[Federal Register Volume 77, Number 225 (Wednesday, November 21, 2012)]
[Notices]
[Pages 69797-69806]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-28345]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XB041
Small Takes of Marine Mammals Incidental to Specified Activities;
Pile Driving in Port Townsend Bay, WA
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of incidental harassment authorization.
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SUMMARY: Pursuant to the Marine Mammal Protection Act (MMPA) as
amended, NMFS provides notice that we have issued an Incidental
Harassment Authorization (IHA) to the Washington State Department of
Transportation Ferries Division (WDF) to incidentally harass, by Level
B harassment only, 11 species of marine mammals during the transfer
span replacement project at the Port Townsend ferry terminal in Port
Townsend Bay, Washington.
DATES: This authorization is effective from November 12, 2012, through
February 15, 2013.
ADDRESSES: An electronic copy of the IHA and related documents are
available by writing to Michael Payne, Chief, Permits and Conservation
Division, Office of Protected Resources, National Marine Fisheries
Service, 1315
[[Page 69798]]
East-West Highway, Silver Spring, MD 20910-3225.
An electronic copy of the application containing a list of the
references used in this document may be obtained by visiting the
Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. For
members of the public who are unable to view these documents on the
Internet, a copy may be obtained by writing to the address specified
above or telephoning the contact listed below (see FOR FURTHER
INFORMATION CONTACT). Documents cited in this notice may also be
viewed, by appointment, during regular business hours, at the
aforementioned address.
FOR FURTHER INFORMATION CONTACT: Brian D. Hopper, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce 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 specific 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 authorization is
provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
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.''
Section 101(a)(5)(D) of the MMPA established an expedited process
by which citizens of the United States can apply for an authorization
to incidentally take small numbers of marine mammals by harassment.
Section 101(a)(5)(D) further established a 45-day time limit for NMFS'
review of an application, followed by a 30-day public notice and
comment period on any proposed authorizations for the incidental
harassment of marine mammals. Within 45 days of the close of the
comment period, NMFS must either issue or deny the authorization.
Except with respect to certain activities not pertinent here, 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].
Summary of Request
In August 2011, NMFS received an application from WSF, requesting
an IHA for the take, by Level B harassment, of small numbers of harbor
porpoises (Phocoena phocoena), Dall's porpoises (Phocoenoides dalli),
Pacific white-sided dolphins (Lagenorhynchus obliquidens), killer
whales (Orcinus orca), gray whales (Eschrichtius robustus), humpback
whales (Megaptera novaeangliae), minke whales (Balaenoptera
acutorostrata), Pacific harbor seals (Phoca vitulina richardii),
California sea lions (Zalophus californianus), northern elephant seals
(Mirounga angustirostris) and Steller sea lions (Eumatopius jubatus)
incidental to pile driving activities conducted during the replacement
of a transfer span at the Port Townsend ferry terminal, which is
located inside Port Townsend Bay in northern Puget Sound (see Figure 1-
9 in the WSF IHA application). Upon receipt of additional information
and a revised application (submitted October 2011), NMFS determined the
application complete and adequate on January 5, 2012.
The applicant's project will replace the current cable-lift
transfer span at Slip 1 of the Port Townsend ferry terminal with a
hydraulic lift H span (see Figure 1-3 in the WSF IHA application). The
project will include removal of the existing transfer span, lift
towers, tower foundations, and a portion of the bridge seat and replace
them with a new transfer span, bridge seat, and lift cylinder shafts.
During the project, up to 56 piles will be removed (40 timber and 16
steel), and require installation of up to 26 piles (16 steel, 8
temporary H-piles, and 2 cylinder shaft casings). Because elevated
sound levels from pile driving have the potential to result in marine
mammal harassment, NMFS issued an IHA for take incidental to the
specified activity.
Description of the Specified Activity
The project will replace an aging cable-lift transfer span with a
new hydraulic lift span at the Port Townsend ferry terminal in northern
Puget Sound, Washington. Transfer spans are moveable traffic bridges
that connect ferries with the terminal dock, allowing the transfer span
to be raised or lowered depending on the daily tide levels (see Figure
1-2 in WSF's IHA application). The new hydraulic lifts, or H-spans,
will be operated vertically by two hydraulic cylinders located under
the offshore ends of the transfer span. The proposed project will
involve the removal of the existing transfer span, lift towers, tower
foundations, and a portion of the bridge seat. Once the old structures
are removed, they will be replaced with a new transfer span, bridge
seat, and lift cylinder shafts (see Appendix A of the IHA application).
To replace the aging transfer span, 40 timber piles and 16 steel
piles (four 30-inch and four 24-inch wingwall steel piles, and eight
temporary piles) will be removed using a vibratory hammer. The
vibratory hammer will then be used to install up to 8 steel piles (five
30-inch and up to three 24-inch), up to 8 temporary steel piles, up to
8 piles for the new wingwall fender panels and reaction frames (up to
four 24-inch and up to four 30-inch), and two 80-inch cylinder shafts
that will house the hydraulic lifts. The use of an impact hammer will
be limited to the ``proofing'' of five 30-inch piles and three 24-inch
piles in order to drive them the last two feet into the substrate. A
breakdown of pile types and associated activity are shown in Table 1.
Table 1--Summary of Total Pile Removal and Installation Activities
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Total time to remove/ Days to
Activity Number of piles (maximum) install complete
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Removal of timber piles.................. 40......................... 10 hrs..................... 2
Removal of steel wingwall piles.......... 16......................... 4 hrs...................... 4
Install steel piles...................... 8 (5 30-inch and up to 3 24- 2 hrs. 40 min.............. 3
inch).
