® E PA
US Army
Corps of Engineers
® San Francisco District
Final Evaluation and Environmental Assessment
for Expansion of the Existing
Humboldt Open Ocean Disposal Site (HOODS)
Offshore of Eureka, California
Samoa
State Marine
Conservation Area
Buoy 46244
'Reference]
Existing
HOODS
(No Action)
•Areata
Alternative 1
HOODS
Boundary
Nearshore Sand
Placement Site
Eureka"
, "
Alternative 2
HOODS
Boundary
Cutten
cRidgewood
/ Fields Uanding
Prepared by
US Environmental Protection Agency, Region 9
US Army Corps of Engineers, San Francisco District
October 19, 2020
HOODS Expansion: Environmental Assessment and MPRSA Criteria Evaluation
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HOODS Expansion: Environmental Assessment and MPRSA Criteria Evaluation
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SUMMARY AND FINDINGS
Project Name: Hoods Expansion
Purpose: Ocean dredged material disposal sites are designated by the Environmental
Protection Agency (EPA) under the 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. The Humboldt Open Ocean Disposal Site (HOODS) was originally designated by EPA in
1995 based on a full Environmental Impact Statement (EIS) (EPA, 1995). Since then the HOODS
site has experienced significant mounding, creating the possibility of potentially hazardous
navigation conditions in the future if the mounding worsens. Today, HOODS has limited capacity
to receive future dredged material disposals. If disposal capacity at HOODS is not expanded by
the end of 2020, the ability to maintain Humboldt Bay navigation channels, and the commercial
and recreational uses they support, could begin to be at risk. While the situation does not
constitute an imminent hazard, EPA and USACE have determined that expedited management
action is required to prevent adverse conditions from developing.
The continued availability of an ocean dredged material disposal site in the vicinity of Humboldt
Bay is necessary to maintain safe deep-draft navigation via authorized federal channels and
other permitted shipping facilities. In this Environmental Assessment (EA) the EPA evaluates
the potential impacts associated with a proposed rulemaking to expand the boundaries of the
existing HOODS for continuing use by approved navigation dredging projects in and around
Humboldt Bay, California. This EA also evaluates a possible future nearshore placement area for
beneficial use of clean sand dredged from the Humboldt Bay.
Project Description: Alternative 1, the Proposed Action, is to slightly reorient and expand the
existing HOODS boundary by 1 nmi to the north (upcoast) and 1 nmi to the west (offshore).
Alternative 1 is the Proposed Action because it would provide environmentally acceptable
disposal capacity for many years without causing any significant adverse impacts, while also
affording the most operational flexibility for managing the dredged material in a manner that
would further minimize even physical impacts over time. This configuration would result in the
total area of the site increasing from 1 square nmi to 4 square nmi. If today's disposal practices
were to continue unchanged (i.e., if 1 million cy of entrance channel sand per year were to
continue being placed at HOODS indefinitely), the site would reach capacity again in about 75
years. However, the effective life of the expanded site could be much longer than 75 years if
nearshore placement of clean dredged sand for beach or littoral system support were to begin at
some point. In that event, disposal of fine sediment would continue in the expanded HOODS
footprint, but it could be managed in such a way that little or no additional long-term mounding
would occur at all. Alternative 1 would be operated under a Site Management and Monitoring
Plan (SMMP), that includes adaptive management provisions to ensure that significant
environmental impacts do not occur.
HOODS Expansion: Environmental Assessment and MPRSA Criteria Evaluation
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Findings: Disposal site locations are chosen based on several general and specific site
selection factors designed to ensure that disposal operations are conducted in a manner that
allows them to operate without significant adverse impacts to the marine environment, and
without significant conflicts with other uses of the ocean. Based on the evaluation in this EA,
including consultation with resource agencies and consideration of the four general criteria
and eleven specific factors for selecting ocean disposal sites listed at 40 CFR 228.5 and 228.6,
respectively, EPA has determined that the proposed action - Alternative 1 (expansion of the
existing HOODS boundaries by one nmi to the north and one nmi to the west) - will have no
significant adverse impacts and therefore no Environmental Impact Statement (EIS) is
necessary. EPA published the draft EA for a 30-day public comment period on May 29, 2020
and accepted comments until June 29, 2020. Simultaneously with the draft EA, EPA issued
for public comment a proposed rule to implement Alternative 1. The proposed rule is
functionally equivalent to a preliminary Finding of No Significant Impact (FONSI). Both the
draft EA and proposed rule were available at www.regulations.gov f Docket ID No. EPA-R09-
OW-2020-0188) and at https://www.epa.gov/ocean-dumping/humboldt-open-ocean-
disposal-site-hoods-documents. EPA received feedback from a total of four commenters on
the draft EA and proposed rule. Based on the comments received, only minor, clarifying
wording changes have been made to this final EA, the final rule, and the updated Site
Management and Monitoring Plan (SMMP). Appendix E to this final EA includes all
comments received, and EPA's responses to each.
Disposal of suitable material (i.e., dredged material evaluated and determined to be suitable
under the MPRSA and its implementing regulations) at the existing HOODS has resulted in no
significant adverse impacts over 25 years of continuous site use, and EPA's conclusion based on
the analysis in this EA is that the expansion proposed under Alternative 1 would similarly have
no significant adverse impacts if managed under an updated SMMP that includes site use
requirements similar to those in the existing SMMP. A draft updated SMMP was included with
the draft EA as Appendix D, and was also available separately for download and review at
https://wwwepa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-hoods-documents.
EPA made minor modifications to the draft updated SMMP, to clarify that the minimal area
necessary within the expanded HOODS would be affected by disposal activity in any year. The
final updated SMMP, included as Appendix D to this final EA and also available at the link noted
above, will go into effect when the HOODS expansion takes effect, 30 days following publication
of the final rule in the Federal Register.
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Table of Contents
SUMMARY AND FINDINGS iii
1 INTRODUCTION 1
1.1 Location 2
1.2 Humboldt Bay Navigation and Dredging History 3
1.3 Ocean Disposal at HOODS 7
1.4 Sand Mounding at HOODS 9
2 Purpose and Need for Action 14
2.1 Statutory and Regulatory Requirements 14
2.2 Purpose of the Proposed Action 15
2.3 Need for the Proposed Action 16
3 ALTERNATIVES, INCLUDING THE PROPOSED ACTION 18
3.1 Alternatives Eliminated from Consideration 18
3.2 Alternatives Considered 19
3.2.1 No Action Alternative 20
3.2.2 Alternative 1 (Proposed Action): Expansion by 1 nmi 21
3.2.3 Alternative 2: Expansion by 1/2 nmi 21
3.3 Elements Common to Alternatives 1 & 2 22
3.3.1 Sediment Quality 22
3.3.2 Need for Ocean Disposal 24
3.3.3 New Reference Site for HOODS 24
3.4 Nearshore Placement Site for the Beneficial Use of Sand 25
4 AFFECTED ENVIRONMENT and Environmental Impacts 27
4.1 Physical Setting and Impacts 27
4.1.1 Oceanography and Waves 27
4.1.2 Sediment Quality 28
4.1.3 Disposal Plume Dynamics 32
4.1.4 Air Quality 34
4.2 Biological Resources and Impacts 35
4.2.1 Planktonic Community 35
4.2.2 Benthic Community 36
4.2.3 Fish Communities, Including EFH 39
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4,2.4 Special Status Species (ESA Consultations) 46
4.3 Other Potential Impacts 48
5 Description of the Potential Nearshore Sand Placement Site (NSPS) 55
5.1 Need for a NSPS 55
5.2 Minimum and Maximum Depths for a Potential NSPS 59
5.3 "Thin-Layer" Sand Placement Operations in the Potential NSPS 63
5.4 Recommended Monitoring of Demonstration Sand Placement 64
5.4.1 Tracking of Sand Placement Events 65
5.4.2 Bathymetric and Topographic Surveys 65
5.4.3 Grain-Size Assessments 65
5.4.4 Instrument Deployments 66
5.4.5 Demonstration Project Monitoring Results 66
6 OCEAN DUMPING SITE SELECTION CRITERIA 67
6.1 Overview 67
6.1.1 Four General Criteria for Selection of Ocean Disposal Sites 67
6.1.2 Eleven Specific Factors for Selection of Ocean Disposal Sites 67
6.2 Evaluation of the Four General Criteria 68
6.2.1 Minimize Interference with Other Activities 68
6.2.2 Minimize Changes to On-Site Water Quality and Other Conditions 69
6.2.3 Limit the size of sites to facilitate management and monitoring 70
6.2.4 Locate sites off the continental shelf or where historical disposal has occurred
70
6.3 Evaluation of the Eleven Specific Factors 71
6.3.1 Geographical Position, Depth of Water, Bottom Topography and Distance from
Coast 71
6.3.2 Location in Relation to Breeding, Spawning, Nursery, Feeding, or Passage Areas
of Living Resources in Adult or Juvenile Phases 71
6.3.3 Location in Relation to Beaches and Other Amenity Areas 71
6.3.4 Types and Quantities of Disposal, and Proposed Methods of Release 71
6.3.5 Feasibility of Surveillance and Monitoring 72
6.3.6 Dispersal, Horizontal Transport and Vertical Mixing Characteristics of the Area,
including Prevailing Current Direction and Velocity 72
6.3.7 Existence and Effects of Current and Previous Discharges and Dumping in the
Area (including Cumulative Effects) 72
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6.3.8 Interference with Shipping, Fishing, Recreation ... and Other Uses of the Ocean
73
6.3.9 Existing Water Quality and Ecology of the Sites as Determined by Available
Data or Trend Assessment of Baseline Surveys 73
6.3.10 Potential for Development or Recruitment of Nuisance Species 73
6.3.11 Existence of Significant Natural or Cultural Features of Historical Importance
74
7 SUMMARY OF COORDINATION, AND COMPLIANCE With relevant acts and orders.... 75
7.1 Public Scoping and Outreach 75
7.2 Tribal Consultation 75
7.3 National Environmental Policy Act 76
7.4 Endangered Species Act and Marine Mammal Protection Act 76
7.5 Magnuson-Stevens Fisheries Conservation and Management Act 76
7.6 Coastal Zone Management Act 76
7.7 National Historic Preservation Act 76
7.8 Clean Water Act 77
7.9 Farmland Protection Policy Act 77
7.10 Wild and Scenic River Act 77
7.11 Estuary Protection Act 77
7.12 Submerged Lands Act 77
7.13 Rivers and Harbors Act 77
7.14 E.0.11990, Protection of Wetlands 77
7.15 E.0.11988, Flood Plain Management 77
7.16 E.0.12898, Environmental Justice 77
7.17 E.0.13089, Coral Reef Protection 78
7.18 E.0.13112, Invasive Species 78
8 Findings: SELECTION OF HOODS eXPANSION ALTERNATIVE 1 79
9 REFERENCES 80
APPENDICES
Appendix A - HOODS 2008 and 2014 Monitoring: Synthesis Report (link) 84
Appendix B - Scoping Meetings and Resource Agency and Tribal Consultations (link) 85
Appendix C - Previous (2006) Site Management and Monitoring Plan (link) 86
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Appendix D - Updated (2021) Site Management and Monitoring Plan 87
Appendix E - Response to Comments on the Draft EA and Proposed Rule 109
Appendix F - California Coastal Commission Staff Report 114
LIST OF FIGURES
Figure 1. Humboldt Bay area 2
Figure 2. Federal navigation channels in Humboldt Bay 4
Figure 3. Humboldt Bay's federal navigation channels and the typical volume of sediment (cy) dredged
FROM EACH 6
Figure 4. HOODS Detail 8
Figure 5. Shaded relief depiction of bathymetry at HOODS as of August 2014 10
Figure 6. Map of HOODS disposal cells overlain on bathymetry from August 2014 10
Figure 7. Open and closed disposal cells at HOODS starting in 2015 11
Figure 8. Locations of actual disposal events at HOODS in 2015 12
Figure 9. Open disposal cells at HOODS for 2020 13
Figure 10. Proposed Action area, showing historic ocean disposal sites, the current HOODS site, and
THE POTENTIAL NEARSHORE BENEFICIAL USE DEMONSTRATION SITE FOR CLEAN SAND 17
Figure 11. Proposed Action area, showing the current HOODS site and the two boundary expansion
ALTERNATIVES 23
FIGURE 12. SEDIMENT SAMPLING STATIONS OCCUPIED IN THE 2008 EPA MONITORING SURVEY AT HOODS 37
Figure 13. Sampling stations for the 2014 EPA monitoring and baseline surveys at HOODS 30
Figure 14. Density (Panel A), richness (Panel B), and diversity (Panel C) of infaunal organisms captured
AT EACH STATION 38
Figure 15. Overall Groundfish EFH zone. (From Pacific Coast Groundfish FMP, August 2016.) 42
Figure 16. Habitat Areas of Particular Concern (HAPC) in the Groundfish FMP 43
Figure 17. Locations of historic shipwrecks near HOODS and the NSPS 49
Figure 18. Locations of three "magnetic anomalies" near HOODS 50
Figure 19. Location of existing outfall relative to the potential NSPS 53
Figure 20. Location of a potential Nearshore Sand Placement Site (NSPS) 56
Figure 21. Looking northeast toward the Humboldt Entrance Channel and Jetties 57
Figure 22. Reference stations and shoreline shifts at selected surveys 58
Figure 23. Humboldt Bay Demonstration Site as proposed byUSACE in 2012 61
Figure 24. Location of the potential Nearshore Sand Placement Site (NSPS) in relation to the Samoa
SMC A, HOODS, AND THE FAIRHAVEN POWER PLANT OUTFALL 62
Figure 25. Aerial view of the Essayons during nearshore thin-layer sand placement operations near the
MOUTH OF THE COLUMBIA RIVER 63
Figure 26. Trajectory of the dredged sand during placement 64
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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LIST OF TABLES
Table 1. General Chronology of Humboldt Harbor and Bay navigation improvements 5
Table 2. Description of Humboldt Harbor Federal Navigation Channels 6
Table 3. Recent annual dredging volumes for the federal channels, in 1,000s of cy 7
Table 4. Existing corner coordinates of HOODS (NAD 83) 8
Table 5. HOODS Expansion Alternatives corner coordinates (NAD 83) 22
Table 6. Averages and ranges of sediment physical and chemical parameters at "Inside" vs "Outside"
SAMPLING STATIONS IN 2014 31
Table 7. Summary of the dominant taxa in each major group of benthic invertebrates 37
Table 8. Sediment Mobility Tool inputs and results for the nearshore area off Humboldt Bay 60
Table 9. Corner and centroid coordinates for the potential NSPS (NAD 83) 62
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Humboldt Open Ocean Disposal Site (HOODS) Expansion:
Environmental Assessment and MPRSA Criteria Evaluation
1 INTRODUCTION
This Ocean Dredged Material Disposal Site (ODMDS) Evaluation and Environmental Assessment
(EA) has been prepared by the U.S. Environmental Protection Agency (EPA) Region 9 in
coordination with the U.S. Army Corps of Engineers (USACE) San Francisco District. The purpose
of this document is to evaluate the potential impacts associated with a rulemaking by EPA to
expand the boundaries of the existing Humboldt Open Ocean Disposal Site (HOODS) for continuing
use by approved navigation dredging projects in and around Humboldt Bay, California. It also
provides initial documentation for a possible future nearshore placement area for beneficial use of
clean sand dredged from the Humboldt Bay entrance channel.
HOODS was originally designated by EPA in 1995 based on a full Environmental Impact Statement
(EIS) (EPA 1995, available on-line at https://www.epa.gov/ocean-dumping/humboldt-open-
ocean-disposal-site-hoods-documents). The current evaluation will determine if the proposed
expansion of the HOODS boundaries would continue to meet all criteria and factors set forth in the
Ocean Dumping regulations published at Parts 228.5 and 228.6 of Title 40 Code of Federal
Regulations (CFR). These regulations were promulgated in accordance with the criteria set out in
Sections 102 and 103 of the Marine Protection, Research and Sanctuaries Act of 1972 (MPRSA).
Further, this document is intended to provide sufficient information to determine compliance with
the National Environmental Policy Act, the National Historic Preservation Act, the Coastal Zone
Management Act, and Endangered Species Act. Use of HOODS would continue to be for disposal of
material dredged by USACE from the federally authorized navigation channels in Humboldt Bay, as
well as for disposal of dredged material from other navigation dredging projects in the area.
The continued availability of an ocean dredged material disposal site in the vicinity of Humboldt
Bay is necessary to maintain safe deep-draft navigation via authorized federal channels and other
permitted shipping facilities. The HOODS site has experienced significant mounding, creating the
possibility of potentially hazardous navigation conditions in the future if the mounding worsens.
Today, HOODS has limited capacity to receive future dredge material disposals. While the situation
does not constitute an imminent hazard, EPA and USACE have determined that expedited
management action is required to prevent adverse conditions from developing. If disposal capacity
at HOODS is not expanded by the end of 2020, the ability to maintain Humboldt Bay navigation
channels, and the commercial and recreational uses they support, could begin to be at risk.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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1.1 Location
Humboldt Harbor and Bay is located in Humboldt County on the coast of Northern California
(Figure 1), approximately 225 nautical miles north of San Francisco and approximately 156
nautical miles south of Coos Bay, Oregon, Humboldt Bay is the second largest coastal estuary in
California. It is the only harbor between San Francisco and Coos Bay with channels large enough to
permit the passage of large ocean-going vessels.
J Dyne aar /
Ifftoa&Ct
,*«fl "O* Sj 26
Iv 1 J
.MafA/
'AW/*
EUREKA
ftMtm&wtl
9^ 'frSpOGtf/ted fj t
IXplh ttvm a* 2Q0Q*
17 O'Jf
Taole &nf
HOODS
HuntoidJ Hi«v^
too
rcata
~ ndULro*
56
70y
W ($) Y 20s
Pm
ze ^ S3
Figure 1. Humboldt Bay area, showing the location of the existing Humboldt Open Ocean Disposal Site
(HOODS).
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Humboldt Bay lies in a narrow coastal plain surrounded by rolling terraces, steep mountains, and
narrow valleys typical of the coastal ranges in the region. Much of the forested area consists of
coastal redwoods and Douglas fir. Eureka, the largest city on the north coast of California and the
seat of Humboldt County, and its neighbor, Areata, are the two largest cities bordering the Bay.
Eureka, which is approximately five miles east of the entrance to the Bay, is accessible from the
water by the North Bay and Eureka channels. Areata, which is approximately seven miles north of
Eureka, was once accessible from the Bay by the Areata Channel; however, this channel is no
longer in use.
Humboldt Bay is a naturally land-locked estuary composed of two large bays, the relatively
shallow South Bay to the south and the larger Areata Bay to the north. The Bay extends north and
south for a distance of approximately 14 miles, covering 26.5 square miles at high tide and
approximately 7.8 square miles at low tide. A long, narrow thalweg and a small bay, the Entrance
Bay, connect South and Areata Bays and provide an outlet to the Pacific Ocean. Humboldt Bay is
separated from the Pacific Ocean by a sand spit that is incised by two large armored rubble-mound
jetties - the North and South Jetties. These fabricated rubble-mound jetties, constructed by USACE,
which are approximately 2,000 feet apart, define the entrance channel to Humboldt Harbor, which
requires regular dredging to maintain safe navigation.
1.2 Humboldt Bay Navigation and Dredging History
Humboldt Bay has been dredged for navigation purposes for nearly 140 years (Table 1). USACE
first began dredging Humboldt Bay's interior channels in 1881 to provide safe navigation within
the bay. The first attempt at stabilizing the Entrance Channel to Humboldt Bay commenced in
1889 when USACE started constructing the North and South Jetties; they were completed in 1900.
Since then, there have been periodic changes to Humboldt Harbor and Bay to provide safe
navigation for ocean-going vessels of many sizes. Humboldt Bay is also a designated harbor of
refuge with an important U.S. Coast Guard presence.
Today the USACE conducts annual operation and maintenance (O&M) dredging activities of the
federal navigation channels in Humboldt Bay with disposal of the dredged material at HOODS
(Figure 2). O&M dredging to maintain Humboldt Bay's navigation channels occurs in the Bar and
Entrance Channels and in the Interior Channels (Table 2) any time between mid-March through
the end of September. Typically, a large hopper dredges (e.g., the Essayons] works sandy areas at
and near the entrance channel because smaller hopper dredges, and mechanical (clamshell) or
cutterhead/pipeline dredges cannot operate safely in the rough seas encountered in the Entrance
Channel. Smaller hopper dredges (e.g., the Yaquina] can safely work the Federal channels inside
the Bay, and mechanical or pipeline dredging can be conducted in the interior marinas and
commercial docks of Humboldt Bay.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Fields
Landing
Figure 2. Federal navigation channels in Humboldt Bay.
During recent years, because of Federal budget limitations, USAGE has focused on maintaining the
Bar and Entrance Channel where clean sand deposits build up quickly. Entrance channel dredging
alone has averaged approximately 1 million cubic yards (cy) each year, while interior channels and
marinas/docks are dredged less frequently and generally dredge a relatively small volume
compared the Bar and Entrance Channel (Figure 2, Table 3). However, USACE estimates that there
is currently a backlog of approximately 4.5 million cy of sediment that would need to be dredged
to return all of the Federal Channels to full authorized depth.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Table 1. General Chronology of Humboldt Harbor and Bay navigation improvements
Date Description
1806 First recorded chart of Humboldt Bay (Bay of the Indians) by the Wiyot Indians.
1849 Humboldt Bay rediscovered and named Trinity Bay.
1850 Renamed Humboldt Bay.
1853 First marker buoys used for the Bay.
1856 Light tower construction completed on North Spit.
1871 Studies for navigation improvements begin.
1881 600 vessels per year using the Bay.
1881 Brush and plank jetties constructed but destroyed the following winter.
1881 First USACE project authorized, the Eureka Channel is dredged.
1881 Areata, Samoa, and Hookton Channels dredged for the first time.
1883 First survey for a low water jetty on the South Spit
1884 South Jetty authorized.
1887 Training wall was shown on South Spit Jetty plans.
1888 Dual jetties authorized.
1889 South Jetty construction commences (brush and stone construction).
1891 North Jetty construction commences.
1894 North Jetty built out to Bend 420, South Jetty built out to Bend 230.
1896 Bar Channel deepened to 25 feet deep and 100 feet wide.
1900 Initial jetty construction completed: 8,000 feet long, 5 to 10 feet above MLLW.
1911-1917 Jetties damaged, repaired, and raised from original elevation of 10 to 12 feet MLLW to
a reconstructed height of 18 feet above MLLW.
1939 Dual rubble-mound jetties completed.
1939 Entrance Channel completed: 30 feet deep and 500 feet wide.
1939 Eureka, Samoa, Areata, and Fields Landing Channels initial construction completed.
1954 Entrance Channel deepening completed to 40 feet.
1954 Eureka and Samoa Channels deepening (30 feet) completed and North Bay Channel
initial construction completed.
1959 Engineering and design study; repair North and South Jetties.
1960-1963 Repair jetty damage of winter 1957-1958.
1964-1965 Extreme damage to jetties, 100-ton blocks washed away.
1966-1967 Repair and maintenance on North and South Jetties.
1969 Jetty repair study and model conducted by the USACE' Engineering Research and
Design Center (ERDC) in Vicksburg, Mississippi.
1971 Humboldt Bay Bridge completed, connecting the North Spit with Eureka.
1971-1973 Heads of both jetties destroyed, Dolos blocks placed on jetties.
1977 USACE names jetties a historical engineering landmark.
1995 EPA designates HOODS as a new permanent ODMDS
1999 Bar and Entrance Channel deepened to 48 feet MLLW and segments of the interior
channels to -38 MLLW.
1999 Deepening of Samoa Turning Basin to 38 feet MLLW.
To Date USACE places an average of ~1,000,000 cy/year of sand at HOODS
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Table 2. Description of Humboldt Harbor Federal Navigation Channels
Authorized
Channel
Depth
Width
Length
Typical Annual
Sediment Type
(ftMLLW)
(FT)
(ft)
Volume (cy)
Bar and
Entrance
48
500-1,600
8,500
1,100,000
Sand & gravel
North Bay
38
400
18,500
100,000
Sand
Samoa +
Turning Basin
38
400 -1,000
8,100 + 1,000
20,000
Sand
Eureka
35
400
9,700
25,000
Silt
Field's Landing
+ Turning Basin
26
300 - 600
12,000 + 800
6,000
Sand & Silt
i
20,000 (sand)
^Kik OCMft
EurfW inner Re*ch
EurriuDufCf Rfjch
Morlti Bay C^nti
24,000 (silt)
r&Hin
1,082,000 (sand and
gravel)
WW-"-"
IjwCWAp
Field* UrxJttwj Channel
FteMt Uwhftfl Tumirxj Bum
89,000 (sand)
Add local marinas,
berths, ramps:
~20,000 cy/yr ave
6,000 (silt)
Figure 3. Humboldt Bay's federal navigation channels and the typical volume of sediment (cy) dredged from
each, on an annualized basis. Note that several additional facilities are managed by other
permittees (including the City of Eureka, the Humboldt Bay Harbor and the US Coast Guard).
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation page 6
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Table 3. Recent annual dredging volumes for the federal channels, in l,OOOs of cy.
Year
Bar & Entrance; North
Other Interior
Bay Channels
Channels
2007
1,123
173
2008
1,094
217
2009
955
108
2010
770
0
2011
1,199
155
2012
1,183
0
2013
573
102
2014
625
0
2015
715
0
2016
1,715
0
2017
1,047
0
Total
10,999
755
Average
1,000
69
1.3 Ocean Disposal at HOODS
Ocean dredged-material disposal sites around the nation are designated by the Environmental
Protection Agency (EPA) under the 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 based on several general and specific site selection factors (EPA 1995,
and Chapter 6), designed to minimize cumulative environmental effects of disposal to the area
where the site is located. Disposal operations must be conducted in a manner that allows each site
to operate without significant adverse impacts to the marine environment, and without significant
conflicts with other uses of the ocean.
The HOODS location was first used as a disposal site in September 1990, under a temporary
designation by USACE pursuant to Section 103 of MPRSA. In 1995, EPA Region 9 released a final
EIS entitled Designation of an Ocean Dredged Material Disposal Site off Humboldt Bay, California
(EPA, 1995). The EPA's final rule on designating HOODS as a multi-user disposal site under Section
102 of MPRSA was published in the Federal Register on September 28,1995 (60 Fed. Reg. 50,108).
The site designation became effective on October 30,1995 for a period of 50 years. Since then,
approximately 25,000,000 yd3 of dredged material have been placed there (EPA, 2016), the vast
majority of which has been clean sand from the Bar and Entrance Channel.
HOODS is a square disposal site, currently covering one square nautical mile (nmi2) of the sea floor
(Figure 1, and Figure 4) in water depths naturally ranging from approximately 150 to 180 feet. Its
centroid is located approximately 3.5 nmi offshore of the seaward end of the Entrance Channel
into Humboldt Bay. Table 4 lists the corner coordinates of the overall site.
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STATION CG49N
40 48" 24N
124 16' 22" W
Buffer
tne-No Disposal (Red)
QUAD
Disposal Zone (Green)
OUAI)
#4
STATION CG49C
40 4?'38"N
124 17'13" W
Mjuteal kfites
HOODS Dump Site
3-mile Maritime Limit
(Nautical Miles)
10-meter Bathymetric
Contour Lines
Data Sources
Bathymetric Contours: California Department of Fisii
and Game,10 meter uatiiymetrlc cortour lines to 600
meters depth on the Catforns coast. July 2000
3-male Maritime Unit MOAA's Office of Coast Survey
(OCS), September 2005
WTRQ601347,2 May 2006
SB*
STATION CG55N
40 49" 3.0" N
124 17' 22" W
STATION CG55C
40 48'17"N
124 18' 13" W
Figure 4. HOODS Detail. The site is divided into 4 quadrants and 36 individual cells. Initially, dredged-
material disposal was only allowed in the green interior cells, so that material placed at the site
would remain largely contained within the overall site.
Table 4. Existing corner coordinates of HOODS (NAD 83).
Corner Latitude Longitude Centroid Lat, Centroid Long.
North 40° 49' 03" N 124° 17' 22" W
East 40° 48' 24" N 124° 16' 22" W
40° 48'20" N 124° 17' 17" W
South 40° 47' 38" N 124° 17' 13" W
West 40° 48' 17" N 124° 18' 13" W
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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The site-designation EIS for HOODS identified a 50,000,000-cy capacity, and an estimated life of 50
years for HOODS based on a presumed average disposal rate of 1,000,000 cy/yr. The 50,000,000-
cy capacity equated to a mound at the site whose top elevation would not exceed approximately -
130 feet mean lower low water (MLLW). Mounding to much higher elevations (meaning, that
created water shallower than -130 feet) was predicted to be capable of starting to affect the wave
climate around the site during the largest winter storms. To avoid any such effect, and thereby
avoid creating any potential navigation safety concerns, EPA has strictly managed how disposal
occurs at HOODS. Under the current HOODS Site Management and Monitoring Plan (SMMP), a cell-
based management approach has been used to ensure that disposed material builds up (mounds)
evenly at the site and does not substantially spread outside the site. Perimeter cells were used as a
no-disposal buffer zone to ensure that most dredged material would be deposited on the seafloor
within the overall site boundary. Individual dump loads are required to be disposed into interior
cells only, and subsequent dumps must move to different interior cells. No cell can be used again
until all allowable cells have been used. This method has ensured that mounding proceeds evenly,
as confirmed by annual bathymetry surveys conducted by USACE. However, because the peripheral
cells were used as a no-disposal buffer area, the effective capacity was reduced to approximately
25 million cy and 25 years from the original expectation of 50 million cy and 50 years.
1.4 Sand Mounding at HOODS
The USACE San Francisco District monitors bathymetric condition at HOODS typically twice each
year, before and after dredging and disposal. (Hydrographic surveys going back to at least 2009 are
available on a USACE web site1). Over the years, several cells (especially near the center of the site)
began to reach the -130-foot target depth. As this occurred, EPA closed such cells to further
disposal. By 2014, the majority of the inner cells had reached, and in some cases somewhat
exceeded, the -130-foot target (Figure 5 and 6). In consequence, beginning in 2015 EPA authorized
ongoing disposal to occur only in deeper areas over the slopes of the disposal mound, halfway into
the buffer cells of the existing site (Figure 7). This adaptation was expected to allow approximately
5 more years of additional disposal (at typical annual volumes), while still retaining the vast
majority of the sand within the site boundaries. (This approach is reasonable specifically because
the material being disposed by USACE is virtually all sand, which does not spread far from the
placement location the way silts or clays could, before settling on the bottom). GPS-based
monitoring of individual disposal events (a requirement of the SMMP for all projects using the
disposal site) confirmed that the dredging equipment used by USACE is capable of successfully
disposing of material with precision, in the new smaller cells (Figure 8).
1 https://www.spn.usace.army.mil/Missions/Surveys-Studies-Strategy/Hydro-Survev/Humboldt-Bay-Channel/
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Figure 5. Shaded relief depiction of bathymetry at HOODS as of August 2014, showing mounding to -130
feet or less over much of the site. Red box is the existing disposal site boundary. Contours are in 5-
foot intervals. Depths are shown in feet MLLW. (Reproduced from eTrac, 2014.)
F1
E1
F2
D1
E2
F3
B1
C1 ^
£
C2
D2
D3
E3
i %
E4
F4
F5
A1
A2
B2
B3
C3
C4
D4
D5
E5
%
F6
E6
.
"
A3
M
B4
B5
C5
C6
D6
<§* /
- 135
£
T3
A5
B6
¦
SF
- 175 §
A6
1
-260
Figure 6. Map of HOODS disposal cells overlain on bathymetry from August 2014.
Depths are in feet MLLW. (Reproduced from eTrac, 2014.)
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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£
T3
175 c?3
3?
Red = Closed Cells
NO DISPOSAL
Yellow = Buffer Zone
NO DISPOSAL
Blue = Open Cells
DISPOSAL OK
NOT FOR NAVIGATION PURPOSES
Figure 7. Open and closed disposal cells at HOODS starting in 2015. Disposal only allowed over the north
and west slopes of the mound including portions of eight Buffer Zone cells on those sides. This
increased short-term disposal capacity by 5.6 - 8 million cy, enough for approximately 5 more
years, or through at least 2020.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Figure 8. Locations of actual disposal events at HOODS in 2015. All disposal actions occurred successfully
within the modified disposal cells, despite most of them being only V2 the size of previously allowed
disposal cells. Dots with lines show starting point and track of individual disposal events. (Source:
EPA compliance records for USAGE 2015 West Coast Hopper contract no. W9127N-15-C-0006).
Bathymetric survey results from March 2018 led EPA to close additional portions of cells B2, C2,
and D2 to further disposal in 2018 and 2019. EPA further modified the allowable disposal area for
2020 based on 2019 bathymetry (Figure 9). Using this adaptive management approach, there is
adequate disposal capacity at HOODS through at least the year 2020, without material
substantially spreading beyond the current site boundaries.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Figure 9: Open disposal cells at HOODS for 2020 are outlined by the bright yellow box. Black grid depicts
the same disposal cells as shown on Figure 7. Here, disposal cell boundaries are overlain on the
most recent (2019) bathymetry with green and yellow shading being deeper areas, and orange and
red shading being shallower.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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2 PURPOSE AND NEED FOR ACTION
2.1 Statutory and Regulatory Requirements
The Marine Protection, Research and Sanctuaries Act of 1972, as amended (MPRSA), also
known as the Ocean Dumping Act, was passed in recognition of the fact that the disposal of
material into ocean waters could potentially result in unacceptable adverse environmental
effects. Under Title I of the MPRSA, the EPA and USACE were assigned responsibility for
developing and implementing regulatory programs to ensure that ocean disposal would not "...
unreasonably degrade or endanger human health, welfare, or amenities, or the marine
environment, ecological systems, or economic potentialities."
