-------
II and lIt 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 are scheduled to be
completed by June 1984. 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 National
Environmental Policy Act of 1969 (NEPA), 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 criteria used to assess the acceptability of proposed DMODS near Coos ay
were those established under Section 102 (a) of MPRSA. The 11 speciEic criteria
established by EPA under 40 CFR 228 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
designation, 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
disposal 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
xxiv
-------
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 (RN) 12.
2) Type 2 - Finer-grained sand and silt containing some volatile solids
typical of sediments from between Coos Bay RN’s 12 and 14.
3) Type 3 - Highly organic fine material (6 to 20 percent volatile
solids) typical of sediments from above Coos Bay RN 14.
These three types of sediments are representative of the types of sediments
found throughout the estuary.
xxv
-------
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. Consequeit-
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.
I— I
-------
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 three to five 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 will be filled to
capacity within 5—10 years (Channel Maintenance Dredging, Coos Bay, FEIS,
1976; Coos Bay Estuary Management Plan, Coos County, 1983; Personal
Communication, L.N. Smith, COE Navigation Division, 1982).
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—2
-------
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 c npar—
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 desig-
nate sites for ocean disposal of dredged material at Coos Bay, Oregon, it
should be understood that site designation in itself does not result in dis-
posal 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 airernative 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
II—’
-------
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 F l
located near the 35 fathom (55 in.) contour; (c) Adjusted Site H located near
the 25 fathom contour; (d) Site G located at approximately 50 fathoms (91 in.);
(e) a continental slope alternative at about 200 fathoms (364 in.); (f) combi-
nations of the above; and (g) no action.
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, and estimated amount and type of dredged material. Sites C 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 altarnative to Site H to avoid impacts to shellfish beds. 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.
11—2
-------
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 RN 12 of Coos Bay (refer-
red to herein as Type 1 material), material from above RN 14 characterized by
relatively fine grain size and relatively high organic solids contents (Type 3
material) and material from between RN’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 3 material.
2.3 ALTERNATIVES ELIMINATED FROM FURTHER STUDY
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 MPRSA and related criteria.
(b) The transport cost associated with disposal at tids 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.
11—3
-------
2.4 EVALUATION OF THE 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
are currently designated on an interim basis and the interim designation is
scheduled to expire December 1984.
By taking no action, present 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
December 1984. As discussed earlier, upland disposal sites are severely
limited, therefore, without ocean disposal the authorized channel depths at
Coos Bay could not be adequately maintained.
2.5 ALTERNATIVES CONSIDERED IN DETAIL
The two interim sites (Site E and F), the 35—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.
2.6 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
11—4
-------
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
analysis prepared by OSIJ and presented in these sections cover an extensive
offshore area which includes adjusted site H.
2.6.1 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 2.5 miles offshore at a depth of 25 fathoms.
Site H is approximately 3.5 miles offshore at a depth of 35 fathoms and site C
is located about 5 miles offshore at a depth of 50 fathoms. General locations
of these sites are shown in figure 2.1 and centroid locations are given in
table 3.1.
2.6.2 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.
11—5
-------
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 C had a large number of filter feeding bivalves indicative of a
less dynamic environment. The benthic fauna of site C was the most diverse
and had the largest numbers of individuals of the areas studies. 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 H. The benthic fauna of adjusted site i-I is most
similar to sites E and F.
2.6.3 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.
Because of the increasing depths, distance from shore, and frequency of
offshore currents, onshore transport of sediments from sites H, adjusted H,
and C 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.
2.6.4 Types and Quantities of Material to be Disposed
As described in the preface to this EIS, there are three basic types of
setlinents from Coos Bay being proposed for ocean disposal. Type 1 sediments
11—6
-------
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 annually
in this area. Type 3 material (above RN 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 3 to
5 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 §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.
11—7
-------
2.6.5 Feasibility of Surveillance and Monitoring
Surveillance of sites E, F, H, adjusted H, and C can be made from shore
facilities or vessels. Approaches to the estuary entrance, including Sites E
and F are currently surveyed at least annually by the Corps with detailed
bathymetric maps made available to the public. The surveyed area can be
expanded to include sites H, adjusted H and G. Surveillance during heavy
weather conditions Is expected to be unnecessary since heavy weather curtails
ocean disposal operations.
2.6.6 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 upsiope
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
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
I I— B
-------
remainder of the year would be limited to major storm events. These sediments
would be stable year round in the vicinity of site C.
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 upsiope 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, H 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.
11—9
-------
2.6.7 Effects of Previous Disposals
Sites E and F : Previous disposal at these sites has averaged about 975,000
cubic yards of Type 1 sediments annually. This disposal has produced a
seaward extension of the tidal. delta as evidenced by the noticeable seaward
bulges in the bathymetric contours of the tidal delta in the vicinities of
these sites. No topographic mound has developed at either site due to the
strong year—round reworking of the disposed sediments. 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.
Projected future disposals are shcwn in Table 2-1, page 11-20.
Adjusted Site H : No previous disposal.
Site H : A test dump of approximately 60,000 cy of Type 3 material was made at
site H during August 1981. Erosion as moving (capping) and mixing of the
dredged material with native sediments was evident in August 1982. Within 19
months of the test dump, the disposal mound has been erased or mixed beyond
recognition with native sediments. No acute conditions were observed during
disposal for temperature, salinity dissolved oxygen, pH, 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 disposni 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 and divers Lty levels was observed for the benthic community during
11—10
-------
the 19 months of the post dump monitoring. No dump effects were observed for
the infauna (Sollitt, et.al 1983).
Site G : No disposal has occurred at this site.
2.6.8 Interference with other uses of the ocean .
The only known commercial or recreational use of sites E, F, and adjusted site
I-i is marine navigation. Disposal activities at these sites would have little
effect on this use. Commercial fishing occurs in the vicinity of sites C and
H but no significant impact would be anticipated. See Sections 3.4 and 4.4.3.
2.6.9 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 most 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 EIS 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
II— 11
-------
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 C was characterized by the most abundant
and diverse benthic community of the sites investigated. The community was
dominated by filter and surface feeders. This to to be expected in a habitat
with stable sediment conditions and sediments having a high content of finer
and volatile solids.
The zone between the nearshore and site C 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.
2.6.10 Potential for Nuisance Species .
There are no known components in the dredged material or consequences of its
disposal which would attract or deposit nuisance species to the proposed
disposal sites.
11—12
-------
2.6.11 Existence of Significant Natural or Cultural Features .
No known significant natural or cultural features exist at or near the
alternative sites — see section 4.4.6 and Appendix C.
2.7 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 1 and 2 material at site C; 3) disposal
of Type 1 material at sites E and F and disposal of Types 1 and 2 material at
site 11; and 4) disposal of Type 1 material at sites E and F and Type 2 and 3
material at adjusted site H (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. tn addition there are no known features of environmental or
11—13
-------
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 I material at sites E and F is acceptable because a) type I
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.
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. Although the turbidity levels may degrade
the esthetic environment, the addition of volatile solids to the sediments of
sites E and F could result in an enhancement of the benthic community. As
demonstrated by the OSU study there is a general correlation between higher
volatile solids content and increased diversity of bent hic species (Sollitt,
et.al. 1983).
11—14
-------
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 C 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 erode 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, would likely result in long term (months) changes
in the substrate habitat of the benthic community. This effect would alter
the benthic community composition in this area. Thus benthic impacts would be
both direct and indirect.
II— 15
-------
Option 3. Disposal of type 1 material at sites E and F and disposal of type 2
and 3 material at site H.
The primary differences between this option and options 1 or 2 is biological
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 turbi-
dity 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 dissi.milar to the sediments of site H, this
is the site the OStJ study recommended for disposal of this material. Factors
contributing to this recommendation are: a) material of concern would be
diluted to below EPA standards; 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 macanal
were disposed of at site C; d) the seasonal and spatial variation of benthic
organisms suggest that they are more tolerant to bottom disturbance than are
species at site G (similarly species at site F should be even more tolerant)
and; e) the downslope currents would contribute to a natural capping of the
disposal material.
Although disposal of type 2 and 3 material outside H would appear acceptable,
the western edge of the site encroaches into the southern boundary of the
scallop fishery bed off Coos Bay. Resource agencies have recommended (meeting
oE Oct. 4, 1983) that If site H is proposed for use that its location be
11—16
-------
adjusted so that a buffer region is established between its western edge and
the 40 fathom contour. (The ocean bottom between 40 and 52 fathoms is the
area that scallops are found in densities high enough to support a fishery).
We have therefore 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. This section would
establish a buffer of approximately one nautical mile between the disposal
site and the scallop bed. In addition, this adjustment would reduce benthic
impacts since the site would be located in a zone with a benthic community
characterized by lower diversity and abundance than at site H. 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 47. greater than the cost of disposal of the same material at
site F.
Because of the possibility that disposal of this material at this location
will enhance diversity and abundance of the benthic community by introduction
of fines and volatile solids into the area, it is difficult to predict a dif-
ferential benthic impact between disposal here and at sites E and F.
11—17
-------
2.8 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 an adjusted site H with a centroid at approximately
25 fathoms. The coordinates of these proposed sites are given in Table 3.1.
The location of these sites is also illustrated in Figure 2.1. The recom-
mended 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 adjusted site H location.
Both sites E and F are needed to reduce the possible mounding that would occur
from the proposed disposal of approximately 1.3 million cubic yards of type 1
material at one site, to maintain flexibility of disposal when currents change
to reduce transport potential of sediments back into the channel entrance,
and to reduce sea keeping hazards to the dredges during periods of adverse
weather conditions.
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—18
-------
43°25’
Figure 2.1
Alternative Disposal Sites Considered in Detail.
43 24
43°23’
43°22’
43°21’N
124°24’ 124°23’
Iw
11—19
-------
hi
hi
F - )
C.)
TABLE 2.1
SUMMARY COMPARISON OF ALTERNATIVE SITES USING MPRSA CRITERIA
Criteria as Listed
in 40 CFR S228—6
E & F
C
I i
Adjusted Site I I
Ci) Ceographical
Location
(2) Location Relative
to lmportsnt
Resource Areas
(3) Distance from
Be aches
(4) Types & Quantities
of Mdttriala
Within 1.5 s. miles of Coos
Bay entrance. See Table 3.1
for centruid locations.
Low density benthic community
some breeding, feeding,
rearing and paasage of motile
species over entire ares.
Little fishing activity,
Close to beaches (about 1.8
mi); onshore transpoit
potential is likely.
Clean sands with average
sediment size similar to
bottom sediments. Appruxi—
mately 1.3 million cy annually
projeLted for Sites E & F.
With 5.0 s. mites of Coos Bsy
entrance. See Table 3.1 for
centroid location.
Most abundant and diverse ben—
thic community of sites
studied. Depth corresponds to
zone of increased fish
activity. Scallop
Major sediment transport is
downalope. Little opportunity
for ups lope transport, onshore
transport or impact.
Same as Site I I.
Within 3.5 s. wiles of
Coos Bay entrance. See
Table 3.1 for centroid
location.
Similar to E and F, but
has a greater diversity
of benthic species and
some fishing activity
Occurs in area.
Major sediment transport—
is downalope. Little
opportunity for onshore
transport or impact.
