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£% V UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
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San Francisco, CA 94105-3901
Ann Garrett, Assistant Regional Administrator - Protected Resources
Gerry Davis, Assistant Regional Administrator - Habitat Conservation
National Marine Fisheries Service
Pacific Islands Regional Office
1845 Wasp Boulevard Building 176
Honolulu, Hawai'i 96818
Re: Programmatic ESA and EFH Consultation for Five Existing Hawai'i Ocean Dredged
Material Disposal Sites
Dear Assistant Regional Administrators Garrett and Davis:
The U.S. Environmental Protection Agency Region 9 (EPA) manages five ocean dredged
material disposal sites (ODMDS) offshore of the Hawaiian Islands to allow for safe disposal of
suitable sediment generated from necessary dredging of harbors and other navigation-related
facilities. Continued availability of appropriately managed ODMDS is a priority for EPA as it is
necessary to maintain safe navigation. EPA originally designated these five sites via rulemaking
in 1981, consulting with the National Marine Fisheries Service (NMFS) as required by the
Endangered Species Act (ESA). At that time, consultation on potential impacts to Essential Fish
Habitat (EFH) was not required by the Magnuson-Stevens Fishery Conservation and
Management Act. Since the ODMDS sites were designated, conditions have changed, including
new species and critical habitat listings. In order to provide for the continued protected of listed
species and critical habitat, EPA reinitiated ESA consultation, including consultation regarding
EFH, working closely with NMFS staff.
As described in the enclosed analysis, EPA has determined that the continued disposal of
approved, suitable dredged material at these five ODMDS under an updated Site Management
and Monitoring Plan may affect but is not likely to adversely affect certain species listed as
threatened or endangered under the ESA. EPA has also assessed the potential impacts of
continued disposal operations on EFH and similarly determined that the continued operations
may affect EFH, however the effects are expected to be minimal. The enclosed analysis
describes proposed and past use of the sites, as well as regulations and management measures in
place to avoid impacts to marine organisms and the marine environment. Also discussed is the
extensive monitoring that EPA has conducted at the sites, the results of which indicate that
existing management practices have been successful at avoiding and minimizing adverse
impacts. We respectfully request that NMFS concur with EPA's determination.
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I greatly appreciate the assistance of your staff as EPA worked through our analysis and I look
forward to our continued coordination. Please feel free to contact me or Brian Ross of my staff
by e-mail (ross.brian@epa.gov) or by phone (415-972-3475) if you have any questions.
Sincerely,
Ellen M. Blake
Assistant Director, Water Division
Enclosure: EPA Analysis for ESA and EFH Consultation: Five Existing Hawai'i Ocean Dredged
Material Disposal Sites
cc:
Mrs. Shelby Creager, Resource Management Specialist, NOAANMFS
Mr. Stuart Goldberg, EFH Coordinator, NOAA NMFS
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EPA Analysis for ESA and EFH Consultation:
Five Existing Hawai'i Ocean Dredged Material Disposal Sites
US Environmental Protection Agency
Region IX
75 Hawthorne Street
San Francisco, CA 94105
October 8, 2020
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Contents
1.0 BACKGROUND 1
2.0 mi: 11 vi; haw aim ocean disposal sites 4
3.0 NEGLIGIBLE IMPACTS TO DATE 4
3.1 Disposal Site Designation 5
3.2 Dredged Material Testing 5
3.3 Alternatives Analysis 7
3.4 Disposal Site Management: Best Management Practices 8
3.5 Disposal Site Management: Site Monitoring 9
Monitoring Methods 9
Monitoring Results 11
3.6 Disposal Site Management: An Adaptive Approach 12
3.7 Enforcement 13
4.0 ESA SPECIES ASSESSMENTS 14
4.1 Potential Impact Summary 14
4.2 Marine Mammals 17
Blue Whale (Balaenoptera musculus) 17
False Killer Whale - Hawaiian Insular DPS (Pseudorca crassidens) 18
Fin Whale (Balaenoptera physalus) 20
North Pacific Right Whale (Eubalaena japonica) 21
Sei Whale (Balaenoptera borealis) 22
Hawaiian Monk Seal (Neomonachus schauinslandi) 24
4.3 Sea Turtles 25
Central North Pacific Green Sea Turtle (Chelonia mydas) 25
Leatherback Sea Turtle (Dermochelys coriacea) 30
Loggerhead Turtle (Caretta caretta) 31
Olive Ridley Sea Turtle (Lepidochelys olivacea) 32
Giant Manta Ray (Manta birostris) 33
Oceanic Whitetip Shark (Carcharhinus longimanus) 34
5.0 EFH ASSESSMENT 36
5.1 Assessment of EFH overlap with Hawai'i Ocean Disposal Sites 36
5.2 Avoidance and Minimization of Impacts to EFH 39
Ocean Disposal Site Selection 39
Pre-Disposal Testing 40
Management of the Hawai'i Ocean Disposal Sites 40
Monitoring at the Hawai'i Ocean Disposal Sites 40
5.3 Overlap with Habitat Areas of Particular Concern 41
Potential Effects to P. filamentosus 41
Potential Effects to Pillow Lava Substrate 42
Effects to other EFH in the Hilo HAPC 42
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5.4 Conservation Measures: Hawai'i FEP Habitat Conservation and Enhancement Recommendations (FEP,
2009): 45
General Recommendations 45
Specific Dredging and Habitat Loss and Degradation Conservation Measures 46
6.0 CONCLUSIONS 48
7.0 REFERENCES 49
Original ESA Consultation for the Five Hawai'i ODMDS (1980) 51
Site Monitoring Synthesis Report for the South O'ahu and Hilo Ocean Disposal Sites (EPA 2015) 86
Preliminary Chemistry Results from the 2017 Monitoring Survey of the Nawiliwili, Kahului, and Port Allen
Ocean Disposal Sites 150
Site Management and Monitoring Plan (SMMP) and Mandatory Disposal Site Use Conditions (2015) 159
List of Figures
Figure 1. Vicinity map, showing the five existing Hawai'i EPA-designated ocean disposal sites 1
Figure 2. Example of a tracking report for an individual disposal trip. Panel A shows the vessel's route to and
from the disposal site, with the blue line indicating the vessel is loaded and purple indicating it is empty
following disposal. Panel B is a closeup of the disposal site's SDZ, showing the disposal (in red) occurring
fully within the zone. Panel C shows the vessel's draft and speed throughout the trip, confirming no substantial
loss of material from the vessel during transport 8
Figure 3. High-resolution bathymetry in the vicinity of the Nawiliwili disposal site. The hard-bottom habitat
and a volcanic escarpment in the southeastern portion of the site precluded benthic sampling in that area. The
yellow box indicates the target for the general area in which the SDZ would be repositioned (see Figure 5 for
final SDZ placement) 10
Figure 4. Schematic of deployment and collection of SPI-PVP photographs (Appendix 2) 10
Figure 5. The Nawiliwili disposal site, showing the realigned SDZ. EPA has moved the SDZ to avoid 13
Figure 6. World map showing the approximate range of the blue whale
(https://www.fisheries.noaa.gov/species/blue-whale) 17
Figure 7. World map showing the approximate range of the false killer whale
(https://www.fisheries.noaa.gOv/species/false-killer-whale#overview) 19
Figure 8. Map showing designated critical habitat for the endangered false killer whale around the Hawaiian
Islands. Approximate locations of the five ocean disposal sites shown as red triangles (not to scale) 19
Figure 9. World map showing the approximate range of the fin whale
(https://www.fisheries.noaa.gov/species/fin-whale) 20
Figure 10. World map showing the approximate of the North Pacific right whale's range
(https://www.fisheries.noaa.gov/species/north-pacific-right-whale) 21
Figure 11. World map showing the approximate range of the sei whale
(https://www.fisheries.noaa.gov/species/sei-whale) 22
Figure 12. World map showing the approximate range of the sperm whale 23
Figure 13. Graphics pertaining to Hawaiian Monk Seal range and habitat: Panel A shows the world map with
the approximate range of monk seal (https://www.fisheries.noaa.gov/species/hawaiian-monk-seal); Panel B
shows a map of the critical habitat; Panel C shows a shows a cross-section view of critical habitat 24
Figure 14. Range of the green sea turtle (https://www.f1sheries.noaa.g0v/species/green-turtle#overview) 25
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Figure 15. World map showing the approximate range of the hawksbill sea turtle
(http://www.californiaherps.eom/turtles/pages/e.i.bissa.html) 30
Figure 16. World map showing the leatherback's range (https://www.fisheries.noaa.gov/species/leatherback-
turtle) 31
Figure 17. World map showing the approximate range of the loggerhead turtle 32
Figure 18. Approximate range of the Olive Ridley sea turtle
(http://www.californiaherps.com/turtles/maps/xlolivaceaworldrangemap4.jpg) 33
Figure 19. World map showing the approximate range of manta rays (https://seethewild.org/manta-ray-habitat-
map/) 34
Figure 20. World map showing the approximate range of the oceanic whitetip shark 35
Figure 21. P. filamentosus juveniles recorded by the BotCam remote drop camera system over volcanic pillow
lava formations off Hilo, Hawai'i (WPRFMC, 2016) 43
Figure 22. Profile images from two Hilo stations showing a surface layer of disposed coarse white dredged
sand that thins from the center of the site (left) to only trace amounts near the site boundary. Scale: width of
each profile image = 14.4 cm (Appendix 2) 43
Figure 23. Spatial distribution of sediment grain-size major mode (phi units) at and around the Hilo ocean
disposal site 44
Figure 24. Deposits of pillow lava in PV image from Station SE6. Scale: width of PV image = 4.1 m 44
List of Tables
Table 1. Dimensions and center coordinates for Hawai'i ocean disposal sites and their SDZs. The underlined
text reflects an update to the 2015 Site Management and Monitoring Plan 1
Table 2. Disposal volumes (cy) at the five Hawai'i ocean disposal sites from 1981-2020 (Data source: EPA
compliance tracking records and USACE Ocean Disposal Database (USACE, 2020a)) 3
Table 3. NMFS-managed Species under ESA in the Pacific Islands Region (NMFS list from 7/31/18) 16
Table 4. Volume of dredged material disposed, and minimum and maximum number of disposal vessel
transits, to and from all Hawai'i ocean disposal sites from 2009-2018 26
Table 5. Ten-year commercial vessel transits by port (USACE waterborne commerce database). These
numbers of transits include receipt (incoming) and shipment (outgoing) transits, but do not include fishing
vessels 27
Table 6. Ten-year commercial fishing vessel trips and transits in Hawai'i (DLNR commercial fishing
database) 28
Table 7. EFH Designations for Managed Commercial Fisheries in Hawai'i (source: Draft PIRO EFH
Designations, 2019) 36
Table 8. HAPC for Managed Commercial Fisheries in Hawai'i 39
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List of Acronyms and Abbreviations
BMP - Best Management Practice
EFH - Essential Fish Habitat
EIS - Environmental Impact Statement
ERL - Effects Range Low
ERM - Effects Range Median
ESA - Endangered Species Act
FEP - Fishery Ecosystem Plan
HAPC - Habitat Area of Particular Concern
MBES - Multibeam Echosounder Survey
MPRSA - Marine Protection, Research, and Sanctuaries Act
MSFCMA - Magnuson-Stevens Fishery Conservation and Management Act
MUS - Management Unit Species
NEPA - National Environmental Policy Act
ODMDS - Ocean Dredged Material Disposal Site
OTM - Ocean Testing Manual
PVP - Plan View Photography
SAP - Sampling and Analysis Plan
SDZ - Surface Disposal Zone
SMMP - Site Management and Monitoring Plan
SPI - Sediment Profile Imaging
TMDL - Total Maximum Daily Load
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Overview of Consultation Document
This document contains the analysis to support the informal update to the programmatic Endangered
Species Act (ESA) Section 7 consultation, as well as an Essential Fish Habitat (EFH) consultation,
for the five existing Hawai'i ocean dredged material disposal sites (ODMDS), specifically for the
transport and disposal of approved dredged material. Please note that this document does not cover
impacts from individual dredging operations, as these impacts are separately evaluated, and project-
specific consultations are conducted as necessary, by the US Army Corps of Engineers (US ACE)
during their permitting process.
The first three sections of this document (Sections 1-3) describe the use of the Hawai'i ocean
disposal sites to date and the EPA regulations and management measures in place to avoid impacts to
marine organisms and the marine environment. Also discussed is the extensive monitoring that EPA
has conducted at the sites, the results of which indicate that existing management practices have been
successful at avoiding and minimizing adverse impacts. These three sections contain information
relevant to both the ESA and EFH analyses. Following these sections, analyses of potential impacts to
ESA species and their critical habitat (Section 4) and to EFH (Section 5), are provided. Based on
EPA's ocean disposal site selection process, rigorous pre-disposal sediment testing, and site
management measures, EPA concludes that the continued use of the existing disposal sites, under
management requirements that are similarly strict to those applied to date, may affect but is unlikely
to adversely affect ESA species and habitat, and may affect EFH, however effects are expected to be
minimal.
In addition, appendices are provided that include:
1. The consultation materials from the original designation of the five disposal sites in 1980;
2. The summary report from extensive monitoring of the two most heavily used disposal sites
(South O'ahu and Hilo) conducted by EPA in 2013;
3. The preliminary chemistry results from the monitoring survey of the Kahului, Nawiliwili, and
Port Allen ocean disposal sites conducted by EPA in 2017; and
4. The 2015 Site Management and Monitoring Plan (SMMP) that includes site use and
management requirements, including best management practices (BMPs) in the form of
enforceable permit conditions (Note: EPA intends to update the SMMP again following
completion of this programmatic consultation update).
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1.0 BACKGROUND
Currently, five EPA-designated ocean dredged material disposal sites (ODMDS) serve the state of
Hawai'i. These sites are off the islands of O'ahu, Hawai'i, Maui, and Kaua'i (Figure 1). They range
from 4 to 6.5 nautical miles (nmi) offshore, in waters from 1,100 to 5,300 feet (330 to 1,610 meters)
in depth (Table 1). Each site includes a small Surface Disposal Zone (SDZ) within which all disposal
actions must take place, and a larger site boundary on the seafloor where most of the sediment is
intended to deposit after falling through the water column.
Port Allen
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Kaiului ODMDS
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Figure 1. Vicinity map, showing the five existing Hawai'i EPA-designated ocean disposal sites.
Table 1. Dimensions and center coordinates for Hawai'i ocean disposal sites and their SDZs. The underlined
text reflects an update to the 2015 Site Management and Monitoring Plan.
Disposal Site
Depth Range
Shape and Dimensions
(Seafloor Footprint)
Surface Disposal Zone
(SDZ) Dimensions
Center Coordinates
(NAD 83)
South O'ahu
375-475 m
(1,230-1,560 ft)
Rectangular
2.0 (W-E) by 2.6 km (N-S)
(1.08 by 1.4 nmi)
Circular
305 in (1000 ft) radius
21° 15' 10" N,
157° 56' 50" W
llilo
330-340 m
(1,080-1,115 ft)
Circular
920 m (3000 ft) radius
Circular
305 m (1000 ft) radius
19° 48' 30" N
154° 58' 30" W
Nawiliwili
840-1,120 ill
(2,750-3,675 ft)
Circular
920 m (3000 ft) radius
Circular, offset
200 m (600 ft) radius:
[21° 55'15" N
159° 17' 13.8" W|
21° 55'00" N
159° 17' 00" W
Port Allen
1,460-1,610 ni
(4,800-5,280 ft)
Circular
920 m (3000 ft) radius
Circular
305 m (1000 ft) radius
21° 50' 00" N
159° 35' 00" W
Kahului
345-365 ill
(1,130-1,200 ft)
Circular
920 m (3000 ft) radius
Circular
305 m (1000 ft) radius
21° 04' 42" N
156° 29' 00" W
1
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The Hawai'i ocean disposal sites were designated together via rulemaking in 1981, based on a 1980
Final Environmental Impact Statement (EIS) completed by EPA Headquarters.1 The National Marine
Fisheries Service (NMFS) was consulted during the planning and selection stages for the designation
of the ocean disposal sites for the purposes of dredged material disposal. This consultation included
narrowing 14 proposed sites down to the five sites currently in use. The consultation focused
specifically on three ESA-listed species: the humpback whale, the Hawaiian monk seal, and the green
sea turtle. NMFS concluded that existing fisheries and endangered species under their jurisdiction
would be unlikely to be adversely impacted by the proposed use of the sites, primarily because of the
depths of the selected sites and the infrequent planned use of the sites. Appendix 1 includes the
portions of the EIS relevant to this consultation, including several letters from NOAA (Note: No
tracking number is included, as EPA does not have a record of NOAA applying tracking numbers to
discussions dating to this time period). Since that time, there have been additional species listed under
ESA. All relevant ESA-listed species are discussed in this assessment (Section 4). In addition,
Essential Fish Habitat (EFH) consultation was not required under Magnuson-Stevens Fishery
Conservation and Management Act (MSFCMA) at the time of site designation, therefore EPA has
included an EFH assessment herein as well (Section 5). EPA has determined that the five Hawai'i
ocean disposal sites overlap with Essential Fish Habitat (EFH) for various life stages of several
commercial fishery management unit species (MUS), including crustaceans, bottom fish, and
pelagics.
Dredged material disposal volumes in Hawai'i are quite modest, with a long-term annual average of
just over 220,000 cubic yards (cy) being disposed at all five sites combined (and even less since
2000; Table 2; USACE 2020a). As a comparison, the other seven ocean disposal sites managed by
EPA Region 9 receive an average total of approximately 3 million cy each year. The Hawai'i sites
also differ among themselves in use, reflecting the differing dredging needs of each island. The South
O'ahu site, which serves US Navy facilities at Pearl Harbor as well as Hawai'i's main commercial
port complex in Honolulu Harbor, is the most heavily used site, with at least some dredging and
disposal occurring in 22 of the 40 years. On average, disposal at the South O'ahu site accounts for
over 80% of all Hawai'i disposal. In recent years (since 2000), Hilo and Nawiliwili have been the
next most frequently used sites (receiving ~9 and 8% of the total material, respectively), followed by
Kahului (-2%). The Port Allen site has received no dredged material since 1999, however some
disposal may occur in 2021.
The Marine Protection, Research and Sanctuaries Act (MPRSA) and EPA regulations call for careful
alternatives analysis, design stipulations, and best management practices (BMPs) to reduce or
eliminate potential adverse effects to marine resources (see Section 3 for further details). For
example, the regulations only allow suitable, non-toxic sediments to be discharged at EPA-designated
ocean disposal sites; even when sediment is suitable for ocean disposal, it is only approved when
there is no practicable alternative. In addition, the disposal site designation process itself is an
important safeguard against any significant adverse impacts to marine resources, as EPA's site
designation criteria explicitly lead EPA to identify disposal sites in locations removed from important
habitat areas, fishing grounds, or other ocean uses, to the maximum extent practicable. Finally, ocean
disposal sites are all managed under a Site Management and Monitoring Plan (SMMP) that
enumerates any site-specific restrictions, limitations, or BMPs that may be needed to further
minimize impacts of ocean disposal. While ocean disposal site designations themselves are completed
1 The 1980 FEIS and other referenced documents supporting this consultation are available via:
https://www.epa.gOv/ocean-duniping/nianaging-ocean-duniping-epa-region-9#hi
2
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via formal rulemaking and are typically permanent, SMMPs are meant to be updated as needed based
on the results of required, periodic site monitoring, or on changed conditions such as updated
consultations.
Table 2. Disposal volumes (cy) at the five Hawai'i ocean disposal sites from 1981-2020 (Data source: EPA
compliance tracking records and USACE Ocean Disposal Database (USACE, 2020a)).
Year
South O'ahu
Hilo
Kahului
Nawilhvili
Port Allen
Total All Sites
1981
0
1982
0
1983
71,400
313,900
385,300
1984
2,554,600
2.554.600
1985
12,000
12.000
1986
0
1987
111,200
111.200
1988
57,400
57,400
1989
75,000
75,000
1990
1,198,000
80,000
58,000
343,000
1.679.000
1991
134,550
134.550
1992
233,000
233,000
1993
322,400
322,400
1994
0
1995
0
1996
27,800
27,800
1997
0
1998
0
1999
27,500
91,000
114,600
20,900
254.000
2000
0
2001
0
2002
53,500
53,500
2003
183,500
183.500
2004
540,000
540.000
2005
3,000
3,000
2006
160,400
160.400
2007
266,500
266.500
2008
0
2009
126,200
126.200
2010
0
2011
18,260
63,879
82.139
2012
70,981
70.981
2013
312,080
312.080
2014
351,920
351.920
2015
0
2016
53,900
118,300
57,200
64,700
294.100
2017
2018
2019
126,160
185,500
185.500
2020
235,000
235.000
Total 1981-2020
6,929,870
336,160
206,200
1.344.100
20,900
8,837,230
Average/year
182,365
8.404
5,155
33,603
523
220,931
Total 2000-2020
2,427,420
256.160
57,200
250,200
0
2,990,980
Average/year
2000-2020
121,371
12.198
2,724
11.914
0
142,428
3
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EPA recently completed extensive monitoring surveys at each of the five Hawai'i ocean disposal
sites. The South O'ahu and Hilo sites (the most heavily used of the Hawai'i sites) were the first to be
monitored, in 2013. The 2015 EPA synthesis report summarizing the results of that monitoring is
included as Appendix 2. Based on the monitoring results, EPA updated the SMMP for all the
Hawai'i sites in 2015 (Appendix 4). Similar monitoring surveys were also completed for the
Nawiliwili, Port Allen, and Kahului sites in 2017,2 and the SMMP for these sites will be updated
again based on those monitoring results and on the outcome of this ESA and EFH consultation with
your office.
2.0 l lll FIVE HAWAI'I OCEAN DISPOSAL SITES
This programmatic consultation update is being conducted for the five existing Hawai'i ocean
disposal sites. Continued use of these existing disposal sites is critical to national defense and the
maritime-related economy of the State of Hawai'i. The sites will continue to be used only for the
disposal of suitable, non-toxic sediment dredged by USACE from the federally authorized navigation
channels in Hawai'i's harbors, as well as for disposal of suitable, non-toxic dredged sediment from
other permitted navigation dredging projects in Hawai'i, including by the US Navy (refer to Section
3.2 for more details on sediment testing and suitability determination). Future disposal operations at
the sites will continue to meet all criteria and factors set forth in the Ocean Dumping regulations
published at 40 CFR Parts 228.5 and 228.6. Ocean disposal will also continue to occur under the
terms of an SMMP that sets forth BMPs in the form of enforceable permit conditions, as well as site
monitoring requirements and contingency actions should any adverse impacts be identified.
Continued use of the five existing Hawai'i sites will not in and of itself increase the need for dredging
or disposal in Hawai'i.
As identified by NMFS during pre-consultation coordination, ocean disposal of dredged material
theoretically has the potential to cause short-term adverse effects to living marine resources in the
water column and long-term effects to seafloor habitats and species. Various life stages of both ESA-
listed species and different commercial fishery MUS could be affected by disposal-related stressors
including turbidity and sedimentation, nutrients, and contaminants. However, EPA's ocean disposal
site selection, rigorous pre-disposal sediment testing, and site management collectively help to ensure
that adverse water column and seafloor effects to listed species, their habitats, and EFH are avoided
or minimized.
3.0 NEGLIGIBLE IMPACTS TO DATE
EPA's disposal site selection, project evaluation, and site management processes are intended to
ensure that ocean disposal produces no long-term, adverse impacts to the marine environment.
Specifically, EPA requires evaluation of disposal sites prior to designation, determination of the need
for ocean disposal, strict testing of sediments proposed for disposal, and management and monitoring
of the sites to ensure that permit conditions are met, the sites are performing as expected, and no
long-term adverse effects are occurring to the marine environment. These processes are described in
more detail in the following paragraphs.
2 A synthesis report is not yet available for the 2017 monitoring work, but the key results are discussed in this
consultation document, and preliminary chemistry results are available in Appendix 3.
4
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3.1 Disposal Site Designation
EPA's ocean disposal site designation process includes criteria for avoiding impacts to the aquatic
environment and to human uses of the ocean to the maximum extent possible, within an economically
feasible transport distance from the area where navigation dredging must occur. The site designation
process and regulations (promulgated under the MPRSA and the National Environmental Policy Act
(NEPA)) independently require evaluation of a variety of factors that minimize the potential effects of
disposal on marine species and their habitat. The MPRSA regulations at 40 CFR Part 228.5 - 228.6,
include the following disposal site selection criteria to avoid or minimize impacts on marine species
and their habitats:
• Disposal activities must avoid existing fisheries and shellfisheries (228.5(a));
• Temporary water quality perturbations from disposal within the site must be reduced to
ambient levels before reaching any marine sanctuary or known geographically limited fishery
or shellfishery (228.5(b));
• The size of disposal sites must be minimized in order to be able to monitor for and control any
adverse effects (228.5(d));
• Where possible, disposal sites should be beyond the edge of the continental shelf (228.5(e));
• The location of disposal sites must be considered in relation to breeding, spawning, nursery,
feeding or passage areas of living resources in adult or juvenile phases (228.6(a)(2));
• Dispersal and transport from the disposal site be must considered (228.6(a)(6));
• Cumulative effects of other discharges in the area must be considered (228.6(a)(7));
• Interference with recreation, fishing, fish and shellfish culture, areas of special scientific
importance and other uses of the ocean must be considered (228.6(a)(8)); and
• The potential for development or recruitment of nuisance species must be considered
(228.6(a)(10)).
Taken together, the site selection criteria are intended to ensure that EPA's ocean disposal site
designations avoid direct impacts to any important fishery or supporting marine habitat to the
maximum extent practicable, before any actual dredged material disposal is permitted. Based on these
site selection criteria, the five Hawai'i sites were identified as the environmentally preferred
alternative locations serving each of the five main Hawai'i port areas.
3.2 Dredged Material Testing
In addition, EPA's regulations establish strict criteria for evaluating whether dredged material is
suitable for ocean disposal (40 CFR Part 227.5-9). The regulations specify that certain prohibited
constituents, such as industrial wastes or high-level radioactive wastes, may not be disposed in the
ocean at all, while other constituents, such as organohalogen compounds or mercury, may only be
discharged if they are present in no more than "trace" amounts that will not cause an unacceptable
adverse impact after dumping. "Trace" is determined by passing a series of bioassays that address the
potential for short- and long-term toxicity and bioaccumulation. EPA and USACE have jointly
published national sediment testing guidance for conducting these evaluations in advance of
dredging, called the "Ocean Testing Manual," (OTM) (EPA, 1991).
5
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Sampling and Analysis Plans
EPA and US ACE review and approve sampling and analysis plans (SAPs) in advance of each
dredging project to ensure that the samples to be tested are representative of the material to be
dredged. The number and location of required sediment samples is informed by the volume to be
dredged and past testing history, but specific attention is focused on sampling near known or potential
sources of contamination such as outfalls, storm drains, repair yards, and industrial sites. Individual
samples may be composited for analysis only within contiguous areas expected to be subject to the
same pollutant sources and hydrodynamic factors (e.g., a single berth in a harbor). Representative
sediment collected pursuant to an approved SAP is then subjected to chemistry evaluations, toxicity
bioassays (for short-term water column and longer-term benthic impacts), and bioaccumulation tests,
as described below. The results are then compared to the same tests conducted with reference site
sediment (Note: The approved reference sediment for the Hawai'i sites is specified in the SMMP).
Sediment Chemistry
An extensive list of potential contaminants of concern is measured in each sediment sample or
composite, and in the reference sediment. Standard analytes and the associated recommended
laboratory methods and target detection limits are listed in the SMMP. These include "conventional"
properties such as grain size and organic carbon content, as well as heavy metals, organotins,
hydrocarbons, pesticides, poly-chlorinated biphenyls, and dioxins/furans. EPA and USACE can add
compounds to this standard list whenever deemed necessary. Sediment chemistry results can be
compared against various sediment guidelines (such as NOAA's effects range low (ERL) and effects
range median (ERM) values) to help inform the biological testing. However, there are no "bright-
line" sediment quality standards in the way that there are for water quality standards. Therefore,
sediment chemistry results alone are rarely adequate to determine whether a sediment "passes" or
"fails" for ocean disposal suitability.
Water-Column Testing
In contrast to the seafloor where potential exposure to disposed sediment is long-term, exposure to
disposal plumes in the water column is temporary. Nevertheless, to be "suitable" for ocean disposal,
water column assessments must confirm that temporary exposure to the suspended sediment
immediately following disposal will not exceed applicable marine water-quality criteria or cause
toxicity to representative sensitive marine organisms after allowance for initial mixing and dilution.
For each tested sediment sample, organisms are exposed to a series of concentrations of elutriate
(water plus suspended particulates) to determine the toxic concentration (LC50). A 100-fold safety a
factor is then applied, such that after initial mixing the water column plume may not exceed 1% of the
LC50 for the most sensitive organism tested. Three separate water-column bioassays are conducted,
with one species being a phytoplankton or zooplankton, one a larval crustacean or mollusc, and one a
fish. Species must be chosen from among a list of sensitive standard test species listed in the national
manual or specified in regional guidance.
All the Hawai'i disposal sites are offshore, in relatively deep water, where initial dilution is rapid and
disposal plumes dissipate to background levels quickly. Although potential water column effects are
assessed for every proposed project as described, water column testing alone has rarely, if ever,
"failed" a project for ocean disposal at any of the Hawai'i sites. Therefore, the potential for direct
effects to water column species, including planktonic species, filter feeders reliant on planktonic
species, or pelagic prey species, is considered discountable. Similarly, cumulative water column
effects are not expected because discharges from disposal vessels typically occur over only a few
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minutes, and individual disposal events are at least several hours apart, even in the most active
circumstances.
Benthic Testing
For the benthic toxicity assessment, at least two "solid phase" bioassays are conducted. For these
tests, sediment-associated species must be used that together represent key exposure routes including
filter-feeding, deposit-feeding, and burrowing life histories. Again, the test species must be chosen
from among a list of sensitive standard test species listed in the national manual (i.e., the OTM) or
regional guidance. If organism mortality is statistically greater than in the reference sediment and
exceeds reference sediment mortality by 10% (20% for amphipods), the sediment is considered
potentially toxic and may not be approved for ocean disposal. Solid phase benthic toxicity is usually
the cause when sediments "fail" for ocean disposal.
Bioaccumulation Testing
Bioavailability - the potential for contaminants to move from the sediment into the food web - must
also be evaluated in advance for each dredging project. Bioaccumulative contaminants are selected
and evaluated by EPA for each project based on their presence in the test sediment. Benthic
organisms are then exposed to the sediment (usually for 28 days), and concentrations of the
contaminants of concern taken into the tissues are measured. The tissue concentrations are then
compared against concentrations in tissues of the same species exposed to the reference sediment.
Depending on results, tissue concentrations may also be used in trophic transfer models, and/or
compared against available benchmarks such as any relevant total maximum daily loads (TMDLs),
state or local fish consumption advisories, and Food and Drug Administration (FDA) "Action Levels
for Poisonous or Deleterious Substances in Fish and Shellfish for Human Food."
"Tier IV" Testing
In the rare circumstance when the standard testing described above is unable to support a suitability
determination for ocean disposal, the presumptive conclusion is that the sediment is not suitable, and
ocean disposal may not be approved. However, if the dredger wishes, additional non-standard testing
may be approved by EPA and USACE. Described in the OTM as "Tier IV" testing, this can include
any evaluations EPA deems necessary to generate adequate information. For example, Tier IV can
involve more or different kinds of bioassays such as chronic sublethal tests or steady-state
bioaccumulation tests, detailed site-specific risk assessments, or forensic toxicity testing procedures
(TIEs, etc.). Because Tier IV testing is "open ended," it can be quite expensive, and there is no
guarantee that it will result in sediment being approved for ocean disposal. Thus, it is rarely applied in
practice.
3.3 Alternatives Analysis
EPA's regulations restrict ocean disposal of dredged material by outlining factors for evaluating the
need for ocean disposal and requiring consideration of alternatives to ocean disposal (40 CFR Part
227.14-16). Alternatives to ocean disposal, including beneficial uses of dredged material, are
considered on a project-by-project basis to ensure that the minimum necessary volume of dredged
material is disposed at any of the ocean disposal sites. Generally, alternatives to ocean disposal in the
islands are more limited than on the mainland. However, even sediments that have been adequately
characterized and found by EPA and USACE to be suitable for ocean disposal will not be permitted
for ocean disposal if there is a practicable alternative available. For example, clean sand that is
otherwise suitable for ocean disposal generally will not be permitted for disposal if it can be feasibly
used to nourish local beaches.
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3.4 Disposal Site Management: Best Management Practices
In addition to careful site selection, extensive sediment testing prior to dredging, and evaluation of
disposal alternatives, EPA actively manages ocean disposal sites to further minimize effects. Once a
dredging project is approved for ocean disposal at one of the Hawai'i sites, additional management
measures are taken to continue to minimize the potential for adverse effects. These management
measures, outlined in the SMMP for the Hawai'i sites (2015; Appendix 4), include:
• a variety of disposal BMPs as enforceable permit conditions for each project;
• satellite tracking all disposal vessels to ensure that disposal activities occur only where and as
required (Figure 2);
• sensors on all disposal vessels to ensure that there is no significant leakage or spilling of
dredged material during transit to the disposal site, especially during transit through the
nearshore zone where corals, seagrasses, and sensitive animals are most likely to be present;
and
• tracking and sensor information reported online for each disposal trip.
Figure 2. Example of a tracking report for an individual disposal trip. Panel A shows the vessel's route to and
from the disposal site, with the blue line indicating the vessel is loaded and purple indicating it is
empty following disposal. Panel B is a closeup of the disposal site's SDZ, showing the disposal (in
red) occurring fully within the zone. Panel C shows the vessel's draft and speed throughout the trip,
confirming no substantial loss of material from the vessel during transport.
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Additionally, disposal vessels using the five Hawai'i ocean disposal sites already operate at slow
speeds (generally 6 to 8 knots) consistent with NMFS recommendations for minimizing vessel
strikes. As exemplified in Figure 2, tracking information collected from dredging vessels indicates
that vessels generally operate at approximately 3 to 4 knots for the first half hour of transit from
shore, only increasing speed slightly in deeper waters. These slower speeds help to reduce the
potential for strike injuries to marine organisms.
3.5 Disposal Site Management: Site Monitoring
Monitoring Methods
As a critical component of site management, EPA periodically conducts surveys of disposal sites to
confirm that only physical effects occur within site boundaries, and that no adverse, physical,
chemical, or biological effects occur outside the disposal site. Research conducted by EPA and
US ACE since the inception of the MPRSA has shown that the greatest potential for environmental
impact from dredged material is in the benthic environment. This is because deposited dredged
material is not mixed and dispersed as rapidly or as greatly as the portion of the material that may
remain in the water column, and bottom-dwelling animals live in, and feed on, deposited material for
extended periods. Therefore, EPA monitoring of ocean disposal sites has focused primarily on the
benthic environment, including the sediment chemistry, physical characteristics of the benthos, and
the benthic community. EPA conducted extensive site monitoring surveys of the Hawai'i ocean
disposal sites in 2013 and 2017 (see Appendix 2 for the final report from the 2013 monitoring
surveys). During these surveys, EPA used a variety of methods to achieve the monitoring objectives,
including high-resolution multibeam echosounder surveys (MBES), sediment profile imaging (SPI)
and plan view photography (PVP), and sediment grabs for sediment chemistry and benthic infauna
sampling.
MBES surveys were successfully conducted for the Nawiliwili, Kahului, and Port Allen sites in 2017
to assist in selecting survey stations for the SPI-PVP and sediment grab sampling (Figure 3). MBES
surveys were also planned for the South O'ahu and Hilo sites in 2013, but they could not be executed
due to equipment issues on the vessel. In the absence of the MBES survey data, analysis of the SPI-
PVP imagery (described below) was used to map the horizontal and vertical extent of the dredged
material footprint and to select stations for the sediment chemistry and benthic infauna sampling.
The SPI-PVP system provides a surface and cross-sectional photographic record of selected locations
on the seafloor to allow a general description of conditions both on and off dredged material deposits
(Figure 4). SPI-PVP surveys were conducted for each ocean disposal site to delineate the horizontal
extent of the dredged material footprint both within and outside the site boundaries, as well as the
status of benthic recolonization. With resolution on the order of millimeters, the SPI system is more
useful than traditional bathymetric or acoustic mapping approaches for identifying a number of
features, including the spatial extent and thickness of the dredged material footprint over the native
sediments of the seabed, the level of disturbance and recolonization as indicated by the depth of
bioturbation, the apparent depth of the redox discontinuity, and the presence of certain classes of
benthic organisms. PVP is useful for identifying surface features in the vicinity of the SPI photos,
thereby providing important surface context for the vertical profiles at each station.
Additionally, sediment samples were collected from a subset of stations at each disposal site using a
stainless steel double Van Veen sediment grab capable of penetrating a maximum of 20 cm below the
sediment surface. The samples were analyzed for sediment grain size, chemistry, and benthic
community parameters.
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Figure 3. High-resolution bathymetry in the vicinity of the Nawiliwili disposal site. The hard-bottom habitat
and a volcanic escarpment in the southeastern portion of the site precluded benthic sampling in that
area. The yellow box indicates the target for the general area in which the SDZ would be
repositioned (see Figure 5 for final SDZ placement).
Plan-view image
"Down" position
1-2 meters On the transecting the sediment-
Deployed from seafloor seafloor water interface
profile
Figure 4. Schematic of deployment and collection of SPI-PVP photographs (Appendix 2).
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Finally, a sub-bottom profiling survey was conducted at the South O'ahu site. The primary purpose of
this survey was to collect cross-sectional images of the native sediment layers and layers indicative of
the dredged material deposit across a wide area surrounding the South O'ahu ocean disposal site. This
type of survey allowed EPA to separately estimate the cumulative volume of dredged material
disposed at the South O'ahu site, compared to volumes permitted for disposal. The South O'ahu site
was selected for the survey, because it receives the most dredged material out of the five Hawai'i
ocean disposal sites.
Monitoring Results
Sediment chemistry. Sediment samples from both inside and outside each of the five Hawai'i
disposal sites were collected successfully and analyzed for the same compounds evaluated during pre-
disposal testing. The bulk chemistry data from the 2013 monitoring surveys showed generally low,
but variable, concentrations of most chemical constituents at the South O'ahu and Hilo sites (the most
frequently used sites) (Appendix 2). The few concentrations above screening levels were relatively
minor in magnitude and, in many cases, were seen at stations both inside and outside the sites. The
few constituents that were at higher concentrations within the disposal sites reflect the contaminant
levels in the dredged material approved for discharge. Because sediments that contain pollutants in
toxic amounts, or elevated levels of compounds that may bioaccumulate in benthic organisms, are
prohibited from ocean disposal, the chemical concentrations identified are not considered to represent
a risk of environmental impacts in and of themselves. Instead, these low concentrations indicate that
the pre-dredge sediment testing regime is adequately protecting the environment of the disposal sites
by identifying and excluding more highly contaminated sediments from being disposed. Sediment
chemistry was also collected at the Nawiliwili, Kahului, and Port Allen ocean disposal sites, and is
currently being analyzed for results (preliminary results are available in Appendix 3; once the report
is finalized, it will be made available to NMFS). Preliminary screening indicates that, similar to the
South O'ahu and Hilo sites, the majority of chemical concentrations fell below the ERL, and the few
concentrations above screening levels were relatively minor in magnitude and, in most cases, were
seen at stations both inside and outside the sites.
Physical substrate. Physical substrate was assessed primarily through SPI-PVP imagery. Monitoring
confirmed that minor physical (substrate) changes have occurred at the disposal sites compared to
pre-disposal baseline data from 1980. Results of the 2013 survey indicated that a detectable dredged
material footprint extended outside of the South O'ahu site, however there have been no documented
"short-dumps" (i.e., discharge or loss of dredged material during transit to an ocean disposal site,
prior to arrival at the site) since EPA required satellite-based tracking of all disposal scows in the
early 2000s, with the exception of a single partial mis-dump that occurred in 2006. Thus, the footprint
outside the South O'ahu disposal site boundary would appear to be relic material deposited more than
10 years ago. At the Hilo site, the substantially smaller cumulative volume of dredged material
disposed (Table 2) appeared to be more fully confined within the designated disposal site boundary.
The results of the 2017 survey indicated that recently disposed dredged material, including coral and
pebble rubble, was present on the seafloor surface within and near the Nawiliwili ocean disposal site.
However, the commonplace presence of coral rubble and other coarse materials and sands at the
seafloor surface across the survey area confounded definitive delineation of the dredged material
footprint. Surveys at Port Allen and Kahului also indicated that the dredged material footprint was
primarily contained within the site boundary, yet some material was detectable beyond the designated
boundary to some extent at both sites. Again, because EPA has required satellite-based tracking of all
disposal scows since the early 2000s, and mis-dumping has not occurred at least since then, the
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dredged material observed outside the sites is also assumed to be relic material. Additionally, due to
benthic activity, dredged material was witnessed to have been reworked into the sediment. For
example, all material at the Port Allen ocean disposal site was observed to have been reworked into
the sediment column by biota to some extent and no thick deposits were observed.
Benthic community. The benthic community was assessed through both SPI imagery and sediment
grab samples. Overall, the changes in substrate may partially account for minor differences in
infaunal assemblages found during the 2013 monitoring at the South O'ahu and Hilo sites (the most
heavily used of the Hawai'i disposal sites). However, minor benthic community changes were also
seen outside those disposal sites and so appear to be partially attributable to region-wide variability as
well. In addition, there were no apparent adverse effects to the infaunal community associated with
the presence of dredged material at the Kahului and Port Allen ocean disposal sites. The vast majority
of stations across both survey areas supported stable benthic structure or advanced stages of infaunal
recolonization. The presence of advanced recolonization at stations containing dredged material
indicates that the benthic community has recovered at these locations post-disposal activity. Because
the Nawiliwili site was so heterogeneous, benthic community grab samples were not successfully
collected inside the site for comparison to the benthic community outside the site. However, the one
SPI replicate that achieved sufficient penetration near the center of the Nawiliwili site indicated the
presence of stage 3 (advanced) fauna. Additionally, as previously mentioned, disposal volumes at
Nawiliwili are relatively low, and preliminary screening of chemistry results indicated that dredged
material disposed did not appear to result in contaminant loading, as most of the contaminants were
below the ERL, and the few concentrations above screening levels were found both inside and
outside of the site. Therefore, all available results from Nawiliwili indicate that dredged material
disposed did not adversely affect the benthic environment. In summary, monitoring at all five sites
confirmed that recolonization begins soon after dredged material is deposited, and that similar
infaunal and epifaunal communities occupy areas both inside and outside the disposal sites. Thus,
long-term impact to benthic habitat quality are discountable and largely contained within the site
boundaries.
3.6 Disposal Site Management: An Adaptive Approach
Ongoing use of the five existing Hawai'i ocean disposal sites will not increase the need for dredging
in Hawai'i, nor the amount of ocean disposal of dredged material that occurs. It is therefore expected
that there would similarly be a lack of significant impacts in the future, provided that the ocean
disposal sites continue to be managed under the same or similar requirements. EPA proposes to
continue managing the five existing Hawai'i disposal sites under site use conditions and BMPs that
are substantially the same as those currently in place (see Appendix 4). The only substantive change
in site management is the recent relocation of the SDZ within the existing Nawiliwili site, as shown
in Figure 5, and as incorporated in permit conditions for the site. 3 This change was made based on
the results of the 2017 monitoring survey, which identified hard-bottom habitat (including a volcanic
escarpment, marking the ancient shoreline) in the southeastern portion of the Nawiliwili site (Figure
3). The relocated SDZ will avoid future deposition of sediment on the hard-bottom habitat and
facilitate future monitoring of dredged material discharges on the natural sediment habitat in the
northwestern portion of the site. This relocation of the SDZ is an example of EPA's adaptive
approach to site management.
3 The new SDZ will also be reflected in the updated SMMP, to be published following completion of these
consultations.
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N
s
0 0.260.5 1 Miles
1 1 I
Figure 5. The Nawiliwili disposal site, showing the realigned SDZ. EPA has moved the SDZ to avoid
deposition over hard-bottom habitat and facilitate monitoring of disposed sediments.
3.7 Enforcement
In addition to active, adaptive management of the five Hawai'i ocean disposal sites, EPA has strong
enforcement authority under the MPRSA for any violations related to disposal operations. Violations
may include dumping of unauthorized materials, dumping of materials in excess of authorized
amounts, dumping outside of designated sites, and spills or leaks from hopper dredges or scows
during transit to the ocean disposal sites. EPA authorities apply to violations of the MPRSA itself (for
unpermitted dumping) or of an MPRSA permit, (including violations relating both to dumping and
transportation for the purpose of dumping). If the provisions of a permit are violated, the permit may
be revoked or suspended; even if the permit is not revoked, the MPRSA authorizes EPA to require
ocean dumping activities to immediately cease when violations are imminent or continuing. EPA may
even suspend the use of the ocean disposal site altogether, if necessary. In addition to ensuring that
ongoing violations are stopped, EPA may impose monetary penalties when ocean dumping violations
occur. Administrative penalties imposed by EPA under the MPRSA can be quite heavy and serve as
an effective deterrent to ongoing ocean dumping violations. Consequently, it is rare that EPA is
forced to refer an ocean dumping case for judicial or criminal penalties.
Although the MPRSA does not expressly authorize penalty assessments for natural resource damages,
EPA considers the gravity of the violation (including effects to sensitive species or habitats), prior
violations, and the demonstrated good faith of the person charged when determining a civil penalty
amount. Finally, the MPRSA authorizes citizen suit enforcement as well However, the MPRSA does
not provide retain and use authority; under the Miscellaneous Receipts Act, fines and penalties are
transmitted to the general treasury rather than for purposes of mitigating any damage in and around
the ocean disposal site.
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Additionally, the BMPs included in EPA's SMMPs become enforceable conditions when attached to
the USACE's ocean disposal permits. Those conditions can include requirements that minimize the
risk of impacts should a violation occur, such as seasonal limitations or specified transit routes to and
from the disposal site. These kinds of specifications have not been applied to the Hawaii ocean
disposal sites in the past, but where necessary and feasible they could be included in the SMMP.
4.0 ESA SPECIES ASSESSMENTS
The five Hawai'i ocean disposal sites have been in use since their designation in 1981. NMFS was
consulted during the planning and selection stages for the designation of the sites. The consultation
focused specifically on three ESA-listed species: the humpback whale, the Hawaiian monk seal, and
the green sea turtle. NMFS concluded that existing fisheries and endangered species under their
jurisdiction would be unlikely to be adversely impacted by the proposed use of the sites, primarily
because of the depths of the selected sites and the infrequent planned use of the sites (Appendix 1).
Since that time, there have been additional species listed under ESA. As part of this informal update
to the programmatic consultation, EPA has assessed potential impacts to all relevant ESA-listed
species in the following sections. Through these assessments, EPA has again determined that the
continued use of the Hawai'i sites may affect, but is not likely to adversely affect, ESA-listed species.
4.1 Potential Impact Summary
NMFS has identified that ocean disposal of dredged material theoretically has the potential to cause
short-term adverse effects to marine organisms in the water column, and long-term effects to seafloor
habitats and species. Various listed species could potentially be affected by disposal-related stressors
including turbidity, sedimentation, and contaminants. However, EPA's management measures,
including ocean disposal site selection, rigorous pre-disposal sediment testing, and site use best
management practices, are effective at preventing adverse impacts to water column species, and
seafloor habitats and species.
Furthermore, marine mammals, sea turtles, and fishes, as well as corals, seagrasses, and other
important habitats, are generally much more susceptible to potential impacts associated with dredging
itself, rather than from open water disposal. Dredging typically occurs in relatively enclosed
waterbodies that may have restricted movement pathways, limiting animals' ability to avoid or
minimize exposure to noise or turbidity. If the sediment being dredged is contaminated, there may
also be increased risk of exposure to resuspended contaminants, depending on the presence and
effectiveness of dredging control measures such as silt curtains or timing restrictions. Dredging may
also temporarily or permanently damage or remove organisms or important habitat features such as
corals and seagrasses. Potential impacts from dredging itself are assessed by USACE on a project-
specific basis, during the USACE permitting process.
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In contrast, regardless of where or when the dredging occurs, placement of the sediment at any of the
five Hawai'i offshore disposal sites has significantly less potential to adversely affect pelagic or
benthic species at all life history stages for several reasons:
1. The sites were designated in locations originally selected to minimize impacts by avoiding
any unique or limited habitats to the extent practicable (as described in Section 3.1).
2. Only "suitable" (non-toxic) dredged material is permitted to be disposed. Rigorous pre-
dredging testing occurs to determine the suitability of material for disposal (as described in
Section 3.2). The testing examines persistence, toxicity, and bioaccumulation to ensure that
material disposed will not cause an unacceptable adverse impact after dumping. This testing
therefore ensures that trophic cascades are unlikely. As confirmed by EPA monitoring and
modelling, no short- or long-term contaminant exposure concerns are associated with the
discharged sediment.
3. Each disposal vessel is closely tracked during transit through the nearshore zone. This
tracking includes sensors to detect any substantial leaking or spilling of material that could
increase turbidity and suspended sediment near sensitive habitats, such as corals and
seagrasses. Disposal vessels that leak or spill must be removed from service and repaired
before being approved for continued use (refer to Section 3.7 on enforcement for more details
on how violations may be addressed).
4. Individual disposal events only last two to four minutes at the surface, and upper water
column plumes dissipate to background levels quickly. Sediments whose plumes would result
in any toxicity to sensitive water column organisms after initial mixing (including a 100-fold
safety factor) may not be permitted for ocean disposal. The short nature of the disposal, as
well as the low toxicity in the water column (as described in Section 3.2) also ensure that
filter feeders and other organisms in the water column are unlikely to be widely impacted by
any contaminants in the dredged material disposed.
5. Discharge volumes from individual disposal events range from approximately 1,000 cy
(which is typical for many harbor dredging projects not conducted by USACE, where
clamshell-dredged material is placed into towed scows) to as much as 5,000 cy at a time
(typical for USACE hopper dredging loads). Based on the average annual disposal volumes
(142,428 cy) since 2000 (Table 2), this equates to an average of 28 to 142 individual disposal
trips going to all five Hawai'i ocean disposal sites combined in any one year. As noted, this
degree of ocean disposal activity is modest in comparison to other disposal sites located in
Region 9.
6. EPA-required satellite tracking confirms that disposal vessels typically travel at maximum
speeds of 6 to 8 knots when transiting the approximate 4 to 6.5 nmi from harbor dredging
locations to the Hawai'i ocean disposal sites. These speeds are consistent with vessel speed
limitations recommended by NMFS to minimize vessel strikes to whales (Refer to Section 4.3
for a discussion on why these speeds are also likely to minimize strikes to sea turtles).
7. Vessels slow to nearly a stop during disposal activities. Additionally, the disposal sites are
several miles offshore in deep water, where there is more space for species to avoid the
vessels, and generally fewer foraging areas for certain listed species, such as turtles. Due to
the low speed of the vessels and the depths of the sites, potential injuries such as crushing
overhead injuries are very unlikely to occur.
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For these reasons, it is appropriate to programmatically assess the potential impacts of disposal of
suitable material at EPA-designated ocean disposal sites and to programmatically apply necessary
avoidance and minimization measures in the SMMP. USACE then includes the disposal sites'
programmatic disposal restrictions (as well as any dredging-related restrictions) as enforceable
conditions in individual permits for dredging projects.
Monitoring conducted in and around the five Hawai'i ocean disposal sites has not identified any
unacceptable adverse impacts resulting from previous disposal, and significant adverse effects are not
expected in the future, due to sediment quality testing procedures and site management measures,
including compliance requirements for vessel tracking. Based on the management and monitoring to
date, EPA has again determined that the continued use of the five Hawai'i ocean disposal sites may
affect but is unlikely to adversely affect the marine mammal, sea turtle, and fish species listed in
Table 3, as discussed below.
Table 3. NMFS-managed Species under ESA in the Pacific Islands Region (NMFS list from 7/31/18).
Species
Status
EPA Recommendation
Marine Mammals -
Cetaceans
Blue Whale
Endangered
May affect, not likely to
adversely affect
Hawaiian Insular False Killer
Whale
Endangered
May affect, not likely to
adversely affect
Hawaiian Insular False Killer
Whale Critical Habitat
May affect, not likely to
adversely affect
Fin Whale
Endangered
May affect, not likely to
adversely affect
North Pacific Right Whale
Endangered
May affect, not likely to
adversely affect
Sei Whale
Endangered
May affect, not likely to
adversely affect
Sperm Whale
Endangered
May affect, not likely to
adversely affect
Marine Mammals -
Pinnipeds
Hawaiian Monk Seal
Endangered
May affect, not likely to
adversely affect
Hawaiian Monk Seal Critical
Habitat
May affect, not likely to
adversely affect OR No Effect
Sea Turtles
Green Turtle, Central North
Pacific DPS
Threatened
May affect, not likely to
adversely affect
Hawksbill Turtle
Endangered
May affect, not likely to
adversely affect
Leatherback Turtle
Endangered
May affect, not likely to
adversely affect
Loggerhead Turtle, North
Pacific DPS
Endangered
May affect, not likely to
adversely affect
Olive Ridley Turtle
Threatened
May affect, not likely to
adversely affect
Olive Ridley Turtle (Mexican
Nesting Population)
Endangered
May affect, not likely to
adversely affect
Fishes
Giant Manta Ray
Threatened
May affect, not likely to
adversely affect
Oceanic Whitetip Shark
Threatened
May affect, not likely to
adversely affect
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4.2 Marine Mammals
Blue Whale (Balaenoptera musculus)
The blue whale is ESA-endangered and protected throughout its range. This species is the largest to
ever live on Earth. It feeds almost exclusively on krill. Blue whales can reach a weight of up to
330,000 pounds (165 tons) and a length of 110 feet. It can be found in very ocean except the Arctic,
They spend summers feeding in polar waters and migrate towards the equator to winter in warmer
waters. Along the western coast of the US, this species spends winters off Mexico and
Central America and can be found summering as far north as the Gulf of Alaska and central North
Pacific waters, but typically summer along the US West Coast. Figure 6 shows the range of this
species. Threats to this species include vessel strikes, entanglement, ocean noise, and commercial
whaling (https://www.f1sheries.noaa.g0v/species/blue-whale#overview).
Conservation efforts are in place through the ESA to minimize vessel strikes, including speed
reduction and avoiding migrations (https://www.fisheries.noaa. gov/species/blue-whale#conservation-
management). There is a slight possibility of the blue whale being present within the disposal sites or
the transit areas to the disposal sites. However, as noted above, disposal vessels using the five
Hawai'i ocean disposal sites already operate at slow speeds (6 to 8 knots) consistent with NMFS
recommendations for minimizing vessel strikes. Given the relatively small number of disposal events
each year, the temporary nature of disposal plumes in the water column, the non-toxic nature of
materials disposed, the limited physical substrate changes within disposal site boundaries, and the
slow speed of disposal vessels, EPA believes that continued operation of the five Hawai'i ocean
disposal sites may affect but is not likely to adversely affect this species.
Figure 6. World map showing the approximate range of the blue whale
(https://www.fisheries.noaa.gov/species/blue-whale).
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False Killer Whale - Hawaiian Insular DPS (Pseudorca crassidens)
The Main Hawaiian Island Insular False Killer Whale (MHIIFKW) is ESA-endangered. This whale
is technically a large member of the dolphin family. These social animals are found in all tropical and
subtropical oceans and generally in deep offshore waters. Population size is estimated at around 150
individuals. Individuals of this species grow to around 3,000 pounds; males grow up to 20 feet and
females grow to 16 feet. False killer whales are top predators; they hunt primarily pelagic fish and
squid and can dive to depths of 1,600 feet (500 m). They hunt in small groups, and occasionally share
prey. This species occurs in tropical, subtropical, and temperate waters of all ocean basins. A
recovery plan outline for the MHI IFKW includes the following recommendations: continue satellite
tagging and photo-identification efforts; research to reduce or eliminate injury and mortality from
fishing gear; educate the public to mitigate or reduce interactions; acquire biopsy samples for
research; and protect, maintain, and enhance habitat (NMFS, 2016). According to the recovery plan
outline, the highest threats to the MHI IFKW are incidental take in fisheries (including hooking,
entanglement, intentional harm) and the small population size of the DPS. However, other medium-
level threats such as environmental contaminants, competition with fisheries for food, effects from
climate change, and acoustic disturbance may also play a role in impeding recovery (NMFS, 2016).
(Figure 7 shows the range of this DPS (https://www.fisheries.noaa.gov/species/false-killer-whale).
The designated critical habitat for the MHI IFKW extends from waters 45 - 3,200 m deep
surrounding the MHI. The physical or biological features of this critical habitat that are essential to
the conservation of the DPS include: adequate space for movement and use within shelf and slope
habitat; prey species of sufficient quantity, quality, and availability to support individual growth,
reproduction, and development, as well as overall population growth; waters free of pollutants of a
type and amount harmful to MHI IFKWs; and sound levels that will not significantly impair false
killer whales' use or occupancy. The designated critical habitat for this species overlaps with each of
the five ocean disposal sites (Figure 8). It is therefore likely that this species will at times be present
in the water column around the disposal site locations. In addition, during their deepest dives these
whales could forage throughout the water column over the South O'ahu, Hilo, and Kahului disposal
sites (the Nawiliwili and Port Allen sites are too deep for this species to reach the seafloor).
However, as previously mentioned (Section 3.2) exposure to disposal plumes in the water column is
temporary. Further, for sediments to be determined "suitable" for ocean disposal, water column
assessments must confirm that temporary exposure to the suspended sediment immediately following
disposal will not exceed applicable marine water-quality criteria or cause toxicity to representative
sensitive marine organisms after allowance for initial mixing and dilution. Three separate water-
column bioassays are conducted on sensitive marine test species, with one species being a
phytoplankton or zooplankton, one a larval crustacean or mollusc, and one a fish. These tests must
confirm that disposal will not result in water column toxicity. Additionally, the Hawai'i disposal sites
are offshore, in relatively deep water, where initial dilution is rapid and disposal plumes dissipate to
background levels quickly. Cumulative water column effects are not expected because discharges
from disposal vessels typically occur over only a few minutes, and individual disposal events are at
least several hours apart, even in the most active circumstances. Finally, as noted above, disposal
vessels using the five Hawai'i ocean disposal sites already operate at slow speeds (6 to 8 knots)
consistent with NMFS recommendations for minimizing vessel strikes. Given the relatively small
number of disposal events each year, the temporary nature of disposal plumes in the water column,
the non-toxic nature of materials disposed, the limited physical substrate changes within disposal site
boundaries, and the slow speed of disposal vessels, EPA believes that continued operation of the five
Hawai'i ocean disposal sites may affect but is not likely to adversely affect the MHI IFKW. For these
18
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same reasons, the continued operation of the five sites may affect, but is not likely to adversely affect
the extent or quality of false killer whale critical habitat.
Figure 7. World map showing the approximate range of the false killer whale
(https://www.f1sheries.noaa.g0v/species/false-killer-whale#overview).
Warning Area ISA and
PMRF Offshore Areas
.r'-: : Kauiefcahi Channel Portion of W-186
r*
/
*»"¦
BOEM call Arises.
/ / ^
Kingfisher R&nge
FORACS
SESEF
Area north & offshore of Molokal
A
Ksula snfli Warning Afea 107
6*a Training Minefield
Warning Areas 196 and 191
Warning Areas 193 end J'
y
Kahoolawe Training Minefield
Hawaii Area Tracking system
Alenyihaho Channel
National Security Exclusions
Economic Exclusions
| Areas Not Eligible for Critical Habitat Designation
Final MHIIFKW Critical Habitat
so
(00 KfcHWtGTS
Figure 8. Map showing designated critical habitat for the endangered false killer whale around the Hawaiian
Islands. Approximate locations of the five ocean disposal sites shown as red triangles (not to scale).
19
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Fin Whale (Balaenopteraphysalus)
The fin whale is ESA-endangered and protected throughout its range. It is the second-largest species
of whale, reaching a weight of 40 to 80 tons (80,000 to 160,000 pounds) and a length of 75 to 85 feet.
This fast swimmer feeds on krill, small schooling fish, and squid during the summer, where it is
typically found in the Arctic and Antarctic. It fasts in the summer while migrating to warmer, tropical
waters. This species is primarily found far offshore in open waters. Figure 9 shows the approximate
range of this species.
Threats to this species include entanglement, vessel strikes, lack of prey due to overfishing, and ocean
noise; whaling is no longer a threat to this species (https://www.fisheries.noaa.gov/species/fin-
whale). Conservation efforts are in place through the ESA to minimize vessel strikes, including speed
reduction and avoiding migrations ( t:ps://www.fisheries.noaa.gov/species/fin-whale#conservation-
management). There is a slight possibility of the fin whale being present within the disposal sites or
the transit areas to the disposal sites. However, as noted above, disposal vessels using the five
Hawai'i ocean disposal sites already operate at slow speeds (6 to 8 knots) consistent with NMFS
recommendations for minimizing vessel strikes. Given the relatively small number of disposal events
each year, the temporary nature of disposal plumes in the water column, the non-toxic nature of
materials disposed, the limited physical substrate changes within disposal site boundaries, and the
slow speed of disposal vessels, EPA believes that continued operation of the five Hawai'i ocean
disposal sites may affect but is not likely to adversely affect this species.
Figure 9. World map showing the approximate range of the fin whale
(https://www.fisheries.noaa.gov/species/fin-whale).
20
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North Pacific Right Whale (Eubalaena japonica)
The North Pacific right whale is ESA-endangered and protected throughout its range, which includes
Alaska and the US West Coast. This whale is the rarest of all large whale species, with an estimated
population in the low 100s. The North Pacific right whale can grow to 100 tons (200,000 pounds) and
reach a length of 45 to 64 feet. It feeds on krill and small fish. Like other whales, it is suspected that
this species winters in warmer, southern waters, and summer in far northern feeding grounds. Figure
10 shows the range of this species.
Threats to this species include vessel strikes, entanglement, ocean noise, and harmful algal blooms.
Mariners are educated about safe vessel speeds to reduce noise and risk of vessel strikes
(https://www.fisheries.noaa.gov/species/north-pacific-right-whale). There is a very small possibility
of the north Pacific right whale being present within the disposal sites or the transit areas to the
disposal sites. However, as noted above, disposal vessels using the five Hawaii ocean disposal sites
already operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations for minimizing
vessel strikes. Given the relatively small number of di sposal events each year, the temporary nature of
disposal plumes in the water column, the non-toxic nature of materials disposed, the limited physical
substrate changes within disposal site boundaries, and the slow speed of disposal vessels, EPA
believes that continued operation of the five Hawai'i ocean disposal sites may affect but is not likely
to adversely affect this species.
Approximate ODMDS
Locations
Figure 10. World map showing the approximate of the North Pacific right whale's range
(https://www.fisheries.noaa.gov/species/north-pacific-right-whale').
21
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Sei Whale (Balcienoptera borealis)
The sei whale is ESA-endangered and protected throughout its range, which includes mid-latitude
waters throughout the world. This whale is primarily observed in deeper waters far from the coastline.
It feeds on plankton, small schooling fish, and cephalopods, and can reach a weight of 100,000
pounds (50 tons) and a length of 40 to 60 feet. Figure 11 shows the sei whale's range.
Threats to this species include vessel strikes, entanglement, and ocean noise. NOAA Fisheries
protects this species by minimizing the effects of noise disturbance, responding to stranded whales,
educating the public about this species, and monitoring population abundance and distribution
(https://www.fisheries.noaa.gov/species/sei-whale). There is very little chance of this species being
found in nearshore waters. Further, as noted above, disposal vessels using the five Hawai'i ocean
disposal sites already operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations.
Given the relatively small number of disposal events each year, the temporary nature of disposal
plumes in the water column, the non-toxic nature of materials disposed, the limited physical substrate
changes within disposal site boundaries, and the slow speed of disposal vessels, EPA believes that
continued operation of the five Hawai'i ocean disposal sites may affect but is not likely to adversely
affect this species.
Figure 11. World map showing the approximate range of the sei whale
(https://www.fisheries.noaa.gov/species/sei-whale').
22
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Sperm Whale (Physeter macrocephalus)
The sperm whale is ESA-endangered and protected throughout its range, which includes all deep
oceans and latitudes. It is the largest of the toothed whales, with females growing to 15 tons (30,000
pounds) and 40 feet, and males growing to 45 tons (90,000 pounds) and 52 feet. Due to the significant
amount of time spent in deep waters, its diet consists of larger species like squid, sharks, skates, and
fish. Migration is not widely seen in this species. Figure 12 shows the range of this species.
While whaling is no longer a threat to this species, vessels, entanglement, ocean noise, marine debris,
and contaminants still pose a threat. Efforts to protect this species include limiting activities that
cause excess noise or increased strike risk, responding to stranded or entangled whales, and educating
the public about the species, and monitoring activities (https .//www, fi sheri es. noaa. gov/speci es/sperm -
whal e# overvi ew). There is very little chance of this species being found in nearshore waters. Further,
as noted above, disposal vessels using the five Hawai i ocean disposal sites already operate at slow
speeds (6 to 8 knots) consistent with NMFS recommendations. Given the relatively small number of
di sposal events each year, the temporary nature of disposal plumes in the water column, the non-toxic
nature of materials disposed, the limited physical substrate changes within disposal site boundaries,
and the slow speed of disposal vessels, EPA believes that continued operation of the five ITawai'i
ocean disposal sites may affect but is not likely to adversely affect this species
Figure 12. World map showing the approximate range of the sperm whale
(https://www.fisheries.noaa.gov/species/sperm-whale').
23
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Hawaiian Monk Seal (Neomonachus schauimlaiidi)
The Hawaiian monk seal is one of the most endangered seal species in the world and endemic to the
Hawaiian archipelago. It is ESA-endangered, and its range encompasses the Pacific islands. This seal
can reach a weight of 400 to 600 pounds, and a length of 6 to 7 feet. It eats a varied diet, depending
on what's available, commonly including fishes, squids, octopuses, eels, and crustaceans. They prefer
warm, subtropical waters and spend 2/3 of their time at sea. They can dive to more than 1,800 feet
(550 m) to forage at the seafloor; however, they more commonly dive an average of 6 minutes to
depths of less than 200 feet (60 m). When on land, seals breed and haul-out to rest, give birth, and
molt on sand, corals, and volcanic rock shoreline. They prefer sandy, protected areas surrounded by
shallow waters for pupping. Figure 13 shows their range and critical habitat. Threats to this species
include food limitation, shark predation, entanglement, male aggression, habitat loss, disease, and
human impacts (https://www.fisheries.noaa.gov/species/hawaiian-monk-seal).
Hawaiian Monk Seal Critical Habitat
_
* O
Approximate
ODMDS
Locations
Panel A
Panel B
Panel C
CROSS-SECTION VIEW OF CRITICAL HABITAT
FOR HAWAIIAN MONK SEALS
Hawaiian monk seal critical habitat in tin? main Hawaiian Islands includes terrestrial
habitat that extends 5 meter? inland from the shoreline between designated boundaiy
points. Marine habitat extendi from the shoreline out to the 200 meter depth contour,
but only includes the seafloor and marine Itabitat 10 meters in height.
3
TERRESTRIAL
HABITAT
MARINE
¦ HABITAT -
5 METERS
* UNLAND **
SHORELINE
THE BOTTOM 10 METERS Of IWHTAT FROM SHORE
OUTTOTHE 200 METER DEPTH CONTOUR
Figure 13. Graphics pertaining to Hawaiian Monk Seal range and habitat: Panel A shows the world map with
the approximate range of monk seal (https://www.fisheries.noaa.gov/species/hawaiian-monk-seal');
Panel B shows a map of the critical habitat; Panel C shows a shows a cross-section view of critical
habitat.
24
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It is likely that this species will at times be present in the water column around the ocean disposal
locations. In addition, during their deepest dives these seals could potentially forage on the seafloor
near the South O'ahu, Hilo, and Kahului disposal sites (the Nawiliwili and Port Allen sites are too
deep for this species to reach). However, the Hawai'i disposal sites do not overlap with the critical
marine habitat for this species, as they are all deeper than the 200-meter contour (Figure 13).
Additionally, while disposal vessels may transit through critical habitat, they already operate at slow
speeds overall (6 to 8 knots), consistent with NMFS recommendations for minimizing vessel strikes,
and they operate at even slower speeds (less than 5 knots) in shallow waters surrounding the ports of
departure. Consequently, given the relatively small number of disposal events each year, the slow
speed of disposal vessels, the temporary nature of disposal plumes in the water column, the non-toxic
nature of materials disposed, and the limited physical substrate changes within disposal site
boundaries, EPA believes that continued operation of the five Hawai'i ocean disposal sites may affect
but is not likely to adversely affect the Hawaiian monk seal and its critical habitat.
4.3 Sea Turtles
Central North Pacific Green Sea Turtle (CheIonia mydas)
The Green sea turtle is one of the largest hard-shelled sea turtles, with adults weighing between 300
and 350 pounds and reaching 3 to 4 feet in length. The Central North Pacific DPS is ESA-threatened.
This species is herbivorous, feeding primarily on sea grasses and algae. They spend most of their time
in surface waters, typically diving no more than approximately 70 feet (20 m). This species of turtle
spends the majority of its time in nearshore waters and bays and lagoons, only entering the open
ocean for migration between foraging and nesting areas (https://www.fisheries.noaa.gov/species/
green-turtle#overview). Figure 14 shows the range of the green sea turtle. Threats to this species
include bycatch, direct killing of turtles and harvest of eggs, degradation and loss of foraging and
nesting habitats, and vessel strikes.
Approximate
ODMDS Locations
Figure 14. Range of the green sea turtle (https://www.fisheries.noaa.gOv/species/green-turtle#overview).
25
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This species is likely to be found within disposal sites or the transit areas to the disposal sites,
especially in nearshore waters during transit of vessels between dredging locations and the offshore
disposal sites. However, as noted above, disposal vessels using the five Hawai'i ocean disposal sites
already operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations for minimizing
vessel strikes. Moreover, tracking information collected from dredging vessels indicates that vessels
generally operate at approximately 3 to 4 knots for approximately the first half hour of transit from
shore, only increasing to 6 to 8 knots in deeper waters. Research conducted by Hazel et al (2007)
indicates that speed restrictions of 4 km/h (~2 knots) may be favorable to prevent vessel injuries in
shallow waters. However, this study was conducted in green sea turtle foraging habitat, from a 6 m
aluminum boat, in water shallower than 5 m. The authors selected these conditions to mimic
recreational boating patterns in sea turtle foraging habitat. EPA does not believe that the vessel type,
the depth of the study, and the habitat in which the study was conducted are representative of the
transport and disposal operations conducted to, and in, the Hawai'i ocean disposal sites. In addition,
the vessel traffic from dredged material disposal operations in Hawai'i is extremely low. Based on the
percent of vessel traffic in Hawai'i that is comprised of disposal vessels, EPA has determined that the
continued use of the Hawai'i ocean disposal sites may affect, but is unlikely to adversely affect, the
green sea turtle. The analysis that led to this conclusion is outlined in the following paragraphs.
Determining the proportion of vessel traffic attributed to disposal vessels
To determine the potential for turtle strikes from disposal vessels transiting to and from the Hawai'i
ocean disposal sites, EPA first attempted to estimate the percent of vessel traffic that is comprised of
disposal vessels. Discharge volumes from individual disposal events range from approximately 1,000
cy (which is typical for many harbor dredging projects not conducted by USACE, where clamshell-
dredged material is placed into towed scows) to as much as 5,000 cy at a time (typical for USACE
hopper dredging loads). A total of 1.24 million cubic yards was disposed at the five Hawai'i sites
combined, in the 10-year period from 2009 to 20184. This equates to an estimated range of 495 to
2,475 total transits to and from the Hawai'i ocean disposal sites during that time (Table 4).
