COOS BAY, OREGON
DREDGED MATERIAL DISPOSAL
SITE DESIGNATION
FINAL ENVIRONMENTAL IMPACT STATEMENT
o
US Army Corps
of Engineers
Poniand District
United States
Environmental Protection Agency
Office of Marine arid Estuarine Protection
Marine Operations Division
Washington, D.C. 20460
-------
841 R86002
FINAL
ENVIRONMENTAL IMPACT STATEMENT
FOR
COOS BAY, OREGON DREDGED MATERIAL
DISPOSAL SITE DESIGNATION
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF MARINE AND ESTUARINE PROTECTION
WASHINGTON, DC 20460
-------
PREFACE
This document was prepared by the Corps of Engineers (COE), Portland
District, with assistance and cooperation from Environmental Protection Agency
(EPA) Region X. Region X provided technical assistance in the drafting and
reviewed drafts of this document. The document was submitted for further
review and approval by EPA Headquarters.
-------
PREPARED BY:
US Army Corps of Engineers
Portland District
P.O. Box 2946
Portland, OR 97208
Telephone (503) 221-6413
Patrick J. j&ough,
Planning Division
Chief
REVIEWED BY:
US Environmental Protection Agency
Water Management Division
Region X
Seattle, WA 98101
Telephone (206) 442-1237
Robert Burd, Director
APPROVED AND SUBMITTED BY:
US Environmental Protection Agency
Office of Marine and Estuarine
Protection
Washington, B.C. 20460
Telephone (202) 382-7166
Tudor T. Davies, Director
-------
SUMMARY SHEET
ENVIRONMENTAL IMPACT STATEMENT
COOS BAY DREDGED MATERIAL DISPOSAL SITES
( ) Draft
(x) Final
( ) Supplement to Draft
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF MARINE AND ESTUARINE PROTECTION
1. Type of Action
(x) Administrative/Regulatory Action
( ) Legislative Action
2. Background
Except for this summary sheet, this Environmental Impact Statement (EIS)
was prepared by the Portland District, U.S. Army Corps of Engineers (CE) in
cooperation with Region X, Environmental Protection Agency (EPA). It has been
reviewed by Region X, EPA and approved by the EPA office of Marine- and
Estuarine Protection. The EIS is being issued by the Office of Marine and
Estuarine Protection, Office of Water, EPA as part of its responsibilities
under the Consent Agreement with the National Wildlife Federation.
3. Brief Description of the Action and Purpose.
The proposed action described in this EIS is the final designation of two
interim designated Ocean Dredged Material Disposal Sites (ODMDS) and the
designation of a new ODMDS off Coos Bay, Oregon. The two finally designated
existing ODMDSs would be used for the disposal of large grained sediments
(dredged material) while the new site further offshore would be used for the
disposal of finer sediments with higher volatile solids content. The purpose
of the action is to provide environmentally acceptable areas for the disposal
of dredged material, in compliance with the EPA Ocean Dumping Regulations and
Criteria.
A. Summary of Major Beneficial and Adverse Environmental and Other Impacts.
The principle beneficial effect is the provision of designated
environmentally acceptable ocean areas for the disposal of dredged material.
Planning for dredged material disposal is enhanced since permanently
designated ocean disposal sites are available for comparison with other
dredged material disposal alternatives. An adverse impact will result from
burial and loss of some bottom organisms within the sites. Burial of bottom
organisms outside the site boundaries should not occur. Other adverse
-------
environmental effects such as mounding, changes in sediment texture, and
disturbance of demersal fish, will be temporary, minor and restricted to the
sites.
5. Major Alternatives Considered.
The alternatives considered in the site evaluation studies and presented
in this EIS were: (1) no action; (2) final designation of the interim
designated sites and one new site; and (3) alternative locations for a new
ocean disposal site.
6. Comments on the Draft EIS were requested from the following:
Federal Agencies and Offices
Council on Environmental Quality
Department of Commerce
National Oceanic and Atmospheric Administration (NOAA)
National Marine Fisheries Service
Maritime Administration
Department of Defense
Army Corps of Engineers
Department of Health, Education, and Welfare
Department of Interior
Fish and Wildlife Service
Bureau of Outdoor Recreation
Bureau of Land Management
Geological Survey
Department of Transportation
Coast Guard
Water Resources Council
National Science Foundation
State and Municipalities
State of Oregon
City of Coos Bay
Coos County
Private Organizations
American Littoral Society
Audubon Society
Center for Law and Social Policy
Environmental Defense Fund, Inc.
National Academy of Sciences
National Wildlife Federation
Sierra Club
Water Pollution Control Federation
ii
-------
Academic/Research Institutions
Oregon State University '
7. The Final statement was officially filed with the Director, Office of
Federal Activities, EPA.
8. Comments on the Final EIS are due 30 days from the date of EPA's
publication of Notice of Availability in the Federal Register which is
expected to be pro 7 |Qgn
r~t=° ii you
Comments should be addressed to;
Paul Pan, Chief
Environmental Analysis Branch
Marine Operations Division (WH-556M)
Office of Marine and Estuarine Protection
Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
Copies of the Final EIS may be obtained from;
Environmental Analysis Branch
Marine Operations Division (WH-556M)
Office of Marine and Estuarine Protection
Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
The Final Statement may be reviewed at the following locations:
Environmental Protection Agency
Public Information Reference Unit, Room 204 (Rear)
401 M Street, SW
Washington, DC 20460
Environmental Protection Agency
Region X
1200 Sixth Avenue
Seattle, WA 98101
Portland District
U.S. Army Corps of Engineers
319 SW Pine
Portland, OR 97204
iii
-------
ENVIRONMENTAL IMPACT STATEMENT
TABLE OF CONTENTS
SUMMARY
TABLE OF CONTENTS
PREFACE
Page
i
iv
ix
I PURPOSE AND NEED
1.1 PURPOSE
1.2 NEED
II ALTERNATIVES INCLUDING THE PROPOSED ACTION
2.1 INTRODUCTION
2.2 ALTERNATIVES CONSIDERED
2.3 ALTERNATIVES ELIMINATED FROM FURTHER STUDY
2.4 EVALUATION OF THE NO ACTION ALTERNATIVE
2.5 ALTERNATIVES CONSIDERED IN DETAIL
2.6 ALTERNATIVES COMPARISON
2.7 IMPACT COMPARISON OF DISPOSAL OPTIONS
2.8 PREFERRED DISPOSAL SITES AND DISPOSAL OPTIONS
III AFFECTED ENVIRONMENT
3.1 INTRODUCTION
3.2 PHYSICAL ENVIRONMENT
3.2.1 Bathymetry of Disposal Site Area
3.2.2 Disposal Area Sediments and Sediment Transport
3.2.3 Coos Bay Sediment and Sediment Transport
3.2.4 Hydrography
3.2.4.1 Currents and Tides
3.2.4.2 Surface Waves
3.2.4.3 Wind Direction and Speed
3.2.4.4 Water Quality
BIOLOGICAL ENVIRONMENT
Introduction
3.3
3.3.1
3.3.2
3.3.3
3.3.4
3.3.5 Endangered Species
3.4 SOCIO-ECONOMIC ENVIRONMENT
3.4.1 Introduction
3.4.2 Local Area Economy
Benthos
Epibenthos and Fisheries
Marine Mammals
1-1
1-1
II-l
II-l
11-2
II-2
11-2
II-3
II-7
II-9
III-l
II I-2
III-2
II I-2
III-3
III-5
III-5
II1-6
III-7
II I-7
III-7
II I-7
III-8
III-9
III-10
111-10
111-10
II I-10
111-10
iv
-------
3.4.3 Population 111-12
3.4.4 State and Local Coastal Management Plans 111-12
3.4.5 Navigation Improvements and Dredging Costs 111-12
3.4.6 Commercial and Recreational Activities in the
Vicinity of the Disposal Sites 111-13
3.4.7 Esthetics 111-14
3.4.8 Cultural Resources 111-15
IV ENVIRONMENTAL CONSEQUENCES -
4.1 INTRODUCTION IV-1
4.2 PHYSICAL IMPACTS IV-1
4.2.1 Bathymetrie Impacts IV-1
4.2.2 Sediment Distribution and Transport IV-2
4.2.3 Water Quality IV-3
4.3 BIOLOGICAL IMPACTS IV-4
4.3.1 Epibenthos and Fisheries IV-4
4.3.2 Marine Mammals IV-4
4.3.3 Rare and Endangered Species IV-4
4.3.4 Benthos IV-4
4.4 SOCIO-ECONOMIC IMPACTS ' IV-8
4.4.1 Local Area Economy IV-8
4.4.2 Comparative Transfer Cost IV-8
4.4.3 Commercial and Recreational Activities IV-9
4.4.4 State and Local Coastal Management Plans . IV-9
4.4.5 Esthetics IV-9
4.4.6 Cultural Resources IV-10
4.5 MITIGATION AND SITE MONITORING IV-10
4.6 ADVERSE ENVIRONMENTAL EFFECTS WHICH ARE UNAVOIDABLE IV-10
4.7 RELATIONSHIP BETWEEN LOCAL SHORT-TERM USES OF THE
ENVIRONMENT AND MAINTENANCE AND ENHANCEMENT OF
LONG-TERM PRODUCTIVITY IV-10
4.8 IRREVERSIBLE OR IRRETRIEVABLE COMMITMENT OF RESOURCES IV-11
V COORDINATION V-l
VI LIST OF PREPARERS VI-1
VII BIBLIOGRAPHY VII-1
INDEX
APPENDIX A - OCMP CONSISTENCY STATEMENT A-l
APPENDIX B - ENDANGERED SPECIES COORDINATION B-l
APPENDIX C - LETTERS OF CLEARANCE C-l
APPENDIX D - SEDIMENT ELUTRIATE ANALYSES D-l
APPENDIX E - COMMENT AND RESPONSE SECTION E-l
-------
LIST OF TABLES
2.1 Summary Comparison of Alternatives 11-12
3.1 Location of Proposed Disposal Sites of the 111-16
Coos Bay Offshore Disposal Study
3.2 Sediment Accumulation Within Upper Coos Bay 111-16
3.3 Chemical Characteristics of Coos Bay Sediment, 111-17
May 1979
3.4 Chemical Characteristics of Coos Bay, October 1979 111-18
3.5 Chemical Characteristics of Coos Bay, March 1980 111-20
3.6 Chemical Analysis of Marine Waters at 111-22
Offshore Sites F, G and H ...
3.7 Most Abundant Epibenthic Species - April 1979 to 111-24
March 1980 Sampling Period
3.8 Most Abundant Epibenthic Species - May 1980 to 111-25
May 1981 Sampling Period
3.9 Marine Mammals Checklist 111-26
3.10 Population, Coos County and Coos Bay Area 111-29
4.1 Cost Comparison for Ocean Disposal Sites IV-12
VI
-------
LIST OF FIGURES
2.1 Alternative Disposal Sites Considered in Detail 11-11
3.1 Disposal Site Locations 111-30
3.2 Disposal Site Bathymetry 111-31
3.3 Extended Offshore Area Median Grain Size 111-32
Distribution (Hancock, et al. 1981)
3.4 Extended offshore area volatile solids 111-32
(Hancock, et al. 1981)
3.5 Median Grain Size vs. Organics Content in Estuarine 111-34
and Coastal Sediments (Hancock, et al. 1981)
3.6 .Median Grain Size vs. Volatile Solids With Site 111-35
Averages and Standard Deviations
(After Nelson, et al. 1983)
3.7 Median Grain Size Belated To Distance From Entrance 111-36
(After Hancock, et al. 1981)
3.8 Volatile Solids Related To Distance From Entrance 111-37
(Hancock, et al. 1981)
3.9 Coos Bay Sediment Sampling Sites (Hancock, et al. 1981) 111-38
3.10 Monthly Wind Vectors Observed at North Bend Airport and 111-39
NOAA Offshore Data Buoys
3.11 Core Sampling Stations - Phase I of Coos Bay Offshore 111-40
Disposal Study (Hancock, et al. 1981)
3.12 Trawl Sampling Locations - Phase I of Coos Bay Offshore 111-41
Disposal Study (Hancock, et al. 1981)
3.13 Core and Trawl Sampling Locations - Phase II of Coos Bay 111-42
Offshore Disposal Study (Nelson, et al. 1983)
3.14 IEC Survey Locations (IEC, 1982) 111-44
3.15 Distribution of Sediment Size 111-45
3.16 Distribution of Volatile Solids 111-46
3.17 Distribution of Wood Chips 111-47
3.18 Distribution of Shells 111-48
Vll
-------
3.19 Distribution of the Carnivorous Snail, Olivella sp. , 111-49
in the nearshore region
3.20 Distribution of the Clam, Tellina modesta, in the 111-50
nearshore region
3.21 Spatial Distribution of the Most Abundant Mollusc 111-51
Distrubtion
3.22 Spatial Distribution of the Most Abundant Polychaetes 111-52
3.23 Spatial Distribution of the Five Most Abundant Crustaceans 111-53
3.24 Total Number of Individuals Collected by IEC at Nearshore 111-54
•Region.
3.25 Distribution of Lumbrineris luti and Maldane glebifex 111-55
3.26 Distribution of Paraphoxus epistotnus and Olivella sp. 111-56
3.27 Navigation Improvements, Coos Bay, Oregon 111-57
Vlll
-------
INTRODUCTION
The proposed action addressed in this Environmental Impact Statement (EIS) is
final designation of ocean dredged material disposal sites (ODMDS) in the
vicinity of Coos Bay, Oregon. The purpose of the site designation process is
to identify environmentally acceptable offshore sites for the disposal of
dredged material from Coos Bay and vicinity, and to avoid or minimize adverse
impacts especially in areas valuable to-critical resources. A site designated
for continuing use is subject to restrictions listed in 40 CRF 220-229 (Ocean
Dumping Regulations). These restrictions include an in-depth environmental
review of any proposed disposal activity. Designation in itself does not
result in disposal of dredged material. A separate evaluation of the suit-
ability of dredged material for -ocean disposal is undertaken for each proposed
site. However, ocean disposal cannot be considered in the absence of a desig-
nated site. In addition, monitoring of these sites will be performed as
described in Section 4.5 of this EIS.
This EIS presents information in regard to the acceptability of the ODMDS
proposed for final designation. The evaluations only compare ocean disposal
sites and do not consider comparisons with other disposal options such as
upland or in-bay. Upland or in-bay evaluations are conducted for each Section
103 permit disposal as required by the ocean dumping regulations. Present
Corps procedures satisfy Section 103 requirements by routinely evaluating
dredged material sediments on a 3 to 5 year basis.
The primary data bases for this EIS were disposal site evaluation and
monitoring studies conducted by Oregon State University (OSU) under contract
to the Corps of Engineers, Portland District (Corps). Additional data were
obtained from a reconnaissance survey conducted by Interstate Electronics
Corporation (IEC) under contract to the Environmental Protection Agency (EPA).
The OSU study was initiated in January 1979 and field work was completed in
September 1983. The study was conducted in 5 phases.
Phase I was a 12-month baseline study of the physical, chemical and biological
conditions of the nearshore area off Coos Bay (an area of approximately 7,500
x 4,000 meters, extending out to the 40 meter contour and including Interim
Ocean Disposal sites E and F) and of the Coos Bay channel from River Mile
(RM) 15 to the entrance. The purpose of the Phase I studies was to provide
information that could be used to select candidate sites for detailed
evaluation during Phases II and III. The criteria used in selecting candidate
sites were:
a. Physical and chemical similarity (compatibility) of dredged material
and site sediment type:
b. Avoidance of impacts on unique or valued biological communities; and,
c. Minimization of onshore transport of fine sediments.
Since the sediments from above RM 12 of Coos River were determined to be
incompatible with sediments of the Phase I ocean study site, a need existed to
conduct detailed studies at sites located further offshore. Therefore, Phase
ix
-------
II and III studies were conducted between April 1980 and June 1981 in an area
of approximately 5,000 x 3,500 meters, and at depths ranging from 40 to 120
meters, which provided additional baseline data for final site designation.
Phase IV and V studies were initiated in July 1981 and field work was
completed in September 1983. Copies of the final report are available from
the Portland District. These studies investigated the effects of a 1981 test
disposal at site H (53-66 meter depths) during and immediately following
disposal and re-investigated the site during 1982 and 1983, to document post
disposal effects.
The EIS is being prepared in accordance with the requirements of the Marine
Protection, Research and Sanctuaries Act of 1972 (MPRSA), the EPA, Ocean
Dumping Regulations and Criteria, 1977 (40 CFR 220-229), and other applicable
Federal environmental legislation. The EIS is also prepared in accordance
with EPA's voluntary policy for preparing an EIS for each site designation to
fulfill the requirements of the National Environmental Policy Act of 1969
(NEPA) (39 FR 16186, May 7, 1974).
The criteria used to assess the acceptability of proposed ODMDS near Coos Bay
were those established under Section 102 (a) of MPRSA and outlined in 40 CFR
Parts 228.5 and 228.6. The 11 specific criteria established by EPA under 40
CFR 228.6 are included in Section 2 of this EIS for the comparison of
alternative sites.
Although the action to be addressed in this EIS is ocean disposal site desig-
nation, the impact evaluation addresses the effects of disposal at or near the
proposed sites. The primary use of the sites, in addition to Section 103 dis-
posal permit activities, is anticipated to be disposal of material dredged
from the Coos Bay navigation channel. As a result, the studies mentioned
above and the EIS were based on the types and quantities of material dredged
from the channel and adjacent areas. The sediments found in Coos Bay can be
classified into the following three basic types:
1) Type 1 - Predominantly clean sand of marine origin typical of
sediments from below Coos Bay river mile (RM) 12.
2) Type 2 - Finer-grained sand and silt containing some volatile solids
typical of sediments from between Coos Bay RM's 12 and 14.
3) Type 3 - Highly organic fine material (6 to 20 percent volatile
solids) typical of sediments from above Coos Bay RM 14.
These three types of sediments are representative of the types of sediments
found throughout the estuary.
-------
I. PURPOSE AND NEED
1.1 PURPOSE
The purpose of final ocean disposal site designation is to identify sites
for the disposal of dredged material from the Coos Bay, Oregon vicinity, in
accordance with the criteria established by EPA under Section 102 of the MPRSA
(See Section 2). On the basis of these criteria, ocean disposal sites can
thus be described as areas within the ocean where various physical, chemical,
and biological impacts will be accepted. Use of the sites would be for
disposal of material dredged for operation and maintenance of the Federally
authorized navigation project at Coos Bay, and for disposal of dredged
material from other dredging projects authorized in accordance with Section
103 of the MPRSA.
1.2 NEED
Coos Bay is a major center of commerce and industry for the State of Oregon.
Within the Coos Bay Region, approximately 50 percent of the 20,000 available
jobs are directly or indirectly dependent on shipping activities. In 1980,
the volume of trade through Coos Bay was more than 6 million tons. The total
number of deep draft vessels using Coos Bay during 1980 was 333. Consequent-
ly, maintenance of the navigation channel to authorized depths is critical to
keeping the harbor open and sustaining these vital components of the state and
local economy.
Approximately 1.5 million cubic yards of sedimentary materials enter Coos Bay
annually from the Coos River and adjoining sloughs, and through the Coos Bay
entrance channel. The Corps is responsible for planning and conducting the
necessary maintenance dredging and disposal operations for the Coos Bay
navigation system to its authorized depth. This requires that sediments be
removed from the entrance channel and lower reaches annually and from the
upper channel (above RM 12) every two to four years. The need for ocean
disposal sites has become more critical in recent years as suitable upland
disposal sites around Coos Bay are limited and most of these within economical
distance to the channel have been filled to capacity. (Coos Bay Estuary
Management Plan, Coos County, 1983; Personal Communication, Nancy Case, COE
Operations Division, 1985).
EPA designated two sites off the mouth of Coos Bay in 1977 for interim use
pending final site designation. Use of these interim-designated sites has
been essential to the Corps' compliance with the MPRSA and its ability to
carry out its statutory responsibility for maintaining the nation's navigable
waterways. To continue these responsibilities it is essential that
environmentally acceptable ocean disposal sites be identified, evaluated, and
permanently designated for continued use.
1-1
-------
II ALTERNATIVES COMPARISON
2.1 INTRODUCTION
This section discusses the alternative ocean disposal sites considered,
including those considered but eliminated from further study, and no action;
describes the sites considered with references to the specific criteria for
evaluating ocean disposal sites required by MPRSA; provides an impact compar-
ison of the alternative sites based upon their potential use; and outlines
the preferred site designations.
Although the purpose of this EIS is to provide information necessary to evalu-
ate proposed sites for ocean disposal of dredged material at Coos Bay, Oregon,
it should be understood that site designation in itself does not result in
disposal of dredged material. The site designation process is a statutory
requirement which defines ocean areas where disposal of acceptable material
may be considered. Actual disposal in these sites can occur only after the
requirement of separate evaluations are met. Thus the availability of a
designated ocean disposal site Is a prerequisite for approval of actual
disposal in the ocean.
Section 2.6 presents Information comparing the alternative sites using the 11
specific MPRSA site selection criteria. The MPRSA criteria evaluates the
relative merits of the sites; however, this format does not lend itself to
comparing impacts at 'the various sites based on their potential use. Section
2.7 provides such a comparison to illustrate the consequences of disposing
different materials at the alternative sites. Section 2.8 describes the
preferred action..
2.2 ALTERNATIVES CONSIDERED
Several potential ocean disposal sites have been identified during the various
studies conducted for offshore disposal at Coos Bay and during preparation of
this EIS (see Figure 2.1). These are: (a) the two interim-designated sites,
(Sites E and F), located near the 10 fathom (18 m.) contour; (b) Site H
located near the 30 fathom (55 m.) contour; (c) Adjusted Site H located near
the 25 fathom contour; (d) Site G located at approximately 50 fathoms (91 m.);
(e) a continental slope alternative at about 200 fathoms (364 m.); (f) combi-
nations of the above; and (g) no action (upland disposal sites would need to
be located).
Sites E and F were considered since they are the sites approved by EPA in 1977
to be used on an interim basis pending final site designation. The location
and dimensions of these sites were selected based upon reasonable distance
from the Coos Bay entrance, depth of water, biological conditions, historical
use, estimated amount and type of dredged material and the desire to keep sand
in the littoral transport system (personal communication, Robert Hopman,
Corps, North Pacific Division, 1985). Sites G and H were considered since
they are areas with bottom sediments similar to the finer materials dredged
from above RM 12 in Coos Bay. Adjusted Site H was selected as an alternative
to Site H to avoid impacts to a previously used scallop bed. In addition, use
of these sites reduces the potential for return of incompatible sediments to
the estuary or beaches. The deepwater site was selected because EPA site
selection criteria requires that a continental slope site be considered.
II-l
-------
Ocean disposal effects were considered by evaluating the potential disposal of
three types of sediments from the Coos Bay area. These were the clean sands
of marine origin found from the Coos Bay Entrance to RM 12 of Coos Bay (refer-
red to herein as Type 1 material), material from above EM 14 characterized by
relatively fine grain size and relatively high organic solids contents (Type 3
material) and material from between RM's 12 and 14 that is intermediate in
character between Type 1 and Type 3 material. This latter material is refer-
red to as Type 2 material.
2.3 ALTERNATIVES ELIMINATED FROM FURTHER STUDY
2.3.1 Continental Slope Alternative
The deepwater site has been eliminated from further study for the following
reasons:
(a) The relatively clean (predominantly sand) sediments dredged from
Coos Bay do not warrant selection of a site a greater distance from shore than
is required to comply with MFRSA and related criteria.
(b) The transport cost associated with disposal at this distance would
be extremely high and not economically justifiable compared to sites located
closer to shore (see Section 4.).
(c) Site sampling and testing costs, and .post-disposal monitoring costs,
would likewise be extremely high due to distance from shore and depth of
water.
2.3.2 No-Action Alternative
The No-action alternative would be to refrain from designating an ocean site,
or sites, for the disposal of dredged material from Coos Bay. Existing sites
E&F were designated on an interim basis. The interim designation was
scheduled to expire on 31 January 1985, but has been extended to 31 December
1988.
By taking no action, these sites would not receive a final designation, nor
would an alternative ocean disposal site be designated. Consequently, an EPA
recommended ocean disposal site would not be available in the area after 31
December 1988. In addition, there would be no disposal site suitable for the
material from above RM 12. The option of ocean disposal of dredged material
would be eliminated.
Type 1 material consists of clean sand and is acceptable for ocean disposal
and has historically been disposed of at ocean sites. The expense of locating
and acquiring adequate upland disposal sites is not justified. Current upland
disposal sites have limited capacity for Type 2 material and no capacity for
Type 3 material. Therefore, without ocean disposal the authorized channel
depths at Coos Bay could not be adequately maintained.
(Note: Upland disposal alternatives will be considered when each disposal
action is evaluated according to the Section 103 permit requirements.)
II-2
-------
2.4 ALTERNATIVES CONSIDERED IN DETAIL
The two interim sites (Site E and F), the 30-fathom site (Site H), the
25-fathom site (adjusted Site H) and the 50-fathom site (Site G), each appear
viable and have been considered in detail* These sites have therefore been
selected for evaluation using the selection criteria established by the
MPRSA.
2.5 COMPARISON OF ALTERNATIVES USING MPRSA SITE SELECTION CRITERIA
This section presents information on sites E, F, G, H, and adjusted site
H relative to each of the 11 specific MPRSA site selection criteria. Each of
the sites are evaluated, where appropriate, for disposal of Type 1,- 2, and 3
dredged material. The information and analysis contained in this section was
summarized from the more detailed information in Sections 3 and 4. A summary
comparision chart is provided in Table 2.1. Please note that although
sections 3 and 4 do not specifically refer to adjusted site H, the data and
analyses prepared by OSU and presented in these sections cover an extensive
offshore area which includes adjusted site H.
2.5.1 Geographic Location
Sites E and F are located approximately 1.5 statute miles offshore of the
entrance to Coos Bay at depths of 10 and 12 fathoms, respectively. Adjusted
Site H is located approximately 3.1 miles offshore at a depth of 25 fathoms.
Site H is approximately 3.7 miles' offshore at a depth of 30 fathoms and site G
is located about 5 miles offshore at a depth of 50 fathoms. General locations
of these sites are shown in figure 2.1 and coordinates are given in table 3.1.
2.5.2 Distance from Important Resource Areas
Breeding, spawning, rearing of marine organisms, and passage of
commercially important marine species occurs at all sites studied. In
addition, a scallop bed is located between the 40 and 52 fathom contours.
Species diversity and abundance of benthic invertebrates were directly related
to water depth and sediment characteristics within the Coos Bay offshore
disposal study area (Section 3). As depth increased and average sediment size
became finer, species diversity and abundance of benthic organisms increased.
Sites E and F were characterized by benthic species adapted to high wave
energy environments. Seasonal variability of benthic species was large. In
contrast, site G had a large number of filter feeding bivalves indicative of a
less dynamic environment. The benthic fauna of site G was the most diverse
and had the largest numbers of individuals of the areas studied. Site H had
species common to both the shallow (10 fathoms) and deeper sites (50
fathoms). Much seasonal variation in diversity and abundance was observed for
the benthic community at site U. The benthic fauna of adjusted site H is most
similar to sites E and F.
2.5.3 Distance From Beaches
Sites E and F are each located within 1.8 miles of a beach, adjusted site
H is within 2.8 miles, site H is within 3.7 miles and site G is within 5.2
miles of a beach. The proximity of sites E & F to the beaches, coupled with
the frequency of onshore transport and seasonal ocean currents parallel to the
coast, contribute to a potential for onshore transport from these two sites.
