Rule2023-06300
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to U.S. Navy Construction at Portsmouth Naval Shipyard, Kittery, Maine
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
March 31, 2023
Effective
April 1, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS, upon request from the U.S. Navy (Navy), hereby issues regulations to govern the unintentional taking of marine mammals incidental to construction at the Portsmouth Naval Shipyard in Kittery, Maine, over the course of 5 years (2023-2028). These regulations, which allow for the issuance of a Letter of Authorization (LOA) for the incidental take of marine mammals during the described activities and specified timeframes, prescribe the permissible methods of taking and other means of effecting the least practicable adverse impact on marine mammal species or stocks and their habitat, as well as requirements pertaining to the monitoring and reporting of such taking.
Full Text
<html>
<head>
<title>Federal Register, Volume 88 Issue 62 (Friday, March 31, 2023)</title>
</head>
<body><pre>
[Federal Register Volume 88, Number 62 (Friday, March 31, 2023)]
[Rules and Regulations]
[Pages 19502-19542]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-06300]
[[Page 19501]]
Vol. 88
Friday,
No. 62
March 31, 2023
Part IV
Department of Commerce
-----------------------------------------------------------------------
National Oceanic and Atmospheric Administration
-----------------------------------------------------------------------
50 CFR Part 217
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental
to U.S. Navy Construction at Portsmouth Naval Shipyard, Kittery, Maine;
Final Rule
Federal Register / Vol. 88 , No. 62 / Friday, March 31, 2023 / Rules
and Regulations
[[Page 19502]]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 230321-0081]
RIN 0648-BL78
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to U.S. Navy Construction at Portsmouth Naval Shipyard,
Kittery, Maine
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Final rule; notification of issuance of Letter of
Authorization.
-----------------------------------------------------------------------
SUMMARY: NMFS, upon request from the U.S. Navy (Navy), hereby issues
regulations to govern the unintentional taking of marine mammals
incidental to construction at the Portsmouth Naval Shipyard in Kittery,
Maine, over the course of 5 years (2023-2028). These regulations, which
allow for the issuance of a Letter of Authorization (LOA) for the
incidental take of marine mammals during the described activities and
specified timeframes, prescribe the permissible methods of taking and
other means of effecting the least practicable adverse impact on marine
mammal species or stocks and their habitat, as well as requirements
pertaining to the monitoring and reporting of such taking.
DATES: Effective from April 1, 2023, through March 31, 2028.
ADDRESSES: A copy of the Navy's application and any supporting
documents, as well as a list of the references cited in this document,
may be obtained online at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-construction-portsmouth-naval-shipyard-kittery-maine-0">https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-construction-portsmouth-naval-shipyard-kittery-maine-0</a>. In case of problems accessing these
documents, please call the contact listed below.
FOR FURTHER INFORMATION CONTACT: Reny Tyson Moore, Office of Protected
Resources, NMFS, <a href="/cdn-cgi/l/email-protection#cb829f9be5bfb2b8a4a5e5a6a4a4b9ae8ba5a4aaaae5aca4bd"><span class="__cf_email__" data-cfemail="337a67631d474a405c5d1d5e5c5c4156735d5c52521d545c45">[email protected]</span></a>, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Purpose and Need for Regulatory Action
We received an application from the Navy requesting 5-year
regulations and authorization to take multiple species of marine
mammals. This rule establishes a framework under the authority of the
MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of take by
Level A and Level B harassment of marine mammals incidental to the
Navy's construction activities related to the multifunctional expansion
and modification of Dry Dock 1 at the Portsmouth Naval Shipyard in
Kittery, Maine. Please see the Background section below for definitions
of harassment.
Legal Authority for the Action
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs
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 specified geographical region for up to 5 years if,
after notice and public comment, the agency makes certain findings and
issues regulations that set forth permissible methods of taking
pursuant to that activity and other means of effecting the ``least
practicable adverse impact'' on the affected species or stocks and
their habitat (see the discussion below in the Mitigation section), as
well as monitoring and reporting requirements. Section 101(a)(5)(A) of
the MMPA and the implementing regulations at 50 CFR part 216, subpart I
provide the legal basis for issuing this rule containing 5 year
regulations, and for any subsequent Letters of Authorization (LOAs). As
directed by this legal authority, this rule contains mitigation,
monitoring, and reporting requirements.
Summary of Major Provisions Within the Regulations
Following is a summary of the major provisions of this rule
regarding the Navy's construction activities. These measures include:
<bullet> Required monitoring of the in-water construction areas to
detect the presence of marine mammals before beginning in-water
construction activities;
<bullet> Shutdown of in-water construction activities under certain
circumstances to avoid injury of marine mammals;
<bullet> Soft start for impact pile driving to allow marine mammals
the opportunity to leave the area prior to beginning impact pile
driving at full power; and
<bullet> Implementation of a bubble curtain during rock hammering
and down-the-hole (DTH) cluster drilling to reduce underwater noise
impacts.
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed or, if the taking is limited to harassment, a notice of a
proposed incidental take 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) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
Summary of Request
On May 9, 2022, NMFS received a request from the Navy for
authorization to take marine mammals incidental to construction
activities related to the multifunctional expansion and modification of
Dry Dock 1 at Portsmouth Naval Shipyard in Kittery, Maine. We provided
comments on the application, and the Navy submitted revised versions
and responses to our comments on July 5, 2022, August 15, 2022, August
19, 2022, and August 25, 2022, with the latter version deemed adequate
and complete. On September 1, 2022, we published a notice of receipt of
the Navy's application in the Federal Register (87 FR 53731),
requesting comments and information related to the request. During the
30-day comment period, we received two supportive letters from private
citizens.
On October 19 and 25, 2022, NMFS was notified by the Navy of
project modifications and shifting Fleet submarine schedules that
required the resequencing of certain activities associated with the
construction at Dry Dock 1 in order to accommodate the modifications
and meet the new vessel docking demands. On October 31, 2022, the Navy
submitted an addendum to its
[[Page 19503]]
application describing these changes. We published a notice of the
proposed rulemaking in the Federal Register on January 18, 2023 (88 FR
3146) incorporating these changes and requested comments and
information from the public. Please see Comments and Responses below.
The regulations are valid for 5 years, from April 1, 2023 through March
31, 2028, and authorize the Navy to take five species of marine mammals
by Level A and Level B harassment incidental to construction activities
related to the multifunctional expansion and modification of Dry Dock 1
at the Portsmouth Naval Shipyard in Kittery, Maine. Neither the Navy
nor NMFS expect serious injury or mortality to result from this
activity.
NMFS previously issued five IHAs to the Navy for waterfront
improvement work at the Portsmouth Naval Shipyard: in 2016 (81 FR
85525, November 28, 2016), 2018 (83 FR 3318, January 24, 2018), 2019
(84 FR 24476, May 28, 2019), a renewal of the 2019 IHA (86 FR 14598,
March 17, 2021), and in 2022 (87 FR 19886, April 6, 2022). The most
recent IHA (87 FR 19886) provided authorization to take marine mammals
during the first year of the construction project described in this
final rule. As required, the applicant provided monitoring reports
(available at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>)
which confirm that the applicant has implemented the required
mitigation and monitoring, and which also shows that no impacts of a
scale or nature not previously analyzed or authorized have occurred as
a result of the activities conducted.
Description of the Specified Activity
Overview
Multifunctional Expansion of Dry Dock 1 (P-381) is one of three
projects that support the overall expansion and modification of Dry
Dock 1, located in the western extent of the Portsmouth Naval Shipyard.
The two additional projects, construction of a super flood basin (P-
310) and extension of portal crane rail and utilities (P-1074), are
currently under construction. In-water work associated with these
projects was completed under the aforementioned separate IHAs issued by
NMFS. The projects have been phased to support Navy mission schedules.
