cbannel
Revere Sugar
Subaqueous B
Subaqueous E
Hinthrop Harbor
Chelsea Creek
Inner Confluence
Mystic River
Heisburger 2
Heisburger 7
Spectacle Island CAD
Boston Light Snip
KBDS
Solidification
>H> FOR CAPACITY:
Landfill
Upland
Shoreline
NOD Shoreline Aquatic
Existing Disposal
Site
CAPACITY
200(d.c.), 200(fill) cy/day '
SOtd.c.). 250(fill) cy/day
75(fill), 250(d.c.) cy/day
158,600
785,500
70,000
210.000
128.000-179,000d
18.0CO-99.000d
303.000"
98,000-135,000d
14,000-199,000*
85,000-136,000d
278.000-609,000
614,000
167,000
207,000
140,000
317,000
780,000-4.660,000
to 6,125.000
600,000-1,450,000
unlinited
unlit! ted
6.000/day
UPUHD
COST .. Al° A2 A3
-------
TABLE 3-13. COST ESTIMATES FOR LANDFILL SITES FOR DISPOSAL OF SILTS FROM BHiNJP.
UtxHIII*
Location
East Brfdgewator
Plalnvllle
Rtehburg/Westmlnater
Distance
(Mies)
25
35
45
Sift
Volume
(CY)
1,310,000
1,319,000
1.319,000
Dredging
CoatWY
$7.10
$9,364.000
$9,364,900
$9,364,900
Dewatartng
Coat /CY
$12.00
$15,820,000
$15.828,000
$15.828.000
Hauling
CoaVCY
$920
$12.25
$12.25
Hauling
Coal
$12,134,800
$16,157,750
$16,157.750
Tipping
Fee
($/CY)
28.00
56.00
70.00
Tipping
Coat
$38,032.000
$73,864.000
$92,330.000
Total
Coat
$74,259,700
$115^14.650
$133,680,650
Unit Cost
for Silt
$56.00
$87.00
$101.00
ASSUMPTIONS
Hauling costs assumed fleet of 20 bucks and 3 loaders woridng 5 days/wk.
Dewaterioq coat based on Massporfs recent bid for Morari Terminal and Includes storafje for up to 15 months.
Real estate coat for lands required for dewatering sites have not been Included.
Total landflH capacity available Is 102,000 CY. Unit cost for sIK Is valid If less volume Is disposed.
-------
TABLE 3-14. COST ESTIMATES FOR LAND-BASED SITES FOR DISPOSAL OF SILTS FROM BHNIP.
Wobum-11
Footprint
(SqR)
617,500
Sit
Volume
(CY)
158,600
Total
Cost
Perimeter
(FT)
3,100
Dredging
CosVCY
$7.10
$1.126.060
Unit Cost
for Silt
DOca Material
(CY)
63.400
Hauling
Cost/CY
$9.30
$1,474,980
Dike Cost
$15.00 /CY
$951.000
fa*n
CostfCY
$15.00
$525.000
Lining Cost
$26.00 /SY
$1.783^89
Dewatering
Cost
$12.00 /CY
$1.903.200
Road FB
$13.00
$1.560,000
Treatment
Cost
$2.00 /CY
$317200
Clearing/
Drainage
$59,200
$9.701.000
$61.00
ASSUMPTIONS
Footprint (area) planimetered from quad sheet
Footprint selected to avoid wetlands and power fines. As a result two of three areas were not large enough to use.
Dike volume computed from dike height of 12*. top width of Iff and side slopes of 1V to 3H ("CAD CELL* program).
Sediment depth 10' with 2' cap thickness.
Liner consists of geomembrane for positive cut-off, 1' of sand and a geotexQe filter.
Also included in cost of iner is a geotexSle filter at the cap layer.
Sand cost $12/CY, geotextfle $3/SY and geomembmne $16/SY.
Volume of road fill calculated for road within the diked area requiring 120,000 CY.
Clearing costs determined by assuming $2800/acre for 14 acres.
Drainage costs assumed to be rerouting local drainage 9 $20,000.
Hauling costs assumed fleet of 30 trucks and 4 loaders working 7 days/wk for 3 months with hauling distance = 30 mites.
Cap was assumed to be trucked from Boston (Boston Blue Clay from Improvement Project).
Dewalaring cost based on Massporf s recent bid for Moran Terminal and includes storage for up to 3 months.
Treatment of teachate from site is expected to require saline tainted water to be reansported
to a local treatment plant, construction of package treatment plant or trucking to the ocean.
Cost of real estate acquisition not included.
-------
TABLE 3-14 (CONTINUED). COST ESTIMATES FOR LAND-BASED SITES FOR DISPOSAL OF SILTS FROM BHNIP.
Wr*nmin>485
Footprint
(Saffi
2,551,000
set
Volume
185,000
HauBng
CosWCY
$12.00
$9.426,000
DikaCoet
$11.00 ICY
$2,035,000
Cap
Cost/CY
$11.00
$1,977^00
Lining Cod
$26.00 /SY
S7.369.556
De watering
Cost ICY
$12.00
$9,426,000
Road Fl
$13.00 /CY
$1,850,000
Treatment
Coat KM
$2.00
$1,571,000
Clearing/
$39,520,000
$50.00
ASSUMPTIONS
Footprint (area) planlmaterad from quad sheet and addad for two separate tited areas.
Footprint selected to avoid wetlands, power fines and residential areas.
Dtovolurno computed from dBwheigtt of 12\ top wMhoftff.ste
Sediment thickness 10' with 2 cap thickness.
Uner consists of gaomembrane for positive cut-off, 1' of sand and a gaotextile Star.
Also Inducted in cost of liner b a geotextBe Star at the cap layer.
Sand cost S12/CY, geotextflo S3/5Y and gaomembrana S16/SY.
Volume of road fl calculated for road wlhin the diked area requirina 150.000 CY.
Clearing costs determined by assuming S2800/acre for 60 acres.
Drainage costs assumed to be rerouting local drainage O $20,000
HauEng costs assumed Seat of 30 trucks and 4 loaders working 7 daysftvk for 15 months with hauling distance = 40 mites.
Cap was assumed to be purchased locally with volume of 179,800 CY determined from "CAD CELL* program.
DowaJaring cost based on Massporf s recent bid for Moran Terminal and includes storage for up to 15 months.
Treatment of leachate from site is expected to require saline tainted water to be transported
to a local treatment plant, construction of package treatment plant or trucking to the ocean.
Cost of real estate acquisition not included.
-------
TABLE 3-14 (CONTINUED). COST ESTIMATES FOR LAND-BASED SITES FOR DISPOSAL OF SILTS FROM BHNIP.
Squantum • (Trucking)
Footprint Perimeter Dice Material
(SqFt) (FT) (CY)
782,500
Silt
Volume
(CY)
210,000
Dewataring
CostfCY
$12.00
4,300
3' Cap
Volume
(CY)
46,000
Road BE
$13.00 /CY
87,900
Total
Volume
(CY)
256,000
Total
Cost
Dike Cost Clearing/
$15.00 JCY Drainage
$1,318,500
Dredging
Cost/CY
$1.914.200
Unit Cost
for S%
$45,200
Hauling
Cost/CY
$5.00
$1,280,000
$2,520,000
$650,000
$7,728,000
$37.00
Squantum - (Barging)
Footprint Perimeter Dke Material
(SqFt) (FT) (CY)
782,500
Silt
Volume
(CY)
210,000
Dredging
Access
(CY)
4.300
31 Cap
Volume
(CY)
46,000
Dredging
Access
$950 /CY
87,900
Total
Volume
(CY)
256,000
RehandEng
Cost
$15.00
Dike Cost
$15.00 /CY
$1.318.500
Dredging
CostfCY
$1.914.200
Total
Cost
Clearing/
Drainage
$45500
Unit Cost
for Sat
160,000
$1,472,000
$5,550,000
$10,300.000
$49.00
ASSUMPTIONS
Footprint (area) planimetered from quad sheet
Footprint selected to avoid wetland.
Dike volume computed from dike height of 12", top width of 101 and side slopes of 1V to 3H time perimeter of 4300*.
Sediment thickness 10' with 21 cap thickness.
Clearing costs determined by assuming $1400/acre for 18 acres.
Drainage costs assumed to be rerouting local drainage d $20,000.
Hauling costs assumed fleet of 10 trucks and 3 loaders working 7 days/wk for 4.5 months with hauling distance = 10 mites.
Dewatering cost based on Masspotfs recent bid for Moran Terminal and includes storage for up to 4.5 months.
Volume of road fill calculated for road within the diked area requiring 50000 CY.
The 2700' x 1751 access channel assumed to have existing depth of -4'MLW and require a 12* depth.
Dredged material from access channel assumed to be disposed at MBDS.
Rehandfing cost is for a barge-mounted crane to unload aH scows.
Dredging costs - parent = $920, silt=$7.10.
Cost of real estate acquisition not included.
1,975,000 CY of additional parent material remain after capping and requires dsposal.
-------
TABLE 3-14 (CONTINUED). COST ESTIMATES FOR LAND-BASED SITES FOR DISPOSAL OF SILTS FROM BHNIP.
Everett-04
Sift
Volume
(CY)
37,000
Dike
(CY)
3' Cap
Volume
(CY)
18,000
Dike
CosVCY
$15.00
Total
Volume
(CY)
55,000
Footprint
Area
(SQFT)
Mechanical
Dredging
Cost/CY
$7.10
$9.20
Average
Depth
(FT)
Rehandllng
Cost/CY
$15.00
Wlar/SItt
Curtain
Cost
Total
Dredging
Cost
$1,253,300
Total
Cost
Bulkhead
(LF)
400
Unit Cost
for Sift
($/CY)
Depth of
Piles
(FT)
105
Bulkhead Cost
($30 per SQFT)
$1,260,000
17,100
$256,500
243,936
$36,590 $2,806,390
$76.00
ASSUMPTIONS
Footprint (area) planlmetered from quad sheet.
Footprint selected to avoid crossing municipal boundary.
Dike volume computed from dike height of 8', top width of 10' and side slopes of 1V to 3H.
Dike length 1700'.
Sediment thickness varies (assumed to be ff on upland site and 18' In water) with cap thickness of 2'.
Rehandlng cost Is for a barge-mounted crane to unload the scows.
Bulkhead costs reflect $30/SF for steel.
Bulkhead assumed to tie to fast ground and only be necessary along fronting water edge.
Wler required and Is based on cost of $0.15/CY of material contained.
Dredge costs - parent = $9.20, sift = $7.10.
-------
TABLE 3-15. COST ESTIMATES FOR AQUATIC SHORELINE OPTIONS
NEARSHORE
AQUATIC SHORELINE
Volume
Revere Sugar
Amstsr
Mystic Pien
Cabot Paint
Uttto Mystic Channel
Reserved Channel-A
Reserved Channel - B
rato
level of:
MLW
MLW
MLW
MLW
•3 MLW
-6 MLW
+9.5 MLW
Sediment
Volume
(CY)
86,000
128,000
98,000
18,000
303,000
14,000
186,000
y Cap
Volume
(CY)
18,000
17,000
13,000
27,000
70,000
44,000
37,000
Total
Volume
(CY)
104,000
145,000
111,000
45,000
373,000
58,000
223,000
Surface
Footprint
(SOFT)
160,000
153,000
120,000
243,000
630,000
390,000
334,000
DreddnoWandfino.
Revere Sugar
Amstar
Mystic Piers
Cabot Paint
Urtte Mystic Channel
Reserved Channel-A
Reserved Channet-B
Revere Sugar
Amstar
Mystic Piers
Cabot Paint
Utfe Mystic Channel
Reserved Channel-A
Reserved Channet-B
Dredging
Cost/CY
(s»t)
$7.10
$7.10
$7.10
$7.10
$7.10
$7.10
$7.10
Dredging
CostfCY
(parent)
$920
$920
$920
$920
$920
$920
$920
Wier/Sat
Curtain
Cost
$24,000
$22.950
$18,000
$36,450
$94,500
$58,500
$50,100
Rehand&ng
Cost/CY
$15.00
$15.00
$15.00
$15.00
$15.00
$15.00
$15.00
Design and
Const Mgt
Cost
$158,000
$250.000
$178.000
$262,000
$517.000
$186.000
$371,000
Total
Dredging
Cost
$1,712200
$2,370200
$1,814,400
$781200
$6,152,300
$1,026200
$3.668.000
Contingency
Cost
(25%)
$603,000
$956,000
$680,000
$1,002,000
$1,974.000
$713,000
$1,417,000
Bufchead
(LF)
165
375
225
930
360
585
585
Total
Cost
$3,016,950
$4,780.400
$3.399.150
$5.011,150
$9,871,800
$3.563200
$7,085,600
Depth
below MLW
(Fn
17.5
25.5
25
5
19
10
8.5
Bulkhead Cost
Depth of
P9e*
(FI)
105
105
105
105
105
90
90
UnlCost
for SiK
WCY)
$35.00
$37.00
$35.00
$278.00
$33.00
$255.00
$38.00
Capacity/
R Depth
(CY)
6,000
6,000
4,000
9,000
23,000
14,000
12,000
Bulkhead
Cost
($30/SQFT)
$519,750
$1,181250
$708,750
$2,929,500
$1,134,000
$1,579,500
$1.579,500
ASSUMPTIONS
Surface area pUuwnetered from navigation chart vertical sides assumed.
Depth is an average *s shown on navigation chart or recent survey.
Dredging cost is not dependent on Distance to depose! site.
Rehand&ng cost b for * barge-mounted crane to unload 60% of the scows (40% of scows to be bottom dumped).
Bulkhead costs reflect $30/SF for steel
Bulkhead assumed to tie to fast ground and only be necessary along fronting water edge.
VWer required if Disposal site to create fast tend (cost fa $0.15 x surface area).
Revere Sugar
Amstar
Mystic Piers
Cabot Paint
Lille Mystic Channel
2,003,000 CY of addHional parent material remain after capping and requires deposa!.
2,004,000 '
£008,000 ' '
1,994,000 '
1,951,000 '
Reserved Channel-A 1,977,000 *
Reserved Channel 1,984,000 '
-------
TABLE 3-16. COST ESTIMATES FOR SUBAQUEOUS DEPRESSION OPTION B-2 FOR DISPOSAL OF SILTS FROM BHNIP.
SubaqueousB
(North)
(South)
Footprint Existing
(Sq Ft) Depth
Below
MLW
(FT)
2,498,000 21
1,116,000 28
Proposed
Depth
Below
MLW
(FT)
15
15
Volume
Silt
Volume
(CY)
278,000
331,000
3' Cap
Volume
(CY)
278,000
124,000
Total
Volume
(CY)
556,000
455,000
Dredging
Cost
$4,531,400
$3,490,900
Design and
Const. Mgt
Cost
$75,000
$65,000
Costs
Contingency
Cost
(25%)
$1,152,000
$889,000
Total
Cost
$5,758,400
$4,444,900
Weighted Average
Unit Cost
for Slit
($/CY)
$21.00
$13.00
$17.00
ASSUMPTIONS
X^
Footprint (area) planimetered from navigation chart.
Two footprint areas result from site being split by Dorchester Channel.
Existing depth calculated from navigation chart soundings within area.
Depth after disposal is finished depth Including a 3 foot cap.
Vertical sides of disposal site are assumed.
Material will not flow out of the disposal she Into adjacent channel.
Design effort involves minimal site hydrographte survey ($20,000) and benthic and fish studies ($10,000).
Contingency is 25%.
Dredging costs - slit« $7.10, parent =» $9.20.
North 1,743,000 CY of additional parent material remain after capping and requires disposal.
South 1,897,000 CY of additional parent material remain after capping and requires disposal.
-------
TABLE 3-16 (CONTINUED). COST ESTIMATES FOR SUBAQUEOUS DEPRESSION OPTION B-2 FOR DISPOSAL
OF SILTS FROM BHNIP.
Subaqueous E (Oov to and Lower MkMla)
Footprint
(SqFt)
Existing
Depth
Below
MLW
(FT)
Proposed
Depth
Below
MLW
(FT)
Volume
Silt
Volume
(CY)
3' Cap
Volume
(CY)
Total
Volume
(CY)
Dredqlnn
Cost
Costs
Deslfln and
Constr. Mgt
Cost
Contingency
Cost
Total
Cost
UnttCost
for Silt
($/CY)
3,451,000
15.0
614,000
383,000
997,000
$7,883,000 $109,000 $1,971,000 $9,963,000
$16.00
ASSUMPTIONS
Footprint (area) planlmetered from navigation chart
Dredged material wilt not flow from the site
Existing depth calculated from navigation chart soundings within area.
Proposed depth Is finished depth Including a 3 foot cap.
Vertical sides of disposal site are assumed
Design cost Includes minimal site hydrographlc survey ($20,000), and benthlc and fish studies ($10,000).
Contingency Is 25%.
Dredging costs • silt • $7.10, parent - $950.
1,638,000 CY of addWonal parent material remain after capping and requires disposal.
(A
-------
TABLE 3-16 (CONTINUED). COST ESTIMATES FOR SUBAQUEOUS DEPRESSION OPTION B-2 FOR DISPOSAL
OF SILTS FROM BiHNIP.
SubuqiiBoua (Wlrrthrop)
Footprint Existing Proposed
(Sq R) Depth Depth
Below Below
MLW MLW
(FT\ fFH
Volume
Silt
Volume
(CY)
3' Cap
Volume
(CY»
Total
Volume
(CY1
Dredging
Cost
Costs
Design and
Const. Mgt
CosL
Contingency
Cost
f2S%1
Total
Cost
Unit Coat
for Sift
MKJY1
374,000
27
12
167,000
42,000
209,000
$1,572,100 $48,000 $393,000 $2,011,100 $12.00
ASSUMPTIONS
Footprint (area) planlmetered f rom navigation chart.
Existing depth calculated from navigation chart soundings within area.
Proposed depth Is finished depth Including a 3 foot cap.
Vertical sides of disposal she are assumed.
Material will not flow out of the disposal site.
Volumes shown are dredged volumes (expansion of dredged material has not been applied).
Design effort involves minimal site hydrographic survey ($20,000) and benthfc and fish studies ($10,000).
Contingency Is 25%.
Dredging costs - silt - $7.10, parent» $9.20.
1,979,000 CY of additional parent material remain after capping and requires disposal.
-------
TABLE 3-17. COST ESTIMATES FOR IN-CHANNEL DISPOSAL OPTION B-3 FOR SILTS FROM BHNIP.
Location
Mystic River
Reserved Channel
Inner Confl.
Chelsea Cr.
Trench
Depth
(ft)
5
5
5
5
Volume
Width
(ft)
441
371
891
191
Length
(ft)
4,400
4,050
900
7,800
Trench
Excav.
(CY)
313,000
235,500
139,000
207,400
Silt
Volume
(CY)
317,800
240,000
140,000
219,600
2' Cap
Volume
(CY)
138,800
106,800
58,400
108,600
Cost
Total
Dredging
Cost
$6,412,940
$4,853,160
$2,810,080
$4,466,360
Contingency
Cost
$1,603,235
$1,213,290
$702,520
$1,116,590
TOTAL
Cost
$8,016,175
$6,066,450
$3,512,600
$5,582,950
Unit Cost
for Silt
($/CY)
$25.00
$25.00
$25.00
$25.00
ASSUMPTIONS
Width of trench designed to avoid impacts to berths and their structures.
Trench is designed to avoid known areas of rock (no blasting is required for trench).
Trench excavation is volume of parent material removed to create trench In addition to that req'd for channel deepening.
Cap volume is a portion of parent material dredged from trench and placed 2* thick.
Top of capped trench is Q elev. -42* MLW or -40' MLW for Chelsea Cr. (overdepth elevation).
Dredging cost - Sllt=$7.10/CY, Parent and Cap=$9.20/CY
Contingency Is 25%.
Mystic 1,882,200 CY of parent material remain after capping and requires disposal.
Reserved 1,914,200
Inner Confl 1,962,600
Chelsea Cr 1,912,400
-------
Tafato 3-18. Cost Estlmat** for Aquatte Borrow Pit Option B-4 for Disposal of Silts from BHNIP
Footprint Perimeter Existing Excavate.
(SqFt) (FT) Depth to Depth"
Betow Below
MLW MLW
(FT) (FT)
Volume
Total
Silt 3' Cap Votum*
Volume* Volume atDlspsHa
(CY) (CYJ (CY)
Coals
Value of
Dredging Design and Contingency Sand and Total
Cost Constr.Mgt Cost Gravel Cost
Cost (25%) $6.00 /CY
Unit Cost
for Silt
3,749,000 7,860
80
93 1,319,000 412,626 1,731,626 $28,320,762 $313,000 $7,080,000 $9,569,000 $26,154,762 $20.00
MaUburgor7
V
Footprint Perimeter Existing Excavate.
(SqFt) (FT) Depth to Depth"
Below Below
MLW MLW
(FT) (FT)
Volume
(CY1
Dredging Design and Contingency
Cost Constr. Mgt Cost
Cost (25%)
Value of
Sand and Total Unit Cost
Gravel Cost for Silt
$6.00 /CY ($/CY)
5,267,500 9,214
BO
90 1,319,000 580,671 1,899,671 $30,944,804 $339,000 $7,736,000 $10,231,000 $28,788,804 $22.00
ASSUMPTIONS
Existing depth obtained from navigation chart soundings.
Proposed sediment thickness Is the difference between existing and excavated depths minus the 3 foot cap.
SHe slopes of 1 vertical to 3 horizontal were assumed.
Dredging costs account for dredging borrow pit and Boston Harbor sediments. (Melsburg mat - $9.49, parent - $920, silt - $7.10).
Cap consists of 2 ft of parent material+1 ft of excavated sand and gravel to restore substrate.
Design effort Involves minimal site hydrographlc survey ($20,000), and benthte and fish studies ($10,000).
Value of excess sand and gravel excavated - $6.00 /CY to be picked up at a shoreline site
Contingency Is 25%.
Melsburger2 1,608,000 CY of parent material remain, after capping and requires disposal.
Melsburger7 1,440,000 '
-------
TABLE 3-18 (CONTINUED). COST ESTIMATES FOR AQUATIC BORROW PIT OPTION B-4 FOR DISPOSAL
OF SILTS FROM BHNIP.
CAD (Spectacle l*l*nd)
Footprint Perimeter
(SqR) (FT)
(acres)
1,974,554 4,980
45
Existing Excavate Volume Costs
Depth to Depth
Below Below Silt 3' Cap Total Dredging Silt Curtain Design and Contingency Total Unit Cost
MLW MLW Volume Volume Volume Cost Cost Const. Mgt Cost Cost for Silt
-------
TABLE 3-13. ALTERNATIVES SCREENING OF TREATMENT TECHNOLOGIES FOR DREDGE MATERIAL DISPOSAL.
TECHNOLOGY/PROCESS0
THERMAL
CRITERIA
Effectiveness Treat PCBs
Treat PAHs
Treat Trace Metal
Project Applicable
Full Scale Test
Environ. Mitigation
Implementability Comm. Availability
Min. Site Size (ac)b
Lead Time (mo.)
Program Compatibility
Est. Cost $/c.y.d
FLUID ROTARY
BED KILN
X X
XV
A
X
XV
A
X X
XV
A
4-7 5-8
24-48 24-48
\r \r
200-350 200-350
VITRIFI-
CATION
X
X
X
X
X
X
N
24-48
N
WET-AIR
OXIDATION
X
X
X
X
X
N
24-48
N
IMMOBILIZATION
CEMENT- LIME-
BASED BASED
X
X
X
X
X
X
X
6-9°
24-48
X
50-60
X
X
X
X
X
X
X
6-9c
24-48
X
50-60
CHEMinAT.
ACID
LEACHING
X
X
X
X
N
N
24-48
N
SURFAC-
TANT
X
X
N
N
24-48
N
*X = meets criterion; Blank = does not meet criterion or undetermined; N = not evaluated.
'These estimates represent first order estimates. Estimates do not include site acquisition or preparation costs,
but do include receiving/storage and handling area, processing area, load out and transport area. Range represents
primarily difference in buffer area assumption.
"Processing plant may be barge-mounted.
dCost estimates based upon cost ranges in selected studies included in Reference List.
-------
TABLE 3-20. COST ESTIMATES FOR USING EXISTING DISPOSAL SITES FOR DISPOSAL OF SILTS FROM BHNIP.
Boston Lightship (BLS)
Footprint
(SF)
8,454,800
Silt
Volume
(CY)
1,319,000
3* Cap
Volume
(CY)
1,055,500
Dredging
Cost
$19,075,500
Design and
Constr. Mgt
Cost
$221,000
Contingency
Cost
$4,769,000
Total
Cost
$24,066,000
Unit Cost
for Silt
($/CY)
$18.00
ihusetts Bay Disposal Site (MBDS)
Footprint
(SF)
Silt
Volume
(CY)
3' Cap
Volume
(CY)
Dredging
Cost
Design and
Constr. Mgt
Cost
Contingency
Cost
Total
Cost
Unit Cost
for Sift
($/CY)
8,454,800 1,319,000 1,055,500 $19,075,500 $221,000 $4,769,000 $24,066,000 $18.00
ASSUMPTIONS
Dredge costs - silt = $7.10/CY, parent and cap = $9.20/CY.
Cap volume calculated for 3' cap over footprint of 9,500,000 SF.
Design includes minimal site hydrographic survey ($20,000) for both sites, and benthic and fish studies ($10,000) for BLS only.
965,500 CY of additional parent material remain after capping and requires disposal.
-------
TABLE 3-21. SCREENING MATRIX FOR DETERMINING THE LEAST ENVIRONMENTALLY DAMAGING PRACTICABLE ALTERNATIVE FOR DISPOSAL OF SILT FROH THE BHNIP.
TYPE
LANDFILL
LAND-BASED-
Inland
Coastal
AQUATIC
Shoreline
(Partial Fill)
PERMANENT
HABITAT LOSS OR
SITE ALTERATION
E. Bridgewater
Fitchburg/Westminster
Plainville/Laidlaw
Woburn
Wrenthom
Everett
Squantum Point
Amstar
Cabot Paint
Little Mystic Channel
Mystic Piers
Reserved Channel
Revere Sugar
no
no
no
no
yes
yes
yes
altered
altered
altered
altered
altered
altered
HATER QUALITY
EXCEEDENCBS
BEYOND
DISPOSAL SITE
no
no
no
no
no
no
no
mitigated
mitigated
mitigated
mitigated
mitigated
mitigated
SOCIOECONOHIC REASONABLE
EFFECTS CAPACITY
displacement of
other users
displacement of
other users
displacement of
other users
traffic
traffic
minor
neigborhood,
traffic
displacement of
MWRA pier
minor
neighborhood
minor
neighborhood,
traffic
minor
no
no
no
no
yes
no
yes
no
no
yes
no
yes
no
BENEFICIAL BSEb
minor
minor
minor
cap landfill
no
no
no
contain contaminants
contain contaminants
contain contaminants
contain contaminants
resource enhancement;
contain contaminants
contain contaminants
LEAST
ENVIRONMENTALLY
COST DAMAGING
($/cy) ALTERNATIVES
$S6
$101
$87
$61
$50
$76
$37-49
$37
$278
$33
$35
$255
$35
*
*
*
*
*
*
*
*
*
(Continued)
-------
TABLE 3-21. (CONTINUED)
TYPE
Subaqueous
In-Channel
Borrow pit
Existing
Disposal Site
TREATMENT
PERMANENT
HABITAT LOSS OR
SITE ALTERATION
Subaqueous B
Subaqueous E
Winthrop Harbor
Chelsea Creek
Inner Confluence
Mystic River
Meisburger 2
Meisburger 7
Spectacle Island CAD
MBDS
Boston Light Ship
Solidification
altered
altered
altered
no
no
no
no
no
no
no
no
no
HATER QUALITY
EXCEEDENCES
BEYOND
DISPOSAL SITE
yes
yes
yes
mitigated
mitigated
mitigated
no
no
mitigated
no
no
no
SOCIOECONOHIC REASONABLE
EFFECTS CAPACITY BENEFICIAL OSEb
minor
minor
interference
with
recreational
boaters
minor
minor
minor
displacement of
fisheries
displacement of
fisheries
minor
minor
displacement of
fisheries
minor
yes no
yes no
yes no
yes no
no no
yes no
yes minable resource
yes minable resource
yes minor
yes no
yes no
yes potentially
LEAST
ENVIRONMENTALLY
COST DAMAGING
($/cy) ALTERNATIVES
$17
$16
$12
$25
$25
$25
$20
$22
$25
$18
$18
$55
A
*
*
*
*
*
*
*
*
•2200,000 cy
bthrough site preparation or use of silt, parent material not included since it has universal benefit
°cost could be reduced by beneficial use of mined sediments
-------
TABLE 3-228. PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY) FOR THE
BOSTON HARBOR NAVIGATION IMPROVEMENT PROJECT
SITE NAME
CAPACITY (cy)
COST
PERCY
PARENT
MATERIAL
AND ROCK
BHNIP
SILT1
HIGH CAPACITY SITES
Boston Lightship
(with capping)
Combined In-Channel Locations
MBDS
Meisburger 2
Meisburger 7
Spectacle Island CAD
Exceeds BHNIP
project and 50-year maintenance needs. Total
capacity unknown.
740,000
Exceeds BHNIP
project and SO-year maintenance
needs. Total capacity unknown.
4,660,000
6,125,000'
1,450,000
S18
S25
$18
S20
S22
$25
X
X
X
X*
(with
capping)
X
X
X
FUTURE
HARBOR
MAIN-
TENANCE2
X
X
X*
(with
capping)
X
X
•Disposal-and-capping (of unsuitable material) is prohibited at MBDS until its efficacy can be effectively demonstrated (40 CFR 228.12 [Amended]).
1BHNIP silt material consists of approximately 1.3 million cubic yards. Additional material from the BHNIP includes approximately 130,000 cy of rock and 2.0 million
cubic yards of parent material
'Future harbor maintenance consists of maintenance dredging approximately 4.4 million cubic yards of material from the Main Ship Channel and 1.8 million cubic yards
of material from the tributary channels. These volumes are estimated as the aggregate accumulation over the 50-year life of the project (as calculated beginning in 1997).
These volumes are expected to be dredged intermittently over the life of the project as needed. Maintenance dredging of the tributary channels is not likley to be needed for
at least 10-year s after the BHNIP project, or not until the year 2007. Minor, spot dredging may be required in the President Roads Anchorage Area and Main Ship
Channel, Outer Harbor, beginning in the year 2002 if shoaling conditions warrant. More extensive maintenance dredging of the outer channels is not expected to be needed
until at least the year 2007.
-------
TABLE 3-22b. POTENTIALLY PRACTICABLE ALTERNATIVES (LISTED ALPHABETICALLY)
BUT LIMITED BY CAPACITY AND COST
SITE NAME
Amstar
Little Mystic Channel
Mystic Piers
Reserved Channel
Revere Sugar
Lined Landfills
CAPACITY (cy)
128,000
303,000
98,000
185,000
85,000
102,000
Unknown
COST
PERCY
$37
$33
$35
$255
$35
$56-$101
$55
PARENT
MATERIAL
AND ROCK
N/A*
N/A
N/A
N/A
N/A
N/A
N/A
BHNIP SILT1
X
X
FUTURE HARBOR
MAINTENANCE2
X
X
X
X
X
X
X
*N/A- Not Applicable
1BHNIP silt material consists of approximately 1.3 million cubic yards. Additional material from the BHNIP includes approximately 130,000 cy of rock and 2.0 million
cubic yards of parent material
"Future harbor maintenance consists of maintenance dredging approximately 4.4 million cubic yards of material from the Main Ship Channel and U million cubic yards
of material from the tributary channels. These volumes are estimated as the aggregate accumulation over the 50-year life of the project (as calculated begmnmgjn 1997).
Th^^mmes are expected to be dredged intermittently over the life of the project as needed. Maintenance dredging of the tributary channels K not bkley to be needed for
atTe^l E^ TaL fce BHNIP project, or not until the year 2007. Minor, spot dredging may be required in the President Roads Anchorage Area and Mam Stop
Channel, Outer Harbor, beginning in the year 2002 if shoaling conditions warrant. More extensive maintenance dredging of the outer channels is not expected to be needed
until at least the year 2007.
and evaluation of treatment technologies resulted in solidification as being the only practicable alternative for the BHNIP project Other technologies were
on availability, quantity of material to be dredged, throughput requirements and costs which, for some of the technolgores screened, could run as bagh as
$350 per cy.
-------
TABLE 3-22C. ALTERNATIVES (LISTED ALPHABETICALLY) EVALUATED BUT POUND NOT PRACTICABLE
DUB TO ENVIRONMENTAL FACTORS OR COST
SITE NAME
Cabot Paint
Everett
Squantum Point
Subaqueous B
Subaqueous E
Winthrop Harbor
Woburn
Wrentham
CAPACITY (cy)
18,000 to MLW
99,000 to MHW
55,000
210,000
600,000
614,000
167,000
158,600
785,500
COST PER
CY
S278
S76
$37-549
S17
S16
S12
$61
$50
PARENT
MATERIAL
AND ROCK
N/A*
N/A
N/A
N/A
N/A
N/A
N/A
N/A
BHNIP SILT1
N/A
N/A
N/A
N/
N/A
N/A
N/A
N/A
FUTURE HARBOR
MAINTENANCE*
X
X
X
X
X
X
X
X
*N/A- Not applicable
1BHNIP silt material consists of approximately 1.3 million cubic yards. Additional material from the BHNIP includes approximately 130,000 cy of rock and 2.0 million
cubic yards of parent material.
•
'Future harbor maintenance consists of maintenance dredging approximately 4.4 million cubic yards of material from the Main Ship Channel and 1.8 million cubic yards
of material from the tributary channels. These volumes are estimated as the aggregate accumulation over the 50-year life of the project (as calculated beginning in 1997).
These volumes are expected to be dredged intermittently over the life of the project as needed. Maintenance dredging of the tributary channels is not likley to be needed for
at least 10-years after the BHNIP project, or not until the year 2007. Minor, spot dredging may be required in the President Roads Anchorage Area and Main Ship
Channel, Outer Harbor, beginning in the year 2002 if shoaling conditions warrant. More extensive maintenance dredging of the outer channels is not expected to be needed
until at least the year 2007.
-------
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4.0 DREDGING MANAGEMENT PLAN
The MEPA certificate required that this EIR/S
include a dredge management plan to provide an
overview of the entire process of dredging and dispos-
al for the project. This section serves as the Plan and
includes a description of equipment to be used for
the dredging and the sequence of construction. This
section also gives an overview of the potential envi-
ronmental impacts of the dredging operations and
likely mitigation measures to be employed.
In this draft stage, and in the absence of a specific
disposal plan, the dredge management plan is limited
to general descriptions of the practicable alternatives
identified earlier (Section 3.0) and is more qualitative
than quantitative. When the Preferred Alternative is
identified in the final EIR/S the plan will be complet-
ed and become site specific with the objective of
maximizing efficiency of the operations within the
known constraints and being responsive to the
comments raised during the public review of the
DEIR/S.
4.1 SELECTION OF DREDGING METHOD
The selection of a dredging method for a given
project, is tied to several factors. These include the
physical characteristics of sediments to be dredged,
quantities to be dredged, dredging depth, distance to
the disposal area, contamination level of sediments,
the method of disposal, the dredging rate required
and the type of dredges available.
There arc three basic types of dredges: hopper,
hydraulic and mechanical. Hopper dredges are self
propelled dredging plants that drag material off the
bottom and pump it into hoppers. The advantages
of hopper dredges include their ability to work in
rough, open water; move quickly to job sites under
their own power; ability to move out of the way of
other ship traffic; dredge to project depths quickly;
and to economically transport dredged material for
long haul distances. Limitations of hopper dredges
are that they cannot work in shallow depths; cannot
dredge continuously (must empty the hoppers);
excavate with less precision; cannot work economi-
cally with contaminated sediments requiring segrega-
tion and special disposal; and cannot easily dredge
hard banks and consolidated substrate.
The second major type of dredge is hydraulic
pipeline. Hydraulic dredges are mostly non-self
propelled units which have the ability to.continuous-
ly dredge using a cutterhead that feeds material
directly into a pipeline which can place material
directly in disposal sites. The advantages of hydraulic
dredges include their ability to excavate most types of
materials, pump directly to disposal sites, dredge
almost continually and dredge some rock types
without blasting. Limitations of hydraulic pipeline
dredges include limited capability in rough open
water; not being able to move quickly under their
own power; difficulty with coarse sand in high
currents; and obstructing traffic with the pipeline. In
addition, hydraulic dredges have limitations related to
pumping distances. It may be very economical for
cases where disposal sites are nearby but generally at
pumping distances over 9,000 feet a booster is re-
quired and the percentage of solids pumped per unit
volume will decrease.
Mechanical dredging by bucket or clamshell is
similar to land based digging operations. The me-
chanical dredge scoops out material and dumps the
contents of the bucket onto a barge which is then
used to transport the material to its disposal or use
location. The advantages of mechanical dredging are
that it is rugged and capable of removing hard packed
material, can remove debris, can work in tight areas
and is efficient for disposal at long haul distances.
Limitations include low production rates compared
to the first two methods described and the necessity
to employ adequate measures to control contaminat-
ed sediments during removal.
4-1
-------
The hopper dredge was not selected as the pre-
ferred dredge because of several factors, principally
the restricted operating areas within the three chan-
nels, the haul distance, and the expected difficulty
with dredging clay and other undisturbed parent
material. The hydraulic dredge, likewise, is not the
preferred dredge because of great pumping distances
required and the high percentage of water it would
entrain in the dredged material. Therefore, the
mechanical dredge is most likely to be the selected
dredge for both the silt and the parent material to be
removed.
4.1.1 Mechanical Dredge Plant
Since the mechanical dredge is basically a crane on
a barge, there is some flexibility available when
choosing the type of clamshell bucket to be used.
Studies (Zappi 1991) have shown that a modified, or
environmental, bucket, which is nearly watertight
when closed, will reduce turbidity in the vicinity of
the dredging site. This bucket is designed so that the
fines in the dredged material are not washed out as it
is drawn up through the water column. Use of a
modified bucket is planned when dredging the silt
sediments. A standard bucket, capable of higher
productivity, is planned for dredging the parent
material which is cohesive and does not contain
contaminant;;.
Bucket size is a variable which is dependent on the
dredge horsepower. Bucket sizes up to 20 to 22 cy
were used by the Third Harbor Tunnel contractor.
The Third Harbor Tunnel contractor used the "Super
Scoop* which provided 2,100 horsepower. The
dredge 'Boston*, which typically lifts up to an 18 cy
bucket, uses a plant with 1,600 horsepower. I-'or
estimating purposes, a 15 cy bucket was assumed for
use on this project.- Actual equipment to be used
will be dependent on availability when ready for use
by contractor. Based on the amount of material to
be dredged a 15 cy bucket would be required at a
minimum.
Scows and barges to hold the dredged material
range from a very small 500 cy capacity to the typical
1,500 to 2,000 cy to the maximum of 4,000 cy size.
Because of their size and initial costs the 3,000 and
4,000 cy scows are likely to be owned only by the
larger dredging contractors. Also, ocean going tugs
must be large enough to handle the larger scows.
The assumed scow size range for the project material
suitable for ocean disposal is 2-3,000 cy. Actual
equipment to be used will of course be dependent on
its availability to the contractor. Small scows or
barges would likely be used for nearshore and shore-
line disposal where transportation distances are short
and maneuvering area is limited.
4.1.2 Rock Blasting Plant
The rock blasting plant will typically consist of a
deck barge with one or more drilling rigs mounted in
such a manner as to allow movement of the rig while
the barge is held fast by an anchoring system. In
addition to the drill barge, there is need of a tug or
tender to move the drill barge or anchors when
necessary. An explosive materials barge may also be
included in the equipment listing.
4.2 SEQUENCE OF DREDGING
OPERATIONS
The operations involved in completing a dredging
project are interrelated yet diverse. The type of equip-
ment and sequence of dredging and disposal opera-
tions depends on the disposal plan. Specific informa-
tion will be provided in the Final EIR/S. A general
description of dredging operations for open water
disposal follows.
4.2.1 Pre-Drcdgc Sequence
Surveys of existing channel and berth bottoms and
utilities for possible relocation or protection are done
4-2
-------
before the dredge plant arrives on site. Also in ad-
vance of the dredge arrival, planning for minimal
interference with continuous vessel traffic will have to
be coordinated with port users. Prior to dredging,
turbidity controls must be assessed and selected.
Turbidity generated by a typical mechanical dredging
operation is the result of sediment resuspension
occurring when the bucket impacts on and is pulled
off the bottom. Also, because most buckets are not
covered, the "surface" material in the bucket and the
material adhering to the outside of the bucket are
exposed to the water column as the bucket is pulled
up through the water column. When the bucket
breaks the water surface, turbid water may spill out
of the bucket or may leak through openings between
the jaws. As stated earlier, to minimize turbidity
from the bucket, and to control contaminated sedi-
ments, a watertight "environmental" bucket is pro-
posed. Research has shown that the use of water-
tight buckets can generate 70% less turbidity in the
water column than typical buckets (USACOE, 1987).
Overall, near-bottom suspended solids are greater
than midwater or surface levels indicating that resus-
pension of bottom material near the clamshell impact
point is probably responsible for most of the material
suspended in the lower portion of the water column.
One method for physically controlling the disper-
sion of near-surface turbid water in the vicinity of
clamshell dredging operations involves placing a silt
curtain or turbidity barrier either downcurrent from
or around the operation. Silt curtains are not recom-
mended for operations in the open ocean, in currents
exceeding 50 cm/sec (1 knot) or in areas frequently
exposed to high winds and large breaking waves.
Silt curtains are impervious, floating barriers that
extend vertically from the water surface to a specified
water depth. The flexible, nylon-reinforced polyvinyl
chloride (PVC) fabric forming the barrier is main-
tained in a vertical position by flotation segments at
the top and a ballast chain along the bottom. A
tension cable is often built into the curtain immedi-
ately above or below the flotation segments to absorb
stress imposed by currents and other hydrodynamic
forces. The curtains are usually manufactured in 30-
m sections that can be joined together at a particular
site to provide a curtain of specified length. An-
chored lines hold the curtain in a deployed configura-
tion that is usually U-shaped or circular. The silt
curtain does not indefinitely contain turbid water, but
instead diverts its flow under the curtain, thereby
minimizing the turbidity in the upper water column
outside the silt curtain. When properly deployed and
maintained, silt curtains can effectively control the
flow of turbid water.
Silt curtain effectiveness, defined as the degree pf
turbidity reduction outside the curtain relative to the
turbidity levels inside, depends on several factors: the
nature of the operation; the quantity and type of
material in suspension within or upstream of the
curtain; the characteristics, construction, and condi-
tion of the silt curtain as well as the area and config-
uration of the curtain enclosure; the method of
mooring; and the hydrodynamic conditions (i.e.,
currents, tides, waves, etc.) present at the site.
Because of the high degree of variability in these
factors the BIINIP dredging design will consider the
appropriateness and practicability of silt curtain
deployment depending on the dredging location and
character of material dredged.
4.2.2 Dredging Sequence
When the dredge is ready to begin work, survey
ranges must be established to ensure the dredge
remains in the proper location. Once the dredge has
been set in place and before dredging, any required
turbidity controls will be set. If a silt curtain is
required, it will be adjusted each time the dredge is
moved and each time a barge is towed out or an
empty barge is brought into the protected area.
Because much of the silt to be removed from Boston
I larbor is considered unsuitable for unconfined open
water disposal, these sediments will need to be
separated from the suitable or parent material. This
4-3
V
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will be accomplished by making two passes over the
same area of the channel. During the first pass, the
dredge, using the modified (environmental) bucket,
will remove the silty maintenance material exposing
the parent materials below. Because the modified
bucket is expected to have small or no teeth, it will
not penetrate deeply into the underlying parent
material. Thus, the silty sediments and only a small
amount of the parent material will be removed during
the first pass. This material will be placed in a scow
and disposed by the selected method.
Parent material will be removed during the
dredge's subsequent pass. A standard bucket will be
used to dredge this material. As this material has
been determined to be suitable for unconfined open
water disposal, it may be transported by scows and
disposed at the Massachusetts Bay Disposal Site, or
another site for beneficial use if needed.
During the dredging of silt it is anticipated that
debris that commonly litters the harbor floor will be
encountered. This debris includes old pilings, cables,
ropes, tires and other litter of various sizes. It is
impractical to remove debris before dredging because
some of it is buried in the silt layer and may not be
detectable until exposed by the dredge. Attempts to
completely remove this debris before dredging would
be very costly and would likely be unsuccessful.
Also, removal of debris could cause sediment re-
suspension.
The dredge operator will take precautions concern-
ing debris when using the environmental bucket. If
the operator encounters debris, that the bucket has
picked up, that is large enough to protrude from the
bucket and prevent a tight seal, he can hold the
bucket just above the bottom and allow sufficient
time for the silt to drain out. The debris will be
brought carefully to the surface for disposal. Only
when the operator can completely close the bucket
will he bring it directly to the surface. Smaller debris,
which may be undetectable by the operator, can
prevent closure of the bucket but silt loss would be
minor.
To reduce water transfer to the disposal barge, the
operator may hold the environmental bucket above
the water surface, within the protected area, to decant
water from the top of the load. If small debris has
prevented bucket closure then the operator may be
required to unload the bucket into the barge without
decanting the water. This would reduce the amount
of silt returning to the water.
Rock is expected to be encountered at the mouth
of the Reserved Channel, in the Inner Confluence
and in the Mystic River Channel. When rock
removal is required, the overlying layers of silts and
parent material will be removed by the dredge first.
The drill barge will then be set up, holes drilled and
filled with explosives. The vessel traffic will be
cleared from the area, and the explosives detonated.
When the drilling and blasting has been completed,
the dredge will return to remove the broken rock by
placing it in scows or on deck barges depending on
the final disposal plan. Blasted rock is suitable for
unconfined open water disposal and may also be
valuable for beneficial uses such as rock reefs for
marine habitat.
Dredging operations will be influenced by weather
conditions, vessel traffic conditions, and environ-
mental restrictions that might be placed on the
project. Winter weather will impact on tug and scow
trips to disposal sites. During stormy weather the tug
captains will make the decision to go or not to go to
the disposal areas. Vessel traffic may have a seasonal
impact since the winter heating fuel requirements
may generate an increase in tanker traffic. Likewise,
recreational traffic will increase during the summer
although the three tributaries do not support signifi-
cant amounts of recreational craft. Environmental
constraints such, as anadromous fish movements,
require cessation or limits for dredging during the
spawning period February 1 through June 15 in the
Mystic River and Inner Confluence.
4-4
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4.2.3 Structural Impacts of Dredging
Dredging has the potential to remove material
necessary for stability of bulkheads along the shore-
lines of the project channels. Engineering studies
conducted prior to the dredging will ensure that
bulkhead stability will not be affected. These studies
may require on-sitc geotechnical and hydrographic
investigations and will be done on a case by case
basis. Dredging also has the potential to damage
utility crossings cither from clamshell impact or
exposing them to passing ves_sel traffic. Coordination
with utility companies has identified known utility
crossings principally in Chelsea Creek which will be
relocated or protected by the project. The Chelsea
Creek portion of the project will require moving
Boston Edison Cables and MBTA cables, removing
an MWRA water tunnel and protecting the Boston
Gas Siphon.
4.2.4 Traffic Considerations
As indicated above, scows will be used to trans-
port dredged material to the open ocean disposal site
and to whatever other disposal site is selected for
material deemed unsuitable for unconfined disposal.
If two dredges are working, each will load a barge in
a 12 hour period. It is expected that up to four barge
loads of material would be taken out of the harbor
daily. Vessel traffic by others in the ship channels
will not be much of a concern because the tow line
(hawser) will not be let out to full length until after
the tug and scow unit has cleared the channel and is
underway in the bay. Harbor activities will continue
as normal. The dredge will be stationary in the
channels. The scows will be tied along side of the
dredge. Vessel traffic will be required to navigate
around the equipment and only the larger commer-
cial vessels will require special coordination with the
dredge operator in order to have the dredge plant
move out of the channel.
Blasting operations, previously mentioned, are
expected to be required in the Mystic River channel,
the Inner Confluence, on the north side of the Re-
served Channel near the mouth, and across the Main
Ship Channel from the Reserved Channel. During
blasting, all vessel traffic will be regulated; the Coast
Guard will impose safety zones to ensure that vessel
traffic remains a safe distance from the blast.
4.3 DISPOSAL OPERATIONS
As mentioned earlier, this dredge management plan
focuses on the disposal options identified as practica-
ble in Section 3.0. While a final option awaits the
results of the public review of the EIR/S some
general operational details can be expected for each
category of disposal options.
4.3.1 Shoreline Disposal
Disposal of unsuitable material behind bulkheaded
areas within the harbor will require rehandling of the
dredged material. Hydraulic dredging with a pipeline
into these disposal areas is the least costly method
but can have adverse water quality impacts. A
hydraulic dredge could be used to skim off the silt
material in the channels and berths and easily deposit
the sediments behind a bulkhead. There would be
no need for rehandling. However, due to pumping
requirements, the use of a hydraulic dredge would
appear to be practical only when the disposal site is
within 9,000 feet of the dredge site. If a mechanical
dredge is used, unsuitable material would be placed
in a scow and towed to the bulkhead. Because of the
time it takes to construct the bulkhead, scows could
be dumped inside the disposal site as long as the
opening in the partially constructed bulkhead is
sufficiently large for the scow and tug to enter and
exit the site until disposed material reaches the
opening. Once the bulkhead closure is completed, a
land based or barge mounted crane would be used to
unload the remaining scows and place the silts and
4-5
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capping material. Weirs or stoplog controls would be
built into the bulkhead to allow excess water to flow
out from behind the bulkhead. Once the material has
been placed the material will be capped with parent
material (depending on the intended use of the site).
The bulkhead would then be cut to allow for tidal
exposure unless the area behind the bulkhead is to
become dry land.
Shoreline disposal will increase the in-harbor
vessel traffic as scows or barges move from the
dredge site to the disposal site and back. If hydraulic
dredging is used, then the pipeline between the dredge
and the disposal site may restrict traffic.
During the placement of the dredged materials,
quality of water flowing from the confined area back
into the harbor will require monitoring. Measures
must be taken to prevent silt from reentering the
harbor. This can be accomplished by regulating the
stoplog structure at the outlet so that placed material
has sufficient time to settle silts.
4.3.2 Subaqueous Depressions and Borrow Pits
Disposal of silts at nearshore sites requires site
preparation such as constructing dikes to contain the
material, excavating, or finding naturally occurring
containment areas. Disposal of parent material at
these sites does not require containment.
If dredging at the site is required before disposal,
the area will require hydrographic surveys to establish
existing bathymetry. Placement of dikes, if required
for containment, would be accomplished by using
scows which would be positioned with buoys and
ranges established for the purpose. Water depths at
the disposal site must be at least 11 or 12 feet to
make the site suitable for bottom dumping. Shallow-
er depths will condition material placement on
favorable tides. For shallow sites that would not
permit bottom dumping, even during high tide,
mechanical removal from the scow will be required.
Dike material placed by scows should be able to
maintain side slopes of at least 1V:3H. Flatter slopes
would consume much of the containment area
making the site less efficient.
The borrow pit disposal sites require excavation
prior to disposal and require a dredge to be stationed
at the site. The open ocean can be dangerous for
equipment not designed for that environment. A
large dredge plant will be required to withstand
weather conditions and quickly finish the job.
Material dredged from the borrow pits may have
commercial value and as such would likely be placed
on a deck barge or in a hopper barge rather than a
dump scow for ease of unloading. If the material had
no commercial value, then dump scows would be
used to carry the material to an ocean disposal site.
When the disposal area preparation is complete the
unsuitable silts will be brought to the site by scow
and deposited using buoys to pinpoint the disposal
location. Depth of material deposited in the area will
vary depending on the site but, in general, greater
depths can be obtained in excavated areas.
When all the unsuitable sediments have been
deposited, or surveys indicate capacity of the site has
been reached, the scows will bring material to cap the
area. The cap should be a minimum of three feet
thick over the entire disposal area and allowance for
the cap must be included when determining the
capacity of the disposal area.
Winter weather will not have as great an impact on
nearshore disposal operations as on offshore opera-
lions. However, winter storms can still make for
treacherous conditions and the tug captains will be
making the decision to put to sea or stay within the
harbor. Seasonal constraints may be imposed de-
pending on the biological resources of concern.
The contractor will mark the disposal site clearly to
avoid interference with fishermen. The final eleva-
tions of the off-shore sites should be no greater than
4-6
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10-15 feet above surrounding areas and should not
pose a threat to navigation. The shallow water sites
are outside of established navigation lanes. The final
elevation at those sites would be no higher than the
adjacent channel depth.
During construction and disposal operations,
additional hydrographic surveys will be required.
These will confirm progress on dike construction and
track filling in the area. Remote photography may
also be employed. Location of the buoys marking
the disposal site would be checked after each severe
storm since they will be subject to movement under
storm conditions.
The contractor will carry an inspector on the tug
to record the time and location of each disposal event
to insure scows are being dumped at the proper loca-
tion.
Hydrographic surveys before and after cap place-
ment will be required to confirm cap thickness. The
cap should be at least three feet thick and will require
coordination during the dredging operation to insure
enough suitable material is available when needed.
Mitigation measures will not be required at the
disposal sites. The disposal sites will be temporarily
impacted from construction activities. When com-
pleted, each site will be returned to its original
configuration. Pioneer benthic organisms will recolo-
nize the cap material and rework the area for succes-
sive trophic level species. Long term monitoring of
subaqueous depressions and borrow pits is expected
to continue through the Corps' Disposal Area
Monitoring System (DAMOS).
4.3.4 In-Channel Disposal
Another alternative considered in Section 3.0 was
disposal in trenches constructed within the Mystic
River, the Inner Confluence and the Chelsea Creek
Channels.
This option will require that prior to construction
of the first segment of the trench, sediments will be
dredged from the overlying area. This material will
be stored temporarily on scows. The trench will be
excavated into parent material. The stored sediments
will then be placed into the trench. Sediments
overlying the next segment of the trench will be
removed and deposited directly into the previous
segment of the trench. The next segment of the
trench will be dredged and sediments deposited and
so forth until the entire trench is completed. The
remaining channel sediments will be dredged and
deposited directly into the trench.
Periodic surveys of the excavated trench may be
necessary to monitor progress for computing volumes
of materials disposed. After capping the trench,
follow-up surveys may be used to assure that mini-
mum cap thickness has been attained and that the
top of cap does not encroach into the overdepth
elevation of the channel bottom.
Once the trench is completed and all sediments are
deposited, the remaining dredging of the parent
material will be completed. This material may be
used to cap the trench. The top of the cap will be
no higher than the overdepth elevation. This assures
that future maintenance of the channel will not
remove the cap and expose the sediments. The
remaining parent material will be disposed at MBDS
or other suitable site.
Because this disposal option is limited to dredging
and disposal operations within the same area that
dredging is taking place, all seasonal and weather
constraints that arc applicable to dredging in the
channel also apply to the disposal in that channel.
The only environmental constraints apply to the
Mystic River and the Inner Confluence as described
previously.
In-channcl disposal will increase the in-harbor
vessel traffic as the dredge plant and scows move
along the trench line during excavation, disposal and
4-7
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capping. The dredge plant will spend more time in
the channels being dredged than other alternatives
and will require more coordination with other vessel
operators to avoid traffic conflicts.
No mitigation is required except for seasonal
constraints at the dredging site for spawning ana-
dromous finfish. This option is attractive because
disposal will take place in areas that have been
previously disturbed.
4.3.5 Open Water- Existing Disposal Sites
These sites include the MUDS and Boston Light-
ship disposal areas. These sites are previously used
disposal sites. MBDS requires no site preparation
other than siting the disposal buoy(s) at the target
location. The Boston Lightship site will require
bathymetric surveys. Bottom dump scows will be
used to haul and place unsuitable silty material at the
target location(s). This sequence will-continue until
all silty material has been deposited. Prior to cap-
ping, surveys of the silt material will be taken and
adjustments to the buoy location made to ensure
complete coverage by the cap. Bottom dump scows
will then place suitable material over the mound of
silty material to form a cap of at least 3 feet in thick-
ness.
Vessel traffic along the haul route to the open
water disposal site af the Massachusetts Bay Disposal
Site is expected to be light. Large commercial vessels
will be crossing the route but chances of a tug and
scow unit meeting a larger vessel on the haul route
are slight. Commercial fishing vessels will have the
greatest opportunity for conflict with the towing
operation. Past experience has shown that early
coordination with the fishermen and a marked haul
route is the best course for both the contractor and
the fishermen.
Monitoring requirements will focus on periodically
confirming the location of the disposal buoy and the
haul route buoys. Hydrographic surveys should be
performed quarterly to note disposal trends and
recommend disposal buoy location. The contractor
will carry an inspector on the tug to verify disposal
takes place at the disposal site buoy. An electronic
recording device or "black box" may also be em-
ployed to confirm location at the time of release of
the scow's load.
During construction and use of the disposal areas,
additional hydrographic surveys will be required.
These will track filling of the area. Remote pho-
tography may also be employed. Location of the
buoys marking the disposal site should be checked
after each severe storm since they will be subject to
movement under storm conditions.
llydrographic surveys before and after cap place-
ment will be required to confirm cap thickness. The
cap should be at least three feet thick and will require
coordination during the dredging operation to insure
enough suitable material is available when needed.
Long term monitoring at MBDS is expected to
continue through the Corps' Disposal Area Monitor-
ing System (DAMOS). Long term monitoring of the
Boston Lightship site also fits in the scope of the
DAMOS program.
4.4 OVERALL SEQUENCE OF
OPERATIONS
Figure 4-1 is a sample timeline showing the se-
quence of operations for dredging and disposal at the
MBDS for each of the navigation channels and the
berth areas. The proposed navigation improvement
dredging is scheduled to occur over a 12 to 18-month
timcframc.
The overall specific sequence of the dredging and
disposal operations depends on the disposal site(s)
selected and will be shown in the final EIR/S.
4-8
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Generally, the final disposal site(s) selected will
have impact on the construction schedule. The
following overview describes how the schedule may
be effected by the preferred disposal plans as com-
pared to that of MBDS as displayed in Figure 4-1:
Shoreline Aquatic Disposal - Before dredging, the
disposal site must be prepared. The schedule would
include construction of bulkheads, water control
structures, other site preparation and mobilization of
all equipment required to handle the dredged material
at the site. These operations would delay the start of
dredging from that shown on Figure 4-1. Once
dredging is initiated, the extra handling of the materi-
al will add time to each dredge/dispose cycle. The
extra time will be partially offset by the shorter travel
time from dredge to disposal than that for MBDS.
It is estimated that the total construction time will
not be significantly different from that shown on
Figure 4-1.
Subaqueous Containment and Borrow Fits -
Before dredging, the disposal site must be prepared.
This duration will delay the start of dredging depend-
ing on the site(s) selected and amount of preparation
required. Once the disposal site is prepared, the
construction would continue as shown on Figure 4-1.
Although the borrow pits are closer to the harbor
than MBDS the savings in the total schedule would
be minor. It is estimated that the overall construc-
tion time will be longer than that shown on Figure
4-1.
Open Water and In-Channel Disposal - The
schedule shown in Figure 4-1 would apply to any
open water site with capping. In-channel disposal
requires multiple handling of the silt and parent
material that would add time to each dredging step.
This additional time may be offset by the significantly
shorter travel time from dredge site to disposal
trench. It is estimated that the overall construction
time will be longer then that shown on Figure 4-1.
4.5 ENVIRONMENTAL IMPACTS
EXPECTED FROM DREDGING
OPERATIONS
This section gives an overview of the potential
impacts of dredging on the water quality, sediment,
biological, cultural and socio-economic resources.
4.5.1 Water Quality/Sediment Quality
The proposed navigation improvement dredging is
scheduled to occur over a 12 to 18-month timeframe.
The activity will generate high turbidities near thp,
actual operation which decrease rapidly with distance.
Some of the exposed particulate silt may be tempo-
rarily unsettled and oxygen depleted at the sedi-
ment/water interface. Subsequent physical and
biological activity will stabilize and oxygenate the
substrate over time. Any underlying parent material
that becomes exposed from the dredging should
remain physically stable. The channel deepening
should not alter the flushing rate of Boston Harbor
appreciably, given the 150 billion gallon plus diurnal
tidal prism that currently exists.
As stated earlier mechanical bucket dredging will be
used to excavate the substrate. Only a relatively
small percentage of the dredged material becomes
suspended in the water column if the appropriate
equipment (i.e., an environmental bucket for the
silts) is used. More of the material would be released
during dredging operations if large debris prevents the
dredge bucket from closing. See Section 4.2.2 for
descriptions of dredging environmental controls and
debris handling. This suspended material is princi-
pally restricted to the silt or clay fraction ( < .06 mm)
with sand particles ( < -06 mm) settling out immedi-
ately after suspension. Grain size analyses (average)
of 18 stations in the channel (see Appendix C2)
identify the substrate as 86.5% fine grained, 2.3%
rock and the remaining material as sand.
4-9
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The organic material associated with the silt/clay
material could depress ambient oxygen concentra-
tions. However, the chemical oxygen demand for all
18 stations sampled averaged 80,509 ppm for surficial
samples, a moderate value. The clean parent material
(approximately 62% of the material to be dredged)
would not exert an oxygen demand on the water
column because this material does not contain
substantial organic materials. Increased turbidity
would reduce light penetration, lessening primary
productivity and possibly reducing oxygen release
from photosynthetic processes. Finally, upon set-
tling, the suspended sediment load, both sand and
silt/clay, could cover non-motile organisms adjacent
to the dredging areas. As discussed in Attachment 1
the benthic community in the inner harbor is domi-
nated by species indicative of a disturbed environ-
ment. No commercial shellfish species are known to
exist in the tributaries. All of these effects are expect-
ed to be spatially and temporally limited to the
immediate area of the dredge and length of the
activity.
Bohlen (1979) analyzed the water column effects
of mechanical dredging of a silt/clay substrate in New
London Harbor, Connecticut. This research con-
cluded the effects of suspended silt on water quality
to be of short duration and localized to the immedi-
ate dredge site. While suspended, silt increases water
turbidity levels. High turbulence reduces vision and
masks odors important to foraging organisms. Sus-
pended silt may also clog or abrade gill structures and
interfere with the feeding mechanisms of filter feeders
(Profiles Research and Consulting Group, 1980).
Turbidity may also interfere with chemical signals
important to anadromous migrations. To eliminate
interference with anadromous species, dredging would
not occur when anadromous species are spawning in
the Mystic River. Other finfish species are expected
to generally avoid or circumvent the area of high
turbidity.
During various dredging operations, scientific
analysis of the spatial and temporal persistence of the
turbidity/organic plume has been quantified. In the
summer of 1977 the extent and duration of the
impacts from dredging the Thames River/New
London Harbor channels were studied (Bohlen et.
al., 1979). The depth of the channel was similar (39
feet) to the navigation channels in Boston Harbor.
The mean tidal range was about one-third less than
Boston Harbor's mean tidal range. Annual average
strcamflow of this system over the past five years has
varied between 70 and 76 cubic meters per second
which is several orders of magnitude greater than the
freshwater flow into Boston Harbor. The Thames
River material was predominantly silt/clay (<.06
mm). Analysis of the composition and concentration
of the plume indicated the majority of suspended
material occurred within 30 meters of the dredge.
Suspended material concentrations were reduced by
a factor often within the first 200 meters downstream
of the dredge. Midwater and near bottom concen-
trations returned to background levels 700 meters
downstream of the dredge. All concentrations were
substantially less than storm induced perturbations of
a magnitude that occur on an average of one to three
times yearly in that harbor.
Monitoring results (EA, 1992) of dredging activities
for the Central Artery/Third Harbor Tunnel (CA/T)
project showed that the Boston Harbor main ship
channel dredge plume was quite diffused and dis-
persed within 500 feet. Background (up-current)
total suspended solids ranged from 8-20 mg/1 and the
plume (500-ft down current) ranged from 8-34 mg/1.
All of the effects associated with increased turbidity
in Boston I larbor would occur in the immediate area
of the dredge, be transported by currents, and settle.
