[Federal Register Volume 89, Number 20 (Tuesday, January 30, 2024)]
[Notices]
[Pages 5865-5877]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-01790]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD639]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Pacific Gas & Electric Sediment 
Remediation Project, San Francisco Bay

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
Pacific Gas & Electric (PG&E) to incidentally harass marine mammals 
during construction activities associated with a sediment remediation 
project in San Francisco Bay.

DATES: The authorization is effective from May 1, 2024 to April 30, 
2025.

ADDRESSES: 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/action/incidental-take-authorization-pacific-gas-electric-sediment-remediation-project-san. In case of problems accessing these documents, 
please call the contact listed below.

FOR FURTHER INFORMATION CONTACT: Kristy Jacobus, Office of Protected 
Resources, NMFS, (301) 427-8401.

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 proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is 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 the 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 the takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

Summary of Request

    On May 4, 2023, NMFS received a request from PG&E for an IHA to 
take marine mammals incidental to a Sediment Remediation Project in 
Remedial Response Areas A and B, Piers

[[Page 5866]]

39 to 43\1/2\, San Francisco Bay. Following NMFS' review of the 
application, PG&E submitted additional information on July 25, 2023 and 
September 26, 2023 and subsequently submitted a revised application on 
November 16, 2023, which was deemed adequate and complete. PG&E's 
request is for take of seven species (eight stocks) of marine mammals 
by Level B harassment only. Neither PG&E nor NMFS expect serious injury 
or mortality to result from this activity and, therefore, an IHA is 
appropriate. There are no changes from the proposed IHA to the final 
IHA.
    This IHA will cover 1 year of a larger project for which PG&E 
intends to request take authorization for subsequent facets of the 
project if necessary. The larger 5 to 7 year project involves 
construction to remediate contaminated sediment.

Description of Activity

Overview

    PG&E is remediating sediments impacted with polycyclic aromatic 
hydrocarbons (PAHs) in San Francisco Bay around the area offshore of 
Pier 43\1/2\ to the east of Pier 45 and offshore area of Pier 43. The 
Project is expected to occur over a period of 5 to 7 years, and this 
IHA will authorize take associated with Year 1 only. PG&E expects that 
Year 1 will include installation of hydroacoustic data collection 
piles; installation of piles to attach a turbidity curtain; dredging of 
impacted sediment; installation of sediment pins to promote slope 
stability; capping of impacted sediment to be left in place; placement 
of armoring as needed; and temporary relocation of the Red and White 
Fleet (RWF). The project's planned activities that have the potential 
to take marine mammals, by Level B only, include impact installation 
and vibratory removal of composite piles; vibratory installation and 
removal of H-piles or steel shell piles less than or equal to 24 inches 
(61 cm) in diameter; vibratory installation and removal of 36-inch 
steel guide piles; vibratory and impact installation of 24-inch steel 
fender piles; vibratory removal of the 24-inch fender piles; and 
vibratory and impact installation of timber piles. In-water 
construction is expected to occur over 50 non-consecutive days over 1 
year.
    A detailed description of the planned construction project is 
provided in the Federal Register noticed for the proposed IHA (88 FR 
82836, November 27, 2023). Since that time, no changes have been made 
to the planned activities. Therefore, a detailed description is not 
provided here. Please refer to that Federal Register notice for the 
description of the specific activity.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to PG&E was published in 
the Federal Register on November 27, 2023 (88 FR 82836). That notice 
described, in detail, PG&E's activity, the marine mammal species that 
may be affected by the activity, and the anticipated effects on marine 
mammals. In that notice, we requested public input on the request for 
authorization described therein, our analyses, the proposed 
authorization, and any other aspect of the notice of proposed IHA, and 
requested that interested persons submit relevant information, 
suggestions, and comments.
    During the 30-day public comment period, NMFS received comments 
from Turtle Island Restoration Network (TIRN) and a letter from the 
U.S. Geological Survey stating that they had no comments. In addition, 
a comment was received from a private citizen expressing general 
opposition to PG&E, which is not related to NMFS' proposed action. All 
relevant, substantive comments, and NMFS' responses, are provided 
below. The comments and recommendations are available online at: 
https://www.fisheries.noaa.gov/action/incidental-take-authorization-pacific-gas-electric-sediment-remediation-project-san. Please see the 
comment submission for full details regarding the recommendations and 
supporting rationale.
    Comment 1: TIRN asserts that NMFS failed to adequately consider the 
potential for delayed mortality of marine mammals or the potential 
long-term impacts of underwater noise on the ecosystem as a whole, and 
states that NMFS ``must require PG&E to submit a request for 
authorization of incidental Level A harassment takes of marine 
mammals.''
    Response: We first note that TIRN conflates take by Level A 
harassment and mortality and serious injury. As defined by the MMPA, 
Level A harassment means ``any act of pursuit, torment, or annoyance 
which has the potential to injure a marine mammal or marine mammal 
stock in the wild'' (16 U.S.C. 1362(18)(A)). Serious injury is defined 
as ``any injury that will likely result in mortality'' under NMFS' MMPA 
implementing regulations (50 CFR 216.3). Level A harassment does not 
include serious injury or mortality, and serious injury or mortality 
cannot be authorized through an IHA.
    NMFS acknowledges that pile driving can impact marine mammals' 
ability to detect prey and can impact marine mammal prey in the 
vicinity of the project area, as discussed in the Federal Register 
notice for the proposed IHA (88 FR 82836, November 27, 2023). However, 
NMFS expects these effects to be temporary and disagrees that these 
impacts are likely to result in long-term disruption or result in 
delayed mortality. TIRN suggests, without evidence, that the specified 
activity is likely to reduce the ability for marine mammals to hunt to 
the extent that such behavioral effects may lead to delayed mortality. 
Any effects to marine mammals' ability to hunt or detect prey are 
expected to be temporary, e.g., on the order of minutes to hours, due 
to marine mammals' transient nature, likelihood to avoid disturbance, 
the short duration of construction, and the mitigation used which will 
reduce marine mammals' exposure to pile driving noise. Mortality can 
result if marine mammal foraging behavior is impeded, but such an 
extreme result would require complete cessation of foraging over an 
extended period of time. There is no potential for such impacts to 
result from this activity given the short durations over which bouts of 
activity will occur and unimpeded access to other areas of equal 
foraging value. The most likely impact to fishes from pile driving are 
expected to be temporary behavioral avoidance, and any behavioral 
avoidance by fish of the disturbed area would still leave significantly 
large potential areas in the nearby vicinity for marine mammals to 
forage. Further discussion of the expected short-term impacts to marine 
mammals and prey can be found in the Potential Effects of Specified 
Activities on Marine Mammals and Their Habitat in the Federal Register 
notice for the proposed IHA (88 FR 82836, November 27, 2023).
    NMFS disagrees that long-term disruptions and delayed mortality of 
marine mammals are likely to occur as a result of PG&E's project and, 
therefore, authorization of Level A harassment or serious injury or 
mortality is not appropriate.

