[Federal Register Volume 84, Number 118 (Wednesday, June 19, 2019)]
[Notices]
[Pages 28474-28489]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-12922]
[[Page 28474]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XG876
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Chevron Richmond Refinery Long
Wharf Maintenance and Efficiency Project in San Francisco Bay,
California
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 we have issued an incidental harassment authorization (IHA) to
Chevron to take small numbers of marine mammals, by harassment,
incidental to the Long Wharf Maintenance and Efficiency Project (LWMEP)
in San Francisco Bay, California.
DATES: This authorization is effective from June 1, 2019, through May
31, 2020.
FOR FURTHER INFORMATION CONTACT: Rob Pauline, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as the issued IHA, may be obtained
online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems
accessing these documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization may be provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth.
Summary of Request
On January 17, 2019, NMFS received a request from Chevron for an
IHA to take marine mammals incidental to pile driving and removal
associated with the LWMEP in San Francisco Bay, California. The
application was deemed adequate and complete on April 8, 2019.
Chevron's request is for take of a small number of seven species of
marine mammals, by Level B harassment and Level A harassment. Neither
Chevron nor NMFS expects serious injury or mortality to result from
this activity and, therefore, an IHA is appropriate.
NMFS previously issued an IHA to Chevron for similar work (82 FR
27240; June 17, 2017). However, the construction schedule and scope was
revised and no work was conducted under that IHA. NMFS issued a second
IHA on May 31, 2018 to Chevron for work not conducted in 2017 (83 FR
27578; June 13, 2018). This IHA covers one year of this larger project
for which Chevron obtained the prior IHA, and Chevron also intends to
request take authorizations for subsequent facets of the project. The
larger multi-year project involves various construction activities that
would allow Chevron to comply with Marine Oil Terminal Engineering and
Maintenance Standards (MOTEMS) and to improve safety and efficiency at
the Long Wharf. Chevron complied with all the requirements (e.g.,
mitigation, monitoring, and reporting) of the previous IHA and
information regarding their monitoring results may be found in the
Estimated Take section.
Because of the similarity of the work and marine mammal impacts to
that covered in previous IHAs, we have often cited back to previous
documents for more detailed descriptions.
Description of Activity
Chevron's Richmond Refinery Long Wharf (Long Wharf) located in San
Francisco Bay, is the largest marine oil terminal in California. Impact
pile driving and vibratory pile driving and removal will be employed
during the planned construction project. These actions could produce
underwater sound at levels that could result in the injury or
behavioral harassment of marine mammal species. Pile driving activities
would be timed to occur within the standard NMFS work windows for
Endangered Species Act (ESA)-listed fish species (June 1 through
November 30) over multiple years. An estimated 67 days of pile driving
activity within the designated work window are planned for 2019.
Additional work in the future will require subsequent IHAs. The IHA is
effective from June 1, 2019 through May 31, 2020.
A detailed description of the planned activities is provided in the
Federal Register notice of the proposed IHA (84 FR 17788; April 26,
2019) for the issued IHA, Federal Register notice of the issuance of
the 2018 IHA for Chevron's LWMEP project (83 FR 27578; June 13, 2018),
the Federal Register notice of the proposed IHA (83 FR 18802; April 30,
2018), as well as Chevron's current IHA application for the 2019 work
season. Therefore, a detailed description is not provided here. Please
refer to that Federal Register notices and application for the
description of the specific activity.
Comments and Responses
A notice of NMFS' proposal to issue an IHA was published in the
Federal Register on March 26, 2019 (84 FR 177880). During the 30-day
public comment period, NMFS received a comment letter from the Marine
Mammal Commission (Commission). Specific comments and responses are
provided below. The Commission's recommendations and our responses are
provided here, and the comments have been posted online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. The Commission recommended
that NMFS issue the IHA, subject to inclusion of the proposed
mitigation, monitoring, and reporting measures.
Comment 1: The Commission recommended that NMFS consult with
external scientists and acousticians to determine the appropriate
accumulation time that action proponents should use to determine the
extent of the Level A
[[Page 28475]]
harassment zones based on the associated SELcum thresholds
for the various types of sound sources, including stationary sound
sources.
Response: NMFS considers this a priority and has formed a Working
Group to focus on the issue of accumulation time. Once the NMFS
internal Working Group develops a proposal, it will be shared with
Federal partners and other stakeholders.
Comment 2: The Commission recommended that, for all relevant
incidental take authorizations, NMFS refrain from using a source level
reduction factor for sound attenuation device implementation during
impact pile driving, including the 60-inch steel piles proposed for use
by Chevron.
Response: While it is true that noise level reduction measured at
different received ranges does vary, given that both Level A and Level
B harassment estimation using geometric modeling is based on noise
levels measured at near-source distances (~10 meters), NMFS believes it
reasonable to use a source level reduction factor for sound attenuation
device implementation during impact pile driving. In the case of the
San Francisco-Oakland Bay Bridge impact driving isopleth estimates
using an air bubble curtain for source level reduction, NMFS reviewed
Caltrans' bubble curtain ``on and off'' studies conducted in San
Francisco Bay in 2003 and 2004. The equipment used for bubble curtains
has likely improved since 2004 but due to concerns for fish species,
Caltrans has not been able to conduct ``on and off'' tests recently.
Based on 74 measurements (37 with the bubble curtain on and 37 with the
bubble curtain off) at both near (<100 meters) and far (>100 meters)
distances, the linear averaged received level reduction is 6 decibels
(dB). If limiting the data points (a total of 28 measurements, with 14
during bubble curtain on and 14 during bubble curtain off) to only near
distance measurements, the linear averaged noise level reduction is 7
dB. Since impact zone analysis using geometric spreading model is
typically based on measurements at near-source distance, we consider it
appropriate to use a reduction of 7 dB as a noise level reduction
factor for impact pile driving using an air bubble curtain system.
Bubble curtains are effective at attenuating sound originating
within the water column. Pile driving does generate sound within the
seafloor as well. This sound travels within the seafloor and emerges
back to the water column, but its intensity is reduced within the
sediment due to absorption by the sediment and reflection at the
sediment/water interface.
NMFS will evaluate the appropriateness of using a certain source
level reduction factor for sound attenuation device implementation
during impact pile driving for all relevant incidental take
authorizations when more data become available.
Comment 3: The Commission recommended that NMFS should direct
Chevron to use its PSOs to monitor more sufficiently both the Level A
and B harassment zones, including the shut-down zones. The Commission
further recommended that one PSO should be located in the near-field to
ensure an unobstructed view of the shut-down zones and one PSO should
be located on the north end of the wharf to monitor harbor seals in the
far field, focusing on the area between the wharf and Castro Rocks.
Response: NMFS believes that the monitoring plan provided by the
applicant is adequate to sufficiently monitor Level A and B harassment
zones, including shut-down zones. Chevron opted to place one PSO on the
east side of the wharf to monitor any marine mammals that occur between
the wharf and the shoreline. The wharf is covered with building and
large equipment resulting in obstructed views. Therefore, it is
impossible for a single PSO on the east side of the wharf to also
monitor the near or far fields on the west side of the wharf. However,
NMFS will recommend that the PSO stationed on the north end of the
wharf will monitor the entire visible area, with extra focus on the
section between Castro Rocks and the wharf.
Comment 4: The Commission recommended that NMFS refrain from
implementing its proposed renewal process for Chevron's subsequent
authorizations. The Commission believes that the renewal process should
be used sparingly and selectively, by limiting its use only to those
proposed incidental harassment authorizations that are expected to have
the lowest levels of impacts to marine mammals and that require the
least complex analyses. Also, the Commission recommended that NMFS
provide the Commission and other reviewers the full 30-day comment
opportunity set forth in section 101(a)(5)(D)(iii) of the MMPA.
Response: Regarding the Commission's comment that Renewal IHAs
should be limited to certain types of projects NMFS has explained on
its website and in individual Federal Register notices that Renewal
IHAs are appropriate where the continuing activities are identical,
nearly identical, or a subset of the activities for which the initial
30-day comment period applied. If Chevron seeks to obtain a Renewal IHA
in the future, NMFS will determine at that time whether the request
meets the necessary conditions under which a Renewal IHA could be
considered.