After completion of the dredging activity, these im-
pacts will cease. The motile organisms should
generally escape this downcurrent sedimentation by
leaving or avoiding the activity area. The remaining
organisms will be impacted. However, most organ-
isms inhabiting Boston Harbor are estuarine species
that arc tolerant of recurring turbidity stresses.
4-10
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One of the functional characteristics of an estuar-
ine system, such as Boston Harbor, is to serve as a
nutrient retention area, increasing the productivity of
its subcomponents. Nutrients are effectively
"trapped" in the sediments where they are stored.
This trapping and storage function also allows for the
retention of pollutants in the same substrates, espe-
cially in fine grained sediment which have a larger
surface area for pollutant adsorption. The physical
removal of these sediments by dredging operations
has the potential to release some of the sediment
bound pollutants.
One group of pollutants that have been of concern
for environmental quality analyses are metals such as
mercury (Hg), cadmium (Cd), chromium (Cr), lead
(Pb), copper (Cu), and zinc (Zn). Recent studies
(Kay, 1985) have shown that even when metals are
found in high concentrations, there is no correspond-
ing substantial release of free (nonbound) metals
from resuspension of bottom sediments during
dredging. Studies performed by the Corps of Engi-
neers Dredged Material Research Program (Gambrell
et al. 1978) conclude that certain trace metals may be
released in the parts per billion (ppb) range, while
others show no release pattern (Chen, 1976). Chen
(1976) also showed that heavy metals are not readily
soluble or excessively mobile through a trophic
system since they are usually adsorbed to sediments
or coprecipitated out of solution. Elutriate testing of
Boston Harbor sediments support these conclusions.
Other classes of contaminants of concern are
PCBs(Polychlorinated Biphenyls), PAIIs (Polycyclic
Aromatic Hydrocarbons) and DDT (Dichloro-
Diphenyl-Trichloroethane: a chlorinated pesticide).
The presence of these chemicals were analyzed by
various testing as described in this section. Bulk et.
al. (1975) demonstrated that the migration of pesti-
cides from bottom sediments into the water column
during dredging is not substantial. Polycyclic Aro-
matic Hydrocarbons (PAHs) are a by-product of
industrialization of estuarine areas. Not all PAIIs are
readily bioavailable, and most do not attain concen-
trations in water that are acutely toxic to aquatic
organisms (Clarke and Gibson, 1987). However,
concern over PAHs as environmental pollutants is
based on the acute toxicity of some compounds such
as anthracene and phenanthrene, and chronic toxicity
of the higher molecular weight compounds (Clarke
and Gibson, 1987). The concentrations of PAHs in
the proposed project area have been analyzed using
the established regional testing protocol
(EPA/ACOE, 1991).
Elevated ( > 1.0 ppm) levels of PCBs were found in
the Mystic River (only one analysis - Station B). At
least one berth from each tributary had elevated PCB
levels for a total of seven berths. Additional sedi-
ment testing for PCB levels was conducted in con-
junction with the bioassay/bioaccummulation testing
procedures.
The dredging of the berths and channel areas
would be performed in a manner to minimize the
possibility of elutriation of sediment contaminants.
A review of the levels of sediment chemistry, the
ambient water quality and the use of an environmen-
tal bucket or clamshell dredge, indicates that a low
potential exists for substantial degradation of ambient
water quality (given its present state) during dredging.
After project completion the benthic substrate of the
Boston Harbor will be less contaminated in the
dredged areas due to the removal of the surficial sedi-
ments which contain a majority of the contaminant
load, thus providing a beneficial effect.
4.5.2 Biological Resources
The harbor benthic fauna! assemblages have been
studied in the lower Mystic River and Inner Harbor
areas (Stewart 1968, MES 1970; 1972, a, b, c; 1973;
1976, a, b; 1977 a, b). The communities are primari-
ly made up of opportunistic deposit feeders such as
polychactes and amphipods which are associated with
the harbor's organic silts. Previous studies have
indicated that the lower Mystic River is dominated
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by the polychaete Caphella capilala (MES, 1977 a,
b), as also is shown in the 1986 NED sampling
program. The harbor is inherently stressful to
bcnthic populations due to low levels of oxygen and
sediment contamination. Benthic organisms which
are tolerant of low levels of dissolved oxygen and
other stresses, on a cyclic basis, survive and become
dominant. Where environmental stresses defaunate
the substrate (eliminating non-mobile bottom dwell-
ing organisms), the tolerant species pioneer the
vacant substrate as stresses decline to tolerable levels.
It is this type of benthic community, in dynamic
equilibrium, that is present in Boston Harbor (dy-
namic in response to environmental stresses and
equilibrated to cycles of defaunation). The removal
of this assemblage of organisms during dredging will
have minimal impact on the ecological productivity
of the harbor as a system.
The primary impact of this project on biological
resources will be the removal of benthic organisms
inhabiting the areas to be dredged. This impact will
represent a low (29 organisms/m2) to high (4,800
organisms/m2) loss of benthic organisms depending
on the season and area to be dredged. Dredging will
expose azoic parent material which will be recolo-
nreed by adult and larval benthic organisms. During
the recolonization period, there will be a large num-
ber of individuals from a few species. Subsequent
populations will recruit a greater number of species,
each having fewer individuals. Concurrent with this
transitional state the clay will be biogenically re-
worked and mixed with other material until it be-
comes aerated and acceptable for colonization by
more species. It is this large number of pioneering
benthic .species that biogenically rework the substrate
in a short time frame. These organisms are also an
important source of forage for juvenile finfish. In
Boston Harbor, seasonal depletion of the water
column oxygen levels maintain the benthic communi-
ty of the inner harbor as a pioneering assemblage in
a state of dynamic equilibrium. The dredging of the
channel will cause a short term loss of benthic
productivity that will be rapidly offset through faunal
rccolonization. This rccolonization potential has
been recently demonstrated by MWRA studies of
harbor areas disturbed by the 1992-93 winter storms.
These areas were extensively recolonized by opportu-
nistic species such as Ampelisca sp. (J. Kelly, pers.
comm. 1993).
Chemical signals essential for anadromous fishery
migrations could become masked by the dredging
operation's suspension of sediments and associated
chemicals. Dredging will be scheduled in non-sensi-
tive areas and periods of the harbor to avoid impact-
ing seasons of critical spawning runs of those species.
Sediment suspension will also displace motile
species that will attempt to avoid gill abrasion, lower
oxygen levels, and reduced sensory opportunities for
predation (masked odors and low visibility) in the
dredging area. These would all be temporary and the
effects would not have long term detrimental impacts
given the recommended mitigation practices.
With the explosive fracturing and mechanical
removal of approximately 88,000 cubic yards of
bedrock, the potential for mortalities of fish and
invertebrates exist. Based on rock density, antici-
pated explosive size during a single blast, open water
fish kill research, and physical characteristics of the
harbor, an estimated fish kill zone during blasting
activities would range from 30m2 to 1400m2 surface
area. Based on this study's limited fish density data
(two seasons of fish trawls and gill net collections)
the average density in Boston I larbor is approximate-
ly 10 fish/m2. If at any given time the fish were
present in the water column directly over the blast
and orientated sideways to it, the maximum morali-
ties may range from 300 to 14,000 fish per blasting
operation. The number of fish kill at the high end
would be unusual. Monitoring of blasting operations
during the navigation improvement project in Ports-
mouth I larbor in New I lampshire did not indicate
fish kills close to these maximum ranges. However,
the monitoring results recorded only the fish seen
floating at the surface, liven if the number of fish
4-12
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killed per blast are high, they are similar to the range
of fish killed in a commercial fish trawl.
Species of marine mammals which may occur in
tidal waters in the vicinity of the project area, include
harbor seals (Phoca vilulind), harbor porpoises
(Phocena phocena), and grampuses (Grampus
griseus). However, their presence in the Boston
Harbor system is uncommon (Cortell, 1990b).
Because most of the dredging impacts will occur well
within the Inner Harbor where marine mammals are
uncommon, the project is not likely to cause adverse
impacts to these species.
4.5.3 Threatened and Endangered Species
The intertidal and subtidal areas including and
adjacent to the Federal channel area are not known
to provide habitat for any Federal threatened and/or
endangered species, or State rare species. Letters
from the U.S. Fish and Wildlife Service, the National
Marine Fisheries Service and the State Natural Heri-
tage Program have confirmed the lack of any threat-
ened, endangered, or rare species in the dredging area.
4.5.4 Historical and Archeological Resources
Boston Harbor has been subject to navigation im-
provement projects since the mid-nineteenth century.
The channels and rivers in and around the harbor
have been deepened, widened, and straightened. This
activity has severely limited the historic and archeo-
logical potential of the harbor.
The dredging portion of the navigation improve-
ment project in Boston Harbor will not adversely
affect sites of historic, architectural or archaeological
significance, as defined by the National Historic
Preservation Act of 1966. The Massachusetts Histor-
ical Commission reviewed the deep-draft navigation
improvement project, including the berthing areas,
and determined that dredging the previously main-
tained channels and berthing areas will not have an
adverse impact on any historical or archaeological
resources.
The Chelsea Street Bridge is considered to be
eligible for the National Register of Historic Places,
as it is the only Strauss heel-trunnion bascule bridge
known to survive in the Commonwealth. Navigation
improvement dredging is not expected to impact this
bridge. Any modification to the bridge would require
coordination with the Massachusetts Historic Com-
mission to outline mitigation measures.
4.5.5 Socio-Economic Environment
In 1992, the combined public and private terminals
in Port of Boston handled more than 16 million tons
of cargo. Petroleum and liquefied natural gas (LNG)
were the dominant bulk cargo, representing 87% of
the total cargo tonnage in the Port. Approximately
14 million tons of the petroleum and LNG were
delivered to the private terminals along the Chelsea
Creek, Mystic River, and Reserved Channel. Mass-
port's public terminals handled approximately one
million tons of general cargo, 96% of it container-
ized.
The economic benefit from the Port in the form of
employment, income, sales, and tax revenues were
generated by the public and private cargo handling
interests. For fiscal year 1992, Massport's terminals
handled 1,053,804 tons of containerized and bulk
cargo and 34,553 automobiles. As a result of its
cargo handling activities, Massport was responsible
for generating nearly $1.86 billion in economic
benefits for the region and providing employment for
more than 6,000 people in jobs directly related to the
cargo industry. An additional 3,000 jobs were
created in the industrial service sector which supports
cargo activity. The total economic impact of the
maritime activities at Massport terminals can be
summarized as follows:
4-13
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- Personal IncomeS 386.92 million
- Sales Revenues 800.38 million
- Business IncomeS 610.09 million
- State/Local TaxesS 60.19 million
Total Economic Impact$l,857.59 million
The private oil and other bulk terminals contribut-
ed additional jobs and revenues, likely substantial but
more difficult to quantify because of the privileged
(i.e., competitive) nature of information about
privately owned operations. The availability and cost
of oil products affect the regional economy through
manufacturing output, job creation and cost of living.
At the national and international scale, aviation fuel
located at Chelsea Creek terminals supports Logan
Airport's role as a gateway for passengers and air
cargo.
The dredging project will have minimal negative
effect, and possibly a beneficial effect, on natural or
human resources in the project area. Vessel traffic in
the channel areas will be required to navigate around
the dredging equipment. Only the largest commercial
vessels will need to be coordinated separately so that
the dredging equipment can move out of the way.
Blasting will be required in the Mystic River Chan-
nel, the Inner Confluence, the north side of Reserved
Channel near the mouth, and across from the Re-
served Channel in the Main Ship Channel. Individu-
al berth areas will accommodate dredging in their
own manner.
Dredging with a mechanical bucket will produce
noise from the engines lowering and lifting the dredge
bucket. The noise produced will be similar to other
diesel engine equipment in the area. Many of the
receptors in the three tributaries are businesses.
Residential areas only exist near the mouth of Chel-
sea Creek and near the Tobin Bridge. Noise may be
greater during the warmer time of year when people
are outside more frequently and windows are open.
Although the dredges are expected to work 24 hours
a day, the noise level will be masked by background
noise of the Tobin Bridge in the Mystic River, noise
levels from Logan Airport activities, and the city
noise in Chelsea. In other words, noise generated by
this project should not be substantially differentiated
from other Harbor baseline noise.
In addition to the noise produced during the dredg-
ing operation, odor from dredged material placed on
barges may occur. Again the odor impact, if any,
would depend on the time of year and the direction
of the wind. The number of barges that would be
filled range from two to four a day. Therefore the
potential impact would be continuous while dredging
the silt. Perception of odor would be minimal during
the cold months of the year. This is due to'the fact
that more human activity would occur indoors and
the cold temperatures would keep the odor causing
bacteria count low. Generally, the dredging activity
will be far enough away from population concentra-
tions (tourist areas, residential complexes, restaurants,
etc.) that mixing with ambient air is expected to be
sufficient to dilute increased odors, except perhaps
under worse case conditions.
The navigation improvement project will have an
effect on the local economy through anticipated
transportation savings of about $3,500,000 annually
for Boston Harbor shippers. It is not anticipated
that the navigation improvement project would per
se result in increased tonnage shipped tlirough the
port of Boston. The project should result in some-
what fewer trips, but larger vessels will be utilized in
transporting cargo to Boston resulting in economy of
scale. As the tonnage of cargo entering Boston
I larbor could remain essentially the same, no second-
ary impacts on the land end of shipping would occur.
The navigation improvement project would also
reduce light loading, lightering, and tidal delays, thus
improving the safety of Boston Harbor by reducing
the potential for an oil spill.
Container ships, part of the economic justification
for deepening Boston Harbor, are also important to
the compctivcncss of the harbor. Despite the difficult
4-14
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economic times for this region and the world, general
cargo tonnage handled in the Port has remained
stable. Containerized cargo has been growing at a
rate of about 1.8% annually since 1985. While
economic recovery is the top priority of the public
and private business leaders, the Port of Boston has
to continue to generate revenues and provide jobs.
Looking beyond the economic recovery and into the
future, Port of Boston would strive, once again, to
become a growing east coast and world cargo distri-
bution center.
Another potential benefit of the navigation im-
provement project would be to reduce the quantity
of contaminated sediment exposed to marine organ-
isms. The current level of contamination in the inner
harbor could have an effect on the structure of the
benthic community as well as the potential for
bioaccumulation by higher trophic levels which feed
in Boston Harbor. Removing the contaminated
sediment and sequestering the associated chemicals
could reduce the risk to human health as well.
Therefore the project may benefit the ecosystem and
human health by removing these sediments from
exposure. Given the other clean-up activities in the
harbor (primarily by MWRA) this project could
contribute to the cumulative positive impacts to
Boston Harbor.
4-15
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Jan Apr Jul Oct Jan Apr Jul
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Physical Complete '
Boston Harbor Dredging Project EIR/S
Figure 4-1 Exampte Schedute
Disposal at Mass. Bay Disposal Site
Source:
New England Division, Corps of Engineers
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5.0 COMPLIANCE REQUIREMENTS
Prior to the implementation of this project, a
variety of federal, state and local permits will need to
be obtained. Acquisition of these permits will confirm
that the project has complied, or will comply, with
these particular regulatory requirements. Other laws
and regulations simply call for consultation between
federal agencies. Exactly which regulations will apply
to the project will vary depending on the disposal
option ultimately selected. This section briefly identi-
fies the key federal and state regulations which will
likely be triggered by the dredging and disposal opera-
tions. Section 5.2 lists the federal statutes and execu-
tive orders which the U.S. Army Corps of Engineers
must comply with in performing the federal portion of
the project. Finally, Section 5.3 contains an outline of
a draft Section 404(b)(l) evaluation to be prepared by
the Corps for the BIT NIP.
5.1
REGULATORY COMPLIANCE
Chapter 21II: This law and attendant regulations,
administered by the Massachusetts Department of
Environmental Protection, provide for the regulation
of solid waste facilities. Among the powers are the
selection of sites for landfills, their design, and opera-
tion. Site assignment powers are vested in local boards
of health.
Chapter 91: Administered by the Massachusetts
Division of Wetlands and Waterways, the Chapter 91
program regulates any dredging, or the building of
structures or the placing of fill below the mean high
tide line (i.e., in tidelands). If permitted, such projects
may be required to provide compensatory water-
related benefits to the public. The law also applies to
former tidelands which were subsequently filled.
Clean Water Act of 1977: Section 401 regulates
discharges to surface waters of the United States, and
as such will impose water quality standards on the
dredging itself, on surface water runoff from upland
disposal, and on the disposal of dredged material in
waters of the United States (seaward to the 3 mile
limit). The water quality certification program is
administered by the Massachusetts Dept. of Environ-
mental Protection, Division of Water Pollution Con-
trol. (The Code of Massachusetts Regulations, in 314
CMR 9.00, classifies dredge or fill material on the basis
of its chemical and physical characteristics). Section
404 controls the disposal of dredged material in waters
of the United States (again, seaward to the 3 mile
limit); this program is administered by the Corps,
subject to review by EPA.
Coastal Zone Management Act of 1972. as
amended: Under the provisions of this act, the Massa-
chusetts Coastal Zone Management Program conducts
reviews of all proposed federal projects, and other
projects requiring federal permits, within the coastal
zone to determine their consistency with applicable
CZM regulatory (13) and non-regulatory (14) policies.
Endangered Species Act of 1973. as amended: The
law requires that any federal agency authorizing,
funding, or carrying out a project shall insure that the
action is not likely to jeopardize the continued exis-
tence of any threatened or endangered species or result
in the destruction of such habitat. A similar state law
is administered by the Massachusetts Natural Heritage
and Endangered Species Program. Consultation with
state and federal resource agencies is continuing.
Fish and Wildlife Coordination Act, as amended:
Any party proposing to impound, divert, or deepen
the channel of a water body is required to consult with
the U.S. Fish and Wildlife Service, other federal
agencies (e.g., the National Marine Fisheries Service),
and the head of the state counterpart fish and wildlife
agency with the objective of eliminating, minimizing,
or mitigating adverse impacts to fish and wildlife
resources.
Marine Mammal Protection Act: The law regulates I
or prohibits the taking of marine mammals. The
Marine Mammal Commission may designate certain
5-1
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species or slocks as "depleted", and subsequently
develop and promulgate conservation plans. The act
is administered by the National Marine Fisheries
Service.
Marine Protection. Research, and Sanctuaries Act
of 1972, as amended: This law regulates the transpor-
tation of dredged material for ocean disposal activities
seaward of the 3 mile limit. Under Section 102, the
U.S. Environmental Protection Agency is authorized
to designate sites for ocean disposal of dredged materi-
al. Under Section 103, the Corps administers a permit
program regulating the use of designated sites (in this
area, the Massachusetts Bay Disposal Site). As
evidenced in the title, MPRSA also is the enabling
legislation which permitted the designation of Stell-
wagen Bank as a National Marine Sanctuary.
Massachusetts Environmental Policy Act: MEPA
requires the filing of an Environmental Notification
Form (ENP) to evaluate whether a proposed project
may cause significant damage to the environment.
Environmental Impact Reports (EIRs) are required, if
so determined by the Executive Office of Environmen-
tal Affairs. Partial compliance has been achieved by
publication of this Draft EIR/S. Full compliance will
follow issuance of the Final EIR/S.
Massachusetts Wetlands Protection Act (Chapt.
131. Sec. 40): This law confers jurisdiction to local
Conservation Commissions for the regulation of
dredging, filling, removing or altering inland or coastal
wetlands through issuance of an Order of Conditions.
Resource Areas, protected by the act, include border-
ing vegetated wetlands; banks, beaches and dunes; land
subject to flooding; and land under water.
National Historic Preservation Act of 1966. as
amended: Requires coordination with Massachusetts
Historical Preservation Commission to consider the
impact of a project on historic or archaeological
resources and to minimize or avoid harm to those
resources. The Commission also administers a similar
state law. Commission files were reviewed for all
disposal sites evaluated in the EIR/S.
National Environmental Policy Act of 1969. as
amended: NEPA requires the preparation of a detailed
statement of environmental impact for each major
federal action which may significantly affect the quality
of the human environment. Preparation of this EIR/S
signifies partial compliance with NEPA. Full compli-
ance will be noted at the time the Final EIR/S is
promulgated and the Record of Decision is signed.
Rivers and Harbors Act of 1899. as amended:
Section 10 of this law authorizes the Corps to regulate
structures and work in or over navigable waters of the
United States.
Safe Drinking Water Act of 1972. as amended: This
act would apply to the project only in the event that
an upland disposal site might jeopardize a sole source
drinking water aquifer; it is administered by EPA.
5.2 COMPLIANCE WITH FEDERAL
STATUTES AND EXECUTIVE ORDERS
5.2.1 Federal Statutes
1. Clean Water Act of 1977 (Federal Water Pollution
Control Act Amendments of 1972) 33 U.S.C. 1251 et
scq.
Compliance: A Section 404 (b)(l) Evaluation and
Compliance Review have been incorporated into this
EIR/S. An application shall be filed for State Water
Quality Certification pursuant to Section 401 of the
Clean Water Act.
2. Marine Protection, Research, and Sanctuaries Act
of 1972, as amended, 33 U.S.C. 1401 et seq.
Compliance: Circulation of this report for public
review, including an evaluation and findings concern-
ing the transportation of dredged material for disposal
5-2
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in ocean water pursuant to Sections 102 and 103
signifies compliance with this Act.
3. National Historic Preservation Act of 1966, as
amended, 16 U.S.C. 470 et seq.
Compliance: The project was coordinated with the
State Historic Preservation Office to determine whether
historic or archaeological resources would be affected
by the proposed project.
4. Preservation of Historic and Archaeological Data
Act of 1974, as amended, 16 U.S.C. 469 et seq. This
amends the Reservoir Salvage Act of 1960 (16 U.S.C.
469).
Compliance: Not applicable; project does not require
mitigation of historic or archaeological resources.
5. Endangered Species Act of 1973, as amended, 16
U.S.C. 1531 et seq.
Compliance: Coordination with the National Marine
Fisheries Service has determined that a Biological
Assessment pursuant to Section 7 of the Endangered
Species Act is required. The results of this Biological
Assessment has been included in this report.
6. The Estuary Protection Act (16 U.S.C. 1221).
Compliance: Not applicable; the navigation improve-
ment project is authorized by Congress.
7. Pish and Wildlife Coordination Act, as amended,
16 U.S.C. 661 et seq.
Compliance: Coordination with the U.S Fish and
Wildlife Service, National Marine Fisheries Service,
and the appropriate State Fish and Wildlife agencies
through the Public Notice signifies compliance with
the Fish and Wildlife Coordination Act. The Division
Engineer has given full consideration to fish and
wildlife conservation in evaluating this project.
8. National Environmental Policy Act of 1969, as
amended, 42 U.S.C. 4341 et seq.
Compliance: Preparation of this report signifies partial
compliance with NEPA. Full compliance shall be
noted when the Record of Decision is issued.
9. Wild and Scenic Rivers Act, as amended, 16 U.S.C.
1271 et seq.
Compliance: Not applicable; this project is not
located in a listed river (Section 2) or proposed for
inclusion (Section 3) in the Act.
10. Coastal Zone Management Act of 1972, as
amended, 16 U.S.C. 1456 et seq.
Compliance: A CZM consistency determination shall
be provided to the State for review and concurrence
that the proposed project is consistent to the maxi-
mum extent practicable with the approved State CZM
program.
11. Clean Air Act, as amended U.S.C. 7401 et seq.
Compliance: Public notice of the availability of this
report to the Regional Administrator of the Environ-
mental Protection Agency for review pursuant to
Sections 176c and 309 of the Clean Air Act signifies
compliance.
12. Federal Water Project Recreation Act, as amend-
ed, 16 U.S.C. 4601-12 et seq.
Compliance: Not applicable.
13. lumd and Water Conservation Fund Act of 1965,
as amended, 16 U.S.C. 4601-1.
Compliance: Public notice of the availability of this
report to the National Park Service and the Office of
Statewide Planning relative to the Federal and State
comprehensive outdoor recreation plans signifies
compliance with this Act.
5-3
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14. Rivers and Harbors Act of 1899, as amended, 33
U.S.C. 401 etseq.
Compliance: No requirements for Corps projects or
programs authorized by Congress. The proposed
navigation improvement project has been Congressio-
nally approved. However, berth dredging is regulated
by this Act.
IS. Watershed Protection and Flood Prevention Act,
as amended, 16 U.S.C. 1001 et seq.
Compliance: Not applicable.
5.2.2 Executive Orders
1. Executive Order 11593, Protection and Enhance-
ment of the Cultural Environment, May 13, 1971 (36
FR 8921, May 15, 1971).
Compliance: This order has been incorporated into
the National Historic Preservation Act of 1980.
2. Executive Order 11988, Floodplain Management,
May 24, 1977, amended by Executive Order 12148,
July 20, 1979.
Compliance: Not applicable.
3. Executive Order 11990, Protection of Wetlands,
May 24, 1977 (42 PR 26961, May 25, 1977).
Compliance: Not applicable.
4. Executive Order 12372, Intergovernmental Review
of Federal Programs, July 14, 1982 (47 FR 3959, July
16, 1982).
Compliance: Not applicable.
5. Executive Order 12114, Environmental Effects
Abroad of Major Federal Actions, January 4, 1979.
Compliance: Not applicable.
5.2.3 Executive Memorandum
1. Analysis of Impacts on Prime or Unique Agricul-
ture I^nds in Implementing NEPA, August 11, 1980.
Compliance: Not applicable.
5.3 EVALUATION OF SECTION 404TB¥n
GUIDELINES FOR BHNIP
The following pages consist of a draft evaluation of
404(b)(l) compliance for the disposal of dredged
material from the BHNIP. The evaluation will be
finalized after review and comment on this draft EIR/S
and when a final disposal option is selected.
5-4
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CLEAN WATER ACT
SECTION 404 (B)(1) GUIDELINES FOR
SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL
Boston Harbor Navigation Improvement Proiect
I. PROPOSED PROJECT
A.
Bay.*
Project Location - Boston Harbor and Massachusetts
B. Project Description - The proposed project would
deepen the Reserved Channel and Mystic River from 35 feet
MLW to 40 feet MLW and deepen Chelsea Creek from 35 feet MLW
to 38 feet MLW. In addition, the berthing areas listed in
Table 1 would also be dredged.
The dredged material could be disposed at one or more of
the following preferred sites: Spectacle Island CAD, and
Meisburger sites 2 or 7 (see figures 3-6, 3-4, and 3-5 in
the DEIR/S). Material disposed at the Boston Lightship or
Massachusetts Bay Disposal Site (MBDS) will be evaluated
under Section 103 of the Marine Protection, Research and
Sanctuaries Act.*
C. Project Authority and Purpose - This project has
been Congressionally authorized in the Water Resources
Development Act of 1990 (P.L. 101-640). The project has
been authorized to reduce tidal delays and limits on vessel
size and loading restrictions.*
D. General Description of the Dredged Material -
Approximately 2.9 million cubic yards of material will be
dredged from the three tributaries and berthing areas. Of
this volume about 88,000 cubic yards is rock, 1.7 million
cubic yards is parent (clay, gravel) material and 1.1
million cubic yards is silt. The silt (maintenance)
material overlays the parent material and will be treated as
unsuitable for unconfined open water disposal. The parent
material does not contain elevated levels of contaminants.*
E. Description of Disposal Method - All of the channels
and berth areas will be dredged using a mechanical bucket
dredge and scow. An environmental bucket will be used for
removal of the silt material. A pit would need to be
dredged first at the three offshore sites (Spectacle Island
CAD, and Meisburger sites 2 and 7). A mechanical dredge
would be used to remove the material from the pit. The
* Please refer to the Boston Harbor Navigation
Improvement Environmental Impact Report/Statement for
additional details.
5-5
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TABLE 1
BERTHING AREAS TO BE DREDGED IN BOSTON HARBOR
Conley 11-13
North Jetty
Boston Army 1-9
Boston Edison Intake
Boston Barge Berth
Conley 14-15
Prolerized
LOCATION
Main Ship Channel/
Reserved Channel
Inner Confluence/
Mystic River
Distrigas
Moran
Revere Sugar
Mystic Piers 2, 49, 50
Mystic Piers 1
Eastern Minerals
Gulf Oil
Chelsea Creek
VOLUME (CY)
46,000
16,000
129,000
1,000
16,000
7,000
8,000
14,000
7,000
13,000
45,000
18,000
40,000
12,000
5-6
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material removed from the pit would be used for
beneficialuse, if appropriate, or taken to the MBDS for
disposal if there is no use for the material. The scow would
transport the dredged material to the disposal site and
release the material through doors located on the bottom of
the scow. The silt material would be deposited into the pit
and then covered with cap material.*
* Please refer to the Boston Harbor Navigation
Improvement Environmental Impact Report/Statement for
additional details.
II. ASSESSMENT OF IMPACTS
The following is an assessment of the potential
short-term and long-term effects of a proposed discharge of
dredged or fill material on the physical, chemical and
biological components of the aquatic environment for those
activities pursuant to Section 404 of the Clean Water Act.
This assessment shall provide information required to
determine compliance with 404 (b) (1) Guidelines in
accordance with Subpart B, 40 CFR Part 230.
A. Potential Impacts on Physical and Chemical
Characteristics of the Aquatic Ecosystem (Subpart C) .
1. Substrate (230.20): (consider impacts to (1) the
physical and chemical characteristics of the substrate, (2)
substrate elevation or contours, (3) dredged material
movement, (4) the benthos) .
Spectacle Island CAD - Spectacle Island is located
southeast of Logan Airport. The construction of the
Spectacle Island CAD would require dredging a pit in the
shallow subtidal flat east of the islarel. Contaminated silt
material would be deposited in the pit and capped to
existing bottom elevation. Circulatior in the vicinity of
the island is dominated by tidal currents. No changes in
circulation or fluctuation should occui once construction is
complete. The benthic community now existing at this site
may change from a community dominated hy benthos adapted to
a sandy substrate to a benthic community dependent on the
make-up of the cap. Original substrate could be deposited
onto of the cap to facilitate recolonization.
Meisburger sites 2 and 7 - These silles are located
offshore approximately 7.5 miles east cf Deer Island. Both
of these sites are in the proximity of the MWRA' s proposed
ocean outfall. The existing sediment (sand and gravel)
would be removed to create a pit for tie silt material and
then capped. The removed material would be used
beneficially for beach nourishment or construction. The
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sites would be restored to their original bathymetry and
physical substrate conditions. No long term impact to the
benthic community is expected.
2. Current patterns and water circulation (230.23):
(consider impacts to (1) current patterns, (2) water
circulation, (3) direction or velocity flow, (4) thermal
stratification and (5) indirect impacts such as alteration
of the hydrologic regime, shoreline erosion and deposition
rate of suspended particulates) .
The proposed disposal sites should have negligble long
term impacts on current patterns and water circulations in
Boston Harbor and Massachusetts Bay. The offshore sites
will be returned to their original elevations.
3. Water (230.22): (consider impacts to water quality
such as (1) clarity, (2) color, (3) odor, (4) taste, (5) pH,
(6) nutrients, and (7) eutrophication) .
/
Temporary impacts to water quality are expected from
disposal of dredged material. Clarity will be reduced and
nurtrients could be released from the suspended solids. The
release of nutrients is not likely to have an affect on
eutrophication due to the tendancy of nutrients to adhere to
silt and clay particles.
4. Salinity gradients (230.25): (consider the direct and
indirect impacts to existing salinity gradients and
patterns) .
None of the proposed disposal sites would change the
composition of freshwater or salinity gradients in Boston
Harbor or Massachusetts Bay.
5. Normal Water Fluctuations (230.24) : (consider the
direct and indirect impacts to the physical, chemical and
biological components of the aquatic ecosystem) .
No long term impact from disposal at the offshore sites
to normal water fluctuation is expected as the bottom
surface will be returned to its original elevation.
6. Suspended particulates/turbidity (230.21): (consider
impacts to the physical and chemical properties of the water
column such as (1) light penetration and rate of
photosynthesis, (2) dissolved oxygen, (3) toxic materials,
(4) aesthetics and (5) those indirectly related to
sight/filter feeding organisms) .
All of the potential disposal sites would have some
characteristics in common. It can be expected that disposal
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operations would cause localized and temporary increases in
suspended solids concentrations (and turbidity) in the water
column. None of the sites proposed fe-ir disposal would
impact (through water quality violations) any shellfish beds
in the area. Water quality impacts would be mostly confined
to the disposal site. Impacts to dissolved oxygen
concentrations in the water column would be expected to be
localized and temporary. Spectacle Island CAD and
Meisburger sites are located in areas with active flushing.
The water may appear turbid from the release of suspended
solids.
7. Contaminant determinations
a. -To the best of your knowledge, does the proposed
project area have any past history of:
1) chemical or oil spills or discharge?
Yes X No
2) upstream or on-site industrial or
municipal discharge
Yes X No
3) chronic pollutant loading from port
or harbor use and/or other indirect
sources of pollutants? • .
Yes X No
To expedite processing for any affirmative answer,
provide as much historical information as you have,
including dates, amounts, concentrations, etc., of such
spills or discharge.
Boston Harbor is an active shipping port with many
industrial complexes along its shore. It is expected that
spills and discharges have occurred without being reported.
Due to the complexity of the port it would be easy to
predict that there have been oil spills, discharges from
metal plants and processing plants.
Jb. What is the expected frequency of maintenance
dredging of this project?
It is estimated that 1.8 million cubic yards of material
will need to be dredged from the tributaries in Boston
Harbor within the next 50 years. The dredging schedule will
depend on the triburary. The Mystic River and Chelsea Creek
will need to be maintained more frequently than the Reserved
Channel.
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Mystic
88.6
5270.0
0.9
3.2
194.4
106.8
121 1
Chelsea
73.4
7275 . 0
0.7
3.2
163 .4
151.4
77.4
Reserved
85.3
1415.0
0.9
2.8
119.0
133.3
110.2
c. Description of the Material to Jbe Dredged
1) Grain Size Analysis
Size Fraction % of total by weight
coarse gravel 64 mm
fine gravel 2-64 mm
sand .063-2 mm
silt .004-063 mm 39 %
clay .004 mm 61 %
2) Chemical Analysis of Sediment
PCBs (ppb)
Total PAH (ppb)
mercury (ppm)
cadmium (ppm)
lead (ppm)
chromium (ppm)
copper (ppm)
This is the average of the silt material from each
tributary. The averages are taken from 1986 and 1990 data.
PCS data is from 1990 only. All of the clay material had
low (Class I) level metals and organics.
State test methods used for each test in A) and B)
above.
The method outlined in the draft regional protocol
prepared by the Corps/U.S. EPA titled "Guidance for
Performing Tests on Dredged Material to be Disposed of in
Open Water"
8. Potential Impacts on Biological Characteristics of
the Aquatic Ecosystem (Subpart D) .
a. Threatened and endangered species (230.30): (consider
the direct and indirect impacts to Federally-Us ted
threatened or endangered species and their habitat;
reference coordination results with the Department of
Interior) .
No impact to threatened or endanged species will occur
from disposal at the Spectacle Island CAD site. Impacts to
threatened or endangered species could occur from disposal
at the Meisburger sites. A Biological Assessement has been
prepared for the National Marine Fisheries Service which
evaluates potential impacts to these species. Based on the
findings of the Biological Assessment prepared for the
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National Marine Fisheries Service, no substantial long term
impacts are anticipated from disposal activities at the
Meisburger sites.
b. Fish, crustaceans, mollusks and other aquatic
organisms in the food web (230.31): (consider temporary and
permanent effects on populations of aquatic organisms
concerning (1) habitat alteration, (2) spawning migrations,
(3) reproduction, (4) food supplies, (5) displacement and
(6) food chain interaction).
There will be a temporary disruption of the benthic
community at the disposal site during construction
activities. The offshore sites will be returned to their
original elevations. Within a couple years the disposal
site should be supporting a benthic community. None of the
disposal sites are known to be unique or unusual in their
habitat.
c. Wildlife (230.32): (consider the direct and indirect
impacts to (1) breeding and nesting habitat, (2) escape
cover, (3) travel corridors, (4) food supplies, (5)^
introduced species and (6) plant and animal diversity and
biological productivity) .
The disposal sites are not known to be significant
wildlife habitat. They have not been recognized as
important breeding, nesting, resting or food sources for
wildlife.
9. Potential Impacts on Special Aquatic Sites (Subpart E) .
a. Sanctuaries and/or refuges (230.40): (consider the
impacts of (1) disrupting breeding, spawning and migratory
activity of resident or transient fish and wildlife
(ACEC/APR) (See CZM regulations)
All of the sites are located several miles from the
Stellwagen Bank National Marine Sanctuary. The Meisburger
sites (the closest to the NMS) are located 10 to 12 miles
from the sanctuary where many of the migratory species
(whales) are found. These species are infrequently found in
the area of the Meisburger sites. Mobile species such as
f inf ish and whales would be expected to avoid the temporary-
cons truction activity.
b. Wetlands (230.41): (habitat loss, alter current
patterns, reduce capacity to to retain storm floods or
dissipate storm surge runoff).
Not applicable.
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&
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c. Mud Flats (230.42): (consider same impacts as above).
The Spectacle Island CAD site will be returned to its
original bathymetry. The benthic community will be
dependent on the type of cap used; either the parent
material or some of the original surficia-1 material.
d. Vegetated Shallows (230.43): (consider same impacts
as above) .
Not applicable
B. Description of the Disposal Site(s) for Dredged
Material.
a. What is the length, width, depth and volume of the
proposed project?
Spectacle Island CAD - Approximately 45 acres large and •
in water with depths of 4 to 15 feet MLW.
Meisburger sites 2 and 7 - Site 2 lies in 80 to 105 feet
of water and is about 4,100 feet long. This site could
yield a minimum of 780,000 to 4.7 million cubic yards of
material. Site 7 has similar characteristics to site 2 but
could hold a greater volume of material (up to 19.5 million
cubic yards) . Water depths would range from 90 to 110 feet
MLW.
b. Has the site been designated by the state or E.P.A.
as a dredge disposal site? Yes No X
If yes, ' supply any available documentation as to effects
of other authorized dumpings that have been made in the
dumping area (e.g., heavy metal background reading and
organic carbon content) .
If no, give a description of the characteristics of the
proposed disposal site and an explanation as to why no
previously designated site is feasible.
The characteristics of the site are described above and
in the Boston Harbor Navigation Improvement EIR/S. There is
no currently designated site that is approved for the
disposal of the silt material which is considered unsuitable
for unconfined open water disposal. The Massachusetts Bay
Disposal Site is not available for the silt material until
issues concerning capping are resolved.
3. Is the anticipated disposal site located within a
designated ocean sanctuary as established by Federal law or
G.L.C. 132A, 13? Yes No X
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4. If disposal is anticipated to occur on land, indicate
drainage characteristics from the results of test pits,
borings and percolation tests, as applicable.
Not applicable.
5. How long is the disposal site estimated to be in
use? Indicated the duration of this disposal action and
anticipated future use of site.
Construction activities are anticipated to occur for
approximately one to one and one-half years. Future use of
Spectacle Island CAD for dredged material is not expected
because of its limited capacity. The Meisburger sites
could be used for the future use of this project or others.
6. Mixing zone determination (consider factors in
Section 230.11 (f) (2) ) .
ADDAMS DUMP models were performed at the Meisburger
sites and Spectacle Island CAD site. All of the models
indicated that water quality violations would not occur
outside the mixing zone. Refer to the Boston Harbor
Environmental Impact Report/Statement for addtional details.
7. Municipal and private water supply
Not applicable
8. Recreational and commercial fisheries
Dredging and disposal activities will have minor impacts
to commercial and recreational fisheries. None of the sites
are commercial shellfish beds and are not known to be of
unusual or rare habitat types. There will be a temporary
and localized loss of benthos. However, the area to be
impacted is small compared to the rest of Boston Harbor and
Massachusetts Bay. As stated above, release of contaminants
and water quality exceedances are expected to be confined to
the disposal site. This is a temporary impact.
9. Water related recreation
The project is not anticpated to have any substantial
affects on the recreational community. Boston Harbor is a
working port with few beaches or boating facilities in the
project area.
C. Determination of Cumulative Effects on the Aquatic
Ecosystem •
No other project is known to propose the use the
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disposal site(s). Although the identification of these
sites as acceptable for unsuitable material may allow their
use by other agencies. It is not anticipated that all of
the above sites would be used by this project.
D, Determination of Secondary Effects on the Aquatic
Ecosytem
No known secondary effects are anticipated from the use
of any or all of the proposed disposal sites.
JJJ. Findings of Compliance or Noncomnliance
The proposed disposal sites for discharge of dredged or
fill material complies with the Section 404 (b)(1)
guidelines
Date
BRINK P. MILLER
Colonel, Corps of Engineers
Commander New England Division
5-14
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5.4 PROJECT FEASIBILITY STUDY AND
ENVIRONMENTAL ASSESSMENTS
During the period 1986-88, the Corps conducted a
feasibility study and environmental assessment for deep
draft navigation improvements to Boston Harbor and
published a report of its findings (U.S. Army Corps of
Engineers, 1988). During the course of the studies,
coordination was maintained with the following
federal, regional, state and local agencies:
Federal Agencies
U.S. Environmental Protection
Agency
U.S. Coast Guard
U.S. Maritime Administration
National Park Service
Bureau of Outdoor Recreation
U.S. Public Health Service
National Marine Fisheries Service
U.S. Pish and Wildlife Service
Economic Development
Administration
U.S. Geological Survey
Federal Highway Administration
Federal Aviation Administration
Regional Commissions
New England Regional Commission
New England River Basins Commission
New England Interstate Water Pollution
Control Commission
Mass. Dcpt. of Public Works
Mass. Office of Coastal Zone Management
(MACZM)
Mass. Turnpike Authority
Mass. Dept. of Environmental Quality Engineering
(MADEQE)
Mass. Pilots Commission
Mass. Historical Commission
Mass. Water Resources Authority (MWRA)
Metropolitan District Commission (MDC)
Mass. Bay Transportation Authority (MBTA)
Massachusetts Port Authority (Massport)
Communities and Agencies
Boston Redevelopment Authority (BRA)
Boston Conservation Commission
Boston Harbormaster
Boston Economic Development and Industrial
Corporation (EDIC)
Boston Harbor Commission
Town of Hull City of Quincy
Town of I lingham City of Revere
Town of Weymouth City of Chelsea
Town of Winthrop City of Everett
Interested Organizations
Maritime Association of Greater Boston
Metropolitan Area Planning Council (MAPC)
Boston Marine Society
Boston Harbor Pilots Association
Propeller Club of the United States - Port of Boston
American Institute of Merchant Shipping
State Agencies
Mass. Executive Office of Environmental Affairs
(EOEA)
Mass. Dcpt. of Environmental Management
(MADEM)
Harbor Users
Massport
Boston Fuel Transportation Inc.
Boston Edison
White Fuel Corporation
5-15
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Distrigas of Massachusetts
U.S. Gypsum Company
Boston Towboat Company
Boston Gas Company
Coordination was also maintained with all con-
cerned state, local or regional interests and all private
groups and individuals who expressed an interest in
this study. Information exchange and coordination
was accomplished through workshops, mailings,
formal public meetings, study progress briefings, and
distribution of reports as needed to maintain an
effective public involvement program.
5.4A Federal EIS Scoping
In June 22, 1992, the Corps issued a public notice
of its intent to prepare an Environmental Impact
Statement for the Boston Harbor Navigation Improve-
ment Project. A scoping meeting was advertised and
held on July 28, 1992, from 2-5 p.m. and 7-10 p.m.
Scoping comments were received from individuals,
private organizations, and governmental agencies both
in person and by mail. Communications generally
contained one or more of the following elements:
»• support for the proposed dredging to maintain
the viability of the Port of Boston,
>• concern for the proper handling of harbor
sediments known or presumed to contain
contaminated material,
»• skepticism about the effectiveness of capping
silt with clean material at depths of 300 feet,
and
f apprehension that use of the MBDS for dis-
posal of unsuitable material might jeopardize
the Stclbwagcn Bank Marine Sanctuary and,
more broadly, Massachusetts Bay.
These comments and others are contained in their
entirety in Appendix E.
Because of a decision by the Corps and Massport in
the spring of 1992 to prepare a joint EIS/R, and
because Massport's Boston Harbor Dredging Project
Advisory Committee and Technical Working Groups
were established and functioning, most of the subse-
quent coordination was conducted in those forums
(sec 5.4.3 below).
5.4.2 Berth Dredging Project Environmental
Notification Form
Massport's project for the dredging of berthing areas
in Boston Harbor was described in its April 30, 1991,
filing of an Environmental Notification Form (ENF)
with the Massachusetts Executive Office of Environ-
mental Affairs (See Appendix A). On June 7, 1991,
then Secretary Susan Ticmey issued the Certificate in
response to the ENF. The Certificate determined that
the project would require an Environmental Impact
Report (EIR). It further spelled out scoping issues to
be addressed in the EIR (See Appendix A). These
principally related to project description, sediment
characterization, dredging methodology and dredging
impacts, feasibility of disposal alternatives, and mitiga-
tion measures. Finally, the Certificate ordered that
copies of the EIR be distributed to commenters on the
ENF and attendees at the ENF scoping session.
5.4.3 Boston Harbor Dredging Project
Advisory Committee
To enhance coordination with agencies and interest
groups over the course of environmental studies and
the preparation of the DEIS/R, Massport convened a
Boston Harbor Dredging Project Advisory Committee
which met for the first time in March, 1992. Member-
ship in the Committee included federal and state
regulatory agencies, harbor user organizations, and
environmental groups (Appendix B). Over the subse-
5-16
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qucnt fifteen months, the Advisory Committee met
seven times. To assist it with highly technical issues,
the Advisory Committee created two Technical
Working Groups, one of which met eight times and
the other six (See Appendix B for lists of participants
and meeting minutes/notes). These forums provided
excellent opportunities for the exchange of information
and frequently for the resolution of differences. The
Sediment Characterization Technical Working Group
provided advice and oversight in the development of
the Sediment Sampling and Analysis Plan and in the
interpretation of test results. The Disposal Options
Technical Working Group helped select criteria for
screening disposal options and reviewed the results of
applying those criteria to individual potential sites.
5-17
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-------
6.0 LIST OF AGENCIES, ORGANIZATIONS AND PERSONS TO WHOM THE BOSTON
HARBOR DREDGING PROJECT DEIS/R WAS SENT
United States Senators:
The Honorable Edward M. Kennedy
U.S. Senate
Room 409
JFK Federal Building
Boston, MA 02203
The Honorable John F. Kerry
U.S. Senate
One Bowdoin Sq., 10th Floor
Boston, MA 02114
United States Congressmen:
The Honorable Peter I. Blute
U.S. House of Representatives
1029 Longworth House Office Building
Washington, D.C. 20515-2103
The Honorable Barney Frank
U.S. House of Representatives
2404 Raybum House Office Building
Washington, D.C. 20515-2104
The Honorable Joseph P. Kennedy, II
U.S. House of Representatives
1210 Longworth House Office Building
Washington, D.C. 20515-2108
The Honorable Edward J. Markey
U.S. House of Representatives
2133 Rayburn House Office Building
Washington, D.C. 20515-2107
The I lonorable Martin T. Meehan
U.S. House of Representatives
1216 Longworth House Office Building
Washington, D.C. 20515
The Honorable John J. Moakley
U.S. House of Representatives
235 Cannon House Office Building
Washington, D.C. 20515
The Honorable John Olver
U.S. House of Representatives
1323 Ixjngworth House Office Building
Washington, D.C. 20515-2101
The Honorable Gerry E. Studds
U.S. House of Representatives
237 Cannon House Office Building
Washington, D.C. 20515-2110
State Governor:
The Honorable William F. Weld
Governor
Commonwealth of Massachusetts
State House
Boston, MA 02133
State Senators:
The Honorable Thomas F. Birmingham
State Senator
Massachusetts State House, Room 212
Boston, MA 02133
6-1
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The Honorable Walter J. Boverini
State Senator
Massachusetts Stale House, Room 333
Boston, MA 02133
The Honorable William M. Bulger
Senate President
Massachusetts State House, Room 330
Boston, MA 02133
The Honorable Robert E. Travaglini
State Senator
Massachusetts State House, Room 416A
Boston, MA 02133
The Honorable W. Paul White
State Senator
Massachusetts Stale House, Room 309
Boston, MA 02133
State Representatives:
The Honorable James T. Brett
State Representative
Massachusetts State House, Room 42
Boston, MA 02133
The Honorable Salvatore DiMasi
State Representative
Massachusetts State House, Room 138
Boston, MA 02133
The Honorable Thomas M. Finneran
State Representative
Massachusetts State House, Room 243
Boston, MA 02133
The Honorable Paul J. Gannon
State Representative
Massachusetts State House, Room 446
Boston, MA 02133
The I lonorable John Klimm
State Representative
Massachusetts State House, Room 146
Boston, MA 02133
The I lonorable Emmanuel G. Serra
State Representative
Massachusetts State House, Room 481
Boston, MA 02133
The Honorable Richard A. Yoke
State Representative
Massachusetts State I louse, Room 343
Boston, MA 02133
Municipal Government:
The I lonorable Thomas M. Menino
Mayor, City of Boston
Boston City Hall
Fifth Floor
Boston, MA 02201
Lewis II. Spcnce, Receiver
Chelsea City Hall
500 Broadway
Chelsea, MA 02150
The Honorable John R. McCarthy
Mayor, City of Everett
484 Broadway
Everett, MA 02149
The Honorable James A. Sheets
Mayor, City of Quincy
1305 Hancock Street
Quincy, MA 02169
Marie T. Turner, Chair
Winthrop Board of Selectmen
1 Metcalf Square
Winthrop, MA 02152
6-2
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Federal Agencies:
Massachusetts Bays Program
100 Cambridge Street - Room 2006
Boston, MA 02202
Attn: Diane Gould, Ph.D.
National Marine Fisheries Service
One Blackburn Drive
Gloucester, MA 01930-2298
Attn: Richard Roe, Director
John Catena
Chris Mantzaris
National Park Service
Charlestown Navy Yard
Charlestown, MA 02129
Atln: David Rose
New England Fisheries Management Council
5 Broadway
Saugus, MA 01906-1097
Attn: Patricia Fiorelli
NOAA/ORCA22
7600 Sand Point Way, N.B.
Bin No. C 15700
Seattle, WA 98115-0070
Attn: Jo Linse
U.S. Army Corps of Engineers
New England Division
424 Trapelo Road
Waitham, MA 02254-9149
Attn: Karen Kirk Adams, Section Chief
Tom Bruha
U.S. Coast Guard
First Coast Guard District
408 Atlantic Avenue
Boston, MA 02110
Attn: Lt. Patrick G. Foran
U.S. 1 Environmental Protection Agency
Region 1
JFK Federal Building
Boston, MA 02203
Attn: John DcVillars, Regional Administrator
Phillip Colaruso
Kymberlce Keckler
lid Reiner
Patience Whitten
U.S. Fish and Wildlife Service
Ralph Pill Marketplace
22 Bridge Street - 4th Floor
Concord, Nil 03301-4901
Attn: Gordon Beckett, Supervisor
Vcrnon Lang
U.S. Geological Survey
Branch of Atlantic Marine Geology
Quissett C3ampus
Woods Hole, MA 02543
Attn: Brad Butman
U.S. Dept. of Interior
Office of Environmental Project Review
Washington, D.C. 20240
Attn: Bruce Blanchard, Director
U.S. Coast Guard
Marine Safety Office
455 Commercial Street
Boston, MA 02109-1045
Attn: Lt. Chris Fahy
I -t. Chris Oelschlegel
6-3
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U.S. Maritime Administration
Office of Port and Intcrnodal
Transportation
400 Seventh St., S.W.
Washington, D.C. 20590
Attn: Joan Yim, Deputy Administrator
State Agencies:
Cape Cod Commission
3225 Main Street
Bamstable, MA 02630
Attn: Richard Armstrong, Chairman
Massachusetts Bay Transportation Authority
500 Arborway
Jamaica Plain, MA 02130
Attn: Peter Walworth, Manager
Environmental Engineering
Massachusetts Department of
Environmental Management
Division of Waterways, 14th Floor
100 Cambridge Street
Boston, MA 02202
Attn: Peter Webber, Commissioner
Leslie K. Lewis
Massachusetts Department of
Environmental Management
Scenic Rivers Program, Room 1404
100 Cambridge Street
Boston, MA 02202
Attn: Cassie Thomas
Massachusetts Department of
Environmental Management
Office of Water Resources
Ocean Sanctuaries Program
100 Cambridge Street, 13th Floor
Boston, MA 02202
Attn: Michael Gildcsgame
Katie I larkens
Massachusetts Department of
Environmental Protection
One Winter Street
Boston, MA 02108
Altn: Daniel S. Grccnbaum, Commissioner
Massachusetts Department of
Environmental Protection
Division of Solid Waste Management
One Winter Street
Boston, MA 02108
Attn: Joel Hartley
Massachusetts Department of
Environmental Protection
Division of Water Pollution Control
One Winter Street, 8th Floor
Boston, MA 02108
Attn: Brian Donahoe, Director
Steve Lipman
Judy Perry
Massachusetts Department of
Environmental Protection
Division of Waterways & Wetlands
One Winter Street, 8th Floor
Boston, MA 02108
Attn: Carl Dicrker
Mitch Zicncina
6-4
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Massachusetts Department of Fisheries,
Wildlife and Environmental l>aw Enforcement
100 Nashua Street, Room 910
Boston, MA 02214
Attn: John C. Phillips, Director
Massachusetts Department of Fisheries,
Wildlife and Environmental I^aw Enforcement
Division of Marine Fisheries
100 Cambridge Street
Boston, MA 02202
Attn: Phillip Coates
I-eigh Bridges
Massachusetts Department of Fisheries,
Wildlife and Environmental L^aw Enforcement
Natural Heritage and Endangered
Species Program
100 Cambridge Street
Boston, MA 02202
Attn: Jay Copeland
Massachusetts Executive Office of
Communities & Development
100 Cambridge Street, Room 1804
Boston, MA 02202
Attn: Mary Padula, Commissioner
Massachusetts Executive Office of Economic Affairs
Division of Energy Resources
100 Cambridge Street, Room 1500
Boston, MA 02202
Attn: Stephen J. Remen, Commissioner
Massachusetts Executive Office of
Environmental Affairs
100 Cambridge Street
Room 2000
Boston, MA 02202
Attn: Trudy Coxc, Secretary
Massachusetts Executive Office of
Environmental Affairs
Board of Underwater Archeology
100 Cambridge Street
Boston, MA 02202
Attn: Vic Mastone, Director
Massachusetts Executive Office of
Environmental Affairs
Coastal Zone Management Program
100 Cambridge Street, Room 2006
Boston, MA 02202
Attn: Peg Brady, Director
Deerin Babb-Brott
Judith Pcdcrson
Massachusetts Executive Office of
Environmental Affairs
Division of Conservation Services
100 Cambridge Street
Boston, MA 02202
Attn: Joel A. 1/jrncr, Director
Massachusetts Executive Office of
Environmental Affairs
Division of Energy Resources
100 Cambridge Street, Room 1500
Boston, MA 02202
Attn: Joanne McBrien
Massachusetts Executive Office of
Environmental Affairs
MEPA Unit
100 Cambridge Street
Boston, MA 02202
Attn: Nancy Baker
6-5
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Massachusetts Highway Department
Central Artery/Tunnel
One South Station
Boston, MA 02110
Attn: Curtis A. Mcininger
Stacy A. Richards
Peter Zuk
Massachusetts Office of Inspector General
1 Ashburton Place
Boston, MA 02108
Attn: Robert A. Ccrasoli
Massachusetts Maritime Academy
101 Academy Drive
Buzzards Bay, MA 02532-3400
Attn: Capt. Jeffrey Monroe
Massachusetts Stale Historical Commission
80 Boylston Street
Boston, MA 02115
Attn: Judith McDonough, Executive Director
»
Massachusetts Water Resources Authority
Giarleslown Navy Yard
100 I^rst Avenue
Charlestown, MA 02129
Attn: Maggie Debbie
Mary lx>u Mofibla
Mark Radville
Metropolitan Area Planning Council
60 Temple Place
Boston, MA 02111
Attn: Martin Pillsbury
Metropolitan District Commission
20 Somerset Street
Boston, MA 02108
Attn: Julia O'Brien
Urban Harbors Institute
University of Massachusetts
100 Morrissey Boulevard
Boston, MA 02125
Attn: Richard Delaney
Jack Wiggins
Municipal Offices:
Boston Conservation Commission
Boston City Hall, Room 805
Boston, MA 02201
Attn: Christopher Kelly, Executive Secretary
Boston Department of Public Works
One City Hall Square
Boston, MA 02201
Attn: Joseph Casazza, Commissioner
Peter Scarpignato
Boston Environmental Department
Boston City Hall
Boston, MA 02201
Attn: Arthur Pugsley
Naomi Schusstcr
Boston Police Department
Harbor Patrol Unit
154 Berkeley Street
Boston, MA 02116
Attn: I ,t. Eric I lahn, I larbormaster
Boston Redevelopment Authority
One City Hall Square
Boston, MA 02201
Attn: Richard B. Mortens
Boston Water & Sewer Commission
425 Summer Street
Boston, MA 02210
Attn: Robert J. Ciolek, Executive Director
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Newburyport I larbor Commission
City Hall
Newburyport, MA 01950
Public Libraries:
Boston Public Libraries:
Main Library, 666 Boylston Street
Charlestown Branch, 179 Main St., Charlestown
East Boston, 276 Meridan Street, E. Boston
Kirstein, 20 City Hall Avenue
North End, 25 Parmenter St.
Orient Heights, 18 Barnes Avenue, E. Boston
South Boston, 646 E. Broadway
Boston Redevelopment Authority Library
Chelsea Public Library
Everett Public Library
FJalmouth Public Library
Hyannis Public Library
Provincetown Public Library
Quincy Public Library
Transportation Building Library, 10 Park
Plaza, Boston
Winthrop Public Library
Public Interest Groups:
The Boston Harbor Association
374 Congress Street, Suite 609
Boston, MA 02210
Attn: Vivien Li, Executive Director
Conservation I/aw Foundation
62 Summer Street
Boston, MA 02110-1008
Attn: lillie Dorsey
Grace Perez
Friends of the Boston Harbor Islands
P.O. Box 9025
Boston, MA 02114
League of Women Voters of Ix>wer Cape Cod
P.O. Box 460
West Chatham, MA 02669
Attn: Marina Zellner, President
Massachusetts Association of Conservation
Commissions
10 Juniper Road
Bclmont, MA 02178
Massachusetts Audubon Society
South Great Road
Lincoln, MA 01773
Atln: Don R. Ilickman, Director of Media Relations
Massachusetts Audubon Society
346 Grapevine Road
Wcnham, MA 01984
Attn: Cindy DelPapa
Move Massachusetts 2000
294 Washington Street, Suite 628
Boston, MA 02108
Attn: Ann Donncr
Save the Harbor/Save the Bay
25 West Street, 4th Floor
Boston, MA 02111
Attn: Joan L/eBlanc
Sheila Lynch
Dave Effross
Sierra Club
3 Joy Street
Boston, MA 02108
Attn: Priscilla Chapman
Dcllabarrc Sullivan
6-7
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Sierra Club - Cape Cod
18 Trcctop I^anc
K. Falmouth, MA 02536-4814
Attn: David Dow, Chair
C-Corc
Memorial University
St. Johns, Newfoundland
Canada, A IB 3X5
Attn: Ian McDermott
Private Entities:
Bay State Cruise Company
67 Long Wharf
Boston, MA 02110
Atln: Carolyn Kiley
Bay State Towing
Pier 1, liast Bremen Street
East Boston, MA 02128
Attn: Michael P. Duarte
Boston I Jne & Service Co.
I Black Falcon Avenue
Boston, MA 02210
Attn: Brian J. Cox
Boston Harbor Docking Pilots
36 New Street
East Boston, MA 02128
Attn: Capt. Dave Galman
Boston Pilots
Pier 1 - South Bremen Street
liast Boston, MA 02128
Attn: Capt. Arthur Whittemorc
The Boston Shipping Association
Charlcstown Navy Yard
33 Third Avenue
Boston, MA 02129-4516
Attn: Al Fn>.clle
Center for Coastal Studies
P.O. Box 1036
59 Commercial Street
Provincctown, MA 02657
Attn: Russell DeConti, Director
HA Engineering
2 Commercial Street
Sharon, MA 02067
Attn: Forest Henderson
Glil Consultants
1021 Main Street
Winchester, MA 01890
Attn: Richard F. Murdock
The Gillette Company
1 Gillette Park
Boston, MA 02127-1096
Attn: Anthony Termine
I.E.P. Inc.
P.O. Box 1840
Sandwich, MA 02563
Attn: Wetlands Group
New England Aquarium
Central Wharf
Boston, MA 02110
Attn: Sharon 1.5. Dean, Conservation Coordinator
William Robinson
Alexis Runstadlcr, Research Department
6-8
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Patterson, Wylde & Co., Inc.
West Building 2 - Suite 305
Boston Fish Pier
Boston, MA 02210
Attn: Capt. A. Ross Pope
Woods Hole Oceanographic Institute
Coastal Research Center
Woods Hole, MA 02543
Attn: Bruce Tripp
Private Individuals:
Patricia Bonanno, Buzzards Bay, MA
Elizabeth Bowen, Washington, D.C.
Gloria Brundage, Yarmouth Port, MA
Beverly Carney, Orleans, MA
Shelli Costa, Brewster, MA
Edith DeAngelis, E. Boston, MA
John Geddie, Albuquerque, NM
Douglas Gifford, Cambridge, MA
John Hegarty, Dorchester, MA
Edward Mahoney, Y. Yarmouth, MA
Stan Murphy, Needham, MA
Bud & Louise Palmer, E. Sandwich, MA
Arv Poshkus, Stoughton, MA
Michael & Robert Russo, E. Boston, MA
George Strawl, Statcn Island, NY
Ray Sutherland, Gloucester, MA
Ilalsey Taylor, Corpus Christi, TX
Gerry Villeneuve, Berlin, Nil
6-9
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7.0
LITERATURE CITED
Averctt, Daniel F,., et. al. 1990. Review of removal,
containment and treatment technologies for
remediation of contaminated sediment in the
Great Lakes. Prepared by USAE Waterways
Experiment Station for USEPA, December,
1990.
Black and Veatch. 1987. Residuals management
facilities plan. Draft Report on Site Screening
Analysis. Vol. II - Site Screening Results
prepared for MWRA.
Bohlen, W. F., D. F. Cundy and J. M. Tramontane.
1979. Suspended Materials Distributions in
the Wake of Estuarine Channel Dredging
Operations. Estuarine and Coastal Marine
Science. 9:669-711.
Breslin, V.T., F.J. Roethal and V.P. Schaeperkoetter.
1988. Physical and chemical interactions of
stabilized incineration residue with the marine
environment. Mar. Pollut. Bull. 19:628-632.
Bulk, R., D. Ciruber and R. Wullschleger, 1975.
Laboratory Study of the Release of Pesticide
and PCB Materials to the Water Column
During Dredging and Disposal Operations.
DMRP Technical Report D-75-6 Environ-
mental Laboratory, U.S. Army Engineer
Waterways Experiment Station, Vicksburg,
Mississippi.
Chen, R. Y., S. K. Gupta, A. Z. Sycip, J. C. S. Lu,
M. Knezevic, and W. Choi. 1976. Research
Study on the Effect of Dispersion, Settling,
and Resedimentation on Migration of Chemi-
cal Constituents During Open-Water Disposal
of Dredged Material. DMRP Contract D-76-
1. Environmental Laboratory, U.S. Army
Engineers Waterway Experiment Station,
Vicksburg, Mississippi.
Clarke, J. U. and A. B. Gibson, 1987. Regulatory
Identification of Petroleum Hydrocarbons on
Dredged Material; Proceedings of a Workshop.
Miscellaneous Paper D-87-3. U.S. Army Engineer
Waterways Experiment Station, Vicksburg, Mis-
sissippi.
Cortell, .I.M., and Associates, Inc. I990b. Aquatic
resource functions and values. Vol. 2: Disposal
sites alternatives assessment. Central Artery (I-
93)/Tunncl (1-90) Project. Prepared for Massa-
chusetts Highway Department.
DcGraaf, R.M., and D.D. Rudis. 1986. New ling-
land wildlife: habitat, natural history, and distri-
bution. Gen. Tech. Rep. NE-108. Broomall,
FA: US Dept. of Agric., Forest Service, North-
eastern Forest Experiment Sta. 491 pp.