The EPA administers and enforces the overall program for ocean disposal. As required by
Section 104(a)(3) of the MPRSA, ocean disposal of dredged material can occur only at a site that
has been designated to receive dredged material. Pursuant to Section 102(c), the EPA has the
responsibility for permanent site designation, while under Section 103 USACE can designate
project-specific disposal sites on a temporary basis if an EPA-designated disposal site is not
available.
The MPRSA criteria (40 CFR, Part 228) state that EPA's site designations under Section 102(c)
must be based on environmental studies, and on historical knowledge of the impact of dredged
material disposal on similar areas. General criteria (40 CFR 228.5) and specific factors (40 CFR
228.6) that mustbe considered prior to site designation were addressed in the 1995 HOODS
EIS, and that evaluation is updated in this EA (Chapter 6).
Related federal statutes applicable to the ocean disposal site designation process include the
National Environmental Policy Act of 1969 as amended; the Coastal Zone Management Act of
1972 as amended; the Endangered Species Act of 1973 as amended; the Magnuson-Stevens
Fisheries Conservation and Management Act of 1976 as amended; and the National Historic
Preservation Act of 1966, as amended. Executive Orders that may apply are also addressed as
appropriate in this EA (Chapter 7).
Finally, an EPA-designated site requires a site management and monitoring plan (SMMP). Use
of the designated site is subject to any restrictions included in the SMMP, which is expected to
be reconsidered at least every 10 years. The SMMP for HOODS was last officially updated in
2006 (EPA 2006, reproduced as Appendix C). However, the 2006 SMMP has effectively been
updated each year since then, via conditions imposed on individual ocean disposal projects to
adaptively manage the mounding described above. A new SMMP, updated to reflect the
expanded HOODS, is included as Appendix D to this final EA and is separately available at
https://www.epa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-hoods-documents.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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2.2 Purpose of the Proposed Action
HOODS Expansion
The primary purpose of the proposed action is to provide capacity for ongoing safe ocean disposal
of suitable dredged material (i.e., dredged material evaluated and determined to be suitable under
the MPRSA and its implementing regulations) from Humboldt Harbor navigation channels and
facilities. Ocean disposal currently remains necessary for most navigation dredging projects in and
around Humboldt Bay, because of a lack of available upland or beneficial use alternatives. Although
various efforts are under way to create upland placement and beneficial use opportunities in the
area, only extremely limited capacity is presently available. Capacity for some degree of ocean
disposal of suitable sediment will remain important in the future, even if new beneficial use
opportunities become available over time.
Identification of a Potential Nearshore Beneficial-Use Site as an Alternative to HOODS Disposal
As noted, the vast majority of the sediment volume dredged each year from Humboldt Bay is clean
sand removed from the Entrance Channel by USACE (or USACE-contracted) hopper dredges. These
vessels are typically available to work the Humboldt federal channels for only a prescribed number
of days each year, and their ability to place material at confined or upland sites is extremely limited
by:
• equipment (e.g., the USACE hopper dredge Essayons can only bottom-dump, including thin-
layer spreading) and
• cost (e.g., pump-off takes at least three times longer than bottom dumping).
Therefore, in parallel to the proposed action, this EA also describes a nearshore site that
represents a potential long-term alternative to HOODS disposal for sand dredged by USACE.
Placement of some or all of the Bar and Entrance Channel sand in the nearshore would constitute
beneficial use, in that it would return sand to the littoral system north of the Humboldt Bay
entrance, helping to limit or buffer against shoreline erosion there. In contrast, sand placed at
HOODS is effectively removed from the littoral system and does nothing to support shoreline
resiliency. In fact, it is a large net remover of sand from the littoral system, potentially adding to
local shoreline erosion effects over time, particularly as sea level rise accelerates in the future. Use
of sand at a nearshore site would also reduce ongoing mounding concerns at HOODS, prolong the
useful life of the expanded ocean disposal site, and allow a smaller offshore disposal "footprint" to
be used over time.
As part of the original designation of HOODS, USACE established the Humboldt Shoreline
Monitoring Program (HSMP) because the California Coastal Commission (CCC) expressed concerns
that placing large volumes of sand at HOODS could have significant adverse impacts to nearby
beaches. The primary concern was that sand that would typically supply local beaches was going
to effectively be removed from the local littoral cell by being placed in waters deeper than seasonal
waves could move it back onshore. The objectives of the HSMP are:
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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• monitoring the surrounding shoreline for excessive shoreline retreat;
• determining the cause of any excessive shoreline retreat that is observed; and
• recommending corrective action should sediment disposal at HOODS be the cause.
The HSMP surveys extend from approximately seven miles south of the South Jetty to seven miles
north of the North Jetty. Over the years, the HSMP identified a general shoreline trend of seaward
movement (accretion) along the South Spit and shoreward movement (erosion) along the North
Spit. However, because the observed changes did not exceed the "excessive-erosion" criteria
agreed on by the CCC and USACE, HOODS has continued to receive all of the material dredged from
the federal channels. (The HSMP is discussed further in Chapter 5.)
An appropriate potential nearshore sand placement area (Figure 10) had been identified by USACE
in its "Five-Year Programmatic Environmental Assessment, 404(b)(1) Analysis, and FONSI,
Humboldt Harbor and Bay Operations and Maintenance Dredging (FY 2012 - FY 2016)" (USACE
2012). (Nearshore placement was not pursued by the USACE at that time, and was not discussed in
the USACE's subsequent 5-year EA.) Beneficial use sites for nearshore sand placement operations
would be regulated under Section 404 of the Clean Water Act (CWA). EPA, in this site expansion
EA, has drawn from and expanded upon information in the 2012 USACE EA. The potential
nearshore site is discussed herein (Section 3.4 and Chapter 5) as an alternative that could be used
in conjunction with disposal at HOODS to help minimize impacts and maximize the overall benefits
of managing Humboldt Bay area dredged sediments. This EA provides documentation pursuant to
NEPA and other applicable Acts that USACE may use as a basis for proposing to conduct future
demonstration nearshore sand placement operations. But any proposal to formally establish the
nearshore site would be a separate EPA-USACE action pursuant to CWA, informed by monitoring
results associated with such a demonstration project. If a nearshore site is established in the
future, it could be used by USACE in conjunction with HOODS but would not eliminate the need for
some disposal at HOODS to continue.
2.3 Need for the Proposed Action
The need for the Proposed Action of expanding the HOODS boundaries is that the existing disposal
site is effectively "full". Since the site was designated in 1995, approximately 25,000,000 cy of sand
has been disposed of there, resulting in a mound with an elevation (averaging approximately -130
feet MLLW) that the original EIS identified as the maximum desirable. Ongoing mounding
substantially above this elevation could begin to affect the action of waves in large storms,
potentially causing navigation safety concerns for vessels transiting the area. At the same time,
ongoing dredging of the Humboldt Harbor navigation channels and related maritime facilities is
necessary to ensure continued safe entering, navigating within, and exiting Humboldt Bay. Such
safe navigation is crucial to the maritime-related commerce of the area. Therefore, reliable
capacity to accommodate disposal or beneficial use of dredged material will continue to be
critically needed, and HOODS as it is currently configured will no longer be able to provide such
capacity beginning in approximately 2021.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Federal Channels
— Bar & Entrance
North Bay
— Samoa
— Eureka
— Fields Landing
Miles
1:150,000
10 m contours
(10 m = 32.8 ft)
ARCATA
DEMONSTRATION SITE
(Proposed for 2013)i
HOODS
(1990 to Present)
Figure 10: Proposed Action area, showing historic ocean disposal sites, the current HOODS site, and the
potential nearshore beneficial use demonstration site for clean sand (as originally identified by
USACE) in relation to the Humboldt Bay Federal navigation channel.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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3 ALTERNATIVES, INCLUDING THE PROPOSED ACTION
3.1 Alternatives Eliminated from Consideration
The original HOODS EIS (EPA, 1995) considered several alternatives to designating HOODS for
managing the projected need for disposal of dredged material from the Humboldt Harbor area. In
addition to the No Action alternative, these included only upland disposal, disposal offshore of the
continental shelf, use of the historic (pre-1990) "SF-3" and "NDS' disposal sites (Figure 9), and
beach nourishment (or nearshore placement).
Only Upland Disposal or Use. At the time of the EIS, upland disposal alternatives were not
considered practicable because of limited availability and capacity relative to the annual dredging
need. These considerations remain true today. However, before ocean disposal is approved
dredging projects are evaluated on a case-by-case basis for the availability of practicable
alternatives. It is possible that as additional upland disposal or beneficial use opportunities
become available over time, the need for ocean disposal may diminish commensurately. But the
need for adequate ocean disposal capacity will still exist. Since upland disposal or use cannot
currently substitute entirely for ocean disposal, it will not be considered further here as a stand-
alone alternative to ocean disposal at HOODS.
Disposal off the Continental Shelf. Similarly, designation of a disposal site off the continental shelf
was eliminated from consideration in the 1995 EIS because of the economics of maintaining the
Federal channels in Humboldt Bay. The continental shelf in this area is approximately 10 nautical
miles (nm) offshore, or approximately 3 times the transport distance to HOODS. USACE's "Zone of
Siting Feasibility" (ZSF) analysis, published with the 1995 EIS, determined based on operational
and economic factors that a disposal site serving Humboldt Bay should ideally be within 4 nmi of
the Bay's entrance. While the original ZSF has not been formally updated, EPA and USACE believe
its basic considerations and conclusions remain valid. The vast majority of dredging for Humboldt
Bay continues to be carried out by USACE using hopper dredges, for which increasing disposal
transport distance equates to both increased costs and a substantially reduced dredging rate.
USACE is already constrained by funding to the point that, aside from the Bar and Entrance
Channel itself, maintenance dredging of the Bay's interior channels has regularly been deferred.
USACE's recent Tier I evaluation for dredging in Humboldt Bay in 2018 (USACE, 2017a) indicated a
backlog of approximately 4,500,000 cy of deferred dredging. Significantly increased transport
distances will further reduce the volume of dredging USACE can accomplish during the number of
dredging days they have available to work at Humboldt in any given year. Finally, EPA has
confirmed that disposal to date at HOODS has not caused any adverse environmental impacts (see
Section 4), so that designation of a completely new disposal site is not warranted environmentally.
Therefore, designating a new ocean disposal site off the continental shelf will not be further
considered here.
Use of Historic (Pre-1990) Ocean Disposal Sites. The 1995 EIS specifically considered two
historically-used ocean disposal sites ("SF-3" and the Nearshore Disposal Site or "NDS", Figure 9)
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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before determining that moving to HOODS would be the environmentally and operationally
superior choice. SF-3, located 1.1 nmi southwest of the entrance channel in water originally about
55 feet deep, was used since the 1940s. The site was ultimately closed in 1990 because of
navigation safety concerns related to mounding (to 40 feet deep) near the entrance channel. The
NDS was located in 50-60 feet of water about 2 nmi south of the harbor entrance channel. It was
only used in 1988 and 1989 as a demonstration site for whether material placed there would
remain in the littoral zone and promote beach nourishment. Its use was discontinued after 1989,
also because of mounding concerns. Both SF-3 and NDS were also objected to by fishing
organizations. For these reasons, and because an environmentally appropriate ocean disposal
alternative (HOODS) already exists to serve the region, use of historic ocean disposal sites will not
be considered further here.
Only Beach Nourishment. The Humboldt Harbor Bar and Entrance Channel and much of the North
Bay channel, are comprised of sandy sediment (Figure 3) that is typically quite compatible with
nearshore placement for beach or littoral system nourishment. In contrast, much of Field's
Landing Channel, and the Samoa and Eureka channels, have sediments that are too fine for beach
nourishment or littoral system support. Similarly, many City and Harbor District wharfs and
marinas contain sediment too fine for beach or littoral placement. Therefore, beach nourishment
cannot serve as a substitute for management of all the material that is periodically dredged from
Humboldt Bay, and an ocean disposal site alternative will continue to be necessary in the future.
However, much of the sediment dredged annually by USACE comes from the Humboldt Harbor Bar
and Entrance Channel and is clean sand that could be beneficially used if an environmentally
appropriate location existed that is practicable for USACE hopper dredges to access. This EA
discusses a nearshore placement site (which would be regulated under CWA Section 404), north of
the entrance channel that could be used in conjunction with HOODS. If found, via monitored
demonstration placements, to be a location that can be used for placement of sand with negligible
adverse environmental impacts, HOODS would continue to receive disposal of fine sediments, as
well as sandy sediments on occasions when conditions do not allow safe nearshore placement. But
it is expected that substantial volumes of sand could be retained in the littoral system using this
approach, rather than removed from it via disposal at HOODS as is the current practice.
3.2 Alternatives Considered
After eliminating infeasible options as described in Section 3.1, the following alternatives are
retained for consideration in this EA, along with the No Action alternative:
1. Proposed Action: Expansion of the HOODS boundaries by 1 nmi to the north and west.
2. Expansion of the HOODS boundaries by V2 nmi to the north and west.
Note that either action alternative could be used in conjunction with identification of a nearshore
site for the beneficial use of sand to support beach and littoral system nourishment. The potential
nearshore site is discussed in Section 3.4 and Chapter 5.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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3.2.1 No Action Alternative
To comply with NEPA, EPA and USACE are required to consider the effects of taking no federal
action on the expansion of HOODS for material dredged from Humboldt Bay. The no action
alternative defines the "without project condition."
The USACE dredges an average of 1 million cy of sand each year to provide safe navigation access
to the bay. Without the expansion of HOODS, the site will reach capacity and disposal of sand
would have to be significantly curtailed within approximately 2 years2. Since there is no other
currently available placement site for this material, rapid shoaling of the entrance channel would
quickly render navigation unsafe, significantly affecting the economy of the greater Eureka area. In
particular there would be increased wave action in the entrance, creating danger to commercial
ships as well as fishing and recreational vessels. This situation would discourage shippers from
using Humboldt Bay for commerce, since it requires additional vessel trips to accommodate "light-
loaded" vessels, resulting in increased transportation costs, decreased vessel safety, and
maneuvering problems. This would have a long-term adverse impact on the local economy. In
addition, use of the bay as a port of refuge could be affected. Finally, ship groundings caused by
improperly maintained deep-draft channels could result in adverse ecological repercussions (i.e.,
oil and fuel spills).
If, under No Action, EPA were forced to close HOODS to ongoing sand disposal, USACE would have
the option under Section 103 of MPRSA to select a temporary and project-specific alternative
ocean disposal location for its dredged material. However, such a site would only be available for 5
years (with an option for one additional 5-year period). Also, it would likely only be available for
USACE federal channel dredging and not other Humboldt Bay dredgers or their projects.
Furthermore, USACE would need to apply the same criteria as used by EPA for a permanent
designation action, and EPA would need to concur with the USACE proposal. It is highly unlikely
that EPA would concur in a temporary site selection action by USACE if it was in any area other
than is already being considered by EPA in this EA for expansion of the HOODS boundaries, in part
because EPA's site selection criteria encourage use of sites that have already been disturbed by
earlier disposal actions before considering using new undisturbed areas. EPA has conducted
extensive baseline environmental survey work in the proposed expansion area and confirmed no
significant adverse impacts from disposal have occurred (see Chapter 4 and Appendix A). In any
event, a temporary USACE site selection would expire after 5 or 10 years, leaving the region in the
same situation it currently faces in terms of lack of capacity for ongoing disposal. Thus, a
temporary disposal site selection under MPRSA Section 103 would only delay, not avoid, the
ramifications described above.
2 It is possible that HOODS could continue to accommodate small volumes of fine sediment (e.g., from marinas and
similar facilities), because unlike the entrance channel sand the fine sediment disperses much more readily and
would not quickly exacerbate the mound elevation at HOODS. However, disposal of large volumes of sand from
USACE entrance channel dredging could no longer occur.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation page 20
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3.2.2 Alternative 1 (Proposed Action): Expansion by 1 nmi
Alternative 1, the Proposed Action, is to slightly reorient and expand the existing HOODS boundary
by 1 nmi to the north (upcoast) and 1 nmi to the west (offshore) (Figure 10). Map coordinates for
Alternative 1 are given in Table 5. Alternative 1 is the Proposed Action because it would provide
environmentally acceptable disposal capacity for many years without causing any significant
adverse impacts, while also affording the most operational flexibility for managing the dredged
material in a manner that would further minimize even physical impacts over time (see Appendix
D). This configuration would result in the total area of the site increasing from 1 square nmi to 4
square nmi, in water depts of approximately 150 to 210 feet mllw. The effective total capacity of
the site would increase from the original 25 million cy (see Section 1.3) to over 100 million cy (i.e.,
allowing for 75 million cy of additional disposal to occur), before mounding to -130 feet could
again occur across the entire site. If today's disposal practices were to continue unchanged (i.e., if 1
million cy of entrance channel sand per year were to continue being placed at HOODS indefinitely),
the site would reach capacity again in about 75 years. However, the effective life of the expanded
site could be much longer than 75 years if nearshore placement for beach or littoral system
support were to begin at some point for the clean dredged sand. In that event, disposal of fine
sediment would continue in the expanded HOODS footprint, but it could be managed in such a way
that little or no additional long-term mounding would occur at all. Alternative 1 will be operated
under an updated Site Management and Monitoring Plan (SMMP), that includes adaptive
management provisions to ensure that significant environmental impacts do not occur (see
Appendix D).
3.2.3 Alternative 2: Expansion by 1/2 nmi
Alternative 2 is the expansion of the existing HOODS boundary by 1/2 nmi to the north (upcoast)
and 1/2 nmi to the west (offshore) (Figure 10). Map coordinates for Alternative 2 are given in
Table 5. This configuration would result in the total area of the site increasing from 1 square nmi
to 2.25 square nmi, in water depths of approximately 150 to 190 feet mllw. The effective total
capacity of the site would increase from the original 25 million cy (see Section 1.3) to
approximately 56 million cy (i.e., allowing for approximately 31 million cy of additional disposal to
occur), before mounding to -130 feet could again occur across the entire site. If today's disposal
practices were to continue unchanged (i.e., if 1 million cy per year of entrance channel sand were
to continue being placed at HOODS indefinitely), the site would reach capacity again in about 31
years. However, the effective life of the expanded site could be much longer than 31 years if
nearshore placement for beach or littoral system support were to begin at some point for some or
all of the clean dredged sand.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Table 5. HOODS Expansion Alternatives corner coordinates (NAD 83)
Alternative 1 (Proposed): Expand by 1 nmi to North and West
Comer
Latitude
Longitude
Centroid Lat.
Centroid Long.
North
40° 50' 18" N
124° 18' 01" W
East
South
40° 49' 16" N
40^
124° 15'46" W
' 124° 17' 05" W
40° 48' 56" N
124° 17'32" W
West
40° 48' 34" N
124° 19' 18" W
Alternative 2: Expand by 1/2 nmi to North and West
Corner
Latitude
Longitude
Centroid Lat.
Centroid Long.
North
40° 49' 36" N
124° 17'45" W
East
South
40° 48' 50" N
40^
124° 16' 06" W
124°~Tr~05^~W
40° 48' 35" N
124° 17' 25" W
West
40° 48' 19" N
124° 18'43" W
Like Alternative 1, even if nearshore placement were to divert some or all of the sand from
disposal at HOODS, fine sediment would continue to be disposed in the expanded HOODS
footprint. Also like Alternative 1, Alternative 2 would be operated under a Site Management and
Monitoring Plan (SMMP), that includes adaptive management provisions to ensure that significant
environmental impacts do not occur (see Appendix D). However, unlike Alternative 1, the space
available to manage ongoing disposal in such a way as to minimize ongoing mounding within the
site boundaries would be reduced.
3.3 Elements Common to Alternatives 1 & 2
3.3.1 Sediment Quality
In accordance with MPRSA and the Ocean Dumping Regulations (40 CFR 227), USACE can only
permit ocean disposal, and EPA will only concur in such disposal, when the dredged sediment is
"suitable" for ocean disposal. Suitable for ocean disposal means that the sediment has no more
than "trace" levels of chemical pollutants, as determined by bioassays showing that it is not
directly toxic to marine organisms, and that any chemical pollutants present would not
bioaccumulate in the food web to levels of ecological or human health concern. Clean sand
dredged from high energy areas that are removed from immediate sources of pollution can often
be determined by EPA and USACE to be suitable for ocean disposal without conducting extensive
physical, chemical, and biological testing each year. This is true of Humboldt Bay entrance channel
sand.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 23
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However, other sediments (such as those along the Eureka waterfront and in other Humboldt Bay
marinas and docks) must be tested to support a suitability determination. In these cases, EPA and
USACE first approve a Sampling and Analysis Plan (SAP) to ensure that the testing to be done is
representative of the sediment to be dredged. The representative sediment samples are
characterized physically and chemically, and a suite of seven bioassays is conducted for potential
toxicity and bioaccumulation. [Sediment testing requirements for ocean disposal are detailed in
the national "Ocean Testing Manual" (OTM) published jointly by EPA and USACE (EPA and USACE,
1991).] Only sediments that pass all of the bioassays can be considered for ocean disposal.
Periodic monitoring of the various ocean disposal sites managed by EPA Region 9 has consistently
confirmed that pre-dredge testing conducted in accordance with the OTM does adequately
represent the sediment that is later dredged and dumped. (Such monitoring was recently
completed for HOODS and is described in Chapter 4 and Appendix A.) Only sediment determined
by EPA and USACE to be suitable for ocean disposal will be allowed for placement at HOODS in the
future under either Alternative 1 or Alternative 2.
3.3.2 Need for Ocean Disposal
Designation of an ocean disposal site does not mean that any future project will be approved to use
it, even if the project's sediment is "suitable." The MPRSA and the Ocean Dumping Regulations (40
CFR 227.14) also direct that dredged sediment may only be permitted to be discharged at an ocean
disposal site if there is a "need for ocean disposal." A need for ocean disposal exists when EPA and
USACE find that there are no practicable alternative locations and methods of disposal or recycling
available for an individual dredging project. For dredged material, an important alternative to
consider is whether there are "beneficial use" options available that would be practicable to use
given the project's location, timing, and logistics. A site for beneficial use that is not already
permitted or otherwise authorized may not be practicable.
The need for ocean disposal is determined on a project-by-project basis. Thus, if beneficial use is
not feasible for an episodic dredging project in one year, it could be feasible in a future year if an
appropriate site becomes available. Cost associated with taking dredged material to a beneficial
use site is a legitimate factor to consider, but cost need not be equal to or less than ocean disposal;
a beneficial use site may be practicable if it is available at a "reasonable incremental cost"
compared to ocean disposal (40 CFR 227.16(b)). Expansion of HOODS does not mean that
beneficial use alternatives will cease to be evaluated for every project. EPA and USACE will
continue to approve ocean disposal at HOODS only for projects that do not have a practicable
alternative to ocean disposal available to them.
3.3.3 New Reference Site for HOODS
Reference sediment test results are an important point of comparison for determining suitability
of a dredging project's sediments for disposal at the particular ocean disposal site. The OTM
defines Reference Sediment as follows:
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 24
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A sediment, substantially free of contaminants, that is as similar as practicable to the grain size of
the dredged material and the sediment at the disposal site, and that reflects the conditions that
would exist in the vicinity of the disposal site had no dredged-material disposal ever taken place,
but had all other influences on sediment condition taken place. These conditions have to be met to
the maximum extent possible. If it is not possible to fully meet these conditions, tests should use
organisms that are not sensitive to the grain-size differences among the reference sediment,
control sediment, and dredged material. The reference sediment serves as a point of comparison
to identify potential effects of contaminants in the dredged material.
The original reference site for HOODS was to the north of the site, in water approximately 170 feet
deep, at 40 deg 50.021 min N and 124 deg 15.372 min W. This location met the OTM definition
and was used by EPA and USACE for project reviews from 1995 through 2014. However, the
original HOODS reference site is within the proposed footprint of the expanded HOODS. As such,
disposal in the future could take place there, and it would no longer qualify as a reference for
HOODS.
EPA identified a new location that will continue to meet the OTM definition of an appropriate
reference site, even after the HOODS boundary is expanded. The new site was identified in the
2014 monitoring survey as station H-14-45 (see the HOODS monitoring synthesis report at:
https://www.epa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-hoods-documents).
This new reference site, which has been in use since 2015, is offshore of the southwest corner of
the Samoa State Marine Conservation Area. It is in water approximately 180 feet deep (similar to
HOODS) but is farther to the north and outside of the direct influence of any future disposal
activity in the expanded HOODS. The coordinates for the new HOODS reference site are: 40 deg
52.450 min N and 124 deg 14.870 min W (NAD 83).
3.4 Nearshore Placement Site for the Beneficial Use of Sand
Although monitoring at HOODS has confirmed that there have been no adverse impacts from
offshore disposal (Chapter 4, Appendix A), neither does offshore disposal provide any direct
environmental benefits. Sand placed at HOODS is in water too deep, and too far offshore, for
normal seasonal transport processes to move it into the active littoral sand transport zone. Placing
sand at HOODS therefore is considered "disposal", as opposed to "beneficial use". An obvious
potential alternative to ocean disposal of clean sand at HOODS would be to place it at a shallower
nearshore site to nourish the littoral system. Shallow-water placement of clean sand happens at
many locations in California, elsewhere on the west coast, and nationwide. Such placement can
help buffer against coastal erosion and the effects of sea level rise.
A nearshore sand beneficial use site could be operated in concert with either Alternative 1 or
Alternative 2 and would directly extend the operational life of either HOODS expansion alternative
by reducing the amount of sand disposal (and therefore mounding) occurring there. If such a site
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 25
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is ultimately shown (via monitored demonstration placements) to have no significant
environmental impacts, EPA and USACE could formally establish it for ongoing use. Establishing
such a site would involve a separate CWA notice and public comment process (under 40 CFR
230.80). Chapter 5 describes the recommended location, management and monitoring of the
demonstration Nearshore Sand Placement Site.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 26
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4 AFFECTED ENVI RON M ENT AN D ENVIRONMENTAL IMPACTS
The physical, biological, and socioeconomic setting relevant to the Humboldt Harbor area,
including HOODS, have been described in the site designation EIS for HOODS (EPA, 1995), as well
as in more recent environmental assessments prepared by USACE in support of dredging in
Humboldt Bay with subsequent disposal at HOODS (e.g., USACE, 2017b). Those descriptions
remain valid and expansion of the existing HOODS site will not affect them for the most part;
therefore, many of those descriptions are not repeated here, but are incorporated by reference.
Please refer to the referenced documents for more details if desired. This chapter focuses on
physical, biological, and socioeconomic impacts associated with the proposed expansion of the
existing HOODS boundaries.
4.1 Physical Setting and Impacts
The physical environmental conditions of the action area (offshore of Humboldt Bay, California),
including its climate, oceanography, air quality, water quality, and sediment quality, provide
context for the evaluations of biological and socio-economic resources presented in this chapter.
These physical conditions have been described in detail in the site designation EIS for HOODS
(EPA, 1995), as well as in more recent assessments prepared by USACE in support of dredging in
Humboldt Bay with subsequent disposal at HOODS. Those descriptions remain valid and apply to
the area of expansion of the existing HOODS site under both Alternative 1 and Alternative 2. With
the exceptions of oceanography (specifically waves) and sediment quality, a detailed description of
the physical setting of the study area is not repeated here. Please refer to the referenced
documents for more details if desired.
4.1.1 Oceanography and Waves
The proposed action area is located in the Pacific Ocean offshore of Humboldt Bay in water depths
ranging from approximately 150-350 feet (45-106 meters). The existing HOODS is approximately
3 to 4 nautical miles (nmi) from the mouth of Humboldt Bay (Figures 1 & 11). It is 1 square
nautical mile (nmi2) in size, in natural water depths between 160 and 180 feet (49-55 meters).
Ocean current monitoring in the vicinity of HOODS has confirmed both up- and down-coast
current directions (depending on the season), with near-surface current velocities on the order of
25 cm/sec (0.5 knot), and deeper-water current velocities being slower (20 cm/sec (0.4 knot) at
45 meters deep, and 15 cm/sec (0.3 knot) at the bottom.
The 1995 EIS indicated that sediments in waters deeper than 40 m (131 feet) in the area were
generally unaffected by surface waves, whereas in shallower depths, bottom sediments began to
be subject to remixing and redistribution due to surface wave energy. A management objective in
the Site Management and Monitoring Plan associated with the original designation of HOODS was
therefore to manage disposed sediments from mounding and creating seafloor depths shallower
than about 130 feet in order to avoid any significant wave energy interaction with the
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 27
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bottom that could result in alteration in surface wave behavior. Dredged material disposal mounds
with bottom seafloor depths greater than 130 feet would not be expected to cause even the largest
storm waves to significantly steepen or break near the mound itself. However, some large waves
may refract as they travel shoreward after contacting the elevated seafloor; that is to say, these
waves could begin to locally change direction in the "wave shadow" of the site as they pass over it.
A refocused wave pattern could concentrate wave energy and wave heights in a manner that would
not naturally be experienced in this otherwise bathymetrically uniform nearshore environment.
This could in turn change wave patterns, especially during storms, near the only entrance channel
to Humboldt Bay, which is a navigational "harbor of refuge."
Although portions of the existing HOODS mound have become somewhat shallower than 130 feet
(for example see Figures 5 and 9), to date there has been no indication that wave energy has been
refocused or wave patterns substantially changed. Expansion of HOODS under ether Alternative 1
or 2 would be managed to ensure that shallower mounding does not occur (see Appendix D), so
that any adverse impacts to navigational safety will continue to be avoided. As such, no wave-
related impacts are expected.
4.1.2 Sediment Quality
Over 25 million cy of suitable dredged material has been disposed at HOODS since 1995. EPA
conducted physical, chemical, and biological (benthic community) monitoring at and around the
site in 2008 (Figure 12), and then conducted much more extensive monitoring throughout a larger
site expansion study area in 2014 (Figure 13). The more extensive 2014 monitoring included
high-resolution multibeam bathymetry, seafloor imagery (both downward looking and sediment
penetrating cross-sectional photography), and retrieval of sediment samples that were then
analyzed for physical, chemical, and biological (benthic community) properties. Together, the two
years of surveys occupied 70 sampling locations that included the existing disposal site itself as
well as "offsite" stations at various depths across the larger study area. The results of the site
monitoring surveys are presented in the "Humboldt Open Ocean Disposal Site (HOODS) 2008 and
2014 Monitoring Synthesis Report" (EPA, 2016; available at https://www.epa.gov/ocean-
dumping/humboldt-open-ocean-disposal-site-hoods-documents).
Detailed results of the sediment physical and chemical analyses from each sampling station are
presented in the Monitoring Synthesis Report. Table 6 summarizes that information, showing the
average values and ranges for "Inside" (onsite, with dredged material) vs "Outside" (offsite,
without dredged material) stations from 2014 (the more extensive survey). The table also shows
NOAA sediment quality screening guidelines for comparison. Sediment chemistry values are
similar onsite vs offsite, and levels of contamination are very low throughout the study area.
Where screening values are exceeded, they are exceeded both onsite and offsite, indicating that
these levels are natural regionally (not associated with dredged material disposal). In several
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 28
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H-08-8
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Figure 12. Sediment sampling stations occupied in the 2008 EPA monitoring survey at HOODS. Surface
sediment grab samples were obtained from 19 stations (4 inside the site boundary - red box)
for physical, chemical, and benthic community analysis. (Mapped on NOAA chart 18620A,
10-19-2009 update; soundings in meters.) (EPA 2016)
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 29
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• SPI station
~ Existing HOODS
| Potential HOODS Expansion Study Area
A
N
0 0.5 1
nautical mile
Humboldt
Bay
Depth (m)
H-14-47
H-14-46 »
H-14-45
^ H-14-28
-224
H-14-49 • H-14"26 * H-1"10
li-14-4z
H-14-48 • H-14-41 H-14-09
H-14-25
H-14-181
H-14-16 • H-14-07
H-14-15 H-14-23 • H-14-06 H-14-29
H-14-40 H-14-14 • * H-14-31 •
H-14-05 • * H"14-30
H-14-34 . H-14-32
H-14-36 • H-14-33 H-14-13V,
H-14-35 H-14-04 h 141?