Fine grained sands with
high organic solids con—
tent. Approximately
200,000 cy annually from
above RN I ? projected for
area on a 4 to S year
cycle.
Within 2.5 a. miles of Coo
Bay Entrance. See Table
3.1 for centroid location.
Similar to Site F.
Similar to Site I I.
Same as Site 11.
C s) Surveillance
and Monitoring
(6) Dispersal, Non—
zoutal transport,
vertical mixing.
Surveillance and monitoring
easy due to nearness to shore,
shallowness of sites, and
availability of historical “
data.
Rapid settling of sands. No
presistent turbidity plume.
Resuspension of material will
be at a maximum during winter
stoma. Predominant trsnsport
dire.t ion will be southward at
10—30 cia/a. Sediments will be
mohile year round due to high
energy conditions,
Similar to that for Site H
except that monitoring would be
more expensive due to distance
from shore and greater depths.
Similar to that for Site 11.
Similar to sites S and F.
Similar to that for Sites
B and F, except that
downslope transport of
bottom sediments predomi—
nate over upalope tram—
port. Maximum depth
averaged suspended sedi—
ment concentration
expected 0.004 percent by
vo3ume.
Same as Site I I.
Similar to Site 11.
-------
TABLE 2.1 (continued)
Criteria as Listed
‘n 40 CFR S228-6
E & F
C
H
AdjustS Site I I
(1) Effects of Previous
Disposal in Ocean
(8) Interference with
other uses of the
ocean
Some seaward expansion of
river delta, no significant
long term, effects on fauna of
area.
Nu interferences recorded for
inttrim disposal and none
expected for future. Arees
o,,tsije zones of commercial
activity except nevigation.—
Ho previous disposal here.
Area is within the zone of major
commercial fishing and shellfish
beds. Ho known mineral deposits
in area,
No acute conditions were
observed during disposal
for temperature, satin—
ity, dissolved oxygen,
pH, oxidation—reduction
potential, or turbLdtty.
No significant mounding
was observed. The
benthic community was
significantly affected
immediately after dis-
posal but recovered to
predisposal conditions
after about 19 months
Area is outside of major
zone of commercial
activity. Adjacent to
shellfish beds. No known
mineral deposits in area.
No previous disposal.
Similar to Sites K and F.
(9) Existing water
q uality and
ecology
(so) Potential fur
nuisance species
(ii) Existence of
significant natural
or uItural
features
Water quality typics for
seewater of the Pacific
Northwest,
Benthic community character—
ized by Low abundance and
diversity and adaption to
unstable sediments.
Uncontaminated sand does not
contain material which would
attract nuiaance epectea.
No known features.
Same as Sites E and F.
Host abundant and diverae
benthic community of sitea
studied.
Same as for Site H.
No known features.
Same as Sites K and F.
Ecological transition
zone between sites F and
C.
Contaminants expected to
be below standards there—
fore no nuisance species
expected.
No known featurea.
Similar to Site F.
Same as for Site H.
No known features.
-------
III AFFECTED ENVIRONMENT
3.1 INTRODUCTION .
This section provides a detailed base description of the existing conditions
in the areas that would 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 35
fathom (53—66 meter) contour, adjusted site H at the 25 fathom (44—58 meter)
contour and site C 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
11, the data gathered by OSU and presented in this section covers an extenive
offshore area which includes adjusted site H. In general, the physical and
biological characteristics of adjusted site H represent a transition between
sites F and H.
I l l— I
-------
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 C, 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 by OSU duing February 1979 through May
1980 form the principal physical, chemical and biological information base of
this EIS.
111—2
-------
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 May 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
bathymetric 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. 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
111—3
-------
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 Tn. 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. lEG
(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 Tn. 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,
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 C 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 du to the presence of fines settled from discharged estuarine
wdters. The average volatile solids content at all sites is at a minimum in
111—4
-------
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 sediiient chemical analyses for the three
disposal sites F, G, and H (Table 3.b). 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 htgher olid3 content, lower volatile solids, and
I 11—5
-------
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 RN 12. Entrance sediments comprise some 976,000
cubic yards annually (75 percent of the total). Sedimentation upstream of RN
12 depends upon annual rainfall and runoff impacts on the local drainage basin
(Louis Smith, COE, personal communication). Between RN’s 12 and 14 some
289,000 cubic yards may accumulate in a given year. Sedimentation above RN 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
lower bay and navigation channel below RN 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 RN 14 (Type 3) is at least one
order of magnitude finer — 0.02 to 0.006 mm. Volatile solids content
increases from less than 17. 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
111—6
-------
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/m]. 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
111—7
-------
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).
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 wateriness 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 in depth. Winter cooling and wind—induced
vertical mixing produce a uniform surface waterinass of 6°C to depths of about
100 m. Summer warming may then develop a strong seasonal thertnocline within
the surface waterruass which results in an intermediate temperature minimum
near the top of the permanent salinity gradient. The Coos Bay waterinass
111—8
-------
consists of the plume of lower salinity water that extends from the estuary
mouth. Upwelling 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 upsiope 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
111—9
-------
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—kin 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
depth on the outer continental shelf with speeds up to 20 cm/s 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) conforms 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 G. 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 i-I may be between 30 to 60 cm/s. Comparable
currents near site C are 2’) t 30 cm/s.
Water transport is generally parallel to bathymetric contours although
estuarine circulation and the shoreline config ir tion tend to produce
LII— 10
-------
significant onshore and offshore flow in the upper water column near sites E &
F, and between site E and Cape Arago, respectively. Springtime upwelling may
also be responsible for shoreward—directed mid—depth mean currents affecting
the vicinity of site C 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 downslope movement may also occur in the vicinity of
site H throughout the winter and to a lesser extent in the vicinity of site
G. IJpslope 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. Inter-
nal 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 up elling
events, internal waves become unstable and cause increased vertical mi.xi ig in
Ill—Il
-------
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
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 in during the summer to over 3.5 in in winter with
corresponding changes in wave period. Detailed observations have shown that
wave—induced currents average between 30 and 60 cm/s 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 in/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 and
Atmospheric Administration (NOAA) data buoy. Since the Coos Head records
appear more similar to those of earlier observations (Duxbury et al., 1966),
111—12
-------
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, C, 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 waterinass 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 C 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 upwellirig.
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—meter squared
box core. Sediment samples were taken at the same time. Epibenthic
111—13
-------
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). Trawis were taken in a similar manner (Figure 3.12).
During the second phase of the OSU study, box core sampling was concentrated
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 cha:acterized 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
11 1—14
-------
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 ( Tellina 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 benchic
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 inollusc 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).
111—15
-------
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).
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 C 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 C
vicinity was lower than the site H vicinity, but higher than that near site
F. Species richness near site C 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
III— 16
-------
and 17 were invertebrates. Epibenthic sampling during April 1979 through
March 1980 was accomplished using a Ballon—Otter trawl. During the May 1980
through May 1981 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 trawis
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.
III — 17
-------
Because the OSU sampling methods did not sample for adult fish
effectively, information collected by Oregon Department of Fish and Wildlife
(ODFW) is used to illustrate the distribution of some species of commercial
importance.
As shown in Appendix B, 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 C 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, etal.,
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, Office of
Endangered Species. No endangered species or their habitats were indicated
111—18
-------
for these sites. A letter to this effect from the U.S. Fish and Wildlife
Service is included in Appendix C.
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. IZ o 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
‘asic iricnrue exceeds 75% when these activities are included. These statistics
III— 19
-------
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 years, 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.
111—20
-------
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 transporatation 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
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
II 1—21
-------
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.”
111—22
-------
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.
As discussed in Section 3.2, dredging quantities total about 1,500,000 cubic
yards annually, and 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 iis d, and upon
t lI—23
-------
disposal site. Average disposal cost would be about $1.40 per cubic yard.
Presently, most of the material dredged from the entrance (about 976,000 cubic
yards) is disposed of in the ocean, and other dredged materials are disposed
of at adjacent local upland sites. Corps studies predicted that the upland
disposal sites would be filled to design capacity within 5 to 10 years
(Channel Maintenance Dredging, Coos Bay, FEIS, 1976). 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 jordani ) is the shrimp species commercially fished
along the Oregon coast. They are usually taken during April through September
I IL— 24
-------
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 (0. 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. (See
Appendix B). The highest abundance of commercial groundfish occurred at
depths greater than 40 meters. Areas of high abundance of grouadfish 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 Appendix B.
In April 1981 a fishery for the Pacific coast weathervane scallop
( Patinopectin caurirtus ) 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
111—25
-------
the fishery. No live scallops were collected by OSU during the 1979—1981
sampling periods. Numerous shells were collected in the vicinity of site C 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
Contt ental shelf lease sale activities have not occurred on the Oregon
shelf since 1964, and no oil or gas production occurs at present (1981).
111—26
-------
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 pleasing
atmosphere with clean sand, weathered driftwood, shorebirds, and breaking
surf. Both areas represent high quality esthetic environments.
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.
II 1—27
-------
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.
111—28
-------
Table 3.1 Location of Alternative Disposal Sites of the Coos Bay Offshore
Disposal Study.
Site xDepth (in) Size (in) Centroid Location
E 17 1097 x 427 43°—21’—47’ N
124°—22’—25” W
F 24 1097 x 427 43°—22’—30” N
1240_22t_OO W
H 55 1097 x 442 43°—23’—59” N
124°—23’—14” W
H (adjusted) 1097 x 442 43—23’—19” N
124°—22’—55” w
-C 93- -—-1097x 442 —43°—24’—44” N
124° —25 t —l5 t1 W
Table 3.2. Sediment Accumulation Within Upper Coos Bay
(cubic yards)
Period
C
RN
oos River
12 to RN 14
1st
RN
hmus Slou
14 to RN
gh
15
149,000
5/80
to
10/80
121,000
10/80
to
10/81
194,000
10/81
to
10/82
289,000
111—29
-------
Table 3.3 Chemical, characteristics of Coos Bay sediments, May 1979
(from Hancock, et. al. 1981).