Table 4. Volume of dredged material disposed, and minimum and maximum number of disposal vessel
transits, to and from all Hawai'i ocean disposal sites from 2009-2018.
Ocean
Disposal Site
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Total
South O'ahu
126,200
18,260
312,080
351,920
53,900
862,360
Hilo
63,879
70,981
118,300
253,160
Kahului
57,200
57,200
Nawiliwili
64,700
64,700
Port Allen
0
Total All Sites
126,200
0
82,139
70,981
312,080
351,920
0
294,100
1,237,420
Min. # of
Trips (both
ways)
50
0
33
28
125
141
0
118
0
0
495
Max. # of
Trips (both
ways)
252
0
164
142
624
704
0
588
0
0
2,475
4 Note: This specific ten-year period was selected for comparison to the most recent vessel transit data available on the
USACE waterborne commerce database.
26
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EPA then estimated total vessel traffic by examining commercial vessel traffic from the US ACE
waterborne commerce database (US ACE, 2020b) and the_Hawai'i Department of Land and Natural
Resources (DLNR) commercial fishing database (Hawai'i DLNR, 2020). The USACE database
includes transits from self-propelled and non-self-propelled dry cargo ships (including passenger
vessels and cruise ships), self-propelled and non-self-propelled tankers, self-propelled towboats, and
non-self-propelled tanker liquid barges. Vessel transits were compiled from all ports in Hawai'i for
which there are records in the database. Over the most recent ten-year period in the database (2009 to
2018) there were a total of 144,925 transits from the ports examined (Table 5; USACE, 2020b). The
DLNR database contains fishing reports from licensed commercial fishermen, including the number
of trips conducted per year by location. EPA compiled all trips reported from 2009 to 2018, and
multiplied the number by two to account for total transits. In total, there were 125,966 transits
(62,983 trips) conducted in Hawai'i from 2009 to 2018 (Table 6; Hawai'i DLNR, 2020).
To estimate the proportion of vessel traffic attributed to disposal vessels, EPA divided the total
transits from disposal vessels by the total transits from commercial vessels reported in the two
databases (270,981). Therefore, the ten-year estimate of 495 to 2,475 disposal vessel transits only
constitutes 0.18% to 0.91% of the total commercial vessel transits.
It is important to note that this estimate of total vessel transits over a ten-year period is highly
conservative, as the combined numbers from the USACE and DLNR databases do not include local
and foreign military nor recreational vessels. Therefore, disposal vessels realistically account for an
even lower percentage of vessel traffic than estimated in this document.
Table 5. Ten-year commercial vessel transits by port (USACE waterborne commerce database). These
numbers of transits include receipt (incoming) and shipment (outgoing) transits, but do not include
fishing vessels.
Port
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
Total
Barbers
Point
Harbor
1,482
1,661
2,415
2,327
2,074
1,938
2,049
1,614
1,784
1,860
19.204
Hana
Harbor
0
0
0
0
0
0
0
0
0
0
0
Hilo
1,066
1,082
1,184
1,815
1,405
1,141
1,262
2,034
1,473
1,499
13,961
Port of
Honolulu
4,207
5,147
5,689
8,435
6,653
4,870
5,716
8,013
6,881
7,029
62,640
Kahului
1,400
1,359
1,601
2,617
2,044
1,357
1,779
2,917
1,967
2,026
19,067
Kailua
0
0
0
0
0
0
0
0
0
0
0
Kalaupapa
Harbor
0
0
0
0
0
0
0
0
0
0
0
Kaunakakai
11
142
252
230
245
246
303
227
411
430
2,497
Kawaihae
Harbor
756
852
907
1,527
1,095
692
1,011
3,509
1,307
1,183
12,839
Nawiliwili
984
1,057
1,172
1,762
1,340
968
1,019
4,175
1,149
1,091
14,717
Pearl
Harbor
0
0
0
0
0
0
0
0
0
0
0
Port Allen
0
0
0
0
0
0
0
0
0
0
0
Total
9,906
11,300
13,220
18,713
14,856
11,212
13,139
22,489
14,972
15,118
144,925
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Table 6. Ten-year commercial fishing vessel trips and transits in Hawai'i (DLNR commercial fishing
database).
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
Total
Total
Trips
4,652
3,916
3,664
4,951
4,944
5,876
9,783
9,258
8,199
7,740
62,983
Total
Transits
9,304
7,832
7,328
9,902
9,888
11,752
19,566
18,516
16,398
15,480
125,966
Estimating turtle mortalities and injuries due to vessels
To determine the potential number of turtle strikes caused by disposal vessels, EPA then estimated
the total mortalities and injuries of green sea turtles in a given year in Hawai'i. EPA used turtle
stranding data from the 2015 NMFS Hawai'i sea turtle stranding report (the most recent year of
complete data available) to estimate the number of green turtle strandings due to vessel strikes
(NMFS, 2015). Because it is not possible to tell whether strike injuries occurred pre- or post-mortem,
EPA conservatively considered all stranded green turtles with strike injuries to have been caused by
vessel strikes, including strandings listed as caused by "shark/boat impact" (two strandings) and those
listed as "unknown" but with signs of vessel strikes (two strandings). In sum, this constituted 23
reported strandings that were potentially caused by vessel strikes in 2015.
Because a high percentage of turtles stranded from vessel strikes subsequently die, EPA assumed that
none of 23 turtles reported as stranded had survived. However, the number of reported strandings is
likely a low estimate of the total turtle mortality due to vessel strikes within a given year; several
studies have determined that the probability that a turtle that has died at sea subsequently strands
ranges from 10 to 20% (Epperly et al. 1996; Hart et al. 2006). Therefore, using 10% as a conservative
estimate, EPA estimates that a total of 230 turtles may have been killed by vessel strikes in 2015.
In addition to lethal vessel strikes, it is also likely that non-lethal vessel strikes occur. Although EPA
was not able to find studies conducted in Hawai'i that estimate the percent of lethal versus non-lethal
turtle strikes, NMFS has estimated that approximately 75% of green turtle vessel strikes in the Gulf of
Mexico would be lethal, and 25% would be non-lethal (NMFS, 2018). Using these percentages and
the previous estimate of 230 lethal turtle strikes, EPA determined that there may have been
approximately 77 non-lethal turtle strikes by vessels in Hawai'i in 2015.
Estimating the number of mortalities and injuries caused by disposal vessels
By multiplying the number of green turtle strikes with the percent of traffic that is composed of
disposal vessels, it can be suggested that disposal vessels may be responsible for less than one to as
many as two vessel strike mortalities, and less than one non-lethal strike per year. However, it is
important to remember that these numbers are likely largely overestimated, as they are based on
numbers that are highly conservative: the vessel traffic data did not include any recreational or
military vessel transits, the upper range of disposal vessel transits based on low dredged material
holding capacity is conservative, and the percentage used to estimate total turtle strikes based on
strandings is conservative. Therefore, the number of strikes attributed to disposal vessels is
realistically even lower than the estimates presented here, and consequently EPA believes the
potential for strikes from disposal vessels is discountable.
28
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Furthermore, disposal vessels operate at much slower speeds than many other vessels operating in
Hawaiian waters. For example, many Navy vessels operate at speeds of 10-15 knots, with certain
vessels achieving speeds of up to 30 to 50 knots while conducting propulsion testing (NMFS, 2018).
Many commercial vessels also operate at speeds exceeding 20 knots in open waters. For example,
container ships typically reach a full speed of 24 knots (Agarwal, 2020). Because vessels operating at
higher speeds are more likely to cause turtle strikes (Hazel, 2007), it can be expected that disposal
vessels are even less likely to cause turtle strikes than other types of vessels that are operating at
greater speeds in Hawaiian waters.
Moreover, vessel strikes are generally more likely to occur in areas with high turtle densities, such as
in proximity to nesting beaches or in nearshore foraging areas. The majority of the transit paths
followed by disposal vessels are offshore, in deep waters, where turtle density is likely to be lower.
As noted, disposal vessels already operate at slower speeds in nearshore environments, where turtle
density is likely to be higher. Tracking information collected from disposal vessels indicates that they
generally operate at approximately 3 to 4 knots for approximately the first half hour of transit from
shore, only increasing to 6 to 8 knots in deeper waters.
Therefore, due to the very low percentage of vessel traffic comprised of disposal vessels, the slow
speed of disposal vessels, and the large majority of operations occurring in deep waters, this species
may be affected but is not likely to be adversely affected by the continued use of the Hawai'i sites.
Hawksbill Turtle (Eretmochelys imbricata)
The hawksbill turtle is ESA-endangered throughout its range. The hawksbill turtle has a diverse
foraging strategy, and its diet, consists primarily of sponges that live on coral reefs, as well as
jellyfish and anemones. This species has a mixed migratory strategy. Some will migrate long
distances between nesting beaches and foraging areas; Hawaiian hawksbills travel 50 to 200 miles
between nesting and foraging grounds. Hawksbills are commonly found in shallow water (less than
60 feet (18 m) around coral reefs. Juveniles are typically found in the open ocean, and slightly older
individuals migrate to shallower coastal feeding grounds. Adults reach a weight of 100 to 150 pounds
and a length 25 to 35 inches. Figure 15 shows the range of this species.
Threats to this species include entanglement, marine debris, disease, chemical pollution, noise, habitat
degradation and loss, and harvest (https://www.fisheries.noaa.gov/species/hawksbill-turtle). Recovery
actions include protecting turtles on nesting beaches, protecting nesting and foraging habitats,
reducing bycatch, reducing the effects of entanglement and ingestion of debris, and supporting
research and conservation projects (https://www.fisheries.noaa.gov/species/hawksbill-
turtle#conservation-management).
It is likely that this species will be present at times in the disposal sites or transit area to the ocean
disposal sites, especially in nearshore waters. However, as discussed above, the low speed and very
low traffic associated with dredged material disposal at the five ocean disposal sites also help to
ensure that strikes are avoided. Given the information presented, this species may be affected but is
not likely to be adversely affected by the continued use of the Hawai'i ocean disposal sites.
29
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Approximate Range of Eretmochelys imbricata - Hawksbiil Sea Turtle
E. i. bissa - Pacific Hawksbiil Sea Turtle
# Most common range
# Less common range and range of oceanic juveniles
E. i. imbricata - Atlantic Hawksbiil Sea Turtle
# Most common range
0 Less common range and range of oceanic juweniies
9 Some nesting areas
Figure 15. World map showing the approximate range of the hawksbiil sea turtle
(http://www.califortiiaherDs.eom/turtles/pages/e.i.bissa.html).
Leatherback Sea Turtle (Dermochelys coriacea)
The Leatherback sea turtle is the largest turtle in the world, growing to 4.5 to 5.5 feet long and
weighing up to 2,200 pounds. This is the only species of turtle that lacks a hard shell and scales and is
instead covered in a leathery skin. This species is highly migratory, swimming up to 10,000 miles a
year between nesting and foraging grounds. The leatherback spends most of its life in the water, with
females beaching only to lay eggs. It preys on soft water column species, like jellyfish and salps
(https://www.fisheries.noaa.gov/species/leatherback-turtle). Although leatherbacks on average dive to
about 540 feet (150 m), they can dive to as much as 4,100 feet (1,250 m), and thus could forage all
the way to the seafloor at the South O'ahu, Hilo, Kahului, and Nawiliwili sites (only Port Allen is too
deep). Figure 16 shows the approximate range of this species.
It is likely that this species will be present at times in the disposal sites or transit area to the ocean
disposal sites. However, as noted above, disposal vessels using the five Hawai'i ocean disposal sites
already operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations for minimizing
vessel strikes. In addition, given the relatively small number of disposal events each year, the non-
toxic nature of materials disposed, the turtle's water column foraging behavior and the temporary
nature of disposal plumes in the water column, EPA believes that continued operation of the five
Hawai'i ocean disposal sites may affect but is not likely to adversely affect the leatherback sea turtle.
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Approximate
ODMDS Locations
Figure 16. World map showing the leathcrback's range (https://www.fisheries.noaa.gov/species/leatherback-
turtle).
Loggerhead Turtle (Caretta caretta)
The North Pacific DPS of this species is ESA-endangered. It can weigh up to 250 pounds and reach a
length of 3 feet. Loggerheads are primarily carnivores; feeding on bottom-dwelling invertebrates like
whelks, mollusks, horseshoe crabs, and sea urchins. This DPS nests only on the coasts of New
Caledonia and Australia, where there are high-energy waves and relatively narrow, steeply sloped,
coarse-grained beaches. It migrates long distances to forage for food and can dive for as long as 10
hours. The deepest reported dive for a loggerhead was 1,100 feet (340 m), although mean dive depths
are 50 m or less.
Threats to this species include harvest, entanglement, marine debris, disease, chemical pollution,
noise, and habitat degradation and loss (https://www.fisheries.noaa.gov/species/loggerhead-
turtle#overview). Conservation efforts for this species include protecting turtles on nesting beaches;
protecting nesting and foraging habitats; reducing by catch; reducing the risk of entanglement;
working internationally to protect endangered species; and supporting research and conservation
efforts (https://www.f1sheries.noaa.g0v/species/loggerhead-turtle#conservation-management). Figure
17 shows the range of the loggerhead.
It is likely that this species will be present at times in the disposal sites or transit area to the ocean
disposal sites. However, as noted above, disposal vessels using the five Hawaii ocean disposal sites
already operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations for minimizing
vessel strikes. In addition, during their deepest dives these turtles could forage on the seafloor near
the South O'ahu, Hilo, and Kahului disposal sites (the Nawiliwili and Port Allen sites are too deep for
this species to reach). However, given the small number of disposal events each year, the slow speed
of disposal vessels, the temporary nature of disposal plumes in the water column, the non-toxic nature
of materials disposed, and the limited physical substrate changes within disposal site boundaries, EPA
believes that continued operation of the five Hawai'i ocean disposal sites may affect but is not likely
to adversely affect the North Pacific DPS of the loggerhead turtle.
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Figure 17. World map showing the approximate range of the loggerhead turtle
(https://www.fisheries.noaa.gOv/species/loggerhead-turtle#overview).
Olive Ridley Sea Turtle (Lepidochelys olivacea)
The olive ridley sea turtle is among the smallest of the world's sea turtles, growing up to 100 pounds
and reaching a length of 22 to 3 I inches. The Mexican nesting population of the olive ridley is
endangered under the ESA, all other populations of the olive ridley sea turtle are threatened.
Individuals from multiple populations may occur in Hawai'i. This turtle spends most of its life in the
open ocean, beaching only to nest. Olive ridleys have been recorded to dive up to 820 feet (250 m);
all the Hawai'i disposal sites are in deeper water than this. They are omnivorous, feeding on algae,
crustaceans, tunicates, mollusks, and fish. Threats to this species include bycatch, harvest,
entanglement, pollution, and habitat degradation and loss
(https://www.fisheries.noaa.gov/species/olive-ridlev-turtle). Figure 18 shows the range of this
species.
While rare in Hawai'i, olive ridley sea turtles have occasionally been killed by commercial fishing
vessels (NMFS-USFWS, 1998). The entanglement of juveniles and adults in marine debris around the
Hawaiian islands is reported from multiple islands, including Hawai'i, Molokai, Maui, and Oahu
(Balazs, 1985). Threats to olive ridleys in the oceans surrounding the main Hawaiian islands are
predominantly marine debris (entanglement or ingesting) and incidental take by fisheries in domestic
and international waters (NMFS-USFWS, 1998). Conservation actions for olive ridley sea turtles in
Hawai'i are focused on cooperating with jurisdictions where nesting occurs to restore nesting habitat
and working to reduce marine debris (Hawai'i DLNR, 2013). While it is likely that this species will
be present at times in the disposal sites or the transit areas to the disposal sites, olive ridley sea turtles
are generally less common in Hawaiian waters. For example, out of the 141 sea turtle strandings on
the island of Maui in 2019, only one olive ridley turtle was reported stranded (in this case due to
entanglement in a fishing net) (MOC Marine Institute, 2020). As mentioned in the analysis of effects
to green sea turtles, disposal vessel traffic consists of a very low percentage of the total vessel traffic
in around the main ITawaiian islands. Further, disposal vessels using the five Hawai'i ocean disposal
sites already operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations for
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minimizing vessel strikes. In addition, given the non-toxic nature of materials disposed, the
temporary nature of disposal plumes in the water column, and that the disposal sites are all in water
deeper than this species dives, EPA believes that continued operation of the five Hawai'i ocean
disposal sites may affect but is not likely to adversely affect the endangered and threatened
populations of the olive ridley sea turtle.
Aepnpanatc Rnje isf Icp&Ktvlj? gkumxi ¦ Ww Rtfa Sw Ttrfe
9 eawsoo rsrs» cf a->3 Ws* m««n«s
• less ouman range xiJti XV ij'je jimmies and rarqe of {raamcjuneniw
• Some
Figure 18. Approximate range of the Olive Ridley sea turtle
(http://www.califomiaherps.com/turtles/maps/xlolivaceaworldrangemap4.ipg).
4.4 Fishes
Giant Manta Rav {Mania birostris)
The giant manta ray is the world's largest ray, with a wingspan of up to 29 feet, a length of up to 23
feet, and a weight of up to 5,300 pounds. It is ESA-threatened throughout its range, which includes
New Engl and/Mid-Atlantic, the Pacific Islands, and the Southeast. This filter-feeding species
consumes large quantities of zooplankton. While manta rays typically feed in shallow waters, they
can dive as deep as 3,300 feet (1,000 m). They are highly migratory, and are commonly found
offshore, in oceanic waters, and near productive coastlines. Trends show that this species migrates
based on prey availability (https://www.f1sheries.noaa.g0v/species/giant-manta-rav#overview).
Figure 19 shows the range of manta rays.
It is likely that this species will be present at times in the disposal sites or the transit areas to the
disposal sites. However, as noted above, disposal vessels using the five Hawai'i ocean disposal sites
operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations for minimizing vessel
strikes. In addition, for sediments to be "suitable" for ocean disposal, water column assessments must
confirm that temporary exposure to the suspended sediment immediately following disposal will not
33
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exceed applicable marine water-quality criteria or cause toxicity to representative sensitive marine
organisms after allowance for initial mixing and dilution (see Section 3.2). Three separate water-
column bioassays are conducted on sensitive marine species, with one species being a phytoplankton
or zooplankton, one a larval crustacean or mollusc, and one a fish. These tests must confirm that
disposal will not result in water column toxicity. Moreover, exposure in the water column is
temporary, and all the Hawai'i disposal sites are offshore, in relatively deep water, where initial
dilution is even more rapid and disposal plumes dissipate to background levels quickly. Therefore,
the potential for adverse effects to water column species, including the filter-feeders like the giant
manta ray, and their planktonic food sources, is considered discountable. Finally, the disposal
volumes are relatively low and infrequent across the five Hawai'i sites. Given the relatively small
number of disposal events each year, the non-toxic nature of materials disposed, the ray's water
column foraging behavior and the temporary nature of disposal plumes in the water column, EPA
believes that continued operation of the five Hawai'i ocean disposal sites may affect but is not likely
to adversely affect this species.
Figure 19. World map showing the approximate range of manta rays (https://seetliewild.org/manta-rav-habitat-
map/).
Oceanic Whitetip Shark (Carcharhinus longimanus)
The oceanic whitetip shark is ESA-threatened throughout its range, which includes New
England/Mid-Atlantic, the Pacific Islands, Southeast, and the US West Coast. It is found in tropical
and subtropical oceans throughout the world Oittps://www.fisheries.noaa.gov/species/oceanic-
whitetip-shaik#overview). This species is pelagic, remaining typically offshore in the open ocean, but
can also be found on the outer continental shelf or around oceanic islands in water depths greater than
600 feet, occupying the upper water column from the surface to about 500 feet. This pelagic species
is a top predator and is an opportunistic hunter. It feeds primarily on bony fishes and cephalopods, but
can be noted feeding on pelagic sportfish, sea birds, other sharks and rays, marine mammals, and
even garbage. Threats to this species include bycatch and harvest for international trade. Figure 20
shows the range of this species.
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It is likely that this species will be present at times in the disposal sites or the transit areas to the
disposal sites. However, as noted above, disposal vessels using the five Hawai'i ocean disposal sites
already operate at slow speeds (6 to 8 knots) consistent with NMFS recommendations for minimizing
vessel strikes. In addition, to be "suitable" for ocean disposal, water column assessments must
confirm that temporary exposure to the suspended sediment immediately following disposal will not
exceed applicable marine water-quality criteria or cause toxicity to representative sensitive marine
organisms after allowance for initial mixing and dilution (see Section 3.2). Three separate water-
column bioassays are conducted on sensitive marine species, with one species being a phytoplankton
or zooplankton, one a larval crustacean or mollusc, and one a fish. These tests must confirm that
disposal will not result in water column toxicity. Moreover, exposure in the water column is
temporary, and all the Hawai'i disposal sites are offshore, in relatively deep water, where initial
dilution is even more rapid and disposal plumes dissipate to background levels quickly. Therefore,
the potential for adverse effects to water column species, including pelagic feeders like the oceanic
whitetip shark and their food sources, is considered discountable. Finally, the disposal volumes are
relatively low and infrequent across the five Hawai'i sites. Given the relatively small number of
disposal events each year, the non-toxic nature of materials disposed, the shark's water column
foraging behavior and the temporary nature of disposal plumes in the water column, EPA believes
that continued operation of the five Hawai'i ocean disposal sites may affect but is not likely to
adversely affect this species.
Figure 20. World map showing the approximate range of the oceanic whitetip shark
(https://www.epicdiving.com/oceanic-whitetip-shark/).
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5.0 EFH ASSESSMENT
5.1 Assessment of EFH overlap with Hawai'i Ocean Disposal Sites
EFH consultation under the Magnuson-Stevens Fishery Conservation and Management Act
(MSFCMA) was not required at the time of the original designation process for the five Hawai'i
ocean disposal sites. Assessment of current EFH designations indicates that the Hawai'i ocean
disposal sites each overlap with designated EFH for life stages of multiple commercial fishery MUS
(Table 7). The water column above the five Hawai'i ocean disposal sites intersect with EFH for the
crustacean (Kona crab egg/larval life stage), bottomfish (eggs and post-hatch pelagic of the shallow,
intermediate, and deep stocks), and pelagic (egg/larval and juvenile/adult life stages) MUS. In
addition, the South O'ahu, Hilo, Kahului sites intersect with the benthic EFH for the bottomfish deep
stocks MUS (post-settlement and sub-adult/adult life stages). None of the sites intersect with EFH for
the precious coral MUS. Additionally, EPA has determined that the Hilo ocean disposal site overlaps
with HAPC designated for bottomfish stocks (Table 8). Based on the assessment below, EPA has
determined that continued use of the five Hawai'i ocean disposal sites may adversely affect EFH,
however the effects are expected to be minimal.
Table 7. EFH Designations for Managed Commercial Fisheries in Hawai'i (source: Draft PIRO EFH
Designations, 2019).
MUS
Stock/ Stock
Complex
Life Stage(s)
EFH Designation
Intersection
with ODMDS
Crustacean
Kona crab
Egg/larval
The water column from the shoreline to
the outer limit of the EEZ down to a
depth of 150 m (75 fm)
All ODMDS
Juvenile/adult
All of the bottom habitat from the
shoreline to a depth of 100 m (50 fm)
None
Deepwater
shrimp
Egg/larval
The water column and associated outer
reef slopes between 550 and 700 m
None
Juvenile/adult
The outer reef slopes at depths between
300-700 m
None
Bottomfish
Shallow
stocks:
Aprion
virescens
Egg
Pelagic zone of the water column
in depths from the surface to 240
m, extending from the official US
baseline to a line on which each
point is 50 miles from the baseline
All ODMDS
Post-hatch
pelagic
Pelagic zone of the water column in
depths from the surface to 240 m,
extending from the official US
baseline to the EEZ boundary
All ODMDS
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MUS
Stock/ Stock
Complex
Life Stage(s)
EFH Designation
Intersection
with ODMDS
Post-settlement
Benthic or benthopelagic zones,
including all bottom habitats, in depths
from the surface to 240 m bounded by
the official US baseline and 240 m
isobath
None
Sub-adult/adult
Benthopelagic zone, including all
bottom habitats, in depths from the
surface to 240 m bounded by the official
US baseline and 240 m isobath.
None
Eggs
Pelagic zone of the water column in
depths from the surface to 280 m (A.
rutilans and P. filamentosus) or 320 m
(H. quernus) extending from the official
US baseline to a line on which each
point is 50 miles from the baseline
All ODMDS
Intermediate
Post-hatch
pelagic
Pelagic zone of the water column in
depths from the surface 280 m (A.
rutilans and P. filamentosus) or 320 m
(H. quernus), extending from the
official US baseline to the EEZ
boundary
All ODMDS
stocks:
Aphareus
rutilans,
Pristipomoides
filamentosus,
Hyporthodus
quernus
Post-settlement
Benthic (H. quernus and A. rutilans) or
benthopelagic (A. rutilans and P.
filamentosus) zones, including all
bottom habitats, in depths from the
surface to 280 m (A. rutilans and P.
filamentosus) or 320 m (H quernus)
bounded by the 40 m isobath and 100 m
(P. filamentosus), 280 m (A. rutilans) or
320 m (H. quernus) isobaths
None
Sub-adult/adult
Benthic (H. quernus) or benthopelagic
(A. rutilans and P. filamentosus) zones,
including all bottom habitats, in depths
from the surface to 280 m (A. rutilans
and P. filamentosus) or 320 m (H.
quernus) bounded by the 40 m isobath
and 280 m (A. rutilans and P.
filamentosus) or 320 m (H quernus)
isobaths
None
Deep stocks:
Etelis
carbunculus,
Etelis
coruscans,
Eggs
Pelagic zone of the water column in
depths from the surface to 400 m,
extending from the official US baseline
to a line on which each point is 50 miles
from the baseline
All ODMDS
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MUS
Stock/ Stock
Complex
Life Stage(s)
EFH Designation
Intersection
with ODMDS
Pristipomoides
seiboldii,
Pristipomoides
zonatus
Post-hatch
pelagic
Pelagic zone of the water column in
depths from the surface to 400 m,
extending from the official US baseline
to the EEZ boundary
All ODMDS
Post-settlement
Benthic zone, including all bottom
habitats, in depths from 80 to 400 m
bounded by the official US baseline and
400 m isobath
South O'ahu,
Hilo, Kahului
Sub-adult/adult
Benthic (E. carbunculus and P. zonatus)
or benthopelagic (E. coruscansi)
zones, including all bottom habitats, in
depths from 80 to 400 m bounded by the
official US baseline and 400 m isobaths
South O'ahu,
Hilo, Kahului
Eggs and post-
hatch pelagic
Pelagic zone of the water column in
depths from the surface to 600 m,
bounded by the official US baseline and
600 m isobath, in waters within the EEZ
that are west of 180°W and north of
28°N
None
Seamount
Groundfish
Post-settlement
Benthic or benthopelagic zone in depths
from 120 m to 600 m bounded by the
120 m and 600 m isobaths, in all waters
and bottom habitat, within the EEZ that
are west of 180°W and north of 28°N
None
Sub-adult/adult
Benthopelagic zone in depths from 120
m to 600 m bounded by the 120 m and
600 m isobaths, in all waters and
bottom habitat, within the EEZ that are
west of 180°W and north of 28°N
None
Pelagic
Tropical and
Egg/larval
The water column down to a depth of
200 m (100 fin) from the shoreline to
the outer limit of the EEZ
All ODMDS
temperate
Juvenile/adult
The water column down to a depth of
1,000 m (500 fin)
All ODMDS
Precious
Coral
Deep-water
Benthic
Six known precious coral beds located
off Keahole Point, Makapu'u, Ka'ena
Point, Westpac bed, Brooks Bank, and
180 Fathom Bank
None
Shallow-water
Benthic
Three beds known for black corals in
the MHI between Miloli'i and South
Point on the Big Island, the Au'au
Channel, and the southern border of
Kaua'i
None
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Table 8. HAPC for Managed Commercial Fisheries in Hawai i.
MUS
Stock/ Stock
Complex
HAPC
Intersection
with ODMDS
Crustaceans
Kona crab
All banks in the NWHI with summits less than or equal to
30 m (15 fm) from the surface
None
Precious
Coral
Deep-water
Makapu"u. Wespac, and Brooks Bank bed
None
Shallow-water
Au'au Channel bed
None
Bottomfish
All bottomfish
stocks
Discrete areas at Ka'cna Point, Kanc'ohc Bay, Makapu"u
Point, Penguin Bank, Pailolo Channel, North Kaho'olawc.
and Hilo
Hilo ODMDS
Seamount
groundfish
Congruent with EFH (See Table 7).
None
Pelagic
All pelagic
fisheries
Water column from the surface down to a depth of 1,000 m
(500 fm) above all seamounts and banks with summits
shallower that 2,000 m (1,000 fm) within the EEZ
None
5.2 Avoidance and Minimization of Impacts to EFH
NMFS has identified that disposal of dredged material may cause adverse effects to EFH resources,
including benthic infauna and various life stages of multiple MUS, by potentially increasing turbidity
and sedimentation, nutrients, and contaminants. Whether EFH is present or not, EPA's site
designation, pre-disposal testing, management, and monitoring processes independently require
evaluation of a variety of factors that minimize the potential effects of disposal on EFH. The EPA
processes to minimize impacts to benthic and water column EFH are discussed in the following
paragraphs.
Ocean Disposal Site Selection
As discussed in Section 3.1, MPRSA regulations at 40 CFR Part 228.5 - 228.6 include disposal site
selection criteria which help directly avoid or minimize impacts to water column EFH (i.e., for the
crustacean, bottomfish, and pelagic MUS at all of the Hawai'i ocean disposal sites) and benthic EFH
(i.e., for bottomfish deep stocks at the South O'ahu, Hilo, and Kahului sites). Importantly, these site
criteria require that, to the extent possible:
• Disposal activities must avoid existing fisheries and shellfisheries (228.5(a));
• Temporary water quality perturbations from disposal within the site must be reduced to
ambient levels before reaching any marine sanctuary or known geographically limited fishery
or shellfishery (228.5(b));
• The size of disposal sites must be minimized in order to be able to monitor for and control any
adverse effects (228.5(d));
• Where possible, disposal sites should be beyond the edge of the continental shelf (228.5(e));
• The location of disposal sites must be considered in relation to breeding, spawning, nursery,
feeding or passage areas of living resources in adult or juvenile phases (228.6(a)(2));
• Dispersal and transport from the disposal site must be considered (228.6(a)(6));
• Cumulative effects of other discharges in the area must be considered (228.6(a)(7));
• Interference with recreation, fishing, fish and shellfish culture, areas of special scientific
importance and other uses of the ocean must be considered (228.6(a)(8); and
• The potential for development or recruitment of nuisance species must be considered
(228.6(a)(10)).
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Taken together, the site selection criteria are intended to ensure that EPA's ocean disposal site
designations avoid and minimize both direct and indirect impacts to any important fishery or
supporting marine habitat to the maximum extent practicable, even before any dredged material is
permitted to be disposed. Based on the consideration of the site selection criteria, the locations of the
five Hawai'i sites were identified as the environmentally preferred alternative locations serving each
of the five main Hawai'i port areas.
Pre-Disposal Testing
Although the five Hawai'i ocean disposal sites intersect with water column EFH for the crustacean,
bottomfish, and pelagic MUS, the conservative sediment elutriate testing and modeling conducted
prior to dredging must confirm that exposure to the disposal plume, including the dissolved oxygen
and turbidity levels, will not cause toxicity to sensitive marine organisms in the water column (refer
to Section 3.2 for more details on the pre-disposal testing regime). Chemistry testing is conducted,
and modeling to screen for water quality standards compliance assumes that 100% of all
contaminants are released to the water column. Elutriate bioassays are performed, and a 100-fold
safety factor is applied such that, after initial mixing, the water column plume may not exceed 1% of
the toxic concentration (LC50) for the most sensitive organism tested. Further, due to the depths and
offshore locations of the Hawai'i sites, dilution of the disposal plumes is rapid.
Additionally, although the South O'ahu, Hilo, Kahului sites intersect with the benthic EFH for the
bottomfish MUS deep stocks (post-settlement and sub-adult/adult life stages), the detailed sediment
testing process also includes two solid phase bioassays and bioaccumulation testing to ensure the
material disposed will not be toxic to benthic organisms and does not include pollutants likely to
bioaccumulate in the food web to levels of biological concern.
Management of the Hawai'i Ocean Disposal Sites
EPA additionally uses an active, adaptive approach to managing ocean disposal sites (see Sections
3.4 and 3.6). More specifically, once a dredging project is approved for ocean disposal at one of the
Hawai'i sites, a variety of disposal BMPs are included as enforceable permit conditions for the
project. For example, satellite tracking is conducted for all disposal vessels, and sensors are placed on
all disposal vessels to ensure there is no significant leakage or spilling of dredged material during
transit to the site. These additional BMPs ensure that direct and indirect effects to water column and
benthic EFH are avoided or minimized. Moreover, EPA periodically monitors the sites (as described
in the following section), and uses those results to ensure that the sites are behaving as expected, or to
inform additional, protective management measures if any unexpected adverse effects are found.
Monitoring at the Hawai'i Ocean Disposal Sites
The South O'ahu, Hilo, Kahului sites intersect with the benthic EFH for the bottomfish MUS deep
stocks. Physical effects are generally anticipated at any disposal site, simply because dredged
sediment's physical characteristics (e.g., grain size and organic carbon content) often differ from that
of the native seafloor in the deep ocean. Nevertheless, these effects are expected to be primarily
confined to the disposal site, and benthic communities are anticipated to recover rapidly following
disposal. Furthermore, the volumes disposed at the five Hawai'i sites are very low, particularly in
comparison to other dredged material disposal sites in EPA Region 9. The low volume of disposed
dredged material further reduces impacts to benthic EFH, and helps ensure that the dredged material
can be more rapidly assimilated into the benthos following disposal. EPA conducted monitoring in
2013 and 2017 to confirm that the sites were behaving as expected and no long-term impacts were
occurring to the marine community from dredged material disposal.
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EPA's site monitoring surveys in 2013 and 2017 confirmed that sediment quality remains as
expected, and that there have been no significant changes to sediment chemistry that would adversely
affect on-site or off-site habitat quality in the long term (see Section 3.5; Appendix 2). This indicates
that the pre-disposal sediment testing program is effective at limiting ocean disposal to only
"suitable" sediment. However, physical effects are still anticipated at any disposal site, and
monitoring confirmed that minor physical substrate changes have occurred compared to pre-disposal
baseline data from 1980. It is possible that these substrate changes may partially account for minor
differences in infaunal assemblages found during the 2013 monitoring at the South O'ahu and Hilo
sites (the two most heavily used of the Hawai'i disposal sites). However, minor benthic community
changes were also seen outside those disposal sites and so appear to be partially attributable to
region-wide variability as well. In addition, monitoring at all five sites confirmed that recolonization
begins soon after dredged material is deposited, and that similar infaunal and epifaunal communities
occupy both on-site and off-site areas. Thus, impacts to benthic habitat quality are considered
minimal and largely contained within the disposal site boundaries.
Because disposal of toxic sediments is not allowed, disposal events are short and infrequent, and the
overall quantities of disposed material are low, effects on water column and benthic EFH are
considered minimal.
5.3 Overlap with Habitat Areas of Particular Concern
In addition to evaluating the broader potential for impacts to water column and benthic EFH, EPA has
also assessed the potential for effects to the HAPC for bottomfish designated off the coast of the
Island of Hawai'i. This HAPC extends for 11 miles along the coast, out from the Hilo Bay, and
overlaps with the Hilo ocean disposal site (Table 8). The EFH within the Hilo HAPC consists of 336
km2 covering the water column and bottom habitat extending from the baseline to 400 m. The Hilo
HAPC for bottomfish was designated in 2016, because it is an ecologically important juvenile P.
filamentosus nursery area and also has rare physical pillow lava habitat (WPRFMC, 2016). While
nursery areas for P. filamentosus are usually flat, open soft substrates (Haight et al, 1993), the camera
deployments recorded juveniles over very hard, rugose volcanic substrate (Figure 21). The
uniqueness of this nursery habitat contributed to the designation of the area as HAPC for bottomfish.
Nevertheless, due to the depth and substrate composition of the Hilo ocean disposal site, EPA does
not believe that ocean disposal will adversely impact juvenile P.filamentosus EFH and the pillow lava
habitat (i.e., the two reasons for the designation of the HAPC), as discussed below.
Potential Effects to P. filamentosus
Because it is an intermediate bottomfish stock, EFH for P. filamentosus encompasses the water
column and bottom habitat in depths from the surface to 280 m. Juvenilq P. filamentosus are
specifically known to occupy areas much shallower than their adult counterparts, ranging in depth
from approximately 40 m to 100 m (WPRFMC, 2016). However, the Hilo ocean disposal site ranges
from 330-340 m deep, therefore any potential effects on P. filamentosus would likely be restricted to
water column effects and not substrate changes. Yet, as previously mentioned, exposure to disposal
plumes in the water column is temporary, and elutriate testing and modeling are required to ensure
that exposure to the disposal plume will not cause toxicity to sensitive marine organisms in the water
column. This includes any potential reductions in dissolved oxygen levels, which would be short-term
and generally restricted to the immediate vicinity of the initial plume generated from the disposal
activity in the upper water column. Further, the Hilo ocean disposal site is offshore, in relatively deep
water with higher water flow patterns, therefore the initial dilution is rapid and disposal plumes
dissipate to background levels quickly. Finally, management measures, such as the specification of an
SDZ and scow tracking, have been put in place to ensure that dredged material is contained within the
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boundaries of the Hilo site to the maximum extent possible and does not adversely affect nearby
habitats. Consequently, the potential for adverse effects to P. fialmentosus is considered to be
minimal.
Potential Effects to Pillow Lava Substrate
EPA monitoring at the Hilo site indicates that, apart from an accumulation of small rock and coral
rubble at the center of the site from previous dredged material deposits, the native sediments within
the site consist of predominantly sandy substrate (77% sand, 22% silt and clay, and only 1% gravel;
Appendix 4; Figure 22). Monitoring outside of the Hilo ocean disposal site boundaries did identify
pillow lava, however these stations were far outside of the site boundaries (Figures 23, 24); No
pillow lava was identified within the site boundaries. Therefore, because of its depth and substrate
composition, the Hilo ocean disposal site does not appear to encompass the environments for which
the Hilo HAPC was designated.
Effects to other EFH in the Hilo HAPC
The Hilo HAPC was primarily designated due to the presence of juvenile P.filamentosus (i.e., an
intermediate stock bottomfish species) and pillow lava formations, however due to its depth and
predominantly sandy substrate, the Hilo ocean disposal site does not appear to represent the area for
which the HAPC was designated. In addition to the specific overlap with HAPC, EPA recognizes that
water column EFH for crustacean, all bottomfish stocks, and pelagic MUS overlap with the Hilo
ocean disposal site (as previously mentioned in Section 5.1). Additionally, benthic EFH for
bottomfish deep stocks overlaps with the Hilo ocean disposal site. Nevertheless, as previously
described (Section 5.2), EPA requires conservative sediment elutriate testing and modeling prior to
dredging to confirm that exposure to the disposal plume, including the dissolved oxygen and turbidity
levels, will not cause toxicity to sensitive marine organisms in the water column (refer to Section 3.2
for more details on the pre-disposal testing regime). The detailed sediment testing process also
includes two solid phase bioassays and bioaccumulation testing to ensure the material disposed will
not be toxic to benthic organisms and does not include pollutants likely to bioaccumulate in the food
web to levels of biological concern. EPA additionally uses an active, adaptive approach to managing
ocean disposal sites (see Sections 3.4 and 3.6), which includes incorporating a variety of disposal
BMPs as enforceable permit conditions for each approved project. These additional best management
practices ensure that direct and indirect effects to water column and benthic EFH are avoided or
minimized. Moreover, EPA periodically monitors the ocean disposal sites, and uses those results to
ensure that the sites are behaving as expected, or to inform additional, protective management
measures if any unexpected adverse effects are found. Consequently, EPA's site designation, pre-
disposal testing, management, and monitoring processes comprise a comprehensive management
regime that minimizes the potential direct and indirect effects of disposal on both water column and
benthic EFH.
Furthermore, the Hilo site has only received 336,160 cy of material in the 40 years since the site was
designated (Table 2). In comparison to the volumes received along the California Coast in EPA
Region 9, this is considered minimal. For example, the San Francisco Deep Ocean Disposal Site has
received over 18 million cy, and the Humboldt Open Ocean Disposal Site has received over 33
million cy of material, since these sites were designation in 1995. Individual disposals are also short
in nature, occurring over approximately two to four minutes. Because individual disposals discharge
from approximately 1,000 cy to 5,000 cy at a time, this equates to between 67 to 336 disposals total,
over the 40 years since the site has been designated. Moreover, these disposal events have only
occurred in five individual years, providing the benthic community time to recover between the
disposal events and assimilate the disposed material. Due to the lack of lava pillow formations in the
42
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Hilo disposal site, the depth of the site, the comprehensive management regime, and the low disposal
volumes that are targeted to the center of the site through an SDZ, EPA believes that continued use of
the Hilo site would not adversely affect the bottomfish HAPC.
Figure 21. P. filamentosus juveniles recorded by the BotCam remote drop camera system over volcanic pillow
lava formations off Hilo, Hawaii (WPRFMC, 2016).
Figure 22. Profile images from two Hilo stations showing a surface layer of disposed coarse white dredged
sand that thins from the center of the site (left) to only trace amounts near the site boundary. Scale:
width of each profile image = 14.4 cm (Appendix 2).
43
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3P|ipV and Sediment Sampling Locations
HloODMDS. Hawaii
June/July 2013
Sediment grain-size
major mode (phi)
# >4 (sift/clay)
# >4-3 (sitty very fine sand)
4-3 (very fine sand)
# 3-2 (fine sand)
# 2-1 (medium sand)
# -4 (pebble)
# Hard Bottom/ Rocky Outcrop
' ) Dump site
"i
H-W4 H-wa
/'
H-NW2 /»
I H-NW1
H-W2H-W1
\ H-SW1 '
H-N2 X * H-NE3
* \h-NE2
~ H-NE1 »
H-C i
*! H-E2
^ H-SEt / H-E4
H-SE2
H-S5
H-S6 .
Sources Esri, GEBCO. NOAA, National Geogrroho. DeLorme. NAVTEQ. Gecrarres.a'j. and ottie1- contr b.uta.re
Figure 23. Spatial distribution of sediment grain-size major mode (phi units) at and around the Hilo ocean
disposal site.
Figure 24. Deposits of pillow lava in PV image from Station SE6. Scale: width of PV image = 4.1 m.
44
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5.4 Conservation Measures: Hawai'i FEP Habitat Conservation and Enhancement
Recommendations (FEP, 2009):
EPA believes that any potential adverse effects to EFH will be minimal, based on the complementary
nature of EPA's management measures to the habitat conservation and enhancement
recommendations, as outlined in the 2009 Fishery Ecosystem Plan for the Hawai'i Archipelago. The
recommendations and EPA's associated actions are described in more detail below.
General Recommendations (pg 206):
"Activities that may result in significant adverse effects on EFH should be avoided where less
environmentally harmful alternatives are available. "
EPA's regulations (40 CFR Part 227.14-16) restrict ocean disposal of dredged material by outlining
factors for evaluating the need for ocean disposal and requiring consideration of alternatives to ocean
disposal (see Section 3.3). Alternatives to ocean disposal (including beneficial uses) are considered
on a project-by-project basis to ensure that the minimum necessary volume of dredged material is
disposed at any of the ocean disposal sites. Even sediments that have been adequately characterized
and found by EPA and USACE to be suitable for ocean disposal will not be permitted for ocean
disposal if there is a practicable alternative available (including a beneficial use option).
"If there are no alternatives, the impacts of these actions should be minimized. Environmentally
sound engineering and management practices should be employed for all actions that may adversely
affect EFH."
The EPA-designated Hawai'i ocean disposal sites were originally located to minimize impacts by
avoiding any unique or limited habitats to the extent practicable (see Section 3.1). Further, the
quantities of dredged material disposal at Hawai'i sites are modest, with a long-term annual average
of just over 220,000 cubic yards (cy) being disposed at all five sites combined (and under 150,000 cy
per year since 2000) (Table 2). Once a project is approved for ocean disposal at one of the Hawai'i
sites, additional management measures are taken to further minimize the potential for adverse
impacts. These management measures, outlined in the SMMP, include:
• applying a variety of disposal BMPs as enforceable permit conditions for each project
(Section 3.4);
• satellite tracking of all disposal vessels to ensure that disposal activities occur only where and
as required;
• sensors on all disposal vessels to ensure that there is no significant leakage or spilling of
dredged material during transit to the disposal site, especially during transit through the
nearshore zone where corals, seagrasses, and sensitive animals are most likely to be present;
• tracking and sensor information is reported online for each disposal trip so any problems are
identified quickly, and corrective action can be initiated;
• periodically monitoring the disposal site (Section 3.5) to confirm that only physical effects
occur within the site boundaries and that no significant adverse physical, chemical, or
biological effects occur outside the disposal site; and
• adaptively managing the site if monitoring identifies any adverse impacts (Section 3.6).
"Disposal or spillage of any material (dredge material, sludge, industrial waste, or other potentially
harmful materials) that would destroy or degrade EFH should be avoided. "
Section 3.1 describes EPA's site designation criteria (40 CFR Part 228.5 - 228.6), which require that
disposal activities must avoid existing fisheries and shellfisheries (228.5(a)); temporary water quality
perturbations from disposal within the site must be reduced to ambient levels before reaching any
45
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known geographically limited fishery or shellfishery (228.5(b)); and the location of disposal sites
must be considered in relation to breeding, spawning, nursery, feeding or passage areas of living
resources in adult or juvenile phases (228.6(a)(2)). Additionally, once a site is designated, EPA's
regulations establish strict criteria for evaluating whether dredged material is suitable for ocean
disposal (Section 3.2), in order to protect marine resources (40 CFR Part 227.5-9).
EPA further includes management measures (Section 3.4) to prevent spillage of any materials on
transit to the ocean disposal site. Each disposal vessel is closely tracked during transit through the
nearshore zone. This tracking includes sensors to detect any substantial leaking or spilling of material
that could increase turbidity and suspended sediment near sensitive habitats such as corals and
seagrasses. Disposal vessels that leak or spill must be removed from service and repaired before
being approved for continued use.
Specific Dredging and Habitat Loss and Degradation Conservation Measures (pgs 207-208; 210)
"Sediments should be testedfor contaminants as per the EPA and U.S. Army Corps of Engineers
requirements."
Sediment testing requirements are described in detail in Section 3.2. EPA and USACE have jointly
published national sediment testing guidance that describes how this testing is to be done (the 1991
OTM). Dredging project proponents (including USACE) wishing to dispose of material at any
Hawaiian ocean dredged material disposal site must first develop an SAP that describes the specific
physical, chemical, and biological testing to be done for the project in accordance with the OTM.
EPA and USACE must approve the adequacy of the SAP and review the subsequent testing results.
Only projects having sediments that pass the tests, and that have no feasible disposal or reuse
alternatives, may be permitted for ocean disposal.
"To the extent possible, fill materials resulting from dredging operations should be placed on an
upland site. Fills should not be allowed in areas with subaquatic vegetation, coral reefs, or other
areas of high productivity. "
EPA prioritizes alternatives to ocean disposal (Section 3.3). Even sediments that have been
adequately characterized and found by EPA and USACE to be suitable for ocean disposal will not be
permitted for ocean disposal if there is a practicable alternative available (including a beneficial use
option). Moreover, the ocean disposal sites have been carefully selected according to a disposal site
selection process designed to protect marine resources. EPA's site designation criteria (Section 3.1)
explicitly lead EPA to identify disposal sites in locations removed from important habitat areas,
fishing grounds or other ocean uses, to the maximum extent practicable. In addition, dredged material
proposed to be placed as fill in wetland or nearshore locations is separately regulated under Section
404 of the Clean Water Act (CWA). CWA Section 404 has similar, strict requirements for avoiding
impacts to "special aquatic sites" (including areas with submerged aquatic vegetation and coral reefs)
to the maximum extent practicable.
"The disposal of contaminated dredge material should not be allowed in EFH. "
Contaminated dredged material is not permitted for ocean disposal (Section 3.2). Any dredged
material that contains levels of chemical contaminants in other than "trace" amounts, that exhibits
toxicity in either suspended or solid phase tests, or that includes pollutants that are likely to
bioaccumulate in the food web to levels of concern, is not considered suitable for ocean disposal.
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"When reviewing open-water disposal permits for dredged material, state andfederal agencies
should identify the direct and indirect impacts such projects may have on EFH. "
This EFH consultation is in direct support of this conservation measure. The potential for disposal-
related impacts is a function of the locations of the ocean disposal sites in relation to EFH, the quality
(suitability) of the dredged material allowed to be disposed at them, the site use requirements and
BMPs applied to each project, and site management and monitoring activities. Each of these factors is
discussed at length in Section 3 of this consultation. Because these factors are similar for each
project, it is appropriate to evaluate them programmatically for each of the Hawai'i ocean disposal
sites.
In contrast, potential dredging-related impacts to EFH vary greatly on an individual project basis.
Marine fishes, sea turtles, and marine mammals are generally much more susceptible to potential
impacts from activities associated with dredging itself, rather than from open water disposal.
Dredging typically occurs in relatively enclosed waterbodies that may have restricted movement
pathways that can limit animals' ability to avoid or minimize exposure to noise, turbidity, or physical
disturbance. If the sediment being dredged is contaminated, there may also be increased risk of
exposure to resuspended contaminants, depending on the presence and effectiveness of dredging
control measures such as silt curtains or timing limitations. Dredging may also temporarily or
permanently damage or remove important habitat features such as corals or seagrasses. These effects
may occur independently of whether the dredged material is subsequently disposed at an ODMDS.
For these reasons potential impacts of dredging itself cannot be assessed programmatically and will
instead continue to be evaluated on a project-specific basis during USACE's permitting process.
"When practicable, benthic productivity should be determined by sampling prior to any discharge of
fill material. Sampling design should be developed with input from state andfederal resource
agencies."
As required by the MPRSA, EPA undertakes site surveys prior to designation to identify baseline
characteristics of the site and surrounding areas. Following designation, EPA endeavors to monitor
sites according to a ten-year schedule, in accordance with the review schedule for the site's SMMP.
Most recently, EPA conducted the 2013 monitoring surveys at South O'ahu and Hilo to assess the
benthic community recovery following disposal events in 2011 and 2012, as well as prior to disposal
events scheduled for 2016. The Nawiliwili and Kahului surveys were conducted following disposal
events in 2016 to assess recovery at the sites. Port Allen was also surveyed, but it has not received
dredged material since 1999. The design of the 2013 monitoring surveys is described in Appendix 4;
a similar design was employed in 2017.
"The areal extent of the disposal site should be minimized. However, in some cases, thin layer
disposal may be less deleterious. All non-avoidable impacts should be mitigated. "
EPA's site designation criteria require that the size of disposal sites be minimized in order to be able
to monitor for and control any adverse effects (40 CFR Part 228.5(d)). Thin-layer placement is often
useful for beneficial use applications such as nearshore placement of sand to support beach
nourishment, but it is generally not useful for disposal at deep water sites. As discussed throughout
this assessment, avoidance and minimization measures are built into both the site designation process
and the individual project permit review process. Remaining unavoidable impacts, primarily physical
substrate changes within the disposal site boundaries, are considered minimal.
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"All spoil disposal permits should reference latitude-longitude coordinates of the site so that
information can be incorporated into GIS systems. Inclusion of aerial photos may also be required to
help geo-reference the site and evaluate impacts over time. "
If material is authorized for ocean disposal, a number of conditions are incorporated into the permit.
For example, EPA permit conditions require disposal to occur within a small surface disposal zone
(SDZ) specified within each of the Hawai'i ocean disposal sites. No more than one vessel may be
present in the SDZ at one time. Further, EPA permit conditions include a requirement for Disposal
Vessel Instrumentation and Tracking: Each disposal vessel must have a primary navigation/tracking
system functioning for each disposal trip, calibrated for accuracy at a minimum at the beginning of
each ocean disposal project, that automatically indicates and records important information
throughout transportation to, disposal at, and return transportation from each of the Hawai'i ocean
disposal sites. The system must record: the position, speed, and heading of the disposal vessel; the
fore and aft draft of the vessel; and the time and location of each disposal event. The system must
record these data at a maximum 5-minute interval while outside the disposal site boundary, and at a
maximum 15-second interval while inside the disposal site boundary and the SDZ. The primary
system must also include a real-time display, located in the wheelhouse or otherwise visible to the
helmsman, showing the position of the disposal vessel relative to the boundaries of the Hawai'i ocean
disposal site and its SDZ, superimposed on the appropriate navigational chart so that the operator can
confirm proper position of the disposal vessel within the SDZ before discharging the dredged
material.
6.0 CONCLUSIONS
Ocean disposal of suitable (non-toxic) dredged material has the potential to cause short-term adverse
effects to living marine resources in the water column and long-term effects to seafloor habitats and
species. Life stages of both listed species and different commercial fishery MUS could be affected by
disposal-related stressors including turbidity and sedimentation, nutrients, and contaminants. In this
informal consultation package, EPA has described the continued use of the Hawai'i ocean disposal
sites, as well as the use of the sites to date and the EPA regulations and management measures in
place to avoid impacts to marine organisms and the marine environment. EPA also presented the
extensive monitoring that the agency has conducted at the sites, the results of which indicate that
existing management practices have been successful at avoiding and minimizing adverse impacts. In
summary, EPA's ocean disposal site selection, rigorous pre-disposal sediment testing, and site
management measures help to ensure that adverse water column and seafloor effects to both listed
species and EFH are avoided and minimized.
Based on the analysis provided in the sections above, EPA has determined that the continued use of
the five Hawai'i ocean disposal sites may affect but is not likely to adversely affect ESA protected
species, and it may adversely affect EFH, yet effects are expected to be minimal. We have used the
best scientific and commercial data available to complete this analysis.
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7.0 REFERENCES
Agarwal, M. 2020. What is the speed of a ship at sea? Marine Insight.
https://www.marineinsight.com/guidelines/speed-of-a-ship-at-sea/
Balazs, G.H. 1985. Impact of ocean debris on marine turtles: Entanglement and ingestion.
Pages 387-429 in R.S. Shomura and H.O. Yoshida (eds.), Proceedings of the Workshop on the
Fate and Impact of Marine Debris, 26-29 November 1984, Honolulu, HI. NOAA Tech.
Memo. NMFS-SWFC-054.
EPA. 1991. Evaluation of Dredged Material Proposed for Ocean Disposal. EPA 503/8-91/001.
Available at: https://www.epa.gov/sites/production/files/2015-10/documents/green book.pdf
Epperly, S. P., and coauthors. 1996. Beach strandings as an indicator of at-sea mortality of sea turtles.
Bulletin of Marine Science 59(2):289-297.
Haight, W., D. Kobayashi, and K. Kawamoto. 1993. Biology and management of deepwater
snappers of the Hawaiian Archipelago. Marine Fisheries Review 55(2): 20-27.
Hart, K. M., P. Mooreside, and L. B. Crowder. 2006. Interpreting the spatio-temporal patterns of sea
turtle strandings: going with the flow. Biological Conservation 129(2):283-290.
Hawaii DLNR. 2013. Fact Sheet: Olive Ridley Sea Turtle. Available at:
https://dlnr.hawaii.gov/wildlife/files/2013/09/Fact-Sheet-olive-ridlev-sea-turtle.pdf
Hawai'i DLNR. 2020. Commercial Fishing Reports. Available at:
https://dlnr.hawaii.gov/dar/fishing/commercial-fishing/
Hazel, J., I. R. Lawler, H. Marsh, and S. Robson. 2007. Vessel speed increases collision risk for the
green turtle Chelonia mydas. Endangered Species Research 3:105-113.
Maui Ocean Center (MOC) Marine Institute. 2020. Sea turtle stranding response &
rescue: 2019 summary of results, Maui, Hawai'i. Available at:
http://mocmarineinstitute.org/turtles/sea-turtle-rescue/
NMFS and USFWS. 1998. Recovery plan for U.S. Pacific populations of the olive
ridley turtle (Lepidochelys olivacea). National Marine Fisheries Service, Silver Spring, MD.
52 pages.
NMFS. 2015. Hawaiian Sea Turtle Stranding Data. Available at:
https://repositorv.library.noaa.gov/view/noaa/12316
NMFS. 2016. Recovery Outline: Main Hawaiian Islands Insular False Killer Whale
(Pseudorca crassidens) Distinct Population Segment. Available at:
https://www.fisheries.noaa.gov/resource/document/recovery-outline-main-hawaiian-islands-
insular-false-killer-whale-distinct
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NFMS. 2018. ESA Biological Opinion on the U.S. Navy Hawaii-Southern California Training and
Testing and the NMFS' promulgation of regulations pursuant to the Marine Mammal
Protection Act for the Navy to "Take" marine mammals incidental to Hawaii-Southern
California Training and Testing. Consultation Tracking Number: FPR-2018-9275.
NMFS. 2018. ESA Section 7 Biological and Conference Opinion on Bureau of Ocean Energy
Management's Oil and Gas Program Activities in the Gulf of Mexico. Office of Protected
Resources, National Marine Fisheries Service, National Oceanic and Atmospheric
Administration, U.S. Department of Commerce.
USACE. 2020a. Ocean Dredged Material Disposal Site Database. Available at:
http s: //odd. el. erdc. dren .mil/
USACE. 2020b. Waterborne Commerce Database. Available at: http://cwbi-ndc-nav.s3-website-us-
east-l.amazonaws.eom/files/wcsc/webpub/#/report-landing/vear/2017/region/4/location/4420
Western Pacific Regional Fishery Management Council (WPRFMC). 2009. Fishery Ecosystem Plan
for the Hawaii Archipelago. Available at:
http://www.wpcouncil.org/fep/WPRFMC%20Hawaii%20FEP%20(2009-09-21).pdf
Western Pacific Regional Fishery Management Council (WPRFMC). 2016. Amendment 4 to the
Fishery Ecosystem Plan for the Hawaii Archipelago Revised Descriptions and Identification
of Essential Fish Habitat and Habitat Areas of Particular Concern for Bottomfish and
Seamount Groundfish of the Hawaiian Archipelago, http ://www. wpcouncil.org/wp-
content/uploads/2013/03/2016-01 -28-FINAL-Hawaii-FEP-Amd-4-Bottomfish-EFH-RIN-
0648-XD907-All-Pages-with-Appendices.pdf
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Appendix 1 to EPA Consultation with NMFS
for Continued Use of Five Existing Ocean Dredged Material Disposal Sites (ODMDS)
in Waters Offshore of Hawai'i
Original ESA Consultation for the Five Hawai'i ODMDS
(1980)
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United States Oil and Special Materials September 1980
Environmental Protection Control Division
Agency Marine Protection Branch
Washington DC 20460
Water
&ERA Environmental Final
Impact Statement
(EIS) for Hawaii
Dredged Material
Disposal Sites
Designation
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—tes Oil and Special Materials September 1980
environmental Protection Control Division
Agency Marine Protection Branch
Washington DC 20460
Water
-&EFW Environmental Final
Impact Statement
(EIS) for Hawaii
Dredged Material
Disposal Sites
Designation
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ENVIRONMENTAL PROTECTION AGENCY
FINAL
ENVIRONMENTAL IMPACT STATEMENT FOR
THE DESIGNATION OF FIVE HAWAIIAN
DREDGED MATERIAL DISPOSAL SITES
Prepared by: U.S. Environmental Protection Agency
Oil and Special Materials Control Division
Marine Protection Branch
Washington, D.C. 20460
iii
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CONTENTS
Chapter Title PaSe
ADDRESSES FOR COMMENTS v
SUMMARY vii
1 PURPOSE OF AND NEED FOR ACTION 1-1
INTRODUCTION 1-1
FEDERAL LEGISLATION AND CONTROL PROGRAMS 1-3
Marine Protection, Research, and Sanctuaries Act .... 1-5
Federal Control Programs 1~5
INTERNATIONAL CONSIDERATIONS 1-12
2 ALTERNATIVES INCLUDING THE PROPOSED ACTION 2-1
THE PROPOSED SITES 2-2
Proposed South Oahu Site 2-2
Proposed Nawiliwili Sites and Port Allen 2-4
Proposed Kahului Site 2-4
Proposed Hilo Site 2-8
NO-ACTION ALTERNATIVE 2-8
CONTINUED USE OF THE PROPOSED SITES IN RELATION TO
ALTERNATIVE SITES 2-11
Environmental Acceptability 2-11
Monitoring, Surveillance, and Economic Considerations . . 2-15
DETAILED BASIS FOR SELECTION OF THE PROPOSED SITES 2-16
"Geographical Position, Depth of Water,
Bottom Topography and Distance from Coast" 2-16
"Location in Relation to Breeding, Spawning, Nursery,
Feeding, or Passage Areas of Living Resources in
Adult or Juvenile Phases" 2-19
"Location in Relation to Beaches and Other
Amenity Areas" 2-19
"Types and Quantities of Wastes Proposed to be
Disposed of, and Proposed Methods of Release,
Including Methods of Packing the Waste, If Any" 2-19
"Feasibility of Surveillance and Monitoring" 2-20
"Dispersal, Horizontal Transport and Vertical Mixing
Characteristics of the Area, Including Prevailing
Current Direction and Velocity" 2-20
"Existence and Effects of Current and Previous
Discharges and Dumping in the Area (Including
Cumulative Effects)" ..... 2-21
"Interference With Shipping, Fishing, Recreation,
Mineral Extraction, Desalination, Fish and Shellfish
Culture, Areas of Special Scientific Importance and
Other Legitimate Uses of the Ocean" , . 2-21
"The Existing Water Quality and Ecology of the Site
as Determined by Available Data or by Trend
Assessment or Baseline Surveys " 2-22
xiii
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CONTENTS (continued)
Chapter. Title Page
"Potentiality for the Development or Recruitment of
Nuisance Species in the Disposal Site" ...
"Existence at or in Close Proximity to the Site
of Any Significant Natural or Cultural Features ^
of Historical Importance" ....
PROPOSED USE OF THE SITES £-22
9 — 21
Recommended Environmental Studies
Types of Material 2-23
• • 9 94
Permissible Material Loadings *¦ ^
Dredging and Disposal Operations " 2-25
Disposal Schedules 2-26
3 AFFECTED ENVIRONMENT 3-1
OCEANOGRAPHIC CHARACTERISTICS OF THE PROPOSED SITES 3-1
Geological Conditions 3-2
Physical Conditions 3-5
Chemical Conditions 3-8
Biological Conditions 3-13
Threatened and Endangered Species 3-20
RECREATIONAL, ECONOMIC, AND AESTHETIC CHARACTERISTICS .... 3-22
Tourism 3-22
National Defense 3-23
Fisheries 3-25
Navigation 3-29
INPUTS AT THE PROPOSED SITES OTHER THAN DREDGED MATERIAL . . . 3-30
Previous Dredging Activities 3-30
Other Waste Inputs 3-30
4 ENVIRONMENTAL CONSEQUENCES 4-1
EFFECTS ON RECREATIONAL, ECONOMIC, AND AESTHETIC VALUES . . . 4-2
Recreational and Economic Values 4-2
Aesthetic Values 4-5
OTHER ENVIRONMENTAL EFFECTS 4-6
Effects on Water Column 4-7
Effects on Threatened and Endangered Species 4-14
Effects on Benthos 4-15
IMPACTS ON OTHER OCEAN USES 4-19
Scientific Uses 4-19
Preservation Areas 4-19
Industrial Use Areas 4-20
Ocean Thermal Energy Conversion (OTEC) 4-20
Ocean Incineration 4-21
Deep-Ocean Mining 4-21
Sand Mining 4-21
Coral Harvesting 4-21
xiv
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CONTENTS (continued)
Chapter Title Page
UNAVOIDABLE ADVERSE ENVIRONMENTAL EFFECTS AND
MITIGATING MEASURES 4-21
RELATIONSHIP BETWEEN SHORT-TERM USE AND LONG-TERM
PRODUCTIVITY 4-23
IRREVERSIBLE OR IRRETRIEVABLE RESOURCE COMMITMENT 4-24
5 COORDINATION 5-1
PREPARERS OF THE EIS 5-1
COMMENTERS ON THE DRAFT EIS 5~3
6 GLOSSARY, ABBREVIATIONS, AND REFERENCES 6-1
GLOSSARY 6-1
ABBREVIATIONS 6-12
REFERENCES 6-14
APPENDICES
A GENERIC SITE CHARACTERISTICS A-l
B DREDGED MATERIAL CHARACTERIZATION B-l
C IMPACT EVALUATION C-l
D SUGGESTED ENVIRONMENTAL STUDIES D-l
E FEDERAL OCEAN DUMPING REGULATIONS E-l
F COMMENTS AND RESPONSES TO COMMENTS ON THE DRAFT EIS ... . F-l
xv
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CONTENTS (continued)
FIGURES
Number Title Page
1-1 Proposed Dredged Material Disposal Sites 1-2
1-2 Dredged Material Permit Cycle - Non-CE Permits 1-8
2-1 Proposed and Alternative Sites - South Oahu 2-3
2-2 Proposed and Alternative Sites - Nawiliwili 2-5
2-3 Proposed and Alternative Sites - Port Allen 2-6
2-4 Proposed and Alternative Sites - Kahului 2-7
2-5 Proposed and Alternative Sites - Hilo 2-9
2-6 Depth Profiles of the Proposed Sites 2-18
3-1 Typical Hawaiian Marine Open Coast Habitats and
Associated Fish Fauna 3-16
3-2 Humpback hhale (Megaptera novaeangliae) Distribution in Hawaii . . 3-21
3-3 Restricted Zones in Mamala Bay 3-24
3-4 State Fish and Game Catch Areas in Vicinity of the Proposed Sites . 3-26
J-5 1977-1978 Dredged Material Source Breakdown 3-32
4-1 Dredged Material Release Scenario 4-8
4-2 Depository Patterns of a Single Discharge 4-9
xv i
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CONTENTS (continued)
TABLES
Number Title Page
Responsibilities of Federal Departments and Agencies
for Regulating Ocean Disposal Under MPRSA 1~6
2-1 Projected Volumes and Dredging Schedules 2-25
3-1 Proposed Site Depths, Offshore Distances, and Sediment
Characteristics 3-3
3-2 Mean Percentages of Carbonate and Basalt Composition at the
Proposed Sites 3-4
3-3 Sediment Median Diameters at the Proposed Sites 3-4
3-4 Partial List of Hurricanes 3-6
3~5 Major Water Masses of the North Pacific 3-7
3-6 Sediment Trace Metal Concentrations at the Proposed Sites 3-11
3-7 Trace Metal Concentrations in Shrimp (Heterocarpus ensifer)
Collected at the Proposed South Oahu Site 3-12
3-8 Trace Metal Concentrations in Zooplankton Collected at the
Proposed South Oahu Site 3-13
3-9 Common Hawaiian Marine Mammals 3-16
3-1U Benthic Organisms Collected at the Proposed Sites 3-17
3-11 Parameters for Shrimp (Heterocarpus ensifer) Caught at the
Proposed Sites 3-20
3-12 Ranking of Recreational Activities near the Proposed Sites .... 3-23
3-13 Fishery Statistics for 1975-1976 in the Vicinity of the
Proposed Sites 3-27
3-14 Dredging Operation Characteristics 3-31
3-15 Point Source Summary for Pearl Harbor and Mamala Bay 3-33
4-1 Trace Metal Concentration Increases After One Dump
of Dredged Material 4-13
4-2 Grain-Size Distribution Comparisons of Sediments at the
Proposed Sites and Dredged Material to be Dumped 4-17
5-1 List of Preparers 5-1
NOTE: Each appendix is preceded by its own Table of Contents
xv ii
-------
TABLE 3-11
PARAMETERS FOR SHRIMP (Heterocarpus ensifer)
CAUGHT AT THE PROPOSED SITES
Parameter
South Oahu
Nawiliwili
Port
Allen
Kahului
Hilo
Mean Number
Per Trap
*
52
283
81
104
141
35
Mean Weight (g)
3.8
8.5
8.3
9.7
8.7
Mean Carapace
Length (cm)
1.8
2.7
2.7
2.7
2.6
Sources: Goeggel, 1978
*Chave and Miller, 1977b
(Taole 3-10). All Bryozoa are erect foliose forms, a type of growth form that
requires a hard, stable surface for attachment. All cnidarians (corals),
chitons, and probably some of the bryozoans were dead when collected. These
organisms may indicate immigrant materials (e.g., transport of skeletons by
currents from shallow water, or residual materials from submerged reefs).
THREATENED AND ENDANGERED SPECIES
Threatened and endangered species of the Hawaiian Islands include the
humpback whale (Megaptera novaeang1iae), Hawaiian monk seal (Monachus
schauinslandi). and the green sea turtle (Chelonia mydas). The humpback whale
breeding grounds are in nearshore Hawaiian Island waters from November until
May. Calving occurs mainly between January and March. Areas frequented by
the humpback whale during these months are shown in Figure 3-2.
The monk seal is endemic to the extreme Northwestern Hawaiian Islands.
The green sea turtle is the only common offshore reptile in Hawaiian
waters. Green turtle breeding (nesting) grounds are entirely in the
Northwestern Hawaiian Islands, primarily at French Frigate Shoals.
3-20
-------
160°W 159° 158° 157° 156° 155°
Figure 3-2. Humpback Whale (Megaptera novaeangliae) Distribution in Hawaii
-------
bottom is directly related to its ability to swim and the size of each
plankton. Great pressures and temperature differentials must also be
considered.
Potentially, a single dump of dredged material could trap and carry to the
bottom 1% of the phytoplankton biomass, 0.3% of the zooplankton biomass, and
0.2% of the micronekton biomass in the proposed South Oahu Site. Most of
these organisms move with the currents, and the water in the proposed South
Oahu Site will be replenished between each dump, thus there will be no
significant adverse impact on the local planktonic community due to trapping
of organisms by the descending dredged materials. Other proposed and
alternative sites are similar to the proposed South Oahu Site, therefore the
same water column trapping effects would occur.
EFFECTS ON THREATENED AND ENDANGERED SPECIES
The Hawaiian Islands provide a critical habitat for three threatened and
endangered marine organisms: the green sea turtle, Hawaiian monk seal, and
humpback whale. Green sea turtle nesting grounds are confined entirely to the
northwestern Hawaiian Islands. The distribution of the monk seal is centered
primarily on the northwestern Hawaiian Islands. Dredged material disposal
produces localized environmental effects which are not expected to affect
these populations. However, the effects on the humpback whale and green sea
turtle, of short-term turbidity resulting from dredged material disposal, are
not known at this time.
During breeding season, humpback whales are sensitive to human presence and
activities. Dredged material disposal, conducted at a time when whales are
actually present within the site vicinity, would most likely induce avoidance
behavior. Out of the breeding season, humpbacks have been reported to be
undisturbed by boat and ship traffic which is not directed towards them
(Norris and Reeves, 1978). Figure 3-2 in Chapter 3 shows that none of the
proposed disposal sites are within areas frequently visited by the whales.
However, dumping operations will be scheduled and conducted in a manner which
minimizes the potential for disturbing humpbacks during breeding season
(November to May).