Install temporary piles.................. 8.......................... 2 hrs...................... 2
[[Page 69799]]
Install wingwall piles................... 8.......................... 2 hrs. 40 min.............. 3
Install cylinder shaft casing............ 2 (80-inch)................ 40 min..................... 2
Proofing of steel piles.................. 8.......................... 1 hr. 20 min............... 2
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Of the eight 24- and 30-inch steel piles, three 24-inch piles will
be installed to support the platform for the new Hydraulic Power Unit
(HPU) and five 30-inch piles would be installed for the new bridge
seat. Up to eight temporary steel piles will be installed using a
vibratory hammer to support a template for construction of the cylinder
shafts. The vibratory hammer will then be used to install the two 80-
inch hollow steel cylinder shafts. The final eight 24- and 30-inch
steel piles will be installed using a vibratory hammer for the new
wingwall reaction frames and wingwall fender panels at the terminus of
the transfer span.
Although the exact duration of pile driving will vary depending on
the installation procedures and geotechnical conditions, the applicant
estimates that the 16 24- to 30-inch permanent piles will each require
20 minutes of vibratory installation. Five 30-inch piles and up to
three 24-inch piles will each require 10 minutes of impact driving or
``proofing'' to verify capacity. The vibratory driving of eight
temporary piles that support the template for the hydraulic cylinder
shafts will each require 15 minutes to install because it will not be
necessary to drive these piles as deep as the permanent piles. The two
80-inch cylinder shaft casing will take approximately 20 minutes each
to install using a vibratory hammer. All piles will be installed with
an APE Model 400 (or equivalent) vibratory hammer; however, it will be
necessary to proof the five 30-inch bridge seat piles and three 24-inch
HPU support piles using an impact hammer. Proofing will require 10
minutes of impact pile driving for each of these eight piles to verify
load-bearing capacity. Sound attenuation devices, such as a bubble
curtain, will be used during impact hammering. The wingwall temporary
piles and the 80-inch cylinder shafts will be driven solely with a
vibratory hammer.
In addition to pile installation, a total of 56 piles will be
removed using vibratory extraction or a crane. These consist of the 16
steel piles and 40 old timber piles. If a timber pile breaks below the
mudline--something older timber piles are prone to do--pile stubs will
be removed with a clamshell bucket, but noise associated with this
activity is expected to be negligible. Once piles and fragments of
piles are removed, they will be loaded onto a barge or container and
disposed of at an approved offsite location. There could be barges in
the water to support these pile removal activities; however, these will
be concentrated in the direct vicinity of the ferry terminal. Because
direct pull and clamshell pile removal, and use of barges do not
release loud sounds into the environment, marine mammal harassment from
these activities is not anticipated.
Region of Activity
The activity will occur at the Port Townsend ferry terminal located
in northern Puget Sound inside Port Townsend Bay.
Dates and Duration of Activity
The Washington Department of Fish and Wildlife's recommended in-
water work window for this area is July 16 through February 15. Timing
restrictions such as this are used to avoid in-water work when ESA-
listed salmonid species are most likely to be present. Proposed pile
installation and removal activities are scheduled to occur between
November 12, 2012, and February 15, 2013, in agreement with the state's
recommendation. The on-site work will last approximately 16 weeks with
actual pile removal and driving activities taking place approximately
25 percent of that time (approximately 4 weeks).
Sound Propagation
Detailed descriptions of sound propagation and sound sources were
provided in the Federal Register notice (77 FR 39471, July 3, 2012).
Significant sound sources during in-water construction activities
associated with the project include vibratory pile removal and pile
installation using both vibratory and impact pile driving.
Since 1997, NMFS has used generic sound exposure thresholds as
guidelines to estimate when harassment may occur. Current practice
regarding exposure of marine mammals to sound defines thresholds as
follows: Cetaceans and pinnipeds exposed to sound levels of 180 and 190
dB root mean square (rms; note that all underwater sound levels in this
document are referenced to a pressure of 1 [micro]Pa) or above,
respectively, are considered to have been taken by Level A (i.e.,
injurious) harassment, while behavioral harassment (Level B) is
considered to have occurred when marine mammals are exposed to sounds
at or above 120 dB rms for continuous sound (such as will be produced
by the WSF activities) and 160 dB rms for pulsed sound, but below
injurious thresholds. For airborne sound, pinniped disturbance has been
documented at 100 dB (unweighted) for pinnipeds in general, and at 90
dB (unweighted) for harbor seals (note that all airborne sound levels
in this document are referenced to a pressure of 20 [micro]Pa).
Data from other Washington State Ferries projects were used for the
noise analysis of vibratory removal of 12-inch timber piles as well as
the vibratory removal and driving of 30-inch and 24-inch hollow steel
piles (Laughlin, 2005; Laughlin, 2010; Laughlin, 2011). Due to the lack
of information related to the vibratory driving of 80-inch hollow steel
cylinder shafts, noise levels recorded for a project using similar
equipment in Richmond, California were used to estimate sound levels
(CalTrans, 2007). For impact pile driving, WSF relied on measurements
for steel piles at other Puget Sound ferry terminal locations
(Laughlin, 2005). Sound levels for impact and vibratory pile driving
are shown in Table 2. Ambient underwater sound levels in the vicinity
of Port Townsend were measured in April 2010 (Stockham et al., 2010).
These data show that local background levels are below 120 dB (50th
percentile between 100 and 104 dB), at least during April; therefore,
the Level B harassment threshold for continuous sound sources (120 dB)
was not adjusted for this location. WSF conducted a site specific
vibratory test pile project in coordination with NMFS at the Port
Townsend Ferry Terminal to determine the distances at which vibratory
pile removal or driving attenuate down to the 120 dB threshold (i.e.,
the threshold level used to measure Level B harassment for continuous
sounds). The site specific test allowed physical factors in Port
Townsend Bay that can
[[Page 69800]]
influence sound attenuation rates to be taken into account, such as
absorption in seawater, absorption in the sub-bottom, scattering from
inhomogeneities (lack of uniformity) in the water column and from
surface and bottom roughness and water depth (bathymetry). During the
test, two hollow steel piles, one 36-inch and one 30-inch, were driven
and removed using a vibratory hammer. An array of hydrophones measured
in-water noise during the test project. Vibratory driving of the 36-
inch steel pile generated 159 to 177 dB rms at 10 m, and vibratory
driving of the 30-inch steel pile generated 164 to 174 dB rms at 10 m.