NMFS has taken a number of steps to ensure the public has adequate
notice, time, and information to be able to comment effectively on
Renewal IHAs within the limitations of processing IHA applications
efficiently. Federal Register notices for the proposed initial IHAs
identified the conditions under which a one-year Renewal IHA might be
appropriate. This information is presented in the Request for Public
Comments section and thus encourages submission of comments on the
potential of a one-year renewal as well as the initial IHA during the
30-day comment period. In addition, when we receive an application for
a Renewal IHA, we will publish notice of the proposed IHA Renewal in
the Federal Register and provide an additional 15 days for public
comment, making a total of 45 days of public comment. We also directly
contact all commenters on the initial IHA by email, phone, or, if the
commenter did not provide email or phone information, by postal service
to provide them the opportunity to submit any additional comments on
the proposed Renewal IHA. Where the commenter has already had the
opportunity to review and comment on the potential for a Renewal in the
initial proposed IHA for these activities, the abbreviated additional
comment period is sufficient for consideration of the results of the
preliminary monitoring report and new information (if any) from the
past year.
Comment 5: The Commission recommended that, NMFS (1) request that
Chevron submit any future authorizations at least 6 months prior to the
planned start date for incidental harassment authorizations and 9
months prior for rulemakings and (2) take all steps necessary to ensure
that it publishes and finalizes proposed incidental harassment
authorizations far enough in advance of the planned start date of the
proposed activities to ensure full consideration is given to any and
all comments received
Response: NMFS encourages all applicants to submit applications for
IHA's 5-8 months in advance of the intended project start date and for
rulemakings/LOA at least 9 months, and preferably 15 months, in advance
of the intended project start date. NMFS provided the required 30-day
notice for public comment, and has adequately considered all public
comments
[[Page 28476]]
received in making the necessary findings.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history, of the potentially affected species.
Additional information regarding population trends and threats may be
found in NMFS's Stock Assessment Reports (SAR; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (https://www.fisheries.noaa.gov/find-species).
Table 1 lists species that may occur in the vicinity of the project
area. A description of the marine mammals in the area of the activities
is found in the Federal Register notice of the issuance of the 2018 IHA
for Chevron's LWMEP project (83 FR 27578; June 13, 2018), the Federal
Register notice of the proposed IHA (83 FR 18802; April 30, 2018), as
well as Chevron's current IHA application for the 2019 work season.
NMFS has reviewed the monitoring data from the initial IHA, recent
draft Stock Assessment Reports, information on relevant Unusual
Mortality Events, and other scientific literature, and determined that
neither this nor any other new information affects which species or
stocks have the potential to be affected or the pertinent information
in the Description of the Marine Mammals in the Area of Specified
Activities contained in the supporting documents for the initial IHA.
Specifically, the only change from the 2018 IHA is an increase in
numbers of the eastern north Pacific stock of gray whale which have
increased from 20,990 to 26,960.
Table 1--Marine Mammals Potentially Present in the Vicinity of the Project Area
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ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Eschrichtiidae:
Gray whale...................... Eschrichtius robustus.. Eastern North Pacific.. -/-; (N) 26,960 (0.05, 25,849, 801 138
2016).
Family Delphinidae:
Bottlenose dolphin.............. Tursiops truncatus..... California Coastal..... -/-;(N) 453 (0.06, 346, 2011). 2.7 >=2.0
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena Phocoena...... San Francisco-Russian -/-;(N) 9,886 (0.51, 6,625, 66 0
River Stock. 2011).
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
California sea lion............. Zalophus californianus. Eastern U.S. stock..... -/-;(N) 296,750 (-, 153,337, 9,200 389
2011).
Northern fur seal............... Callorhinus ursinus.... California stock....... -/-;(N) 14,050 (-, 7,524, 451 1.8
2013).
Family Phocidae (earless seals):
Pacific harbor seal............. Phoca vitulina......... California stock....... -/-;(N) 30,968 (-, 27,348, 1,641 43
2012).
Northern elephant seal.......... Mirounga angustirostris California Breeding -/-;(N) 179,000 (-, 81,368, 4,882 8.8
stock. 2010).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
A description of the potential effects of the specified activities
on marine mammals and their habitat may be found in the Federal
Register notice of the issuance of the 2018 IHA for Chevron's LWMEP
project (83 FR 27578; June 13, 2018) and the Federal Register notice of
the proposed IHA (83 FR 18802; April 30, 2018). This information
remains applicable to the issuance of the 2019 IHA. NMFS has reviewed
the monitoring data from the initial IHA and other scientific
literature, and found no new information that would affect our initial
analysis of impacts on marine mammals and their habitat.
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through this IHA, which will inform both NMFS' consideration
of ``small numbers'' and the negligible impact determination.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as use
of the acoustic source (i.e., pile driving) has the potential to result
in disruption of behavioral patterns for individual marine mammals.
There is also some potential for limited auditory injury (Level A
harassment) to result, primarily for high frequency species (harbor
porpoises) because predicted auditory
[[Page 28477]]
injury zones are larger than for other functional hearing groups and
for phocids (harbor seals) as there is a sizable harbor seal haulout
(Castro Rocks) located in close proximity to the project area. The
required mitigation and monitoring measures are expected to minimize
the severity of such taking to the extent practicable.
As described previously, no mortality is anticipated or authorized
for this activity. Below we describe how the take is estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and, (4)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the authorized take
estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment).
Level B Harassment for non-explosive sources--Though significantly
driven by received level, the onset of behavioral disturbance from
anthropogenic noise exposure is also informed to varying degrees by
other factors related to the source (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007). Based
on what the available science indicates and the practical need to use a
threshold based on a factor that is both predictable and measurable for
most activities, NMFS uses a generalized acoustic threshold based on
received level to estimate the onset of behavioral harassment. NMFS
predicts that marine mammals are likely to be behaviorally harassed in
a manner we consider Level B harassment when exposed to underwater
anthropogenic noise above received levels of 120 dB re 1 microPascal,
root mean square ([mu]Pa (rms) for continuous (e.g., vibratory pile-
driving), and above 160 dB re 1 [mu]Pa (rms) for non-explosive
impulsive (e.g., seismic airguns) or intermittent (e.g., scientific
sonar) sources.
Chevron's planned includes the use of continuous (vibratory pile
driving and removal) and intermittent (impact pile driving) sources
and, therefore, the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are
applicable.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Version 2.0) (NMFS, 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).
Chevron's planned activity includes the use of impulsive (impact pile
driving) and non-impulsive (vibratory pile driving and removal)
sources.
These thresholds are provided in Table 2 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 2--Thresholds identifying the onset of Permanent Threshold Shift
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PTS onset acoustic thresholds \*\
(Received level)
Hearing group -----------------------------------------
Impulsive Non-impulsive
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Low-Frequency (LF) Cetaceans.. Cell 1: Lpk,flat Cell 2: LE,LF,24h:
219 dB; 199 dB.
LE,LF,24h: 183
dB.
Mid-Frequency (MF) Cetaceans.. Cell 3: Lpk,flat Cell 4: LE,MF,24h:
230 dB; 198 dB.
LE,MF,24h: 185
dB.
High-Frequency (HF) Cetaceans. Cell 5: Lpk,flat Cell 6: LE,HF,24h:
202 dB; 173 dB.
LE,HF,24h: 155
dB.
Phocid Pinnipeds (PW)......... Cell 7: Lpk,flat Cell 8: LE,PW,24h:
(Underwater).................. 218 dB; 201 dB.
LE,PW,24h: 185
dB.
Otariid Pinnipeds (OW)........ Cell 9: Lpk,flat Cell 10: LE,OW,24h:
(Underwater).................. 232 dB; 219 dB.
LE,OW,24h: 203
dB.
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* 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 will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
[[Page 28478]]
The project includes impact pile driving, vibratory pile driving
and vibratory pile removal. Source levels of some pile driving
activities are based on hydroacoustic testing performed in 2018 at the
LWMEP location as well as reviews of measurements of the same or
similar types and dimensions of piles available in the literature.