4-14
-------
In the future, Federal, State, or county "humpback parks" or critical
humpback whale habitats may be established. Dredged material disposal
activities must not conflict with these areas or the goal of protecting
humpback whales in their wintering grounds.
EFFECTS ON BENTHOS
Principal effects of dredged material disposal are upon bottom life.
Bottom impacts evaluated include organism trapping, benthic smothering
(burial), alteration of sediment distribution size, associated benthic
community change, and mounding. The intake potential of toxic materials by
organisms was previously discussed for plumes and sediments.
BENTHOS SMOTHERING
As distance from shore and water depth increase, the benthic bioraass
dramatically decreases (Moiseev, 1971; Rowe and Menzel, 1971; Thiel, 1975).
Pequegnat et al., (1978) reported that, on a worldwide basis, the average
deep-ocean biomass is about 0.01% of life on the continental shelf.
Nevertheless, while abundance is low, some organisms in the direct path of
disposal will be buried.
The ability of organisms to survive burial is related to habitat and body
or shell morphology. Organisms of similar lifestyle and morphology react
similarly when covered with sediment (Hirsch et al., 1978). For example, all
epifaunal organisms (animals living above the bottom) are usually killed when
trapped under deposited dredged material, while infaunal organisms (those
living in the sediments) migrate in varying degrees. Hirsch et al. (1978),
report studies which determined that mud crabs and amphipods. (which have
morphological and physiological adaptations for crawling through sediments)
were able to migrate vertically through deposits tens of centimeters thick.
Similarly, Maurer et al. (1978) reported that the majority of animals tested
were able to migrate vertically, with as much as 32 cm of dredged material
piled on top of them.
4-15
-------
Chapter 5
COORDINATION
PREPARERS OF THE EIS
The preparation of this EIS was a joint effort employing members of the
scientific and technical staff of Interstate Electronics Corporation and the
Pacific Ocean Division of the Army Corps of Engineers. The preparers and the
sections of the EIS for which they were responsible are presented in Table
5-1.
TABLE 5-1. LIST OF PREPARERS
Author
Summary
Chapter
Appendix
1
2
3
4
5
6
A
B
c
D
F
M.D. Sands
X
X
X
X
X
X
X
J. Donat
X
X
X
X
X
X
X
X
X
X
M. Howard
X
X
X
X
X
S. Sullivan
X
X
X
X
J. Maragos
X
X
X
X
X
X
X
X
X
X
M. Lee
X
X
X
X
X
X
X
X
X
X
M. DALE SANDS
Mr. Sands, the principal author of this EIS, possesses a B.S. degree in
chemistry and biological sciences and an M.S. degree in environmental health
sciences (env:, .onmental chemistry). He prepared the Summary, Chapters 1, 2,
3, 4, and 5, and Appendix D of the EIS. As EIS coordinator, he directed
writing efforts on other sections of the EIS, edited all chapters, and
maintained liaison with EPA headquarters and the Pacific Ocean Division of the
Army Corps of Engineers.
5-1
-------
JOHN R. DONAT
Mr. Donat holds a B.S. degree in chemical oceanography. He assisted with the
writing of Chapters 1, 2, 3, 4, 5, and 6 and Appendixes A, B, C, and F.
MATTHEW HOWARD
Mr. Howard holds a B.S. degree in physical oceanography. He assisted in the
preparation of Chapters 3 and 4 and Appendixes A, B, and C.
STEPHEN M. SULLIVAN
Mr. Sullivan holds a B.S. degree in biological oceanography. He assisted in
the preparation of Chapters 3 and 4 and Appendixes A and C.
MICHAEL LEE
Mr. Lee is an environmental biologist at the U.S. Army Corps of Engineers
Environmental Resources Section, Pacific Ocean Division, Honolulu, Hawaii. He
holds a B.S. degree in marine biology. Mr. Lee assisted in editing the entire
EIS.
JAMES E. MARAGOS
Dr. Maragos is Chief of the Environmental Resources Section, Pacific Ocean
Division, U.S. Army Corps of Engineers, Honolulu, Hawaii. He holds a B.A.
degree in zoology and a Ph.D. in biological oceanography. Dr. Maragos
assisted in editing the entire EIS.
5-2
-------
COMMENTERS ON THE DRAFT EIS
The following persons submitted written comments:
Sidney R. Galler
Deputy Assistant Secretary for Environmental Affairs
U.S. Department of Commerce
Assistant Secretary for Science and Technology
Washington, D.C. 20230
(February 4, 1980; February 12, 1980)
George C. Steinman
Chief, Environmental Activities Group
Office of Shipbuilding Costs
U.S. Department of Commerce
Maritime Administration
Washington, D.C. 20230
(December 28, 1979)
James W. Rote
U.S. Department of Commerce
National Oceanic and Atmospheric Administration
National Marine Fisheries Service
Director, Office of Fisheries and Habitat Protection
Washington, D.C. 2U235
(February 6, 1980)
Doyle E. Gates
U.S. Department of Commerce
National Oceanic and Atmospheric Administration
National Marine Fisheries Service
Southwest Region
Western Pacific Program Office
P.O. Box 3830
Honolulu, Hawaii 96812
(January 9, 1980)
5-3
-------
Robert B. Rollins
U.S. Department of Commerce
National Oceanic and Atmospheric Administration
National Ocean Survey
Rockville, Maryland 20852
(December 28, 1979)
R. Kifer
U.S. Department of Commerce
National Oceanic and Atmospheric Administration
Office of Coastal 2one Management
Washington, D.C. 20235
(January 7, 1980)
Kisuk Cheung
Chief, Engineering Division
U.S. Department of the Army
Pacific Ocean Division, Corps of Engineers
Building 230
Fort Shafter, Hawaii 96858
(January 2, 1980)
R.D. Eber
CDk, CEC, USN
Facilities Engineer
Headquarters, Naval Base Pearl Harbor
Box 110
Pearl Harbor, Hawaii 96860
(January 11, 1980)
5-4
-------
Frank S. Lisella, Ph.D.
Chief, Environmental Affairs Group
Environmental Health Services Division
Bureau of State Services
U.S. Department of Health, Education, and Welfare
Public Health Service
Center for Disease Control
Atlanta, Georgia 30333
(January 9, 1980)
Patricia Sanderson Port
Regional Environmental Officer
U.S. Department of the Interior
Office of the Secretary
Pacific Southwest Region
Box 36098
450 Golden Gate Avenue
San Francisco, California 94102
(December 18, 1979)
Donald R. King
Director, Office of Environment and Health
Department of State
Bureau of Oceans and International Environmental and
Scientific Affairs
Washington, D.C. 20520
(February 5, 1980)
Adair F. Montgomery
Chairman, Committee on Environmental Matters
National Science Foundation
Washington, D.C. 20550
(January 14, 1980)
5-5
-------
James S. Kumagai, Ph.D.
Deputy Director for Environmental Health
State of Hawaii
Department of Health
P.O. Box 3378
Honolulu, Hawaii 96801
(January 11, 1980)
Richard L. O'Connell
Director, Office of Environmental Quality Control
Office of the Governor
550 Halekauwila Street
Room 301
Honolulu, Hawaii 96813
(January 15, 1980)
Susumu Ono
Chairman, Board of Land and Natural Resources
State of Hawaii
Department of Land and Natural Resources
P.O. Box 621
Honolulu, Hawaii 96809
(December 19, 1979)
Ah Leong Kam
State Transportation Planner
State of Hawaii
Department of Transportation
869 Punchbowl Street
Honolulu, Hawaii 96813
(January 8, 1980)
5-6
-------
Wallace Miyahira
Director and Chief Engineer
Department of Public Works
City and County of Honolulu
650 South King Street
Honolulu, Hawaii 96813
(December 28, 1979)
George S. Moriguchi
Chief Planning Officer
Department of General Planning
City and County of Honolulu
650 South King Street
Honolulu, Hawaii 96813
(December 5, 1979)
Toshio Ishikawa
Planning Director
County of Maui
Planning Department
200 South High Street
Wailuku, Maui, Hawaii 96793
(December 7, 1979)
Sidney Fuke
Director, Planning Department
County of Hawaii
25 Aupuni Street
Kilo, Hawaii 96720
(December 20, 1979)
5-7
-------
Tyrone T. Kusao
Director of Land Utilization
Department of Land Utilization
City and County of Honolulu
650 South King Street
Honolulu, Hawaii 96813
(December 12, 1979)
Doak C. Cox
Director, Environmental Center
University of Hawaii at Manoa
Crawford 317
2550 Campus Road
Honolulu, Hawaii 96822
(January 15, 1980)
Kelley Dobbs
Greenpeace Foundation
P.O. box 30547
Honolulu, Hawaii 96820
(January 14, 1980)
Kenneth S. Kamlet
Assistant Director, Pollution and Toxic Substances
National Wildlife Federation
1412 16th St., N.W.
Washington, D.C. 20036
(January 15, 1980)
5-8
-------
Appendix F
COMMENTS AND RESPONSES TO COMMENTS
ON THE DRAFT EIS
The Draft EIS (DEIS) was issued on 9 November 1979. The public was
encouraged to submit written comments. This appendix contains copies of
written comments received by EPA on the DEIS. There was a great variety of
comments received, thus EPA presents several levels of response:
• Comments correcting facts presented in the EIS, or providing
additional information, were incorporated into the text and the
changes were noted.
• Specific comments which were not appropriately treated as text
changes were numbered in the margins of the letters, and responses
prepared for each numbered item.
Some written comments were received after the end of the comment period.
In order to give every consideration to public concerns, the Agency took under
advisement all comments received up to the date of Final EIS production.
The EPA sincerely thanks all those who commented on the DEIS, especially
those who submitted detailed criticisms that reflected a thorough analysis of
the EIS.
F-l
-------
COMMENT
UNITED STATES DEPARTMENT OF COMMERCE
The Assistant Secretary for Science and Technology
Washington 0 C 20230
12021 377 4 3 35
February 4, 1980
Mr. Henry L. Longest, II
Deputy Assistant Administrator
for Water Program Operations
U.S. Environmental Protection Agency
Washington, D. C. 20460
Dear Mr. Longest:
This is in reference to your draft environmental impact statement
entitled, "The Designation of Five Hawaiian Dredged Material
Disposal Sites." The enclosed comment from the Maritime
Administration is forwarded for your consideration.
Thank you for giving us an opportunity to provide this comment
which we hope will be of assistance to you. We would appreciate
receiving eight (8) copies of the final environmental impact
statement.
Sincerely,
Deputy Assistant Secretary
for Environmental \ffairs
Enclosure Memo from: George C. Steinman
Chief, Division of Environmental
Activities
Office of Shipbuilding Costs
MarAd
RESPONSE
EPA gratefully acknowledges the letter from the Deputy Assistant
Secretary for Environmental Affairs, United States Department of
Commerce.
-------
/v\
V3V
UNITED STATES DEPARTMENT OF COMMERCE
Miritlini Administration
December 28, 1979
MEMORANDUM FOR: Dr. Sidney R. Galler
Deputy Assistant Secretary for Environmental
Affairs
Subject: Environmental Protection Agency Draft Environmental
Impact Statement for the Designation of Five
Hawaiian Dredged Material Disposal Sit€s (DES
CN 7911.10)
The subject document has been reviewed for comment as requested
by your memorandum of November 15, 1979. The proposed action
amends the 1977 interim designation of the EPA Ocean Dumping
Regulations and Criteria by altering the locations of three
dump sites, adding two new dump sites, and making final
designations of all five sites. All the sites are located
close to shore but in deep water where open ocean conditions
prevail. The dredged material, which is mostly terrestrial
silt and clay mixed with sand, is dispersed rapidly at all
five proposed sites. Currents generally flow alongshore or
offshore.
We concur with the analyses and conclusions contained in the
DEIS and have no critical comments to submit. Please send us
a copy of the FEIS.
Of'
GEORGE C. STEINMAN
Chief, Division of Environmental Activities
Office of Shipbuilding Costs
,ovur<0/v
EPA thanks Che Chief of the Division of Environmental Activities,
Office of Shipbuilding Costs, Maritime Administration, United States
Department of Commerce, for reviewing the Draft E1S.
-------
.ay
"
-------
U.8. DEPARTMENT OF COMMERCE
National Oeaanie and Atmoapharic Administration
NATIONAL MARINE FISHERIES SERVICE
Southwest Region
Western Pacific Program Office
P. 0. Box 3830
Honolulu, Hawaii 96812
January 9, 1980
F/SWR1:JJN
I
CJ1
Mr. T. A. Wastler
Chief, Marine Protection Branch
Environmental Protection Agency
Washington, D. C. 20460
Dear Mr. Wastler:
The National Marine Fisheries Service (NMFS) has reviewed the
draft environmental impact statement (DOC DEIS No. 7911.10) for The
Designation of Five Hawaiian Dredged Material Disposal Sites dated
October 1979.
In order to provide as timely a response to your request for
comments as possible, we are submitting the enclosed, comments to you
directly, in parallel with their transmittal to the Department of
Commerce for incorporation in the Departmental response. These comments
represent the views of the NMFS. The formal, consolidated views of
the Department should reach you shortly.
Sincerely yours
J Doyle E. Gates
S ^ Administrator
Enclosure
cc: Gary Smith,F/SWB3, w/encl.
Office of Habitat Protection, F/HP
(4 copies) w/encl.
-------
Comments on DEIS No. 7911.10 - The Designation of Five Hawaiian
Dredged Material Disposal Sites
General Comments
The National Marine Fisheries Service (NMFS) was consulted during
the planning and selection stages For the designation of deep-ocean
disposal sites in the Hawaiian Islands for continued disposal of dredged
material. This included narrowing an original fourteen proposed sices
down co the fivv? sites considered in the subject DEIS.
The NMFS feels that existing fisheries and endangered species under
our jurisdiction will probably not be adversely impacted by the proposed
action, primarily because of the depths of the selected sites and the
planned infrequent use of these sites. However, because of the importance
of the nearshore waters surrounding the main Hawaiian Islands to two
aiarine animals on the endangered species list, we feel the DEIS should
include sections in chapters 3 and 4 specifically dealing with endangered
species. The two species of concern are the endangered humpback whale
(We^a^ter^^iovaean^liae) and the threatened green turtle (Cheloni^jiv^dasK
This section should include a caveat indicating that the effects of
short-term turbidity, such as occurs during dredged material disposaJ, on
humpback whales and green turtles, is not known at this time.
Specific Comments
Chapter 2. ALTERNATIVES INCLUDING THE PROPOSED ACTION.
^Interference^^Lth^hig^in^j^jrishin^^^ .
Paj>e_^^20j_jJ3raj>ra£h_^ This paragraph states that the only fishing which
occurs near the proposed disposal sites is midwater trolling. Midwater
trolling should be changed to surface trolling. In. addition, «nmp hnt-f-nm
handlining for deep water snappers and midwater handlining for akule and
large tunas occurs near several of the proposed sites.
Chapter 3. AFFECTED ENVIRONMENT •
BIOLOGICAL CONDITIONS
Nekton
Pa£e_^^14j_j>araj>ra£h_4. Scientific names should be used for these pelagic
nektonic predators the first time they appear in the text. Common names
preceding the scientific name should be the same throughout the DEIS. As
an example, in this paragraph yellowfin tuna and skipjack tuna are used
while on page 3-27 the Hawaiian names ahi and aku are used respectively
for these tuna.
The suggested information on the two endangered species has been
incorporated into Chapters 3 and 4 under sections entitled
'Threatened and Endangered Species. The "caveat" concerning effects
of short-term turbidity on these endangered species has been included
under the same section in Chapter U.
The suggested changes have been incorporated into the text and appear
in Chapter 2 of the Final EIS under the section "Detailed Basis for
Selection of the Proposed Sites, subsection "Interference with
Shipping, Fishing...
These changes have been incorporated into the text of the Final EIS
and appear in Chapter 3 under the section "Recreational, Economic and
Aesthetic Characteristics, subsection "Fisheries.
-------
2
Page 3-14. paragraph 5. As presented in General Consaents above, the
discussion of endangered and threatened species should be expanded and
placed in a separate section In this chapter of the DEIS.
This paragraph states that "the green sea turtle is the only conmon
offshore reptile, whose breeding grounds are on the leeward side of the
islands." Although it is the only common marine reptile in Hawaiian
4 waters, green turtle breeding (nesting) grounds at present are entirely
in the Northwestern Hawaiian Islands, primarily at French Frigate Shoals.
In addition, the Hawaiian monk seal (Monachus schauinslandi) is indeed
endemic to the Hawaiian Archipelago. However, it is rarely found in the
main islands thus dredged material disposal at the proposed sites will
not adversely impact this endangered seal.
Page 3-16, Table 3-9. Common Hawaiian Marine Mammals. There are several
errors in this table as follows: 1. There is no known pilot whale,
Delphinus melas. The pilot whale found in Hawaiian waters is Globicephala
macrorhynchus. 2. The common name for Stenella attenuata is spotted
^ dolphin. 3. The common dolphin, Delphinus delphis, and the Pacific white-
sided dolphin, Lagenorhynchus obliguidens, are unconfirmed in Hawaiian
waters; therefore they are certainly not common Hawaiian marine mammals.
U. Only one species of bottlenose dolphin occurs in Hawaii, Tursiogs
gilli.
Fisheries
Page_^^23j_j3ara£ra£h_4. This paragraph states that "commercial fishing
(in Hawaii) is confined to surface or pelagic offshore fishing, with little
bottom fishing." This statement is misleading. Bottomfishing for
4s 6 demersal snappers and groupers is an important segment of Hawaiian com-
I mercial fishing, even though the catch is relatively small compared to
**-J the pelagic fisheries.
Page_^-27j_j)aragraph^. The paragraph discusses fisheries in Mamala Bay
and indicates that fishing for aku is the major fishery at the dredged
material disposal site. Actually the majority of aku are taken well
A— 7 seaward of the proposed disposal site. Ulua should be followed by (Caranx
~ and Carangoides spp.)
Chapter U. ENVIRONMENTAL CONSEQUENCES
Fishing
g Page 4-3, paragraph 3. Again the statement is made that "little or no
demersal(bottom)fishing" occurs in Hawaii. This should be corrected.
4-9
Pa£e_4^5j_jjara£ra£h_4. This paragraph discusses recreational fishing
from charter boats and states that mahimahi, swordfish and billfish are
caught. Swordfish are not taken by recreational charter boats which fish
4 — 4 This information has been added to Chapter 3 of the Final EIS under
the section "Threatened and Endangered Species.
4^5 Table 3-9 in the Final EIS has been changed to reflect these
comments.
4*"6l This passage has been amended in the Final EIS to include this
l_7J information and appears in Chapter 3 under the section "Recreational,
Economic, and Aesthetic Characteristics, subsection "Fisheries."
Tne family name Caran^idae is used in the final EIS for ulua instead
of the two species names suggested.
4-81
4-9 J
These changes have been made and appear in Chapter 4 of the Final EIS
under the section "Effects on Recreational, Economic, and Aesthetic
Values, subsection "Fishing"
-------
3
by surface trolling. Long-line fishing is not commonly conducted as a
recreational fishing method.
We hope these comments will be of assistance to you* Please send
us a copy of the final EIS as soon as it becomes available.
-T1
I
00
-------
UNITED STATES DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
NATIONAL OCEAN SURVEY
Rocfrvilie Md 20052
0A/C52x7:SKM
TO: PP - Richard L. Lehman
FROM: 0A/C5 - Robert B. Rollins /
SUBJECT: DEIS #7911.10 - The Designation of Five Hawaiian Dredged
Material Disposal Sites
The subject statement has been reviewed within the areas of the National
Ocean Survey's (NOS) responsibility and expertise and in terms of the impact
of the proposed action on NOS activities and projects.
The following comments from the Ocean Dumping and Monitoring Division,
NOS, are offered for your consideration.
The letter enclosed with the DEIS is most important. It indicates
that the DEIS is for site designation on!v. It contains information of
use to determining acceptability of given dredged material for ocean
dumping but it is not to be considered a final argument for such
acceptability.
The EPA Ocean Dumping Regulations are specific on what needs to be
considered for site designation. Those regulations are Appendix F of
the DEIS and 11 specific considerations are on page F-10. These consti-
tute the cookbook for a site designation DEIS.
On pages 2-14 to 2-21, the 11 considerations are separately dis-
cussed and this is the heart of the DEIS. The basic conclusion of the
DEIS is that the five sites should be designated as dredged material
disposal sites because they are locations of low resource value where
any suspended or dissolved remnant of a dump will be carried seaward
or parallel to the shore while being mixed with surrounding water. I
have no data or information which will cause me to disagree with that
conclusion.
Specific Comments:
P. xii, paragraph 4: Mention is made of a huge assimilative capacity
at the disposal sites, yet a definition of assimilative capacity is not
given in the DEIS. What does huge mean? Relative to what? What does
"assimilative capacity" mean?
5^1 the sentence in question has been changed in Che Final E1S to read:
"The proposed disposal sites can receive dredged materials without
jeopardizing the life-support systems of marine biota due to the
extent of dilution which occurs (approximately 1:1,000,000).
-------
2
P. xii: THE E1S is riddled with confusion, three examples of which
are found on this page. In paragraphs 2 and 3, the word "significant"
appears twice as an adjective and in both cases it is completely unclear
II p as to its meaning. What is "significant dilution and transport"? In the
last sentence on the page, what are "suspended particulates"? Particulate
sediments? Organisms?
P. 2-18, paragraph 1: The discussion of dilution and dispersion of
spoil plumes is too brief to be sufficient. What does "sufficiently
diluted and dispersed" mean? By what standards, and relative to what?
5—3 ^he same COfm,ents aPP^y to paragraph 2 on page 2-19. In both cases, all
quantitative comments about plume behavior should be supported by a refer-
ence to the original source of the information, even though in these cases,
the references are discussed in more detail in later chapters.
Page 3-3: First word on first line, "Goeggel" should not be there.
Page 3-7: The paragraph about currents includes not one reference
to original sources of information. The references should be included.
Page 3-9: Under Trace Metals, some elements "below minimum detec-
table levels" - what are tnose levels? Also, the Zn and Hg concentrations
c_A are given and said to be 10 to 1000 times higher than listed average con-
centrations. If the data are to be given, then some explanation of why
the measured concentrations are so high should also be present.
Pages 3-10 to 3-12: The discussion and tables dealing with metal
contents of sediments and organisms are meaningless as they stand. The
5—5 figures should be presented in relation to what is known of chemical
dynamics and toxicities of the metals.
Pages 3-12 to 3-20: The sunsnary of biological conditions should be
presented in a comparative manner to demonstrate similarities and dif-
ferences, if any, between the regions discussed and surrounding areas.
5—6 sect10n 1S incomplete without this broader, regional perspective.
This section could also be improved by expanding the descriptions of
the various conmunities with names and number of species occupying them.
The last paragraph on page 3-16, for example, could be improved greatly
by inclusion of a few numbers. What does "dominated in abundance and
diversity" mean? How many are "several"? What does "fewer numbers"
mean?
Page 4-12: It is unlikely that dredged material would be declared
acceptable only on basis that Hg and Cd levels in site sediments would
5 — 7 increase by 50 percent or less. This criteria would be sufficient if,
for some reason, bioassays were deemed unnecessary.
The example on the bottom of the page is not comprehensible. If
Q dredge material could be uniformly distributed in the water column, one
O would be seeking other disposal sites.
5-2
The word "significant" has been deleted from the two cited paragraphs
in the FinaL EIS. The phrase "'suspended particulates" has been
changed to ''suspended particulate matter.
5„3 The discussion of dilution and dispersion of the dredged material
plume is a summary of more detailed information found in Appendices A
and C of the Draft and Final EIS. However, appropriate references
have been included as suggested. The word ''sufficiently" has been
deleted from the cited phrase.
5—4 detection limits and an explanation of the high zinc and mercury
values have been included in the Final EIS in Chapter 3 under the
section entitled "Chemical Conditions? subsection "Trace Metals"
The detection limits for silver, cadmium, chromium, and copper were
1 ^g/liter. The detection limits for lead and nickel were 5 pg/liter
and 4 /ig/liter, respectively. The high values for mercury and zinc
occurred due to sample contamination (K. Chave , personal
communication, 1980). (See Conment and Response #9-3.)
5—5 ^he information contained in these tables is presented as background
description for characterization of the disposal sites. Toxic
concentrations of metals in sediment have not been established.
5—0 Complete biological studies were conducted (aee Chapter 3 for
references) at the South Oahu Site only. Chapter 3 of the DEIS
described differences between the pelagic communities at this site
and conmunities in other regions of the Hawaiian Islands. Chapter 3
discussed members of the site biota which could be potentially
impacted by dredged material dumping' Regarding use of qualitative
descriptors of abundances in the DEIS text, reference to an
accompanying table had been omitted inadvertently. This table (3-10)
had been included in the DEIS and is included in the Final EIS.
5-7 The tables and discussion using the 50% increase criterion have been
deleted from this section of the Final EIS. The section entitled
"Toxin Accumulation1' has been rewritten as a result of Comment
#25-10, and is now entitled "Trace Metal and Organohalogen
Accumulation.
5—3 ^he example cited in the section entitled "Trace Metal and
Organohalogen Accumulation" may be viewed as an extreme case, since,
in reality, the metals contained in the dredged material do not
readily enter solution. The example is merely illustrating that,
given the volume of the disposal site and assuming that all metals
contained in the dredged material entered solution completely, the
increases in metal concentrations of the water column are extremely
minimal.
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v-
UNITED STATES DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
"¦I i'i OCZM
Washington, O.C. 20235
DATE: January 7, 1980
TO: PP/EC - R. Lehman
FROM: CZM
:C - R. Lehman .r
- R. Kifer I
SUBJECT: DEIS 7911.10 - The Designation of Five Hawaiian Dredge Material
Disposal Sites - CZM Cofronent
Thank you for the opportunity to review and comment upon the Draft
Environmental Impact Statement (EIS) for The Designation of Five Hawaiian
Dredged Material Disposal Sites.
The Sanctuary Programs Office of the Office of Coastal Zone Management
(OCZM) is concerned about, potential impacts of the proposed action on the
marine environment in general and on the particularly sensitive resources
of areas which have been suggested for possible marine sanctuary status.
At the present time, there are no marine sanctuaries nor active candidates
for marine sanctuary designation within the proposed disposal areas.
However, the interisland waters of Maui County, including waters of the
Pailolo Channel near Kahului Harhor and Kahului Disposal Site, appear on
the Marine Sanctuary List of Recoirenended Areas (11 FR Ho. 212 October 31,
1979). Moreover, the recent Hawaiian Humpback Whale Workshop (Maui:
December 12-14, 1979) convened by OCZM recommended the establishment of
a Hunpback Whale Marine Sanctuary to encompass all waters within the
100-fathom isobath surrounding the High Hawaiian Islands (from Kaula
Island in the northwest to the Island of Hawaii in the southeast). OCZM
is discussing the outcome of the workshop with various government, sci-
entific and environmental entities and is evaluating the recommended
site according to Marine Sanctuary Regulations (44 FR No. 148 July 31,
1 1979) for possible selection as an Active Candidate for marine sanctuary
designation. While the boundaries of the recommended marine sanctuary
and proposed dredge disposal sites do not over Up, they are within close
proximity of each other. It is therefore recommended that appropriate
monitoring studies be undertaken to determine to what extent the marine
environment within these especially sensitive areas would be affected by
disposal operations, especially the likelihood of dredged materials moving
into a marine sanctuary (40 CFR SS 228.10[b]) should one be designated.
Modeling studies on dredged material dispersion were discussed at
length in Appendix C of the OEIb, subsection entitled "Previous
Mathematica 1 Studies. Future environmental studies to provide
additional dredged material dispersion data were recommended in
Appendix D of the DEIS, which included thorough characterizations of
the dredged materials, turbidity and/or nephelometry profiles of the
disposal site water coLumn, and total suspended soli.de load. These
will be performed at the discretion of the District Engineer
(or tfh Regional Administrator), who will determine thu optimal
conditions tor success. When any marine sanctuary near a disposal
s l U' jppi.-ars to be influenced by dredged material dir;poS;il
0[". ration1: , tin- study plan will he reviewed and amended 'incf;
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OCZM is particularly concerned about the welfare of the endangered
humpback whale (Meqaptera noyaeangliae) in relation to any disposal
activity. Figure 3-2 (p 3-17) in the uEIS acknowledges the presence of
humpback whales within the proposed disposal areas. This concurs with
the findings of whale surveys conducted by the National Marine Fisheries
Service (NMFS: 1976-79) and several independent scientific surveys
(1976-78). While the effect of dredge disposal on humpbacks has not yet
been ascertained, it is strongly recoirmended that, should disposal be
carried out as planned, extreme caution be exercised to avoid disposal
if and when humpbacks are reported at or near the disposal sites. Since
humpback residency is seasonal (winter/early spring), it is suggested
that disposal be avoided during this time, especially during what are
believed to be important calving, nursery, and possible courtship and
breeding periods, until it is certain that dumping operations do not
interfere with these key life history events. Further consultation with
NOAA (NMFS and OCZM) is reconmended to coordinate scheduling of disposal
operations to avoid adverse impacts on the whales during their winter
residence i n Hawaii.
As acknowledged in the DEIS, "an effective monitoring program is
usually based on a comprehensive predisposal baseline survey of the site"
(p 2-22) and of the proposed dredge operation site. OCZM therefore
recomnends that the following environmental parameters and consequences
be given full consideration prior to dredge and disposal operations:
° relationship between and conpatibility of sediments at disposal
sites and those to be dredge/disposed, especially since regulations
specify that "... material proposed for dunging is substantially
the same as the substrate ..." at the disposal site. On page
4-19 it is stated that "the bulk of dredge material proposed for
dumping at the South Oahu Site is composed of sand and gravel,
and presents no great variation in disposal site substrate."
No such evaluation is provided for other proposed sites and in-
tended dredge materials. Table 4-5 (p 4-19) does, however, present
grain size distribution comparisons. Sediment compositions given
in this table appear to be significantly different. For example,
sediment at the proposed Nawiliwili Site has a 2% silt-clay
composition whereas sediment to be dredged from the Nawiliwili
Harbor has a 92% silt-clay composition. Since "there is evidence
that the dredged material may consist of considerable fractions
of silt and clay" (p C-10), OCZH recommends further study to
determine if dredged materials are compatible with sediments of
the disposal site.
° the physical and chemical relationship between measured harbor
sediments and sediments in the dredge vessel hoppers before release,
0 the effect of turbidity on marine mammals,
Subsections entitled "Threatened and Endangered Species, relative to
humpback whales and other Hawaiian waters species, have been added to
the Final EIS in Chapters 3 and 4. Several factors would mitigate
disposal effects on these mammals: (1) the sites are not greatly
frequented by humpback whales (see Figure 3-2, Chapter 3), (2) as
described in Chapter 4, humpback whales are apparently undisturbed by
surface traffic not specifically directed at them (Norris and Reeves,
1978), and (3) the proposed dredged material disposal would be a
short-term infrequent activity. Due to potential effects of disposal
on the whales, advanced planning schedules will attempt to avoid
breeding and calving seasons (November to Hay) until additional data
are available. (See Conment and Response #15-2.)
Some of the future study subjects recommended by the Office of
Coastal Zone Management (OCZM) are already included in Appendix D
(e.g., physical/chemical characterization of sediments in dredged
vessel hoppers, measurement of benthic biomass, and recruitment/
recovery rates). Other OCZM-recommended studies are subjects for
research (e.g., effects of turbidity on marine mansnals, cumulative
etfects of organic carbon loading, and dredged material plume effects
on holoplankton and meroplankton). The remaining study recommended
by OCZM, "Determination of Sediment Composition,1 is listed in the
Ocean Dumping Regulations for testing candidate materials for
dumping. Except for the studies prescribed by the Ocean Dumping
Regulations, all recommended studies will be given full discretionary
consideration by the District Engineer (or EPA Regional
Administrator).
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° the organic content of dredged material,
° the cumulative effect of organic carbon loading on the ocean
bottom and in overlying waters (from organic content of dredged
material, biotic trapping and benthic smothering) and the potentia
impact of simultaneous increase in oxygen demand and reduction in
primary productivity due to turbidity and phytoplankton trapping;
0 the effects of suspended and settling sediment on the plankton
and en recruitment/settlement of planktonic larvae and juveniles;
° measurement of benthic biomass and recruitment/recovery rates
at the disposal sites and at the dredged sites.
0 bioassays of key organisms at disposal sites and at dredge sites*
Thank you for considering these recornnendations.
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Appendix 2 to EPA Consultation with NMFS
for Continued Use of Five Existing Ocean Dredged Material Disposal Sites (ODMDS)
in Waters Offshore of Hawaii
Site Monitoring Synthesis Report for the
South O'ahu and Hilo Ocean Disposal Sites
(EPA 2015)
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2013 HAWAII OCEAN DISPOSAL SITE MONITORING
SYNTHESIS REPORT
Prepared by:
Dredging and Sediment Management Team
USEPA Region 9
San Francisco, CA
April 27, 2015
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
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Table of Contents
Executive Summary 1
I. Introduction and Background 1
II. Summary of Site Monitoring Activities 7
2.1. Sediment Profile Imaging (SPI) and Plan View Photography (PVP) 7
2.2. Sediment Sampling for Chemistry and Benthic Communities 13
2.3. Sub-Bottom Profiling Survey of the South Oahu ODMDS 15
III. Survey Results 17
3.1. SPI-PVP Surveys 17
3.1.1 Dredged Material Footprint Mapping 17
3.1.2 Bioturbation Depth 17
3.1.3 Infaunal Successional Stage 24
3.1.4 PI an-View Photography 27
3.1.5 Discussion: SPI-PVP Surveys 30
3.2. Sediment Physical and Chemical Survey Results 30
3.2.1 Physical Results 31
3.2.2 Chemical Results 31
3.3. Benthic Community Analysis Results 34
3.3.1 Abundance of Infauna 34
3.3.2 Diversity of Infauna 35
3.4. Sub-Bottom Profiling Survey (South Oahu Site Only) 36
3.5. Comparison to 1980 Baseline Information 43
3.5.1 South Oahu Disposal Site 43
3.5.2 Hilo Disposal Site 44
IV. Conclusions and Recommendations 46
V. References 47
Appendix: Summary of Planned vs Actual Survey Activities at Hawaii Ocean Dredged
Material Disposal Sites, 2013 A-l
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
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List of Figures
Figure 1. Five ocean dredged material disposal sites serve Hawaii ports and harbors. 3
Figure 2. General location of the South Oahu ocean dredged material disposal site. 4
Figure 3. General location of the Hilo ocean dredged material disposal site. 5
Figure 4. SPI-PVP camera system being deployed from the Hi'ialakai. 8
Figure 5. Schematic of deployment and collection of plan view and sediment profile
photographs. 9
Figure 6. Soft-bottom benthic community response to physical disturbance (top
panel) or organic enrichment (bottom panel). 10
Figure 7. Planned (yellow squares) and actual sample station locations at the South
Oahu ODMDS. 11
Figure 8. Planned and actual sample station locations at the Hilo ODMDS. 12
Figure 9. Double Van Veen sediment sampler deployed from the Hi'ialakai. 13
Figure 10. Subsampling from the Van Veen grab for sediment chemistry. 14
Figure 11. Processing a sediment sub-sample for chemical analysis. 14
Figure 12. Processing a sediment sample for benthic community analysis. 15
Figure 13. Sub-bottom profiler equipment - used only at the South Oahu site. 16
Figure 14. Planned transect lines for the sub-bottom profiling survey around the
South Oahu ODMDS. 16
Figure 15. Profile images from the ambient bottom at the Hilo ODMDS (left,
Station S3) and the South Oahu site (right, Station S6). 18
Figure 16. Plan view images of the dredged material deposit compared to the native
seafloor at South Oahu. 19
Figure 17. Profile images from two Hilo Stations showing a surface layer of disposed
coarse white dredged sand. 20
Figure 18. Dredged material footprint identified at the South Oahu site. 21
Figure 19. Dredged material footprint identified at the Hilo site. 22
Figure 20. Plan view image from the center station of the Hilo ODMDS shows a
high density of small rock and coral rubble. 23
Figure 21. Bioturbation depth at the South Oahu site. 25
Figure 22. Bioturbation depth at the Hilo site. 26
Figure 23. Community structure at the South Oahu site. 28
Figure 24. Community structure at the Hilo site. 29
Figure 25. USGS shaded-relief image showing the boundary of the sub-bottom
survey area around the South Oahu disposal site, as well as major
bedforms in the vicinity. 37
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
List of Figures, cont.
Figure 26. USGS sidescan sonar (backscatter) image showing historic dredged
material deposits around the sub-bottom survey area and the South
Oahu disposal site. 38
Figure 27. Transect lines occupied for the sub-bottom profiling survey of the South
Oahu site. 39
Figure 28. Geological (surface) interpretation from the sub-bottom profiling survey
superimposed with the SPI-based dredged material footprint map shown
in Figure 17. 40
Figure 29. Sub-bottom profile for Diagonal Line 1. 41
Figure 30. Comparison of South Oahu site dredged material volume estimates. 42
List of Tables
Table 1. Disposal volumes (cubic yards) at the 5 Hawaii ODMDS following
designation in 1980. 6
Table 2. Summary of sediment chemistry for the South Oahu Ocean Dredged
Material Disposal Site and vicinity. 32
Table 3. Summary of sediment chemistry for the Hilo Ocean Dredged Material
Disposal Site and vicinity. 33
Table 4. Infaunal species abundances at the South Oahu site. 35
Table 5. Infaunal species abundances at the Hilo site. 35
Table 6. Average Percent Grain Size - South Oahu Site. 43
Table 7. Trace Metal Concentrations - South Oahu Site. 43
Table 8. Percent Abundance - South Oahu Site. 44
Table 9. Average Percent Grain Size - Hilo Site. 44
Table 10. Trace Metal Concentrations - Hilo Site. 45
Table 11. Percent Abundance - Hilo Site. 45
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
2013 HAWAII OCEAN DISPOSAL SITE MONITORING
SYNTHESIS REPORT
EXECUTIVE SUMMARY
In 1981, the US Environmental Protection Agency (EPA) designated five ocean dredged material
disposal sites (ODMDS) offshore of Hawaiian Island ports and harbors. In 1997, EPA and the US
Army Corps of Engineers (USACE) published a Site Monitoring and Management Plan (SMMP)
covering all five of these disposal sites. But since that time, due to lack of available funding, the
sites have not been comprehensively monitored and the SMMP has not been updated. Therefore,
when funding became available for 2013, EPA identified the Hawaii sites as the highest priority to
monitor of all the disposal sites in Region 9. Since only the South Oahu and Hilo sites had
received any disposal activity since the late 1990s, EPA conducted surveys at only these two sites.
Ship and equipment problems resulted in a reduction in the planned survey scope and in the overall
number of samples collected. However, sufficient sampling was completed to provide an adequate
basis to confirm environmental conditions at these sites and to update the SMMP. Based on
analyses of sub-bottom profiling, sediment profile and plan view imaging, and sediment grain size,
chemistry, and benthic community sampling, it appears that the pre-disposal sediment testing
program has protected these sites and their environs from any adverse contaminant loading. The
bulk of the dredged material disposed in the last decade or more appears to have been deposited
properly within the site boundaries. There are minor and localized physical impacts from dredged
material disposal, as expected, but no significant adverse impacts are apparent to the benthic
environment outside of site boundaries. Continued use of the disposal sites, under an updated
SMMP, is recommended.
I. INTRODUCTION AND BACKGROUND
Ocean dredged material disposal sites (ODMDS) around the nation are designated by the
Environmental Protection Agency (EPA) under authority of the Marine Protection, Research and
Sanctuaries Act (U.S.C. 1401 et seq., 1972) and the Ocean Dumping Regulations at 40 CFR 220-
228. Disposal site locations are chosen to minimize cumulative environmental effects of disposal
to the area or region in which the site is located, and disposal operations must be conducted in a
manner that allows each site to operate without significant adverse impacts to the marine
environment. Many ocean disposal sites are located near major ports, harbors, and marinas and are
very important for maintaining safe navigation for commercial, military, and private vessels.
EPA and the US Army Corps of Engineers (USACE) share responsibility for managing ocean
disposal of dredged sediments. First, there is a pre-disposal sediment testing program that is
jointly administered by the agencies to ensure that only clean (non-toxic) sediments are permitted
for ocean disposal. EPA must concur that sediments meet ocean dumping suitability requirements
before USACE can issue a permit for ocean disposal. Post-disposal site monitoring then allows
1
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
EPA and USACE to confirm the environmental protectiveness of the pre-disposal testing. The
agencies also jointly manage the ocean disposal sites themselves. All sites are operated under a
site management and monitoring plan (SMMP), and the Agencies cooperate on updating the
SMMPs if needed, based on the results of periodic site monitoring. EPA is also responsible for
enforcement of potential ocean dumping violations at each site.
The site use requirements in SMMPs for each specific ODMDS can be based on any issues of
concern identified in the original site designation environmental impact statement (EIS) or
environment assessment (EA), and/or on the results of subsequent (post-disposal) monitoring.
Each SMMP typically incorporates a compliance monitoring component to ensure that individual
disposal operations are conducted properly at the site, as well as a requirement for periodic
monitoring surveys to confirm that the site is performing as expected and that long term adverse
impacts are not occurring.
EPA designated five ODMDS offshore of Hawaiian Island ports and harbors in 1981 (Figure 1).
With the exception of the South Oahu site, these disposal sites are used infrequently (generally
only every 5-10 years or so) when USACE conducts maintenance dredging of the federal channels
serving each harbor. Baseline surveys were conducted in the 1970s to support the original site
designation action, but only limited monitoring work has occurred since then at most of the sites.
The USGS, while doing other coastal mapping work in 1994 and 1995, conducted acoustic
backscatter surveys at all five sites for EPA, to map dredged material deposits on the sea floor.
They also collected sediment chemistry samples at the South Oahu site. Based on the USGS
survey results, EPA and USACE published an SMMP in 1997 covering all five Hawaii disposal
sites. Since that time, due to lack of available funding, the sites have not been comprehensively
monitored and the SMMP has not been updated. When increased funding became available for
2013, EPA therefore identified the Hawaii sites as the highest priority to monitor of all the disposal
sites in Region 9. However, because only the South Oahu and Hilo sites had received any disposal
at all since 1999 (Table 1), EPA planned comprehensive monitoring at only these two sites.1
The South Oahu site (Figure 2) is located approximately 3 nautical miles offshore of Pearl Harbor
in water depths ranging from about 1,300 to 1,650 feet (400 to 500 meters). It is a rectangular
ocean disposal site 2 kilometers wide (west-east) and 2.6 kilometers long (north-south), and
occupies an area of about 5.2 square kilometers on the sea floor. Although the overall site is
rectangular, all disposal actions must take place within a 1,000 foot (305 meter) radius Surface
Disposal Zone at the center of the site. Its center coordinates are 21 degrees 15.167 minutes North
Latitude, 157 degrees 56.833 minutes West Longitude (NAD 83).
The Hilo site (Figure 3) is located approximately 4 nautical miles offshore of Hilo in water depths
averaging about 1,150 feet (350 meters). It is a circular ocean disposal site with a radius of 3,000
feet (920 meters) and an area of about 2.7 square kilometers on the sea floor. As at South Oahu,
all disposal actions must take place within a 1,000 foot (305 meter) radius Surface Disposal Zone
at the center of the site. The center coordinates of the Hilo site are 19 degrees 48.500 minutes
North Latitude, 154 degrees 58.500 minutes West Longitude (NAD 83).
1 USACE is again planning to dredge and dispose at all five Hawaii ODMDS in 2016. Future monitoring of the other
sites will be addressed in an updated SMMP for all the Hawaii ODMDS, which is currently in preparation.
2
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 1. Five ocean dredged material disposal sites serve Hawaii ports and harbors.
KAUAI
Port Allen ODMDS
Nawiliwili ODMDS
OAHU
Oahu ODMDS
Kahului ODMDS
V f - MAUI
Hilo ODMDS
HAWAII*
3
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 2. General location of the South Oahu Ocean Dredged Material Disposal Site, showing overall site (yellow box) and
Surface Disposal Zone (red circle).
South Oahu ODMDS
4
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 3. General location of the Hilo Ocean Dredged Material Disposal Site, showing overall site (yellow circle) and Surface
Disposal Zone (red circle).
HAWAI'I
V * <
ft W , I
Hilo ODMDS
O
Hi fo
W ||
*«*
9M
5
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
As shown in Table 1, the South Oahu site has received by far the greatest volume of dredged
material of all 5 Hawaii sites, both historically and more recently. (Table 1 does not include
volume disposed at historic Mamala Bay sites prior to 1981.) This material is generated from
construction and maintenance dredging by the U.S. Navy in Pearl Harbor and maintenance
dredging of the Honolulu Harbor federal channel by US ACE, as well as berth maintenance
dredging by Honolulu Harbor and other minor dredging by private marinas. The Hilo site has
received lesser volumes of dredged material, which in recent years was generated from US Coast
Guard maintenance dredging and from terminal improvement projects in Hilo Harbor.
Table 1. Disposal volumes (cubic yards) at the 5 Hawaii ODMDS following designation in
1981. Source: EPA compliance tracking records and US ACE Ocean Disposal Database.
Year
South Oahu
Hilo
Kahului
Nawiliwili
Port Allen
Total All Sites
1981
0
1982
0
1983
313,900
313,900
1984
2,554,600
2,554,600
1985
12,000
12,000
1986
0
1987
111,200
111,200
1988
57,400
57,400
1989
75,000
75,000
1990
1,198,000
80,000
58,000
343,000
1,679,000
1991
134,550
134,550
1992
233,000
233,000
1993
322,400
322,400
1994
0
1995
0
1996
27,800
27,800
1997
0
1998
0
1999
27,500
91,000
114,600
20,900
254,000
2000
0
2001
0
2002
53,500
53,500
2003
183,500
183,500
2004
540,000
540,000
2005
3,000
3,000
2006
160,400
160,400
2007
266,500
266,500
2008
0
2009
126,200
126,200
2010
0
2011
18,260
63,879
82,139
2012
70,981
70,981
2013
506,870
506,870
Total 1981-2013
6,286,280
217,860
149,000
1,093,900
20,900
7,767,940
Average/year
190,493
6,602
4,515
33,148
633
235,392
Total 2000-2013
1,855,230
137,860
0
0
0
1,993,090
Average/year
2000-2013
132,516
9,847
0
0
0
142,363
6
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
II. SUMMARY OF SITE MONITORING ACTIVITIES
EPA Region 9 developed an overall survey plan and quality assurance project plan (QAPP) for the
South Oahu and Hilo ODMDS monitoring (EPA, 2013); supplemental QAPPs were also written
by sub-contractors. The surveys were conducted in late June and early July 2013. A summary of
the survey design and planned vs actual sampling activities is provided in the Appendix to this
report.
The main objective of site monitoring is to support any necessary updates to the SMMP by
collecting data and samples adequate to determine whether the sites are performing as expected
under existing site management practices. The overall site management goal is that there should
be only minor physical impacts inside the disposal site and no adverse impacts outside the disposal
site. Consequently, the Hawaii site monitoring surveys were designed to:
1. determine the horizontal extent of the dredged material deposit ("footprint") relative to site
boundaries;
2. identify any adverse impacts of disposal of dredged material on or off site; and
3. confirm the protectiveness of pre-disposal sediment testing in avoiding disposal of
contaminated sediments.
Specific survey activities specified in the QAPP included: sediment profile and plan-view imaging
to map the dredged material footprint; sediment sampling and analyses for chemistry and benthic
community structure to identify any chemical or biological effects beyond localized physical
impacts; and a geophysical survey (sub-bottom profiling) to determine wide area distribution of
native sea bed features and deposits of dredged material. EPA contracted with the National
Oceanic and Atmospheric Administration (NOAA) to use its vessel Hi'ialakai, stationed in Pearl
Harbor, for the sediment imaging and sampling surveys at both disposal sites, and with Sea
Engineering for the separate sub-bottom profiling survey.
The surveys conducted from the Hi'ialakai were originally scheduled to occur over 8 days (plus
mobilization and demobilization), but problems associated with readiness of the NOAA ship and
its equipment caused some delays. The surveys were ultimately conducted over a 5-day period
(not including transit between the South Oahu and Hilo sites and the return transit from Hilo to
Pearl Harbor), during which field operations were conducted continuously over a 24-hour period
using two scientific crews working 12-hour shifts. Even though not as many stations were
sampled as originally planned due to the reduced survey time, sufficient sampling was completed
to confirm the performance of each site and to provide an adequate basis to update the SMMP, as
described below.
2.1 Sediment Profile Imaging (SPD and Plan View Photography (PVP)
The SPI-PVP system provides a surface and cross-sectional photographic record of selected
locations on the seafloor to allow a general description of conditions both on and off dredged
material deposits. Detailed methods for the SPI-PVP survey are provided in the supplemental
QAPP prepared by Germano and Associates (2013 a).
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
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SPI-PVP surveys (Figures 4 and 5) were conducted for each ODMDS to delineate the horizontal
extent of the dredged material footprint both within and outside the site boundaries, as well as the
status of benthic recolonization on the deposited material. With resolution on the order of
millimeters, the SPI system is more useful than traditional bathymetric or acoustic mapping
approaches for identifying a number of features, including the spatial extent and thickness of the
dredged material footprint over the native sediments of the seabed, and the level of disturbance and
recoloni zation as indicated by the depth of bioturbation, the apparent depth of the redox
discontinuity, and the presence of certain classes of benthic organisms (Figure 6). PVP is useful
for identifying surface features in the vi cinity of where the SPI photos are taken, thereby providing
important surface context for the vertical profiles at each station. For each station, a minimum of
four SPI photos were taken, coupled with at least a single PVP photo
The SPI-PV camera system was deployed at a total of 86 stations (40 at South Oahu and 46 at
Hilo), compared to the planned 98 (49 at each site). The planned vs actual survey stations around
the South Oahu ODMDS are shown in Figure 7, while the Hilo ODMDS survey stations are shown
in Figure 8. (Specific coordinates for each station are available in the Appendix.)
Figure 4. SPI-PVP camera system being deployed from the Hi'ialakai.
8
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 5. Schematic of deployment and collection of plan view and sediment profile photographs.
(Germano and Assoc., 2013 b).
/
Plan-view image
Deployed
1-2 meters
from seafloor
SPI mage"
On the
seafioor
"Down" position
transecting the sediment-
water interface
9
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 6. Soft-bottom bent hie community response to physical disturbance (top panel) or organic enrichment (bottom panel).
From Rhoads and Germano (1982).
Physical Disturbance Time Normal
Stage 0 I Stage 1 I Stage 2 I Stage 3
Grossly Polluted
Distance
3
Normal
10
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 7. Planned (yellow squares) and actual sample station locations at the South Oahu ODMDS.
(The circle at the east side of the map shows the location of a historic disposal site used before 1981.)
w«4i:
;0-N6
%
^ S0"N5
SPI/PV and Sediment Sampling Locations
South Oahu ODMDS, Hawaii
June 2013
SO-NVW
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SO-NE4
&
SO-NVV3 S°^2 SO-NE3
- \hi irTiiia
% SO-W5 SO-W4 SO-W3
^T) ^
SO-
B a i
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#
^SO-SW3
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SO-SE5
Legend
© Photos
0 Grabs
1 Stations
1 | Dump Sites
Sources: Esn, GEBCO, NOAA. National Geographic, Delorme, NAVTEQ, Geonames.org, and other
contributors
ii
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 8. Planned (yellow squares) and actual sample station locations at the Hilo ODMDS.
SPI/PV and Sediment Sampling Locations
Hilo ODMDS, Hawaii
June/July 2013
12
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
2.2 Sediment Sampling for Chemistry and Benthic Communities
Sediment samples were collected from a subset of stations at each disposal site for sediment grain
size, chemistry, and benthic community analysis. Samples were collected using a stainless steel
double Van Veen sediment grab (Figure 9, showing side-by-side configuration) capable of
penetrating a maximum of 20 centimeters below the sediment surface. Detailed methods for
performing the sediment sampling for chemistry and benthic community analyses are described in
the QAPP (EPA, 2013 a).
After each acceptable grab sample was measured for depth of penetration and photographed, a
subsample for chemistry was extracted from one side of the grab sampler with a stainless steel
spoon (Figure 10). This subsample was homogenized and divided into separate jars (Figure 11)
for chemistry analyses (grain size, metals and organics). After the chemistry subsample was
extracted, the entire volume of the other side of the grab was processed to create a benthi c
community sample for that station (Figure 12). A 500 micron sieve was used to separate
organisms from the sediment, and the separated organisms were placed into bottles where they
were initially preserved with formalin. A total of 18 sediment grab sample stations were sampled
in the two survey areas combined: 10 at South Oahu, and 8 at Hilo (see Figures 7 and 8,
respectively). Chemistry subsamples were collected from all 18 stations and benthic community
samples were collected at 14 of the 18 stations (the lower number of benthic community samples
was due to some grabs being used for field and laboratory chemistry duplicates, and one station
where QAPP metrics were not met for an acceptable benthic sample).
Figure 9. Double Van Veen sediment sampler deployed from the Hi'ialakai.
13
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 10. Subsampling from the Van Veen grab for sediment chemistry.
Figure 11. Processing a sediment sub-sample for chemical analysis.
14
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 12. Processing a sediment sample for benthic community analysis.
2.3 Sub-Bottom Profiling Survey of the South Oahu ODMDS
The primary purpose of this survey was to collect cross-sectional images of the native sediment
layers and layers indicative of the dredged material deposit across a wide area in the environs of
the South Oahu ODMDS. (The Hilo site was not surveyed in this manner during this round of
surveys because much smaller volumes of dredged material have been disposed there over time
which may not be detectable in terms of thickness and contrast.)
This type of survey allows EPA to separately estimate the cumulative volume of dredged materi al
disposed at the South Oahu site, compared to volumes permitted for disposal. The survey was sub-
contracted to Sea Engineering, who conducted the work aboard a separate vessel specially rigged
for this type of survey with an acoustic sub-bottom profiler system (Figure 13). Figure 14 shows
the grid of transects surveyed. Detailed methods for the sub-bottom survey are provided in the
supplemental QAPP prepared by Sea Engineering (2013).
15
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 13. Sub-bottom profiler equipment - used only at the South Oahu site.
Figure 14. Planned transect lines for the sub-bottom profiling survey around the South Oahu
ODMDS (from Sea Engineering, Inc., 2014).
2
m
m
If " 4^ .
-18,000 ft
m
~-v|
16
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
III. SURVEY RESULTS
3.1 SPI - PVP Survey Results
3.1.1 Dredged Material Footprint Mapping
The presence and extent of the dredged material footprint was successfully mapped at both Hawaii
disposal sites. SPI images of typical native sediments (outside of any dredged material deposit)
around the South Oahu and Hilo sites are shown in Figure 15. Dredged material is usually evident
because of its unique optical reflectance and/or color relative to the native pre-disposal sediments.
The presence of dredged material layers can be determined from both plan view images (Figure
16) and from SPI images (Figure 17). In most cases, the point of contact between the two layers is
clearly visible as a textural change in sediment composition, facilitating measurement of the
thickness of the newly deposited layer.
Two off-site stations around the South Oahu site had native hard-bottom habitat (N6 and SW5,
Figure 7); otherwise the native sediment was fairly uniformly muddy fine sand. The overall
dredged material footprint extended well beyond the current disposal site boundary (Figure 18;
also see Figure 28). Given the lack of natural fine grained sediment around the South Oahu site,
dredged material would be expected to remain visible on the seafloor for a substantial amount of
time (decadal scale). Similarly, given the proximity of historic disposal sites to the current
designated site in Mamala Bay and the large cumulative volume of disposed sediments over the
years (Table 1), it is not surprising that traces of dredged material are found outside of the current
designated site boundary. However, the thickest off-site deposits were just north (shoreward) of
the site boundary indicating that "short-dumping" (disposal from scows before they reached the
Surface Discharge Zone at the middle of the site) probably occurred in the past. EPA has required
satellite-based tracking of all disposal scows since the early 2000s, and there have been no "short-
dumps" since a single partial mis-dump occurred in 2006. Thus the footprint outside the disposal
site boundary would appear to be relic material deposited more than 10 years ago.
Compared to South Oahu, native sediments around the Hilo site were finer. Two off-site stations
(E5 and SE6, Figure 8) were on rocky lava outcrops. Even though this area is primarily a silty,
very fine to fine sandy bottom, there are periodic lava deposits or rock outcrops creating some
topographic diversity. The substantially smaller cumulative volume of dredged material disposed
at Hilo appeared to be more fully confined within the designated disposal site boundary (Figure
19). Except at the center of the site where rubble has accumulated (Figure 20), dredged material
thickness was only 3 cm or less within the site boundary, and less than 1 cm thick outside the
boundary.
3.1.2 Bioturbation Depth
The depth to which sediments are biologically mixed is an important indicator of the status of
recovery of the infaunal community following disturbance (e.g., by dredged material disposal).
Biogenic particle mixing depths can be estimated by measuring the depths of imaged feeding voids
in the sediment column. This parameter represents the particle mixing depths of head-down
feeders, mainly polychaetes. This depth is also related to the apparent redox potential
discontinuity (aRPD) depth. In the absence of bioturbating organisms, the aRPD (in muds) will
17
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 15. Profile images from the ambient bottom at the Hilo ODMDS (left, Station S3) and the South Oahu site
(right, Station S6). The ambient seafloor at Hilo has a higher silt-clay content, allowing greater camera
penetration than at South Oahu. Scale: width of each profile image = 14.4 cm. (Germano & Assoc., 2013)
18
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 16. Plan view images of the dredged material deposit compared to the native
seafloor at South Oahu. Station CI on dredged material (top) shows the visual
difference in both sediment color and surface texture/features of dredged
material compared to the ambient bottom at Station NW6 (bottom). Scale: width
of each PV image is approximately 4 m. (Germano & Assoc., 2013)
19
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 17. Profile images from two Hilo Stations showing a surface layer of disposed coarse white dredged
sand that thins from NW1 (left) near the center of the disposal site to only trace amounts at NW3 (right).
Scale: width of each profile image = 14.4 cm. (Germano & Assoc., 2013)
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 18. Dredged material footprint identified at the South Oahu site.
n
Li
SPL/PV and Sediment Sampling Locations
South Oahu ODMDS. Hawaii
June 2013
; SO-N0
IND
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0.00
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0.00
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f SO-S3
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aoo
SO-SE4
0.00
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0.00
Station Average
Dredged Material
Thickness (cm)
o.o
trace
# 0 .1 -1.0 cm
# 1.1-10.0 cm
# >10.0 cm
O Indeterminate (IND)
Dredged material
exceeded penetration?
Oyes
Dump site boundary
SO-S6
0.00 Sources: Esri. GEBCO. NOAA. National Geographic. DeLorme. NAVTEQ. Geonames.org. and other contributors
21
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 19. Dredged material footprint identified at the Hilo site.
SPl^V and S«d»m#nt Sampling Location*
Hilo OOMOS. Hawa.
June/July 2013
Station Average
Dredged Material
Thickness (cm)
00
trace
9 0.1 -10cm
• 1.1-10.0 cm
• >10 0 cm
Dredged material
exceeded penetration?
o
yes
» Dump site
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000
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000
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000
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000
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000
H-NW4
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000
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000
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000
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Sourctv Evi GEBCO. NOAA Nafconai G+ograptuc. D#t.o*m* NAVTEQ. G^e
: arvo
22
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 20. Plan view image from the center station of the Hilo ODMDS shows a high density of small rock and coral rubble.
Rubble falls rapidly through the water column with minimal dispersal, and thus has accumulated only at the center of the site.
Scale: width of PV image is approximately 4 m. (Germano & Assoc., 2013)
23
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
typically reach only 2 mm below the sediment-water interface (Rhoads 1974). However, it is quite
common in profile images to see evidence of biological activity (burrows, voids, or actual animals)
well below the mean aRPD (Germano and Assoc., 2013 b).
At the South Oahu site, the maximum bioturbation depths (>15 cm) were generally found at the
stations that also had the thickest deposits of dredged material (including the off-site stations to the
north with relic dredged material deposits) (Figure 21). A similar pattern was seen for average
feeding void depth, and for the aRPD depth (see Germano and Assoc., 2013 b). This is to be
expected, since dredged material is generally finer, less consolidated, and therefore more
conducive to supporting a richer community of burrowing organisms compared to the native,
consolidated fine sand around the disposal site. Stations with a native fine sand substrate exhibited
lower camera penetration, shallower aRPD depths, and shallower average feeding void depths.
At the Hilo site, where much less dredged material has been discharged and where the native
seafloor is more heterogenous, the pattern was different (Figure 22). Although dredged material
was thickest at the center of the site, a high concentration of gravel and coral rubble prevented full
camera penetration there, so that bioturbation depth and aRPD could not be determined fully.
Other on-site stations showed fairly uniform bioturbation depths of 7-10 cm. Many off-site
stations also had bioturbation depths in this range, although bioturbation depths of 10-18 cm were
also common. Since the native seafloor around the Hilo site is finer-grained than around the South
Oahu site, greater bioturbation depths, and less difference between on-site and off-site stations,
would be expected.
3.1.3 Infaunal Successional Stage
The mapping of infaunal successional stages is readily accomplished with SPI technology.
Mapping of successional stages is based on the theory that organism-sediment interactions in fine-
grained sediments follow a predictable sequence after a major seafloor perturbation (Germano and
Assoc., 2013). This continuum of change in animal communities after a disturbance (primary
succession) has been divided subjectively into four stages: Stage 0, indicative of a sediment
column that is largely devoid of macrofauna, occurs immediately following a physical disturbance
or in close proximity to an organic enrichment source; Stage 1 is the initial community of tiny,
densely populated polychaete assemblages; Stage 2 is the start of the transition to head-down
deposit feeders; and Stage 3 is the mature, equilibrium community of deep-dwelling, head-down
deposit feeders (see Figure 6).
After an area of bottom is disturbed by natural or anthropogenic events, the first invertebrate
assemblage (Stage 1) appears within days after the disturbance. Stage 1 consists of assemblages of
tiny tube-dwelling marine polychaetes that reach population densities of 104to 106 individuals per
m2 These animals feed at or near the sediment-water interface and physically stabilize or bind the
sediment surface by producing a mucous "glue" that they use to build their tubes.
If there are no repeated disturbances to the newly colonized area, then these initial tube dwelling
suspension or surface-deposit feeding taxa are followed by burrowing, head-down deposit feeders
that rework the sediment deeper and deeper over time and mix oxygen from the overlying water
into the sediment. The animals in these later-appearing communities (Stage 2 or 3) are larger, have
lower overall population densities (10 to 100 individuals per m2), and can rework the sediments to
depths of 3 to 20 cm or more.
24
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 21. Bioturbation depth at the South Oahu site - deeper values here are reflective of an active benthic community
reworking deposited dredged material. (Germano & Assoc., 2013)
so-Nwe
o.oo 1
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1156
IND
so-we
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4.98
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6? >
E (I ij
SPl/PV and Sediment Sampling Locations
South Oahu ODMDS. Hawaii
June 2013
Station Maximum
Bioturbation Depth (cm)
# 0.0 -1.0 cm
# 11 -5.0 cm
5.1 -10.0 cm
# 10.0 -15.0 cm
# > 15.0 cm
O Indeterminate (IND)
Dump site boundary
SO-SW3
10J09 ,
SO-SW1 i
17.81
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127
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1353
SO-S3
8.02
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3.44
SO-S5
IND
SO-SE4
IND
SO-SE6
IND
so-se
IND Sources: Esri. GEBCO. NOAA. National Geographic, DeLomne. NAVTEQ. Geonames.org. and other contributors
25
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 22. Bioturbation depth at the Hilo site: on-site and off-site stations show similar depths (much less material has
been disposed here than at South Oahu). (Germano & Assoc., 2013)
SPI/PV and Sediment Sampling Locations
Hilo ODMDS. Hawaii
June/ July 2013
H-N6
4.45
N
Station Maximum
Bioturbation Depth (cm)
•
0 0- 1.0 cm
•
1.1 -5.0 cm
5.1 -10.0 cm
•
10.0 -15.0 cm
•
> 15.0 cm
t *
1
Dump site
H-NW6
13.01
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13.81
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8.93
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3.88
H-NW3
8.47
H-NE4
4.56
H-NW2
9.15 ,
H-W6
18.63
H-W5
13.90
H-W4
16.12
H-W3
929
H-SW3
10.19
H-W2
9.81 '
H-SW2
9.65
H-NW1
7.82
H-W1
8.62
;H-SW1
\ 831
H-N2
10.09
I H-C
000
H-NE3
6.64
• \ H-NE2
\ 8.04
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6.91
H-E2
209
H-SE1
7.29
H-E4
3.35
H-E5
0.00
H-SW4
10.64
H-S1
7.82
H-S2
8.69
H-SE2
7.13
H-SW5
11.87
H-SE3
7.94
H-SW6
11.38
H-SW7 |
1&78 '
H-S3
9.12
H-S4
1264
H-SE4
7.94
H-SE5
7.94
H-SW8
8.44
H-S5
9.56
H-S0
929
H-SE8
0.00
H-SW0
18.54
Sources: Esri. GEBCO. NOAA. National Geographic. DeLorme. NAVTEQ. Geon3rne>.qrg.andidther
26
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Various combinations of these basic successional stages are possible. For example, secondary
succession can occur (Horn, 1974) in response to additional labile carbon input to surface
sediments, with surface-dwelling Stage 1 or 2 organisms co-existing at the same time and place
with Stage 3, resulting in the assignment of a "Stage 1 on 3" or "Stage 2 on 3" designation
The distribution of successional stages in the context of the mapped disturbance gradients is one of
the most sensitive indicators of the ecological quality of the seafloor (Rhoads and Germano 1986).
The presence of Stage 3 equilibrium taxa (mapped from subsurface feeding voids as observed in
profile images) can be a good indication of relatively high benthic habitat stability and quality. A
Stage 3 assemblage indicates that the sediment surrounding these organisms has not been disturbed
severely in the recent past and that the inventory of bioavailable contaminants is relatively small.
At the South Oahu site, infaunal community successional stage was readily apparent on the
dredged material deposit, but was generally unmeasurable (indeterminate) on the native sandy
sediments off-site (Figure 23). Successional stage on the dredged material mound, including the
relic off-site material to the north, was fairly uniformly Stage 1 on 3. While this indicates relatively
rapid recolonization and a well-established infaunal community in the finer, more carbon-rich
dredged sediments, it is clearly a different community than would be supported by the native fine
sand at this location in the absence of dredged material disposal.
At the Hilo site, differences between stations with and without dredged material were less apparent
(Figure 24). Since far less dredged material has been discharged at this site than at the South Oahu
site, less disturbance to the native sediments around the site has occurred. Both on-site and off-site
stations were dominated by Stage 1 on 3 communities, but more heterogenous communities were
present to the east and northeast of the site as well. These stations had either no apparent dredged
material, or only trace thicknesses of dredged material; therefore the different community structure
at these stations may reflect natural heterogeneity of benthic habitat types in this area rather than
any particular effect from dredged material deposition.
3.1.4 Plan-View Photography
Unusual surface sediment textures or structures detected in any of the sediment profile images can
be interpreted in light of the larger context of surface sediment features (for example, is a surface
layer or topographic feature a regularly occurring feature and typical of the bottom in this general
vicinity or just an isolated anomaly?). The scale information provided by the underwater lasers
allows accurate density counts (number per square meter) of attached epifaunal colonies, sediment
burrow openings, or larger macrofauna or fish which may be missed in the sediment profile cross-
sections.
Except for the two stations on hard bottom, the native seafloor around the South Oahu site is a
muddy carbonate sand with rippled bedforms and relatively low abundance of epifauna. Other
than the occasional hermit crab or other decapods such as shrimp or Brachyurans, the presence and
abundance of epifauna was directly proportional to the amount of rock/rubble/outcrop present on
the flat sandy bottom. Anything that provided a hard surface or additional vertical relief for
niche/topographic diversity became a suitable substratum to which organisms could attach
(tunicates, cnidarians, bryozoans) or hide within (echinoderms), which subsequently attracted more
fish to that particular location.
27
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 23. Community structure at the South Oahu site: presence of Stage 3 organisms is indicative of healthy
benthic community. (Germano & Assoc., 2013)
©s
©
~
764
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SP1/PV and Sediment Sampling Locations
South Oahu ODMDS. Hawaii
June 2013
Infaunal Successional Stages
rep 1
Stage 2 — 3
^3 0"" ® Stage 3
^p2 ® Stage I on 3
O Indeterminate
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SO-NE2
SO-W6 SO-W5 SO-W4 SO-W3 io-W2 SO-W1
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Sources: Esri. GEBCO. NOAA. National Geographic. DeLorme. NAVTEQ. Geonames.org. and other contributors
28
-------
2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 24. Community structure at the Hilo site: presence of Stage 3 organisms is indicative of healthy benthic community.
(Germano & Assoc., 2013)
SPl/PV SwnpJmj l«JWx»
Hrto OOMDS Hmu
Amm/Jul? 2013
Into una I Successlonal Stages
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-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
In contrast, the native Hilo sediments had a higher percentage of fine sediments (attracting higher
densities of small prey, evidenced by burrow holes in plan view images) along with more frequent
occurrence of rocky outcrops (creating habitat heterogeneity) both inside and outside the site
boundaries. These characteristics attracted a generally more abundant and varied epifauna and fish
assemblage. Unlike the South Oahu site, the areas of the highest accumulation of dredged material
(near the site center where the surface was a continuous cover of rubble) appeared to have the
lowest faunal attractiveness. But higher densities of fish and anthozoans as well as more frequent
evidence of burrowing infauna were seen throughout the area as a whole, compared to South Oahu.
3.1.5 Discussion: SPI-PVP Surveys
Minor and localized physical impacts are expected within the site as a result of disposal operations.
However, historical and more recent disposal activity appear to have had little lasting adverse
impact on benthic infauna, or epibenthic organisms, at either site. With the exception of the center
station at the Hilo site where an accumulation of disposed rubble has most likely altered the
resident infaunal community on a localized scale, the disposal of dredged material, in general, has
not impeded benthic recolonization or the re-establishment of mature successional stages. At the
South Oahu site, it appears the larger cumulative volume of fine grained, higher carbon content
dredged material deposited over the native coarser grain carbonate sands may have actually
enhanced the secondary benthic production by promoting the settlement and persistence of
subsurface deposit feeders that would not normally exist in the native carbonate sand bottom here.
The prediction in the original EIS (EPA 1980) that disposal of dredged material at both the Hilo
and South Oahu ODMDS will have no lasting adverse impact on the benthic community inside or
outside of site boundaries is supported by the results of the SPI-PVP survey. Stage 3 taxa have
successfully recolonized all but the center station at the Hilo ODMDS, and secondary production
appears to be enhanced at the South Oahu ODMDS within the dredged material footprint. Also
epifauna, in general, are similar on-site and off-site (though different between South Oahu and
Hilo overall.
Based on the results of the SPI-PVP surveys, the authors predicted that the traditional benthic
sampling results would also show a higher species diversity and infaunal abundance in samples
from the Hilo site versus those from the South Oahu site, because of the increased amount of fines
and evidence of increased subsurface burrowing in the images from the Hilo site. (See discussion
of Benthic Community Analysis Results, below.)
3.2 Sediment Physical and Chemical Survey Results
Full physical and chemical analytical results are provided in ALS Environmental (2013) and EPA
(2013 b). Due to vessel and equipment problems, less than half the originally-targeted benthic grab
stations were sampled. But by using the SPI survey results to help select the chemistry (and
benthic community) stations at each site, a sufficient number of samples were collected within and
outside of site boundaries and the dredged material footprints to characterize the native (ambient)
seafloor compared to seafloor areas physically impacted by dredged material disposal.