Tot.* • Chtoro—
Depth SoItde VS S RSC 0 & C 11 1 14—N Inoect. PCB Cd Cu Fe Mn Pb Zn
Stat ton ( c m) ( / ) (mn fg) (ug/g) (ugtg) (ug/g) (ug/g) (ng/g) (ng/1) (ug/1) (ugh) (ugh) (ugh) (ugh) (nghI)
61 5.5 00-20 0.86 80 80 295 80 MD SD 80 1.2 2.1 5000 - 45 14 99
20-60 l iD ND ND ND ND ND 0.3 DOT < 2 ND ND ND ND ND ND
El. 5.5 00—20 0.80 ND 48 860 80 0.5 ND ND 2.5 2.9 4900 48 14 69
20-51 0.82 ED 66 800 80 0.5 MD ND Li 3.0 5100 43 17 200
7.5 00—20 0 85 40 80 340 80 0.3 NO ND 0.8 ND ND MD ND ND
20—60 0.82 50 SD 430 80 0.7 MD MD 1.7 1.8 4600 56 12 20
P .2i 7.5 00—20 0.84 50 50 176 SD lID 80 <.4.3 ND ND ND 1 10 liD l ID
20-60 0.81 29 80 290 SD ND liD ND .1 .9 3200 54 8.6 12
63 9.0 00—20 0.78 30 BD 530 80 1.8 80 l ID 2.3 2.3 5600 44 14 45
20-42 0.17 ED 33 480 SD 1.8 MD ND 16 1.4 5300 43 5.2 48
9.0 00—20 0 80 80 10 390 80 1.3 MD MD 1.1 2.9 6000 38 18 31
20—60 (1.16 63 130 420 147 14 ND 1 10 1.1 3.9 8400 41 16 50
11.0 00-20 0.80 80 SD 410 80 0.6 MD lID 9.1 2.6 5500 33 12 71
20-60 0.79 48 SD 350 SD 8.0 liD lID 2.0 3.3 5800 46 14 65
11.0 00—20 0.10 59 80 910 SD 0.05 SD < 5(Ar1260) 0.9 2.7 9300 53 20 81
20—60 0.16 39 30 760 80 1.0 ( 3 ii 2.5 7500 46 13 38
13.0 00—20 0.56 81 123 2180 540 28 50 80 4.6 13 19500 200 25 540
20—60 0.61 59 221 2100 385 44 SD 80 1.6 1.5 14100 190 15 67
66, 13.0 00—20 0.66 36 1060 1610 282 24 80 1.5 4.7 10500 61 17 61
20—60 0.72 50 10 460 144 12 0.5 DOT SD 1.3 2.1 9200 57 10 49
67 14.5 00-20 0.38 48 126 4500 MD 45 ND ND 2.6 26 35300 330 32 290
20—60 0 39 SI 735 3100 1020 92 ND ND 2 6 5.1 25400 240 26 180
Ela 14 5 00-20 0.49 102 1620 1900 1940 81 SD SD 19 24 22700 173 45 780
20—60 0 53 96 2220 2450 1680 90 MD ND 30 17 17500 155 25 121
LLD 3 10 50 0.1 0.1
Free ,ulfideg uere belou detection (0 1 uglg) n all amnp1ea
-------
Table 3.4 Chemical characteristics of Coos Bay sediments, October 1979
(from Hancock, et. al. 1981).
Tot.
River Depth Solids VS S RSC 0 & G HC
Station Nile (cm) (g/g) (mglg) (ug/g) (ug/g) (ug/g) (ugig)
E4 11.0 00—20 0.82 6 BD 560 BD ND
20—41 0.80 6 BD 350 BD ND
E5 12.0 00—20 0.64 44 920 257.0 440 ND
20—60 0.59 65 590 3200 370 ND
E6 13.0 00—20 0.62 49 770 3020 370 ND
20—60 0.55 94 400 3290 510 ND
E7 14.5 00—20 0.39 105 2150 4240 920 ND
20—60 0.39 112 850 5110 900 ND
E8 13.8 00.20 0.62 57 400 2360 500 ND
20—60 0.56 87 750 2655 680 350
E9 15.0 00—20 0.51 155 1600 4210 1600 ND
20—48 0.41 147 2500 6220 2000 1200
LLD 10 50
Metal. Concentration (ug/g)
As Cd Cu Fe Mn Pb Zn Hg
E4 1.2 0.3 2.1 4590 35 5.2 12 .085
2.0 1.3 2.3 3950 36 5.1 8.4 .125
E5 2.8 1.4 14 21600 105 21 69 .11
3.4 1.7 17 24600 150 24 70 .12
E6 3.1 1.6 14 22300 117 21 70 .97
2.9 1.8 23 29500 363 27 85 .2
E7 4.1 3.0 31 29600 142 40 121 .77
7.7 2.5 33 36800 166 39 154 3.3
E8 1.8 1.5 11 17000 89 16 64 .63
3.0 1.4 12 21000 125 22 61 .45
E9 5.1 2.3 25 25300 IO 31 131 .45
6.8 2.9 34 32100 164 45 128 .27
111—31
-------
Tables 3.4 (CoQt)
Pesticide Concentration, ng/g
Aidrin DDE Dieldrin DDD DDT PCB
E4 ND ND ND ND ND ND
RD BD RD RD BD RD
E5 ND ND ND ND ND ND
ND ND ND ND ND ND
E6 ND ND ND ND ND ND
0.2 RD BD RD BD 3D
E7 ND ND ND ND ND ND
ND ND ND ND ND ND
E8 ND ND ND ND ND ND
ND ND ND ND ND ND
E9 ND ND ND ND ND ND
1.5 RD RD 2.5 1.7 3D
LLD 0.1 0.1 0.1 0.1 0.1 1.0
111—32
-------
Table 3.5 Chemical characteristics of Coos Bay sediments, March 1980
(from Hancock, et. al. 1981).
Tot.
River Depth Solids VS S RSC 0 & G EC
Station Mile (cm) (gig) (mg/g) (ugig) (ugig) (ugig) (ugig)
E4 11.0 00—20 0.82 3 BD 77 ED BD
20—50 0.78 12 ED 1450 BD BD
ES 12.0 00—20 0.59 48 480 2170 490 200
20—60 0.70 26 430 1360 300 130
E6 13.0 00—20 0.52 63 690 1570 670 380
20—60 0.54 64 540 3250 410 180
E7 14.5 00—20 0.38 93 790 3200 1050 670
20—60 0.38 89 2080 4180 970 650
E8 13.8 00.20 0.60 47 215 1620 320 118
20—60 0.57 61 600 2400 490 220
E9 15.0 00—20 0.33 199 470 3900 2800 1200
20—48 0.31 200 1900 6500 1840 880
LLD 10 50 50
Pesticide Concentration, ngig
Aidrin DDE Dieldrin DDD Dur PCB
E4 ND ND ND ND ND ND
<0.02 0.04 0.05 0.02 0.05 ED
E5 ND ND ND ND ND ND
ND ND ND ND ND ED
E6 ND ND ND ND ND ND
0.7 0.13 ND 0.28 0.07 BD
E7 ND ND ND ND ND ND
ND ND ND ND ND ED
E8 ND NI) ND ND ND ND
ND ND ND ND ND ED
E9 ND ND ND ND ND BD
BD 0.3 0.2 2.7 3.0 BD
LLD 0.02 0.02 0.02 0.02 0.02 0.1
111—33
-------
Table 3.5 (Corit)
Metal Concentration (ug/g)
As Cd Cu Fe Mn Pb Zn Hg
E4 1.3 0.8 1.0 5000 31 3.4 12 .06
1.2 1.8 2.8 5400 45 13 13 .09
Z5 3.6 1.6 14 8500 131 19 77 .15
2.4 1.1 5.4 10000 58 7.5 29 .04
E6 3.5 1.8 18 26900 150 25 110 .20
6.1 1.7 18 24500 263 22 87 .39
E7 6.3 2.6 32 33900 209 37 124 .21
9.5 2.4 29 35000 172 33 121 .45
E8 3.0 1.3 32 18600 102 16 67 .15
3.7 1.6 17 23600 103 22 87 .12
E9 9.0 2.3 32 34100 203 38 123 .24
10.6 3.1 34 38700 247 45 129 .39
111—34
-------
Table 3.6 Chemical Analysis of Marine Watere at Offshore Sites F, C t H Coos Bay, Oregon
(From Nelson et.al. 1983)
BOT I’QM
Date
STATION
DEPTH
(fathoms)
p11
SALINITY
(mg/mi)
NH4—N
(ug/nil)
TURBIDITY
(NTU)
TSS
(ug/mi)
VSS
(ug/mi)
As
(ug/uil)
Hg
(ug/mi)
June 1980
F3 8
F3T
G38
G3T
1138
1 13T
13
13
50
50
33
33
7.85
8.00
7.70
8.00
7.45
8.00
32
30
33
31
33
31
RD
110
0.10
RD
RD
RD
2.9
3.7
7.0
3.6
6.0
1.2
22
19
52
26
27
26
6
6
12
8
7
8
BD
ND
ND
ND
ND
RD
ND
BD
ND
ND
RD
ND
Augusl [ 980
F3B
F3T
C3B
03T
1138
113T
N I)
NI)
ND
ND
ND
ND
7.70
/.80
7.60
7.90
7.55
7.70
33
33
33
30
35
32
BD
RD
BD
0.03
RD
BD
4.2
2.0
1.3
4.1
2.6
1.2
26
23
36
20
23
24
10
8
9
1
8
7
ND
RD
RD
ND
RD
ND
RD
ND
ND
ND
ND
BD
December 1980
F’3B
F3T
C3B
C3T
1 13B
113T
13
13
50
50
33
33
7.70
7.80
7.60
7.90
7.55
7.70
33
33
33
30
35
32
110
0.01
BD
0.03
RD
BD
4.2
2.0
1.3
4.1
2.6
1.2
26
23
36
20
23
24
10
8
9
1
8
7
ND
ED
RD
ND
RD
ND
BD
ND
ND
ND
ND
RD
April 1981
F3B
F3T
C3B
C3T
U3B
1 13T
13
13
50
50
33
33
7.50
7.50
7.60
7.60
7.50
lID
35
31
35
32
35
ND
ED
RI)
RD
RD
RD
RD
4.0
3.8
2.8
2.9
3.2
NI)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
RD
RD
ED
RD
ED
ED
ND
ED
RD
ND
ND
BI)
LLD
0.03
0.04
0.05
I-I
Ui
-------
Table 3.6 (Cont)
( STATION METAL CONCENTRATION (ng/inl) PESTICIDE CONCENTRATION (ng/ml )
Date
Cd
Cu
Fe
Mn
Pb
Zn
Aidrin
DIE
Dieldrin
DDD
DDT
Ar1254
Ar1260
June 1980
F3B
F3T
G313
G3T
1DB
113T
ND
1.60
ND
ND
1.80
ND
ND
14.00
ND
ND
8.60
ND
ND
6
ND
ND
33
6
ND
18
ND
ND
14
5
NI)
3.50
ND
ND
3.50
ND
ND
0.50
ND
ND
7.00
ND
0.010
0.004
0.005
0.001
0.005
BD
BD
ED
0.002
0.002
ED
0.004
0.005
0.005
0.005
ED
0.006
BD
0.003
ED
0.002
0.002
0.010
0.003
0.004
0.010
0.004
0.004
0.008
BD
BD
BD
ED
BD
BD
BD
BD
BD
BD
ED
BD
BO
August 1980
F3B
F3T
G3B
G3T
l13B
I(3T
1.40
ND
ND
ND
ND
3.50
11.20
ND
ND
ND
ND
18.20
18
ND
ND
ND
69
11
16
ND
ND
ND
112
21
5.00
ND
ND
ND
ND
5.00
2.50
ND
ND
ND
ND
7.00
0.001
0.002
0.001
0.002
0.001
0.001
0.001
BD
BD
BD
BD
BD
ED
ED
BD
0.001
0.001
ED
0.001
BD
0.002
0.001
ED
ED
0.004
0.005
0.001
ED
0.003
0.002
BD
ED
BD
RD
BD
BD
BD
BD
ED
BD
PD
BD
December 1980
F3B
F3T
C38
C3T
H3B
113T
2.80
ND
ND
2.50
1.40
3.10
34.00
ND
ND
28.80
12.60
13.00
18
ND
ND
ND
69
11
16
ND
ND
ND
112
21
7.00
ND
ND
7.00
3.50
7.00
9.00
ND
ND
7.50
5.00
18.50
0.001
0.002
0.001
0.002
0.001
0.001
0.001
BD
BD
BD
BD
BD
ED
BD
BD
0.001
0.001
BD
0.001
l iD
0.002
0.001
RD
BD
0.004
0.005
0.001
BD
0.003
0.002
BD
BD
BD
ED
BD
BD
BD
ED
BD
ED
BD
ED
April 1981
F33
F3T
C3L1
G3T
u38
1 13T
ND
1.30
1.40
ND
2.20
4.40
ND
9.70
9.50
ND
12.50
13.50
ND
14
38
ND
ND
11
ND
18
76
ND
ND
12
ND
3.50
3.50
ND
2.70
3.50
ND
18.50
15.00
ND
79.00
5.00
BD
BD
BD
BI)
119
BD
BD
RD
BD
0.001
ND
ND
ND
ND
ND
ND
1 11)
ED
ED
B0
BD
0.002
0.002
RD
ED
0.002
ED
0.004
BD
ED
BD
RD
BD
ED
B !)