Based on this information, the source levels described below are
assumed for the underwater noise produced by construction activities.
Eight batter steel pipe piles, 60-inch diameter would be installed
using an impact hammer as it is difficult to vibrate in batter piles.
These piles also have very high axial design loads that can only be
achieved by impact driving methods. Other projects conducted under
similar circumstances were reviewed in order to estimate the
approximate noise effects of the 60-inch steel piles. The best match
found for sound source levels is from summary values provided by
Caltrans in their hydroacoustic guidance document (Caltrans 2015).
Summary values for the impact pile driving of 60-inch steel pipe piles
indicates that noise levels of up to 210 peak, 185 dB SEL (single
strike), and 195 RMS would be produced at 10 meters during pile driving
using no sound attenuation such as a bubble curtain. The use of
properly functioning bubble curtains is expected to reduce the peak and
RMS noise levels by about 7 dB. As a result, noise levels of 203 dB
peak, 178 dB SEL (single strike), and 188 dB are utilized to assess
potential acoustic impacts.
It is expected that just one 60-inch pile would be driven over one
(1) hour of active driving in a given day and that only one (1) pile
would be installed in a given week. Installation could require up to
2,400 blows from an impact hammer, such as a HHK-16 or similar diesel
hammer, producing approximately 173,000 to 217,000 ft. lbs. maximum
energy per blow and 1.5 to 2 sec/blow average. As noted above, bubble
curtains will be used during the installation of the 60-inch steel pipe
piles in order to reduce underwater noise levels, with an assumed
attenuation of 7 dB. NMFS acknowledges that noise level reductions
measured at different project locations as well as different received
ranges can vary widely. However, NMFS believes it reasonable to use a
source level reduction factor for sound attenuation device
implementation during impact pile driving. NMFS reviewed Caltrans'
bubble curtain ``on and off'' studies conducted in San Francisco Bay in
2003 and 2004. Based on near distance measurements (a total of 28
measurements, with 14 during bubble curtain on and 14 during bubble
curtain off), the linear averaged noise level reduction is 7 dB. As a
conservative approach, NMFS will use a standard reduction of 7 dB of
the source level for impact zone estimates.
Installation of 24-inch diameter square concrete piles is planned
for the modifications at the four berths. Approximately one to two of
these piles would be installed in one work day, using impact driving
methods and a bubble curtain attenuation system. Based on measured blow
counts for 24-inch concrete piles driven at the Long Wharf Berth 4 in
2011, installation for each pile could require up to approximately 300
blows from a DelMag D62 22 or similar diesel hammer, producing
approximately 165,000 ft lbs maximum energy (may not need full energy)
and 1.5 second per blow average over a duration of approximately 20
minutes per pile, with 40 minutes of pile driving time per day if two
(2) piles are installed.
To estimate the noise effects of the 24-inch square concrete piles,
the underwater noise measurements recorded for this pile type at the
Long Wharf during the 2018 construction season are utilized. These
measured values were: 191 dB peak, 161 dB SEL (single strike), and 173
dB RMS during attenuated impact driving (AECOM 2018).
As part of the Berth 4 Loading Platform seismic retrofit, four (4)
clusters of 13 composite piles (52 piles total) will be installed to
provide protection to the infrastructure. These plastic encased
concrete piles would be installed with a vibratory pile driver (APE
400B King Kong or similar vibratory driver), with a drive time of
approximately 10 minutes per pile. Up to five (5) of these piles could
be installed in any single work day.
Projects conducted under similar circumstances with similar piles
were reviewed in order to approximate the noise effects of the 12-inch
composite barrier piles. Since these piles will be composed of concrete
encased in plastic, vibratory installation of similarly sized concrete
piles would provide a good surrogate. However, concrete piles are
rarely installed with a vibratory driver, and no suitable data could be
located. In the absence of this data, we are conservatively using data
from the Anacortes Ferry Terminal in Washington State, where 13-inch
plastic coated steel piles were installed with a vibratory hammer. RMS
noise levels produced during this installation varied from 138 to 158
dB RMS at 43 meters (141 feet) from the pile (Laughlin 2012). From
these measurements, a peak noise value of 178 dB and an average RMS
value of 168 dB normalized to a 10 meter (33 feet) distance was used to
estimate the extent of underwater noise from installation of the 12-
inch composite piles. During installation of the 12-inch composite
barrier piles for the planned Project, up to 50 minutes of vibratory
driving could occur per day.
For the Berth 4 Loading Platform seismic retrofit, eight (8) 36-
inch diameter temporary steel piles would be installed using a
vibratory pile driver (APE 400B King Kong or similar vibratory driver)
will be needed to support the guide template for the driving of the
permanent 60-inch steel pipe piles. Each 36-inch temporary pile has an
estimated drive time of approximately 10 minutes per pile. Up to four
(4) of these piles could be installed in any single work day.
Projects conducted under similar circumstances with similar piles
were reviewed in order to approximate the noise effects of the 36-inch
steel pipe. The best match for estimated noise levels is from the
Explosive Handling Wharf-2 (EHW-2) project located at the Naval Base
Kitsap in Bangor, Washington (Illingworth and Rodkin 2013). During
vibratory pile driving associated with this Project, which occurred
under similar circumstances, average peak noise levels were
approximately 180 dB, and the RMS was approximately 170 dB at a 10
meter (33 feet) distance (Caltrans 2015a). Installation of the 36-inch
steel pipe piles is expected to be require 40 minutes per day.
In total, two of the eight 36-inch temporary piles will require
proofing using an impact hammer. Each pile will require up to 30
strikes from an impact hammer during proofing which will take place
during the last foot of pile driving. Up to two (2) piles would be
proofed in one day, with each pile requiring up to 30 strikes from an
impact hammer, for a total of 60 strikes in one day. The best match
found for sound source levels is from summary values provided by
Caltrans in their hydroacoustic guidance document (Caltrans 2015).
Summary values for the impact pile driving of 36-inch steel pipe piles
in water less than 5m deep indicates that noise levels of up to 208
peak, 180 dB SEL (single strike), and 193 RMS would be produced at 10
meters during pile driving. Since impact hammers are often operated at
reduced power output during proofing, the source levels are likely to
be lower than the values for impact driving used here. Due to very
limited time that pile proofing would occur (60 strikes total,
[[Page 28479]]
over a few minutes of active hammering) no sound attenuation would be
used.
The Berth 4 Loading Platform seismic retrofit will require
vibratory installation of, eight (8) 20-inch diameter temporary steel
piles (APE 400B King Kong or similar vibratory driver) to support the
guide template needed for the driving the permanent 60-inch steel pipe
piles. Each 20-inch temporary pile has a drive time per pile of
approximately 10 minutes. Up to four (4) of these piles could be
installed in any single work day. The best match for estimated noise
levels is from vibratory driving of 24-inch piles at the Explosive
Handling Wharf-2 (EHW-2) project located at the Naval Base Kitsap in
Bangor, Washington (Illingworth and Rodkin 2013). During vibratory pile
driving associated with this Project, which occurred under similar
circumstances, measured peak noise levels were approximately 180 dB,
and the RMS was approximately 163 dB at a 10 meter (33 feet) distance
(Illingworth and Rodkin 2013). During installation of the 20-inch steel
pipe piles will require approximately 40 minutes per day.
The project includes the removal of 106 16-inch timber piles, and
five (5) 18 to 24-inch square concrete piles using a vibratory pile
driver. Up to 12 of these piles could be extracted in one (1) work day.
Extraction time needed for each pile may vary greatly, but could
require approximately 400 seconds (approximately seven (7) minutes)
from an APE 400B King Kong or similar driver. The most applicable noise
values for wooden pile removal from which to base estimates for the
LWMEP are derived from measurements taken at the Pier 62/63 pile
removal in Seattle, Washington. During vibratory pile extraction
associated with this Project, which occurred under similar
circumstances, the RMS was approximately 152 dB (WSDOT 2011).