Vibratory removal of the 30-inch steel pile generated 171 dB rms at 10
m. Based on these results, the sound generated from vibratory
installation and removal of 30-inch piles may take up to 4.2 miles (6.8
km) to attenuate to below 120 dB. Because of the project area's
location in a semi-enclosed bay, sound transmission will be stopped by
land masses much earlier in certain directions.
In-air sound from pile driving also has the potential to affect
marine mammals (specifically, pinnipeds) that are hauled out or at the
water's surface. As a result, WSF analyzed the potential for pinnipeds
hauled out or swimming at the surface near the ferry terminal to be
exposed to airborne SPLs that could result in Level B behavioral
harassment. The distance to the 90 dB Level B threshold for airborne
sound was estimated to be 81 m, which is less than the distance to the
nearest known haul out site 3 km away (Kilisut Harbor spit). Although
there are no pinniped haul-out sites near the project area, animals
could be exposed when swimming at the surface with their heads above
the water; however, the airborne sound harassment zone is smaller than
and encompassed by the underwater sound harassment zones for both
vibratory and impact pile driving.
Table 2--Distances to Harassment Thresholds (Vibratory Hammer)
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Sound levels (rms)
Pile type and size Hammer type ------------------------------------------------------
190 dB 180 dB 160 dB 120 dB
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Timber (removal).................. Vibratory............ n/a n/a n/a 2.2 km (1.4 miles).
24-inch steel (removal)........... Vibratory............ n/a n/a n/a 4 km (2.4 miles).
24-inch steel (install)........... Vibratory............ n/a n/a n/a 6.3 km (3.9 miles).
30-inch steel (removal)........... Vibratory............ n/a n/a n/a 18.5 km (15.6
miles).
30-inch steel (install)........... Vibratory............ n/a n/a n/a 39.8 km (24.7
miles).
80-inch steel (install)........... Vibratory............ n/a n/a n/a 50 km (31 miles).
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Table 3--Distances to Harassment Thresholds Without Mitigation (Impact Hammer)
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Sound levels (rms)
Pile type and size Hammer type --------------------------------------
190 dB 180 dB 160 dB
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30-inch steel............................. Impact....................... 5 m 22 m 465 m
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Comments and Responses
We published a notice of receipt of the Navy's application and
proposed IHA in the Federal Register on July 3, 2012 (77 FR 39471).
During the 30-day comment period, NMFS received a letter from the
Marine Mammal Commission (Commission) and a letter from a member of the
public. The letter from a member of the public did not contain
substantive comments. The comments from the Commission, and our
responses, are provided here. All measures proposed in the initial
Federal Register notice are included within the authorization and NMFS
has determined that they will effect the least practicable impact on
the species or stocks and their habitats.
Comment 1: The Commission recommends that we require WSF to
implement ramp-up procedures after 15 minutes if pile-driving or -
removal activities were delayed or shut down because of the presence of
a marine mammal within or approaching the exclusion zone and observers
did not see that marine mammal leave the zone.
Response: We disagree with this recommendation. The Commission
cites several reasons why marine mammals may remain in the exclusion
zone after shutdown and yet be undetected by observers during the 15
minute clearance period (e.g., perception and availability bias). While
this is possible in theory, we find it extremely unlikely that an
animal could remain undetected in such a small zone and under typical
conditions in Port Townsend Bay. The exclusion zone has a 22 m radial
distance, and typical observation conditions in Port Townsend Bay are
excellent. We believe the possibility of a marine mammal remaining
undetected in the exclusion zone, in relatively shallow water, for
greater than 15 minutes is discountable. A requirement to implement
ramp-up after every shutdown or delay less than 30 minutes in duration
would be impracticable, resulting in significant construction delays
and therefore extending the overall time required for the project, and
thus the number of days during which disturbance of marine mammals
could occur.
Comment 2: The Commission recommends that we require WSF to monitor
before, during, and after all ramp-ups of vibratory and impact pile
driving to gather the data needed to determine the effectiveness of
this technique as a mitigation measure.
Response: We disagree that WSF needs to monitor for marine mammals
before, during, and after all ramp-ups. Protected species observers
will be on-site and monitoring for marine mammals at least 30 minutes
prior to, during, and after all impact driving (including during ramp-
ups) and at least two full days per week during all vibratory pile
driving. We believe that monitoring for all impact driving and at least
two days per week of vibratory pile driving days per week will allow
for adequate data collection and interpretation of how marine mammals
are behaving in response to pile driving, including during ramp-ups.
Comment 3: The Commission recommends that we require WSF to monitor
the Level A and B harassment zones to detect the presence and
characterize the behavior of marine mammals during all pile-driving and
[[Page 69801]]
removal activities that use a vibratory or impact hammer.
Response: As stated in the proposed IHA, marine mammal monitoring
will occur 30 minutes before, during, and 30 minutes after all impact
pile driving activities. In addition, at least two NMFS-approved
protected species observers will conduct behavioral monitoring out to
1,900 m during all vibratory pile driving for the first two weeks of
activity to validate take estimates and evaluate the behavioral impacts
pile driving has on marine mammals out to the Level B harassment
isopleth. NMFS believes this is an adequate effort of monitoring
because sounds from vibratory pile driving will not exceed the Level A
harassment threshold and sounds from impact pile driving only exceed
the Level A harassment threshold 22 m from the source.