B!)
BD
BD
ED
BD
111)
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.) Species Taxonom.ic Family Number
10—19 Speckled Sanddab ( Pleuronectidae ) 414
Night Smelt ( Osmeridae ) 294
Northern Anchovy ( Engraulididae ) 57
Sand Sole ( Pleuroriectidae ) 45
English Sole ( Pleuronectidae ) 36
Bay Pipefish ( Syngnathidae ) 29
Warty Poacher ( Agonidae ) 28
Pacific Touicod ( Gadidae ) 20
(Twenty—two species observed, of which 14 species were represented by less
than six individuals each.)
20—29 Speckled Sariddab ( Pleuronectidae ) 1,467
English Sole ( Pleuronectidae ) 193
Pacific Torncod ( Gadldae ) 68
Rockfish ( Scorpaenidae ) 43
(Nineteen species observed, of which 13 species were represented by less than
14 individuals each.)
30—45 Speckled Sanddab ( Pleuronectidae ) 2,259
Hybrid Sole ( Pleuronectidae ) 108
Pacific Sanddab ( Pleuronectidae ) 73
Night Smelt ( Osrneridae ) 59
English Sole ( Pleuronectidae ) 44
Pacific Torncod ( Gadidae ) 26
(Twenty—two species observed, of which 16 species were represented by less
than seven individuals each.)
Depth (rn.) Species Taxonomic Family Number
46—70 Speckled Sariddab ( Pleuronectidae ) 369
Pacific Sanddab ( Pleuronectidae ) 322
Pacific Toincod (Gadidae) 203
English Sole ( Pleuronectidae ) 177
Pygmy Poacher ( Agonidae ) 70
Hybrid Sole ( Pleuronectidae ) 32
Dover Sole ( Pleuronectidae ) 23
(Eighteen species observed, of which 11 species were represented by less than
12 individua.ls each.)
*75—120 Pacific Sanddab ( Pleuronectidae ) 212
Speckled Sanddab ( Pleuronectidae ) 46
Rockfish ( Scorpaenidae ) 26
Pacific Torncod ( Gadidae ) 21
Rex Sole ( P leuronectldae ) 17
(Twelve species observed, of which 7 species were represented by less than 6
individuals each.)
I i i —:
* Results of two trawis. All other depths are results of four trawls each.
-------
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 trawis each site) (1—tn
beam trawl).
Depth (tn.) Species Taxonomic Family Ntnnber
20—40 Speckled Sanddab ( Pleuroriectidae ) 998
(Site F) Brown Irish Lord ( Cottidae ) 79
Pacific Sanddab ( Pleurotiectidae ) 70
English Sole ( Pleuronectidae ) 63
Cabezon ( Cottidae ) 50
Slim Sculpin ( Cottidae ) 43
Prickeibreast, Poacher ( Agonidae ) 35
(Twenty—eight species observed of which there were less than 20 individuals
each of 21 species.)
Depth (m.) Species Taxonomic Family Number
45—70 Pacific Sanddab ( Pleuronectidae ) 918
(Site H) English Sole ( Pleuronectidae ) 218
Speckled Sanddab ( Pleuronectidae ) 160
Rockflsh ( Scorpaeriidae ) 55
Rex Sole ( Pleurouectidae ) 31
(Twenty—five species were observed, of ‘which there were less than 20
individuals each of 20 species.)
75—120 Pacific Sanddab ( Pleuronectidae ) 754
(Site C) Slender Sole ( Pleuronectidae ) 463
Slim Sculpin ( Cottidae ) 403
Rex Sole ( Pleuronectidae ) 103
Blackbeily Eelpout ( Zoascidae ) 84
Rockfish ( Scorpaenidae ) 36
Dover Sole ( Pleuronectidae ) 34
(Thirty species observed, of which there were less than 20 individuals each of
23 species.)
111—38
-------
rable 3.9
A list of the Marine Mammals occuring off the Oregon Coast and their status under the Marine Mammal
Protection Act.
FAMILY AND SPECIES
Balaentdae
Eubalaena glaclalis
Eachrichtl idde
Eschr ichtiub robuatus
Bal.aeitopterldae
Bal.aennptera musculus
Fcilaenoptera phy8alus
Balaeuuptero borealis
B daenoptera acutoroatrata
Megaf.tera novaeangliae
Physetertdae
Physeler catodon
Kogia breviceps
Ziphiidae
tlesophodon 8tejflegeri
Mesophodon carlhubbsi
C OMMON NAME
North right whale
Grey whale
Tilue .*iale
Fin whale
Sei whale
Minke whale
Humpback whale
Sperm whale
Sperm whale
Pygmy Sperm whale
Beaked whale
N.P. Beaked whale
lIubb8 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
-------
BLE 3.9 (Cont
M1LY_ANt) SPI C1ES
ZfptIIuH caviro tris
Berardlus batrdii
lphinidae
GJ.oblce phala macrorhynchus
Grampus griseus
Orcinus orca
Pseudorea crassidens
Deiphintin deiphis
Lissodeiphis borealis
Stenella coeruleoalba
Lagenorhynchus obliguidens
iocoenfdae
Phocoenioldea dalli
Phocoena phocoena
ustelidae
Enhydra lutria
h tdci
COMMON NAME
Cuvier’s Beaked whale
Giant Bottlenose whale
Short—finned Pilot whale
Grainpus dolphin
Killer whale
Fabe Killer whale
Common dolphin
Northern right whale Dolphin
Striped Dolphin
Pacific white sided Dolphin
Dall’s Porpoise
Harbor Porpoise
Sea Otter
PROTECTED
No
No
No
No
No
No
No
No
No
No
No
No
Yes
( X CIJRRENCE OFF OREGON
Rare, three strar 1ings
Unccnmon June to Oct.
Winter
Uncommon, Spring to Summer
Winter
Uncommon
Uneomiuon, Spring, Summer
Rare) Spring to Summer
Rare, three standings
Common throughout year
Common, throughout year
Common, throughout year
Rare, introduction program failed
-------
TABLE 3.9 (Cont)
FAMILY AND SPECIES
Phoca vitulina
Phoca hiapida
Phoca fa ciata
Mirounga augustirostis
Otariidae
Eumetopias jubatus
Zalophys californianus
Callorhinus ursinus
I-1
I-I
I— .
COMMON NAME
Harbor Seal
Ringed Seal
Ribbon Seal
Northern Elephant Seal
Steller Sea Lion
California Sea Lion
Northern Fur Seal
PROTECTED
Yes
No
No
Yes
No
No
No
OCCURRENCE OFF OREGON
Comtr n, 4,000 in Oregon
Rare, single sighting
Rare, single sighting
Ra r a
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 Z Change
Coos County 63,300 61,750 —2.5
Coos y City 14,275 13,710 —4.0
North nd City 9,670 9,320 —3.6
Source: Center for Population Research and Ceisus, Portland State
111—42
-------
Figure 3.1 Offshore Coos Bay study area.
111—43
-------
Figure
Locations of Alternative DISpOSOI
Sites
(Depths reported in fothoms 1
NOS chart 18580)
-------
0.1 mm
0.1
Offshore Coos Boy
Median Grain Size (mm)
Figure 3.3
o
.O .08
SITE C
S
S
S
S
S -
0
.03
17
0.15mm
H
0
.14 .14 .17
.ia
.17
QI?
.16
0 00
.12 0 .16
II .13
0.15mm
©
.17
0
0
0 16
.17
317
.16
020
0
.18
5t iions I-64 Oct. l6 1979
SIoI.oA 6 -83 Jon 22, 1980
Yo ’. 6 1980
0
.17.
16
.17 .17
©
Extended offshore area median grain size distribution
(Hancock, ec al. 1981).
111—45
-------
2 O ’/
I 87
O(fshore Coos Boy
Orgonics Conteni
(0/0 Volatile Solids)
Sioiion 1-64: Oct 16. t 79
5iotion 65-33W Jo 22. teeO
Mo, 6 1960
2.72 2.74
, 0#
, 10
2.48
SITE C
6
3.97
1 63
I .. •l
I. ., J O
C
.12
6
I 89
.47
.76
63
.59
66 62
68
©
.77
6
83
88
.84
9’
87
©
.14
II
13
88
C
.94
Figure 3.4 Extended offshore area volatile solids (Hancock, et al. 1981).
111—46
-------
0
to
a
.4 -
E
0
a
C
0,5
0.I
0.05
0.0I
0.005
0.t
Orçcnics Content (% voictile soI ds)
Figure 3.5 Medi r. 3rairi size vs. or anics content in estuarine and
coastal edinents (}ianc ck, et a . 19 1).
0.5 1.0 5 JO
III—d7
-------
I0
Orgonics Content (% Volatile Solids)
Figure 3.6
Median grain size vs. volatile solids with site average and
standard deviation (after Nelson, et. al. 1983).
- - 2 ——‘—— L _ L
0.5
050
(mm)
01—
005 -
-Aver ge
Standard deviation
003o 05
Tt J — , — -— I -
50
111—48
-------
Distance from Entrance (kilometers)
4 8 12 16 20
0.5-
0.I
0.05 -
0.010 2 4 6 8 tO 12 14 16 18 20
Distance from Entrance (statute miles)
Figure 3.7 Median grain size related to distance from entrance (after
Hancock,et al. 1981).
32
‘ .4
C , -)
C
C
C
a)
24 28
I I I [ I j
+ - + + Coos
0 +. + River
0=
a ac
00
= a
Coos Bay, Oregon Trcnsec/
+Arnesofl
oNSF zsmmus
•OSU (1979)
cOSU offshore (1979) Slough +
A Hopper dredge (1973)
0
0
• , I • ,
III— 4)9
-------
Distance from Entrance (kilometers)
8 2 16 20
24 28 32
0.16 2 4 6 8 10 12 14 16 18 20
Distance from Entrance (statute miles)
Figure 3.8
Volatile solids related to distanae from entrance (Hancock,
et al. 1981).