II-3
-------
Because of the increasing depths, distance from shore, and frequency of
offshore currents, onshore transport of sediments from sites H, adjusted H,
and G is less likely and dispersion would distribute type 2 and 3 sediments
predominately offshore. The fraction of material moving onshore would not
reach detectable volumes.
2.5.4 Types and Quantities of Material to be Disposed
As described in the preface to this EIS, there are three basic types of
sediments from Coos Bay being proposed for ocean disposal. Type 1 sediments
from Coos Bay entrance to RM 12 are predominantly clean sand of marine
origin. Median grain size is relatively constant at 0.2-0.3mm and volatile
solid content varies between 0.1 and 2.0 percent. Approximately 1.3 million
cubic yards of this material are dredged annually. The second category of
sediment (Type 2) lies between RM's 12 and 14. Median size here varies .
between 0.02 and 0.2mm and volatile solids content varies from 2 to 10 per-
cent. Approximately 200,000 cubic yards of material are dredged every two to
four years in this area. Type 3 material (above RM 14) is highly organic,
varying in median grain size from 0.006 to 0.02mm and from 6 to 20 percent
volatile solids. Less than 200,000 cubic yards of this material is dredged
every two to four years.
Future dredged material volumes may exceed present volumes if the navigational
safety of the channel necessitates expanded dredging efforts or if other
dredged material is disposed at the site. Any materials disposed at the sites
must be within the capacity of the sites and must comply with EPA dredged
material criteria in Part 227.13 subpart B of the Ocean Dumping Regulations
(40 CFR 220 to 229).
It is anticipated that the dredged material will continue to be transported by
hopper dredge equipped with a subsurface release mechanism. However, other
means of transportation and release, consistent with the environmental
requirements of the sites, may be utilized. None of the dredged material will
be packaged in any manner.
2.5.5 Feasibility of Surveillance and Monitoring
Surveillance of sites E, F, H, adjusted H, and G can be made from shore
facilities or vessels. Approaches to the estuary entrance, including Sites E
and F are currently surveyed annually by the Corps with detailed bathymetric
maps made available to the public. The surveyed area can be expanded to
include site H. Surveillance during heavy weather conditions is expected to
be unnecessary since heavy weather curtails ocean disposal operations.
2.5.6 Dispersal, Horizontal Transport, and Vertical Mixing
Characteristics of Area
All Sites; Average currents in the region generally flow parallel to
bathymetric contours with downslope components predominating over upslope
components near the bottom. Local current strength and direction, however,
reflect the variability of local winds. Since weather conditions restrict
ocean disposal operations to the period April through November, the
predominant direction of transport of materials suspended in the water column
will be southward at 10 to 30 cm/s in the vicinity of sites E, F, H and G.
Northerly transport may occur at these sites in late fall. Current strength -
II-4
-------
and direction of currents at these sites are highly variable in spring and
fall. Sediments reaching the bottom would experience resuspension and
spreading. Local currents at all sites can resuspend finer Type 3 materials
year round. The coarser sediment Type 1 and 2 would be mobile year round near
sites E and F. These coarse sediments would have some bedload movement in the
vicinity of site H during the dredging season but resuspension during the
remainder of the year would be limited to major storm events. These sediments
would be stable year round in the vicinity of site 6.
Sites E and F; All sediments disposed of at these sites would be rapidly
reworked by strong tidal and surface-wave generated currents. Winter
reworking would be especially intense, resulting in the erasure of any
mounding and the distribution of coarser size fractions over the tidal delta.
Finer size fractions would be transported with the mean currents. During the
disposal season, there would be a greater tendency for shoreward transport of
fines from site F than from site E where downslope transport predominates due
to effects of shoreline configuration. Strong upslope transport, however, can
occur at site E during late fall and winter.
Sites H, adjusted H, and G; The areal impact of disposal at sites
adjusted H, H and G increases in proportion to depths doubling approximately
every 20 fathoms. However, thickness.would be substantially less and larger
fractions of the dredged material would be initially suspended in the water
column at the deeper sites. Type 3 sediments would be mobile at each site
year round but only the finer fractions of Type 3 sediments would be mobile at
site G. Mobilization of the coarser sediments' at sites H and adjusted H would
occur primarily during summer and winter storm periods.
Dredged material mound height per 100,000 cy of Type 3 sediments reaching the
bottom of sites adjusted H, 11 and G would be measured in inches, with
subsequent-erosion occuring more slowly than at sites E and F. Portions of
the mounds at sites adjusted H, H and G would be covered by local sources of
moving sediments (a natural capping phenomena). Thus mounds at these sites
would endure longer than a mound at sites E and F.
2.5.7 Effects of Previous Disposals
Sites E and F: Previous disposal at these sites has averaged about 800,000
cubic yards of Type 1 sediments annually. There appear to be noticeable
seaward bulges in the bathymetric contours of the tidal delta in the
vicinities of sites E and F, but they have not been definitely attributed to
disposal activity. There is some mounding at the sites following the dredging
season, but this is normally erased by winter storm activity and no long-term
bathymetric changes occur. The material deposited at sites E and F moves
along the coast with the littoral drift system. Short term increases in the
turbidity of the water column occur, but such an impact has been very minor
considering the clean nature of the historically deposited materials. No
significant biological impacts have been associated with this disposal.
Adjusted Site H; No previous disposal.
Site H; A test dump of approximately 52,000 cy of Type 3 material was made at
site II during August 1981. Erosion as moving and capping of the dredged
material with native sediments was evident in August 1982. Within 19 months
of the test dump, the disposal mound had been erased or mixed beyond
II-5
-------
recognition with native sediments. No acute conditions were observed during
disposal for temperature, salinity dissolved oxygen, pU, oxidation-reduction
potential or turbidity. Borderline acute toxicity conditions of some water
column examples were observed for ammonia-nitrogen, copper and manganese.
These conditions were of short duration. Sediment samples obtained one year
and 1.5 years after disposal showed a definite trend of return to background
conditions. The benthic community was significantly depressed in the area of
disposal impact immediately after disposal. A steady recovery to predisposal
abundance levels was observed for the benthic community during the 19 months
of the post dump monitoring, suggesting that the effects of dumping on the
infauna were of short duration. (Sollitt, et.al 1983). These observations
indicate that the benthic community has the capacity to recover to background
conditions and that disposal of type 3 material on a 2- to 4-year cycle as
proposed would not cause any long-term adverse impact.
Site G; No disposal has occurred at this site.
2.5.8 Interference with other"vises"of the' ocean.
The only known commercial or recreational use of sites £, F, and adjusted site
H is marine navigation. Disposal activities at these sites would have little
effect on this use. Commercial fishing occurs in the vicinity of sites G and
H but no significant impact would be anticipated. See Sections 3.4 and 4.4.3.
2.5.9 Existing Water Quality and Ecology.
Water quality analysis for surface and bottom water at all sites did not
indicate an atypical or polluted condition for seawater of the Pacific
Northwest, nor an atypical ecological condition. See Section 3. The ecology
of the area is typical of uiost regions of the Oregon Coast. Distribution and
abundance of pelagic fish is closely tied to the influence of the ocean
currents, and the distribution and abundance of bottom dwelling organisms is
tied to the character of bottom conditions. The group of greatest interest to
this E1S is the benthic community since it is the group that would be most
directly affected.
The abundance, diversity and species composition of the benthic community is
tied to the character of bottom conditions. As water depth increases, sea
floor currents and sediment grain size decrease while organic, chemical
constituents, and biological abundance tend to increase. This relationship is
well illustrated in the OSU Study. The benthic community in the near shore
region had the lowest abundance and diversity of the sites studied. In
addition, it was dominated by burrowing species and deposit or opportunistic
feeders.
Much seasonal variation in distribution and abundance was observed of these
species. This is to be expected in an environment characterized by major
perturbations in sediment conditions due to high wave energy environments.
This adaptation to adverse habitat conditions is however a desirable
characteristic for proposing an area for ocean disposal.
In contrast, the region around site G was characterized by the most abundant
and diverse benthic community of the sites investigated. The community was
dominated by filter and surface feeders. This is to to be expected in a
II-6
-------
habitat with stable sediment conditions and sediments having a high content of
finer materials and volatile solids.
The zone between the nearshore and site G can be classified as a physical and
biological transition zone. Species composition in the shallow regions is
most similar to that of the nearshore region and vice versa. Seasonal
variation in abundance is high.
2.5.10 Potential for Nuisance Species.
The major component which would attract nuisance species is the organic
material. The clean sand (type 1) disposed at sites E and F does not include
this component. The material to be disposed at site U does contain organic.
material, but the O.S.U. studies have not demonstrated that nuisance species
are attracted to disposal sites. The rapid incorporation of the dredged
material with the native material further reduces the possibility of nuisance
species becoming established at sites E, F or E.
2.5.11 Existence of Significant Natural or Cultural Features.
No known significant natural or cultural features exist at or near the
alternative sites - see section 4.A.6 and Appendix. C.
2.6 IMPACT COMPARISON OF DISPOSAL OPTIONS.
Four disposal options were considered for ocean dumping of 'dredged material at
the alternative sites. These options were: 1) disposal of all types of
dredged material at the interim sites E and F; 2) disposal of Type 1 material
at sites E and F and disposal of Type 2 and 3 material at site G; 3) disposal
of Type 1 material at sites E and F and disposal of Type 2 and 3 material at
site H; and 4) disposal' of Type 1 material at sites E and F and Type 2 and 3
material at adjusted site U (centroid at 25 fathoms).
The impacts associated with ocean disposal off Coos Bay, Oregon can be reduced
to 5 general categories. These impact categories are 1) the volume of the
material to be disposed, 2) the nature of the material, 3) the environmental
(primarily benthic habitat) sensitivity of the site(s) considered, 4) the
incremental increase in impacts over that associated with historical disposal
options, and 5) the incremental increase in cost of disposal between sites.
Option 1. Disposal of all dredged material from Coos Bay at sites E and F.
These sites are located within 1.5 miles of the entrance to Coos Bay thus the
cost of disposal of this option would be the lowest of the options
considered. In addition there are no known features of environmental or
historical significance in these two sites. These two sites are characterized
by high energy bottom environments and benthic communities that have low
species diversity and a high variance in seasonal abundance. These two sites
are the least sensitive biological areas of the sites studied.
Disposal of type 1 material at sites E and F is acceptable because a) type 1
material is very similar to the native sediments in the areas, b) it meets all
criteria of 40 CFR, 227.3(b) for ocean disposal without further testing and c)
there is no record of significant impacts associated with historical disposal
of type 1 material at these sites.
II-7
-------
In addition disposal of type 1 material at any other site would result in long
term bottom habitat changes. For these reasons disposal of type 1 material at
sites other than E and F was not considered in the best public interest.
The disposal of either type 2 or 3 material at sites E and F is questionable
since this material is physically and chemically dissimilar to the sediments
of these sites. In addition there is the possibility that ammonia-nitrogen,
copper and manganese levels may approach EPA standards of concern. High
levels of turbidity could also result from disposal of type 2 and 3 materials
at these sites. Toxicity conditions would be measured in hours but turbidity
could be measured in days since the sediments would be continually reworked by
the high energy bottom currents. The turbidity levels would temporarily
degrade the esthetic environment.
Option 2. Disposal of type 1 material at sites E and F and types 2 and 3
material at site G.
The primary difference in effects of this option and those associated with
option 1 is the incremental impacts to the benthic communities and differences
in turbidity effects. Economic impacts should not be of major concern since
the increase in cost of transporting type 2 and 3 material to site G rather
than dumping it at sites E and F is 16% (see Figure 4.1). Because of the
greater depth of water at site G the possibility of short term (hours) acute
toxicity conditions is reduced. Turbidity will be reduced below standards
within 4 hours of the dump. Disposal of type 2 and 3 material at this site
would be unacceptable because a) the area is characterized by the most
abundant, diverse, and stable benthic community of the sites studied, b) the
site lies near the scallop bed located between 40 and 52 fathoms and the
predominant northerly currents would possibly transport type 2 and 3 sediments
into the bed, c) the site is within the zone of commercial fishing and d) the
low rate of sediment erosion from the area would result in the development of
mounds of dredged material at this site.
Although type 2 and 3 sediments are most similar, of the sites studied, to the
bottom sediments of site G, they remain measurably different (see Figures 3.5
and 3.6). Disposal of these materials at site G, coupled with the slow
erosion rate at this site and the large impact area that would result from
disposal, may result in long term changes in the substrate habitat of the
benthic community. This effect may alter the benthic community composition in
this area. Thus benthic impacts would be both direct and indirect.
Option 3. Disposal of type 1 material at sites E and F and disposal of type 2
and 3 material at site U.
The primary differences between this option and options 1 or 2 are
environmental effects. Economic impacts would not be significant since, the
increase in cost of transporting type 2 and 3 material to site H rather than
dumping it at sites E and F is 8% (see Table 4.1). Ammonia-nitrogen, copper
and manganese effects would approach the standards of concern for short
periods and turbidity conditions would dissipate within 4 hours of the dump
(Sollitt et.al. 1983). These characteristics satisfy the economic and
pollutant concerns of dumping type 2 and 3 material at this site.
Although type 2 and 3 material is dissimilar to the sediments of site H, this
is the site the OSU study recommended for disposal of this material. Factors
II-8
-------
V-v V^V^Vl&W^iW^
contributing to this recommendation are: a) material of concern would be
diluted to levels below those allowed by EPA water quality criteria; b) the
predominant downslope and north-south currents effectively preclude
resuspended sediments from being transported shoreward; c) benthic impacts
would be substantially less than if the material were disposed of at site G;
d) the seasonal and spatial variation of benthic organisms observed at site U
during the O.S.U. studies suggest that they are more tolerant to intermittent
bottom disturbance than are species at site G or E and F and would recover
more rapidly from the effects of disposal and; e) natural capping of the
disposed material appears to occur at site U.
Although disposal of type 2 and 3 material at site H would appear acceptable,
the western edge of the site was previously thought to lie near the southern
boundary of the scallop fishery bed off Coos Bay. Resource agencies initially
recommended (meeting of Oct. 4, 1983) that if site H is proposed for use that
its location be adjusted so that a buffer region is established between its
western edge and the 40 fathom contour. (The western edge of site H lies at
35 fathoms. The ocean bottom between 40 and 52 fathoms is the area that
scallops were found in densities high enough to support a fishery). We
developed the following option in response to these concerns.
Option 4. Disposal of type 1 material at sites E and F and type 2 and 3
material at the 25 fathom contour (adjusted site H).
This option was considered in an attempt to avoid potential disposal impacts
on the scallop bed located between 40 and 52 fathoms. Use of adjusted' site H
would establish a buffer of approximately one nautical mile between the
disposal site and the scallop bed. In addition, this adjustment could reduce
benthic impacts since the site would be located in a zone with a benthic
community characterized by lower species richness and abundance than at site
H. However, benthic information regarding adjusted site H is limited; thus
more information would have been needed to verify impact comparison. The
benthic impacts of disposal of type 2 and 3 material in this area would be
similar to those predicted for disposal of the same material at sites E and
F. Disposal at this site would also resolve the concerns for aesthetic
impacts in that downslope transport of material predominates at this
location. The estimated increase in cost of disposal of type 2 and 3 material
at this location is approximately 4% greater than the cost of disposal of the
same material at site F.
2.7 PREFERRED DISPOSAL SITES AND DISPOSAL OPTIONS
Based upon our review of the available information and assessment of the
relative impacts we recommend the designation of three sites off Coos Bay,
Oregon for the disposal of dredged material. These sites are the interim
disposal sites E and F, and site U with a centroid at approximately 31
fathoms. The coordinates of these proposed sites are given in Table 3.1. The
locations of these sites are also illustrated in Figure 2.1. The recommended
use of these sites is disposal of type 1 material at sites E and F and
disposal of type 2 and 3 material at the site H location.
Both sites E and F are needed to maintain flexibility of disposal when
currents change and to reduce sea keeping hazards to the dredges during
periods of adverse weather conditions. Site H is needed to accommodate the
finer type 2 and 3 material since it is not compatible with sites E and F.
11-9
-------
The draft EIS recommended adjusted site H location as the preferred
alternative for the disposal of type 2 and 3 materials, primarily to avoid
impacts to the scallop bed. As a result of further information obtained after
the publication of the draft EIS, and in consultation with affected Federal
and State resource agencies at a January 9, 1985 meeting (Braun, 1985), site H
is now recommended as the preferred location for disposal of these materials,
based on consideration of the following points:
1. The scallop bed is located further from site H than it was originally
believed to be;
2. No living scallops were found at site H and very few were found
beyond the site in the general area of the scallop bed during the O.S.U.
sampling. The Oregon Department of Fish and Wildlife (ODFW) has indicated
that the scallop bed has been fished out (Rick Starr, ODFW, personal
communication);
3. Sediments transported from site H are highly unlikely to move toward
the scallop bed (Charles K. Sollitt, Oregon State University, personal
communication);
4. The deeper water will significantly reduce bottom transport of
material deposited at site H and;
5. Baseline data for monitoring at adjusted site H is lacking.
The dimensions of the sites are determined by the anticipated spreading
pattern of material dumped from hopper dredges in relation to the time
required for disposal. These areas are considered to be large enough to
encompass the impact zone of disposal. Based upon the expected erosion and
dispersal rates associated with bottom currents these dredged materials will
be dispersed within 1 to 3 years.
11-10
-------
1 I 7 I I
I I
I
I I
43°25'
43°24'
43°23'
43°22'
43°21'N
124°26' 124°25' 124°24< 124°23' 124°22' 124°21' 124°20' 124°19'W
Figure 2.1 Alternative Disposal Sites Considered in Detail.
11-11
-------
TABLE 2.1
SUNMART COMPARISON OF ALTERNATIVE SITES USING HPBSA CRITERIA
Criteria •• Llated
ID 40 CFR 0228-6
(1) GeO(t«phlc«l
Loca tlon
(2) Location Relative
to Important
Reaourca Araaa
(3) Dlatanea froB
Baachea
(4) Typaa 4 Quantltlee
of Naterlala
(5) Surveillance
and Nonltotlng
(6) Dlaperaal, Horl-
lontal trioiport,
vertical nixing.
(7) Effeete o( Pravloua
Dlapoaal In Ocaan
'
(8) Interference with
othac uaaa of tha
oeaan
(») Exlatlng water
quality and
ecology
(10) Potential (or
nulianca apaclaa
(11) Exlataneo of
algnlflcant natural
ot cultural
featuraa
E & F
Within 1.3 a. allae a( Cooa
Bajr antranea. Saa Tabla 3.1
for cantrold locatlona.
Low danalty banthle commit?
tarn* breeding, faadlng,
raarlng and paaaaga of votlla
•paclaa over antlra araa.
Llttla flahlng activity.
Cloaa to baachaa (about 1.8
•1); onahora tranaport
potantlal la likely.
Claan aanda witb average
eadUent alia ilallar to
botton ledUenta. Approxi-
mately 1.3 million ey annually
projactad (or Sltaa 1 4 t.
Snrralllanea and aonl toeing
ahallowneaa of altaa, and
availability of hlatorleal
data.
Rapid aattllng of aanda. Mo
paralatant turbidity plume*
Raauapanalon of materiel Mill
ba at a maximum during winter
atorma. Predominant tranaport
dlractlon will ba aouthwerd at
10-30 cm/ •. SadUanta will ba
•obi la yaar round dua to high
aaargy condition!.
SOM eaevard axpanalon of
river delta, no algniflcant
long tan, affacta on fauna of
araa.
Mo Intarfarancaa racordad for
interim dlapoaal and nona
axpactad for futura. Araaa
ontalda aonaa of conarclal
activity axeapt naTlgatlon.
Uatar quality typical for
aaavatat of tha Pacific
Northvaat.
Banthle commit? charactar-
laad by lo» abundanea and
dlvaralty and adaption to
unatabla aadlaanta.
UncontaBlnatad aand doaa not
contain vatarlal which would
attract nulaanca apaciaa.
No known faaturaa.
0
Hlth 3.0 a. allaa of Cooa Bay
antranea. Saa Tabla 3.1 for
cantrold location.
Neat abundant and dlraraa ban-
thle coaaunlty of altaa
atudlad. Dapth corraaponda to
aona of Ineraaaad fllh
activity. Maar aeallop bad.
Major aadlaant ttanaport la
downalopa. Llttla opportunity
for upalopa traoaport( onahora
tranaport or lipact.
Sam aa Slta H.
Monitoring would ba aora axpan-
graatar dlatanea from ahora and
graatar daptha.
SUllar to that for Sita H.
No pravloua dlapoaal hara.
,
Araa la within tha aona of >ajor
eoraarcial flahlng and ahallfiah
bada. No known alnaral dapoalta
in araa.
Saaa aa Sltaa E and F.
Moat abundant and dlraraa
banthle eoraunlty of altaa
atudlad.
Sau aa tor Slta H.
No known faaturaa.
H
Within 3.7 a. Bllaa of
Cooa Bay antranea. Saa
Tabla 3.1 for eantrold
location.
Slillar to S and r, but
haa a graatar dlvaraity
of banthle apaeiaa and
IOM fiahlng activity
oeeura In araa.
Major aadlmant tranaport-
la downalopa. Ltttla
opportunity for onahora
tranaport or impact.
rina gralnad aanda with
high organic aollda con-
tant. Approxlaataly
400,000 cy fro*, abova RM
12 projactad for araa on
a 2 to 4 yaar cyela.
Slallar to altaa E and t.
SlDllar to that for Sitaa
S and F, axeapt that
downalopa tranaport of
botto* aadloanta pradoal-
nata ovar upalopa trana-
port. Maxlnu* dapth
avaragad auapandad aadl-
•ant concantration
axpaetad 0.004 pareant by
volwaa.
No aeuta eondltlona wara
obaarvad during dlapoaal
for tanparature, aa Un-
ity, diaaolvad oxygan.
pH, oxldatioo-raductlon
potantlal, or turbidity.
No aignlfleant sounding
waa obaarvad. Tha
banthle coomualty waa
algnifleantly affaetad
Iniiadtataly attar dla-
poaal but racovarad to
pradlapoaal condltlona
aftar about 19 nontha.
Araa la outalda of najor
•ona of eooaarcial
activity. Adjacant to
ahallfiah bada. No known
•Inaral dapoalta in araa.
Saia aa Sitaa S and F.
Ecological tranaltlon
aona batwaan altaa F and
G.
No nuiaanca apaclaa
axpaetad.
No known faaturaa.
Adjnatad Slta H
Within 3.1 a. mil** of Cooa
Bay Entrance. Saa Tabla
3.1 for eantrold location.
SUllar to Slta F.
Similar to Slta H.
Sau aa Slta H.
Sana aa Slta H.
SUllar to Slta H.
No pravloua dlapoaal.
Slallar to Sltaa E and F.
SUllar to Slta F.
.
Sana aa for Slta H.
No known faaturaa.
11-12
-------
Ill AFFECTED ENVIRONMENT
3.1 INTRODUCTION.
This section provides a detailed base description of the existing conditions
in the areas that wouid be affected by ocean disposal of material dredged from
Coos Bay, and a general description of the Coos Bay socio-economic environ-
ment. In addition, this section includes a detailed description of existing
sediments typically found in Coos Bay. The primary information base for the
physical and biological descriptions is from reports provided to the Corps of
Engineers, Portland District (Corps) by Oregon State University (OSU) in
compliance with requirements of "The Coos Bay Offshore Disposal Site
Investigation", Contract Number DACW57-59-C0040. Chapter 3 tables and figures
are included at the end of this section.
The Coos Bay Offshore Disposal Study was initiated in 1979. The study area
encompassed the two interim disposal sites (E and F) at the 10 fathom (17-20
meter) and 12 fathom (20-26 meter) contours respectively, (site H) at the 30
fathom (53-66 meter) contour, adjusted site H at the 25 fathom (44-58 meter)
contour and site G at the 50 (90-97 meter) fathom contour. Location
descriptions of these sites are given in Table 3.1 and Figure 3.1. Please
note that although this section does not specifically refer to adjusted site
H, the data gathered by OSU and presented in this section covers an extenive
offshore area which partially includes adjusted site H. In general, the
physical and biological charateristices of adjusted site H represent a
transition between sites F and H.
The study area was divided into two segments based upon depth. The area
extending to the 40 meter contour is referred to as the nearshore area, which
includes sites E and F, and is approximately 12 square miles in size (7,500 by
3,900 meters). The area extending from the 40 meter contour to the 120 meter
contour is referred to as the offshore area. This area includes sites G, H
and adjusted site H and is approximately 7 square miles in size (5,100 by
3,600 meters).
The nearshore and offshore study areas are approximately 36 and 23 times
larger, respectively, than the area of the two interim disposal sites. This
size of a study area provides the opportunity to not only describe the condi-
tions at a proposed disposal site but also its immediate environs. This
allows for a better interpretation of the possible effects and a greater
flexibility in determining final site locations and sizes.
The OSU study proceeded in distinct phases designed to address the 11 specific
and 5 general criteria required in the Federal Register and discussed in this
EIS. The objective of the first phase was to obtain a comprehensive descrip-
tion of the physical, chemical, and biological conditions of the study area.
The objective of the second phase of study was to concentrate on the collec-
tion of physical, chemical, and biological information in the vicinity of the
ocean sites. This phase provided baseline data for the evaluation of the
effects of a test disposal of dredged material. Results of test disposal
monitoring are contained in phases four and five of the OSU study. Data was
not collected at site E in the second phase since conditions at sites E and F
were so similar. The data collected and analyzed by OSU during the period
III-l
-------
from February 1979 through September 1983 form the principal physical,
chemical and biological information base of this EIS.
Interstate Electronics Corporation (IEC) under contract to EPA conducted a
single survey of the Coos Bay interim ocean disposal sites and environs during
26 April to 1 Hay 1980. Data from the IEC Report of Field Survey (1982) is
incorporated into the EIS where appropriate.
3.2 PHYSICAL ENVIRONMENT
3.2.1 Bathymetry of Disposal Site Area
The continental shelf off Coos Bay is some 22 km wide. Regional offshore
bathymetrie contours generally run northeast-southwest parallel to the
coastline (Figure 3.2). Nearshore contours bulge seaward off the entrance to
Coos Bay, reflecting the presence of the river delta, the disposal of dredged
materials, and the Cape Arago landmass (Figures 3.1 and 3.2). The top of the
foreslope of the river delta is at about 24 m and its base is at about 42 m,
relative to mean lower low water. The two interim sites are located on the
oceanward limits of the river delta and are clearly defined by seaward
bulges in the foreslope contours to some 42 m depth. These bulges have not
been definitely attributed to dredged material disposal. There is some
mounding at the sites following the dredging season, but this is normally
erased by winter storm activity and no long-term bathymetrie changes
occur. Sites G and H lie offshore of the influence of the river delta. The
deepwater site lies on the continental slope some 30 km off the entrance to
Coos Bay.
3.2.2 Disposal Area Sediments and Sediment Transport
Hancock et al (1981) and Nelson et al (1983) report that nearshore
sediments to approximately 70 m depth are clean fine sands of marine origin
with median grain diameters of 0.15 to 0.20 mm and less than 1.5 percent of
volatile solids (Figures 3.3-3.6). The uniform nature of these highly mobile
sands reflects .the winnowing action of surface waves and tidal and wind-driven
currents. Coarser sediments are found in the river delta to depths of about
42 m. These sediments have median grain diameters in excess of 0.20 mm,
volatile solids concentrations are as low as 0.2 percent and owe their
character to the combined influences of their nearness to the source of
coarser river materials, strong ebb currents from the estuary, and the
disposal of river and entrance materials during dredging operations. IEC
(1982) reported similar findings. Volatile solids concentrations increase
rapidly beyond the river delta to between 2 and 3 percent and gradually
increase with increasing depth. Between the foreslope of the tidal delta and
70 m, the sediment is relatively uniform in grain size and volatile solids
content. Below 70 m depth, grain size decreases and volatile solids concen-
trations continue to increase due to the decreasing influence of surface waves
and ebb currents from the estuary entrance as depth increases. Mixed sand and
mud covers the continental shelf in this region out to the shelf break .at
about 170 m. Muddy sediments cover the continental slope. (OSU, 1977, p.
