[Federal Register Volume 84, Number 215 (Wednesday, November 6, 2019)]
[Notices]
[Pages 59773-59794]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-24190]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XR043


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Astoria Waterfront Bridge 
Replacement Phase 2 Project

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from the City of Astoria (City) 
for authorization to take marine mammals incidental to pile driving and 
construction work in Astoria, OR. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an incidental harassment authorization (IHA) to incidentally take 
marine mammals during the specified activities. NMFS is also requesting 
comments on a possible one-year renewal that could be issued under 
certain circumstances and if all requirements are met, as described in 
Request for Public Comments at the end of this notice. NMFS will 
consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorizations, and agency responses 
will be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than December 
6, 2019.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities without change. All 
personal identifying information (e.g., name, address) voluntarily 
submitted by the commenter may be publicly accessible. Do not submit 
confidential business information or otherwise sensitive or protected 
information.

FOR FURTHER INFORMATION CONTACT: Leah Davis, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems 
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth.
    The definitions of all applicable MMPA statutory terms cited above 
are included in the relevant sections below.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment. This action is consistent with categories of 
activities identified in Categorical Exclusion B4 (incidental 
harassment authorizations with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has 
preliminarily determined that the issuance of the proposed IHA 
qualifies to be categorically excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On June 3, 2019 NMFS received a request from the City of Astoria 
(City) for an IHA to take marine mammals incidental to pile driving and 
construction work in Astoria, Oregon. The application was deemed 
adequate and complete on October 17, 2019. The

[[Page 59774]]

City's request is for take of a small number of California sea lion 
(Zalophus californianus) and harbor seal (Phoca vitulina richardii) by 
Level A and Level B harassment, and a small number of Steller sea lion 
(Eumetopias jubatus) by Level B harassment only. Neither the City nor 
NMFS expects serious injury or mortality to result from this activity, 
and, therefore, an IHA is appropriate.
    This proposed IHA would cover one year of a larger, two-year 
project that involves removal and replacement of six bridges on the 
Astoria, Oregon waterfront. NMFS previously issued an IHA to the City 
for removal and replacement of three bridges (83 FR 19243, May 2, 
2018). The City complied with all the requirements (e.g., mitigation, 
monitoring, and reporting) of the previous IHA and information 
regarding their monitoring results may be found in the Proposed 
Monitoring and Mitigation Section. The monitoring report exposed the 
need for clarification of monitoring requirements, specifically those 
involving Protected Species Observer (PSO) coverage of Level A and 
Level B zones. NMFS has clarified those requirements with the 
applicant.

Description of Proposed Activity

Overview

    The City of Astoria, Oregon proposes to remove and replace three 
bridges connecting 6th, 8th, and 10th Streets with waterfront piers 
near the mouth of the Columbia River. The bridges are currently 
supported by decayed timber piles. Among all three bridges, an 
estimated 150 timber piles will be removed as will other timber 
structural elements and concrete footings. 65 temporary 36-inch steel 
casings will be installed to help guide the installation of 65 
permanent 24-inch steel piles. Pile driving and removal activities will 
be conducted using a vibratory and impact hammer. The contractor may 
need to conduct preboring inside of the temporary casings using a 
vibratory hammer and a 14-inch H-pile to prepare the new pile sites. In 
the event that preboring is not effective, the contractor may conduct 
down-the-hole drilling inside of the 36-inch piles to prepare the site 
for the permanent piles. It is unlikely that the contractor will need 
to conduct down-the-hole drilling, as it was not necessary during Phase 
1. The roadway and railway superstructures will also be replaced, and a 
temporary, above-water work platform will be created for the 
construction. The use of vibratory and impact hammers for pile driving 
and site preparation is expected to produce underwater sound at levels 
that may result in behavioral harassment or auditory injury of marine 
mammals. Human presence and use of general construction equipment may 
also lead to behavioral harassment of sea lions hauled out along the 
riverbank below the bridges.
    The impacted area extends outward from the three bridge sites to a 
maximum distance of 21.54 km (13.28 mi). The project will occur over 
one year beginning in December 2019, with in-water activities expected 
to occur over an estimated 21 days during the months of November 
through April.

Dates and Duration

    The IHA will be effective from December 2019 to October 2020. 
Project work is expected to begin in November 2019 with concurrent 
above-water and in-water demolition activities. In-water activities 
will be conducted during the Oregon Department of Fish and Wildlife-
prescribed in-water work period (IWWP) for the Lower Columbia River 
(November-February). The IWWP is imposed to protect the following 
species: MAR (various marine species of fish), SHL (various marine 
shell fish), CHF (Chinook salmon, fall), CHS (Chinook salmon, spring), 
SS (sockeye salmon), CO (coho salmon), STW (steelhead winter), STS 
(steelhead summer), CT (cutthroat trout--including sea run). It is 
possible that the City will request an IWWP extension through April. 
In-water construction activities will occur intermittently over the 
entire proposed IWWP, and above-water work is expected to occur during 
the IWWP and over the remainder of the IHA period. Work will take place 
over approximately 21 in-water work days, and 11 days per month for 
over-water activities.

Specific Geographic Region

    The project site is located in the Baker Bay-Columbia River sub-
watershed near the mouth of the Columbia River. This section of the 
lower Columbia River represents the most saline portion of the river's 
estuarine environment. Tidal influence extends 146 miles upriver to the 
Bonneville Dam (LCEP, 2016). The Columbia River is over nine miles wide 
in the area around Astoria and contains multiple islands, buoys, and 
sandbars that marine mammals utilize to haul out. The upland portions 
of the region of activity have been highly altered by human activities, 
with substantial shoreline development and remnants of historical 
development. This includes thousands of timber piles, overwater 
buildings, a railroad trestle, and vehicular bridges. The downtown 
Astoria waterfront is a busy area for pedestrians, vehicles, and boats. 
In addition to onshore development, the lower Columbia River is 
utilized by various types of vessels, including cargo ships, dredging 
vessels, fishing vessels, trawlers, pollution control vessels, and 
search and rescue vessels, among others. The remainder of the region of 
activity is located within the river channel within the intertidal and 
subtidal zones. The substrate in this area is primarily made up of 
historical rip rap and other rocks/cobbles.
    All in-water construction will occur in the intertidal and subtidal 
zones. Some piles may be removed and installed completely in the dry 
while others may be in water more than 75 percent of the time.

[[Page 59775]]

[GRAPHIC] [TIFF OMITTED] TN06NO19.000

Detailed Description of Specific Activity

    Phase two of the project involves the removal and replacement of 
three bridges connecting 6th, 8th, and 10th Streets to waterfront 
piers.
    Demolition Activities--Demolition of the existing bridge crossings 
will require the removal of the bridge decks and other above-ground 
components for the trestle crossings and roadway approaches. Demolition 
of the superstructures will likely be accomplished using standard 
roadway and bridge construction equipment, including an excavator, 
backhoe, jackhammer, and concrete and chain saws, as well as a crane 
will be used to remove larger timber elements. Source levels for these 
equipment are included in Table 1. Source levels are mostly based on 
acoustic data collected during the City of San Diego Lifeguard Station 
Demolition and Construction Monitoring project. All equipment will be 
operated from the existing roadway, trestle, and upland areas, and 
removed materials will be hauled off-site to an approved upland 
location for disposal.

   Table 1--Superstructure Construction Equipment Sound Source Levels
------------------------------------------------------------------------
                                   Peak source
                                 level (dB root
           Equipment              mean squared          Reference
                                  (RMS)) at 20
                                     meters)
------------------------------------------------------------------------
Air Compressor.................              78  WSDOT, 2016.
Backhoe........................              78  Hanan & Associates,
                                                  2014.
Chain Saw......................              78
Concrete Saw...................              93
Crane..........................              89
Excavator......................              91
Generator Powered Jackhammer...              87
Hand Tools.....................              85
------------------------------------------------------------------------

    Construction activities associated with removal of the roadway 
approach superstructures will be situated away from the river. 
Buildings and other above-grade structures will reduce noise by 
physically blocking it and reflecting it away from the river, due to 
structural noise reduction (FHWA, 2011). The pier structures will also 
block noise from reaching the river and bank areas by deflecting it 
upwards. Based on the sound levels produced by the proposed equipment, 
existing site conditions, the likely location of the pinnipeds within 
the area in relation to the associated construction activities, and 
Phase 1 monitoring, removal of the roadway approach superstructures is 
not expected to disturb nearby marine mammals, and will not be 
considered further.
    At each of the three bridge sites, the City will remove 
approximately 50 existing 14-inch timber piles (Table 2) using a 
vibratory hammer and via direct pull. Abandoned, cutoff timber piles 
that are located within close proximity to proposed pile locations will 
also be removed. Old pilings are often in very poor condition near and 
above the ground surface, making attachment to the pilings for 
extraction very difficult. Old vertical piles and other obstructions 
encountered near the surface may need to be extracted or cut below the 
ground surface elevation per Federal Aid Highway Program (FAHP) 
programmatic criteria. Due to uncertainty in the precise timing of 
extraction, and therefore the tidal state, all piles are assumed to be 
in-water during removal in effort to conduct a conservative analysis of 
the project impacts.