4
1000
50
I 1 • •
VoJatile Solids
Coos Bay, Oregon
+ Arneson
o NSF
‘CStJ (1979)
COSU offshore (1979)
Hopper dredge (1973)
U,
0
C,,
a
C
Isthmus +
S/cu
10.0
5.0
1.0
0.5’
S
+
+
+
a
C
-C
0
+
+
+ Co ,s
• River +
.4.
S
C
S
+
S
• C
C
• C
+
S
- 1 - t
L t 1
111—50
-------
/,
C. (iS.e9 $S.Il.*$
I. T.u.sUI.I $SaII.as
U. OU.h.,. ISaulam.
& 1...I*aaS liii ..
9 C..iu.M U.S. .
t1 liSa.
Figure 3.9 Coos Bay sediment sampling sites (Hancock, et. a!. 1981).
-------
2 4 4 S IC
• I I I I
Monthly wind vectors observed at North Bend Airport and
NOAA offshore data buoys.
WINO SP EO I 1 KNO1S
CREG N
Figure 3.10
111—52
-------
Figure 3.11
Core sampling stations — Phase I of Coos Bay Offshore
Disposal Study (Hancock, et al. 1981).
.Tani*rv/k r. . ,. iqgn
111—53
-------
April and October 1979 crawl cracks
Figure 3.12 Trawl sampling locations — Phase I of Coos Bay Offshore
Disposal Study (Hancock, et al. 1981).
1980 crawl tracks
111—54
-------
Figure 3.13 Core and trawl sampling locations — Phase II of Coos Bay
Offshore Disposal Study (Nelson, et al. 1983).
111—55
-------
Figure 3.13
Cant inued
111—56
-------
£ WATER COLUMN
• BOX CORE — 3IOLOG 1CAL AND C AIN SIZE
1 BOX CORE — CHEMICAL AND CRAIN SIZE
TRAWL TRACX
STATION S
,—i_ ‘
/ Si
‘‘V
—
STATION 4
STATION B
4324w
4322w
432O
o I
Ki lomelrr
0.3
N uSicaI MiI
12424’ 1242T 1242O W
Figure 3.14
IEC survey locations (IEC 1982).
111—57
-------
— .14—.17”n
—
— .22
•&.•S
0
C
—.14—.L7
—
— p.22
.4 .
-V. -
* •ISS
Figure 3.15 Distribution of sediment size;
(from Hancock et al., 1981)
Cruise I & II, 1978
C,
0
0
111—58
-------
4 _ // -
• 1.
1 ,
•1 J 1 __
Figure 3.16 Distribution of volatile solids; Cruise I & II, 1979
(from Hancock et al.,.1981)
— o.L—0.4
— Q.5—0.8 ’
— 0.9—1.2 ’
c!J - o.i-o.’ z
o — 0.5—0.32
© —0.9—1.22
C,
0
0
I,,, $ I$$
III —99
-------
0— toy con tn t3tLOfl
0 Me u concentration
:
Figure 3.17 Distribution of wood chips; Cruise I & II, 1979 (from
Hancock et al., 1981)
111—60
- t w concentration
— Madiuo concentration
— icavy concentration
0 — Absent
,it, $a ,tI,
5pfl I , ISS U $ M •I S $e.. •$
-------
Figure 3.18 Distribution of shells;
et al. , 1981)
Cruise I & II, 1979 (from Hancock
- z ow concerttr&t ion
— Medium concentration
— Moavy concentration
0 —
— toy o absant coucencrat ion
— Low CoEtCSncraciOfl
0 concsncr3cion
— Msavy concentration
0— Absent
111—61
-------
Figure 3.19
Distribution of the carnivorous snail Olivella . in
the nearshore region, April and September 1979 (from
Hancock et al., 1981).
111—6.2
— 0—11 anint*1s/m 2
Q — 1255 .2%iaai5I’11 2
- 56-110 anim*1s/ii 2
— )]11 ariiiiali/ii 2
a.... S D, SaM * $*Mt*$
-------
FIgure 3.20 Distribution of the clam, Tellina modesta , in the nearshore
region, April and September 1979 (from Hancock et al., 1981)
- 0-11 animals/rn 2
e — 12—55 animalS/Ill 2
— 56—110
— >111 animals/a 2
413 — 0—li a n imals /a 2
o — 12—53 animals/rn 2
o — 36—110 animals/rn 2
— ‘l U animals/lit 2
111—63
-------
Qlivelta
SYCM
Azinopside
serric ta
AREA F
OIIveflc
bipllcata
Ofivella
boetica
Teltina
nuculoides
AREA H
MyuIIa
oIeuflc
Acilo
çastrensn
$ 412 I
AREA
G
Axinoasida Ada
serf cpt co 3trensl
Macama
• imøtp
Toldia
scis urota
,
$4321 $4321
5432$
5432$
Figure 3.21 Spatial distribution of the most abundant móllusc species
in areas F, H, and C; Cruise 4, May 1980
- 1
ii
o
a,
C
C
I-e
3OO
2 o-
200 -
50-
111—64
-------
l2
75.
50.
25.
50
25
MAY 98O
54321 5432k 54321 54321 5432J
III H1 H
I]
Area F
Area H
Area G
Figure 3.22 Spatial distribution of the most abundant po] .ychaete species
in areas F, H, and C; Cruise 4, May 1980
3
C.;
—
V
- :2
a—
0
1.-a
410
3>
C
0
543V 54321 54321 54321 54321
VIIJFJHI
III_6
-------
MAY 1980
AREA F
:lLiiIc::LI
54321 54321
I-
4..
3-
I.
54321
F xipha(u Mandibutoohoxus mce1isca Hioporn!don nchiocoIuri .
unicirostratus mocrocephoto denticulatus occidentoljs
AREA G
54321
5432.1
Metoohoxu
freguens
Foxiphotus Heterophoxus
similis oculotus
AREA H
14
12
4.
2-
I iL
54321 432l
Synchelidium Echoustorius
shoemokeri sencillus
Hemilomprc s
cotifornico
Euchilomedes Repoxynius
corthcrodcnta epistomus
Figure 3.23
Spatial distribution of the five n ost abundant crustacean
species in areas F, H, and G; Cruise 4, May 1980
4.
5 43 2 I
0
SI
•0
0
SI
SIC
C
SI _
2,
SI
—
SIC
.0
C
SI _
Eudoreilo
pacifico
3.
2.
Repoxynius
dobouis
111—66
-------
4324
soo
700
00
300
400
300
200
100
S
A
1!
in n
S
0
gfl.
fl
S
[ I
.
STATION 1 STATION 2 STATION 4 STATIONS 3TATION
Figure 3.24 Total number of individuals collected by IEC at nearshore
region (April—May 1980)
5
+
4
0
124W
124
1242 W
A
a
F1
‘I
U
z
C
C
C
2
C
S
0
2
-
.Ic
C
00
300
400
300
200
TOTAL (ALL TAXA lNauoINc
MINOI PHV1M
OIYO4MTA
A&THIOPOOA
D MOUU$CA
• STATION NSJMUI
STATION 7 STATION $ STATION S
111—67
-------
Figure 3.25 Distribution of Lumbrineris luti and fa1dane glebifex ;
Cruise III, 1980 (from Hancock et al. , 1981)
111—68
-------
Figure 3.26 DistrIbution of Paraphoxus epistornus and Olivella
Cruise III, 1980 (from Hancock et al., 1981)
Oliu.LZ4 ‘c iip1sz’
111—69
-------
.O P3 OF (.e6lN(F $
( ata
.. j . A
MLL
r.. is
SECTK N 0-0
CHARLESTON BREAKWATER
SECTION A-A
SOUTH JETTY
K S • •UI
• OUAII.’A’
— . S sitPèU. I
r 1 T • ‘ r •’
‘ S ..
•‘ • :
: . . .
IMPROVEMENTS . -
• COOS BAY, 0REG0N.::
ssaism,u
r.? N r : ‘
* * MT t’C*It OSTIC PomiJa.
CORPS O £MsS .t U -
‘ S. I
* Ifl Nt MN
I I gsiri• .27
U.S. AMMY
• .I.q’ ‘. . -• :. I ••. .•..
• 1M4
4. . •
‘ 5 ‘ • . oOs
I ‘ : “ j 4vi’.
J .4
. .. ‘- ‘ I . ‘ * • 1
1. u â s. ••
‘*It
fM-• . S aè.Jb
— w._ *
•MN *‘.e S i .!
— — , MN— N’
— .1
-------
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 ]2), b) some 289,000 cubic yards annually of
Type 2 material (finer material like that found between RM’s 12 and 14) and;c)
some 164,000 cubic yards on a 3 to 5 year cycle of Type 3 material
(fine—grained material like that found above RN 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. In general, impacts
of disposal of type 2 and 3 material at adjusted site H would be less than
disposal of these materials at sites E, F, or H.
4.2 PHYSICAL IMPACrS
4.2.1 Bathymetric Impacts
Disposal of Type 1 sediments at sites E and F would contribute to the natural
prc radation of the river delta. The finer size fractions would be winnowed
IV- 1
-------
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. 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, C, or
continental slope) would produce longer—lived but broader bathymetric 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 bathymetric 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 buiJdup would be expected. Similar disposal of
Type 2 and 3 sediments would produce permanent deposits but again the buildup
would likely be minor.
I V— 2
-------
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, C, 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 dumped material that reached the
bottom were about 50, 38, and 34 percent for sites F, H, and C, respectively.
Clearly a major fraction of the dumped material remains suspended in the water
column and is ultimately deposited over a very great area. 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 C 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 C would erode more slowly and may be covered by mobile ambient
sediments, further increasing the time required to erase a mound. After 1
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. coin.). The num-
bers cited from this study are not exact but only indicate relative differ-
ences. Future reports currently in preparation at OSU will address the accu-
racy of the Koh—Chang model.
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
IV— 3
-------
estuary sediment types. Type 1 sediments are physically and chemically corn—
patible with sediments at site F. Site H sediments are slightly finer than
these estuarine sediments and site C 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 fades 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 C 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 C. 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
time in winter at site F and 30 percent of the time during the rest of the
year. Resuspension at sites H and C 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 sedi ients is expected for the continental slope site. Type 3
IV- 4
-------
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 C,
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 upsiope 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 C 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 quikly 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 C may not
‘v—s
-------
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-avera ged
concentration after one hour. Consequently, it stay 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
the finer size fractions, it is reasonable to assume that the disper a1 of the
chemical couta tnants would be proportional to the dispersion of the fine
fractions. Adoption of preliminary estimates by Nelson etal (1983) suggests
that between 50 and 75 percent of the sediment would remain in suspension when
IV- 6
-------
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 analysis (Hancock et
al. , 1981) 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 dilutions just discussed, it appears
likely that 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).
4.3 BIOLOGICAL D PACT
4.3.1 Epibenthos and Fisheries .
Since the majority of the material (87%) to be disposed can be classified
as clean, non—toxic, organic materials, and since the epibenthic and fish
fauna are nobile, we do not expect any ineasureable effect from ocean disposal
of Coos ay sediments. 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.
IV-7
-------
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
No known rare or endangered species or their critical habitat would be
impacted by disposal at any of the alternative sites. See U.S. Fish and Wild-
life Service Letter in Appendix C.