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. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS'

[[Page 5867]]

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' website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species or stocks for which take is expected and 
authorized for this activity, and summarizes information related to the 
population or stock, including regulatory status under the MMPA and 
Endangered Species Act (ESA) and potential biological removal (PBR), 
where known. 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' SARs). While no 
serious injury or 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 or 
stocks 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' 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. All managed stocks in this region are assessed in 
NMFS' U.S. Pacific and Alaska SARs. All values presented in table 1 are 
the most recent available at the time of publication and are available 
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                     Table 1--Marine Mammal Species Likely Impacted by the Specified Activities \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin..............  Tursiops truncatus.....  Coastal California.....  -,-,N               453 (0.06, 346, 2011).        2.7      >=2.0
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  San Francisco-Russian    -,-,N               7,777 (0.62, 4811,             73      >=0.4
                                                                River.                                       2017).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    California Sea Lion.............  Zalophus californianus.  United States..........  -,-,N               257,606 (N/A, 233,515,     14,011      >=321
                                                                                                             2014).
    Northern Fur Seal...............  Callorhinus ursinus....  California.............  -,-,N               14,050 (0.03, 7,524,          451        1.8
                                                                                                             2013).
    Northern Fur Seal...............  Callorhinus ursinus....  Eastern North Pacific..  -, D, Y             626,618 (0.2, 530,376,     11,403        373
                                                                                                             2021).
    Steller Sea Lion................  Eumetopias jubatus.....  Eastern North Pacific..  -,-,N               43,201 (N/A, 43,201,        2,592        112
                                                                                                             2017).
Family Phocidae (earless seals):
    Harbor Seal.....................  Phoca vitulina.........  California.............  -,-,N               30,968 (N/A, 27,348,        1,641         43
                                                                                                             2014).
    Northern Elephant Seal..........  Mirounga angustirostris  California Breeding....  -,-,N               187,386 (N/A, 85,369,       5,122       13.7
                                                                                                             2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\2\ 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.
\3\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ 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, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range.

    As indicated above, all seven species (with eight managed stocks) 
in table 1 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur. Gray whales and 
humpback whales rarely enter the Bay but may occasionally pass offshore 
of the Project Area. However, if either of these species are to 
approach the Level B harassment zone construction will be shutdown. 
Therefore, no take is expected of these species, and these species will 
not be discussed further.
    A detailed description of the of the species likely to be affected 
by the sediment remediation project, including brief introductions to 
the species and relevant stocks as well as available information 
regarding population trends and threats, and information regarding 
local occurrence, were provided in the Federal Register notice for the 
proposed IHA (88 FR 82836, November 27, 2023); since that time, we are 
not aware of any changes in the status of these species and stocks; 
therefore, detailed descriptions are not provided here. Please refer to 
that Federal Register notice for these descriptions. Please also refer 
to NMFS' website (https://www.fisheries.noaa.gov/find-species) for 
generalized species accounts.

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. 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, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). 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

[[Page 5868]]

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 2.

                  Table 2--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.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from PG&E's sediment remediation 
activities have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the project area. The notice of 
proposed IHA (88 FR 82836, November 27, 2023) included a discussion of 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from PG&E's construction on marine mammals 
and their habitat. That information and analysis is incorporated by 
reference into this final IHA determination and is not repeated here; 
please refer to the notice of proposed IHA (88 FR 82836, November 27, 
2023).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through the IHA, which will inform both NMFS' consideration 
of ``small numbers,'' and the negligible impact determinations.
    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 will be by Level B harassment only, in the form of 
disruption of behavioral patterns and/or temporary threshold shift 
(TTS) for individual marine mammals resulting from exposure to 
vibratory and impact pile driving. Based on the nature of the activity 
and the anticipated effectiveness of the mitigation measures (i.e., 
shutdown) discussed in detail below in the Mitigation section, Level A 
harassment is neither anticipated nor authorized.
    As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
take numbers are estimated.
    For acoustic impacts, 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) the number of days of activities. We note 
that while these factors can contribute to a basic calculation to 
provide an initial prediction of potential 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 take estimates.