Applicable sound values for the removal of concrete piles could not be
located, but they are expected to be similar to the levels produced by
wooden piles described above, as they are similarly sized, non-
metallic, and will be removed using the same methods.
For pile driving that does not have project specific hydroacoustic
data available, the practical spreading model with a transmission loss
coefficient of 15 (4.5 dB per doubling of distance) is used. However,
project-specific transmission loss values have been measured for the
impact driving of concrete piles and resulted in a measured
transmission loss factor of 20 (~8 dB per doubling of distance) which
has been applied to calculate distances to harassment isopleths for
those specific piles. This value is calculated from hydroacoustic
monitoring of attenuated impact driving of concrete piles conducted as
part of the LWMEP. The results of the 2018 hydroacoustic monitoring are
provided in Appendix A of the application.
When the NMFS Technical Guidance (2016) was published, in
recognition of the fact that ensonified area/volume could be more
technically challenging to predict because of the duration component in
the new thresholds, we developed a User Spreadsheet that includes tools
to help predict a simple isopleth that can be used in conjunction with
marine mammal density or occurrence to help predict takes. We note that
because of some of the assumptions included in the methods used for
these tools, we anticipate that isopleths produced are typically going
to be overestimates of some degree, which may result in some degree of
overestimate of Level A harassment take. However, these tools offer the
best way to predict appropriate isopleths when more sophisticated 3D
modeling methods are not available, and NMFS continues to develop ways
to quantitatively refine these tools, and will qualitatively address
the output where appropriate. For stationary sources (such as impact
and vibratory pile driving), NMFS User Spreadsheet predicts the closest
distance at which, if a marine mammal remained at that distance the
whole duration of the activity, it would not incur PTS. Inputs used in
the User Spreadsheet, and the resulting isopleths are reported below in
Table 3.
Table 3--Inputs for User Spreadsheet
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet tab used E.1-2: Impact pile E.1-2: Impact pile E.1-2: Impact pile A.1: Vibratory A.1: Vibratory A.1: Vibratory A.1: Vibratory
---------------------------------- driving driving driving driving driving driving driving
--------------------------------------------------------------------------------------------------------------------------------------------------------------
Pile type 60-in steel 24-inch concrete 36-in steel 12-inch composite 36-in steel 20-in steel Wood/ concrete
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level..................... 178 SEL.............. 161 SEL.............. 180 SEL.............. 168 RMS.............. 170 RMS.............. 163 RMS............. 152 RMS.
Weighting Factor Adjustment (kHz) 2.................... 2.................... 2.................... 2.5.................. 2.5.................. 2.5................. 2.5.
Number of strikes in 1 h OR 2,400................ 300.................. 30................... NA................... NA................... NA.................. NA.
number of strikes per pile.
Number of piles per day.......... 1.................... 2.................... 2.................... 5.................... 4.................... 4................... 12.
Propagation (xLogR).............. 15................... 20................... 15................... 15................... 15................... 15.................. 15.
Duration to drive single pile NA................... NA................... NA................... 10................... 10................... 10.................. 7.
(minutes).
Distance of source level 10................... 10................... 10................... 10................... 10................... 10.................. 10.
measurement (meters) \+\.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table 4 shows the Level A harassment isopleths as determined
utilizing inputs from Table 3. Note that for all calculations, the
results based on SELss are larger than SPLpk,
therefore, distances calculated using SELss are used to
calculate the area. Level B Harassment isopleths for impact and
vibratory driving and extraction are shown in Table 5.
[[Page 28480]]
Table 4--Radial Distances to Level A Harassment Isopleths During Impact and Vibratory Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source levels at 10 meters (dB) Distance to Level A threshold \1\ meters (feet)
----------------------------------------------------------------------------------------------------------------------
Project element requiring pile High-
installation Peak \2\ RMS/SEL Low- frequency Mid- frequency frequency Phocid Otariid
cetaceans cetaceans cetaceans pinnipeds pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Attenuated Impact Driving (with
bubble curtain):
60-inch steel pipe (1 per 203 178 SEL.............. 831 (2,726) 30 (97) 990 (3,247) 445 (1,459) 32 (106)
day).
24-inch square concrete (1-2 191 161 SEL.............. 19 (64) 2 (5) 22 (73) 12 (40) 2 (6)
per day).
Impact Pile Proofing (no bubble
curtain):
36-inch steel pipe pile (2 208 180 SEL.............. 97 (317) 3 (11) 115 (377) 52 (170) 4 (12)
total).
Vibratory Driving/Extraction:
12-inch Composite Barrier 178 168 RMS.............. 18 (58) 2 (5) 26 (86) 11 (35) 1 (2)
Pile (5 per day).
36-inch steel pipe pile (4 195 170 RMS.............. 21 (68) 2 (6) 31 (101) 13 (41) 1 (3)
per day).
20-inch steel pipe pile (4 180 163 RMS.............. 7 (23) 1 (2) 10 (34) 4 (14) 0 (1)
per day).
Wood and concrete pile No Data 152 RMS.............. 2 (7) 0 (<1) 3 (10) 1 (4) 0 (<1)
extraction (12 per day).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
For calculation worksheets used to develop these numbers is provided in Appendix B.
\1\ Level A thresholds are based on the NMFS 2016 Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing; cSEL
threshold distances are shown. See footnote 3 below.
\2\ All distances to the peak Level A thresholds are less than 33 feet (10 meters).
Distances are rounded to the nearest foot or to ``<1.0 (0)'' for values less than 1 foot.
Peak and cSEL are re: 1 [micro]Pa and 1 [micro]Pa\2\-sec, respectively.
dB = decibels.
SEL = sound exposure level.
RMS = Root Mean Square.
Table 5--Radial Distances to Level B Harassment Isopleths During Impact and Vibratory Driving
----------------------------------------------------------------------------------------------------------------
Source levels at 10 meters (dB) Distance to
----------------------------------------------------- threshold 160/120
Pile type dB RMS (Level B)
Peak RMS * meters (feet)
----------------------------------------------------------------------------------------------------------------
Attenuated Impact Driving (with bubble
curtain):
60[dash]inch steel pipe (1 per day). 203............................. 188 736 (2,413)
24[dash]inch square concrete (1-2 191............................. 173 45 (147)
per day).
Impact Pile Proofing (no bubble
curtain):
36-inch steel pipe pile (2 total)... 208............................. 190 1,000 (3,280)
Vibratory Driving/Extraction:
12-inch Composite Barrier Piles (5 178............................. 168 15,849 (51,984)
per day).
36-inch steel pipe pile (4 per day). 180............................. 170 21,544 (70,665)
20-inch steel pipe pile (4 per day). 180............................. 163 7,356 (24,129)
Wood and concrete pile extraction No Data Available............... 152 1,359 (4,459)
(12 per day).
----------------------------------------------------------------------------------------------------------------
Notes:
dB decibels.
RMS root mean square.
* For underwater noise, the Level B Harassment threshold is 160 dB for impulsive noise and 120 dB for continuous
noise.
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
For the 2019 IHA application, a combination of nearby haul-out
occupancy and at-sea densities were used to develop take estimates, in
order to account for both local movements of harbor seals that haul out
at Castro Rocks and other individuals that may be foraging in the more
distant part of the Level B Harassment zone. By using hydroacoustic
data collected in 2018, the extent of the harassment zones was refined
for attenuated impact driving of
[[Page 28481]]
concrete piles by using the transmission loss measured during 2018
project (20logr). As the Level B Harassment zones estimated for the
2019 IHA are generally more localized, only the occupancy from the
local Castro Rocks haul-out is used.