Nevertheless, only qualitative (vs statistical) analysis of the physical and chemical results was
conducted given that only four "on site" and five "offsite" stations were ultimately sampled at
South Oahu, and only three "on site" and four "offsite" stations were sampled at Hilo.
30
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
3.2.1 Physical Results
Minor and localized physical impacts are expected within the site boundary as a result of disposal
operations. Tables 2 (South Oahu) and 3 (Hilo) compare areas within the disposal sites that have
dredged material deposits (indicated as "Inside") and off site areas without any dredged material
deposits (indicated as "Outside"). Physical on-site differences are most apparent at the South
Oahu site, which has received an order of magnitude more dredged material over the years than the
Hilo site. At South Oahu (Table 2), "inside" stations have substantially more gravel, more fines
(silt and clay), and higher organic carbon content than the "outside" stations that represent ambient
or native seafloor conditions. This reflects the character of dredged material typically disposed at
this site, which often includes grave-size coral rubble, and fines from land-side runoff that settles
in harbors, berths, and navigation channels. In contrast, native sediments around the South Oahu
site are uniformly sandier, with lower carbon. These on-site physical changes are expected to be
persistent, but are not considered to be a significant or adverse impact.
Physical characteristics of the off-site ambient or native sediments around the Hilo site are more
variable (Table 3) reflecting the more heterogeneous nature of the seafloor in the area, which
includes a mixture of hard bottom features (submerged reef and terraces) coupled with areas of
accumulated finer grained sediments (USGS, 2000). The dredged material disposed at the Hilo
site has not substantially altered the physical nature of the disposal site in part due to this natural
variability, and in part because only a relatively small volume of material has been disposed at
Hilo (especially compared to disposal volumes at South Oahu).
3.2.2 Chemical Results
Although physical differences are expected as a result of disposal operations, pre-disposal
sediment testing is intended to minimize any degradation to the site which might be caused by
introduction of contaminants which are bioavailable and/or pose a toxicity risk to the marine
environment. The bulk chemistry data show low but variable concentrations of most chemical
constituents at both sites (Tables 2 and 3). At both "inside" and "outside" stations, four to six
metals were at concentrations above NOAA's effects-based 10th percentile screening value (ER-L),
below which adverse effect are predicted to rarely occur (NOAA, 2008). Of these metals, only
chromium, copper, and mercury were slightly higher at "inside" stations compared to "outside"
stations, and only at the South Oahu site. At Hilo, the metals concentrations were virtually
indistinguishable between "inside" and "outside" stations.
Only nickel exceeded its 50th percentile screening value (ER-M), above which adverse effects are
expected to frequently occur (NOAA, 2008). It was most elevated at Hilo, but was at similar
elevated concentrations at both "inside" and "outside" stations there. Nickel is often naturally
elevated in certain sediments, including volcanic sediments.
Organic constituents were also low at both sites. Only two constituents exceeded NOAA ER-L
screening levels, and again only at the South Oahu site. PCBs and DDTs each slightly exceeded
their respective ER-Ls at one "inside" station and one "outside" station. PCBs were generally
higher at the "inside" stations, even when not exceeding the ER-L. There were no exceedances of
ER-Ls for organics at either "inside" or "outside" stations at the Hilo site.
31
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 2. Summary of sediment chemistry for the South Oahu Ocean Dredged Material Disposal site and vicinity.
Survey Station:
South Oahu site
"
nside"
"Outside"
NOAA Screening
Analyte
Units (dw)
SO-N1
SO-N1 dup*
SO-N2
SO-SW1
SO-W1
SO-SE4**
SO-W5
SO-S6
SO-E6
SO-E4
ER-L
ER-M
Gravel
%
21
3
69
3
12
1
1
0
1
11
-
-
Sand
%
43
53
29
47
50
78
79
82
83
64
—
—
Silt
%
21
24
11
25
24
16
12
12
10
20
--
--
Clay
%
14
17
4
15
11
5
4
5
5
7
—
--
Total Organic Carbon
%
1.25
1.78
1.25
1.02
1.48
0.58
0.53
0.43
0.41
0.81
--
--
Arsenic
mg/kg
20
13
24
33
19
40
39
27
30
27
8.2
70
Cadmium
mg/kg
0.6
0.69
0.39
ND
0.43
ND
0.42
ND
ND
ND
1.2
9.6
Chromium
mg/kg
100
160
100
110
120
68
100
47
45
73
81
370
Copper
mg/kg
65
84
47
43
56
22
36
11
13
37
34
270
Lead
mg/kg
25
31
22
15
95
19
37
10
15
23
46.7
218
Mercury
mg/kg
0.2
0.13
0.13
0.1
0.38
0.09
0.1
0.02
0.05
0.19
0.15
0.71
Nickel
mg/kg
68
140
68
71
92
37
63
24
30
53
20.9
51.6
Selenium
mg/kg
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
—
-
Silver
mg/kg
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
1
3.7
Zinc
mg/kg
78
130
76
75
86
52
79
34
35
69
150
410
Dioxins - Total TEQ
ng/kg
6.33
3.88
4.49
1.27
4.12
1.06
0.91
0.07
0.95
4.01
-
-
Total DDTs
ug/kg
ND
2.1
ND
ND
ND
ND
ND
ND
ND
2.6
1.58
46.1
Total Organotins
ug/kg
1.73
4.67
4
1.46
2.21
0.71
5.83
ND
4.1
2.09
—
—
Total PAHs
ug/kg
741
264
274
182
160
344
153.8
ND
263
1501
4022
44792
Total PCB Congeners
ug/kg
21.43
17.49
35.98
8.87
14.11
6.07
7.16
0.09
2.7
23.15
22.7
180
"Inside" stations are both within the disposal site boundary AND on the dredged material deposit as determined by the SPI-PVP survey.
"Outside" stations are both outside the site boundary AND off the dredged material deposit.
* Field duplicate sample from a separate grab taken at a different time at the same station
** This station was chosen for full OTM testing on upcoming dredging project(s) as a possible new reference site for future Hawaii projects.
32
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 3. Summary of sediment chemistry for the Hilo Ocean Dredged Material Disposal site and vicinity.
Survey Station:
Hilo site
Units (dw)
"Inside"
"Outside"
NOAA Screening
Analyte
H-Wl
H-Wl dup*
H-Nl
H-SW1
H-SE4
H-NE5
H-SW6
H-W6
ER-L
ER-M
Gravel
%
2
3
2
0
0
0
0
0
—
—
Sand
%
62
61
47
69
72
85
26
14
—
—
Silt
%
25
24
21
26
21
16
61
70
—
—
Clay
%
5
8
7
5
7
5
11
17
-
-
Total Organic Carbon
%
0.83
0.98
0.81
0.81
0.69
0.57
2.43
3.27
—
-
Arsenic
mg/kg
36
36
32
36
26
28
48
55
8.2
70
Cadmium
mg/kg
0.4
ND
0.5
0.6
0.72
0.5
0.71
0.62
1.2
9.6
Chromium
mg/kg
110
120
140
130
140
140
150
160
81
370
Copper
mg/kg
30
35
31
31
30
31
51
56
34
270
Lead
mg/kg
11
11
11
12
9.6
11
19
21
46.7
218
Mercury
mg/kg
0.05
0.06
0.05
0.06
0.04
0.04
0.14
0.17
0.15
0.71
Nickel
mg/kg
160
200
290
230
320
290
88
82
20.9
51.6
Selenium
mg/kg
ND
ND
ND
ND
ND
ND
ND
ND
—
—
Silver
mg/kg
ND
ND
ND
ND
0.75
ND
1.1
1.2
1
3.7
Zinc
mg/kg
70
81
83
78
87
83
91
95
150
410
Dioxins - Total TEQ
ng/kg
3.02
1.99
2.19
1.96
1.58
0.831
4.84
7.65
-
—
Total DDTs
ug/kg
IMD
ND
ND
ND
ND
ND
ND
ND
1.58
46.1
Total Organotins
ug/kg
ND
ND
0.86
ND
ND
ND
ND
ND
—
-
Total PAHs
ug/kg
2.2
2.3
10.2
1.8
ND
ND
3
17.4
4022
44792
Total PCB Congeners
ug/kg
0.3
0.5
ND
ND
ND
ND
0.25
0.28
22.7
180
"Inside" stations are both within the disposal site boundary and ON the dredged material deposit as determined by the SPI-PVP survey.
"Outside" stations are both outside the site boundary and OFF the dredged material deposit.
* Field duplicate sample from a separate grab taken at a different time at the same station
33
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
The screening level exceedances were relatively minor in magnitude and, in many cases, were seen
at both "inside" and "outside" stations. The few constituents that were at higher concentrations
within the disposal sites reflect the contaminant levels in the dredged material approved for
discharge. All sediments discharged at ocean disposal sites are fully characterized before approval
for ocean disposal is granted. Sediments that contain toxic pollutants in toxic amounts, or that
contain elevated levels of compounds that will readily bioaccumulate into tissues of organisms
exposed to them on the seafloor, are prohibited from being discharged. Thus the chemical
concentrations identified are not considered to represent a risk of environmental impacts in and of
themselves; also, these low concentrations indicate that the pre-dredge sediment testing regime is
adequately protecting the environment of the disposal sites by identifying and excluding more
highly contaminated sediments from being disposed.
3.3 Benthic Community Analysis Results
Less than half of the original targeted stations were sampled for sediment grab sampling due to
ship and equipment problems. Nevertheless, by selecting stations based on the results of the SPI-
PVP surveys, sufficient samples were collected within and outside of site boundaries and the
dredged material deposit footprint to provide general characterization of benthic communities
occupying native (ambient) seafloor and seafloor physically impacted by dredged material
disposal.
3.3.1 Abundance of Infauna
As noted earlier, some physical changes (e.g., grain size and organic carbon content) were
apparent at stations with dredged material, especially at the South Oahu site. However, overall
abundances of different organism classes, while low, were not statistically different between
"inside" and "outside" stations at either disposal site (Tables 4 and 5) (EcoAnalysts, Inc., 2014).
At South Oahu, where both disposal volume and physical changes were greatest, crustaceans were
similarly abundant at "inside" and "outside" stations; annelids appeared to be somewhat less
abundant at "inside" stations; while mollusks and other miscellaneous taxa appeared to be
somewhat more abundant at "inside" stations. But considering all infauna classes, overall
abundance was very similar on-site and off-site.
At Hilo, Crustacea appeared to be somewhat more abundant at "inside" stations, but annelids,
mollusks and other miscellaneous taxa appeared to be somewhat more abundant at "outside"
stations. Overall abundance of infaunal organisms appeared to be slightly greater off-site than on-
site but these results were not statistically significant, perhaps due in part to the small sample size.
As predicted from the SPI-PVP survey results, overall infaunal abundance appeared to be slightly
greater at Hilo than at South Oahu.
Dredged material had been fairly recently deposited at both sites, and these infaunal abundance
results are consistent with relatively rapid recolonization following disposal.
34
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 4. Infaunal species abundances at the South Oahu site.
"Inside"
"Outside"
Category
SO-N1
SO-N2
SO-W1
SO-SW1
SO-W5
SO-S6
SO-SE4
SO-E4
SO-E6
Annelida
390
540
700
400
1190
120
50
660
670
Annelida
Average
507.5
538
Crustacea
0
10
10
10
20
0
0
10
10
Crustacea
Average
7.5
8
Mollusca
10
40
20
20
0
30
0
10
0
Mollusca
Average
22.5
8
Miscellaneous
Taxa
30
50
130
40
20
10
0
110
60
Miscellaneous
Taxa Average
62.5
40
Totals
430
640
860
470
1230
160
50
790
740
Overall
Averages
600
594
Table 5. Infaunal species abundances at the Hilo site.
"Inside"
"Outside
»
Category
H-Nl
H-SW1
H-NE5
H-SW6
H-SE4
Annelida
900
320
490
930
650
Annelida
610
690
Average
Crustacea
20
20
10
0
10
Crustacea
20
6.7
Average
Mollusca
50
10
10
260
10
Mollusca
30
93.3
Average
Miscellaneous
50
50
50
80
100
Taxa
Miscellaneous
50
76.7
Taxa Average
Totals
1020
400
560
1270
770
Overall
710
866.7
Averages
3.3.2 Diversity of Infauna
Based on species lists and statistics presented in EcoAnalysts, Inc. (2014), the overall benthic
community at the South Oahu site was shown to be different from the assemblage at the Hilo site.
This finding is not surprising given that the Hilo site is located in a relatively heterogeneous area
containing a mixture of hard bottom features (submerged reef and terraces) coupled with areas of
accumulated finer grained sediments (USGS, 2000), while the South Oahu site is located on a
more homogeneous sandy seafloor with some scattered hard bottom features. However, as is
expected of deep-sea benthic habitats overall, both sites have well developed benthic communities
with high diversity and relatively low abundances, and presence of several undescribed taxa.
35
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
For both sites combined, there were 126 taxa found. A total of 85 infaunal taxa were identified
from the South Oahu ODMDS sampled locations and a total of 79 taxa were identified from the
Hilo ODMDS sampled stations. Within the polychaetes identified from both locations, 24 of 89
species were determined to likely be undescribed (EcoAnalysts, Inc., 2014).
At the South Oahu site, diversity was high and abundances tended to be low at all stations.
Stations located inside the disposal site were not statistically different in terms of diversity,
abundances, or species richness when compared to stations located outside the disposal site. Thus
there is no evidence that dredge material is negatively impacting the benthic communities at the
South Oahu ODMDS sites sampled.
Similarly at the Hilo site, there were no significant differences in diversity between inside and
outside stations. As at South Oahu, diversity was high while abundances were relatively low,
which was expected of deep-sea benthic habitats. Based on these results there is no evidence that
dredge material is negatively impacting the benthic communities at the Hilo ODMDS stations
sampled, other than the expected reduction of abundances due to physical impacts from rubble
disposed at the center of the site.
3.4 Sub-Bottom Profile Survey (South Oahu site only)
The survey area, approximately 8 square nautical miles, covered the current designated site and
surrounding abyssal plain seafloor areas, including existing hard bottom features (such as relic
reefs and other outcrops) (Figure 25). The contrast between high reflectance native bottom bed
forms and lower reflectance non-native deposited sediments allowed for identification of dredged
material deposits throughout the study area.
While dredged material was identified within the current disposal site boundary, deposits of
dredged material were still identifiable outside the site boundaries as well (Figure 26), probably
due to past (pre-1981) disposal at historic disposal sites as well as mis-dumping before the 2000's
(when satellite tracking systems began being required to help ensure proper disposal within site
boundaries). Transects lines for the survey are shown on Figure 27. Figure 28 superimposes an
area-wide surface geological map from the sub-bottom profiling survey with the SPI-based
mapping of the dredged material footprint, showing excellent concordance between the two
methods. Sub-surface results for a typical transect are shown on Figure 29, which presents a cross-
section through the center of the disposal site looking down through both the dredged material
deposit and the native sediment underlying it.
The analysis of the full sub-bottom data set (Sea Engineering, Inc., 2014) suggests that the dredged
material deposits in and around the South Oahu site generally vary between 3 and 12 feet (1- 4 m)
in thickness. An order of magnitude approximation of the total amount of dredged material within
the study area was calculated using an average thickness of 6 feet (2 meters). The total volume of
dredged material mapped throughout the entire study area, including historic disposal outside the
current site boundaries, was thus calculated to be 27,885,600 cubic yards (21,320,000 cubic
meters). However, the total volume of dredged material mapped within the current South Oahu
site boundary was calculated to be 1,736,000 cubic yards (1,327,350 cubic meters). This compares
quite favorably with the recorded volume of 1,855,230 cubic yards of material known to have been
disposed from 2000 through 2013 (Table 1, and Figure 30).
36
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 25. USGS shaded-relief image showing the boundary of the sub-bottom survey area around the South Oahu
disposal site, as well as major bedforms in the vicinity (shaded relief imagery from USGS, 2000). (Sea
Engineering, 2014)
1UI ^ >.qr-Tc^»
F1 R 4s 25fMM 'T .
t' ftf
H,-.
i
9
„ PfilSt 8
id***
27
G '1*
HO 4s
Obstri
10
•' VUli'V
g» I \ s '/s '"-
ODMDS
ODMDS
BEDFORMS
¦ \l*V
* / J RfeEF ' SURVEY LIMIT
,'Akeef reef
- : L_
SURVEY
LIMIT
HIGH RELIEF
AREA
BEDFORMS
37
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 26. USGS sidescan sonar (backscatter) image showing historic dredged material deposits around the sub-bottom
survey area and the South Oahu disposal site (sidescan imagery from USGS, 2000). (Sea Engineering, 2014)
l!/ '
Vf A.
if (a
IK
12
DREDGED MATERIAL
DEPOSITS
.SUftVEY
-«.«T
9S&
DREDGED MATERIAL
DEPOSITS
38
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 27. Transect lines for the sub-bottom profiling survey of the South Oahu site. Results for Diagonal line 1
through the center of the disposal site (arrows) are given in Figure 29. (Sea Engineering, 2014)
39
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 28. Geological (surface) interpretation from the sub-bottom profiling survey superimposed with the SPI-
based dredged material footprint map shown in Figure 17. (DM = dredged material; HSL = hard sand layer;
HR/DM = high-relief terrain with dredged material.) (Sea Engineering, 2014)
SURVEY LIMIT
.S6
A. A
£6
•SE6 J
HSL
SPI.PV aid Sadment Sairiplnj Loutoni
South uaiu OLMQS, Hawai
Juno
Station Average
Dredged Material
Thickness (cm)
Dump site
0.0
lr»C*
0 0 1 -1.0 cm
# 1.1-10 0 cm
0 > 10.0 cm
O lnt)et«rrr\*ia(e (IKD)
Dredged material
excnnded penelration?
40
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 29A. Sub-bottom profile - NE portion of Diagonal Line 1. (Sea Engineering, 2014)
Siity very fine sand with
ODMDS
Match with E
IRREGULAR HIGH-RELIEF
TERRAIN CONSISTENT WITH
LIMESTONE REEF OR BEDFORMS
THIN COVER OF SAND AND DM
THIN SAND (1m)
OVER DM
Discrete sand over silty
sand layering. Debris,
mudclasts, and organism tubes
at SWI.
-"RU-
THIN SAND AND DM (3m) *
OVER HIGH-RELIEF TERRAIN
I LACK OF -
! SUB-BOTTOM FEATURES
I INDICATIVE OF DM
Figure 29B. Sub-bottom profile - SW portion of Diagonal Line 1. (Sea Engineering, 2014)
Match with A
LACK OF SUB-BOTTOM FEATURES
INDICATIVE OF DREDGED MATERIAL (DM)
| O
-*•4
: ro
DM - Discrete deposits, fines at depth
arid winnowed sands at SWI.
LACK OF SUB-BOTTOM FEATURES
INDICATIVE OF OHEOGEO MATERIAL (DM)
DM - Discrete layering,
medium sand over silty
very firie sand & muds.
V)
S
ODMDS
Trace DM - Silty fine to
medium sand with some silt
No DM - Medium sand with
interstitial fines and silt.
5UB-BOTTOM FEATURES
APPEAR WHEN DM THINS OS IS NOT PRESENT
41
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 30. Comparison of South Oahu site dredged material volume estimates: from sub-
bottom mapping versus recorded disposal volumes for 2000-2013 (see Table 1).
Comparison of Disposal Volumes:
Sub-Bottom Profile Survey versus
Disposal Records
Estimated Volume of Dredged Material
Disposed at the South Oahu ODMDS
Based on Sub-Bottom Profile Results:
Volume estimated in overall Study Area:
27,885,600 cy (21,320,000 m^)
Volume estimated within ODMDS limits only:
1,736,000 cy (1,327,350 m3)
Disposal Records:
Year
Cubic Yards
2000
0
2001
0
2002
53,500
2003
183,500
2004
540,000
2005
0
2006
160,400
2007
266,500
2008
0
2009
126,200
2010
0
2011
18,260
2012
0
2013
506,870
Total:
1,855,230
Although the volume of dredged material estimated by the sub-bottom profiling survey to be
within the South Oahu disposal site boundary (1.74 million cy) compares well with the actual
disposal records since 2000 (1.85 million cy), Table 1 shows that a total of 6.3 million cy has
actually been disposed since the site was designated in 1981. It is likely that some substantial
portion of the total 6.3 million cy disposed at the South Oahu site since 1981 is actually
represented within the approximately 26 million cy of historic material estimated to be outside the
site boundaries. Prior to the early 2000s, automatic satellite-based tracking and recording of
disposal scow position was not required 2, and "short-dumping" (resulting in material depositing
outside site boundaries) probably occurred fairly frequently. Still, it is highly likely that much of
the material disposed between 1981 and 2000 was nevertheless deposited on-site, so more than 1.8
million cy should be present. It is to be expected that physical consolidation of any dredged
material deposit would occur over time, reducing its apparent volume compared to disposal
records. For all these reasons, the sub-bottom profiling survey's rough estimate is certainly low.
However, it is also certainly within an order of magnitude, and is an interesting cross-check on
other disposal site monitoring results.
2 The 1997 SMMP (USEPA and USAGE, 1997) required a navigation system capable of 30 m accuracy, but did
not specify that the system show the position of the disposal scow itself (as opposed to the tug or towing
vessel). Similarly, the 1997 SMMP did not require "black box" recording of the actual disposal location, so
independent confirmation that disposal only occurred at the center of the disposal site (as required) was
difficult. But beginning in the 2000s, as both commercial GPS accuracy and vessel sensor technology
advanced, and EPA and USAGE began requiring sophisticated automatic tracking systems as conditions for
all individual project's ocean disposal permits.
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3.5 Comparison to 1980 Baseline Information
EPA Region 9
3.5.1 South Oahu Disposal Site
Comparison of the data contained in the 1980 EIS to the data collected from the 2013 survey
shows that the grain size proportions in the disposal site have shifted to a higher percentage of silt
and clay, as well as higher percentage of sediments coarser than sand (Table 6). This is not
surprising because maintenance dredged material tends to be finer grained in comparison to the
native bottom sediments which contain a higher percentage of sand, as described in the 1980 EIS.
New work (deepening) dredging projects in areas such as Pearl Harbor have likely removed deeper
layers of reef formation material, thus contributing to the gravel-sized fraction. This much coarser
material is expected to sink rapidly to the bottom, without dispersing and drifting outside of the
site boundary, in contrast to fine grained dredged material.
Table 6. Average Percent Grain Size - South Oahu Site
Grain Size
1980 EIS
2013 - Disposal
2013 - Outside of
2013 - Entire
Category
(Pre-Disposal)
Site only
Disposal Site
Survey Area
Gravel
12.0
21.6
2.8
12.2
Sand
75.0
44.4
77.2
60.8
Silt & Clay
13.0
33.2
19.2
26.2
Comparison to baseline sediment chemistry is limited to the trace metal concentrations shown in
the 1980 EIS. When comparing the 1980 trace metal data to the data collected from the 2013
survey, it is apparent that dredged material disposal operations generally have not appreciably
increased contaminant loading on-site, or relative to the surrounding environs, except for copper
(Table 7). The slightly elevated on-site copper concentration is higher than the NOAA ER-L
screening level, but is much lower than the ER-M screening level where toxicity effects are more
likely to occur. As discussed in Section 3.2, all sediments discharged at ocean disposal sites are
fully characterized before approval for ocean disposal is granted. Sediments that contain toxic
pollutants in toxic amounts are prohibited from being discharged. Thus the slightly elevated
concentration of copper compared to the 1980 baseline is not considered to represent a risk of
environmental impact.
Table 7. Trace Metal Concentrations - South Oahu Site
Analyte
1980 EIS
2013 - Disposal
2013 - Outside of
2013-
Entire
ER-L
ER-M
(Pre-Disposal)
Site only
Disposal Site
Survey Area
Range
Ave.
Range
Ave.
Range
Ave.
Range
Ave.
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
Cadmium
4.0-6.3
5.2
0.0-
0.69
0.4
0.0-0.42
0.08
0.0-0.69
0.25
1.2
9.6
Mercury
0.5-0.9
0.7
0.10-
0.38
0.18
0.02-
0.19
0.09
0.02-
0.38
0.14
0.15
0.71
Copper
17.6-
45.5
31.0
43.0-
84.0
59.0
11.0-
37.0
23.8
11.0-
84.0
41.4
34
270
Lead
38.1-
59.0
48.6
15.0-
95.0
37.6
10.0-
37.0
20.8
10.0-
95.0
29.2
46.7
218
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The 1980 EIS characterized the benthic community as typical for abyssal depths, with low infaunal
abundance relative to shallow depth communities. Infaunal abundances were similar in the 2013
surveys, although on-site percent abundances of crustaceans and other miscellaneous taxa
appeared to be slightly lower than in 1980 (Table 8). Nevertheless, even these minor differences
are most likely attributable to natural variability across the study area rather than to disposal
activities. This conclusion is supported by abundances of crustaceans and other miscellaneous
taxa in 2013 being greater inside the disposal site compared to outside it.
Table 8. Percent Abundance - South Oahu Site
Taxonomic Group
1980 EIS
2013 - Disposal
2013-Outside of
2013- Entire Survey
(Pre-Disposal)
Site only
Disposal Site
Area
Annelida (includes
82.9
84.6
90.6
87.9
polychaetes)
Crustacea
2.9
1.3
1.3
1.3
Mollusca
0.8
3.8
1.3
2.4
Miscellaneous taxa
13.3
10.4
6.7
8.4
3.5.2 Hilo Disposal Site
Comparison of the data contained in the 1980 EIS to the data collected from the 2013 survey
shows that the grain size character has shifted to a somewhat higher percentage of silt and clay
(Table 9). This is not surprising because maintenance dredged material tends to be finer grained in
comparison to the native bottom sediments which contain a higher percentage of sand, as described
in the 1980 EIS. But these physical changes are less obvious and widespread than at the South
Oahu site, where much more dredged material has been disposed. Also in contrast to the South
Oahu site, new work (deepening) dredging projects have not placed such a high volume of much
coarser reef formation material, and as a result, the gravel-sized fraction has not increased
significantly.
Table 9. Average Percent Grain Size - Hilo Site
Grain Size
1980 EIS
2013 - Disposal
2013 - Outside of
2013- Entire
Category
(Pre-Disposal)
Site only
Disposal Site
Study Area
Gravel
1.0
1.75
0.0
0.9
Sand
77.0
59.8
49.3
54.5
Silt & Clay
22.0
30.3
52.0
41.1
Comparison to baseline sediment chemistry is limited to the trace metal concentrations shown in
the 1980 EIS. When comparing the 1980 trace metal data to the data collected from the 2013
survey, it is apparent that dredged material disposal operations at the Hilo site have not caused any
significant increase in contaminant loading, except for copper (Table 10.). The slightly elevated
copper concentration is higher than the NOAA ER-L screening level, but is much lower than the
ER-M screening level, where toxicity effects are more likely to occur; therefore the slightly
elevated copper is not considered to represent a risk of environmental impact. In addition, the
copper elevation is shoreward and outside the disposal site. Possible explanations include
contaminants from other shore-side source, or historic short-dumping from disposal scows (prior to
the early 2000's, after which "black box" compliance monitoring was required).
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 10. Trace Metal Concentrations - Hilo Site
Analyte
1980 EIS
2013 - Disposal
2013 - Outside of
2013-
Entire
(Pre-Disposal)
Site only
Disposal Site
Survey Area
ER-L
ER-M
Range
Ave.
Range
Ave.
Range
Ave.
Range
Ave.
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
Cadmium
—
3.4
0.0-0.6
0.4
0.50-
0.72
0.64
0.0-
0.72
0.51
1.2
9.6
Mercury
0.10-
0.59
0.35
0.05-
0.06
0.06
0.04-
0.17
0.10
0.04-
0.17
0.08
0.15
0.71
Copper
33.9-
38.1
36.0
30.0-
35.0
31.8
30.0-
56.0
42.0
30.0-
56.0
36.9
34
270
Lead
19.5-
29.0
24.3
11.0-
12.0
11.2
9.6-
21.0
15.2
9.6-
21.0
13.2
46.7
218
The 1980 EIS characterized the benthic community at the Hilo site as typical for abyssal depths,
with low infaunal abundances relative to shallow depth communities. Compared to data presented
in the site designation EIS, some minor differences in percent abundance appear to have occurred
(Table 10). Mollusks and miscellaneous taxa appear to be very slightly lower on-site compared to
off-site in 2013 (though not statistically significantly so), and miscellaneous taxa appear to be less
abundant in 2013 than they were in 1980. However, in 2013 miscellaneous taxa were lower both
inside and outside the disposal site, while mollusks were more abundant region-wide than in 1980.
As noted earlier, the native benthic environment around the Hilo site is more heterogeneous than
around the South Oahu site to begin with. These minor differences may in infaunal abundances
therefore are at least substantially attributable to natural variability across the study area rather
than to disposal activities.
Table 11. Percent Abundance - Hilo Site
Taxonomic Group
1980 EIS
2013 - Disposal
2013-Outside of
2013- Entire Survey
(Pre-Disposal)
Site only
Disposal Site
Area
Annelida (includes
80.0
85.9
79.6
81.8
polychaetes)
Crustacea
2.2
2.8
1.0
1.5
Mollusca
1.1
4.2
10.8
8.5
Miscellaneous taxa
16.7
7.0
8.8
8.2
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IV. CONCLUSIONS AND RECOMMENDATIONS
Multiple survey activities were conducted in 2013 to assess the condition and performance of the
EPA-designated South Oahu and Hilo ocean dredged material disposal sites. Over the past two
decades, South Oahu and Hilo have been the most heavily used of the five disposal sites that serve
the ports and harbors of the Hawaiian Islands. The survey results are intended to identify whether
any adverse impacts of dredged material disposal are occurring compared to baseline conditions, to
confirm the protectiveness of the pre-disposal sediment testing required by EPA and USACE, and
to serve as a basis for updating the Site Management and Monitoring Plan (SMMP) as appropriate.
The dredged material deposit (footprint) was mapped at each site. Significant deposits of dredged
material are apparent outside the South Oahu site boundaries, but this likely resulted from short-
dumping prior to the early 2000s when EPA and USACE began requiring "black box" tracking
systems. Since that time, virtually all material disposed at South Oahu is documented as having
been discharged properly within the Surface Disposal Zone at the center of the site. At the Hilo
site, almost all of the dredged material footprint is contained within the site boundary.
Sediment sampling confirms that there have been no significant adverse impacts as a result of
dredged material disposal operations at either of the disposal sites monitored. Only minor physical
effects (grain size and organic carbon content changes) have occurred at either site, despite the
order-of-magnitude greater volume that has been disposed at the South Oahu site over the last 15
years. Chemical analysis of both on-site and off-site stations indicated only low concentrations of
chemicals of concern, both on-site and off-site. Benthic community analyses showed that
recolonization occurs after dredged material is deposited, and similar infaunal and epifaunal
communities occupy both on-site and off-site areas. Taken together, these results also provide
support that the pre-disposal sediment testing program is effective in not allowing highly
contaminated sediments to be discharged at either site.
The 2013 monitoring results also indicate a lack of significant adverse impacts compared to 1980
baseline conditions. Only minor and localized physical changes are apparent as a result of disposal
operations at either site.
Overall, these findings suggest that ongoing use of the South Oahu and Hilo ocean dredged
material disposal sites, under testing and management conditions at least as stringent as have been
applied over the past 15 years, should similarly result no significant adverse effects. Permit
conditions should be updated in the revised SMMP, and a more specific site monitoring schedule
should be established for the future. But based on all the monitoring results, no significant
changes to sediment testing or to the overall site management framework appear to be warranted
for these sites.
Continued use of the other three Hawaii ocean dredged material disposal sites that were not
monitored in 2013 is also supported by inference. These sites have received far less frequent
dredged material disposal than South Oahu or even Hilo, and impacts can be expected to be
negligible there as well. Nevertheless, the other Hawaii sites should be considered for
confirmatory monitoring after the next round of disposal operations, currently expected to occur in
2016.
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V. REFERENCES
ALS Environmental, 2013. South Oahu Ocean Sediments. (Analytical chemistry results for grain
size, total solids, TOC, PCBs, Dioxins/Furans, and butyltins.) Prepared under EPA contract
EP-C-09-020 for ERG Inc., Chantilly, VA.
EcoAnalysts, Inc., 2014. Final Report for Benthic Community Analysis for Site Monitoring of
EPA-Designated Ocean Disposal Sites in Region 9: South Oahu and Hilo Sites (EPA
Contract EP-C-09-020, Work Assignment 4-27). Woods Hole, MA.
Germano & Associates, 2013 a. Confirmatory Site Monitoring of the South Oahu and Hilo Ocean
Dredged Material Disposal Sites Utilizing Sediment Profile and Plan View Imaging:
Quality Assurance Project Plan. Prepared under EPA contract EP-C-09-020 for ERG Inc.,
Chantilly, VA.
Germano & Associates, 2013 b. Monitoring Survey of the EPA-Designated South Oahu and Hilo
Ocean Dredged Material Disposal Sites: Sediment Profile & Plan View Imaging Results,
2013 (Project No. 0268.04.027/2, EPA Contract EP-C-09-020, Work Assignment 4-27).
Bellevue, WA.
NOAA, 2008. Sediment Quick Reference Tables (SQuiRT), NOAA OR&R Report 08-1, Office of
Response and Restoration Division, Seattle, WA.
Rhoads, 1974. Organism-sediment relations on the muddy seafloor. Oceanography and Marine
Biology: An Annual Review; 12:263-300.
Rhoads and Germano. 1982. Characterization of benthic processes using sediment profile
imaging: An efficient method of remote ecological monitoring of the seafloor (REMOTS™
System). Mar. Ecol. Prog. Ser. 8:115-128.
Sea Engineering Inc., 2013. Quality Assurance Project Plan: Sub-Bottom Profiler Survey for
Confirmatory Site Monitoring of the South Oahu Ocean Dredged Material Disposal Sites.
Prepared under EPA contract EP-C-09-020 for ERG Inc., Chantilly, VA
Sea Engineering Inc., 2014. South Oahu Ocean Dredged Material Dump Site Sub-Bottom Survey,
Honolulu, HI (EPA Contract No. EP-C-09-020, Work Assignment 4-27; Subcontract
0268.04.027/1). Waimanalo, HI.
Torresan and Gardner, 2000. Acoustic Mapping of the Regional Seafloor Geology in and
Around Hawaiian Dredged Material Disposal Sites (USGS Open File Report 00-124).
USACE. Ocean Disposal Database, http://e 1 ,erdc,usace.army.roi 1/odd/QDMDSSearch.efro.
USEPA, 1980. Final Environmental Impact Statement for Hawaii Dredged Material Disposal Site
Designation, US Environmental Protection Agency, Oil and Special Materials Control
Branch, Marine Protection Branch. Washington, D.C.
USEPA, 2013 a. Work Plan QAPP (EPA Contract No. EP-C-09-020, Work Assignment 4-27);
EPA Region 9, San Francisco, CA.
USEPA, 2013 b. Analytical Testing Results, Project R13W07, SDG 13189B. EPA Region 9
Laboratory, Richmond, CA.
USEPA and USACE, 1977. Site Management Plan (SMP) for the Hawaii Ocean Dredged
Material Disposal Sites. Special Joint Public Notice. April 7, 1997.
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APPENDIX
SUMMARY OF PLANNED VS ACTUAL SURVEY ACTIVITIES AT
HAWAII OCEAN DREDGED MATERIAL DISPOSAL SITES, 2013
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APPENDIX
SUMMARY OF PLANNED VS ACTUAL SURVEY ACTIVITIES AT
HAWAII OCEAN DREDGED MATERIAL DISPOSAL SITES, 2013
General Survey Information:
Site Name (Region): South Oahu and Hilo Ocean Dredged Material Disposal Sites (Region 9)
Survey Chief Scientist/Organization: Allan Ota (EPA Region 9)
Telephone: 415-972-3476
E-mail: ota.allan@epa.eov
Other Key Personnel/Organization: Brian Ross (EPA Region 9)
Telephone: 415-972-3475
E-mail: ross.briam@epa.gov
Science Crew/Organization:
Amy Wagner (EPA Region 9)
Leslie Robinson (US Navy, HI)
Sean Hanser (US Navy, HI)
Thomas Smith (USACE, HI)
Robert O'Connor (NO A A, HI)
Joseph Germano (Germano & Assoc., WA)
David Browning (Germano & Assoc., WA)
Christine Smith (ANAMAR, FL)
Schedule of Operations:
Number of survey days: 8 planned, 5 actual (plus 2 for mobilization/demobilization)
Mobilization date (Location): 24-25 June 2013 (Ford Island, Pearl Harbor, Oahu)
Demobilization date (Location): 03 July 2013 (Ford Island, Pearl Harbor, Oahu)
Original Problem Definitions/Task Descriptions (from Quality Assurance Project Plan)
1. Using the Hi'ialakai, collect MBES images to confirm overall bathymetry and identify
any features of interest to adjust sediment sampling locations as appropriate:
a. Is the overall bathymetry different from the standard NOAA charts?
b. Are there unusual or unique features that suggest that adjustment of planned
sampling station locations is necessary to improve interpretation of site
monitoring data?
2. Using the Hi'ialakai, collect SPI and PVP images at up to 49 stations covering each
EPA ODMDS and adjacent areas outside of site boundaries to address the following
management questions:
a. Is the footprint of recently deposited dredged material contained within site
boundaries? Are dredged materials in a single mound feature or contained
in multiple mounds?
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b. Are the sediments within the dredged material deposit footprint visually
similar or dissimilar from ambient bottom sediments?
c. Are there indications of disposal of materials other than dredged materials?
d. Are there indications of an undisturbed or disturbed environment (adverse
impacts)?
3. Using the Hi'ialakai, collect up to 20 sediment grab samples at each EPA ODMDS and
adjacent areas outside of site boundaries to address the following management
questions:
a. Are sediment contamination levels at the sites within the range predicted by
pre-disposal sediment testing of dredged material approved for disposal?
b. Are levels of contaminants at historic disposal sites (>10 years since used)
adjacent to the active South Oahu site similar to or below ambient levels
(undisturbed native sediments - outside of deposit footprint or site
boundaries)?
c. How do the biological communities compare, between within the site and
outside of site boundaries?
d. How do the biological communities compare to what existed when these
permanent sites were designated?
4. Using a contracted (Sea Engineering) vessel, collect high resolution sub-bottom seismic
profiles within selected basin locations to address the following management questions:
a. Based on the acoustic signal contrast between native bottom sediments and
dredged material layer, what is the horizontal extent of the dredged material
deposit footprint relative to the site boundaries? - i.e., does the dredged material
deposit appear to reside mostly or completely within site boundaries, suggesting
site is performing as expected?
b. Based on the acoustic signal contrast between native bottom sediments and
dredged material layer, what is the apparent thickness of the dredged material
deposit footprint? - i.e., does the bulk of the dredged material volume appear to
reside mostly or completely within site boundaries, suggesting site is
performing as expected?
c. How does the calculated volume of the dredged material identified by this
survey compare with dredging records for projects using the site? - i.e.,
comparison of volumes from compiled disposal records to the calculated
volume using information from (a) and (b) above.
Actual Sequence of Tasks/Events
The surveys were originally scheduled to occur over 8 days (plus mobilization and
demobilization), but problems associated with readiness of the NOAA ship and its equipment
caused some delays. The surveys were ultimately conducted over a 5-day period (not including
transit between the South Oahu site and the Hilo site, and the return transit to Pearl Harbor from
the Hilo site). Field operations were conducted continuously over a 24-hour period (two scientific
crews workingl2-hour shifts).
The survey sampling objectives were not fully accomplished due to the following problems:
1. Departure was delayed by one day, due to:
a. Hole/rupture in the NOAA ship's bilge tank which had to be repaired.
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b. The original contracted marine winch, which was installed during the previous
week, was not working properly and its hydraulic unit had to be replaced.
2. The replacement winch operated at a slower rate (about 20 meters per minute, instead of
40-60 meters per minute) than what was expected when the survey plan was conceived,
resulting in less than half of the planned sediment grab sampling stations being occupied in
the time remaining for survey work.
3. Hard bottom features were encountered and multiple attempts were needed at several
stations to obtain acceptable samples, as judged by QAPP metrics (i.e., adequate
penetration and undisturbed appearance).
4. The multi-beam echo sounder (MBES) survey initially planned for both sites was not
executed due to the equipment on the NOAA vessel not functioning properly at the
beginning of the first survey leg. As a result, no MBES data was collected at either site. In
the absence of the MBES survey data, the combination of SPI and PVP photography and
analysis of the SPI visual parameters provided information on the horizontal and vertical
extent of the dredged material footprint, and context for the other (sediment) sampling
results.
Survey Activities/Operations Conducted to Address Problem Definitions:
The following are the survey activities executed at both sites:
1. Sediment Profile Imaging (SPI) and Plan View Photography (PVP)
SPI-PVP surveys were conducted for each ODMDS to delineate the horizontal extent
of the dredged material deposit footprint within the site, and outside of site boundaries
if any deposits exist (Figure 2). A total of 86 stations were occupied with the SPI/PV
camera system (40 at South Oahu and 46 at Hilo), compared to the planned 98 (49 at
each site). With optimal resolution on the order of millimeters, the SPI system is
particularly useful for identifying a number of features, including the edges of the
footprint as they overlay native sediments of the seabed, identifying dredged material
layers relative to native sediments, and the level of disturbance as indicated by presence
of certain classes of benthic organisms (Figures 3 and 4). PVP is useful for identifying
surface features where the SPI photos are taken, thereby providing surface context for
the vertical profiles at each station. For each station, a minimum of four SPI photos
were taken, coupled with a single PVP photo.
2. Sediment Sampling for Chemistry and Benthic Communities:
Sediment samples were collected for sediment grain size, chemistry, and benthic
community analysis with a stainless steel double Van Veen sediment grab (Figure 5)
capable of penetrating a maximum of 20 centimeters of depth below the sediment
surface. Sediment grab samples were judged acceptable based on approved QAPP
metrics. After each acceptable grab sample was measured for depth of penetration and
photographed, sufficient volume of chemistry subsample were extracted from one of
the two grabs with a stainless steel spoon for further processing (Figure 6). The
chemistry subsample was then homogenized and divided into the different chemistry
analysis jars (i.e., grain size, metals and organics). After the chemistry subsample was
extracted, the entire volume of the other grab was processed (Figure 7) to create a
benthic community sample for that station. A 500 micron sieve was used to separate
organisms from the sediment, and the separated organisms were then initially preserved
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with formalin. A total of 18 sediment grab sample stations were occupied in the two
survey areas combined, relative to the original targeted 40 locations. 18 chemistry
samples were processed (10 at South Oahu, and 8 at Hilo), 3 of which were field or
laboratory duplicates. A total of 14 benthic community samples were collected; the
lower number than the chemistry samples was due to some grabs being used for field
and laboratory chemistry duplicates, and one station where QAPP metrics were not met
for an acceptable benthic sample (lack of time to re-deploy).
The following survey activity was executed only at the South Oahu site:
3. Collection of high-resolution sub-bottom seismic-reflection profiles:
The primary purpose of this survey was to collect cross-sectional images of the native
sediment layers and identify layers indicative of the dredged material deposit footprint
in the environs of the South Oahu ODMDS. (The Hilo site was not surveyed in this
manner during this round of surveys, primarily due to the much smaller volumes of
dredged material which may not be detectable in terms of thickness and contrast.) The
survey was contracted to Sea Engineering, who conducted the work aboard a separate
vessel specially rigged for this type of survey with an acoustic sub-bottom profiler
system (Figure 8), which was more cost effective than attempting to install the
equipment on the NOAA vessel. The results of this survey allowed EPA to calculate an
estimate of cumulative volume of dredged material in the South Oahu site.
The study areas are depicted in Figures 9 and 10 (South Oahu) and 11, and 12 (Hilo) The target
sampling station coordinates are listed in Tables 2 (South Oahu) and 3 (Hilo).
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Figure 9. General location of the South Oahu ODMDS
EPA Region 9
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
Figure 10. Planned and actual sample station locations at the South Oahu ODMDS:
EPA Region 9
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
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Table 2. South Oahu ODMDS Sampling Station Coordinates (NAD83). SPI and PVP
photographic samples at all stations; sediment grab samples at highlighted stations.
Station ID
Latitude
Longitude
Sampling Notes
C
21 14.970 N
157 56.670 W
SPI-PV only
N1
21 15.220 N
157 56.670 W
SPI-PV and sediment grab
Nl-A
2115.199 N
157 56.647 W
SPI-PV and sediment grab (field dupe)
N2
21 15.470 N
157 56.670 W
SPI-PV and sediment grab
N3
21 15.720 N
157 56.670 W
SPI-PV only
N4
21 15.965 N
157 56.670 W
SPI-PV only
N5
2116.215 N
157 56.670 W
SPI-PV only
N6
21 16.470 N
157 56.670 W
SPI-PV only
SI
21 14.720 N
157 56.670 W
SPI-PV only
S2
21 14.465 N
157 56.670 W
SPI-PV only
S3
21 14.220 N
157 56.670 W
SPI-PV only
S4
21 13.965 N
157 56.670 W
SPI-PV only
S5
21 13.720 N
157 56.670 W
SPI-PV only
S6
21 13.465 N
157 56.670 W
SPI-PV and sediment grab
W1
21 14.970 N
157 56.940 W
SPI-PV and sediment grab
W2
21 14.970 N
157 57.210 W
SPI-PV only
W3
21 14.970 N
157 57.475 W
SPI-PV only
W4
21 14.970 N
157 57.740 W
SPI-PV only
W5
21 14.970 N
157 58.000 W
SPI-PV and sediment grab
W6
21 14.970 N
157 58.275 W
SPI-PV only
El
21 14.970 N
157 56.400 W
SPI-PV only
E2
21 14.970 N
157 56.135 W
SPI-PV only
E3
21 14.970 N
157 55.870 W
SPI-PV only
E4
21 14.970 N
157 55.600 W
SPI-PV and sediment grab
E5
21 14.970 N
157 55.340 W
SPI-PV only
E6
21 14.970 N
157 55.070 W
SPI-PV and sediment grab
NW1
2115.140 N
157 56.865 W
Station not occupied
NW2
21 15.300 N
157 57.070 W
SPI-PV only
NW3
21 15.470 N
157 57.270 W
Station not occupied
NW4
21 15.650 N
157 57.450 W
SPI-PV only
NW5
21 15.825 N
157 57.635 W
Station not occupied
NW6
2116.010 N
157 57.820 W
SPI-PV only
A-8
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table 2, continued. South Oahu ODMDS Sampling Station Coordinates (NAD83). SPI and PVP
photographic samples at all stations; sediment grab samples at highlighted stations.
NE1
2115.140 N
157 56.480 W
Station not occupied
NE2
21 15.300 N
157 56.280 W
SPI-PV only
NE3
21 15.470 N
157 56.090 W
Station not occupied
NE4
21 15.650 N
157 55.900 W
SPI-PV only
NE5
21 15.825 N
157 55.710 W
Station not occupied
NE6
2116.010 N
157 55.530 W
SPI-PV only
SW1
21 14.790 N
157 56.865 W
SPI-PV only
SW2
21 14.620 N
157 57.050 W
SPI-PV and sediment grab
SW3
21 14.435 N
157 57.225 W
SPI-PV only
SW4
21 14.245 N
157 57.400 W
SPI-PV only
SW5
21 14.070 N
157 57.590 W
SPI-PV only
SW6
21 13.900 N
157 57.785 W
SPI-PV only
SE1
21 14.790 N
157 56.480 W
Station not occupied
SE2
21 14.620 N
157 56.280 W
SPI-PV only
SE3
21 14.435 N
157 56.090 W
Station not occupied
SE4
21 14.245 N
157 55.910 W
SPI-PV and sediment grab
SE5
21 14.070 N
157 55.720 W
Station not occupied
SE6
21 13.900 N
157 55.530 W
SPI-PV only
A-9
-------
2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
Figure 11. General location of the Hilo ODMDS:
EPA Region 9
~ o
°o *
- » <
nhL.
%aMl
-------
2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 12. Planned and actual sample station locations at the Hilo ODMDS:
A-ll
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table 3. Hilo ODMDS Sampling Station Coordinates (NAD83). SPI and PVP photographic
samples at all stations; sediment grab samples at highlighted stations.
Station ID
Latitude
Longitude
Notes
C
19 48.315 N
154 58.340 W
SPI-PV only (grab failed)
N1
19 48.565 N
154 58.320 W
SPI-PV and sediment grab
N2
19 48.815 N
154 58.295 W
SPI-PV only
N3
19 49.065 N
154 58.285 W
Station not occupied
N4
19 49.315 N
154 58.270 W
SPI-PV only
N5
19 49.570 N
154 58.260 W
Station not occupied
N6
19 49.820 N
154 58.245 W
SPI-PV only
SI
19 48.075 N
154 58.365 W
SPI-PV only
S2
19 47.825 N
154 58.395 W
SPI-PV only
S3
19 47.570 N
154 58.425 W
SPI-PV only
S4
19 47.325 N
154 58.450 W
SPI-PV only
S5
19 47.075 N
154 58.475 W
SPI-PV only
S6
19 46.820 N
154 58.500 W
SPI-PV only
W1
19 48.335 N
154 58.600 W
SPI-PV only
W2
19 48.355 N
154 58.870 W
SPI-PV only
W3
19 48.375 N
154 59.125 W
SPI-PV only
W4
19 48.400 N
154 59.385 W
SPI-PV only
W5
19 48.430 N
154 59.655 W
SPI-PV only (grab failed)
W6
19 48.460 N
154 59.920 W
SPI-PV and sediment grab
El
19 48.290 N
154 58.075 W
Station not occupied
E2
19 48.270 N
154 57.810 W
SPI-PV only
E3
19 48.250 N
154 57.545 W
Station not occupied
E4
19 48.230 N
154 57.285 W
SPI-PV only
E5
19 48.210 N
154 57.020 W
SPI-PV only
E6
19 48.190 N
154 56.755 W
Station not occupied
NW1
19 48.490 N
154 58.530 W
SPI-PV only
NW2
19 48.675 N
154 58.700 W
SPI-PV only
NW3
19 48.880 N
154 58.860 W
SPI-PV only
NW4
19 49.060 N
154 59.040 W
SPI-PV only
NW5
19 49.265 N
154 59.200 W
SPI-PV only
NW6
19 49.470 N
154 59.365 W
SPI-PV only
NE1
19 48.480 N
154 58.130 W
SPI-PV only
NE2
19 48.650 N
154 57.935 W
SPI-PV only
A-12
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table 3, continued. Hilo ODMDS Sampling Station Coordinates (NAD83). SPI and PVP
photographic samples at all stations; sediment grab samples at highlighted stations.
NE3
19 48.815 N
154 57.735 W
SPI-PV only
NE4
19 48.975 N
154 57.535 W
SPI-PV only
NE5
19 49.130 N
154 57.330 W
SPI-PV and sediment grab
NE6
19 49.275 N
154 57.110 W
Station not occupied
SW1
19 48.155 N
154 58.540 W
SPI-PV and sediment grab
SW2
19 48.015 N
154 58.760 W
SPI-PV only
SW3
19 47.865 N
154 58.970 W
SPI-PV only
SW4
19 47.720 N
154 59.185 W
SPI-PV only
SW5
19 47.565 N
154 59.385 W
SPI-PV only
SW6
19 47.415 N
154 59.600 W
SPI-PV and sediment grab
SW7
19 47.257 N
154 59.827 W
SPI-PV only (station added in field)
SW8
19 46.989 N
155 00.245 W
SPI-PV only (station added in field)
SW9
19 46.648 N
155 00.587 W
SPI-PV only (station added in field)
SE1
19 48.110 N
154 58.180 W
SPI-PV only
SE2
19 47.925 N
154 58.010 W
SPI-PV only
SE3
19 47.715 N
154 57.850 W
SPI-PV only
SE4
19 47.530 N
154 57.690 W
SPI-PV and sediment grab
SE5
19 47.325 N
154 57.520 W
SPI-PV only
SE6
19 47.135 N
154 57.340 W
SPI-PV only
A-13
-------
Appendix 3 to EPA Consultation with NMFS
for Continued Use of Five Existing Ocean Dredged Material Disposal Sites (ODMDS)
in Waters Offshore of Hawaii
Preliminary Chemistry Results from the 2017 Monitoring Survey
of the Nawiliwili, Kahului, and Port Allen Ocean Disposal Sites
-------
2017 EPA Monitoring Survey of the Kahului, Nawiliwili,
and Port Allen Ocean Disposal Sites in Hawai'i:
Preliminary Chemistry Results
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results
DRAFT - DO NOT DISTRIBUTE
Figure 1. Map of the stations in the Kahului ocean disposal site survey area. A subset of these stations was selected for sediment grabs.
1
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 1. Sediment chemistry results from the Kahului ocean disposal site (first of two tables).
NOAA
Kahului site
"Inside"
Reference
Screening
Analyte
Units
(dw)
KH00
KH01
KH12
KH20
KH28
KH28
KH34
KH37
KH44
KH03
KH21
KH27
KH30
KH39
Site
ER-L
ER-M
TOC
%
3430.00
4020.00
4170.00
5270.00
3970.00
3460.00
3510.00
4160.00
3520.00
4210.00
7220.00
4000.00
3400.00
4240.00
0.58
-
-
Arsenic
mg/kg
16.00
16.00
22.00
17.00
17.00
18.00
22.00
16.00
17.00
22.00
18.00
20.00
23.00
18.00
40
8.2
70
Cadmium
mg/kg
0.36
0.36
0.40
0.38
0.37
0.37
0.38
0.34
0.37
0.40
0.39
0.41
0.41
0.38
ND
1.2
9.6
Chromium
mg/kg
55.00
54.00
80.00
64.00
59.00
61.00
69.00
46.00
59.00
79.00
68.00
80.00
67.00
65.00
68
81
370
Copper
mg/kg
23.00
23.00
31.00
26.00
26.00
25.00
26.00
20.00
23.00
29.00
27.00
31.00
24.00
25.00
22
34
270
Lead
mg/kg
4.70
5.30
13.00
7.20
5.40
6.60
6.90
3.40
7.70
11.00
8.30
12.00
6.50
7.90
19
46.7
218
Mercury
mg/kg
0.02
0.03
0.05
0.03
0.03
0.03
0.05
0.02
0.06
0.04
0.03
0.05
0.03
0.03
0.09
0.15
0.71
Nickel
mg/kg
52.00
56.00
54.00
52.00
50.00
55.00
53.00
57.00
47.00
54.00
50.00
51.00
42.00
51.00
37
20.9
51.6
Selenium
mg/kg
1.50
1.40
1.60
1.50
1.50
1.50
1.50
1.40
1.50
1.60
1.60
1.70
1.60
1.50
ND
-
-
Silver
mg/kg
0.73
0.71
0.79
0.76
0.74
0.74
0.76
0.69
0.75
0.80
0.79
0.83
0.81
0.77
ND
1
3.7
Zinc
mg/kg
41.00
43.00
47.00
65.00
44.00
43.00
46.00
40.00
40.00
45.00
45.00
48.00
44.00
44.00
52
150
410
Dioxins &
Furans
TEQ
0.93
4.24
0.88
0.53
0.78
0.56
0.89
0.79
1.01
1.17
1.01
1.02
0.94
0.70
1.06
Total DDTs
ug/kg
14.40
13.80
15.60
15.00
14.40
15.00
15.00
13.80
15.00
52.00
15.60
16.20
16.20
15.00
ND
1.58
46.1
Total
Organotins
ug/kg
806.30
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
7.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
53.40
67.10
92.00
54.20
48.80
68.30
84.20
51.60
91.80
71.00
55.00
73.70
73.00
60.20
344
4022
44792
Total PCBs
ug/kg
0.00
0.00
0.30
0.00
0.00
0.00
0.00
0.31
0.00
0.00
0.00
2.73
0.00
8.32
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
2
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 2. Sediment chemistry results from the Kahului ocean disposal site (second of two tables).
NOAA
Kahului site
"Outside"
Reference
Screening
Analyte
Units
(dw)
KH05
KH09
KH14
KH16
KH23
KH32
KH36
KH41
KH41
KH46
KH48
KH50
KH53
KH56
Site
ER-L
ER-M
TOC
%
5380.00
3680.00
4440.00
5630.00
4900.00
3700.00
3950.00
4230.00
4250.00
3610.00
3200.00
2700.00
2610.00
4500.00
0.58
-
-
Arsenic
mg/kg
33.00
32.00
21.00
24.00
20.00
23.00
21.00
20.00
24.00
19.00
30.00
29.00
33.00
23.00
40
8.2
70
Cadmium
mg/kg
0.39
0.37
0.41
0.42
0.41
0.41
0.38
0.40
0.41
0.39
0.40
0.38
0.36
0.41
ND
1.2
9.6
Chromium
mg/kg
82.00
74.00
75.00
89.00
78.00
68.00
69.00
74.00
86.00
68.00
78.00
78.00
67.00
72.00
68
81
370
Copper
mg/kg
24.00
20.00
27.00
31.00
29.00
25.00
25.00
28.00
30.00
24.00
24.00
24.00
19.00
26.00
22
34
270
Lead
mg/kg
6.90
4.70
11.00
13.00
11.00
4.80
8.30
9.20
16.00
9.10
8.60
5.80
4.10
8.30
19
46.7
218
Mercury
mg/kg
0.03
0.02
0.05
0.05
0.04
0.02
0.05
0.05
0.05
0.05
0.06
0.05
0.02
0.05
0.09
0.15
0.71
Nickel
mg/kg
52.00
50.00
47.00
55.00
51.00
41.00
46.00
49.00
55.00
46.00
52.00
53.00
57.00
47.00
37
20.9
51.6
Selenium
mg/kg
1.60
1.50
1.60
1.70
1.70
1.60
1.50
1.60
1.60
1.60
1.60
1.50
1.40
1.60
ND
-
-
Silver
mg/kg
0.79
0.74
0.82
0.84
0.83
0.82
0.77
0.79
0.82
0.79
0.80
0.76
0.72
0.82
ND
1
3.7
Zinc
mg/kg
43.00
38.00
41.00
43.00
47.00
45.00
41.00
44.00
43.00
40.00
45.00
44.00
41.00
46.00
52
150
410
Dioxins &
Furans
TEQ
1.13
0.61
1.40
0.97
0.88
0.48
0.55
0.88
1.00
1.03
0.92
0.58
0.70
0.76
1.06
-
-
Total DDTs
ug/kg
15.60
14.40
16.20
16.80
16.20
16.20
15.00
15.60
50.50
15.60
15.60
15.00
14.40
16.20
ND
1.58
46.1
Total
Organotins
ug/kg
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
59.00
58.40
71.00
61.80
52.80
60.00
59.20
79.00
81.80
70.80
68.00
64.20
33.40
65.80
344
4022
44792
Total PCB
ug/kg
0.00
0.00
0.00
35.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
17.46
0.31
4.27
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
3
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results
DRAFT - DO NOT DISTRIBUTE
Nawiliwili
Depth (m)
2017 SWPV Station
Ctepasal Ste
KJom#t«rs
INSPIRE
Data T»rr>90f»C SUIV»y ZP1 /
D0Cufr*nt tonw OCPD HI FlW 3*1 SVis
Dat«: 2'22i2C 1
Coordinate Syst«rti OCS WGS 19B4
Figure 2. Map of the stations in the Nawiliwili ocean disposal site survey area. A subset of these stations was selected for sediment grabs.
4
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 3. Sediment chemistry results from the Nawiliwili ocean disposal site.
Nawiliwili Site
"Inside"
"Outside"
Reference
NOAA
Screening
Analyte
Units
(dw)
NW01
NW19
NW55
NW07
NW18
NW23
NW59
NW10
NW15
NW52
NW57
NW57D
Site
ER-L
ER-M
TOC
%
2300
2540
1970
1320
3400
1170
2730
2200
780
3690
1260
1140
0.58
-
-
Arsenic
mg/kg
18
19
15
12
19
16
21
14
9
22
12
No
data
40
8.2
70
Cadmium
mg/kg
0.37
0.35
0.38
0.37
0.39
0.41
0.40
0.36
0.42
0.41
0.40
ND
1.2
9.6
Chromium
mg/kg
84
75
80
62
110
64
120
46
31
130
52
68
81
370
Copper
mg/kg
17.00
21.00
19.00
14.00
24.00
16.00
27.00
7.20
7.30
27.00
13.00
22
34
270
Lead
mg/kg
2.20
7.90
2.30
2.40
2.40
2.40
2.40
2.10
2.50
2.40
2.40
19
46.7
218
Mercury
mg/kg
0.02
0.03
0.02
0.02
0.02
0.02
0.03
0.02
0.02
0.03
0.02
0.09
0.15
0.71
Nickel
mg/kg
88
87
100
52
100
95
110
27
32
110
54
37
20.9
51.6
Selenium
mg/kg
1.50
1.40
1.50
1.50
1.60
1.60
1.60
1.40
1.70
1.60
1.60
ND
-
-
Silver
mg/kg
0.74
0.69
0.77
0.74
0.79
0.81
0.79
0.71
0.84
0.82
0.79
ND
1
3.7
Zinc
mg/kg
43
35
43
25
48
37
53
15
17
55
29
52
150
410
Dioxins &
Furans
TEQ
0.92
No
data
1.26
0.66
1.03
0.61
0.69
1.03
0.56
1.09
0.62
0.65
1.06
-
-
Total DDTs
ug/kg
14.40
13.80
15.00
14.40
15.60
16.20
15.60
13.80
16.80
16.20
15.60
ND
1.58
46.1
Total
Organotins
ug/kg
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
48.40
45.60
48.20
49.40
50.00
49.00
49.00
50.40
52.80
50.00
36.40
344
4022
44792
Total PCBs
ug/kg
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3.80
0.00
0.00
0.00
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
5
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results
DRAFT - DO NOT DISTRIBUTE
1»
100
200
300
4CO
SCO
bCO
7 CO
8CO
900
lOOO
1100
1200
1300
1400
1500
1600
1700
1800
1900
2CC0
2100
2D17 SPI/PV Station
Kilometers
rcrrjiwng V Jl
JNSPIR
Docuftttnt Nam* OCPD HI PA SPl stf»&
Coordinate System OCS WQ8 1984
Date: 2/22/201B
Figure 3. Map of the stations in the Port Allen ocean disposal site survey area. A subset of these stations was selected for sediment grabs.
6
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 4. Sediment chemistry results from the Port Allen ocean disposal site.
NOAA
Port Allen Site
"Inside"
"Outside"
Reference
Screening
Analyte
Units
(dw)
PA00
PA13
PA31
PA53
PA15
PA27
PA29
PA34
PA49
PA51
PA55
Site
ER-L
ER-M
TOC
%
4400
6500
3770
6000
2340
6200
5000
3700
4160
5200
6070
0.58
-
-
Arsenic
mg/kg
19
19
18
23
14
21
21
17
22
23
23
40
8.2
70
Cadmium
mg/kg
0.46
0.43
0.42
0.50
0.38
0.44
0.42
0.42
0.47
0.48
0.55
ND
1.2
9.6
Chromium
mg/kg
150
160
130
180
72
170
140
140
150
190
180
68
81
370
Copper
mg/kg
42
46
41
54
15
46
37
45
52
63
53
22
34
270
Lead
mg/kg
4.00
4.20
3.00
6.00
2.30
5.90
4.20
4.00
6.90
6.80
7.70
19
46.7
218
Mercury
mg/kg
0.10
0.09
0.08
0.11
0.02
0.09
0.05
0.06
0.11
0.10
0.10
0.09
0.15
0.71
Nickel
mg/kg
190
140
130
190
65
150
120
120
130
180
170
37
20.9
51.6
Selenium
mg/kg
1.60
1.70
1.70
1.70
1.50
1.80
1.70
1.70
1.70
1.80
1.80
ND
-
-
Silver
mg/kg
0.82
0.86
0.84
0.85
0.75
0.88
0.85
0.85
0.87
0.88
0.88
ND
1
3.7
Zinc
mg/kg
62.00
65.00
56.00
76.00
28.00
66.00
55.00
58.00
62.00
83.00
70.00
52
150
410
Dioxins &
Furans
TEQ
3.03
3.66
1.61
5.72
1.32
2.53
1.84
3.82
2.67
4.07
7.24
1.06
-
-
Total DDTs
ug/kg
16.20
16.80
16.80
16.80
15.00
17.40
16.80
16.80
17.40
17.40
17.40
ND
1.58
46.1
Total
Organotins
ug/kg
0.00
5.60
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
76.30
73.00
83.60
88.50
70.10
82.20
74.50
59.80
89.60
116.80
80.40
344
4022
44792
Total PCBs
ug/kg
28.61
29.00
29.00
30.00
25.00
32.00
27.21
25.00
25.29
26.00
26.59
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
7
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U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
NATIONAL MARINE FISHERIES SERVICE
Pacific Islands Regional Office
1845 Wasp Blvd., Bldg 176
Honolulu, Hawaii 96818
(808) 725-5000¦ Fax: (808) 725-5215
November 27, 2020
Mr. Hudson Slay
U.S. Environmental Protection Agency
Region IX
75 Hawthorne Street
San Francisco, CA 94105
RE: Request for Informal ESA Consultation on the reinitiation of the updates and extensions proposed for the
five existing Hawaii. EPA-designated ocean dredged material disposal sites at O'ahu, Hawai'i, Maui,
and Kaua'i (PIRO-2020-02769)
Dear Mr. Slay:
On June 22, 2020, NOAA's National Marine Fisheries Service (NMFS) received your written request for
reinitiation and concurrence that the U.S. Environmental Protection Agency's (EPA) proposed action to
continue utilizing the five EPA-designated ocean dredged material disposal sites (ODMDS) at O'ahu, Hawai'i,
Maui, and Kaua'i is not likely to adversely affect (NLAA) the 15 endangered or threatened species listed in
Table 2, or designated critical habitat under NMFS' jurisdiction, which includes the designated critical habitat
for Main Hawaiian Islands (MHI) insular false killer whales and Hawaiian monk seals. This response to your
request was prepared by NMFS pursuant to Section 7 of the Endangered Species Act of 1973 (ESA), as
amended (16 U.S.C. §1531 et seq.), implementing regulations at 50 CFR 402, and agency guidance for the
preparation of letters of concurrence.
The Hawaii ocean disposal sites were designated in 1981 based on a 1980 Final Environmental Impact
Statement (EIS) completed by EPA Headquarters. NMFS was consulted during the planning stages for the
designation of the ocean disposal sites for the purposes of dredged material disposal. The previous consultation
included narrowing 14 proposed sites down to the five sites currently in use, and covered the humpback whale,
Hawaiian monk seal and green sea turtle. In that consultation NMFS concluded that the species listed above may
be affected, but not likely adversely affected due to the site depths and infrequent use of the sites. No tracking
number was provided, as EPA does not have a record of NOAA applying tracking numbers during this time
period.
On July 22, 2020, NMFS sent the EPA a request for additional information via email to clarify and add
information to their draft consultation package. The EPA responded on August 16, 2020, with an updated draft.
On September 30, 2020, NMFS sent a second request for additional information via email to clarify the EPA's
effects determinations for the MHI insular false killer whale and their designated critical habitat, the agreement
to add the endangered olive ridley population, and to address the effects of chemical compounds. The EPA
responded on October 2, 2020, and NMFS initiated consultation that day.
This response to your request was prepared by NMFS pursuant to Section 7 of the Endangered Species Act of
1973 (ESA), as amended (16 U.S.C. §1531 et seq.), implementing updated regulations at 50 CFR 402 (84 FR
44976; 10/28/2019), and agency guidance for the preparation of letters of concurrence. We have reviewed the
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information and analyses relied upon to complete this letter of concurrence in light of the updated regulations
and conclude the letter is fully consistent with the updated regulations.
This letter also underwent pre-dissemination review using standards for utility, integrity, and objectivity in
compliance with applicable guidelines issued under the Data Quality Act (section 515 of the Treasury and
General Government Appropriations Act for Fiscal Year 2001, Public Law 106-554. A complete record of this
consultation is on file at the Pacific Island Regional Office, Honolulu, Hawaii.
Proposed Action
The EPA proposes to reinitiate and update their programmatic rule for the continued use of five EPA-designated
ODMDS's at O'ahu, Hawaii, Maui, and Kaua'i and to include the newly listed species and designated critical
habitats not originally covered in the 1981 rule-making. The purpose of this consultation is to allow for the
continuation of sediment dumping at these sites which is critical to national defense, the maritime-related
economy of the State of Hawaii, and for the continued dredging needed in the federally authorized navigation
channels in Hawaii's harbors. It is important to note that this consultation does not cover impacts from the
individual dredging operations, as these actions are separately evaluated, and project-specific consultations are
conducted when needed, by the US Army Corps of Engineers (US ACE) during their permitting process.
The sites will continue to be used only for the disposal of suitable, non-toxic sediment dredged by USACE from
federally authorized navigation channels in Hawaii's harbors, as well as for disposal of suitable, non-toxic
dredged sediment from other permitted navigation dredging projects in Hawaii, including by the US Navy. All
disposal activities at the sites will continue to meet the criteria and factors stated in the Ocean Dumping
regulations published at 40 CFR Parts 228.5 and 228.6. Ocean disposal will also continue to occur under the
terms of a Site Management and Monitoring Plan (SMMP) that sets forth Best Management Practices (BMPs) in
the form of enforceable permit conditions, as well as site monitoring requirements and contingency actions
should any adverse impacts occur.
The Hawaii sites are used differently amongst each other and reflect the differing dredging needs of each island.
Dredged material disposal volumes in Hawaii have had a long-term annual average of approximately 220,000
cubic yards (cy) being disposed at the five sites combined (USACE 2020). Discharge volumes from individual
disposals range from approximately 1,000 cy to as much as 5,000 cy each time (common for USACE hopper
dredging loads). Based on the average annual disposal volumes (142,428 cy) since 2000, this equates to an
average of 28 to 142 individual disposal trips going to all five Hawaii ocean disposal sites combined in any one
year.
The South O'ahu site, which serves US Navy facilities at Pearl Harbor as well as Hawaii's main commercial
port complex in Honolulu Harbor, is the most frequently used, with at least some dredging and disposal
occurring in 22 of the 40 years. On average, disposal at the South O'ahu site accounts for over 80% of all
Hawaii disposal. In recent years (since 2000), Hilo and Nawiliwili have been the next most frequently used sites
(receiving approximately 9 and 8% of the total material, respectively), followed by Kahului (approximately
2%). There has been no dredged material disposal at the Port Allen since 1999, however some disposal may
occur in 2021.
There are no seasonal disposal restrictions on use or no annual disposal volume limits at any of the sites.
However, the EPA and/or USACE may place volume limits and seasonal or other restrictions in individual
project's permits or authorizations if deemed necessary. Alternatives to ocean disposal (including beneficial
uses) are considered on a project-by-project basis to ensure that the minimum necessary volume of dredged
material is disposed at any ODMDS. Each site is restricted to the authorized disposal of suitable dredged
material only. The suitability of dredged material for ocean disposal is determined based on criteria in the
MPRSA and in EPA's Ocean Dumping Regulations (40 CFR Part 227). EPA and USACE have a joint national
sediment testing manual titled Evaluation of Dredged Material Proposedfor Ocean Disposal (EPA and
USACE, 1991), or the Ocean Testing Manual or OTM. The OTM details the testing and sampling methods
needed to comply with the MPRSA and EPA's regulations. The Marine Protection, Research and Sanctuaries
Act (MPRSA) and EPA regulations call for careful alternatives analysis and BMPs to reduce or eliminate
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potential adverse effects to marine resources. Importantly, the regulations only allow for suitable, non-toxic
sediments to be discharged at EPA-designated ocean disposal sites; even when sediment is suitable for ocean
disposal, it is only approved when there is no practicable alternative.