Acoustic Thresholds

    NMFS recommends the use of 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 permanent threshold shift (PTS) of some 
degree (equated to Level A harassment).
    Level B Harassment--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 or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 micropascal (re 1 [micro]Pa)) for continuous (e.g., vibratory pile 
driving, drilling) and above RMS SPL 160 dB re 1 [micro]Pa for non- 
explosive impulsive (e.g., seismic

[[Page 5869]]

airguns) or intermittent (e.g., scientific sonar) sources. Generally 
speaking, Level B harassment take estimates based on these behavioral 
harassment thresholds are expected to include any likely takes by TTS 
as, in most cases, the likelihood of TTS occurs at distances from the 
source less than those at which behavioral harassment is likely. TTS of 
a sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    PG&E's activity includes the use of continuous (vibratory pile 
driving) and impulsive (impact pile driving) sources, and therefore the 
RMS SPL thresholds of 120 and 160 dB re 1 [micro]Pa are applicable.
    Level A Harassment--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). PG&E's 
activity includes the use of impulsive (impact pile driving) and non-
impulsive (vibratory pile driving) 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 3--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: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 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 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]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 are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the project. Marine 
mammals are expected to be affected via sound generated by the primary 
components of the project (i.e., pile driving and removal).
    The project includes vibratory pile installation and removal and 
impact pile driving. Source levels for these activities 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 
activity are presented in table 4. Source levels for vibratory 
installation and removal of piles of the same diameter are 
conservatively assumed to be the same.
    The majority of source levels were selected from a single source, 
as shown in table 4 below. For the vibratory installation of 36-inch 
steel shell piles and vibratory installation of timber piles, NMFS 
determined it appropriate to use an average of source levels. NMFS 
reviewed all available monitoring reports of vibratory driving of 36-
inch steel piles in San Francisco Bay (Gast &Associated Environmental 
Consultants, 2021, 2023; Illingworth & Rodkin, 2018, 2020). Averaging 
of sound levels was performed by first converting from dB to linear 
units of pressure (Pascals [Pa]), averaging, and converting back to dB. 
The mean RMS level at 10 meters (m) for San Francisco Bay was 
approximately 168 dB re 1 [micro]Pa RMS. Therefore, NMFS has selected 
this average value as the most appropriate value for vibratory driving 
of 36-inch steel pipe piles during the project. With regard to 
vibratory installation of timber piles, there are limited data 
available, and none from San Francisco Bay. Therefore, NMFS evaluated 
all available timber pile data (three projects from Puget Sound, WA, 
and one project from Norfolk, VA) (Greenbusch Group, 2018; Illingworth 
and Rodkin, 2017; Laughlin, 2011; U.S. Navy, 2016) and calculated the 
mean and maximum RMS values for each project and for all projects 
together. The overall mean RMS value was approximately 158 dB re 1 
[micro]Pa RMS. NMFS therefore selected this as an appropriate proxy 
value for vibratory driving of timber piles during the project.

                          Table 4--Sound Source Levels for Pile Driving Activities \1\
----------------------------------------------------------------------------------------------------------------
                                                   Peak sound
                                                  pressure (dB    RMS (dB re 1    SEL (dB re 1
          Pile type                 Method            re 1         [micro]Pa)      [micro]Pa2         Source
                                                   [micro]Pa)                         sec)
----------------------------------------------------------------------------------------------------------------
                                          Hydroacoustic Data Collection
----------------------------------------------------------------------------------------------------------------
18-inch composite/plastic....  Impact Install..             185             160             150  Caltrans, 2020;
                                                                                                  extrapolated
                                                                                                  from 13-inch
                                                                                                  composite.

[[Page 5870]]

 
18-inch composite/plastic....  Vibratory                    N/A             152             N/A  WSDOT, 2012; 13-
                                Removal.                                                          inch composite
                                                                                                  used as proxy.
----------------------------------------------------------------------------------------------------------------
                                                Turbidity Curtain
----------------------------------------------------------------------------------------------------------------
Steel H-Pile.................  Vibratory                    N/A             143             N/A  Caltrans, 2020.
                                Install and
                                Removal.
Steel Shell Pile <=24-inches.  Vibratory                    N/A             153             N/A  Caltrans, 2020;
                                Install and                                                       24-inch pipe
                                Removal.                                                          pile used as
                                                                                                  proxy.
----------------------------------------------------------------------------------------------------------------
                                                 RWF Relocation
----------------------------------------------------------------------------------------------------------------
24-inch steel shell..........  Vibratory                    N/A             153             N/A  Caltrans, 2020.
                                Installation
                                and Removal.
24-inch steel shell..........  Impact                       208             193             178  Illingworth &
                                Installation                                                      Rodkin, Inc.
                                \2\.                                                              2014.
36-inch steel shell..........  Vibratory                    N/A             168             N/A  Gast &
                                Installation                                                      Associated
                                and Removal.                                                      Environmental
                                                                                                  Consultants,
                                                                                                  2021, 2023;
                                                                                                  Illingworth
                                                                                                  and Rodkin,
                                                                                                  2018, 2020.
                                                                                                  See
                                                                                                  explanation
                                                                                                  above.
----------------------------------------------------------------------------------------------------------------
                                               Slope Stabilization
----------------------------------------------------------------------------------------------------------------
14 to 16 inch Timber.........  Vibratory.......             N/A             158             N/A  Greenbusch
                                                                                                  Group, 2018;
                                                                                                  Illingworth
                                                                                                  and Rodkin,
                                                                                                  2017;
                                                                                                  Laughlin,
                                                                                                  2011; U.S.
                                                                                                  Navy 2016. See
                                                                                                  explanation
                                                                                                  above.
14 to 16 inch Timber.........  Impact..........             184             157             145  Caltrans, 2020.
14 to 16-inch Composite......  Vibratory.......             N/A             152             N/A  WSDOT, 2012. 13-
                                                                                                  inch composite
                                                                                                  used as proxy.
14 to 16-inch Composite......  Impact..........             177             153             145  Caltrans, 2020.
----------------------------------------------------------------------------------------------------------------
\1\ All values are at 10 m from the source.
\2\ PG&E will use a bubble curtain attenuation system for impact pile driving of the RWF 24-inch steel shell
  piles, and we conservatively assumes a 5 dB reduction in source level from those presented here due to use of
  the attenuation system.

    Level B Harassment Zones-- 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 topography. The general formula for 
underwater TL is:

TL = B * Log10 (R1/R2),

where
TL = transmission loss in dB;
B = transmission loss coefficient;
R1 = the distance of the modeled SPL from the driven 
pile; and
R2 = the distance from the driven pile of the initial 
measurement.