P-381 will be constructed within the same footprint of the super flood
basin over an approximate 7-year period, during which 5 years of in-
water work will occur. An IHA was issued by NMFS for the first year of
P-381 construction activities between April 1, 2022 and March 31, 2023
(87 FR 19866, April 6, 2022). This request is associated with the
remaining 4 years of P-381 in-water construction activities planned to
occur from April 1, 2023 through March 31, 2028, as well as for
additional in-water construction activities associated with the removal
of emergency repair components of the super flood basin that will occur
during the period of effectiveness for the regulations. Although the
in-water construction described in this rule is anticipated to be
completed by December 2026, unanticipated schedule delays could result
in the Navy conducting construction activity over the full 5 years.
The purpose of the Navy's project (P-381) is to modify the super
flood basin to create two additional dry docking positions (Dry Dock 1
North and Dry Dock 1 West) in front of the existing Dry Dock 1 East.
The Navy's specified activity also includes emergency repairs of the P-
310 super flood basin. Construction activities will include the
excavation and/or installation of 1,118 holes, 198 shafts, and 580
sheet piles via impact and vibratory pile driving, hydraulic rock
hammering, rotary drilling, and mono and cluster DTH. The construction
activities are expected to require approximately 2,498 days if the
activities are considered independently over the 5-year period.
However, the actual construction duration is expected to be within 4
years as many of the construction activities will occur concurrently.
Dates and Duration
The in-water construction activities associated with this rule are
anticipated to begin in April 2023 and proceed to December 2026 (4
years); however, the incidental take authorization is valid for 5 years
in the event of unexpected scheduled delays. In-water construction
activities will occur consecutively over a 4-year period. The Navy
plans to conduct all in-water work activities with expected potential
for incidental harassment of marine mammals during daylight hours.
Table 1 provides the estimated schedule and production rates for P-
381 construction activities. Many of the activities included in Table 1
will span across multiple construction years and/or will occur
concurrently. Because of mission requirements and operational schedules
at the dry docking positions and berths, this schedule is subject to
change. In-water construction activities for P-381 will occur
consecutively over a 4-year period. Note, for the purposes of this
analysis, the construction years are identified as years 2 through 5;
Year 1 of the Navy's construction activities is currently ongoing in
association with a previously issued IHA (87 FR 19886, April 6, 2022).
Vibratory pile driving and extraction is assumed to occur for 141 days.
Impact pile driving will occur for 34 days. DTH excavation (mono-hammer
and cluster drill) will occur for 1,446 days. Rotary drilling will
occur for 238 days (assuming that casings and sockets for cluster
drills will be set, excavated, and removed in a single day). Rock
hammering will occur for 277 days. Note that pile driving days are not
necessarily consecutive, and certain activities may occur at the same
time, decreasing the total number of actual in-water construction days.
The contractor could be working in more than one area of the berths at
a time.
Table 1--In-Water Construction Activities
----------------------------------------------------------------------------------------------------------------
Total amount and
Activity estimated dates Activity Daily production Total
ID Activity (construction component Method rate production
years *) days
----------------------------------------------------------------------------------------------------------------
A1 \1\.... Center Wall-- Drill 18 shafts Install 102-inch Rotary drill.... 1 shaft/day 1 \4\ 18
Install Apr 23 \3\ to diameter outer hour/day.
Foundation Aug 23 (2). casing.
Support Piles.
A2 \1\.... Pre-drill 102- Rotary drill.... 1 shaft/day 9 \4\ 18
inch diameter hours/day.
socket.
A3 \1\.... Remove 102-inch Rotary drill.... 1 casing/day 15 \4\ 18
outer casing. minutes/casing.
A4 \1\.... Drill 78-inch Cluster drill 6.5 days/shaft \4\ 117
diameter shaft. DTH. 10 hours/day.
R \1\..... Dry Dock 1 North Install 48 sheet 28-inch wide Z- Impact with 8 sheets/day 5 \4\ 6
Entrance--Insta piles Apr 23 shaped sheets. initial minutes and 300
ll Temporary \3\ to May 23 vibratory set. blows/pile.
Cofferdam. (2).
[[Page 19504]]
1......... Berth 11--Remove Remove 112 Concrete shutter Hydraulic rock 5 hours/day..... \4\ 56
Shutter Panels. panels Apr 23 panels. hammering.
\3\ to May 23
(2).
2......... Berth 1--Remove Remove 168 sheet 25-inch-wide Z- Vibratory 4 piles/day..... \4\ 42
Sheet Piles. piles Apr 23 shaped. extraction.
\3\ to Jun 24
(2, 3).
3......... Berth 1--Remove 2,800 cubic Removal of Hydraulic rock 2.5 hours/day... \4\ 47
Granite Block yards (cy) Apr granite blocks. hammering.
Quay Wall. 23 \3\ to Jun
24 (2, 3).
4......... Berth 1--Top of 320 linear feet Mechanical Hydraulic rock 10 hours/day.... \4\ 74
Wall Removal (lf) Apr 23 \3\ concrete hammering.
for Waler to Jun 24 (2, removal.
Installation. 3).
5......... Berth 1--Install Install 28 sheet 28-inch-wide Z- Impact with 4 piles/day 5 \4\ 8
southeast piles Apr 23 to shaped. initial minutes/pile
corner Support Jul 23 (2). vibratory set. and 300 blows/
of Excavation pile.
(SOE).
6......... Berth 11-- 700 cy Apr 23 Excavate Bedrock Hydraulic rock 12 hours/day.... \3\ \4\ 60
Mechanical Rock \3\ to Aug 23 hammering.
Removal at (2).
Basin Floor.
7......... Berth 11 Face-- Drill 924 relief 4-6 inch DTH mono-hammer. 27 holes/day 22 \4\ 35
Mechanical Rock holes Apr 23 diameter holes. min/hole.
Removal at \3\ to Aug 23
Basin Floor. (2).
8......... Install Install 14 sheet 28-inch-wide Z- Impact with 4 piles/day 5 4
Temporary piles Apr 23 to shaped. initial minutes/pile
Cofferdam Jun 23 (2). vibratory set. and 300 blows/
Extension. pile.
9a........ Gantry Crane Drill 16 shafts Set 102-inch Rotary drill.... 1 shaft/day 1 16
Support Piles Apr 23 to Aug diameter casing. hours/day.
at Berth 1 West. 23 (2).
9b........ Pre-drill 102- Rotary drill.... 1 shaft/day 9 16
inch rock hours/day.
socket.
9c........ Remove 102-inch Rotary drill.... 1 casing/day 15 16
casing. minutes/casing.
9d........ 72-inch diameter Cluster drill 5 days/shaft 10 80
shafts. DTH. hours/day.
10 \2\.... Berth 1-- 300 cy Apr 23 Excavate Bedrock Hydraulic rock 13 cy/day 12 \5\ 25
Mechanical Rock \3\ to Sep 23 hammering. hours/day.
Removal at (2).
Basin Floor.
11........ Dry Dock 1 North Drill 50 rock 9-inch diameter DTH mono-hammer. 2 holes/day 5 \4\ 25
Entrance--Drill anchors Apr 23 holes. hours/hole.
Tremie Tie \3\ to Oct 23
Downs. (2).
12........ Center Wall-- Install 15 sheet 28-inch wide Z- Impact with 4 piles/day 5 4
Install Tie-In piles Apr 23 to shaped. initial minutes/pile
to Existing Dec 23 (2). vibratory set. and 300 blows/
West Closure pile.
Wall.
13a....... Dry Dock 1 Drill 20 shafts Set 102-inch Rotary drill.... 1 shaft/day 1 20
North--Temporar May 23 to Nov diameter casing. hours/day.
y Work Trestle 24 (2, 3).
Piles.
13b....... Pre-drill 102- Rotary drill.... 1 shaft/day 9 20
inch rock hours/day.
socket.