[[Page 59776]]

    The City estimates it will remove approximately 15 additional 
structural elements at each bridge site, consisting of the timber 
columns, bottom plates, lower braces and/or cross bracings. These 
elements will be removed during low tides and will not require the use 
of a vibratory hammer. Standard construction equipment will be used to 
remove these elements.
    In addition to the timber substructures, an estimated seven 
concrete footings will need to be extracted, two at the 8th Street 
bridge, and five at the 10th Street bridge. It is anticipated that the 
contractor will use an excavator, positioned on the existing roadway or 
adjacent gravel/asphalt parking areas, to reach down and remove the 
concrete footings. If the vertical or horizontal distance makes a 
footing unreachable, the contractor will likely drill an anchor into 
the concrete then attach the crane to the anchor with a chain and pull 
upwards to extract the concrete. The existing concrete footings are 
located just below/above the MHHW elevation, so this work is likely to 
occur in the dry during low tides.
    The contractor will set up temporary work containment systems to 
catch debris during demolition activities. Selection of the appropriate 
equipment and design of the work containment systems is the 
responsibility of the contractor; however, additional pilings to 
support these structures are not anticipated as the contractor will 
utilize the existing substructure to support them.
    Site Preparation for New Bridges--A total of 65 permanent, 24-inch 
steel piles are proposed for this project, as well as installation and 
removal of 65 temporary 36-inch steel casings (Table 2). The contractor 
is likely to create a template to facilitate pile installation. The 
template will consist of a grid pattern in-line with the existing 
boardwalk grade comprised of steel H-piles and steel angle iron/
channels, among other materials. The template will guide the vibratory 
installation of 36-inch temporary casings at the locations of all new 
24-inch steel piles.
    A variety of large debris and fill may be present at the pile 
sites, given the history of the area, results from the preliminary 
geotechnical investigation during which most of the borings encountered 
riprap, and Phase 1 construction. To avoid inducing unacceptable 
vibration levels on adjacent structures, the contractor may predrill 
the piling locations to an elevation of about 3 feet below 
mean sea level (msl); though the need to predrill will be determined 
on-site once the contractor has identified the exact pile locations. 
Predrilling work, also referred to as down-the-hole drilling, would be 
conducted inside the 36-inch temporary casings, and no sediment will be 
removed from within the temporary casing during this site preparation 
activity. The source level for down-the-hole drilling (166.2dB RMS SPL, 
Denes et al., 2016) is below the source level for vibratory 
installation of 36'' piles (Table 6). Predrilling was not required 
during Phase 1 of the project, and the applicant considers it unlikely 
for this phase; therefore, the analysis for vibratory installation of 
36-inch piles was used to estimate the Level B harassment zone for 
potential down-the-hole drilling, and the impact installation of 24-
inch piles was used to estimate the Level A harassment zone. (See 
additional explanation in the Ensonified Area section below.) If pre-
drilling is not required, the contractor may use a 14-inch H-pile 
equipped with a torched point at the end to break up the ground at each 
piling location using the vibratory hammer. The H-pile site preparation 
was used in Phase 1. The contractor may also manually remove riprap and 
other obstructions from the riverbed and banks, if such materials 
prohibit the installation of the temporary casings and permanent 
pilings.
    Bridge Design--The 6th Street Bridge will require a total of 21 
plumb piles. Estimated pile depths range from -74 to -77 feet below 
msl. The trestle crossing will consist of two end bents and one 
interior bent each consisting of three piles. The trolley bridge will 
be constructed using precast concrete tee beams. The roadway approach 
will consist of two bents supported by a total of 12 steel piles, with 
a pre-cast prestressed slab bridge.
    The 8th Street Bridge will consist of a total of 23 plumb piles. 
Estimated pile depths range from 84 to -85 feet below msl. The trestle 
crossing will consist of two end bents, one comprised of four piles and 
the other composed of three piles, and one interior bent comprised of 
four piles. The trolley bridge will be constructed using precast 
concrete tee beams. The roadway approach will consist of two bents 
supported by a total of 12 steel piles, with a pre-cast prestressed 
slab bridge.
    The 10th Street Bridge will consist of a total of 21 plumb piles. 
Estimated pile depth is -64 feet below msl. The trestle crossing will 
consist of two end bents and one interior bent each comprised of three 
piles. The trolley bridge will be constructed using precast concrete 
tee beams. The roadway approach will consist of two bents, each 
constructed on six piles for a total of 12 piles, with a pre-cast 
prestressed slab bridge.
    Bridge Construction--The contractor will install a temporary 36-
inch casing at the site of each of the 65 permanent, 24-inch piles. The 
temporary casings will be installed to a depth of approximately 7 feet 
below the ground surface elevation using a vibratory hammer. The 
permanent piles will be installed inside the casings, and will be 
driven open-ended into very soft siltstone and mudstone to develop the 
required axial resistance using a vibratory hammer followed by a diesel 
impact hammer. It is estimated that the contractor will be able to 
advance the permanent piles to roughly 80 percent of the desired depth 
using the vibratory hammer, then will use the diesel hammer to seat the 
piles at the desired depths.

                      Table 2--Pilings Expected To Be Removed and Installed at Each Bridge
----------------------------------------------------------------------------------------------------------------
                                                                               36-inch temporary
                                                                Timber piles      steel casings    24-inch steel
                            Bridge                                 removed      (each installed     piles to be
                                                                                  and removed)       installed
----------------------------------------------------------------------------------------------------------------
6th Street Bridge............................................              50                 21              21
8th Street Bridge............................................              50                 23              23
10th Street Bridge...........................................              50                 21              21
                                                              --------------------------------------------------
    Total....................................................             150                 65              65
----------------------------------------------------------------------------------------------------------------


[[Page 59777]]

    The contractor has six temporary casings on-site, so they will need 
to remove the casing once the permanent 24-inch piles are advanced to a 
low enough depth with the vibratory hammer that the casing prohibits 
driving the 24-inch pile with the diesel impact hammer. Removal of the 
temporary casings will be completed using a vibratory hammer. The 
removed pile will then be positioned elsewhere within the template to 
guide additional pile installation. All bridge construction equipment 
will be operated from the existing roadway and upland areas.
    It is anticipated that the contractor may employ two crews during 
construction. These crews would work concurrently at two different 
bridge sites to keep the project on schedule. Implications for project 
analysis and potential take are discussed in the Ensonified Area 
section, below.
    Abutment Wingwalls--Wingwalls will need to be constructed at the 
10th Street crossing to help contain the roadway approach fill. The 
wingwalls will be cast-in-place concrete retaining walls. Construction 
of the wingwalls will require the operation of general construction 
equipment (see Table 1 for source levels). The contractor will first 
excavate existing ground to the desired elevation using an excavator 
and dump truck positioned on the existing roadway. Then the contractor 
will frame the wall using pneumatic tools or hammer and nails. Once 
framed, concrete will be poured into the frame and allowed to cure. It 
is anticipated that the contractor will be able to do this work in the 
dry; however, the contractor will install isolation measures when 
necessary. All equipment will be operated from the existing roadway and 
upland areas.
    Superstructures--The rail superstructures are comprised of precast, 
prestressed slabs with a 2-inch wearing surface. Possible construction 
equipment includes a crane, excavator, concrete saw, and concrete 
mixer. Source levels are included in Table 1.
    Roadway improvements will consist of curb and sidewalk 
construction, asphalt paving, inlet construction, and utility 
relocates. The roadway work will be completed using standard roadway 
construction equipment, such as excavators and backhoes, dump trucks, 
pavers, and rollers. Other equipment that may be employed includes air 
compressors, jack hammers, concrete pumps and mixers, and pneumatic 
tools. (See Table 1 for above-water equipment source levels). The work 
will be conducted landward of the trolley crossings, will not require 
IWW, and equipment will be operated away from the river. In-air noise 
produced by roadway construction equipment will range from 78 dB RMS to 
93 dB RMS at 20 meters from the source (Hanan & Associates, 2014).
    Buildings and other above-grade structures will reduce noise during 
roadway construction by physically blocking it and reflecting it away 
from the river, due to structural noise reduction (FHWA, 2011). The 
pier structures will also block noise from reaching the river and bank 
areas by deflecting it upwards. Additionally, noise levels from much of 
the construction equipment used for removal of the existing 
superstructures are no different than many of the existing noise 
sources in the area. Based on the sound levels produced by the proposed 
equipment, existing site conditions, the likely location of the 
pinnipeds within the area in relation to the associated construction 
activities, and Phase 1 monitoring, roadway improvements are not 
expected to disturb nearby marine mammals, and will not be considered 
further.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 3 lists all species with expected potential for occurrence in 
Astoria and summarizes information related to the population or stock, 
including regulatory status under the MMPA and ESA and potential 
biological removal (PBR), where known. For taxonomy, we follow 
Committee on Taxonomy (2016). PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS's 
SARs). While no mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. For Steller sea lion (Eumetopias jubatus) the stock 
abundance is the best estimate of pup and non-pup counts, which have 
not been corrected to account for animals at sea during abundance 
surveys. All managed stocks in this region are assessed in NMFS's U.S. 
2018 SARs (e.g., Caretta et al. 2019). All values presented in Table 3 
are the most recent available at the time of publication and are 
available in the 2018 SARs (Caretta et al. 2019, Muto et al. 2019).

                                           Table 3--Species With Expected Potential for Occurrence in Astoria
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       Stock abundance
                                                                                ESA/MMPA status;       (CV, Nmin, most                     Annual M/SI 3
           Common name               Scientific name           Stock           Strategic  (Y/N) 1      recent abundance         PBR
                                                                                                          survey) 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale...................  Megaptera            Central North        -, -, Y                 10,103 (0.300,                   83              26
                                    novaeangliae.        Pacific.                                     7,891, 2006).

[[Page 59778]]

 
Humpback whale...................  Megaptera            California/Oregon/   -, -, Y                 2,900 (0.05, 2,784,            16.7    =
                                    novaeangliae.        Washington.                                  2014).                                        40.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion..............  Zalophus             U.S................  -, -, N                 257,606 (N/A,                14,011           >=321
                                    californianus.                                                    233,515, 2014).
Steller sea lion.................  Eumetopias jubatus.  Eastern U.S........  -, -, N                 41,638 (See SAR,               2498             108
                                                                                                      41,638, 2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific harbor seal..............  Phoca vitulina       Oregon/Washington    -, -, N                 Unknown (Unknown,      Undetermined            10.6
                                    richardii.           Coast.                                       Unknown, 1999).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable [explain if this is the case].
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
Note--Italicized species are not expected to be taken or proposed for authorization.

    All species that could potentially occur in the proposed survey 
areas are included in Table 3. However, the temporal and spatial 
occurrence of humpback whales is such that take is not expected to 
occur, and they are not discussed further beyond the explanation 
provided here. Humpback whales occasionally enter the Columbia River to 
feed (Calambokidis, et al., 2017), however their presence is rare. They 
were not observed during Phase 1 of the City's project (OBEC Consulting 
Engineers. 2019), and are not expected during Phase 2.