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, known as practical spreading. As 
is common practice in coastal waters, here we assume practical 
spreading (4.5 dB reduction in sound level for each doubling of 
distance) for all impact and vibratory installation and removal of 
piles with the exception of vibratory installation and removal of the 
36-inch steel pipe piles in the RWF Relocation. Illingworth & Rodkin 
conducted hydro-acoustic monitoring for the 2017 WETA Downtown San 
Francisco Ferry Terminal Expansion Project and calculated a TL 
coefficient of 18.7 for vibratory installation of 36-inch steel shell 
piles (Illingworth & Rodkin, 2018). Given the proximity to the project 
area, PG&E determined that 18.7 was an appropriate transmission 
coefficient to use for the vibratory installation of the 36-inch steel 
shell pile, and NMFS concurs.
    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources such as pile driving, the optional User Spreadsheet 
tool predicts the distance at which, if a marine mammal remained at 
that distance for the duration of the activity, it would be expected to 
incur PTS. Source levels are provided above in table 4. Inputs used in 
the optional User Spreadsheet tool are provided below in table 5. 
Resulting estimated Level A and B harassment isopleths are provided in 
table 6.

                      Table 5--User Spreadsheet Inputs (Source Levels Provided in Table 4)
----------------------------------------------------------------------------------------------------------------
                Pile type                           Method                     Duration              Piles/day
----------------------------------------------------------------------------------------------------------------
                                          Hydroacoustic Data Collection
----------------------------------------------------------------------------------------------------------------
18-inch composite/plastic...............  Impact Install............  400 strikes/pile..........              10
18-inch composite/plastic...............  Vibratory Removal.........  20 minutes................              10
----------------------------------------------------------------------------------------------------------------

[[Page 5871]]

 
                                                Turbidity Curtain
----------------------------------------------------------------------------------------------------------------
Steel H-Pile............................  Vibratory.................  10 minutes................               4
Steel Shell Pile <=24-inches............  Vibratory.................  10 minutes................               4
----------------------------------------------------------------------------------------------------------------
                                                 RWF Relocation
----------------------------------------------------------------------------------------------------------------
24-inch steel shell.....................  Vibratory.................  10 minutes................               4
24-inch steel shell.....................  Impact....................  400 strikes/pile..........               4
36-inch steel shell.....................  Vibratory.................  20 minutes................               4
----------------------------------------------------------------------------------------------------------------
                                            Sediment Pin Installation
----------------------------------------------------------------------------------------------------------------
Timber..................................  Vibratory.................  20 minutes................              20
Timber..................................  Impact....................  400 strikes/pile..........              20
14 to16-inch Composite..................  Vibratory.................  20 minutes................              10
14 to 16-inch Composite.................  Impact....................  400 strikes/pile..........              10
----------------------------------------------------------------------------------------------------------------


                           Table 6--Level A Harassment and Level B Harassment Isopleths From Vibratory and Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   Level A/PTS isopleth (m)
                                                                 ------------------------------------------------------------
                                                                                        Hearing groups                          Level B    Level B area
                       Pile type & method                        ------------------------------------------------------------  Isopleth         of
                                                                               Cetaceans                     Pinnipeds            (m)     ensonification
                                                                 ------------------------------------------------------------                 (km\2\)
                                                                      LF          MF          HF        Phocids    Otariids
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Hydroacoustic Data Collection Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
18-inch composite (Impact)......................................          16          <1          19           9          <1          10         <0.01
18-inch Composite (Vibratory)...................................           4          <1           6           3          <1       1,360          3.58
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Turbidity Curtain
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steel H-Pile (Vibratory)........................................          <1           0          <1          <1          <1         341          0.29
Steel Shell Pile <= 24-inches (Vibratory).......................           2          <1           4           2          <1       1,585          4.61
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             RWF Temporary Relocation Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch Steel Shell Pile (Vibratory)............................           2          <1           4           2          <1       1,585          4.54
24-inch Steel Shell Pile (Impact, Attenuated)*..................         294          11         351         158          12         736          1.06
36-inch Steel Shell Pile (Vibratory)............................          20           3          28          14           2       3,688         23.46
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Sediment Pins
--------------------------------------------------------------------------------------------------------------------------------------------------------
14 to 16-inch Timber Pile (Vibratory)...........................          16           2          23          10           1       3,415         19.17
14 to 16-inch Timber Pile (Impact)..............................          12          <1          14           6          <1           6         <0.01
14 to 16-inch Composite Pile (Vibratory)........................           4          <1           6           3          <1       1,360           3.2
14 to 16-Inch Composite Pile (Impact)...........................           7          <1           9           4          <1         3.4         <0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------
* 5 dB reduction in sound due to use of bubble curtain assumed.

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations.
    Because reliable marine mammal density information is not available 
for the San Francisco Bay, several datasets were used to attain 
estimates of the abundance of marine mammals in the Bay. Datasets used 
included 5 years of sighting and stranding data from The Marine Mammal 
Center (TMMC) (NMFS, 2021a); 5 years of sighting and stranding data 
from the California Academy of Sciences (CAS) (NMFS, 2021b); citizen-
reported live sightings from iNaturalist.org; 5 days of sighting data 
during sediment investigation in 2020 during the initial phase of the 
project (Haase, 2021); and counts from haulouts. Data from all sources, 
when available, were considered. Depending on the distribution of 
sightings and granularity of data, different sources have been used to 
estimate the number of individuals of each species with the potential 
to occur in vicinity of the project. The largest ensonified area is 
during vibratory installation of 36-inch steel shell piles, which 
results in a 3,688 m isopleth and 23.46 kilometers squared (km\2\) area 
of ensonification.