13c....... Remove 102-inch Rotary drill.... 1 casing/day 15 20
casing. minutes/casing.
13d....... 84-inch diameter Cluster drill 3.5 days/shaft 70
shafts. DTH. 10 hours/day.
14........ Dry Dock 1 Remove 20 piles 84-inch diameter Rotary drill.... 1 day/pile 15 20
North--Remove May 23 to Nov drill piles. minutes/pile.
Temporary Work 24 (2, 3).
Trestle Piles.
15a....... Dry Dock 1 Drill 18 shafts Set 84-inch Rotary drill.... 1 shaft/day 1 18
North--Install May 23 to Nov casing. hours/day.
Leveling Piles 24 (2, 3).
(Diving Board
Shafts).
15b....... Pre-drill 84- Rotary drill.... 1 shaft/day 9 18
inch rock hours/day.
socket.
15c....... Remove 84-inch Rotary drill.... 1 casing/day 15 18
casing. minutes/casing.
15d....... 78-inch diameter Cluster drill 7.5 days/shaft 135
shaft. DTH. 10 hours/day.
16a....... Wall Support Drill 20 shafts Set 102-inch Rotary drill.... 1 shaft/day 1 20
Shafts for Dry Jun 23 to Nov diameter casing. hours/day.
Dock 1 North 24 (2, 3).
(Berth 11 Face
and Head Wall).
16b....... Pre-drill 102- Rotary drill.... 1 shaft/day 9 20
inch rock hours/day.
socket.
16c....... Remove 102-inch Rotary drill.... 1 casing/day 15 20
casing. minutes/casing.
16d....... Drill 78-inch Cluster drill 7.5 days/shaft 150
diameter shaft. DTH. 10 hours/day.
17a....... Foundation Drill 23 shafts Set 126-inch Rotary drill.... 1 shaft/day 1 23
(Floor) Shafts Jun 23 to Nov diameter Casing. hours/day.
for Dry Dock 1 24 (Const.
North years 2, 3).
(Foundation
Support Piles).
17b....... Pre-drill 126- Rotary drill.... 1 shaft/day 9 23
inch rock hours/day.
socket.
17c....... Remove 126-inch Rotary drill.... 1 casing/day 60 23
casing. minutes/casing.
17d....... Drill 108-inch Cluster drill 8.5 days/shaft 196
diameter shafts. DTH. 10 hours/day.
18........ Berth 11 End Remove 60 sheet 28-inch wide Z- Vibratory 8 piles/day 5 \5\ 10
Wall--Remove piles Jul 23 to shaped. extraction. minutes/pile.
Temporary Guide Aug 23 (2, 3).
Wall.
19........ Remove Berth 1 Remove 28 sheet 28-inch-wide Z- Vibratory 8 piles/day 5 \4\ 5
southeast piles Jul 23 to shaped. extraction. minutes/pile.
corner SOE. Sep 23 (2).
[[Page 19505]]
20 \2\.... Removal of Berth Remove 108 sheet 28-inch-wide Z- Vibratory 6 piles/day 5 18
1 Emergency piles Apr 23 shaped. extraction. minutes/pile.
Repair Sheet \3\ to Jul 23
Piles. (2).
21 \2\.... Removal of Berth 500 cy Apr 23 Mechanical Hydraulic rock 4 hours/day..... 15
1 Emergency \3\ to Aug 23 concrete hammering.
Repair Tremie (2). removal.
Concrete.
22........ Center Wall Install 72 rock 9-inch diameter DTH mono-hammer. 2 holes/day 5 36
Foundation--Dri anchors Aug 23 holes. hours/hole.
ll in Monolith to May 24 (2,
Tie Downs. 3).
23........ Center Wall-- Remove 16 sheet 28-inch-wide Z- Vibratory 8 piles/day 5 \5\ 3
Remove Tie-In piles \6\ Aug shaped. extraction. minutes/pile.
to Existing 23 to Aug 24
West Closure (2, 3).
Wall (Dry Dock
1 North) \4\.
24........ Center Wall Install 23 sheet 28-inch wide Z- Impact with 2 piles/day 5 12
East--Sheet piles Aug 23 to shaped. initial minutes/pile
Pile Tie-In to Oct 24 (2, 3). vibratory set. and 300 blows/
Existing Wall. pile.
25........ Remove Tie-In to Remove 15 sheet 28-inch wide Z- Vibratory 8 piles/day 5 \5\ 3
West Closure pile Dec 23 to shaped. extraction. minutes/pile.
Wall (Dry Dock Dec 24 (2, 3).
1 West).
26........ Remove Center Remove 23 sheet 28-inch wide Z- Vibratory 8 piles/day 5 \5\ 12
Wall East-- piles Dec 23 to shaped. extraction. minutes/pile.
Sheet Pile Tie- Dec 24 (2, 3).
In to Existing
Wall (Dry Dock
1 West).
27........ Dry Dock 1 North Remove 96 sheet 28-inch wide Z- Vibratory 8 piles/day 5 12
Entrance--Remov piles Jan 24 to shaped. extraction. minutes/pile.
e Temporary Sep 24 (Const.
Cofferdam. years 2, 3).
28........ Remove Temporary Remove 14 sheet 28-inch wide Z- Vibratory 8 piles/day 5 2
Cofferdam piles Jan 24 to shaped. extraction. minutes/pile.
Extension. Sep 24 (2, 3).
29a....... Dry Dock 1 West-- Drill 20 shafts Set 102-inch Rotary drill.... 1 shaft/day 1 20
Install Apr 24 to Feb diameter casing. hours/day.
Temporary Work 26 (3, 4).
Trestle Piles.
29b....... Pre-drill 102- Rotary drill.... 1 shaft/day 9 20
inch rock hours/day.
socket.
29c....... Remove 102-inch Rotary drill.... 1 casing/day 15 20
casing. minutes/casing.
29d....... 84-inch diameter Cluster drill 3.5 days/shaft 70
shafts. DTH. 10 hours/day.
30........ Dry Dock 1 West-- Remove 20 piles 84-inch diameter Rotary drill.... 1 day/pile 15 20
Remove Apr 24 to Feb piles. minutes/pile.
Temporary Work 26 (3, 4).
Trestle Piles.
31a....... Wall Support Drill 22 shafts Set 102-inch Rotary drill.... 1 shaft/day 1 22
Shafts for Dry Jun 24 to Feb diameter casing. hours/day.
Dock 1 West 26 (3, 4).
(Berth 1 Face).
31b....... Pre-drill 102- Rotary drill.... 1 shaft/day 9 22
inch rock hours/day.
socket.
31c....... Remove 102-inch Rotary drill.... 1 casing/day 15 22
casing. minutes/casing.
31d....... 78-inch diameter Cluster drill 7.5 days/shaft 165
shaft. DTH. 10 hours/day.
32a....... Foundation Drill 23 shafts Set 126-inch Rotary drill.... 1 shaft/day 1 23
(Floor) Shafts Jun 24 to Feb casing. hours/day.
for Dry Dock 1 26 (3, 4).
West
(Foundation
Support Piles).
32b....... Pre-drill 126- Rotary drill.... 1 shaft/day 9 23
inch rock hours/day.
socket.
32c....... Remove 126-inch Rotary drill.... 1 casing/day 15 23
casing. minutes/casing.
32d....... Drill 108-inch Cluster drill 8.5 days/shaft 196
diameter shaft. DTH. 10 hours/day.
33a....... Dry Dock 1 West-- Drill 18 shafts Set 84-inch Rotary Drill.... 1 shaft/day 1 18
Install Jun 24 to Feb casing. hours/day.
Leveling Piles 26 (3, 4).
(Diving Board
Shafts).
33b....... Pre-drill 84- Rotary drill.... 1 shaft/day 9 18
inch rock hours/day.
socket.