* H-14-37 H14?? V1-14"12
H-14-50 H-14-22
H-14-03»\ / * H-14-11
II 14 3
-------
Table 6. Averages and ranges of sediment physical and chemical parameters at "Inside" vs "Outside"
sampling stations in 2014. "Inside" stations are within the existing disposal site boundary or at
locations with some dredged material present, while "Outside" stations are outside the existing site
boundary and without dredged material present. NOAA ER-L and ER-M sediment chemistry
screening values are included for comparison3; green indicates some values exceed their
corresponding ER-L; yellow values exceed their corresponding ER-M. (EPA 2016)
"Outside"
NOAA Screening
Analyte
Units (dw)
Average Range
Average
Range
ER-L
ER-M
Gravel
%
0.06
0-0.16
0.07
0-0.56
—
—
Sand
%
48.58
27.75-56.93
22.53
1.07-78.94
—
—
Silt
%
40.31
30.34-60.07
62.48
13.1-76.8
—
—
Clay
%
11.04
6.93-12.58
14.92
3.9-31.55
—
—
Total Organic Carbon
%
0.82
0.54-1.23
0.90
0.31-1.51
-
—
Arsenic
mg/kg
6.28
5.4-7.1
6.38
5.4-7.8
8.2
70
Cadmium
mg/kg
ND
ND
ND
ND
1.2
9.6
Chromium
mg/kg
74.60
69-84
78.30
70-89
81
370
Copper
mg/kg
17.40
16-20
22.09
11-31
34
270
Lead
mg/kg
6.16
4.5-7.5
7.65
5.7-10
46.7
218
Mercury
mg/kg
0.11
0.05-0.36
0.06
0.026-0.096
0.15
0.71
Nickel
mg/kg
88.60
83-99
92.30
76-110
20.9
51.6
Zinc
mg/kg
61.00
55-67
67.70
56-84
150
410
Dioxins - Total TEQ
ng/kg
0.13
0.078-0.182
0.13
0.013-0.594
—
—
Total DDTs
ug/kg
ND
ND
ND
ND
1.58
46.1
Total Organotins
ug/kg
2.00
1.51-2.56
2.25
1.54-4.28
—
—
Total PAHs
ug/kg
21.28
14.6-31.8
18.37
9.8-44.3
4022
44792
Total PCB Congeners
ug/kg
0.44
0-2.17
0.00
0
22.7
180
instances the onsite dredged material has lower chemistry than native offsite sediments. This is
because most of the dredged material present is clean sand, with relatively less organic carbon to
absorb trace contaminants than the finer native sediment outside the disposal site. The overall
conclusion documented in the Monitoring Synthesis Report (EPA 2016) was:
It is clear that the bulk of dredged material discharged at HOODS in the last decade or more has
been deposited properly within the site boundaries. There are minor and localized physical
impacts from dredged material disposal', as expected, but there has been no significant
contaminant loading and no significant adverse impacts are apparent to the benthic environment
outside of the site boundaries. It therefore appears that the EPA/USACE pre-disposal sediment
testing program, coupled with a strict site management approach, has protected HOODS and its
environs from adverse chemical or biological impacts. However; mounding of dredged material
(primarily due to the large volumes of clean sand dredged annually from the Humboldt Bay
Entrance Channel) has resulted in the site, as it is currently configured, effectively reaching
capacity.
3 NOAA ER-L ("Effects Range - Low"] values reflect sediment chemical concentrations at or below which adverse
effects generally would not be expected, while ER-M ("Effects Range - Median") values reflect concentrations
above which adverse effects could be expected (Long et al., 1995).
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 31
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Continued disposal of suitable non-toxic dredged material at HOODS under either Alternative 1 or
2 is expected to have similar, insignificant impacts on chemical sediment quality. Site expansion
will provide flexibility to manage disposal events for reduced physical impacts in the future as
well. Specifically, management of the expanded HOODS could allow for either:
• spreading material throughout the site so that there would be more time for benthos to
recolonize and to re-work disposed sediment into the native sediment between disposal
events); or
• concentrating material to slowly build the edges of the existing mound so most of the site is
not disturbed at all by disposal for many years.
Alternative 1, the larger site expansion, provides the greatest flexibility and would allow for the
greatest benefit/least impact in this regard. If a Nearshore Sand Placement Site is established in
the future and a proportion of the sand currently disposed at HOODS is diverted there for littoral
cell support, changes to physical sediment quality within HOODS will be even less.
4.1.3 Disposal Plume Dynamics
Disposal Plumes At HOODS
For moderated depth disposal sites such as HOODS, fine sediment that is initially dumped from a
scow or hopper dredge descends as a mass and hits the bottom with some momentum. That
momentum then continues laterally near the bottom, carrying fines with it for some distance
before the momentum dissipates and the fines can settle. (Also, the point of release from the
USACE hopper dredge Essayons starts at about 35 feet below the surface to begin with.) Thus, the
suspended sediment plume is substantially larger near the bottom than at the surface, and the
worst case for potential turbidity-related impacts would be to organisms occurring near the
bottom, rather than those living in surface waters.
Two plume monitoring studies conducted in San Francisco Bay are relevant to estimating the
potential intensity and extend of suspended sediment plumes that would occur with disposal at
HOODS. Both used acoustic tracking techniques calibrated with suspended sediment sampling to
document the behavior of suspended sediment plumes near the bottom (most relevant to near-
bottom plume spreading following disposal at HOODS). The first study (USACE and Weston,
2005) found suspended sediment concentrations were at least 600 mg/L (~175 NTU)
immediately adjacent to the dredging equipment, but that it had dissipated to less than 200 mg/L
(~60 NTU) within 5-6 minutes, and to 100 mg/L (~40 NTU) within 7-9 minutes. "Residual"
plumes of 50 mg/L (~20 NTU) lasted for 13 minutes or more but could not be distinguished from
local background after that. Depending on the tidal current velocities at the time of each survey
transect, plume concentrations dissipated to background within 50-200 m on this project. The
second study (Clarke et al., 2005) found similar results even though different kinds of dredging
equipment generated the plume. In this case, suspended sediment concentrations exceeding 275
mg/L were measured only in immediate proximity to the dredging, and concentrations greater
than 100 mg/L were observed only in relatively small pockets of water that dispersed along the
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 32
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bottom. Acoustic signatures generally decayed to background concentrations of 25-50 mg/L
within 200-400 m.
Of course, these studies were conducted under conditions that differed from those at HOODS in
some important ways. First, water depths were shallower than at HOODS. However, the study
results still provide an indication of potential spread and movement of suspended sediments that
are near the bottom, where plumes from sediments disposed at HOODS will be of greatest extent
as noted above. Second, the sediment in the plume tracking studies was substantially finer than
even the siltiest projects typically disposed at HOODS (as noted above only 2-10% of the total
volume disposed at HOODS is sediment that includes any appreciable percentage of fines).
Therefore, the concentration of suspended fines in the monitored plumes, and the extent of their
subsequent spread before settling out or dissipating to background, was likely much greater than
would occur at HOODS. Finally, although the surface current velocities at HOODS (which can vary
seasonally from 0.5 to 2 knots, or 25 to 100 cm/sec) are often greater than the weak currents
(roughly 0.5 knot, 25 cm/sec) encountered during the San Francisco Bay tracking studies, the
velocities near the bottom at HOODS are actually similarly weak (0.3-0.4 knots or 15-20 cm/sec).
Overall, it is likely that the results of the San Francisco Bay studies substantially over-estimate the
spread of suspended sediment plumes associated with HOODS disposal operations.
Nevertheless, based on these studies a conservative estimate for a typical disposal event at HOODS
is that the plume is minimal at the surface, but that it spreads upon encountering the seafloor to
affect an area with a radius of up to 200 m (660 feet) (i.e., a circular area of ~125,500 sq m
or~ 1,350,000 sq ft). This is equivalent to the area of 1.3 of the 36 existing HOODS disposal cells or
3.7% of the overall area of the existing site. Individual worst-case disposal events would result in
some increased near-bottom turbidity over at most 3.7 % of the existing site, or if site expansion
Alternative 1 is selected (expansion by an additional nautical mile to the west and north), slightly
less than 1% of the expanded site. Since the duration of the elevated turbidity from worst-case
disposals would last for only approximately 15 minutes before dissipating to background
concentrations (based on the San Francisco Bay plume tracking studies), and since disposal events
at HOODS generally occur no more frequently than every 2 hours, there would be no cumulative
turbidity impact at the site over time. As discussed earlier, 90% or more of all disposals at HOODS
consist of clean entrance channel sand that includes very little in the way of fines. Therefore, the
vast majority of disposal events should have turbidity effects that are even smaller than the
negligible effects conservatively estimated here.
Sand Disposal Plume Monitoring at Mouth of Columbia River
An even more relevant example comes from video monitoring conducted by NOAA in 2014 and
2015 off the mouth of the Columbia River. That work documented sand disposal events by the
USACE hopper dredge Essayons (the same disposal vessel that often dredges Humboldt Bay and
discharges sand at HOODS). Videos captured the effects of sand disposal plumes on dungeness
crab, flatfish and gastropods on the seafloor at different depths, including a shallow nearshore site
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 33
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where sediment was placed for beach nourishment, and a deeper (70 m, or ~230 ft) disposal site.4
The shallow nearshore site is similar to the potential NSPS along Samoa Spit off Humboldt Bay
(Figure 11), while the 70 m disposal site is in somewhat deeper water than HOODS. At the shallow
site, the disposal vessel purposely released the dredged sand slowly, while moving forward. The
intent of this disposal technique is to nourish the nearshore littoral zone by adding sand thinly and
evenly, as opposed to creating mounds from point-dumping. This kind of "thin layer placement" is
likely what would occur at any NSPS off Humboldt Bay.
For shallow water placement, the NOAA videos documented temporary displacement of crabs and
flatfish as the sand plumes passed by (gastropods were less affected). However, the plumes had
cleared from the monitoring stations within about 4 minutes. Crabs and fish then returned after
30-60 minutes. At the 70 m disposal site, the plume was slower moving and diffuse enough (less
dense) that flatfish were not displaced and instead stayed in place as the suspended sediment
passed by. The plume at the deeper site also cleared the monitoring station in about 5 minutes.
4.1.4 Air Quality
The project area is presently in attainment for all National Ambient Air Quality Standards
(NAAQS). As outlined below, the proposed action is not expected to change this.
Air emissions associated with the proposed action will be generated during transit to and from the
HOODS (or, in the future, possibly to HOODS and the NSPS). These emissions would consist of
dredge exhaust fumes. The California Air Resources Board (CARB) enacted the Commercial
Harbor Craft Regulation in 2009 in order to accelerate the reductions of emissions of diesel
particulate matter (PM) and oxides of nitrogen (NOx) from commercial harbor craft operating in
California Regulated Waters. The Essayons' and Yaquina's engines meet Tier II level standards as
defined by CARB. Also, the Portland District USACE recently applied for and received approval to
operate the engines installed on the dredges Essayons and Yaquina under CARB's statewide
Portable Equipment Registration Program (PERP). PERP registration allows portable engines,
including marine engines, to operate in California while providing minimal notification to the local
air quality management districts.
The Essayons makes use of:
• Two, Tier II, C-280-12 Diesel Main Propulsion Engines;
• Three, Tier II, C-3512 Ship Service Generator Engines; and
• Two, Tier II, C-280 Diesel Dredge Pump Engines.
4 NOAA's monitoring videos are available at https: / /www.youtube.com/user /FishOQHead.
A synopsis video is available at https: //www.youtube.com/watch?v=c49s8 f5ivU.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 34
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The Yaquina makes use of:
• Two, Tier II, MTU 8V4000 M60 Main Propulsion Engines; and
• Two, Tier II, MTU 12V2000 P8 Ship Service Generator Engines.
• Two, Tier, II MTU 12v 2000 P12 Dredge Pump Engines.
The Tier II engines installed on the Essayons and Yaquina greatly reduce NOx emissions compared
to older engines. They also allow the use of low sulfur oxide diesel fuel, resulting in a reduction in
SOx (sulfur oxides) emissions. New electronic governors also reduce the amount of visible
particulate matter released into the atmosphere while making more efficient use of fuel.
Expanding HOODS will not increase the volume of material to be dredged, and it will cause only a
minor increase the transport distance to HOODS. Due to this, as well as the use of CARB-compliant
Tier II engines on the Essayons and Yaquina (as well as contracted hopper dredges), and the
limited duration of annual dredging episodes, it is anticipated that the proposed action will not
significantly increase disposal-related emissions compared to no action. Other dredging-related
air quality effects must be evaluated on a project-specific basis by USACE.
4.2 Biological Resources and Impacts
The open-water environment along the Humboldt coast provides habitat to plankton, benthic
(bottom-dwelling) organisms, fish, birds, amphibians, and marine mammals, some of which are
protected or sensitive. The location of the existing HOODS disposal site (see Figures 1 and 11) was
selected in the 1995 EIS specifically because it had the least potential for impacts to important fish
and shellfish resources (particularly including smelt, flatfish, and decapods which are all most
abundant in waters shallower than 50 m in the area, closer to shore). Please see the 1995 EIS for
general descriptions of biological resources in the vicinity of HOODS. This section updates those
discussions where appropriate based on more recent monitoring data, changes to protected
species status, etc.
4.2.1 Planktonic Community
The open waters off Humboldt Bay are part of the California current region, typified by biological
components from a variety of marine and biotic provinces. Plankton biomass and species
composition in the Humboldt Bay region are influenced by the southerly flowing California current
and the Davidson current that flows northward in the winter.
Disposal of dredged material at the HOODS temporarily increases turbidity (reduces light
penetration into the water column) resulting in a temporary reduction in primary productivity.
Zooplankton may experience a temporary clogging of gills and feeding appendages, which could
reduce growth, survival, and zooplankton biomass. Additionally, increased turbidity may interfere
with the respiratory mechanisms of both planktonic and zooplankton communities.
Implementation of the proposed action would result in less than significant impacts to planktonic
communities for several reasons. Only suitable dredged material is allowed to be disposed at
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HOODS (or any other ocean disposal sites); the suitability determination process includes
confirming that the material is not toxic to sensitive water column organisms and that water
quality standards will not be violated following initial mixing. Disposal plumes are much smaller
at the surface than near the sea floor to begin with, because the discharge point is already roughly
35 feet below the surface. As described above, suspended solids associated with disposal at
HOODS are temporary and return to ambient conditions within minutes after the discharge with
no cumulative effects of turbidity or suspended solids on the water column. Finally, the vast
majority of material disposed at HOODS is clean sand which has the shortest residence time in the
water column before settling out, and which also has the least potential to carry contamination
which may strip off into the water column before settling.
4.2.2 Benthic Community
Potential detrimental effects of non-toxic dredged material disposal on benthic communities
(benthos) mainly include direct physical effects within the site boundaries, including burial of
invertebrates living on or in the seafloor sediments, and physical changes to the substrate (such as
grain size differences) which can affect recolonization and subsequent invertebrate community
structure. (Benthic fishes are generally able to avoid burial by plumes of disposed sediment, and
although they may be displaced from the immediate vicinity of disposal events that displacement
would generally be temporary. Groundfish are discussed in more detail in Section 4.2.3.
The benthic habitat at HOODS and throughout the HOODS expansion study area is a gently sloping,
essentially featureless sedimentary plain that grades evenly from fine sand in shallower depths to
silts in deeper areas. As described in the EIS and confirmed via the monitoring surveys in 2008
and 2014 (EPA 2016, Appendix A), the benthic communities supported by this habitat are
virtually identical (i.e. infaunal organism density and richness are not significantly different) at
similar depths north to south across the entire study area. Density and richness do each increase
going from shallower to deeper areas, as expected based on the substrate's gradation from fine
sand to silt. But across the entire study area, there are no unique or distinctive benthic community
differences.
The initial monitoring in 2008, and the more extensive monitoring in 2014, each documented a
community of infaunal invertebrates (living in or on the sediment) in the vicinity of HOODS that is
dominated by small polychaetes (marine worms), crustaceans, and mollusks. Table 7 summarizes
the invertebrates identified in the 2014 monitoring across the study area. Only directly atop the
disposal mound itself, which is annually disturbed by disposal of large volumes of clean sand, was
there any effect on the infaunal community at all as indicated by organism density, species
richness, or diversity (Figure 14).
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Table 7. Summary of the dominant (5 most abundant) taxa in each major group of benthic invertebrates
collected around HOODS in 2014. In all, 61,215 individual organisms and 323 taxa were collected.
(EPA 2016)
Polvchaetes
n=32,461 individuals (53.0% of all individuals); 138 taxa (42.7% of all taxa)
Percent of total
Taxon
Count
Polychaetes
Siophanes spp
5,745
17.7
Cirratulidae
2,719
8.4
Mediomastus spp
2,571
8.0
Owenia f.
1,684
5.2
Maldanidae
1,472
4.5
Total
14,191
43.7
Crustaceans
n=10,247 individuals (16.7% of all individuals); 69 taxa (21.4% of all taxa)
Percent of total
Taxon
Count
Crustaceans
Photis spp
2,515
24.5
Diastylis spp
996
9.7
Cheirimedeia spp
892
8.7
Isaeidae spp
800
7.8
Protomedeia spp
796
7.8
Total
5,999
58.5
Mollusks
n=9,999 individuals (16.3% of all individuals); 58 taxa (18.0% of all taxa)
Percent of total
Taxon
Count
Mollusks
Axinopsida
3,470
34.7
Bivalva spp
1,986
19.9
Ennucula
923
9.2
Macoma spp
620
6.2
Gastropoda app
567
5.7
Total
7,566
75.7
OtherTaxa
n=8,508 individuals (13.9% of all individuals); 58 taxa (18.0% of all taxa)
Percent of total
Taxon
Count
Other Taxa
Edwardsiidae spp
4,075
47.9
Nematoda spp
1,985
23.3
Echiuridae
955
11.2
Ophiurida spp
353
4.1
Echinoidia
208
2.4
Total
7,576
89.0
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50000
45000
Fall 2014 Density
% 35000
g 30000
T5
E
25000
20000
15000
10000
5000
Expansion Area
Existing ODMS
Outside Expansion Area
B
Fall 2014 Richness
200
150
100
50
Expansion Area
Existing ODMS
Outside Expansion Area
8.00
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
Fall 2014 Species Diversity (H1)
Existing ODMS
rt irt n ci
9 9 9 9
Expansion Area
9
f
Outside Expansion Area
Figure 14. Density (Panel A), richness (Panel B), and diversity (Panel C) of infaunal organisms captured
at each station around HOODS in 2014, grouped by stations within the existing disposal site,
in the expansion area, and outside the expansion area. Stations 12 and 13 were inside the
HOODS boundary but on the periphery; only Station 21 (shown in yellow) was on the disposal
mound itself. (EPA 2016)
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Expansion of HOODS will allow flexibility to manage disposal in the future to reduce the frequency
of repeated deposition (and build-up) of sand in the same location. More time for benthos to
recover (recolonize) and to re-work disposed sediment into the native sediment between disposal
events will result in substantially increased benthic habitat quality and biological productivity
compared to the thick sand mound currently existing at HOODS. Alternative 1, the larger site
expansion, provides the greatest flexibility and would allow for the greatest benefit/least impact in
this regard. If a Nearshore Sand Placement Site is established and a proportion of the sand
currently disposed at HOODS is diverted there for littoral cell support in the future, changes to
physical sediment quality within HOODS will be even less. Thus, no significant adverse impacts
are anticipated under either Alternative 1 or Alternative 2.
4.2.3 Fish Communities, Including EFH
A variety of life history stages of both pelagic (water column) and benthic (bottom-associated) fish
species may be present in the vicinity of HOODS and its expansion alternatives (e.g., see EPA 1995
and USACE 2017b). The HOODS area was identified in the 1995 EIS as having the least potential
for impacts to important fish and shellfish resources (including smelt, flatfish, and decapods which
are all most abundant in waters shallower than 50 m in the area, closer to shore). It concluded
that the potential for impacts to other more pelagic and/or mobile species (including salmonids
and other fishes, as well as seabirds, marine mammals, and turtles) was negligible due to the
seasonal nature of disposal activity, the fact that the majority of material disposed was expected to
be sand (i.e., having lowest potential for lasting turbidity or contaminant effects), and the lack of
any unique habitat features that would make the disposal site's location more attractive,
productive, or valuable to these species than the surrounding region. This section updates those
discussions and focuses particularly on how Fishery Management Plan (FMP) species and
Essential Fish Habitat (EFH) may be affected by disposal at an expanded HOODS, as well as special
status species managed under the Endangered Species Act. (See Appendix B for details of the
completed EFH consultation with NMFS.)
The existing HOODS boundaries as well as the expansion alternatives overlap with
species/habitats managed under the 2016 Pacific Salmon Fisheries Management Plan (FMP), the
2016 Pacific Coast Groundfish FMP, and the 2019 Coastal Pelagic Species FMP. EPA has
determined that under either Alternative 1 or Alternative 2 there will be no effect on fish species
addressed in these FMPs, or their EFH for the reasons discussed below.
Pacific Salmon FMP
The Pacific Salmon Fisheries Management Plan (PFMC, 2016a) describes potential adverse effects
to salmon that may occur as a result of dredging and disposal activities. Consistent with the
discussion above, potential adverse effects are much more likely to be associated with dredging
itself than with disposal. Potential effects from disposal are described in the FMP as follows:
"When not used for beneficial purposes, spoils are usually taken to marine disposal sites
and this in itself may create adverse conditions within the marine community. When
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contaminated dredged sediment is dumped in marine waters, toxicity andfoodchain
transfers can be anticipated, particularly in biologically productive areas. The effects of
these changes on salmon are not known."
Specific to HOODS, the location of the disposal site and the kind of sediment disposed there
(mainly clean sand), coupled with EPA's active management and monitoring program, have
assured that no contaminant-related effects have occurred (including via toxicity or foodchain
transfers).
The Pacific Salmon FMP also generally describes potential conservation measures that may reduce
impacts of dredging and disposal on EFH. As above, most of the potential conservation measures
relate to dredging itself rather than disposal. The potential measures that are most relevant to
potential disposal effects are listed below. EPA agrees that these are appropriate kinds of
measures to consider, and we note that they (as well as other specific measures we institute) are
already incorporated into our management of disposal operations at HOODS.
"When reviewing open-water disposal permits for dredged material, identify direct and
indirect effects of such projects on EFH. Consider upland disposal options as an alternative.
Mitigate all unavoidable adverse effects and monitor mitigation effectiveness."
The potential effects on EFH of the dredging aspects of projects using HOODS are assessed on a
case by case basis during the interagency permit review process. This is appropriate because
dredging has the greatest potential to cause adverse effect, and because the potential effect of each
dredging project is different based on location, timing, presence of contaminants, proximity to
habitats of particular concern (such as eelgrass), etc. However, the ocean disposal aspects are
much less variable, and can appropriately be assessed programmatically, because:
• only suitable sediment (shown through extensive testing to be clean and non-toxic) is
considered for disposal at HOODS;
• even suitable sediment is only approved when other practicable alternatives do not exist;
• the vast majority of material disposed is sand, which settles to the bottom very quickly
(minutes) and does not substantially spread outside the disposal site boundaries; and
• water column effects (turbidity) are extremely temporary with no cumulative effect between
disposal events.
The only effect is the physical sand mound which is constrained to the site boundaries as was
predicted in the original site designation EIS. The presence of the sand mound (which does not
extend into waters shallower than 120 feet) does not limit the amount or quality of open water
migratory or foraging habitat for salmon (and in fact may somewhat enhance habitat quality by
providing the only physical "feature" in this otherwise uniform habitat area. If beneficial reuse of
sand (for example at the Near Shore Placement Site) starts to occur regularly in the future, the
already negligible effects of disposal at HOODS on salmon EFH will be further minimized.
"Test sediments for contaminants prior to dredging and dispose of contaminated
sediments at upland facilities."
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This measure is already fully incorporated in both the Ocean Dumping regulations, and the HOODS
SMMP. All projects are evaluated for potential contaminant effects prior to being approved for
ocean disposal at HOODS. Unsuitable sediment must be managed in an alternative manner,
including at appropriate upland or confined facilities.
"Determine cumulative effects of existing and proposed dredging operations on EFH."
As noted earlier, expansion of HOODS would not increase the need for dredging in Humboldt Bay
or the amount of ocean disposal activity that occurs there. Instead, expanding the site affords the
opportunity to manage ongoing disposal at the site in a manner that could further reduce the
already negligible impacts of disposal (especially under Alternative 1) while allowing more time
for benthic recovery via active bioturbation before subsequent disposal events affect the same
location again. Also as noted above, there would be no cumulative water quality impacts due to
the extremely rapid settlement of discharged sediment (predominantly sand), compared to the
interval between disposal events (averaging 3-4 minutes of discharge once every 2-3 hours during
the relatively short 3-5 week dredging season). For these reasons there would be no cumulative
effects of continued disposal operations at HOODS on EFH for salmon.
"Explore the use of clean dredged material for beneficial use opportunities."
Chapter 5 of this EA describe a potential Nearshore Sand Placement Site (NSPS) that would help
retain clean sand dredged from the Humboldt Entrance Channel in the shallow littoral system
along Samoa beach (see Figure 11). This EA does not propose to designate the NSPS, but provided
that further analysis and pilot placements confirm this location to be environmentally appropriate,
EPA and USACE could move to formalize the site. At that point EPA would consider placement at
the NSPS to be a beneficial reuse alternative to ocean disposal of dredged sand at HOODS.
However, for the time being, there are extremely limited available reuse options in the Humboldt
Bay area, especially for the large quantities of sand needing to be dredged each year to maintain
safe navigation into and out of Humboldt Bay.
Pacific Coast Groundfish FMP
The Pacific Coast Groundfish FMP (PFMC, 2016b) manages 90-plus species over a large and
ecologically diverse area. It includes all west coast offshore waters less than 3,500 m deep (Figure
15), as well as specified seamounts that are greater than 3,500 m deep and other specific areas
identified as habitat areas of particular concern (HAPC, Figure 16). Although HOODS and the
proposed HOODS expansion alternatives lie within the overall groundfish
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-131° -130° -129° -128° -127° -126° -125° -124° -123° -122° -121° -120° -119° -118° -117° -116° -115° -114° -113° -112° -111°
Depths less than 3500 m,
Seamounts (> 3500 m), and
100% HSP area for all species
Seattle
Aberdeen
200m (109fm)
2000m (1094fm)
o Portland
Tillamook
Habitat Suitability Data is described in
Pacific States Marine Fisheries Commission
2004. Risk Assessment for the Pacific
Coast Groundfish FMP
Newport
Yachats
Florence
Map Date: July 5, 2005
Coos Bay
Brookings
b Crescent City
Approximate HOODS
Location
B Bodega Bay
¦u.
an Francisco
Monterey
Morro Bay
anta Barbara
o Los Angeles
Nautical Miles
125 250
M'OTCtC'S
-129° -128° -127° -128° -125° -124° -123° -122° -121° -120° -119° -118° -117° -116° -115°
Figure 15. Overall Groundfish EFH zone. (From PFMC, 2016.) rhttp://WWW.PCOIJNCIT,.ORCn
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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-131° -130° -129° -128° -127° -126° -125° -124° -123° -122° -121° -120° -119° -118° -117° -116° -115° -114° -113° -112° -111°
V
A,/ V (
XX' WA state waters
/ and se^bottorrv.
Q Seattle
\ Thompson
\ Seamount
ffetoria
O Portland
\ Tillamook
Daisy Bank /
Nelson Island
i
/ President Jackson
i Seamount
Mendocino#* >
~~ Ridge
Approximate HOODS
Location
b Newport
0 Yachats
6 Florence
5 Coos Bay
^ 0 Crescent City
irdell Bafck <>B°&%?ay
Morro Bay
HARC'S *
Seagrass
Canopy Kelp
Rocky Reefs
Estuaries
Areas of Interest
Depth
200m (109fm)
2000m (1094fm)
* Some HAPC's are spatially coincident,
(for example, seagrass and estuaries)
Therefore, on this map, only the top layer
will be visible in these cases. The legend
is presented in the order of the map layers
Map Date: March 14, 2006
bQta Barbara
x
^ Los Angeles^
"cfean Francisco
Sumdrop Seamount ;
Pioneer Seamount • w
Guide Seamountf
Tane^^Monterey Canyoflt»j Monterey
Seamount ^ J (($•*'&,
Davidson Seamount
Specified Areas in CIF
1 ^ '""a "5**
> t n'
% 5^-
\
'
\ San Juan Seamoi^it
Nautical Miles
125 25C
Kilometers
tanta Barbara
Los Angeles
rJ i die n *J«teef / Kidney Bank
^PcSlftto Bank * \
E ,V^J
Ban®[ "
^ -v CCH East
-129" -128° -127° -126* -125*
-123" -122*
Figure 16. Habitat Areas of Particular Concern (HAPC) in the Groundfish FMP.
(From PFMC, 2016.) fhttp://WWW.PCOlJNCILORGi
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EFH zone, there are no HAPCs or other ecologically important habitat closure areas that are
affected by disposal operations at HOODS. The nearest areas of concern listed in the Groundfish
FMP are summarized below:
• The Klamath River Conservation Zone (KRCZ, a long-term bycatch mitigation closure area) is
approximately 40 miles to the north.
• The Eel River Canyon (a bottom trawl closure area) is approximately 17 miles to the south.
• The Bottom Trawl Footprint Closure begins at the 700 fathom (4,200 foot) isobath, which in
the vicinity of HOODS is anywhere from 25 to 45 miles offshore to the west.
• Estuaries (Humboldt Bay), rocky reefs, canopy kelp, and seagrass areas.
Ongoing disposal at HOODS of suitable dredged material, which is predominantly clean sand, will
have no effect on any of these nearby areas of special concern. Dredging within the estuary
(Humboldt Bay) could affect seagrasses, but these are assessed (and mitigated as appropriate)
during the permit review process; dredging impacts are not included in this assessment for ocean
disposal.
In addition, HOODS itself is not off limits to commercial, recreational or tribal fishing activities, and
expansion of HOODS would not result in curtailment of ongoing allowable fishing operations. As
discussed earlier, the benthic and water column habitat around HOODS is uniform, with no
physical characteristics that distinguish it from extensive similar habitat in the surrounding area.
The only "effect" on groundfish EFH is the physical sand mound which is constrained to the site
boundaries as was predicted in the original site designation EIS. The presence of the sand mound
(which does not extend into waters shallower than 120 feet) does not independently limit the kind
of fishing that may conducted, and the mound in fact may somewhat enhance groundfish habitat
quality by providing the only physical benthic "feature" in this otherwise uniform habitat area. If
beneficial reuse of sand (for example at the Near Shore Placement Site) becomes routine in the
future, the already negligible effects of disposal at HOODS on groundfish EFH under either
Alternative 1 or 2 will be further minimized.
Coastal Pelagic Species FMP
The Coastal Pelagic Species FMP (PFMC, 2019) includes four finfish (Pacific sardine, Pacific [chub]
mackerel, northern anchovy, and jack mackerel) the invertebrate market squid, and all euphausiid
(krill) species that occur in the West Coast EEZ. CPS finfish are pelagic (in the water column near
the surface and not associated with substrate), because they generally occur or are harvested
above the thermocline in the upper mixed layer. For the purposes of EFH, the four CPS finfish are
treated as a complex because of similarities in their life histories and similarities in their habitat
requirements. Market squid are also treated in this same complex because they are similarly fished
above spawning aggregations.
EFH for the Coastal Pelagic finfish includes all coastal waters of California, Oregon and Washington
offshore to the limits of the EEZ and above the thermocline where sea surface temperatures range
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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between 10°C to 26°C. For krill, the EFH extends from the shoreline to the 1,000 fathom (6,000 ft)
isobath and to a depth of 400 meters. There are currently no systematic closure areas or seasonal
fishing limits under this FMP.
Similar to the discussion above concerning the Pacific Salmon FMP, the existing HOODS site has
had no effect on Coastal Pelagic Species EFH. Expanding the HOODS boundary will continue to
have no effect under either Alternative 1 or 2, for the following reasons:
• only suitable sediment (shown through extensive testing to be clean and non-toxic) is
considered for disposal at HOODS;
• even suitable sediment is only approved when other practicable alternatives do not exist;
• the vast majority (90+%) of material disposed is sand;
• disposed sand settles to the bottom very quickly (minutes) and does not substantially spread
outside the disposal site boundaries; and
• water column effects (turbidity) are extremely temporary with no cumulative effect between
disposal events.
The only effect is the physical sand mound which is constrained to the site boundaries as was
predicted in the original site designation EIS. The presence of the sand mound (which does not
extend into waters shallower than 120 feet) does not limit the amount or quality of open water
habitat for coastal pelagics themselves, or for fishers targeting them. If beneficial reuse of sand
(for example at the Near Shore Placement Site) becomes routine in the future, the already
negligible effects of disposal at HOODS on coastal pelagic EFH will be further minimized.
The Samoa State Marine Conservation Area
The California-designated Samoa Offshore State Marine Conservation Area (which prohibits take
of marine organisms with certain specified commercial, recreational, and tribal exceptions) is
about 5 miles from the center of the existing HOODS, and at its closest point is just over 3 miles
from the northernmost boundary of HOODS expansion Alternative 1 (see Figure 11). (CDFW, 2012:
http://californiampas.org/mpa-regions/north-coast-region/samoa-smca)
The location of the Samoa SMCA was not designated to protect particular distinct habitat features.
Rather, it was chosen "to meet beach habitat spacing and replication guidelines" together with
other SMCAs that protect beaches and soft-bottom habitats (0-30m and 30-100m) up and down
the California coast. This category of SMCA is designed to maintain a moderate to high
preliminary level of protection (LOP). Species likely to benefit include species that are directly
targeted by fisheries, those which are caught incidental to fishing for the target species (bycatch)
and which cannot be returned to the water with a high rate of survival, and those which may be
indirectly impacted through ecological changes within the SCMA itself.