Castro Rocks, located approximately 1.3 km northwest of the project
site, is the largest harbor seal haul out site in the northern part of
San Francisco Bay and is the second largest pupping site in the Bay
(Green et al. 2002). Tidal stage is a major controlling factor of haul
out usage at Castro Rocks with more seals present during low tides than
high tide periods (Green et al. 2002). Additionally, the number of
seals hauled out at Castro Rocks also varies with the time of day, with
proportionally more animals hauled out during the nighttime hours
(Green et al. 2002). Therefore, the number of harbor seals in the water
around Castro Rocks will vary throughout the work period. Pile driving
would occur intermittently during the day with average active driving
times typically of a few hours per day, so varying sets of animals may
be hauled out or in the water. However, there are no systematic counts
available for accurately estimating the number of seals that may be in
the water near Long Wharf at any given time. The National Park Service
provided recent data indicating that up to 176 seals could be present
each day at Castro Rocks. This value was conservatively based on the
highest mean plus the standard error of harbor seals observed at Castro
Rocks per day (Codde, S. and S. Allen 2013, 2015, and 2017), a value of
176 seals. The 2018 draft Long Wharf marine mammal monitoring report
indicated that 24 harbor seals were observed within the Level B
harassment zone and zero individuals were observed within the Level A
harassment zone over 10 days of pile driving, which equals less than 1
percent of the authorized number of harbor seals with an average of 2.4
animals per day. The maximum number observed per day was six.
Since there are no California sea lion haul-outs in the vicinity of
the project area, relatively few animals are expected to be present.
However, monitoring for the RSRB did observe limited numbers in the
north and central portions of the Bay during working hours. During
monitoring for the San Francisco-Oakland Bay Bridge (SFOBB) Project in
the central Bay, 83 California sea lions were observed in the vicinity
of the bridge over a 17-year period from 2000-2017, and from these
observations, an estimated at-sea density of 0.16 animals per square
kilometer is derived (NMFS 2018). This bridge is located approximately
25 km south of the LWMEP location and is considered by NMFS to be the
best available information. The 2018 Long Wharf draft monitoring report
did not record any observations of sea lions.
Small numbers of northern elephant seal may haul out or strand on
coastline within the Central Bay. Monitoring of marine mammals in the
vicinity of the SFOBB has been ongoing for 15 years. From those data,
Caltrans has produced an estimated at-sea density for northern elephant
seal of 0.16 animal per square mile (0.06 animal per square kilometer)
(Caltrans, 2015b). Most sightings of northern elephant seal in San
Francisco Bay occur in spring or early summer, and are less likely to
occur during the periods of in-water work for this project. As a
result, densities during pile driving for the planned action are likely
to be lower. Additionally, this species was not observed by the marine
mammal observers in the vicinity of the Long Wharf during 2018 pile
driving monitoring.
The occurrence of northern fur seal in San Francisco Bay depends
largely on oceanic conditions, with animals more likely to strand
during El Ni[ntilde]o events. Equatorial sea surface temperatures are
above average across most of the Pacific Ocean this year, and El
Ni[ntilde]o is expected to continue through winter of 2019 and into
spring (NOAA 2019). There are no estimated at-sea densities for this
species in San Francisco Bay and no seals were recorded during 2018
Long Wharf marine mammal monitoring.
A small but growing population of harbor porpoises utilizes San
Francisco Bay which are typically spotted in the vicinity of Angel
Island and the Golden Gate (6 and 12 kilometers (3.7 and 7.5 miles)
southwest respectively) and the vicinity of Treasure Island (Caltrans
2018). However, they may occur in other areas in the Central Bay in low
numbers, including the project area. Based on monitoring conducted for
the SFOBB project in 2017, an in-water density of 0.17 animals per
square kilometer has been estimated by Caltrans for this species (NMFS
2018). No members of this species were recorded during 2018 during pile
driving activities at LWMEP.
Bottlenose dolphins are typically found close to the Golden Gate
Bridge when they are observed in San Francisco Bay. There are no
estimated at-sea densities for this species in San Francisco Bay
available for calculating a take estimate. Beginning in 2015, two
individuals have been observed frequently in the vicinity of Oyster
Point (GGCR 2018; Perlman, 2017). The average reported group size for
bottlenose dolphins is five. Reports show that a group normally comes
into San Francisco Bay, is near Yerba Buena Island once per week for
approximately two (2) weeks and then leaves (NMFS, 2017).
Gray whales have been observed entering the Bay during their
northward migration period, and are most often sighted in the Bay
between February and May. Most venture only about 2 to 3 km (about 1-2
miles) past the Golden Gate. However, gray whales have occasionally
been sighted as far north as San Pablo Bay. Pile driving is not
expected to occur during the February-May period, and gray whales are
not likely to be present at other times of year. No whales were
observed as part of 2018 Long Wharf marine mammal monitoring
activities.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
When density data was available, take for the project was
calculated by multiplying the density times the harassment zone (km\2\)
associated with pile driving activities that are underway times the
number of construction days. Since density data was only available for
harbor seals, harbor porpoises, and California sea lions, these were
the only species whose take was calculated using this methodology. For
species without density information, information on average group size
or local observational data was used as described below.
Pacific Harbor Seal
Chevron initially estimated that all harbor seals (176) at Castro
Rocks would be exposed to noise that reaches the threshold for Level B
harassment on every day on which there was pile driving. The areas of
the Level A harassment zones in which take by injury could occur were
determined by subtracting the shutdown zone areas from Level A
harassment zone areas. Chevron estimated Level A take for impact
driving of the 60-inch and 36-inch steel piles by using Level B take
and multiplying it by the ratio of the Level A zone area to the Level B
zone area. Level A take is not requested for vibratory driving. This
resulted in an estimated 11,968 takes by Level B harassment and 513
takes by Level A harassment. However, based on input from the
Commission as well as the size of the Level B zones extending beyond
Castro Rocks, NMFS is authorizing takes for all 176 seals per day
multiplied by 37 days for all piles but 24-inch concrete. For 24-inch
concrete, the max observed, which was two, has been
[[Page 28482]]
multiplied by 30 as resulting in a total of 6,572 Level B takes of
harbor seal as shown in Table 9. For Level A harassment the same
rationale was used. The area of the Level A harassment zone for 60-inch
piles is 0.62 km\2\, while the area of the Level B harassment zone is
1.7 km\2\. The ratio of these two areas was multiplied by 176 seals
resulting in 64 takes per day and a total of 513 authorized Level A
harassment takes as shown in Table 6 and Table 10.
Table 6--Level A and Level B Harassment Estimate for Pacific Harbor Seal
[Per day]
----------------------------------------------------------------------------------------------------------------
Estimated take per day
Level A zone, -------------------------------
Pile type Level B zone Exclusion zone minus Level B take Level A take
(sq km) radius (m) shutdown zone per day-- per day--
(sq km) total total
----------------------------------------------------------------------------------------------------------------
Vibratory Driving
----------------------------------------------------------------------------------------------------------------
12-inch composite pile.......... 165.62 15 0 176 NA
36-inch steel pipe pile......... 187.94 15 0 176 NA
20-inch steel pipe pile......... 87.57 10 0 176 NA
Timber/Concrete Pile Removal.... 5.33 15 0 176 NA
----------------------------------------------------------------------------------------------------------------
Impact Driving
----------------------------------------------------------------------------------------------------------------
24-inch concrete pile........... 0.01 20 0 176 NA
60-inch steel pile.............. 1.70 30 0.62 176 64.06
----------------------------------------------------------------------------------------------------------------
Impact Proofing
----------------------------------------------------------------------------------------------------------------
36-inch steel pile.............. 3.14 30 0.01 176 0.14
----------------------------------------------------------------------------------------------------------------
For impact pile driving of the 60-inch steel piles, the shutdown
zones (30 meters) are notably smaller than the Level A harassment zone
and the applicant has accordingly requested take by Level A harassment
for harbor seal so that pile driving can be completed on schedule
without frequent shutdowns. Individuals occurring within the Level A
harassment zone but outside of the shut-down zone may experience Level
A harassment, if they reside in that area for a long enough duration.
However, these animals can be highly mobile, and remaining within the
small injury zone for an extended period is unlikely, though it could
occur.