33c....... Remove 84-inch Rotary drill.... 1 casing/day 15 18
casing. minutes/casing.
33d....... Drill 78-inch Cluster drill 7.5 days/shaft 135
diameter shaft. DTH. 10 hours/day.
34........ Dry Dock 1 Install 36 rock 9-inch diameter DTH mono-hammer. 2 holes/day 5 18
North--Tie anchors Jul 24 holes. hours/hole.
Downs. to Jul 25 (3,
4).
35........ Dry Dock 1 West-- Install 36 rock 9-inch diameter DTH mono-hammer. 2 holes/day 5 18
Install Tie anchors Dec 25 hole. hours/hole.
Downs. to Dec 26 (4,
5).
----------------------------------------------------------------------------------------------------------------
Total excavated holes/ 1,118/198/580... ................ ................ ................ 2,498
drilled shafts/sheet piles.
----------------------------------------------------------------------------------------------------------------
* Note: for the purposes of this analysis, the construction years are identified as years 2 through 5; potential
marine mammal takes incidental to Year 1 of the Navy's construction activities were authorized under a
previously issued IHA (87 FR 19886, April 6, 2022).
\1\ These activities were not included in the original application made available for public review during the
Notice of Receipt comment period (NOR; 87 FR 53731), but have been added due to changes needed in the
construction schedule.
\2\ These activities were included in the original application, but the amount of activity has been modified due
to changes needed in the construction schedule.
\3\ These activities began in construction year 1.
\4\ These activities began in year 1. Only the number of production days occurring in construction years 2
through 6 are presented.
\5\ Additional production days are included to account for equipment repositioning.
\6\ Sheet piles were installed in construction year 1.
[[Page 19506]]
Specific Geographic Region
The shipyard is located in the Piscataqua River in Kittery, Maine.
The Piscataqua River originates at the boundary of Dover, New
Hampshire, and Eliot, Maine (Figure 1). The river flows in a
southeasterly direction for 2,093 meters (m) (13 miles (mi)) before
entering Portsmouth Harbor and emptying into the Atlantic Ocean. The
lower Piscataqua River is part of the Great Bay Estuary system and
varies in width and depth. Many large and small islands break up the
straight-line flow of the river as it continues toward the Atlantic
Ocean. Seavey Island, the location of the specified activities, is
located in the lower Piscataqua River approximately 500 m, 1,640 feet
(ft) from its southwest bank, 200 m (656 ft) from its north bank, and
approximately 4 kilometers (km) (2.5 mi) from the mouth of the river.
Water depths in the project area range from 6.4 m (21 ft) to 11.9 m
(39 ft) at Berths 11, 12, and 13. Water depths in the lower Piscataqua
River near the project area range from 4.6 m (15 ft) in the shallowest
areas to 21 m (69 ft) in the deepest areas. The river is approximately
914 m (3,300 ft) wide near the project area, measured from the Kittery
shoreline north of Wattlebury Island to the Portsmouth shoreline west
of Peirce Island. The furthest direct line of sight from the project
area is 1,287 m (0.8 mi) to the southeast and 418 m (0.26 mi) to the
northwest.
The nearshore environment of the Shipyard is characterized by a mix
of hard bottom, gravel, soft sediments, rock outcrops, and rocky
shoreline associated with fast tidal currents near the installation.
The nearshore areas surrounding Seavey Island are predominately hard
bottom (65 percent of benthic habitat) and gravel (26 percent) habitat,
with only 9 percent soft bottom sediments within the surveyed area
around Seavey Island (Tetra Tech, 2016). Much of the shoreline in the
project area is composed of hard shores (rocky intertidal). In general,
rocky intertidal areas consist of bedrock that alternates between
marine and terrestrial habitats, depending on the tide. Rocky
intertidal areas consist of ``bedrock, stones, or boulders that singly
or in combination cover 75 percent or more of an area that is covered
less than 30 percent by vegetation'' (Federal Geographic Data
Committee, 2013).
The lower Piscataqua River is home to Portsmouth Harbor and is used
by commercial, recreational, and military vessels. Between 150 and 250
commercial shipping vessels transit the lower Piscataqua River each
year (Magnusson et al., 2012). Commercial fishing vessels are also very
common in the river year-round, as are recreational vessels, which are
more common in the warmer summer months. The shipyard is a dynamic
industrial facility situated on an island with a narrow separation of
waterways between the installation and the communities of Kittery and
Portsmouth (Figure 2). The predominant noise sources from Shipyard
industrial operations consist of dry dock cranes; passing vessels; and
industrial equipment (e.g., forklifts, loaders, rigs, vacuums, fans,
dust collectors, blower belts, heating, air conditioning, and
ventilation (HVAC) units, water pumps, and exhaust tubes and lids).
Other components such as construction, vessel ground support equipment
for maintenance purposes, vessel traffic across the Piscataqua River,
and vehicle traffic on the shipyard's bridges and on local roads in
Kittery and Portsmouth produce noise, but such noise generally
represents a transitory contribution to the average noise level
environment (Blue Ridge Research and Consulting (BRRC), 2015; ESS
Group, 2015). Ambient sound levels recorded at the shipyard are
considered typical of a large outdoor industrial facility and vary
widely in space and time (ESS Group, 2015).
BILLING CODE 3510-22-P
[[Page 19507]]
[GRAPHIC] [TIFF OMITTED] TR31MR23.000
[[Page 19508]]
[GRAPHIC] [TIFF OMITTED] TR31MR23.001
BILLING CODE 3510-22-C
[[Page 19509]]
Detailed Description of the Specified Activity
The Navy's P-381 project will modify the super flood basin to
create two additional dry docking positions (Dry Dock 1 North and Dry
Dock 1 West) in front of the existing Dry Dock 1 East. The super flood
basin provides the starting point for the P-381 work. Several steps are
required to convert the super flood basin to a dry dock with two
positions fully capable of supporting the maintenance of submarines
while maintaining access to the existing interior dry dock (Dry Dock 1
East). The dry dock positions (including the center wall) will be
constructed using large precast segments (referred to as monoliths)
that require both sidewall and base support. The monoliths will be
manufactured offsite and transported to the construction site. Segments
will be floated and/or lifted into place to create the center wall,
followed by Dry Dock 1 North, and finally Dry Dock 1 West. Once the
monoliths are set and grouted in place, the respective dry docks can be
dewatered allowing the remaining interior construction to be performed
in dry conditions.
P-381 years 2 through 5 (i.e., the time period of the Navy's
specified activity for this rule) construction activities will complete
bedrock removal and the preparation of the walls and floors of the
super flood basin to support the placement of the monoliths and the
construction of the two dry dock positions. Most of the in-water
construction will occur behind the existing super flood basin walls
that will act as a barrier to sound and will contain underwater noise
to within a small portion of the Piscataqua River. However, the west
closure wall will be removed in order to install the Dry Dock 1 North
entrance structure and caisson. In addition, the caissons may not
always be in place throughout in-water construction. As such, the
analyses presented herein conservatively assume the west closure wall,
as well as the future caissons, will not be present throughout in-water
construction activities.
The Navy's request also considers emergency repairs of the P-310
super flood basin. During P-310 super flood testing in January 2022,
excessive exfiltration (i.e., transport of material outside of the
basin) was observed along Berths 1 and 2 and between the west closure
wall and super flood basin entrance structure. Emergency structural
repairs were required to reduce excessive transport of material through
the berths and west closure wall/entrance structure and prevent further
damage. As a result, 216 28-inch Z-shaped sheet piles were installed
along the Berth 1 face. After installation, these sheet piles were cut
off approximately 3 m (10 ft) above the mudline and concrete was tremie
placed behind them to plug any gaps in the existing structure that
contributed to the exfiltration. The removal of these 216 Berth 1
emergency repair piles and excess tremie concrete (approximately 382
cubic meters, 500 cubic yards (cy)) will be completed during this LOA
period and are accounted for in the Navy's request. Similarly, 10 28-
inch wide, Z-shaped sheet piles were installed between the super flood
basin entrance structure and the west closure wall, cut off
approximately 3 m (10 ft) above the mudline, and had concrete tremie
placed behind them. These 10 sheet piles will be removed during the P-
381 year 1 IHA period (covered under the IHA issued by NMFS for the
first year of P-381 construction activities; 87 FR 19866, April 6,
2022).