Thus, although it was not created under the auspices of EFH, the presence and management of the
Samoa SCMA are directly complementary to EFH goals. Vessels engaged in ongoing ocean disposal
operations will not enter into the Samoa SMCA. In fact, EPA has established a location just outside
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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the southwestern boundary of the Samoa SMCA as the reference sediment station for HOODS (see
Section 3.3.3, and Figure 11). This is the clean "unaffected" reference sediment against which the
acceptability of dredged sediment for proposed ocean disposal at HOODS is tested.
4.2.4 Special Status Species (ESA Consultations)
When HOODS was originally designated in 1995, the ESA consultation with NMFS focused on the
endangered Sacramento River winter-run chinook salmon and the threatened Steller sea lion (no
EFH consultation was conducted), while the ESA consultation with USFWS focused on tidewater
goby, marbled Murrelet, and green sturgeon. Since 1995 there have been changes to the listed
species that could potentially occur in the vicinity of HOODS. This section summarizes the
updated ESA consultations with NMFS and USFWS for expanding HOODS.
Pursuant to Section 7 of the Endangered Species Act (ESA) (16 U.S.C. § 1536(c)), as well as the
Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA) regulations (50 C.F.R. §
600.920(e)(3)), EPA prepared ESA and EFH analyses and informally consulted with USFWS and
NMFS regarding these analyses. The consultation materials are presented in Appendix B
(including updated species lists and distribution maps) and are summarized below.
An additional special status fish species, the longfin smelt (Spirinchus thaleichthys), is listed as
threatened under the California Endangered Species Act (but not under the federal ESA). The
1995 EIS for HOODS noted that smelt were present in the area but were much more abundant in
shallower nearshore waters (and inside Humboldt Bay) that in the deeper offshore water in the
vicinity of HOODS. However, coordination with the California Department of Fish and Wildlife
(CDFW) indicated that at least one recent study (Mulligan and Jones, 2011) had identified longfin
smelt in samples taken in the immediate vicinity of HOODS. On this basis, it must be considered
that longfin smelt could be present within the expanded HOODS.
Marine fishes, sea turtles, marine mammals, and sea birds 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
seagrasses.
In contrast, no matter where or when the dredging occurs, disposal of the sediment at an
appropriate offshore disposal site such as HOODS has significantly less potential to adversely affect
species for several reasons:
1. HOODS was originally located to minimize impacts by avoiding any unique or limited
habitats. As noted above, the benthic habitat is quite uniform throughout the entire
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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expanded HOODS study area, with no physical features that would be expected to attract
marine life differentially compared to the surrounding areas.
2. Only "suitable" (clean, non-toxic) dredged material is permitted to be disposed at HOODS.
As confirmed by EPA monitoring, no short- or long-term contaminant exposure concerns are
associated with the discharged sediment, on-site or off.
3. Disposal at HOODS by USACE is distinctly seasonal and typically occurs over 3-5 weeks in
the spring (late May to early July), although occasionally USACE dredges in the fall as well.
Tracking of USACE disposal events shows that approximately 200 individual disposal trips to
HOODS occur each year, with an average of just over 8 disposals per day during peak times.
Each disposal event lasts only 3-4 minutes.
4. Disposal vessels placing dredged material at HOODS typically travel at 7-10 knots when
transiting the approximate 3-4 nmi from the Humboldt Bay entrance. (They then slow to a
virtual stop during the 3-4-minute disposal operation.) These speeds are already consistent
with the vessel speed limitations recommended by NMFS (and imposed in certain areas) to
minimize vessel strikes to whales.
5. The vast majority (more than 90%) of sediment placed at HOODS to date has been sand
from the Bar and Entrance Channel. Sand not only has the least potential to carry
contaminants, it also descends to the bottom and settles very quickly. Turbidity from
individual disposals is thus very localized and short-term (minutes), with ample time for
water column turbidity to disperse between events in the immediate vicinity of the disposal
cell.
For these reasons, EPA determined that the expansion of the HOODS boundary under either
Alternative 1 or 2 will have no effect on marine mammals or sea turtles and is unlikely to adversely
affect anadromous fish species (salmonids, Eulachon, and green sturgeon) as discussed in
Appendix B. EPA has also determined that the proposed action is unlikely to adversely affect
longfin smelt. (Note that this determination does not necessarily extend to the potential future
NSPS.)
To ensure that any impacts of ocean disposal operations will continue to be negligible, short term,
and highly localized EPA has included overall ocean disposal site use conditions in its proposed
updated SMMP for HOODS (Appendix D). These conditions are then included (and updated or
supplemented as necessary) as enforceable provisions in EPA's project-specific concurrence letter
for each ocean disposal project. EPA believes that all practicable avoidance and minimization
measures are incorporated into the proposed expansion of HOODS, and that further mitigation
measures are not needed. Also, as noted, additional management options to further reduce the
already negligible effects of disposal at HOODS may be available if a Nearshore Sand Placement
Site (NSPS) is established in the future to be an environmentally appropriate alternative for some
or all of the Federal channel sand dredged each year.
As part of the EFH consultation NMFS included a Conservation Recommendation for continued
mounding (below -130 feet), rather than distributing the sediment evenly across the expanded
site. According to the NMFS Conservation Recommendation. "Mounding spoils to the maximum
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allowed height is likely to provide higher frequencies of usage by managed species, and may allow
for a larger area to remain undisturbed." The updated SMMP presented in Appendix D includes a
proposed disposal management approach that would result in greater seafloor complexity within
the greater HOODS boundary over time, as well as limiting the area disturbed by deposition in any
one year.
4.3 Other Potential Impacts
Recreation (boating, fishing, other):
The majority of recreational uses near HOODS (or the potential NSPS) center on fish, wildlife, and
aesthetic values. Recreational opportunities include, e.g.: beach walking, wildlife viewing, boating
and kayaking, surfing, and fishing. Dredging activities may affect recreationists utilizing the waters
offshore of Humboldt Bay for boating, kayaking, windsurfing, and fishing by displacing them from
the immediate vicinity of HOODS during active disposal. HOODS and the waters surrounding it are
not off-limits to fishing, boating, etc., at any time, so any displacement would be very short term.
In addition, given that the disposal site boundary begins 3 miles offshore, the immediate area of
potential impact would be small compared to the offshore area available for recreation and would
be temporary in nature (i.e. four to six weeks). Finally, expansion of the HOODS boundary will not
increase the amount of dredging or disposal activity at HOODS. (In facts, possible future
placement of sand at a NSPS would reduce disposal activity, and therefore any recreational
disturbance, at HOODS.) For these reasons, potential effects to recreation are expected to be less
than significant under either Alternative 1 or 2.
Navigation:
During active dredging and disposal activities, there is the potential for minor conflicts with
navigation in the project area. However, the purpose of dredging the Bay's navigation channels is
to maintain safe conditions for navigation, and the purpose of expanding the HOODS boundary is
similarly to allow ongoing disposal of sediments to avoid any impacts to navigation (as a result of
mounding). Either Alternative 1 or 2 would therefore have significant long-term benefits to
navigation for commercial deep-draft vessels and recreational vessels alike.
Public health and safety:
The proposed action would avoid creation of potentially unsafe navigation condition offshore of
Humboldt Bay, minimizing the risk of ship groundings and subsequent fuel release and other
hazardous materials into the natural environment. Thus, either Alternative 1 or 2 would result in a
beneficial impact. Under the no action alternative, mounding at HOODS could affect local wave
climate, potentially affecting navigation safety, which could result in substantial public health and
safety issues.
Cultural, historical and archeological resources:
The implementing regulations of Section 106 of the National Historic Preservation Act (36 C.F.R.
Part 800) require federal agencies to assess a project's effects on historic and cultural resources
listed or eligible for listing in the National Register of Historic Places. Impacts are considered
significant if such resources would be physically damaged or altered, isolated from their historic
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context or if project elements were introduced that are out of character with the significant
property or setting. California law also protects some shipwrecks as archeological sites. The
California State Lands Commission's (CSLC) shipwreck database5 documents five historic
shipwrecks in the general vicinity of HOODS (Figure 17), two of which - the Brooklyn and the
Milwaukee6 - are on the shoreline adjacent to the potential NSPS. The Brooklyn broke up, but
some remains of the Milwaukee's bulkheads remain visible a short distance offshore of Samoa
during very low tides (look for the rock monument just off Hwy 255 south of Cookhouse Rd.).
Figure 17. Locations of historic shipwrecks near HOODS and the NSPS. None of these shipwrecks
would be affected by disposal activities at HOODS. Similarly, no impacts would be anticipated
from possible future placement of sand in a NSPS, because these wrecks are in areas too
shallow for direct placement of sand.
The 1995 EIS also documented three potential magnetic anomalies in the vicinity of HOODS that
could represent the remains of shipwrecks. The 2014 high-resolution multibeam bathymetry
survey of HOODS found no indication of structures or debris extending above the sediment surface
at the locations of these three magnetic anomalies. Figure 18 shows the locations of the magnetic
anomalies relative to the existing HOODS disposal mound. Since these anomalies do not extend
above the surface now, and apparently have not since at least 1991 (when the survey cited in the
1995 EIS was conducted), their exact character remains unknown. Ongoing disposal operations
under either Alternative 1 or 2 may effectively bury these features further but will not harm or
otherwise directly affect them.
5 https://www.s1c.ca.gov/wp-content/up1oads/2018/12/ShipwreckInfo.pdf
6 https://en.wikipedia.org/wiki/USS Milwaukee fC-211
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Figure 18. Locations of three "magnetic anomalies" near HOODS. Evaluation of high-resolution data
from the 2014 multibeam echosounder survey confirmed that these features, if still present
at all, are buried and do not project to or above the sediment surface. (Red shading is the
existing HOODS mound.)
Historic monuments, parks, national seashores, wilderness areas, etc:
The proposed action area does not lie within the boundaries of any historic monument, parks,
national seashores, wild or scenic rivers, wilderness area or research site. Thus, no impacts to
such areas are anticipated. However, California recently established the Samoa State Marine
Conservation Area a few miles north of HOODS (Figure 11). The Samoa SMCA is discussed in
Section 4.2.3 above. For the reasons discussed there, expansion of HOODS under either Alternative
1 or 2 is expected to result in no impacts on the Samoa SMCA.
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Hazardous and toxic materials:
Expanding the boundaries of HOODS will not increase the volume or frequency of ocean disposal
activity there. Therefore, no increase in the use of or risks from hazardous or toxic material such as
diesel fuel, lubricants, and solvents are anticipated, compared to No Action. The handling,
transport, and disposal of such materials would be of limited nature, but nonetheless would be
guided by Best Management Practices (BMPs) associated with each government-owned or
contracted disposal vessel. In the event of any spills to surface water bodies, a Spill Control Plan
will specific to each dredging project be adhered to, and containment clean-up activities would be
implemented, among other activities identified in the Spill Control Plan. Thus, no impacts are
expected under either Alternative 1 or 2.
Socio-economic conditions:
The average 1 million cy of annual maintenance dredging of Humboldt Bay's navigation channels
and maritime facilities is imperative to the economy of Humboldt County. Without an available,
environmentally appropriate disposal site for clean dredged material, dredging could slow or
cease, and the channels would eventually shoal thereby generating unsafe navigation conditions.
Expansion of the boundaries (and therefore the disposal capacity) of HOODS is needed in order to
facilitate ongoing dredging, and the maritime-related economy it supports. Either Alternative 1 or
Alternative 2 would result in improved socioeconomic conditions when compared with the no
action alternative.
Energy consumption or generation:
Under either Alternative 1 or 2, disposal within the expanded HOODS boundaries would have a
minor impact on energy consumption associated with the dredge vessels experiencing a slightly
(up to 1 mile) longer transport distance depending on the location of open disposal cells in any
particular year. This effect is considered to be negligible in comparison to no action.
Environmental justice:
Environmental justice conditions in and around Humboldt Bay would remain unchanged under
either Alternative 1 or 2 or the no action alternative. No impacts are anticipated.
Growth inducing impacts (community growth, regional growth):
The proposed action would not increase the need for dredging in the area, and therefore would not
have any growth inducing impacts. Community and regional growth in Humboldt County and in
the Humboldt Bay area would remain unchanged under the either Alternative 1 or 2 or the no
action alternative. No impacts are anticipated.
Conflict with land use plans, policies or controls:
Alternative 1 or 2, and the no action alternative, would not directly conflict with any land use
plans, policies, or controls governing the area, including for the Samoa SMCA. No impacts are
anticipated.
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Irreversible changes, irretrievable commitment of resources:
The slightly increased use of fossil fuels to continue accessing the expanded disposal site would be
an irretrievable commitment of resources under either Alternative 1 or 2, but would be limited
and minor.
Cumulative effects potentially related to the proposed action:
Past and Present Activities
Expansion of HOODS under either Alternative 1 or 2 will result in a cumulatively greater area of
the seafloor off Humboldt Bay having non-toxic dredged material placed on it. For the past 25
years, benthic disturbance from sediment disposal has been limited to less than the one square
nautical mile defined by the existing disposal site boundary. In the future an area of up to 4 square
nautical miles (under Alternative 1) would be subject to disturbance from disposed sediment.
However, as noted elsewhere in this EA, effects from past disposal at HOODS have been negligible
and limited to physical impacts (mounding). It is expected that future impacts would continue to
be negligible under either Alternative 1 or 2.
The only other discharge in the vicinity of HOODS is from DG Fairhaven Power LLC's Fairhaven
Power Facility on the Samoa Peninsula. Fairhaven Power is permitted to discharge a maximum of
0.35 million gallons per day of powerplant-related process water, cooling tower water, and other
wastewater under terms of their current National Pollutant Discharge Elimination System
(NPDES) permit No. CA0024571, issued by the State of California's North Coast Water Board. The
company discharges through an existing outfall into ocean waters adjacent to the Samoa Peninsula
(Figure 19). The NPDES permit prohibits discharging wastewater in violation of effluent
standards or prohibitions established under Section 307(a) of the Clean Water Act, and it also
prohibits discharging sewage sludge. The 800-foot diffuser section at the end of the 48-inch
diameter steep pipe is located approximately 1.3 nautical miles (2.5 kilometers) offshore in
approximately 80 feet (25 m) water depth. It is approximately 1.6 nmi (3 kilometers) east
(inshore) of the nearest HOODS boundary. Prevailing nearshore currents would direct discharge
plumes from this outfall up or down the coast, depending of the seasonal current regime, not
offshore towards HOODS. EPA believes that there will be no adverse cumulative or synergistic
impacts between the use of HOODS (under either Alternative 1 or 2) and discharges from the
outfall described.
If a NSPS is established in the future, the area of cumulative disturbance within the expanded
HOODS boundary would be substantially less but the total area of temporary disturbance from
sand placement could increase. Also, the existing outfall pipe extending through (and past) the
site (Figure 19) could be subject to sand placement over the top of it. It is expected that thin layer
sand placement over and around this existing steel outfall will not affect either its ongoing
operation, or its potential future use(s). The diffuser structure is offshore of the NSPS in deeper
water and would not receive any direct placement of sand. The potential NSPS is discussed in
detail in Chapter 5.
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Potential
NSPS
Outfall
Diffuser
Existing
Outfall
Figure 19. Location of existing outfall relative to the potential Nearshore Sand Placement Site (NSPS).
Activities likely to occur within the foreseeable future
In the foreseeable future, possible activities that could be affected by expansion of HOODS include
offshore wind energy development and placement of new communications cables. The US Bureau
of Ocean Energy Management (BOEM) is considering possible wind energy lease sales several
miles offshore of HOODS. The lease area itself would not be in any conflict with expansion of
HOO DS as proposed; but if wind energy production does occur in the future any energy
transmission equipment would have to come ashore via a route that does not pass through HOODS
or its immediate vicinity. The same is true for any future communications cables, such as fiber-
optic cables.
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Unburied or thinly covered cables or other equipment on the seafloor near HOODS would be
incompatible uses, because:
1. Disposal operations could directly damage the cables or equipment when sand loads of
5,000 cy or more each are discharged.
2. EPA's ability to monitor and manage ocean disposal sites requires periodic collection of
sediment samples. Samplers can penetrate up to 2 feet into the sediment, depending on the
equipment used. This necessary sediment sampling could also damage or destroy
unburied cables of equipment.
During site monitoring, sediment samples are taken both within the disposal site itself as well as
for some distance outside the disposal site. Unburied cables or equipment would be at similar risk
in the potential NSPS discussed in Chapter 5. Thus, while expansion of HOODS, and possible future
establishment of the NSPS, would not preclude future offshore activities (such as wind power), it
would require any such projects to route any equipment (such as cables) around the immediate
vicinity of HOODS (and the potential NSPS if designated).
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5 DESCRIPTION OF THE POTENTIAL NEARSHORE SAND PLACEMENT SITE (NSPS)
Placing clean sand in the nearshore along the open California coast can help mitigate the effects of
coastal erosion and sea level rise. If such placement can be accomplished without significant
adverse impacts on resident species and human uses, it is considered beneficial use and is
regulated under the Clean Water Act (CWA) as "fill" as opposed to being regulated under the
MPRSA as ocean disposal of dredged material. Sand placement for beach nourishment or littoral-
zone support already occurs at a variety of locations in California and nationwide. Offshore of
Eureka, California there is the potential for economically viable use of sand dredged from the
Humboldt Bay Bar and Entrance Channel, if a suitable nearshore placement site can be identified.
The USACE identified a potentially appropriate nearshore sand-placement site in its "Five-Year
Programmatic Environmental Assessment, 404(b)(1) Analysis, and FONSI, Humboldt Harbor and Bay
Operations and Maintenance Dredging (FY2012 - FY2016)" (USACE 2012). The USACE did not
pursue designating a nearshore site at that time. The current EA, however, draws from and adds to
the 2012 USACE EA and discusses a potential nearshore site (Figure 20) as an alternative that
could be used in conjunction with disposal at HOODS to help minimize impacts and maximize the
overall benefits of managing Humboldt Bay area dredged sediments. This EA provides
documentation pursuant to NEPA and other applicable Acts that USACE may use as a basis for
proposing to conduct future demonstration nearshore sand-placement operations. Any proposal
to formally establish a nearshore site would be a separate EPA-USACE action pursuant to the CWA
Section 404(b)(1) Guidelines (40 CFR Part 230.80), informed by monitoring results associated
with such a demonstration project.
5.1 Need for a NSPS
As part of the designation of the Humboldt Open Ocean Disposal Site (HOODS), USACE established
the Humboldt Shoreline Monitoring Program (HSMP). The HSMP was established because the
California Coastal Commission (CCC) expressed concerns that the disposal of large volumes of
sand in the relatively deep water at HOODS (130 to 160 feet) could have significant adverse
impacts to nearby beaches (Figure 21). The primary concern was that sand, which would typically
supply local beaches, was going to effectively be removed from the littoral cell by being placed in
water deeper than the limiting depth of sediment movement. The HSMP was therefore developed
to: (1) monitor the surrounding shoreline for excessive shoreline retreat, (2) determine the cause
of any excessive shoreline retreat that is observed, and (3) recommend corrective action should
sediment disposal at HOODS be the cause.
The criterion for "excessive shoreline retreat" was established in an agreement between USACE
and the CCC (USACE, 1995), based on historical shoreline change rates derived from an analysis of
aerial photographs (Moffatt & Nichol Engineers, 1991). The initial analysis found that rates of
shoreline change had varied substantially for different periods at several locations. The analysis
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/////// / ,
Federal Channels
Bar & Entrance 1333
f
North Bay
Samoa
Eureka
Fields Landing
Samoa
SMCA
/ {Proposed)
HOODS r
.Expansion
(Proposed)
'¦HOODS
.(1990-Presentf'
Miles
1:150,000
Depths in Feet
ARCATA
EUREKA
Figure 20. Location of a potential Nearshore Sand Placement Site (NSPS) for demonstrating beneficial
use of clean dredged sand, in relation to the Humboldt Bay federal navigation channels,
HOODS, and the Samoa SMCA.
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Figure 21. Looking northeast toward the Humboldt Entrance Channel and Jetties. Note the spits with
beaches and extensive dune systems to the north and south of the Entrance Channel
(photograph by Gary Todoroff).
estimated "natural" shoreline change rates based on the 1948 to 1974 period, the 1974 to 1990
period, and the 1948 to 1990 period. In the absence of specific guidance, USAGE initially defaulted
to the more recent shoreline change rate (1974 to 1990) as the basis for comparison.
Using the 1974 to 1990 period as the baseline, USACE concluded that the excessive shoreline
retreat criterion had not been exceeded. However, USACE and the CCC are reconsidering whether
the 1948 to 1974 period may be more representative of natural shoreline retreat at this location,
based on evidence that jetty repairs in the 1970s may have caused an anomalous period of
shoreline adjustment. When the 1948 to 1974 period is used as the baseline for comparison, it is
possible that the excessive shoreline retreat criterion may have been exceeded at times for several
of the reference stations along the north spit.
Independent of any final determinations from USACE and the CCC on this issue, it is clear that
there is often net erosion to the north of the Humboldt Bay entrance channel, and that placement
of dredged sand back into the littoral zone in this area could help address this erosion.
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5.2 Minimum and Maximum Depths for a Potential NSPS
Nearshore placement of sand for littoral system support is generally more effective the shallower
it can be placed. Relatively shallow initial placement allows relatively smaller waves to transport
and spread sand grains within the littoral cell. Even if placed sand grains do not end up being
transported to the beach (i.e., at intertidal elevations or higher), the additional sand can help
mitigate coastal erosion by broadening the subtidal zone and causing waves to break farther
offshore. To successfully reintroduce sand into the littoral zone7 that supports the shoreline and
beach, however, sand must be placed in water shallower than the "depth of closure" (DOC) for the
area. Depth of closure is the depth beyond which wave energy at a given location is unable to
transport sediment particles between the nearshore and the offshore.
Recent analyses suggesting that DOC is generally -40 to -80 feet annually under typical wave
conditions near the Humboldt Bay entrance (Brutsche et al., 2016). As a result, sand placed at
HOODS (depths of-130 to -180 feet) would not be subject to onshore transport to beaches.
The USACE's online Sediment Mobility Tool8 estimates depth-of-closure based on site-specific
parameters including wave characteristics from nearby wave-monitoring buoys. The "Hallermeier
Inner (Simplified)" theoretical relationship was used to estimate the depth of closure in the
nearshore zone off Humboldt Bay. Applying parameters appropriate to the area (Table 8), the
Sediment Mobility Tool estimates that the depth of closure along the Samoa spit for sand with an
average diameter of 0.2 mm (similar to the material dredged from the bar and entrance channel) is
about -63 ft MLLW. Consequently, a nearshore beneficial-use site should be in water depths no
greater than approximately 70 feet.
However, to be practicable for USACE to use with its currently available equipment, placement
must be in water deep enough for USACE's hopper dredges to operate safely. The USACE hopper
dredge Essayons is the vessel most often used for dredging sand from the Humboldt Bay Bar and
Entrance Channel. Because the Essayons draws about 35 ft fully loaded, -35 to -40 ft MLLW is
considered the minimum practicable depth for a NSPS.
Based on -40 ft as the minimum depth for safe operation, and -70 ft as the maximum depth above
which sand is likely to be transportable within the littoral zone, any NSPS in the area north of the
Humboldt Bay entrance channel should span the -40 to-70 ft depth range. Sand placed within this
depth range should not result in permanent mounding, as has occurred at HOODS, because
seasonal wave and current action would be able to move the sand within the littoral system.
7 The littoral zone (or shoreface) is situated seaward of the low water line. This zone extends seaward to some
distance beyond the breaker zone. In this zone, dynamic littoral processes take place, related mainly to longshore
sediment transport and cross-shore sediment transport.
8 http://navigation.usace.armv.mil/SEM/SedimentMobilitv
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Table 8. Sediment Mobility Tool inputs and results for the nearshore area off Humboldt Bay.
Model Input Parameters
Shoreline Angle
31°
Placement Site Latitude
40.85° N
Placement Site Longitude
-124.21° W
Wave Monitoring (WIS) Station
83046
Years of WIS Data
1980 - 2016
Mean Grain Size (d50)
0.2 mm
Average Placement Depth
45.00 ft
Mean Annual Significant Wave Height
8.5 ft
Average Period of Significant Wave
11.7 sec
Std Dev of Significant Wave Height
4.2 ft
Height of Largest 10% of Waves
14.2 ft
Greatest (0.137%) Wave Height
26.5 ft
Period of Greatest Wave
17.2 sec
Estimated Depth of Closure
Hallermeier Inner Simplified 63.39 ft
An effective potential NSPS should be located to enhance the prospects for incident waves to
transport sand shoreward into the shallower part of the littoral zone where it could act as a source
of beach sand or, at the least, could act as a sacrificial supplement to existing littoral sand that
supports the beach. Conceptually, sand placed at the NSPS during the spring and early summer, a
time of smaller, accretionary waves, would move shoreward and help provide a buffer to coastal
erosion the following winter, a time of larger, erosive waves.
The USACE's 2012 dredging EA identified a "Humboldt Bay Demonstration Site" (HBDS) north of
the entrance channel, where net erosion is occurring, but where movement of sand back into the
navigation channel was not expected. The HBDS was somewhat larger than the NSPS currently
proposed. At the time, USACE identified an overall area approximately 4.8 nmi (9 km) long by 1.3
nmi (2.1 km) wide (Figure 23).
Based on the information presented in this EA, including recognition of the relatively new Samoa
State Marine Conservation Area to the north, the EPA and USACE reduced the overall area of the
potential NSPS to approximately 3 nmi (5.5 km) by 0.6 nmi (1.1 km) (Figure 24).
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1.29 mi
0.64 mi
300' (0.0€mi) Along-shore X1700' (0.32 mi)
Cross-shore - 96 Cells
m
-------
Samoa SMCA
Figure 24. Location of the potential Nearshore Sand Placement Site (NSPS) in relation to the Samoa
SMCA, HOODS, and the Fairhaven Power Plant outfall. The red arc is set at the distance (3.7
nmi) from the north jetty to the HOODS center point (centroid), showing that transport
distance to much of the NSPS is shorter than to HOODS.
Table 9. Corner and centroid coordinates for the potential NSPS (NAD 83).
Corner
Latitude
Longitude
Centroid Lat.
Centroid Long.
Southeast
40° 47'38.38s
N
124° 13' 28.29"
W
Southwest
40° 47' 55.50"
N
124° 14' 09.91"
W
40°49' 6.26"N
124° 12' 51.13"W
Northwest
40° 50' 33 07"
N
124° 12' 20 05"
W
Northeast 40° 50' 16.21" N 124° 11' 36.67" W
In addition, offshore transport distance to the southern half of the NSPS would be only 1.6-3 nmi:
closer than areas that will still be available for disposal at HOODS after it is expanded (most of the
cells in the original HOODS will be permanently closed when the site is expanded, so transport
distance to the new disposal cells will be slightly greater than in the past). Shorter average
transport distances to the placement site can help offset increased fuel costs (and any increased
air emissions) associated with the extra time needed for each nearshore thin-layer placement
event (which can take 10-30 minutes) compared to disposal events at HOODS (which typically take
2-5 minutes).
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The water depth at the potential NSPS ranges from about 30-80 ft, encompassing the preferred
sand placement depth range of 40-70 feet discussed above while providing for some operational
and navigation flexibility, as well as a buffer zone if needed. The ocean bottom at and near the
NSPS is completely covered by sand and is essentially featureless with no hard-bottom outcrops
(similar to the greater HOODS expansion study area).
5.3 "Thin-Layer" Sand Placement Operations in the Potential NSPS
On average, the Essayons holds a dredge-material volume of approximately 5,200 cy in one large
compartment (120 ft long and 48-ft wide) in the vessel hull. Dredged material exits the vessel from
12 independently opening doors (each one is 10-ft long by 8.7-ft wide) located on the ship's
bottom. The doors are positioned in two rows of six with one row along the starboard side and the
other row along the port side of the vessel. The doors can open simultaneously or in pairs. For thin
layer placement in shallow nearshore waters, the doors are opened only partially, while the vessel
moves forward slowly (Figure 25).
Figure 25. Aerial view of the Essayons during nearshore thin-layer sand placement operations near the
mouth of the Columbia River. The disposal vessel moves forward slowly with hull doors only
partially opened, so that sand is spread thinly in long, narrow tracks. The ship's propellers
help to further disburse the sand.
As the sand falls through the water column, it spreads out (Figure 26), creating a narrow mound
whose height can be regulated by how fast the Essayons moves during placement. The total
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duration for thin-layer placement of each full load is approximately 10 to 30 minutes. For a
dredged-sand volume of 1 million cy, the Essayons will make approximately 200 trips to the NSPS
over the course of 3-5 weeks, releasing the sand in an overlapping pattern to create a layer only a
few centimeters thick each time. This beneficial-use technique has been successful at the Mouth of
the Columbia River where the USACE Portland District has a nearshore, beneficial-use site in a
depth of about 35-60 feet, outside of the south jetty (see Section 4.1.3 above).
-10
0
10
CL
20
30
40
50 —
-150
-100
-50 0 50
Distance from Barge (ft)
100
150
Figure 26. Trajectory of the dredged sand during placement. The dashed line represents the collapse
zone, or where the material begins to interact with the bed.
5.4 Recommended Monitoring of Demonstration Sand Placement
Only clean sand from the Bar and Entrance and interior channels of Humboldt Bay would be
approved for placement at the NSPS. Silty dredged material from interior channels and other
facilities would continue to be placed at HOODS. In addition, whether during a demonstration
project or in the future if the NSPS is ultimately designated for ongoing use, the captain of the
dredge vessel will only place material in the NSPS if it is safe to do so based on sea conditions and
other navigational or operational considerations. If on a load-by-load basis, the captain determines
that the NSPS is not safe to operate in, that load may be placed at HOODS instead. Both HOODS and
the NSPS are expected to have adequate placement capacity for dredged material, singly or in
combination with each other, for many years.
A monitored demonstration project for sand placement at the NSPS should be conducted in such a
manner as to provide performance information about the site itself, as well as to help generate
sufficient environmental information for its possible designation as a permanent beneficial-use
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site in the future. Specifically, monitoring should include pre-placement (baseline) environmental
surveys (including for fish and macroinvertebrates) in addition to monitoring various operational
and physical aspects of initial sand placement and the effects of subsequent littoral processes on
the placed sand as described below.
To better understand the littoral processes in the system and to track the evolution of the material
placed in the nearshore, a monitoring program should include bathymetric and topographic
surveys, grain-size analyses, and instrument deployments. Additional techniques could be
included if warranted by initial monitoring results. The recommended measures summarized
below are modeled after the established, successful monitoring of similar nearshore placement
that was implemented at the Mouth of the Columbia River (see Section 4.1.3 above).
Demonstration nearshore sand placements and associated monitoring efforts would depend on
annual funding levels.
5.4.1 Tracking of Sand Placement Events
Ocean disposal at HOODS requires satellite tracking of disposal vessel locations, coupled with
collection of data from other sensors that indicate precisely when and where material is being
discharged. Figure 8 above shows how individual placement events can be mapped and indicates
that placement locations can be precisely controlled. Similar tracking should be required of any
vessels placing sand in the NSPS, whether during a demonstration project or during routine
placements if the site is ultimately established as a permanent use site.
In addition, similar to monitoring conducted by NOAA at the Mouth of the Columbia River (see
Section 4.1.3) video monitoring on the seafloor should be performed in conjunction with enough
demonstration nearshore placements to illustrate the extent and duration of plumes, and any
effects on megafauna (such as displacement).
5.4.2 Bathymetric and Topographic Surveys
Pre- and post-placement, high-resolution multi-beam surveys should be used to evaluate the
bathymetric changes and coverage area. Additional multi-beam surveys should be conducted bi-
annually to assess temporal changes to the placement mound and placement footprint.
Topographic and jet-ski bathymetric surveys should be conducted quarterly to measure the
change in the nearshore profile in areas too shallow to utilize multi-beam survey equipment.
5.4.3 Grain-Size Assessments
In the area of the NSPS, the bottom is covered by well-sorted, medium-to-fine sand that contains
relatively little or no silt or clay (Evans, 1994). Grain-size analyses of the dredged material show
that the most similar sediment would come from the Bar and Entrance Channel and the North Bay
Channels, which typically comprise greater than 90 percent fine sand with a median particle size
of approximately 0.2 mm. Dredged material from the Samoa or Fields Landing Channels is slightly
less sandy (80-90%) but could also be beneficially used in the NSPS if dredged using vessels like
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the Essayons that have the capability of safely maneuvering in the nearshore environment adjacent
to Humboldt Bay But for demonstration project purposes, it is presumed that only material from
the Bar and Entrance Channel and the lower section of the North Bay Channel (the areas typically
dredged every year) will be initially placed at the NSPS.
Benthic sediment grain size samples should be taken along transects perpendicular to the
shoreline within and in-shore of the NSPS, before (baseline) and after a demonstration placement
project, as an adjunct to the bathymetric and topographic surveys noted above.
5.4.4 Instrument Deployments
Acoustic Doppler Current Profilers (ADCP) and Optical Backscatter Sensors (OBS) should be
deployed at various water depths in the study area. The ADCP measures waves, vertical structure
of currents, backscatter, and water levels in a specified time interval. The OBS measures sediment
concentration that later would be correlated to ADCP data to estimate sediment flux in the water
column.
5.4.5 Demonstration Project Monitoring Results
Results from the demonstration project monitoring outlined above should be compiled by USACE
and made available to the public. The report(s) should address whether there were any adverse
environmentally impacts from the nearshore sand placement operations, and if not, whether the
NSPS would be feasible for USACE to continue to use in the future. If results are positive, EPA and
USACE could propose to establish the NSPS for ongoing use under the Clean Water Act 404(b)(1)
Guidelines (40 CFR Part 230.80).