Disposal Area Monitoring System (DAMOS). 1979.
Disposal Area Monitoring System Annual Data
Report -1978, Supplement D, Massachusetts Bay
Disposal Sites; Naval Underwater Systems Center
Newport, Rhode Island. New England Division,
Corps of Engineers.
. 1979b. Disposal Area Monitoring
System Annual Data Report -Proceedings of
Symposium 14-15 May 1979. Volume II, Biolog-
ical Observations. New England Division, Corps
of Engineers.
EA Engineering, Science and Technology. 1992. EA
Engineering Science and Technology. 1992.
Water Quality Monitoring Reports for the Central
Artery/Third Harbor Tunnel, Boston. Prepared
for the Massachusetts Department of Environ-
mental Protection, Divisionof Water Pollution
Control.
Environmental Protection Agency/Corps of Engi-
neers (EPA/ACOE). 1991. Evaluation of
Dredged Material Proposed for Ocean Disposal,
Testing Manual. EPA-50318-91/001.
7-1
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Gambell, R.P., R.A. Khalid and W.H. Patrick, Jr.
1978. Disposal Alternatives for Contaminated
Dredged Material as a Management Tool to
Minimize Adverse Environmental Effects.
Tech. Rpt. DS-78-8. Prpared for U.S. Army
Corps of Engineers, Waterways Experiment
Station, Vicksburg, MS. 148 p.
Gilbert, T.R. 1975. Studies of the Massachusetts
Bay Foul Area. Prepared for the Common-
wealth of Massachusetts, Division of Water
Pollution Control. New England Aquarium,
Boston, MA.
Johnson, B.II. 1990. User's guide for models of
dredged material disposal in open water. Wa-
terways Experiment Station. Tech. Rpt. D-
90-5. 29 pp + App.; App. C, April 1993.
U.S. Army Corps of Engineers, Vicksburg,
MS.
Kay, S. II. 1985. Biomagnification of Contaminants
in Aquatic Food Webs as a Result of Open-
Water Disposal of Dredged Material. Envi-
ronmental Effects of Dredging Technical
Notes, EEDP-01-1. U.S. Army Engineer
Waterways Experiment Station, Vicksburg,
MS.
Knebel, IIJ. 1993. Sedimentary environments
within a galaciated estuarine-inner shelf sys-
tem: Boston Harbor and Massachusetts Bay.
Marine Geology 110:7-30.
Manomet Bird Observatory (M.B.O.). 1987. Char-
acterization of Whale Use of the Massachu-
setts Bay and Cape Arundel, Maine Areas. In
Association with Sanford Ecological Services,
prepared for the New England Division, U.S.
Army Corps-of Engineers, January, 1987.
Marine Environmental Services (MES). 1970. Eco-
logical Field Survey, Mystic River. Prepared
for Stone and Webster Engineering Corp., I Ian-
over, New Hampshire, 29 pp.
Marine Environmental Services (MES). 1972a.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp., Hanover, New Hampshire, 23 pp.
Marine Environmental Services (MES). 1972b.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp., Hanover, New Hampshire, 27 pp.
Marine Environmental Services (MES). 1972c.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp., Hanover, New Hampshire, 25 pp.
Marine Environmental Services (MES). 1973.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp., Hanover, New Hampshire, 28 pp.
Marine Environmental Services (MES). 1976a.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp., Hanover, New Hampshire, 25 pp.
Marine Environmental Services (MES). 1976b.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp., Hanover, New Hampshire, 25 pp.
Marine Environmental Services (MES). 1977a.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp., Hanover, New Hampshire, 16 pp.
Marine Environmental Services (MES). 1977b.
Ecological Field Survey in the Mystic River.
Prepared for Stone and Webster Engineering
Corp-. Hanover, New Hampshire, 21 pp.
7-2
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Massachusetts Water Resource Authority (MWRA).
1993. Contaminated sediments in Boston
Harbor. U.S. Environmental Protection
Agency, Region I, Boston, MA.
Metcalf and Eddy. 1976. Eastern Massachusetts
Metropolitan Area Study.
Metcalf and Eddy Inc. 1992. Preliminary site evalu-
ations for a nearshorc disposal facility in the
metro-Boston area for contaminated dredged
material. Report prepared for U.S. EPA,
Region I (9/92). 32 pp. + App.
Profiles Research and Consulting Group. 1980.
Seasonal Restrictions on Dredging Projects by
NMFS in THe Northeast. Vol 1 Prepared for
Environmental Assessment Branch, NOAA,
Marine Fisheries under contract SB 1408(a) -
79-C-169.
SAIC. 1986. Environmental Infonnation in Sup-
port of Site Designation Documents, for the
Foul Area Disposal Site. Science Applications
International Corporation and HMM Associ-
ates. NED Contract #DACW33-85-D-0008.
July 24, 1986 Report No. SAIC-85/7528, p.
93.
SAIC. 1987. Environmental Information in Support
of Site Designation Documents for the Foul
Area Disposal Site: Physical Oceanography
(SAIC Report # SAIC-85/7528 & 93). U.S.
Army Corps of Engineers, New England Divi-
sion, Waltham, MA.
SAIC. 1993. Monitoring Cruise at the Massachu-
setts Bay Disposal Site, August, 1990.] Draft
SAIC Report #SAIC-90/7599 & C90 in
preparation to the U.S.Army Corps of Engi-
neers.
Sasaki Associates. 1983. Upland Dredged Material
Disposal Site Analysis. Prepared for Mass. CZM
Office, Boston, MA.
Schubel, J.R. et al. 1978. Field investigations of the
nature, degree, and extent of turbidity generated
by open water pipeline disposal operations. WES
Tech. Rpt. D-78-80.
Stewart, R. K. 1968. Biological Aspects of Water
Quality, Charles River and Boston Harbor,
Massachusetts, July-August 1967. Federal Water
Pollution Control Administration.
U.S. Army Corps of Engineers (ACOE, NED), New
England Division. 1988. Feasibility report and
environmental assessment for deep-draft naviga-
tion improvements to Boston Harbor including
Mystic River, Chelsea River and Reserved Chan-
nel.
U.S. Environmetal Protection Agency (EPA). 1989.
Draft Environmental Impact Statement for the
Designation of the Massachusetts Bay Disposal
Site.
U.S. Environmental Protection Agency (EPA).
1993. Assessment of potential impact of the
MWRA outfall on endangered species. Biological
Assessment prepared pursuant to Section 7 of the
Endangered Species Act.
University of Rhode Island. 1981. A Characteriza-
tion of Marine Mammals and Turtles in the Mid
and North Atlantic Area in the United States
Outer Continental Shelf, Annual Report for 1979.
Cetacean and Turtle Assessment Program. Con-
tract No. AA551-CT8-48 Prepared for Bureau of
I /and Management, Department of Interior.
Waterways Experiment Station, Corps of Engineers.
1986. Fate of dredge material during open water
disposal. linv. Effects Dred. Tech. Note EEDP-
01-2. 12 pp.
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Wcnte, M.M. and F J. Roethal. 1993. Stony Brook
researchers investigate mobility of dioxins and
furans from stabilized incineration residue in
seawater. SUNY Newsletter.
Whitlatch, R.B. 1982. The ecology of New England
tidal flats: a community profile. U.S. Fish
and Wildlife Sendee, Biological Services pro-
gram, Washington D.C. FWS/OBS-81/01.
125 pp.
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8.0
GLOSSARY OF TCRMS
ADDAMS model - Acronym for Automated
Dredging and Disposal Alternatives Management
Systems; a computerized program developed by
the U.S. Army Corps of Engineers Waterways
Experiment Station to model and assess the
impacts of waterborne contaminants due to
disposal of dredged material in open water.
aerobic - Having the presence of oxygen.
amphipod toxicity tests - A laboratory testing
procedure using a sensitive marine crustacean to
determine the potential acute toxicity of
proposed dredged material intended for ocean
disposal. This testing is part of the U.S. EPA
and Corps of Engineers national and regional
testing protocol.
anadromous - Pertaining to fish that ascend
freshwater rivers and streams from the sea to
spawn.
Anaerobic bioreclamation - The process of
transforming an organic. contaminant into
another less threatening form by using biological
organisms (microbes) in a non-oxygenated
environment.
anchorage - A designated area, usually adjacent to
the navigation channel, for temporary mooring of
vessels; the Boston Harbor anchorage is used
principally for lightering and ship traffic control.
aquatic borrow pit - A disposal site located offshore
in a manmade pit; this type of disposal site is
intended for containment of material.
aquatic shoreline - A diked disposal site (for dredged
material) located in coastal water but attached to
shore.
aquatic subaqueous - A (dredged material) disposal
site located below the intertidal zone, usually
offshore.
Areas of Critical Concern (ACECs) - Areas within
the Commonwealth of Massachusetts that have
been designated for special protection or
management because of their importance;
examples include coastal beaches, estuaries,
barrier beach systems, salt marshes, shellfish
concentration areas and habitat for threatened,
rare or endangered species.
artificial reefs - A man-made structure located in the
ocean for the purpose of habitat enhancement.
August Effect - A substantial reduction in the
amount of dissolved oxygen which occurs in
certain shallow estuaries and harbors during the
late summer. This change is felt to cause a
corresponding depression in biological activity in
the affected area.
azoic parent material - Sediment, rock or other
material that has been in place since geologic
time and presently supports no life.
bathymctric - Pertaining to ocean depths in order to
determine sea floor topography.
beneficial uses - Utilization of (dredged) material for
an economic, environmental or other useful
purpose.
beneficiaries - Those ship terminals and other water
related facilities that would benefit economically
by deepening the Federal channel in the Boston
Harbor Navigation Improvement Project
(B11NIP).
bcnthic infauna - Aquatic animals which live in the
bottom sediment of a body of water.
bcnthic organisms - Aquatic animals which live on or
in the sea floor substrate.
BIINIP - Acronym for Boston Harbor Navigation
Improvement Project which is the Federal
(Corps) portion of this EIR/S.
bioaccumulation - The uptake of a contaminant in a
living organism and the increase in concentration
of a chemical of interest in an animal when
exposed to proposed dredged material for a
specified period of time. This testing is part of
the national and regional testing protocol
regulated under the Ocean Dumping Act.
biota - Environmental life forms; examples include
fish, lobster, crabs, marine worms and clams.
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Boston Blue Clay - Naturally occurring clay parent
material commonly found in Boston Harbor.
bulk cargo - Goods that are transported in large
ocean going vessels; examples include salt, coal,
petroleum and grain.
bulk chemical analyses - The laboratory testing of
sediment to determine the chemical
concentrations of key parameters of interest.
This testing is part of the U.S. EPA/Corps
Regional testing protocol.
bulkhcading - To partition off a section of shoreline
by constructing a vertical wall for containment of
(dredged) material.
capping - The process of isolating contaminated
dredged material by covering (capping) with a
layer of clean material of sufficient thickness.
Central Artery/Third Harbor Tunnel (CA/T) - A
major dredging project in Boston Harbor
involving removal of several million cubic yards
of sediment and its disposal using several
alternatives.
chelatSon - A chemical process involving the
retention of a hydrogen or metal atom between
two atoms of a single molecule.
colonization - The establishment of a viable
population of benthic animals.
containerized cargo - Dry bulk goods that are
transported on large ocean going vessels in steel
containers.
CSOs - Combined sewer outfalls; there are many
CSOs that discharge into Boston Harbor.
cy - The abbreviation for cubic yards; approximately
1 cubic yard of dredged material weighs about
1.5 tons.
DAMOS - Disposal Area Monitoring System;
acronym for the open water disposal of dredged
material monitoring program conducted by the
U.S. Army Corps of Engineers, New England
Division).
demersal - Living at or near the bottom of the sea.
dewatering - The process of removing excess water
from (dredged) material; dewatering includes
removal of ponded or surface water and could
also include removal of water bound into the
sediment (pore water).
digestion - The process of breaking down a material
or chemical compound into an absorbable
and/or simpler chemical form.
dredge - The mechanical device that is used to
remove sediment from a channel, berth or other
portion of a waterbody. The three basic types of
dredges are mechanical, hydraulic and hopper.
dredged material - Marine sediment that has been
removed by dredging activity; dredged material
was historically referred to as "spoil."
early benthic phase lobster - A term used to identify
. a post-larval stage of development in which
animals are large enough (5 mm to 35 mm) to
swim and gain a negative buoyancy. This phase
is the most critical period in the life and
recruitment of lobsters.
EBP - Early benthic phase.
elutriate testing - A testing method designed to
evaluate the extent to which chemicals are
released from sediment to the water column
while agitated during the dredging and disposal
processes.
entraining - The process of carrying material
suspended in the water column.
environmental bucket - A specially designed
clamshell dredge bucket that is relatively
watertight to minimize the release of material to
the water column during the dredging process.
cstuarinc - Relating to a semi-enclosed coastal
waterbody that is measurably diluted with fresh
water from rivers or other significant freshwater
sources.
existing aquatic - An existing open water site for
unconfmed open water disposal; an example is
the Massachusetts Bay Disposal Site.
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expansion factor - A method of accounting for the
increase in volume of consolidated material due
to changes during dredging which include: 1)
particle structure rearrangement; 2) reduction in
confining pressure; and 3) increase in water
content.
fastland - Land created by filling an area previously
occupied by water.
filter feeders - An organism that traps particles
suspended in water to facilitate the feeding
process.
furan homologs - Various organic compounds of a
group represented by a diunsaturated ring of four
carbon atoms and one oxygen atom.
Green Book - The national guidance manual
developed by the U.S. EPA and Army Corps of
Engineers used to evaluate impacts of dredged
material disposal in ocean waters. This provides
the technical framework for performing a
stepwise or tiered evaluation in conformance
with the Ocean Dumping Act.
hopper dredge - A self-propelled floating dredge that
removes sediment by hydraulically pumping the
material and water into an onboard hopper. The
dredged material is transported to the disposal
site by the vessel and material removed by
bottom operating doors.
hydraulic dredge - A floating dredge that removes
sediment by hydraulically pumping the material
and water through a floating pipeline to the
discharge area.
hydrographic surveys - Exploration of a body of
water to determine depth and bottom contour.
improvement dredging - The dredging of an area to
a new deeper depth and possibly a new width.
Dredged material removed in improvement
dredging is often termed parent material, that is,
material which has never been dredged before.
incineration - The process of burning a material at a
very high temperature to break down the
chemical structure of the material.
intertidal - Pertaining to the part of the coast that is
subjected to the rise and fall of the tides.
landfill - Specified land based disposal sites for a
variety of material, including household garbage,
refuse, construction material and other wastes
including dredged material. Some landfills are
lined to protect groundwater from leachate.
Icachate - The product of a substance or chemical
that was able to separate or dissolve into solution
and be transported; an example is the separation
of a chemical from sediment into water which
seeps into a nearby site.
least environmentally damaging alternative - The
disposal alternative that will result in the least
impact to the environment.
lightering - The process of removing cargo from a
vessel before it enters port in order to allow the
vessel to proceed into shallower water; in Boston
Harbor petroleum tanker ships are commonly
lightered before entering Boston Harbor for
offloading the remaining load.
I,NG - Liquified Natural Gas, a commodity brought
into Boston Harbor by tanker vessels.
MADEP - Massachusetts Department of
Environmental Protection.
MBDS - Acronym for Massachusetts Bay Disposal
Site which is located about 20 miles east of
Boston Harbor. The site is utilized for dredged
material disposal that meets the Ocean Dumping
Act criteria.
maintenance material - Silt material which has
accumulated due to settling by migration from
another location.
MANHESP - Massachusetts Natural Heritage and
Endangered Species Program.
Massachusetts CZM - Massachusetts Office of
Coastal Zone Management.
Massachusetts DEP - Massachusetts Department of
Environmental Protection.
Massport - Massachusetts Port Authority - local
sponsor for the BIINIP.
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mechanical dredge - A barge mounted crane that uses
a clamshell bucket to remove sediment. The
material is typically placed into an awaiting barge
or scow to hold and transport the material to be
offloaded on land or dumped at sea.
MFiPA - Acronym for Massachusetts Environmental
Policy Act (301 CMR 11.00-12.00) which is
regulated by the Executive Office of
Environmental Affairs; the purpose of this EIR/S
is to satisfy the requirements established under
MEPA for dredging and disposal of the proposed
material.
MI 1C - Massachusetts Historical Commission.
mitigation - The process of reducing or compensating
for adverse impacts; examples for dredging
projects include lime of year restrictions, use of
turbidity control curtains, environmental bucket.
MLW - The abbreviation for mean low water.
M WRA - Massachusetts Water Resources Authority.
National Historic Preservation Act of 1966 - Section
106 of this Act provides for the identification,
assistance and protection of historic properties,
structures or sites that may be affected by
proposed projects. The BHNIP is subject to
review and coordination with the Massachusetts
Historical Commission in determining
compliance with this Act.
nautical mile - A unit of distance used principally in
navigation; one nautical mile equals 6080.27 feet
or 1.1516 statue miles.
NIiPA - Acronym for National Environmental
Policy Act (40 CFR 1500-1508) directs Federal
agencies to prepare an environmental impact
statement (EIS) for any major Federal action
significantly affecting the quality of the human
environment; the Corps is voluntarily preparing
an EIS for the BHNIP as a joint effort with
Massport who is preparing the EIR.
non-Federal cost sharing partner - The project
proponent (local sponsor) who participates with
the Corps by providing a share of funds needed
to carry out the design and construction of the
project.
non-Federal interests - Participants in the project
that arc not Federal agencies or Federally funded.
They include the sponsor, project beneficiaries,
and others who contribute to or benefit from the
project.
non-halogenated semivolatiles - Those organic
compounds (PAHs) and metals that are semi-
volatile but do not contain any elements of the
halogen family (i.e., fluorine, chlorine, bromine,
iodine, and astatine).
nucleophilic substitution - A chemical process used
to remove chlorine from chlorinated compounds
to change their chemical structure.
organic - Containing plant and other decaying
matter; examples include peat and muck soils.
Silty dredged material may or may not contain
organic material.
parent material - Formerly undisturbed sand or clay
which has never been dredged.
polychlorinated biphenyls (PCBs) - A colorless liquid
used as an insulating fluid in electrical
equipment. PCBs are a known carcinogen.
polynuclear aromatic hydrocarbons (PAHs) -
I lydrocarbon molecules with two or more nuclei;
examples include benzene, benzo(a) pyrene and
naphthalene.
practicable - A reasonable combination of logistics,
technology and cost.
Project Cooperation Agreement (PCA) - An
agreement by the Federal Government and the
non-Federal sponsor which is made prior to
construction of a planned Federal project.
prop wash - The result of ship propellers in shallow
water disturbing the bottom sediments.
protocols - Established procedures for conducting a
specified activity.
pyrolytic process - To subject organic compounds to
very high temperature for decomposition.
8-4
-------
rare and endangered species - Those plant and animal
species that are identified by Federal and state
regulatory agencies as being at risk of elimination
and warrant special protection.
River and Harbor Act of 1899 - This Act (33 CFR
320-330)authorizes the U.S. Army Corps of
Engineers to maintain Federal navigable
channels, anchorages, etc. and regulate all work
in navigable waters through a permit program.
SA waters - Waters assigned to this class are
designated for the uses of protection and
propagation of fish, other aquatic life and
wildlife; for primary and secondary contact
recreation; and for shellfish harvesting without
depuration in approved areas.
SB waters - Waters assigned to this class are
designated for the uses of protection and
propagation of fish, other aquatic life and
wildlife; for primary and secondary contact
recreation; and for shellfish harvesting with
depuration (Restricted Shellfish Areas).
SC waters - Waters assigned to this class are
designated for the protection and propagation of
fish, other aquatic life and wildlife; and for
secondary contact recreation.
Section 101 of WRDA 1986 - That portion of the
Water Resources Development Act that describes
the cost sharing requirements of the non-Federal
sponsor.
silt material - Sediment that is finer than sand but
coarser than clay. Silt is usually the main
component of maintenance dredge material in
the Boston Harbor area.
siitation rate - The rate at which sediment falls out of
suspension from the water column and
accumulates on the seafloor. This is usually
measured as thickness of settled material in
centimeters or inches per year.
sole source aquifer - A water reservoir having only
one locale or source for replenishment.
Stellwagen Bank - An area in Massachusetts Bay
about 15 miles east of Boston Harbor that is
included as part of Federal Marine Sanctuary.
The MBDS is located just west of this area.
substrate - The physical make-up of the seafloor;
substrate typically consists of clay, silt, sand,
gravel and rock.
subtidal - Pertaining to the part of the ocean that is
below the plane of mean low water.
tankers - Ocean going vessels designed to carry large
volumes of petroleum and other liquid products.
Tier I - The initial evaluation step as provided in the
Green Book. This phase includes the review of
existing information to determine whether
sediment testing will be required (Tiers II and
III).
Tier II - The second step in evaluating a perspective
dredging project according to the Green Book.
This phase includes bulk chemical analyses of the
sediment and a mathematical assessment of the
bioaccumulation potential and water quality
impacts.
Tier III - The third step in evaluating a prospective
dredging project according to the Green Book.
This phase includes biological testing to
determine acute toxicity and bioaccumulation
potential for target contaminants.
toxicity - The measure of mortality a substance
incurs on a target organism.
treatment technologies - Various methods used to
remove or stabilize contaminants in dredged
material.
tributary channels - Channels connected to the Main
Ship Channel.
trophic level - Any of the feeding levels which allows
the passage of energy through an ecosystem;
examples arc finfish feeding on marine worms
and bivalves (clams) feeding on the waterbome
nutrients.
turbidity - A measure of clarity of the water column
due to the amount and type of particles in
suspension.
turbidity plume - A cloud of material suspended in
the water column; dredging can create a turbidity
plume consisting of fine grained sediments.
8-5
-------
unconfincd open water disposal - Disposal of dredged
material in open water such that the material is
not contained by a physical structure.
upland coastal - A land based disposal site located in
proximity to the coast.
upland inland - A land based disposal site located
away from the coast.
USACOE - U.S. Army Corps of Engineers (New
England Division).
vitrification - The process of formation of a glassy or
noncrystalline material.
water column - The entire vertical length of water
that would be involved; an example would be the
travel distance of a dredge bucket from the
harbor bottom to the water surface as the bucket
is raised during the dredging process.
water quality criteria - EPA established concentration
levels of chemicals of interest above which may
produce toxic or sublethal effects.
Water Resources Development Act of 1990 - the Act
passed by Congress and signed by the President,
which includes the authorization to construct the
BITNIP.
8-6
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-------
iil! rlH
ii! i ; i
I -.-
-------
9.0 INDEX
Subject
Advisory Committee
Air Quality
Alternatives
Amstar
Anadromous Fish
Aquatic Resources Impacts
Archaeological
Bacteria Levels
Barge Traffic
Beneficial Use
Benthos
Birds
Bivalves
Boston Lightship
Cabot Paint
Capping
Contaminated Sediments
Central Artery/Third Harbor
Tunnel Project (CA/T)
Chelsea Creek
Circulation
Clams
Coastal Zone Management Act
Combined Sewer Overflows
(CSO)
Conley Terminal
Costs
Cumulative Impacts
Currents
Designated Port Area
Dissolved Oxygen
Disposal Options Technical
Working Group
Dredged Materials, Analysis of
Dredged Materials, Disposal
Dredging
Economics
Paqe(s)
ES-1, 1-7, APPEN B
4-4
ES-6, 2-1, 3-1
3-8, 3-14, 3-47
3-51, 4-12, Al-111
4-11
4-13, ATT 1
Al-107
ES-5, 4-5
3-21
3-28, 3-31, 3-33, 3-36
3-38, 3-40, 3-42, 3-45
3-48, 3-49, 3-52,
ATT 1
3-33, 3-36, -3-42, 3-45
ATT 1
3-48, Al-108, Al-110
3-16, 3-28, Al-101
3-8, 3-14, Al-46
3-11, 3-22, 3-29
APPEN G
2-13
ES-5, 4-2
ES-1, 1-1, 1-5, 2-1
2-2, 2-4, 2-6, 2-7
Al-105
3-30, Al-105
Al-108, Al-110
3-4, 5-1, 5-3
3-38, 3-41, 3-44
Al-107
ES-1, 1-1, 1-6, 2-4
ES-3, 1-6, 3-25
3-54
3-30, 3-32, 3-34, 3-36
3-38, 3-42, 3-48, 3-51
3-53, Al-105
3-40, 3-41, 3-47, 3-50
3-52
Al-107
ES-2, 1-8, APPEN B
2-8, APPEN C
3-1
2-1, 4-1, 4-9
1-2
9-1
-------
Energy
Environmental Consequences
Environmental Bucket
Everett
Fecal Coliform
Pilling
Fish Run
Fish, Species in Project Area
Geology
Historic
Hydrology
In- Channel Sites
Industrial Development
Intertidal Communities
Least Environmentally Damaging
Practicable Alternative (LEDPA)
Little Mystic Channel
Lobsters
Macroalgae
Main Ship Channel
Mammals
Marine Mammals
Massachusetts Bay Disposal Site
(MBDS)
Massachusetts Port Authority
(Mas sport)
Massachusetts Water Resources
Authority (MWRA)
Meisburger 2
Meisburger 7
MEPA (Massachusetts Environmental
Policy Act)
Mitigation
Moran Terminal
Mystic Piers
Mystic River
Navigation Improvement Project
NEPA (National Environmental
Policy Act)
3-55
3-28, 3-32, 3-34, 3-36
3-38, 3-40, 3-42, 3-45
3-48, 3-51, 3-53, 4-9
ATT 1
4-3, 4-4
3-6, Al-13
Al-107
3-41, 3-43, 3-47, 3-49
3-52
3-51, 4-12, Al-111
3-28, 3-31, 3-33, 3-36
3-42, 3-48, 3-50, 3-52
Al-109, Al-111
1-2
5-2, 5-3
Al-105
3-4, 3-10, 3-40, Al-62
1—2 2—8
3-42, 3-45, 3-47, 3-51
3-52
ES-7, 3-26
3-14, 3-41, 3-39, 3-40
Al-51
3-39, 3-40
,3-42, 3-43, 3-47, 3-48
1-1, 1-2, 2-5
3-31
3-31, 4-13, 5-1
3-16, 3-29, Al-95
ES-1, 1-1, 1-5, 3-25
ES-5, Al-106
ES-2, 3-10, 3-15, 3-25
3-33, Al-70
ES-2, 3-10, 3-14, 3-25
3-35, Al-70
1-9, 5-2
3-55, 4-3
1-1, 1-4, 2-4
2-4, 3-8, 3-14, 3-49
Al-33
ES-1, 1-1, 1-2, 2-4
ES-1, 1-1, 3-25
1-9, 5-3
9-2
-------
Noise
President Roads
Proj ect Sponsors
Reserved Channel
Residential Developments
Revere Sugar
Rock Blasting
Runoff
Salt Marshes
Sea Turtles
Seals, Harbor
Secondary Impacts
Sediment Characterization
Technical Working Group
Sediments
Sewage Treatment Plant
Shellfish
Solid Waste
Spectacle Island CAD
Squantum Point
Subaqueous Containment Site B
Subaqueous Containment Site E
Suspended Sediments
Suitability Determination
Technical Working Groups
Threatened and Endangered Species
Tidal Exchange
Treatment Technology
U.S. Army Corps of Engineers
(Corps; ACOE)
Utilities
Wastewater Discharge
Water Quality Impacts
Wetlands
Wildlife
Winthrop Harbor
Woburn
Wrentham
1-1, 1-2, 2-3
3-52
4-14
ES-1, 2-5
1-5
ES-1,
3-43
2-4, 3-8, 3-14,
2-3, 4-2
2-2
ATT 1
APPEN A-3
3-31, 4-13
3-54
ES-2, 1-8
2-8
Al-106
Al-108, Al-110
5-1
3-10, 3-15, 3-25,
3-37, Al-63
3-6, 3-13, 3-15, Al-3
3-9, Al-77
3-9, Al-83
4-9
2-8
ES-2, 1-8
3-29, 3-31, 3-35, 3-36
3-39, 3-43, 3-46, 3-51
3-53, 4-13, ATT 1
Al-106
3-17, 3-53
ES-1, 1-1
Al-105, Al-107
Al-105
3-6, 3-8, 3-9, 3-10
4-9, ATT 1
ATT 1
ATT 1
3-9, Al-88
3-6, 3-13, 3-15, Al-18
3-6, 3-13, 3-15, Al-24
APPEN # = APPENDIX
ATT 1 = ATTACHMENT 1
9-3
-------
-------
-------
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lEaafflSHp^ -"i £i^!
±|*Ki2ffiiia Hi^IE»^
i i : ; : : i iiiiliij i i
' ! 1
I ii
I
ll'li, 'ilililiilii'BBiBlll!',! iili!li:,»iilli;;!iiiiil
-------
ATTACHMENT 1:
AFFECTED ENVIRONMENT AND ENVIRONMENTAL
CONSEQUENCES EVALUATED FOR POTENTIAL
DREDGING AND DISPOSAL SITES
TABLE OF CONTENTS
1.0 INTRODUCTION
PAGE
Al-1
2.0 ENVIRONMENTAL EVALUATION: DISPOSAL SITES
2.1 SITE EVALUATIONS: LAND-BASED COASTAL SITES
2.1.1 Squantum Point (QUI-03)
2.1.1.1
2.1.1.2
Existing Conditions
Environmental Consequences
Al-2
Al-3
Al-3
Al-3
Al-8
2.1.2 .Everett. (EVR-04) .................................... Al-13
2.1.2.1 Existing Conditions ........
2.1.2.2 Environmental Consequences
2.2 SITE EVALUATIONS: LAND-BASED INLAND SITES
2.2.1 Woburn (WOB-11)
2.2.1.1
2.2.1.2
Existing Conditions
Environmental Consequences
Al-13
Al-15
Al-18
Al-18
Al-18
Al-21
2.2.2
2.2.3
Wrentham (WREN-495) ............................... Al-24
2.2.2.1 Existing Conditions ........
2.2.2.2 Environmental Consequences
Al-24
A 1-28
Landfill Sites - An Overview ............................ Al-30
2.2.3.1
2.2.3.2
Existing Conditions
Environmental Consequences
2.3 SITE EVALUATIONS: NEARSHORE AQUATIC SITES
2.3.1 Mystic Piers (Massport Piers 49 & 50)
2.3.1.1 Existing Conditions
2.3.1.2 Environmental Consequences
Al-30
Al-31
Al-33
Al-33
Al-33
Al-36
2.3.2
Revere Sugar Al-38
Al-i
-------
PAGE
2.3.2.1 Existing Conditions A!~^n
2.3.2.2 Environmental Consequences A1-40
2.3.3 Amstar AM2
2.3.3.1 Existing Conditions Al-42
2.3.3.2 Environmental Consequences A1-44
2.3.4 Cabot Paint ' AM6
2.3.4.1 Existing Conditions
2.3.4.2 Environmental Consequences
2.3.5 Little Mystic Channel -A1'5,1
2.3.5.1 Existing Conditions Al-51
2.3.5.2 Environmental Consequences A1-53
2.3.6 Reserved Channel AI'56
2.3.6.1 Existing Conditions '. AJ"co
2.3.6.2 Environmental Consequences A1-59
2.4 SITE EVALUATIONS: IN-CHANNEL AREAS AND BORROW PITS . Al-62
2.4.1 In-Channel A1"62
2.4.1-1 Existing Conditions Al-62
2.4.1.2 Environmental Consequences Al-62
2.4.2 Spectacle Island Confined Aquatic Disposal (CAD) A1-63
2.4.2.1 Existing Conditions A1-63
2.4.2.2 Environmental Consequences Al-66
2.4.3 Meisburger Sites 2 and 7 . .'. • Al-70
2.4.3.1 Existing Conditions Al-70
2.4.3.2 Environmental Consequences A1-73
2.5 SITE EVALUATION: SUBAQUEOUS AREAS Al'77
2.5.1 Subaqueous Containment Site B (Subaq B) A1-77
2.5.1.1 Existing Conditions A1-77
2.5.1.2 Environmental Consequences A1-79
2.5.2 Subaqueous Containment Site E (Subaq E) A1-83
2.5.2.1 Existing Conditions i~oc
2.5.2.2 Environmental Consequences A1-85
Al-ii
-------
PAGE
2.5.3 Winthrop Harbor Al-88
2.5.3.1 Existing Conditions Al-88
2.5.3.2 Environmental Consequences Al-91
2.6 SITE EVALUATIONS: EXISTING AQUATIC DISPOSAL SITES .... Al-95
2.6.1 Massachusetts Bay Disposal Site (MBDS) Al-95
2.6.1.1 Existing Conditions Al-95
2.6.1.2 Environmental Consequences Al-98
2.6.2 Boston Lightship Disposal Site (BLDS) Al-101
2.6.2.1 Existing Conditions Al-101
2.6.2.2 Environmental Consequences A1-102
3.0 ENVIRONMENTAL EVALUATION - DREDGING SITES Al-105
3.1 OTHER PROJECT CONSIDERATIONS Al-105
3.2 EXISTING CONDITIONS - ENVIRONMENTAL RESOURCES Al-105
3.2.1 Water Quality - Al-105
3.2.2 Sediment Characteristics Al-108
3.2.3 Biological Resources Al-109
4.0
LITERATURE CITED AM 13
Al-iii
-------
LIST OF FIGURES
A1-1. General locations of short-listed disposal site alternatives
A1-2. Site map for potential disposal site, Quincy-03 (Squantum Point)
Al-3. Site map for potential disposal site, Everett
A1-4. Site map for potential disposal site, Woburn-11
Al-5. Site map for potential disposal site, Wrentham-495
Al-6. Site map for the Plainville Landfill site
A1-7- Site map for the Fitchburg/Westminster Landfill site
Al-8. Site map for BFI Northern Disposal Inc. (E. Bridgewater) Landfill site
A1-9. Site map for Mystic Piers site
Al-10. Site map for Revere Sugar site
A1-11- Site map for Amstar site
Al-12. Site map for Cabot Paint site
A I-13. Site map for Little Mystic Channel site
AI-14. Site map for Reserved Channel site
Al-15. Site map for Spectacle Island CAD site
Al-16. Site map for Meisburger 2 site
A1-17. Site map for Meisburger 7 site
Al-18. Site map for potential disposal site, Subaqueous-B
Al-19. Site map for potential disposal site, Subaqueous-E
Al-20. Site map for potential disposal site, Winthrop Harbor
AJ-21. Site map for Boston Lightship and MBDS sites
A1-22. Prohibited and restricted clam beds in Boston Harbor
Al-iv
-------
LIST OF TABLES
Al-l. LANDFILL CHARACTERISTICS
A1-2.
Al-3.
A1-4.
Al-5.
ESTIMATED ABUNDANCE (NO./m2) OF BENTHIC INFAUNA (RE-
TAINED ON A 0.5 mm MESH SIEVE) COLLECTED BY 0.023 m2 PONAR
GRAB FROM PROPOSED DISPOSAL SITES IN BOSTON HARBOR,
APRIL 28-29, 1993
SEDIMENT CHARACTERISTICS IN THE VICINITY OF POTENTIAL
DISPOSAL SITE EAST OF SPECTACLE ISLAND, 1988a
COPPER CONCENTRATIONS AT A POSITION WHEN COPPER IS
DILUTED BELOW WATER QUALITY CRITERIA AT THE SPECTACLE
ISLAND CAD DURING FLOOD AND EBB TIDES OF DIFFERENT
VELOCITIES
DOMINANT FISH SPECIES3 AND LOBSTERS IN TRAWLS CONDUCTED
IN AN AREA JUST WESTb OF THE MWRA PROPOSED OUTFALL BY
MASSACHUSETTS DIVISION OF MARINE FISHERIES, 1991-92
A1-6 MAXIMUM CONCENTRATION (mg/1) OF COPPER AND SILT/CLAY IN
THE WATER COLUMN AT THE MEISBURGER 7 DISPOSAL SITE
UNDER STRATIFIED CONDITIONS ESTIMATED BY THE ADDAM'S
MODEL FOUR HOURS AFTER A SINGLE DUMP OF 2,000 CU. YDS
Al-7 SEDIMENT CHARACTERISTICS IN VICINITY OF PROPOSED SUB-
AQUEOUS CONTAINMENT SITES B AND E AND WINTHROP
HARBOR CONTAINMENT SITE
A1-8 MAXIMUM CONCENTRATION (mg/1) OF COPPER AND SILT/CLAY IN
THE WATER COLUMN AT THE SUBAQUEOUS E SITE DURING
MAXIMUM EBB AND FLOOD TIDES UNDER UNSTRATIFIED
CONDITIONS ESTIMATED BYTHE ADDAM'S MODEL FOUR HOURS
AFTER A SINGLE DUMP OF 1,000 CU. YDS
Al-9. PHYSICAL AND BULK CHEMICAL ANALYSIS OF WINTHROP HARBOR
SEDIMENTS1
Al-10. WINTIIROP HARBOR BENTHIC INVERTEBRATES, FALL 1989
Al-l 1 MAXIMUM CONCENTRATION (mg/1) OF COPPER AND SILT/CLAY IN
THE WATER STRATIFIED COLUMN AT THE BOSTON LIGHT SHIP
DISPOSAL SITE UNDER SUMMER CONDITIONS ESTIMATED BY
THE ADDAM'S MODEL FOUR HOURS AFTER A SINGLE DUMP
OF 2,000 CU. YDS
Al-12. WATER QUALITY DATA, BOSTON HARBOR
Al-13 AVERAGE CONCENTRATION OF TOTAL ORGANIC CARBON AND
TOTAL PETROLEUM HYDROCARBONS. MASSPORT DREDGING
PROJECT
Al-v
-------
Al-14. COMPARISON OF AVERAGE LEAD AND CHROMIUM CONCENTRA-
TIONS (MG/L) WITH MASSACHUSETTS DEP BULK SOIL CONCEN-
TRATIONS (MG/L) FOR TCLP ANALYSIS. MASSPORT DREDGING
PROJECT
Al-15. CONCENTRATION OF SODIUM AND CHLORIDE FOR MASSPORT
DREDGING PROJECT
Al-16. FINFISH SAMPLING IN BOSTON HARBOR - JULY 1986
Al-17. DOMINANT SPECIES BY TRIBUTARY
Al-vi
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ATTACHMENT 1:
AFFECTED ENVIRONMENT AND
ENVIRONMENTAL CONSEQUENCES
EVALUATION AT POTENTIAL DREDGING
AND DISPOSAL SITES
1.0 INTRODUCTION
The purpose of this Affected Environment and
Environmental Consequences Evaluation is to
provide more detailed descriptions of dredging sites
and potential disposal sites, as summarized in Sec-
tions 2.0, 3.0 and 4.0 of this EIR/S. Described
herein are the .baseline environmental conditions,
proposed site uses and potential environmental
consequences from dredging or disposal at each site.
This evaluation is designed to provide a description
of both the "existing conditions" and "environmental
consequences" at the potential sites, in accordance
with the MEPA EIR and Federal BIS guidelines.
Although the full project, in its entirety, is spon-
sored by Masssport, the dredging activities (and sites)
are broken down into two components:
1) Federal Project: This includes deepening por-
tions of the federal channels to 40 feet includ-
ing areas within the:
»• Mystic River
> Chelsea Creek (to 38-feet MLW)
•• Inner Confluence
>• Main Ship Channel
»• Reserved Channel
This portion of the project is being administered
by the Army Corps of Engineers-New England
Division (ACOE NED).
2) Non-federal Project: This includes the dredg-
ing of several berth areas throughout the Inner
Harbor, Mystic River, Chelsea Creek, and the
Reserved Channel. This portion of the project
is administered by Massport and includes the
following sites:
»• Prolerizcd
»• Distrigas
»• Moran
*• Mystic Piers
> Eastern Minerals
* Gulf Oil
«• North Jetty
»• Army Base
•• Boston Edison Intake
•• Boston Edison Barge Berth
»• Conley
The project is described in Section 2.1, Volume 1 of
the Environmental Impact Report/Statement
(EIR/S). This evaluation focuses on the environ-
mental conditions and impacts at the disposal sites.
Al-1
-------
2.0 ENVIRONMENTAL EVALUATION:
DISPOSAL SITES
As part of this EIR/S process, an extensive site
screening process (Section 3.0 in CIR/S) was under-
taken to identify potential disposal sites for this
project's dredged material. As a result of this pro-
cess, 24 candidate sites were deemed potentially
suitable for material disposal. They are grouped
according to site type as follows:
Land-Based Coastal Sites
Squantum Point (QUI-03)
Everett (EVR-04)
Land-Based Inland Sites
Wobum (WOB-l I)
Wrentham (WREN-495)
Plainville Sanitary Landfill
Fitchburg/Westminster Sanitary landfill
BFI-Northern Disposal, Inc. (East
Bridgcwatcr)
Aquatic Sites
In-Channel Disposal (3 sites)
Subaqueous Containment Site B
Subaqueous Containment Site E
Winthrop Harbor
Nearshore Aquatic Sites
Mystic Piers (Massport 49 & 50)
Revere Sugar
Amstar
Cabot Paint
I jltle Mystic Channel
Reserved Channel
Borrow Pit Sites
Spectacle Island Contained Aquatic
Disposal (CAD) •
Mcisburger Sites 2 and 7
Existing Open Water Sites
Massachusetts Bay Disposal Site
Boston Lightship Disposal Site
locations of these potential sites are shown in Figure
A1-1 and presented in more detail on figures con-
tained in the following sections. The sites are de-
scribed generally in the order given above; their order
has no bearing on their status as an acceptable or
preferred alternative.
The environmental evaluation process included a
review of previous environmental studies and reports
followed by site investigations to supplement and fill
primary data gaps. Field groups were comprised of
senior scientists in disciplines such as wetland ecolo-
gy, wildlife ecology, marine ecology, estuarine ecolo-
gy, water quality planning, and engineers experienced
in environmental issues at landfills, materials disposal,
site drainage, and site planning. During the in-field
site investigations, these experts recorded their find-
ings for baseline environmental conditions for each
candidate site. Outer harbor and offshore sites were
not field surveyed, but relied on available information
for this assessment.
This evaluation examines impacts to each poten-
tially sensitive resource at each of the candidate sites.
Summaries of project impacts at each candidate site
arc presented in Section 3.0 of the EIR/S.
Al-2
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Squantum Point (QUI-03)
2.1 SITE EVALUATIONS;
LAND-BASED COASTAL SITES
2.1.1 Sauantum Point fOUI-03>
2.1.1.1 Existing Conditions
The Squantum Point site is depicted on Figure
A1-2.
GEOLOGY/SOILS
The site appears to consist of historic tidelands
that were filled for the construction of a small naval
air station. The area is generally flat and surrounded
on the shoreline perimeter by an eroded and dilapi-
dated metal and concrete seawall. Soils in the project
area are primarily Udorthents, which are classified as
areas filled with excavated materials (SCS 1989a).
Thickness of material is generally six feet or more,
although the actual depth of fill at this site is un-
known.
The type of bedrock underlying the site can only
be inferred since no outcrops of bedrock are evident.
Based on the mapping by Kaye (1980) this area may
be underlain by conglomerate or by tuffaccous
sediments. Depth to bedrock is unknown.
HYDROLOGY/WATER QUALITY
The hydrology of the site is not fully understood
and is complicated by remains of the old airport's
storm drain system (observed during site walks by
project staff, November 1990, and May 1993). After
a heavy rainstorm, water was observed in small pools
in the upland areas, while the wetland did not appear
to be storing any runoff. Closer observation revealed
a graded storm drain on the edge of the wetland and
an outfall pipe to Dorchester Bay that, at that time,
was clearly discharging water. It is not known
whether the wetland was the sole source of this storm
water flow or if other storm drains contributed as
well. Water in the wetland drain was later observed
to have reversed direction, flowing back into the
wetland. This indicates that the wetland area is
hydrologically connected to Dorchester Bay and
influenced by tides, although the wetland plant
community reflects only mildly brackish conditions.
The erosion behind the decayed seawall indicates that
overland flow to the bay does occur, although the
erosion is in part due to tide and wave action.
No information concerning groundwater resources
at this site was available. However, groundwater
appears strongly influenced by tides and could be
highly saline. Any groundwater at this site should
not be suitable for public water supply.
The Ncponset River and Dorchester Bay are both
classified as SB by the Massachusetts Department of
Environmental Protection, hereafter referred to as
MADEP, in the surface water regulation (314 CMR
4.00). This classification protects saline water bodies
for the following uses: propagation of fish and
aquatic life and wildlife, primary and secondary
contact recreation, and shellfish harvesting with
depuration. Abundant shellfish beds are present in
the tidal flats off Squantum Point as noted during a
site visit in October 1990. However, as these shellfish
cannot be reliably depurated, Massachusetts Depart-
ment of Marine Fisheries (MADMF) has closed the
area for harvesting except for bait (Ralph Stevens,
MADMF, 1993, personal communication).
Limited water quality data are available for the
Ncponset River at its confluence with Dorchester
Bay; however, water quality in the river is likely
influenced by combined scwcr overflows (CSOs) and
non-point source pollution (NAI 1990). Historical
data have shown high variability in fecal coliform
concentrations at the mouth of the Ncponset River
(NAI 1991a). Bacteria and dissolved oxygen are
likely the two most limiting factors on water quality
in Dorchester Bay, although a complete assessment
of water quality cannot be made at this time.
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AQUATIC RESOURCES
There are no freshwater streams or ponds on the
Squantum Point site, although several depressions
may intermittently retain surface water.
Marine resources are influenced by conditions in
both the Neponset River and Dorchester Bay. Thus,
although the intertidal area is broadly defined as tidal
flat with a fringing, patchy salt marsh, substrate
conditions vary dramatically, depending on exposure.
The following description of intertidal communities
is based on studies performed by NAI in 1990.
Physical conditions appeared little changed in subse-
quent site visits by NAI in May 1993.
The intertidal zone was narrowest (65 feel) in the
easternmost portion of the site, broadening to more
than 1000 feet at the northwest corner. Salt marsh
vegetation was patchy and best developed along the
western side of the parcel. Sediments in the upper
intertidal zone were predominantly sand, grading to
pebbles and then silty sand within about 50 feet of
the bulkheaded shoreline. At the northern end of the
point, sandy sediments extended 100+ feet from the
shoreline. Seaward, sediments were silty sand/sandy
silt with large quantities of shell hash. There were
extensive blue mussel (Mytilus edulis) beds in the
lower intertidal zone along much of the northern
border of the site.
Dominant benthic infauna of the northerly ex-
posed tidal flat included the spionid polychaetes
Slrcblospio benediclt, Polydora cornuta and Pygospio
elegans; oligochacles; soft-shell clam spat (Mya
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Squanlum Point (QUI-03)
other mollusks, with soft-shell clams being numeri-
cally dominant. Dominant annelids were the same
ubiquitous taxa. Few burrowing species were repre-
sented. Chlorophyll a values were moderate to high.
Finfish and epibenthic fauna were not investigated.
The abundance of and diverse habitat available for
benthic infauna indicate the suitability of the Squan-
tum Point intertidal zone to provide trophic support
for these consumers. Species such as Green crabs
(Cardnus maenas) and other crabs (Cancer sp.) are
likely to forage among the mussel beds and open
tidal flats and, in turn, be preyed upon by wading
birds. Flounder and other demersal fish, particularly
juvenile stages, use intertidal areas extensively for
feeding. The MADMF officially recognizes the
Neponset River as a spawning run for rainbow smelt.
MADMF considered the anadromous fishery re-
source of the Neponset River to include a large smelt
run, a limited shad run and a river herring (alewife
and blucback) run (MADMF 1990, personal com-
munication).
An area of potential concern in the vicinity of the
Squantum Point site is a bed of submerged vegeta-
tion in the Neponset River that extends from Com-
mercial Point to an area beyond Tenean Beach
(MWRA 1987). The extent and character of this
resource has not been determined.
The Squantum Point intertidal area was rated as
having a high potential for aquatic diversity and
abundance and a moderate-to-high potential for
nutrient retention/transformation (NAI 1990). The
extensive shellfish beds around the entire flat and fine
sediments on the western shoreline suggest a high
potential for sediment/toxicant retention. This site
has a high potential for shellfish habitat as indicated
by the variety of substrate conditions and mollusk
species present. The large food resources in this
tidally influenced area indicate a moderate-to-high
potential for providing fish habitat. Similarly, the
tidal flat resources are potentially important for
migratory shorcbirds. The breadth of the intertidal
area offers sediment and shoreline stabilization,
although the open exposure to the north and erosion
behind the sheetpilc wall indicate that storm tides
reach the upland edge of the site.
VEGETATION
Random seed dispersal and tolerance of the de-
graded and artificial substrates remaining after past
uses have influenced the type of vegetation that has
developed on the site. Vegetation has not developed
to the point of presenting well-defined classes with
good structure and habitat, owing at least in part to
the compacted fill substrate which serves as soil.
Two broad upland vegetation classes currently exist
within the confines of the seawall: early successional
shrubland, approximately 10-15 feet tall; and old field
encroaching on the abandoned runways and perime-
ter road.
Most of the site is covered by aggressive plant
species, able to withstand disturbed conditions. The
mixture of shrubs, grasses and forbs is dominated by
sumac (Rhus lyphina), bayberry (Myrica pensylvan-
ica), poison ivy (Toxicodendron radicans) and
multiflora rose (Rosa multiflora), making foot travel
difficult. Grass species include quackgrass (Agropy-
ron repens), upland bent (Agrostis perermans) and
broom beardgrass (Schizachyrium scoparium), while
the forbs are predominantly Eurasian invaders,
including wild carrot (Daucus carola), mugwort
(Artemisia vulgaris), heath aster (Aster ericoides) and
tansy (Tanacetum vulgare).
WETLAND RESOURCES
The on-site and adjacent wetland areas described
herein were field delineated by NAI in 1990 using the
1989 Federal identification methodology (NAI 1990)
and arc those areas estimated to fall within the review
of Section 404 of the Federal Clean Water Act. Also
documented are those associated wetland resource
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areas, identified from published references or by field
observation, that arc protected under the jurisdiction
of the Massachusetts Wetlands Protection Act (MGL
c 131, s 40) and its implementing regulations (310
CMR 10.00). These include: 1) L-and Under the
Ocean, 2) Coastal Beach, 3) Salt Marsh, 4) Land
Containing Shellfish, 5) Fish Run, 6) l-and Subject
to Coastal Storm Howage, and 7) Bordering Vegetat-
ed Wetland. Also present is a regulated buffer zone
extending 100 feet inland and/or upland of the coastal
beach, salt marsh, and bordering vegetated wetland.
During the 1990 wetland delineation, on-site
construction activities associated with the Deer Island
staging facility had continuously changed terrestrial
site characteristics. Therefore, the team of wetland
scientists had problems clearly identifying on-site
conditions. Although the 1993 site visit indicated
more stable conditions. Existing fill soils and transi-
tional vegetation greatly complicate wetland delinea-
tion. Should Squantum be chosen for final design a
comprehensive wetland resource evaluation and
boundary delineation will be required using the
current state and federally approved methodologies.
Several acres of salt marsh are found on Squantum
Point, outside and adjacent to the seawall. These are
interspersed with areas of tidal flat and coastal beach.
The largest band of salt marsh lies on the northwest
comer, outside the wall, and runs southward beyond
the site. This salt marsh band consists almost
entirely of cordgrass (Spartina allerniflord), with
minor sea lavender (Limonium cf. nashii) and seaside
goldcnrod (Solidago sempcrvirens), and has a sub-
strate of sand and cobbles. The width of the marsh
averages approximately 30 feet, with its upper limit
coinciding with the high tide level. A strip of coastal
beach approximately 10 feet wide included the
apparent mean high tide line, above which beach
grass (Ammophila brevigulatd) dominated to the base
of the seawall. Several small patches of salt hay
tens) were interspersed with beach grass.
Squantum Point (QUI-O3)
Landward of the seawall, fills and disturbed surfac-
es dominate the area. The hydrology is very difficult
to discern, owing to the presence of an old subsurface
drainage system of unknown extent. At one culvert
break along the northern wall, erosion has initiated a
depression along 15 feet of the wall, now colonized
by some beach and salt marsh species: cordgrass (S.
allerniflord), reed (Pkragmites auslralis), sea-blight
(Suaedalinearis), seaside goldenrod (S.sempervirens)
and saltwort (Salicornia europaea).
The northwestern shore supports a more patchy,
irregular salt marsh which extended seaward from the
base of the seawall. Dominated by cordgrass, this
marsh was obviously situated in a high energy
environment as indicated by the eroding peat on its
seaward face, and the deteriorating condition of the
seawall behind it.
A 1.0± acre brackish wetland with an ephemeral
hydrologjc connection with Dorchester Bay lies
about 300 feet inside the seawall, and is surrounded
by upland vegetation and soils. Appearing as an open
herbaceous community, the plant species include a
mixture of freshwater and salt-tolerant plants. It is
dominated by red-top (Agrostis alba), rushes (Juncus
effusus and Juncus gerardi), cattail (Typha
angtatifolia), three-square sedge (rush) (Scirpus
americanus), purple loosestrife (Lythrum salicarid)
and seaside goldenrod (S. sempervircns). This
wetland drains to the northwest through a low-lying
iron catch basin and culvert placed at such an eleva-
tion and slope that allows the highest spring and
storm tides to back flow through the culvert, bringing
salt water into the wctland's northwest comer. The
wetland soil is mineral, and clearly hydric. It has
some permeability but little or no organic content, as
would be expected with recently formed soil. Imme-
diately following a two-day, 2 to 4 inch rainfall, the
wetland had no ponded waters, but the fill substrate
was fully saturated. Approximately 0.1 cubic feet per
second (CPS) was running out of the culvert. Other
small areas of wetland may occur in slight depres-
sions among early-succession shrublands and would
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Squantum Point (QUI-O3)
require delineation if this site was selected for final
design.
In 1990, the inland wetland was evaluated using
the Hollands-Magee freshwater wetland model (NAI
1990). Results indicated that the wetland had a very
low hydrologic and structural diversity, resulting in
low biological value. Scores for nine often wetland
functional elements using the Hollands-Magee model
rated below median; only aesthetics rated above
median, mostly due to the abundance of showy
flowering plants. This means that this wetland ranks
below most New England inland wetlands in the
NAI database for all the Hollands-Magee values but
aesthetics.
WILDLIFE
line old-field portion of the site is somewhat
diverse, with an intricate mix of shrub and herb
layers providing habitat/edge conditions. The shrub
layers form an interconnecting network, providing
habitat for numerous ground animals, including cover
and food for small to medium-sized mammals and
resident, migratory and wintering bird species.
Observed on-site mammal species included: muskrat,
house cat, mouse (evidence); and several bird species:
common gracklc, ring-necked pheasant, northern
flicker, American goldfinch, song sparrow, Eastern
kingbird, gray catbird, American robin, yellow
warbler and short-cared owl. The tangles of poison
ivy and multifiora rose provide cover and food (e.g.,
berries) for many of these species. Small trees, such
as red cedar and poplar, provide nesting places for
birds with substantial height requirements (e.g.,
American goldfinch, Eastern kingbird), whereas the
rose-ivy tangles arc excellent for low nesters (e.g.,
song sparrow: Harrison 1975). Animal movement
into and out of the area is restricted mainly to urban
species, aquatic species, and birds because of the
site's isolation from other wild or open areas.
Little wildlife value can be attributed to the
inland wetland community, due to the low food
value of the plants and low value for cover. Outside
the seawall, however, the mixture of salt marsh,
beach and tidal flats provides extensive habitat for
migrating and resident shorebirds. These interspersed
resources, combined with the high diversity of marine
invertebrates, provide excellent food resources for
birds such as turnstones, yellowlegs, sanderlings and
smaller sandpipers. During field visits, double-crested
cormorants were observed utilizing open water, with
herring gulls, great black-backed gulls, ring-billed
gulls, brant, greater yellowlegs, black-bellied plovers
and mallard ducks in the beach and tidal flat areas.,
THREATENED AND ENDANGERED
SPECIES
The Massachusetts Natural Heritage and Endan-
gered Species Program (MANHESP) records did not
identify any protected species or habitats which occur
on the site (MANHESP, letter dated March 1, 1993).
A short-eared owl was observed on-site during
field work on November 5, 1990. This species is
listed by Massachusetts as an endangered breeding
species. This species is of worldwide distribution. In
New England, it is most commonly seen as a migrant
and winter visitor in coastal fields, airports and salt
marshes (Johnsgard 1988). It is known to actually
breed in a very few locations in New England, mostly
coastal. It prefers open grassland habitats where
abundant small mammals are available as prey -
especially meadow voles (Microbes pensylvanicus).
Brackish marshes connected to tidal flowage and wet
grassland areas often have an abundance of such
small mammals.
This owl is presumed to have been migrating from
the more populated Canadian tundra breeding
grounds or occupying a wintering ground at the time
it was seen. Most short-eared owls in the east breed
much farther north in open country and then winter
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Squantum Point (QUI-03)
from northern New England south to the Chesapeake
Bay (Johnsgard 1988). This species may utilize any
wet meadow habitat in the Boston Harbor area
during the winter. The Squantum Point area is
unlikely to provide suitable habitat for breeding, due
to small size, urban setting and high present levels of
disturbance.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
Detailed information regarding historical and
archeologjcal resources on Squantum Point was
obtained in 1990, when the site was under consider-
ation for development (NAI 1990). For that study,
documentary research for assessing possible historical
and archeologjcal resources included consultation of
the State Register of Historic Places, files and materi-
als at the Massachusetts Historical Commission
(MIIC), the Quincy Historical Society and the
Boston Landmarks Commission as well as insurance
atlases and maps. Data on known prehistoric sites
were collected from the MIIC, interviews with local
archaeologists and individuals, and cultural resource
management reports. USDA soil surveys were
examined for straligraphic data. A site walk was
conducted to locate surface cultural remains and to
assess the archeological sensitivity of the site. The
1990 study and a follow-up file review at MIIC in
1993 revealed no known historic resources on the site
or its environs.
Approximately II prehistoric sites are recorded
from the Squantum area. These sites include shell
middens as well as dog and human burial areas,
which primarily date to the Late Woodland, Contact
and Early Historic periods. No sites are recorded for
the project area.
SOCIO-ECONOMIC/LAND USE
This former naval air station, a 44±_ acre site, is
now owned by the Metropolitan District Commis-
sion (MDC), which intends to build a waterfront
park as funds become available. Part of the site is
used as a ferry docking facility to transport construc-
tion personnel to Deer Island for the Boston Harbor
Clean-up Project (reference). This facility includes
parking for 930 vehicles. The ferry facility will be
made available to the MDC upon completion of the
construction of the sewage treatment plant at Deer
Island. The remainder of the site is a mixture of
paved area and shrubs. To the east of the site is the
Village at Marina Bay, a mixed-use development
including residences, a marina, offices, restaurants and
shops.
Quincy has a long history, beginning as a prosper-
ous farming community and the home of two Presi-
dents. Major industrial facilities including the former
Fore River Shipyard now line its coast along with
residential uses. Much of the land area in Quincy is
devoted to park use. The population of 86,182 is
90% white and 6% Asian. The median family
income is $44,184. Higher-income households have
settled in Quincy with the development of new
housing in and adjacent to Marina Bay.
Access to the subject site is via 1-93 south to
Neponsct Circle, Route 3A to Quincy Shore Drive,
an MDC parkway and from there, to a connector
road to Commander Shea Boulevard. Existing
mudflats around Squantum Point presently constrain
marine access unless dredging is undertaken.
2.1.1.2 Environmental Consequences
GEOLOGY/SOIL
The placement of 935,880 cy of dredged material
(predominantly silts) should not severely impact the
previously altered site geology and soil conditions.
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Squantum Point (QUI-03)
These silts would not be placed in or on any existing
resources (c.g., wetlands), and will be placed with
appropriate containment (capping) sedimenta-
tion/erosion controls.
Assuming the disposed silts are appropriately
contained, the placement of dredge materials at this
site should not pose a threat to continued surround-
ing site usage or sensitive receptors (e.g., Dorchester
Bay and shellfish beds); future development of the
site would have to consider the presence of this
confined silt material.
HYDROLOGY/WATER QUALITY
Groundwater impacts are difficult to anticipate due
to the complex drainage system currently underlying
the site, but are expected to be minor because of the
likely dominance of marine hydrology. Surface water
from runoff will be directed so as to minimally alter
current hydrologjc budgets of surrounding lands and
tidal flats. The site's flat topography will naturally
limit impacts from altered runoff patterns.
Because the quality of groundwater resources at
this site is unknown, potential impacts cannot be
fully addressed. However, a liner would be required
by the MADEP and should minimize Icachate
contamination of the groundwater.
Primary impacts to surface water quality will be
necessary for the dewatcring process during the
dredge disposal phase. The dredged material would
be partially dewatered on the barge prior to reaching
the site. Final dcwatering would occur on-site via an
outflow weir with stop logs to control primary
settling. Water would then pass through a sedimen-
tation basin prior to being discharged into Dorchester
Bay. This process is expected to remove most of the
suspended particles from the water column; however,
the smallest size fraction, the clays, would remain
suspended and therefore would pass with the dis-
charge waters. Sediment characterization studies for
the dredging project indicate that the silts are unsuit-
able for ocean dumping, although it is likely that a
small amount of clay from the underlying substrates
would incidentally be excavated during the sediment
dredging process. It is expected that most of the
potential contaminants would be removed with the
sills. This should effectively reduce the probability
that harbor waters would become recontaminated by
the dcwatering process.
The dewatering discharge outfall should empty
into subtidal water so as to minimize impacts to
aquatic resources. Two alternatives exist and include:
1) into the bottom of the barge channel, and 2)
below the low-tide line into the Neponset River.
Should Squantum Point be selected as a disposal site,
a better understanding of circulation patterns sur-
rounding the site would help to properly locate the
outfall in an area of maximum flow. By discharging
directly into the water column, impacts to the inter-
tidal zone would be minimized. Discharge waters
and suspended clays are expected to dissipate with
tidal currents. The clays would not settle out of the
water column quickly, so they would be widely
dispersed. However, no substantial adverse impacts
from this process are anticipated.
In the 2± years anticipated for the dredge disposal
phase, the outfall will be discharging in a regular
pulse pattern, where supernatant water will be drawn
off in a single event from each barge-load of dredged
material. The plume from the outfall will very likely
be visible due to its suspended clay load. This
visibility may detract from the aesthetics of the site,
and may somewhat reduce primary productivity in
the path of the plume. This latter effect would be
minor in its magnitude and extent, due to both the
pulsing nature of the discharge, which would allow
photosynthesis to resume in between discharge
events, and the varying location of the plume de-
pending on tidal conditions. After capping and
closure of the site, dewatcring and discharge through
the outfall would cease.
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Squantum Point (QUI-03)
AQUATIC RESOURCES
Dredged material would most likely be delivered to
the ate via barge, requiring dredging of a 60-foot-
wide channel from the Deer Island ferry channel to
the northeast corner of the site. This dredging would
impact approximately 1.4 acres (13,000 cy) of sub-
tidal habitat, and 0.3 acres (6500 cy) of intertidal
habitat, some of which may include a narrow band of
salt marsh. Impacts to aquatic resources would
include destruction of existing benthic communities
in the dredged channel, although the new channel
bottom, which would be an average of 6 feet deeper
than present depths, is likely to be re-colonize by
benthic organisms similar to those impacted. In-
creased turbidity and redeposition of suspended
sediments during the dredging process could cause
temporary impacts to adjacent benthic communities.
Channel dredging in the 0.3± acre intertidal zone
would result in the conversion of tidal flats and
approximately 03± acre of salt marsh to subtidal
habitat. It is presumed that the tidal flats and salt
marsh between them provide protection of wildlife
habitat and of marine fisheries including shellfish,
storm damage prevention, groundwater supply, flood
control and prevention of pollution. Primary func-
tional losses include a 0.3 acre reduction in migratory
bird nesting and feeding areas, intertidal productivity,
water quality treatment and shoreline stability.