Harbor Seal

    Harbor seals in the Bay forage mainly within 7.0 miles (mi; (11.3 
km)) of their primary haulout site (Grigg et al. 2012), and often 
within just 1 to 3 miles (1 to 5 km) (Torok, 1994). The only harbor 
seal haulout within 7 miles (11.3 km) of the project site is Yerba 
Buena Island (YBI), which is 3.1 mi (5 km) to the east of the Project 
Area. Noise from the project is not expected to reach the haulout, 
however, harbor seals that use this haulout are likely to forage within 
ensonified areas from the project. Harbor seal take estimates were 
based on observations conducted by Marine Mammal Observers (MMOs) over 
a 5 day period in 2020, during sediment investigation in the initial 
phase of the project, within remedial response areas A, B, and C (See 
Haase, 2021). A maximum of 20 harbor seals were observed per day. PG&E 
therefore estimates 20 harbor seals per day within

[[Page 5872]]

the project area per day. NMFS concurs with this assumption.

Northern Elephant Seal

    TMMC recorded 903 elephant seals in the Bay from 2016 to 2021 
(NMFS, 2021a). The CAS reported an additional 6 for a total of 909 over 
5 years in the Bay from 2016 to 2021 (NMFS, 2021b), yielding an average 
of 0.5 elephant seals per day. To ensure sufficient authorization of 
take of northern elephant seals, PG&E assumed 0.5 elephant seals will 
occur in the area per day (i.e., one elephant seal every 2 days). NMFS 
concurs with this assumption.

California Sea Lion

    The Pier 39 K-Dock haulout is the only regularly used California 
Sea Lion haulout in the vicinity of the Project Area, adjacent to Area 
C. The Sea Lion Center at Pier 39 regularly counted the sea lions at K-
Dock from 1991 through 2018. From 2016 through 2018, the yearly average 
ranged from 89 to 229 animals per day. The average per day over all 3 
years was 191 sea lions (Pacific Gas & Electric, 2023). Although there 
are times of the year when the K-dock is unoccupied or there are few 
individuals present, it is difficult to predict abundance based on time 
of year. In order to ensure sufficient authorization of sea lions, PG&E 
is assuming a local abundance estimate of 191 sea lions per day within 
the estimated harassment area, and NMFS concurs.

Northern Fur Seal

    TMMC recorded 44 northern fur seals in the Bay from 2016 to 2021 
(NMFS, 2021a). CAS recorded an additional 3 for a total of 47 over 5 
years (NMFS, 2021b), yielding 0.03 per day, or approximately 10 per 
year. In the fall and winter, northern fur seals occasionally strand on 
YBI and Treasure Island (Pacific Gas & Electric, 2023), approximately 
2.0 mi (3.2 km) from the project area. Using PG&E's assumption of 
approximately 0.03 fur seals per day over the course of 50 days of pile 
driving plus known fur seal strandings near the project area, NMFS has 
determined it appropriate to assume five fur seals in the project area 
during the project time period.

Steller Sea Lion

    Steller sea lions are rare in San Francisco Bay. TMMC recorded four 
Steller sea lions in the Bay from 2016 to 2021 (NMFS, 2021a), while CAS 
reported no Steller sea lions during this time (NMFS, 2021b). In 2020 
and 2021, INaturalist.org recorded four Steller sea lions in the Bay. 
On rare occasions, Steller sea lions are seen on the Pier 39 K-dock 
haulout. An adult male was spotted there in May 2023 (Segura, 2023) and 
in previous years a single male Steller sea lion had been observed 
using the Pier 39 K-dock haulout intermittently during July and August 
and occasionally September (Pacific Gas & Electric, 2023). Given these 
known occasional occurrences of the Steller sea lion at Pier 39, PG&E 
feels it is appropriate to assume five Steller sea lions in the project 
area during the time period of the project, and NMFS concurs.

Bottlenose Dolphins

    Historically, observations of bottlenose dolphins have occurred 
west of Treasure Island and were concentrated in the Project vicinity 
along the nearshore area of San Francisco south to Redwood City. Since 
2016, one individual has been regularly seen near the former Alameda 
Air Station and five animals were regularly seen in the summer and fall 
of 2018 in the same location (Pacific Gas & Electric, 2023). A recent 
study reports that dolphins have been sighted in the vicinity of the 
Golden Gate Bridge, around Yerba Buena and Angel Islands, and in the 
central Bay (Keener et al., 2023). PG&E is assuming that one group of 
bottlenose dolphins will enter into the project isopleth per month of 
pile driving, and NMFS concurs. A group size is estimated to be five 
animals based on sightings of bottlenose dolphins in the Bay (Pacific 
Gas & Electric, 2023).

Harbor Porpoise

    Harbor porpoises are primarily seen near the Golden Gate Bridge, 
Marin County, and the city of San Francisco on the northwest side of 
the Bay (Keener et al., 2012; Stern et al., 2017), in the vicinity of 
the project area. Limited data exists on the abundance of harbor 
porpoises in the Bay, and therefore data from MMOs in 2020 was used 
(see Haase 2021). An individual harbor porpoise was seen in the project 
zone on 2 of the 5 days, and a group of two individuals was reported on 
a separate day of the 5 day observation period (Haase, 2021). To ensure 
sufficient authorization of take of harbor porpoise, it is estimated 
that two harbor porpoises will occur within the estimated harassment 
area per day.

Take Estimation

    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and is authorized.
    Take estimate calculations vary by species. To calculate take by 
Level B harassment for harbor seals, California sea lions, northern 
elephant seals, and harbor porpoises, NMFS multiplied the daily 
occurrence estimates described in the Marine Mammal Occurrence section 
by the number of project days (table 7).
    For northern fur seals, PG&E is assuming a total of five animals in 
the area of the project during the duration of the project, based on 
sightings in the Bay and known strandings on YBI (see Marine Mammal 
Occurrence above), and is therefore requesting, and NMFS has 
authorized, take of five northern fur seals by Level B harassment 
(table 7).
    Although Steller sea lions are rare in San Francisco Bay, based on 
sighting data and known occurrence of Steller sea lions on the Pier 39 
K-dock haulout (PG&E, 2023; Segura, 2023), PG&E is conservatively 
requesting five takes by Level B harassment of Steller sea lions during 
the time period of the project, and NMFS concurs (table 7).
    For bottlenose dolphins, PG&E estimates that one group of five 
bottlenose dolphins may be taken by Level B harassment per month of 
pile driving. Based on 5 months of pile driving, NMFS has authorized 25 
takes by Level B harassment of bottlenose dolphins.