California Sea Lion
Monitoring data from the SFOBB Project over a 17-year period was
used to develop a density of 0.16 California sea lions per square
kilometer. This density and the areas of the potential Level B
Harassment zones are used in Table 7. Level A harassment take of this
species is not requested, due to the small size of the Level A
harassment zone for otariid pinnipeds,
Table 7--Level B Harassment Estimate for California Sea Lion
[Per day]
------------------------------------------------------------------------
Level B take
estimate
(based on
Pile type Level B zone Central Bay
(km\2\) density of
0.16 animals
per km\2\)
------------------------------------------------------------------------
Vibratory Driving
------------------------------------------------------------------------
12-inch composite pile.................. 165.62 26.50
36-inch steel pipe pile................. 187.94 30.07
20-inch steel pipe pile................. 87.57 14.01
Timber/Concrete Pile Removal............ 5.33 0.85
------------------------------------------------------------------------
Impact Driving
------------------------------------------------------------------------
24-inch concrete pile................... 0.01 0.01
60-inch steel pile...................... 1.70 0.27
------------------------------------------------------------------------
Impact Proofing
------------------------------------------------------------------------
36-inch steel pile...................... 3.14 0.50
------------------------------------------------------------------------
[[Page 28483]]
Harbor Porpoise
Based on monitoring conducted for the SFOBB project in 2017, an in-
water density of 0.17 animals per square kilometer has been estimated
by Caltrans for this species (NMFS 2018). Using this in-water density
and the areas of potential Level A and Level B harassment, take is
estimated for harbor porpoise as provided in Table 10. Level A
harassment zone areas in which PTS could occur were determined by
subtracting the shutdown zone areas from Level A harassment zone areas.
Level A take is not requested for vibratory driving.
Table 8--Level A and Level B Harassment Estimate for Pacific Harbor Porpoise
[Per day]
----------------------------------------------------------------------------------------------------------------
Level B
Level A zone, estimate Estimated
Pile type Level B zone Exclusion zone minus Central Bay Level A take
(km\2\) (m) shutdown zone in-water--0.17 per day
(km\2\) per km\2\
----------------------------------------------------------------------------------------------------------------
Vibratory Driving
----------------------------------------------------------------------------------------------------------------
12-inch composite barrier pile.. 165.62 50 NA 28.16 NA
36-inch steel pipe pile......... 187.94 50 NA 31.95 NA
20-inch steel pipe pile......... 87.57 50 NA 14.89 NA
Timber/Concrete Pile Removal.... 5.33 50 NA 0.91 NA
----------------------------------------------------------------------------------------------------------------
Impact Driving
----------------------------------------------------------------------------------------------------------------
24-inch concrete pile........... 0.01 50 0 0.01 0
60-inch steel pile.............. 0.21 50 0.23 0.29 0.52
----------------------------------------------------------------------------------------------------------------
Impact Proofing
----------------------------------------------------------------------------------------------------------------
36-inch steel pile.............. 3.14 80 0 0.53 <0.01
----------------------------------------------------------------------------------------------------------------
Northern Elephant Seal
As noted above, elephant seal densities are expected to be
extremely low. Therefore, Chevron did not use density data to calculate
take. Additionally, this species was not observed by the marine mammal
observers in the vicinity of the LWMEP during 2018 pile driving marine
mammal monitoring activities. Therefore, Caltrans will conservatively
assume that a lone northern elephant seal may enter the Level B
Harassment area once per every three days during pile driving. As such,
NMFS has authorized a total of 23 takes by Level B harassment. Level A
harassment of this species is not expected to occur.
Northern Fur Seal
With weak El Ni[ntilde]o conditions predicted to continue into
spring and, perhaps, summer (NOAA 2019). There is a chance that fur
seals could occur near the project area. Since there are no estimated
at-sea densities for this species in San Francisco Bay, NMFS has
authorized 10 takes of fur seals by Level B harassment. Level A
harassment of this species is not anticipated.
Bottlenose Dolphin
As noted above, there are no estimated at-sea densities for this
species in San Francisco Bay available for calculating a take estimate
although they have been observed. Beginning in 2015, two individuals
have been observed frequently in the vicinity of Oyster Point (GGCR,
2016; GGCR 2017; Perlman, 2017). The average reported group size for
bottlenose dolphins is five. Assuming the dolphins come into San
Francisco Bay once every 10 days, 30 takes would be anticipated, if the
group enters the areas over which the Level B harassment thresholds may
be exceeded. Therefore, NMFS has authorized the take of 30 bottlenose
dolphins.
Gray Whale
Gray whales are most often sighted in the Bay between February and
May. However, LWMEP pile driving is not expected to occur during this
time, and gray whales are unlikely to be present at other times of
year. However, should pile driving occur during the northward migration
period, Chevron requests and NMFS has authorized two (2) Gray whale
takes by Level B harassment.
The Level B Harassment estimates shown in Table 9 are based on the
number of individuals assumed to be exposed per day, the number of
piles driven per day and the number of days of pile driving expected
based on an average installation rate.
Table 9--Summary of Estimated Take by Species for 2019 Work Season
[Level B harassment]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Species
Number of Number of ------------------------------------------------------------------------------------
Pile type Pile driver type piles driving Harbor CA sea Harbor Gray whale N elephant N fur Bottlenose
days seal lion porpoise * seal ** seal * dolphin *
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
60-inch steel pipe............................. Impact............................ 8 8 1,408 2.18 2.31 NA 2.66 NA NA
36-inch steel pipe pile ***.................... Vibratory......................... 8 4 704 120.28 127.80 NA 1.33 NA NA
36-inch steel pipe pile........................ Impact Proofing................... 2 1 176 0.50 0.53 NA 0.33 NA NA
20-inch steel pipe pile........................ Vibratory......................... 8 4 704 56.04 59.56 NA 1.33 NA NA
Concrete pile removal.......................... Vibratory......................... 5 1 176 0.91 0.97 NA 0.33 NA NA
[[Page 28484]]
24-inch concrete............................... Impact............................ 39 30 60 0.3 0.04 NA 10 NA NA
12-inch composite pile installation............ Vibratory......................... 52 11 1,936 291.50 309.72 NA 3.66 NA NA
Timber pile removal............................ Vibratory......................... 106 9 1,584 7.68 8.16 NA 3 NA NA
------------------------------------------------------------------------------------------------------------
Total Take by Species (2019)............... .................................. .......... .......... 6,572 479 509 2 23 10 30
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Take is not calculated by activity type for these species, only a total estimate is given.
** Assumes 1 take every 3 days of driving.
*** Level B take for this pile type is based on vibratory driving only, as the method produces the larger Level B zone.
Table 10--Summary of Estimated Take Level A Harassment for 2019 Work Season
----------------------------------------------------------------------------------------------------------------
Number of Number of Harbor
Pile type Pile driver type piles driving days Harbor seal porpoise
----------------------------------------------------------------------------------------------------------------
60-inch steel pipe............ Impact.......... 8 8 512.49 4.18
36-inch steel pipe pile....... Vibratory....... 8 4 0 0
36-inch steel pipe pile....... Impact Proofing. 2 1 0.14 <0.01
20-inch steel pipe pile **.... Vibratory....... 8 4 0 0
Concrete pile removal......... Vibratory....... 5 1 0 0
24-inch concrete.............. Impact.......... 39 30 0 0
12-inch composite pile Vibratory....... 52 11 0 0
installation.
Timber pile removal........... Vibratory....... 106 9 0 0
---------------------------------------------------------------
Total Take................ ................ .............. .............. 513 4
----------------------------------------------------------------------------------------------------------------
Table 11--Authorized Take and Percentage of Stock or Population
----------------------------------------------------------------------------------------------------------------
Percent
(instances of
Species Stock Authorized Authorized take compared
Llevel A takes Level B takes to population
abundance)
----------------------------------------------------------------------------------------------------------------
Harbor seal........................... California.............. 513 6,572 22.9
California sea lion................... Eastern U.S............. .............. 479 0.16
Harbor porpoise....................... San Francisco--Russian 4 509 6.1
River.