EPA's regulations also establish strict criteria for evaluating whether dredged material is suitable for ocean
disposal (40 CFR Part 227.5-9). The regulations specify that certain prohibited constituents (for example,
industrial wastes or high-level radioactive wastes) may not be disposed in the ocean, while other constituents
such as organohalogen compounds or mercury, may only be discharged if they are present in no more than
"trace" amounts that will not cause an unacceptable adverse impact after dumping. "Trace" is determined by
passing a series of bioassays that address the potential for short- and long-term toxicity and bioaccumulation.
Among sediment testing prior to disposal, careful site selection, and disposal alternative evaluations, the EPA
actively takes additional management measures at the sites to further minimize adverse effects to the marine
environment once a dredging project has been approved for ocean disposal. These measures, outlined in the
SMMP and in the Mandatory Disposal Site Use Conditions (2015) for the Hawaii sites (see Appendix B),
include:
• a variety of disposal BMPs as enforceable permit conditions for each project;
• satellite tracking all disposal vessels to ensure that disposal activities occur only where and as required;
ensors on all disposal vessels to ensure that there is no significant leakage or spilling of dredged material
during transit to the disposal site, especially during transit through the nearshore zone where corals,
seagrasses, and sensitive animals are most likely to be present; and
• tracking and sensor information reported online for each disposal trip.
Recent Monitoring Results
The EPA recently completed monitoring surveys within the past decade at each of the five Hawaii ocean
disposal sites. Multiple stations "inside" and "outside" the disposal site were tested. The South O'ahu and Hilo
sites (the most heavily used of the Hawai'i sites) were first monitored in 2013 and results were summarized in a
2015 Hawaii. Ocean Disposal Site Monitoring Synthesis Report. The EPA updated the SMMP for all the Hawaii
sites in 2015 based on these monitoring results. Similar monitoring surveys were also completed for the
Nawiliwili, Port Allen, and Kahului sites in 2017, and the SMMP for these sites will be updated again based on
those monitoring results and on the outcome of this ESA and EFH consultation with NMFS.
2013 chemical results, as summarized in the 2015 Hawaii. Ocean Disposal Site Monitoring Synthesis Report
Substrate: The EPA observed that the South O'ahu site had substantially more gravel, more fines (silt and clay),
and higher organic carbon, but was determined by the EPA that these findings would not result in significant or
adverse impacts. At the Hilo site, the dredged material has not substantially altered the physical nature of the
disposal site.
Chemical: Most of the chemistry data showed low but also variable concentrations of most chemical
constituents at both sites. At both inside and outside the disposal sites, four to six metals were at concentrations
above NOAA's effects-based 10th percentile screening value (ER-L), below which adverse effect are predicted
to rarely occur (NOAA, 2008). Only chromium, copper, and mercury were shown to be slightly higher inside
the disposal boundaries compared to the outside stations at the South O'ahu site. At Hilo, they're levels were
almost indistinguishable between inside and outside stations.
Nickel exceeded its 50th percentile screening value (ER-M), above which adverse effects are expected to occur
(NOAA, 2008). It was greatest at the Hilo site, but was at similar elevated concentrations at both inside and
outside the site. Organic constituents were also low at both sites, and there were no exceedances of ER-Ls for
organics at either "inside" or "outside" stations at the Hilo site. Only two constituents exceeded NOAA ER-L
screening levels, and only at the South O'ahu site. Polychlorinated biphenyls (PCBs) and
dichlorodiphenyltrichloroethanes (DDTs) slightly exceeded their respective ER-Ls at one inside station and one
outside station. PCBs were generally higher at the inside stations, even when not exceeding the ER-L.
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Benthic Community: As noted above, some physical changes (e.g., grain size and organic carbon content) were
apparent at stations with dredged material. However, overall abundances of different organism classes, while
low, were not statistically different between inside and outside stations at either disposal site (EcoAnalysts, Inc.,
2014).
Diversity was high at the South O'ahu site but abundances tended to be low at all stations monitored. Diversity,
abundance, or species richness were not significantly different between stations both outside and inside the
disposal site. The EPA determined that this presented no evidence that the dredged material disposed here has
negatively impacted the benthic communities at the South O'ahu ODMDSs sampled.
At the Hilo site, the EPA also concluded that there were no significant differences in diversity between inside
and outside stations. As similarly identified at the South O'ahu site, diversity was high while abundances were
low. Based on these results, the EPA determined that there has been no evidence that dredge material is
negatively impacting the benthic communities at the Hilo ODMDS, with the exception of the expected low
abundances due to physical impacts from rubble disposed at the center of the site.
Compared to the baseline conditions in 1980, the 2013 monitoring results indicate a lack of significant adverse
impacts. Based on these findings, the EPA has determined that disposal activities that have occurred at these two
sites since 1981 have resulted in only minor and localized physical changes. Overall, these findings suggest that
the continuing disposals at both sites should similarly result in no significant adverse impacts. EPA has stated
that permit conditions should be updated in the revised SMMP, and a more specific site monitoring schedule
should be established for the future. However, based on all the monitoring results, no significant changes to
sediment testing or to the overall site management framework appear to be needed for these sites.
Preliminary chemistry results from the 2017 Monitoring Survey of the Nawiliwili, Kahului, and Port Allen
Ocean Disposal Sites
Dredged sediment testing was conducted in 2017 at the Nawiliwili, Kahului, and Port Allen sites and the
preliminary results were included in the EPAs consultation request package. In summary, all three disposal sites
presented elevated levels of arsenic and total DDTs that exceeded NOAA's ER-L but did not exceed the ER-M
screening. The Nawiliwili site also showed traces of chromium that exceeded the ER-L, and the Port Allen site
showed traces of copper and total PCBs that exceeded the ER-L. In addition, testing results at all three sites also
identified elevated levels of nickel that exceeded the ER-M.
Action Area
The action area for the proposed disposal activities encompasses five EPA-designated ODMDSs located off the
islands of O'ahu, Hawaii, Maui, and Kaua'i, and the area transited to and from those sites (Figure 1). The EPA
developed criteria for avoiding impacts to the marine environment and to human uses of the ocean to the
maximum extent possible as part of their disposal site designation process, within an economically feasible
transport distance from the area where navigation dredging must occur. All of the Hawaii ODMDSs are in
relatively deep water. Each site ranges from 4 to 6.5 nautical miles (nmi) offshore in water depths that range
from 1,100 to 5,300 feet (ft) (330 to 1,610 meters [m]). Each site includes a small Surface Disposal Zone (SDZ)
within which all disposal actions must take place, and a larger site boundary on the seafloor where most of the
sediment is intended to deposit after falling through the water column (Table 1). To date, the total disposal
volumes for all five sites between the years of 1981 and 2020 have equaled to 8,837,230 cy.
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.-^npuv
JfKAUAl
¦ •
oovtos
» Nawiiwil' ODMDS
Port Allen OOVOS
OaHuODMDS
jrr:
®y^v
Kaiului ODMDS
vli
MAUI
.
VJ^B) ?1' Hlo ODMDS
rtAVVATW »
w&Wm
w/f 4s !
Figure 1. Map showing the five existing disposal sites (provided by EPA).
Table 1. Dimensions and center coordinates for Hawaii ocean disposal sites and their SDZs (provided by EPA).
Disposal Site
Depth Range
Shape and
Dimensions
(Seafloor
Footprint)
Surface Disposal
Zone (SDZ)
Dimensions
Center
Coordinates
(NAD 83)
South O'ahu
375-475 m
Rectangular, 2.0
(W-E) by 2.6 km
(N-S) (1.08 by
1.4 nautical
miles [nmij)
Circular, 305 m
radius
21° 15' 10" N,
157° 56' 50" W
Hilo
330-340 m
Circular, 920 m
radius
Circular, 305 m
radius
19° 48' 30" N
154° 58' 30" W
Nawiliwili
840-1,120 m
Circular, 920 m
radius
Circular, offset
200 m (600 ft)
radius: [21° 55'
15" N; 159° 17'
13.8" W]
21° 55' 00" N
159° 17' 00" W
Port Allen
1,460-1,610 m
Circular, 920 m
radius
Circular, 305 m
radius
21° 50' 00" N
159° 35'00" W
Kahului
345-365 m
Circular, 920 m
radius
Circular, 305 m
radius
21° 04' 42" N
156° 29' 00" W
Listed Species
The ESA-listed threatened and endangered species under NMFS' jurisdiction listed in Table 2 are known to
occur, or could reasonably be expected to occur, in the action area, and may be affected by the proposed
activities. Detailed information about the biology, habitat, and conservation status of the animals listed in Table
-------
2 can be found in their status reviews, recovery plans, federal register notices, and other sources at
https://www.fisheries.noaa.gov/topic/endangered-species-conservation.
Table 2. Common name, scientific name, ESA status, effective listing date, and Federal Register reference for ESA-listed
species considered in this consultation.
Species
Scientific Name
ESA Status
Effective
Listing Date
Federal
Register.
Reference
Green Sea Turtle
Central North
Pacific
Chelonia mydas
Threatened
05/06/2016
81 FR 20057
Hawksbill Sea
Turtle
Eretmochelys imbricata
Endangered
06/03/1970
35 FR 8491
Loggerhead Sea
Turtle North Pacific
Caretta caretta
Endangered
10/24/2011
76 FR 58868
Olive Ridley Sea
Turtle
Lepidochelys olivacea
Threatened
08/27/1978
43 FR 32800
Olive Ridley Sea
Turtle, Mexican
Nesting Population
Lepidochelys olivacea
Endangered
08/27/1978
43 FR 32800
Leatherback Sea
Turtle
Dermochelys coriacea
Endangered
06/03/1970
35 FR 8491
Hawaiian Monk
Seal
Neomonachus
schauinslandi
Endangered
11/23/1976
41 FR 51612
Blue Whale
Balaenoptera musculus
Endangered
12/02/1970
35 FR 18319
Fin Whale
Balaenoptera physalus
Endangered
12/02/1970
35 FR 18319
Sei Whale
Balaenoptera borealis
Endangered
12/02/1970
35 FR 18319
Sperm Whale
Physeter macrocephalus
Endangered
12/02/1970
35 FR 18319
North Pacific Right
Whale
Eubalaena japonica
Endangered
04/07/2008
73 FR 12024
False Killer Whale
Main Hawaiian
Island Insular
Pseudorca crassidens
Endangered
12/28/2012
77 FR 70915
Oceanic Whitetip
Shark
Carcharhinus longimanus
Threatened
03/01/2018
83 FR 4153
Giant Manta Ray
Manta birostris
Threatened
02/21/2018
83 FR 2916
Critical Habitat
Hawaiian monk seals
9/21/2015
80 FR 50925
Main Hawaiian Island Insular false killer whales
8/23/2018
83 FR35062
Critical Habitat.
In designated areas of the Main Hawaiian Islands (MHI), critical habitat for monk seals includes the marine
environment with a seaward boundary that extends from the 200-m depth contour line (relative to mean lower
low water), including the seafloor and all subsurface waters and marine habitat within 10-m of the seafloor,
-------
through the water's edge 5-m into the terrestrial environment. Detailed information on Hawaiian monk seal
critical habitat can be found at https://www.fisheries.noaa. gov/species/Hawaiian-monk-seal#conservation-
management.
The essential features for the conservation of the Hawaiian monk seal are the following:
1. Terrestrial areas and adjacent shallow, sheltered aquatic areas with characteristics preferred by monk
seals for pupping and nursing;
2. Marine areas from 0 to 200 m in depth that support adequate prey quality and quantity for juvenile and
adult monk seal foraging; and
3. Significant areas used by monk seals for hauling out, resting or molting.
Critical habitat for Main Hawaiian Island insular false killer whales includes the geographic area of the 45-m
depth contour to the 3200-m depth contour in waters that surround the Main Hawaiian Islands from Niihau east
to the Island of Hawaii . Critical habitat for the main Hawaiian Islands insular false killer whale consists of one
essential feature comprised of four characteristics:
1. Space for movement and use within shelf and slope habitat
2. Prey species of sufficient quantity, quality, and availability to support individual growth, reproduction,
and development, as well as overall population growth;
3. Waters free of pollutants of a type and amount harmful to MHI IFKWs; and
4. Sound levels that would not significantly impair false killer whales' use or occupancy.
Detailed information on Main Hawaiian Islands insular false killer whale critical habitat can be found at:
https://www.f1sheries.noaa.g0v/species/false-killer-whale#conservation-management.
Analysis of Effects.
In order to determine that a proposed action is not likely to adversely affect ESA-listed species, NMFS must
find that the effects of the proposed action are expected to be insignificant, discountable1, or completely
beneficial. As defined in the joint USFWS-NMFS Endangered Species Consultation Handbook, beneficial
effects are contemporaneous positive effects without any adverse effects to the species. Insignificant effects
relate to the size of the impact and should never reach the scale where take occurs2. Discountable effects are
those extremely unlikely to occur. Based on best judgment, a person would not: 1) be able to meaningfully
measure, detect, or evaluate insignificant effects; or 2) expect discountable effects to occur (USFWS & NMFS
1998). This standard, as well as consideration of the probable duration, frequency, and potential for interactions,
was applied during the analysis of effects of the proposed action on ESA-listed marine species, as is described in
the consultation request.
The EPA has identified the following stressors that have the potential to affect listed marine species in the action
area:
• Elevated turbidity levels;
• Contaminants/bioaccumulation
NMFS has identified the additional following potential stressors:
• Exposure to wastes and discharges
1 When the terms "discountable" or "discountable effects" appear in this document, they refer to potential effects that are found to
support a "not likely to adversely affect" conclusion because they are extremely unlikely to occur. The use of these terms should not be
interpreted as having any meaning inconsistent with our regulatory definition of "effects of the action."
2 Take" is defined by the ESA as harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect any threatened or endangered
species. NMFS defines "harass" as to "create the likelihood of injury to wildlife by annoying it to such an extent as to significantly
disrupt normal behavioral patterns which include, but are not limited to, breeding, feeding, or sheltering." NMFS defines "harm" as
"an act which actually kills or injures fish or wildlife." Such an act may include significant habitat modification or degradation where
it actually kills or injures fish or wildlife by significantly impairing essential behavioral patterns, including breeding, spawning,
rearing, migrating, feeding or sheltering. Take of species listed as endangered is prohibited at the time of listing, while take of
threatened species may not be specifically prohibited unless NMFS has issued regulations prohibiting take under section 4(d) of the
ESA.
-------
• Disturbance and physical impact from equipment (vessel and disposal operation); and
• Vessel collision
Elevated turbidity levels
Turbidity is a term which describes the optical properties that cause light to be observed or scattered within the
water column and is related to the concentration of suspended sediments whether inorganic, organic, or artificial
(Birtwell 1999). Kjellad et al. (2015) determined after extensive literature review that the long term affects to
aquatic species are not well understood but are important to determine exposure limits and thresholds which
could potentially alter relevant population dynamics. By understanding these principles, mitigation strategies
and measures can be employed to reduce the affects to these populations (Kjellad et al. 2015). It should be noted
that much of the literature on the effects of suspended sediments and turbidity to aquatic animals focuses on
fresh water systems and biota, particularly salmonids. However, some resounding themes provide clarity on the
important aspects which affect aquatic organisms. As Birtwell (1999) describes, the European Inland Fisheries
Advisory Committee (EIFAC) determined five mechanisms which can deleteriously affect aquatic organisms
which in turn established defined threshold levels based on concentrations of suspended sediments and can be
applicable to marine species as well. These mechanisms are (EIFAC 1964):
• The reduction in the resistance to disease, growth rate, or mortality of the individual animal subjected to
the concentration;
• the prevention of the normal developmental processes of eggs and/or larvae;
• modification of an animal's migration or movement patterns;
• decrease in the abundance or quality of forage; and
• affecting the ability of an animal to successfully capture prey.
These mechanisms are further substantiated by literature produced by the U. S. EPA (Berry et al. 2003; U.S.
EPA 2012). Furthermore, turbidity can also reduce the concentration of dissolved oxygen in the water, and
increase water temperatures as suspended particles absorb heat. Reductions in dissolved oxygen can cause
behavioral responses such as increased air breathing or surface respiration, alterations in an animal's activity, or
changes in the vertical or horizontal use of the habitat (Kramer 1985).
For species under consideration in this consultation, sub-lethal effects must be considered as well. These effects
can be a result or reflection of stress and could pertain directly to the individual, the species, or to a mechanism
of their survival by alteration in their respective trophic pathway(s). Sub-lethal effects would be more applicable
to the species under consideration as they are higher on the food chain and may not be subjected to direct
impacts of increased sedimentation in the water column. Sub-lethal effects have been described in detail and
include variables such as gill trauma to fish (Servizi and Martens 1987; Hess et al. 2015), increased chance of
predation (Mesa et al. 1994; Birtwell et al. 1999; Chivers et al. 2013), decreased feeding efficiency and growth
rates of invertebrates (i.e. food sources) (Hynes 1970; Tjensvoll et al. 2015; Pineda et al. 2017), alterations in
social behaviors, disrupted feeding patterns, displacement, and increased susceptibility to disease (Scriverner et
al. 1994), delayed coral reef fish larval development (Wenger et al. 2014), transgenerational effects (Kjellad et
al 2015), alterations of habitat complexity by the reduced ability for coral recruitment (i.e. effects to coral
larvae, shading, etc.) to occur (Rogers 1990; Jones et al. 2015), coral reef community responses (Pastorok and
Bilyard 1985; Erftemeijer et al. 2012), and finally, the compromise of an individual's normal physiological
performance (Farrell et al. 1998; Jain et al. 1998). Many sub-lethal effects can be considered trait mediated
indirect interactions and are described in an ecological context by Peacor and Werner (2001) and Werner and
Peacor (2003). While not an exhaustive review of all literature on this topic, this consultation attempts to define
mechanisms and pathways which can potentially affect those species listed in Table 2 using the best scientific
data available.
Species considered in this consultation would potentially be exposed to increased sediment loads and thus
higher levels of turbidity within the water column by the proposed action, which could cause a range of effects
such as these, if mitigation measures were not implemented. It is important to also clarify that natural events
such as rain, floods, tidal events and cycles, storms, etc., occur regularly which increase sediment loads to the
nearshore environment and/or ocean. Effects to these species could be variable depending on the length of
-------
exposure, the concentration of the sediment within the water column - referring to the severity of the exposure,
and the frequency of exposure, or as Wilber and Clarke (2001) declare as the "scope, timing, duration, and
intensity."
Regarding the direct effects of increased turbidity, given that listed sea turtles and marine mammals breathe air,
increased turbidity will not affect their respiration. Although turtles are sometimes observed in turbid areas, it is
possible that they will temporarily avoid any localized turbidity plumes in favor of clearer water, reducing
exposure risk. Marine mammals are also capable of quickly leaving unsuitable areas if they so choose.
Determining whether an animal moves from an area based on an increased turbidity concentration or a
conscious decision for various other reasons is speculative at best.
We would not expect turbidity or increased sediment loads to affect the development process of eggs, larvae, or
the reproductive capacities of the species under consideration. The exposure interval for this proposed activity is
expected to be of minimal duration in context of the species life histories and may or may not coincide with
reproduction activities either temporally or spatially when considering species like the oceanic whitetip shark, or
the giant manta ray. Elasmobranches, like the giant manta ray have been known to congregate for reproduction
or pupping purposes (Duncan and Holland 2006; Miller and Klimovich 2016). However, we do not expect the
turbidity created by the proposed action to interfere or affect those species in those areas during the time interval
they congregate for these purposes, as these species are highly mobile and will likely avoid the disturbance
caused by sediment dumping if in the action area. Additionally, neither the giant manta ray nor the oceanic
whitetip shark have documented congregations for reproduction purposes in the proposed action area.
Sea turtles lay eggs onshore, marine mammals either pup onshore or give live-birth in an open ocean
environment, and the ESA-listed elasmobranches are viviparous. We would not expect these species to produce
offspring or mate within the action area during the proposed event. Furthermore, we would not expect the
concentration of sediments to elicit mortality in the species under consideration as they are regularly exposed to
natural events of greater severity and are not affected.
Due to the proposed action's footprint, short duration of activities that would cause turbidity, and the species'
ranges and distributions, we do not expect the action to produce an effect that would alter or prevent any ESA-
listed animal from altering their migration or movement patterns. While species may avoid perturbations, such
as those resulting from the proposed disposal activities, we would not expect the action to create a situation that
would stop an animal from foraging or traveling. The species under consideration are highly mobile and
typically have ample opportunities and large ranges to forage. Exposure in the water column is temporary, and
all the Hawaii disposal sites are offshore, in relatively deep water, where initial dilution is even more rapid and
disposal plumes dissipate to background levels quickly. Cumulative water column effects are not expected
because discharges from disposal vessels typically occur over only a few minutes, and individual disposal events
are at least several hours apart, even in the most active circumstances. Finally, the disposal volumes are
relatively low and infrequent across the five Hawaii sites. Considering these factors, we would not expect
migration activities or corridors to be affected by the proposed action. Thus, we would not expect turbidity
created from this proposed project to alter migration or movement patterns of these species.
Additionally, we would not expect any elevated turbidity resulting from this proposed action to affect any ESA-
listed animal's ability to capture prey. Elevated turbidity levels such as those expected from the proposed action
are not expected to create long-term affects to these species by altering the normal trophic structure within the
immediate area (i.e. alterations in algae composition or species, reduced ability to identify prey, etc.) (Weiffen et
al. 2006; Chivers et al. 2013). Ambush predator species, such as the oceanic whitetip shark, may even be
attracted to the turbidity plumes from disturbance, thus benefiting from the turbidity. Furthermore, we would not
expect this proposed activity to create a significant effect based on use of all established BMPs and adherence to
Federal mandates required for this project to be implemented.
In summary, the amount of material (i.e. sediment) mobilized is expected to be localized, short-lived (only
lasting two to four minutes at the surface), and given limited exposure, potential effects would be unlikely to
result in take or a quantifiable effect, as such effects would be within the range of normal behaviors that would
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not alter their ability to grow and reproduce for those species under consideration. Such effects to ESA-listed
species from turbidity from the proposed action are therefore insignificant.
Lastly, the boundary for the MHI insular false killer whale critical habitats overlaps with the five disposal sites
and the turbidity caused from disposals may affect the four essential features of MHI insular false killer whale
critical habitat. However, all the Hawaii disposal sites are limited in size (for example, the Surface Disposal
Zones where all disposal must occur are generally only about 0.11 square mile in area). The disposal sites are in
deep, open water where disposal plumes will dissipate quickly, and disposals typically occur over only just a
few minutes in duration and are several hours apart from each other. For these reasons, the potential for adverse
effects to components of MHI insular false killer whale critical habitat (space for movement, prey availability,
waters free of pollutants, and sound levels) is considered discountable. Turbidity will have no effect on
Hawaiian monk seal critical habitat, as the critical habitat boundaries do not overlap with any of the five
disposal sites.
Contaminants/bioaccumulation
Disposal activities may expose listed species to toxic metals contained within the dredged sediment. Data from
the surveys conducted in 2013 confirm the presence of multiple chemicals in the dredged material used for
disposal, some of which exceed NOAA's 50th percentile screening value (such as nickel). Contaminants
contained within the sediment plumes could pass through the gills of listed species such as oceanic whitetip
sharks. Contaminants may also bioaccumulate directly into an animal's tissue, or in prey items such as plankton
and other bony fish and move its way up the food chain.
For example, a previous study by Mongillo et al. (2016) assessed the effects of toxic chemical exposure on the
endangered Southern Resident killer whales. Tissue samples were analyzed to assess how contaminants were
affecting the health of the species. The high levels of contaminants such as PCBs, polybrominated diphenyl
ethers (PBDEs), and DDTs in Southern Resident killer whales have multiple health consequences that are
correlated with stressors such as abundance of prey (Chinook salmon), interactive effects of contaminant
mixtures, and the vulnerability of life stages. Chinook salmon are an important summer food source for this
species of killer whale, and based on the fish's geographic range and evidence of contaminant levels, they are
likely also a main source of contaminants to the Southern Residents. It's suggested that the high levels of
contaminants in these salmon populations may be great enough to negatively impact the overall health of the
fish and to indirectly affect the killer whales' food source (Mongillo et al. 2016). Although the health
implications to transient killer whales are not discussed (which generally have higher persistent organic
pollutant [POP] levels than resident killer whales), the stressors affecting Chinook salmon are expected to be
similar in the Southern Residents. Thus, the high levels of PCBs, PBDEs, and DDTs are thought to be a growing
concern despite data gaps and insufficient data to indicate that Southern Residents are experiencing adverse
health effects from POP exposure. Research conducted within the past decade has confirmed that the high levels
of contaminants and limited prey have become a prioritizing threat, but cannot be addressed without a more
long-term commitment.
Although this is a main issue for Southern Residents, and may be a similar growing concern we see for MHI
insular false killer whales, the issue with Southern Residents is different. These individuals are eating prey who
spend a portion of their time in estuaries that were superfund sites for many decades. Further, the EPA disposal
sites are far offshore and in deep water where the false killer whales' primary prey feed and are not in superfund
sites. There would need to be significant exposure and extreme circumstances, along with enough data to
suggest that bioaccumulation is occurring at a level that is adversely affecting individuals, and thus would be
discountable.
Despite these concerns, the EPA confirms that all five Hawaii ODMDSs are restricted to the authorized disposal
of suitable dredged material, only. The suitability of dredged material for ocean disposal is determined based on
criteria in the MPRSA and in the EPA Ocean Dumping Regulations (40 CFR Part 227). The EPA and USACE
have published a joint national sediment testing manual entitled Evaluation of Dredged Material Proposedfor
Ocean Disposal (EPA and USACE, 1991), also known as the Ocean Testing Manual (OTM). As a critical
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component of site management, EPA also periodically conducts surveys of disposal sites to confirm that only
physical effects occur within site boundaries, and that no adverse, physical, chemical, or biological effects occur
outside the disposal site.
Only suitable, non-toxic, dredged material is permitted to be disposed. Strict pre-dredging testing occurs to
determine the suitability of material for disposal. Sediments that contain pollutants in toxic amounts, or that
contain elevated levels of compounds that will readily bioaccumulate into tissues of organisms exposed to them
on the seafloor, are prohibited from being discharged. Water column assessments must confirm that temporary
exposure to the suspended sediment immediately following disposal will not exceed applicable marine water-
quality criteria or cause toxicity to representative sensitive marine organisms after allowance for initial mixing
and dilution.
The potential for contaminants to move from the sediment into the food web must be evaluated in advance for
each dredging project. Bioaccumulation testing examines persistence, toxicity, and bioaccumulation to ensure
that material disposed will not cause any adverse impact to listed species post-dumping and ensures that trophic
cascades are unlikely. Bioaccumulative contaminants are selected/evaluated by the EPA for each project based
on their presence in the test sediment. They expose the benthic organisms to the sediment, usually for 28 days,
and tissues are measured for the contaminants concentrations. The tissue concentration results are then
compared against concentrations in tissues of the same species exposed to the reference sediment.
In addition to these measures, each disposal events only last two to four minutes at the surface, is occurring in
deep/open water, and any plume that forms within the upper water column usually dissipates quickly. Sediments
whose plumes would result in any toxicity to sensitive water column organisms after initial mixing are not
authorized for ocean disposal. Given the short duration of each disposal event, low toxicity in the water column,
we would not anticipate adverse effects to filter feeders and other species that may be exposed to the toxic
chemicals.
Furthermore, the 2017 preliminary screening data indicated that the majority of chemical concentrations fell
below the ER-L, similar to the South O'ahu and Hilo sites, and the few concentrations above screening levels
(ER-M) were relatively minor in magnitude and, in most cases, were seen at stations both inside and outside the
sites. Therefore, the concentrations of contaminants found within the sediment plumes are not expected to cause
adverse effects to listed species. As confirmed by EPA monitoring and modeling, no short or long-term
contaminant exposure concerns are associated with the discharged sediment.
Additionally, the animals and their prey would only potentially be exposed for a brief amount of time and only
on those occasions when dumping occurs. The sediments are expected to remain at the bottom of the dump sites
for the foreseeable future and any contaminants that are present would not be expected to affect any of the ESA-
listed species listed in table 2, or any feature of any designated critical habitat. Thus, any indirect and direct
effects to the ESA-listed species in Table 2 or to its water column prey species are determined insignificant.
The boundaries for the MHI insular false killer whale critical habitats overlap with the disposal sites and
contaminants may negatively affect the essential features. However, the action will not degrade the essential
features of critical habitat because the level of contaminants are not high enough to reduce the quality of the
water column, nor high enough to reduce the quality of the prey base or poison them which would indirectly
harm individuals that use that habitat. Therefore, the potential for contaminant exposure to result in adverse
effects to prey availability and waters free of pollutants is considered discountable. This stressor will have no
effect on the sound levels or space for movement essential features. The presence of toxic chemicals will also
have no effect on Hawaiian monk seal critical habitat, as the critical habitat boundaries do not overlap with any
of the five disposal sites.
Exposure to wastes and discharges
Equipment spills, discharges, and run-off from vessels transiting to the disposal site and in the project area could
contain chemicals such as fuel oils, gasoline, lubricants, hydraulic fluids and other toxicants, which could
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expose ESA-listed species. Depending on the chemicals and their concentration, the effects of exposure may
range between animals temporarily avoiding an area to death of the exposed animals. Vessel staff are expected
to adhere to applicable BMPs pertaining to the elimination of discharges and waste, and would have
contingency response protocols for accidental leaks, spills, and discharges aboard their vessels.
The EPA has strong enforcement authority under the Marine Protection, Research and Sanctuaries Act (MPRS)
for disposal violations. Such violations may include: dumping unauthorized materials, unauthorized excess
dumping, dumping outside of designated sites, and spills or leaks from hopper dredges or scows during transit.
If any violations occur, the permit may be revoked or suspended. Even if the permit is not revoked, the MPRSA
authorizes EPA to require ocean dumping activities to cease immediately when violations are imminent or
continuing. EPA may even suspend the use of the ocean disposal site altogether, if necessary. In addition to
ensuring that ongoing violations are stopped, EPA may impose monetary penalties when ocean dumping
violations occur.
According to the SMMP, the permittee will also ensure that dredged material is not spilled or leaked from
disposal vessels during transit to the five ODMDSs. EPA will ensure the use of a Grizzly (steel mesh to catch
large debris) to prevent large uncharacterized material such as trash, vessels, and other dredged debris from
being discharged at the disposal sites. Transportation will only be authorized when weather at sea conditions are
safe and will not result in risk of leak, spillage, or the loss of any other dredged material. The permittee will also
report any actual, potential, or anticipated variances from compliance with the Standard Conditions, and any
additional project-specific Special Conditions, to EPA Region IX and the Honolulu District USACE within 24
hours of discovering such a situation.
Each disposal vessel is also closely tracked during transit through the nearshore zone. This tracking includes
sensors to detect any substantial leaking or spilling of material that could increase turbidity and suspended
sediment near sensitive habitats, such as corals and seagrasses. Disposal vessels that leak or spill must be
removed from service and repaired before being approved for continued use.
Moreover, it is anticipated that leaks or spills would be infrequent, small, and quickly cleaned. Any resulting
discharges would be at extremely low concentrations, exposure to which is expected to cause no effect on an
exposed individual's health, and result in no behavioral response. Potential exposure to wastes and discharges
resulting from the proposed project would therefore have insignificant effects on ESA-listed marine species
under NMFS' jurisdiction identified in Table 2.
MHI false killer whale critical habitat may be negatively impacted by the effects of discharges and waste at the
disposal sites, and Hawaiian monk seal critical habitat may be negatively impacted by the effects of discharges
and waste during vessel transit. However, with the adherence to SMMP and measures discussed above, the
effects from this stressor will be discountable.
Disturbance and physical impact from equipment (vessel and disposal)
The majority of the sounds generated from this project will be from vessel movement and disposal events. ESA-
listed species will be exposed to short periods of noises from moving parts of the equipment, noise and physical
contact of the sediment being dumped in the water, and vessel motors. However, we expect minimal risk from
behavioral changes by these species' exposure to sounds generated during disposal events and vessel transit.
ESA-listed species may respond to these noises by avoiding, halting their activities, experience reduced hearing
by masking, or attraction to source noises; although the true cause of those anticipated behavior responses are
unclear since animals can use other cues such as vision to trigger behavior response. Avoidance is most likely,
and a common natural reaction by ESA-listed species and considered low risk. ESA-listed species are large,
highly mobile, and capable of swimming away safely from any disturbance that would harm them. Response by
a listed vertebrate species to any potential disturbance by vessel noise generation or vessel movements expected
to be implemented would be limited to temporary avoidance with no injury to the individual.
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ESA-listed species are also at risk of injury from physical impact from dumped sediment if present at the surface
in the action area during disposal events. However, these species are highly mobile and will likely avoid the area
from an approaching vessel before any sediment is disposed. In the rare case that an animal is physically struck
with sediment, it is unlikely that this action will be adverse to result in the level of take. Therefore, it is highly
unlikely that any such disturbances would cause any measurable behavioral effects to any ESA-listed species
under NMFS' jurisdiction identified in Table 2, and would thus be insignificant.
Lastly, disturbance from vessel transits from port may affect the essential features of Hawaiian monk seal
critical habitat and disrupt monk seal pupping, nursing, and foraging, as well as adjacent and significant shallow
areas used by monk seals for hauling out, resting or molting. However, due to the infrequent use of the disposal
sites and adherence to slow vessel speeds, effects to these essential feature are discountable. This stressor will
also have no effect on any of the MHI insular false killer whale critical habitat essential features.
Vessel collision
The proposed action would expose all ESA-listed marine species under NMFS' jurisdiction found in Table 2 to
the risk of collision with vessels during transit to disposal sites. Depending on the severity of contact, the
collision could cause injuries including bruising, broken bones or carapaces, lacerations, or even death in severe
cases.
While specific studies have not been conducted for oceanic white tips or giant manta rays for vessel avoidance,
they are elasmobranchs and are highly mobile species. Giant manta rays in particular are known to rest near the
surface. However, while the function of the lateral line in manta rays is poorly understood, they also have a suite
of other biological functions which are considered highly sophisticated sensory systems (Bleckmann and
Hoffmann 1999; Deakos 2010). This suggests that they possess capabilities of detection and could avoid slow
moving vessels as well.
Given the high vessel traffic volume around Hawaii, collisions between turtles and vessels are relatively rare
events. NMFS conservatively estimated 37.5 sea turtle and 0.45 Hawaiian monk seal vessel strikes and
mortalities per year from an estimated 577,872 vessel trips per year in Hawaii . This includes fishing and non-
fishing vessels (NMFS 2008). This calculates to a 0.006% probability of a vessel strike with sea turtles for all
vessels and trips, many of who are not reducing speeds or employing lookouts for ESA-listed species.
In addition, Vanderlaan and Taggart (2007) report that the severity of injury to larger whale species is directly
related to vessel speed. They found that the probability of lethal injury increased from 21% for vessels traveling
at 8.6 knots, to over 79% for vessels moving at 15 knots or more. We assume collisions at higher speeds would
result in more severe injuries for all animals.
There are data suggesting that the probability of vessel collisions between whales and vessels associated with
this action would be more uncommon than that of sea turtle vessel strikes. Lammers et al. (2013) estimated at
most, the risk was 7 humpback whale strikes per year, which is less than 1/5 of the number reported for sea
turtles (or 2/5 if you consider that humpback whales are in Hawaii, for half the year). Lammers et al. (2013) also
noted that most strikes occurred in February and March, which is the peak of the humpback whale season in
Hawaii . This increases the odds of a vessel strike. Furthermore, most recorded vessel strikes occurred with
calves. These trends are relevant because they represent a biased rate of collision.
False killer whales commonly travel in pods and are known to approach vessels and ride the bows of vessels.
The density of MHI insular false killer whales is expected to be very low along the transit routes closer to ports
but higher around the disposal sites since these whales are generally found in deeper areas just offshore, (median
preferred depth is 1679 m) rather than nearshore areas (Baird et al. 2010; Baird et al. 2012). However, we have
little to no data on vessel strikes on false killer whales, but false killer whales are much more agile than baleen
whales and few have been reported. False killer whales are also highly mobile and have adequate space to avoid
possible collision. Thus, we expect the probability of vessel strikes of false killer whales to be low.
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In addition, EPA-required satellite tracking confirms that disposal vessels typically travel at maximum speeds of
6 to 8 knots when transiting the approximate 4 to 6.5 nmi from harbor dredging locations to the Hawaii ocean
disposal sites. These speeds are consistent with vessel speed limitations recommended by NMFS to minimize
vessel strikes to whales. Vessels also slow to nearly a stop during disposal activities. The disposal sites are
several miles offshore in deep water, where there is more space for species to avoid the vessels, and generally
fewer foraging areas for certain listed species such as sea turtles. Due the slow speeds to be used during most
operations, depths at the sites, temporary nature of the disposal events, and the expectation that ESA-listed
marine species would be widely scattered throughout the proposed areas of operation and avoid the disturbance,
the potential for an incidental boat strike is extremely unlikely to occur. Thus, the effects of this stressor to any
ESA-listed marine species under NMFS' jurisdiction identified in Table 2 are discountable.
Vessel movement may affect the space for movement and use within the shelf and slope habitat essential
features of MHI insular false killer whale critical habitat; however, the low number of vessels transiting from the
ports to the disposal sites each year are extremely unlikely to affect these features, and are therefore
discountable.
Conclusion
Considering the information and assessments presented in the consultation request and available reports and
information, and in the best scientific information available about the biology and expected behaviors of the
ESA-listed marine species considered in this consultation; NMFS concurs with your determination that the
proposed action is not likely to adversely affect the following ESA-listed species, and designated critical habitat:
endangered sperm, fin, blue, sei, and North Pacific right whales; endangered Main Hawaiian Island insular false
killer whales; endangered Hawaiian monk seals; threatened Central North Pacific green turtles; endangered
hawksbill turtles; threatened North Pacific Ocean loggerhead turtles; threatened olive ridley and endangered
olive ridley sea turtles; endangered leatherback turtles; threatened oceanic whitetip sharks; threatened giant
manta rays; and designated critical habitat for Hawaiian monk seals and Main Hawaiian Islands insular false
killer whales.
This concludes your consultation responsibilities under the ESA for species under NMFS's jurisdiction. If
necessary, consultation pursuant to Essential Fish Habitat would be completed by NMFS' Habitat Conservation
Division in a separate communication.
Conservation Recommendations
Section 7(a)(1) of the ESA directs Federal agencies to use their authorities to further the purposes of the ESA by
carrying out conservation programs for the benefit of the threatened and endangered species. Specifically,
conservation recommendations are discretionary agency activities to minimize or avoid adverse effects of a
proposed action on ESA-listed species or designated critical habitat (50 CFR 402.02).
NMFS recommends that the EPA assess lower-level trophic species (fish and plankton) for
chemicals/compounds in the area where sediment dumping is occurring.
Reinitiation Notice
ESA Consultation must be reinitiated if: 1) take occurs to an endangered species, or to a threatened species for
which NMFS has issued regulations prohibiting take under section 4(d) of the ESA; 2) new information reveals
effects of the action that may affect ESA-listed species or designated critical habitat in a manner or to an extent
not previously considered; 3) the identified action is subsequently modified in a manner causing effects to ESA-
listed species or designated critical habitat not previously considered; or 4) a new species is listed or critical
habitat designated that may be affected by the action.
If you have further questions, please contact Shelby Creager (808) 725-5144 or shelby.creager@noaa.gov.
Thank you for working with NMFS to protect our nation's living marine resources.
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Sincerely,
Ann M. Garrett
Assistant Regional Administrator
Protected Resources Division
NMFS File No.: PIRO-2020-02769
PIRO Reference No.:. I-PI-20-1846-AG
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sediment prolongs larval development in a coral reef fish. Journal of Experimental Biology. 217(Pt 7): 1122-
1128.
Werner, E. E., and S. D. Peacor. 2003. A review of trait-mediated indirect interactions in ecological
communities. Ecology. 84(5): 1083-1100.
Wilber, D. H., and D. G. Clarke. 2001. Biological effects of suspended sediments: a review of suspended
sediment impacts on fish and shellfish with relation to dredging activities in estuaries. North American Journal
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Appendix A
Data Quality Act Documentation and Pre-Dissemination Review
The Data Quality Act (DQA) specifies three components contributing to the quality of a document. They are
utility, integrity, and objectivity. This section of the letter addresses these DQA components, documents
compliance with the DQA, and certifies that this letter has undergone pre-dissemination review.
Utility
Utility principally refers to ensuring that the information contained in this consultation is helpful, serviceable,
and beneficial to the intended users. The intended users of this letter are FHWA. Other interested users could
include permittees listed in Table 1 and others interested in the conservation of listed species and their
ecosystems. Individual copies of this were provided to the FHWA. The document will be available within two
weeks at the NOAA Library Institutional Repository rfattps://repository.library.noaa.gov/welcomel. The format
and naming adheres to conventional standards for style.
Integrity
This consultation was completed on a computer system managed by NMFS in accordance with relevant
information technology security policies and standards set out in Appendix III: Security of Automated
Information Resources, Office of Management and Budget Circular A-130; the Computer Security Act; and the
Government Information Security Reform Act.
Objectivity
Information Product Category: Natural Resource Plan
Standards: This consultation and supporting documents are clear, concise, complete, and unbiased; and were
developed using commonly accepted scientific research methods. They adhere to published standards including
the NMFS ESA Consultation Handbook, and the ESA regulations, 50 CFR 402.01 et seq.
Best Available Information: This consultation and supporting documents use the best available information, as
referenced in the References section. The analyses in this letter contain more background on information sources
and quality.
Referencing: All supporting materials, information, data and analyses are properly referenced, consistent with
standard scientific referencing style.
Review Process: This consultation was drafted by NMFS staff with training in ESA and reviewed in accordance
with Pacific Island Region ESA quality control and assurance processes.
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^TGr^
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
NATIONAL MARINE FISHERIES SERVICE
Pacific Islands Regional Office
1845 Wasp Blvd., Bldg 176
Honolulu, Hawaii 96818
(808) 725-5000 • Fax: (808) 725-5215
January 21, 2021
Ellen Blake
Assistant Director, Water Division
U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
RE: NMFS, Pacific Islands Regional Office, essential fish habitat (EFH) conservation
recommendations for the Environmental Protection Agency's (EPA) continued use of five
ocean dredged material disposal sites in Hawai'i
Dear Ms. Blake,
The National Marine Fisheries Service, Pacific Islands Regional Office (NMFS), received the U.S.
Environmental Protection Agency's (hereafter, EPA) request to initiate an essential fish habitat
(EFH) consultation for the five existing Hawai'i ocean dredged material disposal sites. NMFS
provided an early coordination technical assistance letter for this project on August 30, 2018,
conducted a conference call on June 26, 2020 to provide EFH consultation guidance to the EPA,
and completed a review of the draft EFH Assessment on September 22, 2020. We have reviewed
your EFH consultation request and the accompanying EFH Assessment pursuant to the EFH
provision of the Magnuson-Stevens Fishery Conservation and Management Act (MSA; Section
305(b)(2) as described by 50 CFR 600.920). We have determined that the proposed activities may
adversely affect EFH. We have provided EFH conservation recommendations that, when
implemented and adhered to, will ensure that potential adverse effects will be avoided,
minimized, offset for, or otherwise mitigated.
Project Description
The EPA has requested consultation for the five EPA-designated offshore dredged material
disposal sites for Hawai'i for which the EPA oversees permitting for dredged sediment disposal.
The sites are used only for the disposal of suitable, non-toxic sediment dredged by the U.S. Army
Corps of Engineers (USACE) from the federally authorized navigation channels in Hawai'i's
harbors, and from other permitted navigation dredging projects in Hawai'i, including those by the
Navy. The Hawai'i ocean disposal sites were designated together via rulemaking in 1981 based on
a 1980 Final Environmental Impact Statement completed by EPA Headquarters. While an
Endangered Species Act consultation was completed, an EFH consultation under the MSA was
not required.
Nfifc
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The disposal sites are offshore of the islands of O'ahu, Hawai'i, Maui, and Kaua'i ranging from 4
to 6.5 nautical miles offshore in waters from 330 to 1,610-meters (m) deep (Table 1). Each site
includes a small Surface Disposal Zone within which all disposal actions must occur, and a larger
site boundary on the seafloor where most of the sediment deposition is intended to occur. From
2000-2020, the average sediment disposal volumes for the South O'ahu, Hilo, Kahalui, Nawiliwili,
and Port Allen sites were: 121,371, 12,198, 2,724, 11,914, and 0 cubic yards, respectively.
Table 1. Description of the five EPA-designated Hawai'i offshore dredged material
Disposal Site
Depth Kangc
Shape unci Dimensions
(Senfloor Footprint)
Surface Disposal /.one
(SDK) Dimensions
('enter Coordinates
(NAD 83)
South 0'ahu
375-475 m
(1.230-1.560 ft}
Rectangular
2.0 (W-E) by 2.6 km (N-S)
(1.08 bv 1.4 tuni)
Circular
305 m< 1000 ft) radius
21° 15' 10" N,
157° 56' 50" W
Hilo
330-340 m
(1 >080-1.115 ft}
Circular
920 m (3000 ft) radius
Circular
305 in (1000 ft) radium
19° 48' 30" N
154" 58* 30" W
Nawiliwili
840-1,120 m
(2,750*3 ,<575 ft)
Circular
920 m (3000 ft) radius
C uvular, offset
200 ni (600 ft) radius:
[21° 55* 15" N
IS?0 17' 13.8" W]
21° 55' 00" N
159 ' 17 00" W
Port Allen
1.460-1.610 m
(4,800-5.280 ft}
Circular
920 m (3000 ft) radius
Circular
305 m (1000 ft) radius
21° 50* 00" N
159° 35' 00" W
Kahutui
343-345 m
(1,130-1.200 ft)
Circular
920 m (3000 ft) radius.
Circular
305 m (1000 fl) radius
21° 04' 42" N
156° 29,00" W
Disposal Site Designation Process
The EPA notes that the site designation process for ocean disposal includes criteria to avoid
impacts to the aquatic environment and to human ocean use to the maximum extent possible. The
site designation process and regulations (promulgated under the Marine Protection, Research, and
Sanctuaries Act (MPRSA) and the National Environmental Policy Act (NEPA)) independently
require evaluation of a variety of factors intended to minimize the potential effects of disposal on
marine species and their habitat. The MPRSA regulations at 40 CFR Part 228.5-228.6 include the
following disposal site selection habitat and species avoidance and minimization criteria:
• Disposal activities must avoid existing fisheries and shellfisheries (228.5(a)).
• Temporary water quality perturbations from disposal within the site must be reduced to
ambient levels before reaching any marine sanctuary or known geographically limited fishery
or shellfishery (228.5(b)).
• The size of disposal sites must be minimized in order to be able to monitor for and control any
adverse effects (228.5(d)).
• Where possible, disposal sites should be beyond the edge of the continental shelf (228.5(e)).
• The location of disposal sites must be considered in relation to breeding, spawning, nursery,
feeding or passage areas of living resources in adult or juvenile phases (228.6(a)(2)).
• Dispersal and transport from the disposal site be must considered (228.6(a)(6)).
• Cumulative effects of other discharges in the area must be considered (228.6(a)(7)).
• Interference with recreation, fishing, fish and shellfish culture, areas of special scientific
importance and other uses of the ocean must be considered (228 .6(a)(8)).
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• The potential for development or recruitment of nuisance species must be considered
(228.6(a)(10)).
• Based on these site selection criteria, the five Hawai'i sites were identified as the
environmentally preferred alternative locations serving each of the five main Hawai'i port
areas.
Dredged Material Testing
The EPA's regulations establish strict criteria for evaluating whether dredged material is suitable
for ocean disposal (see 40 CFR Part 227.5-9). These regulations specify that certain prohibited
constituents, such as industrial wastes or high-level radioactive wastes, may not be disposed in the
ocean at all, while other constituents, such as organohalogen compounds or mercury, may only be
discharged if present in no more than "trace" amounts that will not cause an unacceptable adverse
impact after dumping. "Trace" is determined by passing a series of bioassays addressing the
potential for short- and long-term toxicity and bioaccumulation. The EPA and the U.S. Army
Corps of Engineers (USACE) have jointly published national sediment testing guidance for
conducting these evaluations in advance of dredging (i.e., the Ocean Testing Manual (OTM)).
Sampling Analysis Plans
The EPA and the USACE review and approve sampling and analysis plans (SAPs) in advance of
each dredging project; this is intended to ensure that the samples to be tested are representative of
the material proposed for dredging. The number and location of required sediment samples is
informed by expected dredge volumes and past testing history; however, specific attention is
focused on sampling near known or potential sources of contamination such as outfalls, storm
drains, repair yards, and industrial sites. Individual samples may be composited for analysis only
within contiguous areas expected to be subject to the same pollutant sources and hydrodynamic
factors (e.g., a single berth in a harbor). Representative sediment collected pursuant to an approved
SAP is then subjected to chemistry evaluations, toxicity bioassays (for short-term water column
and longer-term benthic impacts), and bioaccumulation tests. The results are compared to the same
tests conducted with reference site sediment.
Sediment Chemistry
An extensive list of potential contaminants is measured in each sediment sample or composite, and
in the reference sediment. These include conventional properties such as grain size and organic
carbon content, as well as heavy metals, organotins, hydrocarbons, pesticides, poly-chlorinated
biphenyls, and dioxins/furans. The EPA and the USACE can add compounds to this standard list
whenever deemed necessary. Sediment chemistry results can be compared against various
sediment guidelines (such as NOAA's effects range low (ERL) and effects range median (ERM)
values) to help inform the biological testing.
Water-Column Testing
In contrast to the seafloor, where potential exposure to disposed sediment is long-term, the EPA
has determined that exposure to disposal plumes in the water column is temporary. Nevertheless,
to be "suitable" for ocean disposal, the EPA requires that water column assessments must confirm
that temporary exposure to the suspended sediment immediately following disposal will not
exceed applicable marine water-quality criteria or cause toxicity to representative sensitive marine
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organisms after allowance for initial mixing and dilution. For each tested sediment sample,
organisms are exposed to a series of concentrations of elutriate (water plus suspended particulates)
to determine the toxic concentration (LC50). A 100-fold safety factor is applied such that after
initial mixing the water column plume may not exceed 1% of the LC50 for the most sensitive
organism tested. Three separate water-column bioassays are conducted, with one species being a
phytoplankton or zooplankton, one a larval crustacean or mollusk, and one a fish. Species must be
chosen from among a list of sensitive standard test species listed in the OTM or specified in
regional guidance.
All of the Hawai'i disposal sites are offshore, in relatively deep water; the EPA expects that initial
dilution is rapid and disposal plumes would dissipate to background levels quickly. Although
potential water column effects are assessed for every proposed project as described, water column
testing alone has rarely, if ever, "failed" a project for ocean disposal at any of the Hawai'i sites.
Therefore, the EPA considers the potential for direct effects to water column species, including
planktonic species, filter feeders reliant on planktonic species, or pelagic prey species,
discountable. Similarly, the EPA expects that cumulative water column effects would not occur
because discharges from disposal vessels typically occur over only a few minutes, and individual
disposal events are at least several hours apart, even in the most active circumstances.
Benthic Testing
For the benthic toxicity assessment, the EPA requires that at least two "solid phase" bioassays be
completed. For these tests, sediment-associated species are utilized that, together, represent key
exposure routes including filter feeding, deposit feeding, and burrowing life histories. The test
species must be chosen from among a list of sensitive standard test species listed in the OTM or
regional guidance. If organismal mortality is statistically greater than in the reference sediment
and exceeds reference sediment mortality by 10% (20% for amphipods), the sediment is
considered potentially toxic and may not be approved for ocean disposal. Solid phase benthic
toxicity is usually the cause when sediments "fail" for ocean disposal.
Bioaccumulation Testing
The EPA requires that bioavailability—the potential for contaminants to move from the sediment
into the food web—must also be evaluated in advance for each dredging project. Bioaccumulative
contaminants are selected and evaluated by EPA for each project based on their presence in the
test sediment. Benthic organisms are then exposed to the sediment (usually for 28 days), and
concentrations of the contaminants of concern taken into the tissues are measured. The tissue
concentrations are compared against concentrations in tissues of the same species exposed to a
reference sediment.
Depending on results, tissue concentrations may also be used in trophic transfer models, and/or
compared against available benchmarks including relevant total maximum daily loads (TMDLs),
state or local fish consumption advisories, and Food and Drug Administration (FDA) "Action
Levels for Poisonous or Deleterious Substances in Fish and Shellfish for Human Food."
Alternatives Analysis
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The EPA's regulations restrict ocean disposal of dredged material by outlining factors for
evaluating the need for ocean disposal and requiring consideration of alternatives to ocean disposal
(40 CFR Part 227.14-16). Alternatives to ocean disposal, including beneficial uses of dredged
material, are considered on a project-by-project basis to ensure that the minimum necessary
volume of dredged material is disposed at any of the ocean disposal sites. Generally, alternatives
to ocean disposal in the islands are more limited than on the mainland. However, even sediments
that have adequately been characterized and found by the EPA and the USACE to be suitable for
ocean disposal will not be permitted for ocean disposal if there is a practicable alternative available.
For example, clean sand that is otherwise suitable for ocean disposal generally is not permitted for
disposal if it can be feasibly used to nourish local beaches.
Disposal Site Management
The EPA expects that ongoing use of the five existing Hawai'i ocean disposal sites will not
increase the need for dredging in Hawai'i, nor the amount of ocean disposal of dredged material
that occurs. The EPA therefore expects that there would similarly be a lack of significant impacts
in the future, provided that the ocean disposal sites continue to be managed under the same or
similar requirements. The EPA proposes to continue managing the five existing Hawai'i disposal
sites under site use conditions and best management practices (BMPs) that are substantively the
same as those currently in place. The only substantial change in site management is the recent
relocation of the SDZ within the existing Nawiliwili site, and as incorporated in permit conditions
for the site. This change was made based on the results of the 2017 monitoring survey, which
identified hard-bottom habitat (including a volcanic escarpment, marking the ancient shoreline) in
the southeastern portion of the Nawiliwili site. The relocated SDZ will avoid future deposition of
sediment on the hard-bottom habitat and facilitate future monitoring of dredged material
discharges on the natural sediment habitat in the northwestern portion of the site. This relocation
of the SDZ is an example of EPA's adaptive approach to site management.
Enforcement
In addition to active, adaptive management of the five Hawai'i ocean disposal sites, EPA has
strong enforcement authority under the MPRSA for any violations related to disposal operations.
Violations may include dumping of unauthorized materials, dumping of materials in excess of
authorized amounts, dumping outside of designated sites, and spills or leaks from hopper dredges
or scows during transit to the ocean disposal sites. EPA authorities apply to violations of the
MPRSA itself (for unpermitted dumping) or of an MPRSA permit, (including violations relating
both to dumping and transportation for the purpose of dumping). If the provisions of a permit are
violated, the permit may be revoked or suspended; even if the permit is not revoked, the MPRSA
authorizes EPA to require ocean dumping activities to immediately cease when violations are
imminent or continuing. EPA may even suspend the use of the ocean disposal site altogether, if
necessary. In addition to ensuring that ongoing violations are stopped, EPA may impose monetary
penalties when ocean dumping violations occur. Administrative penalties imposed by EPA under
the MPRSA can be quite heavy and serve as an effective deterrent to ongoing ocean dumping
violations. Consequently, it is rare that EPA is forced to refer an ocean dumping case for judicial
or criminal penalties.
Although the MPRSA does not expressly authorize penalty assessments for natural resource
damages,
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EPA considers the gravity of the violation (including effects to sensitive species or habitats), prior
violations, and the demonstrated good faith of the person charged when determining a civil penalty
amount. Finally, the MPRSA also authorizes citizen suit enforcement. However, the MPRSA does
not provide retain and use authority; under the Miscellaneous Receipts Act, fines and penalties are
transmitted to the general treasury rather than for purposes of mitigating any damage in and around
the ocean disposal site.
Additionally, the BMPs included in EPA's Site Management and Monitoring Plans (SMMPs)
become enforceable conditions when attached to the USACE' ocean disposal permits. Those
conditions can include requirements that minimize the risk of impacts should a violation occur,
such as seasonal limitations or specified transit routes to and from the disposal site. These kinds
of specifications have not been applied to the Hawaii ocean disposal sites in the past, but where
necessary and feasible they could be included in the SMMP.
Essential Fish Habitat
The marine water column from the surface to a depth of 1,000 meters (m) from the shoreline to
the outer boundary of the Exclusive Economic Zone (200 nautical miles), and the seafloor from
the shoreline out to a depth of 700 m around Hawaii have been designated as EFH. As such, EFH
is designated for the water column of the Pacific Ocean at the Port Allen site, and the water column
and seafloor of the Pacific Ocean at the South O'ahu, Hilo, Nawiliwili, and Kahului sites. These
waters and substrates support various life stages for the management unit species (MUS) identified
under the Western Pacific Fishery Management Council's, Pelagic and Hawaii Fishery Ecosystem
Plans. The MUS life stages found in these waters include eggs, larvae, juveniles, and adults of
Bottomfish, Pelagics, and Crustacean MUS. Specific types of habitat considered as EFH include
coral reef, patch reefs, hard substrate, artificial substrate, seagrass beds, soft substrate, mangrove,
lagoon, estuarine, surge zone, deep-slope terraces and pelagic/open ocean. Habitat Areas of
Particular Concern (HAPC) are subsets of EFH that exhibit one or more of the following traits:
rare, stressed by development, provide important ecological functions for federally managed
species, or are especially vulnerable to anthropogenic (or human impact) degradation. HAPC's
can cover a specific location (a bank or ledge, spawning location) or cover habitat found at many
locations (e.g., coral, nearshore nursery areas, or pupping grounds). A HAPC for bottomfish MUS
offshore of the island of Hawaii overlaps with the Hilo dumping site.
Baseline Condition
Research conducted by the EPA and the USACE since the inception of the MPRSA suggests that
the benthos is most susceptible to potential adverse effects dumping. This is because deposited
dredged material mixes more rapidly in the water column than in the benthos where bottom-
dwelling animals reside and recycle dredged material for extended time periods. Therefore, the
EPA's monitoring of ocean disposal sites has focused on the benthos, including sediment
chemistry, physical characteristics, and organismal community structure and function.
The EPA conducted extensive site monitoring surveys of the Hawai'i ocean disposal sites in 2013
and 2017. During these surveys, the EPA used a variety of methods to achieve the monitoring
objectives, including high-resolution multibeam echosounder surveys (MBES), sediment profile
imaging (SPI) and plan view photography (PVP), and sediment grabs for sediment chemistry and
benthic infauna.
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Sediment samples from both inside and outside each of the five Hawai'i disposal sites were
collected successfully and analyzed for the same compounds evaluated during predisposal testing.
The bulk chemistry data from the 2013 monitoring surveys showed generally low, but variable,
concentrations of most chemical constituents at the South O'ahu and Hilo sites (the most
frequently used sites). The few concentrations above screening levels were relatively minor in
magnitude and, in many cases, seen at stations both inside and outside the sites. The few
constituents that were at higher concentrations within the disposal sites reflect the contaminant
levels in the dredged material approved for discharge. Because sediments that contain pollutants
in toxic amounts, or elevated levels of compounds that may bioaccumulate in benthic organisms,
are prohibited from ocean disposal, the EPA does not consider the chemical concentrations
identified to represent a risk. Instead, the EPA has interpreted that these low concentrations
indicate that the pre-dredge sediment testing regime is adequately protecting the disposal site
environments by identifying and excluding more highly contaminated sediments from being
disposed. Sediment chemistry was also collected at the Nawiliwili, Kahului, and Port Allen sites,
and is currently being analyzed for results (preliminary results are available in Appendix 3; once
the report is finalized, it will be made available to NMFS). Preliminary screening indicates that,
similar to the South O'ahu and Hilo sites, the majority of chemical concentrations fell below the
ERL, and the few concentrations above screening levels were relatively minor in magnitude and,
in most cases, were seen at stations both inside and outside the sites.
Monitoring confirmed that minor physical (substrate) changes have occurred at the disposal sites
compared to pre-disposal baseline data from 1980. Results of the 2013 survey indicate that a
detectable dredged material footprint extended outside of the South O'ahu site, however there have
been no documented "short-dumps" (i.e., discharge or loss of dredged material during transit to an
ocean disposal site, prior to arrival at the site) since EPA required satellite-based tracking of all
disposal scows in the early 2000s (with the exception of a single partial mis-dump in 2006). Thus,
the footprint outside the South O'ahu disposal site boundary would appear to be relic material
deposited more than 10 years ago. At the Hilo site, the substantially smaller cumulative volume of
dredged material disposed appeared to be more fully confined within the designated disposal site
boundary.
The results of the 2017 survey indicated that recently disposed dredged material, including coral
and pebble rubble, was present on the seafloor surface within and near the Nawiliwili ocean
disposal site. However, the commonplace presence of coral rubble and other coarse materials and
sands at the seafloor surface across the survey area confounded definitive delineation of the
dredged material footprint. Surveys at Port Allen and Kahului also indicated that the dredged
material footprint was primarily contained within the site boundary, yet some material was
detectable beyond the designated boundary to some extent at both sites. It is the EPA's position
that because the EPA has required satellite-based tracking of all disposal scows since the early
2000s, and mis-dumping has not occurred at least since then, the dredged material observed outside
the sites is also assumed to be relic material. Additionally, due to benthic activity, dredged material
was witnessed to have been reworked into the sediment. For example, all material at the Port Allen
ocean disposal site was reworked into the sediment column by biota to some extent and no thick
deposits were observed.
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The benthic community was assessed through both SPI imagery and sediment grab samples.
Overall, the EPA has determined that the changes in substrate may partially account for minor
differences in infaunal assemblages found during the 2013 monitoring at the South O'ahu and Hilo
sites (the most heavily used of the Hawai'i disposal sites). However, minor benthic community
changes also occurred outside those disposal sites and so appear to be partially attributable to
region-wide variability as well. In addition, the EPA found no apparent adverse effects to the
infaunal community associated with the presence of dredged material at the Kahului and Port Allen
ocean disposal sites. The vast majority of stations across both survey areas supported stable benthic
structure or advanced stages of infaunal recolonization. The EPA has determined that the presence
of advanced recolonization at stations containing dredged material indicates that the benthic
community has recovered post-disposal activity at these locations. Because the Nawiliwili site was
so heterogeneous, benthic community grab samples were not successfully collected inside the site
for comparison to the benthic community outside of the site. However, the one SPI replicate that
achieved sufficient penetration near the center of the Nawiliwili site indicated the presence of stage
3 (advanced) fauna. Additionally, as previously mentioned, disposal volumes at Nawiliwili are
relatively low, and preliminary screening of chemistry results indicated that dredged material
disposed did not appear to result in contaminant loading, as most of the contaminants were below
the ERL, and the few concentrations above screening levels were found both inside and outside of
the site. Therefore, the EPA has determined that all available results from Nawiliwili indicate that
dredged material disposed did not adversely affect the benthic environment. In summary, the EPA
has determined that monitoring at all five sites confirmed that recolonization begins soon after
dredged material is deposited, and that similar infaunal and epifaunal communities occupy areas
both inside and outside the disposal sites. Thus, the EPA has determined that long-term impacts to
benthic habitat quality are discountable and largely contained within the site boundaries.
Overlap with a HAPC
The bottomfish HAPC near the Hilo site extends for 11 miles along the coast of the island of
Hawai'i, out from Hilo Bay, and overlaps with the Hilo ocean disposal site. The EFH within the
Hilo HAPC consists of 336 square kilometers covering the water column and bottom habitat
extending from the baseline to 400 m. The Hilo HAPC for bottomfish was designated in 2016,
because it is an ecologically important juvenile P. filamentosus nursery area and also has rare
physical pillow lava habitat. While nursery areas for P. filamentosus are usually flat, open soft
substrates, the camera deployments recorded juveniles over very hard, rugose volcanic substrate.
The uniqueness of this nursery habitat contributed to the designation of the area as a HAPC for
bottomfish. Nevertheless, due to the depth and substrate composition of the Hilo ocean disposal
site, the EPA does not believe that ocean disposal will adversely impact juvenile P.filamentosus
EFH and the pillow lava habitat (i.e., the two reasons for the designation of the HAPC), as
discussed below (see Adverse Effects section).
Adverse Effects
The proposed dumping of dredged sediment may result in adverse effects to water column and
benthic EFH from sedimentation and turbidity, nutrient enrichment, introduction of invasive
species, and pollution and chemical contamination. Habitat conversion may occur as disposed
dredged material migrates outside of disposal site boundaries, which may adversely affect EFH
for various MUS.
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Bottomfish HAPC
Because it is an intermediate bottomfish stock, P. filamentosus EFH encompasses the water
column and bottom habitat in depths from the surface to 280 m. Juvenile P. filamentosus are
specifically known to occupy areas much shallower than their adult counterparts, ranging in depth
from approximately 40 m to 100 m. The Hilo ocean disposal site ranges from 330-340 m deep,
therefore any potential effects on P. filamentosus would likely be restricted to water column effects
to life history stages rather than substrate changes. While there may be adverse effects to P.
filamentosus from disposal in the water column, elutriate testing suggests that the plume should
not cause toxicity to sensitive marine organisms.
HAPC Pillow Lava Substrate
EPA monitoring at the Hilo site indicates that, apart from an accumulation of small rock and coral
rubble at the center of the site from previous dredged material deposits, the native sediments within
the site consist of predominantly sandy substrate (77% sand, 22% silt and clay, and only 1%
gravel). Monitoring outside of the Hilo ocean disposal site boundaries did identify pillow lava,
however these stations were far outside of the site boundaries; no pillow lava was identified within
the site boundaries.
Proposed Best Management Practices
The EPA ensures that the following BMPs are implemented for permitted disposal activities:
• A variety of disposal BMPs as enforceable permit conditions for each project, including:
o Prohibition on leaking and spilling of material during transit.
o Prohibition of trash and debris disposal, with required use of a 12- by 12-inch grizzly
screen. All material captured by the grizzly must be separately removed and disposed,
o Completion of a scow certification checklist.
o No portion of the vessel from which the materials are to be released (e.g., hopper
dredge, or barge) shall be further than 305 m from the center of the ODMDS, unless
specified by a project-specific special permit condition,
o Backup navigation and disposal tracking systems in the case that sensors fail,
o Posting disposal information tracking on the internet within 24 hours of disposal,
o Email alerts for dumping material outside of prescribed/designated dumping zones,
o Daily record keeping and monthly reporting,
o 24-hour requirement for notification of leaks or mis-dumps,
o Completing a Project Completion Report within 60 days.
• Alternatives to ocean disposal will be prioritized, including upland disposal and beneficial use.
• Contaminated dredge material will not be permitted for ocean disposal. Any dredged material
that contains levels of chemical contaminants in other than "trace" amounts, that exhibits
toxicity in either suspended or solid phase tests, or that includes pollutants that are likely to
bioaccumulate in the food web to levels of concern, is not considered suitable for ocean
disposal.
• Satellite tracking all disposal vessels to ensure that disposal activities occur only where and as
required.
• Sensors on all disposal vessels to ensure that there is no significant leakage or spilling of
dredged material during transit to the disposal site, especially during transit through the
nearshore zone where corals, seagrasses, and sensitive animals are most likely to be present.
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• Tracking and sensor information reported online for each disposal trip.
• Potential inclusion of project-specific conditions to protect marine resources, such as adjusting
timing of activities to avoid coral spawning.
In addition, the MPRSA regulations for site selection described at 40 CFR Part 228.5-228.6 (see
above) include disposal site selection criteria which help directly avoid or minimize impacts to
water column and benthic EFH.
Pre-Disposal Testing
Although the five Hawai'i ocean disposal sites intersect with water column EFH for the crustacean,
bottomfish, and pelagic MUS, the conservative sediment elutriate testing and modeling conducted
prior to dredging must confirm that exposure to the disposal plume, including the dissolved oxygen
and turbidity levels, will not cause toxicity to sensitive marine organisms in the water column.
Chemistry testing is conducted, and modeling to screen for water quality standards compliance
assumes that 100% of all contaminants are released to the water column. Elutriate bioassays are
performed, and a 100-fold safety factor is applied such that, after initial mixing, the water column
plume may not exceed 1% of the toxic concentration (LC50) for the most sensitive organism tested.
Further, due to the depths and offshore locations of the Hawai'i sites, dilution of the disposal
plumes is rapid. In addition, although the South O'ahu, Hilo, and Kahului sites intersect with the
benthic EFH for bottomfish MUS, the detailed sediment testing process also includes two solid
phase bioassays and bioaccumulation testing. This ensures that the material disposed will not be
toxic to benthic organisms and does not include pollutants likely to bioaccumulate in the food web.
Site Management
The EPA additionally uses an active, adaptive approach to managing ocean disposal sites. More
specifically, once a dredging project is approved for ocean disposal at one of the Hawai'i sites, a
variety of disposal BMPs are included as enforceable permit conditions for the project. For
example, satellite tracking is conducted for all disposal vessels, and sensors are placed on all
disposal vessels to ensure there is no significant leakage or spilling of dredged material during
transit to the site. These additional BMPs ensure that direct and indirect effects to water column
and benthic EFH are avoided or minimized. Moreover, the EPA periodically monitors the sites to
ensure that adverse effects are minimized within and nearby.
Monitoring
The South O'ahu, Hilo, Kahului sites intersect with the benthic EFH for the bottomfish MUS deep
stocks. The EPA expects that physical effects are generally anticipated at any disposal site, simply
because dredged sediment's physical characteristics (e.g., grain size and organic carbon content)
often differ from that of the native seafloor in the deep ocean. Nevertheless, the EPA expects that
these effects to be primarily confined to the disposal site, and benthic communities are anticipated
to recover rapidly following disposal. Furthermore, the volumes disposed at the five Hawai'i sites
are very low, particularly in comparison to other dredged material disposal sites in EPA Region 9.
The EPA expects that the low volume of disposed dredged material further reduces impacts to
benthic EFH, and helps ensure that the dredged material can be more rapidly assimilated into the
benthos following disposal. The EPA's monitoring results from 2013 and 2017 suggests that there
are minimal long-term impacts to the marine community from dredged material disposal.
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NMFS Concerns
NMFS has various concerns with repetitive dumping of dredged material at offshore locations near
the main Hawaiian Islands. Dumping dredged sediment fines into the water column will
temporarily increase turbidity while resuspending low concentrations of contaminants. Elevated
turbidity levels may temporarily reduce primary and secondary production rates and therefore alter
the flow of energy and nutrients up the pelagic food chain within the euphotic zone and beyond;
there is no demonstrated research on how these activities affect plankton productivity rates and
community structure and function. Elevated turbidity, particulate and dissolved organic carbon
and nitrogen loads, and the presence of low concentrations of chemical contaminants may
adversely affect eggs and larvae for various MUS.
NMFS is also concerned about the potential for dredged material to settle on EFH outside of
disposal site boundaries, which has occurred at some of the sites. Migration of dredged spoils
outside of the disposal areas may convert soft and hard bottom habitats to a different type of habitat
that may or may not be as conducive as current substrate is for supporting MUS. It is unclear from
the EFH Assessment how the EPA plans determine whether disposed sediment outside of disposal
site boundaries is relic or new; this is a critical gap that needs resolution so as to abide with the
EPA-proposed BMP for minimizing impacts to federally managed fisheries.