Several additional preparatory activities (e.g., torch cutting,
dredging, etc.) will not create noise expected to result in harassment
of marine mammals. Noise created during dredging of sediment and
demolition debris (e.g., bedrock, granite blocks, concrete) is unlikely
to exceed that generated by other normal shipyard activities and is not
expected to result in incidental take of marine mammals. Activities
such as grouting (i.e., pouring of concrete) and torch cutting are not
noisy by design and will not result in incidental take of marine
mammals. These activities are not addressed in the analyses of noise
producing actions in the Navy's request, and are not considered by NMFS
in our analysis, but are included in the work descriptions to clarify
the construction progression.
P-381 In-Water Construction Activities
The work remaining for P-381 can be generally grouped into five
categories for ease of explanation: temporary structures, mechanical
bedrock removal, continued demolition of super flood basin wall
components, center wall tie-downs, and dry dock foundation and gantry
crane support. Each category involves one or more activities expected
to generate noise that could result in injury or harassment of marine
mammals. Some of these activities are a continuation of work started in
year 1, which were covered under a separate IHA issued by NMFS on April
6, 2022 (87 FR 19886).
Temporary Structures--Several temporary structures will be
installed and removed to facilitate the construction of the dry docks.
The conversion of the existing west closure wall to the Dry Dock 1
North entrance requires reinforcement of the section of the west
closure wall that will become the new dry dock entrance. The existing
west closure wall structure will be surrounded by a temporary
cofferdam. The cofferdam will be constructed with 48 28-inch wide, Z-
shaped sheet piles. The sheet piles will be installed using an initial
vibratory set followed by driving with impact hammers to refusal.
The temporary guide wall along the Berth 11 end wall installed
during year 1 (60 28-inch wide, Z-shaped sheet piles) will be removed
with a vibratory hammer. An extension to the temporary cofferdam around
the Dry Dock 1 entrance structure installed during P-381 year 1 will
also be constructed. The extension will consist of 14 28-inch wide, Z-
shaped sheet piles. The extension and the cofferdam (96 28-inch wide,
Z-shaped sheet piles) will be removed in 2024 using a vibratory hammer.
A temporary work trestle will be constructed to support the
excavation of large shafts within the individual dry docking positions.
The trestle will be installed in Dry Dock 1 North first and then
relocated to Dry Dock 1 West. The trestle system will be supported by 4
84-inch steel pipe piles and will be relocated five times within each
dry dock. As a result, the piles will be installed and removed 20 times
in Dry Dock 1 North and 20 times in Dry Dock 1 West. The piles will be
installed with a cluster drill consisting of multiple DTH hammers and
removed with a rotary drill. Before the cluster drill will be deployed,
a 102-inch casing will be set into bedrock and a 5-ft (1.5-m) deep rock
socket will be excavated with a rotary drill (see Figure 1-4 in the
Navy's application). The socket will be filled with concrete and a
second, 84-inch casing will be installed inside the larger casing and
set in the concrete. No drilling will be required to install the second
casing. The outer casing will then be removed with a rotary drill. The
84-inch diameter cluster drill will operate independently inside the
second casing to excavate the shaft. Once the shaft is drilled the
inner casing will be removed by torch cutting.
A temporary tie-in consisting of 15 28-inch wide, Z-shaped sheet
piles will be installed between the center wall foundation and the west
closure wall at Dry Dock 1 West. Twenty-three 28-inch wide, Z-shaped
sheet piles will also be installed on the easterly end of Dry Dock 1
West to provide a similar temporary tie-in to the center wall
foundation near the entrance to Dry
[[Page 19510]]
Dock 1 East. The sheet piles will be installed using an initial
vibratory set followed by driving with impact hammers. These tie-ins
will be removed using a vibratory hammer along with the Dry Dock 1
North tie-in to the west closure wall (16 28-inch wide, Z-shaped sheet
piles) that was installed under the P-381 year 1 IHA (87 FR 19886).
To support excavation activities along Berth 1, 28 28-inch wide, Z-
shaped sheet piles will be installed at the southeast corner of the
berth using a combination of vibratory and impact hammers. These piles
will be removed using a vibratory hammer.
Mechanical Bedrock Removal--Mechanical removal of bedrock will be
completed by the end of 2023 using various methods appropriate for the
removal location and as needed to avoid damage to adjacent structures.
Bedrock removal will occur along the Berth 11 face and abutment and
along Berth 1.
Bedrock will be removed by breaking it up with a hydraulic hammer
(i.e., hoe ram or breaker). To protect adjacent structures during
mechanical bedrock removal, 924 4-6-inch diameter relief holes will be
drilled using a DTH mono-hammer. A total of approximately 918 cubic
meters (1,200 cy) of bedrock are anticipated to be removed.
Demolition of Super Flood Basin Wall Components--Demolition of
existing wall components will include the removal of shutter panels,
granite quay walls, sheet piles, and concrete making up the super flood
basin. Demolition of existing wall structures will be conducted using a
rock hammer. Specifically, the remaining sections of the existing
concrete shutter panels making up the face of Berth 11 (112 panels),
portions of the granite block quay wall (2,141 cm, 2,800 cy) at Berth
1, and the remaining existing sheet pile wall at Berth 1 (168 25-inch
wide, Z-shaped sheet piles) will be removed.
The installation of a structural support waler (steel beam) at
Berth 1 will also be completed. To complete the installation of the
waler, about 98 m (320 linear ft) of concrete wall will be demolished
using a hydraulic rock hammer.
Center Wall Tie-downs--Additional work in the center wall area will
involve the installation of support tie downs for future tremie
concrete work. The tie downs require the placement of a total of 194
rock anchors requiring 9-inch diameter holes. The rock anchors will be
installed using a DTH mono-hammer.
Dry Dock and Gantry Crane Support--The location of the future
center wall requires reinforcement to allow placement of the large pre-
cast monolith structures forming the separation between the two new dry
docking positions. Specifically, the floor of the existing basin must
be able to provide an adequate foundation for the pre-cast monoliths
that will make up the dry dock interiors and center wall. The basin
floor will be reinforced by excavating 18 78-inch diameter shafts
throughout the footprint of the center wall that will be filled with
concrete to create the structural support piles for the center wall.
The shafts will be excavated using a cluster drill consisting of
multiple DTH mono-hammers. Before the cluster drill is deployed, a 102-
inch diameter casing will be set into bedrock and a 1.5 m (5 ft) deep
rock socket will be excavated using a 102-inch diameter rotary drill
(see Figure 1-4 of the Navy's application). The rock socket will be
filled with concrete and a second, 78-inch diameter casing will be
installed inside the 102-inch casing and set in the concrete. No
drilling is required to install the second casing. The 102-inch
diameter outer casing will then be removed with a rotary drill.
The future Dry Dock 1 North and Dry Dock 1 West require significant
structural reinforcement to provide an adequate foundation for the
installation of the large pre-cast monolith structures forming the dry
dock interior. Reinforcement of the individual dry dock foundations and
walls will begin first at Dry Dock 1 North and, once completed,
continue at Dry Dock 1 West. Twenty 78-inch diameter shafts will be
excavated along the Berth 11 face and head wall to support the walls of
Dry Dock 1 North. Along the floor of Dry Dock 1 North, 23 108-inch
diameter shafts will be excavated for the installation of the
foundation support piles and 18 78-inch diameter shafts will be
excavated for the installation of leveling piles (i.e., diving board
shafts).