17).
Figure 3.6 presents averaged median grain sizes and volatile solids percent-
ages for three seasons of resampling at 5 stations in the vicinity of sites F,
III-2
-------
lir i*. lii&T.'tt'ni »!£*.•.". i.
G, and H. The error bars indicate the standard deviation of station mean
values relative to the overall mean. Also included are graphic boundaries
that contain all sample medians for each site. The seasonally-averaged median
grain sizes for the areas around sites F, H, and G are 0.26 mm, 0.16 mm, and
0.08 mm, respectively, and volatile solids average 0.53 percent, 1.06 percent,
and 2.56 percent by weight. Winter sediments are somewhat more poorly sorted
than average due to the presence of fines settled from discharged estuarine
waters. The average volatile solids content at all sites is at a minimum in
summer and at a maximum in winter with the contrast most clearly developed
near site H. Spatial variability in volatile solids content is also highest
near site H with the area near site F having least spatial variability. The
greater seasonal and spatial changes in volatile solids near site H and
various grain size statistics suggest that the area near site H experiences a
greater variability in fine-grained material than the area around sites F or
G. Site F and G sediments are more poorly sorted than sediments near site H.
The variability near site F reflects the nature of the river delta sediments
and possibly the effects of dredged material disposal. The variability near
site G is in part due to the increasingly quiescent environment that allows a
broader spectrum of grain sizes to settle out, and the periodic input of fine
sands from shallower regions during periods of heavy wave action coupled with
an offshore component of the current. The well sorted nature of material near
site H is consistent with the nature of nearshore fine marine sands.
Hancock et al. (1981) performed detailed bulk sediment chemical analysis on
offshore sediments. In general, both water and volatile solids fractions
increase with distance from the estuary entrance. This correlates with
decreasing grain size. Chemical concentrations in these offshore sediments
are similar to those of the less contaminated lower estuary sediments and
significantly lower than concentrations in upper estuary sediments.
Nelson et al. (1983) present detailed sediment chemical analyses for the -three
disposal sites F, G, and H (Table 3.6). Parameter levels are consistent
within a site and obvious differences exist between sites. No chemical
analysis at any site appeared atypical or indicative of a polluted condition.
Site F sediments have higher solids content, lower volatile solids, and
generally lower levels of all chemical parameters as compared to the other two
sites. Volatile solids levels and most chemical parameter levels increase
with depth and decreasing grain size such that site H has levels intermediate
with sites F and G. Concentrations of copper, iron, lead, manganese, and zinc
showed a strong inverse correlation with mean grain size.
3.2.3 Coos Bay Sediment and Sediment Transport
Sedimentation in Coos Bay channel has averaged about 1,300,000 cubic
yards annually downstream of RM 12. Entrance sediments comprise some 800,000
cubic yards annually (60 percent of the total). Sedimentation upstream of RM
12 depends upon annual rainfall and runoff impacts on the local drainage basin
(Louis Smith, COE, personal communication). Between RM's 12 and 14 some
289,000 cubic yards may accumulate in a given year. Sedimentation above RM 14
is more variable but may be as much as 164,000 cubic yards in a given year
(see Table 3.2).
Estuarine sediments are predominantly clean fine sands of marine origin in the
III-3
-------
lower bay and navigation channel below RM 14 but become finer and more organic
in the upper bay and in sloughs. Median grain size in the lower bay is
relatively constant at 0.2-0.3 mm between the estuary entrance and the Coos
River (Figures 3.5 and 3.7). Sediment above RM 14 (Type 3) is at least one
order of magnitude finer - 0.02 to 0.006 mm. Volatile solids content
increases from less than 1% at the estuary entrance to about 6-20% at river
mile 15 in the Coos River (Figures 3.5 and 3.8). Type 3 sediment organic
levels are up to five times the levels in the lower Coos River. The finer
grain size and higher organic content of Type 3 sediments reflect the limited
tidal exchange between sloughs and the estuary, the lack of significant
inflows of fresh water in sloughs, the proximity of clearcut areas that act as
sources of fines, and plentiful local sources of organics from log rafts, chip
piles, etc. The tidally-induced currents in the main navigation channel are
sufficiently strong to transport fine sediments in suspension, thereby
maintaining relatively uniform grain size and low organic content over its
length.
Hancock et al. (1981) conducted a detailed chemical analysis of sediments in
and adjacent to the Coos Bay navigation channel (Figure 3.9). Both bulk
sediment (Tables 3.3 - 3.5) and elutriate chemical (Appendix D) analyses were
performed. With the exception of total sulfides, there was no apparent
consistent chemical difference between sediment in the navigation channel and
adjacent subaqueous sediments. The total sulfide level was higher in
non-channel sediments, reflecting lower turnover rates .in areas removed from
the navigation channel (OSU, 1977b) but no free sulfides were detected. One
non-channel sample from above RM 14 had elevated total concentrations of
cadmium, lead, and zinc. Two other side-channel samples in the mid-estuary
had detectable PCB concentrations. Elutriate test results were also generally
comparable for adjacent and mid- channel samples. Cadmium was released from
several samples in concentrations high enough to exceed EPA's 5 ng/ml
criterion. Manganese concentrations from samples of Type 2 and Type 3
sediments were also above the 100 ng/ml maximum for shellfish protection (EPA
1976). Dilution by a factor of 35 would bring cadmium and manganese levels
into compliance.
It is clear that the major chemical contamination occurs in the upper reaches
of Coos Bay and in sloughs. As shown in Figure 3.8, total and volatile solids
increase with distance from the estuary entrance. This correlates with a
decrease in median grain size and reflects lower energy regimes for wave,
tidal, and river flows in the upper estuary. In fact, nearly all chemical
parameters increased as the sediments became finer. Type 3 sediments are
clearly more polluted with total sulfides, reduced sulfides capacity,
ammonia-nitrogen, oil and grease, petroleum hydrocarbons, and trace metals
than are sediments from below RM 14. Figure 3.5 and Tables 3.3 to 3.5 from
Hancock et al. (1981) detail sediment chemical characteristics.
Elutriate samples from navigation channel sediments did not exhibit the
increase in bulk sediment chemical concentration with increasing distance from
the entrance. In fact, there appeared to be a poor correlation between total
sediment contaminant levels (Tables 3.3 - 3.5) and their solubility during
resuspension as measured by the test (Appendix D).
III-4
-------
3.2.4 Hydrography
Coastal waters off Coos Bay may be divided into three watermasses that
have typical ranges of salinity and temperature (Conomos et al. 1972, Huyer
and Smith 1977). These are the surface oceanic, subsurface oceanic, and Coos
Bay watermasses. The subsurface watermass has salinities in excess of 33.4
ppt and temperatures below 8°C. It is overlain by the surface watermass which
has salinities lower than 32 ppt and strong seasonal temperature changes of up
to 6°C. The boundary between these watermasses is a strong vertical salinity
gradient between 100 and 200 m depth. Winter cooling and wind-induced
vertical mixing produce a uniform surface watermass of 6°C to depths of about
100 m. Summer warming may then develop a strong seasonal thermocline within
the surface watermass which results in an intermediate temperature minimum
near the top of the permanent salinity gradient. The Coos Bay watermass
consists of the plume of lower salinity water that extends from the estuary
mouth. Upwe11ing during the spring and summer brings subsurface water to the
surface along oceanic "fronts" (surfaces defined by strong thermal and
salinity gradients). The scale and duration of these events are extremely
variable but upwelling keeps surface waters relatively cool (about 10°C)
through the summer. With the cessation of upwelling in early fall, surface
temperatures rise to 15°C, then decrease to 10°C in the winter. Bottom
temperatures also decrease during the upwelling due to the upslope movement of
subsurface waters to replace upwelling shelf water.
Turbidity within the water column maximizes near the bottom, at the top of the
permanent pycnocline, and in the surface waters (Harlett, 1972). It has been
postulated that bottom turbidity results from the resuspension of bottom
sediments by surface and internal waves and from the downslope movement of
turbid waters from the surf zone. The intermediate turbid layer results from
materials settling from surface layers and from the surf zone. The Coos Bay
watermass would also contribute turbid waters to surface layers during periods
of high runoff as would dredged material disposal operations.
3.2.4.1 Currents and Tides
Coastal circulation reflects the combined influences of seasonally-
reversing regional currents and winds, the tides, and other periodic
phenomena. The California and Davidson currents determine seasonal transport
along the Oregon coast (Sverdrup et al. 1942). The 500-km wide California
current flows southward parallel to bathymetic contours over the entire Oregon
continental shelf during the spring and summer with average speeds of 10
cm/s. Northerly and northwesterly winds reinforce this flow with maximum
current strength in the spring. Strong vertical velocity gradients
characterized the lower half of the flow (Huyer et. al. 1975). Under the
influence of southeasterly winter winds, this shear layer expands upward and
shoreward until northward flow results (Sobey 1977). Ultimately, this
northward flow develops into the 150-km wide Davidson current that lies
between the shore and the southerly flowing California current. Circulation
over the continental shelf is now northward parallel to isobaths and currents
are nearly uniform throughout the water column. Upwelling from February
through July weakens and ultimately destroys the Davidson Current to some 200
m depth. Net transports above this depth is thereafter southward as an
extension of the California current. The Davidson current persists below that
III-5
-------
depth on the outer continental shelf/with speeds up to 20 cm/a and is probably
responsible for the strong velocity gradients that develop in the deeper inner
shelf waters in summer.
Detailed current measurements in the study area by Hancock et. al. (1981) and
Nelson et. al. (1983) conform to the generalized circulation scheme just
presented. Current strength and directional variability reflect the
variability of local surface winds. Mid-water currents (those measured at
one-third the depth) and near-bottom currents are generally between 10 and 20
cm/s in the vicinity of sites F, H, and 6. Mid-depth summer median currents
near site F are slightly stronger (20 to 30 cm/s) while median winter and
spring currents near sites F and H may be between 30 to 60 cm/s. Comparable
currents near site G are 20 to 30 cm/s.
Water transport is generally parallel to bathymetrie contours although
estuarine circulation and the shoreline configuration tend to produce
significant onshore and offshore flow in the upper water column near sites E &
F, and between site £ and Cape Arago, respectively. Springtime upwelling may
also be responsible for shoreward-directed mid-depth mean currents affecting
the vicinity of site G and, presumably, site H. Near-bottom currents exhibit
higher variability in direction than do mid-water currents but downslope flow
components predominate over upslope flow. Downslope flow is clearly present
near the bottom in summer along the toe of the river delta and between Cape
Arago and site E. Strong downs lope movement may also occur in the vicinity of
site H throughout the winter and to a lesser extent in the vicinity of site
G. Upslope flow can occur between Cape Arago and site E during spring upwel-
ling or winter periods of strong northerly flow of the Davidson Current.
Annual and seasonal variations in atmospheric conditions determine the
regional circulation just described. Superimposed upon this slowly-varying
circulation are periodic currents due to the tides, inertial currents, inter-
nal waves, etc. While variations in wind speed-and direction for periods
longer than 2.5 days are reflected in surface currents, shorter period varia-
tions can give rise to inertial currents (Huyer and Patullo, 1972).
Inertial currents have periods of 17.4 hours and speeds up to 10 cm/s (Cutchin
and Smith, 1973). Tidal curents with amplitudes of several tens of cm/s occur
at periods of 12.4 and 24.8 hours. Other periodic circulation features
include shelf or topographic (Rossby) waves that propagate northward with
periods of 4.5 days and, possibly, southward with periods of 7.1 days.
Internal waves of varying periods and wavelengths can propagate along the
permanent and seasonal pycnoclines, causing short-term current oscillations in
the order of an hour. When stratification abruptly decreases, as during
upwelling events, internal waves become unstable and cause increased vertical
mixing in the water column. It is also probable that breaking internal waves
can cause sediment resuspension where the pycnocline intersects the
continental shelf.
3.2.4.2 Surface Waves
The prevailing wave direction off Coos Bay is from the west. Summer
waves approach from the west-northwest and littoral transport of beach
sediments is to the south. During the remainder of the year, waves approach
III-6
-------
from the west and southwest driving littoral transport to the north.
Significant wave heights - the average of the highest one-third of all waves -
range from a little over 1 m during the summer to over 3.5 m in winter with
corresponding changes in wave period. Detailed observations have shown that
wave-induced currents average between 30 and 60 cm/a year-round in the study
area (Hancock et al. 1981). Speeds up to 120 cm/s or more were observed
during the winter.
3.2.4.3 Wind Direction and Speed
Prevailing winds are from the south-southeast in January, averaging 5.5
m/s, from the north-northeast for June through September at 5.2 m/s, and from
the southeast at 4.6 m/s during the remaining months (Figure 3.10). Wind
speeds and directions are most variable during March, April and September.
Significant geomorphic effects of the Cape Arago headland and different
methods of observation cause local wind statistics to differ significantly in
direction and speed from observations at the offshore National Oceanic
andAtmospheric Administration (NOAA) data buoy. Since the Coos Head records
appear more similar to those of earlier observations (Duxbury et al., 1966),
the Coos Head observations are considered more appropriate for the study of
local processes (Hancock et al 1981). The NOAA buoy records are likewise more
appropriate to open ocean studies of wind generated waves and currents.
3.2.4.4 Water Quality
Table 3.6 presents the results of water quality analyses for surface and
bottom waters in the vicinity of sites F, G, and H for each of the four.
seasons (Nelson et al. 1983). Tests for heavy metals and pesticides did not
indicate an atypical or polluted condition for any water sample. Salinities
characteristic of the surface watermass were observed throughout the water
column at all three sites in June 1980, at all but the bottom near site H in
August and December 1980, and only in the surface for all sites in April
1981. The occurrence of higher salinities at the bottom in the vicinity of
site H as compared to the vicinity of site G is unexplained for August and
December 1980. The April 1981 samples imply recent upwelling while the June
1980 samples suggest the development of the surface watermass and the absence
of upwelling.
3.3 BIOLOGICAL ENVIRONMENT
3.3.1 Introduction
OSU biological studies of the Coos Bay offshore study concentrated on
sampling benthic invertebrates, epibenthic macro-invertebrates, and fish of
the study area. Benthic Invertebrates were sampled with a 0.096 square meter
box core. Sediment samples were taken at the same time. Epibenthic
invertebrates and fish were sampled with a Ballon-Otter Trawl and a one-meter
beam trawl.
During the first phase of the study, box core sampling locations were randomly
located throughout the study area in such a method as to comprehensively cover
the area (Figure 3.11). Trawls were taken in a similar manner (Figure 3.12).
During the second phase of the OSU study, box core sampling was concentrated
III-7
-------
in and about the location of the northern interim disposal site (site F) and
two possible candidate disposal sites in the offshore area (including sites H
and G)(Figure 3.13). Trawl sampling was also concentrated across and near the
three study sites (Figure 3.13). Figure 3.14 illustrates the sampling
locations established by IEC during April and May 1980.
3.3.2 Benthos
The distribution, abundance and species of benthic invertebrates in the
study area were typical of habitats that vary from a coarse-grained sediment
with high levels of bottom turbulence in nearshore areas, to a
fine-grained/marine mud sediment region with a low level of bottom
turbulence. A total of 321 benthic invertebrate species were collected in the
study area, and their distribution is associated with the three major sediment
patterns of the area.
The nearshore region (depths of 10 to 40 meters), as noted in previous
sections, is characterized by high wave energy, high bottom turbulence and
coarse-grained sands. Figures 3.15-3.18 illustrate seasonal dynamics of
habitat charactertistics of the nearshore region. The benthic fauna in this
region, while diverse, show a considerable degree of seasonal variation in
abundance.
Dominant benthic invertebrates in the nearshore region during the first phase -
of the study were carnivorous snails (Olivella spp.) , a clam (TelUna modesta)
and several species of polychaete worms and amphipods. Figures 3.19 and 3.20
illustrate the variation in the distribution of carnivorous snails (Olivella)
and the clam (Tellina modesta) between two sampling periods of the nearshore
area. Similar seasonal variations were also observed for the other species
mapped (see Hancock, et al., 1980).
Results of the Phase II benthic sampling in the nearshore region showed a low
abundance and relatively high variation of polychaete, mollusc, and crustacean
species between the five sampling stations in and about site F (Figures 3.21
to 3.23). These abundance patterns are consistent with the data collected in
the nearshore area during the Phase I work. Figure 3.24 shows the benthic
abundance at 9 stations of the nearshore as sampled by IEC in 1980 (IEC,
1982).
Hancock, et al, 1980, reports that the offshore region lying between the 45-
and 65-meter contour is a transition zone for both faunal and sediment
characteristics. This area has a high species diversity and a mix of sediment
types from coarse to fine sands. Polychaete and mollusc species abundance
during the second phase of the study were highly variable between the five
sampling stations. This variability was strongly associated with sediment
characteristics and location within the sampling area (Figures 3.21 and
3.22). In contrast, the five most abundant crustacean species did not vary
greatly between the five sampling stations (Figure 3.23).
The sediments lying between the 70- and 120-meter contours are relatively
stable. The sediment types in this area grade from fine sand to marine mud.
The distribution of the abundant benthic species collected during the first
phase of the study indicate a zonal distribution. (Figures 3.25 and 3.26).
III-8
-------
These figures also illustrate a separation in abundance of animals between the
45- to 65-meter contour area and that for the 70- to 120-meter contour area.
Similar zonal patterns were observed for other species (Hancock, et al.,
1980).
Hancock, et al., 1980, reports that those patterns are likely the result of
competition between sympatric species, affinities to sediment types, and, in
some cases, to volatile solids distribution patterns.
Results of the Phase II benthic sampling in the vicinity of site G showed
significant variation between stations for polychaete, bivalve, and crustacean
species, but no significant variation for gastropod species (Figures 3.21 to
3.23) . The more abundant benthic species in the area of site G differed from
those near either site F or H. Total abundance of crustaceans in the site G
vicinity was lower than the site H vicinity, but higher than that near site
F. Species richness near site G was greater than that observed near sites F
or H.
3.3.3 Epibenthos and Fisheries
Seventy-nine epibenthic invertebrates and fish species were collected by
OSU during the period of April 1979 through May 1981 (see Hancock et al.,
1980, and Nelson, et al., 1983). Fifty-two of these species were vertebrates
and 17 were invertebrates. Epibenthic sampling during April 1979 through
March 1980 was accomplished using a Ballon-Otter trawl. During the May 1980
through February 1983 period, a beam trawl was used.
Tables 3.7 and 3.8 show the most abundant epibenthic species and the number of
species collected at various depths by OSU during 1979-1980 and 1980-1981.
Fish were mostly "0" age class suggesting that the study area is used by these
species as spawning and rearing areas. The absence of fish of older age
classes, however, may reflect more trawl avoidance than absence of these fish
in the area. The most common fish caught were flatfish (sanddabs and sole).
The number of species collected during each of the epibenthic sampling periods
was relatively constant for all periods and depths sampled (Tables 3.7 and
3.8). Approximately twenty species were collected in each of four trawls
during 1979 and 1980, and 25 to 30 species were collected in each of 15 trawls
in 1980 to 1981. Because of the low number of individuals for most species,
it is difficult to ascertain if there were real differences in use of areas by
species.
Hancock, et al. (1980), indicates that the distribution of flatfish within the
area may be the result of fish that recently settled out of the plankton in
the nearshore area (inside the 40-meter contour) and movement out of the
nearshore area as the fish increase in size. Hancock reports that the
distribution of shrimp in the study area also reflects a seasonal movement
pattern, with these animals moving back and forth between nearshore and
offshore areas.
Because the OSU sampling methods did not sample for adult fish
effectively, information collected by Oregon Department of Fish and Wildlife
(ODFW) and published in the' report Marine Resource Surveys on the Continental
III-9
-------
Shelf Off Oregon, 1971-74 (ODFW, 1976) was used to determine the distribution
of some species of commercial importance. According to this report, most of
the commercially important species sampled were more abundant at depths
greater than 100 fathoms (183 meters) off Coos Bay in September. The
exceptions were rockfish, cod, and shrimp which are fished closer inshore.
The scallop fishery that developed off Coos Bay was located between the 40 and
50 fathom contours with its southern extent near sites G and H.
3.3.4 Marine Mammals
A number of species of marine mammals occur in the oceanic area near the
proposed disposal sites. Most of the species, such as the whales, dolphins
and porpoises occur off Oregon only during migrations to and from feeding and
breeding areas. Harbor seals and sea lions, however, are residents on the
Oregon coast and one population is known from Coos Bay. (Maser, et al.,
1981). A list of the marine mammals, their occurrence in Oregon, and their
status under the Marine Mammal Protection Act is given in Table 3.9.
3.3.5 Endangered Species
A list of rare and endangered species in the vicintiy of the proposed
disposal sites was requested from U.S. Fish and Wildlife Service (USFVS),
Office of Endangered Species and the National Marine Fisheries Service
(NMFS). No endangered species or their habitats were indicated for these
sites in the letter from the USFWS. The NMFS, however, indicated that the
Gray Whale may occur in the area. A biological assessment was prepared which
concludes that the proposed action would have no impact on this endangered
species. The USFWS and NMFS letters and the biological assessment are found
in Appendix B.
3.4 SOCIO-ECONOMIC ENVIRONMENT
3.4.1. Introduction
Coos Bay, an estuary on the Oregon coast about 200 miles south of
Columbia River, is the largest water-based exporter of forest products in the
United States, by virtue of its natural harbor and its strategic location
relative to timber stands along the southwest Oregon coast. This position has
been achieved through extensive development of industrial processing and
handling facilities around the bay, and through extensive publicly and
privately financed improvements to the harbor. The wood products industry
relies on waterborne transport both for local log movement and for export
trade. The progressive deepening of the Coos Bay Navigation System over the
years has permitted successful use of larger export vessels.
3.4.2 Local Economy
Lumber and wood products is by far the dominant basic sector in Coos
County and the Coos Bay area. In 1979, it accounted for 20.1% of all
employment, and 81% of manufacturing employment. The industry also accounts
for approximately two-thirds of the county's basic employment and payrolls.
Trucking, warehousing, and waterborne transportation in Coos Bay are primarily
involved in handling forest products, the industry's share of the county's
III-10
-------
basic income exceeds 75% when these activities are included. These statistics
clearly illustrate the dominance of the forest and timber processing indus-
tries in the Coos County economy. However, long term changes in the industry
have placed it and the regional economy in a state of transition. Since 1960,
there has been both absolute and relative declines in the county's lumber and
wood products employment (CCDEIA, 1980). More recently, market fluctuations
have resulted in mill closures and substantial layoffs; Coos County unemploy-
ment for January 1982 was reported by the Oregon State Employment Division to
be 16.4%. Studies done on trends in the timber industry and its future
generally indicate that there will be further declines in employment in this
sector. Bueter estimates that job losses in Coos County resulting from a
declining timber industry could range from 900-1100 jobs in the 1990*s
(Bueter, 1976).
Recognition of the potential for declines in timber employment have brought
the focus of economic improvement efforts on diversification of products with-
in the lumber industry and expansion/diversification within the area's other
basic sectors. Currently the fishing industry is the second most important
industry in the county. A good harbor, with relatively safe access during the
adverse weather, and proximity to rich fishery resources, has contributed to
Coos Bay fisheries development. Historically, Coos Bay has had the second
highest landings in Oregon. In recent yearsr the harvesting and marketing of
bottom fish and other previously underutilized species has served to overcome
some of the traditional constraints of the industry. Given the new 200 mile
fisheries jurisdiction, the large resource off of Coos Bay, and expanding
markets for the harvest, expansion of this part of the industry may be
expected to continue.
The Coos Bay estuary, in conjunction with port developments, harbor
facilities, and improvements, in inland waterways, has been primarily
responsible for the County's oceanborne transportation and the related
land-side trucking and warehousing, a large share of commercial fishing and
fish and seafood processing, and some share of tourism. The natural waterway
permits efficient movement and storage of economically important
locally-handled bulk commodities. The port and related transportation
facilities are a base for a large amount of local outputs to move into world
markets. These facilities also facilitate the movement of such incoming
commodities as sand, gravel and crushed rock, basic chemicals, distillate fuel
oil, and gasoline.
Waterborne traffic in 1977 was 7,599,400 tons. Rafted logs and wood chips
accounted for more than five million tons of the traffic. Other commodities
included lumber, exported logs, and petroleum. The average annual traffic for
the period of 1968-77 was 6,769,400 tons. More recent traffic has continued
at about this level.
The major docks in Coos Bay are concentrated along the three to four mile
eastern waterfront of Coos Bay/North Bend. New dock facilities are beginning
to expand along the north spit. The dock facilities are primarily equipped to
export forest products and secondarily are outfitted to receive petroleum
imports. Twelve of the sixteen docks manage lumber and forest products. Five
of the lumber docks are equipped to export wood chips; two handle wood chips
exclusively. Four of the docks' receive petroleum products — two by barge and
III-11
-------
two by deep draft tankers. Only one dock, Central, handles general cargo/ as
well as forest products, on a regular basis. Large integrated forest products
processing plants are situated next to many of these docks, particularly on
the Coos Bay/North Bend waterfront.
3.4.3 Population
Coos County has the largest population of the coastal counties in
Oregon. From 1910 through 1980 Coos County area has experienced yearly
population growth; However, the percentage change in population growth has
been declining since 1950.
Because of the Coos Bay area's dependence upon the building/lumber industries,
and since the building/lumber industries have declined, the area population
has declined to below 1980 levels (See Table 3.10).
3.4.4 State and Local Coastal Management Plans
Coos Bay is identified in the overall Oregon estuary classification as a
deep-draft development estuary. As such, and as stipulated in Goal Number 16,
Estuarine Resources, the Oregon Coastal Management Program (OCMP) recognizes
that deep-draft port developments, navigation channels, and associated
dredging and dredged material disposal are allowed and will continue. In
addition, under Goal Number 19, Ocean Resources,- the OCMP recognizes the need
to "provide for suitable sites and practices for the open sea discharge of
dredged materials which do not substantially interfere with or detract from
the use of the continental shelf for fishing, navigation, or recreation, or
from the long-term protection of natural resources."
The Coos County Comprehensive Plan, which has been locally adopted and is
presently being reviewed for approval by The Oregon Department of Land
Conservation and Development (DLCD), contains policy statements and estuary
management plans for maintaining Coos Bay as a deep-draft development port.
In keeping with these plans and policies, Coos County recognizes the need to
utilize ocean sites for disposal of material dredged from the navigation
channel system.
3.4.5 Navigation Improvements and Dredging Costs
The authorized Coos Bay Navigation project, modified by the River and
Harbor Act of 1970, provides for two jetties at the entrance; an entrance
channel 45 feet deep and 700 feet wide; a channel 35 feet deep and 300 feet
wide to channel mile 9, and from there 35 feet deep and 400 feet wide to mile
15; and with turning basin and anchorage areas along the channel. Deepening
of the channel from the entrance to mile 15 was completed several years
earlier. Two jetties at the entrance were completed in 1928-29; the
small-boat basin at Charleston was completed in 1956; and the south jetty was
rehabilitated about 25 years ago. See Figure 3.27. The total Federal
construction and maintenance costs through September 1978 was
$63,303,000--$29,194,000 for construction, $2,336,000 for jetty restoration,
and $31,773,000 for maintenance.