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6 OCEAN DUMPING SITE SELECTION CRITERIA
6.1 Overview
The determination to designate (or in this case expand) an ocean disposal site for dredged
material is based on consideration of four general criteria and eleven specific factors listed at 40
CFR 228.5 and 228.6, respectively. These criteria and factors (which overlap to a degree) are listed
below and evaluated relative to each action alternative in the sections 6.2 and 6.3 below.
6.1.1 Four General Criteria for Selection of Ocean Disposal Sites
a) The dumping of material into the ocean will be permitted only at sites or in areas
selected to minimize the interference of disposal activities with other activities in the
marine environment, particularly avoiding areas of existing fisheries or shell fisheries,
and regions of heavy commercial or recreational navigation.
b) Locations and boundaries of disposal sites will be chosen so that temporary perturbations
in water quality or other environmental conditions during initial mixing caused by
disposal operations anywhere within the site can be expected to be reduced to normal
ambient seawater levels or to undetectable contaminant concentrations or effects before
reaching any beach, shoreline, marine sanctuary, or known geographically limited fishery
or shell fishery.
c) [Effective January 9, 2009, 40 CFR Part 288.5 was amended by removing and reserving
paragraph (c) which referred to "Interim" ocean disposal sites.]
d) The sizes of ocean disposal sites will be limited in order to localize, for identification and
control, any immediate adverse impacts and to permit the implementation of effective
monitoring and surveillance programs to prevent adverse, long-range impacts. The size,
configuration, and location of any disposal site will be determined as a part of the disposal
site evaluation or designation study.
e) EPA will, whenever feasible, designate ocean dumping sites beyond the edge of the
continental shelf and other such sites that have been historically used.
6.1.2 Eleven Specific Factors for Selection of Ocean Disposal Sites
a) Geographical position, depth of water, bottom topography, and distance from coast.
b) Location in relation to breeding, spawning, nursery, feeding or passage areas of living
resources in adult or juvenile phases.
c) Location in relation to beaches or other amenity areas.
d) Types and quantities of waste proposed to be disposed and proposed methods of
release, including methods of packaging the waste, if any.
e) Feasibility of surveillance and monitoring.
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f) Dispersal, horizontal transport, and vertical mixing characteristics of the area,
including prevailing current velocity, if any.
g) Existence and effects of present or previous discharges and dumping in the area (including
cumulative effe cts).
h) Interference with shipping, fishing, recreation, mineral extraction, desalination, shellfish
culture, areas of special scientific importance and other legitimate uses of the ocean.
i) Existing water quality and ecology of the site, as determined by available data or by trend
assessment or baseline surveys.
j) Potential for the development or recruitment of nuisance species within the disposal site.
k) Existence at or in close proximity to the site of any significant natural or cultural
features of historical importance.
6.2 Evaluation of the Four General Criteria
As described in the 1995 EIS, HOODS was specifically selected to comply as much as feasible with
the general site selection criteria. First, HOODS is not a significant fishery area, is not a major
navigation area and otherwise has no geographically limited resource values that are not similarly
abundant in other parts of this coastal region. Second, dredged material disposed of at the site
does not to reach any significant area such as a marine sanctuary, beach, or other important
natural resource area. Third, the site was limited size and allows for effective monitoring. Fourth,
although the site is not located beyond the continental shelf, it is located in an area historically
used for dumping and its use has not resulted in any significant adverse environmental impacts.
Extensive site monitoring since designation has confirmed the EIS evaluation. The following
sections update the original EIS evaluation with respect to the alternatives for expansion of the
original site boundaries.
6.2.1 Minimize Interference with Other Activities
The original (1995) EIS evaluated the potential for an ocean disposal site offshore of Humboldt
Bay to interfere with other activities and uses of the ocean. It concluded that there would be no
significant conflicts with other activities including but not limited to fishing, recreational boating,
commercial navigation, etc. Even though several such activities may spatially overlap with the site,
the disposal of dredged material within either of the proposed HOODS expansion alternatives
would not interfere with the activities at a level that would result in significant effects to the
activity. For example, baseline studies determined that while smelt and several flatfish species, as
well as shrimp and dungeness crab, were abundant in shallower waters (<40 m deep), they were
nearly absent in the deeper water where HOODS is situated. So the potential for direct conflicts
with fishing activities focused on those species would be negligible. Similarly, fishing for pelagic
species such as salmon certainly occurs across the region (including within the existing HOODS as
well as either expansion alternative's boundaries). However, commercial and recreational fishing
are not precluded within the disposal site boundaries. And since the vast majority of disposal
occurs for a finite number of days per year (USACE dredging averages 3-5 weeks annually), any
interaction between dredge vessels and vessels engaged in pelagic fishing at and near HOODS
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should be limited. Finally, expansion of HOODS will not in itself result in an increased number of
disposal site trips or an increased volume of sediment being disposed there. The number of
disposal trips and the volume of sediment disposed is directly related to USACE dredging budgets
that have not been constrained (to date) by the size or capacity of HOODS. So the potential that
expansion of HOODS would cause an increase in direct interference with other uses of the ocean,
compared to the status quo of the past 25 years of operations at the existing HOODS site, is
negligible.9
In terms of potential interference with other uses of the ocean, there are two main changes that
have occurred since HOODS was designated. First, the state of California has established the
Samoa State Marine Conservation Area (SMCA) to the north of HOODS. As shown on Figure 10
there is no overlap between the Samoa SMCA and any of the HOODS expansion alternatives. At its
closest point, the fully expanded (Alternative 1) site boundary for HOODS would be approximately
2.9 nmi (5.4 km) away from the southern boundary of the Samoa SMCA. The closest point to the
smaller Alternative 2 HOODS boundary would be nearly 3.5 nmi (6.4 km). Therefore conflicts
between disposal operations at HOODS and any uses or activities of the SMCA are not expected.
Second, on October 19, 2018 the US Bureau of Ocean Energy Management (BOEM) published in
the Federal Register a "Call for Information and Nominations" for commercial leasing of certain
outer continental shelf areas off the California coast for possible wind power development,
including an area several miles offshore of Humboldt Bay.10 The potential wind power lease
blocks off Humboldt Bay do not directly overlap with either of the HOODS expansion alternative or
with the NSPS. However, power transmission infrastructure routes from any future offshore wind
power installations in the area would likely need to come ashore somewhere in the vicinity of
Humboldt Bay. Power transmission infrastructure would be incompatible with an ocean dredged
material disposal site, because both disposal activity and periodic site monitoring work within and
around the disposal site could damage the line. EPA has advised BOEM to avoid the footprints of
the HOODS expansion alternatives and of the NSPS in their planning for energy transmission
corridor(s) from any potential offshore wind energy lease blocks that may be developed in the
future.
6.2.2 Minimize Changes to On-Site Water Quality and Other Conditions
The second of the four general criteria is that ambient water quality conditions outside the
disposal site must be within water quality criteria, and that contaminants should not reach
beaches, shoreline, sanctuaries, or geographically limited fisheries or shellfisheries. No significant
contaminant or suspended solids releases outside the HOODS boundaries are expected. This is
first addressed when initially sizing a new disposal site: modeling is done to predict whether any
water column plumes from discharges of suitable material will meet water quality criteria before
9 This is separate from potential interferences that may be associated with placement at the NSPS.
10 https://www.regulations.gov/docketBrowser?rpp=25&so=DESC&sb=commentDueDate&po=0&D=BOEM-2018-
0045
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dispersing outside the disposal site boundaries. Potential impacts are further avoided because
EPA and USACE require pre-disposal testing to confirm that sediments are not toxic or significantly
contaminated. Clean sand disposed at HOODS (which is the majority of what has traditionally
been placed there) settles quickly and thus has the least impact on water quality. Suitable fine-
grained material disposed at HOODS also settles quickly, with water column plumes dissipating to
background levels within the site boundaries. Expansion of HOODS would allow for even greater
mixing and dilution. Therefore, water quality effects from disposal within the boundaries of either
HOODS expansion alternative would not reach any beach, shoreline, known geographically limited
fishery or shellfisheiy, or the Samoa SMCA.
6.2.3 Limit the size of sites to facilitate management and monitoring
The location, size, and configuration of the proposed expanded HOODS boundaries provide long-
term capacity, while permitting effective site management and monitoring, and limiting
environmental impacts to the surrounding area to the greatest extent practicable. EPA considered
two alternatives for expanding HOODS: expansion by % nmi to the north and west; and expansion
by 1 nmi to the north and west (the proposed action). Under the proposed action, the effective
total capacity of the site would increase from the original 25 million cy to over 100 million cy (i.e.,
allowing for 75 million cy of additional disposal to occur), before mounding to -130 feet could
again occur across the entire site. If today's disposal practices were to continue unchanged (i.e., if
an average of 1 million cy of entrance channel sand per year were to continue being placed at
HOODS indefinitely), the site would reach capacity again in about 75 years. In contrast, the smaller
expansion alternative would provide effective capacity for about 30 years of disposal. However,
this smaller footprint would also limit on-site management options more than the proposed
action.
When determining the size of the proposed site, the ability to implement effective monitoring and
surveillance programs was considered to ensure that the environment of the site could be
protected, and that navigational safety would not be compromised by the mounding of dredged
material. EPA and USACE have demonstrated that the expanded HOODS area is feasible to manage
and monitor, as shown by successful surveys in 2008 and 2014. The SMMP describes the future
monitoring and management activities EPA and USACE will implement to confirm that disposal at
the site is not significantly affecting adjacent areas.
6.2.4 Locate sites off the continental shelf or where historical disposal
has occurred
The continental shelf break is approximately 10 mni offshore at Eureka, California. The Zone of
Siting Feasibility (ZSF) analysis prepared by USACE in support of the original (1995) HOODS
designation determined that an economically practicable ocean disposal site serving Humboldt
Harbor could not be located off the continental shelf, but rather would have to be within
approximately 4 nmi from the ends of the entrance channel jetties. The original HOODS boundary
was 2.5 to 3.7 nmi from the jetties. The expanded HOODS boundary will extend from 3 nmi to 5
nmi from the jetties. While portions of the expanded site will be slightly beyond the original ZSF
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threshold of 4 nmi, the expansion area remains as close to the entrance channel as practicable
while allowing capacity for future disposal needs without creating potentially unsafe mounding.
Also, the expansion of HOODS will occur immediately adjacent to where disposal of virtually
identical material has occurred for the past 25 years. This allows the least area to be disturbed
overall from ongoing and future disposal activity.
6.3Evaluation of the Eleven Specific Factors
6.3.1 Geographical Position, Depth of Water, Bottom Topography and
Distance from Coast
The proposed expanded HOODS boundary is on the continental shelf three to five nmi offshore of
Eureka, California in water depths of approximately 150 to 200 feet (45 to 61 m). The seafloor in
this area is comprised of a gently sloping, essentially featureless sedimentary plain that grades
evenly from fine sand in shallower depths to silts in deeper areas. Pre-designation baseline
surveys and subsequent monitoring confirm that the HOODS expansion is in a depositional area.
The site's depositional nature and natural topography helps minimize the extent of potential
impacts to the benthos and facilitates long-term containment of disposed material as well as site
monitoring activities.
6.3.2 Location in Relation to Breeding, Spawning, Nursery, Feeding, or
Passage Areas of Living Resources in Adult or Juvenile Phases
The HOODS area provides feeding and breeding areas for common resident benthic organisms,
fish, marine mammal, turtle, and seabird species. Floating larvae and eggs of various species are
expected to be found at and near the water surface at the site as well as throughout the area.
However, the proposed modified HOODS boundaries have been selected to avoid the presence of
any unique or limited breeding, spawning, nursery, feeding, or passage areas for adult or juvenile
phases of living resources and designation of the site is not expected to affect any geographically
limited (i.e., unique) resources or habitats. ESA and EFH consultations with USFWS and NMFS,
respectively, confirmed that ongoing disposal operations in an expanded HOODS will not have
significant impacts to sensitive living resources or their habitats.
6.3.3 Location in Relation to Beaches and Other Amenity Areas
The proposed expanded HOODS boundaries begin at approximately three nmi offshore and the
square site extends two nmi further offshore. It is therefore well removed from beaches or
amenity areas, and currents in the area are not expected to transport material disposed at HOODS
toward shore. No significant impacts to beaches or amenity areas associated with the existing
HOODS have been detected, and none are expected in the future.
6.3.4 Types and Quantities of Disposal, and Proposed Methods of Release
Only suitable dredged material that meets the Ocean Dumping Criteria in 40 CFR 220-228 and
receives a permit or is otherwise authorized for dumping by the USACE, and concurred with by
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EPA, will be disposed in the proposed expanded HOODS. Dredged materials dumped in this area
will be primarily sand with some fines, and most will originate from Humboldt Harbor. Average
yearly disposal of dredged material is expected to continue to be approximately 1,000,000 cubic
yards, primarily by government owned or contracted hopper dredges. However, if a Nearshore
Sand Placement Site (NSPS) is established nearby in the future, the volume of sand disposed at
HOODS could substantially decrease. None of the material is packaged in any manner.
6.3.5 Feasibility of Surveillance and Monitoring
EPA expects monitoring and surveillance at the proposed expanded HOODS to continue to be
feasible and readily performed from ocean or regional class research vessels. The area of the
proposed expanded HOODS has been successfully surveyed and sampled in 2008 and 2014. The
EPA and USACE will continue to periodically monitor the site for physical, biological and chemical
attributes, as described in the updated SMMP for the site (Appendix D).
6.3.6 Dispersal, Horizontal Transport and Vertical Mixing Characteristics
of the Area, including Prevailing Current Direction and Velocity
Ocean current monitoring in the vicinity of HOODS has confirmed both up- and down-coast
current directions (depending on the season), with near-surface current velocities on the order of
25 cm/sec (0.5 knot), and deeper-water current velocities being slower (20 cm/sec (0.4 knot) at
45 meters deep, and 15 cm/sec (0.3 knot) at the bottom. These conditions have not adversely
affected the ability to successfully and precisely dispose of approved sediments at HOODS in the
past and are not expected to affect disposal in the future.
6.3.7 Existence and Effects of Current and Previous Discharges and
Dumping in the Area (including Cumulative Effects)
Previous disposal of dredged material at the existing HOODS has resulted in mounding of sand and
burial of benthic organisms within the site but no discernable physical, chemical, or biological
effects offsite. Water quality effects from active disposal are temporary, spatially limited, and
return to background levels prior to the next disposal event. Short-term, long-term, and
cumulative effects of dredged material disposal in the proposed expanded HOODS would be
negligible, and similar to those for the existing HOODS.
The only other discharge in the vicinity of HOODS is from DG Fairhaven Power LLC's Fairhaven
Power Facility on the Samoa Peninsula. Fairhaven Power is permitted to discharge a maximum of
0.35 million gallons per day of powerplant-related process water, cooling tower water, and other
wastewater under terms of their current National Pollutant Discharge Elimination System
(NPDES) permit No. CA0024571, issued by the State of California's North Coast Water Board.
The company discharges through an existing outfall into ocean waters adjacent to the Samoa
Peninsula. The NPDES permit prohibits discharging wastewater in violation of effluent standards
or prohibitions established under Section 307(a) of the Clean Water Act, and it also prohibits
discharging sewage sludge. The outfall is located approximately 3.5 nautical miles (6.5 kilometers)
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east of the HOODS. Prevailing nearshore currents would direct discharge plumes from this outfall
up or down the coast, depending of the seasonal current regime, not offshore towards the HOODS.
EPA believes that there will be no adverse cumulative or synergistic impacts from the use of
HOODS and discharges from the outfall described.
6.3.8 Interference with Shipping, Fishing, Recreation ... and Other Uses of
the Ocean
Minor, short-term interferences with commercial and recreational boat traffic may occur within
Humboldt Harbor during dredging operations. However, interference as a result of the transport
and disposal of dredged material to HOODS would be even less because disposal vessels move
slowly, remain in established navigation channels, and their operations are announced via US
Coast Guard Notice to Mariners. There may be minor, temporary interferences with recreational
fishing in the offshore area during disposal operations, but HOODS is not closed to fishing or other
uses. HOODS has not been identified as an area of special scientific importance. There are no
aquaculture areas near the site. The likelihood of direct interference with such activities is
therefore negligible.
6.3.9 Existing Water Quality and Ecology of the Sites as Determined by
Available Data or Trend Assessment of Baseline Surveys
Water quality of the existing site is typical of the open northern California coast. Monitoring
conducted in the vicinity of the proposed modified HOODS and experience with past disposals in
the existing HOODS have not identified any adverse water quality impacts from ocean disposal of
dredged material. Water column plumes associated with disposal events rapidly return to
background, before subsequent events occur. The seafloor in this area is comprised of a gently
sloping, essentially featureless sedimentary plain that grades evenly from fine sand in shallower
depths to silts in deeper areas. The site supports benthic and epibenthic fauna characteristic of
the region, but there are no unique or limited habitats in the vicinity. No adverse impacts to
benthos outside the disposal site have been identified based on comprehensive monitoring.
6.3.10 Potential for Development or Recruitment of Nuisance Species
Nuisance species, considered as any undesirable organism not previously existing at a location,
have not been observed at, or in the vicinity of, the proposed modified ODMDS. Disposal of
dredged material, as well as monitoring, has been ongoing for the past 25 years. The dredged
material to be disposed at HOODS is expected to be from similar locations to those dredged
previously; therefore, it expected that any benthic organisms transported to the site would be
relatively similar in nature to any that may already present.
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6.3.11 Existence of Significant Natural or Cultural Features of Historical
Importance
EPA evaluated state records and coordinated with the State Lands Commission concerning historic
shipwrecks near HOODS. The nearest recorded shipwreck sites are close to shore and would not
be affected by ongoing disposal at HOODS. In addition, USACE conducted a survey for potential
shipwrecks near the existing HOODS in 1991 (prior to designation of HOODS). The USACE survey
identified three magnetic anomalies that could potentially be associated with unrecorded
shipwrecks. Each of these anomalies is off the existing HOODS disposal mound. EPA collected
high-resolution multibeam echo sounder data in 2014 at the locations of each magnetic anomaly,
and confirmed that no debris, structures, or other material extended above the sediment surface at
any of these locations. Since these anomalies do not extend above the surface now, and apparently
have not since at least 1991, their exact character remains unknown. Ongoing disposal operations
may effectively bury these features further but will not otherwise directly affect them.
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7 SUMMARY OF COORDINATION, AND COMPLIANCE WITH RELEVANT ACTS AND
ORDERS
7.1 Public Scoping and Outreach
EPA and USACE held a series of public scoping meetings in Eureka, California in early August 2019
(see Appendix B). These meetings included presentations on the need for and alternatives to the
proposed action. EPA and USACE also met separately with Eureka area staff from USFWS and
NMFS and gave an informational presentation to the California Coastal Commission (CCC) at their
hearing which was held in Eureka during the same week. No significant conflicts or controversies
were identified from the scoping process related to the expansion of HOODS. Materials presented
at the scoping meetings and to the CCC are available on EPA's HOODS web site:
https: //www.epa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-hoods-documents.
7.2 Tribal Consultation
EPA sent scoping information in February and April 2019 to 10 recognized Tribes potentially
affected by the proposed action (see Appendix B). This information included detailed project
descriptions and a discussion of alternatives. EPA and USACE also offered to meet separately with
these tribes when the public scoping meetings occurred in Eureka in August. No substantive
comments were received during the scoping phase. The ten tribes contacted include:
• Bear River Band, Rohnerville Rancheria
• Big Lagoon Rancheria
• Blue Lake Rancheria
• Cher-Ae Heights, Trinidad Rancheria
• Hoopa Valley Tribe
• Karuk Tribe
• Quartz Valley Reservation
• Resighini Rancheria
• Wiyot Tribe
• Yurok Tribe
In addition, government-to-government consultation offer letters along with links to the
supporting documents were sent to these same Tribes before EPA finalized this EA, the site
expansion rule or the SMMP. The Tribal Historic Preservation Offices of three of them (Wiyot
Tribe, Blue Lake Rancheria, and Bear River Band of the Rohnerville Rancheria) requested further
discussion concerning any potential for effects on cultural resources of concern. Based on those
discussions, the tribes determined that the offshore location of the HOODS expansion would not
affect onshore cultural resources.
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7.3 National Environmental Policy Act
The action is in compliance with NEPA. Environmental information has been compiled on the
project and alternatives, and this final EA has been prepared. The final rule, signed by the EPA
Regional Administrator, is the equivalent of a Finding of No Significant Impact and completes the
NEPA process.
7.4 Endangered Species Act and Marine Mammal Protection Act
The EPA initiated informal consultation under Section 7 of the Endangered Species Act of 1973, as
amended (16 United States Code (U.S.C.) Sections 1531 to 1544) with the U.S. Fish and Wildlife
Service and the National Marine Fisheries Service. Those consultations were completed in
December 2019 and January 2020, respectively. Appendix B includes the consultation materials
and determinations.
7.5 Magnuson-Stevens Fisheries Conservation and Management Act
EPA prepared an essential fish habitat (EFH) assessment pursuant to Section 305(b), 16 U.S.C.
1855(b)(2), of the Magnuson-Stevens Act, as amended, 16 U.S.C. 1801 to 1891d, and submitted
that assessment to the National Marine Fisheries Service. NMFS completed its review of the EFH
assessment and provided a single Conservation Recommendation in December 2019. The EFH
consultation materials are included in Appendix B.
7.6 Coastal Zone Management Act
The Coastal Zone Management Act (CZMA), as amended, 16 U.S.C. 1451 to 1465, requires federal
agencies to determine whether their actions will be consistent to the maximum extent practicable
with the enforceable policies of approved state programs. The California Coastal Commission
(CCC) developed the California Coastal Management Program (CCMP) pursuant to the
requirements of the CZMA. The enforceable policy components of the CCMP are contained in
Chapter 3 of the California Coastal Act of 1976, as amended (Division 20, Cal. Pub. Resources Code).
The EPA submitted a Consistency Determination (CD) package to the California Coastal
Commission (CCC) on July 20, 2020 following the close of the public comment period on the draft
EA and the proposed rule. The CD package specifically addresses how the proposed action to
expand HOODS is consistent to the maximum extent practicable with the California Coastal Act
Chapter 3 policies. On October 9, 2020, the CCC unanimously concurred with EPA's CD and did not
propose any additional measures beyond those already contained in the updated SMMP. The CCC
staff report is reproduced as Appendix F to this Final EA.
7.7 National Historic Preservation Act
The National Historic Preservation Act, as amended, 16 U.S.C. 470 to 470a-2, requires federal
agencies to take into account the effect of their actions on districts, sites, buildings, structures, or
objects, included in, or eligible for inclusion in the National Register. EPA determined in 1995. that
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no historic properties were affected, or would be affected, by the original designation of HOODS.
EPA has similarly determined that the proposed expansion of the existing HOODS boundaries will
have no effect on historic properties.
7.8 Clean Water Act
As the proposed expansion area is located outside of the jurisdictional limits of the Clean Water
Act, a Section 404(b) evaluation is not applicable to this project and was not prepared.
7.9 Farmland Protection Policy Act
This act is not applicable, because no prime or unique farmland would be impacted by
implementation of this project.
7.10 Wild and Scenic River Act
This act is not applicable, because no designated Wild and Scenic river reaches would be affected
by project related activities.
7.11 Estuary Protection Act
No designated estuary would be affected by project activities. This act is not applicable.
7.12 Submerged Lands Act
The project would not occur on submerged lands of the State of California, so this act is not
applicable.
7.13 Rivers and Harbors Act
The expansion, and continuing use, of HOODS would not obstruct navigable waters of the United
States. The proposed action is in full compliance with this act.
7.14 E.O. 11990, Protection of Wetlands
No wetlands would be affected by project activities. This project is in compliance with the goals of
this Executive Order.
7.15 E.O. 11988, Flood Plain Management
This project does not occur in any floodplain; therefore, this Executive Order does not apply to
project activities.
7.16 E.O. 12898, Environmental Justice
The proposed activity would not result in adverse human health or environmental effects or
exclude persons from participating in, deny persons the benefits of, or subject persons to
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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discrimination because of their race, color, or natural origin. Further, the proposed activity would
not impact "subsistence consumption of fish and wildlife." The proposed project complies with
this Executive Order.
7.17 E.O. 13089, Coral Reef Protection
There are no coral reefs in the project area. This order is not applicable to the propose action.
7.18 E.O. 13112, Invasive Species
The proposed action will not positively or negatively affect the status of invasive species.
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8 FINDINGS: SELECTION OF HOODS EXPANSION ALTERNATIVE 1
Based on the evaluation in this EA, including consultation with resource agencies and
consideration of the four general criteria and eleven specific factors for selecting ocean disposal
sites listed at 40 CFR 228.5 and 228.6, respectively, EPA has determined that the proposed
action - Alternative 1 (expansion of the existing HOODS boundaries by one nmi to the north and
one nmi to the west) - will have no significant adverse impacts and therefore no Environmental
Impact Statement (EIS) is necessary. Simultaneously with this EA, EPA issued for public
comment a proposed rule to implement Alternative 1. Comments on the draft EA and proposed
rule were received from four entities. The comments, and EPA's responses, are provided in
Appendix E to this EA.
Disposal of suitable material (i.e., dredged material evaluated and determined to be suitable under
the MPRSA and its implementing regulations) at the existing HOODS has resulted in no significant
adverse impacts over 25 years of continuous site use, and EPA's conclusion based on the analysis
in this final EA is that the expansion proposed under Alternative 1 would similarly have no
significant adverse impacts if managed under an updated SMMP that includes site use
requirements similar to those in the existing SMMP. The updated SMMP is included with this final
EA as Appendix D, and is also available separately for download and review at
https: //www.epa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-hoods-documents.
Simultaneously with this final EA, EPA is issuing a final rule to formally expand the HOODS
boundary as described in Alternative 1. The final rule, signed by the EPA Regional Administrator,
is the equivalent of a Finding of No Significant Impact and completes the NEPA process for this
action. The expanded HOODS boundaries, and the updated HOODS SMMP, will become effective 30
days after publication of the final rule in the federal register.
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9 REFERENCES
Brutsche, K., J. Rosati III, C. Pollock, and B. McFall, 2016. Calculating Depth of Closure Using WIS
Hindcast Data. US Army Engineer Research and Development Center publication
ERDC/CHL CHETN-VI-45, March 2016.
CDFW, 2012. Samoa State Marine Conservation Area web page. California Department of Fish and
Wildlife, http://californiampas.org/mpa-regions/north-coast-region/samoa-smca.
CSLC shipwreck database web site: https://www.slc.ca.gov/wp-
content/uploads/2018/12/ShipwreckInfo.pdf. California State Lands Commission.
Clarke, D., A. Martin, C. Dickerson, and D. Moore, 2005. Suspended Sediment Plumes Associated with
Mechanical Dredging at the Port of Oakland, California. Prepared for US Army Engineer
District San Francisco, CA.
eTrac, 2014. Humboldt Open Ocean Disposal Site Survey, August 2014. Multibeam Survey
and Sediment Classification. Prepared for Battelle, San Diego, CA. eTrac
Engineering, San Rafael, CA. (In: EPA, 2016. Humboldt Open Ocean Disposal Site
(HOODS) 2008 and 2014 Monitoring Synthesis Report, available at:
https://www.epa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-
hoods-documents.l
EPA, 1995. Final Environmental Impact Statement for Designation of an Ocean Dredged Material
Disposal Site off Humboldt Bay, California. Prepared by EPA Region 9. Available at:
https://www.epa.gov/sites/production/files/2Q19-
07/documents/feis humboldt open ocean disposal site-hoods-1995-07.pdf.
EPA 2006. Site Management and Monitoring Plan (SMMP)for Humboldt Bay (HOODS) Ocean
Dredged Material Disposal Site. Prepared by EPA Region 9, available at:
https://www.epa.gov/sites/production/files/2Q15-
10/documents/r9 hoods smmp 2006.pdf
EPA, 2016. Humboldt Open Ocean Disposal Site (HOODS) 2008 and 2014 Monitoring
Synthesis Report, available at: https://www.epa.gov/ocean-dumping/humboldt-
open-ocean-disposal-site-hoods-documents
EPA and USACE, 1991. Evaluation of Dredged Material Proposed for Ocean Disposal: Testing
Manual. EPA 503/8-91/001. Available at: https://www.epa.gov/ocean-
dumping/evaluation-dredged-material-proposed-ocean-disposal-green-book.
Evans, 1994. Humboldt Bay Numerical Hydrodynamics and Sedimentation Study. U.S. Army Corps of
Engineers, Waterways Experiment Station, Miscellaneous Paper HL-94-2. July, 1994.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Long, E.R., MacDonald, D.D., Smith, S.L., and Calder, F.D, 1995. Incidence of adverse biological effects
within ranges of chemical concentrations in marine and estuarine sediments. Environmental
Management 19,1, 81-97.
Moffatt & Nichol Engineers, 1991. Shoreline mapping Pacific Coast near entrance to Humboldt Bay,
California, Moffatt & Nichol Engineers, San Francisco, CA, 1 August 1991.
Mullins, T., and M. Jones, 2011. PG&E Wave Connect Project, Final Report: (k) Baseline Fisheries
Studies. Department of Fisheries Biology, Humboldt State University, Areata, CA.
NOAA 2014-2015. Videos of sand placement at Mouth of the Columbia River, available at:
https://www.youtube.com/user/FishOOHead. and
https: //www.voutub e.com/watch?v=c49s8 f5ivU.
PFMC, 2016a. Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational
Salmon Fisheries off the Coasts of Washington, Oregon, and California, as revised through
Amendment 19. Pacific Fishery Management Council, http://WWW.PCOUNCIL.ORG.
PFMC, 2016b. Pacific Coast Groundfish Fishery Management Plan for the California, Oregon and
Washington Groundfish Fishery. Pacific Fishery Management Council,
http://WWWPCOUNCIL.ORG.
PFMC, 2019. Coastal Pelagic Species Fishery Management Plan, as Amended through Amendment 17.
Pacific Fishery Management Council, http://WWW.PCOUNCIL.ORG.
USACE, 1995 Draft Humboldt dredging memorandum of agreement, US Army Engineer District San
Francisco, CA. 5 July 1995.
USACE, 2007. Humboldt Shoreline Monitoring Analysis of Data, 1992 through 2005. Submitted to
CESPN-PM-B on 30 January 2007.
USACE, 2012. Five-Year Programmatic Environmental Assessment, 404(b) (1) Analysis, and FONSI:
Humboldt Harbor and Bay Operations and Maintenance Dredging (FY2012-2016). Prepared
by US Army Engineer District San Francisco, CA. April 2012.
USACE, 2017a. Humboldt Harbor Federal Channels 2018 Maintenance Dredging - Tier I Evaluation.
Prepared by US Army Engineer District San Francisco, CA. December 2017
USACE, 2017b. Environmental Assessment and Draft FONSI, Humboldt Harbor and Bay Operations
and Maintenance Dredging, Humboldt Bay, Humboldt Harbor, CA (FY2017-2020). February
2017. Available at:
https://www.spn.usace.army.mil/LinkClick.aspx?fileticket=bKpZM7kwWIg%3d&portalid=
68
USACE hydrographic surveys web site: https://www.spn.usace.army.mil/Missions/Surveys-
Studies-Strategy/Hydro-Survey/Humboldt-Bav-Channel/
USACE Sediment Mobility Tool web site: http://navigation.usace.armv.mil/SEM/SedimentMobility
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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USACE and Weston, 2005. Characterization of Suspended Sediment Plumes Associated with
Knockdown Operations at Redwood City, California. Prepared for US Army Engineer District
San Francisco, CA.
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APPENDICES
Each of the four original appendices to the draft EA was available for download and review during
the public comment period via www.regulations.gov (Docket ID No. EPA-R09-OW-2020-0188).
They are also available from EPA at: https://www.epa.gov/ocean-dumping/humboldt-open-
ocean-disposal-site-hoods-documents. The fifth and sixth Appendices (E and F) are new and are
included only with this Final EA.
Appendix A - HOODS 2008 and 2014 Monitoring: Synthesis Report
Appendix B - Scoping Meetings, and Resource Agency and Tribal Consultations
Appendix C - Previous (2006) Site Management and Monitoring Plan
Appendix D -Updated (2021) Site Management and Monitoring Plan
Appendix E - Response to Comments on the Draft EA and Proposed Rule\
Appendix F - CA Coastal Commission Staff Report
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Appendix A
Humboldt Open Ocean Disposal Site (HOODS)
2008 and 2014 Monitoring
SYNTHESIS REPORT
HOOT?* 'f***
ss-& gw
. i-Air&AAS1
Prepared by
U.S. EPA Regions
Dredging St Sediment Management Team
San Francisco, CA
September 2016
This report is available for download at: https://www.epa.gov/ocean-dumping/humboldt-open-
ocean-disposal-site-hoods-documents.
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Appendix B
Public Scoping Meetings, and
Resource Agency and
Tribal Consultations
This Appendix includes information about public and agency scoping meetings
and agency and Tribal consultations regarding the proposed expansion of HOODS,
including:
• Scoping meeting comments
• Informal ESA consultation with USFWS
• Informal ESA, MMPA, and EFH consultations with NMFS
• Coordination with potentially affected tribes
This appendix is available for download at: https://www.epa.gov/ocean-dumping/humboldt-
open-ocean-disposal-site-hoods-documents.