The dry dock foundation and wall support pile and leveling pile
shafts will be filled with concrete to create the support piles for the
dry dock walls and floors. The shafts will be excavated using a cluster
drill consisting of multiple DTH hammers in the same manner as
previously described for the temporary work trestle piles. Once the
wall and foundation support piles and leveling piles for Dry Dock 1
North have been installed, foundation and wall support piles and
leveling piles will be installed for Dry Dock 1 West. Twenty-two 78-
inch diameter shafts will be excavated along the Berth 1 face to
support the walls of Dry Dock 1 West. Twenty-three 108-inch diameter
shafts will be excavated along the floor of Dry Dock 1 West for the
installation of foundation support piles and 18 78-inch shafts will be
excavated for the installation of leveling piles (i.e., diving board
shafts). The casing sizes and rotary drill sizes for each shaft are
specified in Table 1.
The large concrete monolithic sections used to create the dry docks
and the center wall separation will be placed using a gantry crane. The
gantry crane system will be structurally supported by the installation
of 16 72-inch diameter shafts installed along the western extent of the
Berth 1 face. The shafts will be installed using a DTH cluster drill as
described for the temporary work trestle piles. The casing sizes and
rotary drill sizes for the gantry crane support shafts are specified in
Table 1.
P-310 Emergency Repairs
Testing of the super flood basin on January 5, 2022 resulted in
excess exfiltration through Berths 1 and 2, prompting the need for
emergency repairs along Berth 1 as well as between the super flood
basin entrance structure and the west closure wall. Emergency repairs
consisted of the installation of sheet piles and the tremie pouring of
concrete to fill in gaps along the structure walls and floor.
Installation of emergency repairs at Berth 1 and the installation and
removal of emergency repairs at the west closure wall and entrance
structure occurred before the period described in the Navy's LOA
application. Only the removal of Berth 1 emergency repair components
will occur during the requested LOA period.
The removal of the 216 28-inch wide, Z-shaped sheet piles along the
Berth 1 face will be completed through direct pulling via barge-mounted
crane or by vibratory hammer. Specific methods will be determined by
the contractor based on resistance to extraction from the seabed.
Direct pulling via crane is not anticipated to generate harmful levels
of underwater sound. If required, the use of the vibratory hammer to
extract the installed sheet piles will be limited to an initial effort
to break the sheets loose, allowing them to be directly pulled out. As
a conservative measure, vibratory extraction of these sheet piles is
assumed for all analyses.
The removal of 765 cubic meters (1,000 cy) of tremie concrete is
anticipated to require use of a hydraulic rock hammer to break up
material into smaller pieces. Smaller pieces will then be retrieved via
excavator bucket for offsite disposal. The Navy estimates daily active
use of the rock hammer for the removal of concrete from emergency
repairs to be 4 hours per day.
[[Page 19511]]
Means and Methods for Noise Producing Activities
Only 28-inch wide, Z-shaped sheet piles will be installed or
removed with pile-driving equipment during P-381 construction. The
installation of 28-inch wide, Z-shaped steel sheet piles will be
installed initially using vibratory means and then finished with impact
hammers, if necessary. Impact hammers will also be used to push
obstructions out of the way and where sediment conditions do not permit
the efficient use of vibratory hammers. Pile removal activities will
use cranes and vibratory hammers exclusively.
The removal of bedrock and concrete and the demolition of concrete
shutter panels at Berth 11 and granite blocks and sheet piles at Berth
1 during P-381 construction will be by mechanical means. These features
will be demolished using a hydraulic rock hammer (i.e., hoe ram). The
type/size of rock hammers used will be determined by the contractor
selected to perform the work.
Two methods of rock excavation will be used during P-381
construction; DTH excavation and rotary drilling. During P-381
construction, rotary drilling will be used to set the casings and pre-
drill rock sockets for DTH cluster drills. DTH excavation using mono-
hammers will be used to create shafts for rock anchors and tie downs
and for the excavation of relief holes during mechanical bedrock
removal. For the largest shafts (greater than 42-inches in diameter),
DTH excavation will use a cluster drill. A cluster drill uses multiple
mono-hammers within a single bit to efficiently break up bedrock and
create large diameter holes (see Figure 1-5 in the Navy's application).
Concurrent Activities
In order to maintain project schedules, it is likely that multiple
pieces of equipment will operate at the same time within the basin. No
ancillary activities are anticipated during the construction period
that will require unimpeded access to the super flood basin. Therefore,
it is anticipated that there will be space available within the project
area for additional construction equipment. A maximum of 13 pieces of
equipment could potentially operate in the project area at a single
time. While this is an unlikely scenario, it could occur for a very
brief period. Construction equipment will be staged along the perimeter
of the super flood basin (Berth 11, Berth 1 and head wall) as well on
multiple barges within the super flood basin. Table 2 provides a
summary of possible equipment combinations that could be used
simultaneously over the course of the construction period.
Table 2--Summary of Multiple Equipment Scenarios
----------------------------------------------------------------------------------------------------------------
Year Quantity Equipment
----------------------------------------------------------------------------------------------------------------
2023................................... 5 Rock Hammer (2), Vibratory Hammer (2), Impact Hammer
(1).
5 Rock Hammer (2), Vibratory Hammer (1), Impact Hammer
(1), DTH Mono-hammer (1).
5 Rock Hammer (1), Vibratory Hammer (1), Impact Hammer
(1), DTH Mono-hammer (1), Rotary Drill (1).
5 Rock Hammer (1), Vibratory Hammer (1), DTH Mono-hammer
(1), Cluster Drill (2).
5 Cluster Drill (2), Vibratory Hammer (1), Mono-hammer
DTH (1), Rotary Drill (1).
5 Rock Hammer (1), Impact Hammer (1), DTH Mono-hammer
(1), Cluster Drill (2).
6 Rock Hammer (2), DTH Mono-hammer (2), Cluster Drill
(1), Rotary Drill (1).
6 Rock Hammer (2), Vibratory Hammer (1), DTH Mono-hammer
(1), Rotary Drill (2).
8 Rock Hammer (2), Vibratory Hammer (2), DTH Mono-hammer
(2), Cluster Drill (2).
10 Rock Hammer (3), Vibratory Hammer (2), Impact hammer
(1), DTH Mono-hammer (2), Cluster Drill (2).
13 Rock Hammer (5), Cluster Drill (2), Vibratory Hammer
(2), Impact Hammer (1), Mono-hammer DTH (3).
2024................................... 8 Rock Hammer (2), Vibratory Hammer (2), DTH Mono-hammer
(2), Cluster Drill (2).
5 Cluster Drill (2), DTH mono-hammer (1), Vibratory
hammer (1), Impact Hammer (1).
3 Cluster Drill (2), DTH mono-hammer (1).
3 Cluster Drill (1), Rotary Drill (1), DTH mono-hammer
(1).
3 Rotary Drill (2), DTH mono-hammer (1).
2025................................... 3 Cluster Drill (2), DTH mono-hammer (1).
3 Cluster Drill (1), Rotary Drill (1), DTH mono-hammer
(1).
3 Rotary Drill (2), DTH mono-hammer (1).
2 Rotary Drill (2).
2 Cluster Drill (2).
----------------------------------------------------------------------------------------------------------------
Source: 381 Constructors, 2022.
Mitigation, monitoring, and reporting measures are described in
detail later in this document (please see Mitigation and Monitoring and
Reporting).