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.
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 are species that actively burrow
vertically or horizontally or are deposit feeders. These species are
IV-8
-------
( Spiaphanes bosibyx) ( Olivella pycna) , (0. biphlienta), ( Ophelia n. Sp.) and
( Tellina nucoloides) . 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, disposal of Type 1 sediments would likely have a
short term impact on the benthic communities of sites E and F. The most
immediate effect would be almost total mortality of benthic species in the
impact zone with some 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
a].., 1983).
IV -9
-------
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 C. 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 at., 1983). The
numbers of filter feeding and surface dwelling benthic species at site H
are higher than that in the nearshore region.
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 siiilar 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. Dnly two species, Repoxynius epistamus and R. debouis hadon
were evenly distr.. .uted.
‘v-LU
-------
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 E 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
IV—ll
-------
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 dowtislope. A long term change in sediment type and
habitat could occur at site H if Type 3 materials are routinely deposited
there. This change could enhance the site since a more diverse biological
fauna are associated with sediments having higher organic content.
Site C, 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
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 C would result in the
greatest biological impact of the three areas studied. Two factors contribu-
ting to this are the high numbers of species and individuals that occupy the
IV-12
-------
area, and the Large impact area that would result from disposal. As noted in
Section 4.2.1, the areal coverage at site G would be nearly four times larger
than disposal of the same kind and amount of material at a nearshore site and
twice the size of a similar disposal at site H.
Disposal of Type 1. material would have the greatest biological impact of the
three sediment types on site C due to: (a) Dissimilarity of disposal and
bottom sediments, and (b) 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 C, because of the similarity of sediment
types, would likely have the least long-term biological impact of the three
sediment types. However, the initial impact would be larger than that of
coarser-grained Type 1 sediments due to the larger impact area resulting from
disposal of the finer sediments.
Disposal of Type 3 qiateria]. at site C would cause an immediate loss of
existing benthic communities in the impact areas. Long-term disposal of this
material at site G would alter the habitat character of the area. Because
Type 3 material is finer, the areal coverage would also be larger than that
for coarse-grained sands. 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.
IV—13
-------
In swninary, 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 unstable environment, the low abundance and
diversity of species (relative to the other areas) and the adaptability of the
existing benthic species to an unstable environment.
Disposal at site H 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 pets. 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 C would result in a greater loss of species and individuals
than disposal at sites B, 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 -14
-------
4.4 SOCIO-ECONOHIC 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 975,000
cubic yards annually, have been disposed at sea (sites E and F). Yet, because
of the probable future lack of upland or in-channel sites, ocean disposal of
all dredged material is considered in this analysis. The following channel
reaches would be involved:’!
a. Entrance channel (RH 0.0 to 2.0), consisting of about 975,000 cubic
yards annually of fine entrance sands.
L/ These figures were taken from U.S. Army Corps Engineers, Portland
District, Coastal Projects Operation and Maintenance, 1982 (pages 84 through
94).
IV- 15
-------
b. Lower channel (RH 2.0 to 12.0), consisting of about 360,000 cubic
yards annually of sands, silts, and clays.
c. Upper channel (above RH 12.0), consisting of approximately 200,000
cubic yards annually 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 8-hour day, and it would take one hour to load the dredge; the dredge
travels at 10 miles per hour, end 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 RH 1.0; Lower
channel at RH 7.0; and Upper channel at RH 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
at sites H, G, and the continental shelf respectively than at sites E and F.
Correspondingly it is 1.3, 31., and 156 percent more expensive to dispose of the
IV —16
-------
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 than 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).
14•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
IV - 17
-------
suitable offshore sites for disposal of dredged materials. The OCNP
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.
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 resuspension 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.
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.
‘v—la
-------
4.5 1ITIGATIOM AND SITE MONITORING
Specific mitigation actions to offset disposal impacts have not been
identified. However, use of adjusted site H for disposal of fine sediments is
a proposed action designed to minimize potential adverse effects to local
beaches and the Lower Coos Bay estuary. In addition, 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 coinpatability of type 1 materIal for sites E and F,
monitoring, if done, should be limited to periodic bathymetric surveys. If
monitoring is initiated we recommend that it be concentrated at adjusted site
H. In addition, we recommend that If monitoring be conducted, it be based on
a hierarchical system of progressive complexity. That is, first, concentrate
on monitoring the physical and chemical characteristics of the sediments and
proceeding on to the more complex and difficult biological characteristics if
it can be established that EPA sediment and water quality standards are
exceeded.
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:
IV— 19
-------
The bottom topography of the sites would be altered (may or may not be
adverse);
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
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.
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 very
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.
IV- 20
-------
4.8 IRREVERSIBLE OR IRRETRIEVABLE COMMITMENT OF RESOURCES
Permanent designation of the proposed sites for disposal of dredged material
would commit the sites and their resources primarily to that use. Other uses
such as oil and gas exploration, and to varying degrees, mining, fishing, and
use by certain aquatic species, would be precluded.
IV —21
-------
TABLE 4.1 COST COMPARISON FOR DISPOSAL OF MATERIAL FROM THREE DIFFERENT LOCATIONS IN COOS BAY AT FIVE
DIFEERENT OCEAN SITES
Sites
Continental
Dredging Location E (1.5) F (1.5) H (3.5) G (5.0) Shelf (24 )
Entrance (RH 1.0,
97’,,000 cii. yd.)
/8 hour work days 49 49 61 70 186
Estimated Cost (millions) 1.96 1.96 2.44 2.80 7.44
Lower Bay (RM 7.0,
3b0,000 cu. yd.)
8 hour work days 32 32 36 42 82
Estimated Cost (millions) 1.28 1.28 1.44 1.68 3.28
Upper Bay (RH 13.5,
200,000 Cu. yd.)
il8 hour work days 26 26 28 30 54
Estim ited Cost (millions) 1.04 1.04 1.12 1.20 2.16
These costs are for comparison purposes only. Costs are based upon the assumptions outlined on pages 1V16.
** Statute miles from the entrance into Coos Bay.
-------
V COORDINATION
5.1 General . Preparation of this Draft EIS has been coordinated with several
Federal, state, and local agencies, and the public. Federal agencies
contacted include EPA, U.S. Fish and Wildlife Service, National Marine
Fisheries Service, and U.S. Coast Guard. State agencies include DLCD, Oregon
Division of State Lands, and ODFW. Local agencies included Coos County and
the Cities of Coos Bay and North Bend.
5.2 Scoping . The EIS scoping process has provided the basis for
coordination. The purpose of the scoping process under current NEPA
regulations is to identify the pertinent issues which need to be addressed in
the EIS. The scoping process was initiated through public notice which
identified the proposed actions and preliminarily identified significant
issues. The public notice, which was distributed to government agencies,
environmental groups, news media, and other interested public, requested input
on issues considered significant and warranting in—depth analysis.
The issues identified in response to the public notice include the following:
Effects on local beaches
Effects on marine biota
Effects on cotninerical fishing
Effects on Coos Bay estuary
Effects on the local economy
V—i
-------
Effects on ocean bottom topography
Effects on water quality
These specific environmental issues identified through EIS scoping correspond
with the EPA criteria for evaluation of sites proposed for site designation.
These issues and criteria were utilized in outlining the significant issues
addressed in detail in this EIS.
Contacts with the agencies have been maintained throughout the drafting of the
Environmental Impact Statement. Adequate opportunity has been provided for
the agencies to identify the significant issues and potential for impacts to
be evaluated in this impact statement.
V—2
-------
VI LIST OF PREPARERS
Principal Authors: Experience: Contribution to EIS
Steven .J. Stevens Land use planning, EIS Purpose and need, alter—
BS, Landscape Architecture preparation (12 years) natives comparison, land
use/CZM consistency, es-
thetics, EIS coorination
Thomas E. Morse Wildlife research bio, Physcial/biological de—
BS, MS Wildlife Management resource planner, biol. scription and assess—
Ph.D Ecology assessment (12 years) ment alternatives corn—
parision study coordi-
nation.
William Boodt Industrial, regional and Socio—economic environ—
MS, Ph.D. Economics resource economic analysis ment and impacts; cost
feasibility and impact analysis.
studies (22 years)
Patricia Hodge Economics assistant! Socio—economic environ—
BA, MA Letters and Science regional economics ment; cost analysis.
Economics Specialist (6 years)
VI- 1
-------
David Askren Physical and geological Physical environment
BS Geology oceanography (10 years) description and impacts
MS Oceanography Coastal navigation pro— assessement.
MS Civil Engineering ject planning and main-
tenance (4 years)
Kim Larson Biological (fisheries) Biological environment
BS Zoology, MS Fishery studies; environmental description and impacts
Biology impact assessment assessment.
(7 years)
Robert A. Freed Archeological irtvestiga— Cultural resources
MA Anthropology tion and cultural re-
sources management
(8 years)
VI-2
-------
VII BIBLIOGRAPHY
PHYSICAL/BIOLOGICAL
Conomos, T.J., M.G. Gross, C.A. Barnes, F.A. Richards. 1972. River—Ocean
Nutrient Relations in Sun er 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. Mccary. 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.
VII—l
-------
Harlett, J.C. 1972. Sediment Transport on the Northern Oregon Continental
Shelf. PHD thesis, Oregon State University, Corvallis, OR.
Uuyer, A and J.G. Patullo. 1972. A Comparison Between Wind and Current
Observations over the Continental Shelf off Oregon, Su=ier, 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, 39 7 pp.
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.
Kob, 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
1980—June 1981. Report Submitted to the U.S. Army Corps of Engineers,
VII—2
-------
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 l977a. 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.
Sverdrup, H.U., M.W. Johnson, R.H. Fleming. 1942. The Oceans. Prentice
Hall, Inc., Englewood Cliffs, N.J. 1058 pp.
VII—3
-------
SOCIO—ECONOMIC
Beuter, .J.R. 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—4
-------
APPENDIX A
OCNP CONSISTENCY STAT NT
-------
OREGON STATEWIDE COALS
CONSISTENCY STATEMENT
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 asaure an adequate factual base
for such decisions and actions.
. ACRTCULTIJRAL LANDS. To preserve and
aintain agricultural lands.
4. FOREST LAND. To Conserve forest
lands for forest uses.
5. OPEN SPACES, SCENIC AND HISTORIC
AREAS AMD 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.
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 La a state and local function. The Corps has coordinated
the site designation alternatives will all agencies that have planning
responsibility for the affected area. The proposed project is coniatent
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 Bite designation and resulting ocean disposal
would not detract from the areas 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.
8. RECREATION NEEDS. To satisfy the
recreational needs of the citizens of the
state and visitors.
-------
ORECON STATE%JTflE COALS CONSISTENCY STATEMENT
9. ECO it HY OF THE STATE. To diversify Maintenance of the Coos Bay Navigation System i.s considered vitally
and improve the economy of the state, important to local regional and state economic vitality. Ocean disposal
site designation is an integral part of the navigation system maintenance
plan.
10. HOUSiNG. To provide for housing The proposed site designation would not affect local planning or
needs of citizens of the State. implementation of plans which provide for the housing need of citizens.