Description of Marine Mammals in the Area of the Specified Activity
Due to Port Townsend's location on the boundary between two inland
water regions, 11 marine mammal species may occur at some time of year
in the vicinity of the ferry terminal: Harbor porpoise, Dall's
porpoise, Pacific white-sided dolphin, killer whale, gray, whale,
humpback whale, minke whale, Pacific harbor seal, California sea lion,
northern elephant seal, and Steller sea lion. The Steller sea lion,
Southern Resident killer whale, and humpback whale are the only marine
mammals that may occur in the vicinity of the ferry terminal that are
listed under the ESA; the Southern Resident killer whale and humpback
whale are listed as endangered and the eastern distinct population
segment (DPS) of Steller sea lion is listed as threatened. All marine
mammal species are protected under the MMPA. The Federal Register
notice (77 FR 39471, July 3, 2012) summarizes the population status and
abundance of these species and provides detailed life history
information.
Potential Effects of the Specified Activity on Marine Mammals
Impact and vibratory pile driving are the construction activities
associated with the proposed action with the potential to take marine
mammals. Elevated in-water sound levels from pile driving in the
proposed project area may temporarily impact marine mammal behavior.
However, elevated in-air sound levels are not expected to affect marine
mammals because the nearest pinniped haul-out is approximately 3 km
away and the zone of harassment for airborne sound is encompassed
within the zones of harassment for underwater sound. The Federal
Register notice (77 FR 39471, July 3, 2012) provides a detailed
description of marine mammal hearing and of the potential effects of
these construction activities on marine mammals.
Anticipated Effects on Habitat
The proposed activities at the Port Townsend ferry terminal would
not result in permanent impacts to habitats used directly by marine
mammals, such as haul-out sites, but may have potential short-term
impacts to food sources such as forage fish and salmonids. There are no
rookeries or major haul-out sites within 3 km, foraging hotspots, or
other bottom features of significant biological importance to marine
mammals that may be present in the vicinity of the project area.
Therefore, the main impact issue associated with the proposed activity
would be temporarily elevated sound levels and the associated direct
effects on marine mammals, as discussed previously in this document.
The most likely impact to marine mammal habitat occurs from the effects
of pile removal and installation on likely marine mammal prey (i.e.,
fish) near the ferry terminal and minor impacts to the immediate
substrate during removal and installation of piles during the transfer
span replacement project. In addition, removal of the 40 creosote-
treated wood piles from the marine environment will have long-term
benefits due to improvements in water and sediment quality. The Federal
Register notice (77 FR 39471, July 3, 2012) describes these potential
impacts in greater detail.
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must, where applicable, set forth the permissible methods of
taking pursuant to such activity, and other means of effecting the
least practicable adverse 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 (where relevant).
The applicant will implement the following mitigation measures to
minimize adverse impacts to marine mammals:
Temporal Restrictions
The Washington Department of Fish and Wildlife recommends an in-
water work window of July 16 through February 15, annually. This work
window was designed to avoid in-water work when ESA-listed salmonids
are most likely to be present, but may also be beneficial to marine
mammals that prey on salmon. Actual construction activities will take
place from November 12, 2012, through February 15, 2013, which ensures
that these activities do not coincide with salmonid use of the action
area. The daily construction work window for in-water work will begin
no sooner than 30 minutes after sunrise and will end at sunset (or
shortly after sunset) when visibility decreases to the point where
effective marine mammal monitoring is no longer possible.
Use of Noise Attenuation During Pile Driving With Impact Hammer
To the extent possible, a vibratory hammer would be used to drive
all piles. It is anticipated that an impact hammer will be necessary to
``proof'' five 30-inch hollow steel piles. During impact pile driving,
a bubble curtain will be used as an attenuation device to reduce
hydroacoustic sound levels and avoid the potential for injury. In the
event that hydroacoustic monitoring during in-water construction
activities involving impact pile driving indicates that the proper
attenuation is not being achieved, the proposed harassment and
exclusion zones (described next) will be modified to account for the
reduced attenuation.
Establishment of an Exclusion Zone
During impact pile driving, WSF will establish a marine mammal
exclusion zone of 22 m around each pile to avoid exposure to sounds at
or above 180 dB. The 190 dB (pinniped) injury isopleth is contained
within the 22 m exclusion zone. The exclusion zone will be monitored
during all impact pile driving to ensure that no marine mammals enter
the 22 m radius. The purpose of this area is to prevent Level A
harassment (injury) of any marine mammal species. Typically, an
exclusion zone for vibratory pile driving is unnecessary to prevent
Level A harassment, as source levels would not exceed the Level A
harassment threshold; however, in response to a recommendation from the
Marine Mammal Commission, a 5 m exclusion zone will be established
during vibratory pile driving of the two 80-inch piles.
Pile Driving Shut Down and Delay Procedures
Monitoring will be initiated 30 minutes prior to the commencement
of pile driving activities. If a protected species observer sees a
marine mammal within or approaching the exclusion zone prior to start
of impact pile driving, the observer will notify the on-site
construction manager (or other
[[Page 69802]]
authorized individual), who will then be required to delay pile driving
until the marine mammal has moved outside of the exclusion zone or if
the animal has not been resighted within 15 minutes. If a marine mammal
is sighted within or on a path toward the exclusion zone during pile
driving, pile driving will cease until that animal has cleared and is
on a path away from the exclusion zone or 15 minutes has lapsed since
the last sighting.
Soft-Start Procedures
A ``soft-start'' technique will be used at the beginning of each
day's pile installation or removal, or if installation or removal has
ceased for more than one hour, to allow any marine mammal that may be
in the immediate area to leave before the pile hammer reaches full
energy. For vibratory pile driving, the soft-start procedure requires
contractors to initiate noise from the vibratory hammer for 15 seconds
at 40-60 percent reduced energy followed by a 1-minute waiting period.