Average.dredging quantities total about 1,500,000 cubic yards annually, and
III-12
-------
estimated in 1982 dollars, would cost about $2,100,000 for dredging and
disposal. The disposal cost ranges from about $1.00 to $3.50 per cubic yard
depending upon area dredged, type of equipment used, and upon disposal site.
Average disposal cost would be about $1.40 per cubic yard. Presently, all of
the material dredged from the entrance (about 800,000 cubic yards) is disposed
of in the ocean, and most of the dredged materials from River Miles 2 to 12
are disposed of at in-water sites within the estuary. The Corps predicted
that the upland disposal sites would be filled to design capacity within 5 to
10 years in the Channel Maintenance Dredging, Coos Bay, FEIS, prepared in
1976. Existing upland disposal areas adjacent to the channel have limited
capacity for Type 2 material and the capacity for Type 3 material has been
exhausted (personal communication, Nancy Case, COE Operations Division).
Alternate disposal sites such as ocean disposal will be necessary to maintain
the present navigation system.
3.4.6 Commercial and Recreational Activities in the Vicinity of the
Disposal Sites
3.4.6.1 Commercial Fishing
The area offshore of Coos Bay is fished commercially for salmon, shrimp,
crabs, bottom fish and scallops. Thirty-six million pounds of food fish were
landed at Coos Bay in 1981 with a value of 14 million dollars.
Dungeness crab (Cancer Magister) fishing is done along most of the coast.
Tanner crabs (Chinocetes sp.) are also taken incidentally. Crabs are usually
fished from December to the middle of August with pots on sand or mud bottoms
at depths of 50 to 300 meters. Most commercial vessels used in the crab
fishery are also used in other fisheries (combination fishing boats).
Approximately 1.3 million pounds of crabs.were landed at Coos Bay in 1981.
The pink shrimp (Pandalus jordant) is the. shrimp species commercially fished
along the Oregon coast. They are usually taken during April through September
by trawl over mud or sand bottoms at depths of 30-200 meters. Eight million
pounds of shrimp were landed at Coos Bay in 1981.
The commercial ocean salmon fishery off Oregon is for chinook (Oncorhynchus
tshawytscha) and coho (£. kisutch). Pink salmon (0_. garbuscha) are also taken
when they are available. One million pounds of salmon were landed at Coos Bay
in 1981.
The bottom fish fishery off Oregon is for a number of fish that can be
generally divided into 3 groups, flatfish (soles, flounder and halibut),
rockfish, and round fish (ling cod, pacific cod, hake, and sable fish). Based
upon distribution maps developed by the Oregon Department of Fish and Wildlife
(ODFW) for groundfish (ODFW 1976) we concluded that the area within 6 miles of
the mouth of Coos Bay had a relatively low abundance of groundfish. The
highest abundance of commercial groundfish occurred at depths greater than 40
meters. Areas of high abundance of groundfish near Coos Bay were off Cape
Arago, a cliff outcrop area just beyond site G, and an area 10-15 miles north
of Coos Bay (ODFW, 1976.)
Distribution maps for salmon, crab, and shrimp along' the Oregon Coast are also
found in the ODFW report (ODFW, 1976).
111-13
-------
In April 1981 a fishery for the Pacific coast weathervane scallop
(Patinopectin caurinua) began in Oregon off Coos Bay. This fishery expanded
rapidly, peaking by mid-June with 20 million pounds taken and 16.7 million
landed at Oregon ports (7.5 million pounds at Coos Bay.) Oregon imposed a
license moratorium in July 1981 and 145 vessels obtained permits. The catch
fell off rapidly after July and by the end of 1981 only 5 vessels continued in
the fishery. Mo live scallops were collected by OSU during the 1979-1981
sampling periods. Numerous shells were collected in the vicinity of site G in
1981. Hancock (personnal communication) believes that these shells are from
the scallop fishing boats. Scallops were shelled aboard the vessels and the
shells were dumped overboard. The scallop fishing beds off Coos Bay were
located between the 40 and 50 fathom contours with its southern extent near
sites G and H.
3.4.6.2 General Marine Recreation
Marine recreation in the coastal region of Coos Bay, and Oregon in
general, is limited due to normally cool atmospheric and water conditions and
severe winter weather. Fishing, clamming and beach-combing are the principal
activities.
3.4.6.3 Shipping
As discussed in Section 3.4.2, an average of about 6.8 million tons of
cargo enter and exit the Coos Bay port facilities annually (Port of Coos Bay,
1981). The Coos Bay region is a major source of lumber and wood chips for
domestic and international commerce. During 1980, 333 deep draft vessels used
Coos Bay facilites (Port of Coos Bay, Waterborne Statistics, 1980). The
fishing industry is the second largest user of port facilities.
3.4.6.4 Oil and Gas Exploration and Mining
Continental shelf lease sale activities have not occurred on the Oregon
shelf since 1964, and no oil or gas production occurs at present (1981).
During 1964 and 1965 only a small number of exploratory wells were drilled,
and only a portion of those were in the Coos Bay shelf region. The Oregon
continental shelf is not included in the present (1981-1986) 5-year lease sale
plan (USGS, 1981, personal communication). The earlier exploratory wells
indicated the presence of hydrocarbons, but extensive exploration is necessary
to more accurately determine the commercial production potential and the
locations of such areas. It is very likely that exploration will eventually
begin as studies of more favorable areas are completed. No mining or mineral
extraction exists or is planned for the vicinity of the disposal sites.
3.4.7 Esthetics
The esthetics of the disposal site area is characterized by relatively
clear ocean water, typical marine salt air smells, views of the relatively
undisturbed shoreline, and intermittent sounds of breaking waves, buoy bells
and horns, and seabirds. The nearby ocean beaches likewise present a
pleasingatmosphere with clean sand, weathered driftwood, shorebirds, and
breaking surf. Both areas represent high quality esthetic environments.
Ill-14
-------
3.4.8 Cultural Resources
A review of the latest published version of the National Register of
Historic Places and addenda shows that the alternative areas do not contain
any registered properties or properties determined to be eligible for
nomination to the National Register. A clearance letter from the State of
Oregon Historic Preservation Office is included in Appendix C.
Ill-15
TV ;
-------
Table 3.1 LOCATION OF ALTERNATIVE DISPOSAL SITES FOR THE
COOS BAY OFFSHORE DISPOSAL STUDY i
x Depth (m)
17
Size (m)
1097 x 427
24
1097 x 427
H
55
H (adjusted)
50
93
1097 x 442
1097 x 442
1097 x 442
— Buoys will be placed at the center of sites E, F, and H to mark
their locations.
Coordinates
43°21'59"N, 124°22'45"W
43°21'48"N, 124°21'5911W
43021'35"N, 124022'05"W
43°21'46"N, 124022t51"W
43022'44"N, 124°22'18"W
43022'29"N, 124°21'34"W
43°22'16"N, 124021'42"W
43°22'31"N, 124°22'26"W
43°23'53"N, 124022'48"W
43°23'42"N, 124023I01"W
43°24'16"N, 124°23'26"W
43°24I05"N, 124023'38"W
43°23'13"N, 124°22I30"W
43°23'04"N, 124°22'A2"W
43°23'36"N, 124°23'07"W
43°23'25"N, 124°23'19"W
43°24'44"N, 124°25'15"W (centroid)
Table 3.2. Sediment Accumulation Within Upper Coos Bay
(cubic yards)
•U'Al
Period
5/80 to 10/80
10/80 to 10/81
10/81 to 10/82
Coos River
RM 12 to RM 14
121,000
194,000
289,000
Isthmus Slough
RM 14 to RM 15
149,000
21,000
164,000
-------
Table 3.3 Chemical characteristics of Coos Bay sediments, May 1979
(from Hancock, et. al. 1981).
Station
El
Els
E2
E2s
E3
M
M "•
1
|__l
^ . E4
E4s
E6
E6s
E7
E7s
LLD
5.5
5.5
7.5
7.5
9.0
9.0
11.0
11.0
13.0
13.0
14.5
14.5
Depth
(cm)
00-20
20-60
00-20
20-51
00-20
20-60
00-20
20-60
00-20
20-42
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
Solids*
(g/g)
0.86
ND
0.80
0.82
0.85
0.82
0.84
0.81
0.78
0.77
0.80
0.76
0.80
0.79
0.70
0.76
0.56
0.61
0.66
0.72
0.38
0.39
0.49
0.53
VS
(mg/g)
BD
ND
ND
BD
40
BD
BD
29
30
BD
BD
63
BD
48
59
39
81
59
56
50
48
51
102
96
3
Tot.*
(ug/g)
BD
ND
48
66
BD
BD
BD
BD
BD
33
10
130
BD
BD
BD
30
123
221
1060
10
126
735
1620
2220
10
RSC
(ug/g)
295
ND
860
800
340
460
176
290
530
480
390
420
410
350
910
760
2180
2100
1610
460
4500
3100
1900
2450
0 & C
(ug/g)
BD
ND
BD
BD
BD
BD
BD
BD
BD
BD
BD
147
BD
BD
BD
BD
540
385
282
144
ND
1020
1940
1680
50
NH4-N
(ug/g)
ND
ND
0.5
0.5
0.3
0.7
ND
ND
1.8
1.8
1.3
14
0.6
8.0
0.05
1.0
28
44
24
12
45
92
81
90
Chloro-
Insect.
(ng/g)
BD
0.3 DDT
ND
ND
ND
ND
BD
ND
BD
ND
ND
ND
ND
ND
BD £
BD
BD
BD
0.5 DDT
ND
ND
BD
ND
0.1
PCB
(ng/1)
BD
< 2
ND
ND
ND
ND
< 4.3
ND
BD
ND
ND
ND
ND
ND
5( Ar 1 260)
<_ 3
BD
BD
BD
BD
ND
ND
BD
ND
0.1
Cd
(ug/1)
1.2
ND
2.5
1.5
0.8
1.7
ND
.7
2.3
16
1.1
1.1
9.1
2.0
0.9
11
4.6
1.6
1.5
1.3
2.6
2.6
19
30
Cu
(ug/1)
2.1
ND
2.9
3.0
ND
1.8
ND
.9
2.3
1.4
2.9
3.9
2.6
3.3
2.7
2.5
13
7.5
4.7
2.1
26
5.1
24
17
Fe
(ug/1)
5000
ND
4900
5100
ND
4600
ND
3200
5600
5300
6000
8400
5500
5600
9300
7500
19500
14100
10500
9200
35300
25400
22700
17500
Mn
(ug/1)
45
ND
48
45
ND
56
ND
54
44
45
38
41
33
46
53
46
200
190
61
57
330
240
173
155
Pb
(ug/1)
14
ND
14
17
ND
12
ND
8.6
14
5.2
18
16
12
14
20
13
25
15
17
10
32
26
45
25
Zn
(ng/1)
99
ND
69
200
ND
20
ND
12
45
48
31
SO
71
65
81
38
540
67
61
49
290
180
780
121
Free eulfides were below detection (071 ug/g) in all samples
BD=below detection limit (LLD)
ND=no data available
-------
Table 3.4 Chemical characteristics of Coos Bay sediments, October 1979
(from Hancock, et. al. 1981).
Tot.
Station
E4
E5
E6
E7
E8
E9
LLD
River
Mile
11.0
12.0
13.0
14.5
13.8
15.0
Depth
(cm)
00-20
20-41
00-20
20-60
00-20
20-60
00-20
20-60
00.20
20-60
00-20
20-48
Solids
(g/g)
0.82
0.80
0.64
0.59
0.62
0.55
0.39
0.39
0.62
0.56
0.51
0.41
VS S
(mg/g) (ug/g)
6
6
44
65
49
94
105
112
57
87
155
147
Metal Concentration
E4
E5
E6
E7
E8
E9
As
1.2
2.0
2.8
3.4
3.1
2.9
4.1
7.7
1.8
3.0
5.1
6.8
Cd
0.3
1.3
1.4
1.7
1.6
1.8
3.0
2.5
1.5
1.4
2.3
2.9
Cu
2.1
2.3
14
17
14
23
31
33
11
12
25
34
Fe .
4590
3950
21600
24600
22300
29500
29600
36800
17000
21000
25300
32100
BD
BD
920
590
770
400
2150
850
400
750
1600
2500
10
(ug/g)
Mn
35
36
105
150
117
365
142
166
89
125
108
164
RSC
(ug/g)
560
35~0
2570
3200
3020
3290
4240
5110
2360
2655
4210
6220
Pb
5.2
5.1
21
24
21
27
40
39
16
22
31
45
0 & G
(ug/g)
BD
BD
440
370
370
510
920
900
500
680
1600
2000
50
Zn
12
8.4
69
70
70
85
121
154
64
61
101
128
HC
(ug/g)
ND
ND
ND
ND
ND
ND
ND
ND
ND
350
ND
1200
Hg
.085
.125
.11
.12
.97
.2
.77
3.3
.63
.45
.45
.27
III- 18
-------
Tables 3.4 (Cont)
Pesticide Concentration, ng/g
E4
E5
E6
E7
E8
E9
LLD
Aldrin
ND
BO
ND
ND
ND
0.2
ND
ND
ND
ND
ND
1.5
0.1
DDE
ND
BD
ND
ND
ND
BD
ND
ND .
ND
ND
ND
BD
0.1
Dieldrin
ND
BD
ND
ND
ND
BD
ND
ND
ND
ND
ND
BD
0.1
DDD
ND
BD
ND
ND
ND
BD
ND
ND
ND
ND
ND
2.5
0.1
DDT
ND
BD
ND
ND
ND
BD
ND
ND
ND
ND
ND
1.7
0.1
PCB
ND
BD
ND
ND
ND
BD
ND
ND
ND
ND
ND
BD
1.0
III-19
-------
Table 3.5 Chemical characteristics of Coos Bay sediments, March 1980
(from Hancock, et. al. 1981).
Tot.
Station
E4
E5
E6
E7
E8
E9
LLD
River
Mile
11.0
12.0
13.0
14.5
13.8
15.0
Depth
(cm)
00-20
20-50
00-20
20-60
00-20
20-60
00-20
20-60
00.20
20-60
00-20
20-48
Solids
(g/g)
0.82
0.78
0.59
0.70
0.52
0.54
0.38
0.38
0.60
0.57
0.33
0.31
Pesticide
E4
E5
E6
E7
E8
E9
LLD
Aldrin
ND
<0.02
ND
ND
ND
0.7
ND
ND
ND
ND
ND
BD
0.02
DDE
ND
0.04
ND
ND
ND
0.13
ND
ND
ND
ND
ND
0.3
0.02
VS
(mg/g)
3
12
48
26
63
64
93
89
47
61
199
200
S
(ug/g)
BD
BD
480
430
690
540
790
2080
215
600
470
1900
10
RSC
(ug/g)
77
1450
2170
1360
1570
3250
3200
4180
1620
2400
3900
6500
0 & G
(ug/g)
BD
BD
490
300
670
410
1050
970
320
490
2800
1840
50
HC
(ug/g)
BD
BD
200
130
380
180
670
650
118
220
1200
880
50
Concentration, ng/g
Dieldrin
ND
0.05
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.2
0.02
ODD.
ND
0.02
ND
ND
ND
0.28
ND
ND
ND
ND
ND
2.7
0.02
DDT
ND
0.05
ND
ND
ND
0.07
ND
ND
ND
ND
ND
3.0
0.02
PCB
ND
BD
ND
BD
ND
BD
ND
BD
ND
BD
BD
BD
0.1
III- 20
-------
Table 3.5 (Cont)
Metal Concentration (ug/g)
E4
E5
E6
E7
E8
E9
As
1.3
1.2
3.6
2.4
3.5
• 6.1
6.3
9.5
3.0
3.7
9.0
10.6
Cd
0.8
1.8
1.6
1.1
1.8
1.7
2.6
2.4
1.3
1.6
2.3
3.1
Cu
1.0
2.8
14
5.4
18
18
32
29
12
17
32
34
Fe
5000
5400
8500
10000
26900
24500
33900
35.000
18600
23600
34100
38700
Mn
31
45
131
58
150
263
209
172
102
103
203
247
Pb
3.4
13
19
7.5
25
22
37
33
16
22
38
45
Zn
12
13
77
29
110
87
124
121
67
87
123
129
Hg
.06
.09
• 15
.04
.20
.39
.21
.45
.15
• 12
.24
.39
III-21
-------
Table 3.6 Chemical Analysis of Marine Waters at Offshore Sites F, G & H Coos Bay, Oregon
(From Nelson et.al. 1983)
Date STATION
June 1980 F3B
F3T
G3B
G3T
H3B
H3T
BOTTOM
DEPTH
(fathoms)
13
13
50
50
33
33
PH
7.85
8.00
7.70
8.00
7.45
8.00
SALINITY
(mg/ml)
32
30
33
31
33
31
NH4-N
(ug/ml)
BD
BD
0.10
BD
BD
BD
•
TURBIDITY
(NTU)
2.9
3.7
7.0
3.6
6.0
1.2
TSS
(ug/ml)
22
19
52
26
27
26
VSS
(ug/ml)
6
6
12
8
7
8
As
(ug/ml)
BD
ND
ND
ND
ND
BD
Hg
(ug/ml)
ND
BD
ND
ND
BD
ND
August 1980
December 1980
April 1981
F3B
F3T
G3B
G3T
H3B
H3T
F3B
F3T
G3B
G3T
H3B
H3T
F3B
F3T
G3B
G3T
H3B
H3T
ND
ND
ND
ND
ND
ND
13
13
50
50
33
33
13
13
50
50
33
33
7.70
7.80
7.60
7.90
7.55
7.70
7.70
7.80
7.60
7.90
7.55
7.70
7.50
7.50
7.60
7.60
7.50
ND
33
33
33
30
35
32
33
33
33
30
35
32
35
31
35
32
35
ND
BD
BD
BD
0.03
BD
BD
BD
0.01
BD
0.03
BD
BD
BD
BD
BD
BD
BD
BD
4.2
2.0
1.3
4.1
2.6
1.2
4.2
2.0
1.3
4.1
2.6
1.2
4.0
3.8
2.8
2.9
3.2
ND
26
23
36
20
23
24
26
23
36
20
23
24
ND
ND
ND
ND
ND
ND
10
8
9
1
8
7
10
8
9
1
8
7
ND
ND
ND
ND
ND
ND
ND
BD
BD
ND
BD
ND
ND
BD
BD
ND
BD
ND
BD
BD
BD
BD
BD
BD
BD
ND
ND
ND
ND
BD
BD
ND
ND
ND
ND
BD
ND
BD
BD
. ND
ND
BD
. I
1 KJ
10
LLD
0.03
0.04
0.05
-------
Table 3.6 (Cont)
( STATION
METAL CONCENTRATION (ng/ml)
PESTICIDE CONCENTRATION (ng/ml)
M
M
to
OJ
Date
June 1980
August 1980
December 1980
April 1981
F3B
F3T
G3B
G3T
H3B
H3T
F3B
F3T
G3B
G3T
H3B
H3T
F3B
F3T
G3B
G3T
H3B
H3T
F3B
F3T
G3B
G3T
H3B
U3T
Cd
ND
1.60
ND
ND
1.80
ND
1.40
ND
ND
ND
ND
3.50
2.80
ND
ND
2.50
1.40
3.10
ND
1.30
l.AO
ND
2.20
4.40
Cu
ND
14.00
ND
ND
8.60
ND
11.20
ND
ND
ND
ND
18.20
34.00
ND
ND
28.80
12.60
13.00
ND
9.70
9.50
ND
12.50
13.50
Fe
ND
6
ND
ND
33
6
18
ND
ND
ND
69
11
18
ND
ND
ND
69
11
ND
14
38
ND
ND
11
Mn
ND
18
ND
ND
14
5
16
ND
ND
ND
112
21
16
ND
ND
ND
112
21
ND
18
76
ND
ND
12
Pb
ND
3.50
ND
ND
3.50
ND
5.00
ND
ND
ND
ND
5.00
7.00
ND
ND
7.00
3.50
7.00
ND
3.50
3.50
ND
2.70
3.50
Zn
ND
0.50
ND
ND
7.00
ND
2.50
ND
ND
ND
ND
7.00
9.00
ND
ND
7.50
5.00
18.50
ND
18.50
15.00
ND
79.00
5.00
Aldrin
0.010
0.004
0.005
0.001
0.005
BD
0.001
0.002
0.001
0.002
0.001
0.001
0.001
0.002
0.001
0.002
0.001
0.001
BD
BD
BD
BD
BD
BD
DDE
BD
BD
0.002
0.002
BD
0.004
0.001
BD
BD
BD
BD
BD
0.001
BD
BD
BD
BD
BD
BD
BD
BD
0.001
ND
ND
Dieldrin
0.005
0.005
0.005
BD
0.006
BD
BD
BD
BD
0.001
0.001
BD
BD
BD
BD
0.001
0.001
BD
ND
ND
ND
ND
BD
BD
DDD
0.003
BD
0.002
0,002
0.010
0.003
0.001
BD
0.002
0.001
BD
BD
0.001
BD
0.002
0.001
BD
BD
BD
BD
BD
0.002
0.002
BD
DDT
0.004
0.010
0.004
0.004
0.008
BD
0.004
0.005
0.001
BD
0.003
0.002
0.004
0.005
0.001
BD
0.003
0.002
BD
0.002
BD
0.004
BD
BD
Arl254
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
Arl260
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
LLD
0.020 0.001
0.001
0.002 0.020
0.020
-------
TABLE 3.7 Most abundant epibenthic species found at varying depths during the
April 1979 to March 1980 epibenthic sampling period by Oregon State
University, Coos Bay Offshore Disposal Study (Ballon-Otter trawl).
Depth (m.)
10-19
Species
Speckled Sanddab
Night Smelt
Northern Anchovy
Sand Sole
English Sole
Bay Pipefish
Warty Poacher
Pacific Tomcod
Taxonomic Family
(Pleuronectidae)
(Osmeridae)
(Engraulididae)
(Pleuronectidae)
(Pleuronectidae)
(Syngnathidae)
(Agonidae)
(Gadidae)
Number
414
294
57
45
36
29
28
20
(Twenty-two species observed, of which 14 species were represented by less
than six individuals each.)
20-29
Speckled Sanddab
English Sole
Pacific Tomcod
Rockfish
(Pleuronectidae)
(Pleurone ct i dae)
(Gadidae)
(Scorpaenidae)
1,467
193
68
43
(Nineteen species observed, of which 13 species were represented by less than
14 individuals each.)
30-45
Speckled Sanddab
Hybrid Sole
Pacific Sanddab
Night Smelt
English Sole
Pacific Tomcod
(Pleuronectidae)
(Pleurone ct i dae)
(Pleuronectidae)
(Osmeridae)
(Pleuronectidae)
(Gadidae)
2,259
108
73
59
44
26
(Twenty-two species observed, of rtiich 16 species were represented by less
than seven individuals each.)
Depth (m.)
46-70
Species
Speckled Sanddab
Pacific Sanddab
Pacific Tomcod
English Sole
Pygmy Poacher
Hybrid Sole
Dover Sole
Taxonomic Family Number
(Pleuronectidae) 369
(Pleuronectidae) 322
(Gadidae)203
(Pleuronectidae) 177
(Agonidae) 70
(Pleuronectidae) 32
(Pleuronectidae) 23
(Eighteen species observed, of which 11 species were represented by less than
12 individuals each.)
*75-120
Pacific Sanddab
Speckled Sanddab
Rockfish
Pacific Tomcod
Rex Sole
(Pleuronectidae)
(Pleuronectidae)
(Scorpaenidae)
(Gadidae)
(Pleuronectidae)
212
46
26
21
17
(Twelve species observed, of which 7 species were represented by less than 6
individuals each.)
* Results of two trawls. All other depths are results of four trawls each.
Ill-24
-------
TABLE 3.8 Most abundant epibenthic species found near sites F, H, and G
during the May 1980 through May 1981 epibenthic sampling period by Oregon
State University, Coos Bay Offshore Disposal Study (15 trawls each site) (1-m
beam trawl).
Depth (m.)
20-40
(Site F)
Species
Speckled Sanddab
Brown Irish Lord
Pacific Sanddab
English Sole
Cabezon
Slim Sculpin
Prickelbreast, Poacher
Taxonomic Family Number
(Pleuronectidae) 998
(Cottidae) 79
(Pleuronectidae) 70
(Pleuronectidae) 63
(Cottidae) 50
(Cottidae) 43
(Agonidae) 35
(Twenty-eight species observed of which there were less than 20 individuals
each of 21 species.)
Depth (m.)
45-70
(Site H)
Species
Pacific Sanddab
English Sole
Speckled Sanddab
Rockfish
Rex Sole
Taxonomic Family
(Pleuronectidae)
(Pleuronectidae)
(Pleuronectidae)
(S corpaenidae)
(Pleuronectidae)
Number
918
218
160
55
31
(Twenty-five species were observed, of which there were less than 20
Individuals each of 20 species.)
75-120
(Site G)
Pacific Sanddab
Slender Sole
Slim Sculpin
Rex Sole
Blackbelly Eelpout
Rockfish
Dover Sole
(Pleuronectidae)
(Pleuronectidae)
(Cottidae)
(Pleuronectidae)
(Zoascidae)
(S corpaenidae)
(Pleuronectidae)
754
463
403
103
84
36
34
(Thirty species observed, of which there were less than 20 individuals each of
23 species.)
111-25
-------
Table 3.9 A list of the Marine Mammals occuring off the Oregon Coast and their status under the Marine Mammal
Protection Act.
i
to
FAMILY AND SPECIES
Balaenidae
Eubalaena glacialis
Eschrichtiidae
Eschrichtius robustus
Balaenopteridae
Balaenoptera musculus
Balaenoptera physalus
Balaenoptera borealis
Balaenoptera acutorostrata
Megaptera novaeangliae
Physeteridae
Physeter catodon
Kogia breviceps
Ziphiidae
Mesophodon stejnegeri
Mesophodon carlhubbsi
COMMON NAME
North right Whale
Grey whale
Blue whale
Fin whale
Sei whale
Minke whale
Humpback whale
Sperm whale
Sperm whale
Pygmy Sperm whale
Beaked whale
N.P. Beaked whale
Hubbs Beaked whale
PROTECTED
Yes
(endangered)
No
(endangered)
Yes
Yes
Yes
No
Yes
Yes
Yes
No
No
No
No
OCCURRENCE OFF OREGON
Along Oregon coast in winter
Along Oregon coast during Feb.
to May While migrating to and
from breeding and feeding grounds
Off Oregon coast from late May
to June and.August to October
Occur off Oregon May to September
Summer to early fall
Late summer to fall
April to October
Late summer to fall
Very rare, one stranding
Very rare, one stranding
Very rare, one stranding
Very rare, one stranding
-------
TABLE 3.9 (Cont)
FAMILY AND SPECIES
Ziphius cavirostris
Berardius bairdii
Delphinidae
Globice phala macrorhynchus
Grampus griseus
Orcinus orca
Pseudorca crassidens
Delphinun delphis
Lissodelphis borealis
Stenella coeruleoalba
Lagenorhynchus obliguldens
Phocoenldae
Phocoenioides da Hi
Phocoena phocoena
Mustelidae
Enhydra lutris
Phocidae
COMMON NAME PROTECTED
Cuvier's Beaked whale No
Giant Bottlenose whale No
Short-finned Pilot whale No
Grampus dolphin No
Killer whale No
Fabe Killer whale No
Common dolphin No
Northern right whale Dolphin No
Striped Dolphin No
Pacific white sided Dolphin No
Ball's Porpoise No
Harbor Porpoise No
Sea Otter Yes
OCCURRENCE OFF OREGON
Rare, three strandings
Uncommon June to Oct.