Impacts to migratory bird habitat will include the
permanent loss of the dredge channel area as well as
temporary impacts in the vicinity due to disturbance
from project activity. Loss of intertidal productivity
will be greatest in the salt marsh area where primary
productivity is highest. Nutrient transformation is
significant in both tidal flat and salt marsh habitats,
although the shallow subtidal dredge channel, when
recolonized, will also perform that function to some
extent. Shoreline stability will be affected by both
loss of the buffering capacity provided by existing
gentle grades, and the disruption of the erosion-
resistant salt marsh peat that currently forms a
continuous band along the northeastern (exposed)
side of the site. Engineered protection against storm-
driven waves and long-shore currents or refilling the
access channel after disposal may be required to
minimize erosion.
Impacts to intertidal resources are not anticipated
from the dewatering process. Subtidal impacts may
include a reduction in primary productivity due to
clouding by clay particles suspended in the discharge
plume; however, this impact is expected to be vari-
able and ephemeral. Adverse impacts on infauna by
discharge waters in the vicinity of the outfall are also
a possibility, as a result of relatively constant expo-
sure to the fine particulates.
Upon capping and closure of the project, freshwa-
ter runoff will be directed via swales to outfalls on
the north and west sides of the site. The outfalls
would open at the concrete/sheetpile seawall, and
runoff would then cross the bands of salt marsh.
During storm events, freshwater flow across the
intertidal zone may impact infauna by creating
osmotic stress. This would be most significant for
species whose recruitment period is limited, such as
soft-shell clams. Adults can isolate themselves from
short-term perturbations by retracting their siphons.
Spat are located at the sediment surface. Those
located in the runoff path may die if freshwater
runoff coincided with low tide.
Runoff would reach mussel beds only during
major storm events, due to the location of this
resource in the lower intertidal zone. This would
likely be of little impact due to the animal's ability to
seal itself off, and to the short duration of exposure
in each tidal cycle.
Loss of productivity on the tidal flat would depend
on the design of the outfall and quantity of flow.
The overall ability of the tidal flat to support finfish
and shorcbirds could be reduced by the intermittent
loss of productivity in the runoff path, both by
benthic microfiora and invertebrates. However, this
may be a minor impact since only a relatively small
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Squantum Point (QUI-03)
portion of the Flat would be affected. Other func-
tions of the intertidal area would be little affected.
No freshwater ponds or streams occur on the
Squantum Point site, so there will be no impacts on
these resources.
VEGETATION
The placement of dredge spoil and any contain-
ment features will smother all existing tolerant and
opportunistic terrestrial plant species within the
footprint. Once the disposal activities cease and
capping, the site will re-vegctate and undergo an
early-successional process as is presently occurring.
WETLAND RESOURCES
The avoidance of any filling or other activity
directly affecting protectable resource areas were
established as one of the design criteria for the
containment facility. Therefore, impacts are limited
to dredging a barge access route, and are described in
the previous section. A detailed final investigation
will be required to confirm that no other jurisdic-
tional wetland resources occur in the shrub tangles
on the site. Encroachment into the buffer zone
associated with the Coastal Beach would be minimal,
limited to a drainage discharge from the proposed
sedimentation basin in the site's southwest corner.
No encroachment into the buffer zone associated
with the Bordering Vegetated Wetland is proposed.
fisheries and wildlife habitat. Clearly, the proposed
encroachment into the buffer zone associated with
the Coastal Beach (drainage pipe) would be in
conformance with all required performance standards.
WILDLIFE
Disposal of materials on the upland old-field areas
would impact the existing upland wildlife habitat
values until after capping and revegetation are com-
plete. The final use of this site will determine the
wildlife community that re-establishes on the site.
Wildlife habitat of the salt water and wetland
resources would also be temporarily disturbed for the
duration of the project because of fugitive dust,
altered runoff patterns, noise and activity. These
impacts could be lessened or avoided by proper site
design and monitoring.
THREATENED AND ENDANGERED
SPEC!
The site is not designated to contain any threat-
ened or endangered species (MANIIESP), although
a short-eared owl, a Massachusetts breeding endan-
gered species, was observed on the site in November
1990. This individual was probably overwintering or
migrating through- Impacts of materials disposal on
the grassy areas of Squantum Point would have a
direct impact on the utilization of the site by short-
cared owls. This is because microtine rodents, found
in grass areas, would no longer be available as prey.
The performance standards for projects affecting
Coastal Beach state that any project shall not have
an adverse effect by increasing erosion, decreasing the
volume or changing the form of any such Coastal
Beach or an adjacent or downdrift Coastal Beach.
Furthermore, water-dependent projects shall be
designed and constructed, using best available mea-
sures, so as to minimize adverse effects on marine
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
Because there are no listed historical or archeologi-
cal resources at or near the proposed Squantum
Point site, no impacts are anticipated. However, the
site is an artificially filled landform, and cultural or
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Squantum Point (QUI-03)
prehistoric resources could lie buried below. No
adverse impact is expected as long as no subsurface
activity is conducted. If excavation is required, then
machine-excavation with archeological monitoring is
recommended to determine the existence of potential-
ly significant remains from either the Naval Air base
or small, isolated, intact prehistoric sites.
SOCIO-ECONOMIC/LAND USE
The site is proposed for development of a water-
front park by the MDC. Use of Squantum Point for
dredge disposal may delay and potentially alter these
plans. Potential mitigation for loss of the planned
park would be to design a park that would be com-
patible with the site after it was capped.
Odor and noise from the dredge disposal could
affect residences and businesses in the Village at
Marina Bay. Odor could be minimized by covering
the disposal daily with clean material. If trucking
were selected as the transport option, truck traffic
into the she would increase noise and traffic in the
Village at Marina Bay and could create safety and
odor problems as well. The road through the Village
at Marina Bay ends at the Deer Island staging area.
It is used primarily for access to the village, the
marina and the ferry parking area, which has parking
for 930 vehicles. There appears to be little existing
truck traffic. Transporting the dredged material by
barge to the site would eliminate these transporta-
tion-related impacts.
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Everett (EVR-04)
2.1.2 Everett (EVR-04)
The site is depicted on Figure A1-3.
2.1.2.1 Existing Conditions
GEOLOGY/SOILS
Soils on the site consist primarily of Udorthents
with a wet substratum. Udorthents are defined as fill
soils over former tidal marshes, and other wetland
resources (SCS 1989a, 1989b). The depth of fill
ranges from 2 to 20 feet or more, with seasonal high
groundwater ranging from 3 to 5 feet below the
surface.
Based upon the mapping of Kaye (1980), the
central portion of the site is underlain by bedrock
consisting of sandstone or quartzite while the north-
ern and southern portion of the site is underlain by
sandstone argiliite, with minor interbedded sandstone
and/or quartzite. Bedrock has been mapped as
outcropping near the site and the average depth to
bedrock on site may be relatively shallow.
HYDROLOGY/WATER QUALITY
There are no surface waters on the site, so the
hydrology is fairly simple. The topography of the
site is flat, therefore most precipitation will infiltrate
to the groundwater or be taken up through evapo-
transpiralion. Any water that does run off most
likely will run into the Mystic River.
The site consists of low-yield aquifers ( < 100 gpm)
with half the site being classified as low and the other
half as very low (MADEP Groundwatcr Overlay
Maps). There are no wells on site or within 0.1 +
mile. Groundwater quality is influenced by tidal
action and is probably saline in nature. Also, there
are several hazardous waste sites near the site which
may have an influence on groundwater quality. The
site is not suitable as a drinking water supply. No
data were available for groundwater quality at the
site.
The Mystic River is classified as Class SC by
MADEP. Waters under this classification are saline
and designated for the protection and propagation of
marine life and for secondary contact recreation.
Water quality in the vicinity of the site is most likely
influenced by several NPDES discharges into the
Mystic River.
Water quality data for the Mystic River are avail-
able from sampling done by MADEP in 1982-1986, •
(Menzic-Cura and Associates 1991). Samples were
taken downstream and near the confluence of Island
End River. Results of this sampling indicate that the
average concentration for cadmium, copper, and lead
exceeded the chronic criteria for aquatic life. The
acute aquatic life criteria for cadmium, chromium,
copper, lead, and zinc were exceeded at least on one
occasion.
AQUATIC RESOURCES
The aquatic resources near the Everett site were
not sampled; however, substrates appeared to be
made up of fine-textured sediments in the exposed
intertidal areas. It is likely that the subtidal commu-
nities are similar to those observed in the Mystic
River and pier areas of Mystic Piers, Revere Sugar,
and Amstar (as detailed in later sections). The
intertidal areas may support soft-shell clams (M.
arenaria), but are likely to have small populations
due to the fine-textured substrates.
VEGETATION
The upland portion of the site is flat and dominat-
ed by early-successional grasses, forbs and scattered
saplings. Plant cover is sparse on approximately
50% of the site, where gravel and old asphalt domi-
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Everett (EVR-04)
nate. These areas have poor quality rooting sub-
strates and also appear to be periodically used by
vehicles entering the site. The remainder of the site
has better herbaceous cover: dominant species
include several clovers (Trifolium spp.), grasses
including broom bcardgrass (Schizachyrium scopar-
/um), mugwort (Artemisia vulgaris), goldenrods
(Sofidago spp.), milkweeds (Asdeplas spp.) and bird's
foot trefoil (Lotus cornictdatus). Scattered saplings
of cherries (Prunus sp.), trembling aspen (Poptdus
tremubides), gray birch (Betula populifolia), and
staghom sumac (R. typhind) occurred across the site,
and are most prevalent on the western leg of the
parcel. This leg in general appeared to be less
disturbed, with better herbaceous and sapling cover.
Common reed (P. auslralls) occurred in patches
around the periphery of the inlet,at the top of the
bulkheads. Because the bulkheads appear to be well
above the high tide line, and would not impound
freshwater, these stands of common reed appear to be
opportunistic, occurring in upland settings. One
exception may be the seaward edge of a small stand
in the northwest corner of the inlet. In this area the
fill behind the bulkhead has collapsed and may be
exposed to tidal inundation during exceptionally high
tides.
WETLANDS RESOURCES
No delineation of jurisdictional resources was
performed at Everett; however, areas of tidal waters
will fall within the purview of Section 404 of the
Federal Clean Water Act. Massachusetts jurisdic-
tional resources ((MGL c.131, s.40, and 310 CMR
10.00)) on the site include coastal bank, tidal flats,
coastal beach and land under the ocean. A 100-foot
buffer area, inland of the tope of the coastal bank
occurs on the east' and west portions of the site.
Small areas of coastal beach and coastal bank occur
along the seaward end of the east and west portions
of the site. These resources arc composed of eroding
fill, and have been partially reinforced by boulders
and rubble.
With the possible exception of the seaward edge of
the common reed stand as described in the previous
section, no vegetated freshwater wetlands occur on
site. During the site visit, a pool of standing freshwa-
ter was observed in an asphalt depression in the
northeast corner of the site. The lack of requisite soils
and vegetation preclude this as a wetland.
WILDLIFE
The paucity of vegetation and the surrounding
urbanization limit the value of the Everett site for
terrestrial wildlife. Animals typical of urban settings,
such as rock doves, European starlings, house spar-
rows, and house mice might use the site, as would
birds that nest on bare ground, such as killdeer. The
western leg of the site, which is somewhat more
densely vegetated, also would support species typical
of herbaceous or "old field" habitats: for example,
common yellowthroat, song sparrow, and meadow
vole (DeGraaf and Rudis 1986). A song sparrow was
heard in this area during 1993 site visits.
The intertidal flats and river bordering the site
would be of more value to wildlife than would the
site. Herring gulls and great black-backed gulls were
observed feeding on the intertidal flat between the
inlet and Route 99 on May 12, 1993. On May 25,
1993, a black-bellied plover, a semipalmated plover,
and a killdeer were observed foraging on the intertidal
flat along the Mystic River on the southwest corner
of the project area. Common terns, a Massachusetts
Species of Special Concern (321 CMR 10.60) were
observed courting and apparently nesting on the
dilapidated pier on the western side of the inlet.
While only pilings remained for most of the length of
the pier, the outermost section remained intact and
formed an isolated platform on which the birds were
seen. A great black-backed gull, a potential nest
predator, also seemed to be sitting on a nest on the
Al-14
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Everett (EVR-04)
same platform on May 12, but a gull observed on
May 25 exhibited no nesting behavior.
THREATENED AND ENDANGERED
SPECIES
MANHESP records indicate that no protected
species or habitats occur on the site (MANHESP,
letter dated March 1, 1993).
Common terns feeding and courting were observed
near the Everett site during two site visits in May
1993. As stated above, the common tern is a Species
of Special Concern in Massachusetts. Four terns
were sitting on the dilapidated pier in the inlet on
May 12. One was seen to stand and pull material on
the ground closer to itself. This activity and the
posture of the birds suggested that they were sitting
on nests on the old pier. During a subsequent field
visit on May 25, six common terns were observed to
exhibit nesting behavior. Terns were also observed
foraging in the Mystic River near the site.
playground facility across Broadway and to the north
of the site.
Everett was originally a territory of Charlestown,
its neighbor across the Mystic River. A fanning
community for 150 years, Everett evolved into an
industrial city with the advent of the railroads that
facilitated transportation to Boston. Factories for
brick manufacturing and the production of chemicals,
located in Everett in the 19th century, have been
joined by facilities for metal product fabrication and
machinery in the past 100 years. The predominant
land use in Everett is residential. Everett's popula-
tion of 35,701 is predominantly white with a median
family income of $37,397.
Land access to the site is from 1-93 to Sullivan
Square in Charlestown, and traveling north on Route
99 (Broadway) across the Mystic River. The parcel
surrounding the basin abuts Route 99 to the east.
Mud flats extend along the Mystic River edges,
making access for vessels difficult. Some dredging
would be required to accommodate barges related to
the material disposal project.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeological
resources on the Everett site. A jackknife bridge was
inventoried by MHC within 1000 feet upstream of
the site. It has been for sale since 1990 and may
have been dismantled (Mr. W. Smith, MIIC, pers.
comm.).
2.1.2.2 Environmental Consequences
GEOLOGY/SOILS
As with Squantum Point, the on-site udorthents
represent an unnatural/altered site condition. There-
fore, the placement of dredge spoils should not
severely alter or change existing geological and/or soil
conditions.
SOCIO-ECONOMIC/LAND USE
This site is a narrow basin abutting 28+ acres of
vacant land on the north side of the Mystic River in
Everett. It is surrounded by industrial uses including
a Boston Edison power station. A rail line abuts the
western boundary of the site. There is a park and
HYDROLOGY/WATER QUALITY
Because of the Everett site's proximity to tidal
waters, impacts to hydrologic conditions from dredge
material disposal, capping and closure should be
minimal. Infiltration would be eliminated by the
liner system required by MADEP, minimizing
Al-15
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Everett (EVR-04)
impacts to groundwater flow. Surface runoff will be
directed to minimize alterations to current hydrologic
budgets of surrounding lands and tidal flats.
Minor impacts to surface water quality may occur
due to discharge from the dewatering process entering
tidal waters adjacent to the site. The dewatering
process would be similar to that proposed for Squan-
tum Point. The risk of concentrated settling and
bioaccumulation is potentially lower at the Everett
site because the steep bathymetry along the Mystic
River would allow the discharge to be pumped
directly into a deep water area, which will aid disper-
sion and dilution. Clays and fine silts in the dis-
charge waters will be borne away from the project
site and productive shallow waters by both tidal
flushing and the Mystic River flow. Impacts to
aesthetics and primary productivity by a reduction of
water clarity in the path of the plume would also be
a possibility at the Everett site, although the in-
creased dispersion should serve to lessen the plume's
impacts. Dewatering sedimentation controls would
work to minimize this problem in the first place
AQUATIC RESOURCES
The preferred route to provide barge access to the
site is to deepen the inlet channel to reach the exist-
ing granite bulkhead, and would require dredging of
approximately 0.3 acres (2300 cy) of subtidal habitat.
The dredging process would destroy any benthic
communities in the dredging corridor, although it is
likely that similar benthos would re-establish in the
deepened channel. Existing depths average 5.0 feet,
therefore dredging an additional 5.0 feet would be
necessary to achieve a final 10.0 foot channel depth.
Turbidity and redeposition of suspended sediments
may cause temporary impacts to adjacent benthic
communities during the dredging process.
A second possible approach for barge traffic would
provide access from the western leg of the site.
However, this would require dredging of O.2.+. acres
(5000 cy) of intertidal, and 0.03 acres (200 cy) of
subtidal habitats. This approach would also impact
an area of coastal beach, coastal bank and buffer.
Because of the variety and extent of impacts to
protected resources, this approach is considered a less
desirable alternative than the inlet channel.
No freshwater runoff impacts at site closure are
anticipated because runoff could be discharged
directly into subtidal waters, therefore eliminating
impacts to intertidal communities.
VEGETATION
/
The placement of dredge spoils and the proposed
containment facility would eliminate all existing
vegetation within the disposal footprint. Upon
completion of all on-site activities, natural recruit-
ment and early stage succession of tolerant and
opportunistic species should occur.
WETLAND RESOURCES
Under the preferred barge access route, no wetland
resources other than Land Under Ocean would be
impacted (see previous section). The containment
facility footprint will not impact any protected
resources.
WILDLIFE
The site is a vacant lot in an urban setting, and as
such offers habitat for typical urban species such as
song sparrows, rock doves, and house mice. Most of
this habitat would be impacted with the construction
of the containment facility, and the resident animals
displaced or destroyed. Upon capping and closure of
the project, its value as open space in an urban
setting would be restored, and most of the species
currently using the site should return.
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Everett (EVR-04)
Activities during construction of the facility and
dredge disposal may discourage use of the adjacent
tidal flats by shorebirds; however, this is a limited
resource in terms of area and location, so the inter-
ruption is not expected to be an adverse impact. Use
of the site by these birds should resume after capping
and closure.
THREATENED AND ENDANGERED
SPECIES
Noise and disturbance during construction and
operation of the containment facility may disrupt use
of the dilapidated pier by nesting common terns.
The extent of use and success of these small, isolated,
urban breeding sites is poorly understood, therefore
impacts from adjacent construction activities are
difficult to assess. It is likely that the birds would
abandon the breeding site during project operation,
and may return upon project closure.
eventually could be developed as an industrial or
commercial venture if it is not used by the project.
The project may affect certain future uses.
A playground is located a block away from the
site, and a school is less than a half-mile away. Odor
from the site and from trucks travelling to the site
would be the greatest impact to these sensitive
receptors. Daily cover of the dredged material may
be required, reducing final storage capacity. Truck
traffic already is heavy along Route 99, so the in-
crease in safety hazard and noise caused by transpor-
tation of the dredged material may need to be evalu-
ated, although increases over existing levels may not
be noticeable. It is unknown to what extent any
increase in truck traffic would result in additional
traffic delays. If barges are used to transport material
to the site, traffic impacts would be eliminated. Noise
from industries and traffic akeady occurs in the area.
Therefore, it is not expected that the increase in
project noise would be a problem.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
Because there are no identified historical or archeo-
logical resources at the Everett site, no impacts are
anticipated. The jackknife bridge upriver of the
project would not be impacted.
SOCIO-ECONOMIC/LAND USE
The project site is divided into two parcels by the
Boston-Everett City boundary line. The part of the
site in Boston is owned by the City of Boston;
therefore, the Project would not cause any loss of tax
revenue to the city. The Everett parcel is owned by
Boston Edison Company. Use of this land by the
project would result in a loss of taxes by Everett.
The site is partially used by the MDC as a pump-
ing station, and is located in an industrial area. It
Al-17
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23, SITE EVALUATIONS: LAND-BASED
INLAND SITES
2.2.1 Woburn (WOB-in
The site is depicted on Figure Al-4.
2.2.I.I Existing Conditions
GEOLOGY/SOILS
The topography of the Woburn site is irregular
with rounded uplands separated by relatively flat
lowlands. The topography of the site reflects the
surficial and bedrock geology of the area. The
surficial deposits at the site consist of stratified drift
and glacial till. The low lying areas of the site are
underlain by stratified drift which includes kame and
kame terrace deposits of sand and gravel (Castle
1959). Portions of the lowlands have been mined to
extract the sand and gravel for use as aggregate
material. The upland portions of the site are under-
lain by dense, poorly sorted glacial deposits of silt,
sand and gravel.
Outcrops of bedrock have also been observed
(Castle 1959). The bedrock underlying the site has
been mapped as Precambrian age metamorphosed
mafic to felsic intrusive and volcaniclastic rocks (Zen
1983).. These rocks are part of a large fault-bound
block which trends northeast to southwest.
The majority of the soils on site are classified as
landfill or udorthcnts (SCS 1989b). Two udorthents
are distinguished: on the southern parcel is a sandy
udorthent with 3-8% slopes; and on the eastern
parcel is a udorthent with a wet substratum. The
depth of fill over wetland material is unknown, and
within the udorthent scries can range from 2-20 feet.
(SCS 1989b). Small areas of native soil occur on the
northern boundary (Charlton-IIollis-Rock complex,
3-8% slopes) and adjacent to the stream in the
southern parcel (Windsor loamy sands, 3-8% slopes).
Woburn (WOB-Jl)
HYDROLOGY/WATER QUALITY
The site is located in the Mystic River Basin
immediately south of its drainage divide with the
Ipswich River Basin. Runoff at the site appears to
flow to a small stream in the middle of the property,
which flows west to east across the site and then
south into Hall's Brook (also known as Willow
Brook). Locally, groundwater is recharged by the
infiltration of precipitation into the surficial deposits.
Groundwater appears to flow through the stratified
drift deposits to the southeast and then discharge to
the valley fill deposits of the Aberjona River.-
Most of the site consists of low and very low yield
aquifer with 20% of the site consisting of medium
yield aquifer (100-300 gpm) (MADEP Groundwater
Overlay Maps). There are no groundwater quality
data available for the site. It is not known if water
quality has been degraded by the existing landfill on
the site. The Woburn residential areas near the site
rely on Quabbin water through the MWRA, so no
private drinking water wells are known to occur
downgradient of the site.
At its northern boundary, the site is approximately
1200 feet away from the nearest boundary of the
Wilmington Groundwater Protection District A.
This district is designated to protect the 'zones of
contribution of the existing municipal supply wells"
(Town of Wilmington 1990). The nearest Wilming-
ton water supply well, the Town Park well, is over
0.8 miles to the north and upgradient of the Woburn
site. Three other Wilmington municipal wells are
within approximately 1.0 mile of the site.
The site is located in the upper portion of the
Mystic River drainage basin. The only surface water
on the site is a tributary of Halls Brook which is
classified as a Class B waterway. Waters under Class
B arc freshwatcrs designated for the uses of protec-
tion and propagation of aquatic life and wildlife and
for primary and secondary contact recreation. There
Al-18
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are no surface water supplies downstream of the site.
No water quality data exist for this brook, but as
with groundwater, the on-site landfill may have the
potential to influence water quality.
AQUATIC RESOURCES
No aquatic resources occur within the proposed
footprint of the Wobum site. A stream tributary to
Hall's Brook flows through the southwestern portion
of the site. At the time of the site visit, the stream
flowed very slowly in an easterly direction and was
approximately 6-10 feet wide and 1 foot deep. A red
brown floe coated many of the stream's bottom
features, including the vegetation. No culvert was
visible where the access road crossed the stream,
although a slight current was apparent. It is assumed
that the hydraulic crossing is that of a "farm drain"
which allows flow through rock placed at the base of
the road and permits flow through their interstices.
VEGETATION
The major portion of the site is a disturbed early-
successional field and shrubland. Several small stands
of hardwoods remain on the northern portion of the
site, and along the small stream. Scattered shrubs,
representative of disturbed-site species and most of
Eurasian origin, have become established throughout
the site.
On the northern parcel, dominant species on the
closed landfill include mugwort (ArtemLsia vulgaris),
alfalfa (Medicago lupulind), grasses (Two Poa spp.
and Bromus teclontm), clovers (Trifolium repens and
T. pratense), and goldenrods (Solidago spp.). Scat-
tered small individuals of black locust (Robinia
pseudoacacia), honeysuckle (Lonicera tatarica), and
tree of heaven (Ailanlhus allissima) have become
established across the cap. On the steep slopes of the
landfill, stands of trees approximately 30-40 feet in
height occurred on the east and north sides. Com-
Woburn(WOB-ll)
mon species included trembling aspen (P. tremii-
loides), gray birch (B. populifolia), and staghorn
sumac (R. typhina).
The disturbed old field portions of the southwest-
cm and eastern parcels support species similar to the
plant community on the landfill cap in the northern
parcel.
WETLAND RESOURCES
Several areas of freshwater wetlands which will fall
within the purview of Section 404 of the FederaJ
Clean Water Act were observed on the Wobum site.
Wetland resources as protected by the Massachusetts
Wetlands Protection Act and Regulations (MGL
c.131, s.40, and 310 CMR 10.00) include Bordering
Vegetated Wetlands, Isolated Land Subject to Flood-
ing, land Under Water Bodies and Waterways, and
Banks. The following describes the various wetland
resources from general observation. No jurisdictional
wetland boundary delineations were performed since
site access was limited.
Adjacent vegetation was primarily woody. On
the eastern side of the access road, shrubs overhung
most of the stream's length; species included com-
mon and European buckthorn (Rhamnus calhartica
and R. franguld), red maple (Acer rubnuri), willow
(Salix sp.) and honeysuckle (L. talaricd). On the
western side of the access road, small trees (20-30 feet
in height) of red maple, mulberry (Morns alba), black
willow (Salix nigra), and gray birch dominated the
stream corridor.
Small isolated wetlands occur in depressions
elsewhere on the site. Under the powerline, several
herbaceous wetlands less than 0.1 acre in size were
observed; along with considerable trash, common
plant species included cattail (T. anguslifolia), blue-
joint grass (Calamagrostis canadensis), soft rush (J.
ejjTusta), and }cwclwccd (Impatient capensu). North-
west of the on-sitc landfill, a small apparently isolated
Al-19
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forested wetland occurred at the base of the landfill
slope. Standing water in the middle open portion of
the wetland was estimated to be 2.0± feet deep at the
time of the site visit, and stagnant in appearance
(heavy pollen accumulation, dark brown in color).
I^asl year's herbaceous stems were visible well into
the flooded zone, which suggests that water levels will
drop significantly as the growing season progresses.
The canopy was quite open, and dominated by red
maple, black willow and big-tooth aspen (Populus
grandidentata^with willow and European buckthorn
in the shrub layer. The herb layer contained limited
species; a composite thicket condition formed a dense
homogenous herbaceous cover in the flooded portion
of the wetland. Along the edges, jewelweed and
water horehound (Lycoptts sp.) occurred, along with
common reed (P, australis) and Japanese knotweed
(Pafygomim cuxpidalwri) which crept down the slope
of the landfill and encroached on the wetland.
A review of aerial photography revealed a small
pond further to the north, occurring very close to the
Wobum town line, and a more extensive forested
wetland system in Wilmington in close proximity to
the northern edge of the site. Neither area was
visited during field work, but would not be impacted
by the project design.
WILDLIFE
Mammal species typical of sites such as the closed
landfill, with sparse herbaceous vegetation, include
woodchucks and eastern cottontails. The scattered
shrubs and adjacent forest also provided perches or
nest sites for species such as indigo buntings, song
sparrows and common grackles, all of which use
open land or forest edge. Eastern kingbird, tree
swallow, and hoary bat arc examples of wildlife
species that forage over open land and also use
adjacent trees for perching, nesting or roosting
(DcGraaf and Rudis 1986). The many rocks and
other debris on the landfill top also provided good
Woburn(WOB-lI)
cover for species such as brown snakes and common
garter snakes (Hunter et al. 1992).
The hardwood forest on the side slopes of the
landfill area was young, with an open canopy (about
40-50% cover), and well-developed shrub and herba-
ceous layers. Species observed in the forest/shrub
habitat included gray catbird, common yellowthroat,
song sparrow, and yellow warbler. All of these
species typically are associated with brushy habitats.
Several forested wetlands occurred in the area
north of the landfill. Wildlife species most likely to
occur in these wetlands would include those'also able
to use the adjacent landfill (e.g., common yellow-
throat, song sparrow), adjacent developed sites (e.g.,
skunk), or the adjacent fragmented forest (e.g.,
coyote, raccoon). Some species typical of forested
wetlands would be unlikely to use the smaller site
(e.g., northern waterthrush and veery: DeGraaf and
Rudis 1986, Robbins et al. 1989).
Wildlife species observed on the site on either May
12 or 27, 1993, include the following:
Common garter snake (Thamnophis sirlalis)
Red-tailed hawk (Buleo jamaicensis)
American kestrel (Falco sparverius)
Ring-necked pheasant (Phasianus colchicus)
Killdecr (Charadrius vociferus)
Northern dicker. (Colaples auralm)
Blue jay (Cyanocilla cristatd)
American crow (Corvus brachyrhynchos)
American robin (Turdus migralorius)
Gray catbird (Dumetella carolinensis)
Northern mockingbird (Mimtis polyglottos)
European starling (Sturnus vulgaris)
Yellow warbler (Dendroica petechia)
Common yellowthroat (Geolhlypis trichas)
Rosc-brcastcd grosbeak (Pheuclicus ludovicianus)
Indigo bunting (Pasxerina cyanea)
Field sparrow (Spizella piailla)
Song sparrow (Meloxpiza melodia)
A1-20
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Woburn (WOB-1!)
Red-winged blackbird (Agelaiut phoeniceus)
Common grackle (Qidtcalux quitcula)
House finch (Carpodacus mexicamit)
American goldfinch (Carduelit tristis)
Rabbit (Lcporidae family)
Woodchuck (Marmola monax)
THREATENED AND ENDANGERED
SPECIES
The Mystic Valley Amphipod (Crangonyx aber-
rant) is a crustacean that occurs in cool, shallow,
slow-moving or stagnant fresh water with leaf litter;
and is only known to occur in New England (MAN-
IIESP 1991). It is a Species of Special Concern in
Massachusetts. C. aberrant has been recorded south
of the site in Hall's Brook (Lincoln 1993; MAN-
HESP, letter dated March 1| 1993). The on-site
tributary has several of the habitat characteristics
required by the Mystic Valley Amphipod: shallow
depth, sluggish velocity and leaf litter.
No search for C. aberrant was undertaken on the
study area, but a 1991 survey sampled the tributary
to Hall's Brook downstream of the study area (NAI
I991b). One immature Crangonyx, which could not
be identified to species, and 17 Crangonyx pteudo-
gracilis were collected at this sample point, but no
adult C. aberrant were recorded at any sample point
during the 1991 study. Since C. pseudogracilit
typically occupy the same habitat as C. aberrant
(Smith 1983 cited by NAI 1991), this survey reported
no C. aberrant even in suitable habitat.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeological
resources identified on or within 1000 feet of the
Woburn site.
SOCIO-ECONOMIC/LAND USE
Woburn (11) is an 59± acre site containing a city
landfill and vacant land. Boston Edison power
transmission lines cross the site, dividing it into three
pieces. People use the site for dirt-biking. The
Boston and Maine Railroad tracks run in a
north/south direction east of the site. Adjacent to
this site is an office park to the east; another office
park to the south, along with an industrial park and
some residential use; general industrial and residential
to the west; and general industrial to the north with
some limited residential use.
•,/
Wobum, originally known as Charlestown Village,
was settled in 1636 by people seeking relief from
crowded conditions in Charlestown. Once a fanning
community, Woburn housed leather tanning and
shoe manufacturing operations in the 19th century
after the Middlesex Canal was built. These industries
have been superseded by metal fabrication and the
manufacture of electrical equipment. The predomi-
nant land use remains low-density housing. The
population of Wobum declined 2% to 35,943 from
1980 to 1990 . The median family income in Wo-
burn is $50,428.
2.2.1.2 Environmental Consequences
GEOLOGY/SOILS
On-site udorthcnts represent an unnatural and
altered soil condition. Given the sandy gravelly
deposits, placement of silty dredge spoils could
change the surficial character of on-site soils not
associated with the landfill. The dredge spoils could
provide quality material for capping of the landfill
area.
Al-21
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Woburn (WOB-1I)
HYDROLOGY/WATER QUALITY
Because the quality of groundwater resources at
the Wobum site is unknown, potential impacts
cannot be fully addressed. However, a liner would be
required by MADBP and should minimize leakage of
contaminants from the dredged material into the
groundwater. A potential benefit of using this site is
that an unsecured landfill would be capped by the
dredging project. This action may result in improve-
ment of the groundwater quality by eliminating the
present infiltration and leaching of that portion of the
waste deposited above the water table. Any waste in
contact with groundwater would continue to leach.
To avoid impacts from high chloride levels, the
dredged material would be dewatered at Boston
Harbor prior to transport to the Woburn site.
Dewatering facilities are described in the dredge
management plan (Section 3.0 of the EIR/S); moni-
toring requirements of M ADEP would be in place to
keep impacts from the dewatering process to an
acceptable level in the surface waters of Boston
Harbor.
No impacts to surface waters surrounding the
disposal site are anticipated during the dredge dispos-
al phase. The leachate collection system and the
Hner would be used to collect any excess water or
contaminants. I^eachate treatment will be controlled
to prevent impacts to the surrounding environment.
At the end of the dredge disposal phase (2± years),
the site would be capped with an impermeable cover
to prevent further infiltration or surface water runoff
from the dredged material.
After the site has been capped and revegetated,
runoff quality should resemble that of adjacent
undeveloped land. Runoff quality should also
improve because the currently sparse vegetation,
steep slopes, exposed soils and trash are all likely to
degrade existing runoff quality.
AQUATIC RESOURCES
Runoff into wetlands adjacent to the site will be
controlled to keep sediments from entering the
wetland during the dredge disposal phase. After site
closure, runoff will be redirected to best approximate
the pre-project water budget of these wetlands.
VEGETATION
The placement of dredge spoils and the proposed
containment facility would eliminate all existing
vegetation within the construction footprint:,'
/
Upon completion of all on-site activities, early-
stage succession of tolerant and opportunistic species
should occur. A vegetation plan may be required for
the landfill cap, since shallow-rooted species are
generally preferable in maintaining cap integrity.
WETLAND RESOURCES
The preliminary design incorporates avoidance and
minimization of all wetland resource impacts in its
design criteria. As a result, most of the wetlands on
the Woburn site and their buffer zones would not be
impacted. The exception is a small l.0± acre forested
wetland on the northwest side of the site, in which
fill may be placed to ensure adequate sideslope
stability during closure of the existing landfill. More
detailed site information would be necessary to
further quantify surface area impacts to wetland from
any fill. The functions and values of this wetland
have not yet been evaluated but due to its small size,
isolation, and disturbed conditions, the wetland is
expected to be of relatively low value for biological
support, flood control, wetland wildlife habitat and
water quality functions. Aesthetic, recreational, and
educational values are also expected to be low
because of its disturbed setting and lack of public
access. Therefore, impacts to this area of wetland are
expected to be minor. Proposed compensation for
A1-22
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Woburn (WOB-11)
these impacts is discussed in Section 2.3 of the
EIR/S.
WILDLIFE
Construction of the containment facility would
result in the loss of all upland wildlife habitat within
the disposal footprint until the capping and closure of
the site were completed. Wildlife in the immediate
vicinity would be disturbed for the duration of site
activity because of noise, and human presence.
Upon closure of the project, there would be an
opportunity for natural recruitment and restoration
and improved habitat quality by eliminating exposed
trash and future dumping. As described above, a
limited permanent wetland wildlife habitat loss would
also occur, but is expected to be of minimal signifi-
cance.
THREATENED AND ENDANGERED
SPECIES
No known threatened and endangered species use
the Woburn site; therefore, no impacts are anticipat-
ed.
the City of Woburn, since no work would be done
near the powerline. The powerlines and pipeline on
the site would not be impacted by the project. Also,
capping the she after the project is completed would
save the City of Wobum the expense of capping the
existing landfill.
The site is primarily industrial, with some nearby
residences. Noise and odors from the site could
affect some of these residences. Odors may need to
be controlled daily by covering the dredged material.
Daily cover requirements would reduce the available
site capacity. Noise and odor also would be lessened
by prevailing winds. The direction of prevailing
winds is from the west, and no residences occur
immediately east of the site.
Travel to the site would be along secondary and
local roads and would pass by residences. Truck
traffic to the site could increase noise and odor levels
and could create safety problems, particularly along
Merrimac Street and New Boston Road. A new exit
from Route 1-93 or development of a new rail siding
east of the site could markedly reduce transport
impacts.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeological
resources on or near the Woburn site; therefore, no
impacts are anticipated.
SOCIO-ECONOMlCfLAND USE
The site is an abandoned landfill, intersected by
powerlines and a sewage pipe. The site is primarily
owned by the City of Woburn, with a parcel owned
by the Boston Edison Co. Use of this site for the
project would not result in any loss of tax revenue to
A1-23
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Wrentham (WREN-495)
2,22 Wrenfham (WREN-495)
This site is depicted on Figure A1-5.
2.2.2.1 Existing Conditions
GEOLOGY/SOILS
The topography of the Wrentham site ranges from
an upland area in the northeast portion of the prop-
erty to several water filled depressions in the central
and southern portions of the property. The upland
areas are underlain by dense, poorly sorted glacial till
and bedrock. The lowland areas in the central and
southern portions of the property are underlain by
stratified drift. Portions of the stratified drift deposits
in the southern portion of the property have been
mined for sand and gravel.
Outcrops of bedrock are found in the upland
portions of the property. Based upon the Bedrock
Geological Map of Massachusetts (Zen 1983), the
bedrock underlying the site consists of the Precambri-
an Age Dedham Granite. Dedham Granite is part of
a structural block which trends northeast to south-
west. In the vicinity of the property the Dedham
Granite is traversed by a north to south trending
normal fault.
Soils on the site are predominantly well drained
and somewhat excessively drained outwash and till
soils (SCS 1989a). Except for the level idorthcnts in
the quarry areas, slopes range from 3-8% to 15-35%.
TheCharlton-IIollis-RockOutcropcomplexincludcs
a dominant sandy till, but also included are till areas
of Canton fine sandy loam, and outwash deposits of
Ilinckley fine sandy loam and Merrimac fine sandy
loam. A linear unit of ponded Freetown muck, a
very deep organic deposit, is associated with a small
stream on the western edge.
HYDROLOGY/WATER QUALITY
The site is underlain by medium yield aquifer
(MADEP Groundwater Overlay Maps). There are
no municipal drinking water wells located on the site
as the area is primarily serviced by a municipal piped
system. No groundwater quality data were available
for the site. There is a proposed municipal well
approximately 0.15 miles west of the site. This
proposed well location is in the Biackstone River
basin, out of the watersheds of the project study site;
however, actual groundwater divides may not coin-
cide with surface watershed boundaries.
/ '
The north and west portions of the site are located
in the Charles River basin while the south portion is
in the Ten Mile River basin. There are several small
ponds and a stream located on the site, but no water
quality data were available. Surface waters on the
site in both watersheds are classified as Class B
waterbodies. Waters under Class B are fresh and
designated for the uses of primary and secondary
contact recreation and for the protection and propa-
gation of aquatic life and wildlife. Several private
wells are near the site for residences on portions of
Green Street and Route 1A.
AQUATIC RESOURCES
Several small kettlehole ponds occur within the
central project area. Most appeared to be steep sided;
however, the largest pond (on the eastern side of the
site) was shallow, with aquatic vegetation visible
throughout. On the western edge of the site lies an
unnamed stream which drains to Eagle Brook after
flowing north through a series of off-site ponds. In
June, the stream was approximately 4.0 feet wide and
6 to 8 inches deep, with a sand and detritus bottom
and sluggish flow.
AI-24
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VEGETATION
Vegetation cover types and wetland identification
were ascertained from stereo aerial photographs
(black and white, 1:6000, dated December 1991), and
ground truthed only peripherally from the old rail-
road grade, Green Street, and an improved gravel
road bisecting the site. Should this site be selected,
a more thorough site investigation would be required
to determine jurisdictional wetland boundaries and
more detailed vegetation descriptions.
The scrubland northwest of the active quarry area
was on a low rolling dry plain bordered by several
prominent rock outcrops. Based on vegetation
composition and structure, the soil appeared to be
well-drained poor sands with an average litter layer.
The vegetation was dominated by a mixture of oaks,
approximately 15 feet tall and many with multiple
stems. Oak species included red oaks (probably
Quercus coccinea and Q. rubra), scrub oak (Q.
Ulicifolia) and white oak (Q. alba). Minor represen-
tatives of other tree species such as red maple (Acer
rubnuri), cherries (Primus spp.) and gray birch (B.
popidifolid) were also observed. Tall snags of white
pine (Pinus strobus) were scattered across the site.
The understory was dominated by a lowbush blue-
berry (Vaccinhim sp.), with sweet fern (Comptonia
peregrlna), meadowsweet (Spirea lalifolid) and
blackberry (Rubies sp.) also common. The herba-
ceous layer was sparse and indicative of dry site
conditions: bracken (Pteridium aquilinuni), Pennsyl-
vania sedge (Carex pensyh'anicd) and haircap moss
(Pofytrichum sp.) were dominant species. Even a
small swale running the length of the site appeared to
be dominated by upland species, again supporting the
SCS classification of well-drained soils on the site.
Shrublands elsewhere on the site were similar in
structure and general species composition. Other
common species included multiflora rose (Rosa
multiflora), willows (Salix spp.), poison ivy (7'.
radicans), and trce-of-hcaven (A. allissima). The
forested portions of the site were hardwood-dominat-
Wrcnlham (WREN-49S)
ed with red oaks and white ash (Fraxinus americana)
as the principal species. Other observed species
include sassafras (Sassafras albidum), sugar maple
(Acer saccharum), big-tooth aspen (P. grandidenlata)
and white pine. Understory species included white
oak, gray birch, black cherry (P. serolina), poison
ivy, and lowbush blueberry as well as canopy species.
Structure was typical of second-growth forests of the
area; canopy height was approximately 70 feet, with
a maximum stem diameter at breast-height of about
18 inches, and an estimated 70% canopy closure.
Several small open areas of old field occurred.
Soils were obviously poor and well drained, with-
many surface rocks and cobble. The vegetation was
typically early-successional, dominated by forbs such
as asters, goldenrods, yarrow (Achillea sp.), ragweed
(Ambrosia arlemisiifolia), wild carrot (Daucus sp.),
grasses (Poa compressa and others), and sedges
(Carex brevior). Scattered shrubs (willows, meadow-
sweet and sweet fern) were established.
WETLAND RESOURCES
Several areas of freshwater wetland occur across
the Wrcntham site will be subject to review under
Section 404 of the Federal Clean Water Act. Juris-
dictional resources under Massachusetts Wetlands
Protection Act and Regulations (MGL c.131, s.40,
and 310 CMR 10.00) on the Wrentham site include
Bordering Vegetated Wetlands, Land Under Water
Bodies and Waterways, Isolated Land Subject to
Hooding, and possibly Banks.
In the northern and western portions, forested
wetlands occurred either in isolated depressions on
the landscape or associated with small ponds. On
the far western edge lies an unnamed stream system
which drains into Eagle Brook. The stream is
bordered by a wide swath of wooded wetlands,
except where it traverses a residential landscaped lot.
The wooded wetland is primarily red maple (A.
rubruni) with a minor clement of white ash and other
A1-25
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species. The understory was relatively dense with
woody species such as red maple, swamp azalea (R.
viscoswri) and spice bush (L. benzoin). Herbaceous
species included sensitive fem (Onoclea sensibilis),
royal fem (Osmunda regalis), skunk cabbage (Sym-
plocarpus foetidus) and sedges (Carex sp.). Immedi-
ately bordering the stream, the ovcrstory opened up
to a dense shrub swamp.
On the southern and eastern portions of the site,
where the vegetation is predominantly low secondary
growth, scattered shrub wetlands in isolated basins
and in small drainages occur. Under the powerlines,
vegetation is maintained by mowing or herbicides,
and emergent/shrub wetlands were evident on the
aerial photographs. Several small kettlehole ponds
dot the central portion of the site. These ponds
generally appear to be steep sided with few bordering
wetlands. The largest pond was observed from the
railroad tracks to have a narrow band of shrub
swamp bordering its shores. The pond was shallow
throughout, with pond lilies and emergent species
dominating most open water areas. A narrow shrub
swamp separated this pond from an adjacent smaller
pond, but a surface hydrologic connection almost
surely occurs at high water levels.
WILDLIFE
The scrublands could be expected to support many
of the species typical of dry, brushy habitat (e.g:,
American redstart, gray catbird, New England cotton-
tail: DeGraaf and Rudis 1986; redbelly snake:
Hunter et al. 1992). The rufous-sided towhee, is
typical of brushy habitat, forages in leaf litter
(DeGraaf and Rudis 1986), which was abundant at
this site.
The hardwood forest had a good vertical structure,
with well-developed shrub and herbaceous layers.
Wood thrush and woodland jumping mouse are
typical of this forest type (DeGraaf and Rudis 1986).
A well-developed layer of duff, a stonewall, and
Wrentham (WREN-495)
abundant logs would favor small animals requiring
cover: for example, chipmunks, masked shrews, and
redback salamanders (DeGraaf and Rudis 1986).
A small early successional field in the southern
corner of the site contained sparse herbaceous vegeta-
tion, with some scattered shrubs and an occasional
tree. Common yellowthroat, song sparrow and
mourning dove would be expected in this habitat
type. This habitat may be suitable for the northern
hairstreak, a butterfly which is described in the
"Threatened and Endangered Species' section.
The ponds appear to have poor interspersion of
vegetation types and vegetation and water. There-
fore, it is likely not to be important for waterfowl
brood rearing. Canada goose scat was observed on
the pond edge. These geese probably were feeding
there.
The stream, moist soil and dense shrub layer in the
red maple swamp would attract species such as veery,
short-tailed shrew and yellow warbler (DeGraaf and
Rudis 1986) as well as two-lined salamanders (Hunter
ct al. 1992), all of which would not occur in the
other, drier cover types.
Some wildlife species may use a combination of
habitats. For example, American kestrels may perch
in the snags jutting above the scrubland and forage
above the scrubland and in the adjacent early succes-
sional field (DeGraaf and Rudis 1986). White-tailed
deer from the forest may browse on saplings and
shrubs in the scrubland. Eastern kingbirds or eastern
phocbcs may hawk insects above the shrubs from
perches at the forest edge or in the supercanopy
snags.
The Wrentham site and its vicinity are intersected
by a powerlinc, an interstate highway, several second-
ary roads, a dirt road, and a gravel mining operation.
It is too fragmented to be used by species that breed
in large tracts of unbroken forest (e.g., black-throated
blue warbler: Robbins et al. 1989). However,
AI-26
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wildlife species that use a variety of habitats and that
have home ranges of a half-mile or more in diameter
may use the site as part of their domain. Examples
include red fox, striped skunk and raccoon (DeGraaf
and Rudis 1986).
The following species of wildlife were observed on
the project site on May 12 and June 21, 1993:
Bullfrog (Rana catesbeiand)
Canada goose (Branta canadensis)
Red-tailed hawk (Buteo jamaicensis)
Kilideer (Charadrius vodferus)
Rock dove (Columba livid)
Mourning dove (Zenaida macrawd)
Eastern phoebe (Sayornis phoebe)
Eastern kingbird (Tyrannus lyrannus)
Blue jay (Cyanodtta crislatd)
Tufted titmouse (Pants bicolor)
American robin (Turdus migratorius)
Gray catbird (Dumetella carolinensis)
Northern mockingbird (Mimus polyglottos)
European starling (SttoTtus vulgaris)
Blue-winged warbler (Vermivora pinus)
Prairie warbler (Dendroica discolor)
Indigo bunting (Passerina cyanea)
Rufous-sided towhee (Pipilo erylhrophlhalmus)
Song sparrow (Melospiza melodid)
Common grackle (Qtdscalus quisadd)
House finch (Carpodacus mexicanus)
THREATENED AND ENDANGERED
SPECIES
Two species identified by the State of Massachu-
setts as of Special Concern occur adjacent to the site
(MANHESP, letter dated March 1, 1993): and
include the northern hairstreak butterfly (Fixsenia
Ontario), and Philadelphia panic grass (Panicum
philadelphicum). Both species are typical of open
ground.
The northern hairstreak occurs at disturbed sites
that are dry, open and sparsely vegetated, such as
Wrcntliam (WREN-495)
power lines, railroad rights-of-way, and abandoned
gravel pits (Hildreth, undated). The old fields and
parts of the powerlinc right-of-way and abandoned
railroad bed may provide appropriate habitat for this
species. These areas would need more intensive
investigation to determine whether they provide
suitable conditions.
The Philadelphia panic-grass occurs in open areas
or thin woods (Fernald 1950). In Massachusetts, it
has been found in open wetlands, along the shores of
water bodies, and in depressions (MANHESP 1992).
The most likely place for it to occur on the study
area would be in the wetlands within the powerline.
corridor and along the banks of open water through-
out the study area.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeologjcal
resources on or within 1000 feet of the Wrentham
site.
SOCIO-ECONOMIC/LAND USE
This 181-acre site is predominantly open land,
with an active quarry and asphalt plant at its south-
em tip. It is located immediately southwest of the
Route 1A Interchange on Route 1-495 and near the
Wrentham State Forest. The vast-majority of the
site is undeveloped shrub and forestland containing
some ponds and wetlands. There are some residences
abutting the property.
Wrentham was first settled in 1669 and was con-
sidered part of Dedham. Industries that developed in
the town during the 19th century included the pro-
duction of straw hats and jewelry. The major em-
ployer in the town today is the State, reflecting the
presence of a state school for the retarded. The
Al-27
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Wrentham (WREN-495)
population of Wrentham is 98% white. The median
family income is $51,184.
Access to the site is via 1-93 south to Route 1-95
south, and northwest on Route 1-495 to Route 1A to
High Street to Green Street and onto the site.
2.2.2.2 Environmental Consequences
GEOLOGY/SOILS
The site would require regrading prior to construc-
tion of the lined containment facility and deposition
of the dredge spoil (silts). These activities may require
extensive earthmoving of sandy/gravelly till and filling
with silt, thus potentially changing general surface
soil characteristics. Blasting or drilling may be re-
quired to remove all or a portion of the existing
bedrock outcrops.
The site is presently worked, and represents an
altered condition; therefore, the placement of the
containment facility and dredge spoils should not
adversely impact existing geologic and/or soil condi-
tions.
HYDROLOGY/WATER QUALITY
Because little is known about the quality of
groundwater resources at this site, potential impacts
cannot be fully addressed. However, a liner would be
required by MADEP and should prevent leakage of
contaminants into the groundwater.
As with the Wobum site, impacts to surface water
would be minimized during the dredge disposal phase
by a combination of dewatering the dredged material
prior to transport to the site, and by maintenance of
the leachatc collection system.
These actions would prevent chloride, sediment
and any sediment-related contaminants from entering
surface waters. I^ewatcring facilities arc described in
the dredge management plan in Section 3.0 of the
EIR/S; MADEP discharge and monitoring require-
ments would keep dewatering impacts to surface
water quality within an acceptable range in Boston
Harbor.
Runoff from capped portions of the disposal site
would be controlled so as to minimb.e erosion risks
prior to entering any surface water system.
AQUATIC RESOURCES
As described in the Water Quality section,,the on-
site stream and small ponds would be protected from
contamination during the dredge disposal phase by
dewatering prior to on-site disposal, and by the liner-
leachatc collection system. Surface runoff from the
project would be treated using appropriate erosion
control methods and controlled to avoid directly
entering aquatic habitats. After site closure, runoff
from the project area would be redirected to best
approximate the pre-project water budgets of sur-
rounding aquatic habitats.
VEGETATION
The placement of dredge spoils and construction
of the proposed containment facility will eliminate all
existing vegetation within the footprint. Being a
disturbed site, the existing vegetative composition and
structure is of a shrubland, scrubland, and forb
dominated old field. Following capping and closure
of the site, this type of vegetative character should
return.
WETLAND RESOURCES
'ITic preliminary design incorporates avoidance and
minimisation of impacts to wetland resources in its
design criteria. As a result, most of the larger wet-
lands and wetland complexes would be avoided
A1-28
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altogether (based on the restricted in-field wetland
assessment and findings to date). Several smaller
isolated wooded wetlands in the interior portions of
the two parcels would be filled. Under the proposed
preliminary design, approximately 4.0 acres of identi-
fied wetland resources protected under the Federal
Clean Water Act would be impacted. Under Massa-
chusetts regulations, this acreage includes both
Bordering Vegetated Wetlands and Isolated Land
Subject to Flooding. Additional field survey would
be necessary to determine the extent and proportion
in each resource category. Impacts to the functions
and values of these shrub swamps and forested
wetlands cannot be addressed until site-specific
wetland evaluations have been performed. Should
the Wrentham site be selected as suitable for dredge
disposal, more detailed studies would likely be
necessary to ascertain more fully the proposed
impacts to wetland resources.
WILDLIFE
Construction of the containment facility would
result in the loss of all wildlife habitat within the
project footprint until capping and closure of the site
was completed, and revegetation commenced.
Additionally, a relatively large tract of undeveloped
land would be fragmented, which may discourage use
by those species which require large areas. This
impact is expected to be moderate because the forest
and shrub communities are common in the region,
and the study area presently contains an active gravel
and asphalt operation. Upon completion of the
project, the site would be restored to open land, and
should regain much of its value as wildlife habitat.
THREATENED AND ENDANGERED
SPECIES
The on-site potential for use by the Philadelphia
panic grass and Northern hairstreak should be
verified, because both species have been recorded at
nearby locations. The scrub-shrub wetlands and old-
Wrentham (WRBN-495)
field areas are the most likely habitats in which to
find these two species, respectively. These habitats
occur throughout the southern portion of the site.
Upon detailed field investigation by experts of these
two species, impacts to areas identified as potential
habitat could be avoided.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
Since there are no listed historical or archeological
resources on or near the Wrentham site, no impacts
are anticipated.
SOCIO-ECONOMIC/LAND USE
The project site is owned by Simeone Corpora-
tion, which has proposed to extract sand and gravel
from the portion of the site that abuts Route 1-495 in
preparation for an industrial subdivision (Landmark
Engineering of New England, Inc. 1993). Use of the
northern part of the site by the project would deprive
the Town of Wrentham of existing tax revenue as
well as the potential tax revenue from the subdivi-
sion. Use of the southwestern parcel would result in
loss of existing tax revenues, as well as any potential
for future development.
Green Road already is used heavily by quarry
trucks. The project would increase truck traffic.
Odors from dredged material along the truck route
could be a concern.
Odor and noise from the site should not be a
concern near the quarry and asphalt plant because
they may not be distinguishable from existing noise
and odor levels there. However, in the northern part
of the project, which is farther away from the plant
and closer to the residences, these could become a
concern. Daily cover of dredged material may be
required to control odors; this would reduce overall
capacity for actual dredge material disposal.
Al-29
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Landfills
223 Landfill Sites- An Overview
Three private solid waste landfills within reason-
able haul distance have been identified that could
accept portions of the dredged silt material. These
three sites include Laidlow Waste Systems Sanitary
Landfill at Plainville, BFI-Northem Disposal, Inc. in
East Bridgewater and Fitchburg/Westminister Sani-
tary Landfill in Fitchburg. All are lined facilities with
leachate collection systems. None have special waste
permits but all are willing, within their MADEP
Solid Waste Site Assignment restrictions, to accept
dredged material pending MADEP and local board
of health approval. Table A1-1 summarizes the
features and constraints of each site for comparative
purposes.
Use of a portion of the dredged material as daily
and intermediate cover is also a possibility at all three
sites. To be considered suitable for intermediate
cover the material must meet the physical and
chemical standards described under 310 CMR 19.00
and expanded on by MADEP. Use as final cover
should also be considered, provided the material
meets the 310 CMR 19.00 standards, including
criteria for Toxic Characteristic leaching Procedures,
Ph, solids, and reactivity.
As required by 310 CMR 19.00, the introduction
of a special waste to any of the candidate sites should
not impact the public health, safety and the environ-
ment by comprehensively regulating the storage
transfer process, treatment, disposal, use and reuse of
solid waste. Protection of these issues generally
requires a comprehensive site evaluation and/or
assessment which evaluates on-site and offsite condi-
tions and receptors relative to public health and
environmental risk. Since these candidate landfill sites
are lined and presumed suitable to receive "special
wastes," all issues of public health and environmental
risk have been addressed previously. Therefore, both
existing and proposed condition narratives, as con-
tained herein, are brief and as follows. Potential
impacts for each candidate landfill site are summa-
rized in Table 2.3.2-7 of the EIR/S.
2.2.3.1 Existing Conditions
PLAINVILLE SANITARY LANDFILL
I^idlaw Waste Systems' Landfill of Plainville is a
double-lined RCRA facility, operated by Laidlaw
Waste Systems, Inc. in Plainville, MA (Figure A1-6).
Access is via Route 1-495 to Route 1 N and Madison
Street, with an approximate travel time of 1.0 hour
from Boston Harbor (35± miles).
Although no dredged material has been landfllled
at the Plainville site, they have accepted grit and
screenings from MWRA sewage treatment projects.
Plainville was considered for the disposal of dredged
material from the Moran terminal on Boston Harbor
but a different site was selected. The landfill can
accept materials containing up to 1000 ppm total
petroleum hydrocarbons. Materials must contain at
least 40% solids. Laidlaw engineers must review
bulk sediment test results, and materials for disposal
must contain no free-standing water. Any further
need for testing will be determined by the MADEP.
Coordination with the Plainville Board of Health
consists of submitting an information package about
the proposed disposal to the Board for review.
The landfill is very concerned about odor control,
because of a campground near the site. Deodorizing
agents will be required after disposal should odor
problems develop.
Plainville expects to exceed its permitted capacity
in 1995, but has several expansion proposals in
various stages of preparation. One of the proposals,
currently undergoing MADEP review, would extend
the site's capacity for approximately one year, if
approved. Three other expansions could potentially
provide disposal capacity until the year 2000.
A1-30
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Landfills
m'CHBURG/WESTMINSTER SANITARY
LANDFILL
Fitchburg/Westminster is a lined solid waste
facility operated by Resource Control, Inc. in Fitch-
burg, MA (Figure A1-7). Access is gained via
Princeton Road off Route 2, with an approximate
travel time of 1V4 hours from Boston Harbor (45±
miles).
The landfill has not received dredged material for
disposal but has accepted petroleum-contaminated
soil and wastewaler treatment plant sludge. In
addition to meeting 310 CMR 19.00 standards, waste
disposal material must be at least 25% solids and
contain no free-standing water upon arrival at the
site. No nuisance materials can be accepted at the
landfill, so disposal material must be odor-free.
Local coordination with both the Westminister and
Fitchburg Boards of Health is required.
Fitchburg/Westminster expects to exceed its
permitted capacity in 1997. No expansions are
currently proposed.
BFI-NORTHERN DISPOSAL. INC.
Northern Disposal, Inc. is a lined facility operated
by Browning Ferris Industries in East Bridgewater
(Figure Al-8). Access requires taking Route 24 to
Route 27 onto Thatcher Street. Time of travel is
estimated to be 45 minutes from Boston Harbor (25±
miles).
This landfill has accepted dredged material from
another project in the last three years, as well as
small volumes of sewage sludge and petroleum
contaminated soils. This landfill was selected for the
disposal of dredged material from the Moran Termi-
nal on Boston Harbor. The landfill can accept
materials with no free-standing water and a minimum
of 20% solids. Approval for disposal is required
from both DKP and the Town of F,ast Bridgewater
Board of Health. Odor is a particularly sensitive
problem as several residences are located very close to
the landfill. Deodorizing agents will be required after
disposal in the event that odor problems develop.
Northern Disposal, Inc. expects to exceed its
current permitted storage capacity in 1996, although
it may pursue a vertical expansion.
2.2.3.2 Environmental Consequences
The three landfills under consideration for disposal
of the silt sediments are all constructed to handle the
material so as to avoid impacts on the environment.
They arc all lined facilities and strictly regulated for
waste-stream handling and disposal. Because of their
similarities, they will be addressed together in terms
of project impacts using landfills as disposal options.
GEOLOGY/SOILS
Geological and soil conditions at landfills are
generally accepted to be severely altered from pre-
landfill dumping activities. Landfills designated for
waste or special waste disposal can readily accept
several forms of waste which meet their specific
designation. Therefore, specific impacts on geolo-
gy/soil will not be an issue.
HYDROLOGY/WATER QUALITY
The dredged material would be dewatered at
Boston Harbor prior to being trucked to a landfill
site. Dcwatering is required to eliminate standing
water and to achieve the criteria for percentage of
solids specified by each landfill. Dewatering at
Boston Harbor would reduce the volume of dredged
material and therefore the Project truck traffic, and
would minimize the problem of chloride handling in
a freshwater environment. The dewatering facility
described under the Dredge Management Plan
Al-31
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(Section 4.0 of the EIR/S) would also be utilized for
the landfill disposal option. As with the upland
inland sites, no adverse water quality impacts to
Boston Harbor are anticipated due to the MADEP
permit requirements.
AQUATIC RESOURCES
No impacts to aquatic resources would occur at
the landfill sites or Boston Harbor as a result of
dewatering.
WETLAND RESOURCES
No impacts to wetland resources would occur at
the landfill sites or Boston Harbor as a result of
dewatering.
WILDLIFE
No impacts to wildlife would occur at the landfill
sites or Boston Harbor as a result of dewatering.
Landfills
SOCIO-ECONOMIC/LAND USE
Each are existing and active landfills so that their
individual or collective use should not pose any
additional socio-economic/land use impacts on their
respective communities.
THREATENED AND ENDANGERED
SPECIES
No threatened or endangered species arc known to
occur at any of the landfill sites, or at the Boston
Harbor dewatering facility, so no impacts would
occur.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
No historical or archcological resources are known
to occur at any of the landfill sites, or at the Boston
Harbor dewatering facility, so no impacts would
occur.
Al-32
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Mystic Fieri
2.3 SITE EVALUATIONS: NEARSHORE
AQUATIC SITES
2.3.1 Mvstic Piers (Massoort Piers 49 & 50)
The site is depicted on Figure A1-9.
2.3.1.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Like all of Boston Inner Harbor, the Mystic Piers
site is a depositional environment (EG&G 1984),
accumulating fine grained sediments (silts and clays).
Sediment sampling along the harbor-face of Mass-
port's Mystic Piers 1 (Station 1), 49 and 50 (Stations
1 and 2), adjacent to the proposed disposal site,
revealed that the silt-clay component was 41-78%,
averaging 60% (see EIR/S Section 2.2). Benthic
grabs collected within the proposed disposal area
contained predominantly silty sediments, although
gravel was present in one sample.
No within-berth data were available for assessing
sediment quality. However, all stations sampled to
characterize berth-area dredged materials were within
approximately 400 feet of the mouth of the proposed
Mystic Pier disposal site and may be indicative of
sediment quality. Assuming these data reflect condi-
tions within the Mystic Pier site, the sediments are
likely to contain moderate to high levels of metals
and organics. Arsenic, chromium, copper and
mercury likely occur in Category II levels; lead and
zinc likely occur in Category III levels. Total PAIIs
concentrations are likely to be high ( > 10 ppm), with
fluoranthene and benzo(g,h,i)perylene contributing
the highest concentrations. Total organic carbon is
likely to be 2-3% of dry weight, indicating a rela-
tively high potential for •bioaccummulation of con-
taminants.
WATER QUALITY AND CIRCULATION
The area of Boston Harbor adjacent to the Mystic
Pier site has been classified as Class SC waters by the
MADEP. This designates these saline waters for the
protection and propagation of marine life and sec-
ondary contact recreation. Water quality of Boston
Inner Harbor is strongly influenced by the numerous
discharges into the harbor, including CSOs, NPDES
discharges and non-point source urban runoff. There
is no site-specific water quality data for the Mystic
Pier Site; however, water quality can be characterized
by Boston Inner Harbor data which are described in
Section 4.1.1 of the EIR/S. At the Mystic Pier site
there is an outfall pipe, which is a minor discharge
consisting of either stormwater, sanitary waste water
or from a minor industrial discharge such as non-
contact cooling of equipment (Menzie-Cura and
Assoc. 1991).
The opening of the Mystic Piers site indicates that
water exchange between Boston Harbor and the site
is not restricted. Thus, water movement at the
Mystic Pier site can be characterized by Boston Inner
Harbor currents (described in Section 4.1 of the
BIR/S) which are tidally diverse.
In general, water quality and circulation are driven
by tidal cycles, and influenced by seasonal weather
patterns. High summer temperatures have been
reported to depress dissolved oxygen concentrations,
often resulting in defaunation in the benthos in
Boston Harbor (Hubbard and Bellmer 1989). This
condition is commonly referred to as the 'August
Effect," and will be also referred to throughout this
document.