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Appendix C
Previous (2006)
Site Management & Monitoring Plan for HOODS
EPA-designated ocean disposal sites require a Site Management and Monitoring Plan (SMMP).
Disposal at a designated site is subject to any project-specific restrictions from EPA or USACE,
as well as the overall conditions included in the SMMP. SMMPs also lay out the periodic
monitoring plan for each site, as well as potential management actions that will be considered
in the event that monitoring identifies any adverse impacts. SMMPs are expected to be
reconsidered at least every 10 years, based on the results of the periodic site monitoring.
The previous SMMP for HOODS may be downloaded via the link below. It was last officially
updated in 2006; however, it has effectively been updated each year since then, via conditions
imposed on individual ocean disposal projects to adaptively manage sand mounding at the site.
The 2006 SMMP for HOODS is available at:
https://www.epa.gov/sites/production/files/2015-10/documents/r9 hoods smmp 2006.pdf
A new (2021) SMMP, updated to reflect the expanded HOODS, is included as Appendix D to this
final EA and is also separately available for download at: https://www.epa.gov/ocean-
dumping/humboldt-open-ocean-disposal-site-hoods-documents.
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Appendix D
Updated (2021)
Site Management & Monitoring Plan for HOODS
EPA-designated ocean disposal sites require a Site Management and Monitoring Plan (SMMP).
Disposal at a designated site is subject to any project-specific restrictions from EPA or USACE,
as well as the overall conditions included in the SMMP. SMMPs also lay out the periodic
monitoring plan for each site, as well as potential management actions that will be considered
in the event that monitoring identifies any adverse impacts. SMMPs are expected to be
reconsidered at least every 10 years, based on the results of the periodic site monitoring. This
Appendix presents a new SMMP, updated to reflect Alternative 1 for expanding HOODS as
described in this final EA.
EPA, in coordination with USACE, finalized this updated SMMP after considering comments
received on the draft EA and proposed rule that were published simultaneously in the Federal
Register. (No comments specific to the SMMP were received.) This updated SMMP will take
effect when the HOODS expansion is effective, 30 days following publication of the HOODS final
rule in the Federal Register. However, even after it is finalized, the SMMP may be updated
further as needed at any time by EPA and USACE, following opportunity for additional public
comment.
This updated SMMP is also available separately for download at: https://www.epa.gov/ocean-
dumping/humboldt-open-ocean-disposal-site-hoods-documents.
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UPDATED SMMP
Site Management and Monitoring Plan for the Expanded
Humboldt Open Ocean Disposal Site (HOODS)
Effective January 1, 2021
Quadrant 4
Quaarant 2
Quadrant 1
(CLOSED)
NOT FOR NAVIGATION PURPOSES
Prepared by US EPA Region 9
in coordination with the
San Francisco District, USACE
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Site Management and Monitoring Plan for the Expanded
Humboldt Open Ocean Disposal Site (HOODS)
Effective January 1, 2021
I. INTRODUCTION
This updated Site Management and Monitoring Plan (SMMP) was developed jointly by Region 9 of the
US Environmental Protection Agency (EPA) and the San Francisco District of the US Army Corps of
Engineers (USACE). It describes proposed management and monitoring of the expanded HOODS
beginning in 2021. The SMMP is designed to ensure that disposal operations continue to comply with
established site use conditions, and to confirm that adverse environmental conditions do not occur either
within or outside the site boundary. It describes the kinds of periodic site monitoring surveys that EPA
and USACE will conduct as needed, as well as a range of potential management actions that EPA may
take depending on the results of the periodic monitoring.
The Marine Protection, Research and Sanctuaries Act (MPRSA) of 1972 (33 USC Section 1401 et seq.)
is the primary legislative authority regulating the disposal of dredged material into ocean waters. The
MPRSA prohibits disposal activities that would unreasonably degrade or endanger human health or the
marine environment. Under the act, the EPA and the USACE have joint authority for regulating ocean
disposal of dredged material and for managing ocean disposal sites. Management of an ocean disposal
site consists of: (a) regulating the quantities, times, rates, and methods of disposing dredged material;
(b) implementation of an effective monitoring program for the site; (c) considering changes to site use
practices or the designation itself if warranted based on the results from periodic site monitoring; and
(d) enforcement of permit conditions.
Section 506 of the Water Resources Development Act (WRDA) amended Section 102(c) of the
MPRSA to require, in part, that a site management plan be developed for each designated ocean
disposal site, before the final designation takes effect. Site management plans must include:
An assessment of baseline (pre-disposal) conditions at the site;
a program for monitoring the site;
special management practices necessary for protection of the site;
consideration of the quantity and contaminant levels of material to be disposed at the site;
consideration of the lifespan of the site and any management requirements after closure; and
a schedule for review and revision of the site management plan.
Ocean disposal sites are intended to be monitored at least every 10 years (subject to available funding),
and SMMPs are updated and revised based on the results of the site monitoring. The issues that Section
102(c) of the MPRSA requires be included in SMMPs mean that the document should be iterative and
adaptive over time, responsive to the results of monitoring and changing conditions. As such, SMMPs
are generally not themselves rules but do nonetheless identify conditions and practices that may be
incorporated as enforceable project-specific requirements via EPA concurrence letters (either for
USACE permits or for USACE authorizations of its Federal dredging projects involving the
transportation and disposal of dredged materials).
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In the case of the Humboldt Open Ocean Disposal Site (HOODS) (Figure 1), the original designation
action took effect on October 30, 1995, and an initial Site Management and Monitoring Plan (SMMP)
was put in place at the same time. Baseline conditions for the original site were assessed in the site
designation EIS (EPA 1995). Since its designation, HOODS has received an average of approximately
one million cubic yards (cy) of dredged material each year, almost all of it sand from dredging of the
Federal navigation channels in Humboldt Bay. Site monitoring during the first 10 years of site use
consisted of annual bathymetric surveys conducted by USAGE, Based on that monitoring, which
documented the growth of the sand mound inside the site boundaries, EPA took two key management
actions. First, EPA published an updated SMMP for HOODS in 2006, which included site use
conditions for all permitted users of HOODS, to more closely manage the mounding. EPA also initiated
plans to conduct more intensive site monitoring in 2008. That site monitoring confirmed that no
significant adverse environmental impacts were occurring at HOODS. But it also confirmed that
mounding was effectively filling the site such that expansion would be necessary within a few years in
order for HOODS to continue to provide capacity for ongoing ocean disposal. EPA therefore initiated
planning to conduct even more comprehensive monitoring, as well as additional baseline surveys
throughout a larger site expansion study area. These surveys were conducted in 2014. The results of
the 2008 and 2014 surveys of HOODS and the surrounding area are available at:
https://www.epa.gov/ocean-duniping/humboldt-open-ocean-disposal-site-hoods-documents.
Chart 18622
J Ejjnp
/Ms nato Sh 26
C-!2011
& Samoa#
aiftEXA
HOODS
ta
jqY'166'
N(5)Y20*
Prrv
Figure 1. HOODS from 1995 to 2020 as originally designated. Showing location in relation to Humboldt Bay
and the City of Eureka, CA.
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Since the 2014 surveys, EPA has effectively updated the 2006 SMMP annually by placing additional
project-specific conditions on each dredging project using the site. These conditions were designed to
manage ongoing mounding within the existing site boundary, while preparation of an Environmental
Assessment and a rulemaking to expand the site were under way. The annual site use condition updates
ensured that disposal only occurred on portions of the site that had not yet mounded to 130 feet deep
(relative to mean lower low water, mllw). The criterion that mounding at HOODS should not occur
much shallower than about 130 feet deep is based on the original (1995) site designation EIS. The EIS
estimated that at shallower depths the largest seasonal waves passing over the site could begin to
interact with the bottom substrate, and potentially start to re-focus or redirect them. A change in wave
behavior near the Humboldt Harbor entrance channel could in turn potentially affect navigation safety.
Expanding HOODS will allow EPA and USACE to continue managing the site so that mounding
shallower than 130 feet will not occur. EPA is therefore conducting a rulemaking to formally expand the
existing HOODS boundaries by 1 nautical mile (nmi) to the north, and 1 nmi to the west. The proposed
rulemaking was published in the Federal Register on May 29, 2020 for public comment, and the final
rule expanding boundaries would be effective by the end of the year. The Environmental Assessment
(EA) supporting the expansion rulemaking is available at: https://www.epa.gov/ocean-
dumping/humboldt-open-ocean-disposal-site-hoods-documents. It is expected that the expanded
HOODS will continue to receive an average of approximately one million cy of material each year,
dredged primarily from the navigation channels in Humboldt Bay and the surrounding area. Most of
this material will likely continue to be fine sand, while a small proportion may be silty material dredged
from marinas, commercial docks, and other maritime facilities. Only material meeting the suitability
requirements for ocean dumping will be disposed.
Relation to a potential future Nearshore Sand Placement Site (NSPS). This updated SMMP
presently does NOT address any activities in the potential NSPS described in the EA for expanding
HOODS. Similarly, it does not address activities related to any monitored demonstration sand
placement project that USACE may undertake. If the NSPS is formally established in the future
following such a demonstration project, this SMMP will be updated again to reflect how disposal at
HOODS (regulated under MPRSA) inter-relates with beneficial use placement of sand at the NSPS
(regulated under CWA). For example, it is expected that fine-grained dredged material (which is not
suitable for placement in the NSPS) would continue to be disposed at HOODS and be subject to the
HOODS SMMP. Disposal of at least some sand would also continue at HOODS, and be subject to the
HOODS SMMP, if/when weather or wave conditions are unsafe for placement at the NSPS, or when the
NSPS is otherwise unavailable for use.
II. DESCRIPTION OF ORIGINAL vs. EXPANDED HOODS
Original HOODS. The original HOODS was a square site, extending from 3-4 nmi offshore and
covering 1 square nmi (Figure 1). It was divided into quadrants and cells (Figure 2) to facilitate
management of individual disposal events so that mounding would not substantially exceed the target
depth of 130 feet mllw. The outermost cells constituted a no-disposal buffer zone, to help ensure that
most of the dredged material discharged would settle on the seafloor within the site boundaries.
Because the majority of sediment disposed at HOODS since 1995 has been sand that stays in place after
disposal in these water depths, this approach resulted in a symmetrical mound, with a surface elevation
averaging approximately 130 feet deep, covering all of the internal cells (Figure 3).
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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STATION CG55N
40 49 * 3.0" N
124 17*22" W
STATION C640N
40 48' 24 " N
124 16* 22** W
J\f
STATION CG55C
40 48'17~N
124 18' 13" W
1
3
h
• i •
\p f I
f"A
'
Buffer Zone-No
disposal (Tied)
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)
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#3
'
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^ 1/
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.
/ A
STATION CG40C
40 47'38"N
124 iz'n-w
Figure 2. Layout of HOODS as originally designated, showing division into quadrants and cells. Disposal
was allowed only in interior cells, while outer cells were a no-disposal buffer zone.
-
I
A1 B2 C3 D4 E5 F6
A2 B3 C4 D5 E6
A3 B4 C5 D6
A4 B5 C6 f
5, x A5 B6 y ,
"O \ 1 /
> I A6
Figure 3. Map of HOODS disposal cells overlain on bathymetry from August 2014.
Depths are in feet Ml.LAV. (Reproduced from eTrac, 2014.)
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As interior disposal cells reached (and in some cases slightly exceeded) the 130-foot depth target over
time, EPA closed those cells to further disposal and restricted ongoing disposal to fewer and fewer cells
By 2020, disposal was only allowed in the inner portions of the buffer zone cells on the north and west
sides of the site, along the slopes of the mound (Figure 4). This ensured that incremental growth of the
mound would only occur in the directions that EPA proposed expanding the site footprint. Buffer zone
cells on the south and east sides of the site remained off-limits for disposal because EPA did not
anticipate allowing disposal to the south (closer to the Humboldt Bay entrance channel) or to the east
(inside the 3-mile limit, which are also State waters).
Figure 4: Open disposal cells at HOODS for 2020 are outlined by the bright yellow box. Black grid depicts the
same disposal cells as shown on Figure 3. Here, disposal cell boundaries are overlain on the most
recent (2019) bathymetry with green and yellow shading being deeper areas, and orange and red
shading being shallower.
Expanded HOODS. The expanded HOODS overlaps with the original site (superseding the original
boundary), and extends an additional 1 nmi to the north and west (Figure 5). It covers 4 square nmi and
is in water depths ranging from approximately 150 to 210 feet. Table 1 provides the outer corner
coordinates of the expanded site. The effective total capacity of the site will increase from the original
25 million cy to over 100 million cy (i.e., allowing for 75 million cy of additional disposal to occur),
before mounding to -130 feet could again occur across the entire site. So, if today's disposal practices
were to continue unchanged (i.e., if on average 1 million cy of dredged sand per year were to continue
being placed at HOODS indefinitely), the site would reach capacity again in about 75 years. However,
the effective life of the expanded site could be much longer than 75 years if nearshore placement of sand
for beach or littoral system support were to begin at some point in the future (as discussed in the EA). In
that event, disposal of finer sediment would continue in the expanded HOODS footprint, but it could be
managed in such a way that little or no additional long-term mounding would occur at all.
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Expanded
HOODS
Boundary
Eureka
Potential
Nearshore Sand
Placement Site
<^Buoy 46244
HOODS Reference (H-14-45)
o
Original
HOODS
(1995-2020)
Figure 5. Expanded HOODS, beginning 2021. Showing location in relation to the original HOODS, the new
HOODS reference site, the Samoa State Marine Conservation Area, the potential future Nearshore
Sand Placement Site (NSPS), and the city of Eureka, California.
Table 1. Expanded HOODS corner coordinates and centroid (NAD 83).
Alternative 1 (Proposed): Expand by 1 nmi to North and West
Corner Latitude Longitude Centroid Lat Centroid Long.
North 40° 50' 18" N 124° 18' 01" W
40° 48'56" N 124° 17'32" W
East
: O
1 o
I
49' 16"
N
124°
^ I
U] I
1
<3)!
W
South
O
o
47' 33"
N
124°
17' 05"
W
West 40° 48' 34" N 124° 19' 18" W
The expanded HOODS is also divided into quadrants and cells (Figure 6). Each quadrant is 1 square
nmi (the size of the original HOODS) and each is divided into 36 square cells that are approximately
1,000 feet by 1,000 feet in size. The mound in the original HOODS occupies Quadrant 1 of the
expanded site and will remain closed to ongoing disposal. The outermost cells of the expanded site will
also continue to serve as a buffer zone closed to disposal. The 75 remaining cells in Quadrants 2, 3, and
4 are available to be specified in permits for disposal. However, initially only the 39 cells nearest the
mound will be used, with the other 36 reserved for possible future use if needed (Figure 7).
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NOT FOR NAVIGATION PURPOSES
Quadrant 3
Quadrant 4
Quadrant 2
Quadrant 1
(CLOSED)
Figure 6. Map showing the overall layout of quadrants and disposal cells in the expanded HOODS.
beginning in 2021. Quadrant 1 includes the original HOODS, which is closed to further disposal. The
outermost cells of the expanded site (red shading) comprise a buffer zone that is also closed to
disposal. Allowable disposal cells will be specified on a project-specific basis.
Quadrant 3
Quadrant 4
Quaarant 2
Quadrant 1
(CLOSED)
NOT FOR NAVIGATION PURPOSES
Figure 7. Map showing the layout of Reserved vs Available (yellow box) disposal cells m the expanded
HOODS, beginning in 2021. Disposals will occur over the slopes of the existing mound, slowly
growing it to the north and west overtime while leaving the remainder of the site undisturbed for as
long as possible. EPA will specify allowable disposal cells on a project-specific basis.
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For individual projects, a subset of disposal cells will be specified in each EPA ocean disposal
concurrence, to manage future mounding. In any year, ongoing disposal will be limited to occurring
over the northern and western slopes of the existing mound. As the mound slowly expands laterally in
these directions, specified allowable disposal cells will be shifted outward as well, so that the mound
does not increase in height (i.e., so that it does not become shallower than the minimum target depth of -
130 feet mllw). Furthermore, no disposal will be allowed in the buffer cells around the edges of the site,
or in the 36 interior cells marked as "Reserved" in Figure 7. Use of the "Reserved" cells will only be
considered in the future when the mound is again nearing capacity in the Available cells. At that time, a
revision to this SMMP will be issued with an opportunity for public comment.
III. MANAGEMENT PLAN
Ocean disposal site management consists of three main activities jointly undertaken by EPA Region 9
and the USACE' San Francisco District. These activities include:
Application of specific ocean dumping site use requirements as outlined in this SMMP and
implemented by any EPA conditions applied to individual permitted projects or to authorizations
for USACE project involving ocean dumping;
Periodic site monitoring; and
Consideration of permit compliance and site monitoring results to determine whether disposal
site use changes may be needed.
The overall goal for management of the expanded HOODS is to ensure that only physical effects occur
within the site boundaries, and that no adverse physical, chemical or biological effects occur outside the
site. The objectives for meeting this overall goal, including the manner in which disposal of dredged
material will be managed within the expanded site, are described in this Section III. Section IV
describes the periodic site monitoring program for HOODS, and Section V lists the potential
management actions EPA and USACE may take if needed based on site monitoring results.
Management Objectives for the Expanded HOODS
The following overall objectives apply to the expanded HOODS. Specific enforceable conditions for
achieving these goals are outlined below.
• No disposal may occur at HOODS unless USACE has issued a permit (or authorization for a
Federal project involving ocean dumping) pursuant to Section 103 of the MPRSA, the related
ocean dumping regulations published at 40 CFR Parts 220-228, and USACE permitting
regulations at 33 CFR Parts 320-330 and 335-338.
USACE may not issue a permit or other authorization for ocean disposal unless EPA has
concurred in writing that the sediment to be disposed is suitable for ocean disposal (is non-toxic
and otherwise meets the requirements described in 40 CFR Part 227 and the testing program
outlined in the joint EPA-USACE national Ocean Testing Manual, or OTM).
EPA and USACE will continue to review and approve in advance Sampling and Analysis Plans
(SAPs) for dredging projects to ensure suitability determinations are based on adequate,
representative sampling.
EPA encourages the beneficial use of dredged sediment whenever feasible. EPA will not concur
on ocean disposal, even for otherwise suitable material, if a "need for ocean disposal" has not
been demonstrated - i.e., if an alternative to ocean disposal is practicable.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Approved disposal actions at HOODS must occur only where and as specified in the site use
conditions described in this SMMP and specified by EPA in project-specific concurrence letters
on the MPRSA permit or authorization. USACE must include EPA's required conditions in the
MPRSA permit or authorization.
Disposal at HOODS will continue to be managed to avoid creation of a mound with a seafloor
shallower than approximately 130 feet mllw.
Automated GPS-based tracking and recording of transport to and disposal at HOODS will
continue to be required for each dump.
Periodic site monitoring at HOODS as outlined in Section IV will continue to occur.
Management options as described in Section V will be considered if any significant
environmental impacts are identified via periodic site monitoring.
This SMMP will be updated if a NSPS as described in the EA is formally established.
New Reference Site for the Expanded HOODS
Reference sediment test results are an important point of comparison for determining suitability of a
dredging project's sediments for disposal at the particular ocean disposal site. The OTM defines
Reference Sediment as follows:
A sediment, substantially free of contaminants, that is as similar as practicable to the grain size of
the dredged material and the sediment at the disposal site, and that reflects the conditions that would
exist in the vicinity of the disposal site had no dredged-material disposal ever taken place, but had
all other influences on sediment condition taken place. These conditions have to be met to the
maximum extent possible. If it is not possible to fully meet these conditions, tests should use
organisms that are not sensitive to the grain-size differences among the reference sediment, control
sediment, and dredged material. The reference sediment serves as a point of comparison to identify
potential effects of contaminants in the dredged material.
The original reference site for HOODS was to the north of the site, in water approximately 170 feet
deep, at 40 deg 50.021 min N and 124 deg 15.372 min W. This location met the OTM definition and
was used by EPA and USACE for project reviews from 1995 through 2014. However, the original
HOODS reference site was within the proposed footprint of the expanded HOODS. As such, disposal in
the future could take place at the site and it would no longer qualify as an appropriate reference for
HOODS.
EPA therefore identified a new location that will continue to meet the OTM definition of an appropriate
reference site, even after the HOODS boundary is expanded. The new site was identified in the 2014
monitoring survey as station H-14-45 (see the HOODS monitoring synthesis report at:
https://www.epa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-hoods-documents). This new
reference site, which EPA has required to be used since 2015, is offshore of the southwest corner of the
Samoa State Marine Conservation Area. It is in water approximately 180 feet deep (similar to HOODS)
but is farther to the north and outside of the direct influence of any future disposal activity in the
expanded HOODS. The coordinates for the new HOODS reference site are:
40 deg 52.450 min N and 124 deg 14.870 min W (NAD 83)
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Site Use Conditions for the Expanded HOODS
Enforceable conditions for dredged material disposal operations at the HOODS are included in USACE-
issued permits and authorizations for Federal projects, based on EPA's and USACE's identification of
necessary conditions under 103(a) or through EPA's concurrence under 103(c) of the MPRSA, and the
ocean dumping regulations at 40 CFR Parts 220-228. The following provisions of this SMMP are
intended to be applicable both to dredging projects permitted by US ACE, and to USACE-authorized
Federal dredging projects (whether using Government owned and operated dredging equipment such as
the hopper dredges Essayons and Yaquina, or using contracted equipment such as under USACE's West
Coast Hopper Contract).
These conditions and reporting requirements become enforceable when and as specified or confirmed by
EPA in its ocean disposal concurrence letters for individual projects and would be in addition to any
other conditions USACE may include in its MPRSA Section 103 permits or authorizations. In the event
of any conflict or inconsistency between the conditions in EPA's project-specific concurrence letter and
the most recent SMMP, the EPA concurrence establishes the enforceable obligations. EPA may
determine not to include one or more of the conditions identified below, or to require additional
conditions, on a project-specific basis. Otherwise, EPA intends to apply each of the following
conditions (along with any supplemental conditions included in EPA concurrence letters) for all projects
involving transportation and disposal of dredged material at HOODS. Violations of the MPRSA
(including conditions established in an MPRSA permit or Federal project authorization) by a permittee
or dredging contractor are subject to compliance action including possible assessment of substantial
administrative, civil, or criminal penalties.
Definitions:
A. "Permit" and "permittee" as used here mean USACE ocean dumping permits issued to others
under Section 103 of the MPRSA, and authorizations that USACE issues to itself or its
contractors for USACE dredging projects (see MPRSA section 103(e) and 40 CFR 220.2).
B. "Disposal vessel" is any barge, scow, or self-propelled vessel (such as a hopper dredge) that
carries dredged material during transit and from which the dredged material is discharged,
typically by opening doors in the bottom of the hull or by splitting the hull.
C. "Towing vessel" is any self-propelled tug or other marine vessel used to transport (tow or push)
the "disposal vessel" for any portion of the transit to HOODS.
D. "Transit" or "transport" to the disposal site begins as soon as dredged material loading into the
disposal vessel is completed and the disposal vessel begins moving to the disposal site (either
under its own power or with the aid of a towing vessel).
E. "Buffer cells" are the outermost cells of the overall disposal site, adjacent to the site boundaries.
NO DISPOSAL is allowed in the buffer cells unless specified by EPA on a project-by-project
basis.
F. "Closed cells" are specified cells in the interior of the overall disposal site that EPA has
identified as having mounded to a degree that DISPOSAL IS NO LONGER ALLOWED.
Closed cells at a minimum include the interior cells of the original HOODS.
G. "Allowable Disposal Cells" are specified cells in the interior of the overall disposal site within
which the disposal vessel must discharge all of the dredged material.
H. "Substantial leakage/spillage" or other loss is an apparent loss of draft of one foot or more
between the time that the disposal vessel begins transport to the HOODS and the time of actual
disposal.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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In addition to any project-specific conditions provided in EPA's concurrence for a project, the following
model conditions are expected to be included in US ACE ocean dumping permits, and authorizations for
Federal projects involving the transportation and disposal of dredged material at the HOODS.
1. All disposal operations at the HOODS shall be conducted in accordance with the version of the
Site Management and Monitoring Plan (SMMP) (available at: https://www.epa.gov/ocean-
dumping/humboldt-open-ocean-disposal-site-hoods-documents). that exists as of the date of
EPA's concurrence for a project.
2. Dredged material shall not leak or spill from disposal vessels during transit to the HOODS.
Transportation of dredged material to the HOODS shall only be allowed when weather and sea
state conditions will not interfere with safe transportation and will not create risk of spillage,
leak or other loss of dredged material in transit to the HOODS. No disposal vessel trips shall be
initiated when the National Weather Service has issued a gale warning for local waters during
the time period necessary to complete dumping operations, or when wave heights are 16 feet or
greater.
3. No more than one disposal vessel may be present within the HOODS at any time.
4. NO DISPOSAL cells: Disposal may not occur in buffer cells or closed cells, including interior
cells of the original HOODS or other cells in which mounding has resulted in a seafloor depth
of 130 feet or less, mllw. Closed cells will be identified in project-specific concurrence letters
from EPA or in updates to this SMMP as the case may be.
5. Allowable disposal cells: Disposal events shall occur only in designated cells, and where
depths exceed 130 feet MLLW. Specific allowable cells for individual projects will be
identified in EPA concurrence letters. In general EPA will specify allowable cells over the
western and northern slopes of the existing mound, to minimize the area of new disturbance of
seafloor habitat at any time. To manage mounding, dredged material from sequential trips shall
not be disposed in the same cell; rather, to the maximum extent practicable consistent with safe
vessel operation, disposal events shall progress to all specified allowable disposal cells before
returning to a previously used cell. (Note, this does not mean disposal must happen in order
from one cell to the next. Nor does it mean that single disposal events cannot cross a cell's
boundary and discharge material in multiple authorized cells.)
6. The disposal vessel must have an automated disposal tracking system, and the system must be
operational before any individual disposal trip to HOODS is initiated. Throughout transit to
the disposal site, during disposal, and for at least 10 minutes after disposal is complete, the
disposal tracking system must automatically indicate and record the position, speed and draft
of the disposal vessel. These data must be generated at a maximum 1-minute interval while en
route to the HOODS, and at a maximum 15-second interval while within 1/4 mile of and inside
the HOODS boundary. The tracking system must also indicate and record the time and
location of the beginning and end of each disposal event (e.g., opening and closing of scow
hull or hopper doors).
7. "E-mail alerts" regarding any degree of apparent dumping outside the HOODS boundary,
and/or regarding any apparent substantial leakage/spillage or other loss of material en route to
the HOODS must be sent within 24 hours of the permittee becoming aware of the apparent
issue, to staff of EPA Region 9, the San Francisco District USACE, and the California Coastal
Commission as specified in the EPA concurrence letter.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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8. In addition to any alerts pursuant to Condition 7 above, data recorded from the disposal
tracking system must be provided to EPA Region 9, the San Francisco District USACE, and the
California Coastal Commission at a minimum on a monthly basis during disposal operations
(due by the 15th day of the following month). For each disposal trip the records must include
disposal trip number and date, estimated bin volume of material disposed, and a visual display
of the beginning and ending locations of the disposal event relative to the HOODS boundaries
and internal cells. The reports shall include a cover letter describing any problems complying
with these Ocean Disposal Special Conditions, the cause(s) of the problems, any steps taken to
rectify the problems, and whether the problems occurred on subsequent disposal trips.
9. A post-disposal bathymetric survey of the HOODS, extending at least 2,000 feet outside the
boundaries of the project's allowable disposal cells in all directions, shall be conducted within
60 days of completion of disposal operations, and provided to EPA Region 9 and USACE
within 30 days of completion. (Note that EPA may waive this requirement for individual
smaller-volume projects, based on USACE continuing to conduct annual bathymetric surveys
of the entire expanded HOODS.)
IV. SITE MONITORING PLAN
Site monitoring plans evaluate whether the disposal site's management goals and objectives are being
met, and whether any unanticipated environmental impacts are occurring. Periodic ocean disposal site
monitoring is intended to occur at least every 10 years. SMMPs are then re-evaluated based on the site
monitoring results and updated if needed (with opportunity for public input).
This site monitoring plan for the expanded HOODS is designed to address the following management
questions:
1. Is the physical presence of disposed dredged material primarily restricted to the disposal site itself
(retained within the site boundaries)?
2. Is the sand mound being successfully managed so that it does not substantially exceed the 130-foot depth
target?
3. Are there indications that adverse chemical-related?
4. Are there indications that any adverse environmental impacts may be occurring beyond the site
boundaries, related to dredged material disposal
To do this, periodic site monitoring activities have physical, chemical, and biological components,
including:
• Physical - identify the extent of the dredged material "footprint" within and outside HOODS, including
the height of dredged material mound(s);
• Chemical - confirm that chemical concentrations in disposed sediment are as expected based on pre-
dredge testing, and that chemical concentrations are not elevated to levels of concern off site as a result of
dredged material disposal; and
• Biological - qualitatively and/or quantitatively identify the status of the benthic community within and
outside the site.
Depending on results from the site monitoring surveys, EPA and USACE may consider taking site
management actions as described in Section V. These management actions can include additional or
more intensive site monitoring activities if necessary.
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Physical Monitoring - Disposal Footprint Mapping
At HOODS, mapping the physical extent of disposed material on the seafloor (the disposal footprint),
including the size and height of the disposal mound, will happen in two primary ways.
Bathymetric Surveys
Acoustic bathymetric surveys of the seafloor are appropriate for mapping the height and extent of
mounded dredged material within HOODS. Such surveys have been conducted in and just beyond the
HOODS boundaries by USACE at least once per year in the past. It is expected that USACE will
continue to conduct at least annual surveys of the entire expanded HOODS and extending at least 500
feet beyond the site boundary in all directions. The acoustic bathymetric survey method used must be
capable of identifying seafloor depths with a (tidally corrected) accuracy of at least 0.2 feet. Bathymetric
surveys are a site use condition applicable to all approved users of HOODS (see site use Condition 9
above). However, in years when USACE provides a high-resolution survey of the entire site, EPA may
waive this requirement for other individual disposal projects. Also, if adequate high-resolution
bathymetric survey data are available from recent (within one year) annual monitoring, EPA may decide
not to conduct an additional bathymetric survey during periodic (every 10 year) site monitoring surveys.
Sediment Profile Imaging
The Sediment Profile Imaging-Plan View camera system (SPI/PV) is a dual-camera instrument that is
lowered to the seafloor. The SPI camera is inserted into the sediment to capture a high-resolution image
of a cross-section of the upper sediment column (up to 20 cm depending on density of the sediment).
Several replicate images are captured around each station. This method is capable of discerning dredged
material deposits of as little as a few millimeters from underlying native sediment. Thus, the SPI system
can document thin dredged material deposits on the bottom that would not be detectable in a
bathymetric survey. In conjunction with bathymetric surveys, SPI helps provide a comprehensive
footprint mapping result. In addition to footprint mapping, the SPI system in conjunction with its PV
component also provides valuable biological and habitat information, as discussed later in this section.
Figure 8 presents a schematic of the SPI system in use.
Chemical Monitoring - Sediment Collection and Analysis
A major purpose of periodic chemical monitoring is to confirm that dredged material disposed at
HOODS is not substantially different, in terms of contaminant levels, compared to the pre-dredge
sediment testing on which the approval to dispose of the material was based. In other words, analyzing
the chemistry of material disposed at the site is important confirmation that the pre-dredge sampling and
testing that EPA and USACE require is appropriately representative, and that significantly contaminated
sediment is not being missed by the testing and being disposed at HOODS. Another major purpose of
chemical monitoring is to compare disposed sediment with undisturbed off-site sediment, to confirm that
contaminants are not being transported off site and causing any significant adverse biological impacts
outside of the HOODS.
Sediment may be appropriately retrieved from the seafloor in and around HOODS by a variety of
sampling methods. Since this site is relatively shallow compared to many of the ocean disposal sites in
EPA Region 9, more complicated and expensive equipment such as large box core samplers are
generally not needed. Instead, to date EPA has utilized simpler double Van Veen samplers. But any
equipment capable of retrieving undisturbed samples of the upper 5-10 cm of the sediment column could
be employed.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 101
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3PI mage
Plan-view image
"Down" position
1-2 meters On the transecting the sediment-
Deployed from seafloor seafloor water interface
Figure 8. Schematic of deployment and collection of sediment profile images and plan view
photographs. (Reproduced from Germano & Assoc., 2014).
Once collected, sediment samples are processed, preserved, and shipped to the lab for analysis of a
variety of chemicals. Chemical analysis is typically performed for the same extensive suite of
parameters and potential contaminants as for pre-dredge testing, such as those shown in Table 2.
Biological Monitoring
Trawl sampling for fish and macroinvertebrates was conducted during baseline surveys prior to the
original designation of HOODS in 1995. The location of HOODS was chosen in part based on those
surveys (and other existing information) that indicted fish and macroinvertebrates were generally much
more abundant in shallower water closer to shore in this area. Subsequent site monitoring at HOODS
has therefore not included further trawl surveys, and instead has focused on monitoring the benthic
(sediment-dwelling) community in other qualitative and quantitative ways, as follows.