                     Table 7--Authorized Take by Level B Harassment Authorized and Estimated Take as a Percentage of the Population
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                 Estimated Level B
                Species                             Stock                Expected occurrence            take        Stock abundance *   Percent of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific Harbor Seal....................  California................  20 seals per day..........               1000             30,968                3.2
Northern Elephant Seal.................  California Breeding.......  0.5 seals per day.........                 25            187,386               0.01
California Sea Lion....................  United States.............  191 sea lions per day.....              9,550            257,606                3.7

[[Page 5873]]

 
Northern Fur Seal......................  California; Eastern North   5 seals over project                        5    14,050; 626,618        0.04; 0.001
                                          Pacific.                    duration.
Steller sea lion.......................  Eastern United States.....  5 sea lions over project                    5             43,201               0.01
                                                                      duration.
Bottlenose dolphin.....................  Coastal California........  5 dolphins per month of                    25                453                5.5
                                                                      project.
Harbor Porpoise........................  San Francisco-Russian       2 porpoises per day.......                100              7,777                1.3
                                          River.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports reports.

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 the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the 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 the 
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, NMFS 
considers 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 and impact on 
operations.
    PG&E must follow mitigation measures as specified below.
    PG&E must ensure that construction supervisors and crews, the 
monitoring team, and relevant PG&E staff are trained prior to the start 
of all pile driving activities, so that responsibilities, communication 
procedures, monitoring protocols, and operational procedures are 
clearly understood. New personnel joining during the project must be 
trained prior to commencing work.

Shutdown Zones

    PG&E must establish shutdown zones and Level B monitoring zones for 
all pile driving activities. The purpose of a shutdown zone is 
generally to define an area within which shutdown of the activity will 
occur upon sighting of a marine animal (or in anticipation of an animal 
entering the defined area). Shutdown zones are based on the largest 
Level A harassment zone for each pile size/type and driving method, and 
behavioral monitoring zones are meant to encompass Level B harassment 
zones for each pile size/type and driving method, as shown in table 6. 
A minimum shutdown zone of 10 m will be required for all in-water 
construction activities to avoid physical interaction with marine 
mammals, and the radii of the shutdown zones are rounded to the next 
largest 10 m interval in comparison to the Level zone for each activity 
type. Marine mammal monitoring will be conducted during all pile 
driving activities to ensure that marine mammals do not enter Level A 
shutdown zones, that marine mammal presence in the isopleth does not 
exceed authorized take, and to prevent take of the humpback and gray 
whale. Shutdown zones for each activity type are shown in table 8.
    Prior to pile driving, shutdown zones and monitoring zones will be 
established based on zones represented in table 8. Observers will 
survey the shutdown zones for at least 30 minutes before pile driving 
activities start. If marine mammals are found within the shutdown zone, 
pile driving will be delayed until the animal has moved out of the 
shutdown zone, either verified by an observer or by waiting until 15 
minutes has elapsed without a sighting. If a marine mammal approaches 
or enters the shutdown zone during pile driving, the activity will be 
halted. Pile driving may resume after the animal has moved out of and 
is moving away from the shutdown zone or after at least 15 minutes has 
passed since the last observation of the animal.
    All marine mammals will be monitored in the Level B harassment 
zones and throughout the area as far as visual monitoring can take 
place. If a marine mammal enters the Level B harassment zone, in-water 
activities will continue and PSOs will document the animal's presence 
within the estimated harassment zone.
    If a species for which authorization has not been granted (i.e., 
gray whale or humpback whale), or a species which has been granted but 
the authorized takes are met, is observed approaching or within the 
Level B monitoring zone, pile driving activities will be shutdown 
immediately. Activities will not resume until the animal has been 
confirmed to have left the area or 15 minutes has elapsed with no 
sighting of the animal.

[[Page 5874]]



    Table 8--Shutdown Zones and Level B Monitoring Zones by Activity
------------------------------------------------------------------------
                                    Shutdown zone for   Monitoring zone
       Pile type and method          all species (m)          (m)
------------------------------------------------------------------------
                   Hydroacoustic Data Collection Piles
------------------------------------------------------------------------
18-inch Composite/Plastic (impact)                 20                 10
18-Inch Composite/Plastic                          10              1,360
 (vibratory removal)..............
------------------------------------------------------------------------
                            Turbidity Curtain
------------------------------------------------------------------------
Steel H-Pile (Vibratory Install                    10                341
 and Removal).....................
24-inch steel shell pile                           10              1,585
 (Vibratory install and removal)..
------------------------------------------------------------------------
                          RWF Relocation Piles
------------------------------------------------------------------------
24-inch steel shell pile                           10              1,585
 (Vibratory install and removal)..
24-inch steel shell pile (impact-                 360                736
 attenuated)......................
36-inch steel shell pile                           30              3,688
 (vibratory)......................
------------------------------------------------------------------------
                              Sediment Pins
------------------------------------------------------------------------
14 to 16-inch timber (Vibratory)..                 30              3,415
14 to 16-inch timber (impact).....                 20                 10
14 to 16-inch composite (impact)..                 10                 10
14 to 16-inch composite (vibratory                 20              1,360
 install).........................
------------------------------------------------------------------------

Protected Species Observers (PSOs)

    The placement of PSOs during all pile driving activities (described 
in the Monitoring and Reporting section) will ensure that the entire 
shutdown zone is visible. Should environmental conditions deteriorate 
such that the entire shutdown zone will not be visible (e.g., fog, 
heavy rain), pile driving will be delayed until the PSO is confident 
marine mammals within the shutdown zone could be detected.
    PSOs will monitor the full shutdown zones and as much of the Level 
B harassment zones as possible. 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 areas 
outside the shutdown zones and thus prepare for a potential cessation 
of activity should the animal enter the shutdown zone.