Comments and Responses
A notice of NMFS' proposed rulemaking to the Navy was published in
the Federal Register on January 18, 2023 (88 FR 3146). That proposed
rule described, in detail, the Navy's activities, the marine mammal
species that may be affected by the activities, and the anticipated
effects on marine mammals. In that proposed rule, we requested public
input on the request for authorization described therein, our analyses,
the proposed authorization, and any other aspect of the notice of
proposed rulemaking, and requested that interested persons submit
relevant information, suggestions, and comments. This proposed rule was
available for a 30-day public comment period.
During the 30-day public comment period, NMFS received no comments.
Changes From the Proposed IHA to Final IHA
No public comments were received during the comment period;
however, NMFS made a few minor clarifications and corrections in this
final rule. In the sections of the documents that refer to the use of a
bubble curtain, it was established that the bubble curtain will be used
in cases where the Level A harassment zone extends to the full region
of influence (ROI). To clarify this further, NMFS adds that this refers
to all rock hammering and DTH cluster drilling. In addition, for bubble
curtains, NMFS clarified that the air flow to the bubblers will be
balanced across the entrance openings to the super flood basin, rather
than the piles. Finally, NMFS removed the mitigation condition
requiring that protected species observers (PSOs) work in shifts
lasting no longer than 4 hours (hrs) with at least
[[Page 19512]]
a 1-hr break between shifts and limiting PSO duties to no more than 12
hrs in a 24-hr period. This is not a required condition for the Navy
for these construction activities, rather it is related to other
activity types, such as offshore seismic surveys, but was accidentally
included. That said, NMFS communicated to the Navy that observers
should be given adequate breaks and work in shifts to reduce observer
fatigue to ensure their ability to best monitor for marine mammals.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, referenced here, instead of reprinting the
information. Additional information regarding population trends and
threats may be found in NMFS' Stock Assessment Reports (SARs;
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS'
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 3 lists all species or stocks for which take is expected and
authorized for this activity, and summarizes information related to the
population or stock, including regulatory status under the MMPA and
Endangered Species Act (ESA) and potential biological removal (PBR),
where known. PBR is defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population (as described in NMFS' SARs). While no
serious injury or mortality is expected to occur, PBR and annual
serious injury and mortality from anthropogenic sources are included
here as gross indicators of the status of the species or stocks and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All stocks managed under the MMPA in this region
are assessed in NMFS' U.S. Atlantic and Gulf of Mexico SARs. All values
presented in Table 3 are the most recent available at the time of
publication (including from the 2022 draft SARs) and are available
online at: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>).
Table 3--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stock abundance Nbest,
ESA/MMPA status; (CV, Nmin, most recent Annual M/
Common name Scientific name MMPA stock strategic (Y/N) abundance survey) \2\ PBR SI \3\
\1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises):
Harbor Porpoise................. Phocoena............... Gulf of Maine/Bay of -; N 95,543 (0.31; 74,034; 851 164
Fundy. 2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... Western North Atlantic. -; N 61,336 (0.08, 57,637; 1,729 339
2018).
Gray seal....................... Halichoerus grypus..... Western North Atlantic. -; N 27,300 \4\ (0.22; 1,389 4,453
22,785; 2016).
Harp seal....................... Pagophilus Western North Atlantic. -; N 7,600,000 426,000 178,573
groenlandicus. (unk,7,100.000, 2019).
Hooded seal..................... Cystophora cristata.... Western North Atlantic. -; N 593,500............... Unknown 1,680
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a> assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable (N.A.).
\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.
\4\ This abundance value and the associated PBR value reflect the US population only. Estimated abundance for the entire Western North Atlantic stock,
including animals in Canada, is 451,600. The annual M/SI estimate is for the entire stock.
As indicated above, all five species (with five managed stocks) in
Table 3 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur.
A detailed description of the species likely to be affected by the
Navy's construction activities, including brief introductions to the
species and relevant stocks as well as available information regarding
population trends and threats, and information regarding local
occurrence, were provided in the Federal Register notice for the
proposed rule (88 FR 3146, January 18, 2023). Since that time, we are
not aware of any changes in the status of these species and stocks;
therefore, detailed descriptions are not provided here. Please refer to
that Federal Register notice for these descriptions. Please also refer
to the NMFS website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) for
generalized species accounts.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings,
[[Page 19513]]
2008). To reflect this, Southall et al. (2007, 2019) recommended that
marine mammals be divided into hearing groups based on directly
measured (behavioral or auditory evoked potential techniques) or
estimated hearing ranges (behavioral response data, anatomical
modeling, etc.). Note that no direct measurements of hearing ability
have been successfully completed for mysticetes (i.e., low-frequency
cetaceans). Subsequently, NMFS (2018a) described generalized hearing
ranges for these marine mammal hearing groups. Generalized hearing
ranges were chosen based on the approximately 65 decibel (dB) threshold
from the normalized composite audiograms, with the exception for lower
limits for low-frequency cetaceans where the lower bound was deemed to
be biologically implausible and the lower bound from Southall et al.
(2007) retained. Marine mammal hearing groups and their associated
hearing ranges are provided in Table 4.
Table 4--Marine Mammal Hearing Groups
[NMFS, 2018a]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
Cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al., 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018a) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from the Navy's construction
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of the
proposed rulemaking (88 FR 3146, January 18, 2023) included a
discussion of the effects of anthropogenic noise on marine mammals and
the potential effects of underwater noise from the Navy's construction
activities on marine mammals and their habitat. That information and
analysis is referenced in this final rule and is not repeated here;
please refer to the notice of the proposed rulemaking (88 FR 3146,
January 18, 2023).
Estimated Take
This section provides an estimate of the number of incidental takes
authorized under the rule, which will inform both NMFS' consideration
of ``small numbers'' and NMFS' negligible impact determinations.
As described previously, no serious injury or mortality is
anticipated or authorized for this activity. Harassment is the only
type of take expected to result from these activities. Except with
respect to certain activities not pertinent here, section 3(18) of the
MMPA defines ``harassment'' as any act of pursuit, torment, or
annoyance, which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild (Level A harassment); or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering (Level B harassment).
Authorized takes will primarily be by Level B harassment, as use of
the acoustic sources (i.e., impact and vibratory pile installation and
removal, rotary drilling, DTH, and rock hammering) has the potential to
result in disruption of behavioral patterns for individual marine
mammals. There is also some potential for auditory injury (Level A
harassment) to result, primarily for high frequency species and/or
phocids because predicted auditory injury zones are larger than for
mid-frequency species and/or otariids. The requirements pertaining to
mitigation and monitoring are expected to minimize the severity of the
taking to the extent practicable. Below we describe how the authorized
take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the estimated take numbers.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur PTS of some degree (equated to Level A
harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict
[[Page 19514]]
(e.g., Southall et al., 2007, 2021; Ellison et al., 2012). Based on
what the available science indicates and the practical need to use a
threshold based on a metric that is both predictable and measurable for
most activities, NMFS typically uses a generalized acoustic threshold
based on received level to estimate the onset of behavioral harassment.
NMFS generally predicts that marine mammals are likely to be
behaviorally harassed in a manner considered to be Level B harassment
when exposed to underwater anthropogenic noise above root-mean-squared
pressure received levels (RMS SPL) of 120 dB (referenced to 1
micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile-
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources. Generally speaking, Level B harassment take
estimates based on these behavioral harassment thresholds are expected
to include any likely takes by TTS as, in most cases, the likelihood of
TTS occurs at distances from the source less than those at which
behavioral harassment is likely. TTS of a sufficient degree can
manifest as behavioral harassment, as reduced hearing sensitivity and
the potential reduced opportunities to detect important signals
(conspecific communication, predators, prey) may result in changes in
behavior patterns that would not otherwise occur.