Winter
Uncommon, Spring to Summer
Winter
Uncommon
Uncommon, Spring, Summer
Rare, Spring to Summer
Rare, three'standings
Common throughout year
Common, throughout year
Common, t hroughout ye ar
Rare, introduction program failed
-------
TABLE 3.9 (Cont)
FAMILY AND SPECIES
Phoca vitulina
Phoca hispida
Phoca fasciata
Mirounga augustirostis
Otariidae
Eumetopias jubatus
Zalophys californianus
M
M Gallorhinus ursinus
i
OO '
COMMON NAME PROTECTED
Harbor Seal Yes
Ringed Seal No
Ribbon Seal No
Northern Elephant Seal Yes
Steller Sea Lion No
California Sea Lion No
Northern Fur Seal No
OCCURRENCE OFF OREGON
Common, 4,000 in Oregon
Rare, single sighting
Rare, single sighting
Rare
Common, 3,000 in Oregon
Common, 3,500 in Oregon, population off
Coos Bay
Rare
-------
TABLE 3.10 POPULATION OF COOS COUNTY 1981 AND 1982
1981 1982 % Change
Coos County 63,300 61,750 -2.5
Coos Bay City 14,275 13,710 -4.0
North Bend City 9,670 9,320 -3.6
Source: Center for Population Research and Census, Portland State
III-29
-------
m,
ADJUSTED SITE H f
* I MM I«U«II MIMI-MMIMt.«
COOS Mr OrfSMMC MVOSM JIUfll
igure 3.1 Offshore Coos Bay study area.
111-30
-------
MILE
Figure 3.2
Locations of Alternative Disposal
Sites.
(Depths reported in fathoms;
NOS chart 18580)
-------
.0.1 mm
O.ISmm
SITE
O.I mm
Offshore Coos Bay
Median Grain Size (mm)
Station* 1-64: Del. 16. 1979 .16
Stations 65-83= Jon. Z2, I98O /fv @
Mar. 6, I960 .,7 .17
.IS
Figure 3.3 Extended offshore area median grain size distribution
(Hancock, et al. 1981).
HI-32
-------
SITE G ,'\
2.0%
I.OV.
Offshore Coos Bay
Orgonics Content
(% Volatile Solids)
Slolions I-64: Ocl. 16. 1979
Siolion* 65-83: Jan. 22, I960
Mot. 6. I960
Figure 3.4 Extended offshore area volatile solids (Hancock, et al. 1981).
111-33
-------
0,5
E
J
o
o
..
w
4>
E
o
TJ
0)
0.1
0.05
0.01
0.005
Estuary Sediments
I I RM 0-12
EZ3 RM 12-14
FTTl Above RM 14
Coastal Sediments
fTl Tidal delta
txs^l Nedrshore 60m
I::':•'! Nearshore 60-l04m
O.I
0.5 1.0 5 10
Organics Content (% volatile solids)
Figure 3.5 Median grain size vs. organics content in estuarine and
coastal sediments (Hancock, et al. 1981).
111-34
-------
0.5
°50
(mm)
01
005
003
.Average
Standard deviation
i r
j i
02
05 10
Organics Content (% Volatile Solids)
50
Figure 3.6 Median grain size vs. volatile solids with site average and
standard deviation (after Nelson, et. al. 1983).
Ill-35
-------
Distance from Entrance (kilometers)
1.0
0.5
8
12
20 24 28 32
C/5
•I 0.1
o
a
"•o 0.05
0.01
' I '
1 1 • r
-------
100
50
^
(A
"3
CO
j»
"o
10.0
5.0
1.0
0.5'
O.I
Distance from Entrance (kilometers)
4 8 12 16 20 24 28
32
Volatile Solids
Coos Bay, Oregon
+ Arneson
oNSF
•OSU (1979)
QQSU offshore (1979)
* Hopper dredge (1973)
-a en
A
•
+
Isthmus
Offshore
j--0
Transect
2 4 6 8 10 12 14 16 18 20
Distance from Entrance (statute miles)
Figure 3.8 Volatile solids related to distance from entrance (Hancock,
et al. 1981).
Ill-37
-------
H
H
I
U)
C» , '
/
orriHOM DISPOSAL
•IIC IMVMTI0AIIOM
»lilll« L*»lloM
Figure 3.9 Coos Bay sediment sampling sites (Hancock, et. al. 1981),
-------
AM 'MAY
Figure 3.10 Monthly wind vectors observed at North Bend Airport and
NOAA offshore data buoys.
Ill-39
-------
kl
Figure 3.11 Core sampling stations - Phase I of Coos Bay Offshore
Disposal Study (Hancock, et al. 1981).
Ill- 40
-------
April and October 1979 trawl tracks
: March, 1980 trawl tracks
Figure 3.12,-Trawl sampling locations - Phase I of Coos Bay Offshore
Disposal Study (Hancock, et al. 1981).
Ill-41
-------
H
M
I
*-
to
H-
V)
e
u>
o o
Hi O
H> H
cn n
o p>
H 3
n> o.
O rt
O M
(0
PI CO
rt
C
O.
OQ
Z O
n> o
M »
co rt
O H-
3 O
• 3
CO
(D
rt I
pi h3
I-1 3*
. pi
(0
H- (D
VO
00 H
U) H
\^
• O
i-h
O
O
o
(0
w
p>
\
-------
\
\
00
o
o
a
n>
-------
A WATER COLUMN
• BOX CORE - BIOLOGICAL AND GRAIN SIZE
• BOX CORE - CHEMICAL AND GRAIN SIZE
| TRAWL TRACK
43'24'
43*22'
43*20'N
124'24'
124'22'
124'20'W
Figure 3.14 IEC survey locations (IEC, 1982).
111-44-
-------
• • . . ' " ' • •-•:• • . ••••:.•';.•••:• . ' • : irvr-a .••. : • .
Figure 3.15 Distribution of sediment size; Cruise I & II, 1978
(from Hancock et al., 1981)
III-45
- —
..
-------
gj - 0.1-0.4*
Q - 0.5-0.8\
- 0.'9-1.2*
Figure 3.16 Distribution of volatile solids; Cruise I & II, 1979
(from Hancock et al.,,1981)
III-46
-------
Low concentration
Medium concu
Heavy conccntrati
Absent
Figure 3.1,7 Distribution of wood chips; Cruise I & II, 1979 (from
.Hancock et al., 1981)
III- 47
-------
Low concentration
Medium concentration
Heavy concentration
Absent
Figure 3.18 Distribution of shells; Cruise I & II, 1979 (from Hancock
et al., 1981)
111-48
-------
© - 0-11 animals/to
Figure 3.19 Distribution of the carnivorous snail Olivella. sp., in
the nearshore region, April and September 1979 (from
Hancock et al., 1981).
111-49
-------
ATftll Iflt IANQOM
Q - 0-11 animals/m
Q - 12-55 anlma
© - 56-110 animal
g - >lll.animala/i
/c.
Figure 3.20 Distribution of the clam, Tellina modesta. in the nearshore
region, April and September 1979 (from Hancock et al., 1981)
111-50
-------
Olivello
pyc.no
AREA F
illvello
biplicoto
Ttllino
nuculoides
84321 8431
S 4 J 2 I
AREA H
AKinopiido Olivtllo Mysello
tetficato boetico oleutlco
AREA G
Axinoptldo Acllo Mocoma
sefricoto eoitfentlt etimoto
Acilo
eostrenils
9O-
28-
S 432 I
Yoldjg
iciisufota
84321 8 4 J 2
S 4 » 2 I
84921
Figure 3.21 Spatial distribution of the most abundant mollusc species
in areas F, H, and G; Cruise 4, May 1980
III-51
-------
MAY I960
54321 54321 94321 64321 94321
180
>-«. I29-
£%
H «
e >
.1
I*
25-
S432I 94321 94321 94321 94321
Area F
Area H
Area G
94321 94321 94321 94321 94321 94321
O.S •> MI 5 .91 .2
15 IH SI g
1
Figure 3.22 Spatial distribution of the most abundant polychaete species
in areas F, H, and G; Cruise 4, May 1980
111-52
-------
MAY I960
AREA F
3 >
c "O
c .£
S o
54321
Fonipholiia
moior
1
I
ll
54321 54321 54321 54321
Mondibuloohoxua Amoelisco Hi Doomed of) flnchiocolurus
unicirostrohjs mocroceoholo denticulotus occidentoUs
«.
AREA G
2.0-
IS-
L»
54321
Metoohoxua
frequens
54321
Foxipholus
similis
54321
Heterophoxus
oculotus
e1
Jlh
54321
Hemilompfoos
colifornico
54321
EudoreUo
pocifico
AREA H
2 §
E ""
3 '5
-2 5^
— •«
c.£ 2
o
S o '
•1
it-
14.
12
10-
I
C
4
!i
10
20-
II-
I*.
14
12-
54321 54321 54321 54321
Svnchetidium Eohoustorius Euphilomedes Repoxynius
shoemokeri sencillus corchorodonto epistomus
54321
Repoxynius
dobouis
Figure 3.23 Spatial distribution of the five most abundant crustacean
species in areas F, H, and G; Cruise 4, May 1980
III- 53
-------
a
o
3
z
^
O
124-M*
1141T
BOO
700
600
SOO
400
300
200
100
g
I
'
STATION 1
800
700
SOO
400
300
200
100
0
V
4V24-
4JTTH
114TO-W
N
K
i
STATION 2
STATION 4
STATIONS
STATIONS
B TOT At (AUTAXA INCLUDING
MINO« PNYLA)
0 POLYCHAITA
0 AITHIOPOOA
^ MOUUSCA
• STATION NUMUI
STATION 7
STATIONS
STATION 9
Figure 3.24 Total number of individuals collected by IEC at nearshbre
region (April-May 1980)
111-54
-------
X
lumbrineria luti
Q - 0-11 animals/ii2
Q - 12-55 anlmals/m2
O - 56-110 animals/02
anlmala/iB2
• Maldana glebifex
Q - 0-11 anlmals/m2
Figure 3.25 Distribution of Lumbrineris luti and Maldane glebifex;
Cruise III, 1980 (from Hancock et al., 1981)
III-55
-------
Paraphoxua epiatomis / \
Q - 0-11 animals/m2
Q - 12-55 animals/m2
- 56-110 anlmala/m
- >111 animals/m2
IX
Olioella 'complex'
O - 0-11 animals/m2
Q - 12-55 animals/m2
© - 56-110 animals/ID2
- >111 animals/m2
Figure 3.26 Distribution of Paraphoxus epistomus and Olivella sp.;
Cruise III, 1980 (from Hancock et al., 1981)
III-56
-------
Figure 3.27
-------
IV ENVIRONMENTAL CONSEQUENCES
4.1 INTRODUCTION
This section evaluates the environmental consequences of ocean disposal of:
a) some 1.3 million cubic yards annually of Type 1 material (coarse-grained
material from the entrance to RM 12), b) some 200,000 cubic yards on a two to
four year cycle of Type 2 material (finer material like that found between
RH's 12 and 14) and; c) some 200,000 cubic yards on a 2 to 4 year cycle of
Type 3 material (fine-grained material like that found above RM 14). Physical
and chemical descriptions of these sediments are found in Section 3. These
materials represent the physical and chemical range of the most likely
materials to be considered for ocean disposal from the Coos Bay area. Neither
this section nor this EIS attempts to compare or evaluate impacts of upland or
estuarine disposal. The effects analysis developed in this section provides
the basis for evaluation and comparisons of the alternatives described in
Section 2. Please note that although this section does not specifically refer
to adjusted site H, the analysis prepared by OSU and presented in this section
covers an extensive offshore area which includes adjusted site H.
4.2 PHYSICAL IMPACTS
4.2.1 Bathyme trie Impacts
Disposal of Type 1 sediments at sites E and F would contribute to the natural
progradation of the river delta. The finer size fractions would be winnowed
from the sediments and transported offshore and alongshore by local mean
currents. Some of the fines would also be transported onshore and back into
the estuary by tidal currents. Some down-slope movement of suspended fine
sediments may also occur in the turbid layer at the bottom but since ocean
disposal is limited to the April through November period of south flowing mean
currents, most transport of fines would be along contours to the south.
Northward transport of fines can be expected during the period of the Davidson
Current and winter storms that would completely rework and spread out the
disposal mound. Net transport would be to the north as a result of this
winter storm wave action. Disposal of Type 3 sediments at this site would
increase local turbidity both in the short and long term since the majority of
the disposed sediment would be unstable in the local energy regime. Increased
turbidity levels would be encountered downstream of the disposal site and more
fines can be expected to be transported back into the estuary.
Disposal of Coos Bay sediments at deeper sites (H, adjusted H, G, or
continental slope) would produce longer-lived but broader bath/metric mounds
since these sediments are coarser than the ambient sediment and the greater
depth allows more spreading. The mound can be expected to slowly spread
parallel to bathyme trie contours. Type 3 sediments would be unstable at these
sites, but resuspension and erosion of any bathymetric mound would be slower
as depth increases since these processes depend on the influence of surface
waves. Type 3 sediments would only be stable if disposed of on the muds of
the continental slope. Dispersion of sediments during their fall through the
water column at the continental slope site would spread the sediments so
widely that no bathymetric buildup would be expected. Similar disposal of
Type 2 and 3 sediments would produce permanent deposits but again the buildup
would likely be minor.
IV-1
-------
Using a simplified but uncalibrated version of the Koh-Chang (1973)
computerized dredged material dispersion model, Nelson et al. (1983) compared
plume and bottom deposits at sites F, G, and H for sediments having median
grain sizes of 0.015 mm, similar to Type 3 sediments. Under representative
summer current conditions, the percentages of dredged material that reached
the bottom were estimated to be about 50, 38, and 34 percent for sites F, H,
and G, respectively. The model predicted a major fraction of the dredged
material would remain suspended in the water column within one foot of the
bottom. The maximum bottom deposit thickness was estimated at 23 cm (9.2
inches) per 100,000 dumped cubic yards at site F, 9 cm (3.6 inches) at site H,
and 7 cm (2.7 inches) at site G. The areal impact on the bottom increases
with increasing depth due to greater mixing during settling. Areal coverage
at site H was about twice that for site F and at site G nearly four times as
great, as that for site F. Coverage at the continental slope site was not
assessed. Local erosion would quickly rework and erase any mound at site F.
It is likely that any mound at sites H and G would erode more slowly and may
be covered by mobile ambient sediments, further increasing the time required
to erase a mound. Monitoring will be required at site H to insure sediment
movement associated with dredged material disposal does not cause adverse
environmental impact (Section 4.5). The numbers cited from this study are not
exact but only indicate relative differences. A test dump consisting of
approximately 52,000 cy of dredged material was disposed at site H in August
1981. After one year approximately 50 percent of the test material deposited
at site H had been eroded away or covered up by natural bedload movement and
after 18 months little remained of the test dump material (Sollitt 1983 pers.
com.).
4.2.2 Sediment Distribution and Transport
Figures 3.5 and 3.6, Section 3, illustrate the natural variability of
median grain size and volatile solids for sites F, H, and G, and for the three
estuary sediment types. Type 1 sediments are physically and chemically com-
patible with sediments at site F. Site H sediments are slightly finer than
these estuarine sediments and site G sediments are substantially finer and
richer in volatile solids. Type 2 sediments are similar in median grain size
to site G sediments but these ocean sediments have lower volatile solids.
Type 3 sediments are not physically compatible with sediments of any of the
three sites since it is very fine and rich in volatile solids. Compatibility
for these fine sediments may be found in the mud faces on the upper
continental slope.
Sediments that are finer than ambient sediments are expected to be more mobile
than ambient sediments. The opposite is expected for coarser sediments.
Consequently, all estuarine sediments can be expected to be mobile in the
vicinity of site F while only Type 2 and 3 sediments would be mobile at site
H. Type 2 sediments would be moderately mobile at site G while Type 3
sediments are mobile at all sites except at the continental slope site.
Detailed current measurements by Hancock et al. (1981) support these
generalities and suggest that the frequency of resuspension is relatively
uniform during spring, summer, and possibly autumn but is significantly
greater in winter. It also appears that the differences in resuspension
frequency between sites F and H are greater than the differences between Sites
H and G. Such generalities are in keeping with the seasonal characteristics .
of surface waves and their rapidly decreasing influence with increasing
depth. Fine Type 1 sands may be expected to be mobilized 75 percent of the
IV-2 .
-------
time in winter at site F and 30 percent of the time during the rest of the
year. Resuspension at sites H and G may be 20 to 30 percent of the time in
the winter and 10 and 25 percent during the remainder of the year. Little or
no reworking of sediments is expected for the continental slope site. Type 3
sediments would be almost constantly erodible at site F in the winter and
mobile in excess of 80 percent and 50 percent of the time at Sites H and G,
respectively, during the winter, and in excess of 50 percent of the time for
both sites during the rest of the year.
The direction of sediment transport is highly variable with both upslope and
downslope transport occurring at all shelf sites during all seasons.
Preliminary analysis of detailed near-bottom current measurements by Hancock
et al. (1981) suggests that downslope transport is generally more frequent
than upslope transport at all three sites and that this tendency is stronger
for the non-cohesive fine sands than for Type 3 sediments.
Transport of fine sediment back into the estuary is likely to occur from site
F. Onshore transport from the vicinity of sites H and G is less likely and
dispersion would scatter the sediments to the point that detectable volumes of
material would not reach the coastline. Sediments suspended in the water
column are similarly more likely to impact the estuary and coastal shorelines
with disposal of Type 3 material at site F.
4.2.3 Water Quality
Water quality impacts may be divided into physical and chemical aspects.
Increased turbidity is the principal physical effect. Disposal of the clean
Type 1 sands would produce a very local short term increase in water column
turbidity which would quickly be dissipated by local currents at all-sites
under consideration. Reworking of materials in any bottom mound would produce
longer term impacts. Reworking of sediments at site F is expected to occur
during the dredging season while complete reworking at sites H and G may not
be completed until the winter storm period. Consequently, resuspension of
fines from site F can be expected to be strong and continuous following dis-
posal, whereas deeper sites may have continual but weaker erosion of fines
during the summer but rapid winnowing in the winter. No reworking of sedi-
ments would be expected for the continental slope site.
Nelson et al. (1983) applied an experimental version of the Koh-Chang (1973)
computer model for dredged material plume dispersion of Type 3 sediments.
While their results are yet to be verified, the study suggests that the dis-
posal of 3,000 cubic yards of sediments under summer conditions could produce
maximum vertically-averaged suspended sediment concentrations after one hour
of 0.04 percent by volume at site F, 0.004 percent at site H, and 0.0001 per-
cent at site G. These values represent dilutions by factors of 500; 5,000;
and 200,000, respectively. These levels may be compared to summer field
measurements by Plank and Pak (1973) off Newport. Averaging surface, mid-
depth and bottom concentration for three stations less than 110 m deep yields
volume concentrations between 0.05 percent and 0.12 percent. The lower figure
is approximately equal to the model's highest-projected vertically-averaged
concentration after one hour. Consequently, it may be assumed that disposal
operations will, under worst case conditions, produce a local turbidity impact
comparable to natural events.
Since the majority of chemical contaminants appear to correlate strongly with
IV-3
-------
the finer size fractions, it is reasonable to assume that the dispersal of the
chemical contaminants would be proportional to the dispersion of the fine
fractions. The final report from preliminary estimates by Nelson e£ al^ (1983)
suggested that between 50 and 75 percent of the sediment would remain in
suspension when dumped and would be transported from the disposal sites by
mean currents. This material would likely contain much of the chemical
contaminants with dilution comparable to those just mentioned. Elutriate
analyses (Hancock et al., 1981) indicate that only ammonium-nitrogen,
manganese, and cadmium may be released to seawater in sufficient concentration
to possibly exceed EPA water quality criteria. Considering the dilutions
measured during the 1981 test dump, these concentrations would be well below
the levels of concern prior to exceeding the boundaries established by the
four hour mixing zone. In addition, no significant differences were observed
between tests and controls of the bioassay tests conducted. Bioaccumulation
in test animals was lower than but in proportion to the concentration of
chemicals and metals in the sediments (Nelson et. al. 1983). The bioassay and
bioaccumulation tests showed that the material is environmentally acceptable
for ocean dumping.
4.3 BIOLOGICAL IMPACT
4.3.1 Epibenthos and Fisheries.
Since the majority of the material (87%) to be disposed can be classified
as clean, non-toxic, inorganic materials, and since the epibenthic and fish
fauna are mobile, we do not expect any measureable effect from ocean disposal
of Coos Bay sediments in the amounts discussed in this EIS. The greatest
impact to these organisms would be the loss of available food organisms due to
the loss of benthic invertebrates. Reduction of these food resources may
increase competition for food resources in other areas. This impact would
reduce in proportion to the rate of recruitment.
4.3.2 Marine Mammals
Although a number of marine mammals are known to occur in the vicinity of
the sites, it is unlikely due to their high mobility that they would be
impacted by disposal operations at any of the alternative sites.
4.3.3 Rare and Endangered Species
According to a letter from the National Marine Fisheries Service, the
Gray Whale occurs in the vicinity of the disposal sites. A biological
assessment has been prepared which concludes that the site designation would
not have an impact on the Gray whale. The NMFS letter and biological
assessment are presented in Appendix B.
4.3.4 Benthos
Disposal of dredged material at any of the proposed sites would result in
a loss of some of the benthic invertebrates at the site. This mortality may
be direct or delayed. The rate of recruitment of a site by benthic inverte-
brates would depend upon the frequency of dumping and type of material dis-
posed at a given site.
IV-4
-------
The nearshore sites (E and F) are the most biologically and physically dynamic
of the proposed disposal areas. Bottom turbulence caused by river outflow and
tidal and wave induced currents result in extensive sediment movement and
dispersion of sediment types in this area.
Dominant benthic species of the nearshore marine environment are species that
are highly motile or rapid burrowers. These species are (Spiaphanes bombyx)
(Olivella pycna), (0_. biphlienta), (Ophelia n. Sp.) and (Tellina hucolbides).
In general, surface dwelling benthic species were present in very low. numbers
in the nearshore region or restricted to the deeper portions of the area.
Many species groups consisted of juveniles recently settled out of the
plankton. Hancock et al. (1980) found no significant post disposal effects on
the biological community at sites E and. F.
Based upon this information and considering the effects of previous disposal,
disposal of Type 1 sediments would likely have only a short term impact on the
benthic communities of sites E and F. The most immediate effect would be some
mortality of benthic species in the impact zone with most burrowing benthic
species surviving, depending upon their burrowing capabilities and the depth
of the disposal mound. Based upon the low content of organic material and
fines in Type 1 sediments (Figures 3.5 and 3.6), and the expected rapid
dispersion rate of fines at sites E and F, we would not expect any measurable
degree of mortality of filter feeding benthic species outside of the impact
zone due to turbidity factors.
Disposal of Type 2 and 3 material, however would increase mortality of filter
feeding benthic invertebrates at sites E and F. Although an increase in
mortality due to turbidity factors may be expected, it is doubtful if this
increase would be significant since (a) There are few filter feeding benthic
species in the nearshore area; (b) suspended sediment values would be lower
than that caused by natural events (see Section 4.1.3); and, (c) sediments
would be rapidly dispersed or covered (Hancock et al., 1980, and Nelson et
al., 1983).
Based on the above, effects of disposal at sites E and F would be short term
and rapid recruitment would occur.
This assessment is based on: (a) no evidence of disposal impacts (Hancock
et. al. 1980); (b) the high degree of seasonal variability in distribution of
the nearshore species; (c) the adaptation of the dominant benthic species to a
high energy environment; and, (d) plankton being the principal source of
species recruitment for the surface benthic species.
The offshore zone, represented by site H, between the 45- and 65-meter
contours, is a transition zone between the high energy nearshore and the
deeper, more stable offshore area represented by site G. Sediment in this
transition zone ranges from sand in the shallower areas to silt and clay in
the deeper areas. This zone is represented by a high species diversity, high
variation in numbers of individuals of a species across the area, and high
seasonal variation in species distribution (Nelson, et al., 1983). The
numbers of filter feeding and surface dwelling benthic species at site H
are higher than that in the nearshore region.
IV-5
-------
In general, species distribution and abundance of benthic species in the
transition zone is directly related to the distribution of sediment types.
The shallow areas have a benthic fauna similar to the nearshore region and
deeper areas have faunal characteristics more like site G. The filter feeding
bivalves and scaphopods are almost exclusively limited to the mud sediments in
the deeper regions. Polychaetes and gastropods tend to be limited to the
sandy sediments of the shallower zones. Crustaceans were unevenly distributed
across the area. Only two species, Repoxynius epistamus and R. debouis hadoti
were evenly distributed.
Disposal of material from the Coos Bay navigation channel in this transition
zone would have varying effects depending upon the type of sediment disposed
and the location of the disposal. Disposal of Type 1 material in the shallow
sandy bottom area would have impacts similar to disposal of the same material
at sites R and F. However, because there tends to be a higher number of
species and individuals of species here than at sites E or F, the direct
mortality would be greater. This impact would be primarily due to smothering
with little mortality due to turbidity.
Although the disposal of Type 1 material in the shallow areas of the
transition zone would have direct impacts similar to disposal of this material
at sites E and F, there should also be additional long term impacts. These
impacts would be due to disposal of coarse-grained material over fine-grained
material. These changes in habitat may result in changes in the species
composition of the area.
Disposal of Type 1 material in the deeper portions of the transition zone
(site H) would result in the mortality of most organisms in the impact area
and the change of habitat conditions from fine sands and muds to coarse
sands. This change in habitat conditions could result in a change in benthic
species distribution' and abundance at the site.
Disposal of Type 2 materials into the transition zone (site H) would have
similar effects. Because of the similarity of sediment types in the disposal
material to that existing at site H, it is doubtful if there would be
measurable long-term effects. This is because the fines and organic material
would likely be rapidly transported further offshore. It is anticipated that
some mortality of filter feeding species would occur due to turbidity
factors. As indicated in Sections 4.2.2 and 4.2.3, turbidity impacts would be
a short-term event. Reworking and transport of material downslope would be
primarily limited to the winter storm period. Turbidity levels would likely
be comparable to that occurring naturally.
Disposal of Type 3 material at site H area would also have similar effects.
A larger area would be impacted, however, since the finer-grained materials
would be transported downslope. A long term change in sediment type and
habitat could occur at site H if Type 3 materials are routinely deposited
there. Since net transport from site H has been shown to have a strong
offshore component, movement of both fine and coarse material from site H
should be offshore.
Site G, at depths of 70 to 120 meters with mud sediments, is the more stable
and productive environment of the three sites for benthic infauna. Large
numbers of mollusca, scaphopod, and crustacean species were present in the
IV-6
-------
area. Filter feeding bivalves were the most abundant species here. The
polychaete group, while numerous, varied significantly between sampling
stations. Gastropod species were present, but in low numbers. The carnivo-
rous snail (Mitrella gouldi) was the only gastropod that consistently exceeded
1 percent of the total molluscan numbers.
Disposal of any of the materials from Coos Bay at site G would result in the
greatest biological impact of the three areas studied. Two factors
contributing to this are the high numbers of species and individuals that
occupy the area, and the large impact area that would result from disposal.