The procedure will be repeated two additional times before full energy
may be achieved. For impact hammering, contractors will be required to
provide an initial set of three strikes from the impact hammer at 40
percent energy, followed by a 1-minute waiting period, then two
subsequent three-strike sets.
In-Water Pile Driving Weather Delays
Should environmental conditions (e.g., fog, high sea state, poor
lighting) obscure the harassment zone, pile driving will be suspended
until visibility returns.
NMFS has carefully evaluated the applicant's proposed mitigation
measures and considered a range of other measures in the context of
ensuring that NMFS prescribes the means of effecting the least
practicable adverse impact on the affected marine mammal species and
stocks and their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another: (1)
The manner in which, and the degree to which, the successful
implementation of the measure is expected to minimize adverse impacts
to marine mammals; (2) the proven or likely efficacy of the specific
measure to minimize adverse impacts as planned; and (3) the
practicability of the measure for applicant implementation, including
consideration of personnel safety, and practicality of implementation.
Based on our evaluation of the applicant's proposed measures, NMFS
has determined that the proposed mitigation measures provide the means
of effecting the least practicable adverse impacts on marine mammals
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, where applicable, 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 IHAs 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.
WSF has developed a monitoring plan that includes monitoring the
harassment and exclusion zones during pile driving and collecting
sighting data for each marine mammal species observed during in-water
construction activities. To implement this plan, qualified marine
mammals observers will be on-site at all times during pile removal and
installation. WSF must designate at least one biologically-trained, on-
site individual, approved in advance by NMFS, to monitor the area for
marine mammals 30 minutes before, during, and 20 minutes after all
impact pile driving activities and call for shut down if any marine
mammal is observed within or approaching the designated exclusion zone
(preliminarily set at 22 m for impact pile driving and 5 m for
vibratory installation of the 80-inch piles). In addition, at least two
NMFS-approved protected species observers would conduct behavioral
monitoring at least two days per week to estimate take and evaluate the
behavioral impacts pile driving has on marine mammals out to the Level
B harassment isopleths. Note that for impact hammering, this distance
is about 465 m. For vibratory hammering, this estimated distance is
about 6.8 km. Protected species observers will be provided with the
equipment necessary to effectively monitor for marine mammals (for
example, high-quality binoculars, spotting scopes, compass, and range-
finder) in order to determine if animals have entered into the
exclusion zone or Level B harassment isopleth and to record species,
behaviors, and responses to pile driving.
WSF will also conduct acoustic monitoring during vibratory pile
installation of 24-inch and 80-inch steel piles. Acoustic monitoring
during timber pile removal and installation and removal of 30-inch
steel piles will not be conducted because data from these activities
was collected in 2010 during the Port Townsend test pile driving
project (Laughlin, 2010; Stockham et al., 2010) and during a 2010
dolphin replacement project in Port Townsend.
Protected species observers will be required to submit a report to
NMFS within 120 days of expiration of the IHA or completion of pile
driving, whichever comes first. The report would include data from
marine mammal sightings (such as species, group size, and behavior),
any observed reactions to construction, distance to operating pile
hammer, and construction activities occurring at time of sighting.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here, 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].
All anticipated takes will be by Level B harassment, involving
temporary, short-term modifications of behavior by small numbers of
marine mammals within the action area. Marine mammals may also
temporarily avoid the area during construction. The planned mitigation
and monitoring measures are expected to avoid injurious or lethal takes
such that take by Level A harassment, serious injury or mortality is
considered remote.
If a marine mammal responds to an underwater sound by changing its
behavior (e.g., through relatively minor changes in locomotion
direction/speed or vocalization behavior), the response may or may not
constitute taking at the individual level, and is typically unlikely to
affect the stock or the species as a whole. However, if a sound source
displaces marine mammals from an important feeding or breeding area for
a prolonged period, impacts on animals or on the stock or species could
potentially be significant (Lusseau and Bejder, 2007; Weilgart, 2007).
Given the many uncertainties in predicting the quantity and types
of impacts of sound on marine mammals, it is common practice to
estimate take based on how many animals are likely to be present within
a particular distance of a given activity, or exposed
[[Page 69803]]
to a particular level of sound. Typically, potential takes are
estimated by multiplying the ensonified area by the local marine mammal
densities of the species that may occur within that zone. There are no
density estimates for any Puget Sound population of marine mammals. As
a result, for this IHA, takes were estimated using local marine mammal
data sets (e.g., Orca Network, state and federal agencies), opinions
from state and federal agencies, and incidental observations from WSF
biologists. For example, between 1990 and 2005, an average of 1.75
killer whale groups were reported in the quadrant that includes Port
Townsend, with most sightings occurring between September and December,
and March. On the basis of that information, an estimated amount of
potential takes for killer whales is presented here. However, while a
pod of killer whales could potentially visit again during the project
timeframe, and thus be taken, it is more likely that they would not.
The project area is not believed to be particularly important
habitat for marine mammals, although harbor seals are year-round
residents and have a known haul-out site within 3 km of Port Townsend
(haul-out sites for other pinniped species are located at a distance of
7 km or greater from the project site). Therefore, behavioral
disturbances that could result from anthropogenic sound associated with
the proposed activities are expected to affect only a relatively small
number of individual marine mammals, although those effects could be
recurring if the same individuals remain in the project vicinity.
WSF requested authorization for the potential taking of small
numbers of Steller sea lions, California sea lions, harbor seals,
northern elephant seals, killer whales, Dall's porpoises, harbor
porpoises, Pacific white-sided dolphins, gray whales, humpback whales,
and minke whales in Port Townsend Bay and Admiralty Inlet that may
result from pile removal and installation during construction
activities associated with the transfer span replacement project
described previously in this document. Based on comments received from
the Marine Mammal Commission, the takes requested for harbor seals,
California sea lions, Steller sea lions, and harbor porpoise have been
corrected to account for the number of days during which the activity
will occur instead of the number of hours extrapolated to days. The
corrected numbers are reflected in the following paragraphs. The takes
requested are expected to have no more than a minor effect on
individual animals and no effect at the population level for these
species. Any effects experienced by individual marine mammals are
anticipated to be limited to short-term disturbance of normal behavior
or temporary displacement of animals near the source of the sound.