11. PUBLIC FACILTIES AND SERVICES. To Facilities and services associated with the Coos Bay Navigation channel
plan and develop a timely, orderly and are already in place. Ocean disposal site designation would help insure
efficient arrangement of public the continued use of these facilities and services.
facilities and services to serve as a
developoment
12. TRANSPORTATION. To provide and The continued use of a safe convenient and economical water transportation
encourage a safe, convenient and system in Coos Bay is at least partially dependent upon the use of ocaen
economic transportation system, disposal sites for channel maintenance.
13. ENCERCY CONSERVATION. To conserve The use of close—in disposal sites would provide for n re efficient
engergy. channel maintenance, resulting in net energy savings.
14. URBANIZATION. To provide for an Ocean disposal site designation is not expected to have any effect on the
orderly and effieicent transition from or patterns of urbanization.
rural to urban land use.
15. WILLAMETTE RIVER CREENWAY. To Not applicable.
protect, conserve, enhance and maintain
the natural, scenic, historical,
agricultural, economic and recreational
qualities of lands dong the Willamette
River as the Willamete River Greenway.
-------
OREGON STATEWIDE COALS
CONSISTENCY STATEMENT
16. E ;TJJARlNE RESOURCES. To recognize
and prote’t the unique environmental
econo 1 nic. and social values of each
e ruary and associated wetlands; and to
protect, maintain, where appropriate
develop and where appropriate restore
tt lot g term environmental, economic
and &OCLd! values, diversity and
b& iietit of Oregon’s estuaries.
11. COASTAl. SHOREJANDS. 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 benejfta of coa8tal beach and dune
areas; and to reduce the hazatd to human
life and property from natural or man
induced actions associated with these
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 not significant impact on estuarine resources.
Ocean disposal site designation would help alleviate the need for disposal
on coastal shorelande.
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.
a, eas.
-------
OREGON STATEWIDE GOALS
19. OCEAN RESOURCES. To conserve the
long—term values, benefits, and natural
resources of the nearahore 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
Fish Distribution Data
From Marine Resource Surveys on
the Continental Shelf Of f Oregon
1971—1974 Oregon Department
of Fish and Wildlife 1976
-------
f It. . . . .. \:
f \. •. I -. .4J 1 t6’N
PMKAUA3A ‘It’ •S • S
____ ‘-? ‘
ç ‘b • • •
:.1 \ .t’:
-- . 1 • r’ •
•.
F
‘N .::
- BAY
o
k ‘ • SI,
4. .•.. . : :
w
1 Loc2xion of cr2wI sczions of grcwidfish survcys off Oregon, 1971.74. Heavy•
line de& survey &mz (d p .w lzrnic lower portion. 1974 only) Sedzment vyp
after Byrne and Panshin (1972). PM C. an3tic2I
-------
1971-72
-
• •. •.•
4 — •
- 2
2
- 4? -L S /
: L: :‘ ‘
fi .
•,
- coos aAY
Figure 2. DLs uzic and reI dve abuodancc (weight) of Dover sole
• • 73.74 off Orcg by AC r lica y bi k lkz s liaiic
___ O( w ’cy
1973-74
-------
.4
F
• I _c
..
- 10 T t23
• -. - • I •:
- - • •._ •1 : -‘ 1 Ø iwwc43-
• : J/ • “
.) , y) Quii.wiuliu
‘ - + -
j ri 7 -
7-
3’ D 1bUtiOQ and rc ñvc abundance (wàgb )o( IngUs i soic i 5cpc n V71-72 . . -
H ku 6hmct f
______ _:t: -: _:: ’ :.’ . _. -_ -
-------
;:
I •
• --. •
• - • :
- : -•
• : • •r: ‘•4 -
- -i : •
-. 1 rf k:i •. o Cwns)
) .I ) Qu LsM --
-, ‘1 Z +L3Ny
:: ;
971-72
+
•4t
“.l•
:1
Figure 4.. Distribwio and rcL tivc abundance (weight) of petrale 6 e n Sepccmber 1971.72 nd
1973-74 off Oregon as dcurrnu cd by groundfish survcys Hc vy brck m line I&mit o(
d
— . 7 t
_______ ____: - t• _ . -
-------
I
/
i::.
•
I .
I . —
I
5’
I ” - -
-
- .
___\ rJ
.::;.!+ .N
-, ; 1 i I! y/ l2ew
.r 1 .-z
• P gure 5. Discribt nd rththve 2bucd2nce (wcigbOo( Rcx soic Scpc nbcr 7L-fl aod
p7344 off Orcpi dcr rmncd by g rveys. Ic vy brok Iuac Iiin of
JtVC
197 -7 .
+
Ti -lG 123 J
o
•
9u.u L M
-------
.1
•1 - —
.1
1:
973-7i
• f2
£ J
‘— ‘••d-
• ,:; :.,+ 43’&. ...
- 12ew
fi;
j I
I r’ ).
( i
:
-.
,
o o-
- 3-
• ( 3:
Q
wd rdadve abuDd2nce (weigbt)o( P3dEc s ndd2b in Scpcenibcr 1971 -72
74 off O gon as by
gL go(wcy ,_y-$ — -. -
-- ... --
-------
•
I;
: • -
- .‘. -. .
• - . S..
‘ S . .
::! -: “
S i
o T....-6O..I2i ,)
o o- 3-45
o
•
o
•••- •
P guzc 7. D butio ui4 relative abund2nce (weight) of arrowtooth flounder in September 1971-72
d 1973.74 off Orcgoc ,as by groundfish surveys. Heavy btckai I e limit of
rrvcy . ,
-------
:4 .•..
L5’
t
o -‘ ‘ — 3- .i --
0
• ‘I — -.
431 N
:: : :
‘ :
.‘.- I
Figure 8 Distribucioa 2nd relative abundance (weight) of rodcfisb Scpc n&r 71-T2 and
73-74 affOregcxi as t rrnned by gr indfith ixvc }Icr y b c I e s 1m o(
, vcy. e
97i
W737i
-------
V
• -
I
I:: t:
:.
I
: j
. - .
4 ’.
• .1 •.1
••, Y’ r i:
1 .. •
-.
,4$ •I •
guxe 9. D 2bu Or* and re1 ve 2buzldance (wcight)c( lingcod i Sqxember 1971-72 nd
1973.74 off Orcgoa s á icd by gzowidfz h xvcy*. H vy bivk i linc is
.
-r
I
-------
I . ;
- )
-
I -
t — 141
I
o T -6Q t33 J
o 3 -1
0
o tM*. h ls
;1’4 ‘
•:
I ..
45 .
-
I •. .
I : _ -
I ‘ - ••- -
I - : -
•
+43
• - :12Iw
Figure 10 . D utio 2nd re!2zivc abundance (weight) of sabk sh in September 1971.72 and
1973.74 off Oregou as d’r Tnnd by groundfisb wveys. Hàvy b line is limit of
* :vcy. . ,
-,
•
a.’,
I
f.
1
1.
I
I
+
—
• •- . , . . .-4.•-• ,
F :
-------
• .:.. .•• .: .. •.
S.
c
I 4
I
.
:‘ “,‘ ks: . .
•
( . lø ’
? ‘ -
: .- : - -.
+ • - 1 :• ‘ ‘ : :, ‘.. , +44 ’
124W
Figure U. Distribution and relative abundance (weight) of spiny dogfish ii Scp nb 1971.72
and 73..74 off Orepa d’r ” d by gmund sh s rvcy .. Hàvy broken line s limit of
-
b3
50- 100 - 3- SIi 1
10
• ,
t
0
- I
•1
t -. I
1- - .• 1
• •‘ -.1
1—
‘: ••
-------
2r
I
.:
$
I .—
.. ::
.N
t’ ..- .--
I
• :.:. •:
- -
t:
-
1.1 : . —. . - -
.. •.•
Fzgux 12. D tribuzion 2x 4 reladve abunthrice (weigkiz)o( skac September 1971-72 d
1973-74 off Oregoci 2S APr ?mined by groundfish surveys. H vy brckei 1 e
b n o( arvq
÷
• - .• .• _-t.
3O—I ii.i b,
ICO-2 I
-------
• - . — . -
a J —
..
A •
••La .•4i.
it a ’ : ; t ° ’
• • • - z LIa5tfl ’ :e . a a: , /
• - • . • - :-.. -
-. - •f •. •. -
- e -. • i-... .1
• t i . b . .
• J:. •: ____________
c . - f PiotPsa -J*M . 23 h&
- O ah&
t : ::=tt
- - ? 5 ..c 1 :) +
...I %*.*3
- •.. __t s_-
- • •- • “ - .- , ‘• -tdJ , •
re vc abundance (weighdd t nthth in Scpcexnbcr 1971 .72 and
1973 -74 off Oregon as daniiS by groundfisb mrvcys. Hcvy brokci line. is
limE O(Slrvcy r. - ?
— _ _ _ _ _ _ :t Ti .?-
-•
• - - : - :-.
• ‘ - • 1 ’J
-• •_ :
-
-------
D Mud . . • .•• . . - .7
I Sand Sediment
8
- - . . - . • - S D -: Ar’ -’
22% “i flounder :•‘•
uiI QQn o 0 _______________
______ _______ _ DQflrtfl’
I
-r !-T -r rr £ r .
92%. T l varsole
: ri.
U92%
ii____
1 .1 .600
400
200
i. 6.
.4.
• 2.
0
: , :.6.
2.
0
2.
-.0
8
: -
.‘ Engllshso1e
— “ -I.’ Y ’
I
- I
D43% . - .: - : Petrale sole 5
7% • :‘ ,
Rex sole
.... 2,
IIcir-irr7., .fl..,
.
• ¼
I .
D 3 2 % Dogfish ‘ ?“
- ‘- : _ : .; t:-
-;
47 ‘ i ‘VS1 .
D8% skates
A L? r :
I:kr—
j •i : ..
T ?
C28%:. ’,R atffsfl
a 72% - . -
-q . b ‘ .} r
JiE T ”
It! . _T7_T
c 54
•f 4 %
— .r
I I I I I I
I I I
• -
.. . • -‘ - ‘ -I -.
o S5 ” L lngcod ‘: ‘
-. I
- - -.... .. -. -
— 0 r
8,
sanddab 6
6 o33%
167%
2
20 4G’
Picific
ii :,
4 4 I 4_i • . , . ‘
o9o% -: sabl.f i h..
a io -
IIfl
I I I U
60 •80 100
DEPTH. (fin)
300
• ; 4.
u rT T
‘ 100 300
:hh1 : DEPTH (fin)
• . Figure
-S
14. CorrelatIon of abundance of selected species with depth and
• Sediment type within depth 1973—74. Percent shows abundance
releted to sediment types Note change in strata at 100 fin.
Ta4 l O Omt -
-------
OREGON
Astoria
Tillamook Head
Cape Falcon
Nehalem River
Tillamoak Bay
Tillamook
Netarts Bay
Cape Lookout
Nestucca Bay
Cascade Head
Sile Bay
Oepoe Bay
Yaqusnia Head
Newport
Yaquina River
— Alsea Bay
Cape Perpetua
Siuslaw River
Florence
Raedsport
Umpqua River
Winchestee Bay
i Bunco
4\Port Orford
old Beach
Cape Sebastian
e River
Brookings
Nit OREGON
Pigure 16’ : Principal Shrimp Pishing
Grounds along the Oregpn
.coast.