AQUATIC RESOURCES
The site was visited during low tide on April 28,
1993, to evaluate habitat conditions. The intertidal
zone is restricted to the tidal excursion vertically
along the walls and pilings surrounding the Mystic
A1-33
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Piers site, except in the southwest corner where
rubble has accumulated in sufficient quantity to be
exposed at low tide. Intertidal portions of the
western and northern walls are covered extensively
with algae (primarily Fttats sp. with some Spongo-
morpha sp.)- The pilings along the southern perime-
ter were heavily covered with barnacles, blue mussels
(Myttfus edtilis) and green algae (Spongomorpha sp.)
with algal cover increasing with distance from the
mouth. Diatoms were present on the algae and
rubble. Mussels and macroalgae both provide
habitat for other organisms. These communities may
be exploited for food or shelter by crustaceans and
finfish.
Benthic Infauna
Two areas were sampled (in April 1993) for
benthic infauna. Results (extrapolated to num-
bcr/m2) arc reported on Table A1-2. Station MP-1,
adjacent to the pilings, was nearly azooic (two taxa
totalling 86 individuals/m2) while Station MP-2, near
the head of the site, contained 17,759 individuals/m2
(11 taxa) of which 11,954/m2 were nematodes. The
total abundance at MP-2 was in the range observed
by the Corps in the Chelsea Creek and Confluence
Area in 1986. However, the channel stations were
dominated by polychaetes ( > 70%) while the Mystic
Pier station was dominated by nematodes (67%).
Capllella capilataand oUgochaetes comprised 85% of
the remaining organisms. These predominant taxa
arc classified as pioneer taxa. Nematodes are early
settlers in organically enriched sediments whose
presence stimulates microbial degradation of organics
(Tieljcn 1982). Oligochaetes and C. capitata are
typically associated with organically enriched, stressed
environments. Its reproductive strategy enables C.
capitata to colonize disturbed sediments rapidly. No
ampliipods or live mollusks were collected. The
moderate abundance of infauna (17,759/m2) in at
least a portion of the site contributes to the produc-
tivity of Boston Harbor and these near-surface
dwelling organisms arc available as prey items for
Mystic Piers
crabs and demersally feeding fish. Winter flounder
(Pleuronectes americanus) have been documented as
feeding on C. capilata in Boston Harbor (Haedrich
and Haedrich 1974; NAI 1985), although their
preferred prey includes amphipods and large worms.
Finfish
Finfish were not sampled in this site. It is likely
that most species that reside in or migrate through
Boston Inner Harbor could enter this area. The
pilings and wharf, shading the area below, offer
shelter from predators. The orientation of the site
perpendicular to the main channel provides shelter
from currents. Both subtidal and intertidal benthic
resources provide prey items. Soft substrate could
support feeding by demersal species (e.g., winter
flounder). Fish such as cunner (Tautogolabnts
adspersus), tomcod (Microgadus tomcod) and scul-
pins (Myoxocephalus spp.) could feed on the fouling
community on the walls and pilings (Edwards et al.
1982; Menge 1982; Ojedaand Dearborn 1990). Two
species of particular concern are alewife (Alosa
psuedoharengus) and winter flounder. The anadro-
mous alewife spawns above the head of tide of the
Mystic River so reproductive adults migrate upriver
past the Mystic Piers site between April and May
(Whitlatch 1982). Adults descend the river during
the summer, juveniles swim downriver past the site
from late summer-fall (Loesch 1987). Another
anadromous species, rainbow smelt, may also use this
portion of the Harbor. Winter flounder is one of the
most abundant species in Boston Harbor where it is
considered to be a resident. It prefers to spawn on
sand common in the outer harbor (Bigelow and
Schrocder 1953). Site-specific data for winter floun-
der were not available.
A1-34
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Mystic Piers
WETLAND RESOURCES
Under the jurisdiction of the Massachusetts Wet-
lands Protection Act (MGL c.131, s.40 and 310
CMR 10.00) the Mystic Piers site is a Designated
Port Area (DPA). DPAs are almost completely
developed areas where few or no natural land forms
or vegetation remain. They tend to be paved, bulk-
headed, and used for heavy industry so that they
have virtually no significance to the interests of the
Act, except for Land Under the Ocean. Land Under
the Ocean in DPAs are significant to flood control,
storm damage prevention, and the protection of
marine fisheries, as is l^nd Under the Ocean outside
of DPAs. The major addition is that Land Under the
Ocean in designated port areas also provides support
for coastal engineering structures, such as bulkheads,
seawalls, revetments, and solid fill piers. The site is
primarily Land Under the Ocean, potentially impor-
tant to marine fisheries, storm damage prevention
and flood control. I^and Under the Ocean within the
Mystic Pier provides food resources and shelter;
however, the silty substrate is not preferred spawning
habitat for winter flounder, nor are the saline condi-
tions conducive to spawning of the anadromous
alewife. Storm damage protection and flood control
are provided by the vertical granite wall surrounding
the perimeter of the site.
Under federal wetlands guidelines, the entire
Mystic Piers site is defined as tidal water. The fine-
grained character of sediments at the site, as weD as
proximity to identified contaminants, suggest that the
potential for retention of sediments, toxicants and
nutrients exists. Abundance and diversity of the
benthic fauna varied substantially in the site. Com-
pared to other locations in the harbor, Mystic Piers
exhibited moderate potential for supporting higher
trophic levels. Construction activities could be more
sensitive at this site due to its proximity to an ana-
dromous fish run (in the Mystic River).
WILDLIFE
The aquatic area of Mystic Piers may .be used by
waterfowl that dive for food (e.g., bufflehead and
common goldeneye), birds that hunt fish in the water
(e.g., red-breasted merganser and double-crested
cormorant), or those that hunt fish from the air (e.g.,
common tern and belted king fisher). Coastal areas
are particularly important to waterfowl during the
winter. Inland feeding areas usually freeze, so water-
dependent birds such as American black ducks move
to unfrozen waters on the coast.
Abandoned piers provide roosting sites for gulls
and common terns. Norway rats are also commonly
associated with waterfronts (DeGraaf and Rudis
1986). Harbor seals may occasionally occur since
they generally feed in shallow water inshore (FAO
Adv. Comm. 1976, cited by Chapman and Feld-
hamcr 1982).
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or anticipated to occur
within the boundaries of the Mystic Piers site (Lin-
coln 1993). Although common terns have been
observed nesting within Boston Harbor, no evidence
of nesting was present at the Mystic Piers site on
April 28, 1993.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There arc no listed historical or archeological
resources at the Mystic Piers site.
SOCIO-ECONOMIC/LAND USE
The inlet between the Mystic Pier No. 1 and Pier
49 is no longer used for cargo handling at Massport's
A1-35
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Mystic Piers
Moran Terminal in Charlcstown. Charlestown is a
neighborhood within the City of Boston. Recre-
ational vessels docking here in the late 1970s were
removed to accommodate shipping activity. The
recreational docking has not been reinstated even
though the port-related shipping activity ceased to
operate in the inlet. There are no residential areas
abutting this property. The closest residential neigh-
bors are across the Little Mystic Channel in the
Charles Newtowne complex and in the former Navy
Yard.
Charlestown, with a population of 14,731, is a
dense residential community surrounded by industrial
land use on the north and south edges. To the
southeast, the former Boston Naval Shipyard has
been redeveloped into a mixed use complex including
residences, institutions, shops, offices and recreational
facilities. The population of Charlestown is 95%
white. From 1980 to 1990 the population shifted
with a reduction in the percentage of children and an
increase in the 25-44 year age group. This reflects
the new condominiums and apartments constructed
in the Navy Yard and along Main Street. The
median family income is $41,638.
23.1.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
This site would be filled with the dredged material,
capped and converted into an upland area. The silt
sediments placed at the disposal site would be stabi-
lized by a retaining wall and 3 foot cap of clean
sediment. The elevation after filling would be equal
to the adjacent land. Sediment samples collected in
close proximity to this site indicated that the sedi-
ments within the pier are likely to have moderate to
high levels of metals and organics (see Section 4.1 of
the EIR/S). The existing poor sediment quality
would be covered by capping, eliminating the poten-
tial for further dissemination of existing contaminants
into the water column and for further bioaccumula-
tion.
WATER QUALITY AND CIRCULATION
The average current velocity at this site is less than
0.5 knots. In general, water circulation at the Mystic
Pier site is driven by tidal cycles and influenced by
seasonal weather patterns. This should not be
affected by filling of a relatively limited area of
existing lideland. During disposal operations, sus-
pended solids would be released into the Boston
Harbor waters. As a result, there would be localized
and temporary increases in suspended solids concen-
trations in the water column as discussed below. The
use of a dragline at this site would also contribute to
a higher amount of suspended sediment at this site;
however, the use of a silt curtain would trap most of
the suspended sediment. Disposal activity would
occur for a 6- to 9-month period and if controlled
there would be only temporary impacts of the sus-
pended solids concentrations on the water quality in
the vicinity of the site. A sedimentation basin or a
settling pond could be used as a means to mitigate
water quality impacts.
The effects of disposal on the Boston Harbor
water column chemistry are likely to be minor;
mitigativc measures (silt curtains, etc.) would mini-
mJ7.e release of sediment contaminants into the water
column. There should be no degradation of the
Class SC waters.
AQUATIC RESOURCES
In the intertidal zone there would be a permanent
loss in macroalgae, barnacles, and blue mussel
production on the hard substrate (vertical seawalls
and pilings) present at the site. The construction of
a retaining wall across the pier opening would replace
some of that habitat.
A1-36
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Mystic Piers
Bcnthic Infauna
Benthic invertebrates at the Mystic Piers site
would be buried during disposal operations. The
overall high abundance of infauna in at least a
portion of the site contributes to the productivity of
Boston Harbor and these near-surface dwelling
organisms are available as prey items for crab and
dermersally feeding fish. The dredged material placed
at the site would fill the site to the adjacent land
elevation. Therefore, 2.71± acres of soft substrate
would be lost.
Fmfish
Disposal operations would have some impact on
fish at the disposal site. Some displacement and/or
mortality of fish eggs, larvae, and adult fish would
occur during disposal events due to burial or expo-
sure to high suspended sediment levels. Finfish are
likely to use the site for shelter from currents and
predators and for feeding. The anadromous alewife
spawns at the head of tide in the Mystic River, so
reproductive adults migrate upriver past the Mystic
Piers site between April and May. Adults descend
the river during summer. Winter flounder could
spawn in the close proximity to this site from March
to September (Section 4.1 of the EIR/S). Thus,
seasonal disposal restrictions would be enforced at
this site (See Section 3.0 of the EIR/S). Most fish
species would avoid the area during disposal and thus
be displaced; there would be permanent loss of finfish
refuge and foraging habitat.
WETLAND RESOURCES
There would be a permanent loss of 2.71 ± acres of
Land Under the Ocean in a DPA and Tidal Waters
at this site. The impacts for the biological resources
protected are discussed above.
WILDLIFE
Disposal of dredged material at the Mystic Piers
site is not expected to have substantial adverse
impact on wildlife populations (e.g., birds) occurring
near the disposal site because it is not a high quality
environment for their use.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of the Mystic Piers site.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
The proposed project would have no effect upon
any structure or site of historic, architectural or
archcological significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 100 barge trips to the Mystic Piers site. This
would result in some minor delays to commercial and
recreational boat traffic using the harbor; the Coast
Guard would regulate these activities. Construction
activities would have some aesthetic impact, and
result in slightly elevated noise levels.
Filling at this location would not displace any
marine cargo loading or unloading operation. The
active berths with cargo handling equipment at
Moran Terminal are located on the north side of the
site abutting the Mystic River as well as the east side
of the site abutting the Inner Harbor. Since place-
ment of material would occur from the water, there
will be no impact on adjacent streets caused by truck
traffic delivering material to the site.
A1-37
f
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Revere Sugar
The site is depicted on Figure A1-10.
2.3.2.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Bcnthic samples from the interior portions of the
site revealed the sediments to be anoxic silts with an
oily sheen. At the mouth of the site there was a thin
oxygenated layer overlaying anoxic black silts. No
samples were collected within the site boundaries for
sediment characterization, but Stations 1 and 2
sampled along the Mystic River berth at Revere
Sugar (Appendix C of the EIR/S) represent probable
sediment conditions. Contaminant loads in these
sediments were generally high: Category II levels of
chromium and copper; Category HI levels of arsenic,
lead, zinc and PCBs; high levels of total PAHs (18-44
ppm) and total petroleum hydrocarbons. Individual
PAIIs exhibiting particularly high values (> 5 ppm)
were pyrene, phenanthrene, fluoranthene and chry-
sene. TOC values (3-3.6%) indicate that the poten-
tial for bioaccumulation is high.
WATER QUALITY AND CIRCULATION
Tidal flow and land-based discharges to the Mystic
River influence the water quality of the Revere Sugar
site, which is classified as Class SC waters. Dissolved
oxygen experiences August Effect fluctuations at this
site.
Circulation within the Revere Sugar site is gov-
erned by tidal flow and physical structures. The
northeast comer of the site is likely to experience
reduced flows or eddies during flood tide since the
eastern boundary of the site is perpendicular to the
primary flow. Similarly, the northwest corner would
experience reduced flows or eddies during ebb tides.
The pilings across the mouth of the site interrupt
Revere Sugar
linear flow and can reduce current speed, enhancing
the likelihood of sediment deposition. The even
more numerous pilings along the western and south-
ern edges of the site create the same effect in these
areas.
AQUATIC RESOURCES
Habitat conditions were examined at the Revere
Sugar site on April 28, 1993. The intertidal zone is
restricted primarily to vertical excursion on pilings
and walls. The wooden retaining wall along the
eastern boundary and the abandoned pier, on the
southern side supported small quantities of macro-
algae (predominantly Fucus sp. with some green
algae). Barnacles and littorinid snails were present
but not numerous. The barnacle cover increased
along the western pilings towards the mouth. The
granite wall behind the pilings supported some algae
cover {Fucus sp. and green algae). Barnacle cover
was heaviest on the metal pilings at the mouth of the
site. Mussels were observed only at the northwest
comer of the site.
Breaching of the retaining wall along the southeast
portion of the site has allowed erosion into the
aquatic zone, creating a small intertidal zone of
rubble and fine-grained sediments.
Bcnthic Infauna
Benthic infauna was sampled in three locations
(Table A1-2). Nematodes accounted for >80%of
the abundance at Stations RS-1 and RS-2 (98% RS-
1 84% RS2); C. capiiata and oligochaetes were also
numerically important components of the fauna.
Abundances at RS-3 were low, made up primarily of
the cirratulid polychacte Caullariella sp. and nema-
todcs. Species richness at RS-1, near the mouth of
the site, indicates that, at least seasonally, benthic
infauna can be relatively diverse in this site. The
polychactcs present arc primarily surface deposit
A1-38
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feeders, indicative of the stressed sediment conditions.
The tube dwelling amphipod Microdeutopux gryllo-
talpa, is commonly found associated with docks,
algae and mussels (Bousfield 1973). Its presence in
the infauna suggests it is present among the fouling
organisms on the pilings and bulkheads. The paucity
of suspension feeders (e.g., bivalves) indicate that
suspended particulates or siltation rates are higher
than suitable.
Fmfish
As with Mystic Piers, finfish are likely to utilize the
Revere Sugar site for shelter from currents and
predators, and for feeding. Species feeding indiscrim-
inantly on the bottom would encounter prey.
Species that prefer to browse on hard substrates
would find little food, while winter flounder could
spawn in this area, their preferred spawning habitat
(sand) may not occur at this site. Revere Sugar is
located well below the head-of-tide, so does not
provide suitable conditions for anadromous species to
spawn.
WETLAND RESOURCES
The Revere Sugar site is located within the Mystic
RiverDPA(310CMR 10.00). Under Massachusetts
wetlands regulations, most of the site would be
designated as Land Under the Ocean and have the
potential to be significant to marine fisheries, storm
damage prevention and flood control. This site could
provide both refuge (from currents and predators)
and feeding opportunities (primarily for demersal
feeders). It is unlikely to provide spawning habitat
for either winter flounder, as it appeared to lack
sandy sediments, or anadromous species (e.g., ale-
wife), as it is located well below the head-of-tide.
Storm damage prevention and flood control are
enhanced at this site by the man made boundaries,
although the seawall at the southern end of the site
is in disrepair and offers limited protection against
Revere Sugar
exceptionally high tides. The greatest potential for
storm damage prevention and flood control occurs
during low tides.
Intcrtidal resources include a debris strewn beach
in the southeastern corner and the granite walls and
pilings surrounding the site. The beach could be
categorized as Coastal Beach but is not significant in
the DPA. No natural intertidal features exist at this
site.
Under federal regulations, the entire site is catego-
rized as Tidal Waters. This resource provides two
functions not specifically identified by Massachusetts.
for DPAs. The fine-grained character of the sedi-
ments indicates the potential for sediment/toxicant
retention and for nutrient retention/transformation
exists. Aquatic diversity/abundance is moderate at
this site as it appears to vary spatially, being highest
at the mouth. Potential construction at this site may
be more sensitive because of its location on a river
that has an anadromous fish run.
WILDLIFE
Wildlife use of the Revere Sugar site is expected to
be similar to that described for Mystic Piers (Section
2.3.1.1 of this evaluation).
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or anticipated to occur
within the boundaries of the Revere Sugar site
(Lincoln 1993). Although the state-listed common
tern has been observed in Boston Harbor, no evi-
dence of nesting activities of this species were seen
during a site visit on April 28, 1993.
A1-39
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HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeological
resources on or within 1000 feet of the Revere Sugar
site.
SOCIO-ECONOMIC/LAND USE
Revere Sugar, a site containing 6.5± acres in
Chariestown, is currently under lease from Massport
by the MWRA which has constructed a water
transportation facility for the ferrying of construction
personnel to Deer Island. Construction personnel
can park vehicles on the Revere Sugar property
before boarding the ferry to Deer Island. The lease
for the ferry operation runs to 1998. The dock is
located on the west side of the property. The proper-
ty is between two industrial sites and between the
Mystic River and Medford Street. Across Medford
Street are residences and a cemetery. Land side
access to the site from Moran Terminal is via Termi-
nal Street to Medford Street. These streets have
mixed uses.
The neighborhood closest to Revere Sugar has a
very low percentage of people below the poverty line
and a high median family income compared to other
locations in Chariestown.
2.3.2.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
This site would be filled with the dredged material,
capped and would be converted into an upland area.
The silt sediments placed at the disposal site would
be stabilized by a'retaining wall and 3 foot cap of
clean sediment. The elevation after filling would be
equal to the adjacent land. Sediment samples collect-
ed in close proximity to this site indicated that the
sediments are likely to contain high concentrations of
Revere Sugar
metals and organics (see Section 2.2 of the EIR/S).
The existing poor sediment quality would be isolated
by capping and bulkheading, eliminating the potential
for further exposure of contaminants to the water
column and for bioaccumulation.
WATER QUALITY
The average current velocity at this site is less than
0.5 knots. Circulation within the Revere Sugar site
is governed by tidal flow and physical structures.
Disposal activities would occur for a 6- to 9-month
period with some potential for temporary, .impacts
from the suspended solids in the vicinity of the site.
As with other pier sites, silt curtains and other
mitigative measures (settling basin, etc.) would be
necessary to prevent unacceptable levels of suspended
sediments from entering the river and harbor. Partial
bulkheading during site construction and disposal
would help restrict openings to the river and provide
better opportunities for point-source controls.
The effects of disposal on the Mystic River water
column chemistry are likely to be minor. Release of
sediment-borne contaminants into the water column
are expected to be controlled so that there would be
no degradation of the Class SC waters.
AQUATIC RESOURCES
There will be a permanent loss of intertidal sub-
strate and secondary production of macroalgae,
barnacles, and littorinid snails on the hard substrate
(pilings and vertical seawalls). The construction of a
retaining wall across the pier opening would replace
some of that habitat on its outside wall.
A1-40
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Revere Sugar
Benthic Infauna
Benthic invertebrates at the Revere Sugar site will
be permanently buried and displaced during disposal
operations. Nematodes accounted for > 80% of the
abundance, also, C. capitata and oligochaetes were
numerically important components of the fauna. The
dredged material placed at the site would fill the site
to the adjacent land elevation. Therefore, 3.67± acres
of soft substrate would be loss.
Fmfish
Since finfish are likely to use the site for shelter
from currents and predators and for feeding, some
displacement and/or mortality of adult fish would
occur during disposal events due to burial or expo-
sure to high suspended sediment levels. Most fish
species should avoid the area once construction is
initiated. There would be permanent loss of finfish
refuge, foraging, and possibly spawning habitat once
construction is complete.
WETLAND RESOURCES
There would be a permanent loss of 3.67 ± acres of
Land Under the Ocean in a DPA and Tidal Waters
at this site. The impacts on the biological resources
protected under l^nd Under the Ocean (310 CMR
10.00) are discussed above.
WILDLIFE
Disposal of dredged material at the Revere Sugar
site would not adversely impact wildlife populations
(e.g., birds) occurring near the disposal site; loss of
aquatic habitat would occur.
THREATENED AND ENDANGERED
SPECIES
Since no federally or state-listed threatened or
endangered species are identified or expected to occur
within the vicinity of the Revere Sugar site, there
should be no related impacts.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
The proposed project should have no effect upon
any structure or site of historical, architectural or
archcological significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
SOriO-ECONOMlC/LAND USE
The disposal operations would involve approxi-
mately 100 barge trips to Revere Sugar. This would
result in some minor delays to commercial and
recreational boat traffic using the harbor which would
have to be controlled by the U.S. Coast Guard.
Construction activities would have some aesthetic
impact, and result in slightly elevated noise levels.
Any fill on the westerly portion of this site would
eliminate the docking facility recently constructed by
the MWRA. The current lease which runs to 1998
would need to be bought out. Filling out to the
pierhead/bulkhead line on the portion of the site
abutting Somcrvillc Lumber is unlikely to affect the
utility of this site for port shipping in the future
provided that the fill is contained. Since placement
of material would occur from the water, there will be
no construction-related impact on adjacent streets
caused by truck traffic delivering material to the site.
Al-41
Ifl
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Amstar
233 Amstar
The site is depicted on Figure A1-11.
2.33.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Benthic samples collected at Amstar contained
odorless, grey silly sediments. No chemical analyses
were performed on sediments from the Amstar site,
but Station 3 from the Revere Sugar berth was
located approximately 300 feet from the mouth of the
she and is assumed to be representative to on-site
conditions (see EIR/S Section 2.2). That station had
a 73% silt-clay component (Category III). Chromi-
um, copper and nickel all occurred at Category II
levels; arsenic, lead, zinc and PCBs were Category III
concentrations. Total PAI Is were among the highest
(46.41 ppm) observed during the 1992 berth area
sampling. Benzo (b)fluoranthene, benzo(k)fluoran-
thene, fluoranthcne and pyrene each contributed
more than 5 ppm to the total concentration. Total
petroleum hydrocarbons were 3540 ppm. Total
organic carbon was 6.6%, among the higher values
observed during the berth sampling, suggesting that
potential for bioaccumulation of contaminants is
lower at Amstar than other sites in Boston Harbor.
Zinc and PAII uptake may be exceptions to this
generalization, as these constituents were found at
higher levels at Revere Sugar Station 3 than at other
berths.
influenced by two discharges on the southern and
western banks which arc most likely minor discharges
consisting of stormwater. There is also a NPDES
discharge from Cambridge Electric in the vicinity of
the Amstar site (Menzie-Cura and Assoc. 1991).
Amstar opens directly on the Mystic River with no
obstructions. Like Revere Sugar, the northeast
corner of the site may experience reduced flows or
eddies during flood tides as currents are diverted
around the end of the wharf. This phenomenon
would occur during ebb tides at the northwest corner.
The pilings supporting the eastern wharf and the
floating dock slow currents and contribute, to sedi-
mentation under the wharf.
AQUATIC RESOURCES
There arc three types of intertidal habitat occur at
the Amstar site. Pilings and vertical seawalls along
the eastern side provide hard substrate that has been
colonized by barnacles, mussels and green algae.
Beneath the ramp to the floating dock is a small,
gently sloping gravel-cobble beach. The cobble
support green algae. The rest of the south boundary
is a rip-rap slope comprised of boulders that are
heavily covered with Fucus sp. There is little Fucus
sp. on the western rip-rap slope except at the mouth
of the site. Along the western boundary barnacles
and periwinkles (Ltllorina sp.) were numerous; green
algae was present above and below the barnacle zone.
WATER QUALITY AND CIRCULATION
In general water, quality at this site is expected to
be similar to conditions in the Mystic River since
there are no obstructions to flow. Again, the water
quality classification is Class SC. The character of
the sediments observed within this site suggest that it
may experience the late summer hypoxia (August
Iiffect). Water quality on the site may also be
Benthic Infauna
Most of the site is submerged continuously.
Differences in species composition at the two sam-
pling locations (Table A1-2) may reflect differences in
circulation, exposure and adjacent substrate condi-
tions. Species present at Station AM-1 (dominants:
ncmatodcs, Polydora cornuta, oligochaetes) are
typically abundant harbor-wide. Total abundance
Al-42
-------
(18,287/m2) at AM-1 was moderate relative to other
areas sampled. Station AM-2 supported low abun-
dances of several species, two of which (Crangon
seplemspinosa and harpacticoid copepods) are
motile. Sediment at this station was gelatinous, with
an oily sheen.
Finfish
Finfish could utilize this area for refuge from
predators, particularly among the pilings at any tide
and among the Fucus sp. of the southern boundary
during high tides. The entire site could provide
refuge from peak currents due to its orientation
perpendicular to the channel. Anadromous fish
could use the site for this purpose. Subtidal regions
could provide food resources for demersal browsers.
Intertidal food resources arc limited except for fish
that browse green algae.
The Amstar site does not provide spawning habitat
for anadromous species as freshwater input is limited
to three drainage pipes. Winter flounder spawning
opportunities are limited since the site's sediments are
not sandy.
WETLAND RESOURCES
Amstar is located within the Mystic River DPA
(310 CMR 10.00). The site is primarily Land Under
the Ocean, under Massachusetts regulations, and is
considered to be significant to marine fisheries, storm
damage prevention and flood control. As described
under Aquatic Resources, the Amstar site could
provide both refuge (from predators and currents) to
many fish species and feeding opportunities (primari-
ly demersal species). It is unlikely to provide impor-
tant spawning habitat.
Man-made features at Amstar were designed to
contribute to storm damage prevention and flood
control. Surrounding land elevations are several feet
Amstar
above mean high water. The rip-rap slopes along the
southern and western boundaries are effective in
dissipating currents and waves.
The intertidal area under the floating dock ramp
could be categorized as Coastal Beach, but is not
significant in the DPA.
The entire site is classified as Tidal Waters, under
federal regulations. The fine-grained sediments found
at this site, in conjunction with nearby sediment
sampling, suggest that this site has the potential for
sediment/toxicant retention and for nutrient reten-
tion/transformation. Bcnthic fauna were moderate in
abundance and diversity compared to other sites
examined. As anadromous fish species are known to
transverse the Mystic River, it is possible that Amstar
could be used by them as well.
WILDLIFE
Wildlife use of the Amstar site is expected to be
similar to that described for Mystic Piers site.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or 'anticipated to occur
within the boundaries of the Amstar site. The state-
listed common tern has been observed to nest in
Boston Harbor. No nesting activities were observed
during field investigations on this site on April 28,
1993.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical and archeologjcal
resources on or within 1000 feet of the Amstar site.
A1-43
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SOCIO-ECONOMIC/LAND USE
Amstar is an industrial site containing approxi-
mately 20 acres in Charleslown. It is currently
available for sale, although there are several industrial
tenants. One tenant runs a sand and gravel operation
and uses the dock for material transfer. The site is in
the City's Maritime Economy Reserve Zone which
is geared to water dependent activities. It is sur-
rounded by industrial uses to the east and west.
Across Medford Street from the site are residences
and a park. Access to Amstar is the same as that to
Revere Sugar. Demographic characteristics are
similar to those described for Revere Sugar.
2.3.3.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
This site would be filled with the dredged material,
capped and converted into an upland area. The silt
sediments placed at the disposal site would be stabi-
lized by a retaining wall and 3 foot cap of clean
sediment. The elevation after filling would be equal
to the adjacent land. Sediment samples collected in
close proximity to this site indicated that the sedi-
ments within the site are likely to be moderately to
highly contaminated (see Section 4.1 of the KIR/S).
The existing poor sediment quality will be isolated by
capping and bulkheading, reducing the potential of
disseminating contaminants into the water column
and of bioaccumulation.
WATER QUALITY AND CIRCULATION
The average current velocity at this site is less than
0.5 knots. During disposal operations suspended
solids could be released into the Mystic River waters
resulting in localized and temporary increases in
suspended solids concentrations in the water column.
Therefore, the use of a silt curtain at this site would
be appropriate to trap most of the suspended sedi-
Atnstar
ment. Disposal activity will occur for a 6- to 9-
month period; if properly controlled effects from the
suspended solids concentrations on the water quality
in the vicinity of the site should be minimized. A
sedimentation basin or a settling pond may be
necessary to mitigate water quality impacts. There
would be no degradation of the Class SC waters.'
AQUATIC RESOURCES
In the intertidal zone, there would be a permanent
loss in production from barnacles, mussels and green
algae on the hard substrate (pilings, vertical seawalls
and rip-rap) present at the site. The construction of
a retaining wall across the pier opening would replace
some of that habitat. The small gravel-cobble beach
beneath the ramp would also be lost.
Bcnthic Infauna
Benthic invertebrates at the Amstar site will be
permanently buried and displaced from disposal
operations. Nematodes, the polychaete P. cornula
and oligochaeles were typically abundant harbor-wide
and were the abundant species at this site. The
dredged material placed at the site would fill the site
to the adjacent land elevation. Therefore, 3.51 ± acres
of soft substrate would be lost.
Finfish
Disposal operations would impact fish utilization
of this site. Some displacement and/or mortality of
adult fish would occur during disposal events due to
burial or exposure to high suspended sediment levels.
Anadromous river herring could no longer use this
area for refuge. Subtidal regions would not be
available to provide food resources for demersal
browsers. Most fish species could avoid the area of
disposal, but there would be permanent loss of finfish
refuge and foraging habitat (i.e., 3.51 ± acres).
Al-44
-------
Amstar
WETLAND RESOURCES
There would be a permanent loss of 3.51 ± acres of
Land Under the Ocean in a DPA and Tidal Waters
at this site. The impacts for the biological resources
protected under l-and Under the Ocean (310 CMR
10.00) are discussed above.
WILDLIFE
Disposal of dredged material at the Amstar site
would have no substantial impact on wildlife popula-
tions (e.g., birds) occurring near the disposal site,
although there would be permanent loss of foraging
habitat for shorcbirds and waterfowl.
aesthetic impact, and result in slightly elevated noise
levels.
Adjacent to the Amstar site is Revere Sugar which
has an active water transportation facility. Any filling
at the Amstar property would require a bulkhead to
contain material so as to prevent any effect on the
dock at Revere Sugar. Partial filling of the property
would restrict ship to shore transfer of people or
freight including the current sand and gravel opera-
tion. However, it would not restrict marine-related
storage of material. Since placement of material
would occur from the water, there will be no impact
on adjacent streets caused by truck traffic delivering
material to the site. -'
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of the Amstar site; therefore, no
impacts are anticipated.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
The proposed project would have no effect upon
any structure or site of historic, architectural or
archeological significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 130 barge trips to Amstar. The Coast Guard
would have to coordinate any minor delays to
commercial and recreational boat traffic using the
harbor. Construction activities would have some
Al-45
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2.3.4 Cabot Paint
The site is depicted on Figure Al-12.
2.3.4.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Benthic samples collected at Cabot Paint contained
odorless, gray silty sediments. No chemical analyses
were performed on sediments from Cabot Paint site,
but Station 1 of Eastern Minerals was located ap-
proximately 2000 feet from the Cabot Paint site (sec
Section 2.2 of the EIR/S). This station had a 66.5%
sill-clay component with arsenic, chromium, lead,
mercury, zinc and PCB concentrations all occurred at
Category II levels. Total PAIIs occurred at levels
(11.38 ppm), and benzo(b)fluoranthene contributed
3.67 ppm to the total concentration. Total organic
carbon was 3.6%, suggesting some bioaccumulation
of contaminants may likely occur.
The ACOE conducted chemical sampling in 1986
at eight (8) stations (A through II) in Chelsea Creek.
Station G was located in the vicinity of the Cabot
Paint site. It is assumed for this level of site evalua-
tion that the chemical constituents at Station G
should be similar to that of the Cabot Paint site.
Station G had a sandy organic clay composed of
68% fine grained material with a moderate chemical
oxygen demand (102,000 ppm). The only contami-
nant detected in high concentrations was lead at 283
ppm (Category III). Levels of mercury (1.14 ppm),
zinc (276 ppm) and chromium (185 ppm) were
present at Category II.
WATER QUALITY AND CIRCULATION
The Chelsea Creek is classified as SC waters by the
MADEP. Such waters are saline and classified as
suitable for aesthetic enjoyment, recreational boating,
industrial cooling and process use, and as habitat for
Cabot Paint
indigenous wildlife and forage for game fish. Cabot
Paint opens directly into the Chelsea Creek, but the
wooden pilings on the north of this site slow currents
and contribute to some sedimentation in the vicinity
of the pilings.
Dissolved oxygen readings collected in April 1993,
ranged from 8.6 - 9.0 mg/L at water temperatures
ranging from 6.6-8.2° C. Salinity data collected on
that date ranged from 22.6-28.4 ppt at low tide,
indicating the influence of freshwater inputs.
AQUATIC RESOURCES
The intcrtidal habitats within the Cabot Paint site
vary and comprise 1) a sloping rip-rap embankment
on the north side, 2) gravel beaches on the northeast
and northwest sides, 3) the wooden pilings on the
north side, 4) a wooden bulkhead and concrete slab
on the northwest side, 5) an abandoned boat ramp
on the northwest end, and 6) abandoned barges and
boat on the northwest end. Microalgae cover (Fucus
sp. and green algae) varied throughout the site's
intertidal areas. Limited cover was observed on the
rip-rap, while approximately 40% of the gravel beach
was covered. The abandoned boat ramp was also
covered with Fucus sp. The wooden pilings were
completely covered with barnacles and Fucus sp. and
the wooden bulkhead had some of these species.
Benlhic Infauna
The composition of the bcnthic infauna is shown
in Table A1-2. The two sampling locations may
reflect the differences in substrate conditions, circula-
tion, and exposure. Station CP-1 was located in the
vicinity of the submerged pilings, where the most
abundant species were Oligochaeta, S. benedicti, and
Ncmatoda. The total percentage composition of
these three species was 59% at Station CP-1. Total
abundance at this station (of 9,202 individuals/m2)
was moderate when compared with the other areas
A1-46
-------
Cabot Paint
sampled. At station CP-2 (located in an open area
between the pilings) the most abundant species were
S. benedicli and Nematoda. This station had a total
abundance of 3,354/m2, low when compared with the
other stations. The total percentage composition of
these three species was 96% at Station CP-2. Species
richness at both stations was low (5-9).
Fmfish
The ACOE NF,D collected finfish samples by
gUlnct in July and November, 1986 during a 48-hour
effort on two different sampling days in the Chelsea
Creek. The dominant finfish species found in the
July sampling effort were rainbow smelt (Osmems
mordax) and alewife (A. pseudoharengus). In the
November sampling effort, no fish were caught.
Given the limited amount of data for comparison, no
real conclusions can be drawn at this time. Finfish
could use the wooden pilings and Fucus sp. for
shelter from predators during high tide. The sandy
substrate in the Chelsea Creek may provide spawning
habitat for winter flounder (P. americanus) (ACOE
1988).
WETLAND RESOURCES
Cabot Paint is located within the Chelsea River
DPA and primarily contains Land Under the Ocean,
as defined under Massachusetts Wetlands Protection
regulations (310 CMR 10.00). Land Under the Ocean
is considered to be significant to marine fisheries,
storm damage prevention and flood control. The
sloping rip-rap embayment on the north side of the
site was designed for storm damage prevention and
control. The gravel beaches could be categorized as
Coastal Beach, but this designation is not significant
in the DPA.
Many species of marine fishes, including anadro-
mous fish, may inhabit DPAs. Anadromous fish
such as rainbow smelt (O. mordax) and alewife (A.
pseudoharengtts) are known to traverse the Chelsea
Creek. As described in the Aquatic Resources
section, the Cabot Paint site could provide both
shelter from predators and feeding opportunities for
these fish species. This site may also provide spawn-
ing habitat for winter flounder.
The entire site is classified as Tidal Waters under
federal regulations. The fined-grained sediment grain
size and the results of the samples analyzed, indicate
that this site has the potential for sediment/toxicant
affinity and nutrient retention. Benthic infauna
species diversity was low-moderate and species
richness was low at this site.
WILDLIFE
On-sitc wildlife resources appear limited, and very
similar to the Mystic Piers site.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of the Cabot Paint site.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There arc no sites or structures of historical,
architectural or archeological significance as defined
by MI 1C or the National Historical Preservation Act,
as amended.
SOCIO-ECONOMIC/LAND USE
This site, containing 6.5± acres off Marginal Street
in Chelsea is a mixed use parcel, fully occupied by
industrial tenants and a major car rental storage
Al-47
-------
Facility. The current owner has demolished some of
the industrial buildings on site and adapted the
remaining buildings to support several industrial uses.
The wooden bulkhead along Chelsea Creek has
deteriorated and currently poses navigation problems
for vessels traversing Chelsea Creek. A commuter
ferry service to Boston operated briefly out of this
location during 1990 in an effort to reinstate ferry
service from this site, llie service was discontinued.
The City of Chelsea evolved from a summer resort
community to a residential suburb of Boston. A
major lire in 1908, in which over 17,000 residents
•were left homeless, changed the landscape perma-
nently. The Chelsea which emerged from the fire
was primarily commercial with manufacturing and
shipping facilities. Several of the industries have
closed in recent years succeeded by service and
distribution operations. The population of Chelsea
is 28,710 and is 70% white with a high percentage
also reporting Hispanic origin. The median family
income is $29,039. High end residential use has been
developed on property surplused by the military,
contrasting with more modest housing in densely
populated sections of Chelsea.
Access to this site over land is via 1-93 to the
Tobin Bridge to Chestnut Street, and from Chestnut
south to Williams Street, then east on Williams to
Marginal Street.
2.3.4.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
This site would be filled with the dredged material,
capped and converted into an upland area. The
contaminated dredged sediments placed at the dispos-
al site would be stabilized by a retaining wall and 3
foot cap of clean sediment. The elevation after filling
would be equal to the adjacent land. Sediment
samples collected in close proximity to this site
Cabot Paint
indicated that the sediments likely have moderate to
high levels of some chemicals (Section 2.2 of the
FiIR/S). The existing poor sediment quality would be
isolated by capping and bulkheading, eliminating the
potential of disseminating contaminants into the
water column and of bioaccumulation.
WATER QUALITY AND CIRCULATION
The average current velocity at this site is less than
0.5 knots. During disposal operations, suspended
solids could be released into the Chelsea River waters
resulting in localized and temporary increases in
suspended solids concentrations in the water column.
The use of silt curtains in combination with appro-
priate bulkheading at this site would be appropriate
to trap most of the suspended sediment. Disposal
activity would occur for a 6- to 9-month period; if
properly controlled effects from the suspended solids
concentrations on the water quality in the vicinity,of
the site should be minimized. At this site a sedimen-
tation basin or a settling pond may be necessary to
mitigate water quality impacts. There would be no
permanent degradation of the Class SC waters.
AQUATIC RESOURCES
In the intcrtidal zone there would be a permanent
loss in Fucus sp. and barnacle production on the
hard substrate (rip-rap and bulkhead). The construc-
tion of a retaining wall across the pier opening would
replace some of that habitat. The small gravel
beaches on the northeast and northwest side of the
site would be lost.
Iknthic Infauna
Bcnlhic invertebrates at the Cabot Paint site would
be buried during disposal operations. At this site, the
most abundant species were Oligochacta, S. benedicti
and Ncmatoda. The dredged material placed at the
A1-48
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Cabot Paint
site would fill the site to the adjacent land elevation.
Therefore, 5.59± acres of soft substrate would be lost.
Finfish
Disposal operations would impact fish utilization
of this site. Some displacement and/or mortality of
adult fish could occur during disposal events due to
burial or exposure to high suspended sediment levels.
The dominant finfish species in the Chelsea Creek are
rainbow smelt (O. mordax) and alewife (A. pseudo-
harengus). Most fish species would avoid the area of
disposal, but there would be permanent loss of finfish
refuge and foraging habitat.
WETLAND RESOURCES
There would be a permanent loss of 5.59* acres of
Land Under the Ocean within a DPA and Tidal
Waters at this site. The impacts for the biological
resources protected under Land Under the Ocean
(310 CMR 10.00) are discussed above.
WILDLIFE
Disposal of dredged material at the Cabot Paint
site would have no significant impact on wildlife
populations (e.g., birds) occurring near the disposal
site, although there would be permanent loss of
foraging habitat for shorebirds and waterfowl.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of the Cabot Paint site; therefore,
no impacts are anticipated.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
The proposed project would have no effect upon
any structure or site of historic, architectural or
archeological significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 70 barge trips to the Cabot Paint site. TJie
Coast Guard would have to coordinate any minor
delays to commercial and recreational boat traffic
using the harbor. Construction activities would have
some aesthetic impact, and result in slightly elevated
noise levels.
Partial filling at this mixed use property would
isolate sediments already on the site from biological
resources. However, more extensive filling may be
required to accommodate the volume of material.
The additional filling might necessitate adjustments
to current operations on site during the placement
operation. The restoration of the premises to its
previous use after placement of the material may
require special foundation preparation. Thus, there
could be a reduction in land value resulting from the
material being placed on the premises.
Operations on the adjacent parcels should not be
disturbed by the dredge spoil and disposal at Cabot
Paint. I lowcvcr, perception about the containment
of material will be important if the adjacent sites are
to be competitive in the current sluggish market for
industrial land. The seaward bulkhead currently
impedes navigation in Chelsea Creek. Boston
Harbor Pilots would prefer to see the existing bulk-
head pulled landward so as to better facilitate move-
ment through this constricted area. Barges involved
in Filling or repairing this bulkhead could interfere
temporarily with navigation on Chelsea Creek.
Al-49
/I
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Cabot Paint
Access to this site by land entails traveling through
a densely developed urban area comprising residences
interspersed with industrial buildings. Truck traffic is
already heavy in Chelsea because of the convenient
highway access and the resulting siting of distribution
facilities.
A1-50
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Uttle Mystic Channel
2.3.5 Uttle Mystic Channel
The site is depicted on Figure A1-13.
2.3.5.1 Existing Conditions
SEDIMENT CHARACTERISTICS
No samples were collected within the site bound-
aries for sediment characterization, but Stations 2 and
3 at the Mystic Pier sites are in close proximity to the
Little Mystic Channel and should represent probable
sediment conditions. The sediment texture was
predominately fine grained with a range of 76.3% -
78.4% silt-clay (Category II). Bulk sediment metals
test results showed that at Station 2, arsenic, chromi-
um, copper, lead, mercury, and zinc all occurred at
Category II levels (Appendix C). At Station 3,
arsenic, lead and zinc were found to be Category III,
and cadmium, chromium, copper, and mercury were
found to be Category II concentrations. Total PAIIs
ranged from 5.23 and 29.75 ppm at Stations 2 and 3
in Mystic Pier 1. Station 3 contained the highest
levels of metals of the three stations at this site. At
Station 3, benzo(a)anthracene and benzo(a)pyrene,
chrysene, fluoranthene and pyrene were present in
concentrations above 4 ppm. But at Station 2, only
fluoranthene was above 5 ppm. At Mystic Pier 1,
total petroleum hydrocarbon concentrations were
among the highest observed during the 1993 berth
area sampling. At Mystic Pier 1, there have been
approximately twelve minor oil spills (U.S. Coast
Guard, Marine Safety Office, letter dated May 13,
1992). This may have influenced the concentration
of PAIIs and TPIIs at this site. PCBs were present
at Category III concentrations at Stations 2 and 3.
Total organic carbon ranged from 2.1-4.9% at both
stations. This is an average value, indicating that
there are moderate levels of food resources for
benthic deposit feeders, suggesting that some bioac-
cumulation of contaminants may be occurring.
WATER QUALITY AND CIRCULATION
The water quality of the Uttle Mystic Channel is
influenced by tidal exchange, the six discharge pipes
that were observed on the north side of the site, and
a Combined Sewerage Overflow (CSO). These storm
drainage pipes add urban runoff pollutants (e.g., oil
and grease, detergents etc.) into the Channel. There
is one CSO, the Chelsea Street Extension outfall,
which discharges directly to the Little Mystic Chan-
nel on the south shore. The currents in Little Mystic
Channel are primarily lidally driven. The Little
Mystic Channel is classified as SC water by the
MADEP. Such waters are saline and suitable for
aesthetic enjoyment, recreational boating, industrial
cooling, and as habitat for indigenous wildlife and
forage for game fish. Dissolved oxygen readings
collected in April 1993 ranged from 9.0-9.4 ppm. As
temperatures peak in August, available dissolved
oxygen levels diminish within Boston Harbor and
cause a corresponding depression in biological
activity at the sediment water interface (August
Effect). This oxygen depletion contributes to a
significant fauna! depiction on a cyclic basis (Hub-
bard and Bellmcr 1989). Salinity data collected in
April 1993 ranged from 16.8-28.9 % at low tide,
indicating the influence of freshwater inputs to the
I larbor. Little Mystic Channel flows directly into the
Main Ship Channel, but the Mystic-Tobin bridge
pilings slow currents and contribute to some sedi-
mentation in the vicinity of the pilings.
AQUATIC RESOURCES
The intcrtidal habitats within the Mystic Channel
vary and include, 1) vertical granite walls on the
north and south side which contain approximately
80% Fucus sp. and a one-inch layer of barnacles; 2)
sloping rip-rap embankment on the west side which
is covered with Fucus sp. and green algae; 3) wooden
bridge pilings on the eastern side which were covered
with periwinkles (Liltorina sp.), barnacles and green
algae; 4) submerged logs and boat on the north side;
Al-51
-------
5) a metal bulkhead which was covered with Fucus
sp., heavy barnacle settlement, and some mussels
approximately 50 feet from the bridge; 6) a
sandy/gravel beach on the south side which was
sparsely covered with green algae; and 7) a rock ledge
beach on the north side which was covered with
Fucus sp.
BENTH1C INFAUNA
Composition of the benthic infauna at the site is
shown in Table AI-2. The four sampling locations
may reflect the differences in substrate conditions,
circulation and exposure. Station LMC-2, located in
the vicinity of the sloping rip-rap cmbayment, was
most diverse in terms of species composition. The
total abundance of organisms was 27,907 individu-
als/m2 at this station, a moderate level relative to
other harbor areas sampled. Oligochaeta was the
dominant taxon and had an abundance of 13,717/m2.
Station LMC-1 supported low abundance of two
taxa, Catdleriella sp. (86/m2) and S. benedicti (43/m2)
at extremely low levels compared to all the other sites
for these taxa. Station LMC-3 supported a low
abundance of 10 taxa, the most abundant being
Ncmatoda and 5. benedicti. Station LMC-4 had a
low abundance of six taxa, the most abundant being
Nematoda. The sediment samples collected at this
site for benthic infauna observations were fine and
grayish-black in color with a mild sulfur odor.
Finfish
The dominant finfish species recorded in the Main
Ship Channel include winter flounder (P. ameri-
canus), rainbow smelt (O. mordax), and alewife (A.
pseudoharengus) (ACOE, NED 1988). There
probably is movement of at least some of these
species in and out of the Little Mystic Channel.
Finfish could use the wooden bridge pilings, sub-
merged logs and boat and Fucus sp. for shelter from
predators during high tide. The predominant
Little Mystic Channel
sandy/sill sediment present at this site provides
suitable habitat for winter flounder. There is also a
fair supply of C. capitala in part of the channel
(1892/m2 at Station LMC-2); these are consumed by
winter flounder according to Haedrich and Haedrich
(1974).
WETLAND RESOURCES
Little Mystic Channel is located within the Mystic
River DPA (310 CMR 10.00). The site is primarily
land Under the Ocean, under the State regulations,
and is considered to be significant to marinefisheries,
storm damage prevention and flood control. The
vertical granite wall on the north and south side,
together with the sloping rip-rap embayment on the
west of the site, were all structures designed for storm
damage prevention and flood control. Significance to
marine fisheries is discussed above.
Anadromous fish are known to traverse the Main
Ship Channel and there may be movement into the
. Little Mystic Channel. As described hi the Aquatic
Resources section, the Little Mystic Channel could
provide both shelter from predators and feeding
opportunities for several fish species. This site might
also provide spawning habitat for anadromous
species.
The entire site is classified as Tidal Waters under
federal regulations. The fined-graincd sediments
results of the samples analyzed at Mystic Pier, which
is in close proximity to Little Mystic Channel,
indicate that this site has the potential for sedi-
ment/toxicant affinity and nutrient retention. Ben-
thic infauna were moderately diverse in species
composition at one station and showed low abun-
dance at the other three stations sampled at this site.
A1-52
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Little Mystic Channel
WILDLIFE
Wildlife use in the Little Mystic Channel is expect-
ed to be similar to that described at the Mystic Pier
site.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of the Little Mystic Channel.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeological
resources at the Little Mystic Channel site.
SOCIO-ECONOMIC/LAND USE
This little-used channel in Charlestown is sur-
rounded by a mixture of land uses including residen-
tial, recreational and maritime-industrial. The
channel provides a visual buffer between the residenc-
es to the south and the marine terminal to the north.
A public boat ramp is located on the north side of
the channel. However, this ramp has not received
the use anticipated when it was installed in the early
1970s. Demographic characteristics of this area arc
similar to those described at the Mystic Pier site.
Marine access to this site is constrained by the 12
foot vertical clearance under the Little Mystic Chan-
nel Crossing at the mouth of the channel. I^andside
access to this site is via Terminal Street from Moran
Terminal.
2.35.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
Sediments in the Little Mystic Channel contain
moderate to high levels of metal and organic com-
pounds. PCBs, arsenic,lead and zinc were found at
Category HI. The dredged sediments placed at the
disposal site would be stabilized by a retaining wall
and a 3 foot cap of clean sediment. Final elevations
would result in clean, shallow subtidal habitat.
Given its present condition, partially filling it with silt
material would not adversely affect the existing
sediment quality. The degraded sediment quality,.
would be stabilized and improved by capping, reduc-
ing the likelihood of disseminating contaminants into
the water column and of bioaccumulation.
WATER QUALITY AND CIRCULATION
The Little Mystic Channel can be characterized as
a low energy environment, thus making it more
suitable for dredged material disposal and contain-
ment. The average current velocity at this site is
approximately 0.5 knots. During disposal operations,
suspended solids would be released into the Little
Mystic Channel waters. Because of these potential
impacts, use of a silt curtain or other mitigative
methods at this site to contain most of the suspended
sediment would likely be necessary to maintain water
quality standards during construction.
Movement through the water column would
expose and mix the sediment during its descent.
About 5% of released material has been estimated to
remain suspended in the water and transported
outside the disposal site (Truitt 1988). The
ADDAM's model (Appendix F) has been utilized to
evaluate and predict suspended solid impacts at
several of the candidate sites. Reference will be
throughout this evaluation to specific site results as
are relevant. The results for this project site indicated
that those levels may be 3% or less (Appendix F).
A1-53
-------
LJUle Mystic Channel
Although most of the chemical constituents are tied
up with the sediment, there would be some release of
contaminants into the water column. Disposal
activity will occur for approximately a 6- to 9-month
period. Therefore, there would be localized impacts
from the suspended solids and chemical concentra-
tions on the water quality within the site. As men-
tioned above, silt curtains would be appropriate to
contain these materials within the channel until
construction is complete.
AQUATIC RESOURCES
In the intertidal zone, there would be temporary
reduction in Fuctts sp., green algae, and barnacle
production on the hard substrate (granite wall, rip-
rap and bulkhead) present at the site. The small
gravel/sandy beach on the south side of the site
would be temporarily impacted.
Bcnthic Infauna
Benthic invertebrates in the Little Mystic Channel
would be buried during disposal operations. There
would be a temporary loss of 15.0± acres of soft
substrate. Dredged material placed at the site would
quickly be re-colonized by 5. benedicli, oligochaetes,
and other common species occurring in the harbor
sediments. In the Little Mystic Channel, S. benedicli
and oligochaeles were found to range from 0-
13717/m2 and 43-2709/m2 respectively in the 1993
bcnthic analysis. Recolonization should result in a
bcnthic community similar to that presently existing
in the I Jtlle Mystic Channel subtidal areas. Howev-
er, since the cap material would be clean, a more
diverse population could occur.
Siltation caused 'by disposal operations would
probably have some short-term adverse impacts on
invertebrates occurring in the immediate adjacent
areas. However because of the recruitment potential,
no long-term adverse impacts on invertebrate com-
munitics in the shallow subtidal area of the Little
Mystic Channel arc expected; in fact some improve-
ment could occur.
Finfish
Some mortality of juvenile and adult fish could
occur during disposal events due to burial or expo-
sure to high suspended sediment levels. The domi-
nant finfish species in the Main Ship Channel are
winter flounder (P. americamis), rainbow smelt (O.
mordax), and alewife (A. pseudoharengus). There
probably is some movement of these species^into the
Little Mystic Channel. Impacts will be limited to the
immediate vicinity of the disposal site. Disposal of
dredged material would temporarily reduce prey
available to species that feed primarily on benthic
invertebrates, such as winter flounder. Since the
predominant sandy/silt sediment present in the Little
Mystic Channel may provide suitable habitat for
winter flounder, restriction of work and disposal
activities to between June and February could help
minimize impacts to spring migratory and/or spawn-
ing activities. There would be a temporary loss of
finfish refuge until the construction is complete;
foraging habitat should return when recolonization of
benthic fauna occurs (within a year or so).
WETLAND RESOURCES
There would be a short-term impact on 15.0±
acres of Land Under the Ocean also classified as
Tidal Waters at this site. The site would be restored
after construction and maintained as a shallow
subtidal area. The impacts for the biological resourc-
es protected under Land Under the Ocean (310 CMR
10.00) arc discussed above.
Al-54
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WILDLIFE
Disposal of dredged material in Little Mystic
Channel should have no adverse long-term impacts
on wildlife populations (e.g., birds) occurring near the
disposal site. However, there would be a temporary
loss of foraging habitat for some species (e.g., diving
ducks).
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of Little Mystic Channel.
HISTORICAL AND ARCHEOLOG1CAL
RESOURCES
The proposed project would have no effect upon
any structure or site of historical, architectural or
archeological significance as defined by MHC the
National Historic Preservation Act of 1966, as
amended.
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 170 to 224 barge trips to the Mystic Pier.
This would result in some minor delays to commer-
cial and recreational boat traffic using the harbor
which would be controlled by the Coast Guard.
Approximately 11,700 to 15,200 truck trips (assuming
20 cy per truck) would be involved in transporting
the dredged material from the Mystic Pier to the
Little Mystic Channel. There would be some impact
of noise and traffic from these truck trips. Construc-
tion activities would have some aesthetic impact, and
result in slightly elevated noise levels. Given the
industrial'nature of this site, however, these impacts
should not be notably adverse.
Uttk Mystic Channel
While the most direct effect of partial filling of the
channel would seem to be compromising the boat
dock facility, this is not the case because the dock has
not been used for its intended purpose. Partial filling
of the channel would not permanently change the
water view which residents of the Charles Newtowne
housing complex currently enjoy. The residences and
the recreational facility would be sensitive receptors
with the greatest potential for effects from the dispos-
al activity; but, such activities would only be tempo-
rary.
Al-55
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Reserved Channel
2.3.6 Reserved Channel
The site is depicted on Figure Al-14. Two areas
in the Reserved Channel are being evaluated as
candidate sites for disposal, Areas A and B, respec-
tively.
Area A—This area is located at the mouth of the
inlet on the inner side of the bridge (away from
open water). It is approximately 8.9 acres in size
with water depths ranging from 6 to 12 feet. A
floating dock and the yacht club are located in this
portion of the site. The passage under the Summer
Street Bridge is 40 feet in width. Northwest of the
bridge is a vertical granite wall approximately 50
feet in length. Continuing west-northwest, the
granite wall is replaced by a metal bulkhead. On
the far northwestern end of the bulkhead are some
abandoned wood pilings and an old floating dock.
On the southwestern side of the site from the
bridge is a sloping rip-rap embankment for ap-
proximately 50 feet. From this rip-rap toward the
neck arc discarded concrete slabs and trash materi-
al. West of the trash material are wooden pilings
and behind the pilings is a vertical granite wall.
Area B—This portion of the site extends from the
neck on the northwest toward the tip of the penin-
sula. It is .approximately 7.7 acres in she with
water depths ranging from 0 to 16 feet. A steel
bulkhead extends for approximately 75 feet. Con-
tinuing along the western tip and along the south-
western side of the inlet is a sloping rip-rap em-
bankment. Between the bulkhead and the rip-rap
is a pile of rubble. On the southwestern side
toward the neck the rip-rap is replaced by a granite
wall, which is fronted by a rocky beach. In front of
the rocky beach arc one or two sunken boats and
some abandoned pilings. In the middle of the tidal
area is a floating lobster pot dock.
2.3.6.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Benlhic samples collected at the Reserved Channel
contained odorless, gray-black clay/silt sediment. No
chemical analyses were per formed on these sedi-
ments, but Station 3 of the Boston Edison Intake
was located approximately 1000 feet from the Re-
served Channel Area B (see Section 2.2 of the EIS).
This station had a 66.2% silt-clay component (Cate-
gory II) and indicated PCB and PAH levels at
Category III. Fluoranthene, ideno(l,2,3-cd)pyrene,
and pyrene contributed more than 50% to. the total
PAIIs concentrations. Cadmium, Lead, and Nickel
were found at Category II at this station. Total
organic carbon was 13%, the second-highest value of
all the sites analyzed for TOC. This indicates that
the potential for bioaccumulation at the Reserved
Channel Area B is lower than other sites in the
Boston Harbor. The total petroleum hydrocarbon at
this station was 4270 ppm.
The ACOE conducted chemical sampling during
1986 at four stations (A, B, C, and D) in the Re-
served Channel. Station A was located in the west-
ern end of the Reserved Channel close to Area B. At
Station A a 18-23 cm core section was analyzed. It
had a 18.2 cm layer of black organic clay. This
upper organic clay consisted of 93% line grain
material with a moderate chemical oxygen demand
(79,000 ppm). 1 -ead was the only chemical constitu-
ent present at Category III concentrations (221 ppm).
Mercury (1.48 ppm), zinc (264 ppm), chromium (186
ppm), and nickel (58 ppm) were detected at Category
II.
PCB samples were collected at 8 stations by
Boston Survey Consultants in November 1982, from
the Reserved Channel west of Summer Street Bridge
within Area A (MADEP-Boston Files, 1983). PCB
concentrations at all eight stations occurred at Cate-
gory III and ranged from 1.0-34.5 ppm. ,
Al-56
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WATER QUALITY AND CIRCULATION
The water quality of the Reserved Channel is
influenced by the three combined sewerage overflows
(CSO) observed approximately 700 feet northwest of
Pappas Street, at Summer Street, and at I street.
These CSOs can add urban runoff pollutants (e.g.,
PAHs, nutrients, detergents, bacteria, etc.) into the
Channel. Boston Edison has a NPDES discharge
pipe in the vicinity of Summer Street; the NPDES
permit limits the thermal influence on surface waters
in the Reserved Channel.
The Reserved Channel flows directly into the Main
Ship Channel. The Summer Street bridge pilings slow
and deflect currents and contribute to some sedimen-
tation in the vicinity of the pilings.
The Reserved Channel is classified as SC Water by
the MADEP. Such waters are saline and suitable for
aesthetic enjoyment, recreational boating, industrial
cooling, as habitat for indigenous wildlife, and forage
for game fish. In both Areas A and B, dissolved
oxygen readings collected in April ranged from 8.4-
8.7 ppm and 6.8-8.9 ppm respectively. As tempera-
tures peak in August in Boston Harbor, available
dissolved oxygen levels can diminish and cause a
corresponding depression hi biological activity at the
sediment water interface (August Effect). This oxygen
depletion contributes to a significant faunal depletion
on a cyclic basis (Hubbard and Bellmer 1989).
Salinity data collected in April 1993, ranged from
27.0-31.2 ppt at Area A and 23.4-33.4 ppt at Area B
during low tide, indicating the influence of freshwater
inputs to the Harbor.
AQUATIC RESOURCES
The intertidal habitats within the Reserved Chan-
nel include:
Area A:- Wooden bridge pilings and a floating
yacht club dock which were sparsely covered with
Reserved Channel
green algae. A vertical granite wall on the north-
west side of Summer Street which was covered
with approximately 20% of algae. A metal bulk-
head on the northwest side which was covered
with green algae and barnacles. Sloping rip-rap
embankment on the southwest side which was
covered with Fucus sp., barnacles, Ultornia sp.,
and green algae. Some concrete slab and trash
material was present which had no visible growth;
there were some abandoned wooden pilings and an
old floating dock on the far northwestern side.
Area B:- A steel bulkhead on the northwest side
which was approximately 90% covered with
barnacles. A sloping rip-rap embankment on ihe
western tip and southwestern side which was
moderately covered with Fucus sp., Enteromorpha
(tubular green algae), and other green algae. A
granite wall on southwestern side towards the
narrow neck which had moderate growth of Fucus
sp., Ulva sp., and barnacles. A rocky beach in
front of the granite wall was sparsely covered with
Liitornia sp., Fucus sp., and green algae. There
were also sunken boats, abandoned pilings and a
floating lobster dock present.
Bcnthic Infauna
The composition of the benthic infauna is shown
in Table A1-2. The four sampling locations may
reflect the differences in substrate conditions, circula-
tion and exposure. Stations RC-1 and RC-2 were
located in Area A and RC-3 and RC-4 located hi
Area B.
Area A:- Station RC-2 was located in the vicinity
of the Granite wall on the southwestern side of
Area A, had the most diversified species composi-
tion. Oligochacta and 5. benedicti was the two
most abundant taxa (15,480/m2 and 1548/m2,
respectively) of all the sites sampled. The total
abundance was 21,156/m2 at Station RC-2 which
was moderate relative to other areas sampled.
A1-57
-------
Reserved Channel
Station RC-1 supported low abundance of seven
species, the most abundant being Oligochaeta
(2451/m2). Oligochaetes were was moderately
abundant at this site compared with all the other
sites. The total abundance was 3,096/m2 at Sta-
tion RC-2, and was low relative to other areas
sampled.
Area B:- Station RC-3, located in the vicinity of
the lobster dock, supported very low abundance of
four taxa, the most abundant being 5. benedicli
(215/m2). At Station RC-4 Oligochaeta
(26,574/m2), Corop/ihan insidiosum (2580/m2),
and Nematoda (16,641/m2) were the most abun-
dant taxa. The first two taxa reached their maxi-
mum abundance at this site of all the sites sam-
pled. The total abundance at Station RC-4 was
49,837/m2, fairly high relative to the other areas
sampled.
The sediment samples collected at this site for
benthic infauna observations were odorless, clay/silt,
and grayish black in color.
(310 CMR 10.00); this classification is considered to
be significant to the protection of marine fisheries,
which are discussed above. Nearshore areas of Land
Under the Ocean such as Areas A and B are likely to
be significant to storm damage prevention and flood
control. The vertical granite wall and bulkhead,
together with the sloping rip-rap embankment at the
site, were all structures designed for storm damage
prevention and flood control. Nearshore areas of
l,and Under the Ocean also provide important food
for birds; for example, waterfowl can feed on the
algae. The sloping rip-rap embankment and the
rocky beach (Coastal Beach) at this site were covered
with algae. •,.'•'
/'
The entire site is classified as Tidal Waters under
federal regulations. The fined-grained sediment and
chemical levels in the samples analyzed show that
this site has had an affinity for toxicant and nutrient
retention. Benthic infauna were moderately diverse
in species composition at two stations and showed
low abundances and species richness at the other two
stations sampled at this site.