Current NMFS practice regarding exposure of marine mammals to
anthropogenic noise is that in order to avoid the potential for injury
(PTS), cetaceans and pinnipeds should not be exposed to impulsive
sounds of 180 and 190 dB or above, respectively. This level is
considered precautionary as it is likely that more intense sounds would
be required before injury would actually occur (Southall et al., 2007).
Potential for behavioral harassment (Level B) is considered to have
occurred when marine mammals are exposed to sounds at or above 160 dB
for impulse sounds (such as impact pile driving) and 120 dB for non-
pulse noise (such as vibratory pile driving), but below the
aforementioned thresholds. These levels are also considered
precautionary.
Based on empirical measurements taken by WSDOT and Caltrans (which
are presented in the Description of Specified Activities section
above), estimated distances to NMFS' current harassment threshold sound
levels from pile driving during the proposed construction activities
are presented in Table 4. The 22 m distance to the Level A harassment
threshold and the establishment of a 5 m exclusion zone for vibratory
installation of the 80-inch piles provides protected species observers
a reasonably sized area to monitor during impact pile driving.
Monitoring these zones and implementing mitigation measures will
prevent marine mammals from being exposed to sound levels that reach
the Level A harassment threshold.
Table 4--Distances to NMFS' Marine Mammal Harassment Thresholds (Without Attenuation)
----------------------------------------------------------------------------------------------------------------
Level B Level B
Level A (190/180 dB) harassment harassment
(160 dB) (120 dB)
----------------------------------------------------------------------------------------------------------------
Impact hammering.............................. 22 m............................ 465 m n/a
Vibratory hammering........................... 5 m (80-inch piles only)........ n/a 6.8 km
----------------------------------------------------------------------------------------------------------------
For each of the 11 marine mammal species that may occur within the
proposed action area, incidental take was determined by estimating the
likelihood of a marine mammal being present with the Zone of Influence
(ZOI) during pile driving activities (Table 5). Typically, incidental
take is estimated by multiplying the area of the ZOI by the local
animal density. This provides an estimate of the number of animals that
might occupy the ZOI at any time; however, there are no density
estimates for marine mammal populations in Puget Sound. Therefore, the
take requests were estimated using local marine mammal data sets (e.g.,
Orca Network, state and federal agencies), opinions from state and
federal agencies, and incidental observations from WSF biologists.
Expected marine mammal presence was determined by past observation and
general abundance near the Port Townsend ferry terminal during the
construction work window. Distances to the applicable NMFS thresholds
for Level A and Level B harassment take for each type of pile
(vibratory and impact) were presented in Section 1.6.6 in the IHA
application. These distances were used to calculate the various ZOIs or
area ensonified by sounds at or greater than threshold. For example,
for the Level A threshold, the estimated distance to the 180 dB
isopleth was 22 m for impact pile driving, which equates to a 1,520
square meter ZOI. The distance to the 160 dB isopleths during impact
pile driving was estimated at 465 m, which equates to a 0.45 square km
(only half the area is water). The distance to the 120 dB threshold for
vibratory pile driving was estimated at 6.8 km, which equates to a ZOI
of approximately 42 square km in water. Both of these areas will be
monitored during construction to report actual marine mammal takes by
Level B harassment.
[[Page 69804]]
Table 5--Population Abundance Estimates, Total Authorized Take, and the Percentage of the Population or Stock
That May Be Exposed to Sounds Resulting in Level B Harassment During the Proposed Ferry Terminal Replacement
Project
----------------------------------------------------------------------------------------------------------------
Percentage of
Species Abundance Take population or
authorization stock
----------------------------------------------------------------------------------------------------------------
Gray Whale...................................................... 20,000 2 0.01
Humpback Whale.................................................. 1,100 2 0.18
Minke Whale..................................................... 1,000 2 0.2
Killer Whale (Transient)........................................ 314 3 1
Killer Whale (Southern Resident)................................ 86 27 31
Harbor Porpoise................................................. 10,682 306 2.8
Dall's Porpoise................................................. 57,000 9 0.02
Pacific White-sided Dolphin..................................... 25,233 10 0.04
Harbor Seal..................................................... 14,612 180 1.2
California Sea Lion............................................. 238,000 108 0.04
Northern Elephant Seal.......................................... 101,000 5 0.005
Steller Sea Lion (eastern DPS).................................. 48,500 90 0.19
----------------------------------------------------------------------------------------------------------------
Airborne noises can affect pinnipeds, especially resting seals
hauled out on rocks or sand spits. The airborne 90 dB Level B threshold
for hauled out harbor seals was estimated at 81 m, and the airborne 100
dB Level B threshold for other pinnipeds was estimated at 17 m. No
haulout sites are within the disturbance threshold distances; the
nearest harbor seal haulout is approximately 3 km from the ferry
terminal. In addition, the airborne noise harassment ZOI is smaller
than both the impact and vibratory hammer underwater noise harassment
ZOIs, and therefore is encompassed in the underwater noise take
estimates.