Seafloor imagery using the SPI-PV dual camera system provides visual information on benthic
community structure and health, including key aspects of benthic habitat structure and recolonization
following disturbance. In addition to vertical profile images captured by the SPI camera, a plan view
(PV) camera captures images from several feet above the seafloor (see Figure 8). Each replicate PV
image documents the general benthic habitat type (including the presence of any surface features), as
well as fish and macroinvertebrates (such as crab or shrimp) in an approximately 3-4 square meter
downward-oriented view. The SPI/PV system allows information to be collected quickly and efficiently
from a large number of sites, and for the results to be used in near real time for modifying other site
surveys (i.e., selecting the stations from which sediment should be retrieved for chemical analysis), and
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 102
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Table 2. Typical chemical parameters to be analyzed in periodic site monitoring surveys for the
expanded HOODS. (Note that EPA may modify this list, based on emerging contaminants of
concern, dredging project testing, special management and monitoring needs, etc.)
Parameter
Analysis Method
Reporting Limit (BL)
Conventional
Total Solids {percent}
EPA 2450-G
+0.1
Total Organic Carbon f percent)
EPA 53108 mod or EPA 9060
+0.1
Grain Size j percent}
siumo 1991z
+0,1
Metals (mg/kg)
Antimony
EPA 6010/6020
0,5
Arsenic*
EPA 6010/6020'
1,0'
Ba-iun
EPA 6010/6020
2.0
Beryl'hjm
EPA 6Q1G/6C20
1,0
Csdn-urr *
EPA 6010/6020
0,5
Cbroil bn*
EPA 6010/6020
2,0
Cobait
EPA 6010/6020
3,0
Coppe'1
EPA 6010/6020
3,0
Lead*
EPA 601C/6020
3.0
Mercury*
t PA 7471
0,05
Molybdenum
EPA 6010/6020
-
Nickel*
EPA 6010/6020
5,0
Selenium*
EPA 7740
0,1
Silver*
EPA 6010/6020
0,5
Thallium
EPA 6010/6020
_
Vanadium
EPA 601Ci'6G20
3.0
Zinc*
E?A o01C/i>j'20
3,0
Polymsclear Aromatk Hydrocarbons (fig/kg)
i-VethylnaphthateTie
EPA 8270
20
1-Methylobienantrrene
EPA 8270
20
2,3,5- Tnriethylnapbthalene
EPA 8270
20
2,6-Dimentnyinapsitb.alene
EPA £270
20
2-Vethylnaphthatene
EPA 8270
20
Acenaphthalene
EPA 5270
20
Acenaphthylene
EPA 3270
20
Anthracene
EPA 8270
20
Bipbenyf
EPA 8270
20
Benzo(s)antbracene
EPA S270
20
Beizo(a)pyrene
EPA 8270
20
Benzol t>)fiuoranthene
EPA 8270
20
Benzofejayene
EPA S270
20
Benzo(g,n,ilperylene
EPA 8270
20
Benzo(k)fi'jorarthene
EPA 8270
20
Chryser-e
EPA S27C
:c
Dibenzcfa.hla^tbfacene
EPA 8270
20
Dibenctfviophene
EPA 2270
20
Pliorene
EPA S270
20
Flucii'ranthene
EPA 5270
20
h den c (i, 2,3 -c, dj pv-ene
E»A 8270
20
Nsphir.aiene
EDA SI 70
2C
Peryiene
E--A 3270
'tp-
PS'enanthrene
EPA S270
:c
Pyrene
E-A :2"C
i p
~otal F AHs*
E-A S270
_
Pesticides Uig/kg.)
Aldrin
'EPA SOSiA
2
Aipna-3HC
EPA SCS1A
2
Beta-BHC
EPA SCS1A
2
Ce":a-BHC
epa sob:a
2
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 103
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Table 2, continued.
Analysis fviethori
fiesort-'iij Limit -RLI
Gamma-BMC
r" .
_
Total BHCs"
EPA SOSIA
_
Chwrdsne
EPA BOSIA
20
Total Cterdanes*
EPA SOSIA
2C
Die'd'in*
EPA 8CSIA
2
Trans-nonachlor
EPA SOS ift
2
2,4 -DDD
EPA SCSlA
2
2,4 -DDE
EPA SCSIA
2
2,4"-DDT
EPA SCSiA
2
4,4"-ODD
EPA SCS'-A
2
4,4'-D0E
EPA SCSIA
2
4,4'-DDT
EPA SCSiA
2
Tctal DDIs*
EPA SCSiA
-
Endosulfan 1
EPA SCSIA
2
Endosulfan 11
EPA SCSIA
2
Endosulfan sulfate
EPA SCSiA
2
Endrln
EPA SCSIA
2
Endrir afcjehy;e
EPA BCSIA
2
Endrin Ketone
EPA SCSIA
2
Heptachksr
EPA SCSIA
2
Heptacr>lor Epor.de
EPA SCBlA
2
Methoxychlar
EPA SCSI A
2
Tcxsphine
EPA SCSIA
20
Aisna Cnlordar.e
EPA SCSIA
2
Gamms Chlord&ne
EPA SCSIA
2
Cis-norachlor
EPA SCSaA
2
| Polychlomated Biphenylf
-------
Table 2, continued.
Analysis Method
Re;.x>; ting Limit {RLj
PCB17Q
EPA 8082 GC/ECD
0.5
PCB174-
EPA 8082 GC/ECD
0,5
PCB177
EPA 8082 GC/ECD
0.5
PCB180
EPA 8082 GC/ECD
0.5
PCB183
EPA 8082 GC/ECD
0.5
PCB187
EPA 8082 GC/ECD
0,5
PCB194
EPA 8082 GC/ECD
C.5
PCB195
EPA 8032 GC/ECD
0,5
PCB201
EPA 8082 SC/ECD
0.5
PCB203
EPA 8082 GC/ECD
0.5
Total PCBs*
EPA 8082 GC/ECD
_
Butfitiiis fiig/kg!
Tetrabutyltiri
Krone (1989)
10
Tributyfttn
Krone (1989)
10
Dibutyltin
Krone (1989)
10
Monobutyltin
Krone {1989)
10
gjtyhi-1:.
Krc--:e
Dioxim fpg/g)
£ ioxi¦ ¦; ¦ C jO lQ). t
EPA •
7 0
1 H _i r0 C-'l GTV 3cl~'": 0 9 \n*5.
-.t sii.jning jrter"e'sn':e;: site-spscf-:
met^cc mc-d;fi may be
!¦¦=:!:! to 3£h"r\"= these Ru ir some
cf -• S? S .
1 PL-mb. R-. Jr
" fc:~ b^n-sti'Mai 'euse o* d;'-;dgec =—.-starjai
even for making important site management decisions. But this approach does not identify all species in
the community to a low taxonomic level or quantify the numbers of species, or individuals in each
species, that may be present.
In contrast, sediment collected from a subset of sampling stations (taken at the same time and with the
same equipment as the chemistry samples) is processed to screen out and preserve all of the organisms
(greater than 0.5 mm in size) living in the surface sediment. These samples are then sent to taxonomy
laboratories for identification of the organisms (to the species level where possible), and quantification
of benthic community parameters such as abundance, density, diversity, and other indices. Although this
approach yields an abundance of quantitative data, it is very expensive to collect, process, and analyze,
so it can only be done for a limited number of stations compared to using SPI-PV imagery. In addition,
it can take more than a year for results for be available. Finally, this approach does not directly show the
structure of the benthic community in the sediment column. The results from past biological monitoring
at HOODS are presented in EPA's 2016 site monitoring synthesis report.11
The synthesis report documents that no significant effects on the benthic community, aside from the
presence of the sand mound itself, have resulted from the past 25 years of disposal at HOODS. EPA
expects the lack of impacts to the benthic community to continue, as long as the majority of sediment
disposed at HOODS continues to be sand, and as long as the site continues to be managed (as proposed)
to slowly enlarge the mound by disposing over its side slopes as opposed to spreading sediment
throughout the site each year. EPA may therefore opt to continue monitoring benthic community status
qualitatively using the SPI-PV system, and not to regularly include quantitative benthic community
sampling unless a need for it is otherwise indicated.
Available at: https://www.epa.gov/sites/production/files/2016-
09/documents/humboldt open ocean disposal site hoods 2008-2014 monitoring synthesis report.pdf
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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HOODS Periodic Site Monitoring - Typical Sampling Approach
Physical, chemical, and biological samples are collected from an array of stations that include
representative locations from both within and outside the disposal site boundaries, as well as from
locations both with and without the presence of disposed dredged material. Figure 9 shows a typical
sampling array, in this case with 30 stations including the new HOODS reference site. SPI-PV images
would initially be collected at all 30 stations, with 3-5 replicate images at each. (Additional SPI-PV
stations may be needed if the dredged material deposit boundary is not adequately defined.) Sediment
samples for chemistry (and possibly biology) would be collected at a subset of 1/3 to 1/2 of the stations.
Figure 9. Typical sediment sampling station array for periodic site monitoring at FLOODS. The
expanded FIOODS is outlined in yellow, the original HOODS (now closed) is outlined in
black, and the potential future Nearshore Sand Placement Site is outlined in orange. The new
HOODS reference site is also shown.
The final determination of the subset of stations from which to retrieve sediment samples for chemical
and/or biological evaluation in the laboratory is generally made in the field following evaluation of the
most recent physical (bathymetric) survey, and preliminary analysis of the SPI-PV imagery. Sediment
collection stations are selected to ensure that, overall, the collected sediment is representative of the
seafloor:
• within the expanded site boundaries;
• outside the expanded site boundaries;
• on the mound within the original HOODS boundary;
• with disposed dredged material present;
• without disposed dredged material (i.e., native seafloor); and
• at the reference site.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 106
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Additional stations may be added or dropped, and/or planned stations moved, depending on the
preliminary review of the SPI-PV imagery in the field. Similarly, weather and sea state conditions may
also affect the field activities and limit the number of planned stations that can be sampled.
EPA develops a specific monitoring plan, including a detailed Quality Assurance Project Plan (QAPP),
in advance of each periodic site monitoring event. These plans detail such things as field operations,
sample collection and handling methods, and laboratory analytic requirements. Once results from all of
the completed surveys are available (which typically takes 3-6 months, to well over a year if quantitative
benthic community analysis is included), EPA will make the results reports (or a monitoring synthesis
report if available) publicly available.
V. SITE MANAGEMENT OPTIONS
Based on the results of site monitoring (whether the annual bathymetric surveys or the more
comprehensive periodic monitoring studies), EPA and the US ACE will determine whether changes to
the SMMP may be needed in order to ensure that any impacts are addressed and that the site remains in
compliance with the MPRSA.
This SMMP does not specify particular responses to any identified or potential adverse impact indicated
from monitoring. However, EPA and the US ACE will consider the following range of example
management actions (listed in order of increasing severity) as appropriate:
1. No Action. Monitoring results do not indicate unanticipated adverse impacts; site use may
continue under the current SMMP requirements.
2. Minor modification to current disposal practices. If a potential issue is identified that can be
addressed in the immediate term without collecting additional monitoring data, for example by
temporarily avoiding disposal in a specific portion of the expanded HOODS, such changes can
be made without modifying the SMMP or accelerating site monitoring plans.
3. Collect additional data during the next periodic monitoring survey. If a potential issue is
identified that warrants closer evaluation, but that is not so serious that site management changes
need to be made right away (or that can be avoided in the interim), special focus during the next
scheduled (e.g., 10-year) periodic site monitoring survey may be appropriate. Additional data
collection could include additional imagery, addition of more stations for sediment collection
(for chemistry and/or biology), or completely different kinds of surveys (such as evaluation of
tissue chemistry in on-site vs off-site marine organisms).
4. Collect additional data before the next periodic monitoring survey. If a potential impact is
identified that could be serious enough to warrant site management changes, but that is uncertain
or cannot be avoided in the interim, collection of additional data sooner than the next scheduled
(e.g., 10-year) periodic site monitoring survey may be appropriate.
5. Revise site use practices. A variety of changes to site use requirements could be made to address
impacts identified as a result of site monitoring. These may include, but are not limited to:
a. revise the number, size, or location of closed vs allowable disposal cells;
b. require specific dredging practices (e.g., use of a grizzly to exclude large debris);
c. limit the volume or timing of disposal at the site;
d. reconfigure the disposal site boundaries (enlargement requires rulemaking).
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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6. De-designate (close) the disposal site entirely. Closing the expanded HOODS could be
appropriate if monitoring indicates that disposal at HOODS has caused unacceptable
environmental impacts within or beyond the site boundary, and that other corrective actions are
or would be ineffective in preventing or correcting them. Closing the disposal site may have to
be preceded by identification of an acceptable alternative ocean disposal site. Monitoring of the
closed site may need to continue, to ensure that adverse effects do not worsen and to allow any
necessary remedial actions to proceed in a timely manner.
VI. UPDATING THE SMMP
SMMP updates are required to be considered at least every 10 years, based on the results of periodic site
monitoring. This draft SMMP is expected to be in effect for ocean disposal activity at HOODS
beginning in 2021, following completion of the rulemaking process to expand HOODS. Therefore,
absent any modifications or updates in the interim, this SMMP could be in place through 2031 before it
would need to be updated again. EPA will provide another opportunity for public input before the next
SMMP update. In particular, any proposed substantive changes to the provisions of this SMMP (such as
some of the management actions listed in Section V) would be highlighted, and the need for them
specifically discussed.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 108
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Appendix E
Response to Comments
On the
Draft EA and Proposed Rule
EPA published the draft EA for a 30-day public comment period on May 29, 2020 and accepted
comments until June 29, 2020. Simultaneously with the draft EA, EPA issued for public comment a
proposed rule to implement Alternative 1. The proposed rule is functionally equivalent to a
preliminary Finding of No Significant Impact (FONSI). Both the draft EA and proposed rule were
available at www.regulations.gov (Docket ID No. EPA-R09-OW-2020-0188) and at
https: //www.epa.gov/ocean-dumping/humboldt-open-ocean-disposal-site-hoods-documents.
EPA received feedback from a total of four commenters on the draft EA and proposed rule. Based
on the comments received, only minor, clarifying wording changes have been made to the EA and
proposed rule. The comments received, and EPA's responses, are provided in this Appendix.
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
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Commenter
Date
Comments
EPA Responses
1. Citizen - no name
given
5-31-2020
(A) I think this is a great idea to enlarge the dumping site. Has
this site been enlarged before? And do you think it will be
enlarged again in the future?
(B) I think it is important to have specified dumping sites
throughout the country and the fact that this is being
monitored will help keep this regulation in order. Are
there any strict punishments for people that are caught
dumping elsewhere?
(C) I hope that this enlargement of the site does not cause any
harm to marine life in the area
(A) Thank you for your comments. HOODS
has not been enlarged before. If
disposal continues at the present rate,
and no new alternatives become
available, the EA estimates that HOODS
would not need to be enlarged again for
approximately 75 years.
(C) EPA manages about 100 ocean
dumping sites for dredged material
around the country. HOODS is one of 6
sites along the California coast
Dumping is only permitted at
designated sites, and only with EPA and
USACE approval. Disposers must
comply with all site use conditions in
their permits, and under the Marine
Protection, Research and Sanctuaries
Act (MPRSA), EPA has authority to
enforce the ocean disposal permit
conditions. Civil penalties for violating
the conditions can be quite substantial.
(D) The evaluation in the EA considered
this issue in detail. There have been no
significant adverse impacts on marine
life or habitat in 25 years of disposal at
HOODS, and it is expected that similar
disposal in the expanded site in the
future also will not result in any
significant adverse impacts.
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Commenter
Date
Comments
EPA Responses
2. Lance C. Roddy,
Cartographer,
NOAA
6-5-2020
Dear Mr. Ross, The Marine Chart Division of NOAA's Office of
Coast Survey is responsible for charting U.S. coastal waters
and certain inland waterways. In keeping with that
responsibility, the division depicts the locations of Ocean
Dredged Material Disposal Sites in navigable waterways as
shown on NOAA ENC - Electronic Navigational Charts. My
credentials follow: I am a nautical cartographer; member
since December 2004 of the Nautical Data Branch / Marine
Chart Division / Office of Coast Survey. I have extensive
experience in examining boundaries and regulations
associated with Federal Register Proposed and Final Rules as
they relate to nautical charting. The purpose of my comments
is to provide feedback regarding the Proposed Rule published
in Federal Register Vol. 85, No. 104, pp. 32340 - 32346,
Friday, May 29, 2020; Docket ID EPA-R09-OW-2020-0188.
Subject: Ocean Dumping: Modification of an Ocean Dredged
Material Disposal Site Offshore of Humboldt Bay, California
Humboldt Open Ocean Disposal Site (HOODS) My comments
follow: Per the Summary section on Page 32340, Column 2,
"The primary purpose for the site modification is to enlarge
the site to serve the long-term need for disposal of permitted,
suitable material dredged from Humboldt Harbor and
vicinity..." According to Section III, Environmental Statutory
Review, Page 32344, Column 2, "Alternative 1, the Proposed
Action, is to slightly reorient and expand the existing HOODS
boundary by 1 nmi to the north (upcoast) and 1 nmi to the
west (offshore)." In Esri ArcMap, I plotted the
latitude/longitude corner coordinates for the existing HOODS
boundary (see attached 40 CFR Part 228.15, Ch. I, Page 250
[7-1-19 Edition]), and the latitude/longitude corner
coordinates for the proposed, modified HOODS boundary as
stated on page 32341 (II. Background, Paragraph (b), Column
2) and page 32346 (Section (i), Column 3) of the proposed
rule.
The proposed expansion encompasses a substantial portion
of the existing boundary, but the proposed expansion does
(A) Thank you for your comments. It is
indeed EPA's intention that the new
boundary for HOODS completely
replaces the previous boundary, which
must eventually be removed from all
maps, charts and related publications.
We have added a sentence to the EA
and the final rule to make this clear.
Generally, EPA's headquarters office
periodically coordinates with NOAA
regarding updates to the NOAA maps
and charts based on final rulemakings
that have occurred since the previous
round of updates. But we appreciate
your catching this issue now, and we
look forward to working with NOAA to
ensure that charts and maps depicting
the expanded HOODS are properly
updated at the next appropriate
opportunity.
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not fully encompass the eastern and southern portions of the
existing boundary. The HOODS boundary as depicted on ENC
US5CA94M coincides with existing boundary as described in
the CFR mentioned above. Please refer to the attached file,
"Attachmentl_Boundary_and_Chart_Evaluation.pdf".
(A) Is it your agency's intent to expand the boundary
without fully encompassing the existing boundary? I
request that you re-evaluate the proposed boundary
and consider the following three options for
publishing the boundary in the Final Rule: 1. Revise
the coordinates of the proposed boundary to fully
encompass the existing boundary. 2. Retain the
coordinates of the proposed boundary and add
additional coordinates to represent the vertices
formed by the intersection of the existing and
proposed boundaries. 3. Based on my evaluation of
the EPA Environmental Assessment (pp. 8,11), dated
4/15/2020, the small areas outside the proposed
boundary appear to coincide with a Buffer Zone (No
Disposal) of the existing HOODS. If your evaluation
unequivocally indicates that dredged material does
not exist within the areas of the existing boundary
outside of the proposed boundary, then perhaps you
could state in the Final Rule that the new boundary
completely replaces the previous boundary, which
must be removed from all maps, charts and related
publications. My goal is to ensure that the
cartographic production team of the Marine Chart
Division will receive a revised boundary description
and coordinates that your Agency explains clearly,
and which do not conflict with the charted boundary.
The achievement of this goal can lead to an efficient
process of revising the boundary on the affected
charts. If you have any questions or comments, please
feel free to contact me per the contact information
that I have provided.
Respectfully, Lance C. Roddy, Cartographer
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Commenter
Date
Comments
EPA Responses
Larry Simon
6-23-2020
The Commission staff submits the following comment on the
May 29, 2020, Federal Register notice regarding the proposed
boundary modification to HOODS.
(A) The Commission staff looks forward to receiving EPA's
consistency determination for the proposed boundary
modification and to working with EPA staff on this
submittal. Best regards,
Larry Simon
Manager, Federal Consistency Unit
Energy, Ocean Resources and
Federal Consistency Division
California Coastal Commission
(A) Thank you for your comment EPA
looks forward to presenting our Coastal
Consistency Determination (CCD)
package for the Commission's review in
the coming weeks, and to addressing
any specific comments the Commission
and staff may have. EPA will not
publish the final rule for expanding
HOODS until any Commission
comments have been fully considered.
Tessa Beach and
Mark Wiechmann,
USACE San Francisco
6-29-2020
From: Wiechmann, Mark J CIV USARMY CESPN (USA):
Tessa,
I'm still looking it over.
I have one correction so far:
(A) Section 4.1.1, middle of last paragraph (p.2 8) - change the
word "ether" to "either".
Everything else, so far, looks fine.
-M
From: Beach, Tessa E CIV USARMY CESPN (USA)
Hi Mark,
Thanks for your review! If it is just editorial, as with your
comment below,
(B) I think letting John and Brian know would be fine, we
won't need to submit anything formally.
Appreciate you wrapping up this review and please let me
know if you do end up having any other comments.
Respectfully,
Tessa Eve Beach, Ph.D.
Chief, Environmental Sections
Thank you for your review and comments.
EPA appreciates the close working
relationship our agencies have enjoyed, and
the assistance USACE staff has provided,
during development of the HOODS EA and
proposed rule.
(A) The typographical error in Section 4.1.1
has been corrected.
(B) No additional comments from USACE
were received.
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Appendix F
California Coastal Commission
Staff Report on the
Expansion of HOODS
HOODS Expansion, Environmental Assessment and MPRSA Criteria Evaluation
page 114
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STATE OF CALIFORNIA - CALIFORNIA NATURAL RESOURCES AGENCY
GAVIN NEWSOM, GOVERNOR
CALIFORNIA COASTAL COMMISSION
455 MARKET STREET, SUITE 228
SAN FRANCISCO, CA 94105-2219
VOICE (415) 904-5200
FAX (415) 904-5400
F 11a
Filed: 7/23/20
60th Day: 9/21/20
75th Day: 10/6/20
Extended Through: 10/13/20
Staff: M. Flier/L. Simon - SF
Staff Report: 9/17/20
Hearing Date: 10/9/20
STAFF REPORT: REGULAR CALENDAR
Consistency Determination No.: CD-0001-20
Federal Agency:
Location:
Project Description:
Staff Recommendation:
U.S. Environmental Protection Agency (EPA)
EPA-designated Humboldt Open Ocean Disposal Site
(HOODS), between three and four nautical miles west of
Humboldt Bay, Humboldt County (Exhibit 1).
Expansion of HOODS boundary by one nautical mile to
the north and west, thereby increasing the designated
disposal area from one square nautical mile to four
square nautical miles.
Concurrence
SUMMARY OF STAFF RECOMMENDATION
The Humboldt Open Ocean Disposal Site (HOODS) is an offshore area where the federal
government and other agencies dispose of sediment that is dredged from Humboldt Bay
navigation channels. The U.S. Environmental Protection Agency (EPA) has submitted a
consistency determination for the expansion of the existing HOODS boundaries by one
nautical mile to the north and west, thereby increasing the HOODS disposal area from one
to four square nautical miles. Since the original HOODS was established in 1995, the site
has approached capacity and cannot provide for additional disposal without creating
undesirable mounding. The proposed expansion would allow for 75 years of additional
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CD-0001-20 (USEPA)
disposal capacity, assuming a continuation of the annual average disposal of one million
cubic yards of sediment from Humboldt Bay channels. The consistency determination
includes a revised Site Management and Monitoring Plan, which includes provisions for
regulating disposal operations, monitoring the site, using adaptive management to protect
marine habitat and resources, and enforcing disposal permit conditions. The consistency
determination also includes a description of a nearshore disposal site along the North Spit
that represents a potential disposal alternative to retain sand in the littoral system. The
consistency determination does not propose establishment of this site nor request
Commission concurrence with such a program. In addition, the consistency determination
does not include any proposals for, or requests for Commission concurrence with, any
disposal projects. All future disposal at HOODS will continue to require separate federal
consistency review by the Commission or Executive Director.
Expansion of HOODS will allow greater flexibility to manage disposal in the future over a
larger area to reduce the frequency of repeated deposition of sand in the same location.
The HOODS expansion area does not support rare or unique marine habitat but rather is
comprised of soft-bottom habitat that extends far beyond the expansion footprint.
Monitoring of HOODS since 1995 has documented that disposal has not resulted in any
adverse long-term effects to water quality or to soft bottom habitat, given its abundance in
the region and the ability of benthic organisms to rapidly recolonize disturbed areas.
Monitoring by the EPA of the expanded HOODS for potential adverse effects on marine
resources and water quality will identify any unanticipated potential long-term and/or
cumulative impacts from dredged material disposal. Should effects to any marine
resources or water quality be confirmed, the EPA will implement management alternatives
to minimize those impacts. The staff recommends that the Commission find the HOODS
expansion consistent with the marine resource and water quality policies of the Coastal Act
(Sections 30230 and 30231).
The existing HOODS was selected based in part on the fact that this location had the least
potential for adversely affecting fish and shellfish resources that are important to the
commercial and recreational fishing industries of the region. Annual maintenance dredging
in Humboldt Bay that relies on the availability of adequate disposal capacity at HOODS is
essential for the safety and continued operation of the commercial and recreational fishing
fleet based in Humboldt Bay. The staff recommends that the Commission find the HOODS
expansion is consistent with the commercial and recreational fishing policies of the Coastal
Act (Sections 30230, 30234, and 30234.5).
The vast majority of dredged sediments disposed at HOODS are physically and chemically
suitable for beach nourishment and/or nearshore placement. In an effort to consider all
viable options to retain sediment within the local littoral system, the use of previous
nearshore disposal sites was evaluated by the EPA. These sites were deemed infeasible
due to navigation and fisheries issues. EPA also evaluated a potential nearshore sand
placement site along the North Spit, but determined that this site was not currently a
feasible alternative to HOODS expansion due to the need for a monitored and successful
sediment disposal pilot project at this location and the need for subsequent regulatory
actions by EPA and the Corps of Engineers for site designation.
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CD-0001-20 (USEPA)
Even with the expansion of HOODS the Commission will continue to evaluate proposed
disposal projects on a case-by-case basis. If dredged sediment is determined to be
physically and chemically suitable for disposal at HOODS, that disposal project can only
be approved if there are no feasible beneficial re-use alternatives available given a
particular project's location, timing, and logistics. The proposed expansion of HOODS does
not relieve sponsors of future dredging projects of the requirement to undertake a rigorous
disposal alternatives analysis in order to determine if beneficial reuse of dredged materials
is feasible. The HOODS expansion does not preclude the Commission from requiring
beneficial reuse of dredged sediments should such an alternative prove feasible. Given the
lack of a designated suitable nearshore placement site at this time, or of other feasible
alternative disposal sites capable of handling up to one million cubic yards of clean
dredged sediments from Humboldt Bay, the staff recommends that the Commission find
the HOODS expansion consistent with the sand supply policy of the Coastal Act (Section
30233(b).
The staff recommends that the Commission concur with EPS's consistency determination
CD-0001-20. The motion and resolution are on Page 5 of this report. The standard of
review for this consistency determination is the Chapter 3 policies of the Coastal Act.
3
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CD-0001-20 (USEPA)
TABLE OF CONTENTS
I. FEDERAL AGENCY'S CONSISTENCY DETERMINATION 5
II. MOTION AND RESOLUTION 5
III. FINDINGS AND DECLARATIONS 5
A. Project Description 5
B. Project Background and Regulatory History 7
C. Other Governmental Approvals and Consultations 9
D. Marine Resources and Water Quality 10
E. Recreational and Commercial Fishing 13
F. Sand Supply 15
SUBSTANTIVE FILE DOCUMENTS 18
EXHIBITS
Exhibit 1 - Project Location Map
Exhibit 2 - Bathymetry Map of Current and Proposed HOODS Boundaries
Exhibit 3 - U.S. Army Corps of Engineers Shoreline Monitoring of North and South Spits
4
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CD-0001-20 (USEPA)
I. FEDERAL AGENCY'S CONSISTENCY DETERMINATION
The U.S. Environmental Protection Agency has determined the project is consistent to the
maximum extent practicable with the California Coastal Management Program.
II. MOTION AND RESOLUTION
MOTION:
/ move that the Commission concur with consistency determination CD-0001-
20 that the project described therein is fully consistent, and therefore consistent
to the maximum extent practicable, with the enforceable policies of the
California Coastal Management Program (CCMP).
Staff recommends a YES vote on the motion. Passage of this motion will result in a
concurrence with the determination and adoption of the following resolution and
findings. An affirmative vote of a majority of the Commissioners present is required to
pass the motion.
RESOLUTION:
The Commission hereby concurs with consistency determination CD-0001-20
by the U.S. Environmental Protection Agency, on the grounds that the project
described therein is fully consistent, and therefore consistent to the maximum
extent practicable, with the enforceable policies of the California Coastal
Management Program.
III. FINDINGS AND DECLARATIONS
A. Project Description
The U.S. Environmental Protection Agency (EPA) submitted a consistency determination
for the expansion of the existing Humboldt Open Ocean Disposal Site (HOODS), located
three to four nautical miles west of the Humboldt Bay entrance channel (Exhibit 1). The
current HOODS encompasses one square nautical mile in water depths naturally ranging
from 150 to 180 feet mean lower low water (MLLW). EPA states that HOODS has
effectively reached its original design capacity for dredged material disposal. Since
HOODS was designated in 1995 (concurred with by the Commission in CD-072-95),
approximately 25 million cubic yards (cu.yds.) of sand has been disposed at the site. This
has created a mound with an elevation averaging approximately -130 feet MLLW. The
1995 EIS for the site designation identified this mound height as the maximum desirable,
as a greater height at this location could affect the action of waves in large storms and
cause navigation safety concerns for vessels transiting the area.
The Draft Environmental Assessment (DEA) for the proposed expansion of HOODS states
that:
5
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CD-0001-20 (USEPA)
At the same time, ongoing dredging of the Humboldt Harbor navigation
channels and related maritime facilities is necessary to ensure continued
safe entering, navigating within, and exiting Humboldt Bay. Therefore,
reliable capacity to accommodate disposal or beneficial use of dredged
material will continue to be critically needed, and HOODS as it is currently
configured will no longer be able to provide such capacity beginning in
approximately 2021.
The proposed expansion will increase the disposal site to four square nautical miles,
elongating the existing HOODS boundaries by one nautical mile to the north and west in
water depths of approximately 150 to 210 feet MLLW (Exhibit 1). The effective total
capacity of the site would increase from the original 25 million cu.yds. to 100 million
cu.yds. The expansion would allow for the addition of 75 million cubic yards of clean
sediment disposal before mounding to -130 feet MLLW could occur, effectively allowing for
an additional 75 years of disposal site capacity (Exhibit 2). This 75-year timespan
assumes an annual average of one million cubic yards of disposal at the site. However, if
future disposal rates are lower due to increased beneficial reuse of sediment or
establishment of a nearshore sand placement site (NSPS), the effective life of the
expanded HOODS could be much longer. The expanded site was specifically chosen per
EPA's general and site-specific factors (discussed in further detail below) for the selection
of ocean disposal sites.
The 2020 Draft EA analyzed an alternative, smaller expansion of the HOODS footprint by
one-half nautical mile to the north and west, which would allow for approximately 31 years
of additional disposal. Given the current uncertainty regarding feasibility of future beneficial
reuse projects and/or establishment of a NSPS, the EPA selected the proposed larger
expansion in order to accommodate maximum dredged material disposal requirements in
the region. However, after discussions with Commission staff, the EPA submitted a
clarification letter to the Commission in August 2020 stating that disposal at HOODS would
be managed for the foreseeable future as if the site was only expanded to the north and
west by one-half nautical mile. This would be accomplished through the inclusion of
enforceable restrictions in the Site Management and Monitoring Plan. This approach is
also consistent with the National Marine Fishery Service's recommendation that potential
disturbance to the marine environment at HOODS be kept within the smallest footprint
possible.
The consistency determination for the proposed expansion of HOODS also includes
development and implementation of a revised Site Management and Monitoring Plan
(SMMP). The SMMP includes: (1) regulating the quantities, times, rates, and methods of
disposing dredged material; (2) implementing periodic physical, chemical, and biological
monitoring programs for the site; (3) considering changes to site use practices or the
designation itself if warranted based on the periodic site monitoring results; (4) developing
adaptive management recommendations (every ten years at a minimum) based on prior
monitoring results; and (5) enforcing disposal permit conditions. The SMMP also includes
a set of disposal operation requirements to be attached to each ocean disposal permit or
authorization (similar to best management practices), including but not limited to: (1)
identification of particular disposal locations for each project within the expanded site (to
6
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CD-0001-20 (USEPA)
manage mounding); (2) weather and wave limitations for disposal; and (3) disposal vessel
tracking, record-keeping, and reporting requirements.
The consistency determination also includes a description of a nearshore site along the
North Spit of Humboldt Bay that represents a potential long-term alternative for disposal of
sand dredged from Humboldt Bay federal navigation channels by the Corps of Engineers.
Additional details and analysis of this program are provided in Section F (Sand Supply) of
this report. However, the EPA's consistency determination is not proposing establishment
of a nearshore sand placement site nor requesting Commission concurrence with such a
program. Rather, this information is provided in order to further advance the concept and
to support the feasibility of this dredged material disposal alternative that would retain sand
in the littoral system and help to limit or buffer against shoreline erosion along the North
Spit, particularly as sea level rise accelerates in the future.