C os Bay
6
-------
/
Figure. 17 Major Chinook and Coho Troll
Areas along the Oregon Coast.
(1967—68 data. Source: ODFW
1976)—(includes only major,
A _• wAsHINGTaN
OREGON
Astoria
Tillamook Head
Cape Falcon
/ Nehalern River
Tillamaok Bay
Tillamook
Netarts Bay
Cape Lookout
Nestucca Bay
Cascade Head
Siletz Bay
,Depoe Bay
v.. .... .: 1 Head
irt
,, ‘Caos River
1os Bay
Arago
Coquille River
Bandon
...;i Blanco
Orford
River
Beach
Cape Sebastian
Brookings
4 Chetco River OREGON
CALIFORNIA
Alsea
Bay
Cape Perpetua
Siuslaw River
Reedsport
tJmpqua River
“ Winchestee Bay
very good, and good categories)
26
-------
WASHINGTON
Figure 18. Major Inshore Crab FIshing
Areas.
Siuslaw River
ice
Astoria
OREGON
Nehalern River
Caps lookout
Ne tucca Say
SiIe Bay
port
Yaquina River
Alsea Bay
River
is River
Cheico
River
OREGON
CALIFORNIA
36
-------
APPENDIX C
LETThRS OP CLEARANCE
-------
Department of Transportation
STATE HISTORIC PRESERVATION OFFICE
Parks and Recreation Division
525 TRADE STREET S.E., SALEM, OREGON 97310
Novmeber 16, 1982
DAVIS G MORIUCHI
PORTLAND 01ST CORPS OF ENGINEERS
PC 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 corwnent
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 coriinents. We feel the area of the project is
not of historic significance and since ground disturbance of
previously undisturbed ground is minimal, this office feels that
there will be no likely impact to archeological resources. We
therefore feel no cul tural resource surveys are requi red and that
the project is in compliance with Public Law 89—665 and Executive
Order 11593.
For further information regardi
Gilsen, state preservation archeolog
Deputy
rs III
IP O
DWP/LG: kc
-------
United States Department of the Interior
FISH AND WILDLIFE SERVICE
Endangered Species
2625 Parkmont Lane S.W., B-2
Olympia, WA 98502
February 14, 1983
Mr. Richard N. Duncan
Chief, Fish and Wildlife Branch
Portland District, Corps of Engineers
P.O. Box 2946
Portland, Oregon 97208
Refer to: l-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,
To the best of our present knowledge there are no listed or proposed
species 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 your
concern for endangered species and look forward to continued coorcina-
tion with ybur agency.
Sincerely,
Jim A. Bottor f
Endangered Spedes Team Leader
Attachments
cc: RO (AFA-SE)
ES, Portland
ODFW, Non-Game Program
-------
LISTED 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 - S P -133
LISTED :
None
PROPOSED :
None
CANDI DATE :
None
Attachment A
-------
A.PPENDIX D
SEDtMENT ELUTRIATE ANALYSES
FROM
HANCOCK et.al.. 1981
-------
Table 3—5
Sediment Elutriate Analyses (May 1979)
= + Chloro-
Depth S NH 4 —N TOC Pesticides PCB
Station (cm) pH ( g/ml) ( .ig/ml) ( .zg/ml) (ng/ml) (ng/ml)
El 00-20 7.7 60 ND 4.7 ND ND
20-60 7.6 60 ND 4.4 ND ND
Els 00—20 7.6 80 80 4.2 ND ND
20-51 7.55 80 80 5.1 ND ND
E2 00-20 7.6 80 80 3.1 BD 80
20-60 7.6 BD 0.14 4.2 ND ND
E2s 00-20 7.5 80 ND 4.0 ND ND
20-60 7.6 BO ND 4.4 ND ND
E3 00—20 7.65 80 0.38 5.9 BO BD
20—42 7.6 80 0.36 6.4 ND ND
E3s 00—20 7.5 0.25 5.9 ND MO
20-60 7.6 BD 60 7.1 ND NO
E4 00—20 7.5 80 0.1 4.0 80 60
20—50 7.5 80 60 7.1 ND ND
E4s 00—20 7.4 80 80 4.6 BO 80
20—60 7.4 80 80 5.2 80 80
E6 G0—20 7.2 80 3.7 12 80 80
20—80 7.1 80 5.0 6.9 0.007 DDE ND
E6s 00—20 7.7 80 3.9 9.7 ND ND
20-60 7.5 80 2.0 12 80 80
E7 00—20 7.5 80 3.9 10.8 BD 80
20—60 7.5 80 6.5 49 80 80
E7s 00—20 7.4 60 7.1 8.7 80 80
20—60 7.1 60 9.4 11.7 ND NO
LLD 0.1 0.1 0.001 0.003
Note: Salinity = 26—28 mg/mi for all samples.
-------
Table 3—5 (continued)
Sediment Elutriate Analyses (May 1979)
Depth Metal Concentration (ng/rnl )
Station (cin) Cd Cu Fe Mn Pb Zn
El 00—20 68 8.5 105 90 BD 65
20—60 2.4 20.2 55 20 80 59
Els 00-20 80 14 10 55 BO 81
20—51 15 17 60 30 5.5 53
E2 00—20 16 9.5 35 56 BO 97
20-60 ND MD 9 28 ND 14
E2s 00-20 4 10 BO 8 BD 75
20—50 17 4 BD 10 2 71
E3 00—20 17 5 BO 40 5.6 57
20—42 0.2 13 BD 26 2 55
E3s 00—20 5.2 20 60 11 BO 52
20—60 15 10 10 63 BD 65
E4 00—20 0.6 12.3 2 22 2 85
20-50 3.7 20.5 70 70 9 75
E4s 00—20 BD 21.6 7 43 BD 48
20-60 0.6 24 15 70 6 48
E6 00-20 BD 9,5 2040 1200 2 ND
20—80 BD 6 4840 665 SD ND
E6s 00—20 14.6 15.3 80 335 BD 114
20—60 2.0 13.6 60 20 BD 114
E7 00—20 4.6 13.5 20 230 SD 118
20-60 7.8 16 40 85 80 75
E7s 00—20 BD 7 3550 1450 30 3
20—60 BO 4 3880 2720 50 6
LLD 0.3 0.5 0.2
-------
Table 3-6
Sediment Elutriate Ana1y is (October 1979)
+ Chioro—
Depth Sal. S TOC NH4-N Insect. PCS
Station (cm) pH (mg/mi) ( ig/m1) ( .ig/m1) ( ig/inl) (ng/rril) (ng/ml )
E4 00-20 7.7 24 80 11 BC BO 80
20-41 7.5 25 80 2 80 ND ND
ES 00-20 7.3 24 80 8 5.0 80 80
20-60 7.1 24 80 10 9.1 80 BO
E6 00—20 7.2 24 80 12 6.8 BO 80
20—60 6.8 24 80 15 18.0 80 BO
£7 00—20 7.3 27 80 15 7.0 80 BC
20—60 7.3 27 80 22 16.0 BD BC
£8 00—20 7.4 23 80 15 4.6 80 80
20—60 7.4 24 80 8 7.8 80 80
ES 00—20 7.3 29 80 4 5.3 80 80
20—48 7.2 24 80 12 19 80 BO
Seawater 7.5 27 BD 4 80 80 80
Blanks 7.5 26 BO 2 BO 80 80
7.8 25 80 5 BC 80 80
LLD 0.1 0.1 0.001 0.003
-------
Table 3—6 (continued)
Sediment Elutriate Analyses (October 1979)
Depth Metals Concentration (ng/rnl )
Station (cm) As Cd Cu Fe Mn Pb Zn Hg
E4 00—20 ND 3 2.5 10 40 3 2 BD
20—41 B0 2 2 20 20 2 2 1
E5 00—20 ND 1100 1600 BD
20—60 ND 700 1300 80
E6 00—20 ND 66 1 1900 960 3 23 2
20—60 BD 57 1 6500 3300 2 29 3
El 00—20 ND 1300 1300 80
20—60 ND 680 790 BO
E8 00—20 ND 690 160 BD
20—60 ND 740 250 80
E9 00—20 ND 8.5 0.5 500 980 3 •18 ?D
20—48 SD 17 0.5 950 420 2 24 J
Seawater
Blank SD BO BD 110 20 SD BD 80
LID 20 0.3 0.3 0.2 0.10.5
-------
Table 3-7
Sediment Elutriate Analyses (March 1980)
Depth DO Sal. Turb. S TOC NH 4 -M AS Hg
Station (cm) pH ( ig/ml) (mg/mi) (NTV) ( .ig/ml) (i.jglml) (i.ig/rnl) (ng/ml) (ng/nil )
E4 00—20 ND 6.3 27 53 BO 5 0.1 ND 80
20—50 7.5 7.0 28 86 BD 5 0.4 80 80
E5 00—20 7.5 2.7 MD 83 BD 9 11 MD 80
20-60 ND 4.4 29 101 80 5 7 MD 80
E6 00—20 7.5 2.7 26 81 80 9 11 ND 80
20—60 7.2 4.7 26 165 BO 11 11 80 80
E7 00-20 7.0 2.8 MD 120 BD 19 20 ND 80
20—60 7.2 2.5 28 66 80 5 11 ND 60
E8 00—20 7.3 3.4 28 107 BD 5 4 ND BD
20-60 7.4 3.0 28 115 80 4 4 MD 60
E9 00—20 7.4 5.6 28 56 80 5 6 ND 60
20—60 7.7 5.4 ND 75 80 5 4 BO 80
Seawater
Blank #1 7.7 7.9 26 1.8 80 1 0.1 ND 80
Seawater
Blank #2 7.7 7.7 31 0.8 80 4 0.3 80 60
LLD 0.1 20 0.5
-------
Table 3—7 (continued)
Sediment Elutriate Analyses (March 1980)
Depth Pesticide Concentration (ng/ml )
Station (cm) Aidrin DDE Die ldrin DOD DOT PCB
E4 00-20 0.006 0.002 BC 0.03 0.009 BC
20-41 0.004 0.005 BC 0.03 0.02 80
£5 00—20 0.003 BC SD 0.01 0.004 BC
20-60 0.002 0.005 BC 0.02 0.02 BC
E6 00—20 0.007 BO BC 0.02 BC BC
20—60 0.06 0.002 BD 0.02 0.01 BC
57 00-20 0.003 80 BD 0.015 0.009 80
20—60 0.016 0.0006 0.004 0.003 0.005 BC
E8 00-20 0.02 0.006 0.002 0.003 0.001 SD
20-60 0.002 lID BO 0.01 0.01 SD
59 00—20 0.02 80 BC 0.02 0.007 80
20-60 0.01 0.004 80 0.03 0.01 80
Seawater
Blank #1 0.01 ND 0.02 0.01 80
Seawater
Blank #2 SD 0.003 0.003 0.03 0.02 80
Distilled
Water
Blank #1 ND BC .0C4 0.006 0.01 BC
Distilled
Water
Blank #2 ND BC 0.003 0.006 0.008 30
LLD 0.001 0.001 0.001 0.002 0.003 0.003
-------