Surveys conducted during the fall/winter of 2009/2010 by biologists
contracted by the Snohomish Public Utility District recorded about 10
harbor seals per day (Tollit et al., 2010). The applicant estimates
that the total number of pile driving and removal hours would not
exceed 18 eight-hour work days; therefore, the estimated number of
seals that could be harassed would be 180. The survey conducted by
Tollit et al. (2010) also recorded sightings of California sea lions
passing Admiralty Head (located directly across Admiralty Inlet from
Port Townsend) and reported six animals over the course of 88 days
between October 2009 and February 2010. Similarly, the Washington
Department of Fish and Wildlife recorded eight California sea lions in
Admiralty Inlet during vessel-based surveys in Puget Sound between 1992
and 2004. Based on the results from these surveys, WSF estimates that
up to six California sea lions could enter the 160 dB harassment zone
per day, or a total of 108 during the 18 eight-hour work days that
would involve in-water pile installation and removal activities. These
surveys did not, however, report any sightings of northern elephant
seals in Admiralty Inlet. Wintering elephant seals haul out on
Protection Island, which is 12 km to the west of Port Townsend, and
Smith and Minor Islands 24 km to the north, but may forage as far south
as Admiralty Inlet. Therefore, it is possible that elephant seals could
enter Port Townsend Bay during the proposed activity at the ferry
terminal, and WSF believes that a couple northern elephant seals could
be exposed to sound from pile driving and removal activities each day,
especially since they are capable of spending prolonged periods below
the water where they cannot be detected. Based on these considerations,
WSF requests a total of 5 northern elephant seal takes by Level B
harassment during the three eight-hour work days that involve pile
driving and removal. Among pinnipeds, Steller sea lions are relatively
common in Admiralty Inlet during the winter as they move between the
Strait of Juan de Fuca and Puget Sound; hauling out at Craven Rock east
of Marrowstone Island, or on channel buoys. The survey conducted by
Tollit et al. (2010) recorded nearly 800 Steller sea lions over 88
days, or about 9 Steller sea lions per day. Considering that pile
driving activities are expected to take about 18 work days to complete,
WSF estimates that 90 Steller sea lions could be exposed to sound
resulting in Level B harassment.
Take estimates for cetaceans also relied on recent survey data
because density estimates for the inland waters of Washington are not
available. Harbor porpoises are frequently observed in Admiralty Inlet,
Tollit et al. (2010) recorded over 1,500 harbor porpoises during 88
survey days between October 2009 and February 2010, or approximately 17
per day. WSF estimates that pile driving activities will take about 18
work days to complete; therefore, approximately 306 harbor porpoises
may be exposed to sound levels resulting in Level B harassment during
this period. The survey by Tollit et al. (2010) did not positively
identify any Dall's porpoises, and their preference for deeper waters
and spatial distribution in Puget Sound make it unlikely that Dall's
porpoises transiting through Admiralty Inlet would regularly enter the
shallow waters of Port Townsend Bay; however, it is possible for Dall's
porpoises to approach close enough to the proposed pile-driving
activity to be exposed to sound resulting in Level B harassment.
Therefore, based on an average winter group size of three animals
(PSAMP data), WSF estimates that three Dall's porpoise may enter the
Level B harassment zone three times during pile driving activities, and
request a total of nine Dall's porpoise takes by Level B harassment.
The inland distribution of Pacific white-sided dolphins is largely
limited to the Strait of Juan de Fuca and Haro Strait on the west side
of the San Juan Islands. Because these dolphins appear confined to the
deeper channels of the inland waters of Washington State, they may
occur in Admiralty Inlet, but are unlikely to enter the shallower
waters of Port Townsend Bay. In addition, these animals move to warmer
waters in the fall and winter and may be entirely absent from the area
during the proposed ferry terminal replacement project. Without better
evidence on the reports of Pacific white-sided dolphins sighted in
Admiralty Inlet during the winter or on the likelihood of these
dolphins occurring in the vicinity of the ferry terminal, WSF requests
10 takes of Pacific white-sided dolphins by Level B harassment, which
is based on their average group size exposed to one day of pile driving
activity. Similar to Pacific white-sided dolphins, killer
[[Page 69805]]
whales are not expected to be present near Port Townsend during the
proposed fall/winter activity period. Transient killer whale rarely
occur in Puget Sound, and Southern Resident killer whales spend much of
the winter in the vicinity of the Fraser River; however, based on the
unpredictable nature of transient movements and past records of
Southern Resident sightings, it is possible that a pod of killer whales
could pass through Admiralty Inlet and be within the Level B harassment
zone. For example, Tollit et al. (2010) did report three sightings of
Southern Resident killer whales passing Admiralty Head in October 2009,
and one group of transients passed by in December 2009 (neither group
entered Port Townsend Bay). Therefore, WSF requests 30 killer whale
takes by Level B harassment, which equates to one group of three
transients plus the 27 animals that comprise J pod--the Southern
Resident pod most likely to occur in Puget Sound during the proposed
activity period.
The IHA application also requests takes of three species of baleen
whale--gray whale, humpback whale, and minke whale. Gray whales
generally enter the inland waters of Washington from March through May
and sightings during the fall and winter are infrequent. However,
because gray whales that enter Puget Sound tend to localize around
Admiralty Inlet and Possession Sound, the possibility of a gray whale
occurring in the vicinity of Port Townsend Bay during the proposed pile
driving activity cannot be discounted. Therefore, based on the average
gray whale group size, WSF requests two gray whale takes by Level B
harassment. Humpback whales are also occasionally observed in Puget
Sound, but most sightings occur during the summer months and nearly all
recent winter and fall sightings have been confined to the vicinity of
the San Juan Islands. Although humpback whales are not expected in the
vicinity of Port Townsend Bay during the proposed action, the
possibility of a sighting cannot be fully discounted. Based on the
average group size, WSF requests two humpback whale takes by Level B
harassment. Minke whales are also very rare in Puget Sound during the
winter; however, of the few reported sightings in Puget Sound, most
have occurred in the vicinity of Admiralty Inlet. Given the rarity of
these animals in winter, WSF only anticipates that minke whales would
make an occasional transit, if any, of Admiralty Inlet during the
proposed activity with the remote possibility of one or two whales
entering Port Townsend Bay. Therefore, based on these considerations,
WSF requests two minke whale takes by Level B harassment.