Finfish
The dominant finfish species in the Main Ship
Channel are flounder (P. amcricanus), rainbow smelt
(O. mordax), and alewife (A. pseudoharengus).
There may be movement of these species into the
Reserved Channel. Finfish may use the wooden
bridge pilings, floating dock, and Fucus sp. for shelter
from predators during high tide. The Reserved
Channel may provide spawning habitat for winter
flounder, although it lacks the preferred substrate.
WETLAND RESOURCES
Areas A and B of the Reserved Channel are not
located within a Designated Port Area (310 CMR
10.00). The site is primarily I^and Under the Ocean
under Massachusetts Wetlands Protection regulations
WILDLIFE
Wildlife use at the Reserved Channel is expected to
be similar to that described for Mystic Piers (Section
2.3.1.1 of this evaluation).
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of the Reserved Channel.
A1-58
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Reserved Channel
HISTORICAL AND ARCIIEOLOGICAL
RESOURCES
There are no listed historical or archeological
resources at the Reserved Channel site.
SOCIO-ECONOMIC/LAND USE
This channel is generally surrounded by industrial
and office uses in South Boston. There is a sewer
outfall at the southerly end of the Channel which
would require relocation if this area were to be filled.
There is a yacht club immediately adjacent to the
Summer Street Bridge, and a passive water viewing
area has been created for the general public to use on
the west side of the channel. This viewing area is not
6(f) land because it was not purchased or improved
with funds from the I^nd and Water Conservation
Act (16 USC 460). As noted earlier there is a float-
ing lobster pot dock in the middle of Area B; the
extent of its use is not known.
While the South Boston peninsula was settled
early in Boston's history, much of the land area
between the subject site and Boston Harbor was
created by filling the tidal flats. The filled land
supported maritime shipping and railroad terminal
uses. The area to the south of the channel has
traditionally been a densely populated, predominantly
residential neighborhood. The population of South
Boston is 29,464 of which 96% is white. The
median family income in the subject area is $34,200.
Marine access to this site is restricted by the
vertical clearance on the Summer Street Bridge over
the Channel. That clearance is only 6 feel at high
tide. The most direct landside access would be 1-93
south to Summer Street and then east to the Re-
served Channel.
2.3.6.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
Samples collected in close proximity to Area B
(the only samples for this area) indicated that lead
was the only chemical present at Category HI con-
centrations; mercury, zinc, chromium and nickel were
detected at Category II levels by ACOE in 1986.
The silt sediments placed at the disposal sites would
be scaled with a 3-foot cap of clean sediment; final
elevations would create shallow subtidal habitat at
Areas A and B. Thus, the existing poor sediment
quality would be isolated and improved by capping,
preventing the dissemination of contaminants into
the water column and of bioaccumulation. Benefits
from this alternative include holding the silt material
within the channel, and reducing the amount of silt
exposed to biological resources within the harbor.
WATER QUALITY ANT> CIRCULATION
Areas A and B of the Reserved Channel can be
characterized as low energy environments suitable for
dredged material disposal and containment. During
disposal operations, suspended solids would be
released into the Reserved Channel waters. As a
result, there would be localized and temporary
increases in suspended solids concentrations in the
water column in this area. The use of a silt curtain
and other mitigative measures would be necessary to
contain most of these suspended sediments until
construction is complete. Because of the open end of
the channel at the outer perimeter of Area A, more
extensive engineering controls may be necessary to
keep water quality levels at acceptable levels in the
outer Reserved Channel and the Main Ship Channel
during construction. Temporary isolation of the
disposal area may be necessary, if feasible.
A1-59
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AQUATIC RESOURCES
Area A - There would be a temporary reduction in
green algae, barnacles, Fucus sp., barnacles and
IMtorina sp. production on the hard substrate
(wooden bridge pilings, vertical granite wall, metal
bulkhead, sloping rip-rap, and concrete slab) in the
intcrtidal zone.
Area B - In the inlertidal zone there would be
temporary reduction in Fucus sp., green algae, and
barnacle production on the hard substrate (steel
bulkhead, rip-rap, and granite wall) present at the
site. The small rocky beach in front of the granite
wall on the southwestern side of the site would be
temporarily impacted.
Bcnthic Infauna
Area A - Benthic invertebrates in Area A of the
Reserved Channel would be buried during disposal
operations. There would be a temporary loss of
8.94± acres of soft substrate. Dredged material
placed at the site should quickly be colonized by S.
benedicti, oligochaetes, and other common species
occurring in the adjacent harbor sediments. Area
A had the most diverse species composition of all
the sites sampled, with oligochaetes found to be
the most abundant taxon (15,480/m2).
Area B - Benlhic invertebrates in Area B of the
Reserved Channel would be buried during disposal
operations. This area supported low to moderate
abundances of taxa including 5. benedicti, Oligo-
chacta, and Nematoda. There would be a perma-
nent loss of 7.66 acres of subtidal substrate.
However, with tidal flushing, intertidal benthos
would become established.
Siltation caused by disposal operations would
probably have some short-term adverse impacts on
invertebrates occurring in adjacent subtidal and
intertidal areas. However, no long-term adverse
impacts on invertebrate communities in the shallow
Reserved Channel
subtidal area of Area A in the Reserved Channel are
expected; the area should recolonize to a similar or
better habitat. Subtidal habitat in Area B will be lost
and replaced with saltmarsh. Thus, a resource with
different species composition and different functions
and values would result; this habitat would be of
high value in Boston I larbor.
Finfish
Some displacement and/or mortality of juvenile
and adult fish would occur during disposal events due
to burial or exposure to high suspended sediment
levels. The dominant finfish species in me Main
Ship Channel are flounder (P. americanus), rainbow
smelt (O. mordax), and alewife (A.pseudoharengus).
There probably is movement of at least winter
flounder into the Reserved Channel. Impacts should
be limited to the immediate vicinity of the disposal
site. Disposal of dredged material in Area A, which
would remain subtidal would reduce prey available to
species which feed primarily on benthic invertebrates,
such as winter flounder, at least until recolonization
occurs (estimated at a year or so). In Area B, which
would be replaced with salt marsh, there would be
permanent loss of finfish refuge and foraging habitat.
Salt marsh habitat may provide temporary refuge and
forage habitat during high tides.
WETLAND RESOURCES
Area A - There would be a short-term impact on
8.94± acres of I^and Under the Ocean (and Tidal
Waters) at this site. The site would be maintained
as a shallow subtidal area after construction.
Area B - There would be a permanent loss of
7.66± acres of Land Under the Ocean and Tidal
Waters. The impacts for the biological resources
protected under Land Under the Ocean (310 CMR
10.00) arc discussed above. Converting Area B
A1-60
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Reserved Channel
into a salt marsh would provide 7.66± acres of
valuable out-of-kind wetland resource replacement.
WILDLIFE
Disposal of dredged material in Areas A and B
should have no long-term adverse impact on wildlife
populations (e.g., birds) occurring near the disposal
site. Temporary displacement impacts would occur
during construction while the site is disturbed.
Converting Area B into a salt marsh would provide
new habitat for various wildlife species.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of Areas A and B.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
The proposed project would have no effect upon
any structure or site of historic, architectural or
archeological significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
activities would have some aesthetic impact, and
result in elevated noise levels.
The impacts of disposal at this location should be
limited to water dependent uses in the Channel. The
value of surrounding industrial land is already affect-
ed by high PCB levels in the Channel, and the
engineered placement of sediments should have a
positive benefit by isolating these sediment from
biological resources. The sewer outfall would require
relocation. Depending on the extent of fill material
placed in this portion of the channel, the yacht club
operation may be affected. Construction may have
to be timed to avoid the period of maximum dock/
usage (summer). The yacht club boats could have a
draft problem if fill material is not carefully placed
and avoided in certain areas. If any fill is placed in
the yacht club area, it would prohibit future dredging
of that area and/or any future expansion of the dock
areas.
The Summer Street Bridge poses a major con-
straint to access to the site by water. Because of the
6-ft vertical clearance, access must be timed to
accommodate the tide. Access over land using
Summer Street will send truckers through the con-
gested Dewey Square area of Downtown Boston.
Further, South Boston residents object to the use of
Summer Street as a regular truck route. A more
circuitous route might be required to reach this
destination over land.
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 25 barge trips to the North Jetty for Area A
and 110 for Area B. This would result in some
minor delays to commercial and recreational boat
traffic using the harbor. A total of 1,800 truck trips
would be involved in transporting the dredged
material from the North Jetty to Area A, and 8,000
to Area B. There would be some impact of noise
and traffic from these truck trips. Construction
Al-61
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In-Channel Areas
2.4 SITE EVALUATIONS: IN-CHANNEL
AREAS AND BORROW PITS
2.4.1 In-Channd Areas
2.4.1.1 Existing Conditions
The In-Channel disposal scenario is simply the
placement and capping of dredged material within the
channel/tributary from which it had been dredged.
Silt and sedimentation would be dredged from each
channel, placed on a barge, a deeper trench would
then be dug in the channel, and the silt and sediment
placed within the trench and capped. The proposed
use and methods are described in more detail in
Section 3.0 of the EIR/S. Each channel/tributary
would contain its own silt material and be capped
therein. As the environmental resources and conse-
quences for this disposal alternative are the same as
for the dredging site, the existing conditions of the
water and sediment quality, biological and socio-
economic environment in each site are described in
the Section 3.0 of the EIR/S.
The sediment characteristics of parent material
with the channels have been described in Section 2.2;
bulk sediment analysis indicated that no parameter
exceeded Category I limits. The remaining parent
material (after capping) would be disposed at the
MBDS or other suitable site. Since the channels are
already filled with the silt material, returning it to its
place of origin and capping it would provide an
environmental benefit by isolating the material more
or less in-place. The substrate surface would change
from a silty material to a clay and/or gravel material.
The bcnthic community may change slightly but
should be healthier as the chemicals of concern
would no longer be available to the biological com-
munity. No federally or state-listed threatened or
endangered species have been identified to occur in
the channel and tributaries, so adverse impacts are
not expected.
This disposal alternative would have no effect
upon any structure of historic or archeological
significance as defined by MI 1C or the National
Historic Preservation Act of 1966, as amended.
2.4.1.2 Environmental Consequences
General site conditions would be the same as
described for each channel/tributary; the end result is
still each channel dredged to the proposed full project
depth. However, the channel bottom would consist
of a cap under which would lie the silt material.
The proposed disposal sites occur in tributaries
currently used by ship traffic. Coordination (by the
Coast Guard) between ships needing to use the
tributary and disposal activities (including dredging
and barge storage of the silt) would need to occur to
minimize interference with shipping traffic. The cap
would be of sufficient thickness to sustain disturbance
from ships and storms.
A1-62
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Spectacle island CAD
2.4.2 Spectacle Island Confined Aquatic
Disposal (CAD)
The site is depicted on Figure A I-15 herein.
2.4.2.1 Existing Conditions
SEDIMENT CHARACTERISTICS
The CA/T project examined sediments in and near
this area with ponar grabs and borings to characterize
the surficial material and underlying sediments
(Cortell 1990b) (Table A1-3). Surface sediments
tended to form broad areas of uniform grain size.
Fine sand (with some silt) predominated in a 500-
foot band following the northeastern shoreline to
about mid-island, 300 feet beyond MLW and re-
curred beyond the mussel bed several hundred feet
further south. From mid-island and beyond the
southern sand band, sediments were primarily silty,
with some clay. Seaward of these areas, surface
sediments were clay with some silt (Cortell 1990b).
Bulk sediment analysis of borings indicated that
surface and near surface sediments offshore of the
eastern shoreline of Spectacle Island were generally
free of contaminants (Cortell 1990b). Three of the
five borings (ST1-7, ST1-9, ST1-II; Table A1-3) in
the area proposed were classified as Category I under
the Massachusetts criteria for the classification of
dredged materials, although volatile solids at ST1-11
were within the Category II range (7-9 ppm) (Table
A1-3). lilevated levels of arsenic, a naturally occur-
ring metal in New England soils, caused surface
sediments at ST1-8 and ST1-12 to be classified as
Category II (12-20 ppm); subsurface concentration of
arsenic resulted in Category HI ( > 20 ppm) classifica-
tion of sediments below one foot at ST1-8 (Appendix
C-l; Table 2 of the Sampling Plan). Because of
these findings, the proposed disposal location has
been designed to involve only those areas where
Category I sediments were recorded (see Figure Al-
15).
WATER QUALITY AND CIRCULATION
The hydrodynamics around Spectacle Island were
examined for the CA/T (Cortell 1990b). Circulation
is dominated by tidal currents, affected by the distri-
bution of islands and channels in the Outer Harbor.
Ebb tide currents passing the east side of Spectacle
Island can reach 0.6 knots on spring tides, while
spring flood tides reach 0.4 knots. The broad shallow
subtidal area off the eastern shore diverts currents
toward the channels (President Roads to the north;
Sculpin Ixxlge to the southeast). The area proposed
for the. CAD is subjected to lower tidal currents
created by eddies. Waves in the vicinity of Spectacle
Island arc primarily storm driven. The maximum
fetch for Spectacle Island is 7.1± nautical miles.
Wave energy for the area was calculated for the
Massport I^Jgan Inclined Safety Area (ISA) EIR for
storms with wind velocities from 10 to 50 knots.
The wave breaker height near Spectacle Island ranged
from 0.09 to 2.60 feet with wave powers of 0.1 to
412.9 ft-lb/sec.
The waters in the vicinity of Spectacle Island have
been classified as Class SB waters. This classification
protects saline waters for the propagation of marine
life, primary and secondary contact recreation and
shellfish harvesting with depuration. Water quality in
the outer harbor area historically has been influenced
by raw sewage discharges, CSO's, various industrial
discharges, urban runoff and the pollutants flowing
from the inner harbor system. I lowever, as upgrades
to treatment processes are completed, water quality
in the harbor has, and will continue to improve.
AQUATIC RESOURCES
Bcnthic Infauna
Bcnthic resources east of Spectacle Island were
examined for the CA/T project (Stations 6, 7, 9, 10;
Cortell 1990b). Comparison of stations (through
A1-63
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Spectacle Island CAD
duster analysis) indicates that these stations were
similar in terms of species structure (Battelle 1988).
The faunal community was dominated by the tube
dwelling amphipod Arnpelisca dhdila (37%) and the
gastropod Nassarius Irivittalus (20%), reflecting rela-
tively clean, sandy sediments. Nephtyid polychaetes
(Nephtys caeca and N. ciliata) were also numerically
important at these stations. Total abundance (rang-
ing from 653-3107/m2) was low compared to other
sandy areas (Massachusetts Bay) and silty areas of
the Inner Harbor (up to 241,230/m2). Station 10, off
the northeast shoreline of Spectacle Island, had the
highest abundance and number of taxa of the 11
stations sampled around the island. Larger fauna
were evaluated qualitatively along transects swum for
lobster investigations (Transects 3 and 4 reached the
shoreward portions of the proposed CAD site;
Cortell 1990). In addition to Nassarius sp. and
Arnpelisca sp. the offshore portions of these transects
supported nereid worms (sand worms), Pagurus sp.
(hermit crabs), Panopeus sp. (mud crabs) and Cancer
irroratus (rock crabs).
The purpose of the lobster transects was to quanti-
fy lobster use of the area and evaluate the substrate
for use or potential use by early bentbic phase
lobsters, considered to be a vulnerable stage for this
species because of limited habitat availability (Wahle
and Stcncck 1991). CA/T transects I (southern-
most), 2, 3, 4 and 5 (northernmost) were located
along the east side of Spectacle Island (Cortell 1990);
transects 3 and 4 were within the area proposed for
the CAD. Free-living lobsters were most abundant
off the north shore of Spectacle Island (Transect 5
yielded 0.0027/ft2; Transect 6 yielded 0.0035/ft2);
Transect 3 yielded the third highest abundance
(0.0022/ft2). Abundances along Transects 1,2 and 4
were low (0.0003-0.0004/ft2). These average abun-
dances, however, do not account for the fact that
lobsters were concentrated towards the deeper end of
all transects except Transect 3. Lobster pot markers
were present in the proposed site during all three
surveys in 1990. Pot markers tended to be most
heavily concentrated off the northern shoreline of the
island and farther east of the island in Sculpin Ledge
Channel (Cortell 1990a).
During a lobster monitoring program run from
early May to early July, 1992 in the Harbor, Cortell
(1992) reported that an average of five lobsters
(average catch per 3-day haul, all size classes) per
trap were collected at a station just to the north of
Spectacle Island, the southern side of the ship chan-
nel. This catch was typical of several other stations
in this study. Other trawl sampling indicated that
abundances were generally lower at a site (closest to
Spectacle Island) just north of the Ship Channel in
President Roads, compared with four other;'stations
in the channel area. I^obstermen do fish/this area
along the edge of the channel between Spectacle and
Ixuig Island.
No early benthic phase (EBP) lobsters were found
in samples collected along lobster transects. The
preferred cobble substrate (Wahle and Steneck 1991)
was common only along the nearshore portions of
Transects 1 and 5. Mussel beds may also enhance
substrate suitability (Wahle and Steneck 1991).
Mussel beds occurred along the nearshore portions of
Transects 2, 4 and 5. It was speculated that the
anoxic sediments underlying these mussels would
preclude use by EBP lobsters (Cortell 1990b). The
borings collected offshore of these transects indicated
that sediments were fine-grained, unsuitable for EBP
lobsters (Cortell 1990b)!
Finfish
Based on the on-going development of the artificial
reef design, as required by the Individual Per-
mit— I xuidfill Closure and Maintenance at Spectacle
Island for CA/T (ACOE no. 199202207; 2/16/93),
target fish species in the Spectacle Island area include
forage species such as Atlantic merhaden, Atlantic
herring and rainbow smelt, and predator species such
as winter flounder, striped bass, bluefish, pollock,
Atlantic cod, tautog and cunncr. The northeastern
Al-64
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Spectacle Island CAD
half of Sculpin l-edge Channel is the recommended
location for the proposed terrace reef (NAI 1993).
WETLAND RESOURCES
The Spectacle Island CAD location is considered
Land Under the Ocean under the Massachusetts
Wetland Protection Act (310 CMR 10.00) and Tidal
Waters under the Federal Clean Water Act (40 CFR
230). As Land Under the Ocean, the site is consid-
ered to be significant to the protection of marine
fisheries, protection of land containing shellfish,
storm damage prevention, flood control and protec-
tion of wildlife habitat. This area has been demon-
strated to provide habitat for free-living, but not early
benthic phase, lobsters and juvenile rock crabs
(Cortell 1990b). Active use of the area by finfish has
not been examined but is likely to occur to some
degree for feeding (although benthic fauna is sparse)
and passage. Waterfowl may feed in this area.
Portions of the nearshore area of Spectacle Island are
classified as l,and Containing Shellfish (mussels).
The proposed subtidal location of Spectacle Island
CAD, intercepts the tidal currents from the channels,
reducing their intensity. This increases deposition
offshore from the shellfish beds, protecting them
from excess siltation. Shoreline erosion is reduced by
the reduction in currents. Storm energy is dissipated
by the shallow subtidal expanse cast of the island.
Because this is an open water area, however, the
shore east of Spectacle Island provides little flood
control.
Classified as Tidal Waters under federal regula-
tions, Spectacle Island CAD was evaluated for its
ability to provide the functions of sediment/toxicant
retention, nutrient retention/transformation, recre-
ation and uniqueness/heritage. Sediment sampling at
this site revealed only low levels of chemicals and
low-to-moderate levels of fine-grained sediments.
However, reduced currents provide Spectacle Island
CAD with greater potential for performing the
functions of sediment/toxicant retention and nutrient
retention/transformation than the adjacent channel
areas. It is likely that recreational boaters with
shallow-draft vessels cross this area. Human use of
the island will increase once park development is
underway.
WILDLIFE
Waterfowl, including great cormorant (Phalacroco-
rax carbo), herring gull (Larus argentatus), white
winged scoter (Melanllta deglandi), common golden-
eye (Kucephala clangula), bufllehead (Bucephala
albeola), mallard (Anas platyrhynchos), black duck*'
(Anas ntbripes), merganser (Mergus spp.) and scaup
(Aylhya spp.) have been observed in the vicinity of
Spectacle Island (Cortell 1990a). Each of these
species feed on fish and invertebrates (Martin et al.
1951; Whitlatch 1982; DeGraaf and Rudis 1986) that
occur in the area proposed for Spectacle Island CAD.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the immediate vicinity of Spectacle Island
CAD. Common terns have nested on a dilapidated
pier on the northwestern end of Long Island, approx-
imately 0.6 miles away, across Sculpin Ledge Chan-
nel. All marine mammals are protected under the
Federal Marine Mammals Protection Act. Harbor
seals (Phoca vilulina), harbor porpoises (Phocena
pkocena) and grampuses (Grampus griseus) occur
occasionally in the harbor. None of these species are
listed as threatened or endangered. There are no
natural occurrences of exposed ledge that would be
suitable as seal haul-outs in the vicinity of Spectacle
Island CAD.
A1-65
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Spectacle Island CAD
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There arc no listed historical or archeological
resources at the Spectacle Island CAD site.
SOCIO-ECONOMIC/LAND USE
Activities at the subtidal area east of Spectacle
Island would be visible from Spectacle Island, Long
Island, and Deer Island as well as from vessels using
Sculpin Ledge Channel and President Roads. Cur-
rently public access to Spectacle Island and Long
Island is limited although park development on
Spectacle Island is expected to begin in 1995. Vessels
using President Roads are predominated by commer-
cial ships, whereas Sculpin Ledge Channel is actively
used by fishing vessels and pleasure boats.
This location is currently used only by fishermen
and recreational boaters. The site is less than 1000 ft.
from the proposed dike which the Massachusetts
Highway Department intends to construct as part of
its closure of the abandoned landfill at Spectacle
Island.
2.4.2.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
Bulk sediment analysis of borings at Spectacle
Island indicates that surface and near surface sedi-
ments offshore of the eastern shoreline of Spectacle
Island were generally low in contaminant levels
(Cortcll 1990a). "Hie dredged sediments placed at the
disposal site would be stabilized by a 3-foot cap of
clean sediment which would render surface sediment
quality in the disposal site cleaner than existing
conditions. The cap eventually will be buried by fine
sediments deposited by natural processes. Contami-
nated dredged material placed in open-water disposal
sites may be chemically and/or biologically isolated
by capping with clean dredged material (Tmitt 1985).
The cap and the dredged sediments would be
confined within the walls of the pit below the level of
the harbor floor. Therefore in the long term, a
deposit in a capped pit would be less likely to release
contaminants because it is not in direct contact with
the water column. Even more important, because of
this site's location in an area of active deposition, it
is less likely that its contaminant-laden sediments
could be lost through natural erosion (current action)
or extraordinary storm events. Therefore, the site
vulnerability to storms should be negligible,because
of the added protection of greater depth 6f the pit
and the pit walls (Bokuniewicz et al. 1981).
There should be no significant impact on the
sediment quality in the vicinity of Spectacle CAD site
as a result of the disposal of the dredged material at
the borrow pit.
WATER QUALITY AND CIRCULATION
In the vicinity of the Spectacle Island, circulation
is dominated by tidal currents. The ebb tide currents
flowing on the east side of the island range from 0.4-
0.6 knots. During the course of the new pit con-
struction, it is anticipated that turbidity levels in and
around the immediate construction area would be
increased by the dredging. The turbidity plume so
generated would be restricted to a very limited area in
the vicinity of the dredge, with 95-99% of the sus-
pension material settling within a few yards (Schubel
ct al. 1978). It is unlikely that the construction
process would increase sedimentation in the vicinity
as the material would be mostly sand, and the new
hole itself would serve as a sink for suspended
materials. In addition, an environmental bucket may
be used during this process.
During the disposal operations in open water,
suspended solids would be released into the sur-
Al-66
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Spectacle Island CAD
rounding waters. The dredged material would be
released from a barge above the borrow pit. It would
descend through the water column as a dense mass.
During this descent anywhere from 1 to 5% of the
dredged material may be lost to the water column
(WES 1986). Movement through the water column
would expose and mix the sediment during its de-
scent. As a result, there would be localized and
temporary increases in suspended solid concentra-
tions in the water column.
The ADDAM'S model (Johnson 1990; see Appen-
dix F) was used to examine the spatial extent of
potential water quality impacts from disposal at this
CAD site. Since currents in the adjacent Sculpin
Ledge Channel appear to run 0.4 and 0.6 kn during
maximum flood and ebb tides (Cortell, 1990a),
respectively, these were used in the model; however,
since the CAD site is in an eddy area, a lower current
regime was run as well (Table A1-4). An important
point to remember, however, is that the model
simulation is for level bottom; in reality, the disposal
would be into a borrow pit approximately twice as
deep as the overlying water depth at MLW. This
physical restriction will help contain settling sedi-
ments and associated silt plumes. With this in mind,
the result in Table Al-4 may be worst case. These
results estimate that the silt cloud (at a depth of 6 ft
and approximately 1990 ft in diameter) from a single
disposal event would be below the water quality
criteria at a distance of approximately 9,000 ft (during
maximum flood tide) and 13,000 ft (during maximum
ebb tide) from the disposal site. At half this velocity,
which is more typical of the CAD area, these distanc-
es would be half as far. Given the current directions
within this area, silt clouds during ebb tide would
flow into the Main Ship Channel and toward the
mouth of the Harbor. During flood tides, they
would flow southwest through Sculpin Ledge Chan-
nel toward the area east of Thompson Island.
However, given the expected depth of the pit (20
feet) compared to the depth of the overlying water
(9-11 ft at MLW) much of the silt should settle to
within the confines of the hole before it is spread to
the distances predicted by the ADDAM'S model.
Generally, the common methods of open water
disposal do not alter the chemical properties of the
dredged material, and therefore do not break the
bonds that hold contaminants to sediment particles
(Burns and Schubel 1983; Bokuniewicz et al. 1986).
The binding of pollutants to sediment particles
(particularly the fine-grained organic and/or clay
components) tend to immobilize the contaminants
and prevent their release to the water column
(O'Connor and O'Connor 1983). As a result, any
sediment that may remain suspended after the main
deposit reaches the bottom would not likely release
its bond contaminants to the water column. This is
consistent with field studies at disposal sites in New
York Harbor conducted by the Army Corps of
Engineers-New York District; none have ever detect-
ed a significant increase in contaminant or nutrient
level in the water at disposal sites (ACOE 1984;
Bokuniewicz ct al. 1986).
Even though the material is to be disposed within
a constructed depression, the shallow nature of this
site means that specific construction techniques (i.e.,
barge access channels, berms, etc.) may need to be
applied to this site. It is also expected that mitigation
techniques (specialized silt curtains, etc.) may need be
applied to this construction site in order to control
and contain silt and potential containment plumes
during disposal.
AQUATIC RESOURCES
Bcnthic Infauna
The CA/T project found that the benthic faunal
community in the area east of Spectacle Island was
dominated by the tube-dwelling Ampelisca abdila
(reflecting relatively clean, sandy sediments), and the
gastropod N. trivitlalus (Cortell 1990a). In digging
the pit, the benthic community within the construc-
Al-67
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Spectacle Island CAD
lion site would be completely lost. The digging
would be a. continual process for several months, and
the subsequent disposal operations would occur for
an additional period of 6-9 months. During this
period, the site would be under a constant state of
disturbance, precluding reestablishment of any
benthic populations for that period. Upon comple-
tion, the site would be capped with parent material
and sediment similar to that from the area, returning
it to its former bathymetry. In this case it is reason-
able to expect a quick recolonization to the previous
benthic type as would occur after filling an existing
hole. As construction and final capping should take
approximately 1-2 years, the recolonization, of the
complete community may not occur for 1 year
following disturbance (McCall 1977). Recolonization
of a Long Island dredged material disposal site
following dredging occurred within 3 months (100
days) for A. abditaand N. trivillatus (Rhoads 1978).
The nature of the final benthic community will
depend on the make-up of the cap. For this Project
it is proposed that Boston blue clay be used as the
cap, with existing substrate placed over the clay cap.
Sediments will continue to be deposited by natural
processes; therefore, it is reasonable to expect rapid
recolonization of S. benedicll (one of the most
opportunistic species), from the undisturbed areal
populations a relatively short time frame (Cerrato
and Scheir 1983). The new community would then
be similar to the existing harbor benthos.
A portion of the blue mussel beds which extend
into the southern and northern portions of the CAD
would be affected. The mussel bed substrate could
potentially provides a favorable bottom for habitation
by early benthic phase (EBP) lobsters. However, a
recent survey did not find any evidence of EBP
lobsters in the CAD area or elsewhere around Spec-
tacle Island (Cortell 1990a). Although free-living
lobsters were observed during a diver transect study
around Spectacle Island (Cortell Associates 1990a),
neither ncarshorc nor offshore substrates provide
ideal structural habitat for lobster (i.e., rock, boulder,
cobble, kelp). During the construction of the CAD
and disposal operations, lobsters in the immediate
vicinity would be displaced until suitable food re-
sources returned. These impacts would be restricted
to the construction period (mining and
disposal/capping operations).
Siltation caused by the pit construction and
disposal operations would probably have some short-
term adverse impacts on invertebrates occurring in
adjacent subtidal and intertidal areas. Siltation
should have no long-term or wide spread adverse
impact on harbor invertebrate communities.
Fish and Shellfish
Disposal operations should have only minor,
short-term effects on fisheries resources around
Spectacle Island in the vicinity of the disposal site.
Some mortality of juvenile and adult fish should
occur during construction of the pit and disposal
events due to burial or exposure to high suspended
sediment levels and noise. Impacts would be limited
to the immediate vicinity of the site. Pit construction
and disposal of dredged material would temporarily
reduce prey available to species which feed primarily
on benthic invertebrates, such as winter flounder.
As mentioned earlier, lobstcrmcn fish the area
along the channel between Spectacle Island and Long
Island. In addition, as part of the mitigation plan for
the Spectacle Island Landfill closure, an artificial fish
reef, covering approximately one acre, is being
planned for Sculpin I.-cdge Channel between the
proposed CAD site and I.x>ng Island, with construc-
tion currently to take place in 1995 (Paul Geoghegan,
NAI, 1993, pcrs. comm.). Because of these adjacent
resources, special mitigation measures may be neces-
sary to minimize the size and extent of silt plumes
during construction and disposal activities at this site.
Because of prevailing tidal current directions in the
area in relation to the above resources, the greatest
caution may be necessary during ebb tides.
A1-68
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Spectacle Island CAD
WETLAND RESOURCES
There would be a short-term impact of 20-70 acres
of I^and Under the Ocean and Tidal Waters. The
site would be restored after construction. The
impacts for the biological resources protected under
I,and Under the Ocean (310 CMR 10.00) are dis-
cussed above.
WILDLIFE
Construction of the borrow pit and disposal of
dredged material in the borrow pit would not have
long-term adverse impacts on wildlife populations
occurring near the disposal site.
THREATENED AND ENDANGERED
SPECIES
The proposed project would not impact species
considered threatened or endangered by the U.S. Fish
and Wildlife Service (USFWS), National Marine
Fisheries Service (NMFS) or MANIIESP.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeological sites
at or near the Spectacle Island CAD site.
If the filling is restricted to the depth of the sur-
rounding area, there will be no permanent impact on
recreational boating. However, the placement of the
material may necessitate temporary restrictions on
recreational boating. Because this is a shallow
subtidal area, dredging would be required. This will
necessitate testing and a determination of the appro-
priate disposal location for the sediments removed
from this site.
The Massachusetts Highway Department (MHD)
is currently constructing a dike adjacent to this
proposed disposal site for the purpose of containing
and closing the landfdl at Spectacle Island. Lack of
impacts from dredging the CAD on the integrity/of
the dike structure will need to be demonstrated to the
MHD as well as to the owners of Spectacle Island,
the City of Boston and the Massachusetts Depart-
ment of Environmental Management.
Part of the Spectacle Island Landfill Closure Plan
also includes the installation of an artificial reef in the
northeastern half of Sculpin Ledge Channel. De-
pending on the timing of the Project, the fill place-
ment at the Spectacle Island CAD location may need
to be coordinated with the construction and/or
location of the fish reef to minimize interference and
impacts. As mentioned above, if the fish reef is in
place during the CAD construction/use, special
mitigation measures may be necessary to prevent silt
plume exposure to this facility:
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 660 barge trips. This would require Coast
Guard coordination of barges with the commercial
and recreational boat traffic using the harbor. Con-
struction activities would have a minor adverse
aesthetic impact, and result in slightly elevated noise
levels.
A1-69
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Mcisburger Sites 2 and 7
2.43 Mcisbiirgcr Sites 2 and 7
These sites are depicted on Figures A1-16 and Al-
17.
2.43.1 Existing Conditions
SEDIMENT CHARACTERISTICS
The sand and gravel deposits that characterize
these sites were first described by Meisburger (1976)
from sub-bottom data. The sites are in approximate-
ly 100 ft of water (80-110 range). Sand and gravel
form much of these irregularly shaped deposits and a
layer of medium sand (up to three feet thick) may
cover some of these areas locally. Because these sites
are within the ncariield study area of the proposed
MWRA outfall, they have received recent detailed
inspection (Shea et al. 1991, Butman et al. 1992 and
Blake et al. 1993). A 4 x 5 nautical mile area around
the proposed outfall was characterized in detail by
Butman et al., (1992) and the most common sedi-
ment type in the area surveyed was coarse sand and
gravel (42%). These deposits lay between gravel and
boulder covered drumlins which comprised 23% of
the study area. Fine-grain sediments (6%) and
highly variable or patchy distribution of mud, sand
and gravel (29%) made up the remainder of the
cover. The areas described by Meisburger (1976) are
predominately covered with sand and gravel although
the boulder areas border some of the deposits in
these areas. Results of other studies in this area
(Blake et al. 1993; Shea et al. 1991) are generally
consistent with the above findings although most of
their data were collected from REMOTS images
from representative data. Studies from this area
point out that bottom sediments indicate higher
energy areas in some locations while other areas
appear to be depositional (silt, clay sediments), with
sand underneath.
WATER QUALITY AND CIRCULATION
Again, because of the proximity of these site
locations relative to the MWRA offshore outfall site,
recent studies have focussed on this area and long-
term monitoring of water quality and hydrography is
planned (MWRA 1991). Although a 3-D hydrody-
namic model of Massachusetts/Cape Cod Bays is still
in development, intensive physical oceanographic
surveys were conducted between April 1990 and June
1991 (Butman et al 1992). Some of this long-term
monitoring is located immediately adjacent to the
MWRA outfall at Buoy "B". While the report
should be referenced for the details of initial findings,
some relevant findings to this assessment include:
»• There is an absence of well-defined current in
this area, but water and particle transport takes
place by a variety of actions, including tides,
winds and river flow;
•• Maximum tidal currents 1.0 m off bottom are in
the range of 6-8 cm/s in this area (the mean is in
the 2-4 cm/s range), compared with much faster
currents (18-20+ cm/s) at the mouth of Boston
Harbor and somewhat slower currents (4-6
cm/s) at the MBDS. Mean water currents at 5.0
m at this site are typically in the 4-7 cm/s range;
»• Maximum re-suspension of fine-grain materials
coincides with storm events that show a 2-4 fold
increase in suspended material in the water
column compared to background (i.e. non-storm
periods) in the winter.
The waters in this area have been classified as
Class SA. This classification protects the saline
waters for the propagation of marine life, primary
and secondary contact recreation and shellfish har-
vesting without depuration in approved areas.
A1-70
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Meisburger Sites 2 and 7
AQUATIC RESOURCES
Benthic Infauna
Recent studies (Blake et al. 1993) have involved
benthic sampling adjacent to Meisburgcr 2 in areas
shown by Butman et al. (1992) to have a patchy
distribution of mud, sand and gravel or a mud or fine
sand cover. Although the five stations nearest the
outfall in Blake's study had 290% sand and gravel,
their sediments appear to be not quite characteristic
of the coarse sand and gravel representative of the
Meisburger 2 and 7 sites. Nevertheless, at these five
stations infaunal benthic densities ranged from 15,600
to 100,100 per m2 with the number of species run-
ning from 49 to 81 (samples were collected through
a 0.3 mm sieve). The dominant species for these
stations were typically an amphipod/polychaete
combination (i.e, Corophlum crassicorne/Exogene
hebes) or a polychaete assemblage dominated by
Spio limicola, Polydora socialis, and Mediomaslius
californiensis. The former species group was charac-
teristic of the transitional area (composed of these
five stations) between the soft bottom area and the
hard substrate and thus may be more characteristic of
the Meisburger sites; total densities of this station
group (5 stations) averaged 20,492 individuals/m2.
Finfish
Trawl data provided by the MADMF (1991-92
Resource Assessment/Surveys, unpublished data) for
a station two nautical miles west of the MWRA
outfall indicated that three commercial finfish species
(winter flounder, Atlantic cod and yellowtail) made
up 40-60% (collectively) of the total catch (Table
A1-5). The total catch (all fish) from two spring
(May '91 and '92) collections were 655 (20 min. tow)
and 685 (13 min. tow); a total of 17 and 60 lobsters
were also collected from these same tows. Rock and
Jonah crabs were found in small numbers. Total
abundances of fish and lobster at this site were
average to above average compared with 10 sampling
events (in May and August 1991-92) distributed
offshore from Nantasket Beach to the MBDS.
From a commercial fisheries perspective, these sites
are within the area of greatest territorial harvest for
coastal lobster fishery (unpublished data, MADMF
1991). For example, Area #4 (which extends from
Lynn to Cohassct) accounted for 41.1% of the
11,000,500 pounds caught (on Coastal licenses) in
Massachusetts territorial waters. Site-specific catch
data for these disposal sites were not available.
WETLAND RESOURCES
The Mcisburger sites exist beyond the geographical
and depth jurisdiction of the Massachusetts Wetlands
Protection Act and Regulations (MGL c.131, s.40,
and 310 CMR 10.00). These sites fall within the
federal designation of tidal waters since they fall
within the territorial sea of Boston Harbor, and the
associated 3 mile limit of jurisdiction required for the
discharge of dredged or fill material under Section 404
of the Clean Water Act.
WILDLIFE
Approximately 35 species of marine mammals, 5
species of marine turtles and 40 species of seabirds
occur within the Gulf of Maine. Aerial surveys were
conducted for the ACOE to assess the use of the
Massachusetts Bay Disposal Site (MBDS) by marine
mammals, reptiles and seabirds (MBO 1987). The
dominant species observed within the MBDS locale
arc typical of the offshore waters of Massachusetts
(Mcisburgcr and Boston Lightship sites).
Scabirds observed include northern fulmar (Ful-
mamts glacialis), shearwater (Pufflmts sp.), storm
petrels (Ilydrobatrae), northern gaument (Sila bac-
saus), Pomarinc jaeger (Sleriovarius pomarinwri),
gulls (larinac) and Alcids (Alcidae). Dominant
noncndangcrcd mammals include minke whale
Al-71
-------
(Delasnoplera aartorosirala), white-sided dolphin
(iMgenorhynchits aculus), and harbor porpoise
(JPhocena phoccna). Although five species of turtles
potentially could occur on Massachusetts Bay, only
the Icalhcrback turtle (Dermochelys coriaced) is
typical in the area.
THREATENED AND ENDANGERED
SPECIES
The following threatened and endangered aquatic
species can occur in the Western North Atlantic
including parts of Massachusetts Bay (U.S. Depart-
ment of the Interior 1991):
Cetaceans
right whale (Eubalaena gracilis) (Endangered)
humpback whale (Megaplera novaeangliae)
(Endangered)
finback whale (Bcdaenoptera physdus) (Endangered)
sci whale (B. borcalls) (Endangered)
sperm whale (Physeler macrocephalus) (Endangered)
blue whale (B. musculus) (Endangered)
Turtles
Kemp's ridley (Lepldocftelys kempt) (Endangered)
leatherback (Dermochaelys coreacea) (Endangered)
hawksbill (Eretmodielys imbricata) (Endangered)
loggerhead (Caretta core.tld) (Threatened)
green (Chelonia mydas) (Threatened)
Fish
shortnose sturgeon (Acipenser brevirostrwri)
(Endangered)
Studies have shown that the majority of local
threatened and endangered whale sightings have been
concentrated near the tip of Cape Cod in the north-
Meisburgcr Sites 2 and 7
cm and central areas of the Great South channel and
north of Cape Cod along Stellwagen Bank and
Jeffrey's Lx:dge (ADL 1992). The sightings offshore
from Boston Harbor are typically concentrated
eastward of the MBDS, within the newly designated
Stellwagen Bank National Marine Sanctuary. The
Meisburger sites are approximately half way between
Boston Harbor and the MBDS and are not a report-
ed area of concentration for these species. Whale
watch cruises out of Boston Harbor do not attend
these areas.
Of the five threatened or endangered turtles that
could occur in this area, the leatherback, v'Kemp's
ridley and the Loggerhead are the most'regularly
observed in Massachusetts and Cape Cod Bays. Of
these species, the leatherback is the most frequently
encountered, with the western North Atlantic esti-
mated to support 16,000 individuals (Lazell 1980);
however, it is primarily an oceanic species. The
loggerhead may show the most common inshore
occurrence, with 7,700 individuals estimated to be in
north and middle Atlantic coastal water (CETAP
1982). The Kemp's ridley turtle would be the most
rare, with the Atlantic population estimated to be less
than 500 individuals (Carr and Mortimer 1980).
There is nothing unique about the Meisburger 2 and
7 sites that would attract these species nor are we
aware of any specific sightings for this area.
The shortnose sturgeon inhabits estuarine and
freshwater areas along the eastern coast of the U.S.
and Canada and would not be an inhabitant of these
open water alternative disposal sites.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There arc no listed historical or archeologjcal
resources on the Meisburger 2 and 7 sites.
A1-72
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Mcisburger Sites 2 and 7
SOCIO-ECONOMIC/LAND USE
The Meisburger 2 and 7 sites are located in an area
used for recreational boating and for commercial
fishing. The sites are easily reached by barge during
fair weather conditions. The sites are within one
mile of the Massachusetts Water Resources Author-
ity's Ocean Outfall, currently scheduled for comple-
tion in 1995.
2.4.3.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
The proposed action at this site includes mining
the existing sand and gravel at the preferred site and
depositing the silt material in the resulting borrow
pit.
The dredged sediments placed at the disposal site
would then be stabilized by a 3-foot cap of parent
sediment. Contaminated dredged material placed in
open-water disposal sites may be chemically and/or
biologically isolated by capping with clean dredged
material (Truitt 1986). The cap eventually will be
buried by sediments deposited by natural processes.
The area available can fall within a 140±-acre area of
seabed for Meisburger 2, and 106 to 403 ± for Meis-
burger 7.
The cap and the dredged sediments would be
confined within the walls of the pit below the level of
the harbor floor. Therefore in the long term, a
deposit in a borrow pit would be less likely to release
contaminants because it is not in direct contact with
the water column. Even more important, because of
its location under the seafloor, the borrow pit would
be less likely to lose its chemical-laden sediments
through natural erosion (current action) or extraordi-
nary storm events. Therefore, the site's vulnerability
to storms should be negligible because of the added
protection because of greater depth and the pit walls
(Bokuniewicz et al. 1981).
During development of the borrow pit some of the
excavated material will be stored and replaced as a
final cap layer, restoring the area to its original
condition.
WATER QUALITY AND CIRCULATION
During the course of the new pit construction (i.e.,
removal of the sand and gravel), it is anticipated that
turbidity levels in and around the immediate con-
struction areas would be increased by both the
dredging and barge overflow. However, use of a
mechanical dredge would greatly reduce potential-'
water quality impacts from this operation. The
turbidity plume generated would be restricted to a
very limited area in the vicinity of the dredge, with
95-99% of the suspension material settling within a
few yards (Schubel et al. 1978). Because of the
coarseness of the sand removed, resuspension would
be minimal. The construction process would in-
crease turbidity locally for a very short time period as
the material is mostly sand, and the new hole itself
would serve as a sink for suspended materials; no
other water quality impacts are expected.
As a result of the disposal operations there would
be localized and temporary increases in suspended
solids concentrations (and turbidity). The dredged
material would be released from a barge above the
pit. It would descend through the water column as
a dense mass. During this descent any where from
3% to 5% of the dredged material may be lost to the
water column (WES 1986). Movement through the
water column would expose and mix the sediment
during its descent.
Sediment disposal simulations for the Meisburger
sites conducted with ACOE's ADDAM's model
showed that four hours after a 2,000 cy dump that
water quality criteria for copper (assumed to be the
conservative parameter) would not be exceeded
outside the site's boundary at any depth (Appendix
F). Table A1-6 depicts the predicted maximum
A1-73
-------
Mcisburger Sites 2 and 7
concentration of copper and silt/clay in the water
column under stratified conditions at the Meisburger
7 site. This was true for the summer (stratified)
conditions; therefore, it is safe to assume it would
hold for winter (unstratified) conditions as well.
Within the disposal site copper concentrations in the
water column were also estimated not to exceed
water quality criteria after four hours. Temporary
(<4 hours) exceedences within the disposal site are
allowable within the Section 103 regulations and not
unexpected with silty material of this quality. After
a four hour period the silt/clay cloud was estimated
to have adiameter of 2581 feet; however, 97% of the
sediment volume would have settled out by this time.
Results indicated that risks to marine organisms
outside the disposal site should be minimal, since
water quality criteria are met within the four hour
period allowed.
The above model results notwithstanding, there
may be concerns about chemicals associated with the
sediments elutriating excessively into the water
column during their descent to the bottom. I lowev-
er, common methods of open water disposal do not
alter the chemical properties of the dredged material,
and do not break the bonds that hold contaminants
to sediment particles (Bums and Schubel 1983;
Bokuniewicz et al. 1986). The binding of pollutants
to sediment particles (particularly the fine-grained
organic and/or clay components) tend to immobilize
the contaminants and prevent their release to the
water column (O'Connor and O'Connor 1983). As
a result, any sediment that may remain suspended
after the main deposit reaches the bottom would not
likely release its bonded contaminants to the water
column. Tliis is consistent with field studies at
disposal sites in New York Harbor; none have ever
detected a significant increase in contaminant or
nutrient level in the water at disposal sites (ACOF,
1984; Bokunicwic7. et al. 1986).
AQUATIC RESOURCES
Benthic Infauna
Recent studies (Blake et al. 1993) indicated that
the dominant species in the general vicinity of Meis-
burger 2 and 7 were an amphipod/polychaete combi-
nation (Corophium crassicorne/Exogene hebes). In
digging the pit, the benthic community within the
construction footprint would be completely lost. The
digging would be a continual process for several
months, and the subsequent disposal operations
would occur for an additional period of 6-9 months.
During this period the site would be under a Constant
state of covering, thereby precluding reestablishment
of any benthic populations for that period. Upon
completion, the site would be capped with parent
material and potentially covered with sediment
similar to that from the area, and returned to its
former bathymetry. In this case it is reasonable to
expect a quick recolonization to the previous benthic
type as would occur after filling an existing hole. As
construction and final capping should take approxi-
mately 1-2 years, recolonization may not occur for at
least a year following cessation of site activity (Mc-
Call 1977).
The nature of the final community will depend on
the make-up of the final cap and the response of the
surrounding populations to that available substrate.
For this project it is proposed that Boston blue clay
be used as the cap; a layer of clean sand may be
placed on top of the cap. This cap would also
eventually be covered by sediments deposited by
natural processes. Therefore, it is reasonable to
expect rapid rccolonization of C. crassicorne and E.
hebes, the dominant species from the undisturbed
populations around the pit, perhaps in as short a
time frame as 1 ycar(Ccrrato and Scheir 1983). The
new community on the site would then be similar to
the existing community. In immediately adjacent
subtidal and intertidal areas siltation caused by the pit
construction and disposal operations could have
some short-term, ncarficld adverse impacts on inver-
AI-74
-------
Meisburger Sites 2 and 7
tcbrates. However, no long-term adverse impacts on
the invertebrate communities in these adjacent
offshore areas are expected.
Lobsters were common in collections conducted
by MADMF (unpublished data from 1991-1992) at
a station 2 miles west of the MWRA outfall in an
area expected to be representative of the Meisburger
sites. The major physical effect of construction of
the pit and disposal operations on aquatic popula-
tions are turbidity, direct burial and temporary loss of
habitat. There would be some localized turbidity
impact on the biota. Lobsters in the immediate
vicinity would be impacted to some extent as a result
of impacts to potential foraging habitat; some im-
pacts to living habitats (i.e. burrows) are anticipated.
These impacts are expected to be restricted to the
short-term and within the immediate area of the
disposal site only.
Fmfish
Disposal operations should have only minor,
short-term effects on fish in the vicinity of the bor-
row pit/disposal site. Some mortality of adult fish
may occur during construction of the pit and disposal
events due to burial or exposure to high suspended
sediment levels. Three commercial finiish species
(winter flounder, Atlantic cod and yeliowtail floun-
der) made up 40-60% (collectively) of the total catch
in collections conducted by MADMF (unpublished
data from 1991-1992) at a station 2 miles west of the
MWRA outfall in an area expected to be representa-
tive of the Meisburger sites (Table A1-5). Therefore,
there may be some displacement of these species
from construction activities. Impacts would be
limited to the immediate vicinity of the site. Pit
construction and disposal of dredged material would
temporarily reduce prey available to species which
feed primarily on benthic invertebrates, (such as
winter and yeliowtail flounders, American lobster,
etc.)
WETLAND RESOURCES
Temporary impacts to Tidal Waters are anticipated
during disposal and construction activities. Upon
completion of capping and closure, both sites should
rccolonixc/re-populate through natural recruitment.
Clean substrates will be restored to existing bathy-
metry providing better habitat conditions for benthic
community redevelopment.
WILDLIFE
Construction of the pit and disposal of dredged
material in the borrow pit should not adversely
impact wildlife populations occurring near the dispos-
al site.
THREATENED AND ENDANGERED
SPECIES
Several endangered whales and turtles species can
occur in the Massachusetts and Cape Cod Bays
primarily, in more offshore areas near Stellwagen
Bank and environs. There is nothing unique about
Meisburger 2 and 7 sites that would attract these
species nor are we aware of any specific sightings for
this area. Therefore, the proposed project should not
adversely impact species considered threatened or
endangered by the U.S. Fish'and Wildlife Service,
National Marine Fisheries Service, or the State of
Massachusetts. This is consistent with EPA studies
for cumulative impacts to these taxa from the
MWRA outfall and the BIINIP disposal at MBDS
(EPA 1993). Potential impacts to these species have
been addressed further in a Biological Assessment
prepared by ACOIi, NED (Appendix A).
Al-75
-------
Meisburgcr Sites 2 and 7
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There arc no listed historical or archeological
resources at the Mcisburger sites.
acceptable strategy to the ACOE. However, costs
which must be factored into this option include
testing, processing and transporting the material, as
well as alternate use or storage costs for that portion
of the material not appropriate for beach nourish-
ment.
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 660 barge trips. This would result a level of
traffic that would need to be closely coordinated by
the Coast Guard with commercial and recreational
boat traffic using the harbor. Construction activities
would have a minor adverse aesthetic impact.
The disposal operation at the site would prevent
fishing and recreational boating for the duration of
the filling activity. A notice to fishermen warning
them to avoid this area may be necessary as may be
a Coast Guard hazards to navigation notice (due to
the regular pressure of barges). Although the project
activity could provide a point of nuisance to fisher-
men for 1% to 2 years, adverse impacts to their fish
catch arc not anticipated given the relatively small
area affected compared to what is available for similar
fishing ground. Long-term impacts to the fishery are
not expected because the dredge material would be
isolated and not exposed to benthos or fish. The
proximity of the sites to the MWRA's ocean outfall
assures some level of monitoring (by MWRA) before
and during placement of material; any construction
impacts from the filling operation could be evaluated
from these data.
Use of these locations will entail dredging of
existing sand and gravel prior to placement of materi-
al. Some of the sand might be suitable for ACOE
beach nourishment projects provided it meets grain
size, availability and suitability criteria for the specific
beach nourishment project. The ACOE is working
with the MDC on beach nourishment projects in the
Commonwealth including Nantasket Beach, among
others. 'Piggybacking" projects in this manner is an
A1-76
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Subaqueous Containment Site B (SUBAQ B)
2.5 SITE EVALUATION:
Sim AQUEOUS AREAS
2.5.1 Subaqueous Containment Site B (Snbaq B>
The site is depicted on Figure A1-18.
25.1.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Boring sites STl-14 and STl-15, sampled by the
CA/T program (Cortell 1990a) and presented in
Table A1-7, were located off the northern side of
Spectacle Island and represent the same exposure to
currents, waves and storms as Subaq B. Surface
sediments at STl-14 and STl-15 were predominantly
sand (77-84%) and gravel (11-20%) with a small
silt/clay component (3-5%). Bulk sediment analysis
indicated that no parameters exceeded Category I
limits.
WATER QUALITY AND CIRCULATION
Waters in the vicinity of the Subaq B site have
been classified as Class SB waters by MADEP.
Specific water quality data is presented in Section 3.0
for the outer harbor area. Typically the greatest
impact to water quality in this area is from the
numerous discharges and CSO's originating in the
Inner Harbor areas. Water quality improves with
increasing distance from the Inner Harbor.
The fastest tidal currents in Boston Outer Harbor
occur in the deep ship channels (up to 1.4 knots)
during spring tides in the southern lane of the Main
Ship Channel. The mouth of Dorchester Channel
attains spring tide currents of 0.8 knots on ebb tide
and 0.6 knots on flood tides (Cortell 1990a). Locat-
ed near the edge of the Main Ship Channel, Subaq B
may experience among the fastest currents.
Subaq B is exposed and vulnerable to northeaster-
ly storms. The nearest sheltering landfall is Deer
Island (2.0± miles across the harbor). Nearby sedi-
ment conditions indicate the area is occasionally
scoured.
AQUATIC RESOURCES
Bcnthic Infauna
Subtidal benthic macrofauna in the vicinity of the
northwest portion of Spectacle Island were examined
during benthic infauna and lobster surveys (Cortell
1990a). As with other sampling locations around
Spectacle Island, abundances of benthic infauna
(retained on a 0.5 mm-mesh sieve) north of the
island were low (1113 individuals/m2). Nematodes,
the gastropod N. trivittalus and the polychaete N.
caeca predominated.
Sediment samples collected during the lobster
survey were sieved through a 2.5 mm-mesh sieve and
analyzed qualitatively. The polychaetes Nereidae and
Glycera sp., Nassarius sp. and post-larval crabs were
the most frequently collected organisms. Soft-shell
clam (M. arenaria) spat and razor clams (E. directus)
were also encountered.
Lobster fishing activity in the vicinity of Subaq B
was examined during the summer of 1990 for the
CA/T project (Cortell 1990a). Pot markers were
observed at Subaq B on each of the three dates
examined. Despite being in a navigational channel,
pot markers were as numerous at Subaq B as at
other areas around Spectacle Island. Transects were
swum by divers to document use of the substrate
around Spectacle Island by lobsters, including EBP
lobster. The greatest density of lobsters was observed
off the northeast portion of Spectacle Island (0.0027-
0.0035/ft2). Lobsters occurred at about half that
density (about 0.0012/ft2) off the northwest portion
of the island (near Subaq B); abundances elsewhere
around the island were generally much lower. Most
A1-77
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lobsters were observed at the deeper portions of the
transects. No EBP lobsters were observed around
Spectacle Island; little suitable habitat was encoun-
tered for this lifestage.
Finfish
Based on the on-going development of the artificial
reef design, as required by the Individual Per-
mit—Landfill Closure and Maintenance at Spectacle
Island for CA/T (ACOE no. 199202207; 2/16/93),
target fish species in the offshore coastal waters and
Boston Harbor areas include forage species such as
Atlantic menhaden, Atlantic herring and rainbow
smelt, and predator species such as winter flounder,
striped bass, bluefish, pollock, Atlantic cod, tautog
and cunner.
WETLAND RESOURCES
Subaq B is defined as Land Under the Ocean and
falls under the jurisdiction of the Massachusetts
Wetlands Protection Act (310 CMR 10.00). By
definition, this resource is supposed to be significant
to the protection of marine fisheries, protection of
land containing shellfish, storm damage prevention,
flood control and protection of wildlife habitat.
Although food resources appear to be limited in this
area (low benthic infaunal abundances), the area in
the vicinity of Subaq B has been shown to support
lobsters and is likely to support winter flounder. The
sandy substrate may provide spawning habitat for
winter flounder.
The closest significant shellfish resource to Subaq
B is in the vicinity of Governors Island Flats across
the Main Ship Channel to the north of Subaq B
where soft-shell clams are harvested by Master
Diggers. The Main Ship Channel influences currents
substantially so that Dorchester Channel has little
effect north to Governors Island Flats. The tidal flat
on the southeastern side of Thompson Island also
Subaqueous Containment Site B (SUBAQ B)
supports a substantial soft-shell clam resource
(Cortcll 1990b). Shallow bathymetric conditions
between the islands and the configuration and orien-
tation of Spectacle and Thompson Islands result in
relatively slow currents passing from Subaq B to the
Thompson Island Flats (0.2 knots, spring flood,
Cortcll 1990b). Spring flood currents through the
deeper Dorchester Channel (passing north of
Thompson Island) are about 0.5 knots.
located at the mouth of the Dorchester Channel,
Subaq B offers little storm damage protection be-
cause its depth is greater than surrounding areas.
Storm waves would travel to shallower areas and
crest before reaching land. Because it is in relatively
open water, Subaq B also has little potential for
storing flood water.
Dissipation of storm waves helps to protect shal-
lower areas, such as the subtidal flat southeast of
Pleasure Bay. Such shallows can be important
feeding resources for waterfowl, including those
species observed on and adjacent to Spectacle Island
(see next section).
Subaq B is classified as Tidal Waters under federal
regulations (33 CFR 328.4(b)). Tidal Waters may
provide sediment/toxicant retention, nutrient reten-
tion/ transformation, recreation and uniqueness/heri-
tage. Subaq B is not likely to contribute substantial-
ly to retention of sediments and toxicants, nor to
retention or transformation of nutrients. Relatively
swift currents prevent deposition of fine grained
sediments that tend to absorb contaminants. Nearby
sediments contained only low concentrations of
metals and organic pollutants. Recreational vessels
are among those using the channel.
WILDLIFE
Waterfowl, including great cormorant (P. carbo),
herring gull (/~ argentalus), white winged scoter (M.
deglandi), common goldeneye (B. clangida), bufile-
Al-78
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Subaqueous Containment Site B (SUBAQ B)
head (B. albeold), mallard (A. platyrhynchos), black
duck (A. rubripes), merganser (Mergus spp.) and
scaup (Aythya spp.) have been observed in the
vicinity of Spectacle Island (Corteli 1990a). It is
likely that these same species of waterfowl use the
Subaqueous B site area for feeding and resting).
Each of these species feed on fish and invertebrates
(Martin et. al. 1951; Whitlatch 1982; and DeGraaf
and Rudis 1986) that occur in the area.
This open water site is in the path used by the
commuter boats to Boston. The site is within 1200
feet of Spectacle Island, an abandoned landfill which
is being closed and capped by the Massachusetts
Highway Department, and which will be the site of
a park owned by the City of Boston and the Com-
monwealth Department of Environmental Manage-
ment. The site is more than one-half mile from at
the Castle Island, an MDC Park and 0.75 miles from
Thompson Island.
THREATENED AND ENDANGERED
SPECIES
No threatened or endangered species listed by
federal or state authorities are identified or anticipated
to occur within the boundaries of Subaq B. Several
marine mammals not listed as threatened or endan-
gered, including harbor seals (P. vilulind), harbor
porpoise, (P. phocend) and grampuses (G. griseia),
occur occasionally in the area. These species are all
protected under the Federal Marine Mammals
Protection Act.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
Previous dredging and maintenance of the Main
Ship Channel and the Dorchester Channel have likely
disturbed any evidence of historic or archeological
remains.
SOCIO-ECONOMIC/LAND USE
Subaq B is an entirely submerged aquatic site
within view of Spectacle Island, Thompson Island,
Fort Independence on Castle Island, lagan Airport
and Deer Island. It lies-within a presently marked
navigational channel (Dorchester Channel) at its
convergence with Western Way and the Main Ship
Channel. Lobstermcn fish this area.
23.1.2 Environmental Consequences
SEDIMENT CHARACTERISTICS /
Sediments placed in the site would be stabilized by
a 3 foot cap of clean material. The cap eventually
will be buried by fine sediments deposited by natural
processes. Truitt (1986) demonstrated that contami-
nated dredged material placed in open-water disposal
sites may be chemically and/or biologically isolated
by capping with clean dredged material. The cap and
the dredged sediments would be confined within the
walls of the depression below the level of the harbor
floor. Therefore, in the long term, a deposit in a
depression/pit would be less likely to release contami-
nants because it is not in direct contact with the
water column. Even more important, because of its
location under the seafloor, in an area of active
deposition, the depression/pit would be less likely to
lose its chemical-laden sediments through natural
erosion (current action) or extraordinary storm
events. Therefore, the site vulnerability to storms
should be substantially mitigated because of the
added protection of both depth and the pit walls
(Bokunicwic/. ct al. 1981).
WATER QUALITY AND CIRCULATION
Subaq B is located near the edge of the Main Ship
Channel, where the tidal currents are the fastest in
Boston I larbor (approx. 1.4 knots). Studies done by
Al-79
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the ACOE (1988) showed that currents directed
towards areas of depression are slowed by the depres-
sion, and then regain speed as they pass by.
During disposal operations, there will be localized
and temporary increases in suspended solids concen-
trations in the water column. The dredged material
will be released from a barge above the site. It would
descend through the water column as a dense mass.
During this descent any where from 3% to 5% of the
dredged material may be lost to the water column
(WES 1986). ADDAM's model results for this
project site indicate that this should be 3% or less
(see below). Movement through the water column
would expose and mix the sediment during its de-
scent.
Common methods of open water disposal do not
alter the chemical properties of the dredged material,
and therefore do not break the bonds that hold
contaminants to sediment particles (Burns and
Schubel 1983;Bokuniewiczetal. 1986). The binding
of pollutants to sediment particles (particularly the
fine-grained organic and/or clay components) tends
to immobilize the contaminants and prevent their
release to the water column (O'Connor and
O'Connor 1983). As a result, any sediment that may
remain suspended after the main deposit reaches the
bottom would not likely release its bond to contami-
nants and disperse them to the water column. This
is consistent with field studies at disposal sites in
New York Harbor; none have ever detected a signifi-
cant increase in contaminant or nutrient level in the
water at disposal sites (ACOE, NYD 1984;
Bokunicwicz et al. 1986).
The ACOE ADDAM's model was used to demon-
strate potential water quality impacts at a representa-
tive in-harbor site (Subaqueous E: Table A1-8).
Under maximum flood tide conditions, a sediment
plume diameter of 2220 feet was predicted with a
silt/clay concentration of 9.7 mg/L above back-
ground; background is about 4.5 mg/L (New Eng-
land Aquarium 1990). It was calculated that approx-
Subaqueous Containment Site I) (SUBAQ B)
imately 3% of release material would remain sus-
pended in the water four hours after disposal. Under
maximum ebb tide conditions a sediment plume
diameter of 2205 feet was predicted with a silt/clay
concentration of 0.815 mg/L above background, it
was calculated that < 2% of release material would
remain suspended in the water four hours after
disposal under this scenario. The modeling analysis
indicated that suspended solids would be transported
beyond the disposal site and may extend for 4,700
feet; Governors Island flat and Deer Island flats could
be reached if tidal events would move the material in
that direction.
V '
After a four hours disposal simulation,-the model
calculated a maximum copper concentration within
the plume of 0.0058 ppm under maximum flood tide
conditions, and 0.0019 ppm under maximum ebb tide
conditions. Since the Massachusetts water quality
criteria for copper is 0.0029 ppm. under maximum
tidal flood conditions, the water criteria was predicted
to be exceeded; however, under maximum ebb tide
this condition was not predicted. Tidal-dependent
disposal periods as well as engineering mitigation
methods to control sediment plume expansion would
be necessary to control water quality impacts from
this disposal option.