California sea lions

    California sea lions are distributed throughout the Eastern North 
Pacific from central Mexico to southeast Alaska, with breeding areas 
restricted primarily to island areas off southern California (the 
Channel Islands), Baja California, and in the Gulf of California 
(Wright et al., 2010). There are five genetically distinct geographic 
populations of California sea lions in U.S. waters (Schramm et al., 
2009). In Oregon, California sea lions are from the Pacific Temperate 
population, and commonly occur in Oregon from September through May 
(ODFW, 2015). The estimated net productivity rate for the species is 7 
percent annually (Laake et al., 2018). Threats to this species include 
incidental catch and entanglement in fishing gear, such as gillnets; 
gunshot wounds and other human-caused injuries; entanglement in marine 
debris; and oil exposure (Caretta et al., 2019).
    Almost all California sea lions in the Pacific Northwest are sub-
adult or adult males (NMFS, 2008). California sea lions feed in the 
Columbia River and adjacent nearshore marine areas, and have been 
observed near several bridge crossings within the project site. They 
are often seen swimming around underneath the existing structures, and 
commonly use these areas when transiting from known temporary haul-outs 
and foraging sites in the river channel. A small group haul out at the 
Buoy Beer facility near the 8th Street bridge location. However, their 
primary haulout in Astoria is the East Mooring Basin, which is located 
over one mile (1.6km) upstream from the project site.
    The bulk of the construction activities coincide with the season of 
lowest California sea lion abundance in the Columbia River basin. 
However, the in-water work period includes the tail end of peak usage 
of the lower Columbia River by California sea lions. Additionally, 
construction of the new rail superstructures will be partially above 
the high mean tide elevation which is directly above the river banks 
where California sea lions may be temporarily hauled-out.

Steller sea lions

    The Steller sea lion range extends along the Pacific Rim, from 
northern Japan to central California (Loughlin et al., 1984). Steller 
sea lions inhabiting U.S. waters are divided into two stocks, the 
Western U.S. stock and the Eastern U.S. stock. Steller sea lions that 
occur within the Lower Columbia River are part of the Eastern U.S. 
sock. The Eastern U.S. stock was de-listed in 2013 following a 
population growth from 18,000 in 1979 to 70,000 in 2010 (and an 
estimated annual growth of 4.18 percent) (NMFS, 2013). Threats to 
Steller sea lions include: Boat/ship strikes, contaminants/pollutants, 
habitat degradation, illegal hunting/shooting, offshore oil and gas 
exploration, and interactions (direct and indirect) with fisheries 
(NOAA, 2016b).
    Steller sea lions are present year-round at the mouth of the 
Columbia River, and they are at their peak in the lower river from 
September through March. The primary haulout point is on the top of 
South Jetty (ten miles downstream from the project site). At the South 
Jetty, typical single day counts are approximately 100 individuals, 
while at Phoca Rock/Bonneville Dam, there are approximately 40 
individuals in a single day (Susan Riemer, pers. comm., 2016). Steller 
sea lions feed in both the Columbia River and adjacent nearshore marine 
areas. The timing of this

[[Page 59779]]

construction project coincides with peak presence of Steller sea lions 
but they are not known to haul out near the project site. Steller sea 
lions may be swimming past the project site in the main channel of the 
river, however, no Steller sea lions were observed within the region of 
activity during Phase 1 construction.

Harbor seals

    On the U.S. west coast, Pacific harbor seals (Phoca vitulina 
richardii) range from Alaska to Baja California, Mexico (ODFW, 2015). 
Three separate harbor seal populations are recognized on the U.S. west 
coast: California Stock, Washington Inland Waters Stock, and Oregon/
Washington Coast Stock (Caretta et al., 2019). In 1999, the Oregon/
Washington Coast stock abundance was estimated to be 24,732. However, 
the data used to publish that abundance was eight years old at the time 
and no more recent stock abundance estimates exist (Caretta et al., 
2019). The Oregon/Washington Coast stock of harbor seals is not listed 
under the ESA nor are they considered depleted or strategic under the 
MMPA.
    Harbor seals utilize specific shoreline locations on a regular 
basis as haulouts including beaches, rocks, floats, and buoys. They 
must rest at haulout locations to regulate body temperature, interact 
with one another, and sleep (NOAA, 2016a). Harbor seals are present 
throughout the year at the mouth of the Columbia River and adjacent 
nearshore marine areas. They are infrequently present at the Astoria 
Mooring Basin, but they are known to transit through the main river 
channel past the project site. Their closest haulout and pupping area 
is Desdemona Sands which is downstream of the Astoria-Megler Bridge. 
Pupping occurs from Mid-April to July, outside of the proposed project 
work period (Susan Riemer, pers. comm., 2016). Due to their year-round 
occurrence in the Columbia River, harbor seals are likely to be found 
transiting the area during in-water construction.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 4.

                  Table 4--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
               Hearing group                Generalized hearing  range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen        7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,     150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true         275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus cruciger
 & L. australis).
Phocid pinnipeds (PW) (underwater) (true    50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea    60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Three marine mammal species (all pinnipeds) have the reasonable 
potential to co-occur with the proposed construction activities. Of 
those pinniped species, two are otariids (Steller sea lion and 
California sea lion) and one is a phocid (harbor seal). Please refer to 
Table 3.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take by Incidental Harassment section 
later in this document includes a quantitative analysis of the number 
of individuals that are expected to be taken by this activity. The 
Negligible Impact Analysis and Determination section considers the 
content of this section, the Estimated Take by Incidental Harassment 
section, and the Proposed Mitigation section, to draw conclusions 
regarding the likely impacts of these activities on the reproductive 
success or survivorship of individuals and how those impacts on 
individuals are likely to impact marine mammal species or stocks.

Description of Sound Sources

    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz (Hz) or cycles per second. Wavelength is the 
distance between two peaks of a sound wave; lower frequency sounds have 
longer wavelengths than higher frequency sounds. Amplitude is the

[[Page 59780]]

height of the sound pressure wave or the `loudness' of a sound and is 
typically measured using the decibel (dB) scale. A dB is the ratio 
between a measured pressure (with sound) and a reference pressure 
(sound at a constant pressure, established by scientific standards). It 
is a logarithmic unit that accounts for large variations in amplitude; 
therefore, relatively small changes in dB ratings correspond to large 
changes in sound pressure. When referring to sound pressure levels 
(SPLs; the sound force per unit area), sound is referenced in the 
context of underwater sound pressure to 1 microPascal ([mu]Pa). One 
Pascal is the pressure resulting from a force of one Newton exerted 
over an area of one square meter. The source level (SL) represents the 
sound level at a distance of 1 m from the source (referenced to 1 
[mu]Pa). The received level is the sound level at the listener's 
position. Note that all underwater sound levels in the document are 
referenced to a pressure of 1 [mu]Pa and all airborne sound levels in 
this document are referenced to a pressure of 20 [mu]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures. When underwater objects 
vibrate or activity occurs, sound-pressure waves are created. These 
waves alternately compress and decompress the water as the sound wave 
travels. Underwater sound waves radiate in all directions away from the 
source (similar to ripples on the surface of a pond), except in cases 
where the source is directional. The compressions and decompressions 
associated with sound waves are detected as changes in pressure by 
aquatic life and man-made sound receptors such as hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and the sound level 
of a region is defined by the total acoustical energy being generated 
by known and unknown sources. These sources may include physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction).
    A number of sources contribute to ambient sound, including the 
following (Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kilohertz (kHz) (Mitson, 1995). In general, ambient sound levels tend 
to increase with increasing wind speed and wave height. Surf noise 
becomes important near shore, with measurements collected at a distance 
of 8.5 km from shore showing an increase of 10 dB in the 100 to 700 Hz 
band during heavy surf conditions;
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times;
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz;
     Anthropogenic: Sources of ambient noise related to human 
activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise 
typically dominates the total ambient noise for frequencies between 20 
and 300 Hz. In general, the frequencies of anthropogenic sounds are 
below 1 kHz and, if higher frequency sound levels are created, they 
attenuate rapidly (Richardson et al., 1995). Sound from identifiable 
anthropogenic sources other than the activity of interest (e.g., a 
passing vessel) is sometimes termed background sound, as opposed to 
ambient sound.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the Project 
include impact pile driving, vibratory pile removal and driving, 
potential down-the-hole drilling (included in vibratory pile removal 
and driving analysis), and potential preboring using an H-pile. The 
sounds produced by these activities fall into one of two general sound 
types: pulsed and non-pulsed (defined in the following). The 
distinction between these two sound types is important because they 
have differing potential to cause physical effects, particularly with 
regard to hearing (e.g., Ward 1997 in Southall et al., 2007). Please 
see Southall et al., (2007) for an in-depth discussion of these 
concepts. Pulsed sound sources (e.g., impact pile driving) produce 
signals that are brief (typically considered to be less than one 
second), broadband, atonal transients (ANSI 1986; Harris 1998; NIOSH 
1998; ISO 2003; ANSI 2005) and occur either as isolated events or 
repeated in some succession. Pulsed sounds are all characterized by a 
relatively rapid rise from ambient pressure to a maximal pressure value 
followed by a rapid decay period that may include a period of 
diminishing, oscillating maximal and minimal pressures, and generally 
have an increased capacity to induce physical injury as compared with 
sounds that lack these features. Non-pulsed sounds can be tonal, 
narrowband or broadband, brief or prolonged, and may be continuous or 
non-continuous (ANSI 1995; NIOSH 1998). Some of these non-pulsed sounds 
can be transient signals of short duration without the essential 
properties of pulses (e.g., rapid rise time). Examples of non-pulsed 
sounds include those produced by vessels, aircraft, machinery 
operations such as drilling or dredging, vibratory pile driving, and 
active sonar systems (such as those used by the U.S. Navy). The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment. Impact