Disposal of Type 1 material would have the greatest biological impact of the
three sediment types on site G due to: (a) Dissimilarity of disposal and
bottom sediments, (b) burial of organisms less tolerant to smothering and
recolonization, and (c) the low rate of sediment transport that could
eventually change the species composition and productivity in the area if
disposal occurs here.
Disposal of Type 2 material at site G, because of the similarity of sediment
types, would likely have the least long-term biological impact of the three
sediment types. The fauna, however, typically has an evolutionary history of
stable sediment conditions and is therefore less adapted to recovery from
initial disposal impacts.
Disposal of Type 3 material at site G would cause an immediate loss of
existing benthlc communities in the impact areas. Long-term disposal of this
material at site G would alter the habitat character of the area. In
addition, the high organic and volatile solids content of this material would
result in a change in character of the bottom sediments. This could result in
indirect mortality of existing species and a change in species composition.
In summary, disposal of any of the Coos Bay sediments at sites E and F would
result in the least immediate impact on benthos of the three sites. The
primary reasons for this are the dynamic physical environment, the similarity
of the sediment types, the low abundance and species richness (relative to the
other areas) and the adaptability of the existing benthic species to an
unstable environment.
Disposal at site U of any Coos Bay sediments would have greater benthic
impacts than at sites E or F. Although species diversity was high in this
area there was also large seasonal variation in species abundance. This
suggests that benthic recovery should be relatively rapid. Preliminary
observations of the 1981 test dump support this assessment (Jones pers. comm.
1983).
Disposal of coarse-grained or highly organic materials at site H would modify
sediment (habitat) characteristics of the area, and change species composi-
tion. Disposal of Type 2 and 3 material at site H may increase the abundance
of species common to site G.
Disposal at site G would result in a greater loss of species and individuals
than disposal at sites E, F, or H. In addition, disposal of coarse-grained
sand or Type 3 material would result in long-term changes in habitat
characteristics with a probable reduction in species diversity and abundance.
IV-7
-------
4.4 SOCIO-ECONOMIC IMPACTS
4.4.1 Local Area Economy
Maintenance of the Coos Bay navigation system is necessary to support
Coos Bay's current economic base, maintain the area's important competitive
advantage, and allow it to handle reasonable future expansion. Ocean disposal
is important to the present channel maintenance program, and, as stated in
Section 3, future navigation channel maintenance will depend upon ocean
disposal. Without adequate channel depths, Coos Bay would possibly lose a
large share of its export market and would have to absorb the high transfer
costs to other ports. The ultimate result would be a significant adverse
impact upon the local economy.
4.4.2 Analysis of Comparative Transfer Costs
Historically, only entrance channel sediments, averaging about 800,000
cubic yards annually, have been disposed at sea (sites E and F) . Yet, because
of the lack of upland and limited in-channel (used up to RM 12) sites, ocean
disposal of all dredged material is considered in this analysis. The
following channel reaches would be involved: /
a. Entrance channel (RM 0.0 to 2.0), consisting of about 800,000 cubic
yards annually of s'and.
b. Lower channel (RM 2.0 to 12.0), consisting of about 500,000 cubic
yards annually of sands, silts, and clays.
c. Upper channel (above RM 12.0), consisting of approximately 400,000
cubic yards on a two to four year cycle of fine sediments.
Available data and present conditions indicate that the following assumptions
would be appropriate in this case: the average dredge cost would be $40,000
per 24-hour day, and it would take one hour to load the dredge; the dredge
travels at 10 miles per hour, and holds 4,000 cubic yards; it would take 5
minutes to dump the dredge, and all dredged material would be dumped in one
site only and the dredge will be operated 24 hours a day. For these
estimates, base points to ocean sites were: Entrance channel at RM 1.0; Lower
channel at RM 7.0; and Upper channel at RM 13.5.
Using these assumptions, Table 4.1 displays the comparative cost summaries for
each of the alternative disposal sites.
The data presented in Table 4.1 shows that disposal costs are a direct
function of the proportionate increase in distance needed to transport the
material and the amount of material to be transported. For example, it is 24,
43 and 280 percent more expensive to dispose of the material from the entrance
~7 These figures were taken from U.S. Army Corps Engineers, Portland
District, Coastal Projects Operation and Maintenance, 1982 (pages 84 through
94).
IV-8
-------
«t sites U, 6, and the continental shelf respectively than a£ sites E and F.
Correspondingly it is 13, 31, and 156 percent more expensive to dispose of the
material from the Lower Bay at sites H, G, and the continental shelf than at
sites E or F. Similar cost increases for the upper bay material would be 8,
15, 108 percent, respectively.
If we assume that a 10 percent increase in costs is the level of significant
economic difference then disposal of material from the entrance and lower bay
is acceptable only at sites E and F. Correspondingly, there would be no
significant difference in disposal costs of material from the upper bay
between sites E, F, and H (Table 4.1).
Costs of disposing any of the Coos Bay material at the continental shelf
location varies from 100 to 300 percent more expensive than disposal of the
same kind and amount of material at sites E, F, or H (Table 4.1).
4.4.3 Commercial and Recreational Activites
Commercial and recreational activities would not be significantly
affected by the proposed disposal site location and use. No gas, oil, or
mineral exploration is anticipated in the vicinity of the disposal sites. As
discussed in Section 4.3, commercial fishing activities would not be affected
by the use of the disposal sites.
4.4.4 State and Local Coastal Management Plans
As stated in Section 3.4.4, the Oregon Coastal Management Program (OCMP)
and the Coos County Comprehensive Plan recognize the need to provide for
suitable offshore sites for disposal of dredged materials. The OCMP
stipulates that the location of the sites and disposal practices must not
substantially impact fishing, navigation, or recreation activities, or the
natural resources of the continental shelf. The previous discussions on
impacts of dredged material disposal in the proposed disposal sites (Sections
4.1 and 4.2) Indicate that no substantial impacts on these uses or resources
are anticipated.
A statement of consistency with the OCMP has been prepared and is included in
Appendix A. The Oregon Land Conservation and Development Commission (LCDC)
concurred with the consistency determination in the Draft EIS. A supplemental
consistency determination has been requested from the LCDC because site H is
now being proposed for the disposal of Type 2 and 3 materials instead of
adjusted site H.
4.4.5 Esthetics
The esthetics of the disposal sites would be impacted primarily by short
term turbidity during and after a disposal operation (See discussion in
Section 4.2.3). Finer sediments would remain in suspension for longer periods
and are more susceptible to reauspension by current and wave activity.
Disposal of finer sediments at the nearshore sites would create more turbidity
than disposal in the offshore area. Additional discussion of sediment
suspension and transport is included in Section 4.2.2.
IV-9
-------
4.4.6 Cultural Resources
As stated in Section 3.4.8, no known significant cultural resources exist
in the Coos Bay offshore area. Therefore, no cultural resources of historic
or archeologic significance would be affected by the proposed site
designations or resultant ocean dumping.
4.5 MITIGATION AND SITE MONITORING
Specific mitigation actions to offset disposal impacts have not been
identified. Extensive monitoring of existing ocean disposal activities has
been conducted to determine potential adverse impacts (see Section 3). These
actions, designed to determine any adverse effects and/or minimize those
effects, are considered mitigation actions.
Due to the unique compatability of type 1 material for sites E and F,
monitoring will be limited to periodic bathytuetric surveys. Bathymetric
surveys will also be conducted at site H. In addition, a set of stations
should be established around site U at which sediment samples are collected
'annually. Because of the characteristic difference in sediment-size and
volatile solids content between the dredged material and the disposal area,
the presence of fine material or high volatile solids outside of site H could
be used to indicate sediment movement. Flans for additional testing and/or
corrective measures will be developed if movement outside of site H is
discovered.
Monitoring at site H will begin with the first disposal action at the site in
the fall of 1985. The future analysis of dredged material sediment on a 3 to
5 year cycle will help to identify any changes in contaminant levels.
4.6 ADVERSE ENVIRONMENTAL EFFECTS WHICH ARE UNAVOIDABLE
The permanent designation of ocean disposal sites at Coos Bay would allow
continued disposal of dredged material in these sites with the following
effects:
The bottom topography of the sites would be altered;
Disposal operations would create temporary turbidity in the vicinity of the
disposal site(s);
Volatile solids and chemical contaminants found in upper bay sediments would
temporarily impact water quality in the vicinity of the disposal site(s).
Benthic organisms would be smothered by disposal operations. Benthic habitat
and associated communities would be altered by disposal activity perturbations
and changes in bottom sediment;
Loss of benthic organisms would at least temporarily remove a food source for
organisms higher in the food chain. However, since the disposal areas are
small relative to the total area for the species, long-term impact on the food
chain is not anticipated.
IV-10
-------
4.7 RELATIONSHIP BETWEEN LOCAL SHORT-TERM USES OF THE ENVIRONMENT AND
MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY
Disposal of dredged material in the proposed ocean sites would have a
presently unquantifiable but apparently minor short- and long-term effect on
the productivity of the marine environment. Use of the sites would have a
long-term beneficial effect on the economy of Coos Bay and Coos County.
4.8 IRREVERSIBLE OR IRRETRIEVABLE COMMITMENT OF RESOURCES
'ermanent designation of the proposed sites for disposal of dredged material
rould commit the sites and their resources primarily to that use. Other uses
iuch as oil and gas exploration, and to varying degrees, mining, fishing, and
ise by certain aquatic species, would be precluded.
IV-11
-------
TABLE 4.1 COST* COMPARISON FOR DISPOSAL OF MATERIAL FROM THREE DIFFERENT LOCATIONS IN COOS BAY AT FOUR
DIFFERENT OCEAN SITES
'
Dredging Location
Entrance (RM 1.0,
800,000 cu. yd.)
#24 hour work days
Estimated Cost (millions)
Lower Bay (RM 7.0,
500,000 cu. yd.)
#24 hour work days
Estimated Cost (millions)
^ . Upper Bay (RM 13.5,
,L 400,000 cu. yd.)***
M #24 hour work days
Estimated Cost (millions)
Sites
E (1.5)**
49
1.96
32
1.28
26
1.04
F (1.5)**
49
1.96
32
1.28
26
1.04
H (3.5)**
61
2.44
36
1.44
28
1.12
G (5.0)**
70
2.80
42
1.68
30
1.20
Continental
Shelf (24)
186
7.44
82
3.28
54
2.16
•; * These costs are for comparison purposes only. Costs are based upon the assumptions .outlined on pages IV-16.
.-• ** Statute miles from the entrance into Coos Bay.
> *** Every 2 to 4 years.
-------
V COORDINATION
5.1 General. Preparation of this EIS has been coordinated with interested
Federal, State, and local agencies, and the public. A scoping letter was
distributed on 30 September 1982.
The draft EIS was distributed for a 45-day public review on 9 September
1984. Comment letters were received from the following Federal, State and
local government agencies. Copies of these comment letters are presented in
Appendix E along with responses to those comments as required.
National Marine Fisheries Service
National Ocean Service
Oregon Department of Land Conservation and Development
U.S. Department of the Interior
U.S. Environmental Protection Agency, Region X
U.S.' Department of Health and Human Services
U.S. Coast Guard
Coos County
V-l
-------
VI LIST OF PREPARERS
Principal Authors
Steven J. Stevens
BS, Landscape Architecture
Thomas E. Morse
BS, MS Wildlife Management
Ph.D Ecology
William Boodt
MS, Ph.D Economics
Patricia Hodge
BA, MA Letters and Science
Economics Specialist
David Askren
BS Geology
MS Oceanography
MS Civil Engineering
Kim Larson
BS Zoology, MS Fishery
Biology
Robert A. Freed
MA Anthropology
Eric P. Braun
BS Wildlife Management/
Biology
Experience:
Land use planning, EIS
preparation (12 years)
Wildlife research bio,
resource planner, biol.
assessment (12 years)
Industrial, regional and
resource economic analysis
feasibility and impact
studies (22 years)
Economics assistant/
regional economics
(6 years)
Physical and geological
oceanography (10 years)
Coastal navigation pro-
'ject planning and main-
tenance (4 years)
Biological (fisheries)
studies; environmental
impact assessment
(7 years)
Archeological investiga-
tion and cultural re-
sources management
(8 years)
Environmental Impact
Assessment (4 years)
Contribution to EIS
Purpose and need, alter-
natives comparison, land
use/CZM consistency, es-
thetics, EIS coordina-
tion
Physical/biological de-
scription and assess-
ment, alternatives com-
parison, study coordi-
nation.
Socio-economic environ-
ment and impacts; cost
analysis.
Socio-economic environ-
ment; cost analysis.
Physical environment
description and impacts
assessement.
Biological environment
description and impacts
assessment.
Cultural resources
EIS coordination
and preparation
VI-1
-------
VII BIBLIOGRAPHY
PHYSICAL/BIOLOGICAL
Braun, E. 1985. Memorandum to the Files. Coos Bay Meeting to Discuss
Alternative Sites H and Adjusted H, 9 January 1985. NPPPL-NR-EQ.
Conomos, T.J., M.G. Gross, C.A. Barnes, F.A. Richards. 1972. River-Ocean
Nutrient Relations in Summer in the Columbia River Estuary and Adjacent Ocean
Waters, A.T. Pruter and D.L. Alverson, eds., University of Washington Press,
Seattle WA, 868 pp.
Cutchin, D.L. and R.L. Smith. 1973. Continental Shelf Waves: Low Frequency
Variations in Sea Level and Currents over the Oregon Continental Shelf,
Journal of Physical Oceanography, 3 (1), 73-82.
Duxbury, A.C., P.A. Morse, N. McGary. 1966. The Columbia River Effluent and
Its Distribution at Sea, 1961-1963. Technical Report No. 156, University of
Washington, Dept of Oceanography, Seattle WA.
EPA. 1976. Quality Criteria for Water, EPA-440/9-76-023, U.S. Environmental
Protection Agency, Washington, D.C.
Hancock, D.R., P.O. Nelson, C.K. Sollitt, K.J. Williamson. 1981. Coos Bay
Offshore Disposal Site Investigation Interim Report Phase I, Feburary
1979-March 1980. Report to U.S. Army Corps of Engineers, Portland District,
Portland, OR for contract No. DACW57-79-C0040. Oregon State University,
Corvallis, OR.
Harlett, J.C. 1972. Sediment Transport on the Northern Oregon Continental
Shelf. PHD thesis, Oregon State University, Corvallis, OR.
Huyer, A and J.G. Patullo. 1972. A Comparison Between Wind and Current
Observations over the Continental Shelf off Oregon, Summer, 1969. Journal of
Geophysical Research, 77 (18), 3215-3220.
Huyer, A, R.D. Pillsbury, R.L. Smith. 1975. Seasonal Variation of the
Alongshore Velocity Field Over the Continental Shelf off Oregon. Limnology
and Oceanography, 20 (1), 90-95.
Huyer, A and R.L. Smith. 1977. Physical Characteristics of Pacific
Northwestern Coastal Waters, in the Marine Plant Biomass of the Pacific
Northwest Coast, R.W. Krauss, ed., Oregon State University Press, Corvallis,
OR, 397pp.
Interstate Electronics Corporation. 1983. Appendixes to Coos Bay, Oregon
Ocean Dredged Material Disposal Site Designation. Report of Field Survey.
U.S. Environmental Protection Agency, Wahsington D.C.
Koh, R.C.Y., Y.C. Chang. 1973. Mathematical Model for Barged Ocean Disposal
of Wastes, Environmental Protection Technology Series EPA 660/2-73-029,
December 1973, U.S. Environmental Protection Agency, Washington, D.C.
Nelson, P.O., C.K. Sollitt, K.J. Williamson, D.R. Hancock, 1983. Coos Bay
Offshore Disposal Site Investigation Interim Report Phase II, III, April
VII-1
-------
1980-June 1981. Report Submitted to the U.S. Army Corps of Engineers,
Portland District, Portland, OR, under contract No. DAW57-79-C0040, Oregon
State University, Corvallis, OR.
Oregon Dept. of Fish and Wildlife. 1976. Marine Resource Surveys on the
Continental Shelf Off Oregon, 1971-74. State of Oregon.
OSU 1977a. The Marine Plant Biomass of the Pacific Northwest Coast. R.W.
Krauss, ed., Oregon State University Press, Corvallis, Oregon, p. 17 of 397.
OSU 1977b. Environmental Impact of Dredging in Estuaries, Department of
Engineering and Oceanography, Oregon State University, Corvallis, Oregon.
Plank, W.S. and H. Pak. 1973. Observations of Light Scattering and Suspended
Particulate Matter off the Oregon Coast, June - October 1972. OSU School of
Oceanography Data Report 55, Corvallis, Oregon.
Sobey, E.J.C. 1977. The Response of Oregon Shelf Waters to Wind
Fluctuations: Differences and Transition between Winter and Summer PhD
thesis, Oregon State University, Corvallis, Oregon.
Sollitt, C.K., D.R. Hancock and P.O. Nelson. 1984. Coos Bay Offshore
Disposal*Site Investigation Interim Report Phase IV and V, July 1981 -
September 1983. Report to U.S. Army Corps of Engineers, Portland District,
Portland, OR for contract No. DACW57-79-C0040. Oregon State University,
Corvallis, OR.
Sverdrup, H.U., M.W. Johnson, R.H. Fleming. 1942. The Oceans. Prentice
Hall, Inc., Englewood Cliffs, N.J. 1058 pp.
SOCIO-ECONOMIC
Beuter, J.H. 1976. Timber for Oregon's Tomorrow. Oregon State University
Forestry Research Laboratory, Corvallis, Oregon.
Coos County. 1982. Coos County Comprehensive Plan. Coos County Board of
Commissioners. Coquille, Oregon.
Coos-Curry-Douglas Economic Improvement Association 1980. Comprehensive
Economic Development Strategy, 1980-81. Action Program. Roseburg, Oregon.
Oregon Dept. of Fish and Wildlife. 1976. Marine Resource Surveys on the
Continental Shelf Off Oregon, 1971-74.
Oregon Land Conservation and Development Commission. 1976. Statewide
Planning Goals and Guidelines. Salem, Oregon.
Port of Coos Bay. 1980. Waterborne Statistics. Coos Bay, Oregon
Portland State University. 1983. Center for Population Research and Census.
Portland, Oregon.
U.S. Army Corps of Engineers, Portland District. .1982. Coastal Projects
Operations and Maintenance, pp. 84-94. Portland, Oregon
VII-2
-------
APPENDIX A
OCMP CONSISTENCY STATEMENT
-------
OREGON STATEWIDE GOALS
1. CITIZEN INVOLVEMENT. To develop a
citizen involvement program that insures
the opportunity for citizens to be
involved in all phases of the planning
process.
2. LAND USE PLANNING. To establish a
land use planning process and policy
framework as a basis for all decisions
and to assure an adequate factual base
for such decisions and actions.
3. AGRICULTURAL LANDS. To preserve and
aintain agricultural lands.
4. FOREST LAND. To Conserve forest
lands for forest uses.
5. OPEN SPACES, SCENIC AND HISTORIC
AREAS AND NATURAL RESOURCES. To
conserve open space and protect natural
and scenic resources.
6. AIR, WATER AND LAND RESOURCES. To
maintain and improve the quality of the
air, water, and land resources of the
tate.
7. AREAS SUBJECT TO NATURAL DISASTERS
& HAZARDS. To protect life and property
from natural disasters and hazards.
8. RECREATION NEEDS. To satisfy the
recreational needs of the citizens of the
state and visitors.
CONSISTENCY STATEMENT
The Corps has included citizens in the planning of this proposed porject
through distribution of the EIS "scoping" letter. Citizens will have the
additional opportunity to- review and comment through the Draft EIS and
and Final EIS review processes.
Land use planning is a state and local function. The Corps has coordinated
the site designation alternatives with all agencies that have planning
responsibility for the affected area. The proposed project is conistent
with Oregon's Coastal Management Program and other applicable statewide
goals, the Coos County comprehesive plan and with the Coos Bay Estuary
Management plan.
This goal is not applicable.
This goal is not applicable.
There are no known historic and cultural resources in the area (see
Appendix C). The proposed site designation and resulting ocean disposal
would not detract from the area's scenic quality or significantly impact
natural resouces.
Turbidity would increase slightly above background levels during disposal
operations. Any increase in turbidity would be temporary. The proposed
action will not affect air and land Resources.
Ocean disposal would indirectly reduce risks of ship grounding in the
entrance bar.
Recreation boating and sport fishing are expected to continue in the area
with or without the proposed site designation.
-------
OREGON STATEWIDE GOALS
9. ECONOMY OF THE STATE. To diversify
and improve the economy of the state.
10. HOUSING. To provide for housing
needs of citizens of the State.
11. PUBLIC FACILTIES AND SERVICES. To
plan and develop a timely, orderly and
efficient arrangement of public
facilities and services to serve as a
developoment
12. TRANSPORTATION. To provide and
encourage a safe, convenient and
economic transportation system.
13. ENGERGY CONSERVATION.
engergy..
To conserve
14. URBANIZATION. To provide for an
orderly and effieicent transition from
rural to urban land use.
15. WILLAMETTE RIVER GREENWAY. To
protect, conserve, enhance and maintain
the natural, scenic, historical,
agricultural, economic and recreational
qualities of lands along the Willamette
River as the Willamete River Greenway.
CONSISTENCY STATEMENT
Maintenance of the Coos Bay Navigation System is considered vitally
important to local regional and state economic vitality. Ocean disposal
site designation is an integral part of the navigation system maintenance
plan.
The proposed site designation would not affect local planning or
implementation of plans which provide for the housing need of citizens.
Facilities and services associated with the Coos Bay Navigation channel
are already in place. Ocean disposal site designation would help insure
the continued use of these facilities and services.
The continued use of a safe convenient and economical water transportation
system in Coos Bay is at least partially dependent upon the use of ocaen
disposal sites for channel maintenance.
The use of close-in disposal sites would provide for more efficient
channel maintenance, resulting in net energy savings.
Ocean disposal site designation is not expected to have any effect on the
or patterns of urbanization.
Not applicable.
-------
OREGON STATEWIDE GOALS
16. ESTUARINE RESOURCES. To recognize
and protect the unique environmental,
economic and social values of each
estuary and associated wetlands; and to
protect, maintain, where appropriate
develop and where appropriate restore
the long-term environmental, economic
and social values, diversity and
benefits of Oregon's estuaries.
17. COASTAL SHORELANDS. To conserve
protect, where appropriate develop and
where appropriate restore the resources
and benefits of all coastal shorelands,
recognizing thier value of protection
and maintenance of water quality, fish
and wildlife habitat, water-dependent
uses, economic resources and recreation
and esthetics. The management of these
shoreland areas shall be compatible with
the characteristics of the adjacent
coastal waters; and to reduce the hazard
to human life and property, and the
adverse effects upon water quality and
fish and wildlife habitat, resulting
from the use and enjoyment of Oregon's
coastal shorelands.
18. BEACHES AND DUNES. To conserve
protect, where appropriate develop, and
where appropriate restore the resources
and beneifts of coastal beach and dune
areas; and to reduce the hazard to human
life and property from natural or man
induced actions associated with these
areas.
CONSISTENCY STATEMENT
Ocean disposal site designation would help alleviate the need for disposal
in or adjacent to the estuary. The proposed use of the ocean disposal sites
would have no significant impact on estuarine resources.
Ocean disposal site designation would help alleviate the need for disposal
on coastal shorelands.
Dredged material disposed of at sites E and F may be carried ashore by
wave-induced currents. The material deposited at these sites would be
essentially clean and sand and would have a primarily positive effect of
beach nourishment.
1,
-------
OREGON STATEWIDE GOALS
19. OCEAN RESOURCES. To conserve the
long-term values, benefits, and natural
resources of the nearshore ocean and the
continental shelf.
CONSISTENCY STATEMENT
The general productivity of the area may be negatively affected due to
continuous disposal of material from maintenance dredging. Benthic organisms
at the. sites would be impacted by smothering. No other natural resources are
expected to be significantly affected by the disposal of dredged material.
-------
APPENDIX B
ENDANGERED SPECIES COORDINATION
-------
United States Department of the Interior
FISH AND WILDLIFE SERVICE
Endangered Species
2625 Parkmont Lane S.W., B-2
Olympia, WA 98502
February 14, T983
Mr. .Richard N. Duncan
Chief, Fish and Wildlife Branch
Portland District, Corps of Engineers
P.O. Box 2946
Portland, Oregon 97208
Refer to: 1-3-83-SP-133
Dear Mr. Duncan: ' •
This is in response to your letter, dated January.17, 1983, for infor-
mation on listed and proposed endangered and threatened species which
may be present within the area of the proposed Ocean Disposal Site(s)
near Coos Bay, Oregon. Your request and this response are made pursuant
to Section 7(c) of the Endangered Species Act of 1973, 16 U.S.C. 1531,
et seq.
To the best of our present knowledge there are no listed or proposed
spec,ies occurring within the area of the subject project. (-See
•attachments) Should a'species become officially listed or proposed
before completion of your project, you will be required to reevaluate
your agency's responsibilities under the Act. We appreciate ydur
concern for endangered species and look forward to continued "coordina-
tion with your agency.
Jim A. Bottor'fl
Endangered Species Team Leader
Attachments
%
cc: RO (AFA-SE)
ES, Portland
OOFW, Non-Game Program
-------
™ AND PROPOSED ENDANGERED AND THREATENED SPECIES AND
CANDIDATE SPECIES THAT MAY OCCUR WITHIN THE AREA OF THE PROPOSED
OCEAN DISPOSAL SITE(S) NEAR COOS BAY, OREGON
1-3-83-SP-133
LISTED:.
None •
PROPOSED:
None
CANDIDATE:
None
Attachment A
-------
UNITED STATES DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
NATIONAL MARINE FISHERIES SERVICE
Environmental & Technical Services Division
847 N.E. 19th Avenue, Suite 350
Portland, Oregon 97232-2279 .
(503) 230-5400
March 11, 1985
F/NWR5-418:AG
Richard N. Duncan
Chief, Fish and Wildlife Branch
Portland District Corps of Engineers
P.O. Box 2946
Portland, Oregon 97208
Dear Mr. Duncan:
This letter is in response to your request of February 27, 1985 for lists
of threatened and endangered species under jurisdiction of the National Marine
Fisheries Service (NMFS) that may be present in offshore dredge disposal sites
at Yaquina and Coos Bays, Oregon.
The only listed species likely to occur in these areas is the gray whale,
Eschrichtius robustus.
Sincerely,
Dale R. Evans
Division Chief
RECE I VED
MAf: i..; 1235
-------
COOS AND YAQUINA BAYS, OREGON
DREDGED MATERIAL DISPOSAL SITE DESIGNATION
BIOLOGICAL ASSESSMENT
GRAY WHALE
Coastal waters of Oregon serve as a migratlonal corridor for gray whales
moving to and from their breeding, calving, and assembly areas off mainland
Mexico-Baja California and their primary foraging areas in the Arctic (Sumich,
1984). Southward migration occurs in November-December with northbound
migrants present from February-April. Recently, it has become apparent that
summer occurrence of gray whales off the west coast of North America is more
common than previously assumed (Sumich, 1984).
Gray whales summer along the Oregon Coast (Sumich, 1984). Over 1200 gray
whale sightings were reported during a 1977-1980 study of gray whale
occurrence off coastal Oregon by Sumich (1984). A 100 km section of coastline
from the Sluslaw River to Government Point just north of Depoe Bay, appeared
to be relatively important to gray whales as 60 percent of the 460
observations in 1977 occurred in that portion of the coastline (Sumich,
1984). The author noted that'it was not determined if whales were more
numerous or just easier to detect along that section of coast, than along
other portions of the Oregon Coast. Sumich (1984) concentrated 1978 study
efforts in the 100 km section from Siuslaw River to Government Point because
of the higher incidence of sightings. His 1978 data indicated that gray
whales were most commonly observed in the northern half of his study area;
approximately Alsea River to Government Point which contrasted with 1977
results. Sumich (1984) reported a maximum observed occurrence of 0.2-0.3
whales/km of coastline for the 100 km study area for the 1977 and 1978 study
years.