Lastly, NMFS is interested to learn more about the process that permittees complete for collecting
and reporting sediment chemistry data for material destined for offshore disposal. Permittee
reporting of sample sizes and chemical characteristics for individual samples is extremely helpful
for our consultation process. We have had consultations that have reported small sediment sample
sizes (n=6) as one bulk sample value across a small area of benthic substrate; however, neither a
standard error nor a standard deviation was provided. Further, the permittee determined that this
mean value was representative for an area of bottom substrate where there actually was a gradient
in sediment chemistry character and sediment size fraction. In essence, NMFS is unable to
delineate different sediment types from one another due to this reporting style and approach, which
is not statistically powerful and has the potential to be scientifically misleading. It would be helpful
for our consultations involving offshore dredged material disposal if we could learn more about
the sediment sampling process and contribute to the conversation about sediment sampling design,
replication, and reporting prior to when activities occur.
Conservation Recommendations
NMFS provides the following EFH conservation recommendations pursuant to 50 CFR 600.920
that when implemented and adhered to would ensure that potential adverse effects to EFH from
the proposed action are sufficiently avoided and/or minimized:
Conservation Recommendation 1 (CR#1): The EPA should continue to monitor dredged sediment
disposal levels and chemical character in both the water column and along the benthos inside and
outside of disposal site boundaries.
Conservation Recommendation 2 ('CR#2): The EPA should develop a method to track/measure
and determine whether dredged material disposed outside of disposal site boundaries is relic or
new. This will help inform whether disposal activities need to be stopped and site boundaries
reassessed.
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Conservation Recommendation 3 (CR#3): If dredged material is substantially accumulating
outside of site boundaries, the EPA should assess if benthic habitat conversion is occurring.
Conservation Recommendation 4 (CR#4): If benthic habitat conversion is occurring outside of site
boundaries, the EPA should assess whether this conversion is adversely affecting managed
fisheries, including Bottomfish, Crustaceans, and Pelagic MUS.
Conservation Recommendation 5 (CR#5): If assessments from CR#4 reveal that stocks of MUS
are adversely affected by habitat conversion outside of dredge boundaries, then the EPA should
restore converted habitat or develop equitable compensation to offset for the loss of this habitat.
NMFS is ready and willing to coordinate on any potential discussions.
Conservation Recommendation 6 (CR#6): The EPA should ensure that SAP sediment sampling
methods, designs, and data reporting requirements for permittees are statistically robust while
ensuring that gradients in sediment types and size fractions and clearly depicted. If possible,
consider including NMFS in early permit coordination discussions so that we can provide guidance
on what permittees will need to include in their EFH assessments.
Conservation Recommendation 7 (CR#7): The EPA should consider supporting new research to
understand how dredged material disposal may alter primary and secondary production rates in the
water column, while evaluating shifts in phytoplankton and microbial community structure and
function. This will help to inform how plumes may temporarily change ambient conditions and
the flow of carbon and energy through the food web.
Conclusion
NMFS appreciates the opportunity to provide EFH conservation recommendations to the EPA for
the proposed programmatic activities at these Hawaii offshore dredged material dumping
sites. We also greatly appreciate the early coordination and cooperative approach that the
EPA implemented with us. We have determined that EPA-permitted activities to dump
dredged sediment at these sites may impart adverse effects to EFH. We have provided EFH
conservation recommendations that when implemented will help the EPA comply with the
MSA by ensuring that potential adverse effects to EFH are sufficiently avoided, minimized,
offset for, or otherwise mitigated.
Please be advised that regulations (Section 305(b)(4)(B)) to implement the EFH provision of the
Magnuson-Stevens Act require that federal activities agencies provide a written response to this
letter within 30 days of its receipt and, a preliminary response is acceptable if more time is needed.
The final response must include a description of measures to be required to avoid, mitigate, or
offset the adverse effects of the proposed activities. If the response is inconsistent with our EFH
conservation recommendations, an explanation of the reason for not implementing the
recommendations must be provided at least 10 days prior to final approval of the activities.
We are committed to providing continued cooperation and subject matter technical expertise as
identified in the conservation recommendations, and as requested, to the EPA in order to achieve
the project goals and sufficiently comply with the EFH provision of the MSA. Please do not
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hesitate to contact Stuart Goldberg (stuart. goldberg@noaa. gov) with any comments, questions or
to request further technical assistance.
cc by e-mail:
Malia Chow, NMFS
Juliette Chausson, EPA
Brian Ross, EPA
Hudson Slay, EPA
Sincerely,
Assistant Regional Administrator
Habitat Conservation Division
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#¦ ** '
l ssu
Gerry Davis
Assistant Regional Administrator - Habitat Conservation
National Marine Fisheries Service
Pacific Islands Regional Office
1845 Wasp Boulevard Building 176
Honolulu, Hawai'i 96818
Re: EPA Response to NMFS EFH Conservation Recommendations for Continued Use
of Five Existing Hawai'i Ocean Disposal Sites
Dear Assistant Regional Administrator Davis:
On October 13, 2020 EPA transmitted an informal programmatic "EPA Analysis for ESA and EFH
Consultation: Five Existing Hawai'i Ocean Dredged Material Disposal Sites" to your office.1 As
described in that document, since the five Hawai'i ocean disposal sites were designated in 1981, the
Region 9 Ocean Dumping Management Program has been successful in managing these five Hawai'i
ocean disposal sites to avoid and minimize the effects of dredged material disposal on surrounding
fisheries and aquatic habitat. As EFH consultation was not required at the time of designation, this
analysis marked the informal initiation of consultation for the five Hawai'i ocean disposal sites. We
greatly appreciate the early and active coordination with your staff in helping us prepare, and now in
reviewing, our analysis. This letter transmits EPA's responses to the Essential Fish Habitat (EFH)
Conservation Recommendations included in your January 21, 2021 letter.
In general, EPA agrees with NMFS' proposed Conservation Recommendations (CR). As described in
the attached document and based on conversations with your staff, we discuss how we will implement
practicable solutions to address the intent of the original CRs. The CRs will be included, as appropriate,
into an updated Site Management and Monitoring Plan (SMMP) for the five Hawai'i ocean disposal
sites, which will be published jointly with the U.S. Army Corps of Engineers (USACE). We agree that
the CRs, as described in the attached document, are appropriate and feasible to implement, subject to
available funding for future monitoring surveys.
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, CA 94105-3901
i
The ESA portion of this informal programmatic consultation concluded with the November 27, 2020 letter from Ann
Garrett, concurring with our determination that the proposed action is not likely to adversely affect a number of ESA-
listed species and critical habitat managed by NMFS.
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We look forward to completing this programmatic consultation covering the transport and disposal of
dredged material to the five Hawai'i ocean disposal sites and to hearing from NMFS as to whether the
described measures adequately address the EFH recommendations. If there are any questions regarding
this letter, please feel free to contact me or Juliette Chausson of my staff by e-mail
(chausson.juliette@epa.gov) or by phone (415-972-3440).
Sincerely,
Ellen M. Blake
Assistant Director, Water Division
Enclosure: Conservation Recommendations for Five Hawai'i Ocean Disposal Sites
cc: Malia Chow, NOAA NMFS
Stuart Goldberg, NOAA NMFS
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U.S. EPA Responses to NMFS EFH Conservation Recommendations
for Continued Use of Five Hawai'i Ocean Disposal Sites
February 22, 2021
In its letter dated January 21, 2021, NFMS included seven Conservation Recommendations
(CRs) to protect Essential Fish Habitat (EFH) that could be affected by permitted ocean
disposal of dredged material at five existing EPA-designated Hawai'i ocean disposal sites:
South O'ahu, Hilo, Kahului, Nawiliwili, and Port Allen. Each of NMFS's original CRs is
reproduced below, followed by a description of the measures that EPA will undertake to
address them. Please note that these CRs programmatically apply to the transport and disposal
of dredged material at the five Hawai'i ocean disposal sites, and to EPA's management of
those sites. Dredging site impacts may also occur and may require separate project-specific
consultation. Any such consultation is conducted by USACE as part of their permitting
process.
NMFS Conservation Recommendations and EPA Responses
Conservation Recommendation 1 (CR#1): EPA should continue to monitor dredged
sediment disposal levels and chemical character in both the water column and along the
benthos inside and outside of disposal site boundaries.
EPA Response: EPA agrees with this CR regarding benthic monitoring. However, we
disagree that routine water column (disposalplume) monitoring is necessary or would be
beneficial, for the reasons described below.
Sediment Physical and Chemical Monitoring:
Research conducted by EPA and USACE since the inception of the MPRSA has shown that the
greatest potential for environmental impact from dredged material is in the benthic
environment. This is because deposited dredged material is not mixed and dispersed as rapidly
or as greatly as the small portion of the material that remains temporarily in the water column.
Additionally, bottom-dwelling animals live in, and feed on, deposited material for extended
periods. Therefore, EPA monitoring of ocean disposal sites to-date has focused primarily on
the benthic environment, including the sediment chemistry, physical characteristics of the
benthos, and the benthic community. EPA will continue to periodically monitor the physical
and chemical characteristics of dredged material disposed at the five Hawai'i ocean disposal
sites, both inside and outside of site boundaries.
Water Column Monitoring:
EPA does not routinely conduct water column monitoring in association with disposal events at
deep ocean disposal sites, for several reasons. First, periodic site monitoring surveys can often
occur several months, or even years, following a disposal event. Water column data collected
even a few hours removed from a disposal event would not provide useful information about
the location, duration, or chemistry of a disposal plume at a deep-water site, due to the plume's
rapid dispersion following a disposal event. This is particularly true for offshore, deep ocean
disposal sites, such as the Hawai'i sites, where initial dilution is rapid and disposal plumes
dissipate to background levels quickly. Second, in contrast to the seafloor where potential
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EPA Responses to NMFS EFH Conservation Recommendations
exposure to disposed sediment is long-term, exposure to disposal plumes in the water column
is quite temporary. Third, standard pre-disposal sediment testing includes three separate
suspended sediment toxicity bioassays. These tests ensure that no material is discharged that
would be toxic to sensitive water column organisms after initial dilution. Finally, as
summarized below, extensive water column monitoring studies at the San Francisco Deep
Ocean Disposal Site (SF-DODS) in the past confirmed the lack of any lasting or large-scale
water column impacts.
Past Water Column Monitoring at SF-DODS:
EPA conducted monitoring during disposal events at the San Francisco Deep Ocean Disposal
Site (SF-DODS), which demonstrated that there are no distinguishable impacts to the water
column from the disposal (McGowan et al, 2001; McGowan et al, 2003). For the first several
years of disposal operations at SF-DODS (from 1996 - 2001 *), regional monitoring of water
column parameters and pelagic organisms (principally plankton and juvenile fish) was
conducted seasonally each year. The monitoring surveys were focused on water quality
parameters, including nutrients, and pelagic organisms, including species important to
commercial and recreational fisheries, over a study area of about 25 square nautical miles
centered on the SF-DODS. These studies characterized the distribution and abundance of
species, and later assessed physiological condition of species, within and outside of the
boundaries of the SF-DODS. The biological data were complemented by oceanographic
measurements (i.e., physical and chemical seawater properties) in order to differentiate
whether any patterns seen were caused by disposal of dredged materials or by naturally
occurring variations in physical and chemical properties of seawater in the region. Analysis of
the data showed no direct or indirect effects of disposal operations on population abundance,
species distribution, or physiological condition of selected zooplankton, fish larvae, or juvenile
fishes. Instead, regional oceanographic conditions and seasonal and interannual variability,
including El Nino and La Nina events, appeared to be the major influences on the distribution
and abundance of upper water column organisms.
Additionally, mid-water sediment traps and caged mussels were deployed to confirm plume
movement and to evaluate the potential for bioaccumulation as a result of long-term exposure
to repeated suspended sediment plumes (SAIC, 2001). The sediment trap and caged mussel
studies confirmed that long-term bioaccumulation was not occurring via water-column
exposure to suspended sediment plumes from repeated disposal events. Therefore, because
these studies have demonstrated that disposal of suitable material does not have observable
effects on organisms in the water column, EPA has since dedicated its limited monitoring
resources primarily to benthic monitoring, and place emphasis instead on ensuring that water
column testing is conducted for every project prior to determination of suitability.
For the reasons described above, EPA believes that including additional water column
monitoring at the five Hawai'i open water ocean disposal sites is not necessary and would not
be beneficial. However, EPA will continue to ensure that water column tests are conducted as a
component of standard pre-disposal testing for ocean disposal.
1 For context, the SF-DODS received approximately 9.7 million cubic yards of dredged material in the six year
period of this study (1996-2001), whereas all five Hawai'i sites combined received a total of approximately 8.8
million cubic yards of material in the 30 year period since their designation (1981 - 2020) (USEPA, 2010).
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EPA Responses to NMFS EFH Conservation Recommendations
Conservation Recommendation 2 (CR#2): EPA should develop a method to track/measure
and determine whether dredged material disposed outside of disposal site boundaries is relic
or new. This will help inform whether disposal activities need to be stopped and site
boundaries reassessed
EPA Response: EPA agrees with this CR and will continue to track depositions of dredged
material both through periodic disposal site monitoring surveys and through satellite tracking
of individual disposal events.
EPA's site monitoring surveys include stations both inside and outside the five Hawai'i
disposal sites to delineate the presence of dredged material. This monitoring generally involves
using a sediment profile imaging camera (SPI), which provides a cross-sectional photographic
record of selected locations on the seafloor. During image analysis, the thickness of the
deposited sedimentary layers can be determined by measuring the distance between the pre-
and post-deposition sediment-water interface. Recently deposited material is usually evident
because of its different optical reflectance and/or color relative to the underlying material in the
predisposal surface. Also, in most cases, the point of contact between the two layers is usually
clearly visible as a textural change in sediment composition, facilitating measurement of the
thickness of the newly deposited layer. Therefore, through analysis of the images collected
with the SPI camera, EPA is able to determine the presence and physical characteristics of
dredged material and evaluate whether the material has been recently deposited.
Surveys at the Hawai'i disposal sites indicated that the dredged material footprint was
primarily contained within the site boundary, yet some material was detectable beyond the
designated boundary to some extent at all sites. However, the quantities of dredged material
present outside the sites are generally extremely low and primarily consist of "trace" layers
(i.e., < 0.1cm). For example, at the Hilo disposal site, which is located within a bottomfish
HAPC, only one station outside the site had an indication of dredged material greater than
0.1cm (see Figure 19 in USEPA 2015 (i.e., Enclosure 2 in the original consultation package)).
The remaining few stations outside the site with indications of dredged material only had
indications of "trace" dredged material. These results indicate that management measures,
including the requirement of disposal being conducted within a smaller surface disposal zone,
are effective at containing the dredged material within the ocean disposal sites.
In contrast, more dredged material is evident outside the South Oahu site boundaries than at the
other Hawai'i sites. For example, a side-scan sonar survey of the Mamala Bay seafloor
conducted by USGS showed the widespread presence of non-native sedimentary material,
mainly centered on historic (pre-1981) ocean disposal site locations (the USGS imagery is
shown in Figure 26 of USEPA 2015). In our EFH assessment, we state, "Results of the 2013
survey indicated that a detectable dredged material footprint extended outside of the South
O'ahu site, however there have been no documented "short-dumps" (i.e., discharge or loss of
dredged material during transit to an ocean disposal site, prior to arrival at the site) since EPA
required satellite-based tracking of all disposal scows in the early 2000s, with the exception of
a single partial mis-dump that occurred in 2006. Thus, the footprint outside the South O'ahu
disposal site boundary would appear to be relic material deposited more than 10 years ago." In
fact, the majority of this relic material was likely deposited more than 40 years ago.
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EPA Responses to NMFS EFH Conservation Recommendations
Conservation Recommendation 3 (CR#3): If dredged material is substantially
accumulating outside of site boundaries, EPA should assess ifbenthic habitat conversion is
occurring.
EPA Response: EPA agrees with this CR. We will continue to monitor for any accumulation
of dredged material outside of site boundaries, and in particular to evaluate whether any such
accumulation is causing a shift in benthic habitat type.
As mentioned above (CR#2), EPA monitors stations both inside and outside the five Hawai'i
disposal sites to determine the presence of dredged material. This monitoring is conducted
using a sediment profile imaging camera (SPI), which provides a cross-sectional photographic
record of selected locations on the seafloor, as well as a plan-view camera that documents the
habitat type immediately surrounding the SPI images. Through these images, EPA is able to
determine the presence of dredged material and evaluate the extent to which the dredged
material has been reworked into the native sediment through bioturbation.
Surveys at the Hawai'i disposal sites indicated that the dredged material footprint was
primarily contained within the site boundary, yet some material was detectable beyond the
designated boundary at all sites. However, the quantities of dredged material present outside
the sites are generally extremely low and mostly consist of "trace" layers (i.e., < 0.1cm). The
monitoring surveys also provided evidence that dredged material is reworked into the vertical
sediment profile through bioturbation: benthic community analyses have confirmed that there
are only minor differences in community structure between stations inside and outside the
Hawai'i disposal sites. Further, many stations both inside and outside the sites had evidence of
stage 3 benthic infauna, which are larger, later-stage recolonizers that are able to rework the
sediment to depths of 20 cm or more. These results indicate that management measures,
including the requirement of disposal being conducted within a smaller surface disposal zone,
are effective at containing the dredged material within the ocean disposal sites and preventing
changes to benthic communities outside of the disposal sites.
It is also important to highlight that EPA designates sites in areas that avoid impacts to the
aquatic environment and to human uses of the ocean to the maximum extent practicable,
including avoiding impacts to fisheries and shellfisheries. Generally, monitoring in and outside
the five Hawai'i disposal sites has not revealed any presence of unique habitat or species that
would require any additional protection measures. In fact, in the rare cases nationally when
such habitat has been found, such as for the Charleston Ocean Dredged Material Disposal Site,
EPA has immediately altered the boundaries of the site to ensure that disposal activities would
not impact such areas. With respect to the Hawai'i ocean disposal sites, EPA did identify
hardbottom habitat at south eastern stations that were far removed from the Hilo ODMDS.
However, the stations with hard-bottom (H-SE6 and H-E5) did not have evidence of dredged
material (see Figure 19 in USEPA, 2015), and stations along the same transect yet closer to the
site had no indication of dredged material either, indicating that the dredged material footprint
is largely contained within the site and not reaching the hard bottom habitat.
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EPA Responses to NMFS EFH Conservation Recommendations
Conservation Recommendation 4 (CR#4): Ifbenthic habitat conversion is occurring
outside of site boundaries, EPA should assess whether this conversion is adversely affecting
managedfisheries, including Bottomfish, Crustaceans, and Pelagic MUS.
EPA Response: EPA agrees with this CR and will work with NMFS to assess any impacts to
benthic communities if monitoring surveys indicate habitat conversion is occurring outside
disposal site boundaries as a result of permitted activities.
EPA uses a tiered approach to monitoring to ensure that necessary information is collected in a
cost-effective manner. In this tiered approach, results of either project-specific compliance
monitoring (e.g., disposal vessel tracking) or periodic site monitoring surveys can trigger
further monitoring, and/or consideration of whether management actions (discussed further
under CR#5, below) are necessary to ensure environmentally acceptable conditions. Such a
review could be triggered, for example, if substantial dredged material is being deposited
outside the site boundary, if sediment chemistry values substantially greater than expected are
found inside or outside the site boundary, or if there are indications that the offsite benthic
community is being adversely affected by contaminants from the disposal site.
If EPA determines that there is substantial habitat conversion outside the boundaries as a result
of permitted activities, then EPA will assess the extent of this conversion and how it may have
impacted the benthic communities. If impacts to benthic communities are determined, then
EPA will inform NMFS of the findings and will work with NMFS to determine whether further
assessment or other management actions may be needed to protect managed fisheries in the
area.
Conservation Recommendation 5 (CR#5): If assessments from CR#4 reveal that stocks of
MUS are adversely affected by habitat conversion outside of dredge boundaries, then EPA
should restore converted habitat or develop equitable compensation to offset for the loss of
this habitat. NMFS is ready and willing to coordinate on any potential discussions.
Note: Through coordination with NMFS staff, EPA understands that "dredge boundaries," in
this CR is intended to mean "disposal site boundaries."
EPA Response: EPA agrees with the intent of this CR, especially regarding any impacts that
occur because of violations of ocean disposal site use conditions contained in permits issued
by US ACE, or violations of the MPRSA from any unpermitted discharges. However, EPA
generally does not pursue benthic habitat restoration at deep ocean disposal sites because, for
the most part, such restoration is not practicable. Similarly, EPA itself does not provide
compensation for such impacts, although settlement agreements for violations may sometimes
include supplemental environmental projects (SEPs) that can provide indirect compensation
for impacts. Instead, EPA will consider a range of possible site management actions as
discussed below. These management actions will also be consideredfor any significant adverse
impacts that may occur due to permitted disposal activity.
Once a dredging project is approved for ocean disposal at one of the Hawai'i sites, several
measures are required to minimize the potential for any habitat conversion to occur outside of
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EPA Responses to NMFS EFH Conservation Recommendations
the disposal site boundaries. These measures are outlined in the SMMP and include: satellite
tracking all disposal vessels to ensure that disposal activities occur only where and as required;
sensors on all disposal vessels to ensure that there is no significant leakage or spilling of
dredged material during transit to the disposal site, especially during transit through the
nearshore zone where corals, seagrasses, and sensitive animals are most likely to be present;
and online reporting of tracking and sensor information for each disposal trip.
Nevertheless, conversion of habitat outside of the ocean disposal site boundaries may occur as
a result of violation of permit conditions. If the provisions of a permit are violated, the permit
itself may be revoked or suspended. In addition, EPA may impose monetary penalties.
Administrative penalties imposed by EPA under the MPRSA can be quite substantial and serve
as an effective deterrent to ongoing ocean dumping violations. However, the MPRSA does not
provide retain and use authority; under the Miscellaneous Receipts Act, fines and penalties are
transmitted to the general treasury rather than for purposes of mitigating any damage in and
around the ocean disposal site. Nevertheless, settlement agreements for violations may
sometimes include supplemental environmental projects (SEPs) that can provide indirect
compensation for impacts.
Conversely, if habitat conversion occurs due to permitted disposals having adverse effects
outside of site boundaries, EPA may modify, suspend, or terminate site use overall (or for
individual projects as appropriate). In general, EPA will modify site use rather than suspend or
terminate site use, when modification will be sufficient to eliminate the adverse environmental
impacts identified. More specifically, potential management actions outlined in the SMMP
include:
• Additional investigations to confirm and delineate the source or extent of the problem,
including additional site monitoring, as appropriate;
• Modification of the Surface Disposal Zone location or the seafloor boundaries of the
site;
• Change to, or additional restrictions on, permissible times, rates and total volume of
dredged material that may be disposed at a site;
• Change to, or additional restrictions on the method of disposal or transportation for
disposal at a site;
• Change to, or additional limitations on the allowable type or quality of dredged
materials based on their physical, chemical, toxicity, or bioaccumulation
characteristics; or
• Permanent site closure if this is the only means for eliminating adverse environmental
impacts.
EPA will inform NMFS of monitoring findings, and any additional management measures that
EPA proposes to put in place to prevent future conversion.
Conservation Recommendation 6 (CR#6): EPA should ensure that SAP sediment sampling
methods, designs, and data reporting requirements for permittees are statistically robust
while ensuring that gradients in sediment types and size fractions and clearly depicted. If
possible, consider including NMFS in early permit coordination discussions so that we can
provide guidance on what permittees will need to include in their EFH assessments.
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EPA Responses to NMFS EFH Conservation Recommendations
EPA Response: EPA agrees with the intent of this CR and will work with USACE to ensure
that NMFS has the opportunity to review and comment on dredging project SAPs.
Both EPA and USACE review and approve SAPs in advance of each dredging project to
ensure that the samples to be tested are representative of the material to be dredged and
disposed. The number and location of required sediment samples is determined in accordance
with guidance in the joint EPA-USACE national ocean disposal testing manual and is based on
bathymetry, the volume to be dredged, proximity to known or potential sources of
contamination (such as outfalls, storm drains, repair yards, and industrial sites) and any past
testing history. Individual samples may be composited for physical, chemical, and biological
analyses within areas expected to be subject to the same pollutant sources and hydrodynamic
factors (e.g., a single berth, or area within a harbor). These areas are usually contiguous and
with similar grain sizes. Since the material in each composite area will get mixed when being
placed into the disposal vessel, EPA generally makes a separate suitability determination for
each composite area rather than for its individual cores. However, since individual cores are
archived, higher-resolution analysis of physical or chemical parameters (such as grain size) can
also occur where needed.
EPA supports the opportunity for NMFS to participate in early coordination discussions,
including review of proposed SAPs. However, under the MPRSA, USACE is the permitting
agency for ocean dumping of dredged material, subject to EPA concurrence. Therefore, EPA
will work with USACE to encourage early coordination with NMFS.
Conservation Recommendation 7 (CR#7): EPA should consider supporting new research
to understand how dredged material disposal may alter primary and secondary production
rates in the water column, while evaluating shifts in phytoplankton and microbial
community structure and function. This will help to inform how plumes may temporarily
change ambient conditions and the flow of carbon and energy through the food web.
EPA Response: EPA does not believe that additional research into potential effects of
temporary plumes from disposal of suitable dredged material at deep-water open ocean
disposal sites is necessary or would be helpful. However, EPA will continue to ensure that
water column tests with appropriate sensitive marine organisms are conducted as a component
of suitability determinations for ocean disposal.
As discussed for CR#1 above, EPA conducted extensive upper water column monitoring
during disposal events at SF-DODS which demonstrated that there were no distinguishable
impacts to water quality or water column organisms from ongoing disposal activity. Therefore,
monitoring resources at deep water sites have since been dedicated primarily to benthic
monitoring. Nevertheless, the potential for water column impacts is still addressed for every
disposal project via required suspended phase testing conducted prior to determination of
suitability. EPA will continue to ensure that water column tests with appropriate sensitive
marine organisms are conducted as a component of suitability determinations for ocean
disposal.
7
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EPA Responses to NMFS EFH Conservation Recommendations
References
McGowan, M., A. Marchi, J. Tustin, C. McCandlish, A. Abel, L. Light, and R. Dugdale. 2001.
SF-DODS upper water column monitoring data report for 1998 and 1999 with
preliminary analyses of the time series for 1996-1999. Report from Romberg Tiburon
Center for Environmental Studies, San Francisco State University. Prepared for US
Army Corps of Engineers, San Francisco District, San Francisco, CA. December 2000,
Revised June 2001.
McGowan, M., C. McCandlish, A. Good, A. Marchi, J. Tustin, and R. Dugdale. 2003. SF
DODS upper water column monitoring in 2000 and 2001. Report from Romberg
Tiburon Center for Environmental Studies, San Francisco State University. Prepared
for US Army Corps of Engineers, San Francisco District, San Francisco, CA.
Science Applications International Corporation (SAIC). 2001. San Francisco Deep Ocean
Disposal Site Modeling Studies - Final Report. SAIC GSA Schedule Numbers 6S-35F-
4461G. Special Item Number 132-51. Submitted to EPA Region 9, San Francisco, CA.
USEPA. 2010. Review/Synthesis of Historical Environmental Monitoring Data Collected at
the San Francisco Deep Ocean Disposal Site (SF-DODS) in Support of EPA
Regulatory Decision to Revise the Site's Management and Monitoring Plan. Prepared
by Germano & Associates, Inc. for EPA Region 9, San Francisco, CA.
USEPA. 2015. 2013 Hawai'i Ocean Disposal Site Monitoring Synthesis Report. Prepared by
Dredging and Sediment Management Team, USEPA Region 9, San Francisco, CA.
USEPA and USACE. 2015. Site Management and Monitoring Plan: Five Hawai'i Ocean
Disposal Sites, https://www.cpa.gov/sites/iproduction/filcs/2015-
II ' 'iocuments/r9 haw&u itiitii¦ '"II |..if
8
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/ ¥ \
National Oceanic and Atmospheric Administration
NATIONAL MARINE FISHERIES SERVICE
Pacific Islands Regional Office
1845 Wasp Blvd., Bldg 176
Honolulu, Hawaii 96818
(808) 725-5000 • Fax: (808) 725-5215
U.S. DEPARTMENT OF COMMERCE
March 5, 2021
Ellen Blake
Assistant Director, Water Division
U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
RE: National Marine Fisheries Service (NMFS) response to the Environmental Protection
Agency's (EPA) February 24, 2021 essential fish habitat (EFH) conservation
recommendations response letter for the Hawai'i five ocean-dredged material disposal sites
EFH consultation.
Dear Ms. Blake,
On February 24, 2021, NMFS received the EPA's letter responding to our January 21, 2021 EFH
conservation recommendations letter for the five existing Hawai'i ocean dredged material disposal
sites consultation. We appreciate the strong coordination between our agencies and the detailed
responses that you provided to the EFH conservation recommendations. Below, we respond to
each of your responses to our EFH conservation recommendations. We have provided clarification
text with regard to avoidance, minimization, and offset as described in the Magnuson-Stevens
Fishery Conservation and Management Act (MSA), and have further detailed our position on
researching water column sediment plumes. This consultation process has satisfied the
requirements of Section 305(b)(D)(2) of the Magnuson-Stevens Fishery Conservation and
Management Act (MSA), and is considered complete. We hope to continue to engage in our
coordination with you for this project in the future.
NMFS Responses
Conservation Recommendation 1 (CR#1): The EPA should continue to monitor dredged sediment
disposal levels and chemical character in both the water column and along the benthos inside and
outside of disposal site boundaries.
EPA Response to CR#1: EPA agrees with this CR regarding benthic monitoring. However, we
disagree that routine water column (disposal plume) monitoring is necessary or would be
beneficial, for the reasons described below.
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NMFS Response: NMFS appreciates that the EPA will continue to monitor dredged sediment
disposal levels and chemical character in the benthos. However, our CR was referring to how
plumes may alter primary and secondary productivity in the upper 1000 m and how this may alter
the flow of nutrients and energy available to support MUS at these sites.
We disagree with your position on the necessity of monitoring water column EFH. Phytoplankton
and microbial communities drive the flow of energy within the water column, including the upper
1000 meters, which is designated as EFH in the Pacific Islands Region. The flow of energy is
driven by primary and secondary producers and directly supports the availability of food for
management unit species (MUS). The field of microbial (i.e., includes autotrophs and
heterotrophs) genomics and metabolomics is advancing at incredible rates. We now understand
that community structure and productivity of these microbes in the subtropical North Pacific varies
as a function of energy and nutrient availability (Mende et al. 2017). Microbial activity oscillates
over remarkably short timescales, with metabolic pathways turning on and off as a function of
physiological and biogeochemical processes in natural populations (Wilson et al. 2017). Further,
the recycling of nutrients and chemicals attached to and within particulate organic matter is a key
process for transporting nutrients and energy to the mesopelagic zone (i.e., 100-1000 m). The
nutrient and chemistry of these compounds can influence genetic diversity of the microbes
congregating these particles, and thus the flow of energy and recycling of nutrients at depth (Pelve
et al. 2017).
More research is needed to understand how disposal of dredged material may alter the magnitude
and flow of energy in these open ocean sites. Dredged material consists of a variety of compounds
and chemicals, and may be enriched in certain macronutrients (such as carbon, nitrogen, and
phosphorus) and trace metals, depending on the source and extent to which it has undergone
degradation. Plumes may stimulate primary and secondary productivity and alter the balance
between heterotrophic and autotrophy along short timescales. Sediments can stick to particles,
causing them to sink faster thereby changing the residence time of energy and calories available
up the food chain within the mesopelagic and euphotic zones. Overall, our position remains that
we, collectively, need to better understand how disposal of dredge plumes affects the flow of
energy at these open ocean sites. We look forward to continuing this conversation with the EPA
into the future.
Conservation Recommendation 2 ('CR#2): The EPA should develop a method to track/measure
and determine whether dredged material disposed outside of disposal site boundaries is relic or
new. This will help inform whether disposal activities need to be stopped and site boundaries
reassessed.
EPA Response: EPA agrees with this CR and will continue to track depositions of dredged material
both through periodic disposal site monitoring surveys and through satellite tracking of individual
disposal events.
NMFS Response: NMFS appreciates that the EPA agrees with this EFH conservation
recommendation, and will continue to track the occurrence of disposal accumulation outside of
disposal site boundaries.
2
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Conservation Recommendation 3 (CR#3): If dredged material is substantially accumulating
outside of site boundaries, the EPA should assess if benthic habitat conversion is occurring.
EPA Response: EPA agrees with this CR. We will continue to monitor for any accumulation of
dredged material outside of site boundaries, and in particular to evaluate whether any such
accumulation is causing a shift in benthic habitat type.
NMFS Response: NMFS appreciates that the EPA agrees with this EFH conservation
recommendation, and will evaluate whether any such accumulation of disposed sediments
monitored outside of the disposal site boundaries is causing a shift in benthic habitat type.
Conservation Recommendation 4 (CR#4): If benthic habitat conversion is occurring outside of site
boundaries, the EPA should assess whether this conversion is adversely affecting managed
fisheries, including Bottomfish, Crustaceans, and Pelagic MUS.
EPA Response: EPA agrees with this CR and will work with NMFS to assess any impacts to
benthic communities if monitoring surveys indicate habitat conversion is occurring outside
disposal site boundaries as a result of permitted activities.
NMFS Response: NMFS appreciates that the EPA agrees with this EFH conservation
recommendation, and will work with NMFS to assess any impacts to benthic communities if
monitoring surveys indicate habitat conversion is occurring outside disposal site boundaries as a
result of permitted activities.
Conservation Recommendation 5 (CR#5): If assessments from CR#4 reveal that stocks of MUS
are adversely affected by habitat conversion outside of dredge boundaries, then the EPA should
restore converted habitat or develop equitable compensation to offset for the loss of this habitat.
NMFS is ready and willing to coordinate on any potential discussions.
EPA Response: EPA agrees with the intent of this CR, especially regarding any impacts that occur
because of violations of ocean disposal site use conditions contained in permits issued by USACE,
or violations of the MPRSA from any unpermitted discharges. However, EPA generally does not
pursue benthic habitat restoration at deep ocean disposal sites because, for the most part, such
restoration is not practicable. Similarly, EPA itself does not provide compensation for such
impacts, although settlement agreements for violations may sometimes include supplemental
environmental projects (SEPs) that can provide indirect compensation for impacts. Instead, EPA
will consider a range of possible site management actions as discussed below. These management
actions will also be considered for any significant adverse impacts that may occur due to permitted
disposal activity.
NMFS Response: NMFS appreciates the clarification and description in the response provided by
the EPA. The MSA requires that Federal action agencies avoid, minimize, offset for, or otherwise
mitigate potential adverse effects imparted by a project action. If such adverse effects to EFH from
a project activity are substantial, then offsetting or otherwise mitigating these effects would be
required for compliance with the MSA. NMFS recognizes the complexities for permitting and
enforcing compliance at these sites. In the unlikely event that substantial adverse effects were to
3
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occur from a permitted action, NMFS would expect to coordinate closely with the EPA to identify
and assess all potential avenues to ensure compliance with the MSA.
Conservation Recommendation 6 (CR#6): The EPA should ensure that SAP sediment sampling
methods, designs, and data reporting requirements for permittees are statistically robust while
ensuring that gradients in sediment types and size fractions and clearly depicted. If possible,
consider including NMFS in early permit coordination discussions so that we can provide guidance
on what permittees will need to include in their EFH assessments.
EPA Response: EPA agrees with the intent of this CR and will work with US ACE to ensure that
NMFS has the opportunity to review and comment on dredging project SAPs.
NMFS Response: NMFS greatly appreciates that the EPA will work with US ACE to encourage
early coordination with NMFS on dredging project Sampling and Analysis Plans (SAPs).
Conservation Recommendation 7 (CR#7): The EPA should consider supporting new research to
understand how dredged material disposal may alter primary and secondary production rates in the
water column, while evaluating shifts in phytoplankton and microbial community structure and
function. This will help to inform how plumes may temporarily change ambient conditions and
the flow of carbon and energy through the food web.
EPA Response: EPA does not believe that additional research into potential effects of temporary
plumes from disposal of suitable dredged material at deep-water open ocean disposal sites is
necessary or would be helpful. However, EPA will continue to ensure that water column tests with
appropriate sensitive marine organisms are conducted as a component of suitability determinations
for ocean disposal.
NMFS Response: NMFS appreciates that the EPA will continue to ensure that water column tests
with appropriate marine organisms are conducted as a component of suitability determinations for
ocean disposal. However, our CR was not referring to appropriate sensitive marine organismal
research; rather, it was referring to how plumes may alter primary and secondary productivity in
the upper 1000 m and how this may alter the flow of nutrients and energy available to support
MUS at these sites.
Phytoplankton and microbial communities drive the flow of energy within the water column,
including the upper 1000 meters, which is designated as EFH in the Pacific Islands Region. The
flow of energy is driven by primary and secondary producers and directly supports the availability
of food for management unit species (MUS). The field of microbial (i.e., includes autotrophs and
heterotrophs) genomics and metabolomics is advancing at incredible rates. We now understand
that community structure and productivity of these microbes in the subtropical North Pacific varies
as a function of energy and nutrient availability (Mende et al. 2017). Microbial activity oscillates
over remarkably short timescales, with metabolic pathways turning on and off as a function of
physiological and biogeochemical processes in natural populations (Wilson et al. 2017). Further,
the recycling of nutrients and chemicals attached to and within particulate organic matter is a key
process for transporting nutrients and energy to the mesopelagic zone (i.e., 100-1000 m). The
nutrient and chemistry of these compounds can influence genetic diversity of the microbes
4
-------
congregating these particles, and thus the flow of energy and recycling of nutrients at depth (Pelve
etal. 2017).
More research is needed to understand how disposal of dredged material may alter the magnitude
and flow of energy in these open ocean sites. Dredged material consists of a variety of compounds
and chemicals, and may be enriched in certain macronutrients (such as carbon, nitrogen, and
phosphorus) and trace metals, depending on the source and extent to which it has undergone
degradation. Plumes may stimulate primary and secondary productivity and alter the balance
between heterotrophic and autotrophy along short timescales. Sediments can stick to particles,
causing them to sink faster thereby changing the residence time of energy and calories available
up the food chain within the mesopelagic and euphotic zones. Overall, our position remains that
we, collectively, need to better understand how disposal of dredge plumes affects the flow of
energy at these open ocean sites. We look forward to continuing this conversation with the EPA
into the future.
NMFS greatly appreciates the opportunity to coordinate with the EPA on this EFH consultation.
We appreciate your thoughtful responses to our EFH conservation recommendations and have
provided our own responses with the intent of clarifying our positions and furthering our future
coordination. We are committed to providing continued cooperation and subject matter technical
expertise as requested by the EPA in order to achieve the project goals and sufficiently comply
with the EFH provision of the MSA. Please do not hesitate to contact Stuart Goldberg
(stuart.goldberg@noaa.gov) with any comments, questions or to request further technical
assistance.
cc by e-mail:
Malia Chow, NMFS
Juliette Chausson, EPA
Brian Ross, EPA
Hudson Slay, EPA
Conclusion
Sincerely,
Gerry Davis
Assistant Regional Administrator
Habitat Conservation Division
5
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References
Mende, D.R., Bryant, J.A., Aylward, F.O., Eppley, J.M., Nielsen, T., Karl, D.M. and DeLong,
E.F., 2017. Environmental drivers of a microbial genomic transition zone in the ocean's interior.
Nature Microbiology, 2(10), pp. 1367-1373.
Pelve, E.A., Fontanez, K.M. and DeLong, E.F., 2017. Bacterial succession on sinking particles in
the ocean's interior. Frontiers in microbiology, 8, p.2269.
Wilson, S.T., Aylward, F.O., Ribalet, F., Barone, B., Casey, J.R., Connell, P.E., Eppley, J.M.,
Ferron, S., Fitzsimmons, J.N., Hayes, C.T. and Romano, A.E., 2017. Coordinated regulation of
growth, activity and transcription in natural populations of the unicellular nitrogen-fixing
cyanobacterium Crocosphaera. Nature microbiology, 2(9), pp. 1-9.
6
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, OA 94105-3901
Katherine Mullett
Field Supervisor
Pacific Islands Fish and Wildlife Office
Prince Kuhio Federal Building, Room 3-122
300 Ala Moana Blvd
Honolulu, HI 96850
Re: Programmatic ESA Consultation for Five Existing Hawai'i Ocean Dredged Material
Disposal Sites
Dear Katherine Mullet:
The U.S. Environmental Protection Agency Region 9 (EPA) manages five ocean dredged
material disposal sites (ODMDS) offshore of the Hawaiian Islands to allow for safe disposal of
suitable sediment generated from necessary dredging of harbors and other navigation-related
facilities. Continued availability of appropriately managed ODMDS is a priority for EPA, as it is
necessary to maintain safe navigation. EPA originally designated these five sites via rulemaking
in 1981, based on a 1980 Final EIS prepared through EPA Headquarters. The original
Endangered Species Act (ESA) consultation focused on species managed by the NOAA
Fisheries Service. Since the ODMDS were designated, conditions have changed, including new
species and critical habitat listings. In order to provide for the continued protected of listed
species and critical habitat, EPA reinitiated ESA consultation, working closely with both NOAA
Fisheries and US Fish and Wildlife Service.
As described in the enclosed analysis, EPA has determined that the continued disposal of
approved, suitable dredged material at these five ODMDS under a comprehensive Site
Management and Monitoring Plan may affect but is not likely to adversely affect certain species
listed as threatened or endangered under the ESA. The enclosed analysis describes the use of the
sites, as well as regulations and management measures in place to avoid impacts to organisms
and the environment. Also discussed is the extensive monitoring that EPA has conducted at the
sites, the results of which indicate that existing management practices have been successful at
avoiding and minimizing adverse impacts. Based on this analysis, we respectfully request that
the US Fish and Wildlife Service concur with EPA's "may affect but is not likely to adversely
affect" determination.
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I greatly appreciate the assistance of your staff during our development of this consultation
package, and we look forward to continuing to work closely with them. Please contact Juliette
Chausson of my staff by e-mail (chausson.juliette@epa.gov) or by phone (415-972-3440) if there
are any questions.
Sincerely,
Ellen M. Blake
Assistant Director, Water Division
Enclosure: EPA Analysis for ESA Consultation: Five Existing Hawai'i Ocean Dredged
Material Disposal Sites
Cc: Lindsy Asman
Darren LeBlanc
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EPA Analysis for ESA Consultation:
Five Existing Hawai'i Ocean Dredged Material Disposal Sites
US Environmental Protection Agency
Region IX
75 Hawthorne Street
San Francisco, CA 94105
November 13, 2020
-------
Contents
1.0 BACKGROUND 1
2.0 mi: 11 vi; haw aim ocean disposal sites 4
3.0 NEGLIGIBLE IMPACTS TO DATE 4
3.1 Disposal Site Designation 5
3.2 Dredged Material Testing 5
3.3 Alternatives Analysis 7
3.4 Disposal Site Management: Best Management Practices 8
3.5 Disposal Site Management: Site Monitoring 9
Monitoring Methods 9
Monitoring Results 11
3.6 Disposal Site Management: An Adaptive Approach 12
3.7 Enforcement 13
4.0 ESA SPECIES ASSESSMENTS 16
4.1 Potential Impact Summary 17
4.2 Short-Tailed Albatross (Phoebastria albastrus) 18
4.3 Hawaiian Petrel (Pterodroma sandwichensis) 19
4.4 Band-Rumped Storm-Petrel (Oceanodroma castro) 20
4.5 Newell's shearwater (Puffmus auricularis newelli) 21
6.0 CONCLUSIONS 22
7.0 REFERENCES 23
8.0 APPENDICES 25
Site Monitoring Synthesis Report (2015) 25
Site Management and Monitoring Plan (SMMP) and Mandatory Disposal Site Use Conditions (2015) 90
Preliminary Chemistry Results from the 2017 Monitoring Survey_of the Nawiliwili, Kahului, and Port Allen
Ocean Disposal Sites 127
List of Figures
Figure 1. Vicinity map, showing the five existing Hawai'i EPA-designated ocean disposal sites 1
Figure 2. Example of a tracking report for an individual disposal trip 8
Figure 3. High-resolution bathymetry in the vicinity of the Nawiliwili disposal site 10
Figure 4. Schematic of deployment and collection of SPI-PVP photographs 10
Figure 5. The Nawiliwili disposal site, showing the realigned SDZ 13
Figure 6. Species range of the short-tailed albatross (Phoebastria albastrus) 19
Figure 7. Species range of Hawaiian petrel (Pterodroma sandwichensis) 20
Figure 8. Species range ofband-rumped storm-petrel (Oceanodroma castro) 21
Figure 9. Species range of Newell's shearwater (Puffmus auricularis newelli) 22
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List of Tables
Table 1. Dimensions and center coordinates for Hawai'i ocean disposal sites and their SDZs 1
Table 2. Disposal volumes (cy) at the five Hawai'i ocean disposal sites from 1981-2020 3
Table 3. Volume of dredged material disposed, and minimum and maximum number of disposal trips, to and
from all Hawai'i ocean disposal sites in from 2009-2018 14
Table 4. Ten-year commercial vessel transits by port 15
Table 5. USFWS-managed species under ESA in the Pacific Islands Region 16
List of Acronyms and Abbreviations
BMP - Best Management Practice
EIS - Environmental Impact Statement
ERL - Effects Range Low
ERM - Effects Range Median
ESA - Endangered Species Act
MBES - Multibeam Echosounder Survey
MPRSA - Marine Protection, Research, and Sanctuaries Act
NEPA - National Environmental Policy Act
ODMDS - Ocean Dredged Material Disposal Site
OTM - Ocean Testing Manual
PVP - Plan View Photography
SAP - Sampling and Analysis Plan
SDZ - Surface Disposal Zone
SMMP - Site Management and Monitoring Plan
SPI - Sediment Profile Imaging
TMDL - Total Maximum Daily Load
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1.0 BACKGROUND
Currently, five EPA-designated ocean dredged material disposal sites (ODMDS) serve the state of
Hawai'i. These sites are off the islands of O'ahu, Hawai'i, Maui, and Kaua'i (Figure 1). They range
from 4 to 6.5 nautical miles (nmi) offshore, in waters from 1,100 to 5,300 feet (330 to 1,610 meters)
in depth (Table 1). Each site includes a small Surface Disposal Zone (SDZ) within which all disposal
actions must take place, as well as a larger site boundary on the seafloor where most of the sediment
is intended to deposit after falling through the water column.
ykAUAl
Ma M$ Nawikwili ODMDS
Port Allen ODMOS *•
OAHI, 1^ Tlill I ¦
Oahu ODMDS
Kanului ODMDS
¦¦71 v tt WAUI
«A'/va It* *
Hio ODMDS
Figure 1. Vicinity map, showing the five existing Hawai'i EPA-designated ocean disposal sites.
Table 1. Dimensions and center coordinates for Hawai'i ocean disposal sites and their SDZs. The underlined
text reflects an update to the 2015 Site Management and Monitoring Plan.
Disposal Site
Depth Range
Shape and Dimensions
(Seafloor Footprint)
Surface Disposal Zone
(SDZ) Dimensions
Center Coordinates
(NAD 83)
South O'ahu
375-475 m
(1,230-1,560 ft)
Rectangular
2.0 (W-E) by 2.6 km (N-S)
(1.08 by 1.4 nmi)
Circular
305 m (1000 ft) radius
21° 15' 10" N,
157° 56' 50" W
Hilo
330-340 ill
(1,080-1,115 ft)
Circular
920 m (3000 ft) radius
Circular
305 in (1000 ft) radius
19° 48' 30" N
154° 58' 30" W
Nawiliwili
840-1,120 m
(2,750-3,675 ft)
Circular
920 m (3000 ft) radius
Circular, offset
200 m (600 ft) radius:
[21° 55' 15" N
159° 17' 13.8" W|
21° 55'00" N
159°17' 00" W
Port Allen
1.460-l,610m
(4,800-5,280 ft)
Circular
920 m (3000 ft) radius
Circular
305 in (1000 ft) radius
21° 50' 00" N
159° 35'00" W
Kahului
345-365 ni
(1,130-1,200 ft)
Circular
920 m (3000 ft) radius
Circular
305 in (1000 ft) radius
21° 04' 42" N
156° 29' 00" W
1
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The Hawai'i ocean disposal sites were designated together via rulemaking in 1981, based on a 1980
Final Environmental Impact Statement (EIS) completed by EPA Headquarters.1 The original
Endangered Species Act (ESA) consultation conducted as part of that action focused on the
humpback whale, the Hawaiian monk seal, and the green sea turtle (species managed by NOAA
Fisheries). EPA can find no records indicating that consultation occurred with the US Fish and
Wildlife Service concerning three seabird species that were listed at that time and may be present near
the existing Hawai'i ocean disposal sites: the short-tailed albatross (Phoebastria albatrus), the
Hawaiian petrel (Pterodroma sandwichensis), and Newell's shearwater (Puffinus newelli). Since that
time, one additional seabird species has been listed: the band-rumped storm-petrel (iOceanodroma
castro). EPA is therefore now presenting an informal, programmatic ESA evaluation and
determination for these four listed seabird species.
Dredged material disposal volumes in Hawai'i are quite modest, with a long-term annual average of
just over 220,000 cubic yards (cy) being disposed at all five sites combined (and even less since
2000; Table 2; USACE 2020a). As a comparison, the other seven ocean disposal sites managed by
EPA Region 9 receive an average total of approximately 3 million cy each year. The Hawai'i sites
also differ among themselves in use, reflecting the differing dredging needs of each island. The South
O'ahu site, which serves US Navy facilities at Pearl Harbor as well as Hawai'i's main commercial
port complex in Honolulu Harbor, is the most heavily used site, with at least some dredging and
disposal occurring in 22 of the past 40 years. On average, disposal at the South O'ahu site accounts
for over 80% of all Hawai'i disposal. In recent years (since 2000), Hilo and Nawiliwili have been the
next most frequently used sites (receiving -9% and 8% of the total material, respectively), followed
by Kahului (-2%). The Port Allen site has received no dredged material since 1999, however some
disposal may occur in 2021.
The Marine Protection, Research and Sanctuaries Act (MPRSA) and EPA regulations call for careful
alternatives analysis, design stipulations, and best management practices (BMPs) to reduce or
eliminate potential adverse effects to marine resources (see Section 3 for further details). For
example, the regulations only allow suitable, non-toxic sediments to be discharged at EPA-designated
ocean disposal sites; even when sediment is suitable for ocean disposal, it is only approved when
there is no practicable alternative. In addition, the disposal site designation process itself is an
important safeguard against any significant adverse impacts to marine resources, as EPA's site
designation criteria explicitly lead EPA to identify disposal sites in locations removed from important
habitat areas, fishing grounds, or other ocean uses, to the maximum extent practicable. Finally, ocean
disposal sites are all managed under a Site Management and Monitoring Plan (SMMP) that
enumerates any site-specific restrictions, limitations, or BMPs that may be needed to further
minimize impacts of ocean disposal. While ocean disposal site designations themselves are completed
via formal rulemaking and are typically permanent, SMMPs are meant to be updated as needed based
on the results of required, periodic site monitoring, or on changed conditions such as updated
consultations.
1 The 1980 FEIS and other referenced documents supporting this consultation are available via:
https://www.epa.gOv/ocean-duniping/nianaging-ocean-duniping-epa-region-9#hi
2
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Table 2. Disposal volumes (cy) at the five Hawai'i ocean disposal sites from 1981-2020 (Data source: EPA
compliance tracking records and US Army Corps of Engineers Ocean Disposal Database (USACE,
2020a)).
Year
South O'ahu
Hilo
Kahului
Nawiliwili
Port Allen
Total All Sites
1981
0
1982
0
1983
71,400
313,900
385,300
1984
2,554,600
2.554.600
1985
12,000
12.000
1986
0
1987
111,200
111.200
1988
57,400
57,400
1989
75,000
75,000
1990
1,198,000
80,000
58,000
343,000
1.679.000
1991
134,550
134.550
1992
233,000
233,000
1993
322,400
322,400
1994
0
1995
0
1996
27,800
27,800
1997
0
1998
0
1999
27,500
91,000
114,600
20,900
254.000
2000
0
2001
0
2002
53,500
53,500
2003
183,500
183.500
2004
540,000
540,000
2005
3,000
3,000
2006
160,400
160.400
2007
266,500
266.500
2008
0
2009
126,200
126.200
2010
0
2011
18,260
63,879
82.139
2012
70,981
70.981
2013
312,080
312.080
2014
351,920
351.920
2015
0
2016
53,900
118,300
57,200
64,700
294.100
2017
2018
2019
126,160
185,500
185.500
2020
235,000
235,000
Total 1981-2020
6,929,870
336,160
206,200
1.344.100
20,900
8,837,230
Average/year
182,365
8.404
5,155
33,603
523
220,931
Total 2000-2020
2,427,420
256.160
57,200
250,200
0
2,990,980
Average/year
2000-2020
121,371
12.198
2,724
11.914
0
142,428
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EPA recently completed extensive monitoring surveys at each of the five Hawai'i ocean disposal
sites. The South O'ahu and Hilo sites (the most heavily-used of the Hawai'i sites) were the first to be
monitored, in 2013. The 2015 EPA synthesis report summarizing the results of that monitoring is
included as Appendix 1. Based on the monitoring results, EPA updated the SMMP for all the
Hawai'i sites in 2015 (Appendix 2). Similar monitoring surveys were also completed for the
Nawiliwili, Port Allen, and Kahului sites in 20172, and the SMMP for these sites will be updated
again based on those monitoring results and on the outcome of this ESA consultation with your
office.
2.0 l lll FIVE HAWAI'I OCEAN DISPOSAL SITES
This programmatic consultation update is being conducted for the five existing Hawai'i ocean
disposal sites. Continued use of these existing disposal sites is critical to national defense and the
maritime-related economy of the State of Hawai'i. The sites will continue to be used only for the
disposal of suitable, non-toxic sediment dredged by US ACE from the federally authorized navigation
channels in Hawai'i's harbors, as well as for disposal of suitable, non-toxic dredged sediment from
other permitted navigation dredging projects in Hawai'i, including by the US Navy (refer to Section
3.2 for more details on sediment testing and suitability determination). Future disposal operations at
the sites will continue to meet all criteria and factors set forth in the Ocean Dumping regulations
published at 40 CFR Parts 228.5 and 228.6. Ocean disposal will also continue to occur under the
terms of an SMMP that sets forth BMPs in the form of enforceable permit conditions, as well as site
monitoring requirements and contingency actions, should any adverse impacts be identified.
Continued use of the five existing Hawai'i sites will not in and of itself increase the need for dredging
or disposal in Hawai'i.
3.0 NEGLIGIBLE IMPACTS TO DATE
Theoretically, ocean disposal of dredged material may have the potential to cause direct short-term
adverse effects to living marine resources in the water column and long-term effects to seafloor
habitats and species through increased turbidity, sedimentation, and contaminants. This in turn has
the potential to indirectly adversely affect various life stages of ESA-listed species that may depend
on marine organisms for subsistence. Additionally, certain ESA-listed seabird species may be
attracted to, or disturbed by, disposal vessel operations. However, EPA's disposal site selection, site
management, and project evaluation processes are intended to ensure that ocean disposal produces no
long-term, adverse impacts to the marine environment and associated species. Specifically, EPA
requires evaluation of disposal sites prior to designation, determination of the need for ocean
disposal, strict testing of sediments proposed for disposal, and management and monitoring of the
sites to ensure that permit conditions are met, the sites are performing as expected, and no long-term
adverse effects are occurring to the marine environment. Further, the low quantity and short nature of
disposal operations greatly reduce the likelihood of potential interactions with ESA-listed species.
More detail is provided in in the following sections.
2 A synthesis report is not yet available for the 2017 monitoring work, but the key results are discussed in this
consultation document, and preliminary chemistry results are available in Appendix 3.
4
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3.1 Disposal Site Designation
EPA's ocean disposal site designation process includes criteria for avoiding impacts to the aquatic
environment and to human uses of the ocean to the maximum extent possible, within an economically
feasible transport distance from the area where navigation dredging must occur. The site designation
process and regulations (promulgated under the MPRSA and the National Environmental Policy Act
(NEPA) independently require evaluation of a variety of factors that minimize the potential effects of
disposal on marine species and their habitat. The MPRSA regulations at 40 CFR Part 228.5 - 228.6,
include the following disposal site selection criteria to avoid or minimize impacts on marine species
and their habitats:
• Disposal activities must avoid existing fisheries and shellfisheries (228.5(a));
• Temporary water quality perturbations from disposal within the site must be reduced to
ambient levels before reaching any marine sanctuary or known geographically limited fishery
or shellfishery (228.5(b));
• The size of disposal sites must be minimized in order to be able to monitor for and control any
adverse effects (228.5(d));
• Where possible, disposal sites should be beyond the edge of the continental shelf (228.5(e));
• The location of disposal sites must be considered in relation to breeding, spawning, nursery,
feeding or passage areas of living resources in adult or juvenile phases (228.6(a)(2));
• Dispersal and transport from the disposal site be must considered (228.6(a)(6));
• Cumulative effects of other discharges in the area must be considered (228.6(a)(7));
• Interference with recreation, fishing, fish and shellfish culture, areas of special scientific
importance and other uses of the ocean must be considered (228.6(a)(8)); and
• The potential for development or recruitment of nuisance species must be considered
(228.6(a)(10)).
Taken together, the site selection criteria are intended to ensure that EPA's ocean disposal site
designations avoid direct and indirect impacts to marine species or supporting marine habitat to the
maximum extent practicable, before any actual dredged material disposal is permitted. Based on these
site selection criteria, the five Hawai'i sites were identified as the environmentally preferred
alternative locations serving each of the five main Hawai'i port areas.
3.2 Dredged Material Testing
In addition, EPA's regulations establish strict criteria for evaluating whether dredged material is
suitable for ocean disposal (40 CFR Part 227.5-9). The regulations specify that certain prohibited
constituents, such as industrial wastes or high-level radioactive wastes, may not be disposed in the
ocean at all, while other constituents, such as organohalogen compounds or mercury, may only be
discharged if they are present in no more than "trace" amounts that will not cause an unacceptable
adverse impact after dumping. "Trace" is determined by passing a series of bioassays that address the
potential for short- and long-term toxicity and bioaccumulation. EPA and USACE have jointly
published national sediment testing guidance for conducting these evaluations in advance of
dredging, called the "Ocean Testing Manual," (OTM) (EPA, 1991).
5
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Sampling and Analysis Plans
EPA and US ACE review and approve sampling and analysis plans (SAPs) in advance of each
dredging project to ensure that the samples to be tested are representative of the material to be
dredged. The number and location of required sediment samples is informed by the volume to be
dredged and past testing history, but specific attention is focused on sampling near known or potential
sources of contamination such as outfalls, storm drains, repair yards, and industrial sites. Individual
samples may be composited for analysis only within contiguous areas expected to be subject to the
same pollutant sources and hydrodynamic factors (e.g., a single berth in a harbor). Representative
sediment collected pursuant to an approved SAP is then subjected to chemistry evaluations, toxicity
bioassays (for short-term water column and longer-term benthic impacts), and bioaccumulation tests,
as described below. The results are then compared to the same tests conducted with reference site
sediment (Note: The approved reference sediment for the Hawai'i sites is specified in the SMMP).
Sediment Chemistry Testing
An extensive list of potential contaminants of concern is measured in each sediment sample or
composite, and in the reference sediment. Standard analytes and the associated recommended
laboratory methods and target detection limits are listed in the SMMP. These include "conventional"
properties such as grain size and organic carbon content, as well as heavy metals, organotins,
hydrocarbons, pesticides, poly-chlorinated biphenyls, and dioxins/furans. EPA and USACE can add
compounds to this standard list whenever deemed necessary. Sediment chemistry results can be
compared against various sediment guidelines (such as NOAA's effects range low (ERL) and effects
range median (ERM) values) to help inform the biological testing. However, there are no "bright-
line" sediment quality standards in the way that there are for water quality standards. Therefore,
sediment chemistry results alone are rarely adequate to determine whether a sediment "passes" or
"fails" for ocean disposal suitability.
Water-Column Testing
In contrast to the seafloor where potential exposure to disposed sediment is long-term, exposure to
disposal plumes in the water column is temporary. Nevertheless, to be "suitable" for ocean disposal,
water column assessments must confirm that temporary exposure to the suspended sediment
immediately following disposal will not exceed applicable marine water-quality criteria or cause
toxicity to representative sensitive marine organisms after allowance for initial mixing and dilution.
For each tested sediment sample, organisms are exposed to a series of concentrations of elutriate
(water plus suspended particulates) to determine the toxic concentration (LC50). A 100-fold safety
factor is then applied, such that after initial mixing the water column plume may not exceed 1% of the
LC50 for the most sensitive organism tested. Three separate water-column bioassays are conducted,
with one species being a phytoplankton or zooplankton, one a larval crustacean or mollusc, and one a
fish. Species must be chosen from among a list of sensitive standard test species listed in the national
manual or specified in regional guidance.
All the Hawai'i disposal sites are offshore, in relatively deep water, where initial dilution is rapid and
disposal plumes dissipate to background levels quickly. Although potential water column effects are
assessed for every proposed project as described, water column testing alone has rarely, if ever,
"failed" a project for ocean disposal at any of the Hawai'i sites. Therefore, the potential for direct
effects to water column species, including potential seabird prey species, is considered insignificant.
Similarly, cumulative water column effects are not expected because discharges from disposal vessels
typically occur over only a few minutes, and individual disposal events are at least several hours
apart, even in the most active circumstances.
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Benthic Testing
For the benthic toxicity assessment, at least two "solid phase" bioassays are conducted. For these
tests, sediment-associated species must be used that together represent key exposure routes including
filter-feeding, deposit-feeding, and burrowing life histories. Again, the test species must be chosen
from among a list of sensitive standard test species listed in the national manual (i.e., the OTM) or
regional guidance. If organism mortality is statistically greater than in the reference sediment and
exceeds reference sediment mortality by 10% (20% for amphipods), the sediment is considered
potentially toxic and may not be approved for ocean disposal. Solid phase benthic toxicity is usually
the cause when sediments "fail" for ocean disposal.
Bioaccumulation Testing
Bioavailability - the potential for contaminants to move from the sediment into the food web - must
also be evaluated in advance for each dredging project. Bioaccumulative contaminants are selected
and evaluated by EPA for each project based on their presence in the test sediment. Benthic
organisms are then exposed to the sediment (usually for 28 days), and concentrations of the
contaminants of concern taken into the tissues are measured. The tissue concentrations are then
compared against concentrations in tissues of the same species exposed to the reference sediment.
Depending on results, tissue concentrations may also be used in trophic transfer models, and/or
compared against available benchmarks such as any relevant total maximum daily loads (TMDLs),
state or local fish consumption advisories, and Food and Drug Administration (FDA) "Action Levels
for Poisonous or Deleterious Substances in Fish and Shellfish for Human Food."
"Tier IV" Testing
In the rare circumstance when the standard testing described above is unable to support a suitability
determination for ocean disposal, the presumptive conclusion is that the sediment is not suitable, and
ocean disposal may not be approved. However, if the dredger wishes, additional non-standard testing
may be approved by EPA and USACE. Described in the OTM as "Tier IV" testing, this can include
any evaluations EPA deems necessary to generate adequate information. For example, Tier IV can
involve more or different kinds of bioassays such as chronic sublethal tests or steady-state
bioaccumulation tests, detailed site-specific risk assessments, or forensic toxicity testing procedures
(TIEs, etc.). Because Tier IV testing is "open ended," it can be quite expensive, and there is no
guarantee that it will result in sediment being approved for ocean disposal. Thus, it is rarely applied in
practice.
3.3 Alternatives Analysis
EPA's regulations restrict ocean disposal of dredged material by outlining factors for evaluating the
need for ocean disposal and requiring consideration of alternatives to ocean disposal (40 CFR Part
227.14-16). Alternatives to ocean disposal, including beneficial uses of dredged material, are
considered on a project-by-project basis to ensure that the minimum necessary volume of dredged
material is disposed at any of the ocean disposal sites. Generally, alternatives to ocean disposal in the
islands are more limited than on the mainland. However, even sediments that have been adequately
characterized and found by EPA and USACE to be suitable for ocean disposal will not be permitted
for ocean disposal if there is a practicable alternative available. For example, clean sand that is
otherwise suitable for ocean disposal generally will not be permitted for disposal if it can be feasibly
used to nourish local beaches.
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3.4 Disposal Site Management: Best Management Practices
In addition to careful site selection, extensive sediment testing prior to dredging, and evaluation of
disposal alternatives, EPA actively manages ocean disposal sites to further minimize effects. Once a
dredging project is approved for ocean disposal at one of the Hawai'i sites, additional management
measures are taken to continue to minimize the potential for adverse effects. These management
measures, outlined in the SMMP for the Hawai'i sites (2015; Appendix 2), include:
• a variety of disposal BMPs as enforceable permit conditions for each project;
• satellite tracking all disposal vessels to ensure that disposal activities occur only where and as
required (Figure 2);
• sensors on all disposal vessels to ensure that there is no significant leakage or spilling of
dredged material during transit to the disposal site, especially during transit through the
nearshore zone where corals, seagrasses, and sensitive animals are most likely to be present;
and
• tracking and sensor information reported online for each disposal trip.
AMWW-KM ||X UaiMN tUO
Trtp Overview Disposal Overview
•Tioc
Panel C
Ate Wat'MM
Aft Draft
MM
Panel A
Panel B
Figure 2. Example of a tracking report for an individual disposal trip. Panel A shows the vessel's
route to and from the disposal site, with the blue line indicating the vessel is loaded and
purple indicating it is empty following disposal. Panel B is a closeup of the disposal site's
SDZ, showing the disposal (in red) occurring fully within the zone. Panel C shows the
vessel's draft and speed throughout the trip, confmuing no substantial loss of material
from the vessel during transport.
8
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3.5 Disposal Site Management: Site Monitoring
Monitoring Methods
As a critical component of site management, EPA periodically conducts surveys of disposal sites to
confirm that no adverse, physical, chemical, or biological effects occur outside the disposal site, and
that primarily physical effects occur within site boundaries. Research conducted by EPA and US ACE
since the inception of the MPRSA has shown that the greatest potential for environmental impact
from dredged material is in the benthic environment. This is because: 1) deposited dredged material
does not mix and disperse as rapidly or as greatly as the portion of the material that may remain in the
water column, and 2) bottom-dwelling animals live within, and feed on, deposited material for
extended periods. Therefore, EPA monitoring of ocean disposal sites has focused primarily on the
benthic environment, including the sediment chemistry, physical characteristics of the benthos, and
the benthic community. EPA conducted extensive site monitoring surveys of the Hawai'i ocean
disposal sites in 2013 and 2017 (see Appendix 1 for the final report from the 2013 monitoring
surveys and Appendix 3 for the preliminary chemistry results from the 2017 survey). During these
surveys, EPA used a variety of methods to achieve the monitoring objectives, including high-
resolution multibeam echosounder surveys (MBES), sediment profile imaging (SPI) and plan view
photography (PVP), and sediment grabs for sediment chemistry and benthic infauna sampling.
MBES surveys were successfully conducted for the Nawiliwili, Kahului, and Port Allen sites in 2017
to assist in selecting survey stations for the SPI-PVP and sediment grab sampling (Figure 3). MBES
surveys were also planned for the South O'ahu and Hilo sites in 2013, but they could not be executed
due to equipment issues on the vessel. In the absence of the MBES survey data, analysis of the SPI-
PVP imagery (described below) was used to map the horizontal and vertical extent of the dredged
material footprint and to select stations for the sediment chemistry and benthic infauna sampling for
the South O'ahu and Hilo sites.
The SPI-PVP system provides a surface and cross-sectional photographic record of selected locations
on the seafloor to allow a general description of conditions both on and off dredged material deposits
(Figure 4). SPI-PVP surveys were conducted for each ocean disposal site to delineate the horizontal
extent of the dredged material footprint both within and outside the site boundaries, as well as the
status of benthic recolonization. With resolution on the order of millimeters, the SPI system is more
useful than traditional bathymetric or acoustic mapping approaches for identifying a number of
features, including the spatial extent and thickness of the dredged material footprint over the native
sediments of the seabed, the level of disturbance and recolonization as indicated by the depth of
bioturbation, the apparent depth of the redox discontinuity, and the presence of certain classes of
benthic organisms. PVP is useful for identifying surface features in the vicinity of the SPI photos,
thereby providing important surface context for the vertical profiles at each station.
Additionally, sediment samples were collected from a subset of stations at each disposal site using a
stainless steel double Van Veen sediment grab capable of penetrating a maximum of 20 cm below the
sediment surface. The samples were analyzed for sediment grain size, chemistry, and benthic
community parameters.
9
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Figure 3. High-resolution bathymetry in the vicinity of the Nawiliwili disposal site. The hard-bottom habitat
and a volcanic escarpment in the southeastern portion of the site precluded benthic sampling in that area. The
yellow box indicates the target for the general area in which the SDZ would later be repositioned (see Figure 5
for final SDZ placement).
U!r
,w L
f SP! mage
Plan-view image
. - U ^
"Down" position
1-2 meters On the transecting the sediment-
Deployed from seafioor seafloor water interface
profile
Figure 4. Schematic of deployment and collection of SPI-PVP photographs (Appendix 1).
10
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Finally, a sub-bottom profiling survey was conducted at the South O'ahu site. The primary purpose of
this survey was to collect cross-sectional images of the native sediment layers and layers indicative of
the dredged material deposit across a wide area surrounding the South O'ahu ocean disposal site. This
type of survey allowed EPA to separately estimate the cumulative volume of dredged material
disposed at the South O'ahu site, compared to volumes permitted for disposal. The South O'ahu site
was selected for the survey, because it receives the most dredged material out of the five Hawai'i
ocean disposal sites.
Monitoring Results
Sediment chemistry. Sediment samples from both inside and outside each of the five Hawai'i
disposal sites were collected successfully and analyzed for the same compounds evaluated during pre-
disposal testing. The bulk chemistry data from the 2013 monitoring surveys showed generally low,
but variable, concentrations of most chemical constituents at the South O'ahu and Hilo sites (the most
frequently used sites) (Appendix 1). The few concentrations above screening levels were relatively
minor in magnitude and, in many cases, were seen at stations both inside and outside the sites. The
few constituents that were at higher concentrations within the disposal sites reflect the contaminant
levels in the dredged material approved for discharge. Because sediments that contain pollutants in
toxic amounts, or elevated levels of compounds that may bioaccumulate in benthic organisms, are
prohibited from ocean disposal, the chemical concentrations identified are not considered to represent
a risk of environmental impacts in and of themselves. Instead, these low concentrations indicate that
the pre-dredge sediment testing regime is adequately protecting the environment of the disposal sites
by identifying and excluding more highly contaminated sediments from being disposed. Sediment
chemistry was also collected at the Nawiliwili, Kahului, and Port Allen ocean disposal sites, and is
currently being analyzed for results (preliminary results are available in Appendix 3). Preliminary
screening indicates that, similar to the South O'ahu and Hilo sites, the majority of chemical
concentrations fell below the ERL, and the few concentrations above screening levels were relatively
minor in magnitude and, in most cases, were seen at stations both inside and outside the sites.
Physical substrate. Physical substrate was assessed primarily through SPI-PVP imagery. Monitoring
confirmed that minor physical (substrate) changes have occurred at the disposal sites compared to
pre-disposal baseline data from 1980. Results of the 2013 survey indicated that a detectable dredged
material footprint extended outside of the South O'ahu site, however there have been no documented
"short-dumps" (i.e., discharge or loss of dredged material during transit to an ocean disposal site,
prior to arrival at the site) since EPA required satellite-based tracking of all disposal scows in the
early 2000s, with the exception of a single partial mis-dump that occurred in 2006. Thus, the footprint
outside the South O'ahu disposal site boundary would appear to be relic material deposited more than
10 years ago. At the Hilo site, the substantially smaller cumulative volume of dredged material
disposed (Table 2) appeared to be more fully confined within the designated disposal site boundary.