[[Page 59781]]

hammers operate by repeatedly dropping a heavy piston onto a pile to 
drive the pile into the substrate.
    Sound generated by impact hammers is characterized by rapid rise 
times and high peak levels, a potentially injurious combination 
(Hastings and Popper, 2005). Vibratory hammers install piles by 
vibrating them and allowing the weight of the hammer to push them into 
the sediment. Vibratory hammers produce significantly less sound than 
impact hammers. Peak SPLs may be 180 dB or greater, but are generally 
10 to 20 dB lower than SPLs generated during impact pile driving of the 
same-sized pile (Oestman et al., 2009). Rise time is slower, reducing 
the probability and severity of injury, and sound energy is distributed 
over a greater amount of time (Nedwell and Edwards, 2002; Carlson et 
al., 2005). Drilling would be conducted inside of the hollow 36-inch 
casings. The pulsing sounds produced by the down-the-hole drilling 
methods are continuous, however, this method likely increases sound 
attenuation because the noise is primarily contained within the steel 
pile and below ground, rather than impact hammer driving methods which 
occur at the top of the pile (R&M, 2016).
    The likely or possible impacts of the City's proposed activity on 
marine mammals could involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of the equipment and personnel; however, any impacts to marine 
mammals are expected to primarily be acoustic in nature. Acoustic 
stressors include effects of heavy equipment operation during site 
preparation and pile installation and removal, and use of above-water 
construction equipment.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal is the primary means by which 
marine mammals may be harassed from the City's specified activity. In 
general, animals exposed to natural or anthropogenic sound may 
experience physical and psychological effects, ranging in magnitude 
from none to severe (Southall et al., 2007). In general, exposure to 
pile driving and drilling noise has the potential to result in auditory 
threshold shifts and behavioral reactions (e.g., avoidance, temporary 
cessation of foraging and vocalizing, changes in dive behavior). 
Exposure to anthropogenic noise can also lead to non-observable 
physiological responses such an increase in stress hormones. Additional 
noise in a marine mammal's habitat can mask acoustic cues used by 
marine mammals to carry out daily functions such as communication and 
predator and prey detection. The effects of pile driving and drilling 
noise on marine mammals are dependent on several factors, including, 
but not limited to, sound type (e.g., impulsive vs. non-impulsive), the 
species, age and sex class (e.g., adult male vs. mom with calf), 
duration of exposure, the distance between the pile and the animal, 
received levels, behavior at time of exposure, and previous history 
with exposure (Wartzok et al., 2004; Southall et al., 2007). Here we 
discuss physical auditory effects (threshold shifts) followed by 
behavioral effects and potential impacts on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal (Kastelein et al., 2014)), and the overlap 
between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward 1960; 
Kryter et al., 1966; Miller, 1974; Ahroon et al., 1996; Henderson et 
al., 2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al., 2008), there are no empirical data measuring PTS 
in marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS, 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS, 2018). Based on data from cetacean TTS measurements (see 
Southall et al., 2007), a TTS of 6 dB is considered the minimum 
threshold shift clearly larger than any day-to-day or session-to-
session variation in a subject's normal hearing ability (Schlundt et 
al., 2000; Finneran et al., 2000, 2002). As described in Finneran 
(2015), marine mammal studies have shown the amount of TTS increases 
with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, 
the amount of TTS is typically small and the growth curves have shallow 
slopes. At exposures with higher SELcum, the growth curves 
become steeper and approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al., 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise (Phocoena phocoena), and Yangtze finless 
porpoise (Neophocoena asiaeorientalis)) and five species of pinnipeds 
exposed to a limited number of sound sources (i.e., mostly tones and 
octave-band noise) in laboratory settings

[[Page 59782]]

(Finneran, 2015). TTS was not observed in trained spotted (Phoca 
largha) and ringed (Pusa hispida) seals exposed to impulsive noise at 
levels matching previous predictions of TTS onset (Reichmuth et al., 
2016). In general, harbor seals and harbor porpoises have a lower TTS 
onset than other measured pinniped or cetacean species (Finneran, 
2015). Additionally, the existing marine mammal TTS data come from a 
limited number of individuals within these species. No data are 
available on noise-induced hearing loss for mysticetes. For summaries 
of data on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007), Finneran and Jenkins 
(2012), Finneran (2015), and Table 5 in NMFS (2018). Installing piles 
requires a combination of impact pile driving and vibratory pile 
driving. For the project, these activities would not occur at the same 
time and there would likely be pauses in activities producing the sound 
during each day. Given these pauses and that many marine mammals are 
likely moving through the action area and not remaining for extended 
periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from site preparation 
activities and pile driving and removal also has the potential to 
behaviorally disturb marine mammals. Available studies show wide 
variation in response to underwater sound; therefore, it is difficult 
to predict specifically how any given sound in a particular instance 
might affect marine mammals perceiving the signal. If a marine mammal 
does react briefly to an underwater sound by changing its behavior or 
moving a small distance, the impacts of the change are unlikely to be 
significant to the individual, let alone the stock or population. 
However, if a sound source displaces marine mammals from an important 
feeding or breeding area for a prolonged period, impacts on individuals 
and populations could be significant (e.g., Lusseau and Bejder, 2007; 
Weilgart, 2007; NRC, 2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound 
are highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 
2007; Weilgart, 2007; Archer et al., 2010). Behavioral reactions can 
vary not only among individuals but also within an individual, 
depending on previous experience with a sound source, context, and 
numerous other factors (Ellison et al., 2012), and can vary depending 
on characteristics associated with the sound source (e.g., whether it 
is moving or stationary, number of sources, distance from the source). 
In general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. Please see Appendices B-C of Southall et al. 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    During Phase 1 of the Astoria Waterfront Bridge Replacement 
project, the City documented observations of marine mammals during 
construction activities (i.e., pile driving and removal) at the bridge 
sites (see 83 FR 19243 for Final IHA Federal Register notice). In the 
marine mammal monitoring report, 604 California sea lions were observed 
within the behavioral disturbance zone (4204 takes when extrapolated 
across unobserved construction days) during pile driving activities 
(i.e., documented as Level B harassment take). Behavioral reactions 
were observed in only five percent of the observed California sea 
lions, and included travel towards and away from construction 
activities. 53 harbor seals were also observed within the behavioral 
disturbance zone (323 takes when extrapolated across unobserved 
construction days), however very few behavioral reactions were observed 
by protected species observers (PSOs). Given that the projects sites in 
Phase 2 are adjacent to those in Phase 1, and the fact the same species 
are involved, we expect similar behavioral responses of marine mammals 
to the specified activity. That is, disturbance, if any, is likely to 
be temporary and localized (e.g., small area movements).
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al., 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked. The 
Lower Columbia River is used by various types of vessels, including 
cargo ships, dredging vessels, fishing vessels, and pollution control 
vessels, among others; therefore, background sound levels in the area 
are sometimes already elevated.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated

[[Page 59783]]

with pile driving and removal that have the potential to cause 
behavioral harassment, depending on their distance from pile driving 
activities. Cetaceans are not expected to be exposed to airborne sounds 
that would result in harassment as defined under the MMPA.
    Airborne noise is primarily an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels exceeding the acoustic thresholds. We recognize that pinnipeds 
in the water could be exposed to airborne sound that may result in 
behavioral harassment when looking with their heads above water. Most 
likely, airborne sound would cause behavioral responses similar to 
those discussed above in relation to underwater sound. For instance, 
anthropogenic sound could cause hauled-out pinnipeds to exhibit changes 
in their normal behavior, such as reduction in vocalizations, or cause 
them to temporarily abandon the area and move further from the source. 
During in-water activities, these animals would previously have been 
`taken' because of exposure to underwater sound above the behavioral 
harassment thresholds, which are, in all cases, larger than those 
associated with airborne sound. However, this project includes above-
water work that occurs near California sea lion haulouts, and there is 
potential for above-water work to result in behavioral harassment of 
these hauled out animals.

Marine Mammal Habitat Effects

    The City's construction activities could have localized, temporary 
impacts on marine mammal habitat by increasing in-water sound pressure 
levels and slightly decreasing water quality. In-water construction 
activities are of short duration and would likely have temporary 
impacts on marine mammal habitat through increases in underwater sound 
and minor visual disturbance due to the construction. Increased noise 
levels may affect acoustic habitat (see masking discussion above) and 
adversely affect marine mammal prey in the vicinity of the project area 
(see discussion below). During impact pile driving and potential site 
preparation activities, elevated levels of underwater noise would 
ensonify the river where both fish and mammals may occur and could 
affect foraging success.
    In-water pile driving and pile removal would also cause short-term 
effects on water quality due to increased turbidity. The City would 
employ standard construction best management practices, thereby 
reducing any impacts. Considering the nature and duration of the 
effects, combined with the measures to reduce turbidity, the impact 
from increased turbidity levels is expected to be discountable.

In-Water Construction Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in the surrounding waters of the 
Columbia River and Pacific Ocean. Pile installation and removal may 
temporarily increase turbidity resulting from suspended sediments. Any 
increases would be temporary, localized, and minimal. In general, 
turbidity associated with pile installation is localized to about a 25-
foot radius around the pile (Everitt et al., 1980). Based on monitoring 
results from Phase 1, pinnipeds in the project area would likely be 
traveling through and could avoid localized areas of turbidity. 
Therefore, the impact from increased turbidity levels is expected to be 
discountable to marine mammals. Furthermore, pile driving and removal 
at the project site would not obstruct movements or migration of marine 
mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity. Impacts to 
habitat and prey are expected to be temporary and minimal based on the 
short duration of activities.

In-Water Construction Effects on Potential Prey (Fish)

    Construction activities would produce continuous (i.e., vibratory 
pile driving) and pulsed (i.e., impact driving) sounds. Fish react to 
sounds that are especially strong and/or intermittent low-frequency 
sounds. Short duration, sharp sounds can cause overt or subtle changes 
in fish behavior and local distribution. Hastings and Popper (2005) 
identified several studies that suggest fish may relocate to avoid 
certain areas of sound energy. Additional studies have documented 
effects of pile driving on fish, although several are based on studies 
in support of large, multiyear bridge construction projects (e.g., 
Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Sound pulses 
at received levels of 160 dB may cause subtle changes in fish behavior. 
SPLs of 180 dB may cause noticeable changes in behavior (Pearson et 
al., 1992; Skalski et al., 1992). SPLs of sufficient strength have been 
known to cause injury to fish and fish mortality.
    The most likely impact to fish from pile driving and drilling 
activities at the project area would be temporary behavioral avoidance 
of the area. The duration of fish avoidance of this area after pile 
driving stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. In general, impacts to marine 
mammal prey species are expected to be minor and temporary due to the 
short timeframe for the project. Uncertainty regarding direct and 
indirect effects on prey species will be mitigated due to the seasonal 
presence of salmonids and other prey present in the area, and the 
mitigation measures in place to reduce impacts to fish under Federal 
Aid Highway Program (FAHP). Further, it is anticipated that some of the 
pile driving activities will occur in the dry, despite the conservative 
project analysis that assumes all pile driving would occur in-water. 
Sound attenuation devices will be installed for in-water pile driving.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect fish in the project area. Increased 
turbidity is expected to occur in the immediate vicinity (on the order 
of 10 feet or less) of construction activities. However, suspended 
sediments and particulates are expected to dissipate quickly within a 
single tidal cycle. Given the limited area affected and high tidal 
dilution rates, any effects on fish are expected to be minor or 
negligible. In addition, best management practices would be in effect, 
which would limit the extent of turbidity to the immediate project 
area.
    In summary, given the large areas of fish and marine mammal 
foraging habitat in the Columbia River outside of the ensonified area, 
and the anticipated rapid return to the project area following 
cessation of in-water work, pile driving and site preparation 
activities associated with the proposed action are not likely to have a 
permanent, adverse effect on any fish habitat, or populations of fish 
species. Thus, we conclude that impacts of the specified activity are 
not likely to have more than short-term adverse effects on any prey 
habitat or populations of prey species. Further, any impacts to marine 
mammal habitat are not expected to result in significant or long-term 
consequences for individual marine mammals, or to contribute to adverse 
impacts on their populations.