AQUATIC RESOURCES
Benthic Infauna
Bcnthic invertebrates at the Subaq B disposal site
would be buried during disposal operations. Nema-
todes, the gastropod Nassarius irivittatus and the
polychactc Nephtys caeca were the dominant species
found in a bcnthic infauna survey done by Cortell
(1990a) in the vicinity of northwest portion of
Spectacle Island. Dredged material placed at the site
would quickly be colonized by the species common
to the surrounding areas. The resulting community
should then be similar to that presently occurring on
the site. Over the long-term, invertebrate productivi-
Al-80
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Subaqueous Containment Site B (SUBAQ B)
ty and diversity should improve. Therefore, partially
filling the depression at the site could improve habitat
quality for invertebrates due to the cleaner sediment.
The closest significant shellfish resource to Subaq
B (soft-shell clams, harvested by Master Diggers) is
in the vicinity of Governors Island Flats, across the
Main Ship Channel to the north of Subaq B.
Lobster fishing activity in the vicinity of Subaq B
was examined during the summer of 1990 for the
CA/T project (Cortell 1990a). It was found that
lobsters occurred at a density of 0.0012/ft2 off the
northwest portion of Spectacle Island, near Subaq B.
The disposal of dredged material at Subaq B should
have no long-term impacts on the soft shell clam and
lobster populations in the vicinity of the site; but
some short-term construction impacts could occur.
lobsters would be displaced from the construction
area; bioaccumulation of silt plume material should
be no different than existing conditions since prey are
already being obtained from surrounding areas with
similar conditions.
The major physical effects of disposal on aquatic
populations are turbidity and direct burial. Shellfish
in the immediate vicinity could be impacted by both
turbidity and burial to some extent. These impacts
are likely to be restricted to the short-term, since the
annual reseeding of clam spat would act as a natural
mitigation to these impacts. Shellfish are filter
feeders and the suspended sediment can interfere with
their feeding mechanism; bioaccumulation of sus-
pended silts and their associated chemicals could be
a risk. Lobsters in the immediate vicinity would be
impacted to some extent as a result of impacts to
potential foraging habitat; impacts to living habitats
(i.e. burrows) are anticipated. These impacts are
expected to be restricted to the short-term.
site. Some displacement and/or mortality of juvenile
and adult fish would occur during disposal events due
to burial or exposure to high suspended sediment
levels. Fish could avoid any adverse conditions from
turbidity. Impacts would be limited to the immediate
vicinity of the disposal site. Disposal of dredged
material would reduce habitat with prey available to
species that feed primarily on benthic invertebrates,
such as winter flounder; recovery of this habitat
should occur within about a year.
WETLAND RESOURCES
There would be a short-term impact of 50-80 acres
of I,and Under the Ocean and Tidal Waters. The
site would be restored after construction. The
impacts for the biological resources protected under
Land Under the Ocean (310 CMR 10.00) are dis-
cussed above.
WILDLIFE
Disposal of dredged material at Subaq B should
not adversely impact wildlife populations, e.g. birds,
occurring near the disposal site.
THREATENED AND ENDANGERED
SPECIES
The proposed project should not adversely impact
species considered threatened or endangered by the
USFWS, NMFS or MANIIESP. Several species
that arc protected under the Federal Marine Mam-
mals Protection Act (e.g. harbor seals, harbor por-
poise) occasionally do occur in this area, these also
should not be adversely impacted by the Project.
Flnfish
Disposal operations should have only temporary
effects on fish in the vicinity of the Subaq B disposal
Al-81
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Subaqueous Containment Site B (SUBAQ B)
HISTORICAL AND ARCHEOLOG1CAL
RESOURCES
The proposed project should have no effect upon
any structure or site of historic, architectural or
archeologjcal significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
SOCIO-ECONOMIC/LAND USE
The disposal operations of silt material would
involve approximately 450 barge trips. This would
result in some delays to commercial and recreational
boat traffic using the harbor. Construction activities
would have a minor adverse aesthetic impact, and
result in sDghtly elevated noise levels. The proposed
project would be unlikely to have long-term impact
on the soft-shell clam fishery in the vicinity of the
site.
If filling is to an elevation below the surrounding
bathymetry, there would be no permanent impact
harmful to the recreational boaters in this area or to
commuter boat traffic using this route to Boston's
Inner Harbor. The act of placing the material may
disrupt boating activity but only to the extent of
requiring vessels to travel around the barge placing
the sediments.
A1-82
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Subaqueous Containment Site E (SUBAQ E)
2.5.2 Subaqueous Containment Site E (Subaq E)
The site is depicted on Figure A1-19.
2.5.2.1 Existing Conditions
SEDIMENT CHARACTERISTICS
No sediment data were available for the immediate
vicinity of Subaq E. Samples collected off the end of
Logan Runway 331., (Massport 1990) and from
Stations E and F in the Main Ship Channel (ACOE
1988a) may be representative of local conditions.
Composed of grey and black oily fine to medium
sand, these sediments contained no constituents
whose concentrations exceeded the range for Catego-
ry I sediments. Surface material at Stations E and F
in the Main Ship Channel, on the other hand, was
a85% silt or clay. Bulk sediment analysis indicated
that most constituents met Category I standards but
lead, chromium and volatile solids occurred at
Category II levels.
WATER QUALITY AND CIRCULATION
Water quality in the vicinity of Subaq E is classi-
fied as SB. When sampled in 1986, Class SB stan-
dards were met except for occasionally excessive
bacterial concentrations (Massport 1990). As water
quality conditions have been improving throughout
the harbor it is likely that this area continues to meet
SB criteria.
As with other sites in Boston Harbor, the hydro-
dynamics of Subaq E are governed primarily by tidal
currents and secondarily by wind. Bounded to the
north and south by shoals, and in close proximity to
the Main Ship Channel, Subaq E is subject to
relatively high current velocities (up to 1.0 knots
flood and 1.3 knots ebb in spring tides). This area
experiences a 1.0-mile northeasterly fetch, buffered
only by Deer Island and is exposed to easterly winds.
The adjacent shoals crest waves rapidly. Greater
depth offers protection to Subaq E.
AQUATIC RESOURCES
Benthic Infauna
Benthic resources at Subaq E may be similar to
those observed nearby in the Main Ship Channel
(Station 6; ACOE 1988a), described in Section 4.1 of
the EIR/S. Seasonal changes in community structure
were apparent. The July (1986) community was
dominated by Nephlys caeca, Ampelisca abdita, £T
directus and N. triviltatus, generally indicative /of
clean, fine sandy sediments. With 32 taxa represent-
ed, the total abundance was a moderate 2775 individ-
uals/m2. In November (1986), the community was
dominated by A. abdita, Polydora ligni, N. trivitlatus,
and S. benedicli. The 26 taxa observed totalled 5738
individuals/m2. P. ligni and 5. benedicli are opportu-
nistic species with short generation times enabling
rapid recruitment following environmental stresses.
Common in the Inner Harbor, their presence in the
Outer Harbor is an indication that this portion of the
Main Ship Channel was affected by periodic stresses.
Subaq E is likely to support some soft shell clam
(M. arenaria), although this species tends to be most
abundant at and slightly above mean low water.
Subaq E is located within approximately 1 nautical
mile of the intertidal mud flats, along the perimeter
of Logan Airport, which are harvested by commercial
clammcrs. 'ITicse mudflats also support extensive
beds of blue mussels (M. edulis), a species also
capable of subtidal existence.
Finfish
Fisheries resources at Subaq E are expected to be
similar to those described for the Main Ship Channel,
as finfish and cpibcnthic crustaceans are well able to
traverse the small distance between these two areas.
A1-83
5ft1
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WETLAND RESOURCES
like Subaq B, Subaq E is comprised of Land
Under the Ocean (under state jurisdiction) and Tidal
Waters (under federal jurisdiction). The Massachu-
setts Wetlands Protection Act (310 CMR 10.00)
assumes that this resource is significant to the protec-
tion of marine fisheries, protection of land containing
shellfish, storm damage prevention, flood control and
protection of wildlife habitat.
Differences in bathymetry and currents between
Subaq E and adjacent areas are likely to make it
attractive to finfish although it would require more
energy to remain in the stronger currents of this
channel. Regular tidal currents are likely to prevent
anoxic or hypoxic conditions from developing during
the summer, enabling finfish to use this area as a
refuge from summer temperatures on the adjacent
shoals.
The presence of the channel partially diverts tidal
energy away from the adjacent shoals. The shoals of
Governor Island Flats, in particular, are likely to
provide soft shell clam habitat which contributes to
the productivity of the area. The abrupt change in
depth between Subaq E and Governors Island Flats
makes the southern edge of the Flats susceptible to
damage from waves generated by easterly and south-
easterly winds, however winds from these directions
are relatively rare. Governors Island Flats plays a
substantial role in protecting intertidal resources and
the shoreline from erostonal forces by dissipating
waves offshore. Like Subaq B, Subaq E is located in
open water and has no capacity for storage of flood
waters.
Classified as Tidal Waters under federal regula-
tions, Subaq E was evaluated for its ability to provide
the functions of sediment/toxicant retention, nutrient
retention/transformation, recreation and unique-
ness/heritage. Because tidal currents tend to be
elevated in channels and keep fine-grained sediments
in suspension, it is unlikely that Subaq E contributes
Subaqueous Containment Site E (SUBAQ E)
to sediment/toxicant retention or nutrient re-
tention/transformation. However, its proximity to
commercial anchorages exposes Subaq E to potential
spills and accidental discharges. This area is used by
recreational boaters for passage into Boston Harbor.
WILDLIFE
Waterfowl, including great cormorant (P. carbd),
herring gull (L. argentatus), white winged scoter
(Melanilta deglandi), common goldeneye (B. dangu-
fa), bufflchead (Bucephala albeola), mallard (A.
plalyrhynchos), black duck (A. rubripes), merganser
(Mergus spp.) and scaup (Aytha spp.) have been
observed in the vicinity of Spectacle Island (Cortell
1990a). It is likely that these same species of water-
fowl also use the Subaqueous E site for feeding and
resting. Each of these species feed on fish and
invertebrates (Martin et al. 1951; Whitlatch 1982; and
DcGraaf and Rudis 1986) that occur in the general
area.
THREATENED AND ENDANGERED
SPECIES
No federally or state-listed threatened or endan-
gered species are identified or expected to occur
within the vicinity of Subaq E. All marine mammals
are protected under the Federal Marine Mammals
Protection Act, whether threatened/endangered or
not. Three species, harbor seals (Phoca vitulina),
harbor porpoises (Pfwcena phocena) and grampuses
(Grampus griseus) occur occasionally in the harbor.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
There are no listed historical or archeological
resources at the Subaq B or Subaq E sites.
A1-84
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Subaqueous Containment Site E (SUBAQ E)
SOCIO-ECONOMIC/LAND USE
Current use of Subaq E is for navigation between
Winthrop Harbor and Boston Harbor (approximately
20 feet MLW). Although entirely submerged, dispos-
al activities at Subaq E would be visible from Deer
Island, Winthrop Harbor, Logan Airport, Fort
Independence (Castle Island), Spectacle Island and
Long Island during construction. Height restrictions
may occur because of its proximity to Logan.
This open water site abuts General Anchorage
Areas to the south and east and is in the path of the
ferries carrying construction personnel to Deer Island
during the Boston Harbor Clean-up Project. It is
farther removed from the parks discussed with regard
to the Subaq B site.
25.2.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
Dredged material placed in the site would be some-
what more coarse than existing sediments, and would
be stabilized by a 3-foot cap of clean sediment. The
cap eventually should be buried by fine sediments
deposited by natural processes. The cap and the
dredged sediments would be confined within the walls
of the trough below the level of the harbor floor.
Therefore in the long term, a deposit in the trough
would be less likely to release contaminants because
it is not in direct contact with the water column.
Even more important, because of its location under
the seafloor, in an area of active deposition, the
trough would be less likely to lose its chemical-laden
sediments through natural erosion (current action) or
extraordinary storm events. Therefore, the site's
vulnerability to storms should be reduced because of
the added protection because of greater depth and the
trough walls (Bokunicwicz et al. 1981).
WATER QUALITY AND CIRCULATION
The hydrodynamics of Subaq E are governed
primarily by tidal currents and secondarily by wind.
Subaq E is located near the Main Ship Channel, the
fastest tidal currents in Boston Harbor occurs in this
area(approx. 1.4 knots). During disposal operations
suspended solids would be released into the Harbor
waters. As a result, there will be localized and
temporary increases in suspended solids concentra-
tions in the water column. The dredged material will
be released from a barge above the site. It would
descend through the water column as a dense mass.
During this descent any where from 3% to 5% of the.,
dredged material may be lost to the water column
(WES 1986).
The common methods of open water disposal do
not alter the chemical properties of the dredged
material, and therefore do not break the bonds that
hold contaminants to sediment particles (Bums and
Schubel 1983; Bokuniewicz et al. 1986). The binding
of pollutants to sediment particles (particularly the
fine-grained organic and/or clay components) tend to
immobilize the contaminants and prevent their
release to the water column (O'Connor and
O'Connor 1983). As a result, any sediment that may
remain suspended after the main deposit reaches the
bottom would not likely release its bonded contami-
nants to the water column. This is consistent with
field studies al disposal sites in New York Harbor;
none have ever detected a significant increase in
contaminant or nutrient level in the water at disposal
sites (ACOK 1984; Bokunicwicz et al. 1986).
The ACOE ADDAM's model was used to demon-
strate potential water quality impacts at this site
(Table 2.7). Under maximum flood tide conditions,
a sediment plume diameter of 2220 feet was predicted
with a silt/clay concentration of 9.7 mg/L above
background; (background is about 4.5 mg/L). It was
calculated that approximately 3% of release material
would remain suspended in the water four hours after
disposal. Under maximum ebb tide conditions a
A1-85
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sediment plume diameter of 2205 feet was predicted
with a. sill/clay concentration of 0.815 mg/L above
background, it was calculated that < 2% of release
material would remain suspended in the water four
hours after disposal under this scenario. The model-
ing analysis indicated that suspended solids would be
transported beyond the disposal site and may extend
for 4,700 feet and could reach Governors Island flat
and Deer Island flats.
After a four hours disposal simulation, the model
calculated a maximum copper concentration within
the plume of 0.0058 ppm under maximum flood tide
conditions, and 0.0019 ppm under maximum ebb tide
conditions. Since the Massachusetts water quality
criteria for copper is 0.0029 ppm., the water quality
criteria was predicted to be exceeded under maximum
flood tide conditions; however, under maximum ebb
tide this condition was not predicted.
AQUATIC RESOURCES
Bcnthic Infauna
Dredged material placed at the site would quickly
be colonized by local species occurring in the harbor
sediments. The resulting community should then be
similar to that presently occurring at the site. Over
the long-term invertebrate productivity and diversity
should improve due to the Boston Harbor Clean-Up
(by MWRA). Therefore, partially filling the trough
at the she would improve habitat quality for inverte-
brates due to the cleaner sediment. Siltation caused
by disposal operations could have some short-term
adverse impacts on invertebrates occurring in adja-
cent areas. Localized siltation should not have long-
term impacts on harbor-wide invertebrate population.
Subaq E is located within 1 mile of the soft shell
clam mudflats in the vicinity of Logan Airport. The
clams in these flats are harvested by commercial
diggers; the mudflats also support blue mussel. The
major impact of concern here is whether cxceedences
Subaqueous Containment Site B (SUBAQ E)
of water quality criteria during flood tide, as predicted
by the ADDAM's model, would result in substantial
bioaccumulation causing undue risk to those bivalves
or to humans consuming them. Given the longevity
of the disposal activity (several months) disposal
during slack and ebb tides may be most appropriate
at this site.
The major physical effect of disposal on aquatic
populations are turbidity and direct burial. Such
impacts would likely be restricted to the short-term,
since the annual reseeding of clam spat would act as
a natural mitigation to these impacts. Shellfish are
filter feeders and the suspended sediment could also
interfere with their feeding mechanism, during the
disposal period.
Finfish
Disposal operations could have some short-term
effects on fish in the vicinity of the Subaq E disposal
site. Some displacement and/or mortality juvenile
and adult fish would occur during disposal events due
to burial or exposure to high suspended sediment
levels. 'ITie outer harbor supports high densities of
winter flounder, Atlantic tomcod, four-spine stickle-
back, and rainbow smelt. Abundance of these
species tend to be highest in September and October.
Any adverse impacts should be limited to the imme-
diate vicinity of the disposal site. Disposal of
dredged material would temporarily reduce prey
available to species which feed primarily on benthic
invertebrates, such as winter flounder.
WETLAND RESOURCES
There would be a short-term impact of 79± acres
of Land Under the Ocean and Tidal Waters. The
site would be restored after construction. The
impacts for the biological resources protected under
I^nd Under the Ocean (310 CMR 10.00) are dis-
cussed above.
A1-86
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Subaqueous Containment Site E (SUBAQ E)
WILDLIFE
Disposal of dredged material at Subaq E should
not adversely impact wildlife populations, e.g. birds,
occurring near the disposal site.
traffic. However, during the installation of the
material, any marine vessels must circumvent this
area to minimize interference with the placement
operation.
THREATENED AND ENDANGERED
SPECIES
The proposed project should not adversely impact
any species considered threatened or endangered by
the USFWS, NMFS and MANHESP. Several
species that are protected under the Federal Marine
Mammals Protection Act (e.g. harbor seals, harbor
porpoise) occur occasionally in this area; construction
activities should discourage them from frequenting
the immediate project site, thus reducing potential
impacts.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
The proposed project would have no effect upon
any structure or site of historic, architectural or
archeological significance as defined by MHC or the
National Historic Preservation Act of 1966, as
amended.
SOCIO-ECONOMIC/LAND USE
The disposal operations would involve approxi-
mately 423 barge trips. This would result in some
delays to commercial and recreational boat traffic
using the harbor. Construction activities would have
a minor adverse aesthetic impact, and result in
slightly elevated noise levels. Any fishing (for lobster,
etc.) in the immediate disposal area would have to be
curtailed during the disposal period.
If filling occurs to the depths of the surrounding
area, there will be no permanent impact on marine
Al-87
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2*53 Winthrop Harbor
This site is depicted in Figure A1-20.
2.5.3.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Sediment grab samples were collected from 17
locations throughout Winthrop Harbor in October
1989 by the ACOE NED (1992). Winthrop Harbor
sediments are predominately clayey silts with low
organic contents and a mean percentage fines content
of about 90%. Fines (silt + clay) content ranged
from 49.3 to 93.4% (mean = 82.4%). Median
particle size ranged from 0.01 to 0.07 mm, and
averaged about 0.024 mm. The bulk" chemical
analysis results for metals are presented in Table Al-
9. Generally, the sediment in Winthrop Harbor
contained low levels of arsenic, cadmium, copper,
nickel, and mercury. Most samples contained mod-
erate levels of lead, but two samples (I and L)
contained relatively high lead levels (Category HI).
Samples from north or northwest of Snake Island
and near Crystal Cove (samples G through Q)
generally contained elevated levels of chromium.
Samples from north of Snake Island and Crystal
Cove had Category II levels of 7.inc. PCB levels in
sediments were below detection levels (< 0.1 ppm)
in all samples. Concentrations of PAHs were also
generally below detection limits (ACOE 1992).
WATER QUALITY AND CIRCULATION
The water quality in Winthrop Harbor is designat-
ed as Class SB by the MADEP. Such saline waters
are suitable for the propagation and protection offish
and other aquatic wildlife, primary and secondary
contact recreation, and shellfish harvesting with
depuration.
Winthrop Harbor
Selected water quality parameters were measured
during an ebb tide on September 2, 1986, by the
ACOE NED. Samples were taken at one meter
depth intervals from four stations within the Harbor.
Temperatures ranged from 16.3 to 15.8°C. Salinity
was 31.5 ppt. Dissolved oxygen (D.O.) levels ranged
from 9.0 to 10.6 and were saturated or supersatu-
rated, presumably due to high rates of photosynthesis
and mixing within the shallow harbor. The pH
ranged between 7.8 and 7.9. Recent studies by Chase
(1993) showed that in July and August 1993 the
temperatures ranged from 17.4°C to 19.2°C and
D.O. from 9.3 to 8.2 ppm. Bottom values were
similar or only slightly lower than surface readings
indicating good tidal mixing and water of adequate
quality to support formal respiration.
Winthrop Harbor is contiguous with Boston
I larbor and receives tidal flow from the outer Harbor
south and east of Deer Island. Currents within the
Winthrop Harbor are tidally dominated and are
strongest in the channel areas (EG&G 1984). Flood
waters flow northwesterly around the tip of Deer
Island and are then funneled northerly into the
Harbor between Snake Island and Point Shirley.
Ebb flows travel in the reverse direction. Average
flood velocities (10.35 cm/sec) are generally greater
than average ebb velocities (8.8 cm/sec). Circulation
within Winthrop Harbor does not appear to be
significantly affected by wind and wave action. The
harbor has a limited fetch and is fairly well protected
from the predominant westerly and northeasterly
winds. The most protected areas in the harbor are
Crystal Cove and Winthrop Basin.
AQUATIC RESOURCES
Bcnthic Infauna
The subtidal sediments in Winthrop Harbor
provide habitat for a variety of benthic invertebrates.
Table A1-10 shows the benlhic invertebrates present
at Winthrop Harbor. Predominant taxa occurring in
Al-88
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Winthrop Harbor
samples collected in the fall of 1989 by the Army
Corps of Engineers were the polychaete (5. bene-
dicli), aquatic oligochaetes, and gammarid amphipod
crustaceans; densities in 1989 were fairly low. Com-
mon benthic invertebrates occurring in intertidal
sediments include spionid polychaetes, clam worms
{Nereis virens), soft shell clams and oligochaetes.
Common epibenthic invertebrates include barnacles
(Balanus noctabis), the common periwinkle (Liltor-
ina Kttorina), the common slipper shell (Crepidula
fornicata), amphipods, and hermit crabs (Pagurus
sp.) (ACOE NED 1992).
Sediments in the area of the borrow pit appear to
have a depauperate invertebrate community. Five
0.04m2 Van-Veen grabs collected from the pit in
October 1989 contained two S. benedicti, and no
other invertebrates. Cerrata and Sceier (1983) have
reviewed the literature on benthic communities in
borrow pits along the east coast. Most such studies
have found the populations within these habitats to
be both less abundant and less diverse than surround-
ing areas, even when there were no noticeable degra-
dations of water quality (lower oxygen, slower
currents and greater sedimentation). Recent studies
reported by Chase (1993) in July and August indicat-
ed however, that up to 55 winter flounder, 47 rain-
bow smelt and 32 lobsters (as well as 9 other taxa)
were caught in an -eight minute tow within the
borrow pit, indicating this area could provide produc-
tive fisheries habitat.
Studies conducted for the ACOE NED in 1985
indicated that Winthrop Harbor sediments are not
toxic to aquatic organisms. Survival of grass shrimp,
clams and sandworms was not significantly (p < .05)
less than organisms exposed to reference sediments.
Bioaccumulation tests done for this study results
showed that clam and worm survival was high for all
sites tested in Boston Harbor (most >95%, none
< 90%). This is considered very good survival and
does not indicate any acute toxicity to the organisms
tested. The test sediments did not cause any statisti-
cally significant mortality compared to the reference
sediments, which was 93% survival for worms and
97.3% for clams.
Soft shell clam (M. arenaria) are abundant in
intertidal mudflats around Snake Island, in the Basin,
and elsewhere in the Harbor. Shell harvesting in the
harbor is prohibited for a greater part of the year
because of fecal coliform contamination. Shellfish
harvesting in Winthrop Harbor is classified as restrict-
ed, and must undergo depuration. Clam harvesting
activities are discussed in more detail below. Blue
mussels (M. edulis) and lobsters (Homarus american-
I/.T) also occur in the Harbor.
VY
Soft shell clam (M. arenaria) are abundant/in
intertidal mudflats around Snake Island, in the Basin,
and elsewhere in the Harbor. Shellfish are a valuable
renewable resource. The maintenance of productive
shellfish beds not only assures the continuance of
shellfish themselves, but also plays a direct role in
supporting fish stocks by providing a major food
source. The young shellfish in the planktonic larval
stage that are produced in large quantities during
spring and summer are an important source of food
for the young stage of marine fishes, many crusta-
ceans.
Finfish
Winter flounder is the most abundant commercial-
ly important species occurring in the harbor. Floun-
der arc likely to be present from the fall through
spring, and spawn in shallow waters with muddy or
sandy bottoms between February and April. The
borrow pit provides a suitable resting habitat for
winter flounder. Of the 88 winter flounder captured
in these 8-minutc tows in the harbor in 1993 (Chase
1993), the majority were young-of-the-year. Catch
rates were similar to trawls in Salem Sound in 1991
and 1992 for this species. Atlantic silverside is
probably the most common forage species in the
harbor. Silvcrsidcs arc typically abundant in near-
shore Massachusetts waters during the spring, sum-
Al-89
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Winthrop Harbor
mcr and fall. Spawning occurs among Spartina from
May through early summer. Rainbow smelt were the
second most abundant finfish species reported subtid-
afly (in trawls) by Chase (1993) in August 1993.
to the values identified under the Massachusetts
Wetlands Protection Act for Land Under the Ocean,
Tidal Waters may provide sediment/toxicant reten-
tion,nutricnt/retention/transformation,recreationand
uniqueness heritage.
WETLAND RESOURCES
Emergent wetlands in Winthrop I larbor are limited
mostly to Snake Island, the northern tip of Point
Shirley, and the basin. Salt marsh grass (S. allerni-
JJora) occurs along about 40% of the Basin shoreline.
The northern tip of Point Shirley and Snake Island
support dense stands of reed (P. communis). Sea
lettuce (U. laclucd) and Entcromorpha sp. occur in
the Basin. These wetland resources may supply
nesting habitats, shelter, and food for some shore-
birds and other wildlife.
This site is primarily Land Under the Ocean, as
defined under State regulations (310 CMR 10.00),
which is classified as significant to marine fisheries,
storm damage prevention and flood control. Most of
Winthrop Harbor shoreline is protected by seawalls.
The seawalls were designed for storm damage preven-
tion and flood control. As described in the Aquatic
Resources section, the borrow pit is suitable as a
resting habitat for flounder, and possibly other
species (i.e. lobsters and crabs).
Land containing shellfish is under 310 CMR 10.34
(3), 'significant to the protection of marine fisheries
as well as to the protection of the interest of landing
containing shellfish'. The shellfish resource in
Winthrop Harbor is discussed above. According to
this regulation, projects that temporarily have an
adverse effect on shellfish productivity but do not
permanently destroy the habitat may be permitted if
the land containing shellfish can and will be returned
substantially to its former productivity in less than
one (1) year.
Winthrop Harbor is also classified as Tidal Waters
under federal regulations (40 CFR 230)). In addition
WILDLIFE
Productive tidal flats in the Basin adjacent to
Snake Island provide good shorebird habitat. Migra-
tory species likely to occur include semipalmated
sandpiper, dunlin, least sandpiper, sanderling, black-
bellied plover, greater yellowlegs, the knot, white-
rumped sandpiper, hudsonian godwit, and shbrtbilled
dowitchcr (ACOE, NED 1992).
THREATENED AND ENDANGERED
SPECIES
No federally listed or proposed threatened or
endangered species are identified or known to exist in
Winthrop I larbor. I lowever, historically the federally
endangered piping plover (Charadrius melodus)
nested on Snake Island. Two state species of special
concern, the least tem (Sterna albifrons) and the
common tem (Sterna hirundo) also once nested on
the island. In addition, the black duck, a species of
special concern to the USFWS regularly winters in
Winthrop Harbor (ACOE, NED 1992).
HISTORICAL AND ARCHEOLOG1CAL
RESOURCES
There arc no known prehistoric sites in the vicinity
of the proposed project. The Winthrop coastal area
and Snake Island have the potential for containing
prehistoric sites. Snake Island is included in the
Boston I larbor Islands Archcological District and is
listed on the National Register of Historic Places.
Al-90
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Winthrop Harbor
There were five known shipwrecks in Winthrop.
Three of these wrecks occurred near Point Shirley.
Due to past dredging in the harbor, it is likely that
these sites have been previously disturbed or de-
stroyed (ACOE NED 1992).
SOCIO-ECONOMIC/LAND USE
Winthrop is a predominantly residential, coastal
community with a high population density. The
1980 US Census reported a total population of
19,294, and a median family income of $22,224.
Winthrop is a popular summer resort. The service,
government, and the wholesale/retail trade sectors arc
the largest source of employment hi the town. Less
than 1 % of the town's workforce is directly em-
ployed in the fishing industry.
The town has two main harbors (Winthrop
Harbor and Belle Island Inlet) which provide anchor-
age for about 800 recreational craft and 34 commer-
cial fishing vessels. About 370 existing recreational
craft are based at slips in Winthrop Harbor, and 124
at slips at the Belle Isle Inlet. Another 270 recre-
ational craft utilize open moorings in the harbor.
There are several private marinas in Winthrop which
provide facilities for recreational craft. The state has
provided a boat ramp and a three acre parking area
along the north shore of the Basin for public access.
The proposed disposal site in Winthrop Harbor is
adjacent to the Winthrop Yacht Club, within 750 feet
of Crystal Cove Marina and about 900 feet from a
public landing. It is in a narrow channel which is
heavily used by recreational boaters.
Most of the 34 commercial vessels fish full-time for
lobsters in eastern Massachusetts waters. Some boats
rig for dragging especially in colder months, in order
to harvest scallops and groundfish from offshore
waters. Virtually all landings are harvested from
outside of Winthrop Harbor (ACOE, NED 1992).
Approximately 30 to 35 master diggers harvest
clams from Winthrop Harbor, principally from flats
around Snake Island, west of Point Shirley, and near
Logan International Airport. Theses areas are
classified as restricted, and all clams harvested must
undergo depuration at the MADMF Newburyport
Shellfish treatment Plant. The average annual
harvest of clams from these fiats for 1992 was 11,036
bushels (Jeffery Kennedy, (MADMF) pers. commun,
June 17, 1993). The wholesale value (to diggers) of
this fishery is approximately $700,000 per year. No
recreational shellfishing is allowed in the harbor.
2.5.3.2 Environmental Consequences /•
SEDIMENT CHARACTERISTICS
Sediment placed in the pit would be somewhat
more coarse than existing sediments. Existing sedi-
ments in Winthrop Harbor contain low to moderate
levels of contaminants. The silt sediments placed at
the disposal site would be stabilized by a 3-foot cap
of clean sediment. The cap eventually will be buried
by fine sediments deposited by natural processes. Silt
material placed in open-water disposal sites can be
chemically and/or biologically isolated by capping
with clean dredged material (Truitt 1986).
The cap and the dredged sediments would be
confined within the walls of the pit below the level of
the harbor floor. Therefore in the long term, a
deposit in a borrow pit would be less likely to release
contaminants because it is not in direct contact with
the water column. Even more important, because of
its location under the seafloor, the borrow pit would
be less likely to expose the buried silt sediments
through natural erosion (current action) or extraordi-
nary storm events. Therefore, the site vulnerability
to storms should be negligible because of the added
protection because of greater depth and the pit walls
(Bokunicwicz ct al. 1981). Recent analysis of Win-
throp Harbor as a subaqueous borrow pit
(Bokuniewicz 1993) indicated (from ADDAM's
Al-91
A
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model results) that a 2000 cy dump would not reach
the sides of the borrow pit at its widest point indicat-
ing the material would probably not escape from the
pit during disposal. This would help ensure its
containment until a cap is placed.
WATER QUALITY AND CIRCULATION
Winthrop Harbor is contiguous with Boston
Harbor and receives tidal flow from the Outer Har-
bor south and east of Deer Island. Currents within
the harbor are tidally dominated and are strongest in
the channel areas (EG&G 1984). Average flood
velocities (10.35 cm/sec) are generally greater than
average ebb velocities (8.8 cm/sec). Studies done by
the ACOE, NYD (1988) showed that currents are
directed toward the area of a manmade depression,
slowing down over it, and speeding up again once
away from its influence. Circulation within Win-
throp Harbor does not appear to be significantly
affected by wind and wave action.
During disposal operations some suspended solids
would be released into the Winthrop Harbor waters
as the dredged material goes to the bottom, even
though it would descend through the water column
as a dense mass. During this descent any where from
3% to 5% of the dredged material may be lost to the
water column (WES 1986). As a result, there would
be localized and temporary increases in suspended
solids concentrations in the water column. Disposal
activity at this site would occur for approximately a
6- to 9-month period. Therefore, there would be
some localized increases of the suspended solids on
the water quality in the vicinity of the site.
The common methods of open water disposal do
not alter the chemical properties of the dredged
material, and therefore do not break the bonds that
hold contaminants to sediment particles (Bums and
Schubel 1983;BokunJewic7.etal. 1986). The binding
of pollutants to sediment particles (particularly the
fine-grained organic and/or clay components) tends
Winthrop Harbor
to immobilize the contaminants and prevent their
release to the water column (O'Connor and
O'Connor 1983). As a result, any sediment that may
remain suspended after the main deposit reaches the
bottom would not likely release its bonded contami-
nants to the water column. This is consistent with
field studies at disposal sites in New York Harbor;
none have ever detected a significant increase in
contaminant or nutrient level in the water at disposal
sites (ACOE, NYD 1984; Bokuniewicz et al. 1986).
The ACOE ADDAM's model was used to demon-
strate potential water quality impacts at a representa-
tive in-harbor site: Subaqueous E (Table 2.7).
Under maximum flood tide conditions, a sediment
plume diameter of 2220 feet was predicted with a
silt/clay concentration of 9.7 mg/L above back-
ground; it was calculated that approximately 3% of
release material would remain suspended in the water
four hours after disposal. Under maximum ebb tide
conditions a sediment plume diameter of 2205 feet
was predicted with a silt/clay concentration of 0.815
mg/L above background; (background is approxi-
mately 4.5 mg/L). It was calculated that < 2% of
release material would remain suspended in the water
four hours after disposal under tliis scenario.
After a four hours disposal simulation, the model
calculated a maximum copper concentration within
the plume of 0.0058 ppm under maximum flood tide
conditions, and 0.0019 ppm under maximum ebb tide
conditions. The Massachusetts water quality criteria
for copper is 0.0029 ppm. Therefore, under maxi-
mum flood tide conditions, the water quality criteria
was predicted to be exceeded; however, under maxi-
mum ebb tide this condition was not predicted. The
modeling analysis indicated that suspended solids and
attendant contaminants would be transported beyond
the disposal site and may extend for 4,700 feet.
Assuming transport from the Winthrop site would be
similar to the Subaqueous E site, then the silt plume
could impinge upon Snake Island flats and the Basin
and the aquatic resources therein.
A1-92
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Winthrop Harbor
AQUATIC RESOURCES
Benthic Infauna
Benthic invertebrates at the Winthrop in-harbor
disposal site would be buried during disposal opera-
tions. Benthic samples taken in the area of the
proposed pit by the ACOE, NED in October 1989
contained two S. benedicti, and no other inverte-
brates. Low invertebrate populations suggest that the
sediments in the borrow pit may be anoxic (ACOE
NED 1992). Furthermore, adverse physical condi-
tions such as poor circulation/exchange rates, low
dissolved oxygen, and higher sedimentation, cause
benthic species in borrow pits to suffer very high
mortality rates (ACOENED, 1988). This condition
was not observed in July and August, 1993
(MADMF, 1993), however, where sampling indicated
that the overlying water was of sufficient quality to
support fauna! respirations.
The nature of the final community will depend on
the make-up of the cap. For this project it is pro-
posed that Boston blue clay be used as the cap, and
possibly a layer of clean sand placed on top of the
cap. This cap would also eventually be buried by
fine sediments deposited by natural processes. There-
fore, it is reasonable to expect rapid recolonization of
S. benedicti from the undisturbed populations around
the pit, perhaps hi as short a time frame as one year
(Cerrato and Scheir 1983). The new community
should then be similar to the existing harbor commu-
nity. Over the long-term, invertebrate productivity
and diversity should be higher than currently found
in depauperate borrow pit bottom sediments. There-
fore, partially filling the 35-foot borrow pit could
improve habitat quality for invertebrates.
Siltation caused by disposal operations could have
some short-term adverse impacts on invertebrates
occurring in subtidal areas immediately adjacent to
the borrow pit. However, siltation should have no
adverse long-term impact on harbor invertebrate
communities.
Soft-shell clam arc abundant in the intertidal
mudflats around Snake Island, in the Basin, and
elsewhere in the Harbor. Some clam mortality could
occur in adjacent areas because of elevated suspended
sediment levels and siltation. Small clams with
minimal energy reserves would probably be most
vulnerable; these can be reseeded (naturally) within a
year, however, so should recover adequately.
ADDAM's model results estimated that siltation
could be on the order of twice normal background
levels over a plume diameter of 2200; this plunie
could reach Snake Island flats on a flood tide.
However, storm and strong wind events can increase
turbidity (total suspended solids) in shallow subtidal
areas so local populations should be naturally adapt-
ed to these conditions. The potentially continuous
nature of the disposed activity over several months,
however, could possibly cause some cumulative
impacts; however, natural reseeding should mitigate
any of these impacts that do occur.
Of greater concern would be exposure to shellfish
by elevated levels of metals and/or organics.
ADDAM's model results indicate that on a flood tide
at subaqueous E, copper levels would not be below
the water quality criteria levels four hours after a
dump (they may be on the order of twice as high).
Since clams are filter feeders, there is the potential for
bioaccumulation of contaminants during flood tide
conditions from disposal in Winthrop Harbor.
Mitigalivc measures to contain siltation and/or more
detailed studies may be necessary to insure that
adverse impacts to shellfish (or human consumers)
do not occur form this disposal at this site.
A1-93
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Winthrop Harbor
FinOsh
Disposal operations should have only short-term
effects on fish in the vicinity of the borrow pit in-
harbor disposal site. Some mortality to juvenile and
adult fish would occur during disposal events due to
burial or exposure to high suspended sediment levels.
Lobsters and crabs inhabiting the area could also
suffer some mortality. Impacts should be limited to
the immediate vicinity of the disposal site. The
resident fish and crustaceans would be displaced from
the disposal site during operations, which should last
over 6-9 months (although not necessarily consecu-
tive months). Disposal of dredged material would
temporarily reduce prey available to species which
feed primarily on bcnthic invertebrates, such as
winter flounder. Partially filling the borrow pit
should still leave a hole suitable as a resting habitat
for flounder and other species.
WETLAND RESOURCES
The proposed project should have no impact on
the emergent wetlands in the vicinity of the site. The
dense stands of reed (P. 'comtnunis) on Snake Island
and salt marsh grass (5. alterniflorari) on the Basin
shoreline should not be impacted by the disposal of
dredged material in the borrow pit. There would be
a short-term impact of 8.14± acres of Land Under
the Ocean and Tidal Waters. The site would be
restored after construction. The impacts for the
biological resources protected under Land Under the
Ocean (310 CMR 10.00) arc discussed above.
WILDLIFE
Disposal of dredged material in the borrow pit
should have no long-term adverse impact on wildlife
populations occurring near the disposal site.
THREATENED AND ENDANGERED
SPECIES
The proposed project should have no adverse
impact on any species considered threatened or
endangered by the USFWS, NMFS and MANHESP.
HISTORICAL AND ARCHEOLOG1CAL
RESOURCES
The proposed project would not affect any struc-
ture or site of historic, architectural or archeological
significance as defined by NHC or the National
Historic Preservation Act of 1966, as amended.
SOriO-KCONOMIC/LAND USE
'Die disposal operations would involve approxi-
mately 160 barge trips. This would result in some
delays to commercial and recreational boat traffic
using the harbor. Construction activities would have
a minor adverse aesthetic impact, and result in
slightly elevated noise levels. Impacts to the soft-
shell clam industry in Winthrop Harbor would have
to be protected by appropriate mitigation and control
of the silt cloud from disposal.
This site is some fifteen feet deeper than the
surrounding area in the channel. Were the site to be
filled to match the surrounding harbor bottom, there
is not likely to be any permanent impact on the
boating activity in the channel. However, the place-
ment of the fill material will clearly affect the boat
traffic unless it is carried out hi the off-season.
Turbidity during placement should be minimized so
as not to affect marine life in the adjacent marshes.
A1-94
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Massachusetts Bay Disposal Site (MBDS)
2.6 SITE EVALUATIONS: EXISTING
AQUATIC DISPOSAL SITES
2.6.1 Massachusetts Bay Disposal Site fMBDS)
This site is depicted in Figure A1-21.
2.6.1.1 Existing Conditions
SEDIMENT CHARACTERISTICS
The physical properties of the substrate near the
disposal point is varying in composition, predom-
inantly sandy silt, reflecting the various harbor
dredging projects disposed here. The natural bottom
covering the majority of MBDS (i.e. areas of the silt
that have not received dredged material) is a fine
silt/clay substrate (ACOENED unpublished data).
The composition of this natural material indicates the
basin is a depositional area capable of containing the
dredged material. If sufficient currents frequented
this area of the basin, the fine grained material would
be suspended and transported with the currents.
Areas of high current velocities would therefore have
a coarse grained (heavier than silt/clay) substrate, a
substrate that is not typical of this basin, but is
present in the shallow (approximately 60 meter deep)
northeast quadrant of MBDS. This area is a
rock/cobble/sand area, at the 60 meter isopleth relief
west of Stellwagen Bank.
The EPA (1989) evaluated the sediment composi-
tion of the MBDS in their draft BIS to evaluate the
continued use of the MBDS. The results of the
metals analysis show that metal concentrations in the
MBDS are either Class I (low) or Class II (moderate)
according to the Massachusetts Division of Water
Pollution Control guidelines for dredged material. In
general these results were similar to levels found
outside the disposal site in Massachusetts Bay: EPA
1989). Petroleum hydrocarbons were detected at a
higher level within the MBDS than outside. Howev-
er, polyaromatic hydrocarbons, a measure of the
aromatic fraction of petroleum hydrocarbons was
more varied inside than outside the disposal site.
Polychlorinated biphenyls (PCBs) levels on dredged
material are somewhat higher than ambient levels.
PCB levels detected in dredged material in the
vicinity of the MBDS are comparable to levels
identified in other Massachusetts Bay studies (EPA
1989).
WATER QUALITY AND CIRCULATION
The oceanography of MBDS is influenced, in part,
by the circulation of the Gulf of Maine. (SAIG
1993). The Gulf of Maine circulation patterns in die
vicinity of the MBDS arc modified to a large extent
by the presence of Stellwagen Bank on the eastern
margin of the Massachusetts Bay. The bank inter-
feres with the exchange of water at depth with the
Gulf and the shelf beyond. Stellwagen Bank is a
popular fishing and whale watching area. This area
was designated as a national marine sanctuary on
November 4, 1992. The MBDS is located outside
the boundary of the Steliwagen Bank national marine
sanctuary.
Results of MBDS oceanographic studies indicate
the site to be located in a low energy, deep water
environment, allowing containment of dredged
material within the site. Physical oceanographic
studies conducted by ACOENED underthe Disposal
Area Monitoring System (DAMOS) program as well
as those by other investigators have shown that the
bottom current velocities at the disposal site are quite
low, averaging less than 7 cm/s (Butman 1977;
Gilbert 1975; SAIC 1987a and SAIC 1993). This is
general agreement with the current data collected for
disposal of dredged material at the MBDS from the
construction of the CA/T (EA Engineering, Science,
and Technology 1992). Occasional higher velocities,
near 20 cm/s in a westerly direction, have been
observed in near bottom waters in response to
easterly storm events that occurred in fall and winter.
Near-bottom currents of this magnitude were not
A1-95
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predicted to be strong enough to resuspend sediments
at MBDS (EPA 1989).
The temperature/salinity cycle of Massachusetts
Bay is characterized by seasonal variability, with
maximum temperatures (18°C at surface) typically
occurring in a stratified water column during August
and September, and minimum temperatures (5°C)
typically occurring in an essentially isothermal water
column in January and February (SAIC 1987a).
Salinity values range from 31-33 ppt (SAIC 1987a).
AQUATIC RESOURCES
Benthic Infauna
Sampling of the benthos at the MBDS (SAIC
1986) described three distinct community assemblages
as occurring. These assemblages reflect the various
sediment regimes within the site.
The northeast section of the site has an unim-
pacted coarse sand and gravel composition. The
bcnthic community, when sampled in the fall of
1985, was numerically dominated by the Syllidae
polychaete Exogone verugera profunda (907/m2);the
Paraonidae polchaete Levinscnia gracilis (350/m2);
and the Spionidae polychaete Prionospio sleenslrupi
(313/m2). A total of 105 species averaging 4,433
organisms per square meter were recovered.
Rock from the CA/T project was deposited in the
northern section of the MBDS. The rock was placed
away from the main disposal activity to allow a
benthic community to develop providing prey for
finfish.
The western portion of the MBDS has been
impacted by continued disposal of dredged material
from the greater Boston region. Approximately three
million cubic yards of dredged material is disposed in
this section of MBDS. This continual disturbance of
the bottom maintains the community of benthic
Massachusetts Bay Disposal Site (MBDS)
organisms in a dynamic equilibrium. The most
adaptable species proliferate. Those species that
reproduce rapidly and have high numbers of offspring
(i.e., larvae) colonize the newly disposed dredged
material (r-strategists of classical ecology) and biogen-
ically rework the substrate. Given time, this pioneer-
ing community would alter the sediment character
and allow a more mature community to develop.
The frequent disposal activity maintains the resident
population of the disposed material area as a pioneer-
ing sere. This assemblage at MBDS was dominated
(in fall 1986) by oligochactes (6,293/m2); the Spioni-
dae polychaete Spio pettibonae (4,607/m2); the
Cirratulidae polychaete Chaelozone v v setosa
(2,160/m2); and the Capitcllidae polychaete Metio-
mastus ambisela (1,757/m2). A total of 78 species
averaging 25,467 organisms per square meter were
recovered.
The southeastern section of MBDS has an unim-
pacted silt/clay sediment make-up. The lack of
physical disturbance (burial) by disposal of dredged
material has allowed a mature benthic assemblage to
become established. Interspecific competition within
a mature community results in a presence of consid-
erably lower densities of individuals (e.g. 8,390/m2)
than found in continually disturbed habitats (e.g.
25,467/m2). The undisturbed southeastern section of
MBDS was dominated by the Paraonitae polychaete
Lcvinsenia gracilis (1,583/m2); oligochaetes
(1,050/m2); and the Capitellidae polchaete Medio-
maxtux ambisela (693/m2). The fall 1985 sampling in
this section of MBDS recovered a total of 57 species
averaging 8,390 individuals per square meter.
The August 1990 bathymetric and REMOTS
sediment profile surveys conducted at MBDS con-
firmed that the dredged material formed a deposit one
meter high at the mound center (SAIC 1993).
Despite the large amount of material (over 340,000
cubic yards) deposited at the site since November
198.8, the REMOTS photography indicate a steady
recovery of the bcnthic ecosystem. This was indicat-
ed by steady increase in Stage III taxa (large burrow-
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Massachusetts Bay Disposal Site (MBDS)
ing deposit feeders, i.e. climax community) (SAIC
1993).
Finfish
Various finfish species have been collected within
the MBDS (SAIC 1986, SAIC 1985, EPA 1989). In
the spring of 1985, the spiny dogfish Squalus acanlh-
ias was the dominant finfish recovered. This species
migrates seasonally in large schools. Those sampled
at MBDS were found to be feeding on flounder,
sculpin, and anemones. Fall 1985 finfish collections
were dominated by the witch flounder or grey sole
Glyptocephalus cynoglossus and the dab or Ameri-
can plaice Hippoglossoides plalessoides. The former
was found to be foraging on polychaetes (e.g.
Chaelozone sp.; Spio sp.; Slernapsis sp. and Tharyx
sp.). The latter was found to be foraging on brittle
stars (Ophiuroidea). Other important species include
redfish, ocean pout, cusk, and Atlantic wolffish.
SuVer and red hake are abundant, commercially
important seasonal migrants.
WETLAND RESOURCES
There are no protectable wetland resources subject
to federal or state jurisdiction at MBDS.
WILDLIFE
Approximately 35 species of marine mammals, 5
species of marine turtles and 40 species of seabirds
occur within the Gulf of Maine. Aerial surveys were
conducted for the ACOE to assess the use of the
Massachusetts Bay Disposal Site (MBDS) by marine
mammals, reptiles and seabirds (MBO 1987).
Seabirds observed include northern fulmar (Ful-
manus glacialis), shearwater (Ptiffmus sp.), storm
petrels (Hydrobatrae), northern gaument (Sila bac-
saus), Pomarine jaeger (Steriovarius pomarinum),
gulls (I^arinae) and Alcids (Alcidae). Dominant
nonendangered mammals include minke whale
(Belasnoplera acutorostrala), white-sided dolphin
(iMgenorhynchus acutus), and harbor porpoise
(Phocena phocena). Although five species of turtles
potentially could occur on Massachusetts Bay, only
the leatherback turtle (Dermochefys coriacea) is
typical in the area.
THREATENED AND ENDANGERED
SPECIES
MBDS is located in Massachusetts Bay, an area
known to be utilized by various marine mammals,
but outside (just west of) the boundaries of the
Stellwagen Bank national marine sanctuary. Endan-
gered whale species are known to congregate above
the shallow (30 meter) Stellwagen Bank (U.R.L
1981) when foraging for prey (e.g. sand lance Am-
monlytes americanus). These species also have been
observed within the two nautical mile circular bound-
ary of the MBDS. Endangered species identified as
transients of MBDS include the finback whale
Balaenoptera physalus; the sci whale Balaenoptera
borealis; the humpback whale Megaptera novae-
angliae and possibly the northern right whale
Eubalaena glacialis(MBO 1987). The impact of the
use of the MBDS on endangered species is currently
being assessed by the ACOE NED. Use of the site
to date has not indicated any impact to threatened or
endangered species. Full coordination with the
NMFS ensures compliance with the protection of
endangered species and their habitats.
Cetaceans arc transients of the disposal site, but
are not likely to be to impacted by ocean disposal.
Some threatened or endangered turtles (i.e., leather-
back, Kemp's ridlcy and loggerhead) have been
recovered in this region as well. If any transient
endangered species entered the area during the project
operation, they should be able to avoid the dredging
or disposal activity. Disposal of dredged material at
the MBDS is not expected to have an adverse impact
A1-97
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on endangered species, their prey, or the habitat
essential for their survival. Consultation with the
NMFS under Section 7 of the Endangered Species
Act of 1973 (as amended, 16 U.S.C. 1531 et seq). has
been initiated to ensure this activity will not jeopar-
dize any endangered or threatened species.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
The MBDS has been used for disposal of dredged
material since the 1940's. No historical or archeolog-
tcal resources are expected to occur at the site.
Consultation by EPA during the designation of the
MBDS with the Massachusetts Board of Underwater
Archeology report that no known historical ship-
wrecks exist at or near the site.
SOCIO-ECONOMIC/LAND USE
MBDS is an active disposal site that has been in
use for several decades. Extensive shipping, fishing,
recreational activities, and scientific investigations
take place in Massachusetts Bay year around. There
arc no known interferences from disposal events on
these activities (EPA ROD 1993). In addition, the
availability of the MBDS for the vast majority of
sediments from Boston Harbor provides an engineer-
ing, social, environmental, and economic solution for
the disposal of such a large amount of material.
2.6.1.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
MBDS has been extensively studied by the ACOE
NED. Precision bathymetry, sediment grab sampling
and REMOTS image analysis (sediment profiling)
have characterized this site as a low energy environ-
ment suitable for dredged material disposal and
containment. Additional occanographic sampling has
Massachusetts Bay Disposal Site (MBOS)
been conducted to designate MBDS as an ocean
dredged material disposal site.
The MBDS is the only U.S. EPA designated
dredged material disposal site in the Boston Har-
bor/Massachusetts Bay area. This site annually
receives approximately 300,000 cubic yards of
dredged material with the exception of this project.
However, this figure is expected to decrease for two
reasons. First, more stringent biological testing for
open water disposal of dredged material means more
material will not be acceptable for open water dispos-
al. In addition, the recent designation of the MBDS
by EPA states that no capping of unsuitablevmaterial
is allowed at the MBDS until it can be derrfbnstrated
that capping can isolate unsuitable material from the
benlhic community. Until this can be demonstrated
to the satisfaction of the EPA and other appropriate
agencies, capping would not occur. Since much of
the sill material dredged from the Boston Harbor
area is unsuitable, this site would be used primarily
for parent material. The ACOE NED has successful-
ly completed many capping projects in New England
and believes capping is a viable option at the MBDS.
Although no capping of unsuitable material will
occur for the Boston I larbor navigation improvement
project at the MBDS, questions raised by EPA about
capping are addressed in Appendix F. Future use of
the site may be considered if the efficacy of capping
can be demonstrated.
Approximately 2.0 million cubic yards of dredged
material (parent material) could be disposed at the
MBDS. The material dredged from the proposed
channels will be placed on barges and transported
(approximately 1500 trips) to MBDS. The disposal
will occur by bringing the barge to a complete stop
at the prcdcscribed point. This disposal point will be
marked by a buoy positioned by the ACOE NED.
The discharge will occur in approximately 100 meters
of water.
A1-98
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Massachusetts Bay Disposal Site (MBDS)
WATER QUALITY AND CIRCULATION
A turbidity plume will be created by the disposal
of the dredged material. During descent, some of the
fine-grained sediment separate from the plume and
remain in suspension. The amount of material that
is dispersed in the disposal plume is dependent upon
the physical characteristics of the sediment, the
volume of material disposed, and method of disposal,
and typically ranges from 3 to 5% (WES 1986).
Recent studies (SMC 1985) concluded that the
concentration of suspended materials in the turbidity
plume, following disposal, will be no greater than 5
to 12 mg/1 forty minutes after disposal. These studies
were conducted at the MBDS with hydraulically
dredged material disposed in 100 meters of water.
This method of dredging mixes the sediment with
water to form a slurry. The disposal of this mixture
represents the maximum possible suspension of
material. The bucket dredging technique to be used
for this project will maintain the disposal sediments
in a cohesive mass, greatly reducing turbidity poten-
tials.
Dredged material which settles on the bottom at
MBDS can be expected to remain in place. Near
bottom currents are low, averaging less than 7 cm/s
(EPA, 1989). Resuspension from storm events is
rare and typically results in resuspension of only 4%
of the surficial material.
As the material descends through the water col-
umn, some of the chemicals adsorbed to the fine
particulates may be eluted from the dredged material.
The concentration values in the turbidity plume will
be considerably less than the bulk chemistry concen-
trations in the dredged material, since most of the
material will remain consolidated. Due to the low
natural levels of metals and other chemicals in the
clay, the water quality impact, if any, will be con-
tained within the disposal site. EPA determined that
water quality impacts from disposal events are
temporary and limited to the period immediately
following the disposal (EPA 1989).
Recent studies (EPA 1993) for the MWRA off-
shore outfall impacts evaluated water quality impacts
at MBDS from the BIINIP, using the ADDAM's
model with input assumptions and data from this
study. In that report, EPA found no water quality
criteria cxcccdcnces outside the mixing zone (disposal
site) for the MBDS after four hours.
Physical parameters such as currents, waves, and
tidal circulations have been closely monitored for the
site (SAIC 1985). This area has contained dredged
material on site and does not disperse sediment'or
chemicals to affect ambient environments. In gener-
al, the proposed disposal of an estimated 1.8 million
cubic yards of material dredged from the project area
will not significantly impact the disposal site given its
physical, chemical and biological characteristics and
general history of use.
AQUATIC RESOURCES
Bcnthic Infauna
Hie disposal site has been used for dredged materi-
al disposal for a number of years. Disposing sedi-
ments at site buries the organisms inhabiting the
impact area. This burial process has been of suffi-
cient frequency at MBDS to maintain a disturbed
environment at the point of disposal. A specialized
population of benthic species have successfully
exploited this disturbed niche and rapidly provide
biomass and bioturbation to the newly disposed
material. These pioneering organisms are already
established on the disposal site (SAIC 1985) and their
action can quickly rework the newly deposited
sediments. The disposal of dredged sediments would
bury non-motile and larval/juvenile organisms at
MBDS. The same pioneering species can quickly
inhabit the newly disposed material by larval and
adult recruitment. The overall process of maintaining
Al-99
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Massachusetts Bay Disposal Site (MBDS)
a disturbed habitat would provide a productive
bcnthic environment for organisms that rework the
substrate. This biological mining of the substrates
(bioturbation) homogenizes and oxygenates the
upper few centimeters of the sediment. This can
allow other organisms to begin inhabiting the sub-
strate (colonization). Larvae settle and metamorphize
and adults emigrate into the area, all contributing to
restore bcnthic productivity.
Endangered whale species have been observed within
the two nautical mile circular boundary of the
MBDS. The impact of the use of the MBDS on
endangered species is currently being assessed by
ACOE NED. Use of the site to date has not indicat-
ed any impact to threatened or endangered species.
Full coordination with the NMFS ensures compli-
ance with the protection of endangered species and
their habitats.
Finfish
Disposal of dredged material will have a temporary
impact on finfish at the site. Adverse impacts to
individual organisms could occur but are not expect-
ed to be substantial considering the mobile nature of
fish. Temporary impacts are expected to come from
the temporary loss of benthic species for foraging.
Due to the already disturbed nature of the site and
the quick recolonizing ability of benthic organisms
recovery should occur in the short-term. Any chang-
es to in benthic community structure should be
localized and with respect to fisheries resources on a
baywide basis.
WETLAND RESOURCES
Since there are no regulated federal or state wet-
land resources associated with MBDS, no impacts
will occur.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
./•/
No impacts are anticipated, since no historical or
archeologjcal resources of record exist at MBDS.
SOCIO-ECONOMIC/LAND USE
Since MBDS is an active dredge material site, no
additional impacts arc expected to site usage or
commerce than may presently exist.
WILDLIFE
No impacts are anticipated to the existing wildlife
at MBDS.
THREATENED AND ENDANGERED
SPECIES
Several endangered whale and turtle species can
occur in the Massachusetts and Cape Cod Bays.
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Boston I jgbtship Disposal Site (BL.DS)
2.6.2 Boston Lightship Disposal Sitc(BLDS)
The site is depicted on Figure A1-21.
BLDS is a historic area for dumping of various
materials -(e-8-> barrels). Therefore, prior to any
disposal of dredge materials at BLDS, surveys to
determine where, if any, barrels occur in the disposal
site, and hydrographic surveys of the area are needed
to determine if the site is stable. BLDS is an area for
which previously collected sidescan sonar records are
being analyzed by the United States Geological
Survey to map acoustic patterns and related sedimen-
tary environments (Butman et al. 1992).
2.6.2.1 Existing Conditions
SEDIMENT CHARACTERISTICS
Information collected under the DAMOS (1979a)
program indicate that the heavy metal content of the
sediments collected from the disposal site were
among the highest found in the study between the
two Massachusetts Bay Disposal sites. Even still,
comparison of the sediment chemistry results with
the Massachusetts Dredged Material guidelines show
that the metal concentration would be classified as
Class I (low).
WATER QUALITY AND CIRCULATION
Water quality and circulation conditions at BLDS
are presumed to be similar to those al MBDS. Both
the MBDS and Boston Lightship are reported to
have extremely weak tidal current but could be
subject to some wave motion (DAMOS, 1979).
AQUATIC RESOURCES
Bcnthic Infauna
A summary of the benthic species collected at
BLDS in December of 1977 and May of 1978 indi-
cate a smaller number of individuals and species than
at other disposal sites located in the Gulf of Maine
(DAMOS 1979b). Dominant benthic species include
the polychaetes Sternapsis scutala, Nepthys incisa,
Maldane sarsl, iMmbrineris fragifis, Ninoe nigrippes,
Goniada maculala, Ampharete aculifronons, nemer-
tean worm Micrura sp., burrowing anemone Edward-
sia elegans, and the amphipod Hippomedon serraliiS
(DAMOS 1979a).
Mussels (Modiolus modiolus) were deployed at
BLDS in 1978 to monitor temporal and spatial
variations in ambient metal and other chemical
concentrations in the sediments (DAMOS 1979b).
Results indicated that the mussels at BLDS had
metal concentrations which approximated those in
animals at Halfway Rock, a reference site. Data
indicates that the reference population at Halfway
Rock, being closer to terrestrial sources of contami-
nation, is probably exposed to similar or higher
concentrations of some trace metals than the mussels
held at the disposal site (DAMOS 1979b). However,
subsequent samples taken from both the reference
and disposal site showed increases of the disposal site
concentrations over those of the reference station.
Finfish
The Massachusetts Bay area is a productive fishery
habitat. l:ish reported to occur in the area of the
disposal site include cod, dab and gray sole, yellowtail
flounder, whiting, Atlantic herring are caught near the
vicinity of the Boston Lightship and the MBDS
(DAMOS 1979a). Lobster and ocean quahogs are
also reported in the area.
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WETLAND RESOURCES
There are no prolectablc wetland resources subject
to federal or state jurisdiction at BLDS.
WILDLIFE
Wildlife, including great cormorant (P. carbd),
herring gull (L. argentalus), white winged scoter (M.
deglandi), common goldeneye (/?. clangula), buffle-
head (B. albeola), mallard (A. platyrkynchos), black
duck (A. Rubripes), merganser (Mergus spp.) and
scaup (Aythya spp.) are likely to intermittently utilize
BLDS for feeding and resting. Each of these species
feed on fish and invertebrates (Martin ct al. 1951;
Whitlatch 1982; DcGraafand Rudis 1986) that occur
in the area.
THREATENED AND ENDANGERED
SPECIES
BLDS is located in Massachusetts Bay, an area
known to be utilized by various marine mammals,
but outside the boundaries of the Stellwagen Bank
national marine sanctuary. Cetaceans are transients of
the disposal site, but are not likely to be impacted by
ocean disposal. Endangered whale species are known
to congregate above the shallow (30 meter) Stell-
wagen Bank (U.R.I. 1981) when foraging for prey
(c.g., sand lance Ammonlyles americanus). Endan-
gered species presumed to be transients at BLDS
include the finback whale Ralaenoplera physalus; the
set whale Balacnoplera borealLr, the humpback whale
Megaplera novacangliae and possibly the northern
right whale Eubalaena glacialis(MRQ 1987). Threat-
ened or endangered turtles could transit this area as
well. The impact of the use of Boston Lightship on
endangered species'is currently being assessed by
ACOENED. Boston Lightship is further removed
from the prime threatened and endangered species
habitat at Stellwagen Bank. Use of the site to date
has not indicated any impact to threatened or endan-
Boston I jghlship Disposal Site (BLDS)
gcred species. Full coordination with the NMFS
ensures compliance with the protection of endangered
species and their habitats.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
BLDS has historically been used for disposal of
dredged material. No historical or archeological
resources arc expected to occur at the site.
SOCIO-ECONOMIC/LAND USE ;<•
/
Extensive shipping, fishing, recreational activities,
and scientific investigations take place in Massachu-
setts Bay year round. There are no known interfer-
ences from disposal events on this activities (EPA
ROD 1993). In addition, the availability of the
BLDS for the vast majority of sediments from
Boston Harbor provides a potential solution for the
disposal of large amounts of dredged material.
2.6.2.2 Environmental Consequences
SEDIMENT CHARACTERISTICS
The BLDS is an historical disposal site located
approximately 16 nautical miles from Boston Harbor.
BLDS was closed to disposal activities in 1977. The
amount of specific site information regarding Boston
Lightship is limited. Several studies conducted by the
EPA to determine if barrels containing radioactive or
other material have been disposed in the area.
Studies conducted by the U.S.G.S for the MWRA
outfall pipe have been conducted in the vicinity of
Boston I jghtship to determine sediment and currents
in Massachusetts Bay.
Disposal of dredged material should not impact a
previously unused site. The material disposed at
BLDS came from Boston Harbor and possibly
Al-102
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Boston Lightship Disposal Site (BLDS)
surrounding areas. Therefore the chemical signature
in the site sediments should be similar to the dredged
material.
Capping with parent material could be a viable
management option for disposal of silt sediments
from Boston Harbor. An argument against disposal
at the MBDS is that capping has never occurred at
the depth of 80 to 100 meters. The depth at BLDS
(60± meters) is similar to the depths at the Portland
Disposal Site. Capping has been used successfully at
this site for many years (DAMOS 1990).