Most sightings of gray whales occurred within 500 m of shore (Sumich,
1984). Gray whales frequented surf or foam lines. Nearshore areas with silty
sediments appear to be foraging areas for gray whales; presumably because of
high amphipod populations in silty sediments (D. Hancock, USAGE, pers. comm.,
1985). Confirmation of foraging areas, prey populations, foraging substrate,
-------
and foraging strategy are necessary. Present tentative conclusions are based
on foraging ecology of gray whales in their summer grounds in the Arctic and
observed behavior and site use off Oregon. Sightings also occurred at
distances 5-80 km offshore in water depths of 50-2700 m (Sumich, 1984); number
of sightings was only 14 comprising 27 whales, however.
Site specific use by gray whales varied both daily and annually (Sumich,
1984), thus the period of maximum occurrence was undetectable. Additionally,
weather, sea state, observer effort, the presence or absence of strategic
observation points, and the unreliability of aerial counts due to the
predominant occurrence of gray whales in surf and foam lines also contribute
to the large variation in observed abundance. Because of these factors,
Sumich considered his abundance estimate of 0.2-0.3 whales/km as conservative.
Sumich (1984) states that the primary activity of summer gray whales off
the Oregon coast appears to be feeding; It is not known what the prey item(s)
are. Benthic infauna, primarily gammarid amphipods, are the principal food
items of gray whales in the Arctic. He speculated that the offshore sightings
(14 occurrences) may indicate pelagic foraging by the species.
Sumich (1984) also determined size of gray whales whenever possible. His
results indicated that calves and yearlings comprised a significantly greater
proportion of the Oregon coast population than would be expected from a random
sample of the population as a whole. His analysis of length data on gray
whales larger than yearlings led to the conclusion that summer gray whales on
the Oregon Coast are predominantly immature or atypically small mature
animals. These animals may be shortening their migration due to insufficient
energy reserves.
Advantages to gray whales discontinuing their migration and foraging
along the Oregon coast may lie in the energetic savings associated with such
behavior (Sumich, 1984). He concluded that the shallow, inshore waters of the
Oregon coast should be considered as a supplementary summer feeding grounds.
As a complete count of gray whales which summer off Oregon is unavailable, the
proportion of the population which is present remains an unknown. However, it
seems reasonable that only a small proportion of the population does exhibit
this tendency to shorten their migration.
-------
Disposal Site Information
Yaquina Bay - The proposed disposal site is located approximately 1.61 km
offshore in approximately 15 m of water. Dimensions of the disposal area are
approximately 1036 x 366 m or 38 hectares. The site is located in a tow boat
lane, hence receives commercial boating traffic.
Recreational use, principally private and charter salmon fishing, also
occurs in the disposal area during summer. Commercial fishing operations,
primarily bottom fishing, salmon trolling, crabbing, and squid fishing are
also present in the project area.
Dredged material disposal operations will occur generally from mid-April
to mid-October with most dredging conducted from May to September. Dredging
will require approximately two weeks for completion. Material disposed of
will primarily be sandy sediments. The substrate of the disposal site is
similar to that of the area dredged. Amphipod population levels are
relatively low at the disposal site.
Coos Bay - Three sites (E,F, and H) are proposed for receipt of dredged
material off Coos Bay, Oregon. Sites E and F are each approximately 1.61 km
offshore and are located in 18-31 m of water. Site H is 5.8 km offshore in
55-67 m of water. Dimensions of all sites are similar; approximately 1097 x
427 m or 47 hectares.
Dredging will be completed in about one months time and will occur
between mid-April and mid-October with most dreding generally occurring
between May and September. Dredged material from the lower estuary is
primarily clean fine sands of marine origin. Above RM 14, sediments are finer
and contain more organic material. Sediments at disposal sites E, F, and H
are also clean fine sands with grain size becoming progressivley smaller from
the nearshore sites (E and F) to site H. Amphipod populations at the disposal
sites are relatively low.
The disposal sites are located in areas which receive heavy sport and
charter salmon fishing pressure. Commercial fishing operations for crab,
salmon, squid, and bottom fish also occur in these areas.
-------
Project Impacts
Gray whales occur In the project areas during distinct seasonal periods;
fall and spring migration and summer. Disposal operations will have no effect
on migrating gray whales as their is a distinct temporal difference in use of
the sites (i.e. dredging occurs between the migratory periods). Migrant
whales also would use the disposal areas only as a travel route.
Based on the limited information available on summer gray whales on the
Oregon Coast, disposal operations should have no effect on this particular
component of the population, either. Disposal locations are located offshore
beyond the nearshore areas most commonly frequented by gray whales. Substrate
composition of disposal locations is different than that in which gray whales
are speculated to forage in along the Oregon Coast. Prey populations of
the disposal locations are relatively low which suggests that they are
unsuitable or at best marginally suitable for gray whale foraging. The
disposal sites are relatively small which coupled with their low prey
populations and distance offshore from apparent preferred foraging sites would
result in minimal if any Impact on forage availability for gray whales. The
recreational and commercial fishing uses, in addition to commercial cargo
traffic would preclude or reduce the probability of whale use of these sites,.
also.
Conclusion
We conclude, based upon the above analysis, that designation and use of
the offshore disposal locations will have no effect to gray whales.
LITERATURE CITATION
Sumich, James L. 1984. Grey Whales Along the Oregon Coast in summer,
1977-1980. The Murrelet. 65:33-40.
-------
APPENDIX C
LETTERS OF CLEARANCE
-------
VICTOW ATIY8H
Department of Transportation
STATE HISTORIC PRESERVATION OFFICE
Parks and Recreation Division
525 TRADE STREET S.E.. SALEM, OREGON 97310
Novmeber 16, 1982
DAY.IS G MORIUCHI •
PORTLAND DIST CORPS OF ENGINEERS
PO BOX 2946
PORTLAND OR 97208 .'
Dear Mr. Moriuchi:
RE: Ocean Disposal
Coos Bay Area . • .
Coos County ..^ ' •
This letter is in response to your request for official comment
from the State Historic Preservation Office regarding impact of. your
federally funded project on cultural resources.
After a careful review of your proposed project, our office can
offer the following comments. We feel the area of the project is
not of historic significance and since ground disturbance of
previously undisturbed ground is minimal, this office feel-s that'
there will be no likely impact to archeological resources. We
therefore feel no cultural resource surveys are required and that
the project is in compliance with Public Law 89-665 and Executive
Order 11593. .^
•qjects, cc
For further information regarding pr
Gil sen, state preservation archeologist,
tact Lei and
Deputy
DWP/LG:kc
-------
APPENDIX D
SEDIMENT ELUTRIATE ANALYSES
FROM
HANCOCK et.al. 1981
-------
Table 3-5
Sediment Elutriate Analyses (May 1979)
Station
El
Els
E2
E2s
E3
E3s
E4
' E4s
E6
E6s
E7
E7s
LLD
Note:
Depth
(cm)
00-20
20-60
00-20
20-51
00-20
. 20-60
00-20
20-60
00-20
20-42
00-20
20-60
00-20
20-50
00-20
20-60
00-20
20-80
00-20
20-60
00-20
20-60
00-20
20-60
Salinity
PH
7.7
7.6
7.6
7.55
7.6
7.6
7.5
7.6
7.65
7:6
7.5
7.6
7.5
7.5
7.4
7.4
7.2
7.1
7.7
7.5
7.5
7.5
7.4
7.1
= 26-28
S=
(vig/ml )
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
0.1
mg/ml for
\
t
I1
NHj-N
(yg/ml )
ND
ND
BD
BD
BD
0.14
ND
ND
0.38
0.36
0.25
BD
0.1
BD
BD
BD
3.7
5.0
3.9
2.0
3.9
6.5
7.1
9.4
0.1
all sampl
TOC
(ug/ml )
4.7
4.4
4.2
5.1
3.1
4.2
4.0
4.4
5.9
6.4
5.9
7.1
4.0
7.1
4.6
5.2
12
6.9
9.7
12
10.8
49
8.7
11.7
es.
Chloro-
Pes tic ides
(ng/ml)
ND
ND
ND
ND
BD
ND
ND
ND
BD
ND
ND
ND
BD
ND
BD
BD
BD
0.007 DDE
ND
BD
BD
BD
BD
ND
0.001
PCB
(ng/ml)
ND
ND
ND
ND
BD
ND
ND
ND
BD
ND
ND
ND
BD
ND
BD
BD
BD
ND
ND
BD
BD
BD
BD
ND
0.003
••/•"-: s'i:-:-:VW^??^
-------
Table 3-5 (continued)
Sediment Elutriate Analyses (May 1979)
Station
El
Els
E2
E2s
E3
E3s
E4
E4s
E6
E6s
E7
E7s
LLD
ueuui
(cm)
00-20
20-60
00-20
20-51
00-20
20-60
00-20
20-50
00-20
20-42
00-20
20-60
00-20
20-50
00-20
20-60
00-20
20-80
00-20
20-60
00-20
20-60
00-20
20-60
Cd
68
2.4
80
15
16
NO
4
17
17
0.2
5.2
15
0.6
3.7
BD
0.6
BD
BD
14.6
2.0
4.6
7.8
BD
BD
0.3
Cu
8.5
20.2
14
17
9.5
ND
10
4
5
13
20
10
12.3
20.5
21.6
24
9.5
6
15.3
13.6
13.5
16
7
4
Fe
105
55'
10
60
35
9
BD
BD
BD
BD
60
10
2
70
7
15
2040
4840
BD
60
20
40
3550
3880
0.5
Mn
90
20
55
30
56
28
8
10
40
26
11
63
22
70
43
70
1200
665
335
20
230
85
1450
2720
Pb
BD
BD
BD
5.5
BD
ND
BD
2
5.6
2
BD
BD
2
9
BD
6
2
BD
BD
BD
BD
BD
BD
BD
0.2
Zn
65
59
81
53
97
14
75
71
57
55
52
65
85
75
48
48
ND
ND
114
114
118
75
3
6
-------
Table 3-6
Sediment Elutriate Analysis (October 1979)
Station
E4
E5
.E6
E7
E8
E9
Depth
(cm)
00-20
20-41
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-48
Seawater
Blanks
pH
7.7
7.5
7.3
7.1
7.2
6.8
7.3
7.3
•7.4
7.4
7.3
7.2
7.5
7.5
7.8
Sal.
(mg/ml )
24
25
24
24
.24
24
27
27
23 •
24
29
24
27
26
25
S"
(yg/ml )
BD
BO
BO
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
TOC
(yg/ml )
11
2
8
10
12
15
15
22
15
8
4
12
4
2
5
NHj-N
(yg/ml )
BD
BD
5.0
9.1
6.8
18.0
7.0
16.0
4.6
7.8
5.3
19
BD
BD
BD
Chloro-
Insect.
(ng/ml)
BD
ND
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
PCB
(ng/ml )
BD
ND
BD
BD
BD
BD
BD
.BD
BD
BD
BD
BD
BD
BD
BD
LLD
0.1
0.1
0.001
0.003
-------
Table 3-6 (continued)
Sediment Elutriate Analyses (October 1979)
Station
E4 .
E5
E6
E7
E8
E9
Seawater
Blank
LLD
uepuri
(cm)
00-20
20-41
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-48
As
ND
BD
ND
ND
ND
BD
ND
ND
ND
ND
ND
BD
BD
20
Cd
3
2
66
57
8.5
17
BD
0.3
Cu
2.5
2
1
1
0.5
0.5
BD
0.3
Fe
10
20
1100
700
1900
6500
1300
680
690
740
500
950
110
Mn
40
20
1600
1300
960
3300
1300
790
160
250
980
420
20
Pb
3
2
3
2
3
2
BD
0.2
Zn
2
2
23
29
18
24
BD
0.1
Hg
BD
1
BD
BD
2
3
BD
BD
BD
BD
BD
BD
BD
0.5
-------
Table 3-7
Sediment Elutriate Analyses (March 1980)
Station
E4
E5
E6
E7
E8
E9
Seawater
Blank #1
Seawater
Blank #2
LLD
Depth
(cm)
00-20
20-50
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
PH
ND
7.5
7.5
ND
7.5
7.2
7.0
7.2
7.3
7.4
7.4
7.7
7.7
7.7
DO
(yg/ml )
6.3 .
7.0
2.7
4.4
2.7
4.7
2.8
2.5
3.4
3.0
5.6
5.4
7.9
7.7
Sal.
(mg/ml )
27
28
ND
29
26
26
ND
28
28
28
28
ND
26
'31
Turb.
(NTV)
53
86
83
101
81
165
120
66
107
.115
56
75
1.8
0.8
S"
(yg/ml )
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
0.1
TOC
(yg/ml )
5
5
9
5
9
11
19
5
5
4
5
5
1
4
NH4-N
(yg/ml)
0.1
0.4
11
7
11
11
20
11
4
4
6
4
0.1
0.3
AS
(ng/ml)
ND
BD
ND
ND
ND
BD
ND
ND
ND
ND
ND
BD
ND
BD
20
Hg
(ng/ml)
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
0.5
1.1
-------
Table 3-7 (continued)
Sediment Elutriate Analyses (March 1980)
Station
E4
E5
E6
E7
E8
E9
Seawater
Blank #1
Seawater
Blank #2
Distilled
Water
Blank #1
Distilled
Water
Blank #2
LLD
UCjJlll
(cm)
00-20
20-41
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
00-20
20-60
Aldrin
0.006
0.004
0.003
0.002
0.007
0.06
0.003
0.016
0.02
0.002
0.02
0.01
0.01
BD
ND
ND
0.001
DDE
0.002
0.005
BD
0.005
BD
0.002
BD
0.0006
0.006
ND
BD
0.004
BD
0.003
BD
BD
0.001
Dieldrin
BD
BD
BD
BD
BD
BD
BD
0.004
0.002
BD
BD
BD
ND
0.003
0.004
0.003
0.001
DDD
0.03
0.03
0.01
0.02
0.02
0.02
0.015
0.003
0.003
0.01
0.02
0.03
0.02
0.03
0.006
0.006
0.002
DDT
0.009
0.02
0.004
0.02
BD
0.01
0.009
0.005
0.001
0.01
0.007
0.01
0.01
0.02
0.01
0.008
0.003
PCB
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
BD
0.00
-------
APPENDIX E
COMMENTS AND RESPONSES
-------
UNITED STATES DEPARTMENT Or COMMERCE
National Oceania and Acmoaphana Administration
kV».nnB::n. nc 5CJ33
November 2. 1984
Mr. Paul Pan
Chief. Environmental Analysis Branch
Office of Marine and Estuarlne Protection
Environmental Protection Agency (WH-546)
401 N St.. S.W.
Washington. DC 20460
Dear Mr. Pan:
This Is In reference to your draft environmental Impact statement
for Coos Bay, Oregon dredged material disposal site designation draft
environmental Impact statement. Enclosed are comments from the National
Oceanic and Atmospheric Administration.
We hope our comments will assist you. Thank you for giving us
an opportunity to review the document. We would appreciate receiving
four copies of the final environmental Impact statement.
Sincerely,
Joyce N. Wood
Chief. Ecology and
Conservation Division
Enclosure
-------
UNITID ITATU Of PARTMEMT O» COMMMCf
Natlmel Oeeaftle enel At
NATIONAL MAW* I
IWiMMXfllMl t TICHWCM. UlXnCil OWIIM
M»n ita AVIMII. *um 110
•outturn Q«IOO« tmi-un
(JOliUO-HOO
October 29, 1984
TO I
F/PP2 - Joyce Hood
- Dale R. Bvani
F/KWRS
SUBJECTi Draft environmental Impact Statement - Coo* Bay Dredged Material.
Ocean Dlapoaal Sit* Designation, Oregon (DEIS 6408.12, May, 1984}
Th« ;repoi«d action described to the lubject Draft Environmental lopect
Stateoent (DEIS) le final deeignctloo of tvo ioteria ocean dredged material
dlapoaal eitee end the 4ael«n»tlon of e new eite off Cooe Bay, Oragon. The
tvo finally designated eltee (Bltet B end F) would be ueed for the diipoiel of
lezge-grelned dredge material, whereae the new elte located further offchore
(adjujted tlte B) Mould be ueed for the diepoeal of fine-grained eedixent«.
The purpoee of the propoted action le to provide environmentally acceptable
ereee for the diipoial of dredge material.
General Comenta
The National Marine rleherlea Service reviewed the iub]ect DEIS and
related euppleoentel information on which the SBIS wee baaed. Our
luppleaentel information review Included the Phaee I, U and III Interim
leporte end the Phaee IV-V Final Report. Bated on available information, we
believe the Dlis lacke eufflcient environmental information on which to baee
an accurate evaluation of the potential adveree impact* of ocean dredge
material dlepoeel on the living marine reeourcoa of the newly deelgnated elte
(adjueted eite B). The DIIS doea not olerify how beeellne deta and teat
A meeting was held between the Portland District, Region X EPA, National
Marine Fisheries Service and Oregon Department of Fish and Wildlife on
9 January 198S In response to this comment. The agencies were presented
with the available Information about site H and adjusted H and asked which
site they would prefer to see used. Based on the availability of baseline
data and the Information on the potential Impacts to the scallop fishery
presented in Section 2.8 of the EIS the resource agencies agreed that
site H should be the preferred disposal site. The Final EIS has been
changed to identify site H as the disposal site for type 2 and 3 materials.
-------
disposal Miulta p*rt*inin9 to initial ait* H are applicable so adju*ted
•it* H. in the abaence of aita ip*citic data, we ctnnot b« aaaured that
reiource valu** at th* new tit* ai* not comparable with tho«e at initial
•it* U. H« r*cooMnd that •uppl*B*nt*l ba**lin* data b« collected at adjusted
•it* H. rollonina. th* collection ot th*** data, a t*it di»po«al uting th*
*)ip«ct*d quantity and quality ot dx*dg* •poil oatazial »hould be conduct*d.
Th«i* n*v baaalin* and t*»t diapoial data (bould be analyzed and autnitt*d fox
t*vi*» ai a »uppl«s»nt to the DEIS.
8p«cttic Comenta
2.6.7 Efftett of Pr*vlou» DiaposaK
»«q« H-10, paragraph a. Thia a*etioa include* a brief di*cu»ion of an
kuguit, 1981 tait difpetal »t initial *it« H. Th* DEIS *tat*a that th*
bcntnie eemunity va* lignificantly d*pr«*a*d in tb* ana mmedittely *ft*r
dlapoial. A ataady recovery to pn-diipeaal abundance and dlvaxtity level*
w*( obMzv*d b***d on po*t-diapo«*l laapling twelve and *i«ht**n month*
Th* teat'1* *tudy dwl^n propoacd th* diapoial of 200,000 cubic yard* of r , .
organic utarial* (!*•* than 0.02mm qrain *iz*l in th* canter of initial ait*
H (Bit* 8-1). Kov*v«x, only 60,000 cubic yaxdf of aatarial were aub**qu*ntly
ui*d in th* t*»t. Further, ipoil oat*riala actually mined th* study d**ign
di*po*«l point and «*z* plac*d northeait of *it* H-4. Subt*qu*nt
pott-diapoial aadioent iampl*i taken ahoitly thereafter revelled th* pr*i*nc*
of apoll material* at only two of th* fiv* H-rel«ted lit**. Neither th* DEI1
nor tb* itudy report* quantify the distance between *ite* (e.g. H-3 to H-4)
The actual dumping occurred slightly northeast of the proposed test disposal
point, but was within 500 yards. Dredged material was observed in 3
of the 5 stations sampled following the test dump, providing sufficient
information to characterize the impacts of the disposed material at site H.
Since site H Is now being proposed for disposal it is no longer necessary
to apply the results at adjusted site H.
I
it
-------
i
nor hen f«r off target teat dumping actually occurred. The authors of the
final study report concluded chat the teat diapcaal did not sinuate what
would occur In a reel dredge spoils disposal (ituation at that tit*. It is
queetionsbis whether th* results of a misplaced test spoil disposal.can b*
applnd to another site, on* oils shoreward< at which iloited, if any,
baseline information ia available.
2.8 Preferred Bispogai Sitea and Disposal Options
Pag* 11-19. Figure 2.1. In several instances th* DIIS contains th* atatement
"...although thla section does not specifically refer to adjusted site H, the
data gathered by OSU and presented in thla section covers an extensive
offshore area which include* adjusted site H.- (Pages II-S, III-l, tv-1).
According to th* figure, th* adjusted site nay touch th* aouthernnoat boundary
of initial sit* H (at approximately H-5). However, it appears that sits
specific baseline data have not been collected froa the proposed disposal
tit*.
Additional discussion of adjusted site H is no longer felt necessary
since site H Is now being proposed for disposal of fine materials.
-------
UNITIO 8TATI8 DiPARTMINT OF COMMBRCf
National Oonnia »nd Atmoiph«ric Admlniitrition
NATIONAL CliSAN SEDViCE
tfaihir.gioiv B.C. SOJJO
N/M821x6:VLS '
TO: PP2 - Joyce M. Wood..
FROM: N - Paul M. Wol«*^
SUBJECT: DEIS 8408.1?'-/ooCBay Dredged Material Ocean Disposal Site
Designation; Oregon {Environmental Protection Agency)
The subject statement has been reviewed within the areas of the National
Ocean Service's (NOS) responsibility and expertise, and in terms of the Impact .
of the proposed action on NOS activities and projects.
Geodetic control survey monuments may be located In the proposed project
area. If there Is any planned activity which will disturb or destroy tnese
monuments, NOS requires not less than 90 days' notification in advance of such
activity In order to plan for their relocation. NOS recommends that funding
for this project Include the cost of any relocation required for NOS monumants.
For further Information about these monuments, please contact Mr. John Spencer.
Chief. National Geodetic Information Branch (N/CG17), or Mr. Charles Novak,
Chief, Network Maintenance Section (N/CG162), at 6001 Executive Boulevard,
Rockvllle. Maryland 20852.
.The NOS Office of Ocean and Marine Assessment had a minor comment regarding
i_ the deepwater site being eliminated based upon consideration of Tyce 1 sediment
"only (page II-3). The use of this site for Type 2 and Type 3 sediments snould
be considered also, they state.
The Oregon Department of Land Conservation and Development 1s In agreetr.;
with the Federal consistency statements in this document according to the NO:
Office of Ocean and Coastal Resource Management.
Geodetic control survey monuments are not located offshore and therefore
will not be impacted by the proposed ocean disposal site designation.
A discussion of the consideration of Type 2 and 3 materials has been added
in the FEIS.
-------
Department of Land Conservation and Development
1175 COURT STREET N.E.. SALEM. OREGON 873104590 PHONE (503) 378-4926
HEM 0 RAH D U H
November 2, 1984
Land Conservation and Development Commission
James F. Ross,
TO:
FROM:
SUBJECT: FEDERAL CONSISTENCY REVfEW OF THE DRAFT ENVIRONMENTAL IMPACT
STATEMENT, COOS BAY, OREGON DREDGED MATERIAL DISPOSAL SITE
DESIGNATION
DATE RECEIVED: September 10. 1984
REVIEWER: Patricia Snow
I. REQUEST
The Environmental Protection Agency has requested that the
Commission concur that the Draft Environmental Impact Statement for
the Coos Bay Dredged Material Disposal Site Designation 1s
consistent to the maximum extent practicable with Oregon's Coastal
Management Program (OCHP).
II. SUMMARY OF RECOMMENDATIONS
Staff recommends that the Commission concur with the Department
analysis that the DEIS Is consistent with the OCMP.
III. BACKGROUND INFORMATION
The Delegation of Authority Rule. OAR 660-02-010(9). provides that
responses to consistency determinations for federal activities
requiring the preparation of an Environmental Impact Statement be
referred to the LCDC for possible review. This referral must be
made at least seven days before the Director's action Is to take
effect. Should two or more members of the LCDC request review, the
Implementation of the Director's action will be suspended pending
this review. The Department normally makes Its consistency
determination at the time of the FEIS. However. EPA has requested
that the Department concur at the DEIS phase for this project. Due
-2-
to the extensive research that provided background for the DMD site
designations, the Department has agreed to this request. A
supplemental consistency determination will be needed If the FEIS
Is different than the DEIS.
The federal activity under review Is the final designation of two
Interim designated ocean dredged material disposal sites (ODMDS)
and the designation of a new ODMDS off Coos Bay, Oregon. The two
finally designated existing ODMDSs would be used for the disposal
of large grained sediments while the new site further offshore
would be for the disposal of finer sediments with higher volatile
solids content.
IV. FINDINGS
The major component of the Oregon Coastal Management Program (OCMP)
which Is applicable to the project Is Goal 19; the Ocean Resources
Goal. Goal 19 requires that renewable ocean resources and uses be
given clear priority over nonrenewable resources. Inventories
developed for specific projects must be sufficient to describe the
long-term Impacts of the proposed action on resources and uses of
the continental shelf and nearshore area. For dredged material
disposal sites, the agency with jurisdiction must determine the
Impact of the proposed project and provide for suitable sites and
practices for the open sea discharge of dredged materials which do
not substantially interfere with the use of the continental shelf
for fishing, navigation, recreation, or from long-term protection
of renewable resources.
The primary data bases for the EIS were disposal site evaluation
and monitoring studies conducted by OSU under contract to the Corps
of Engineers. The study consisted of five phases. The first was a
12-month baseline study of the physical, chemical and biological
conditions of the nearshore area off Coos Bay. This information
was used to select candidate sites for detailed evaluation during
Phases II and III. The criteria used In selecting candidate sites
were:
A. Physical and chemical similarity of dredged material and site
sediment type;
B. Avoidance of Impacts on unique or valued biological
communities; and
C. Minimization of onshore tranport of fine sediments.
Sediments from above RM 12 on the Coos River were determined to be
Incompatible with sediments of the Phase I ocean study site.
Detailed studies had to be conducted at sites located further
offshore. Phases II and III provided Information for areas further
offshore in an area of approximately 5,000 x 3,500 meters at depths
ranging from 40 to 120 meters. Phases IV and V Investigated the
-------
-3-
effects of a 1981 test disposal at site H (53-66 meter depths)
during and following disposal. The site MBS re-Investigated during
1982 and 1983 to document post disposal effects.
There are three basic types of sediment In Coos Bay. The types are:
1. Type 1 - Predominantly clean sand of.marine origin typical of
sediments from below Coos Bay river mile 12.
2. Type 2 - Finer grained sand and silt containing some volatile
solids typical of sediments from between Coos Bay RM's 12 and
14.
3. Type 3 - Highly organic fine material (6 to 20 percent volatile
solids) typical of sediments from above Coos Bay RH 14.
Several disposal alternatives were reviewed (see attached map).
Sites E and F were EPA Interim deslgated sites chosen for their
distance from Coos Bay. depth of water, biological conditions,
historical use and estimated amount and type of dredged material.
They are located approximately 1.5 miles offshore. Sites 6 and H
were considered since they were areas with similar bottom sediments
to the materials dredged from above RH 12 In Coos Bay. They are
located approximately 5 and 3.5 miles offshore, respectively.
Adjusted Site H was selected as an alternative to Site H to avoid
Impacts to shellfish beds. It Is located approximately 2.5 miles
• offshore. A deepwater site was selected to meet EPA site selection
criteria.