[[Page 59784]]

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the vibratory and impact pile hammers, potential drill, and other 
construction equipment has the potential to result in disruption of 
behavioral patterns for individual marine mammals. There is also some 
potential for auditory injury (Level A harassment) to California sea 
lions and harbor seals because they are more likely to occur closer to 
the project site, particularly considering the small, nearby California 
sea lion haulout. Auditory injury is unlikely to occur to other groups, 
and the proposed mitigation and monitoring measures are expected to 
minimize the severity of such taking to the extent practicable.
    As described previously, no mortality or serious injury is 
anticipated or proposed to be authorized for this activity. Below we 
describe how the take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the proposed take 
estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment). Thresholds have also 
been developed identifying the received level of in-air sound above 
which exposed pinnipeds would likely be behaviorally harassed.
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007; 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources. For in-air sounds, NMFS predicts that 
harbor seals exposed above received levels of 90 dB re 20 [mu]Pa (rms) 
will be behaviorally harassed, and other pinnipeds will be harassed 
when exposed above 100 dB re 20 [mu]Pa (rms).
    The City's proposed activity includes the use of continuous 
(vibratory pile driving, preboring and potential down-the-hole 
drilling) and impulsive (impact pile driving) sources, and therefore 
the 120 and 160 dB re 1 [mu]Pa (rms) are applicable for in-water noise.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). The City's proposed activities include 
the use of impulsive (impact hammers) and non-impulsive (vibratory 
hammers, potential down-the-hole drilling) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

 Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
------------------------------------------------------------------------
                                    PTS onset acoustic thresholds *
                                            (received level)
        Hearing group         ------------------------------------------
                                   Impulsive          Non-impulsive
------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.  Cell 1:           Cell 2: LE,LF,24h: 199
                                Lpk,flat: 219     dB
                                dB; LE,LF,24h:
                                183 dB..
Mid-Frequency (MF) Cetaceans.  Cell 3:           Cell 4: LE,MF,24h: 198
                                Lpk,flat: 230     dB.
                                dB; LE,MF,24h:
                                185 dB.
High-Frequency (HF) Cetaceans  Cell 5:           Cell 6: LE,HF,24h: 173
                                Lpk,flat: 202     dB.
                                dB; LE,HF,24h:
                                155 dB.
Phocid Pinnipeds (PW)          Cell 7:           Cell 8: LE,PW,24h: 201
 (Underwater).                  Lpk,flat: 218     dB.
                                dB; LE,PW,24h:
                                185 dB.

[[Page 59785]]

 
Otariid Pinnipeds (OW)         Cell 9:           Cell 10: LE,OW,24h: 219
 (Underwater).                  Lpk,flat: 232     dB.
                                dB; LE,OW,24h:
                                203 dB.
------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever
  results in the largest isopleth for calculating PTS onset. If a non-
  impulsive sound has the potential of exceeding the peak sound pressure
  level thresholds associated with impulsive sounds, these thresholds
  should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and
  cumulative sound exposure level (LE) has a reference value of
  1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect
  American National Standards Institute standards (ANSI 2013). However,
  peak sound pressure is defined by ANSI as incorporating frequency
  weighting, which is not the intent for this Technical Guidance. Hence,
  the subscript ``flat'' is being included to indicate peak sound
  pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure
  level thresholds indicates the designated marine mammal auditory
  weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The
  cumulative sound exposure level thresholds could be exceeded in a
  multitude of ways (i.e., varying exposure levels and durations, duty
  cycle). When possible, it is valuable for action proponents to
  indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving, vibratory 
pile driving and removal, site preparation). The maximum (underwater) 
area ensonified above the thresholds for behavioral harassment 
referenced above is 21.53km (13.38 mi) into the river channel during 
vibratory installation/removal of the 36-inch temporary steel casings, 
though this distance does not account for tide levels. There is a 
chance that pile installation work could be done during low tides, 
where exposed sand bars could significantly reduce the Level B ZOI.
    The project includes vibratory removal of timber piles, vibratory 
and impact pile installation of steel pipe piles and site preparation 
using a vibratory hammer and H-pile. Source levels of pile 
installation/removal activities and site preparation are based on 
reviews of measurements of the same or similar types and dimensions of 
piles available in the literature. Source levels for each pile size and 
driving method are presented in Table 6. Source levels for vibratory 
installation and removal of piles of the same diameter are assumed to 
be the same.
    The source level for vibratory removal of timber piles is from in-
water measurements generated by the Greenbusch Group (2018) from the 
Seattle Pier 62 project (83 FR 39709; April 10, 2018). Hydroacoustic 
monitoring results from Pier 62 determined unweighted rms ranging from 
140 dB to 169 dB. NMFS analyzed source measurements at different 
distances for all 63 individual timber piles that were removed at Pier 
62 and normalized the values to 10 m. The results showed that the 
median is 152 dB SPLrms.

                              Table 6--Sound Source Levels for In-Water Activities
----------------------------------------------------------------------------------------------------------------
                                                              Source level (at 10m)
        Pile size/type              Method      ------------------------------------------------    Literature
                                                     dB RMS        dB SEL \b\        dB peak          source
----------------------------------------------------------------------------------------------------------------
14-inch Timber...............  Vibratory.......             152  ..............  ..............  The Greenbusch
                                                                                                  Group, Inc
                                                                                                  (2018).
14-inch Steel H-pile.........  Vibratory.......             150  ..............  ..............  WSDOT (2016).
24-inch Steel Pipe...........  Vibratory.......             162  ..............  ..............  WSDOT (2010).
                               Impact..........         \a\ 187         \a\ 171         \a\ 200  WSDOT (2016).
36-inch Steel Pipe...........  Vibratory.......             170  ..............  ..............  CA Dept. of
                                                                                                  Transportation
                                                                                                  (2015).
----------------------------------------------------------------------------------------------------------------
\a\ Includes 7dB reduction from use of bubble curtain.
\b\ Sound exposure level (dB re 1 [mu]Pa\2\-sec).

    It is anticipated that the contractor may employ two crews during 
construction to keep the project on schedule. This could result in 
concurrent use of a vibratory hammer and an impact hammer, however, the 
contractor will not operate two of the same hammer type concurrently. 
The hammers would be operated at two different bridges. The ensonified 
zones would likely overlap during concurrent use, but the multiple-
source decibel addition method (Table 7) does not result in significant 
increases in the noise source when an impact hammer and vibratory 
hammer are operated at the same time, because the difference in noise 
source levels (Table 6) between the two hammers is greater than 10dB.

                Table 7--Multiple-Source Decibel Addition
------------------------------------------------------------------------
                                                              Add the
                                                           following to
           When two decibel values differ by:               the higher
                                                               level
------------------------------------------------------------------------
0-1 dB..................................................            3 dB
2-3 dB..................................................            2 dB
4-9 dB..................................................            1 dB
>10 dB..................................................            0 dB
------------------------------------------------------------------------


[[Page 59786]]

    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log10 (R 1/R 2),

where

TL = transmission loss in dB
B = transmission loss coefficient
R 1 = the distance of the modeled SPL from the driven 
pile, and
R 2 = the distance from the driven pile of the initial 
measurement

    Absent site-specific acoustical monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient in the above formula. Site-specific 
transmission loss data for Astoria are not available, therefore the 
default coefficient of 15 is used to determine the distances to the 
Level A and Level B harassment thresholds.

                                 Table 8--In-Water Activity Source Levels and Distances to Level B Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           Source level       Level B                                         Level B
                                                                          at 10 m (dB re   threshold (dB    Propagation     Distance to     harassment
              Pile size/type                           Method               1 [micro]Pa   re 1 [micro]Pa      (xLogR)         Level B       ensonified
                                                                               rms)            rms)                        threshold (m)   area (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch Timber............................  Vibratory...................             152             120              15         1,359.4             3.2
14-inch Steel H-pile......................  Vibratory...................             150             120              15         1,000.0             1.8
24-inch Steel Pipe........................  Vibratory...................             162             120              15         6,309.6            55.3
                                            Impact......................             187             160              15           631.0             0.8
36-inch Steel Pipe........................  Vibratory...................             170             120              15        21,544.4           212.3
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In-Air Disturbance during General Construction Activities--
Behavioral disturbance (Level B harassment take) may occur incidental 
to the use of construction equipment during general construction that 
is proposed in the dry, above water, or inland within close proximity 
to the river banks. These construction activities are associated with 
the removal and construction of the rail superstructures, removal of 
the existing concrete foundations, construction of abutment wingwalls, 
and the construction of a temporary work platform. Possible equipment 
and sound source levels are included in Table 1. Using the Spherical 
Spreading Loss Model (20logR), a maximum sound source level of 93 dB 
RMS at 20 m, sound levels in-air would attenuate below the 90dB RMS 
Level B harassment threshold for harbor seals at 28 m, and below the 
100 dB RMS threshold for all other pinnipeds at 9 m. Harbor seals are 
not expected to occur within 28m of the activity as there are no nearby 
haulouts, and are, therefore, not expected to be harassed by in-air 
sound. Additionally, the City is proposing a 10 m shutdown zone (Table 
16) for all construction work to prevent injury from physical 
interaction with equipment. The City would therefore shut down 
equipment before hauled out sea lions could be acoustically harassed by 
the sound produced. No Level B harassment is expected to occur due to 
increased sounds from roadway construction. However, sea lions may be 
disturbed by the presence of construction equipment and increased human 
presence during above-water construction.
    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources such as pile 
driving, NMFS User Spreadsheet predicts the distance at which, if a 
marine mammal remained at that distance the whole duration of the 
activity, it would incur PTS. Inputs entered in the User Spreadsheet 
(Table 9) and the resulting isopleths are reported below (Table 10).