The results of the 2017 survey indicated that recently disposed dredged material, including coral and
pebble rubble, was present on the seafloor surface within and near the Nawiliwili ocean disposal site.
However, the commonplace presence of coral rubble and other coarse materials and sands at the
seafloor surface across the survey area confounded definitive delineation of the dredged material
footprint. Surveys at Port Allen and Kahului also indicated that the dredged material footprint was
primarily contained within the site boundary, yet some material was detectable beyond the designated
boundary to some extent at both sites. Again, because EPA has required satellite-based tracking of all
disposal scows since the early 2000s, and mis-dumping has not occurred at least since then, the
dredged material observed outside the sites is also assumed to be relic material. Additionally, due to
11
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benthic activity, dredged material was witnessed to have been reworked into the sediment. For
example, all material at the Port Allen ocean disposal site was observed to have been reworked into
the sediment column by biota to some extent and no thick deposits were observed.
Benthic community. The benthic community was assessed through both SPI imagery and sediment
grab samples. Overall, the changes in substrate may partially account for minor differences in
infaunal assemblages found during the 2013 monitoring at the South O'ahu and Hilo sites (the most
heavily used of the Hawai'i disposal sites). However, minor benthic community changes were also
seen outside those disposal sites and so appear to be partially attributable to region-wide variability as
well. In addition, there were no apparent adverse effects to the infaunal community associated with
the presence of dredged material at the Kahului and Port Allen ocean disposal sites. The vast majority
of stations across both survey areas supported stable benthic structure or advanced stages of infaunal
recolonization. The presence of advanced recolonization at stations containing dredged material
indicates that the benthic community has recovered at these locations post-disposal activity. Because
the Nawiliwili site was so heterogeneous, benthic community grab samples were not successfully
collected inside the site for comparison to the benthic community outside the site. However, the one
SPI replicate that achieved sufficient penetration near the center of the Nawiliwili site indicated the
presence of stage 3 (advanced) fauna. Additionally, as previously mentioned, disposal volumes at
Nawiliwili are relatively low, and preliminary screening of chemistry results indicated that dredged
material disposed did not appear to result in contaminant loading, as most of the contaminants were
below the ERL, and the few concentrations above screening levels were found both inside and
outside of the site. Therefore, all available results from Nawiliwili indicate that dredged material
disposed did not adversely affect the benthic environment. In summary, monitoring at all five sites
confirmed that recolonization begins soon after dredged material is deposited, and that similar
infaunal and epifaunal communities occupy areas both inside and outside the disposal sites. Thus,
long-term impact to benthic habitat quality are considered insignificant and largely contained within
the site boundaries.
3.6 Disposal Site Management: An Adaptive Approach
Ongoing use of the five existing Hawai'i ocean disposal sites will not increase the need for dredging
in Hawai'i, nor the amount of ocean disposal of dredged material that occurs. It is therefore expected
that there would similarly be a lack of significant impacts in the future, provided that the ocean
disposal sites continue to be managed under the same or similar requirements. EPA proposes to
continue managing the five existing Hawai'i disposal sites under site use conditions and BMPs that
are substantially the same as those currently in place (see Appendix 2). The only substantive change
in site management is the recent relocation of the SDZ within the existing Nawiliwili site, as shown
in Figure 5, and as incorporated in permit conditions for the site.3 This change was made based on
the results of the 2017 monitoring survey, which identified hard-bottom habitat (including a volcanic
escarpment, marking the ancient shoreline) in the southeastern portion of the Nawiliwili site (Figure
3). The relocated SDZ will avoid future deposition of sediment on the hard-bottom habitat and
facilitate future monitoring of dredged material discharges on the natural sediment habitat in the
northwestern portion of the site. This relocation of the SDZ is an example of EPA's adaptive
approach to site management.
3 The new SDZ will also be reflected in the updated SMMP, to be published following completion of these
consultations.
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N
S
ODMDS Boundary
Realigned SOZ
Original SDZ
0 0.250.5 1 Miies
1 I I I I I I I J
Sourcti' (in GfBCO NOt&A Njtonjl Omqij^c Gvewi,
Hlk£ Gww^*t ind olhM t»ib
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Additionally, the BMPs included in EPA's SMMPs become enforceable conditions when attached to
the USACE's ocean disposal permits. Those conditions can include requirements that minimize the
risk of impacts should a violation occur, such as seasonal limitations or specified transit routes to and
from the disposal site. These kinds of specifications have not been applied to the Hawaii ocean
disposal sites in the past, but where necessary and feasible they could be included in the SMMP or in
individual permits.
3.8 Vessel Transit and Disposal Operations
As previously mentioned, the volumes disposed at the Hawai'i sites are quite modest compared to
other disposal volumes in Region 9. EPA has endeavored to estimate the percent of local vessel
traffic that is comprised of disposal vessels, to determine the likelihood that disposal vessels may
interact with ESA-listed species.
In this assessment, EPA first attempted to estimate the number of transits conducted by disposal
vessels. Individual disposal events discharge anywhere from approximately 1,000 cy (which is typical
for many harbor dredging projects, where clam shell-dredged material is placed into towed scows) to
as much as 5,000 cy at a time (typical for USACE hopper dredging loads). A total of 1.24 million
cubic yards was disposed at the five Hawai'i sites combined, in the 10-year period from 2009 to
20184. This equates to a range of 495 to 2,475 total transits to and from the Hawai'i ocean disposal
sites during that time (Table 3).
Table 3. Volume of dredged material disposed, and minimum and maximum number of disposal trips, to and
from all Hawai'i ocean disposal sites in from 2009-2018.
Ocean
Disposal Site
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Total
South O'ahu
126,200
18,260
312,080
351.920
53,900
862,360
Hilo
63,879
70,981
118,300
253,160
Kahului
57,200
57,200
Nawiliwili
64,700
64,700
Port Allen
Total All Sites
126,200
82,139
70,981
312,080
351,920
294.100
1,237,420
Min. # of
Trips (both
ways)
50
33
28
125
141
118
495
Max. # of
Trips (both
ways)
252
164
142
624
704
588
2,475
4 This specific ten-year period was selected for comparison to the most recent vessel transit data available on the USACE
waterborne commerce database (USACE, 2020b).
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EPA then estimated total vessel traffic by examining commercial vessel traffic from the US ACE
waterborne commerce database (US ACE, 2020b) and the_Hawai'i Department of Land and Natural
Resources (DLNR) commercial fishing database (Hawai'i DLNR, 2020). The US ACE database
includes transits from self-propelled and non-self-propelled dry cargo ships (including passenger
vessels and cruise ships), self-propelled and non-self-propelled tankers, self-propelled towboats, and
non-self-propelled tanker liquid barges. Vessel transits were compiled from all ports in Hawai'i for
which there are records in the database. Over the most recent ten-year period in the database (2009 to
2018) there were a total of 144,925 transits from the ports examined (Table 4; USACE, 2020b). The
DLNR database contains fishing reports from licensed commercial fishermen, including the number
of trips conducted per year by location. EPA compiled all trips reported from 2009 to 2018, and
multiplied the number by two to account for total transits in both directions. In total, there were
125,966 transits (62,983 trips) conducted in Hawai'i from 2009 to 2018 (Table 5; Hawai'i DLNR,
2020).
Table 4. Ten-year commercial vessel transits by port (USACE, 2020b). These numbers of transits include
receipt (incoming) and shipment (outgoing) transits, but do not include fishing vessels.
Port
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
Total
Porl of
Honolulu
4,207
5,147
5,689
8,435
6,653
4,870
5,716
8,013
6,881
7,029
62.640
Kahului
1,400
1,359
1,601
2,617
2,044
1,357
1,779
2,917
1,967
2,026
19,067
Port Allen
0
0
0
0
0
0
0
0
0
0
0
Hilo
1,066
1,082
1,184
1,815
1,405
1,141
1,262
2,034
1,473
1,499
13,961
Nawiliwili
984
1,057
1,172
1,762
1,340
968
1,019
4,175
1,149
1,091
14,717
Pearl Harbor
0
0
0
0
0
0
0
0
0
0
0
Barbers
Point Harbor
1,482
1,661
2,415
2,327
2,074
1,938
2,049
1,614
1,784
1,860
19.204
Kaunakakai
11
142
252
230
245
246
303
227
411
430
2,497
Kawaihae
Harbor
756
852
907
1,527
1,095
692
1,011
3,509
1,307
1,183
12.839
Total
9,906
11,300
13,220
18,713
14.856
11.212
13,139
22,489
14,972
15.118
144,925
Table 5. Ten-year commercial fishing vessel trips and transits in Hawai'i (DLNR commercial fishing
database).
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
Total
Total Trips
4,652
3,916
3,664
4.951
4.944
5,876
9,783
9,258
8,199
7,740
62,983
Total Transits
9,304
7,832
7,328
9,902
9,888
11,752
19,566
18,516
16,398
15,480
125,966
15
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To estimate the proportion of vessel traffic attributed to disposal vessels, EPA divided the total
transits from disposal vessels by the total transits from commercial vessels reported in the two
databases (270,981). Therefore, the ten-year estimate of 495 to 2,475 disposal vessel transits only
constitutes 0.18% to 0.91% of the total commercial vessel transits.
It is important to note that this estimate of total vessel transits over a ten-year period is highly
conservative, as the combined numbers from the US ACE and DLNR databases do not include local
and foreign military nor recreational vessels. Therefore, disposal vessels realistically account for an
even lower percentage of vessel traffic than estimated in this document.
Furthermore, when disposal vessels arrive to the ocean disposal site, individual disposal events only
last two to four minutes at the surface, and upper water column plumes dissipate to background levels
quickly. The low number of transits, combined with the short duration of disposal operations, greatly
reduces potential for interactions with ESA-listed species.
4.0 ESA SPECIES ASSESSMENTS
The five Hawai'i ocean disposal sites have been in use since 1981. Seafloor monitoring has not
identified any unacceptable adverse impacts resulting from previous disposal, and significant adverse
effects are not expected in the future, due to sediment quality testing procedures and site management
measures, including compliance requirements for vessel tracking. It is anticipated that the use of the
sites can continue indefinitely from a capacity standpoint. However, the transit of disposal vessels to
and from the sites has the potential to disturb seabirds that may be present. Therefore, EPA has
determined that continuing use of the five Hawai'i ocean disposal sites may affect, but is unlikely to
adversely affect, the short-tailed albatross {Phoebastria albastrus), Hawaiian petrel (Pterodroma
sandwichensis), band-rumped storm-petrel (Oceanodroma castro), and Newell's shearwater {Puffinus
auricularis newelli) (Table 5). There is no designated critical habitat within the disposal sites and
transit area. A general discussion pertaining to all four ESA-listed species is outlined in Section 4.1,
and species-specific information in provided in Sections 4.2-4.5, The purpose of this informal
consultation is to request US Fish and Wildlife Service concurrence with our "may effect, but not
likely to adversely affect" determination for these listed species.
Table 6. USFWS-managed species under ESA in the Pacific Islands Region (USFWS list from 10/7/2019).
Species
Status
EPA Recommendation
Short-tailed albatross (Phoebastria
albastrus)
Endangered
May affect, not likely to
adversely affect
Hawaiian petrel (Pterodroma
sandwichensis)
Endangered
May affect, not likely to
adversely affect
Band-rumped storm-petrel (Oceanodroma
castro)
Endangered
May affect, not likely to
adversely affect
Newell's shearwater (Puffinus auricularis
newelli)
Threatened
May affect, not likely to
adversely affect
16
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4.1 Potential Impact Summary
Seabirds derive their food from the sea, and their distribution at sea is influenced by oceanographic
and biological processes operating at various temporal and spatial scales. The most serious threats to
seabirds in the Pacific Region include invasive species, fisheries interactions, oil and other pollution,
habitat loss and degradation, disturbance, and climate change (USFWS, 2005). Transiting disposal
vessels may potentially affect ESA-listed seabirds directly through attraction to, or disturbance from,
the vessel itself. Ocean disposal of dredged material may also affect ESA-listed seabirds indirectly
through food chain effects, resulting from potential short-term adverse effects to marine organisms in
the water column, and long-term effects to seafloor habitats and species.
However, most marine species are generally more susceptible to potential impacts associated with
dredging itself, rather than from open water transit and disposal. Dredging typically occurs in
relatively enclosed waterbodies that may have restricted movement pathways, limiting animals'
ability to avoid or minimize exposure to noise or turbidity. If the sediment being dredged is
contaminated, there may also be increased risk of exposure of prey species to resuspended
contaminants, depending on the presence and effectiveness of dredging control measures such as silt
curtains or timing restrictions. Dredging may also alter natural hydrology, potentially degrading
estuarine nesting and roosting habitat (USFWS, 2005). Seabirds could be attracted to the dredging
operations by the presence of dead and disoriented marine organisms brought to the surface, which
could constitute a new foraging resource (US DOI, 2009). Additionally, seabirds may avoid dredging
operations because of the increased noise, or be attracted to the light source (US DOI, 2009). Yet,
potential impacts from dredging itself are assessed by USACE on a project-specific basis, during the
US ACE permitting process and not as part of EPA site designation or updates to site management and
monitoring plans.
In contrast, regardless of where or when the dredging occurs, placement of the sediment at any of the
five Hawai'i offshore disposal sites has significantly less potential to affect ESA-listed seabird
species, both directly from vessel operations, and indirectly from food chain effects, due to the
following:
1. The sites were designated in locations originally selected to minimize impacts by avoiding
any unique or limited marine habitats to the extent practicable (Section 3.1), thereby
minimizing effects to important food chain organisms.
2. Only "suitable" (non-toxic) dredged material is permitted to be disposed. Rigorous pre-
dredging testing occurs to determine suitability for disposal. The testing examines persistence,
toxicity, and bioaccumulation to ensure that material disposed will not cause an unacceptable
adverse impact after dumping. This testing therefore ensures that species in the marine food
chain are not exposed to toxic sediments, limiting any potential biomagnification through the
food chain (Section 3.2). As confirmed by EPA monitoring and modelling, no short- or long-
term contaminant exposure concerns are associated with the discharged sediment.
3. Each disposal vessel is closely tracked during transit through the nearshore zone. This
tracking includes sensors to detect any substantial leaking or spilling of material that could
increase turbidity and suspended sediment outside of the disposal site. Disposal vessels that
leak or spill must be removed from service and repaired before being approved for continued
use (refer to Section 3.7 on enforcement for more details on how violations may be
addressed). This management measure further prevents harm to marine ecosystems that may
sustain prey for ESA-listed seabird species.
17
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4. Disposal vessel traffic generally comprises a very low percent of the total vessel traffic in the
area (less 0.34 to 1.71%; Section 3.8), therefore greatly reducing the potential for interaction
with ESA-listed seabird species.
5. Disposal vessel operations are spatially limited, as they only comprise transit to and from, and
disposal in, the ocean disposal sites. In contrast, seabird species are highly mobile and
generally have large foraging ranges. Therefore, any interruption of seabird movement or
foraging due to disposal vessel transit operations is discountable.
6. Disposal vessel operations are temporally limited: Individual disposal events only last two to
four minutes at the surface, and upper water column plumes dissipate to background levels
quickly. Sediments whose plumes would result in any toxicity to sensitive water column
organisms after initial mixing (including a 100-fold safety factor) may not be permitted for
ocean disposal. The short duration of the disposal reduces potential for direct interactions with
ESA-listed seabird species in the area (Section 3.8). Further, the short duration of the
disposal, as well as the low toxicity in the water column (Section 3.2) ensures that any
potential prey species is unlikely to be widely impacted by any contaminants in the water
column. Therefore, both the direct or indirect effects of disposal activity on seabird foraging
quality or success is insignificant.
7. Disposal vessels do not discharge large quantities of material that may attract seabirds, such as
offal or fisheries discards (although some of the benthic organisms that are incidentally
removed with the dredged sediment, such as worms or clams, may be temporarily available
for opportunistic capture by seabirds during disposal itself).
8. During dredging, EPA requires the use of a "grizzly" to capture and remove debris that may
present entanglement hazards, before the dredged material may be disposed at sea.
For these reasons, it is appropriate to programmatically assess the potential impacts of disposal of
suitable material at EPA-designated ocean disposal sites and to programmatically apply necessary
avoidance and minimization measures in the SMMP. USACE then includes the disposal sites'
programmatic disposal restrictions (as well as any dredging-related restrictions) as enforceable
conditions in individual permits for dredging projects.
4.2 Short-Tailed Albatross (Phoebastria albastrus)
The short-tailed albatross is the largest albatross in the north Pacific, with a wingspan averaging more
than 7 feet. The average lifespan of an individual is between 12 and 45 years (USFWS, 2020a). The
range of the short-tailed albatross extends from Siberia south to the China coast, into the Bering Sea
and Gulf of Alaska south to Baja California, Mexico, and throughout the North Pacific, including the
Northwestern Hawaiian Islands (COSEWIC, 2003; Harrison, 1984; Figure 6). Short-tailed
albatrosses are typically found in the open ocean and tend to concentrate along the edge of the
continental shelf (NatureServe, 2020a). The short-tailed albatross feeds primarily at the water surface
on squid, crustaceans, and fishes. It has been known to occasionally follow fishing vessels
discharging scraps and offal (USFWS, 2012). The breeding range of the species is limited almost
entirely to two islands: Torishima Island, approximately 580 kilometers south of Japan, and Minami-
kojima, about 270 kilometers northeast of Taiwan (NatureServe, 2020a).
The short-tailed albatross was listed as endangered in 1970 (USFWS, 2020a). Its restricted breeding
range makes the species highly vulnerable to any threats at its breeding locations, such as the
potential of a volcanic eruption on the main breeding site (Torishima). Other threats to the short-
tailed albatross include incidental catch in commercial fisheries, ingestion of plastics, contamination
by oil and other pollutants, and nesting space competition with non-native species.
18
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Although found in Hawai'i, the short-tailed albatross is very rare and primarily found on Midway
Atoll (Hawai'i DNLR, 2005). Given the low numbers of short-tailed albatrosses that visit the
Hawaiian Islands, the small number of disposal events each year, and the lack of potential for long-
term effects to upper water column prey species, EPA believes that continued operation of the five
Hawai'i ocean disposal sites may affect but is not likely to adversely affect this species.
Vancouver
San Frudico
Lot Angctei
Mexico City
Figure 6. Species range of the short-tailed albatross (Phoebastrici albastrus) (USFWS, 2020a).
4.3 Hawaiian Petrel (Pterodroina sandwichensis)
The Hawaiian petrel breeds in several colonies throughout the Hawaiian Islands, with the main
colony in Haleakala National Park, Maui (NatureServe, 2020b; Figure 7). Individuals measure an
average of 16 inches in length, with a wingspan of around 3 feet (USWFS, 2020b). The Hawaiian
petrel feeds primarily on marine organisms such as squid, fishes, and crustaceans.
The Hawaiian petrel was listed as endangered in 1967 (USFWS, 2020b). The greatest threat to this
species is predation by mongooses and feral cats. In some cases, predation has caused more than 70
percent nesting failure (USFWS, 2005). Other threats include mosquito-borne diseases, collision with
human-made obstacles, light attraction and subsequent groundings, and habitat destruction (Ainley
and Podolsky, 1993; Simons and Hodges, 1998).
Disposal vessels may transit through areas in which Hawaiian petrels are found. However, given the
relatively small number of disposal events each year, the temporary nature of disposal plumes in the
water column, and the non-toxic nature of materials disposed, EPA believes that continued operation
of the five Hawai'i ocean disposal sites may affect but is not likely to adversely affect the Hawaiian
Petrel.
19
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UNITE OtfTRTES
Figure 7. Species range of Hawaiian petrel (Pterodroma sctndwichensis) (USFWS, 2020b).
4.4 Band-Rumped Storm-Petrel (Ocecinodroma castro)
The band-rumped storm petrel can grow to between 7 to 9 inches, with a wingspan of approximately
17 inches. Storm-petrels are the smallest of all the oceanic seabirds (Onley and Scofield, 2007). They
range throughout the Hawaiian Islands (Figure 8) and are known to nest in remote cliff locations on
Kaua'i and Lehua Island, and on high-elevation lava fields on Hawai'i Island (USFWS, 2020c). They
are often observed in coastal waters around Kaua'i, Niihau, and Hawai'i Island. Band-rumped storm
petrels are known to forage diurnally and primarily in deep waters, but are suspected to forage
nocturnally. They are also known to be attracted to offal and discards from fishing vessels (Onley and
Scofield, 2007).
The band-rumped storm petrel was listed as endangered in 2016 (USFWS, 2020c). This species is
threatened by natural catastrophes such as hurricanes and landslides, predation by introduced rats,
mice, cats, mongooses, and pigs, and collisions with power lines and streetlights at night (USFWS,
2005). Additional threats include commercial fishing, plastic pollution, and the loss and degradation
of forested habitat.
Disposal vessels may transit through areas in which band-rumped storm petrels are found. However,
the band-rumped storm petrel is one of the rarest seabirds in Hawai'i (Hawai'i DLNR, 2015a).
Therefore, given the low numbers of individuals and the small number of disposal events each year, it
is unlikely that disposal vessels may encounter and disturb band-rumped storm petrels. In addition,
given the temporary nature of disposal plumes in the water column and the non-toxic nature of
materials disposed, EPA believes that continued operation of the five Hawai'i ocean disposal sites
may affect but is not likely to adversely affect the band-rumped storm petrels.
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Honolulu
UNITED S
Hmhi
Hllo
o
Figure 8. Species range of band-ramped storm-petrel (Oceanodromct castro) (USFWS, 2020c).
4.5 Newell's shearwater {Puffinus auricularis newelli)
The Newell's shearwater is a medium-sized shearwater measuring 12 to 14 inches with a wingspan of
30-35 inches (USFWS, 2020d). It has a small breeding range in the Hawaiian Islands, almost entirely
restricted to Kaua'i. The Newell's shearwater's movements are strongly nocturnal (Day and Cooper,
1995). They feed on fish, plankton, and occasionally garbage from ships (NatureServe, 2020c). They
spend most of their time in the open ocean year-round (USFWS, 2005) and come ashore only to nest.
The Newell's shearwater was listed as threatened in 1975 (USFWS, 2020d). Primary threats to this
species include introduced predators and disorienting artificial lighting. The two most important
factors limiting population growth are low breeding probability and high rates of predation on adults
and subadults (USFWS, 2011). Predator control in key habitat areas, the establishment of Bird
Salvage-Aid Stations, translocation, and light attraction studies have been initiated to help save the
Newell's shearwater.
Estimates of the Newell's shearwater breeding population indicate that approximately 75 to 90% of
the breeding population nests on Kaua'i (Hawai'i DLNR, 2015). Therefore, this species would be
most likely to potentially interact with vessels transiting to and from the Nawiliwili and Port Allen
disposal sites. However, these two sites combined have only received an average of just over 11,000
cy of material each year. In terms of transits, this translates to approximately 2 to 11 round trips to the
disposal site each year on average. Given the low number of disposal trips, the temporary nature of
disposal plumes in the water column, and the non-toxic nature of materials disposed, EPA believes
that continued operation of the five Hawai'i ocean disposal sites may affect but is not likely to
adversely affect the Newell's shearwater.
21
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Honolulu
UNITED STATES
Hilo
Hm All
Figure 9. Species range of NewelFs shearwater (Piifftnus anricularis newelli) (USFWS, 2020d).
6.0 CONCLUSIONS
Theoretically, transiting disposal vessels may potentially affect ESA-listed seabirds directly through
attraction to, or disturbance from, the vessel itself. Ocean disposal may also affect ESA-listed
seabirds indirectly through food chain effects, including potential short-term, adverse effects to
marine organisms in the water column. In this informal consultation package, EPA has described the
continued use of the Hawai'i ocean disposal sites, as well as the use of the sites to date and the EPA
regulations and management measures in place to avoid impacts to marine organisms and the marine
environment. EPA also presented the extensive monitoring that the agency has conducted at the sites,
the results of which indicate that existing management practices have been successful at avoiding and
minimizing adverse impacts. In summary, EPA's ocean disposal site selection, rigorous pre-disposal
sediment testing, and site management measures help to ensure that adverse effects to listed species
are avoided and minimized.
Based on the analysis provided in the sections above, EPA has determined that the continued use of
the five Hawai'i ocean disposal sites may affect but is not likely to adversely affect ESA-listed
seabird species. We have used the best scientific and commercial data available to complete this
analysis.
22
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7.0 REFERENCES
Ainley, D. G., R. Podolsky, L. de Forest, G. Spencer, andN. Nur. 1995. The ecology ofNewell's
Shearwater and Dark-rumped Petrel on the island of Kaua'i. Final report task 2 to the Electric
Power Research Institute, Palo Alto, California.
Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2003. COSEWIC
Assessment and Status Report on the Short-tailed Albatross Phoebastrie albatrus in Canada.
Ottawa, Canada: Canadian Wildlife Service.
Day, R. H., and B. A. Cooper. 1995. Patterns of movement of dark-rumped petrels and Newell's
shearwaters on Kaua'i. Condor 97:1011-1027.
EPA. 1991. Evaluation of Dredged Material Proposed for Ocean Disposal. EPA 503/8-91/001.
https://www.epa.gov/sites/production/files/2Q15-10/documents/green book.pdf
Harrison, C. S., M. B. Naughton, and S. I. Fefer. 1984. The status and conservation of seabirds in the
Hawaiian Archipelago and Johnston Atoll. Pages 513-526 in Croxall et al., eds. Status and
conservation of the world's seabirds. ICBP Tech. Pub. No. 2.
Hawai'i DLNR. 2005. Fact Sheet: Short-tailed albatross. Hawai'i Comprehensive Wildlife
Conservation Strategy. Retrieved from: https://dlnr.hawaii.gov/wildlife/files/2013/Q9/Fact-
Sheet-short-tailed-albatross.pdf.
Hawai'i DLNR. 2015a. Fact Sheet: Band-rumped storm petrel. Hawai'i Comprehensive Wildlife
Conservation Strategy. Retrieved from: https://www.mauinuiseabirds.org/wp-
content/uploads/Band-rumped-Storm-petrel.pdf
Hawai'i DLNR. 2015b. Fact Sheet: Newell's shearwater. Hawai'i Comprehensive Wildlife
Conservation Strategy. Retrieved from: https://dlnr.hawaii.gov/wildlife/files/2019/Q3/SWAP-
2015-Newells-shearwater-Final.pdf
Hawai'i DLNR. 2020. Commercial Fishing Reports. Available at:
https://dlnr.hawaii.gov/dar/fishing/commercial-fishing/
NatureServe. 2020a. Species profile for the short-tailed albatross. Retrieved from:
https://explorer.natureserve.org/Taxon/ELEMENT GLOBAL.2.103001/Phoebastria albatrus
NatureServe. 2020b. Species profile for the Hawaiian petrel. Retrieved from:
https://explorer.natureserve.org/Taxon/ELEMENT GLOBAL.2.100488/Pterodroma sandwic
hensis
NatureServe. 2020c. Species profile for the Newell's shearwater. Retrieved from:
https://explorer.natureserve.org/Taxon/ELEMENT GLOBAL.2.104360
Onley, D., and P. Scofield. 2007. Albatrosses, Petrels and Shearwaters of the World. Princeton, NJ:
Princeton University Press.
Simons, T. R., and C. N. Hodges. 1998. Dark-rumped Petrel (Pterodroma phaeopygia). In A. Poole
and F. Gill (editors). The Birds of North America, No. 345. The Birds of North America, Inc.
Philadelphia, Pennsylvania.
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US ACE. 2020a. Ocean Dredged Material Disposal Site Database. Available at:
http s://odd.el.erdc. dren .mil/
US ACE. 2020b. Waterborne Commerce Database. Available at: http://cwbi-ndc-nav.s3-website-us-
east-l.amazonaws.eom/files/wcsc/webpub/#/report-landing/vear/2017/region/4/location/4420
US DOI. 2009. Charleston Offshore Dredged Material Disposal Site Sand Borrow Project. Final
Environmental Assessment. US Department of Interior Minerals Management Service
Environmental Division. Prepared by Moffat and Nichol Engineers. OCS EIS/EA MMS 2009-
045. https://www.boem.gov/sites/default/files/documents/marine-minerals/mmp-vour-
state/CharlestonODMDS20Q9Final.pdf
USFWS. 2005. Regional Seabird Conservation Plan, Pacific Region. Portland, OR: U.S. Fish and
Wildlife Service, Migratory Birds and Habitat Programs, Pacific Region.
USFWS. 2011. Newell's Shearwater (Puffinus auricularis newelli) 5-year Review: Summary and
Evaluation. Honolulu, HI: U.S. Fish and Wildlife Service.
USFWS. 2012. Threatened and endangered species fact sheet: Short-tailed albatross (Phoebastria
albastrus). Retrieved from: https://www.fws.gov/migratorybirds/pdf/education/educational-
activities/Short-tailedalbatrossfactsheet.pdf.
USFWS. 2020a. Species profile for the Short-Tailed Albatross. Retrieved from
https://ecos.fws.gov/ecp/species/433.
USFWS. 2020b. Species profile for the Hawaiian Petrel. Retrieved from
https://ecos.fws.gov/ecp/species/6746.
USFWS. 2020c. Species profile for the Band-Rumped Storm Petrel. Retrieved from
https://ecos.fws.gov/ecp/species/1226.
USFWS. 2020d. Species profile for the Newell's Shearwater. Retrieved from
https://ecos.fws.gov/ecp/species/2048.
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Appendix 1 to EPA Consultation with USFWS
for Continued Use of Five Existing Ocean Dredged Material Disposal Sites (ODMDS)
in Waters Offshore of Hawaii
Site Monitoring Synthesis Report
(2015)
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2013 HAWAII OCEAN DISPOSAL SITE MONITORING
SYNTHESIS REPORT
Prepared by:
Dredging and Sediment Management Team
USEPA Region 9
San Francisco, CA
April 27, 2015
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table of Contents
Executive Summary 1
I. Introduction and Background 1
II. Summary of Site Monitoring Activities 7
2.1. Sediment Profile Imaging (SPI) and Plan View Photography (PVP) 7
2.2. Sediment Sampling for Chemistry and Benthic Communities 13
2.3. Sub-Bottom Profiling Survey of the South Oahu ODMDS 15
III. Survey Results 17
3.1. SPI-PVP Surveys 17
3.1.1 Dredged Material Footprint Mapping 17
3.1.2 Bioturbation Depth 17
3.1.3 Infaunal Successional Stage 24
3.1.4 PI an-View Photography 27
3.1.5 Discussion: SPI-PVP Surveys 30
3.2. Sediment Physical and Chemical Survey Results 30
3.2.1 Physical Results 31
3.2.2 Chemical Results 31
3.3. Benthic Community Analysis Results 34
3.3.1 Abundance of Infauna 34
3.3.2 Diversity of Infauna 35
3.4. Sub-Bottom Profiling Survey (South Oahu Site Only) 36
3.5. Comparison to 1980 Baseline Information 43
3.5.1 South Oahu Disposal Site 43
3.5.2 Hilo Disposal Site 44
IV. Conclusions and Recommendations 46
V. References 47
Appendix: Summary of Planned vs Actual Survey Activities at Hawaii Ocean Dredged
Material Disposal Sites, 2013 A-l
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
List of Figures
Figure 1. Five ocean dredged material disposal sites serve Hawaii ports and harbors. 3
Figure 2. General location of the South Oahu ocean dredged material disposal site. 4
Figure 3. General location of the Hilo ocean dredged material disposal site. 5
Figure 4. SPI-PVP camera system being deployed from the Hi'ialakai. 8
Figure 5. Schematic of deployment and collection of plan view and sediment profile
photographs. 9
Figure 6. Soft-bottom benthic community response to physical disturbance (top
panel) or organic enrichment (bottom panel). 10
Figure 7. Planned (yellow squares) and actual sample station locations at the South
Oahu ODMDS. 11
Figure 8. Planned and actual sample station locations at the Hilo ODMDS. 12
Figure 9. Double Van Veen sediment sampler deployed from the Hi'ialakai. 13
Figure 10. Subsampling from the Van Veen grab for sediment chemistry. 14
Figure 11. Processing a sediment sub-sample for chemical analysis. 14
Figure 12. Processing a sediment sample for benthic community analysis. 15
Figure 13. Sub-bottom profiler equipment - used only at the South Oahu site. 16
Figure 14. Planned transect lines for the sub-bottom profiling survey around the
South Oahu ODMDS. 16
Figure 15. Profile images from the ambient bottom at the Hilo ODMDS (left,
Station S3) and the South Oahu site (right, Station S6). 18
Figure 16. Plan view images of the dredged material deposit compared to the native
seafloor at South Oahu. 19
Figure 17. Profile images from two Hilo Stations showing a surface layer of disposed
coarse white dredged sand. 20
Figure 18. Dredged material footprint identified at the South Oahu site. 21
Figure 19. Dredged material footprint identified at the Hilo site. 22
Figure 20. Plan view image from the center station of the Hilo ODMDS shows a
high density of small rock and coral rubble. 23
Figure 21. Bioturbation depth at the South Oahu site. 25
Figure 22. Bioturbation depth at the Hilo site. 26
Figure 23. Community structure at the South Oahu site. 28
Figure 24. Community structure at the Hilo site. 29
Figure 25. USGS shaded-relief image showing the boundary of the sub-bottom
survey area around the South Oahu disposal site, as well as major
bedforms in the vicinity. 37
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
List of Figures, cont.
Figure 26. USGS sidescan sonar (backscatter) image showing historic dredged
material deposits around the sub-bottom survey area and the South
Oahu disposal site. 38
Figure 27. Transect lines occupied for the sub-bottom profiling survey of the South
Oahu site. 39
Figure 28. Geological (surface) interpretation from the sub-bottom profiling survey
superimposed with the SPI-based dredged material footprint map shown
in Figure 17. 40
Figure 29. Sub-bottom profile for Diagonal Line 1. 41
Figure 30. Comparison of South Oahu site dredged material volume estimates. 42
List of Tables
Table 1. Disposal volumes (cubic yards) at the 5 Hawaii ODMDS following
designation in 1980. 6
Table 2. Summary of sediment chemistry for the South Oahu Ocean Dredged
Material Disposal Site and vicinity. 32
Table 3. Summary of sediment chemistry for the Hilo Ocean Dredged Material
Disposal Site and vicinity. 33
Table 4. Infaunal species abundances at the South Oahu site. 35
Table 5. Infaunal species abundances at the Hilo site. 35
Table 6. Average Percent Grain Size - South Oahu Site. 43
Table 7. Trace Metal Concentrations - South Oahu Site. 43
Table 8. Percent Abundance - South Oahu Site. 44
Table 9. Average Percent Grain Size - Hilo Site. 44
Table 10. Trace Metal Concentrations - Hilo Site. 45
Table 11. Percent Abundance - Hilo Site. 45
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
2013 HAWAII OCEAN DISPOSAL SITE MONITORING
SYNTHESIS REPORT
EXECUTIVE SUMMARY
In 1981, the US Environmental Protection Agency (EPA) designated five ocean dredged material
disposal sites (ODMDS) offshore of Hawaiian Island ports and harbors. In 1997, EPA and the US
Army Corps of Engineers (USACE) published a Site Monitoring and Management Plan (SMMP)
covering all five of these disposal sites. But since that time, due to lack of available funding, the
sites have not been comprehensively monitored and the SMMP has not been updated. Therefore,
when funding became available for 2013, EPA identified the Hawaii sites as the highest priority to
monitor of all the disposal sites in Region 9. Since only the South Oahu and Hilo sites had
received any disposal activity since the late 1990s, EPA conducted surveys at only these two sites.
Ship and equipment problems resulted in a reduction in the planned survey scope and in the overall
number of samples collected. However, sufficient sampling was completed to provide an adequate
basis to confirm environmental conditions at these sites and to update the SMMP. Based on
analyses of sub-bottom profiling, sediment profile and plan view imaging, and sediment grain size,
chemistry, and benthic community sampling, it appears that the pre-disposal sediment testing
program has protected these sites and their environs from any adverse contaminant loading. The
bulk of the dredged material disposed in the last decade or more appears to have been deposited
properly within the site boundaries. There are minor and localized physical impacts from dredged
material disposal, as expected, but no significant adverse impacts are apparent to the benthic
environment outside of site boundaries. Continued use of the disposal sites, under an updated
SMMP, is recommended.
I. INTRODUCTION AND BACKGROUND
Ocean dredged material disposal sites (ODMDS) around the nation are designated by the
Environmental Protection Agency (EPA) under authority of the Marine Protection, Research and
Sanctuaries Act (U.S.C. 1401 et seq., 1972) and the Ocean Dumping Regulations at 40 CFR 220-
228. Disposal site locations are chosen to minimize cumulative environmental effects of disposal
to the area or region in which the site is located, and disposal operations must be conducted in a
manner that allows each site to operate without significant adverse impacts to the marine
environment. Many ocean disposal sites are located near major ports, harbors, and marinas and are
very important for maintaining safe navigation for commercial, military, and private vessels.
EPA and the US Army Corps of Engineers (USACE) share responsibility for managing ocean
disposal of dredged sediments. First, there is a pre-disposal sediment testing program that is
jointly administered by the agencies to ensure that only clean (non-toxic) sediments are permitted
for ocean disposal. EPA must concur that sediments meet ocean dumping suitability requirements
before USACE can issue a permit for ocean disposal. Post-disposal site monitoring then allows
1
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
EPA and USACE to confirm the environmental protectiveness of the pre-disposal testing. The
agencies also jointly manage the ocean disposal sites themselves. All sites are operated under a
site management and monitoring plan (SMMP), and the Agencies cooperate on updating the
SMMPs if needed, based on the results of periodic site monitoring. EPA is also responsible for
enforcement of potential ocean dumping violations at each site.
The site use requirements in SMMPs for each specific ODMDS can be based on any issues of
concern identified in the original site designation environmental impact statement (EIS) or
environment assessment (EA), and/or on the results of subsequent (post-disposal) monitoring.
Each SMMP typically incorporates a compliance monitoring component to ensure that individual
disposal operations are conducted properly at the site, as well as a requirement for periodic
monitoring surveys to confirm that the site is performing as expected and that long term adverse
impacts are not occurring.
EPA designated five ODMDS offshore of Hawaiian Island ports and harbors in 1981 (Figure 1).
With the exception of the South Oahu site, these disposal sites are used infrequently (generally
only every 5-10 years or so) when USACE conducts maintenance dredging of the federal channels
serving each harbor. Baseline surveys were conducted in the 1970s to support the original site
designation action, but only limited monitoring work has occurred since then at most of the sites.
The USGS, while doing other coastal mapping work in 1994 and 1995, conducted acoustic
backscatter surveys at all five sites for EPA, to map dredged material deposits on the sea floor.
They also collected sediment chemistry samples at the South Oahu site. Based on the USGS
survey results, EPA and USACE published an SMMP in 1997 covering all five Hawaii disposal
sites. Since that time, due to lack of available funding, the sites have not been comprehensively
monitored and the SMMP has not been updated. When increased funding became available for
2013, EPA therefore identified the Hawaii sites as the highest priority to monitor of all the disposal
sites in Region 9. However, because only the South Oahu and Hilo sites had received any disposal
at all since 1999 (Table 1), EPA planned comprehensive monitoring at only these two sites.1
The South Oahu site (Figure 2) is located approximately 3 nautical miles offshore of Pearl Harbor
in water depths ranging from about 1,300 to 1,650 feet (400 to 500 meters). It is a rectangular
ocean disposal site 2 kilometers wide (west-east) and 2.6 kilometers long (north-south), and
occupies an area of about 5.2 square kilometers on the sea floor. Although the overall site is
rectangular, all disposal actions must take place within a 1,000 foot (305 meter) radius Surface
Disposal Zone at the center of the site. Its center coordinates are 21 degrees 15.167 minutes North
Latitude, 157 degrees 56.833 minutes West Longitude (NAD 83).
The Hilo site (Figure 3) is located approximately 4 nautical miles offshore of Hilo in water depths
averaging about 1,150 feet (350 meters). It is a circular ocean disposal site with a radius of 3,000
feet (920 meters) and an area of about 2.7 square kilometers on the sea floor. As at South Oahu,
all disposal actions must take place within a 1,000 foot (305 meter) radius Surface Disposal Zone
at the center of the site. The center coordinates of the Hilo site are 19 degrees 48.500 minutes
North Latitude, 154 degrees 58.500 minutes West Longitude (NAD 83).
1 USACE is again planning to dredge and dispose at all five Hawaii ODMDS in 2016. Future monitoring of the other
sites will be addressed in an updated SMMP for all the Hawaii ODMDS, which is currently in preparation.
2
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 1. Five ocean dredged material disposal sites serve Hawaii ports and harbors.
KAUAI
Port Allen ODMDS
Nawiliwili ODMDS
OAHU
Oahu ODMDS
Kahului ODMDS
V f - MAUI
Hilo ODMDS
HAWAII*
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 2. General location of the South Oahu Ocean Dredged Material Disposal Site, showing overall site (yellow box) and
Surface Disposal Zone (red circle).
South Oahu ODMDS
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 3. General location of the Hilo Ocean Dredged Material Disposal Site, showing overall site (yellow circle) and Surface
Disposal Zone (red circle).
HAWAI'I
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5
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
As shown in Table 1, the South Oahu site has received by far the greatest volume of dredged
material of all 5 Hawaii sites, both historically and more recently. (Table 1 does not include
volume disposed at historic Mamala Bay sites prior to 1981.) This material is generated from
construction and maintenance dredging by the U.S. Navy in Pearl Harbor and maintenance
dredging of the Honolulu Harbor federal channel by US ACE, as well as berth maintenance
dredging by Honolulu Harbor and other minor dredging by private marinas. The Hilo site has
received lesser volumes of dredged material, which in recent years was generated from US Coast
Guard maintenance dredging and from terminal improvement projects in Hilo Harbor.
Table 1. Disposal volumes (cubic yards) at the 5 Hawaii ODMDS following designation in
1981. Source: EPA compliance tracking records and US ACE Ocean Disposal Database.
Year
South Oahu
Hilo
Kahului
Nawiliwili
Port Allen
Total All Sites
1981
0
1982
0
1983
313,900
313,900
1984
2,554,600
2,554,600
1985
12,000
12,000
1986
0
1987
111,200
111,200
1988
57,400
57,400
1989
75,000
75,000
1990
1,198,000
80,000
58,000
343,000
1,679,000
1991
134,550
134,550
1992
233,000
233,000
1993
322,400
322,400
1994
0
1995
0
1996
27,800
27,800
1997
0
1998
0
1999
27,500
91,000
114,600
20,900
254,000
2000
0
2001
0
2002
53,500
53,500
2003
183,500
183,500
2004
540,000
540,000
2005
3,000
3,000
2006
160,400
160,400
2007
266,500
266,500
2008
0
2009
126,200
126,200
2010
0
2011
18,260
63,879
82,139
2012
70,981
70,981
2013
506,870
506,870
Total 1981-2013
6,286,280
217,860
149,000
1,093,900
20,900
7,767,940
Average/year
190,493
6,602
4,515
33,148
633
235,392
Total 2000-2013
1,855,230
137,860
0
0
0
1,993,090
Average/year
2000-2013
132,516
9,847
0
0
0
142,363
6
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
II. SUMMARY OF SITE MONITORING ACTIVITIES
EPA Region 9 developed an overall survey plan and quality assurance project plan (QAPP) for the
South Oahu and Hilo ODMDS monitoring (EPA, 2013); supplemental QAPPs were also written
by sub-contractors. The surveys were conducted in late June and early July 2013. A summary of
the survey design and planned vs actual sampling activities is provided in the Appendix to this
report.
The main objective of site monitoring is to support any necessary updates to the SMMP by
collecting data and samples adequate to determine whether the sites are performing as expected
under existing site management practices. The overall site management goal is that there should
be only minor physical impacts inside the disposal site and no adverse impacts outside the disposal
site. Consequently, the Hawaii site monitoring surveys were designed to:
1. determine the horizontal extent of the dredged material deposit ("footprint") relative to site
boundaries;
2. identify any adverse impacts of disposal of dredged material on or off site; and
3. confirm the protectiveness of pre-disposal sediment testing in avoiding disposal of
contaminated sediments.
Specific survey activities specified in the QAPP included: sediment profile and plan-view imaging
to map the dredged material footprint; sediment sampling and analyses for chemistry and benthic
community structure to identify any chemical or biological effects beyond localized physical
impacts; and a geophysical survey (sub-bottom profiling) to determine wide area distribution of
native sea bed features and deposits of dredged material. EPA contracted with the National
Oceanic and Atmospheric Administration (NOAA) to use its vessel Hi'ialakai, stationed in Pearl
Harbor, for the sediment imaging and sampling surveys at both disposal sites, and with Sea
Engineering for the separate sub-bottom profiling survey.
The surveys conducted from the Hi'ialakai were originally scheduled to occur over 8 days (plus
mobilization and demobilization), but problems associated with readiness of the NOAA ship and
its equipment caused some delays. The surveys were ultimately conducted over a 5-day period
(not including transit between the South Oahu and Hilo sites and the return transit from Hilo to
Pearl Harbor), during which field operations were conducted continuously over a 24-hour period
using two scientific crews working 12-hour shifts. Even though not as many stations were
sampled as originally planned due to the reduced survey time, sufficient sampling was completed
to confirm the performance of each site and to provide an adequate basis to update the SMMP, as
described below.
2.1 Sediment Profile Imaging (SPD and Plan View Photography (PVP)
The SPI-PVP system provides a surface and cross-sectional photographic record of selected
locations on the seafloor to allow a general description of conditions both on and off dredged
material deposits. Detailed methods for the SPI-PVP survey are provided in the supplemental
QAPP prepared by Germano and Associates (2013 a).
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
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SPI-PVP surveys (Figures 4 and 5) were conducted for each ODMDS to delineate the horizontal
extent of the dredged material footprint both within and outside the site boundaries, as well as the
status of benthic recolonization on the deposited material. With resolution on the order of
millimeters, the SPI system is more useful than traditional bathymetric or acoustic mapping
approaches for identifying a number of features, including the spatial extent and thickness of the
dredged material footprint over the native sediments of the seabed, and the level of disturbance and
recoloni zation as indicated by the depth of bioturbation, the apparent depth of the redox
discontinuity, and the presence of certain classes of benthic organisms (Figure 6). PVP is useful
for identifying surface features in the vi cinity of where the SPI photos are taken, thereby providing
important surface context for the vertical profiles at each station. For each station, a minimum of
four SPI photos were taken, coupled with at least a single PVP photo
The SPI-PV camera system was deployed at a total of 86 stations (40 at South Oahu and 46 at
Hilo), compared to the planned 98 (49 at each site). The planned vs actual survey stations around
the South Oahu ODMDS are shown in Figure 7, while the Hilo ODMDS survey stations are shown
in Figure 8. (Specific coordinates for each station are available in the Appendix.)
Figure 4. SPI-PVP camera system being deployed from the Hi'ialakai.
8
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 5. Schematic of deployment and collection of plan view and sediment profile photographs.
(Germano and Assoc., 2013 b).
/
Plan-view image
Deployed
1-2 meters
from seafloor
SPI mage"
On the
seafioor
"Down" position
transecting the sediment-
water interface
9
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 6. Soft-bottom bent hie community response to physical disturbance (top panel) or organic enrichment (bottom panel).
From Rhoads and Germano (1982).
Physical Disturbance Time Normal
Stage 0 I Stage 1 I Stage 2 I Stage 3
Grossly Polluted
Distance
3
Normal
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 7. Planned (yellow squares) and actual sample station locations at the South Oahu ODMDS.
(The circle at the east side of the map shows the location of a historic disposal site used before 1981.)
w«4i:
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SPI/PV and Sediment Sampling Locations
South Oahu ODMDS, Hawaii
June 2013
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Sources: Esn, GEBCO, NOAA. National Geographic, Delorme, NAVTEQ, Geonames.org, and other
contributors
ii
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 8. Planned (yellow squares) and actual sample station locations at the Hilo ODMDS.
SPI/PV and Sediment Sampling Locations
Hilo ODMDS, Hawaii
June/July 2013
12
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
2.2 Sediment Sampling for Chemistry and Benthic Communities
Sediment samples were collected from a subset of stations at each disposal site for sediment grain
size, chemistry, and benthic community analysis. Samples were collected using a stainless steel
double Van Veen sediment grab (Figure 9, showing side-by-side configuration) capable of
penetrating a maximum of 20 centimeters below the sediment surface. Detailed methods for
performing the sediment sampling for chemistry and benthic community analyses are described in
the QAPP (EPA, 2013 a).
After each acceptable grab sample was measured for depth of penetration and photographed, a
subsample for chemistry was extracted from one side of the grab sampler with a stainless steel
spoon (Figure 10). This subsample was homogenized and divided into separate jars (Figure 11)
for chemistry analyses (grain size, metals and organics). After the chemistry subsample was
extracted, the entire volume of the other side of the grab was processed to create a benthi c
community sample for that station (Figure 12). A 500 micron sieve was used to separate
organisms from the sediment, and the separated organisms were placed into bottles where they
were initially preserved with formalin. A total of 18 sediment grab sample stations were sampled
in the two survey areas combined: 10 at South Oahu, and 8 at Hilo (see Figures 7 and 8,
respectively). Chemistry subsamples were collected from all 18 stations and benthic community
samples were collected at 14 of the 18 stations (the lower number of benthic community samples
was due to some grabs being used for field and laboratory chemistry duplicates, and one station
where QAPP metrics were not met for an acceptable benthic sample).
Figure 9. Double Van Veen sediment sampler deployed from the Hi'ialakai.
13
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 10. Subsampling from the Van Veen grab for sediment chemistry.
Figure 11. Processing a sediment sub-sample for chemical analysis.
14
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 12. Processing a sediment sample for benthic community analysis.
2.3 Sub-Bottom Profiling Survey of the South Oahu ODMDS
The primary purpose of this survey was to collect cross-sectional images of the native sediment
layers and layers indicative of the dredged material deposit across a wide area in the environs of
the South Oahu ODMDS. (The Hilo site was not surveyed in this manner during this round of
surveys because much smaller volumes of dredged material have been disposed there over time
which may not be detectable in terms of thickness and contrast.)
This type of survey allows EPA to separately estimate the cumulative volume of dredged materi al
disposed at the South Oahu site, compared to volumes permitted for disposal. The survey was sub-
contracted to Sea Engineering, who conducted the work aboard a separate vessel specially rigged
for this type of survey with an acoustic sub-bottom profiler system (Figure 13). Figure 14 shows
the grid of transects surveyed. Detailed methods for the sub-bottom survey are provided in the
supplemental QAPP prepared by Sea Engineering (2013).
15
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 13. Sub-bottom profiler equipment - used only at the South Oahu site.
Figure 14. Planned transect lines for the sub-bottom profiling survey around the South Oahu
ODMDS (from Sea Engineering, Inc., 2014).
2
m
m
If " 4^ .
-18,000 ft
m
~-v|
16
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
III. SURVEY RESULTS
3.1 SPI - PVP Survey Results
3.1.1 Dredged Material Footprint Mapping
The presence and extent of the dredged material footprint was successfully mapped at both Hawaii
disposal sites. SPI images of typical native sediments (outside of any dredged material deposit)
around the South Oahu and Hilo sites are shown in Figure 15. Dredged material is usually evident
because of its unique optical reflectance and/or color relative to the native pre-disposal sediments.
The presence of dredged material layers can be determined from both plan view images (Figure
16) and from SPI images (Figure 17). In most cases, the point of contact between the two layers is
clearly visible as a textural change in sediment composition, facilitating measurement of the
thickness of the newly deposited layer.
Two off-site stations around the South Oahu site had native hard-bottom habitat (N6 and SW5,
Figure 7); otherwise the native sediment was fairly uniformly muddy fine sand. The overall
dredged material footprint extended well beyond the current disposal site boundary (Figure 18;
also see Figure 28). Given the lack of natural fine grained sediment around the South Oahu site,
dredged material would be expected to remain visible on the seafloor for a substantial amount of
time (decadal scale). Similarly, given the proximity of historic disposal sites to the current
designated site in Mamala Bay and the large cumulative volume of disposed sediments over the
years (Table 1), it is not surprising that traces of dredged material are found outside of the current
designated site boundary. However, the thickest off-site deposits were just north (shoreward) of
the site boundary indicating that "short-dumping" (disposal from scows before they reached the
Surface Discharge Zone at the middle of the site) probably occurred in the past. EPA has required
satellite-based tracking of all disposal scows since the early 2000s, and there have been no "short-
dumps" since a single partial mis-dump occurred in 2006. Thus the footprint outside the disposal
site boundary would appear to be relic material deposited more than 10 years ago.
Compared to South Oahu, native sediments around the Hilo site were finer. Two off-site stations
(E5 and SE6, Figure 8) were on rocky lava outcrops. Even though this area is primarily a silty,
very fine to fine sandy bottom, there are periodic lava deposits or rock outcrops creating some
topographic diversity. The substantially smaller cumulative volume of dredged material disposed
at Hilo appeared to be more fully confined within the designated disposal site boundary (Figure
19). Except at the center of the site where rubble has accumulated (Figure 20), dredged material
thickness was only 3 cm or less within the site boundary, and less than 1 cm thick outside the
boundary.
3.1.2 Bioturbation Depth
The depth to which sediments are biologically mixed is an important indicator of the status of
recovery of the infaunal community following disturbance (e.g., by dredged material disposal).
Biogenic particle mixing depths can be estimated by measuring the depths of imaged feeding voids
in the sediment column. This parameter represents the particle mixing depths of head-down
feeders, mainly polychaetes. This depth is also related to the apparent redox potential
discontinuity (aRPD) depth. In the absence of bioturbating organisms, the aRPD (in muds) will
17
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 15. Profile images from the ambient bottom at the Hilo ODMDS (left, Station S3) and the South Oahu site
(right, Station S6). The ambient seafloor at Hilo has a higher silt-clay content, allowing greater camera
penetration than at South Oahu. Scale: width of each profile image = 14.4 cm. (Germano & Assoc., 2013)
18
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 16. Plan view images of the dredged material deposit compared to the native
seafloor at South Oahu. Station CI on dredged material (top) shows the visual
difference in both sediment color and surface texture/features of dredged
material compared to the ambient bottom at Station NW6 (bottom). Scale: width
of each PV image is approximately 4 m. (Germano & Assoc., 2013)
19
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 17. Profile images from two Hilo Stations showing a surface layer of disposed coarse white dredged
sand that thins from NW1 (left) near the center of the disposal site to only trace amounts at NW3 (right).
Scale: width of each profile image = 14.4 cm. (Germano & Assoc., 2013)
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 18. Dredged material footprint identified at the South Oahu site.
n
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SPL/PV and Sediment Sampling Locations
South Oahu ODMDS. Hawaii
June 2013
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0.00 Sources: Esri. GEBCO. NOAA. National Geographic. DeLorme. NAVTEQ. Geonames.org. and other contributors
21
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 19. Dredged material footprint identified at the Hilo site.
SPl^V and S«d»m#nt Sampling Location*
Hilo OOMOS. Hawa.
June/July 2013
Station Average
Dredged Material
Thickness (cm)
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22
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 20. Plan view image from the center station of the Hilo ODMDS shows a high density of small rock and coral rubble.
Rubble falls rapidly through the water column with minimal dispersal, and thus has accumulated only at the center of the site.
Scale: width of PV image is approximately 4 m. (Germano & Assoc., 2013)
23
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
typically reach only 2 mm below the sediment-water interface (Rhoads 1974). However, it is quite
common in profile images to see evidence of biological activity (burrows, voids, or actual animals)
well below the mean aRPD (Germano and Assoc., 2013 b).
At the South Oahu site, the maximum bioturbation depths (>15 cm) were generally found at the
stations that also had the thickest deposits of dredged material (including the off-site stations to the
north with relic dredged material deposits) (Figure 21). A similar pattern was seen for average
feeding void depth, and for the aRPD depth (see Germano and Assoc., 2013 b). This is to be
expected, since dredged material is generally finer, less consolidated, and therefore more
conducive to supporting a richer community of burrowing organisms compared to the native,
consolidated fine sand around the disposal site. Stations with a native fine sand substrate exhibited
lower camera penetration, shallower aRPD depths, and shallower average feeding void depths.
At the Hilo site, where much less dredged material has been discharged and where the native
seafloor is more heterogenous, the pattern was different (Figure 22). Although dredged material
was thickest at the center of the site, a high concentration of gravel and coral rubble prevented full
camera penetration there, so that bioturbation depth and aRPD could not be determined fully.
Other on-site stations showed fairly uniform bioturbation depths of 7-10 cm. Many off-site
stations also had bioturbation depths in this range, although bioturbation depths of 10-18 cm were
also common. Since the native seafloor around the Hilo site is finer-grained than around the South
Oahu site, greater bioturbation depths, and less difference between on-site and off-site stations,
would be expected.
3.1.3 Infaunal Successional Stage
The mapping of infaunal successional stages is readily accomplished with SPI technology.
Mapping of successional stages is based on the theory that organism-sediment interactions in fine-
grained sediments follow a predictable sequence after a major seafloor perturbation (Germano and
Assoc., 2013). This continuum of change in animal communities after a disturbance (primary
succession) has been divided subjectively into four stages: Stage 0, indicative of a sediment
column that is largely devoid of macrofauna, occurs immediately following a physical disturbance
or in close proximity to an organic enrichment source; Stage 1 is the initial community of tiny,
densely populated polychaete assemblages; Stage 2 is the start of the transition to head-down
deposit feeders; and Stage 3 is the mature, equilibrium community of deep-dwelling, head-down
deposit feeders (see Figure 6).
After an area of bottom is disturbed by natural or anthropogenic events, the first invertebrate
assemblage (Stage 1) appears within days after the disturbance. Stage 1 consists of assemblages of
tiny tube-dwelling marine polychaetes that reach population densities of 104to 106 individuals per
m2 These animals feed at or near the sediment-water interface and physically stabilize or bind the
sediment surface by producing a mucous "glue" that they use to build their tubes.
If there are no repeated disturbances to the newly colonized area, then these initial tube dwelling
suspension or surface-deposit feeding taxa are followed by burrowing, head-down deposit feeders
that rework the sediment deeper and deeper over time and mix oxygen from the overlying water
into the sediment. The animals in these later-appearing communities (Stage 2 or 3) are larger, have
lower overall population densities (10 to 100 individuals per m2), and can rework the sediments to
depths of 3 to 20 cm or more.
24
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 21. Bioturbation depth at the South Oahu site - deeper values here are reflective of an active benthic community
reworking deposited dredged material. (Germano & Assoc., 2013)
so-Nwe
o.oo 1
SO-NW4
1156
IND
so-we
IND
SO-W5
4.98
SO-W4
6.62
SO-W3
SO-N6
IND
SO-N5
14.42
SO-N4
18.23
l_SO-N3 _
19.55~~
18.54
SO-NW2
tn
SO-N2
825
5.61 '
SO-NE2 i
SO-NE8
IND
'64
SO-NE4
7.87
i r. i
M5.88
$0-W2
21.09
SO-W1
SO-N1
10.76!
6? >
E (I ij
SPl/PV and Sediment Sampling Locations
South Oahu ODMDS. Hawaii
June 2013
Station Maximum
Bioturbation Depth (cm)
# 0.0 -1.0 cm
# 11 -5.0 cm
5.1 -10.0 cm
# 10.0 -15.0 cm
# > 15.0 cm
O Indeterminate (IND)
Dump site boundary
SO-SW3
10J09 ,
SO-SW1 i
17.81
SO-SW2
5.95
SO-SW4
127
SO-SW5
IND
SO-SW6
573
SO-E1 SOj-E2 SO-E3 SO-E4 SO-E5 SO-E0
1059 5.66
• SO-S1
8.67
SO-S2
7.66
SO-SE2
IND
1353
SO-S3
8.02
SO-S4
3.44
SO-S5
IND
SO-SE4
IND
SO-SE6
IND
so-se
IND Sources: Esri. GEBCO. NOAA. National Geographic, DeLomne. NAVTEQ. Geonames.org. and other contributors
25
-------
2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 22. Bioturbation depth at the Hilo site: on-site and off-site stations show similar depths (much less material has
been disposed here than at South Oahu). (Germano & Assoc., 2013)
SPI/PV and Sediment Sampling Locations
Hilo ODMDS. Hawaii
June/ July 2013
H-N6
4.45
N
Station Maximum
Bioturbation Depth (cm)
•
0 0- 1.0 cm
•
1.1 -5.0 cm
5.1 -10.0 cm
•
10.0 -15.0 cm
•
> 15.0 cm
t *
1
Dump site
H-NW6
13.01
H-NW5
13.81
H-N4
8.45
H-NE6
3.59
H-NW4
8.93
H-NE5
3.88
H-NW3
8.47
H-NE4
4.56
H-NW2
9.15 ,
H-W6
18.63
H-W5
13.90
H-W4
16.12
H-W3
929
H-SW3
10.19
H-W2
9.81 '
H-SW2
9.65
H-NW1
7.82
H-W1
8.62
;H-SW1
\ 831
H-N2
10.09
I H-C
000
H-NE3
6.64
• \ H-NE2
\ 8.04
H-NE1
6.91
H-E2
209
H-SE1
7.29
H-E4
3.35
H-E5
0.00
H-SW4
10.64
H-S1
7.82
H-S2
8.69
H-SE2
7.13
H-SW5
11.87
H-SE3
7.94
H-SW6
11.38
H-SW7 |
1&78 '
H-S3
9.12
H-S4
1264
H-SE4
7.94
H-SE5
7.94
H-SW8
8.44
H-S5
9.56
H-S0
929
H-SE8
0.00
H-SW0
18.54
Sources: Esri. GEBCO. NOAA. National Geographic. DeLorme. NAVTEQ. Geon3rne>.qrg.andidther
26
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Various combinations of these basic successional stages are possible. For example, secondary
succession can occur (Horn, 1974) in response to additional labile carbon input to surface
sediments, with surface-dwelling Stage 1 or 2 organisms co-existing at the same time and place
with Stage 3, resulting in the assignment of a "Stage 1 on 3" or "Stage 2 on 3" designation
The distribution of successional stages in the context of the mapped disturbance gradients is one of
the most sensitive indicators of the ecological quality of the seafloor (Rhoads and Germano 1986).
The presence of Stage 3 equilibrium taxa (mapped from subsurface feeding voids as observed in
profile images) can be a good indication of relatively high benthic habitat stability and quality. A
Stage 3 assemblage indicates that the sediment surrounding these organisms has not been disturbed
severely in the recent past and that the inventory of bioavailable contaminants is relatively small.
At the South Oahu site, infaunal community successional stage was readily apparent on the
dredged material deposit, but was generally unmeasurable (indeterminate) on the native sandy
sediments off-site (Figure 23). Successional stage on the dredged material mound, including the
relic off-site material to the north, was fairly uniformly Stage 1 on 3. While this indicates relatively
rapid recolonization and a well-established infaunal community in the finer, more carbon-rich
dredged sediments, it is clearly a different community than would be supported by the native fine
sand at this location in the absence of dredged material disposal.
At the Hilo site, differences between stations with and without dredged material were less apparent
(Figure 24). Since far less dredged material has been discharged at this site than at the South Oahu
site, less disturbance to the native sediments around the site has occurred. Both on-site and off-site
stations were dominated by Stage 1 on 3 communities, but more heterogenous communities were
present to the east and northeast of the site as well. These stations had either no apparent dredged
material, or only trace thicknesses of dredged material; therefore the different community structure
at these stations may reflect natural heterogeneity of benthic habitat types in this area rather than
any particular effect from dredged material deposition.
3.1.4 Plan-View Photography
Unusual surface sediment textures or structures detected in any of the sediment profile images can
be interpreted in light of the larger context of surface sediment features (for example, is a surface
layer or topographic feature a regularly occurring feature and typical of the bottom in this general
vicinity or just an isolated anomaly?). The scale information provided by the underwater lasers
allows accurate density counts (number per square meter) of attached epifaunal colonies, sediment
burrow openings, or larger macrofauna or fish which may be missed in the sediment profile cross-
sections.
Except for the two stations on hard bottom, the native seafloor around the South Oahu site is a
muddy carbonate sand with rippled bedforms and relatively low abundance of epifauna. Other
than the occasional hermit crab or other decapods such as shrimp or Brachyurans, the presence and
abundance of epifauna was directly proportional to the amount of rock/rubble/outcrop present on
the flat sandy bottom. Anything that provided a hard surface or additional vertical relief for
niche/topographic diversity became a suitable substratum to which organisms could attach
(tunicates, cnidarians, bryozoans) or hide within (echinoderms), which subsequently attracted more
fish to that particular location.
27
-------
2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 23. Community structure at the South Oahu site: presence of Stage 3 organisms is indicative of healthy
benthic community. (Germano & Assoc., 2013)
©s
©
~
764
.SO-NE4
SP1/PV and Sediment Sampling Locations
South Oahu ODMDS. Hawaii
June 2013
Infaunal Successional Stages
rep 1
Stage 2 — 3
^3 0"" ® Stage 3
^p2 ® Stage I on 3
O Indeterminate
Dump site boundary
SO-NE2
SO-W6 SO-W5 SO-W4 SO-W3 io-W2 SO-W1
© © © ©
lso-si
©
©
so-swi/y\ ^
m r"fe
Q SO-S4
© SO-S5
41 a
^ s © ©
SO-E1 SOj-E2 SO-E3 SO-E4 SO-€5 SO-E6
©'
©S
©¦
Sources: Esri. GEBCO. NOAA. National Geographic. DeLorme. NAVTEQ. Geonames.org. and other contributors
28
-------
2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 24. Community structure at the Hilo site: presence of Stage 3 organisms is indicative of healthy benthic community.
(Germano & Assoc., 2013)
SPl/PV SwnpJmj l«JWx»
Hrto OOMDS Hmu
Amm/Jul? 2013
Into una I Successlonal Stages
O Stage 2
to i O Stage I on 2
lnv2 ©Stage2-3
# Stage I on 3
O Indeterminate
-*>3©
H-NWO
J V/r / , ,
O
H-NW4 ©
©'
h L
1H*2 X
H-NW2 I
©-
©
©
©
M-NE4
K-NE3
K-NE2
I H-KE1 »
/ r
H-WC
K-WS
H-W4
# _«r ©« @
M-W3 H-W2 « H-W1
H-E2
H-SWSi
\H.SWll • /V~\
^(y)v7Hs£i
H-SW2 (V) h-s"
•e ®
©
H-E4
M-SC2
V H-SE3
IH-SE4
H-SWO |
r /
K-SW8
©
H-S4I
H-S9I
0'
M-SES
©~
__
H-se i
Evt GEBCO, NOAA. G«ogrAphie. NAVTEQ 3
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
In contrast, the native Hilo sediments had a higher percentage of fine sediments (attracting higher
densities of small prey, evidenced by burrow holes in plan view images) along with more frequent
occurrence of rocky outcrops (creating habitat heterogeneity) both inside and outside the site
boundaries. These characteristics attracted a generally more abundant and varied epifauna and fish
assemblage. Unlike the South Oahu site, the areas of the highest accumulation of dredged material
(near the site center where the surface was a continuous cover of rubble) appeared to have the
lowest faunal attractiveness. But higher densities of fish and anthozoans as well as more frequent
evidence of burrowing infauna were seen throughout the area as a whole, compared to South Oahu.
3.1.5 Discussion: SPI-PVP Surveys
Minor and localized physical impacts are expected within the site as a result of disposal operations.
However, historical and more recent disposal activity appear to have had little lasting adverse
impact on benthic infauna, or epibenthic organisms, at either site. With the exception of the center
station at the Hilo site where an accumulation of disposed rubble has most likely altered the
resident infaunal community on a localized scale, the disposal of dredged material, in general, has
not impeded benthic recolonization or the re-establishment of mature successional stages. At the
South Oahu site, it appears the larger cumulative volume of fine grained, higher carbon content
dredged material deposited over the native coarser grain carbonate sands may have actually
enhanced the secondary benthic production by promoting the settlement and persistence of
subsurface deposit feeders that would not normally exist in the native carbonate sand bottom here.
The prediction in the original EIS (EPA 1980) that disposal of dredged material at both the Hilo
and South Oahu ODMDS will have no lasting adverse impact on the benthic community inside or
outside of site boundaries is supported by the results of the SPI-PVP survey. Stage 3 taxa have
successfully recolonized all but the center station at the Hilo ODMDS, and secondary production
appears to be enhanced at the South Oahu ODMDS within the dredged material footprint. Also
epifauna, in general, are similar on-site and off-site (though different between South Oahu and
Hilo overall.
Based on the results of the SPI-PVP surveys, the authors predicted that the traditional benthic
sampling results would also show a higher species diversity and infaunal abundance in samples
from the Hilo site versus those from the South Oahu site, because of the increased amount of fines
and evidence of increased subsurface burrowing in the images from the Hilo site. (See discussion
of Benthic Community Analysis Results, below.)
3.2 Sediment Physical and Chemical Survey Results
Full physical and chemical analytical results are provided in ALS Environmental (2013) and EPA
(2013 b). Due to vessel and equipment problems, less than half the originally-targeted benthic grab
stations were sampled. But by using the SPI survey results to help select the chemistry (and
benthic community) stations at each site, a sufficient number of samples were collected within and
outside of site boundaries and the dredged material footprints to characterize the native (ambient)
seafloor compared to seafloor areas physically impacted by dredged material disposal.
Nevertheless, only qualitative (vs statistical) analysis of the physical and chemical results was
conducted given that only four "on site" and five "offsite" stations were ultimately sampled at
South Oahu, and only three "on site" and four "offsite" stations were sampled at Hilo.
30
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
3.2.1 Physical Results
Minor and localized physical impacts are expected within the site boundary as a result of disposal
operations. Tables 2 (South Oahu) and 3 (Hilo) compare areas within the disposal sites that have
dredged material deposits (indicated as "Inside") and off site areas without any dredged material
deposits (indicated as "Outside"). Physical on-site differences are most apparent at the South
Oahu site, which has received an order of magnitude more dredged material over the years than the
Hilo site. At South Oahu (Table 2), "inside" stations have substantially more gravel, more fines
(silt and clay), and higher organic carbon content than the "outside" stations that represent ambient
or native seafloor conditions. This reflects the character of dredged material typically disposed at
this site, which often includes grave-size coral rubble, and fines from land-side runoff that settles
in harbors, berths, and navigation channels. In contrast, native sediments around the South Oahu
site are uniformly sandier, with lower carbon. These on-site physical changes are expected to be
persistent, but are not considered to be a significant or adverse impact.
Physical characteristics of the off-site ambient or native sediments around the Hilo site are more
variable (Table 3) reflecting the more heterogeneous nature of the seafloor in the area, which
includes a mixture of hard bottom features (submerged reef and terraces) coupled with areas of
accumulated finer grained sediments (USGS, 2000). The dredged material disposed at the Hilo
site has not substantially altered the physical nature of the disposal site in part due to this natural
variability, and in part because only a relatively small volume of material has been disposed at
Hilo (especially compared to disposal volumes at South Oahu).