To summarize, WSF requests, and NMFS authorizes, takes of 180
harbor seals, 108 California sea lions, 5 northern elephant seals, 90
Steller sea lions, 306 harbor porpoises, 9 Dall's porpoises, 10 Pacific
white-sided dolphins, 3 transient killer whales, 27 Southern Resident
killer whales, 2 gray whales, 2 humpback whales, and 2 minke whales.
These numbers do not take the required mitigation measures into
consideration, and are likely overestimates because they represent the
maximum number of animals expected to occur within the Level B
harassment isopleth. The actual number of animals that may be harassed
is likely to be less.
Negligible Impact Determination
NMFS has defined ``negligible impact'' in 50 CFR 216.103 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.'' In making a negligible impact determination,
NMFS considers a number of factors which include, but are not limited
to, number of anticipated injuries or mortalities (none of which would
be authorized here), number, nature, intensity, and duration of Level B
harassment, and the context in which takes occur.
Marine mammals would not be exposed to activities or sound levels
which would result in injury (PTS), serious injury, or mortality. Pile
driving would occur in shallow coastal waters of Port Townsend Bay. The
action area (waters around the ferry terminal) is not considered
significant feeding or reproductive habitat for pinnipeds. The closest
haul-out is 3 km away, which is outside the project area's largest
harassment zone for airborne noise. Any marine mammals--most likely
pinnipeds--approaching the action area would likely be traveling or
opportunistically foraging.
Marine mammals may be temporarily impacted by pile driving noise.
However, marine mammals are expected to avoid the area to some degree,
thereby potentially reducing exposure and impacts. Pile driving
activities are expected to occur for approximately 4 weeks. Although
marine mammal prey species may be affected by pile driving activities,
any impacts would be short in duration and limited to the immediate
vicinity of the ferry terminal. NMFS expects that any fish that exhibit
behavioral responses (i.e., avoidance) while in-water construction
activities occur would resume normal behavior following the cessation
of the activity. Furthermore, Puget Sound is a highly populated and
industrialized area, so animals are likely tolerant or habituated to
anthropogenic disturbance, including low level vibratory pile driving
operations, and noise from other anthropogenic sources (such as
vessels) may mask construction related sounds. There are no known areas
within Port Townsend Bay where any of these species concentrate
specifically for breeding or feeding. Based on all the information
considered, there is no anticipated effect on annual rates of
recruitment or survival of affected marine mammals. Accordingly, the
activity will have a negligible impact on the affected species or
stocks of marine mammals.
Small Numbers Determination
The amount of take WSF requested for each species, and NMFS
authorizes, is considered small (less than five percent) relative to
the estimated populations or stocks of 14,612 Pacific harbor seals,
238,000 California sea lions, 101,000 northern elephant seals, 48,500
Steller sea lions, 10,632 harbor porpoises, 57,000 Dall's porpoises,
25,233 Pacific white-sided dolphins, 314 transient killer whales,
20,000 gray whales, 1,100 humpback whales, and 1,000 minke whales.
The request of up to 27 takes of Southern Resident killer whales by
Level B harassment represents a larger percentage (31%) of the
population; this number was estimated because Southern Resident killer
whales travel in large groups. Although killer whales are unlikely to
occur in the vicinity of the ferry terminal during pile driving, if
they were to appear, it may be as a full group or pod, which
necessitates the need for a larger number of takes requested.
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 mitigation and monitoring
measures, NMFS determines that the proposed pile removal and
installation would result in the incidental take of small numbers of
marine mammals, by Level B harassment only, and that the total taking
would have a negligible impact on the affected species or stocks.
[[Page 69806]]
Impact on Availability of Affected Species for Taking for Subsistence
Uses
There are no relevant subsistence uses of marine mammals implicated
by this action.
Endangered Species Act (ESA)
The Southern Resident killer whale and humpback whale are listed as
endangered under the ESA and the eastern distinct population segment
(DPS) of Steller sea lion is currently listed as threatened, but NMFS
has proposed delisting of the eastern DPS (77 FR 23209, April 18,
2012). These species may occur within the action area. NMFS' Office of
Protected Resources initiated formal consultation on the issuance of an
IHA under section 101(a)(5)(A) of the MMPA for the takes of Southern
Resident killer whales, humpback whales, and the eastern DPS of Steller
sea lions. This consultation is complete, with the determination in a
Biological Opinion that the activity is not likely to jeopardize the
continued existence of the eastern DPS of Steller sea lions, Southern
Resident killer whales, and humpback whales. In addition, the activity
will not destroy or adversely modify designated critical habitat for
Southern Resident killer whales.
National Environmental Policy Act (NEPA)
In compliance with the National Environmental Policy Act of 1969
(42 U.S.C. 4321 et seq.), as implemented by the regulations published
by the Council on Environmental Quality (40 CFR parts 1500-1508), and
NOAA Administrative Order 216-6, NMFS prepared an Environmental
Assessment (EA) to consider the direct, indirect, and cumulative
effects to marine mammals and other applicable environmental resources
resulting from issuance of a one-year IHA and the potential issuance of
additional authorizations for incidental harassment for the ongoing
project. NMFS has made a Finding of No Significant Impact (FONSI) and,
therefore, it is not necessary to prepare an environmental impact
statement for the issuance of an IHA to WSF for this activity.
As a result of these determinations, NMFS has issued an IHA to the
WSF to incidentally take marine mammals during in-water construction
activities associated with the Port Townsend ferry terminal transfer
span replacement project in Port Townsend, WA, provided the previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated.
Dated: November 9, 2012.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2012-28345 Filed 11-20-12; 8:45 am]
BILLING CODE 3510-22-P