                              Table 9--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Weighting                       Number of   Duration to                              Distance from
   Pile size and installation      Spreadsheet tab      factor     Source level at      piles        drive      Number of    Propagation   source level
             method                     used          adjustment         10 m        within 24-h  single pile  strikes per     (xLogR)      measurement
                                                        (kHz)                           period     (minutes)       pile                      (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch Timber Vibratory.......  A.1) Vibratory              2.5  152dB RMS SPL....           50           20  ...........            15              10
                                  pile driving.
14-inch Steel H-Pile...........  A.1) Vibratory              2.5  150dB RMS SPL....           36           25  ...........            15              10
                                  pile driving.
24-inch Steel Vibratory........  A.1) Vibratory              2.5  162dB RMS SPL....           18           20  ...........            15              10
                                  pile driving.
36-inch Steel Vibratory........  A.1) Vibratory              2.5  170dB RMS SPL....           36            8  ...........            15              10
                                  pile driving.
24-inch Steel Impact...........  E.1) Impact pile              2  171dB SEL/207 PK            23  ...........          500            15              10
                                  driving.                         SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 59787]]

    The applicant may conduct down-the-hole drilling, however a 
separate analysis is not provided for that activity, as it is was not 
necessary in Phase 1 of the project, and is not expected to be 
necessary in Phase 2. Should drilling be necessary, the Level B 
harassment zone will be considered to be the same as that calculated 
for vibratory installation/removal of 36-inch steel piles, as that 
Level B harassment zone is clipped in all directions, and therefore is 
the most conservative a Level B harassment zone could be. A 
conservative Level B harassment zone is of particular importance due to 
the fact that the duration of drilling, should it be necessary, is 
unknown. The applicant will consider the Level A harassment zone for 
down-the-hole drilling to be the same as the Level A harassment zones 
calculated for impact pile driving of the 24-inch steel piles. These 
are the largest Level A harassment zones, and Level A harassment zones 
are expected to be smaller for a continuous sound source such as down-
the-hole drilling.

     Table 10--Calculated Distances to Level A Harassment Isopleths
------------------------------------------------------------------------
                                            Level A harassment zone (m)
    Pile size and installation method    -------------------------------
                                              Phocids        Otariids
------------------------------------------------------------------------
14-inch Timber Vibratory................             6.8             0.5
14-inch Steel H-Pile....................             4.7             0.3
24-inch Steel Vibratory.................              16             1.1
36-inch Steel Vibratory.................              47             3.3
24-inch Steel Impact (and down-the-hole          * 431.5            31.4
 drilling, if necessary)................
------------------------------------------------------------------------
* (Peak 7.4)

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals, and how it is brought 
together with the information provided above to produce a quantitative 
take estimate. Estimated takes of each species were calculated using 
information provided by the Oregon Department of Fish and Wildlife 
(Bryan Wright, pers. comm., August 2019), Washington Department of Fish 
and Wildlife (WDFW, 2014) and the Marine Mammal Commission (Tiff 
Brookens, pers. comm., March 2018).
Harbor Seal
    Numbers of harbor seals hauled out at Desdemona Sands have been 
reported to reach into the thousands (Profita, 2015), but specific 
counts were unavailable. Without counts of harbor seals closer to the 
project site, the maximum average count of harbor seals at the South 
Jetty (57 seals; WDFW, 2014) is used to calculate take, as in Phase 1 
(83 FR 19243, May 2, 2018). The Level B harassment zones for Phase 2 
extend far beyond the calculated zones for Phase 1, approaching the 
South Jetty, further supporting the use of these harbor seal counts.
    Harbor seals do not haul out near the project area and would only 
be potentially harassed if they are transiting through the Level A or 
Level B harassment zone during the in-water work period (including the 
extension, if applicable). Level B harassment take was calculated by 
multiplying the maximum average count of harbor seals at the South 
Jetty by days of in-water activity (Table 11).
    Additionally, while harbor seals are unlikely to occur in the Level 
A harassment zone during vibratory pile driving (based on Phase 1 
monitoring), the applicant is concerned that if a few animals occurred 
in the Level A harassment zone during impact pile driving, they may 
need to shut down more frequently than is practical, given the IWWP 
restrictions previously discussed. As such, NMFS is proposing to 
observe a shutdown zone that is smaller than the Level A isopleth for 
impact pile driving and to issue small numbers of Level A harassment 
take of harbor seals (Table 14). This proposed take would avoid 
potentially excessive shut downs should a small group of harbor seals 
enter the project area on each day while impact pile driving activities 
(or down-the-hole drilling, as necessary) are underway. Level A 
harassment take of harbor seals was calculated by multiplying a group 
of two animals by 14 in-water work days. Level A takes may only occur 
during the subset of in-water work days when the applicant conducts 
impact pile driving (or down-the-hole drilling, as required), as the 
shutdown zone contains the entire Level A harassment zone for all other 
in-water work activities.
Steller Sea Lion
    Counts of Steller sea lions at the East Mooring Basin are typically 
in the single digits (B. Wright, pers. comm., March 2018), while the 
average number of Steller sea lions observed at the South Jetty during 
the in-water work period (including the possible extension) from 2000-
2014, was 272 animals (WDFW, 2014). When the applicant consulted ODFW 
for more recent Steller sea lion data, ODFW advised that there were 
only three more recent surveys, none of which occurred during the IWWP 
months (Bryan Wright, pers. comm., September 2019). The Level B 
harassment zones for Phase 2 extend far beyond the calculated zones for 
Phase 1, approaching the South Jetty. Therefore, NMFS expects that that 
average daily count from the South Jetty provides an appropriate daily 
count to calculate potential Steller sea lion Level B harassment take 
during Phase 2. Note the calculation is based on the average daily 
count, not the maximum. The maximum daily count was 606 animals, in the 
month of April. Considering that work will only occur in April if the 
entire IWWP extension is exercised, and the large difference between 
the maximum daily count and the average daily count, NMFS believes that 
using the maximum daily count would greatly overestimate potential 
take.
    For Phase 1 Level B harassment take calculations of Steller sea 
lions, daily estimates were based off of observations at Bonneville Dam 
and Willamette Falls, as these animals must transit past Astoria at 
some point in their travels from the Pacific to the upper Columbia 
River (83 FR 19243, May 2, 2018). The daily count was 67 animals, 63 at 
Bonneville Dam and four at Willamette Falls. However, NMFS believes 
that South Jetty estimates are more appropriate and more conservative 
for Phase 2 take calculations, given the larger Level B harassment 
zones, some of which extend downriver close to the South Jetty.
    Level B harassment take was calculated by multiplying the daily 
counts of Steller sea lions by days of activity (Table 11).

[[Page 59788]]

    Steller sea lions do not haul out near the construction sites and 
would only be potentially harassed if they are transiting through the 
Level B harassment zone during the in-water work period (including the 
extension, if applicable). Steller sea lions are not expected to occur 
within the calculated Level A harassment zone for otariids (Table 10). 
No Level A harassment takes of Steller sea lions are proposed nor 
expected to be authorized.

               Table 11--Level B Harassment Take Calculation for Harbor Seal and Steller Sea Lion
----------------------------------------------------------------------------------------------------------------
                                                                      Maximum       Days of in-
                             Species                               average/daily  water activity    Total take
                                                                       count            \c\          (Level B)
----------------------------------------------------------------------------------------------------------------
Harbor seal.....................................................          \a\ 57              21           1,197
Steller sea lion................................................         \b\ 272              21           5,712
----------------------------------------------------------------------------------------------------------------
\a\ Maximum average count of harbor seals at the South Jetty (WDFW, 2014).
\b\ Average number of Steller sea lions observed at the South Jetty during the in-water work period (including
  the possible extension) from 2000-2014 (WDFW, 2014).
\c\ Includes in-water activity for the entire project.

California Sea Lion
    Aerial surveys of the East Mooring Basin in Astoria from 2011 to 
2018 (Bryan Wright, pers. comm., August 2019) were used to calculate 
in-water Level B harassment take of California sea lions, as in Phase 1 
of this activity (83 FR 19243, May 2, 2018). The data provided to NMFS 
by ODFW included the maximum California sea lion count observed on a 
single day for each month throughout the survey period. These maximum 
counts at the East Mooring Basin ranged from 0 California sea lions on 
a single day in July 2017 to 3,834 on a single day in March 2016. A 
``daily average maximum'' for each IWWP month (Table 12) was calculated 
by averaging the maximum counts on a single day for each survey month 
provided by ODFW. In addition to ODFW aerial surveys, the City 
conducted opportunistic surveys of pinnipeds at the bridge sites in 
December 2017. A maximum of four California sea lions were observed in 
the water surrounding the bridges and piers. Additional California sea 
lions were heard vocalizing from the riverbanks under the bridges but 
the exact number of sea lions could not be determined.

 Table 12--Daily Average Maximum Number of California Sea Lions at East
    Mooring Basin for IWWP Months, Including the Potential Extension
------------------------------------------------------------------------
                                                           Daily average
                          Month                             maximum \a\
------------------------------------------------------------------------
November................................................             141
December................................................             135
January.................................................             408
February................................................             893
March...................................................           1,191
April...................................................             982
------------------------------------------------------------------------
\a\ Daily average maximum was calculated using data from aerial surveys
  of the East Mooring Basin in Astoria from 2011 to 2018 (Bryan Wright,
  pers. comm., 2019).

    California sea lions are the most commonly observed marine mammal 
in the area, and are known to haul out on the riverbanks and structures 
near the bridges, as described above. California sea lions may be 
harassed by underwater sound resulting from vibratory pile removal and 
impact pile driving (at the distances listed above) as well as airborne 
sound resulting from roadway and railway demolition and construction. 
As such, California sea lions may be subject to harassment throughout 
the duration of Phase 2 of the project (December through November).
    NMFS is proposing to authorize 1,056 Level B harassment takes of 
California sea lions associated with above-water construction 
activities taking place during the above-water work period, not 
including the IWWP extension (May to October). Level B harassment takes 
of California sea lions from above-water activities were calculated by 
multiplying the maximum estimate from the City's 2017 opportunistic 
surveys at the bridge sites (16 animals) by the estimated 11 days of 
work per month during the above-water work period.
    NMFS is proposing to authorize 25,011 Level B harassment takes of 
California sea lions associated with in-water and above-water work 
during the IWWP. The City expects approximately 21 in-water work days 
across Phase 2 of the project. However, because the exact construction 
schedule is unknown, there are uncertainties in how many of the 
estimated work days will occur during each month. Therefore, estimated 
Level B harassment take during the IWWP (Table 13) is calculated by 
multiplying the highest daily average maximum (Table 12) during the 
IWWP months (including the potential extension) by the estimated 21 in-
water work days. California sea lions exposed to in-air sound above 
Level B harassment threshold during the IWWP are expected to have 
already been taken by in-water activity, and therefore already be 
included in the take calculation.
    Total California sea lion Level B harassment takes (Table 13) are 
calculated as the sum of above-water work period and IWWP takes.