Finally, it is noted that the subject consistency determination is limited to the proposed
expansion of HOODS to allow for continued use of the site for ocean disposal of suitable
dredged material (as determined by the EPA's Ocean Dumping Regulations, 40 CFR Parts
225-227). The consistency determination also states that disposal at HOODS will continue
to only be approved when there are no practicable alternatives available for beneficial use
of the dredged material. This consistency determination does not include any proposals
for, or requests for Commission concurrence with, any specific dredging or dredged
material disposal projects. All future disposal activities at HOODS will require separate
federal consistency review by the Commission or the Executive Director.
B. Project Background and Regulatory History
Need for Dredging. The expansion of HOODS supports dredging activities in Humboldt
Bay that benefit the Humboldt Bay Harbor and Recreational District, the Coast Guard,
commercial fishing boats, and recreational boats using Humboldt Bay. Maintenance of the
Bar and Entrance Channel and inner channels within Humboldt Bay is necessary to
provide access to berthing, unloading and loading, and vessel repair areas. These
channels need regular dredging in order to maintain the depth necessary for ingress and
egress into the Bay. Without regular dredging, the channels would eventually silt up and
interfere with safe vessel navigation. Typically, deep ocean disposal of clean sandy
dredged material is not the only available disposal option, and certainly not usually the
preferred option. But at Humboldt Bay it has been the only feasible alternative available for
the large volumes of sand dredged annually from the Bar and Entrance Channel. For these
dredging events, other disposal sites in the region have not contained sufficient capacity to
accommodate disposal needs, are more environmentally damaging, or are infeasible due
to cost or suitability constraints.
Site History. Starting in the 1940's, the disposal of dredged material from Humboldt Bay
occurred at a site identified as SF-3, located south of the harbor entrance in about 55 feet
of water. Successful use of the site occurred for a number of years. In 1977, the EPA
granted an interim designation to this site. In the 1980's, the site began to shoal, creating a
navigation hazard to local boaters and fishers. Because of concerns about shoaling, SF-3
was "de-designated." In September 1990, HOODS was first used as a disposal site under
a temporary designation by the Corps of Engineers pursuant to the Marine Protection,
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CD-0001-20 (USEPA)
Research and Sanctuaries Act. In 1995 the EPA formally designated HOODS as a multi-
user ocean dredged material disposal site for a period of 50 years, in order to
accommodate ongoing maintenance dredging of the Humboldt Bay bar, entrance, and
inner-bay channels necessary for safe vessel navigation. Subsequently, the Commission
began concurring annually with consistency determinations for disposal of clean dredged
sediments at HOODS, finding it to be the least damaging alternative for disposal
operations, notwithstanding that sediments placed here were lost to the littoral system.
Since 1995, an average of 1 million cubic yards of clean dredged material has been placed
at HOODS annually. As a result, and as noted previously, sediment disposal has created
mounding and the original site has reached capacity (Exhibit 2). No additional sediment
may be disposed of at HOODS without creating obtrusive mounding. The proposed
expansion of HOODS is necessary as there are currently no feasible offshore, nearshore,
or upland alternatives for the disposal of dredged sediment from Humboldt Bay channels.
Regulatory History. The proposed site designation is authorized by the Marine
Protection, Research, and Sanctuaries Act (Act). The purpose of the Act is to regulate the
dumping of waste material into the ocean. Section 101 of the Act prohibits, unless
authorized by permit, the transportation of waste materials for the purpose of dumping
them into the ocean and the actual dumping of waste materials into the territorial seas of
the United States or into contiguous waters (33 U.S.C. Section 1401).
Section 102 of the Act authorizes the EPA Administrator to designate sites for the dumping
of wastes, including dredge spoils (33 U.S.C. Section 1412[c]). The Act requires that, to
the extent feasible, dredged material be disposed of in sites designated by the EPA (33
U.S.C. Section 1413[b]). The Act also directs the EPA to establish environmental criteria
for site designation. The EPA has developed four general criteria and 11 specific factors
that it considers in designating an ocean dredged material disposal site (40 C.F.R. Section
228.5 and 228.6). These criteria and factors require the EPA to consider the need for
disposal, the effect on human health, fisheries, and the marine ecosystem, appropriate
disposal locations and methods, and the existence of alternative disposal locations. These
criteria are examined thoroughly in the HOODS Expansion DEA and are incorporated by
reference into this staff report. The EPA adhered to these general and specific criteria
during its analysis of the proposed HOODS expansion.
The Act also establishes a permit system for the disposal of dredge spoils into the ocean.
Section 103 of the Act authorizes the Corps of Engineers to issue permits for the disposal
of dredged material into the ocean if the Corps determines that "the dumping will not
unreasonably degrade or endanger human health, welfare, or amenities, or the marine
environment, ecological systems, or economic potentialities" (33 U.S.C. Section 1413[a]).
Before the Corps can issue a permit, it must notify the EPA of its intent. The EPA can
disagree with the Corps' decision to issue a permit if it finds that the project does not meet
the criteria established in its regulations (40 C.F.R. Part 227). If the EPA determines that
the material is not suitable for ocean disposal, the Corps cannot issue the permit (33
U.S.C. Section 1413[c]). In addition, any disposal project at HOODS requires Commission
concurrence with a consistency determination or Executive Director concurrence with a
negative determination under the provisions of the federal Coastal Zone Management Act.
The Commission has concurred with 22 consistency determinations and 21 negative
8
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CD-0001-20 (USEPA)
determinations submitted by the Corps since 1985 for maintenance dredging of federal
navigation channels in Humboldt Bay, and since 1990 those determinations included
disposal of clean sandy sediments at HOODS.
The Commission's Executive Director concurred with a negative determination (ND-0007-
16) submitted by the Corps for the 2016 maintenance dredging at Humboldt Bay and
disposal of dredged sediments at HOODS. In addition, that concurrence letter stated that
there was now a need for the Corps to: (1) undertake a thorough examination of erosion
along the North Spit of Humboldt Bay; and (2) revisit the "excessive shoreline retreat
criterion" originally agreed upon in 1995 between the Commission and the Corps as a
means to establish potential shoreline erosional effects due to offshore disposal at
HOODS. The Commission has since approved three consistency determinations (CD-
0002-17, CD-0005-17, and CD-0005-18) for annual maintenance dredging and disposal at
HOODS. These submittals also included status reports on progress made by the Corps
regarding its North Spit erosion studies. Further details and analysis of shoreline erosion at
this location and the possible connection with disposal at HOODS are provided in Section
F (Sand Supply) of this report.
C. Other Governmental Approvals and Consultations
U.S. Army Corps of Engineers
The EPA developed the 2020 Draft Environmental Assessment jointly with the Corps of
Engineers. In addition, the expanded HOODS will continue to be managed by both the
EPA and the Corps. The Corps must authorize future disposal projects at HOODS under
Section 103 of the Marine Protection, Research, and Sanctuaries Act in consultation with
the EPA.
California State Lands Commission
The EPA coordinated with the State Lands Commission concerning historic shipwrecks
near HOODS and found that none would be affected by ongoing or future disposal
activities. HOODS and the expansion area are not located on submerged lands of the
State of California.
U.S. Fish and Wildlife Service
The EPA initiated informal consultation with the Service under Section 7 of the
Endangered Species Act of 1973, as amended (16 U.S.C. Sections 1531-1544.
Consultations were completed in December 2019 and January 2020.
National Marine Fisheries Service
The EPA initiated informal consultation with NMFS under Section 7 of the Endangered
Species Act of 1973, as amended (16 U.S.C. Sections 1531-1544), and the Magnuson-
Stevens Fishery Conservation and Management Act, as amended (16 U.S.C. 1801-
1891(d)). Consultations were completed in December 2019 and January 2020.
Native American Tribes
The EPA extended government-to-government consultation to ten potentially affected
tribes. The Tribal Historic Preservation Offices of three of them (Wiyot Tribe, Blue Lake
Rancheria, and Bear River Band of the Rohnerville Rancheria) requested further
9
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CD-0001-20 (USEPA)
discussion concerning any potential for effects on cultural resources of concern. Based on
those discussions, the tribes determined that the offshore location of the HOODS
expansion would not affect onshore cultural resources.
D. Marine Resources and Water Quality
Coastal Act Section 30230 states:
Marine resources shall be maintained, enhanced, and where feasible,
restored. Special protection shall be given to areas and species of special
biological or economic significance. Uses of the marine environment shall be
carried out in a manner that will sustain the biological productivity of coastal
waters and that will maintain healthy populations of all species of marine
organisms adequate for long-term commercial, recreational, scientific, and
educational purposes.
Coastal Act Section 30231 states:
The biological productivity and the quality of coastal waters, streams,
wetlands, estuaries, and lakes appropriate to maintain optimum populations
of marine organisms and for the protection of human health shall be
maintained and, where feasible, restored through, among other means,
minimizing adverse effects of waste water discharges and entrainment,
controlling runoff, preventing depletion of ground water supplies and
substantial interference with surface water flow, encouraging waste water
reclamation, maintaining natural vegetation buffer areas that protect riparian
habitats, minimizing alteration of natural streams.
Since HOODS and the proposed expansion footprint are seaward of the coastal zone
boundary, the Commission must evaluate the proposal for potential spillover effects on
coastal resources in the coastal zone. In its consistency determination EPA examined the
future use of the proposed expansion area for the potential to adversely affect water
quality and marine resources of the adjacent coastal zone.
The HOODS Expansion Draft Environmental Assessment (DEA) examined benthic habitat
and potential adverse effects from expansion of HOODS:
The benthic habitat at HOODS and throughout the HOODS expansion area
is a gently sloping, essentially featureless sedimentary plain that grades
evenly from fine sand in shallower depths to silts in deeper areas. As
described in the EIS and confirmed via the monitoring surveys in 2008 and
2014 (EPA, 2016, Appendix A), the benthic communities supported by this
habitat are virtually identical (i.e. infaunal organism density and richness are
not significantly different) at similar depths north to south across the entire
study area . . .
10
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CD-0001-20 (USEPA)
The initial monitoring in 2008, and the more extensive monitoring in 2014,
each documented a community of infaunal invertebrates (living in or on the
sediment) in the vicinity of HOODS that is dominated by small polychaetes
(marine worms), crustaceans, and mollusks . . . Only directly atop the
disposal mound itself, which is annually disturbed by disposal of large
volumes of clean sand, was there any effect on the infaunal community at all
as indicated by organism density, species richness, or diversity (Figure 14).
The EPA concluded that expansion of HOODS will allow greater flexibility to manage
disposal in the future over a larger area to reduce the frequency of repeated deposition of
sand in the same location (as has occurred over the last several years). Site expansion
and the distribution of disposed sediment over a larger area will result in individual disposal
areas having more time for benthos recolonization before disposal would occur again at
that location, thus increasing benthic habitat quality and biological productivity across the
HOODS expansion footprint compared to what currently exists on the sand mound at the
existing HOODS.
The DEA states that pelagic and benthic fish species may be present in the vicinity of
HOODS and the expansion area but that:
The HOODS area was identified in the 1995 EIS as having the least potential
for impacts to important fish and shellfish resources (including smelt, flatfish,
and decapods which are all most abundant in waters shallower than 50 m
[164 feet] in the area, closer to shore). It concluded that the potential for
impacts to other more pelagic and/or mobile species (including salmonids
and other fishes, as well as seabirds, marine mammals, and turtles) was
negligible due to the seasonal nature of disposal activity, the fact that the
majority of material disposed was expected to be sand (i.e., having lowest
potential for lasting turbidity or contaminant effects), and the lack of any
unique habitat features that would make the disposal site's location more
attractive, productive, or valuable to these species than the surrounding
region.
The existing HOODS and the expansion area overlap with species and habitats managed
under the 2016 Pacific Salmon Fisheries Management Plan (FMP), the 2016 Pacific Coast
Groundfish FMP, and the 2019 Coastal Pelagic Species FMP. The EPA determined in the
DEA that the proposed HOODS expansion will not affect fish species addressed in these
FMPs because only suitable clean sediment is considered for disposal at HOODS; the vast
majority of material disposed is sand, which settles to the ocean floor very quickly and
does not substantially spread outside the disposal site boundaries; and water column
turbidity effects are extremely temporary with no cumulative effect between disposal
events.
Regarding marine resources and habitats at the HOODS expansion area, EPA's
consistency determination concluded that:
Monitoring has confirmed that no significant adverse impacts have occurred
outside the disposal site boundaries as a result of over 25 million cubic yards
11
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CD-0001-20 (USEPA)
of dredged material disposal at HOODS since its designation in 1995.
Surveys of the proposed expansion footprint confirm that there are no unique
or limited habitats that would be affected by expanding the boundaries of the
site, and no new or different impacts are expected as a result of continued
disposal of material there under a management plan similar to what has been
in place for the existing site.
The Commission concurs with EPA's determination that the HOODS expansion
area does not support rare or unique marine habitat but rather is comprised of soft-
bottom habitat that extends far beyond the expansion footprint. While benthic
organisms present in the expansion area will periodically be covered by disposed
material, monitoring of HOODS has demonstrated that disposal will not result in any
adverse long-term effects to this habitat type given its abundance in the region and
the ability of benthic organisms to rapidly recolonize disturbed areas.
Dredged sediment can only be disposed at HOODS when the sediment is determined
suitable for ocean disposal. Suitable means that the sediment has no more than trace
levels of chemical pollutants as determined by bioassays, and that any chemical pollutants
present would not bioaccumulate in the food web to levels of ecological or human health
concern. EPA states that:
Clean sand dredged from high energy areas that are removed from
immediate sources of pollution can often be determined by EPA and USACE
to be suitable for ocean disposal without conducting extensive physical,
chemical, and biological testing each year. This is true of Humboldt Bay
entrance channel sand.
Other sediments from within Humboldt Bay proposed for disposal at HOODS must be
tested in order to evaluate potential disposal effects on water quality and to support a
suitability determination. This involves preparation of a sediment sampling and analysis
plan, and subsequent physical, chemical, and, if necessary, bioassay testing of sediment
samples. Only sediments determined by EPA and the Corps of Engineers to be suitable for
ocean disposal will be allowed for placement at the expanded HOODS. The consistency
determination further states that:
Specifically, no material may be disposed at HOODS (or other ocean
disposal sites) that would result in a violation of water quality standards after
allowance for initial mixing within the boundaries of the disposal site. This
includes biological testing of the elutriate (suspended particulate phase) in
order to address the narrative water quality standard (no toxicity after initial
mixing).
The DEA cites EPA's 2016 Monitoring Synthesis Report which states that monitoring at
HOODS over the last decade has determined that:
. . . there has been no significant contaminant loading and no significant
adverse impacts are apparent to the benthic environment outside of the site
boundaries. It therefore appears that the EPA/USACE pre-disposal sediment
12
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CD-0001-20 (USEPA)
testing program, coupled with a strict site management approach, has
protected HOODS and its environs from adverse chemical or biological
impacts.
The DEA and the consistency determination state that 90 percent or more of all disposals
at HOODS consist of clean entrance channel sand that includes very little in the way of
fines. As a result, increased levels of turbidity in the water column at a disposal site likely
persist for less than 15 minutes before returning to ambient conditions, with no cumulative
effects of turbidity or suspended solids on the water column. The DEA also notes that
"clean sand has the shortest residence time in the water column before settling out, and
which also has the least potential to carry contamination which may strip off into the water
column before settling." The Commission concurs with EPA's determination that future
dredged material disposal in the HOODS expansion area will result in only temporary
increases in water column turbidity and that no long-term adverse effects to water quality
at disposal sites will occur.
In conclusion, the Commission finds that the HOODS expansion area and adjacent areas
do not include unique or sensitive marine habitats. Use of HOODS over the last 25 years
has not resulted in adverse impacts to marine resources or water quality. Monitoring by the
EPA of the expanded HOODS for potential adverse effects on marine resources and water
quality will continue and will identify any unanticipated potential long-term and/or
cumulative impacts from dredged material disposal. Should effects to any marine
resources or to water quality be determined as part of the monitoring required in the
updated Site Management and Monitoring Plan, the EPA can and will implement
management alternatives to minimize those impacts.
In addition, and as the Commission found in its concurrence with the designation of
HOODS in 1995 (CD-072-95), if monitoring of sediment disposal at the expanded HOODS
indicates coastal zone impacts substantially different than anticipated, the Commission can
use the federal consistency reopener provisions of the Coastal Zone Management Act (15
CFR § 930.45 and 930.46) and determine if the HOODS expansion remains consistent
with the Chapter 3 policies of the Coastal Act. Finally, the Commission or its Executive
Director will continue to review consistency or negative determinations, respectively, for all
disposal projects at the expanded HOODS. This continued regulatory oversight by the
Commission will ensure that protection of marine resources and water quality remains a
high priority during the evaluation of dredged material disposal projects at the expanded
HOODS. Therefore, the Commission finds the proposed expansion of HOODS consistent
with the marine resources and water quality protection policies of the Coastal Act (Sections
30230 and 30231).
E. Recreational and Commercial Fishing
Coastal Act Section 30220 states:
Coastal areas suited for water-oriented recreational activities that cannot
readily be provided at inland water areas shall be protected for such uses.
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CD-0001-20 (USEPA)
Coastal Act Section 30234 states:
Facilities serving the commercial fishing and recreational boating industries
shall be protected and, where feasible, upgraded. Existing commercial
fishing and recreational boating harbor space shall not be reduced unless the
demand for those facilities no longer exists or adequate substitute space has
been provided. Proposed recreational boating facilities shall, where feasible,
be designed and located in such a fashion as not to interfere with the needs
of the commercial fishing industry.
Coastal Act Section 30234.5 states:
The economic, commercial, and recreational importance of fishing activities
shall be recognized and protected.
The commercial and recreational fishing industries are vital coastal-dependent
components of the area's coastal economy. The Commission considers an effect on those
industries to constitute a coastal resource impact. Thus, impacts to important fish species,
or to marine life on which those species depend, are effects on those industries. The
previous section of this report explained that the selection of the existing HOODS was
based in part on the fact that this location (of those examined in the designation EIS) had
the least potential for adversely affecting fish and shellfish resources that are important to
the commercial and recreational fishing industries of the region. This finding was based the
lack of any unique habitat or locational features that would make HOODS more attractive,
productive, or valuable to fish resources than the surrounding waters offshore of Humboldt
Bay. Also noted previously was the DEA's finding that the 25-year use of HOODS has not
and the proposed expansion would not adversely affect salmonids, groundfish, or coastal
pelagic fish species. The DEA further states that HOODS itself is not off limits to
commercial, recreational, or tribal fishing activities, and expansion of HOODS would not
result in curtailment of ongoing allowable fishing operations.
The proposed expansion of HOODS will provide adequate room for disposal of sediments
dredged from navigation channels in Humboldt Bay, an activity necessary to support
vessel traffic entering and leaving Humboldt Bay. Failure to expand the capacity at
HOODS could adversely affect commercial and recreational fishing by restricting the ability
to eliminate hazardous shoals in the Entrance Channel and inner bay channels and
berthing areas. Annual maintenance dredging in Humboldt Bay that relies on the
availability of disposal capacity at HOODS is essential for the continued operation of the
commercial and recreational fishing fleet based in Humboldt Bay. The proposed expansion
of HOODS will provide support to this vital industry. Therefore, the Commission finds that
proposed expansion of HOODS will not adversely affect fishery habitat or fish species in
the region, will provide the needed capacity to accept sediments dredged from navigation
channels critical to the fishing industry in Humboldt Bay, and is consistent with the
commercial and recreational fishing policies of the Coastal Act (Sections 30230, 30234,
and 30234.5).
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CD-0001-20 (USEPA)
F. Sand Supply
Coastal Act Section 30233(b) states in part:
Dredging and spoils shall be planned and carried out to avoid significant
disruption to marine and wildlife habitats and water circulation. Dredge spoils
suitable for beach replenishment should be transported for these purposes to
appropriate beaches or into suitable longshore current systems.
As discussed in Section D of this report, the proposed expansion of HOODS is consistent
with Coastal Act sections intended to protect and avoid significant disruption to marine
habitats. The proposed expansion also supports the avoidance of significant impacts to
water circulation and wave climates. The EPA's consistency determination states:
...to date mounding of sand at HOODS has not affected waves in the area.
However, mounding to shallower depths does have the potential to begin
affecting the local wave climate... Expanding HOODS is specifically intended
to ensure that mounding to shallower depths does not occur.
The remainder of the criteria stated Section 30233(b), concerning the need for suitable
dredge spoils to be kept within the littoral system, are considered in the following
paragraphs.
The precise level of compatibility of dredged spoils for a given beach nourishment location
ultimately depends on the site-specific testing of grain size and other sediment features at
that particular location. However, given the inevitable trajectory of sediment coming from
the Humboldt Bay channels, it is reasonable to assume that most of the dredged materials
would be suitable for nourishment of the nearby beach areas. In fact, approximately 90%
of the dredge materials from the Bar and Entrance channels as well as the lower portion of
the North Bay channels are comprised of fine sand with an average grain size of 0.2mm
(EPA 2020 Draft EA). Dredged materials from the inland channels are comprised of finer
silt and clay sediments that would not be suitable for beach nourishment.
In an effort to consider all viable options to retain sediment within the local littoral system,
the use of previous nearshore disposal sites was evaluated in the EPA's 2020 Draft EA.
However, each preexisting site was deemed infeasible due to navigation and fisheries
issues. Expanding HOODS was therefore selected as the preferred disposal alternative as
it would have no significant adverse effects on the environment. Concurrently, and
recognizing the overarching need to retain federal navigation channel sediments within the
littoral system, the EPA also evaluated in the HOODS expansion DEA a potential
Nearshore Sand Placement Site (NSPS). This potential NSPS is located along the North
Spit (Exhibits 1 and 3) and may be a viable option for a pilot nearshore disposal project.
However, EPA determined that this nearshore site was not currently a feasible alternative
to expanding HOODS due to the need for a monitored and successful pilot project at this
location and the need for subsequent regulatory actions by EPA and the Corps of
Engineers for site designation.
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CD-0001-20 (USEPA)
The HOODS expansion DEA states that the USACE identified a potentially appropriate
nearshore sand placement site in 2012 but did not pursue designating a site at that time.
However, the DEA notes that:
This EA provides documentation pursuant to NEPA and other applicable Acts
that USACE may use as a basis for proposing to conduct future
demonstration nearshore sand-placement operations. Any proposal to
formally establish a nearshore site would be a separate EPA-USACE action
pursuant to the CWA Section 404(b)(1) Guidelines (40 CFR Part 230.80),
informed by monitoring results associated with such a demonstration project.
The Commission has consistently encouraged evaluation of alternate nearshore sand
disposal sites during its review of Corps of Engineers consistency determinations for
annual maintenance dredging of the federal channels at Humboldt Bay and disposal at
HOODS. The EPA addressed this sediment retention issue, the continued use of HOODS,
and a potential nearshore placement site in its consistency determination:
Annual dredging of the Humboldt Bay Federal Channels by the USACE
generates an average of 1 million cubic yards of clean sand that is indeed
suitable for nearshore placement to support the littoral cell and help buffer
against the effects of coastal erosion and sea level rise. EPA strongly
supports such use and believes that if a nearshore sand placement site is
established in the future the entrance channel sand historically disposed at
HOODS (outside the littoral zone) should be placed at the nearshore site to
the maximum extent practicable. To that end, the EA for expanding HOODS
discusses a potential Nearshore Sand Placement Site (NSPS) in substantial
detail. The intent of that discussion is to facilitate a possible future monitored
pilot project (and the EA even includes a recommended monitoring program).
Such a pilot project could provide the data necessary to allow Federal and
State agencies to consider formal approval of a NSPS for ongoing use. If an
NSPS were to be designated, not only could a substantial volume of sand be
returned to the local littoral cell, but the effective lifetime of the expanded
HOODS would be substantially extended. Note however that establishment
of a NSPS would be a separate action, and that action would occur pursuant
to the Clean Water Act. The expansion of HOODS is occurring under the
Marine Protection, Research, and Sanctuaries Act (aka the Ocean Dumping
Act), and the need to expand HOODS is independent of the current
availability of a potential NSPS.
At the time of the 1995 HOODS designation by EPA and the Corps, the Commission
expressed concerns that the annual disposal of large volumes of sand at HOODS could
potentially create adverse effects on nearby beaches. As a result, the Corps established
the Humboldt Shoreline Monitoring Program (HSMP) as part of the original HOODS
designation in order to: (1) monitor the surrounding shoreline for excessive shoreline
retreat; (2) determine the cause of any excessive shoreline retreat that is observed; and
(3) recommend corrective action should sediment disposal at HOODS be the cause.
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CD-0001-20 (USEPA)
The HSMP uses aerial photography to determine the shoreline position change over time
along the North and South Spits adjacent to the entrance channel. Exhibit 3 depicts some
of the results from this monitoring, clearly indicating that the North Spit has been eroding
over the last several decades while the South Spit has more or less been accreting
sediment. The magnitude and rate of erosion however is highly dependent on the relative
baseline used in the calculations. Prior to 2016, the Corps used the shoreline position from
1974-1990 as the baseline for determining whether "excessive erosion" had occurred.
However, it was later determined that the 1974-1990 period could not adequately
represent baseline shoreline conditions due to the extensive jetty modifications during that
time period. As such, the Corps and the Commission revisited the "excessive erosion"
criteria during the review of CD-0005-18 (for the Corps' 2019 maintenance dredging of the
Humboldt Bay federal channels) and established that the baseline should instead be
based upon the 1948-1974 timeframe in order to adequately capture the effects of
potential erosion due to offshore disposal at HOODS.
In its concurrence with CD-0005-18, the Commission found that:
... (2) there remains a level of uncertainty regarding the significance of
erosion on the North Spit arising from placement of dredged sediments
outside the littoral cell at HOODS; (3) the use of the recommended 1948 to
1972 shoreline change rate (rather than the currently-used 1974-1990 rate)
in the next shoreline monitoring update is expected to determine if excessive
shoreline retreat has persisted along the North Spit. . .
The Corps will update the shoreline monitoring report using the new 1948-1974 baseline
after it undertakes the next round of aerial photos, expected to occur before 2023. Absent
the results of these new erosion calculations, erosion resulting from disposal offshore at
HOODS cannot yet be definitively determined. The Commission looks forward to working
with the Corps and the EPA to interpret the upcoming shoreline monitoring report and to
advance the development of a pilot nearshore placement project should excessive
shoreline retreat on the North Spit be confirmed.
The proposed expansion of HOODS will provide adequate capacity for disposal of clean
dredged sediments from Humboldt Bay navigation channels for decades to come. The
EPA states that while disposal at HOODS will not result in adverse impacts, "neither does
offshore disposal provide any direct environmental benefits." Shallow water placement of
clean sand can nourish the littoral system and help buffer against coastal erosion and the
effects of sea level rise. The Commission notes that even with the expansion of HOODS it
will continue to evaluate proposed disposal projects on a case-by-case basis. Even if
dredged sediment is determined to be physically and chemically suitable for ocean
disposal, that disposal alternative can only be approved under Coastal Act Section
30233(b) if there are no feasible beneficial re-use alternatives available given a particular
project's location, timing, and logistics. The proposed expansion of HOODS does not
relieve sponsors of future dredging projects of the requirement to undertake a rigorous
disposal alternatives analysis in order to determine if beneficial reuse of dredged materials
is feasible. The HOODS expansion does not preclude the Commission from requiring
beneficial reuse of dredged sediments should such an alternative prove feasible.
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CD-0001-20 (USEPA)
Therefore, given the lack of a designated suitable nearshore placement site at this time, or
of other feasible alternative disposal sites capable of handling up to one million cubic yards
of clean dredged sediments from Humboldt Bay, the Commission finds the EPA's
proposed expansion of HOODS is consistent with the sand supply policy of the Coastal Act
(Section 30233(b).
SUBSTANTIVE FILE DOCUMENTS
1. CD-0001-20 (U.S. Environmental Protection Agency, Enlarging the Existing
Humboldt Open Ocean Disposal Site (HOODS) offshore of Eureka, CA).
2. Draft Final Environmental Assessment for Expansion of the Existing Humboldt
Open Ocean Disposal Site (HOODS) offshore of Eureka, CA, USEPA and USACE,
July 2020.
3. Draft Final Rule for Modification of an Ocean Dredged Material Disposal Site
Offshore of Humboldt Bay, California, USEPA.
4. CD-072-95 (U.S. Environmental Protection Agency, Permanent Designation of
Humboldt Open Ocean Disposal Site).
5. CD-0005-18 (U.S. Army Corps of Engineers, 2019 Maintenance Dredging of
Federal Navigation Channels at Humboldt Bay and Disposal at HOODS).
6. CD-0005-17 (U.S. Army Corps of Engineers, 2018 Maintenance Dredging of
Federal Navigation Channels at Humboldt Bay and Disposal at HOODS).
7. CD-0002-17 (U.S. Army Corps of Engineers, 2017 Maintenance Dredging of
Federal Navigation Channels at Humboldt Bay and Disposal at HOODS).
8. ND-0007-16 (U.S. Army Corps of Engineers, 2016 Maintenance Dredging of
Federal Navigation Channels at Humboldt Bay and Disposal at HOODS).
9. Marine Protection, Research and Sanctuaries Act (MPRSA) of 1972.
18
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STATE OF CALIFORNIA - CALIFORNIA NATURAL RESOURCES AGENCY
GAVIN NEWSOM, GOVERNOR
CALIFORNIA COASTAL COMMISSION
455 MARKET STREET, SUITE 228
SAN FRANCISCO, CA 94105-2219
VOICE (415) 904-5200
FAX (415) 904-5400
F 11a
CD-0001 -20 (EPA)
September 17, 2020
EXHIBITS
Table of Contents
Exhibit 1 - Project Location Map
Exhibit 2 - Bathymetry Map of Current and Proposed HOODS Boundaries
Exhibit 3 - U.S. Army Corps of Engineers Shoreline Monitoring of North and
South Spits
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Figure: Proposed Action area, showing the current HOODS site and the two boundary expansion alternatives in
relation to Humboldt Bay, the City of Eureka, and the Samoa State Marine Conservation Area.
Alternative 1 (proposed action, in yellow) would expand the existing boundaries by 1 nmi to the north
and west. Also shown is the location of the potential Nearshore Sand Placement Site and the HOODS
sediment reference site.
Buoy 46244
9
Alternative 1
HOODS
Boundary
Alternative 2
HOODS
Boundary
State Marine
Conservation Arn.j /
tSmmm'i
i
Existing
HOODS S
(No Action)
v /
y
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I Nearshore Sand
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Table: HOODS Expansion Alternative 1 (proposed action) corner coordinates (NAD 83)
Comer
Latitude
Longitude Centroid Lat. Centroid Long.
North
40* 50' 18"
N
124* lS'Ol" W
East
40* 49' 16"
N
124* 15' 46" W
40* 48' 56" N
124' 17' 32" W
South
40' 47' 33"
N
124° 17' 05" W
West
40* 48' 34"
N
124' 19" 18" W
Exhibit 1
CD-0001-20
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• SPinanon
~ Euitmg HOOOS
I I Ptxentul HOOOS E*pamaon Study *»ea
Humboldt
Soy
Rgure 13. Sampling stations for the 2014 EPA monitoring and baseline surveys at HOOOS.
Red box is the existing HOODS boundary, while the larger blue box shows the expanded study
area within which expansion of HOOOS is being considered. Shaded relief bathymetry
depicted within the expanded study area was obtained from a high-resolution MBES survey in
August 2014. September 2014 sampling included sediment images obtained from all 51
stations, sediment grab samples for physical and chemical analysis collected from 26
stations, and benthic community samples collected at 25 of those stations (EPA 2016).
Exhibit 2
CD-0001-20
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Humboldt Harbor USACE Shoreline Monitoring
Shift of Reference Beachface Contours
Relative to 1992 (106 yd3)
•Sm It
Z loo
ai u
c «
0
Q S 100
11995 A
12005 A
2016 A
|MH
7S 6S SS 4S 3S 2S IS IN IB 1C 2N 3N «N SN 6N 7N
Station
• The Reference Contour is -11 ft above MLLW
• Light green rectangle shows the approximate
longshore location of the NSPS off the eroding
North Spit ra-"gi
/ NSPS
t (Proposed)
Figure 22. Reference stations and shoreline shifts at selected surveys (1995. 2005. and 2016) relative to the initial
survey (1992).
Exhibit 3
CD-0001-20
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From:
To:
Subject:
Date:
Simon. LarrvOCoastal
Ross. Brian
CD-0001-20
Friday, October 9, 2020 1:24:56 PM
Hi Brian,
On October 9, 2020, the California Coastal Commission unanimously concurred with
consistency determination CD-0001-20 for expansion of the Humboldt Open Ocean
Disposal Site. The Commission found that the project was consistent with the
California Coastal Management Program. Please contact me should you have any
questions about this matter. Best regards,
Larry
Larry Simon
Manager, Federal Consistency Unit
Energy, Ocean Resources and
Federal Consistency Division
California Coastal Commission
455 Market Street, Suite 228
San Francisco, CA 94105-2219
(415) 904-5288
larry.simon@coastal.ca.gov
www.coastal.ca.gov
NOTE: G iven that the Commission office is closed indefinitely due to the COVID-19 pandemic,
all correspondence, including federal consistency submittals, should be conveyed to me via
email during this time period.
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