3.2.2 Chemical Results
Although physical differences are expected as a result of disposal operations, pre-disposal
sediment testing is intended to minimize any degradation to the site which might be caused by
introduction of contaminants which are bioavailable and/or pose a toxicity risk to the marine
environment. The bulk chemistry data show low but variable concentrations of most chemical
constituents at both sites (Tables 2 and 3). At both "inside" and "outside" stations, four to six
metals were at concentrations above NOAA's effects-based 10th percentile screening value (ER-L),
below which adverse effect are predicted to rarely occur (NOAA, 2008). Of these metals, only
chromium, copper, and mercury were slightly higher at "inside" stations compared to "outside"
stations, and only at the South Oahu site. At Hilo, the metals concentrations were virtually
indistinguishable between "inside" and "outside" stations.
Only nickel exceeded its 50th percentile screening value (ER-M), above which adverse effects are
expected to frequently occur (NOAA, 2008). It was most elevated at Hilo, but was at similar
elevated concentrations at both "inside" and "outside" stations there. Nickel is often naturally
elevated in certain sediments, including volcanic sediments.
Organic constituents were also low at both sites. Only two constituents exceeded NOAA ER-L
screening levels, and again only at the South Oahu site. PCBs and DDTs each slightly exceeded
their respective ER-Ls at one "inside" station and one "outside" station. PCBs were generally
higher at the "inside" stations, even when not exceeding the ER-L. There were no exceedances of
ER-Ls for organics at either "inside" or "outside" stations at the Hilo site.
31
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 2. Summary of sediment chemistry for the South Oahu Ocean Dredged Material Disposal site and vicinity.
Survey Station:
South Oahu site
"
nside"
"Outside"
NOAA Screening
Analyte
Units (dw)
SO-N1
SO-N1 dup*
SO-N2
SO-SW1
SO-W1
SO-SE4**
SO-W5
SO-S6
SO-E6
SO-E4
ER-L
ER-M
Gravel
%
21
3
69
3
12
1
1
0
1
11
-
-
Sand
%
43
53
29
47
50
78
79
82
83
64
—
—
Silt
%
21
24
11
25
24
16
12
12
10
20
--
--
Clay
%
14
17
4
15
11
5
4
5
5
7
—
--
Total Organic Carbon
%
1.25
1.78
1.25
1.02
1.48
0.58
0.53
0.43
0.41
0.81
--
--
Arsenic
mg/kg
20
13
24
33
19
40
39
27
30
27
8.2
70
Cadmium
mg/kg
0.6
0.69
0.39
ND
0.43
ND
0.42
ND
ND
ND
1.2
9.6
Chromium
mg/kg
100
160
100
110
120
68
100
47
45
73
81
370
Copper
mg/kg
65
84
47
43
56
22
36
11
13
37
34
270
Lead
mg/kg
25
31
22
15
95
19
37
10
15
23
46.7
218
Mercury
mg/kg
0.2
0.13
0.13
0.1
0.38
0.09
0.1
0.02
0.05
0.19
0.15
0.71
Nickel
mg/kg
68
140
68
71
92
37
63
24
30
53
20.9
51.6
Selenium
mg/kg
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
—
-
Silver
mg/kg
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
1
3.7
Zinc
mg/kg
78
130
76
75
86
52
79
34
35
69
150
410
Dioxins - Total TEQ
ng/kg
6.33
3.88
4.49
1.27
4.12
1.06
0.91
0.07
0.95
4.01
-
-
Total DDTs
ug/kg
ND
2.1
ND
ND
ND
ND
ND
ND
ND
2.6
1.58
46.1
Total Organotins
ug/kg
1.73
4.67
4
1.46
2.21
0.71
5.83
ND
4.1
2.09
—
—
Total PAHs
ug/kg
741
264
274
182
160
344
153.8
ND
263
1501
4022
44792
Total PCB Congeners
ug/kg
21.43
17.49
35.98
8.87
14.11
6.07
7.16
0.09
2.7
23.15
22.7
180
"Inside" stations are both within the disposal site boundary AND on the dredged material deposit as determined by the SPI-PVP survey.
"Outside" stations are both outside the site boundary AND off the dredged material deposit.
* Field duplicate sample from a separate grab taken at a different time at the same station
** This station was chosen for full OTM testing on upcoming dredging project(s) as a possible new reference site for future Hawaii projects.
32
-------
2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 3. Summary of sediment chemistry for the Hilo Ocean Dredged Material Disposal site and vicinity.
Survey Station:
Hilo site
Units (dw)
"Inside"
"Outside"
NOAA Screening
Analyte
H-Wl
H-Wl dup*
H-Nl
H-SW1
H-SE4
H-NE5
H-SW6
H-W6
ER-L
ER-M
Gravel
%
2
3
2
0
0
0
0
0
—
—
Sand
%
62
61
47
69
72
85
26
14
—
—
Silt
%
25
24
21
26
21
16
61
70
—
—
Clay
%
5
8
7
5
7
5
11
17
-
-
Total Organic Carbon
%
0.83
0.98
0.81
0.81
0.69
0.57
2.43
3.27
—
-
Arsenic
mg/kg
36
36
32
36
26
28
48
55
8.2
70
Cadmium
mg/kg
0.4
ND
0.5
0.6
0.72
0.5
0.71
0.62
1.2
9.6
Chromium
mg/kg
110
120
140
130
140
140
150
160
81
370
Copper
mg/kg
30
35
31
31
30
31
51
56
34
270
Lead
mg/kg
11
11
11
12
9.6
11
19
21
46.7
218
Mercury
mg/kg
0.05
0.06
0.05
0.06
0.04
0.04
0.14
0.17
0.15
0.71
Nickel
mg/kg
160
200
290
230
320
290
88
82
20.9
51.6
Selenium
mg/kg
ND
ND
ND
ND
ND
ND
ND
ND
—
—
Silver
mg/kg
ND
ND
ND
ND
0.75
ND
1.1
1.2
1
3.7
Zinc
mg/kg
70
81
83
78
87
83
91
95
150
410
Dioxins - Total TEQ
ng/kg
3.02
1.99
2.19
1.96
1.58
0.831
4.84
7.65
-
—
Total DDTs
ug/kg
IMD
ND
ND
ND
ND
ND
ND
ND
1.58
46.1
Total Organotins
ug/kg
ND
ND
0.86
ND
ND
ND
ND
ND
—
-
Total PAHs
ug/kg
2.2
2.3
10.2
1.8
ND
ND
3
17.4
4022
44792
Total PCB Congeners
ug/kg
0.3
0.5
ND
ND
ND
ND
0.25
0.28
22.7
180
"Inside" stations are both within the disposal site boundary and ON the dredged material deposit as determined by the SPI-PVP survey.
"Outside" stations are both outside the site boundary and OFF the dredged material deposit.
* Field duplicate sample from a separate grab taken at a different time at the same station
33
-------
2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
The screening level exceedances were relatively minor in magnitude and, in many cases, were seen
at both "inside" and "outside" stations. The few constituents that were at higher concentrations
within the disposal sites reflect the contaminant levels in the dredged material approved for
discharge. All sediments discharged at ocean disposal sites are fully characterized before approval
for ocean disposal is granted. Sediments that contain toxic pollutants in toxic amounts, or that
contain elevated levels of compounds that will readily bioaccumulate into tissues of organisms
exposed to them on the seafloor, are prohibited from being discharged. Thus the chemical
concentrations identified are not considered to represent a risk of environmental impacts in and of
themselves; also, these low concentrations indicate that the pre-dredge sediment testing regime is
adequately protecting the environment of the disposal sites by identifying and excluding more
highly contaminated sediments from being disposed.
3.3 Benthic Community Analysis Results
Less than half of the original targeted stations were sampled for sediment grab sampling due to
ship and equipment problems. Nevertheless, by selecting stations based on the results of the SPI-
PVP surveys, sufficient samples were collected within and outside of site boundaries and the
dredged material deposit footprint to provide general characterization of benthic communities
occupying native (ambient) seafloor and seafloor physically impacted by dredged material
disposal.
3.3.1 Abundance of Infauna
As noted earlier, some physical changes (e.g., grain size and organic carbon content) were
apparent at stations with dredged material, especially at the South Oahu site. However, overall
abundances of different organism classes, while low, were not statistically different between
"inside" and "outside" stations at either disposal site (Tables 4 and 5) (EcoAnalysts, Inc., 2014).
At South Oahu, where both disposal volume and physical changes were greatest, crustaceans were
similarly abundant at "inside" and "outside" stations; annelids appeared to be somewhat less
abundant at "inside" stations; while mollusks and other miscellaneous taxa appeared to be
somewhat more abundant at "inside" stations. But considering all infauna classes, overall
abundance was very similar on-site and off-site.
At Hilo, Crustacea appeared to be somewhat more abundant at "inside" stations, but annelids,
mollusks and other miscellaneous taxa appeared to be somewhat more abundant at "outside"
stations. Overall abundance of infaunal organisms appeared to be slightly greater off-site than on-
site but these results were not statistically significant, perhaps due in part to the small sample size.
As predicted from the SPI-PVP survey results, overall infaunal abundance appeared to be slightly
greater at Hilo than at South Oahu.
Dredged material had been fairly recently deposited at both sites, and these infaunal abundance
results are consistent with relatively rapid recolonization following disposal.
34
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 4. Infaunal species abundances at the South Oahu site.
"Inside"
"Outside"
Category
SO-N1
SO-N2
SO-W1
SO-SW1
SO-W5
SO-S6
SO-SE4
SO-E4
SO-E6
Annelida
390
540
700
400
1190
120
50
660
670
Annelida
Average
507.5
538
Crustacea
0
10
10
10
20
0
0
10
10
Crustacea
Average
7.5
8
Mollusca
10
40
20
20
0
30
0
10
0
Mollusca
Average
22.5
8
Miscellaneous
Taxa
30
50
130
40
20
10
0
110
60
Miscellaneous
Taxa Average
62.5
40
Totals
430
640
860
470
1230
160
50
790
740
Overall
Averages
600
594
Table 5. Infaunal species abundances at the Hilo site.
"Inside"
"Outside
»
Category
H-Nl
H-SW1
H-NE5
H-SW6
H-SE4
Annelida
900
320
490
930
650
Annelida
610
690
Average
Crustacea
20
20
10
0
10
Crustacea
20
6.7
Average
Mollusca
50
10
10
260
10
Mollusca
30
93.3
Average
Miscellaneous
50
50
50
80
100
Taxa
Miscellaneous
50
76.7
Taxa Average
Totals
1020
400
560
1270
770
Overall
710
866.7
Averages
3.3.2 Diversity of Infauna
Based on species lists and statistics presented in EcoAnalysts, Inc. (2014), the overall benthic
community at the South Oahu site was shown to be different from the assemblage at the Hilo site.
This finding is not surprising given that the Hilo site is located in a relatively heterogeneous area
containing a mixture of hard bottom features (submerged reef and terraces) coupled with areas of
accumulated finer grained sediments (USGS, 2000), while the South Oahu site is located on a
more homogeneous sandy seafloor with some scattered hard bottom features. However, as is
expected of deep-sea benthic habitats overall, both sites have well developed benthic communities
with high diversity and relatively low abundances, and presence of several undescribed taxa.
35
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
For both sites combined, there were 126 taxa found. A total of 85 infaunal taxa were identified
from the South Oahu ODMDS sampled locations and a total of 79 taxa were identified from the
Hilo ODMDS sampled stations. Within the polychaetes identified from both locations, 24 of 89
species were determined to likely be undescribed (EcoAnalysts, Inc., 2014).
At the South Oahu site, diversity was high and abundances tended to be low at all stations.
Stations located inside the disposal site were not statistically different in terms of diversity,
abundances, or species richness when compared to stations located outside the disposal site. Thus
there is no evidence that dredge material is negatively impacting the benthic communities at the
South Oahu ODMDS sites sampled.
Similarly at the Hilo site, there were no significant differences in diversity between inside and
outside stations. As at South Oahu, diversity was high while abundances were relatively low,
which was expected of deep-sea benthic habitats. Based on these results there is no evidence that
dredge material is negatively impacting the benthic communities at the Hilo ODMDS stations
sampled, other than the expected reduction of abundances due to physical impacts from rubble
disposed at the center of the site.
3.4 Sub-Bottom Profile Survey (South Oahu site only)
The survey area, approximately 8 square nautical miles, covered the current designated site and
surrounding abyssal plain seafloor areas, including existing hard bottom features (such as relic
reefs and other outcrops) (Figure 25). The contrast between high reflectance native bottom bed
forms and lower reflectance non-native deposited sediments allowed for identification of dredged
material deposits throughout the study area.
While dredged material was identified within the current disposal site boundary, deposits of
dredged material were still identifiable outside the site boundaries as well (Figure 26), probably
due to past (pre-1981) disposal at historic disposal sites as well as mis-dumping before the 2000's
(when satellite tracking systems began being required to help ensure proper disposal within site
boundaries). Transects lines for the survey are shown on Figure 27. Figure 28 superimposes an
area-wide surface geological map from the sub-bottom profiling survey with the SPI-based
mapping of the dredged material footprint, showing excellent concordance between the two
methods. Sub-surface results for a typical transect are shown on Figure 29, which presents a cross-
section through the center of the disposal site looking down through both the dredged material
deposit and the native sediment underlying it.
The analysis of the full sub-bottom data set (Sea Engineering, Inc., 2014) suggests that the dredged
material deposits in and around the South Oahu site generally vary between 3 and 12 feet (1- 4 m)
in thickness. An order of magnitude approximation of the total amount of dredged material within
the study area was calculated using an average thickness of 6 feet (2 meters). The total volume of
dredged material mapped throughout the entire study area, including historic disposal outside the
current site boundaries, was thus calculated to be 27,885,600 cubic yards (21,320,000 cubic
meters). However, the total volume of dredged material mapped within the current South Oahu
site boundary was calculated to be 1,736,000 cubic yards (1,327,350 cubic meters). This compares
quite favorably with the recorded volume of 1,855,230 cubic yards of material known to have been
disposed from 2000 through 2013 (Table 1, and Figure 30).
36
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 25. USGS shaded-relief image showing the boundary of the sub-bottom survey area around the South Oahu
disposal site, as well as major bedforms in the vicinity (shaded relief imagery from USGS, 2000). (Sea
Engineering, 2014)
1UI ^ >.qr-Tc^»
F1 R 4s 25fMM 'T .
t' ftf
H,-.
i
9
„ PfilSt 8
id***
27
G '1*
HO 4s
Obstri
10
•' VUli'V
g» I \ s '/s '"-
ODMDS
ODMDS
BEDFORMS
¦ \l*V
* / J RfeEF ' SURVEY LIMIT
,'Akeef reef
- : L_
SURVEY
LIMIT
HIGH RELIEF
AREA
BEDFORMS
37
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 26. USGS sidescan sonar (backscatter) image showing historic dredged material deposits around the sub-bottom
survey area and the South Oahu disposal site (sidescan imagery from USGS, 2000). (Sea Engineering, 2014)
l!/ '
Vf A.
if (a
IK
12
DREDGED MATERIAL
DEPOSITS
.SUftVEY
-«.«T
9S&
DREDGED MATERIAL
DEPOSITS
38
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 27. Transect lines for the sub-bottom profiling survey of the South Oahu site. Results for Diagonal line 1
through the center of the disposal site (arrows) are given in Figure 29. (Sea Engineering, 2014)
39
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Figure 28. Geological (surface) interpretation from the sub-bottom profiling survey superimposed with the SPI-
based dredged material footprint map shown in Figure 17. (DM = dredged material; HSL = hard sand layer;
HR/DM = high-relief terrain with dredged material.) (Sea Engineering, 2014)
SURVEY LIMIT
.S6
A. A
£6
•SE6 J
HSL
SPI.PV aid Sadment Sairiplnj Loutoni
South uaiu OLMQS, Hawai
Juno
Station Average
Dredged Material
Thickness (cm)
Dump site
0.0
lr»C*
0 0 1 -1.0 cm
# 1.1-10 0 cm
0 > 10.0 cm
O lnt)et«rrr\*ia(e (IKD)
Dredged material
excnnded penelration?
40
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 29A. Sub-bottom profile - NE portion of Diagonal Line 1. (Sea Engineering, 2014)
Siity very fine sand with
ODMDS
Match with E
IRREGULAR HIGH-RELIEF
TERRAIN CONSISTENT WITH
LIMESTONE REEF OR BEDFORMS
THIN COVER OF SAND AND DM
THIN SAND (1m)
OVER DM
Discrete sand over silty
sand layering. Debris,
mudclasts, and organism tubes
at SWI.
-"RU-
THIN SAND AND DM (3m) *
OVER HIGH-RELIEF TERRAIN
I LACK OF -
! SUB-BOTTOM FEATURES
I INDICATIVE OF DM
Figure 29B. Sub-bottom profile - SW portion of Diagonal Line 1. (Sea Engineering, 2014)
Match with A
LACK OF SUB-BOTTOM FEATURES
INDICATIVE OF DREDGED MATERIAL (DM)
| O
-*•4
: ro
DM - Discrete deposits, fines at depth
arid winnowed sands at SWI.
LACK OF SUB-BOTTOM FEATURES
INDICATIVE OF OHEOGEO MATERIAL (DM)
DM - Discrete layering,
medium sand over silty
very firie sand & muds.
V)
S
ODMDS
Trace DM - Silty fine to
medium sand with some silt
No DM - Medium sand with
interstitial fines and silt.
5UB-BOTTOM FEATURES
APPEAR WHEN DM THINS OS IS NOT PRESENT
41
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 30. Comparison of South Oahu site dredged material volume estimates: from sub-
bottom mapping versus recorded disposal volumes for 2000-2013 (see Table 1).
Comparison of Disposal Volumes:
Sub-Bottom Profile Survey versus
Disposal Records
Estimated Volume of Dredged Material
Disposed at the South Oahu ODMDS
Based on Sub-Bottom Profile Results:
Volume estimated in overall Study Area:
27,885,600 cy (21,320,000 m^)
Volume estimated within ODMDS limits only:
1,736,000 cy (1,327,350 m3)
Disposal Records:
Year
Cubic Yards
2000
0
2001
0
2002
53,500
2003
183,500
2004
540,000
2005
0
2006
160,400
2007
266,500
2008
0
2009
126,200
2010
0
2011
18,260
2012
0
2013
506,870
Total:
1,855,230
Although the volume of dredged material estimated by the sub-bottom profiling survey to be
within the South Oahu disposal site boundary (1.74 million cy) compares well with the actual
disposal records since 2000 (1.85 million cy), Table 1 shows that a total of 6.3 million cy has
actually been disposed since the site was designated in 1981. It is likely that some substantial
portion of the total 6.3 million cy disposed at the South Oahu site since 1981 is actually
represented within the approximately 26 million cy of historic material estimated to be outside the
site boundaries. Prior to the early 2000s, automatic satellite-based tracking and recording of
disposal scow position was not required 2, and "short-dumping" (resulting in material depositing
outside site boundaries) probably occurred fairly frequently. Still, it is highly likely that much of
the material disposed between 1981 and 2000 was nevertheless deposited on-site, so more than 1.8
million cy should be present. It is to be expected that physical consolidation of any dredged
material deposit would occur over time, reducing its apparent volume compared to disposal
records. For all these reasons, the sub-bottom profiling survey's rough estimate is certainly low.
However, it is also certainly within an order of magnitude, and is an interesting cross-check on
other disposal site monitoring results.
2 The 1997 SMMP (USEPA and USAGE, 1997) required a navigation system capable of 30 m accuracy, but did
not specify that the system show the position of the disposal scow itself (as opposed to the tug or towing
vessel). Similarly, the 1997 SMMP did not require "black box" recording of the actual disposal location, so
independent confirmation that disposal only occurred at the center of the disposal site (as required) was
difficult. But beginning in the 2000s, as both commercial GPS accuracy and vessel sensor technology
advanced, and EPA and USAGE began requiring sophisticated automatic tracking systems as conditions for
all individual project's ocean disposal permits.
42
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
3.5 Comparison to 1980 Baseline Information
EPA Region 9
3.5.1 South Oahu Disposal Site
Comparison of the data contained in the 1980 EIS to the data collected from the 2013 survey
shows that the grain size proportions in the disposal site have shifted to a higher percentage of silt
and clay, as well as higher percentage of sediments coarser than sand (Table 6). This is not
surprising because maintenance dredged material tends to be finer grained in comparison to the
native bottom sediments which contain a higher percentage of sand, as described in the 1980 EIS.
New work (deepening) dredging projects in areas such as Pearl Harbor have likely removed deeper
layers of reef formation material, thus contributing to the gravel-sized fraction. This much coarser
material is expected to sink rapidly to the bottom, without dispersing and drifting outside of the
site boundary, in contrast to fine grained dredged material.
Table 6. Average Percent Grain Size - South Oahu Site
Grain Size
1980 EIS
2013 - Disposal
2013 - Outside of
2013 - Entire
Category
(Pre-Disposal)
Site only
Disposal Site
Survey Area
Gravel
12.0
21.6
2.8
12.2
Sand
75.0
44.4
77.2
60.8
Silt & Clay
13.0
33.2
19.2
26.2
Comparison to baseline sediment chemistry is limited to the trace metal concentrations shown in
the 1980 EIS. When comparing the 1980 trace metal data to the data collected from the 2013
survey, it is apparent that dredged material disposal operations generally have not appreciably
increased contaminant loading on-site, or relative to the surrounding environs, except for copper
(Table 7). The slightly elevated on-site copper concentration is higher than the NOAA ER-L
screening level, but is much lower than the ER-M screening level where toxicity effects are more
likely to occur. As discussed in Section 3.2, all sediments discharged at ocean disposal sites are
fully characterized before approval for ocean disposal is granted. Sediments that contain toxic
pollutants in toxic amounts are prohibited from being discharged. Thus the slightly elevated
concentration of copper compared to the 1980 baseline is not considered to represent a risk of
environmental impact.
Table 7. Trace Metal Concentrations - South Oahu Site
Analyte
1980 EIS
2013 - Disposal
2013 - Outside of
2013-
Entire
ER-L
ER-M
(Pre-Disposal)
Site only
Disposal Site
Survey Area
Range
Ave.
Range
Ave.
Range
Ave.
Range
Ave.
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
Cadmium
4.0-6.3
5.2
0.0-
0.69
0.4
0.0-0.42
0.08
0.0-0.69
0.25
1.2
9.6
Mercury
0.5-0.9
0.7
0.10-
0.38
0.18
0.02-
0.19
0.09
0.02-
0.38
0.14
0.15
0.71
Copper
17.6-
45.5
31.0
43.0-
84.0
59.0
11.0-
37.0
23.8
11.0-
84.0
41.4
34
270
Lead
38.1-
59.0
48.6
15.0-
95.0
37.6
10.0-
37.0
20.8
10.0-
95.0
29.2
46.7
218
43
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
The 1980 EIS characterized the benthic community as typical for abyssal depths, with low infaunal
abundance relative to shallow depth communities. Infaunal abundances were similar in the 2013
surveys, although on-site percent abundances of crustaceans and other miscellaneous taxa
appeared to be slightly lower than in 1980 (Table 8). Nevertheless, even these minor differences
are most likely attributable to natural variability across the study area rather than to disposal
activities. This conclusion is supported by abundances of crustaceans and other miscellaneous
taxa in 2013 being greater inside the disposal site compared to outside it.
Table 8. Percent Abundance - South Oahu Site
Taxonomic Group
1980 EIS
2013 - Disposal
2013-Outside of
2013- Entire Survey
(Pre-Disposal)
Site only
Disposal Site
Area
Annelida (includes
82.9
84.6
90.6
87.9
polychaetes)
Crustacea
2.9
1.3
1.3
1.3
Mollusca
0.8
3.8
1.3
2.4
Miscellaneous taxa
13.3
10.4
6.7
8.4
3.5.2 Hilo Disposal Site
Comparison of the data contained in the 1980 EIS to the data collected from the 2013 survey
shows that the grain size character has shifted to a somewhat higher percentage of silt and clay
(Table 9). This is not surprising because maintenance dredged material tends to be finer grained in
comparison to the native bottom sediments which contain a higher percentage of sand, as described
in the 1980 EIS. But these physical changes are less obvious and widespread than at the South
Oahu site, where much more dredged material has been disposed. Also in contrast to the South
Oahu site, new work (deepening) dredging projects have not placed such a high volume of much
coarser reef formation material, and as a result, the gravel-sized fraction has not increased
significantly.
Table 9. Average Percent Grain Size - Hilo Site
Grain Size
1980 EIS
2013 - Disposal
2013 - Outside of
2013- Entire
Category
(Pre-Disposal)
Site only
Disposal Site
Study Area
Gravel
1.0
1.75
0.0
0.9
Sand
77.0
59.8
49.3
54.5
Silt & Clay
22.0
30.3
52.0
41.1
Comparison to baseline sediment chemistry is limited to the trace metal concentrations shown in
the 1980 EIS. When comparing the 1980 trace metal data to the data collected from the 2013
survey, it is apparent that dredged material disposal operations at the Hilo site have not caused any
significant increase in contaminant loading, except for copper (Table 10.). The slightly elevated
copper concentration is higher than the NOAA ER-L screening level, but is much lower than the
ER-M screening level, where toxicity effects are more likely to occur; therefore the slightly
elevated copper is not considered to represent a risk of environmental impact. In addition, the
copper elevation is shoreward and outside the disposal site. Possible explanations include
contaminants from other shore-side source, or historic short-dumping from disposal scows (prior to
the early 2000's, after which "black box" compliance monitoring was required).
44
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Table 10. Trace Metal Concentrations - Hilo Site
Analyte
1980 EIS
2013 - Disposal
2013 - Outside of
2013-
Entire
(Pre-Disposal)
Site only
Disposal Site
Survey Area
ER-L
ER-M
Range
Ave.
Range
Ave.
Range
Ave.
Range
Ave.
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
Cadmium
—
3.4
0.0-0.6
0.4
0.50-
0.72
0.64
0.0-
0.72
0.51
1.2
9.6
Mercury
0.10-
0.59
0.35
0.05-
0.06
0.06
0.04-
0.17
0.10
0.04-
0.17
0.08
0.15
0.71
Copper
33.9-
38.1
36.0
30.0-
35.0
31.8
30.0-
56.0
42.0
30.0-
56.0
36.9
34
270
Lead
19.5-
29.0
24.3
11.0-
12.0
11.2
9.6-
21.0
15.2
9.6-
21.0
13.2
46.7
218
The 1980 EIS characterized the benthic community at the Hilo site as typical for abyssal depths,
with low infaunal abundances relative to shallow depth communities. Compared to data presented
in the site designation EIS, some minor differences in percent abundance appear to have occurred
(Table 10). Mollusks and miscellaneous taxa appear to be very slightly lower on-site compared to
off-site in 2013 (though not statistically significantly so), and miscellaneous taxa appear to be less
abundant in 2013 than they were in 1980. However, in 2013 miscellaneous taxa were lower both
inside and outside the disposal site, while mollusks were more abundant region-wide than in 1980.
As noted earlier, the native benthic environment around the Hilo site is more heterogeneous than
around the South Oahu site to begin with. These minor differences may in infaunal abundances
therefore are at least substantially attributable to natural variability across the study area rather
than to disposal activities.
Table 11. Percent Abundance - Hilo Site
Taxonomic Group
1980 EIS
2013 - Disposal
2013-Outside of
2013- Entire Survey
(Pre-Disposal)
Site only
Disposal Site
Area
Annelida (includes
80.0
85.9
79.6
81.8
polychaetes)
Crustacea
2.2
2.8
1.0
1.5
Mollusca
1.1
4.2
10.8
8.5
Miscellaneous taxa
16.7
7.0
8.8
8.2
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
IV. CONCLUSIONS AND RECOMMENDATIONS
Multiple survey activities were conducted in 2013 to assess the condition and performance of the
EPA-designated South Oahu and Hilo ocean dredged material disposal sites. Over the past two
decades, South Oahu and Hilo have been the most heavily used of the five disposal sites that serve
the ports and harbors of the Hawaiian Islands. The survey results are intended to identify whether
any adverse impacts of dredged material disposal are occurring compared to baseline conditions, to
confirm the protectiveness of the pre-disposal sediment testing required by EPA and USACE, and
to serve as a basis for updating the Site Management and Monitoring Plan (SMMP) as appropriate.
The dredged material deposit (footprint) was mapped at each site. Significant deposits of dredged
material are apparent outside the South Oahu site boundaries, but this likely resulted from short-
dumping prior to the early 2000s when EPA and USACE began requiring "black box" tracking
systems. Since that time, virtually all material disposed at South Oahu is documented as having
been discharged properly within the Surface Disposal Zone at the center of the site. At the Hilo
site, almost all of the dredged material footprint is contained within the site boundary.
Sediment sampling confirms that there have been no significant adverse impacts as a result of
dredged material disposal operations at either of the disposal sites monitored. Only minor physical
effects (grain size and organic carbon content changes) have occurred at either site, despite the
order-of-magnitude greater volume that has been disposed at the South Oahu site over the last 15
years. Chemical analysis of both on-site and off-site stations indicated only low concentrations of
chemicals of concern, both on-site and off-site. Benthic community analyses showed that
recolonization occurs after dredged material is deposited, and similar infaunal and epifaunal
communities occupy both on-site and off-site areas. Taken together, these results also provide
support that the pre-disposal sediment testing program is effective in not allowing highly
contaminated sediments to be discharged at either site.
The 2013 monitoring results also indicate a lack of significant adverse impacts compared to 1980
baseline conditions. Only minor and localized physical changes are apparent as a result of disposal
operations at either site.
Overall, these findings suggest that ongoing use of the South Oahu and Hilo ocean dredged
material disposal sites, under testing and management conditions at least as stringent as have been
applied over the past 15 years, should similarly result no significant adverse effects. Permit
conditions should be updated in the revised SMMP, and a more specific site monitoring schedule
should be established for the future. But based on all the monitoring results, no significant
changes to sediment testing or to the overall site management framework appear to be warranted
for these sites.
Continued use of the other three Hawaii ocean dredged material disposal sites that were not
monitored in 2013 is also supported by inference. These sites have received far less frequent
dredged material disposal than South Oahu or even Hilo, and impacts can be expected to be
negligible there as well. Nevertheless, the other Hawaii sites should be considered for
confirmatory monitoring after the next round of disposal operations, currently expected to occur in
2016.
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
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V. REFERENCES
ALS Environmental, 2013. South Oahu Ocean Sediments. (Analytical chemistry results for grain
size, total solids, TOC, PCBs, Dioxins/Furans, and butyltins.) Prepared under EPA contract
EP-C-09-020 for ERG Inc., Chantilly, VA.
EcoAnalysts, Inc., 2014. Final Report for Benthic Community Analysis for Site Monitoring of
EPA-Designated Ocean Disposal Sites in Region 9: South Oahu and Hilo Sites (EPA
Contract EP-C-09-020, Work Assignment 4-27). Woods Hole, MA.
Germano & Associates, 2013 a. Confirmatory Site Monitoring of the South Oahu and Hilo Ocean
Dredged Material Disposal Sites Utilizing Sediment Profile and Plan View Imaging:
Quality Assurance Project Plan. Prepared under EPA contract EP-C-09-020 for ERG Inc.,
Chantilly, VA.
Germano & Associates, 2013 b. Monitoring Survey of the EPA-Designated South Oahu and Hilo
Ocean Dredged Material Disposal Sites: Sediment Profile & Plan View Imaging Results,
2013 (Project No. 0268.04.027/2, EPA Contract EP-C-09-020, Work Assignment 4-27).
Bellevue, WA.
NOAA, 2008. Sediment Quick Reference Tables (SQuiRT), NOAA OR&R Report 08-1, Office of
Response and Restoration Division, Seattle, WA.
Rhoads, 1974. Organism-sediment relations on the muddy seafloor. Oceanography and Marine
Biology: An Annual Review; 12:263-300.
Rhoads and Germano. 1982. Characterization of benthic processes using sediment profile
imaging: An efficient method of remote ecological monitoring of the seafloor (REMOTS™
System). Mar. Ecol. Prog. Ser. 8:115-128.
Sea Engineering Inc., 2013. Quality Assurance Project Plan: Sub-Bottom Profiler Survey for
Confirmatory Site Monitoring of the South Oahu Ocean Dredged Material Disposal Sites.
Prepared under EPA contract EP-C-09-020 for ERG Inc., Chantilly, VA
Sea Engineering Inc., 2014. South Oahu Ocean Dredged Material Dump Site Sub-Bottom Survey,
Honolulu, HI (EPA Contract No. EP-C-09-020, Work Assignment 4-27; Subcontract
0268.04.027/1). Waimanalo, HI.
Torresan and Gardner, 2000. Acoustic Mapping of the Regional Seafloor Geology in and
Around Hawaiian Dredged Material Disposal Sites (USGS Open File Report 00-124).
USACE. Ocean Disposal Database, http://e 1 ,erdc,usace.army.roi 1/odd/QDMDSSearch.efro.
USEPA, 1980. Final Environmental Impact Statement for Hawaii Dredged Material Disposal Site
Designation, US Environmental Protection Agency, Oil and Special Materials Control
Branch, Marine Protection Branch. Washington, D.C.
USEPA, 2013 a. Work Plan QAPP (EPA Contract No. EP-C-09-020, Work Assignment 4-27);
EPA Region 9, San Francisco, CA.
USEPA, 2013 b. Analytical Testing Results, Project R13W07, SDG 13189B. EPA Region 9
Laboratory, Richmond, CA.
USEPA and USACE, 1977. Site Management Plan (SMP) for the Hawaii Ocean Dredged
Material Disposal Sites. Special Joint Public Notice. April 7, 1997.
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
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APPENDIX
SUMMARY OF PLANNED VS ACTUAL SURVEY ACTIVITIES AT
HAWAII OCEAN DREDGED MATERIAL DISPOSAL SITES, 2013
A-l
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
APPENDIX
SUMMARY OF PLANNED VS ACTUAL SURVEY ACTIVITIES AT
HAWAII OCEAN DREDGED MATERIAL DISPOSAL SITES, 2013
General Survey Information:
Site Name (Region): South Oahu and Hilo Ocean Dredged Material Disposal Sites (Region 9)
Survey Chief Scientist/Organization: Allan Ota (EPA Region 9)
Telephone: 415-972-3476
E-mail: ota.allan@epa.eov
Other Key Personnel/Organization: Brian Ross (EPA Region 9)
Telephone: 415-972-3475
E-mail: ross.briam@epa.gov
Science Crew/Organization:
Amy Wagner (EPA Region 9)
Leslie Robinson (US Navy, HI)
Sean Hanser (US Navy, HI)
Thomas Smith (USACE, HI)
Robert O'Connor (NO A A, HI)
Joseph Germano (Germano & Assoc., WA)
David Browning (Germano & Assoc., WA)
Christine Smith (ANAMAR, FL)
Schedule of Operations:
Number of survey days: 8 planned, 5 actual (plus 2 for mobilization/demobilization)
Mobilization date (Location): 24-25 June 2013 (Ford Island, Pearl Harbor, Oahu)
Demobilization date (Location): 03 July 2013 (Ford Island, Pearl Harbor, Oahu)
Original Problem Definitions/Task Descriptions (from Quality Assurance Project Plan)
1. Using the Hi'ialakai, collect MBES images to confirm overall bathymetry and identify
any features of interest to adjust sediment sampling locations as appropriate:
a. Is the overall bathymetry different from the standard NOAA charts?
b. Are there unusual or unique features that suggest that adjustment of planned
sampling station locations is necessary to improve interpretation of site
monitoring data?
2. Using the Hi'ialakai, collect SPI and PVP images at up to 49 stations covering each
EPA ODMDS and adjacent areas outside of site boundaries to address the following
management questions:
a. Is the footprint of recently deposited dredged material contained within site
boundaries? Are dredged materials in a single mound feature or contained
in multiple mounds?
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
b. Are the sediments within the dredged material deposit footprint visually
similar or dissimilar from ambient bottom sediments?
c. Are there indications of disposal of materials other than dredged materials?
d. Are there indications of an undisturbed or disturbed environment (adverse
impacts)?
3. Using the Hi'ialakai, collect up to 20 sediment grab samples at each EPA ODMDS and
adjacent areas outside of site boundaries to address the following management
questions:
a. Are sediment contamination levels at the sites within the range predicted by
pre-disposal sediment testing of dredged material approved for disposal?
b. Are levels of contaminants at historic disposal sites (>10 years since used)
adjacent to the active South Oahu site similar to or below ambient levels
(undisturbed native sediments - outside of deposit footprint or site
boundaries)?
c. How do the biological communities compare, between within the site and
outside of site boundaries?
d. How do the biological communities compare to what existed when these
permanent sites were designated?
4. Using a contracted (Sea Engineering) vessel, collect high resolution sub-bottom seismic
profiles within selected basin locations to address the following management questions:
a. Based on the acoustic signal contrast between native bottom sediments and
dredged material layer, what is the horizontal extent of the dredged material
deposit footprint relative to the site boundaries? - i.e., does the dredged material
deposit appear to reside mostly or completely within site boundaries, suggesting
site is performing as expected?
b. Based on the acoustic signal contrast between native bottom sediments and
dredged material layer, what is the apparent thickness of the dredged material
deposit footprint? - i.e., does the bulk of the dredged material volume appear to
reside mostly or completely within site boundaries, suggesting site is
performing as expected?
c. How does the calculated volume of the dredged material identified by this
survey compare with dredging records for projects using the site? - i.e.,
comparison of volumes from compiled disposal records to the calculated
volume using information from (a) and (b) above.
Actual Sequence of Tasks/Events
The surveys were originally scheduled to occur over 8 days (plus mobilization and
demobilization), but problems associated with readiness of the NOAA ship and its equipment
caused some delays. The surveys were ultimately conducted over a 5-day period (not including
transit between the South Oahu site and the Hilo site, and the return transit to Pearl Harbor from
the Hilo site). Field operations were conducted continuously over a 24-hour period (two scientific
crews workingl2-hour shifts).
The survey sampling objectives were not fully accomplished due to the following problems:
1. Departure was delayed by one day, due to:
a. Hole/rupture in the NOAA ship's bilge tank which had to be repaired.
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
b. The original contracted marine winch, which was installed during the previous
week, was not working properly and its hydraulic unit had to be replaced.
2. The replacement winch operated at a slower rate (about 20 meters per minute, instead of
40-60 meters per minute) than what was expected when the survey plan was conceived,
resulting in less than half of the planned sediment grab sampling stations being occupied in
the time remaining for survey work.
3. Hard bottom features were encountered and multiple attempts were needed at several
stations to obtain acceptable samples, as judged by QAPP metrics (i.e., adequate
penetration and undisturbed appearance).
4. The multi-beam echo sounder (MBES) survey initially planned for both sites was not
executed due to the equipment on the NOAA vessel not functioning properly at the
beginning of the first survey leg. As a result, no MBES data was collected at either site. In
the absence of the MBES survey data, the combination of SPI and PVP photography and
analysis of the SPI visual parameters provided information on the horizontal and vertical
extent of the dredged material footprint, and context for the other (sediment) sampling
results.
Survey Activities/Operations Conducted to Address Problem Definitions:
The following are the survey activities executed at both sites:
1. Sediment Profile Imaging (SPI) and Plan View Photography (PVP)
SPI-PVP surveys were conducted for each ODMDS to delineate the horizontal extent
of the dredged material deposit footprint within the site, and outside of site boundaries
if any deposits exist (Figure 2). A total of 86 stations were occupied with the SPI/PV
camera system (40 at South Oahu and 46 at Hilo), compared to the planned 98 (49 at
each site). With optimal resolution on the order of millimeters, the SPI system is
particularly useful for identifying a number of features, including the edges of the
footprint as they overlay native sediments of the seabed, identifying dredged material
layers relative to native sediments, and the level of disturbance as indicated by presence
of certain classes of benthic organisms (Figures 3 and 4). PVP is useful for identifying
surface features where the SPI photos are taken, thereby providing surface context for
the vertical profiles at each station. For each station, a minimum of four SPI photos
were taken, coupled with a single PVP photo.
2. Sediment Sampling for Chemistry and Benthic Communities:
Sediment samples were collected for sediment grain size, chemistry, and benthic
community analysis with a stainless steel double Van Veen sediment grab (Figure 5)
capable of penetrating a maximum of 20 centimeters of depth below the sediment
surface. Sediment grab samples were judged acceptable based on approved QAPP
metrics. After each acceptable grab sample was measured for depth of penetration and
photographed, sufficient volume of chemistry subsample were extracted from one of
the two grabs with a stainless steel spoon for further processing (Figure 6). The
chemistry subsample was then homogenized and divided into the different chemistry
analysis jars (i.e., grain size, metals and organics). After the chemistry subsample was
extracted, the entire volume of the other grab was processed (Figure 7) to create a
benthic community sample for that station. A 500 micron sieve was used to separate
organisms from the sediment, and the separated organisms were then initially preserved
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
with formalin. A total of 18 sediment grab sample stations were occupied in the two
survey areas combined, relative to the original targeted 40 locations. 18 chemistry
samples were processed (10 at South Oahu, and 8 at Hilo), 3 of which were field or
laboratory duplicates. A total of 14 benthic community samples were collected; the
lower number than the chemistry samples was due to some grabs being used for field
and laboratory chemistry duplicates, and one station where QAPP metrics were not met
for an acceptable benthic sample (lack of time to re-deploy).
The following survey activity was executed only at the South Oahu site:
3. Collection of high-resolution sub-bottom seismic-reflection profiles:
The primary purpose of this survey was to collect cross-sectional images of the native
sediment layers and identify layers indicative of the dredged material deposit footprint
in the environs of the South Oahu ODMDS. (The Hilo site was not surveyed in this
manner during this round of surveys, primarily due to the much smaller volumes of
dredged material which may not be detectable in terms of thickness and contrast.) The
survey was contracted to Sea Engineering, who conducted the work aboard a separate
vessel specially rigged for this type of survey with an acoustic sub-bottom profiler
system (Figure 8), which was more cost effective than attempting to install the
equipment on the NOAA vessel. The results of this survey allowed EPA to calculate an
estimate of cumulative volume of dredged material in the South Oahu site.
The study areas are depicted in Figures 9 and 10 (South Oahu) and 11, and 12 (Hilo) The target
sampling station coordinates are listed in Tables 2 (South Oahu) and 3 (Hilo).
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
Figure 9. General location of the South Oahu ODMDS
EPA Region 9
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
Figure 10. Planned and actual sample station locations at the South Oahu ODMDS:
EPA Region 9
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table 2. South Oahu ODMDS Sampling Station Coordinates (NAD83). SPI and PVP
photographic samples at all stations; sediment grab samples at highlighted stations.
Station ID
Latitude
Longitude
Sampling Notes
C
21 14.970 N
157 56.670 W
SPI-PV only
N1
21 15.220 N
157 56.670 W
SPI-PV and sediment grab
Nl-A
2115.199 N
157 56.647 W
SPI-PV and sediment grab (field dupe)
N2
21 15.470 N
157 56.670 W
SPI-PV and sediment grab
N3
21 15.720 N
157 56.670 W
SPI-PV only
N4
21 15.965 N
157 56.670 W
SPI-PV only
N5
2116.215 N
157 56.670 W
SPI-PV only
N6
21 16.470 N
157 56.670 W
SPI-PV only
SI
21 14.720 N
157 56.670 W
SPI-PV only
S2
21 14.465 N
157 56.670 W
SPI-PV only
S3
21 14.220 N
157 56.670 W
SPI-PV only
S4
21 13.965 N
157 56.670 W
SPI-PV only
S5
21 13.720 N
157 56.670 W
SPI-PV only
S6
21 13.465 N
157 56.670 W
SPI-PV and sediment grab
W1
21 14.970 N
157 56.940 W
SPI-PV and sediment grab
W2
21 14.970 N
157 57.210 W
SPI-PV only
W3
21 14.970 N
157 57.475 W
SPI-PV only
W4
21 14.970 N
157 57.740 W
SPI-PV only
W5
21 14.970 N
157 58.000 W
SPI-PV and sediment grab
W6
21 14.970 N
157 58.275 W
SPI-PV only
El
21 14.970 N
157 56.400 W
SPI-PV only
E2
21 14.970 N
157 56.135 W
SPI-PV only
E3
21 14.970 N
157 55.870 W
SPI-PV only
E4
21 14.970 N
157 55.600 W
SPI-PV and sediment grab
E5
21 14.970 N
157 55.340 W
SPI-PV only
E6
21 14.970 N
157 55.070 W
SPI-PV and sediment grab
NW1
2115.140 N
157 56.865 W
Station not occupied
NW2
21 15.300 N
157 57.070 W
SPI-PV only
NW3
21 15.470 N
157 57.270 W
Station not occupied
NW4
21 15.650 N
157 57.450 W
SPI-PV only
NW5
21 15.825 N
157 57.635 W
Station not occupied
NW6
2116.010 N
157 57.820 W
SPI-PV only
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table 2, continued. South Oahu ODMDS Sampling Station Coordinates (NAD83). SPI and PVP
photographic samples at all stations; sediment grab samples at highlighted stations.
NE1
2115.140 N
157 56.480 W
Station not occupied
NE2
21 15.300 N
157 56.280 W
SPI-PV only
NE3
21 15.470 N
157 56.090 W
Station not occupied
NE4
21 15.650 N
157 55.900 W
SPI-PV only
NE5
21 15.825 N
157 55.710 W
Station not occupied
NE6
2116.010 N
157 55.530 W
SPI-PV only
SW1
21 14.790 N
157 56.865 W
SPI-PV only
SW2
21 14.620 N
157 57.050 W
SPI-PV and sediment grab
SW3
21 14.435 N
157 57.225 W
SPI-PV only
SW4
21 14.245 N
157 57.400 W
SPI-PV only
SW5
21 14.070 N
157 57.590 W
SPI-PV only
SW6
21 13.900 N
157 57.785 W
SPI-PV only
SE1
21 14.790 N
157 56.480 W
Station not occupied
SE2
21 14.620 N
157 56.280 W
SPI-PV only
SE3
21 14.435 N
157 56.090 W
Station not occupied
SE4
21 14.245 N
157 55.910 W
SPI-PV and sediment grab
SE5
21 14.070 N
157 55.720 W
Station not occupied
SE6
21 13.900 N
157 55.530 W
SPI-PV only
A-9
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys
Figure 11. General location of the Hilo ODMDS:
EPA Region 9
~ o
°o *
- » <
nhL.
%aMl
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2013 South Oahu arid Hilo Ocean Disposal Site Monitoring Surveys EPA Region 9
Figure 12. Planned and actual sample station locations at the Hilo ODMDS:
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table 3. Hilo ODMDS Sampling Station Coordinates (NAD83). SPI and PVP photographic
samples at all stations; sediment grab samples at highlighted stations.
Station ID
Latitude
Longitude
Notes
C
19 48.315 N
154 58.340 W
SPI-PV only (grab failed)
N1
19 48.565 N
154 58.320 W
SPI-PV and sediment grab
N2
19 48.815 N
154 58.295 W
SPI-PV only
N3
19 49.065 N
154 58.285 W
Station not occupied
N4
19 49.315 N
154 58.270 W
SPI-PV only
N5
19 49.570 N
154 58.260 W
Station not occupied
N6
19 49.820 N
154 58.245 W
SPI-PV only
SI
19 48.075 N
154 58.365 W
SPI-PV only
S2
19 47.825 N
154 58.395 W
SPI-PV only
S3
19 47.570 N
154 58.425 W
SPI-PV only
S4
19 47.325 N
154 58.450 W
SPI-PV only
S5
19 47.075 N
154 58.475 W
SPI-PV only
S6
19 46.820 N
154 58.500 W
SPI-PV only
W1
19 48.335 N
154 58.600 W
SPI-PV only
W2
19 48.355 N
154 58.870 W
SPI-PV only
W3
19 48.375 N
154 59.125 W
SPI-PV only
W4
19 48.400 N
154 59.385 W
SPI-PV only
W5
19 48.430 N
154 59.655 W
SPI-PV only (grab failed)
W6
19 48.460 N
154 59.920 W
SPI-PV and sediment grab
El
19 48.290 N
154 58.075 W
Station not occupied
E2
19 48.270 N
154 57.810 W
SPI-PV only
E3
19 48.250 N
154 57.545 W
Station not occupied
E4
19 48.230 N
154 57.285 W
SPI-PV only
E5
19 48.210 N
154 57.020 W
SPI-PV only
E6
19 48.190 N
154 56.755 W
Station not occupied
NW1
19 48.490 N
154 58.530 W
SPI-PV only
NW2
19 48.675 N
154 58.700 W
SPI-PV only
NW3
19 48.880 N
154 58.860 W
SPI-PV only
NW4
19 49.060 N
154 59.040 W
SPI-PV only
NW5
19 49.265 N
154 59.200 W
SPI-PV only
NW6
19 49.470 N
154 59.365 W
SPI-PV only
NE1
19 48.480 N
154 58.130 W
SPI-PV only
NE2
19 48.650 N
154 57.935 W
SPI-PV only
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2013 South Oahu and Hilo Ocean Disposal Site Monitoring Surveys
EPA Region 9
Table 3, continued. Hilo ODMDS Sampling Station Coordinates (NAD83). SPI and PVP
photographic samples at all stations; sediment grab samples at highlighted stations.
NE3
19 48.815 N
154 57.735 W
SPI-PV only
NE4
19 48.975 N
154 57.535 W
SPI-PV only
NE5
19 49.130 N
154 57.330 W
SPI-PV and sediment grab
NE6
19 49.275 N
154 57.110 W
Station not occupied
SW1
19 48.155 N
154 58.540 W
SPI-PV and sediment grab
SW2
19 48.015 N
154 58.760 W
SPI-PV only
SW3
19 47.865 N
154 58.970 W
SPI-PV only
SW4
19 47.720 N
154 59.185 W
SPI-PV only
SW5
19 47.565 N
154 59.385 W
SPI-PV only
SW6
19 47.415 N
154 59.600 W
SPI-PV and sediment grab
SW7
19 47.257 N
154 59.827 W
SPI-PV only (station added in field)
SW8
19 46.989 N
155 00.245 W
SPI-PV only (station added in field)
SW9
19 46.648 N
155 00.587 W
SPI-PV only (station added in field)
SE1
19 48.110 N
154 58.180 W
SPI-PV only
SE2
19 47.925 N
154 58.010 W
SPI-PV only
SE3
19 47.715 N
154 57.850 W
SPI-PV only
SE4
19 47.530 N
154 57.690 W
SPI-PV and sediment grab
SE5
19 47.325 N
154 57.520 W
SPI-PV only
SE6
19 47.135 N
154 57.340 W
SPI-PV only
A-13
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Appendix 3 to EPA Consultation with USFWS
for Continued Use of Five Existing Ocean Dredged Material Disposal Sites (ODMDS)
in Waters Offshore of Hawaii
Preliminary Chemistry Results from the 2017 Monitoring Survey
of the Nawiliwili, Kahului, and Port Allen Ocean Disposal Sites
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2017 EPA Monitoring Survey of the Kahului, Nawiliwili,
and Port Allen Ocean Disposal Sites in Hawai'i:
Preliminary Chemistry Results
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2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results
DRAFT - DO NOT DISTRIBUTE
Figure 1. Map of the stations in the Kahului ocean disposal site survey area. A subset of these stations was selected for sediment grabs.
1
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2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 1. Sediment chemistry results from the Kahului ocean disposal site (first of two tables).
NOAA
Kahului site
"Inside"
Reference
Screening
Analyte
Units
(dw)
KH00
KH01
KH12
KH20
KH28
KH28
KH34
KH37
KH44
KH03
KH21
KH27
KH30
KH39
Site
ER-L
ER-M
TOC
mg/kg
3430.00
4020.00
4170.00
5270.00
3970.00
3460.00
3510.00
4160.00
3520.00
4210.00
7220.00
4000.00
3400.00
4240.00
0.58
-
-
Arsenic
mg/kg
16.00
16.00
22.00
17.00
17.00
18.00
22.00
16.00
17.00
22.00
18.00
20.00
23.00
18.00
40
8.2
70
Cadmium
mg/kg
0.36
0.36
0.40
0.38
0.37
0.37
0.38
0.34
0.37
0.40
0.39
0.41
0.41
0.38
ND
1.2
9.6
Chromium
mg/kg
55.00
54.00
80.00
64.00
59.00
61.00
69.00
46.00
59.00
79.00
68.00
80.00
67.00
65.00
68
81
370
Copper
mg/kg
23.00
23.00
31.00
26.00
26.00
25.00
26.00
20.00
23.00
29.00
27.00
31.00
24.00
25.00
22
34
270
Lead
mg/kg
4.70
5.30
13.00
7.20
5.40
6.60
6.90
3.40
7.70
11.00
8.30
12.00
6.50
7.90
19
46.7
218
Mercury
mg/kg
0.02
0.03
0.05
0.03
0.03
0.03
0.05
0.02
0.06
0.04
0.03
0.05
0.03
0.03
0.09
0.15
0.71
Nickel
mg/kg
52.00
56.00
54.00
52.00
50.00
55.00
53.00
57.00
47.00
54.00
50.00
51.00
42.00
51.00
37
20.9
51.6
Selenium
mg/kg
1.50
1.40
1.60
1.50
1.50
1.50
1.50
1.40
1.50
1.60
1.60
1.70
1.60
1.50
ND
-
-
Silver
mg/kg
0.73
0.71
0.79
0.76
0.74
0.74
0.76
0.69
0.75
0.80
0.79
0.83
0.81
0.77
ND
1
3.7
Zinc
mg/kg
41.00
43.00
47.00
65.00
44.00
43.00
46.00
40.00
40.00
45.00
45.00
48.00
44.00
44.00
52
150
410
Dioxins &
Furans
TEQ
0.93
4.24
0.88
0.53
0.78
0.56
0.89
0.79
1.01
1.17
1.01
1.02
0.94
0.70
1.06
Total DDTs
ug/kg
14.40
13.80
15.60
15.00
14.40
15.00
15.00
13.80
15.00
52.00
15.60
16.20
16.20
15.00
ND
1.58
46.1
Total
Organotins
ug/kg
806.30
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
7.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
53.40
67.10
92.00
54.20
48.80
68.30
84.20
51.60
91.80
71.00
55.00
73.70
73.00
60.20
344
4022
44792
Total PCBs
ug/kg
0.00
0.00
0.30
0.00
0.00
0.00
0.00
0.31
0.00
0.00
0.00
2.73
0.00
8.32
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
2
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2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 2. Sediment chemistry results from the Kahului ocean disposal site (second of two tables).
NOAA
Kahului site
"Outside"
Reference
Screening
Analyte
Units
(dw)
KH05
KH09
KH14
KH16
KH23
KH32
KH36
KH41
KH41
KH46
KH48
KH50
KH53
KH56
Site
ER-L
ER-M
TOC
mg/kg
5380.00
3680.00
4440.00
5630.00
4900.00
3700.00
3950.00
4230.00
4250.00
3610.00
3200.00
2700.00
2610.00
4500.00
0.58
-
-
Arsenic
mg/kg
33.00
32.00
21.00
24.00
20.00
23.00
21.00
20.00
24.00
19.00
30.00
29.00
33.00
23.00
40
8.2
70
Cadmium
mg/kg
0.39
0.37
0.41
0.42
0.41
0.41
0.38
0.40
0.41
0.39
0.40
0.38
0.36
0.41
ND
1.2
9.6
Chromium
mg/kg
82.00
74.00
75.00
89.00
78.00
68.00
69.00
74.00
86.00
68.00
78.00
78.00
67.00
72.00
68
81
370
Copper
mg/kg
24.00
20.00
27.00
31.00
29.00
25.00
25.00
28.00
30.00
24.00
24.00
24.00
19.00
26.00
22
34
270
Lead
mg/kg
6.90
4.70
11.00
13.00
11.00
4.80
8.30
9.20
16.00
9.10
8.60
5.80
4.10
8.30
19
46.7
218
Mercury
mg/kg
0.03
0.02
0.05
0.05
0.04
0.02
0.05
0.05
0.05
0.05
0.06
0.05
0.02
0.05
0.09
0.15
0.71
Nickel
mg/kg
52.00
50.00
47.00
55.00
51.00
41.00
46.00
49.00
55.00
46.00
52.00
53.00
57.00
47.00
37
20.9
51.6
Selenium
mg/kg
1.60
1.50
1.60
1.70
1.70
1.60
1.50
1.60
1.60
1.60
1.60
1.50
1.40
1.60
ND
-
-
Silver
mg/kg
0.79
0.74
0.82
0.84
0.83
0.82
0.77
0.79
0.82
0.79
0.80
0.76
0.72
0.82
ND
1
3.7
Zinc
mg/kg
43.00
38.00
41.00
43.00
47.00
45.00
41.00
44.00
43.00
40.00
45.00
44.00
41.00
46.00
52
150
410
Dioxins &
Furans
TEQ
1.13
0.61
1.40
0.97
0.88
0.48
0.55
0.88
1.00
1.03
0.92
0.58
0.70
0.76
1.06
-
-
Total DDTs
ug/kg
15.60
14.40
16.20
16.80
16.20
16.20
15.00
15.60
50.50
15.60
15.60
15.00
14.40
16.20
ND
1.58
46.1
Total
Organotins
ug/kg
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
59.00
58.40
71.00
61.80
52.80
60.00
59.20
79.00
81.80
70.80
68.00
64.20
33.40
65.80
344
4022
44792
Total PCB
ug/kg
0.00
0.00
0.00
35.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
17.46
0.31
4.27
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
3
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2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results
DRAFT - DO NOT DISTRIBUTE
Nawiliwili
Depth (m)
2017 SWPV Station
Ctepasal Ste
KJom#t«rs
INSPIRE
Data T»rr>90f»C SUIV»y ZP1 /
D0Cufr*nt tonw OCPD HI FlW 3*1 SVis
Dat«: 2'22i2C 1
Coordinate Syst«rti OCS WGS 19B4
Figure 2. Map of the stations in the Nawiliwili ocean disposal site survey area. A subset of these stations was selected for sediment grabs.
4
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2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 3. Sediment chemistry results from the Nawiliwili ocean disposal site.
Nawiliwili Site
"Inside"
"Outside"
Reference
NOAA
Screening
Analyte
Units
(dw)
NW01
NW19
NW55
NW07
NW18
NW23
NW59
NW10
NW15
NW52
NW57
NW57D
Site
ER-L
ER-M
TOC
mg/kg
2300
2540
1970
1320
3400
1170
2730
2200
780
3690
1260
1140
0.58
-
-
Arsenic
mg/kg
18
19
15
12
19
16
21
14
9
22
12
No
data
40
8.2
70
Cadmium
mg/kg
0.37
0.35
0.38
0.37
0.39
0.41
0.40
0.36
0.42
0.41
0.40
ND
1.2
9.6
Chromium
mg/kg
84
75
80
62
110
64
120
46
31
130
52
68
81
370
Copper
mg/kg
17.00
21.00
19.00
14.00
24.00
16.00
27.00
7.20
7.30
27.00
13.00
22
34
270
Lead
mg/kg
2.20
7.90
2.30
2.40
2.40
2.40
2.40
2.10
2.50
2.40
2.40
19
46.7
218
Mercury
mg/kg
0.02
0.03
0.02
0.02
0.02
0.02
0.03
0.02
0.02
0.03
0.02
0.09
0.15
0.71
Nickel
mg/kg
88
87
100
52
100
95
110
27
32
110
54
37
20.9
51.6
Selenium
mg/kg
1.50
1.40
1.50
1.50
1.60
1.60
1.60
1.40
1.70
1.60
1.60
ND
-
-
Silver
mg/kg
0.74
0.69
0.77
0.74
0.79
0.81
0.79
0.71
0.84
0.82
0.79
ND
1
3.7
Zinc
mg/kg
43
35
43
25
48
37
53
15
17
55
29
52
150
410
Dioxins &
Furans
TEQ
0.92
No
data
1.26
0.66
1.03
0.61
0.69
1.03
0.56
1.09
0.62
0.65
1.06
-
-
Total DDTs
ug/kg
14.40
13.80
15.00
14.40
15.60
16.20
15.60
13.80
16.80
16.20
15.60
ND
1.58
46.1
Total
Organotins
ug/kg
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
48.40
45.60
48.20
49.40
50.00
49.00
49.00
50.40
52.80
50.00
36.40
344
4022
44792
Total PCBs
ug/kg
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3.80
0.00
0.00
0.00
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
5
-------
2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results
DRAFT - DO NOT DISTRIBUTE
1»
100
200
300
4CO
SCO
bCO
7 CO
8CO
900
lOOO
1100
1200
1300
1400
1500
1600
1700
1800
1900
2CC0
2100
2D17 SPI/PV Station
Kilometers
rcrrjiwng V Jl
JNSPIR
Docuftttnt Nam* OCPD HI PA SPl stf»&
Coordinate System OCS WQ8 1984
Date: 2/22/201B
Figure 3. Map of the stations in the Port Allen ocean disposal site survey area. A subset of these stations was selected for sediment grabs.
6
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2017 EPA Hawai'i Monitoring Survey: Preliminary Chemistry Results DRAFT - DO NOT DISTRIBUTE
Table 4. Sediment chemistry results from the Port Allen ocean disposal site.
NOAA
Port Allen Site
"Inside"
"Outside"
Reference
Screening
Analyte
Units
(dw)
PA00
PA13
PA31
PA53
PA15
PA27
PA29
PA34
PA49
PA51
PA55
Site
ER-L
ER-M
TOC
mg/kg
4400
6500
3770
6000
2340
6200
5000
3700
4160
5200
6070
0.58
-
-
Arsenic
mg/kg
19
19
18
23
14
21
21
17
22
23
23
40
8.2
70
Cadmium
mg/kg
0.46
0.43
0.42
0.50
0.38
0.44
0.42
0.42
0.47
0.48
0.55
ND
1.2
9.6
Chromium
mg/kg
150
160
130
180
72
170
140
140
150
190
180
68
81
370
Copper
mg/kg
42
46
41
54
15
46
37
45
52
63
53
22
34
270
Lead
mg/kg
4.00
4.20
3.00
6.00
2.30
5.90
4.20
4.00
6.90
6.80
7.70
19
46.7
218
Mercury
mg/kg
0.10
0.09
0.08
0.11
0.02
0.09
0.05
0.06
0.11
0.10
0.10
0.09
0.15
0.71
Nickel
mg/kg
190
140
130
190
65
150
120
120
130
180
170
37
20.9
51.6
Selenium
mg/kg
1.60
1.70
1.70
1.70
1.50
1.80
1.70
1.70
1.70
1.80
1.80
ND
-
-
Silver
mg/kg
0.82
0.86
0.84
0.85
0.75
0.88
0.85
0.85
0.87
0.88
0.88
ND
1
3.7
Zinc
mg/kg
62.00
65.00
56.00
76.00
28.00
66.00
55.00
58.00
62.00
83.00
70.00
52
150
410
Dioxins &
Furans
TEQ
3.03
3.66
1.61
5.72
1.32
2.53
1.84
3.82
2.67
4.07
7.24
1.06
-
-
Total DDTs
ug/kg
16.20
16.80
16.80
16.80
15.00
17.40
16.80
16.80
17.40
17.40
17.40
ND
1.58
46.1
Total
Organotins
ug/kg
0.00
5.60
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.71
-
-
Total PAHs
ug/kg
76.30
73.00
83.60
88.50
70.10
82.20
74.50
59.80
89.60
116.80
80.40
344
4022
44792
Total PCBs
ug/kg
28.61
29.00
29.00
30.00
25.00
32.00
27.21
25.00
25.29
26.00
26.59
6.07
22.7
180
* Note: Inside denotes stations inside the dredged material footprint, as determined by the SPI taken. Outside denotes stations outside of the dredged material footprint, as
determined by the SPI taken.
7
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United States Department of the Interior
FISH AND WILDLIFE SERVICE
Pacific Islands Fish and Wildlife Office
300 Ala Moana Boulevard, Room 3-122
Honolulu, Hawaii 96850
r—~—\
FISH Ac WMJM.II'F
si:bvice
In Reply Refer To:
January 28, 2021
01EPIF00-2020-I-0465
Ellen Blake
Assistant Director, Water Division
U.S. Environmental Protection Agency
Region IX
75 Hawthorne Street
San Francisco, CA 94105-3901
Subject: Programmatic Consultation for Five Existing Hawai'i Ocean Dredged Material
Dear Ellen Blake:
The U.S. Fish and Wildlife Service (USFWS) received your November 16, 2020 email request
for consultation. You requested our concurrence with your "may affect, but not likely to
adversely affect" determination for five existing ocean dredged material disposal sites, in
Hawai'i. These sites are off the islands of O'ahu, Hawai'i, Maui, and Kaua'i (Figure 1).
Specifically, you requested consultation for the following Hawaiian seabirds, including
• Short-tailed albatross {Phoebastria albastrus)
• 'Ua'u (Hawai'i) or Hawaiian petrel (Pterodroma sandwichensis)
• 'A'o (Hawai'i) or Ta'i'o (Samoa) or Newell's shearwater (Puffimts auricularis newelli)
• 'Ake'ake (Hawai'i) or Hawai'i distinct population segment (DPS) of band-rumped storm-
petrel (Oceanodroma castro)
We based our analysis and decisions on the Biological Assessment for this project and other
pertinent data. A complete consultation record is on file at our office. Our response is in
accordance with section 7 of the Endangered Species Act of 1973 (Act), as amended (16 U.S.C.
1531 et seq.).
Disposal Sites
INTERIOR REGION 12
PACIFIC ISLANDS
INTERIOR REGION 9
COLUMBIA-PACIFIC NORTHWEST
IDAHO, MONTANA*, OREGON*, WASHINGTON AMERICAN SAMOA, GUAM, HAWAII, NORTHERN
*PARTIAL MARIANA IS LAN D S
-------
Ellen Blake
2
l^KAUAl
a Nawiiiwrt ODMDS
Port Allen OOMOS
OanuODMDS
Kanilut ODMDS
f/AUI
Hie ODMDS
ft A'A/Al
/Ik
Figure 1. Vicinity map, showing the five existing Hawai'i EPA-designated ocean disposal sites.
Project Description
This project includes five designated disposal sites that serve the state of Hawai'i and provide
critical maritime access to navigable waters of Hawai'i. The disposal sites are located
approximately 4 to 6.5 nautical miles offshore of the islands of O'ahu, Hawai'i, Maui, and
Kaua'i (Figure 1), in water depths ranging from 1,100-to 5,300-ft deep. Each site includes a
small zone where disposal actions are required to occur, and also include a larger site boundary
where any drifting sediments are intended to deposit. Annually, approximately 220,000 cubic
yards of dredged sediments are deposited across the five sites combined. The specific quantities
of deposited sediments differ at each site and are based on the dredging needs of each island. For
example, the south O'ahu site serves the U.S. Navy facilities at Pearl Harbor and the commercial
port complex in Honolulu harbor. This site is the most heavily used, with dredging and disposal
occurring for 22 of the past 40 years, accounting for over 80 percent of Hawai'i's dredged
sediment disposal. The remaining disposal sites receive less than 10 percent of the dredged
materials. Use of these disposal sites includes only suitable, non-toxic sediment dredged by the
U.S. Army Corps of Engineers (USACE) and U.S. Navy from navigable waters of Hawai'i.
Over a 10-year period, a total of 1.24 million cubic yards of sediments were disposed of at the
five Hawai'i sites combined (2009 through 2018). This level of dredging required between 495
and 2,475 total transits to and from the Hawai'i ocean disposal sites over this period,
representing less than one percent of the total commercial vessel transits currently occuring in
these locations. When disposal vessels arrive at an ocean disposal site, each disposal occurs for
less than five minutes.
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Ellen Blake
3
Conservation Measures
The following conservation measures will occur to avoid and minimize impacts to listed species
and their habitats:
Water Quality - Protection of Marine Areas Potentially Used by Seabirds
• Avoid disposal within existing fisheries and shellfisheries.
• Water quality monitoring occurs to ensure water quality resumes ambient levels before
sediments reach any marine sanctuary or known geographically fishery or shellfisheries.
Disposal vessels use sensors to avoid leakage or spilling dredged materials during transit
to disposals sites.
• The footprint, or total area of the disposal sites are minimized to ensure effective
monitoring may occur and to control effects. Disposal vessels are tracked using a Global
Positioning System (GPS) to ensure disposals occur in the correct locations.
• Selection of the disposal sites considered whether marine species use the areas for
breeding, spawning, nursing, feeding, or migration, for all life stages.
• Each sediment sample is tested to ensure it meets acceptable criteria for classification as
nontoxic, and deposition will avoid contaminating marine areas and species.
• Debris is removed from dredged materials prior to disposal, including entanglement
hazards (i.e., derelict nets).
Effects of the Proposed Action
The short-tailed albatross, 'ua'u (Hawaiian petrel), 'a'o (Newell's shearwater), and 'ake'ake
(Hawai'i DPS of band-rumped storm-petrel) (collectively known as Hawaiian seabirds) may be
present and exposed to disposal of the dredged sediments.
Disturbance
Hawaiian seabirds may forage or loaf in the areas where dredged sediments are disposed. Any
birds present may flush, prompted by approaching disposal vessels. Flushed birds may
temporarily experience missed feedings or increased levels of stress. Disposal of dredged
sediments occurs for less than five minutes, and occurs within the same designated disposal
locations. The disposal events are predictable, short term, and infrequent relative to baseline
commercial vessel traffic. We expect any flushed birds would resume their normal activities
quickly and would not experience decreased fitness from the disturbances.
Prey Resources
Some dredged materials may contain sources of prey that attract diving seabirds to the disposal
areas such as polychaetes, crustaceans, molluscs, and aquatic invertebrates. The seabirds may be
attracted to the disposal areas during disposal and dive to capture any incidental prey resources
-------
Ellen Blake
4
present. The birds may be exposed to elevated levels of turbidity and be disoriented underwater;
however, this is not expected to cause injury or harm to the seabirds.
Disposal of the sediments may occur in areas that provide prey resources to the seabirds (i.e.,
fish). Sediments containing toxins can poison prey resources, including fish that these seabirds
consume. Only sediments that are deemed suitable for open-water disposal (i.e., nontoxic) are
permissable in these locations. The Hawaiian seabirds are unlikely to be exposed to toxins
associated with disposal of the dredged sediments.
Disposal of dredged sediments can bury aquatic prey resources when disposal occurs in shallow
marine areas (i.e., where water depth is shallow enough for sunlight to allow aquatic vegetation
to photosynthesize and grow). These areas can attract fish and provide rearing and foraging
areas. The disposal areas associated with this consultation are several miles offshore and are
located outside these sensitive marine areas.
Therefore, effects to Hawaiian seabirds from disturbance and effects to prey resources are
discountable and insignificant.
Summary
We have reviewed our data and conducted an effects analysis of your project. By incorporating
the conservation measures listed above, adverse effects to listed species are extremely unlikely to
occur, and are therefore insignificant and discountable. Because impacts from the proposed
project are insignificant and discountable, we concur with your determination that the proposed
action may affect, but is not likely to adversely affect the short-tailed albatross, 'ua'u (Hawaiian
petrel), 'a'o (Newell's shearwater), and 'ake'ake (Hawai'i DPS of band-rumped storm-petrel).
Reinitiation of consultation is required and shall be requested by the Federal agency or by the
Service, where discretionary Federal involvement or control over the action has been retained or
is authorized by law and: (1) new information reveals effects of the action that may affect listed
species or critical habitat in a manner or to an extent not previously considered; (2) if the
identified action is subsequently modified in a manner that causes an effect to the listed species
or critical habitat that was not considered in this letter; or (3) if a new species is listed or critical
habitat designated that may be affected by the identified action.
We appreciate your efforts to conserve endangered species. If you have any questions concerning
this consultation, please contact Lindsy Asman, Fish and Wildlife Biologist, at 808-792-9490 or
by email at lindsy asman@fws.eov. When referring to this project, please include this reference
number: 01EPIF00-2020-I-0465.
Sincerely,
Darren LeBlanc
Planning and Consultation Team Manager
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