Northern elephant seal................ California Breeding..... .............. 23 <0.01
Gray whale............................ Eastern North Pacific... .............. 2 <0.01
Northern fur seal..................... California.............. .............. 10 <0.01
Bottlenose Dolphin.................... California Coastal...... .............. 30 6.6
----------------------------------------------------------------------------------------------------------------
Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat, as
well as subsistence uses. This considers the nature of the potential
adverse impact being mitigated (likelihood, scope, range). It further
considers the likelihood that the measure will be effective if
implemented (probability of accomplishing the mitigating result if
implemented as planned), the likelihood of effective implementation
(probability implemented as planned), and;
(2) the practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
[[Page 28485]]
Mitigation for Marine Mammals and Their Habitat
The following measures will apply to Chevron's LWMEP mitigation
requirements:
Noise Attenuation--Bubble curtains will be used during all impact
pile driving of 60-inch steel shell pile and 24-inch square concrete
piles to interrupt acoustic pressure and reduce impact on marine
mammals. The use of bubble curtains is expected to reduce underwater
noise levels by approximately 7 dB, which greatly reduces the area over
which the cumulative SEL threshold for Level A harassment may be
exceeded. Bubble curtains would also decrease the size of the Level B
harassment zone, reducing the numbers of marine mammals affected by
potential behavioral impacts.
Daylight Construction Period--Work would occur only during daylight
hours (7:00 a.m. to 7:00 p.m.) when visual marine mammal monitoring can
be conducted.
Establishment of a Shutdown Zone--For all pile driving and removal
activities, Chevron will establish shutdown zones. The purpose of a
shutdown zone is generally to define an area within which shutdown of
activity would occur upon sighting of a marine mammal (or in
anticipation of an animal entering the defined area). A shutdown zone
will be established which will include all or a portion of the area
where SPLs are expected to reach or exceed the cumulative SEL
thresholds for Level A harassment as provided in Table 12.
Table 12--Shutdown Zones for LWMEP
----------------------------------------------------------------------------------------------------------------
Exclusion zones meters
-------------------------------------------------------------------------------
Project element requiring pile High-
installation Low- frequency Mid- frequency frequency Phocid Otariid
cetaceans cetaceans cetaceans pinnipeds pinnipeds
----------------------------------------------------------------------------------------------------------------
Attenuated Impact Driving (with
bubble curtain):
60-inch steel pipe.......... 840 30 50 30 35
24-inch square concrete..... 20 10 50 15 10
Impact Pile Proofing (no bubble
curtain):
36-inch steel pipe pile..... 100 10 80 30 10
Vibratory Driving/Extraction:
12-inch Composite Barrier 20 10 50 15 10
Pile.......................
36-inch steel pipe pile..... 20 10 50 15 10
20-inch steel pipe pile..... 10 10 50 10 10
Wood and concrete pile 10 10 50 10 10
extraction.................
----------------------------------------------------------------------------------------------------------------
Establishment of Monitoring Zones for Level A and Level B--Chevron
will establish and monitor Level A harassment zones during impact
driving for harbor seal extending to 450 meters and harbor seals and
extending to 990 for harbor porpoises. These are areas beyond the
shutdown zone in which animals could be exposed to sound levels that
could result in Level A harassment in the form of PTS. Chevron will
also establish and monitor Level B harassment zones which are areas
where SPLs are equal to or exceed the 160 dB rms threshold for impact
driving and the 120 dB rms threshold during vibratory driving and
extraction as shown in Table 5. Monitoring zones provide utility for
observing by establishing monitoring protocols for areas adjacent to
the shutdown zones. Monitoring zones also enable observers to be aware
of and communicate the presence of marine mammals in the project area
outside the shutdown zone and thus prepare for a potential cease of
activity should the animal enter the shutdown zone. Level B harassment
exposures will be recorded and extrapolated based upon the number of
observed take and the percentage of the Level B harassment zone that
was not visible.
10-Meter Shutdown Zone--During the in-water operation of heavy
machinery (e.g., barge movements), a 10-m shutdown zone for all marine
mammals will be implemented. If a marine mammal comes within 10 m,
operations shall cease and vessels shall reduce speed to the minimum
level required to maintain steerage and safe working conditions.
Soft Start--The use of a soft-start procedure are believed to
provide additional protection to marine mammals by providing warning
and/or giving marine mammals a chance to leave the area prior to the
hammer operating at full capacity. Chevron shall use soft start
techniques when impact pile driving. Soft start requires contractors to
provide an initial set of strikes at reduced energy, followed by a
thirty-second waiting period, then two subsequent reduced energy strike
sets.
Pre-Activity Monitoring--Pre-activity monitoring shall take place
from 30 minutes prior to initiation of pile driving activity and post-
activity monitoring shall continue through 30 minutes post-completion
of pile driving activity. Pile driving may commence at the end of the
30-minute pre-activity monitoring period, provided observers have
determined that the shutdown zone is clear of marine mammals, which
includes delaying start of pile driving activities if a marine mammal
is sighted in the zone, as described below.
If a marine mammal approaches or enters the shutdown zone during
activities or pre-activity monitoring, all pile driving activities at
that location shall be halted or delayed, respectively. If pile driving
is halted or delayed due to the presence of a marine mammal, the
activity may not resume or commence until either the animal has
voluntarily left and been visually confirmed beyond the shutdown zone
or 15 minutes have passed without re-detection of the animal. 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 thirty minutes.
Non-authorized Take Prohibited--If a species for which
authorization has not been granted or a species for which authorization
has been granted but the authorized takes are met, is observed
approaching or within the monitoring zone, pile driving and removal
activities must shut down immediately using delay and shut-down
procedures. Activities must not resume until the animal has been
confirmed to have left the area or an observation time period of 15
minutes has elapsed.
Based on our evaluation of the Chevron's measures, as well as other
measures considered by NMFS, we have determined that the mitigation
measures
[[Page 28486]]
provide the means effecting the least practicable impact on the
affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
action area. Effective reporting is critical both to compliance as well
as ensuring that the most value is obtained from the required
monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
Visual Monitoring
The following visual monitoring measures are required as part of
the issued IHA.
One day of biological monitoring would occur within one
week before the project's start date to establish baseline
observations;
Monitoring distances, in accordance with the identified
shutdown, Level A, and Level B zones, will be determined by using a
range finder, scope, hand-held global positioning system (GPS) device
or landmarks with known distances from the monitoring positions;
Monitoring locations will be established at locations
offering best views of the monitoring zone;
Monitoring would be conducted 30 minutes before, during,
and 30 minutes after pile driving and removal activities. In addition,
observers shall record all incidents of marine mammal occurrence,
regardless of distance from activity, and shall document any behavioral
reactions in concert with distance from piles being driven or removed.
Pile driving and removal 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.
Monitoring will be continuous unless the contractor takes
a break longer than 2 hours from active pile driving, in which case,
monitoring will be required 30 minutes prior to restarting pile
installation;
For in-water pile driving, under conditions of fog or poor
visibility that might obscure the presence of a marine mammal within
the shutdown zone, the pile in progress will be completed and then pile
driving suspended until visibility conditions improve;
At least two PSOs will be actively scanning the monitoring
zone during all pile driving activities with one PSO stationed at the
north end of the wharf monitoring the entire observable area with a
special focus on the section between Castro Rocks and the wharf;
Monitoring of pile driving shall be conducted by qualified
PSOs (see below), who shall have no other assigned tasks during
monitoring periods. Chevron shall adhere to the following conditions
when selecting observers:
(1) Independent PSOs shall be used (i.e., not construction
personnel);
(2) At least one PSO must have prior experience working as a marine
mammal observer during construction activities;
(3) Other PSOs may substitute education (degree in biological
science or related field) or training for experience; and
(4) Chevron shall submit PSO CVs for approval by NMFS;
Chevron will ensure that observers have the following
additional qualifications:
(1) Ability to conduct field observations and collect data
according to assigned protocols;
(2) Experience or training in the field identification of marine
mammals, including the identification of behaviors;
(3) Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
(4) 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
(5) 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.