Four disposal options were considered for ocean dumping of dredged
material. These options were: (1) disposal of all types of
dredged material at Interim Sites E and F; (2) disposal of Type 1
material at Sites E and F and disposal of Type 1 and 2 material at
Site 6; (3) disposal of Type 1 material at Sites E and F and
disposal of Types 1 and 2 material at Site H; and (4) disposal of
Type 1 material at sites E and F and Type 2 and 3 material at
adjusted Site H.
The effects of previous disposal at sites E and F Indicates that no
significant biological Impacts have been associated with the
disposal (11-10). At site H. the tenth 1c conmunlty was
significantly depressed 1n the area of disposal Immediately after
disposal. A steady recovery to predlsposal abundance and density
levels was observed during the 19 months of the post-dump
monitoring (11-11).
Alternative 4 1s Identified as the preferred alternative. This
option was selected because the sediment types would be the most
compatible with the disposal sites. Type I material 1s very
similar to the natural sediments at sites E and F (p. 11-14).
Disposal of this material at any other site would result In
long-term bottom habitat changes. For these reasons disposal at
-4-
sites other than E and F was not considered In the public's best
Interest. The disposal of either Type 2 or 3 material at sites E
and F was considered questionable as the material 1s physically and
chemically dissimilar to the sediments at these sites. Disposal of
Type 2 and 3 sediments at Site 6 was not the chosen alternative due
to the slow erosion rate at G. It was felt that the disposal of
these sediments at Site 6 would result 1n long-term changes to the
substrate habitat of the benthlc community (11-15). Adjusted
site H was chosen as a result of resource agency concerns with the
scallop beds located between 40 and 52 fathoms. The adjusted
Site H Is located at the 25 fathom contour, which will establish a
buffer area of approximately one nautical mile between the disposal
site and the scallop bed. The Department will request that a
monitoring program be established for the first year of use of
adjusted Site H.
The DEIS addresses consistency of the proposed action with the OCHP
and the Coos County plan (111-22; IV-A; Appendix A). The DEIS
notes that Goal 19 requires that the location of the sites and
disposal practices must not substantially Impact fishing,
navigation, or recreation activities, or the natural resources of
the continental shelf. The DEIS states that the descriptions of
Impacts of dredged material disposal on the proposed sites Indicate
that no substantial Impacts on these uses or resources are
anticipated. No significant post disposal effects on the
biological community at Sites E and F were found (IV-9). .Disposal
of Type I sediments at Sites E and F would likely have a short-term
Impact on the benthlc communities. The DEIS states that due to the
similarity of sediment types In the disposal material to that
existing at Site H. It Is doubtful that there would be measureable
long-term effects (IV-12). Disposal of any materials from Coos Bay
at Site 6 would result In the greatest biological Impact of the
three areas studied (IV-12). Disposal of any of the Coos Bay
sediment at E and F would result In the least Impact on benthos of
the three sites. The main reasons for this are the unstable
environment, the lower abundance and diversity of species and the
adaptability of the existing benthlc species to an unstable
environment.
Objections: No formal objections to the DEIS have been received to
date.The ODFM and USFMS support the proposed DHD sites (personal
communication, November 2, 1984). The NHFS Is concerned that test
dumping did not occur on adjusted Site H. The Department concludes
that adequate baseline data exists on adjusted Site H to designate
1t 1s a DHD site provided a monitoring program Is established
during the first year of use. The monitoring program will need to
be developed 1n coordination with the state, USFUS. and NHFS. The
new site was selected 1n response to resource agency concerns to
avoid Impacts on shellfish beds located between 40 and 52 fathoms.
-------
-5-
Concluslon: The final designation of the two Interim and the
proposed dredged material offshore disposal sites Is an action
•directly affecting the Oregon Coastal Management Zone. The
Department concurs with the EPA determination that the DEIS and
final designation of the three sites Is consistent with the Oregon
Coastal Management Program, Including Goal 19. The DEIS
establishes that the disposal of approved sediments at sites E. F
and H will not have long-term Impacts on the resources or uses of
the area. The Department concurs that the alternative selected
will have the least Impact on the nearshore environment. Provided
the FEIS does not vary from the DEIS. It will be consistent with
the OCMP as well. If the designations 1n the FEIS are different
than those In the DEIS, a supplemental consistency determination
will be required.
JFR:PS:rog
1300D/9B
The Department of Land Conservation (LCDC) and Development has been Informed
Chat site H is now Che preferred disposal site for type 2 and 3 materials.
EPA has requesced a supplemental consistency decerminadon from LCDC.
-------
BEFORE THE
LAND CONSERVATION AND DEVELOPMENT COMMISSION
OF THE STATE OF OREGON
I
124°Z6' 124°25' i24324' 124°23' 124°22' 124°2i' 124a20' U4°1S>M
Alternative Disposal Sites Considered In Dec*11.
43°2S'
43°24-
43°23'
43°22'
43°21'N
84-FC-339
FINDINGS OF FACT. UlTIHATE
FINDINGS OF FACTS. CONCLUSION OF
LAW. ORDER AND NOTICE FOR
OPPORTNITY FOR ADMINISTRATIVE
AND JUDICIAL REVIEW.
AN ORDER BY THE DEPARTMENT )
THAT THE DRAFT ENVIRONMENTAL )
IMPACT STATEMENT FOR THE )
COOS BAY. OREGON, DREDGED )
MATERIAL DISPOSAL SITE )
DESIGNATION IS CONSISTENT WITH ).
THE OREGON COASTAL MANAGEMENT )
PROGRAM. )
1. Pursuant to the National Environment Policy Act of 1969. the Corps of
Engineers and the Environmental Protection Agency did prepare an
Environment Impact Statement describing the Impacts of dredged material
disposal sites offshore of the mouth of the Coos River. The DEIS was
received by the Department of Land Conservation and Development from the
EPA on September 10. 1984. Pursuant to Title 15. Code of Federal
Regulations. Section 930.41. the Department of Land Conservation and
Development Is responding to the consistency determination as a federal
action which directly affects Oregon's coastal zone.
2. Pursuant to Title 15, Code of Federal Regulations, Section 930.34.
the Environmental Protection Agency did give proper notice directly to
the Department of Land Conservation and Development In which the EPA did
provide a consistency determination pursuant to Section 930.39 of the
same title.
3. The Environmental Protection Agency did properly conclude that
Goal 19 (Ocean Resources) Is the applicable portion of the Oregon Coastal
Management Program and governs the federal action In question. The EPA
did demonstrate through findings compliance with the Statewide Planning
Goal.
-------
-2-
4. The Final Environmental Impact Statement for designation of Coos Bay
offshore disposal sites Mill be consistent If It does not vary from the
DEIS. If the document Is changed, a supplemental consistency
determination will be required.
5. A monitoring plan for adjusted Site H will need to be developed In
conjunction with state and federal agencies for the first year of use.
ULTIMATE FINDINGS OF FACT
The DEIS for the Coos Bay, Oregon, Dredged Material Disposal Site
Designation 1s to the maximum extent practicable consistent with the
Oregon Coastal Management Program. The FEIS will also be consistent If
1t does not vary from the DEIS.
CONCLUSIONS OF LAW
The Department of Land Conservation and Development concurs with the
consistency determination of the EPA that the DEIS for the Coos Bay.
Oregon, Dredged Material Disposal Site Designation Is to the maximum
extent practicable with the Oregon Coastal Management Program according
to the provisions of Title 15, Code of Federal Regulations,
Section 930.41 and Section 307 of the Federal Coastal Zone Management Act
of 1982 as amended. A supplemental consistency determination will be
required If the FEIS varies from the DEIS. A monitoring plan will need
to be developed for adjusted Site H.
The Department of Land Conservation (LCDC) and Development has been Informed
that sice H Is now the preferred disposal site for type 2 and 3 materials.
EPA has requested a supplemental consistency determination from LCDC.
Site H Is now being proposed for the disposal of type 2 and 3 material. A
monitoring plan has been developed by the EPA Region X and the Portland District
and Is discussed In Section 4.S of the FEIS.
Same as above.
-------
-3-
OROER
The three dredged material disposal sites designated In the DEIS may
be used for dredged material disposal projects which meet EPA's ocean
dumping regulations. 40 CFR Part 227. Use of adjusted Site H will also
require a monitoring plan for the first year of use.
s F. Ross. Director
rtraent of Land Conservation
and Development
ArfjJLw ^^ , /f
f* •••••• «—-•-•••—• i
NOTICE: Any person or agency adversely affected by or aggrieved by this
order Is entitled to Judicial review. Judicial review of this order may
be obtained by filing a petition for review within 60 days following the
service of this order. Judicial review Is pursuant to the provisions of
Oregon Revised Statutes. Chapter 183. Section 484.
PS:mg
1305D/9B
$3
Site H is now being proposed for Che disposal of type 2 and 3 material. A
monitoring plan has been developed by the EPA Region X and the Portland District
and is discussed in Section 4.5 of the FEIS.
-------
United States Department of I lie Interior
OFFICE OF THE SECRETARY
pAnnr NORTHWEST KKCION
500 N.E. Mulimrauh Slrctc. Sui;c 11>11. PorllaiJ, Oregon 97:j2
October 25, 1984
ER 84/1137
Mr. kill li am C. Shilling
Criteria and Standards Division (WH-5R5)
Office of Water Regulations and Standards
i|.S. Environmental Protection Agency
•mi :i Street. S.H.
Washington, O.C. 20460
Dear Mr. Shilling:
The Department of the Interior has reviewed the draft environmental
impact statement for designation of the Coos Bay Ocean Dredged Material
Disposal Site Offshore Oregon. We have no objection to the proposed
action. The following comments are for your consideration In preparing
the final statement.
General Comments
While we do not object to the proposed action, please note that specific
activities leading to the use of the proposed disposal site may require
Federal permits from the U. S. Coast Guard and/or the U. S. Army Corps
of Engineers. Such permits will be reviewed separately by the various
agencies of the Department of the Interior to assess the impacts on
resources under their jurisdiction. For example, the U. S. Fish and Mild-
life Service, pursuant to the Fish and Wildlife Coordination Act (1G U.S.C.
661, et seq.), may object to or propose stipulations for future permits
depending on how specific construction practices .of the disposal site
affect fish and wildlife resources In the area.
Specific Comments
agraph
s, wher
measured in days, whereas on page 11-16, paragraph 2, line 6, it states
that turbidity would dissipate within 4 hours. Which is correct?
Page 1V-7, paragraph 2, line 2 - This states that 87 percent of the material
to be dunped is organic material. Type 1 material, which comprises 87 per-
cent of the total 1.5 million cubic yards to be dumped, Is classified on
page 1 1-7 as being "clean sand of marine origin." This seems to be contra-
dictory and should be clarified.
We recognize Chat other Federal pennies may be required and that a Section 103
(Marine Protection, Research and Sanctuaries Act) evaluation will be required
for each specific disposal action. Department of Che Interior will be notified
of these actions and given the opportunity for comment as required by law.
Page 11-14 refers to the Impacts of disposing of type 2 and 3 materials
at sites E and F. where the fine material would be reworked by wave and
current action. Page 11-16 reCerers to the impacts ac site H where the
water Is deeper and the wave and current actions would not continue to
rework and resuspend the fine materials as they would at sites E and F.
This was a typographical error and has been corrected to read "inorganic
material."
-------
Page IV-16, paragraph 3 - This paragraph gives the general specifications
of the dredging operations, but does not state when the operations will
conrence, how many trips will be made per day on the average to the dis-
posal sites, how nany people will be employed in the operation, or how
the operations will increase the vessel traffic in the area.
Thank you for the opportunity to errant on this DEIS. If you have any
questions regarding these comments, please call me at (503) 231-6157.
Sincerely,
Charles S. Polityka
Regional Environmental Officer
cc:
Office of Environmental Project Review
Director, Minerals Management Service
Director, Fisb and Wildlife Service
Regional Director, National Park Service
Director, Geological Survey
Chief. Western Field Operations Center, Bureau of Mines
State Director, Bureau of Land Management
Regional Director, Fish and Wildlife Service
The specifications given are Identified as assumptions used to develop a
cose estimate for transportation of dredged material to each of the
alternative disposal sites. It Is not appropriate to consider the other
factors you have identified at this time as they will be evaluated, as
required, when each disposal action is considered.
-------
qcf 2
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
A CMS Bay Dredged Material Ocean Disposal Site Designation Draft
Environmental Impact Statement
^I'iton Lee, Acting Chief
Environmental Evaluation Branch
•° Chris Shilling, Chief
Ocean Dumping EIS Task Force
We have reviewed the referenced document and find that the recommendations
made In our April 6, 1984, memorandum (see attached) have not been
Incorporated. We trust they will be included In the final EIS.
In addition to our previous consents, we have the following
recotonendatlons:
• (1) Pg. I1-3, first paragraph, last sentnece: the dredged material
Is Type 2 material, not Type 3.
(2) Pg. 111-28 should be eliminated as It contains redundant
Information.
(3) Chapter III: Where feasible, all maps should include as many of
the disposal sites as possible. For example, figures 3.3 and 3.4
(pgs. II1-45 and 111-46), should Include adjusted site H.
(4) We appreciate the addition of explanatory sentences on pgs.
III-l and IV-1 concerning adjusted site H. While these statements
constitute a good first step In incorporating adjusted site H into
the EIS, we feel both chapters must be modified to more completely
characterize the site and the likely environmental Impacts associated
with future dumping operations.
If you have any questions, please contact Mr. Gary Voerman of my staff at
FTS 399-1448.
attachment
This has been corrected in the FEIS.
This has been corrected in Che FEIS.
Adding adjusted site H is no longer felt necessary since site H is now
being proposed for disposal of fine materials.
Additional discussion of adjusted site H is no longer felt necessary
since site B is now being proposed for disposal of fine materials.
C PA F«« 11104111... J-7M
-------
APR 6 1984
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
' Coos Bay Ocean Dredged Material
Disposal Site Draft EIS - Region 10 Appr
'"°7| Ernesta B. Barnes
'Regional Admlnlstator
Mr. UHttaa C. Shilling.
Ocean Dumping EIS Task Force
1
We have reviewed the Draft EIS for the Coos Bay Ocean Dredged Material
Disposal Site designation. Our primary concern with this document Is
the lack of discussion relating to adjusted site H In Chapters 3 and 4.
The Portland District Corps of Engineers has provided sone camera ready
corrected pages (attached) which Incorporate language acceptable to us
as an Interim solution to this problem. We have been assured by the
Portland District that more comprehensive changes will be made In the
EIS.
In addition, we are recommending several minor changes (see attachment)
for Inclusion In the final EIS. Due to the unnecessarily complex
process for effecting change In this document, we feel the effort and
delay required to make changes at this time would not be worth the gain
In docuircnt quality. In the future. EPA should take upon Itself the
responsibility for making changes to any EIS for which It has Issuing
authority.
We recommend releasing the Draft EIS. as corrected by the Corps, to the
public for review. The document provides an accurate assessment of the
environmental Impacts associated with ocean dumping at Coos Bay and
demonstrates compliance with the general and specific ocean dumping
criteria. The conclusions and reconmendatlons are supported by a thorough
research effort. The technical support documents are available for public
review at the Corps' Portland District offices. We request at least one
dozen copies of this document for our public review file.
It Is our understanding that the Ocean Dumping Branch (EPA headquarters)
will prepare a site management plan before final site designation. We
request Involvement of the following agencies in the development of that
plan: Region 10 EPA; Portland District Corps of Engineers; USFWS-Portland
office; National Marine Fisheries Service, Portland office; and the
Oregon Department of Fish and Wildlife.
If you have any questions, please contact Mr. Gary Voenoan of ay staff at
FTS-399-1448.
cc: CCt - Portland
attacnnents
If* tmm I1M4 (•••• !•'•>
An agreement has been reached between EPA Region X and the Portland District
Corps of Engineers concerning a general monitoring plan. This plan is discussed
in Section 4.5 of the FEIS. Other management considerations will be addressed
as specific disposal actions are considered.
-------
Attachment
We recommend the following changes be made in the Draft EIS for the Coos Bay
OOKDS:
I. Page xlil. Preface: Change the last sentence of the first paragraph
to read something like: "In addition, monitoring of these sites will be
required to assess the envir6nmental impacts associated with dredged material
disposal. A monitoring plan will be developed by EPA, In consultation with
state and federal resource agencies, before final site designation.'
Z. Page 11-10. Effects of Previous Disposals: The total amount of
dredged material deposited at sites t and F should be reported In the EIS.
The CIS states that the disposal operations have produced 'noticeable sea-
ward bulges in the bathymetrie contours....in the vicinities of these
sites." Apparently on-stte bathymetric changes have not been significant;
however, the reason for designating an ocean dumping site Is to provide an
area within which the physical Impacts of dredged material disposal are
expected and acceptable. If previous disposal operations have resulted in
material transport and mounding (and the attendant .adverse environmental
Impacts) off site, perhaps sites E and F should be moved or dumping operations
more closely monitored to assure maximum sediment deposition within the
confines of the designated dumpsite. Some discussion of this Issue should
te Included In the final EIS.
3. Page 11-10 to 11-11: There are apparently contradictory statements
made about impacts on the benthlc community. These statements are: "The
benthic community was significantly depressed In the area of disposal
impacts, immediately after disposal* and 'No dump effects were observed for
the infauna". These statements should be reconciled in the final EIS.
4. Page 11-13, Impact Comparison of Disposal Options: Under-disposal
options 2 and 3, the types of material to be disposed of at sites 6 and H
should be changed from types 1 and 2 to types 2 and 3.
S. Page 11-14 and 11-17. last paragraphs: It Is not clear from this
document how probable it is that the addition of volatile solids to the
sediments of sites E, F and adjusted site H would enhance the benthlc
community. Has this occurred in the past? Is there any evidence that the
benthic comunitles in sites E and F are substantially different than adjacent
off-site communities? A'more thorough discussion of this issue should be
provided in the final EIS.
The paragraph has been changed to stace that monitoring will be performed
and refer to the discussion of monitoring In Section 4.5.
(Note: this paragraph Is'found on p. xxll la the Draft EIS.)
While there appear to be noticable seaward bulges in the bathymetric
contours In the vicinity of sites E and F, they have not been definitely
attributed to disposal activity. There is some mounding at the sites
following the dredging season, but this Is normally erased by winter
storm activity and no long-term bathymetric changes occur. The material
deposited at sites E and F then moves along the coast with the littoral
drift system. Because the dredged material dumped at these sites consists
of clean sand which is very similar to the native sediments, It will
not produce any adverse environmental effects and could be beneficial
for beach replenishment^ Therefore, we see no problem with the sand
being slowly transported out of the disposal sites.
This has been corrected In the FEIS.
This has been corrected In the FEIS.
This statement was based on the generalization that areas with finer
bottom materials and higher levels of organic material appear to be more
productive than areas with a coarse bottom. It has been deleted from
the FEIS.
There was no evidence in the Phase I studies that the benthlc comunitles
were statistically different between sites E and F and adjacent areas.
-------
6. Chapters III and IV, General: The OSU studies which provided the
primary Information base-for this document were oriented toward sites
E, F. G, and H. Adjusted site H was not considered until after completion
of the technical reports. .The Corps claims that the sampling schemes are
general enough to allow a reasonable extrapolation of data to adjusted site
H. This Is possible but we should be prepared to defend this approach or
conduct a separate sampling program for adjusted site H. Much will depend
on the comments received by the public and resource agencies.
In any case, chapters III and IV must be updated In the final EIS to Include
a site description of and probable environmental Impacts of dredged material
disposal at adjusted site H. *
In addition, all of the maps In Chapter III should have all proposed disposal
sites located on then If possible. This will allow reviewers to more
readily understand the basis of comparison among the disposal options.
7. Page 111-16. Last Paragraph:
defined.
The tern "species richness" should be
8- Page 111-24: The cited Corps study predicted that upland, disposal
sites would be filled to design capacity within S to 10 years. Since the
study was conducted 8 years ago, It would seen appropriate to discuss Its
predictive powers. The final EIS should briefly discuss the capacity of
remaining upland disposal sites.
9. Page 1V-7. First Paragrapht Second Sentence: Add the tern "EPA"
just before "water quality criteria'
Page IV-19. First Paragraph: Eliminate, the last sentence. Change
in to read:A site monitoring program will be established
10.
the second paragrapl
as part of the site management plan. The details of this program have not
yet been developed, but will be put forward before final site designation.
EPA Is currently considering a monitoring scheme which provides for periodic
sediment quality testing (physical and chemical) and site surveys to detect
off-site sediment movement (using bathymetry and sediment traps). Recom-
mendations for monitoring will be solicited from all Interested parties."
11. Page IV-20. First Paragraph: Eliminate parenthetical phrase
"(may or may not be adverser. Last paragraph: Change first sentence to
read "Disposal of dredged material in proposed ocean dumping sites would
have presently unquantifiable but apparently minor short and long term
effects on the productivity of the marine environment."
Additional discussion of adjusted site H Is no longer felt necessary
since site H la now being proposed for disposal of fine material.
Species richness is a component of species diversity and is expressed as a
ratio between total species and total numbers of individuals present.
(Odum, Eugene P. 1971. Fundamentals of Ecology. U.B. Saunders Company,
Philadelphia, London, Toronto; 574 pp.J
The discussion of upland disposal site capacity has been updated.
This change has been made in the FEIS.
EPA Region X and the Portland District have developed a monitoring plan. This
plan is discussed in Section 4.3 of the FEIS.
These changes have been made in the FEIS.
-------
li
nr.PAIlTMCNT OF HEALTH A IIU.MAN SCRVICCS
Centers for DIMVTW Cnntiol
AllanuGA 30333
October 9, 1984
Mr. William C. Shilling
Criteria and Standards Division (WH-585)
Office of Water Regulations and Standards
Environmental Protection Agency
401 H Street, S.W.
Washington, D.C. 20460
Dear Mr. Shilling:
We have completed our review of the Draft Environmental Impact Statement (EIS)
for Coos Bay, Oregon, Dredged Material Disposal Site Designation. We are
responding on behalf of the U.S. Public Health Service.
The only known commercial or recreational use of the three preferred sites
(sites E, F, and adjusted site H) Is marine navigation. Disposal activities
should have little effect on this use. Sites E and F are "the least sensitive
biological areas of the sites studied," and there is no record of significant
impacts associated with historical disposal of type 1 material (material that
is very similar to the native sediments in the area) at these sites. Two
type 1 sites are apparently needed to reduce mounding and to maintain
flexibility of disposal when currents change.
Our major concern involves the third site, adjusted site H, which will be used
for disposal of type 2 and 3 material containing fine sediments in suspension
and chemical contaminants found in upper bay sediments. Reported elutriate
analyses indicate that only ammonium-nitrogen, manganese, and cadmium may be
released to fresh seawater in sufficient concentration to "possibly exceed
water quality criteria." Considering the dilution factor, it is stated that
these concentrations would be well below the levels of concern prior to
exceeding the boundaries of the established 4-hour mixing zone. Although
impacts are expected to be temporary and minor, it is possible that future
contamination could exceed recommended levels and become an important
consideration. Therefore, we recommend that periodic monitoring be conducted
at this site to determine if EPA sediment and water quality standards are
met. A contingency mitigation plan should be developed for use In the event
contamination reaches levels of concern after final designation of these
disposal sites. This need Is substantiated by Kelson et_ al^ (1983), whose
preliminary estimates (page IV-6) suggest that between 50 and 75 percent of
the finer size sediment would remain In suspension when dumped and would be
transported from the disposal site by currents. This material would likely
contain much of the potential contaminants, therefore, we believe monitoring
efforts should be planned.
Site H is now being proposed for the disposal of type 2 and 3 materials. The
contaminants are associated with the fine size sediments. The monitoring plan
discussed In Section 4.5 of the FEIS would detect the movement of these fine
materials outside of site H. If such movement is discovered, plans for addi-
tional testing and/or corrective measures will be developed. In addition, the
periodic analysis of the dredged material sediments discussed on page xxll of
the FEIS will identify any future changes in contaminant levels.
-------
Page 2 - Mr. William C. Shilling
Thank you for the opportunity to review this Draft EIS. Please send us a copy
of the Final EIS when It becomes available. If you have any questions
concerning our comments, please contact Mr. Ken Holt at FTS 236-4161.
Stephen Mareolls, Ph.rf?
'.".'».•", *.—'!?:-—*".*! i.'ftCrr 7rrrr
Environmental Healch Services Division
Center for Environmental Health
js
US Deportment
f
Anited States
£oost Guard
. DC 2US«
Symoor. (G-WP-3)
ei (202) 426-3300
16477.4b(0029)
10 Oct 84
Mr. William C. Shilling
Environmental Protection Agency
Office of Water Regulations and Standards
Criteria and Standards Division
401 M Street
Washington, D. C. 20460
Dear Hr. Shilling:
We have reviewed the Draft Environmental Impact Statement concerning
the Coos Bay, Oregon, Dredged Materials Disposal Site Designation.
We have no comments at this time.
We appreciate the opportunity to assist your efforts in the
development of this documentation. We look forward to continued
mutual cooperation and coordination of these projects.
Sincerely,
W. H. McGOVERN
Chief, Environmental Compliance and Review Branch
Planning and Evaluation Staff
By direction of the Commandant
-------
County &i Coo»
COUIITHOUSK
97423
coos nnVr
Coquillf,
Phono: (50:
Ext.
September 19, 1984
William C. Shilling
Criteria and Standards Division (Wll-585)
Office of Water Regulations and Standards
Environmental Protection Agency
401 H Street. SW
Washingt9n. D.C. 20460
BOARD UK COMMISSIONERS
Hubert A. F.mmolt
Doc Str.-vrnson
Jack I,. Heche. Sr.
Department of Land Conservation and Development
1175 COURT STREET N.E.. SALEM. OREGON 97310-0590 f-HONE (503) 378-4926
RE i
Garments on "Coo* Bay Dredged Material Ocean Disposal Sit*
Designation Draft Environmental Impact Statement"
Dear Mr. Shillingi
Coos County supports the proposed action to designate ocean disposal sites for
dredged material. Federal maintenance dredging of the navigation channel is
absolutely vita), to the economic well-being of the Coos Bay region. As the
EIS correctly points out. roughly half of the region's 20.000 jobs are
directly or indirectly dependent on shipping activities. Our economy
continues to suffer through a prolonged economic recession, and would be
devastated if maintenance dredging could not continue because of a lack of
suitable disposal sites.
The Coos Bay Estuary Management Plan (CBEMP), which is the basis for all land
and water use decisions, including upland and in-bay dredged material
disposal, in the Coos Bay estuary region, has been "acknowledged" by the
Oregon Land Conservation and Development Commission to be in compliance with
its statewide goals and therefore with Oregon's approved Coastal Zone
Management Program. As such, the CBEMP is the standard against which all
affected projects must be measured for consistency. The project is consistent
with the CBEMP because it provides for ocean disposal of dredged materials to
supplement and replace the rapidly dwindling supply of upland disposal sites.
Sincerely,
COOS COUNTY BOARD OF COMMISSIONERS
October 23. 1984
Million C. Shilling
Criteria and Standards Division (HH-585)
Office of Water Regulations and Standards
Environmental Protection Agency
Washington, O.C. 10460
Dear Mr. Shilling:
I an requesting, pursuant to 15 CFR 930.71(b), a 15-day extension of
review tine for the Coos Bay, Oregon Dredged Material Disposal Site
Designation determination of consistency with the Oregon Coastal
Management Program. The new deadline would be November 9, 1984.
Sincerely,
JFR:PS:sp
14110/88
Absent
Commissioner
toronissioWer
------- |