                      Table 13--Level B Harassment Take Calculation of California Sea Lion
----------------------------------------------------------------------------------------------------------------
                                                                                     Potential
                           Work period                             Daily average     number of       Takes per
                                                                    maximum \b\      workdays          month
----------------------------------------------------------------------------------------------------------------
IWWP \a\........................................................           1,191              21          25,011
May.............................................................              16              11             176
June............................................................              16              11             176
July............................................................              16              11             176
August..........................................................              16              11             176
September.......................................................              16              11             176

[[Page 59789]]

 
October.........................................................              16              11             176
                                                                 -----------------------------------------------
    Total.......................................................  ..............  ..............          26,067
----------------------------------------------------------------------------------------------------------------
\a\ IWWP includes the potential extension, as the month of March has the highest daily average maximum count.
\b\ Daily average maximums during above-water work months are estimates from the City's opportunistic surveys at
  the Phase 1 bridge sites in December 2017.

    Only 4204 Level B harassment takes of California sea lion were 
reported for Phase 1; however, the Phase 2 project area is much larger 
than the area within which marine mammals were reported in Phase 1. 
Therefore, NMFS expects California sea lion take to be higher for Phase 
2 than was reported in the monitoring report for Phase 1.
    As discussed above, the City estimates that approximately 16 
California sea lions haul out near the project sites based on 
opportunistic surveys conducted in December 2017. Frequent construction 
shutdowns are of concern to the applicant, as there is a limited IWWP 
imposed by the Oregon Department of Fish and Wildlife and, therefore, 
the proposed mitigation zone does not entirely contain the area within 
the Level A harassment isopleth for impact pile driving. The applicant 
has requested Level A harassment takes of California sea lions, as the 
animals that haulout nearby may enter the Level A harassment zone as 
they transit between the haulouts and their feeding areas in the 
Columbia River.
    NMFS is proposing to issue 224 Level A harassment takes of 
California sea lions (Table 14). The Level A harassment takes are 
calculated by multiplying the 16 animals that haulout near the project 
site (City of Astoria December 2017 surveys) by 14 in-water work days. 
Level A takes may only occur during the subset of in-water work days 
when the applicant conducts impact pile driving (or down-the-hole 
drilling, as required), as the shutdown zone contains the entire Level 
A harassment zone for all other in-water work activities.

              Table 14--Level A Harassment Take Calculation of Harbor Seal and California Sea Lion
----------------------------------------------------------------------------------------------------------------
                                                                                     Estimated
                                                                                   number of in-      Level A
                             Species                                Daily count     water work      harassment
                                                                                       days            take
----------------------------------------------------------------------------------------------------------------
Harbor seal.....................................................               2              14              28
California sea lion.............................................          \a\ 16              14             224
----------------------------------------------------------------------------------------------------------------
\a\ December 2017 survey estimates of California sea lions by the City at Phase 1 bridge sites.


                                           Table 15--Total Level A and Level B Take Proposed for Authorization
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Level A         Level B
                Common name                             Stock               harassment      harassment      Total take         Stock        Percent of
                                                                               take            take                          abundance         stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal...............................  Oregon/Washington Coast.....              28           1,197           1,225      \a\ 24,732             5.0
Steller sea lion..........................  Eastern U.S.................               0           5,712           5,712          41,638            13.7
California sea lion.......................  U.S.........................             224          26,067          26,291         257,606            10.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ As noted in Table 3, there is no current estimate of abundance available for the Oregon/Washington Coast stock of harbor seal. The abundance
  estimate from 1999, included here, is the most recent.

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case

[[Page 59790]]

of a military readiness activity, personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity.
    In addition to the measures described later in this section, the 
City will employ the following standard mitigation measures:
     The City shall conduct briefings between construction 
supervisors and crews, marine mammal monitoring team, and City staff 
prior to the start of all construction work, and when new personnel 
join the work, in order to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures;
     For those marine mammals for which Level B harassment take 
has not been requested, in-water pile installation/removal and drilling 
will shut down immediately if such species are observed within or on a 
path towards the monitoring zone (i.e., Level B harassment zone); and
     If observed take reaches the authorized limit for an 
authorized species, pile installation will be stopped as these species 
approach the Level B harassment zone to avoid additional take.
    The following measures would apply to the City's mitigation 
requirements:
    Establishment of Shutdown Zones--For all pile driving/removal and 
drilling activities, the City will establish appropriate shutdown 
zones. The purpose of a shutdown zone is generally to define an area 
within which shutdown of activity would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area). 
These shutdown zones would be used to prevent incidental Level A 
exposures from pile driving and removal for Steller sea lions, and to 
reduce the potential for such take of harbor seals and California sea 
lions. During all pile driving and removal activities, as well as 
above-water construction, a minimum shutdown zone of 10m would be 
enforced (Table 16) for all species to prevent physical injury from 
interaction with construction equipment. Additionally, a shutdown zone 
of 32m will be enforced for Steller sea lions during impact pile 
driving to reduce the likelihood of Level A harassment take (Table 16). 
The placement of Protected Species Observers (PSOs) during all pile 
driving and drilling activities (described in detail in the Monitoring 
and Reporting Section) will ensure shutdown zones are visible when they 
are on site. When PSOs are not on site, the Oregon Department of 
Transportation (ODOT) inspector will be responsible for ensuring that 
activities shut down if a marine mammal enters the shutdown zone.

                                            Table 16--Shutdown Zones
----------------------------------------------------------------------------------------------------------------
                                                                                Shutdown zone (m)
                                                                ------------------------------------------------
                     Construction activity                                         Steller sea    California sea
                                                                   Harbor seal        lion             lion
----------------------------------------------------------------------------------------------------------------
All Vibratory Pile Driving/Removal and Site Preparation........              50              10              10
                                                                                ----------------
24-inch Steel Impact Pile Driving..............................  ..............              32
                                                                --------------------------------
Above-water Construction.......................................              10              10
----------------------------------------------------------------------------------------------------------------

    Establishment of Monitoring Zones for Level B Harassment--The City 
would establish monitoring zones to correlate with Level B harassment 
zones or zones of influence. These are areas where SPLs are equal to or 
exceed the 160 dB rms threshold for impact driving and the 120 dB rms 
threshold during vibratory driving and site preparation. For airborne 
noise, these thresholds are 90 dB RMS re 20[mu]Pa for harbor seals and 
100 db RMS re: 20[mu]Pa for all other pinnipeds. Monitoring zones 
provide utility for observing by establishing monitoring protocols for 
areas adjacent to the shutdown zones. Monitoring zones enable observers 
to be aware of and communicate the presence of marine mammals in the 
project area outside the shutdown zone and thus prepare for a potential 
cease of activity should the animal enter the shutdown zone. The 
proposed monitoring zones are described in Table 17. Placement of PSOs 
on the shorelines around the Columbia River allow PSOs to observe 
marine mammals within the project site, however, due to the size of the 
Level B harassment zone during some activities, not all Level B 
harassment takes will be visible to PSOs. Level B harassment exposures 
will be recorded and extrapolated based upon the number of observed 
take and the percentage of the Level B zone that was not visible.

                Table 17--Marine Mammal Monitoring Zones
------------------------------------------------------------------------
           Construction activity                 Monitoring zone (m)
------------------------------------------------------------------------
Above-water Construction..................  28 (harbor seal only).
14-inch Timber Vibratory..................  1,360.
14-inch Steel H-Pile......................  1,000.
24-inch Steel Vibratory...................  6,310.
36-inch Steel Vibratory...................  21,545.
24-inch Steel Impact......................  635.
------------------------------------------------------------------------

    Soft Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact driving, an initial set 
of three strikes would be made by the hammer at 40 percent energy, 
followed by a 1-minute wait period, then two subsequent 3-strike sets 
at 40 percent energy, with 1-minute waiting periods, before initiating 
continuous driving. Soft start would be implemented at the start of 
each day's impact pile driving and at any time following cessation of 
impact pile driving for a period of thirty minutes or longer. Soft 
start is not required during vibratory pile driving and removal 
activities.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal or 
site preparation of 30 minutes or longer occurs, PSOs will observe the 
shutdown and monitoring zones for a period of 30 minutes. The shutdown 
zone will be cleared when a marine mammal has not been observed within 
the zone for that 30-minute period. If a marine mammal is observed 
within the shutdown zone, a soft-start cannot proceed until the animal 
has been confirmed to have left the zone or has not been observed for 
15 minutes. If the Level B harassment zone has been observed for 30 
minutes and non-

[[Page 59791]]

permitted species are not observed within the zone, soft start 
procedures can commence and work can continue even if visibility 
becomes impaired within the Level B monitoring zone. When a marine 
mammal permitted for Level B harassment take is present in the Level B 
harassment zone, activities may begin and Level B take will be 
recorded. As stated above, if the entire Level B zone is not visible at 
the start of construction, piling or drilling activities can begin. If 
work ceases for more than 30 minutes, the pre-activity monitoring of 
both the Level B and shutdown zone will commence.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat);
     Mitigation and monitoring effectiveness.