Hydroacoustic Monitoring
Sound Source Verification (SSV) testing of would be conducted under
this IHA. The purpose of the planned acoustic monitoring plan is to
collect underwater sound-level information at both near and distant
locations during vibratory pile extraction and installation and impact
pile installation. Hydroacoustic monitoring would be conducted by a
qualified monitor during pile extraction and driving activities as
described in the Hydroacoustic Monitoring plan and will likely include
the following during 2019:
Acoustic monitoring for at least two (2) timber piles
(vibratory);
Acoustic monitoring for at least four (4) 24-inch square
concrete piles (impact);
Acoustic monitoring for at least two (2) 20-inch steel
piles (vibratory);
Acoustic monitoring for at least two (2) 36-inch steel
piles (vibratory);
Acoustic monitoring for at least two (2) 60-inch steel
piles (impact); and
Acoustic monitoring of two (2) 12-inch composite piles
(vibratory).
Reporting Measures
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities. It will include an overall description of
[[Page 28487]]
work completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report must include:
Dates and times (begin and end) of all 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 during each
monitoring period (e.g., wind speed, percent cover, visibility, sea
state);
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;
Age and sex class, if possible, of all marine mammals
observed;
PSO locations during marine mammal monitoring;
Distances and bearings of each marine mammal observed to
the pile being driven or removed for each sighting (if pile driving or
removal was occurring at time of sighting);
Description of any marine mammal behavior patterns during
observation, including direction of travel;
Number of individuals of each species (differentiated by
month as appropriate) detected within the monitoring zone, and
estimates of number of marine mammals taken, by species (a correction
factor may be applied to total take numbers, as appropriate);
Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting behavior of the animal, if
any;
Description of attempts to distinguish between the number
of individual animals taken and the number of incidences of take, such
as ability to track groups or individuals; and
Level B harassment exposures recorded by PSOs must be
extrapolated based upon the number of observed takes and the percentage
of the Level B harassment zone that was not visible.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury, serious injury or mortality, Chevron
would immediately cease the specified activities and report the
incident to the Chief of the Permits and Conservation Division, Office
of Protected Resources, NMFS, and the West Coast Regional Stranding
Coordinator. The report would include the following information:
Description of the incident;
Environmental conditions (e.g., Beaufort sea state,
visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS would work with Chevron to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. Chevron would not be able
to resume their activities until notified by NMFS via letter, email, or
telephone.
In the event that Chevron discovers an injured or dead marine
mammal, and the lead PSO determines that the cause of the injury or
death is unknown and the death is relatively recent (e.g., in less than
a moderate state of decomposition as described in the next paragraph),
Chevron would immediately report the incident to the Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS,
and the West Coast Regional Stranding Coordinator. The report would
include the same information identified in the paragraph above.
Activities would be able to continue while NMFS reviews the
circumstances of the incident. NMFS would work with Chevron to
determine whether modifications in the activities are appropriate.
In the event that Chevron discovers an injured or dead marine
mammal and the lead PSO determines that the injury or death is not
associated with or related to the activities authorized in the IHA
(e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), Chevron would report the incident
to the Chief of the Permits and Conservation Division, Office of
Protected Resources, NMFS, and the West Coast Regional Stranding
Coordinator, within 24 hours of the discovery. Chevron would provide
photographs, video footage (if available), or other documentation of
the stranded animal sighting to NMFS and the Marine Mammal Stranding
Network.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely effectiveness
of the mitigation. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. Consistent with the 1989 preamble for NMFS's implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into this
analysis via their impacts on the environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
Pile driving and extraction associated with Chevron's LWMEP project
as outlined previously have the potential to injure, disturb or
displace marine mammals. Specifically, the planned activities may
result in Level B harassment (behavioral disturbance) for seven marine
mammal species authorized for take from underwater sound generated
during pile driving and removal operations. Level A harassment in the
form of limited PTS may also occur to animals of two species. No marine
mammal stocks for which incidental take authorization are listed as
threatened or endangered under the ESA or determined to be strategic or
depleted under the MMPA. No serious injuries or mortalities are
anticipated to occur as a result of Chevron's pile driving activities.
A limited number of animals (513 harbor seals and 4 harbor
porpoises) could experience Level A harassment in the form of PTS if
they stay within the Level A harassment zone during impact
[[Page 28488]]
driving of 60-inch steel and 36-inch steel piles. The degree of injury
is expected to be mild and is not likely to affect the reproduction or
survival of the individual animals. It is expected that, if hearing
impairments occurs, most likely the affected animal would lose a few dB
in its hearing sensitivity, which in most cases is not likely to affect
its survival and recruitment.
The Level B takes that are anticipated and authorized are expected
to be limited to short-term behavioral harassment. Marine mammals
present near the action area and taken by Level B harassment would most
likely show overt brief disturbance (e.g. startle reaction) and
avoidance of the area from elevated noise level during pile driving.
However, this is unlikely to result in any significant realized
decrease in fitness for the affected individuals or stocks for which
take is authorized. While harbor seals from Castro Rocks may experience
some temporary low-level behavioral impacts, the number of seals
potentially affected is conservatively estimated at approximately 23
percent of the stock. This number, however, likely includes multiple
takes of the same individuals. Furthermore, Castro Rocks and the LWMEP
location represent a small portion of the range of the California stock
of harbor seal. These two factors indicate that a much lower percentage
of the stock would potentially be affected and, therefore, no adverse
impacts to the stock as a whole are expected.
The project is not expected to have significant adverse effects on
affected marine mammal habitat. The activities may cause fish to leave
the area temporarily. This could impact marine mammals' foraging
opportunities in a limited portion of the foraging range; but, because
of the relatively short duration of driving activities and the
relatively small area of affected habitat, the impacts to marine mammal
habitat are not expected to cause significant or long-term negative
consequences. Furthermore, there are no biologically important areas
identified in the project area.
The likelihood that marine mammals will be detected by trained
observers is high under the environmental conditions described for the
project. The employment of the soft-start mitigation measure during
impact driving would also allow marine mammals in or near the shutdown
and Level A zone zones to move away from the impact driving sound
source. Therefore, the mitigation and monitoring measures are expected
to reduce the potential for injury and reduce the amount and intensity
of 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
taken place with no reported injuries or mortality to marine mammals,
and no known long-term adverse consequences from behavioral harassment.
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 the species or stock through
effects on annual rates of recruitment or survival:
No mortality is anticipated or authorized;
Anticipated incidences of Level A harassment would be in
the form of a small degree of PTS to a limited number of animals;
Anticipated incidents of Level B harassment consist of, at
worst, temporary modifications in behavior;
No biologically important areas have been identified in
the vicinity of the project area;
The small percentage of the stock that may be affected by
project activities (< 23 percent for all stocks); and
Efficacy of mitigation measures is expected to minimize
the likelihood and severity of the level of harassment.
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 above, only small numbers of incidental take may be
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. Additionally, other qualitative
factors may be considered in the analysis, such as the temporal or
spatial scale of the activities.
Table 13 depicts the number of animals that could be exposed to
Level A and Level B harassment from work associated with Chevron's
project. The analysis provided indicates that authorized take would
account for no more than 23 percent of the populations of the stocks
that could be affected. These are small numbers of marine mammals
relative to the sizes of the affected stocks.
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 would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (incidental harassment authorizations with
no anticipated serious injury or mortality) of the Companion Manual for
NOAA Administrative Order 216-6A, which do not individually or
cumulatively have the potential for significant impacts on the quality
of the human environment and for which we have not identified any
extraordinary circumstances that would preclude this categorical
exclusion. Accordingly, NMFS has determined that the issuance of the
IHA qualifies to be categorically excluded from further NEPA review.
Endangered Species Act (ESA)
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat.
No incidental take of ESA-listed species is expected to occur or
[[Page 28489]]
authorized for this activity. Therefore, NMFS has determined that
formal consultation under section 7 of the ESA is not required for this
action.
Authorization
As a result of these determinations, NMFS has issued an IHA to
Chevron for conducting pile driving and removal activities at Chevron's
Long Wharf from June 1, 2019 through May 31, 2020, provided the
previously mentioned mitigation, monitoring, and reporting requirements
are incorporated.
Dated: May 30, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2019-12922 Filed 6-18-19; 8:45 am]
BILLING CODE 3510-22-P