Pre- and Post-Activity Monitoring

    Monitoring must take place from 30 minutes prior to initiation of 
pile driving activities (i.e., pre-clearance monitoring) through 30 
minutes post-completion of pile driving. Prior to the start of daily 
in-water construction activity, or whenever a break in pile driving 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 
considered cleared when a marine mammal has not been observed within 
the zone for a 30-minute period. If a marine mammal is observed within 
the shutdown zones, pile driving activity will be delayed or halted. If 
work ceases for more than 30 minutes, the pre-activity monitoring of 
the shutdown zones will commence. A determination that the shutdown 
zone is clear must be made during a period of good visibility (i.e., 
the entire shutdown zone and surrounding waters must be visible to the 
naked eye).

Soft-Start Procedures

    Soft-start procedures are used 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 pile driving, contractors will be required to 
provide an initial set of three strikes from the hammer at reduced 
energy, followed by a 30-second waiting period, then two subsequent 
reduced-energy strike sets. Soft start will 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 30 minutes or longer.

Bubble Curtain

    A bubble curtain must be employed during all impact pile 
installation of steel piles less than 24 inches in diameter to 
interrupt the acoustic pressure and reduce impact on marine mammals. 
Impact pile driving will not be allowed for 36-inch steel shell piles. 
The bubble curtain must distribute air bubbles around 100 percent of 
the piling circumference for the full depth of the water column. The 
lowest bubble ring must be in contact with the mudline for the full 
circumference of the ring. The weights attached to the bottom ring must 
ensure 100 percent substrate contact. No parts of the ring or other 
objects may prevent full substrate contact. Air flow to the bubblers 
must be balanced around the circumference of the pile.
    Based on our evaluation of the applicant's measures, NMFS has 
determined that the mitigation measures provide the means of 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.

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 while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the

[[Page 5875]]

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 activity; 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); and,
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
conditions in this section and the IHA. Marine mammal monitoring during 
pile driving activities will be conducted by PSO's meeting NMFS' 
standards and in a manner consistent with the following:
     PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor) and have no other assigned tasks 
during monitoring periods;
     At least one PSO will have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator will be designated. The lead 
observer will be required to have prior experience working as a marine 
mammal observer during construction;
     PSOs will submit PSO resumes for approval by NMFS 30 days 
prior to the onset of pile driving; and,
     PSOs must be approved by NMFS prior to beginning any 
activity subject to the IHA.
    PSOs should have the following additional qualifications:
     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, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
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.
    PG&E will have between one and three PSOs on site at all times 
during pile driving activities. One PSO will be designated as the Lead 
PSO and will receive updates from other PSOs. The Lead PSO will be 
stationed at the active pile driving rig or at the best vantage point 
practicable to monitor the shutdown zones and implement shutdown and 
delay procedures. The other PSOs will be stationed at the best vantage 
points practicable to observe the monitoring zones. Exact locations 
will be determined in the field based on the pile driving site, field 
conditions, and in coordination with contractors, but may include 
docks, barges, and tower structures. PSOs will be equipped with high 
quality binoculars or spotting scopes for monitoring and radios and 
cell phones for maintaining contact with other observers and work crew. 
Monitoring will be conducted 30 minutes before, during, and 30 minutes 
after all in-water construction activities. PSOs will record all 
incidents of marine mammal occurrence, regardless of distance from 
activity, and will document any behavioral reactions in concert with 
distance from piles being driven or removed. Pile driving 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.

Data Collection

    PSOs will use approved data forms to record the following 
information:
     Dates and times (beginning and end) of all marine mammal 
monitoring;
     PSO locations during marine mammal monitoring;
     Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
driven or removed and by what method (i.e., impact or vibratory);
     Weather parameters and water conditions;
     The number of marine mammals observed, by species, 
relative to the pile location and if pile driving or removal was 
occurring at time of sighting;
     Distance and bearings of each marine mammal observed to 
the pile being driven or removed;
     Description of marine mammal behavior patterns, including 
direction of travel;
     Age and sex class, if possible, of all marine mammals 
observed; and,
     Detailed information about implementation of any 
mitigation triggered (such as shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal if 
any.

Reporting

    PG&E must submit a draft marine mammal monitoring report to NMFS 
within 90 days after the completion of pile driving activities, or 60 
days prior to the requested issuance of any future IHAs for the 
project, or other projects at the same location, whichever comes first. 
A final report must be prepared and submitted within 30 calendar days 
following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of receipt of 
the draft report, the report shall be considered final. The marine 
mammal report will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated PSO data 
sheets and/or raw sighting data. Specifically, the report will include:
     Dates and times (beginning and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period including: (a) the number and types of piles driven 
and the method; and (b) total duration of driving time for each pile 
(vibratory driving) and number of strikes for each pile (impact 
driving);

[[Page 5876]]

     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     For each observation of a marine mammal the following must 
be recorded: (a) Name of PSO who sighted the animal(s) and PSO location 
and activity at time of sighting; (b) time of sighting; (c) 
identification of the animal(s) (e.g. genus/species, lowest possible 
taxonomic level, or unidentified), PSO confidence in identification, 
and the composition of the group if there is a mix of species; (d) 
distance and location of each observed marine mammal relative to pile 
being driven or removed for each sighting; (e) estimated number of 
animals (min/max/best estimate); (f) estimated number of animals by 
cohort (adults, juveniles, neonates, group composition, etc.); (g) 
animal's closest point of approach and estimated time spent within the 
harassment zone; (h) description of any marine mammal behavioral 
observations (e.g. observed behaviors such as feeding or traveling), 
including an assessment of behavioral responses thought to have 
resulted from the activity (e.g. no response or changes in behavioral 
state such as ceasing feeding, changing direction, flushing, or 
breaching);
     Number of marine mammals detected within the harassment 
zones, by species; and,
     Detailed information about implementation of any 
mitigation (e.g. shutdowns and delays), a description of specific 
actions that ensued, and resulting changes in behavior of the 
animal(s), if any.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, PG&E will report the 
incident to the Office of Protected Resources (OPR) 
([email protected]), NMFS and to the West Coast 
regional stranding network (866-767-6114) as soon as feasible. If the 
death or injury was clearly caused by the specified activity, PG&E will 
immediately cease the specified activities until NMFS is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the IHAs. PG&E will not resume their activities until notified by 
NMFS. The report will include the following:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and,
     General circumstances under which the animal was 
discovered.