Marine Mammal Visual Monitoring

    Monitoring shall be conducted by NMFS-approved observers. Trained 
observers shall be placed at the best vantage point(s) practicable to 
monitor for marine mammals, and will implement shutdown or delay 
procedures when applicable through communication with the equipment 
operator. Observer training must be provided prior to project start, 
and shall include instruction on species identification (sufficient to 
distinguish the species in the project area), description and 
categorization of observed behaviors and interpretation of behaviors 
that may be construed as being reactions to the specified activity, 
proper completion of data forms, and other basic components of 
biological monitoring, including tracking of observed animals or groups 
of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal and drilling activities. In 
addition, observers shall record all incidents of marine mammal 
occurrence, regardless of distance from activity, and shall document 
any behavioral reactions in concert with distance from piles being 
driven or removed. Pile driving/removal and drilling activities include 
the time to install or remove a single pile or series of piles, as long 
as the time elapsed between uses of the pile driving equipment is no 
more than 30 minutes.
    Three PSOs will be on-site the first day and every third day 
thereafter during vibratory hammer installation and site preparation at 
each bridge. One observer will be stationed at the best practicable 
land-based vantage point to observe the Shutdown Zone and a portion of 
the Level A and Level B harassment zones. One observer will be 
stationed along the north bank of the river at the Washington State 
Department of Transportation Rest Area: Dismal Nitch. One observer will 
be stationed at the best practicable land-based vantage point to 
observe the remainder of the Level A and Level B harassment zones. 
Likely locations include the 6th Street viewing platform and the Pier 
12 parking lot. If vibratory installation of the 36-inch casings 
occurs, this observer will be positioned along the north bank of the 
river downstream of the project site within the Chinook County Park. 
The ODOT on-site inspector will be trained in species identification 
and monitoring protocol and will be on-site during all vibratory 
removal and installation activities to confirm that no species enter 
the 10-meter Shutdown Zone when PSOs are not onsite.
    Two PSOs will be on-site the first day of impact pile driving at 
each bridge, and every third day thereafter. One observer will be 
stationed at the best practicable land-based vantage point to observe 
the Shutdown Zone and a portion of the Level A and Level B harassment 
zones. One observer will be stationed at the best practicable land-
based vantage point to observe the remainder of the Level A and Level B 
harassment zones. Likely locations include the 6th Street viewing 
platform, the Pier 12 parking lot, or the Washington State Department 
of Transportation Rest Area: Dismal Nitch on the north bank of the 
river. The ODOT on-site inspector will be trained in species 
identification and monitoring protocol and will be on-site during all 
impact pile driving activities to confirm that no species enter the 10-
meter Shutdown Zone when PSOs are not onsite.
    PSOs would scan the waters using binoculars, and/or spotting 
scopes, and would use a handheld GPS or range-finder device to verify 
the distance to each sighting from the project site. All PSOs would be 
trained in marine mammal identification and behaviors and are required 
to have no other project-related tasks while conducting monitoring. In 
addition, monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. The City would 
adhere to the following observer qualifications:
    (i) Independent observers (i.e., not construction personnel) are 
required.

[[Page 59792]]

    (ii) At least one observer must have prior experience working as an 
observer.
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience.
    (iv) The City must submit observer CVs for approval by NMFS.
    Additional standard observer qualifications include:
     Ability to conduct field observations and collect data 
according to assigned protocols Experience or training in the field 
identification of marine mammals, including the identification of 
behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of site preparation and pile 
driving and removal activities. It will include an overall description 
of work completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report must include:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury, serious injury or mortality, the City 
would immediately cease the specified activities and report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the West Coast Regional Stranding 
Coordinator. The report would include the following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with the City to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. The City would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that the City discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (e.g., in less than 
a moderate state of decomposition as described in the next paragraph), 
the City would immediately report the incident to the Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
and the NMFS West Coast Stranding Hotline and/or by email to the West 
Coast Regional Stranding Coordinator. The report would include the same 
information identified in the paragraph above. Activities would be able 
to continue while NMFS reviews the circumstances of the incident. NMFS 
would work with the City to determine whether modifications to the 
activities are appropriate.
    In the event that the City discovers an injured or dead marine 
mammal and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), the City would report the incident 
to the Chief of the Permits and Conservation Division, Office of 
Protected Resources, NMFS, and the NMFS West Coast Stranding Hotline 
and/or by email to the West Coast Regional Stranding Coordinator, 
within 24 hours of the discovery. The City would provide photographs, 
video footage (if available), or other documentation of the stranded 
animal sighting to NMFS and the Marine Mammal Stranding Network.

Phase 1 Monitoring Report

    The City's monitoring report from Phase 1 of the project (OBEC, 
2019) was frequently consulted in the NMFS evaluation of the City's 
proposed activities and requested take for Phase 2 of the project. The 
Phase 1 monitoring report indicated recorded take of California sea 
lions and harbor seals (Table 18). Steller sea lions were not observed 
during Phase 1 (Table 18), however, due to their known presence in the 
area, Level B harassment take was still requested for Phase 2 
activities. Additionally, as mentioned above, the calculated Level B 
harassment zones were significantly smaller for Phase 1 than for Phase 
2.

                                      Table 18--Phase 1 Monitoring Results
----------------------------------------------------------------------------------------------------------------
                                                                       Total
                                   Number of     Estimated takes     estimated      Authorized      Percent of
            Species             takes recorded  on days PSOs not      Level B         Level B       authorized
                                    by PSOs          present        harassment      harassment      takes that
                                                                       takes        take number      occurred
----------------------------------------------------------------------------------------------------------------
California sea lion...........             604  3,600 (240 x 15             4204          33,736            12.5
                                                 days).
Steller sea lion..............               0  0...............               0           5,360               0
Pacific harbor seal...........              53  270 (18 x 15                 323           4,560             7.1
                                                 days).
----------------------------------------------------------------------------------------------------------------


[[Page 59793]]

    Level A take was not requested nor authorized for Phase 1 
activities, so the City used the calculated Level A isopleth as the 
shutdown zone to prevent Level A take. Shutdowns occurred on three days 
during Phase 1 activities. In all instances, shutdowns occurred when 
one or more California sea lion entered the shutdown zone. The Phase 1 
and Phase 2 monitoring reports will provide useful information for 
analyzing impacts to marine mammals for potential future projects in 
the lower Columbia River.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Pile driving/removal and drilling activities associated with the 
project as outlined previously, have the potential to disturb or 
displace marine mammals. Specifically, the specified activities may 
result in take, in the form of Level A harassment and Level B 
harassment from underwater sounds generated from pile driving and 
removal. Potential takes could occur if individuals of these species 
are present in zones ensonified above the thresholds for Level A or 
Level B harassment, identified above, when these activities are 
underway.
    The takes from Level A and Level B harassment would be due to 
potential behavioral disturbance, TTS, and PTS. No mortality is 
anticipated given the nature of the activity. Level A harassment is 
only anticipated for California sea lion and harbor seal. The potential 
for Level A harassment is minimized through the construction method and 
the implementation of the planned mitigation measures (see Proposed 
Mitigation section).
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, including Phase 1 of the City's project, will 
likely be limited to reactions such as increased swimming speeds, 
increased surfacing time, or decreased foraging (if such activity were 
occurring) (e.g., Thorson and Reyff 2006; HDR, Inc. 2012; Lerma 2014; 
ABR 2016; OBEC, 2019). Most likely for pile driving, individuals will 
simply move away from the sound source and be temporarily displaced 
from the areas of pile driving and drilling, although even this 
reaction has been observed primarily only in association with impact 
pile driving. The pile driving activities analyzed here are similar to 
Phase 1 activities and numerous other construction activities conducted 
in the Pacific Northwest, which have taken place with no known long-
term adverse consequences from behavioral harassment. Level B 
harassment will be reduced to the level of least practicable adverse 
impact through use of mitigation measures described herein and, if 
sound produced by project activities is sufficiently disturbing, 
animals are likely to simply avoid the area while the activity is 
occurring. While vibratory driving (and potential drilling) associated 
with the proposed project may produce sound at distances of many 
kilometers from the project site, the project site itself is located on 
a busy waterfront and in a section of the Columbia River with high 
amounts of vessel traffic. Therefore, we expect that animals disturbed 
by project sound would simply avoid the area and use more-preferred 
habitats.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that California sea lions and harbor seals 
may sustain some limited Level A harassment in the form of auditory 
injury. However, animals in these locations that experience PTS would 
likely only receive slight PTS, i.e., minor degradation of hearing 
capabilities within regions of hearing that align most completely with 
the frequency range of the energy produced by pile driving, i.e., the 
low-frequency region below 2 kHz, not severe hearing impairment or 
impairment in the regions of greatest hearing sensitivity. If hearing 
impairment occurs, it is most likely that the affected animal would 
lose a few decibels in its hearing sensitivity, which in most cases is 
not likely to meaningfully affect its ability to forage and communicate 
with conspecifics. As described above, we expect that marine mammals 
would be likely to move away from a sound source that represents an 
aversive stimulus, especially at levels that would be expected to 
result in PTS, given sufficient notice through use of soft start.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range; but, because 
of the short duration of the activities and the relatively small area 
of the habitat that may be affected, the impacts to marine mammal 
habitat are not expected to cause significant or long-term negative 
consequences. Other than feeding and the haulout areas previously 
described, the project area does not include any areas or times of 
particular biological significance for the affected species.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality or serious injury is anticipated or 
authorized;
     No serious injury is anticipated or authorized;
     The Level A harassment exposures are anticipated to result 
only in slight PTS, within the lower frequencies associated with pile 
driving;
     The anticipated incidents of Level B harassment would 
consist of, at worst, temporary modifications in behavior that would 
not result in fitness impacts to individuals;
     The area impacted by the specified activity is very small 
relative to the overall habitat ranges of all species;
     The activity is expected to occur over 21 or fewer in-
water work days.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals

[[Page 59794]]

and their habitat, and taking into consideration the implementation of 
the proposed monitoring and mitigation measures, NMFS preliminarily 
finds that the total marine mammal take from the proposed activity will 
have a negligible impact on all affected marine mammal species or 
stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    The number of takes for each species proposed to be taken as a 
result of this project is 5, 13.7, and 10.2 percent of the total stock 
for harbor seal, Steller sea lion, and California sea lion, 
respectively (Table 15). Additionally, the number of takes requested is 
based on the number of estimated exposures, not necessarily the number 
of individuals exposed. Pinnipeds may remain in the general area of the 
project sites and the same individuals may be harassed multiple times 
over multiple days, rather than numerous individuals harassed once.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
preliminarily determined that the total taking of affected species or 
stocks would not have an unmitigable adverse impact on the availability 
of such species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the NMFS West Coast Region 
Protected Resources Division Office, whenever we propose to authorize 
take for endangered or threatened species.
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under Section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the City of Astoria for conducting waterfront bridge 
removal and replacement in Astoria, Oregon from November 2019 to 
October 2020, provided the previously mentioned mitigation, monitoring, 
and reporting requirements are incorporated. A draft of the proposed 
IHA can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed 
project. We also request at this time comment on the potential renewal 
of this proposed IHA as described in the paragraph below. Please 
include with your comments any supporting data or literature citations 
to help inform decisions on the request for this IHA or a subsequent 
Renewal.
    On a case-by-case basis, NMFS may issue a one-year IHA renewal with 
an additional 15 days for public comments when (1) another year of 
identical or nearly identical activities as described in the Specified 
Activities section of this notice is planned or (2) the activities as 
described in the Specified Activities section of this notice would not 
be completed by the time the IHA expires and a Renewal would allow for 
completion of the activities beyond that described in the Dates and 
Duration section of this notice, provided all of the following 
conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA.
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal are identical to the activities analyzed under the 
initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal).
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
     Upon review of the request for Renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: October 31, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-24190 Filed 11-5-19; 8:45 am]
 BILLING CODE 3510-22-P