WATER QUALITY AND CIRCULATION
A turbidity plume would be created and some
chemical would elute into the water column. Sedi-
ment disposal simulations for BLDS site using the
ADDAM's model, showed that four hours after a
2,000 cy dump that water quality criteria for copper
were not exceeded outside the disposal site's bound-
ary (Table A1-11). Since this was true for the
summer (stratified) condition, it would be safe to
assume it would hold for winter (unstratified) condi-
tions as well. Within the site, soluble copper concen-
trations in the water column were also estimated to
not exceed water quality criteria. After a four hour
period the silt/clay cloud was estimated to have a
diameter of 2738 feet; silt/clay concentrations within
that cloud were estimated to be less than. 8 mg/L
(TSS background of 4.5 mg/L + 3.4 mg/L silt/clay).
The total volume of silt within the cloud was esti-
mated at 30 cy of solids which would be equivalent
to about 3.3% of the initial dump volume (solids
plus water). These results indicate that risks to
marine resources should be minimal since water
quality criteria are met after two hours both within
an.d outside the dump site.
Prior to the disposal of dredged material from
Boston Harbor, site specific hydrodynamic studies
would need to be conducted to verify the DAMOS
and USGS studies that show the area is a low energy
area, capable of retaining the material in place.
Recent studies by Knevel (1993), however, indicate
there is such a (depositional) area in the southwestern
portion of BLDS along the 50-m contour.
AQUATIC RESOURCES
Bcnthic Infauna
Since BLDS has not been used for disposal for
several years, it is possible that the bcnthic structure
may have reached or be near a climax community.
Disposal of new material would impact this benthie
community and replace it with a pioneering commu-
nity.
Finfish
Impacts to finfish would be similar to the impacts
described for the MBDS.
WETLAND RESOURCES
Since there arc no regulated wetland resources at
BLDS, there will be no impacts.
WILDLIFE
No impacts arc anticipated to the existing wildlife
usage at BLDS.
THREATENED AND ENDANGERED
SPECIES
Cetaceans may transient the disposal site, but are
not likely to be to impacted by ocean disposal. This
area is about 9 nautical miles west of the Stellwagen
Bank; and thus sufficiently removed from their main
area for feeding and congregating so that problems
Al-103
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Boston Lightship Disposal Site (BLDS)
from disposal activities should not occur. Disposal
of dredged material at BLDS is not expected to have
any substantial adverse impact on endangered species,
their prey, or the habitat essential for their survival.
Consultation with the NMFS under Section 7 of the
Endangered Species Act of 1973 (as amended, 16
U.S.C. 1531 el seq), has been initiated to ensure this
activity will not jeopardize any endangered or threat-
ened species.
HISTORICAL AND ARCHEOLOGICAL
RESOURCES
BLDS is in an area deemed "sensitive" by the
Board of Underwater Archeologjcal Resources
because of the number of shipwrecks that have
occurred there over lime or because historic disposal
sites may contain material of archeological interest.
However, discussion with the staff of the Board
suggests there may not be resources at the specific
disposal site. This will be confirmed by the staff
upon review of the Board's files about the proposed
sites.
SOCIO-ECONOMIC/LAND USE
BLDS is an inactive disposal site. Extensive
shipping, fishing, recreational activities, and scientific
investigations take place in Massachusetts Bay year
around. There are no known or anticipated interfer-
ences from disposal events at this site. The use of
the site could provide a solution for the disposal of
large amounts of unsuitable material by capping and
sequestering the contaminants.
ft*
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3.0 ENVIRONMENTAL EVALUATION -
DREDGING SITES
3.1 OTHER PROJECT CONSIDERATIONS
The majority of the environmental and socio-
economic information concerning Boston Harbor,
and the areas to be dredged for the navigation im-
provement project, are discussed in EIR/S Section
2.0 and 4.0. Therefore, only additional information
is covered here.
Besides the navigation improvement project, a 9.5
mile long sewage outfall tunnel currently is being
constructed from Deer Island underneath the seafloor
into Massachusetts Bay for the MWRA project.
Completion of the outfall pipe is expected in 1995.
The Third Harbor Tunnel will cross the main ship
channel from South Boston to Ix>gan Airport in East
Boston. Dredging for the tunnel was completed in
1993. Placement of the tunnel sections for the Third
Harbor Tunnel was completed in 1993. In addition
barge traffic will be hauling dredged and excavated
materials removed from the Central Artery to Specta-
cle Island.
Interference between construction of the above two
projects and the associated dredging of the navigation
improvement project is not expected to occur.
Construction of the navigation improvement project
is not expected to begin until 1996. No interference
with the MWRA project is expected. Barge traffic
from this project is expected to be minimal. Poten-
tial disposal site locations would not interfere with
the construction of the outfall tunnel.
Deepening the Federal channels may involve
relocating buried utilities. The deepening in the
Chelsea River was limited due to the expense in-
volved with relocating the gas siphon. Utilities that
were identified include a powerline running generally
down the center of the Reserved Channel, telephone
cable across the Inner Confluence, a water tunnel,
electrical cable and bridge cables across the lower
Chelsea River and two water tunnels, a sewer siphon,
a gas siphon, electrical cable and fire alarm cable
across the upper Chelsea River. The following table
lists the known utilities and expected depths.
In most cases, the utilities will be relocated by
burying them deeper under the channel. The gas
siphon is a special case and will have a protective
layer of rip-rap placed over the line rather than
actually relocating the siphon.
The deepening of three harbor tributaries will
require particular care to avoid damaging utilities
crossings. During November 1992 field data were
collected using side scan sonar and an array of
geophysical instruments which enhanced existing
knowledge of buried utilities. While the information
obtained does not precisely locate the depth of
utilities, it does show either the trench or changes in
bottom material densities indicating existence of
trench excavation and fill. This information has not
been published yet, but some data are currently
available.
The berthing areas and bulkheads adjacent to the
navigation channels will be investigated to ensure that
dredging a deeper channel will not undermine the
integrity of the bulkheads.
3.2 EXISTING CONDITIONS - ENVIRON-
MENTAL RESOURCES
3.2.1 Water Quality
The dominant currents in the harbor are tidal in
origin, although wind driven currents occur during
storms. Freshwater discharges from the Mystic,
Charles, and Chelsea Rivers generally overlie the
more dense scawatcr flows from the tides. Freshwater
flows average 350 to 500 cubic feet per second (CFS)
in the summer. Tidal input is several orders of
magnitude greater than freshwater input. Tidal flows
Al-105
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average 320,000 cubic foot per second (CFS) for a six
hour period with volumes ranging from 10.6 billion
gallons at low tide to 179.9 billion gallons at high
tide (Metcalf and Rddy, 1976, and MDWPC, 1986).
Approximately 73.3 billion gallons are exchanged
through three channels linked with the President
Roads area and one channel linked with Nantasket
Roads. In addition, 265 million gallons per. day of
waste water is released into the harbor system from
the Boston regional waslcwater treatment plant on
Deer Island.
The average tidal range in Boston Harbor is 9.5
feet with spring tidal ranges often in excess of 11 feet.
Average current velocities for the Inner Harbor are
less than 0.5 knots. Tidal currents in other portions
of the harbor vary greatly in speed because of the
irregular bottom topography and the large number of
islands (Knebel, et.al., 1991). In general, maximum
near-bottom current speeds are greatest ( > 10 knots)
in constricted channels and depressions, are interme-
diate (3-6 knots) at locations sheltered by islands and
points of land, and are weakest ( < 3 knots) over the
shallow subtidal flats (Bumpus, et.al., 1951; U.S.
Coast and Geodetic Survey, 1953; Mencher, et. al,
1968; National Ocean Survey, 1977; Signell and
Butman, 1990; IN Knebel, et.al., 1991). Maximum
current velocities during spring tide in the areas to be
dredged are as follows: 0.1 knots in the Mystic River,
0.2 knots in the Chelsea Rivers and 0.7 knots in the
Main Ship Channel vicinity (N.O.A.A., 1986).
The quality of water in Boston Harbor has been
the target of considerable expenditures of Federal,
State and private funds. For the most part, raw
sewage and untreated industrial discharges are being
rectified by the Massachusetts Water Resources
Authority (MWRA) under a court order aimed at
cleaniug-up Boston-Harbor. A new primary sewage
treatment plant is currently under construction on
Deer Island, including relocation of the ocean outfall
from the island to nine miles offshore. The construc-
tion of the first battery of secondary treatment
upgrades is to begin shortly. Disposal of sewage
sludge into Boston Harbor ceased in 1992. This has
resulted in a rapid and measurable increase in water
quality (MWRA, 1993). Water quality is expected to
improve further when the secondary treatment facility
on Deer Island is in full operation in the year 2000
(MWRA, 1993). The history of contamination from
these and other sources in Boston Harbor can be
found in the harbor sediments.
Water quality in Boston Harbor has been found to
vary both spatially arid temporally. The data con-
tained in Table Al-12 is in general a seasonal sum-
mary of previously available data. A more^recent
data set for June through October 1985 (MDWPC,
1986 and N.Kngland Aquarium, 1990) is also within
the ranges listed on this summary table.
Barring localized effects around thermal outfalls
from power generating stations, the temperature
regime in the harbor is under normal climatic and
cstuarine controls. The enrichment level in the outer
harbor is generally considered to be at a mesotrophic
scale without excessive primary production (National
Commission on Water Quality, 1976). The inner
harbor is also enriched from combined sewer out-
flows and the high level of nutrients in the river
system feeding the harbor.
AI-106
AH-
-------
UTILITIES
DEPTH (MLW)
MWRA Water Tunnel (McArdle)
N.E. Telephone Cable
Boston Edison Electrical Cable
City of Boston Bridge Cable (McArdle)
City of Boston Fire Alarm Cable
UTILITIES
MWRA Water Tunnel (to be removed)
MWRA Sewer Siphon
MWRA Water Tunnel
Boston Gas Siphon
MBTA Electrical Cable
38.5
45.0
40.0
45.0
45.0
DEPTH (MLW)
35.1
50.8
45.0
40.3
40.0
Vertically averaged dissolved oxygen levels
(MDWPC, 1986) exhibit low values ranging as low
as 4.5 ppm in the project area. These values represent
summer biological activity in conjunction with
organic enrichment of the ecosystem. Oxygen
depletion is a substantial problem in many estuaries
during times of thermal stratification of the water
column. The strengthening and deepening of the
water column thermocline limits the circulation and
oxygen exchange in the nearbottom waters. As
temperatures peak (often in August), available
dissolved oxygen levels decrease and cause a corre-
sponding depression in biological activity at the
sediment water interface. This "August Effect", as it
is commonly referenced, is a major environmental
factor in structuring biological communities in the
project area.
The Massachusetts Water Resources Authority
(MWRA) and the New England Aquarium have
measured dissolved oxygen throughout Boston
Harbor. MWRA (1992) measurements of bottom
waters in the Inner Harbor frequently show DO
below the standard 5.0 mg/1, with occasional
measurements below 2 mg/1. I x>w oxygen conditions
are much rarer in surface waters, and tend to occur in
restricted channels with high combined sewer over-
flows (CSO) input, such as Fort Point Channel and
the Reserved Channel (MWRA, 1992). Dissolved
oxygen in the outer harbor and Dorchester Bay
measured by MWRA and the Aquarium monitoring
programs arc nearly always above the 5 mg/1 standard
for Class SB waters. The water chemistry of the
project area, in particular the organic load and its
subsequent chemical oxygen demand, is a substantial
factor in the ecology of Boston Harbor.
Salinity data indicate the outer harbor is well
mixed, while the various regions of the inner harbor
are under the influence of freshwater inputs. Essen-
tially, the mouth of the harbor is considered stenoha-
line and the Inner and Outer Harbor areas are
curyhalinc. Oil pollution has created problems in
many harbor areas and a permanent oil boom is
maintained at the mouth of Chelsea Creek to protect
the remainder of the harbor from potential spills in
the main tanker terminal areas.
Coliform bacteria counts have been collected by
several agencies for several decades. Bacterial counts
have decreased 10 to 100-fold over the past 50 years
in the inner harbor, near Deer Island, Nut Island,
CJovcrnors Island, President Roads, Nantasket,
Moon Head, and Dorchester Bay (MWRA, 1992).
Al-107
-------
These improvements are related to the construction
of treatment plants. Bacterial counts in the inner
harbor are lower in the 1980s compared to the 1960s.
The extreme violations of fecal coliform water quality
measured near Deer Island by the New England
Aquarium have not been found since 1988, and water
quality near Nut Island has been good since 1987.
This improvement in offshore bacterial water quality
has been associated with more reliable chlorination of
the wastewater treatment plants (MWRA, 1992).
Water quality an the outer harbor varies greatly. In
1989 and 1990, MWRA sampling showed that
Carson Beach, Pleasure Bay and Northern Dor-
chester Bay generally met water quality standards.
Samples taken near Calf Island in the outer harbor
were all within swimming standards. Southern
Dorchester Bay, at the mouth of the Neponset River,
generally showed poorer water quality. This area is
affected by the Neponset River, storm drains outflow,
CSOs and possibly sludge. Samples collected at
Dorchester Bay beaches in 1991 by MDC indicate a
decrease in the number of postings at the two beach-
es in Southern Dorchester Bay; Tenaean and Malibu.
The decrease in postings at these areas can probably
be attributed to the operation of new disinfection
facilities at Pox Point and Commercial Point sewer
outfalls.
In Boston Harbor productive clam beds cover
about 4,700 acres (Figure A1-22) (MWRA 1992).
None of these beds are open for recreational clam-
ming because sewage indicator bacteria counts are
too high (MWRA, 1992). About 2,900 acres of clam
beds are restricted to harvesting only by "master
diggers". These licensed diggers must take all clams
harvested to a depuration facility, where the shellfish
are held in clean water for two days to cleanse
themselves of bacteria.
The Massachusetts Division of Marine Fisheries
monitors shellfish growing water as well as the clams
themselves for bacteriological safety. Some areas of
Boston Harbor, especially in Quincy Bay and Hing-
ham Bay, are often conditionally opened, while other
areas, like Dorchester Bay, are virtually never open
(MWRA, 1992). Clam beds in the inner harbor are
prohibited from harvest.
levels of trace metals in the inner harbor have
been related to the sewage discharges, CSO's, urban
runoff, and the metals contributed by the major
rivers. In the outer harbor, higher levels of metals
have been found around the sewage outfalls. The
U.S. Environmental Protection Agency has devel-
oped water quality criteria designed to protect aquatic
organisms from the adverse effects of environmental
contaminants. Boston Harbor generally ijieets the
water quality criteria for toxic contaminants
(MWRA, 1992). There has been a four-fold decrease
in the amount of metals discharged to the harbor by
the MWRA between 1981 and 1991. Results of
bioaccumulation results conducted by MWRA (1992)
in 1991 and other studies indicate or suggest that
improvements in MWRA discharges are being
reflected in improvements in water quality. Although
the quality of discharge from MWRA treatment
plants is improving, and is expected to improve,
various levels and types of contaminants are still
released into the aquatic system. These discharges
combined with riverine and direct urban runoff
represent a degradation of the Boston Harbor water
quality.
3.2.2 Sediment Characteristics
General Site Environment
The United States Geological Survey (USGS)
currently is conducting studies in Boston Harbor,
Massachusetts Bay and Cape Cod Bay to define the
geological framework of the region and to understand
the transport and accumulation of sediments (But-
man, ct.al., 1992). One of the goals of the USGS
study is to develop a sediment data base. The levels
of contaminants vary throughout the harbor predom-
inantly depending on hydrology and substrate type.
Al-108
-------
In general, metal and organic levels are relatively high
in the Inner Harbor and decrease seaward. The
surficial sediments represent fine grained material
with associated chemicals deposited since the area
was last maintained. The results of the chemical
sampling reflect the normal sedimentological trends
of increased chemical levels with those substrates of
higher total organic carbon and silt-clay content
(Boehm and Farrington, 1984). The Mystic River
(sampling stations A and B) exhibited the highest
contaminant levels and was also the most recently
dredged. The material accumulated at these stations
represents the highest levels in the harbor, apparently
derived from the Mystic River drainage area. In
contrast, the least contaminated material in the
harbor is also found in the Mystic River at Station
C. This station is typical of the pristine lean clay
layer of the deeper sediments without deposition of
a recent silt/clay overburden.
An acoustic impedance survey of the Federal
channels to be dredged was performed by ACOE in
November 1992. This survey was conducted to
locate and determine the amount of silt (maintenance
layer), clay, and rock. This survey was also used to
assist in locating utilities.
Upland Disposal Testing
The Massachusetts Department of Environmental
Protection requires information on additional param-
eters (total petroleum hydrocarbons) and toxic
characteristic leaching procedure (TCLP) in order to
evaluate the suitability of dredged material for upland
disposal. Chemical testing was also performed for
sodium and chlorides at the request of the interagen-
cy work group members and because both sodium
and chloride can have an impact on ground water if
the sediment is disposed of upland and leaching
occurs (at unlined sites).
The averages for total petroleum hydrocarbon
(TPH) concentrations and Total Organic Carbon
(TOC) for all sites tested are presented in Table Al-
13. The highest average concentrations of TPH was
found at the Mystic Pier 1 site and the lowest average
concentration of TPH was found at the Conley 11-13
site. The highest average concentration of TOC
occurred at Edison Barge Intake and Edison Barge
Berth (13.0% and 10.2% respectively) and the lowest
average concentration of TOC occurred at the Gulf
Oil site (1.7%).
Toxic characteristic leaching procedure (TCLP)
If the bulk chemical concentration in the sediment
/ k
tested equaled or exceeded the Massachusetts Depart-
ment of Environment bulk soil concentration for
TCLP analysis, then there is a mathematical chance
that the TCLP test could exceed threshold limits. In
order to know if the parameter of interest would
exceed the EPA regulatory limit, a TCLP test must
be performed in order to verify if the sediment has
hazardous characteristics. Only chromium and lead
exceeded the mathematical thresholds for requiring
TCLP analysis. Table Al-14 is a summary of the
Massachusetts DEP Bulk Soil Concentration limits
along with the lead and chromium bulk and TCLP
concentrations in relation to the regulatory limits. In
all cases the TCLP results were orders of magnitude
below the regulatory levels. Therefore, none of the
sediments to be dredged in Boston Harbor show
hazardous characteristics.
Table A1-15 shows the concentration of sodium
and chloride found at each site tested. The highest
concentration of sodium occurred at Eastern Miner-
als (40140 mg/kg) and the Mystic Piers had the
highest percent of chloride (2.0%).
3.2.3 Biological Resources
In July and November 1986 benthic biological
sampling was conducted at thirteen (13) stations in
the proposed dredging area. Finiish samples and
Al-109
-------
water column parameters were also obtained at
various locations. In general, the benthic population
in Boston Harbor is described below, based on
results from thirteen (13) stations randomly located
throughout the project area and sampled in two
seasons. The sampling program used a 0.04m Van
Veen grab and screened samples through a 0.5mm
sieve. Additional details can be found in the 1988
Environmental Assessment.
All three tributaries of the Boston Harbor naviga-
tion improvement project contained on average a
high number of organisms per square meter (4,798;
S.D. *" 8623.2) in July. The average number of
species recovered in July was eight (S.D. = 8.4).
The dominant organisms were the' polychaetes
Capilella capitata (54.8 %, S.D. = 28.3); Polydora
Bgnl (15.3%, S.D. = 7.1); and Polydora aggregate
(12.3%, S.D. = 11.7).
The inner harbor rivers and the Reserved Channel
undergo remarkable reductions in densities between
seasons. Theoretically, a population can rebound
from nearly an azoic state (induced by low dissolved
oxygen levels) through adult recruitment. Between
July and November, a statistically significant (p <
0.005) reduction in benthic population densities and
diversity occurred. The November population
contained on average a much lower number (29; S.D.
= 71.5) of organisms per square meter and number
of species (0.4; S.D. = 0.7). The dominant organ-
isms were the polychaetes Polydora Kgni (20.0%;
S.D. « 11.5); Slreblospio benedicti (17.9%, S.D. =
16.8); the shore shrimp Crangon septemspinosa
(1 l.O%, S.D. = 19.0); and the amphipod crustacean
Ampelisca abdila (6.7%, S.D. = 11.5).
This tremendous reduction in benthic productivity
is not uncommon in urban estuaries where the
cumulative effects of high organic load, vessel wakes,
increasing water temperature, reduced wind mixing,
and increased water column stratification combine
with microbial activities that peak in laic summer to
reduce dissolved oxygen levels. The dissolved oxygen
stress is often severe enough to eliminate non-motile
benthic populations -- the so-called "August effect".
Given the cyclic (annual) nature of low dissolved
oxygen levels in Boston Harbor, the benthic inhabit-
ants arc well adjusted to colonizing and recolonizing
azoic substrates annually. This type of pioneering
species assemblage can be expected quickly to recolo-
nize a dredged area with minimal disruption in
benthic productivity.
The polychaetes Capilella capilataand Streblospio
benedicti are the dominant benthic organisms present
in the project area. Both of these species are tolerant
of physical and chemical stresses that are characteris-
tic of urban harbors such as Boston. Each of these
species arc "r - strategists," i.e. species whose life
history is characterized by small body size, short
generation times and high reproduction (r) rate
(Grassle and Grassle, 1984). Copitella capitata has
shown generation times as short as three weeks
(Tenore and Chesney, 1985). These life history
attributes allow the proliferation of this species within
the project area on a cyclic basis. High densities of
Capitella capitata were found in July but not in
November. This cycle of proliferation and die-off
keeps the benthic population in a state of dynamic
equilibrium. Project areas which were azoic in both
sampling periods may have a sufficient additional
stress of sulphidic or petroleum compounds accumu-
lating in the substrate so that it is intolerable to even
these species (James and Gibson, 1980). This cycle
of rccolonization by the benthos can be expected to
allow rapid biogcnic reworking and recolonization of
the newly exposed clay layers in the post dredging
phase.
The soft shelled clam Mya arenaria is the most
common commercial shellfish within the Boston
Harbor area. Blue mussels Mytilus eduiis and duck
clams Macoma balthica arc also found in shellfish
beds but are not harvested. Densities of shellfish
beds have been documented by Jerome et al. (1966),
Chcsmore ct al, (1971) and Iwanowicz et al. (1973)
Al-110
-------
and these data can be referred to for detailed informa-
tion.
As described in the previous section, waters overly-
ing the shellfish beds are contaminated by wastes
from sewage outfalls, resulting in the presence of
coliform bacteria in the shellfish. The beds are under
the jurisdiction of Massachusetts Department of
Environmental Protection and are closed to commer-
cial and noncommercial harvesting, except by Master
Diggers who must have the clams depurated at a
purification plant.
Most of the productive soft shelled clam beds near
the proposed dredging project are closed except for
restricted areas near I-ogan Airport and a seasonal
area in Pleasure Bay, the latter located immediately
southwest of Castle Island. Logan Airport beds are
one nautical mile north of President Roads and the
beds at Pleasure Island are about two nautical miles
west of President Roads. Shellfish beds open to
Master Diggers are predominantly within the lower
bays and are distant from the shipping channels and
project areas.
The limited amount of lobstering within the
Boston area takes place primarily in Quincy, Dor-
chester, and Hingham Bays. Lobstering is minimal
or nonexistent in the areas to be primarily affected by
the proposed work.
Fisheries resources of the Inner and Outer Harbors
have been inventoried by previous studies. These
studies include the MES (1972, 1972 a, b, c; 1972;
1976 a, b; 1977 a, b) and Ilaedrich and Ilaedrich
(1974) studies which developed information in the
Lower Mystic River. Data in the Outer Harbor were
developed by Jerome et. al. (1966), Chesmore ct. al.
(1971) and Iwanowicz ct. al. (1973).
The studies on the lower Mystic River were
concentrated in the area between Amelia Earhart
Dam and the Mystic River (Tobin) Bridge. Haedrich
and Ilaedrich (1974) found that the seasonal species
composition was similar to other northeast harbor
communities. Winter flounder, smelt and alewives
are found in the river throughout the year and are,
therefore, considered residents. Ocean pout and
blueback herring are summer residents, whereas sea
herring is considered a winter resident. With the
exception of ocean pout, these residents were identi-
fied in the 1986 NED biological sampling effort.
In July and November 1986 finfish were sampled
by NED using surface and bottom variable mesh (15
cm to 2 cm) gill nets (approximately 2.5 by 70
meters) with paired deployments and a six (6) meter
otter trawl where possible. Rough bottom topogra-/
phy restricted trawling to the Mystic River and heavy
ship traffic destroyed some of the gill nets. Sampling
for fmfish was therefore opportunistic for site and
duration. The results of the July and November
finfish sampling can be found in Table Al-16.
Finfish sampling identified anadromous finfish,
resident finfish and lobster as occurring in the project
area. In a recent report by the National Oceanic and
Atmospheric Administration (N.O.A.A., 1984),
anadromous finfish species were identified as being of
special concern in the project area. Each of these
organisms occur in seasonal cycles throughout the
project area as summarized in Table A1-17.
Information on spawning species, numbers and
quality of spawn and their significance to regional
resources is imprecise and sketchy. Since the princi-
pal streams discharging into the inner harbor rivers
have dams located on them, tidal spawns of smelt
and alewives arc unlikely. In addition, it is not
known if winter flounder use Boston's Inner Harbor
for spawning as well as an area of local feeding.
From the habits of these fish and from their behavior
in the Mystic River channel area, they appear to stay
in particular resident areas within the Inner and
Outer harbors. larval contribution to the eventual
recruitment of these fish in other areas is not known.
Al-111
-------
In summary, a spring/summer movement of
anadromous finfish occurs through the project area
as they move into spawning (freshwater) tributaries.
Lobsters and flounder are generally in the outer
harbor (areas of high productivity) preferring cool
waters. In summer, as water temperatures rise,
productivity in bcnthic habitats sharply decline in
response to low dissolved oxygen in the near bottom
water column, restricting fauna to the outer harbor
(Main Ship Channel) areas. By fall, the Inner
I larbor has juvenile flounder feeding on shore shrimp
while waters are cooling toward winter spawning
temperatures. In winter, finfish, except for the cold
water spawning flounder, and lobster move offshore
as harbor water temperatures decrease. This
fall/winter water cooling allows a balance of the
oxygen depletion that occurred in the warmer sea-
sons. High organic load freshwater inputs and
warming water temperatures initiate the complex
cycle in the spring.
Offshore and longshore areas of the harbor were
trawled for ilnfish in the studies done by the Massa-
chusetts Division of Marine Fisheries. Atlantic
silverside, mummichog and Atlantic tomcod were the
predominant species found in the longshore trawls.
Some of the offshore sampling sites yielded high
densities of winter flounder, Atlantic tomcod, four-
spine stickleback, and rainbow smelt. The highest
densities of finfish were taken during the months of
September and October, with Atlantic silverside and
winter flounder the predominant species. The
densities of finfish dropped during the winter months
of December through March as the fish moved
offshore to winter feeding grounds.
Al-112
-------
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/ *
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/ '
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A1-1I7
-------
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Al-119
-------
-------
Boston Harbor Dredging Project EIR/S
©
Scale: 0 jo
Apprac. Scale in Milts
Figure Al-1. General locations of short-listed
disposal site alternatives.
Source:
USGS Quadrangles
Revised by NAI to reflect pertinent site conditions.
-------
SL- SHRUBLAND
WEM- EMERGENT WETLAND
Boston Harbor Dredging Project EIR/S
Figure Al-2. Site map for potential disposal site,
Quincy-03 (Squantum Point).
Scale:
100
200
Scale in Mettn
Source:
USGS Quadrangle Boston South, MA, 1987
Revised by NAI to Reflect Pertinent Site Conditions
-------
Park
&
Playground
Cnartestown
Pumping /
Station
Powerplant
UO- OPEN URBAN LAND
OF- EARLY SUCCESSIONALFIELD
SL- SHRUBLAND
Boston Harbor Dredging Project EIR/S
(B
SCOle: 0 100 200
Scale in Metert
Figure Al-3. Site map for potential disposal site,
Everett
Source:
USGS Quadrangle North Boston, MA, 1985
Revised by NAI to Reflect Pertinent Site Conditions
-------
Boston Harbor Dredging Project EIR/S
®
Scale:
0 100 200
ScoltixMftm
Figure Al-4. Site map for potential disposal site,
Wobum-11.
Source:
USGS Quadrangle Reading, MA, 1987
Revised by NAI to reflect pertinent site conditions
-------
END OF PHOTO
COVERAGE
KEY:
H • HARDWOOD FOREST
SL- SHRUBLAND
EARLY SUCCESSIONAL RELD
WFH - HARDWOOD FORESTED WETLAND
WSL • SHRUB WETLAND
OW- OPEN WATER
RO- ROCK OUTCROP
SG- SAND & GRAVEL PIT
R- RESIDENTIAL
C- COMMERCIAL STRUCTURES
* OBSERVED IN RELD, SIZE
, AND SHAPE UNKNOWN
•••• -OBKVE&
- '»tc ',, J
, s 5^. v«
Boston Harbor Dredging Project EIR/S
®
0 SO 100
SceUtmHaa*
Figure Al-5. Site map for potential disposal site,
Wrentham-495.
Source:
USCS Quadrangle Franklin, MA 1987
Revised by NAI to reflect pertinent site conditions.
-------
GP Sand and Gravel Pit
X Landfill Location
Boston Harbor Dredging Project EIR/S
®
0^^1000 2000
SealtiaFttt
Figure Al-6. Site map for the Plainville
Landfill site.
Source:
USGS Quadrangle Franklin, MA 1987
Revised by NAI to reflect pertinent site conditions.
jer
-------
X - Landfill Location
Boston Harbor Dredging Project EIR/S
f^^ Scale:
®
0 1000 2000
ScatfinFttt
Figure Al-7. Site map for the Fitchburg/
Westminster Landfill site.
Source:
USGS Quadrangle Htchburg, MA 1988
Revised by NAI to reflect pertinent site conditions.
-------
E. BRIDGEWATER
X - Landfill Location
Boston Harbor Dredging Project EIR/S
®
0 1000 2000
Scale in Feet
RgureAl-8. Site map for BFI Northern Disposal Inc.
(E. Bridgewater) Landfill site.
Source:
USGS Quadrangle Whitman, MA 1977
Revised by NAI to reflect pertinent site conditions.
-------
Boston Harbor Dredging Project EIR/S
(b
Scale:
0 SO 100
Scale in Yards
Figure Al-9. Site map for Mystic Piers site
Source:
Boston Harbor Navigation Chart
-------
Boston Harbor Dredging Project EIR/S
Scale:
Figure Al-10. Site map for Revere Sugar site
Source:
Boston Harbor Navigation Chan
fil-IAj
-------
Boston Harbor Dredging Project EIR/S
Figure Al-11. Site map for Amstar site
Source:
Boston Harbor Navigation Chart
A/-
-------
Boston Harbor Dredging Project EIR/S
Scale:
Figure Al-12. Site map for Cabot Paint site.
Source:
Boston Harbor Navigation Chan
-------
Boston Harbor Dredging Project EIR/S
Figure Al-13.Site map for Little Mystic Channel site.
Scale:
Source:
200
Boston Harbor Navigation Chan
-------
Boston Harbor Dredging Project EIR/S
Figure Al-14. Site map for Reserved Channel site.
Scale:
200
Source:
Boston Harbor Navigation Chan
-------
SPECTACLE
ISLAND CAD
FROM CORTELL {139Q3
Boston Harbor Dredging Project EIR/S
®
Scale:
500
Scale in Yards
0
1000
Figure Al-15. Site map for Spectacle Island CAD site.
Source:
NOS Chart No. 13270
Sediment Classifications from Cortell 1990
-------
EXPLANATION
Bast Potential for sand/gravel
1157 Cart Location
2513
2519
•93-
Hatiqation Fins
Contours in Ft«t
Boston Harbor Dredging Project EIR/S
®
Scale:
Seoli in Yards
t-^riMit— » i— i,. .,.. i
500 0 1000
Figure Al-16. Site map for Meisburger 2 site.
Source:
Metcalf & Eddy Inc., 1992
- I
-------
Boston Harbor Dredging Project EIR/S
®
Seo/e.-
Seal* In Tatai
0 K330 2OOO
Figure Al-17. SitemapforMeisburger7site.
n * GENERAL AREA WITHIN WHICH DISPOSAL
STTE WOULD BE LOCATED.
Source:
Metcalf& Eddy Inc., 1992
-------
Boston Harbor Dredging Project EIR/S
Scale:
1000 3000
Scale in Feet
Figure Al-18. Site map for potential disposal site,
Subaqueous-6
Source:
Boston Inner Harbor Navigation Chan
-------
Boston Harbor Dredging Project EIR/S
®
Scale:
0 400 tOO
Scale in Yards
Figure Al-19. Site map for potential disposal site,
Subaqueous-E.
Source:
Boston Inner Harbor Navigation Chan
-------
WINTHROP
HARBOR
Boston Harbor Dredging Project EIR/S
Rgure Al-20. Site map for potential disposal site,
Winthrop Harbor.
Scale:
401 tOO
Source:
Scale in Yards
Boston Inner Harbor Navigation Chan
-------
Cd
TO
o.
12.
oro
1
a
I
cog1
1
•o
;^^M?;; * t.- h ^^ ^WJR ;'' ^ t*-* 1? ^
MASSACHUSETTS
BAY DISPOSAL SITE
J'"V»^ vK** ^
J ? ^ '' ^
BOSTON LIGHTSHIP
DISPOSAL AREA
(HISTORIC)
Depositional substrates within the disposal sites.
BIDS approximate proposed disposal location = 42° 19' AQ" N
70° 37' 30" W
-------
Rgure Al-22. Prohibited and restricted clam beds in Boston Harbor. There are many acres
of soft-shell dam beds in Boston Harbor, but none are open for unrestricted harvest.
(From MWRA "State of Boston Harbor: 1991" report)
ft-/-/ vy
-------
TABLE Al-1. LANDFILL CHARACTERISTICS
DAILY CAPACITY
Total Waste
Capacity.
Available Waste
Capacity1
Cover Capacity
Available Cover
Capacity
PLAINVILLE
850-925 cy/day
150-200 cy/day
500 cy/day
100 cy/day
FITCHBURG/
WESTMINISTER
350 cy/day
200 cy/day
250 cy/day
Unknown
E. BRID6EWATER
1075 cy/day
75 cy/day
400 cy/day
Variable
ANNUAL TOTAL CAPACITY
STOCKPILING CAPACITY2
WASTE MATERIAL LIMITATIONS
Dewatering
Solids
Odor
COVER MATERIAL LIMITATIONS
350,000 cy/yr
100,000 cy/yr
200,000 cy
250,000 cy/yr
8,000-10,000 cy
ESTIMATED CLOSURE DATE
TOWN/BOARD OF HEALTH
REQUIREMENTS
No free standing water
£40% solids
Deodorizing suggested
Must meet DEP standards
for TCLP3, pH, solids,
reactivity,
ignitability.
1995, but proposed ex-
pansions would extend
until 2000.
Verbal coordination
needed
No free standing water No free standing water
£25% solids £20% solids
Must have no odor If odor, BFI will lime
Must meet 310 CMR 19
regulations.
1997
Coordination with 2
local boards
Must meet DEP standards for
TCLP, PCBs, reactivity, cor-
rosivity, free liquid, sol-
ids. Odor must be inoffen-
sive to community. No large
boulders.
1996
Coordination needed
(Continued)
-------
TABLE Al-1. (CONTINUED).
PLAINVILLE
FITCHBUR6/
WESTMINISTER
E. BRIDGEWATER
I
s:
U
SPECIAL WASTE RECEIVED IN
PAST
TRUCKING LIMITATIONS
Number/day
Operating hours
Waste water treatment
plant grit and screen-
ings
No limitations
7 AM - 3 PM
Wastewater treatment
plant sludge.
No limitations
7 AM - 3 PM
Sewage sludge, petroleum
contaminated soil.
No limitations
7 AM - 3 PM
TIPPING FEE4
DISTANCE TO SITE
$56/cy
35 mi.
$70/cy
45 mi.
$28/cy
25 mi.
•Capacity available for project dredged material.
2Unlined cover material can be stockpiled.
3Toxic Characteristic Leaching Procedure. An EPA-derived test for hazardous characteristics.
^Approximate costs assuming an average ratio of 1.4 tons/cy; actual tipping fees are based on weight.
-------
TABLE Al-2 ESTIMATED ABUNDANCE (NO./m2) OF BENTHIC INFAUNA (RETAINED ON A 0.5 mm MESH SIEVE) COLLECTED BY 0.023 m2 PONAR GRAB FROM
PROPOSED DISPOSAL SITES IN BOSTON HARBOR, APRIL 28-29, 1993.
TAXA MP-1 MP-2
Oligochaeta 43 817
Asabellides
oculata
Capitella 4171
capitate
Caulleciella
sp.
Cirratulidae
Cistenides
hyperborea
Dodecaceria 43
sp.
Eteone sp.
E. heteropoda
E. longa
Fabricia 172
sabella
Haraothoe sp.
ff. extenuate
Hesionidae
Leitoscoloplos
robustus
tlicrophthalttus
aberrans
Nereidae
Nereis
diversicolor
Orbiniidae
Paranaites
kosterieusis
STATION
RS-1 RS-2 RS-3 AM-1 AM-2 CP-1 CP-2 LMC-1 LMC-2 LHC-3 LMC-4 RC-1 RC-2 RC-3 RC-4
473 172 172 559 1806 86 13717 258 86 2451 15480 26574
43
2838 2967 215 43 1892 645 1677
688 43 86 387 43
258
43 • 43
86
86
129 43 215
172 43 43 43
43 «
43
86 172
473 215 129
43 172
43 172
258 215 43
43
(Continued)
-------
TABLE Al-2. (CONTINUED)
STATION
Tm HP-1 HP-2 RS-1 RS-2 RS-3 AH-1 AH-2 CP-1 CP-2 1HC-1 LHC-2 LHC-3 LHC-4 RC-1 RC-2 RC-3 RC-4
Polycirrus sp.
Polydora sp.
P. aggregata
P. cornuta
Pygospio
slogans
Spio of.
Uaicola
S. thulini
Spiophanes
botabyx
Streblospio
benedicti
258
86
43
731
43 43 2107 301 86 559 215
86
43
86 301 301 4902 1548 43 2709 2021 129
172
1419 43 129
43
1548 215
.r
-C
-------
TABLE Al-2. (CONTIMOED)
^P
T"
-c
V
STATION
TAXA MP-1 MP-2 RS-1 RS-2 RS-3 AH-1 AM-2 CP-1 CP-2 LMC-1 LMC-2 LMC-3 LHC*4 RC-1
Microdeutopus 258
sp.
H. gryllotalpa 172 86 43 2322 43
Ostracoda 43
Pa gurus 43
longicarpus
Semibalanus 43
balanoides
Crepidula sp.
C. fornicata 86
C, plana 43 43
Nassarlus 43
trlvitatus
Hiatella sp. D
Littorina 1.29
llttorea
Hya arenarla D 43 86
Mytilidae D D D
Tellioa agilis
Ciona 86 43
Intestinal is
Athecata . p
Obelia P
dicbotoma
Rhynchocoela 43
Netnatoda . 11.954 236,672 17.329 215 9.933 1.806 1,591 2.838 13.932 2.752 129
RC-2 RC-3 RC-4
688 1505
43
129
43
86
86
16.641
(Continued)
-------
TABLE Al-2. (CONTINUED)
STATION
TAXA HP-1 HP-2 RS-1 RS-2 RS-3 AH-1 AH-2 CP-1 CP-2 LHC-1 IHC-2 LHC-3 IHC-4 RC-1 RC-2 RC-3 RC-4
Ascidian
Holgula sp.
Polycarpa
43
43
43
Total
Abundance
(no./m*)
Total No.
Discrete Ta
86 17,759 241,230 20,597 1,161 18,287 430 9,202 3,354
2 11 13 64849 5
129 27,907 16,598 3,096 3,096 21,156 301 49,837
2 22 8 6 7 14 4 10
% Polychaeta
% Crustacea
% Biva
27
1
15
67
0
20
1
80
10
59
2
50
0
100
0
25
IS
14
1
5
11
13
1
22
4
88
12
-------
TABLE Al-3. SEDIMENT CHARACTERISTICS IN THE VICINITY OF POTENTIAL DISPOSAL
SITE EAST OF SPECTACLE ISLAND, 1988*.
PARAMETER"
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Vanadium
Zinc
% Water
% Volatile Solids
% Oil and Grease
~-V^> Total Petroleum
7~-^ Hydrocarbons
• — % Total Organic
^t^ Carbon
^^j Polychlorinated
Biphenyls
% Silt/Clay
Classification
ST1-7
(0-2')b
9.2
0.7
16.0
8.7
7.5
<0.01
15.5
22
32.2
27
3
0.042
<100
0.52
TR
48
1A
ST1-8 ST1-8
(0-1') (1-6.25')
14.8
0.8
19.2
18.0
14.4
0.06
15.8
23
35.8
26
2
0.032
200
1.40
0.02
23
2A
27.8
0.8
25.3
17.1
10.1
<0.01
23.5
39
41.2
37
2
0.020
100
1.20
ND
50
3A
ST1-9
(0-2')
3.8
<0.5
12.1
5.3
9.5
0.02
10.5
17
64.0
27.6
0.8
0.080
<100
0.60
ND
31
1A
ST1-11
(0-2')
2.5
0.8
19.1
22.4
16.1
0.11
20.1
20
37.7
24
9
0.025
<100
0.64
TR
21
IB
ST1-12
(0-1.5')
13.1
2.8
20.9
14.1
11.7
0.06
22.8
37
53.8
20
2
<0.010
<100
0.77
ND
7
2A
Source: Cortell 1990b
aAll results in mg/kg (ppm) dry weight unless otherwise noted.
''Depth below sediment surface --,
TR = Traces below detection limit "'
ND = Not detected
-------
TABLE Al-4. COPPER CONCENTRATIONS AT A-POSITION WHEN COPPER IS DILUTED BELOW HATER QUALITY CRITERIA AT THE SPECTACLE ISLAND CAD
DURING FLOOD AND EBB TIDES OF DIFFERENT VELOCITIES.
EBB TIDE
DEPTH
(ft)
1.0
6.0
10.0
TIME TO
DILUTION (hrs)
2.00
3.67
2.50
0.6
COPPER"
(mg/1)
0.00273
0.00286
0.00251
KNOTS
DISTANCE FROM
DISPOSAL (ft)
7,000
13,000
9,000
SILT CLOUD DIA.
AT TIME (ft)
1,002*
1,985
1,267
0.3 KNOTS
TIHE TO
DILUTION (hrs)
2.17
3.83
2.50
COPPER
(mg/1)
0.00275
0.00262
0.00259
DISTANCE FROM
DUMP (ft)
4,000
7,000
4,500
SILT CLOUD DIR.
AT TIME (ft)
1,089*
2,124*
1,372*
FLOOD TIDE
DEPTH
(ft)
1.0
6.0
10.0
TIME TO
DILUTION (hrs)
2.00
3.67
2.50
0.4
COPPER*
(ag/1)
0.00220
0.00278
0.00277
KNOTS
DISTANCE FROH
DISPOSAL (ft)
5,000
9,000
7,000
SILT CLOUD DIA.
AT TIME (ft)
994
1,991*
1,372*
0.2 KNOTS
TIME TO
DILUTION (hrs)
2.17
3.83
2.33
COPPER
(mg/1)
0.00288
0.00279
0.00254
DISTANCE FROM
DUMP (ft)
2,500
4,500
3,000
SILT CLOUD DIR.
AT TIME (ft)
1,089*
2,102*
1,183*
•Wq criteria for copper = 0.0029 mg/1
*interpolated from values in output
-------
TABLE Al-5. DOMINANT FISH SPECIES3 AND LOBSTERS IN TRAWLS
CONDUCTED IN AN AREA JUST WEST* OF THE MtfRA
PROPOSED OUTFALL BY MASSACHUSETTS DIVISION OF
MARINE FISHERIES, 1991-92.
COMMON NAME
FISH
Ocean pout
Longhorn sculp in
Winter flounder
Atlantic cod
Yellowtail flounder
All other spp.
Total
Total # Indiv.
Trawl length (min)
Total CPU0 est. (20 min)
AMERICAN LOBSTER (Count")
Total # Indiv.
Total CPU0 est. (20 min)
5/91
5/92
PERCENT COMPOSITION
35
21
19
17
7
1
100%
655
20
655
17
17
15
19
33
10
16
7
100%
ABUNDANCE
685
13
1054
60
92
aThose making up > 10% of the catch
bApprox. 42°23' N, 70°49' W ("Rosie's Hole")
°Catch Per Unit
-------
TABLE Al-6. gj™?8Sff^
STOATIFIED CONDITIONS ESTIMATED BY THE ADDAM'S MODEL FOUR
HOURS AFTER A SINGLE DUMP OF 2,000 CU. YDS.
MAX. CONCENTRATION
OUTSIDE THE MIXING
ZONE3
DEPTH
(FT)
5
60
85
95
COPPERb
0.00035
0.00036
0.00066
0.00046
SILT/
CLAY0'6
5.1
10.3
ME
8.2
MAX. CONCENTRATION
WITHIN THE MIXING ZONE
COPPER
0.00035
0.00038
0.0012
0.00064
SILT/CLAY
SILT/ CLOUD
CLAY DIA. (ft)
5.1
10.6
NE
14.9 2581 ,V
*WQ criteria, Copper = 0.0029 mg/1
'Mixing zone = disposal area boundary
Background, Copper = 0.00035 mg/1
Background, TSS =4.5 mg/1 (average value)
dConc. silt/clay = Background TSS (4.5) + concentration on grid above
background.
-------
TABLE Al-7. SEDIMENT CHARACTERISTICS IN VICINITY OF PROPOSED
SUBAQUEOUS CONTAINMENT SITES B AND E AND WINTHROP
HARBOR CONTAINMENT SITE.
PARAMETER3
% Silt/Clay
As
Cd
Cr
Cu
Pb
Hg
Ni
Zn
PCBs
% Volatile
solids
Oil and grease
Total petro-
leum hydrocar-
bon
% Total organ-
ic
carbon
LOCATION
SDBAQ Bb SUBAQ Ec WINTHROP HARBORd
ST1-14 ST1-15 B-33-L MEAN
3
3.3
0.6
12.8
10.5
11.6
0.06
16.2
40.4
TR
1
<100
<100
0.2
5 — 84.4
4.8 9 5.6
1.0 4.9 1.0
30.7 57 123.0
47.7 105 100.0
32.7 62 138.0
0.22 0.34 0.32
30.6 18 28.0
81.7 142 149.0
TR <0.05 <0.1 ppm
1
600 0.40 • -- •
400
0.3 — .70
Results in rag/kg (ppm) unless otherwise noted; all values relative to
dry weight.
Cortell, 1990b
Massport, 1990
Army Corps of Engineers, (NED) 1992
-------
TABL* Al-8.
EBB AND FLOOD TIDES UNDER ^STRATIFIED
CONDITIONS ESTIMATED BY THE ADDAM'S MODEL FOUR HOURS
AFTER A SINGLE DUMP OF 1,000 CU. YDS.
MAX. CONCENTRATION (mg/L)
OUTSIDE THE .MIXING ZONEf
DEPTH
(ft)
1.0
3.0
10.5
COPPERa'b
0.0012
0.0013
0.0017
EBB
SILT/
CLAY0**1
4.9
4.1
NEe
MAX. CONCENTRATION (mg/L)
WITHIN THE MIXING ZONE
TIDE
COPPER .
0.0013
0.0014
0.0019
SILT/
CLAY
5.1
5.3
NE
SILT/CLAY
CLOUD DIA.
(ft)
2220
2220
2220 '
DEPTH
(ft)
1.0
2.0
3.0
COPPERa'b
0.0040b
0.0058b
0.0039fa
FLOOR.
SILT/
CLAY0
14.4
NEd
14.2
TIDE
COPPER
0.0040b
0.0058b
0.0039b
SILT/
CLAY
14.4
NE
14.2
SILT/CLAY
CLOUD DIA.
(ft)
2222
2222
2222
Background, Copper = 0.00035 mg/L.
'VQ Criteria, Copper = 0.0029 mg/L.
cBackground, Total Suspended Solids =4.5 mg/L. A. + A
•Wei results were added to the background level to derive a predicted
value.
*Not estimated in model run.
%ixing zone = disposal site boundary.
if/i
-------
TABLE
FINES
SAMPLE (%)
A 77.3
B • 86.4
C 83.1
D 49.3
E 52.5
F 75.2
G 69.7
H 90.6
I 91.4
J 91.2
K 85.0
L 8.9
M 93.4
N 91.7
0 92.1
P 92.8
Q 90.6 .
MEAN 82.4
Al-9. PHYSICAL AND BULK CHEMICAL ANALYSIS OF WINTHROP HARBOR SEDIMENTS8.
TOC
(%)
0.53
0.65
0.43
0.53
0.42
0.56
0.65
0.66
0.43
0.92
0.61
0.93
0.96
0.89
0.87
0.88
0.93
0.70
As
(ppm)
5.5
5.3
4.9
3.9
2.5
4.5
4.9
6.9
6.5
4.6
6.6
8.4
6.1
6.1
6.1
6.5
- 6.6
5.6
Cd
(ppm)
0.6
1.2
0,6
0.7
0.4
0.9
0.9
1.1
0.5
1.4
0.9
1.9
2.0
2.0
1.9
2.1
1.7
1.0
Cr
(ppm)
57*
120
68
85
46
79
85
140*
72
140*
130*
180*
200*
190*
170*
190*
134*
123*
Cu
(ppm)
40
91
43
77
34
64
70
100
40
110
90
90
170
160
150
170
130
100
Hg
(ppm)
0.14
0.36
0.25
0.24
0.16
0.18
0.18
0.38
0.21
0.33
0.37
0.37
0.46
0.44
0.40
0.45
0.52
0.32
Ni
(ppm)
21
27
23
18
13
20
22
32
30
30
31
31
38
34
30
36
33
28
Pb
(ppm)
85
140*
166*
107*
96
101*
76
140*
230**
170*
130*
250**
200*
100*
100*
100*
150*
138
Zn
(ppm)
79
130
84
96
65
86
110
140
83
130
120
210*
240*
240*
210*
250*
240*
149
TOO: Total Organic Carbon; As: Arsenic; Cd: Cadmium; Cr:
Ni: Nickel; Pb: Lead; Zn: Zinc.
* Class II sediments according to Massachusetts Guidelines.
** Class III sediments according to Massachusetts Guidelines,
al!992. Winthrop Harbor Environmental Assessment.
Chromium; Cu: Copper; Hg: Mercury;
-------
TABLE Al-10. HINTHROP HARBOR BENTHIC INVERTEBRATES, FALL 1989.
SAMPLE STATION
123 9 10 11 12 13
(NUMBER OF INDIVIDUALS PER 0.04m2 VAN VEEN GRAB)
MEAN
% OF
TOTAL
Oligochaeta
Polychaeta
Streblosplo benedict!
Mlcrophthalmus sp.
Nephtys clllata
Polydora llgni
Scoloplos robustus
Clynenella torquata
Scolopios sp.
Cirratulidae
Gastropoda
Nassarius trivittatus
Bivalvia
0
15
0
22
6.5
1
0
0
0
0
0
0
0
28
0
0
0
0
0
0
0
9
0
0
3
0
0
0
0
12
0
0
0
0
0
0
0
57
10
0
0
3
0
1
0
aAll samples collected 31 October, 1989.
See Figure EA-4 for sample locations. V
Source: Army Corps of Engineers, NED. 1992. Winthrop Harbor Environmental Assessment.
0.3
21.4
4
0
0
0
0
0
0
1
20
0
8
0
0
2
0
.0
49
0
1
1
0
0
0
0
16.4
1.3
1.1
0.5
0.4
0.3
0.1
0.1
53.9
4.1
3.7
1.6
1.2
0.8
0.4
0.4
0.4
Mya arenarla
Mytilidae
Crustacea
Ampelisca abdita
Corophium insidiosum
Gammarus sp.
Balanus improvisus
0
0
0
0
0
0
0
0
0
0
0
0
3
1
0
4
2
1
1
0
0
1
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
3
2
0
0
0
0
8
1
0
0
0.5
0.1
1.4
1.1
0.3
0.1
2.1
0.4
4.5
3.7
0.8
0.4
-------
TABLE Al-11.
MAXIMUM CONCENTRATION (mg/1) OF COPPER AND SILT/CLAY IN
THE WATER STRATIFIED COLUMN AT THE BOSTON LIGHT SHIP
DISPOSAL SITE UNDER SUMMER CONDITIONS ESTIMATED BY THE
ADDAM'S MODEL FOUR HOURS AFTER A SINGLE DUMP OF 2,000
CU. YDS.
MAX. CONCENTRATION
OUTSIDE THE MIXING ZONEa
DEPTH
(ft)
1
50
108
145
COPPERb
0.00036
0.00035
0.00051
0.00038
SILT/
CLAY0'*1
5.2
5.5
NE
6.3
MAX. CONCENTRATION
WITHIN THE MIXING ZONE
COPPER
0.00035
0.00036
0.00066
0.00042
SILT/
CLAY
5.2
5.5
NE
7.9
SILT/CLAY
CLOUD DIA.
(ft)
2738
"Mixing zone = Disposal site boundary
*WQ criteria, Copper = 0.0029 Mg/L
Background, Copper = 0.00035 Mg/L
Background, Total Suspended Solids =4.5 mg/L
dConc. silt/clay = Background TSS (4.5) + concentration on grid
above background
-------
TABLE Al-12. WATER QUALITY DATA, BOSTON HARBOR*1)
Parameters'2>
River Complex
Outer Harbor
Outside Harbor
Temperature °C.
Salinity %
0-21
4-32
0-22
21-34
0-20.5
28-34
Chemical!^!
D.O., ppra
Nitrogen mg/1
Ammonia - N
Nitrate - N
Phosphorus mg/1
Total
Ortho
2.41-11.49
0.01-1.0
0.22-1.2424
0.05-1.02
.007-.924
6.02-14.0
0.01-14.0
.001-.570
.024-1.33
.010-1.17
6.48-12.65
0.01-0.40
0.002-.940
0.010-.133
0.018-.082
Zinct3) ppb
Copper*3) ppb
Lead'3' ppb
Nickel*3) ppb
Chromium*S) ppb
Cadmium151 ppb
30.6-62.2
2.8-6.6
2.2-10.6
7.2-13.6
0.2-3.69
0.34-0.56
7.8-16.7
1.9-8.6
1.2-2.7
0.1-13.6
0.1-1.2
0.11-1.10
Biologieaim
Bacterial cts.
(coliform)
0-96,000
0-10,000
0-4,200
(1) Table from Jason Cortell Associates (1977)
(2) New England Aquarium (1973)
(3) New England Aquarium (1972) (values are for soluble phase)
N.B.: Sampling by MDWPC (1986) is within the described ranges, but not
averaged here since it only occurred June through October.
-------
TABLE Al-13. AVERAGE CONCENTRATION OF TOTAL ORGANIC CARBON
AND TOTAL PETROLEUM HYDROCARBONS. MASSPORT
DREDGING PROJECT.
SITE
Army Base 1-3
Army Base 4-9
Boston Edison Intake
Conley 11-13
Conley 14-15
Distrigas
Eastern Minerals
Boston Edison Barge
Berth
Gulf Oil
Moran
Mystic 2, 49, 50
Mystic Pier 1
North Jetty
Prolerized
Revere Sugar
AVG. CONC. TOG (%)
3.9
2.7
5.4
4.1
3.1
6.6
3.6
10.2
1.7
5.6
2.4
3.7
3.1
5.0
4.5
AVG. CONC. TPH
3233
2390
2851
1310
3127
4393
2425
3650
1820
3035
2175
4640
2627
3970
3000
-------
TABLE Al-14.
COMPARISON OF AVERAGE T.KAT) AND CHROMIUM
CONCENTRATIONS (MG/L) WITH MASSACHUSETTS
DEP BULK SOIL CONCENTRATIONS (MG/L) FOR
TCLP ANALYSIS. MASSPORT DREDGING PROJECT.
MASS DEP BULK AVERAGE BULK
SOIL LIMIT SEDIMENT
FOR CR AND PB CONC. (MG/KG)
SITE (MG/KG) CR PB
Array Base
Boston Edison
Intake
Conley
Distrigas
E. Minerals
Boston Edison
Barge Berth
Gulf Oil
Moran
Mystic Piers
North Jetty
Prolerized
Revere Sugar
100
100
100
100
100
100
100
100
100
100
100
100
146
188
149
242
173
135
100
164
189
151
178
111
103
140
657
221
175
156
350
299
321
476
501
EPA REG.
LEVEL FOR TCLP RESULTS
CR & PB (MG/L)
(MG/L) CR PB
5
5
5
5
5
5
5
5
5
5
5
5
ND
ND
ND
ND
ND
ND
0.07
ND
ND
ND
0.16
0.33
0.29,
0.4'i
0.23
0.35
0.17
0.26
0.31
0.46
0.47
0.39
if-/'!
-------
TABLE Al-15. CONCENTRATION OF SODIUM AND CHLORIDE FOR
MASSPORT DREDGING PROJECT.
SITE
SODIUM (MG/KG)
CHLORIDE %
Conley
Army Base
Moran
North Jetty
Eastern Minerals
Mystic Pier
Gulf Oil
3250
3600
5930
5560
40140
6560
10650
1.9
1.8
2.1
1.8
1.6
2.0
1.1
-------
TABLE Al-16. FINFISH SAMPLING IN BOSTON HARBOR - JULY 1986
OUTER MAIN SHIP CHANNEL
Type of Gear: Gillnets
Number of deployments: 4 C2 demersal and 2 pelagic3
Length of deployments: 6 hours each
Species
Total Number
Pleuronectes
amerlcanus
Qsraerus ntordax
Alosa pseiidoharengus
Brevoortia tyrannus
Hoinarus amerlcanus
Cancer boreal is
6
2
1
1
2 Cl male,
1 female)
4 C4 female)
Average
Length Com 3
C+ S.D3
Total
Weight Ckg)
C+ S.D)
33.3C+ 7.03
16.75 C+ 0.353
22.0
35.0
7-5 O 0.423
10.55 C+ 0.66)
0.46
1.0
0. SY
0.28C + 0.04
OUTER MAIN SHIP CHANNEL
Type of Gear: Gillnets
Number of deployments: 4 C2 demersal and 2 pelagic3
Length of deployments: 6 hours each
Species
Total Number
p 1 eur onec t e.s
aroeri canus
Scophtha 1 mus
aquosus
Scomber scombrus
Al osa aesti val is
Myoxocephaliis
ecemsp i nosus
Cancer boreal is
Carclnus meanas
24 C63 % female)
1 Cfemale)
1 Cmale)
1 Cmale3
1Cfemale)
12 C66.7% male)
1 Cmale)
Average Total
Length Com)
O S.D.3
Average
He i ght
Ckg3
O S.D.)
16.6 C+ 11.33 0.5C+O.K
26.0 0.2!
24.0 0.1J
15.9
28.7 0.2!
9-1C+ 1.83 0.0
6.1
Note: Ectoparasitic infection on all Pleuronectes americanus
4V/
-------
TABLE Al-16. (CONTINUED)
MAIN SHIP CHANNEL
Type of Gear: Gillnets
Number of deployments: 2 Cdemersal3
Length of deployments: 6 hours each
Species
Total Number
Average Total
Length Com)
C+ S.D.3
Average
HeightCkg3
C+ S.D.3
P1euronectes
americanus
Scophtha1mus
aguosus
Osmerus mordax
1
1
28.5 C+ 0.123
29.0
15.2
0.48O0.0043
0.45
MAIN SHIP CHANNEL
Type of Gear: Gillnets
Number of deployments: 2 CdemersalD
Length of deployments: 6 hours each
Species
P1euronectes
amer i canus
Osmerus mordax
SCOPthaimus
aauosus
Microgadus tomcod
Cancer boreal is
Carcinus maenas
Total Number
ICfemaleD
5C60X male)
1
Average Total
Length CcmD
C+ S.D.D
18.6C+ 9.973
18.4C+ 3.03
13.2C+ A.73
23.5
6.9 C+0.53
3.2
Average
WeightCkg3
+ S.D.3
0.2
0.12
-------
TABLE Al-16. (CONTINUED)
MYSTIC RIVER
Type of Gear: Gil Inets
Number of deployments: 2 Cdemersal3
Length of deployments: 6 hours each
Species
Total Number
Average Total
Length Ccm3
O S.D.3
Osmer-us mordax 1 15.5
Carcinus raeanas 24 C1005C female) 3.34 O 1.593
Average
Weight Ckg)
O S.D.3
0.015
Finfish Sampling in Boston Harbor - July 1986
Mystic River
Type of Gear: Otter traxl
Number of deployments: 9
Length of deployments: 5 minutes each
Species
Total Number
Average Total Average
Length Com3 Weightd
C+ S.D.3 C + S.D.
None
MYSTIC RIVER
Type of Gear: Gillnets
Number of deployments: 2 Cdemersal3
Length of deployments: 6 hours each
Speci es
Total Number
Average Total Average
Length Com3 WeightCl
O S.D.3
C+ S.D.
Osraerus mordax
Carcinus maenas
16 C75%female3
19.0
4.82
0.673
0.03
-------
TABLE Al-16. (CONTINUED)
MYSTIC RIVER
Type of Gear: Otter Trawl
Number of deployments: ft
Length of deployments: 5 minute each
Species
Total Number
Average Total
Length Com)
O S.D.)
Average
HeightCkg)
C+ S.D.)
Pleuronectes
americanus
Scophthaimus
agousus
Alosa aestivalis
Osmerus mordax
Menidia menidia
Myoxocephalus
octodecemsp i nosus
Crangon septemspinose
Carcinus maenas
23
12
CSS. 3% male 3
female)
2
5796
72 C50JJ female)
9.59 O 3.51) 0.014
8.87 C+4.19) 0.018
11.2 C+1.67D
13.1 C+3.95D •,;••
11.1 C+0.42) ^
8.3C+ 0.42)
C3.62 total)
4.54 C+ 1.12) 0.026
V
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TABLE Al-16. (CONTINUED)
BOSTON HARBOR C19863
MYSTIC RIVER
July
Ni - 277.1, Ns - 2.23
Capitel la capitata C61.8X3
Polydora acrcrretrata C9. 0%3
Polydgra li^rnl C8.l%3
Caullerlella sp. C8.15J3
November
CNi •= 6.25, Ns - 0.253
Streblospio beneticti C33.3%:
Crangon SCPtemspinosa C33.3X3I
Gastropoda C33.32O
July
CHELSEA RIVER AND CONFLUENCE AREA
November
CNi
11,180.4 Ns
16.5)
C28.0JO
licrni
Capitella oapitata C17.2X)
CNi = 51.6, Ns - 0.753
Streblospio benedloti C20.3Jf3|
Tubificidae C32.2X3
Tharyx acutus C16.1X3
RESERVED CHANNEL
July
CNi - 409.4, Ns - 2.03
CaPitella capStata C85.53O
Eteone f lava C5.3JJ3
November
CNi = 15.6, Ns •= 0.383
Poljgdora li^rnl C60.0X3
Ampelj sea abdi ta C20.0X3
ModLo_lus modiolus C20.0X3
Ni - Mean tt of Individuals/m2
Ns ' Mean ft of Species/m
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TABLE Al-17. DOMINANT SPECIES BY TRIBUTARY
BOSTON HARBOR C19863
MYSTIC RIVER
July
Ni = 277.1, Ns = 2.23
Capitel la capitata C61.85£3
Polydora aggregata C9.023
Polydora ligni C8.1%3
Caulleriella sp. C8.1X3
November
CNi = 6.25, Ns = 0.253
Streblosplo beneticti C33.3X3
Crangon spetemsp inosa C33.3X3
Gastropoda €33.3%3
July
CHELSEA RIVER AND CONFLUENCE AREA
November
CNi = 11,180.4 Ns - 16.53
Polydora agqregata C28.0X3
Folydora ligni C24.9JC3
Capitel la capi tata C17.2JC3
CNi = 51.6, Ns = 0.753
Streblospio benedicti C20.3X3
Tubificidae C32.2X3
Tharyx acutus C16.1X3
RESERVED CHANNEL
July
CNi = 409.4, Ns = 2.03
Capitella capitata C85.5X3
Eteone -fIava C5.3X3
November
CNi = 15.6, Ns = 0.383
Polydora ligni C60.0X3
Ampelisca abdita C20.0X3
Modiolus modiolus C20.0X3
Ni = Mean tt of Individuals/m2
Ns = Mean ft of SpeciesXm
M-1
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