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 impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), 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' 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 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).
    To avoid repetition, the discussion of our analysis applies to all 
the species listed in table 1, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be similar. There is little information about the nature or severity of 
the impacts, or the size, status, or structure of any of these species 
or stocks that would lead to a different analysis for this activity.
    Level A harassment is extremely unlikely given the small size of 
the Level A harassment isopleths and the required mitigation measures 
designed to minimize the possibility of injury to marine mammals. No 
serious injury or mortality is anticipated given the nature of the 
activity.
    Pile driving activities have the potential to disturb or displace 
marine mammals. Specifically, the project activities may result in 
take, in the form of Level B harassment from underwater sounds 
generated from impact and vibratory pile driving activities. Potential 
takes could occur if individuals move into the ensonified zones when 
these activities are underway.
    The takes by Level B harassment will be due to potential behavioral 
disturbances. The potential for harassment is minimized through 
construction methods and the implementation of planned mitigation 
strategies (see Mitigation section).
    Behavioral responses of marine mammals to pile driving at the 
project site, if any, are expected to be mild and temporary. Marine 
mammals within the Level B harassment zone may not show any visual cues 
they are disturbed by activities or could become alert, avoid the area, 
leave the area, or display other mild responses that are not observable 
such as changes in vocalization patterns. Given the short duration of 
noise-generating activities per day and that pile driving and removal 
will occur over approximately 50 days during a span of 5 months, any 
harassment will be temporary. There are no other areas or times of 
known biological importance for any of the affected species.
    Take will occur within a limited, confined area of each stock's 
range. Further, the amount of take authorized is extremely small when 
compared to stock abundance.
    No marine mammal stocks for which incidental take authorization are 
listed as threatened or endangered under the ESA. Only one stock, the 
Eastern North Pacific Stock of the northern fur seal, is listed as 
depleted under the MMPA. However, we do not expect the authorizations 
in this action to affect the stock. No injury or mortality is 
authorized, take by Level B harassment is limited (five takes over the 
duration of the project), and the action should have no effect on the 
reproduction of this species. In addition, the five authorized takes 
for the northern fur seal include both the depleted Eastern

[[Page 5877]]

North Pacific Stock and the California stock, which is not depleted.
    The relatively low marine mammal occurrences in the area, shutdown 
zones, and planned monitoring make injury takes of marine mammals 
unlikely. The shutdown zones will be thoroughly monitored before the 
pile driving activities begin, and activities will be postponed if a 
marine mammal is sighted within the shutdown zone. There is a high 
likelihood that marine mammals will be detected by trained observers 
under environmental conditions described for the project. Limiting 
construction activities to daylight hours will also increase 
detectability of marine mammals in the area. Therefore, the mitigation 
and monitoring measures are expected to eliminate the potential for 
injury and Level A harassment as well as reduce the amount and 
intensity of Level B behavioral harassment. Furthermore, the pile 
driving activities analyzed here are similar to, or less impactful 
than, numerous construction activities conducted in other similar 
locations which have occurred with no reported injuries or mortality to 
marine mammals, and no known long-term adverse consequences from 
behavioral harassment.
    The project is not expected to have significant adverse effects on 
marine mammal habitat. There are no known Biologically Important Areas 
(BIAs) or ESA-designated critical habitat within the project area, and 
the activities will not permanently modify existing marine mammal 
habitat.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect any of the species or stocks 
through effects on annual rates of recruitment or survival:
     No serious injury, mortality, or Level A harassment is 
anticipated or authorized;
     The specified activities and associated ensonified areas 
are very small relative to the overall habitat ranges of all species;
     The project area does not overlap known BIAs or ESA-
designated critical habitat;
     The lack of anticipated significant or long-term effects 
or marine mammal habitat; and,
     The presumed efficacy of the mitigation measures in 
reducing the effects of the specified activity.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the 
activity will have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
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. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The amount of take NMFS has authorized is below one-third of the 
estimated stock abundances for stocks (See table 7). These are all 
likely conservative estimates because they assume all takes are of 
different individual animals which is likely not the case. Some 
individuals may return multiple times in a day, but PSOs will count 
them as separate takes if they cannot be individually identified.
    Based on the analysis contained herein of the activity (including 
the mitigation and monitoring measures) and the anticipated take of 
marine mammals, NMFS 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 
determined that the total taking of affected species or stocks will not 
have an unmitigable adverse impact on the availability of such species 
or stocks for taking for subsistence purposes.

Endangered Species Act

    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 whenever we propose to authorize take for 
endangered or threatened species.
    No incidental take of ESA-listed species is authorized 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.

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 action (i.e., the issuance of an IHA) and 
alternatives with respect to potential impacts on the human 
environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NAO 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 determined that the 
issuance of this IHA qualifies to be categorically excluded from 
further NEPA review.

Authorization

    NMFS has issued an IHA to PG&E for the potential harassment of 
small numbers of seven marine mammal species incidental to the sediment 
remediation project in San Francisco Bay, that includes the previously 
explained mitigation, monitoring, and reporting requirements.

    Dated: January 25, 2024.
Catherine G. Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2024-01790 Filed 1-29-24; 8:45 am]
BILLING CODE 3510-22-P