The Navy's activities include the use of continuous (vibratory pile
driving/removal, rotary drilling) and intermittent (impact pile
driving, rock hammering) sources, and therefore the RMS SPL thresholds
of 120 and 160 dB re 1 [mu]Pa, respectively, are applicable. DTH
systems have both continuous and intermittent components as discussed
in the Description of Sound Sources section in the proposed rule (88 FR
3146, January 18, 2023). When evaluating Level B harassment, NMFS
recommends treating DTH as a continuous source and applying the RMS SPL
thresholds of 120 dB re 1 [mu]Pa (see NMFS recommended guidance on DTH
systems at <a href="https://media.fisheries.noaa.gov/2022-11/PUBLIC%20DTH%20Basic%20Guidance_November%202022.pdf">https://media.fisheries.noaa.gov/2022-11/PUBLIC%20DTH%20Basic%20Guidance_November%202022.pdf</a>; NMFS, 2022).
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(NMFS, 2018a) identifies dual criteria to assess auditory injury (Level
A harassment) to five different marine mammal groups (based on hearing
sensitivity) as a result of exposure to noise from two different types
of sources (impulsive or non-impulsive). The Navy's activities include
the use of impulsive (impact pile driving, rock hammering, DTH) and
non-impulsive (vibratory pile driving/removal, rotary drilling, DTH)
sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI, 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the project. Marine
mammals are expected to be affected via sound generated by the primary
components of the project (i.e., impact pile driving, vibratory pile
driving, vibratory pile removal, rotary drilling, rock hammering, and
DTH).
Sound Source Levels--The intensity of pile driving sounds is
greatly influenced by factors such as the type of piles, hammers, and
the physical environment (e.g., sediment type) in which the activity
takes place. The Navy evaluated sound source level (SL) measurements
available for certain pile types and sizes from similar environments
from other Navy pile driving projects, including from past projects
conducted at the Shipyard, and used them as proxy SLs to determine
reasonable SLs likely to result from the pile driving and drilling
activities in their application. Projects reviewed were those most
similar to the specified activity in terms of drilling and rock
hammering activities, type and size of piles installed, method of pile
installation, and substrate conditions. Some of the proxy source levels
used are expected to be more conservative as compared to what may be
realized by the actual pile driving to take place, as the values are
from larger pile sizes. In some instances, for reasons described below,
NMFS relied on alternative proxy SLs in our evaluation of the impacts
of the Navy's activities on marine mammals (Table 6). Note that the
source levels in Table 6 represent the SPL referenced at a distance of
10 m from the source.
[[Page 19515]]
Table 6--Summary of Unattenuated In-Water Pile Driving Source Levels
----------------------------------------------------------------------------------------------------------------
SELss (dB
Installation Peak SPL RMS SPL (dB re 1 re 1
Pile type method Pile diameter (dB re 1 [mu]Pa) [mu]Pa\2\
[mu]Pa) sec)
----------------------------------------------------------------------------------------------------------------
Casing/Socket................ Rotary Drill.... 126-inch........ NA...... 154 (169 at 1 m)....... NA
102-inch........ NA...... 154 (169 at 1 m)....... NA
84-inch......... NA...... 154 (169 at 1 m)....... NA
Shaft........................ DTH Cluster 108-inch........ NA...... 201.6 \5\ (Level A).... NA
Drill. 174 \6\ (Level B)......
84-inch......... NA...... 196.7 \5\ (Level A).... NA
174 \6\(Level B).......
78-inch......... NA...... 195.2 \5\ (Level A).... 181
174 \6\ (Level B)......
72-inch......... NA...... 193.7 \5\ (Level A).... NA
174 \6\ (Level B)......
Rock anchor.................. DTH mono-hammer. 9-inch.......... 172..... 167.................... 146
Relief hole.................. DTH mono-hammer. 4 to 6-inch..... 170..... \6\ 156................ 144
Z-shaped Sheet............... Impact.......... \1\ 28-inch..... 211..... 196.................... 181
Vibratory....... 28-inch \2\..... NA...... 167.................... 167
Vibratory....... 25-inch \3\..... NA...... 167.................... 167
Bedrock and concrete Rock Hammer \4\. NA.............. 197..... 186 \4\................ \4\ 171
demolition.
----------------------------------------------------------------------------------------------------------------
\1\ An appropriate proxy value for impact driving 28-inch wide, Z-shaped sheet piles is not available, so a
value for 30-inch steel pipe piles was used as a proxy value (NAVFAC SW, 2020 [p. A-4]).
\2\ An appropriate proxy value for vibratory pile driving 28-inch wide, Z-shaped sheet piles is not available,
so a value for 30-inch steel pipe piles was used as a proxy value (Navy, 2015 [p. 14]).
\3\ An appropriate proxy value for vibratory pile driving 25-inch sheet piles is not available, so the value for
28-inch wide, Z-shaped sheet piles was used as a proxy.
\4\ Escude, 2012.
\5\ RMS SPL values were derived from regression and extrapolation calculations of existing data by NMFS.
\6\SPLs vary from those proposed in the Navy's application as the NMFS DTH recommended guidance updated the
source level proxy it recommends for some DTH systems after the Navy's application was deemed adequate and
complete (NMFS, 2022).
Notes: All SPLs are unattenuated and represent the SPL referenced at a distance of 10 m from the source; NA =
Not applicable; single strike SEL are the proxy source levels for impact pile driving used to calculate
distances to PTS; dB re 1 [mu]Pa = decibels (dB) referenced to a pressure of 1 microPascal, measures
underwater SPL.; dB re 1 [mu]Pa\2\-sec = dB referenced to a pressure of 1 microPascal squared per second,
measures underwater SEL.
With regards to the proxy values summarized in Table 6, very little
information is available regarding source levels for in-water rotary
drilling activities. As a conservative measure and to be consistent
with previously issued IHAs for similar projects in the region, a proxy
of 154 dB RMS is used for all rotary drilling activities (Dazey, 2012).
NMFS recommends treating DTH systems as both impulsive and
continuous, non-impulsive sound source types simultaneously. Thus,
impulsive thresholds are used to evaluate Level A harassment, and the
continuous threshold is used to evaluate Level B harassment. The Navy
consulted with NMFS to obtain the appropriate proxy values for DTH
mono- and cluster-hammers. With regards to DTH mono-hammers, NMFS
recommended proxy levels for Level A harassment based on available data
regarding DTH systems of similar sized piles and holes (Table 6) (Denes
et al., 2019; Guan and Miner, 2020; Reyff and Heyvaert, 2019; Reyff,
2020; Heyvaert and Reyff, 2021). No hydroacoustic data exist for
cluster DTH systems; therefore, NMFS recommends proxy values based off
of regression and extrapolation calculations of existing data for mono-
hammers until hydroacoustic data on DTH cluster drills be obtained
(NMFS, 2022). Because of the high number of hammers and strikes for
this system, DTH cluster drills are treated as a continuous sound
source for the time component of Level A harassment (i.e., for the
entire duration DTH cluster drills are operational, they are considered
to be producing strikes, rather than indicating the number of strikes
per second, which is unknown), but still used the impulsive thresholds.
At the time of the Navy's application submission, NMFS recommended
that the RMS SPL at 10 m should be 167 dB when evaluating Level B
harassment (Heyvaert and Reyff, 2021 as cited in NMFS, 2021b) for all
DTH pile/hole sizes. However, since that time, NMFS has received
additional clarifying information regarding DTH data presented in Reyff
and Heyvaert (2019) and Reyff (2020) that allows for different RMS SPL
at 10 m to be recommended for piles/holes of varying diameters (NMFS,
2022). Therefore, the following proxy RMS SPLs at 10 m are used to
evaluate Level B harassment from this sound source in this analysis
(Table 6): 156 dB RMS for the 4 to 6 inch mono hammers (Reyff and
Heyvaert, 2019; Reyff, 2020), 167 dB RMS for the 9 inch mono-hammers
(Heyvaert and Reyff, 2021), and 174 dB RMS for all DTH cluster drills
greater or equal to 74 inches (Reyff and Heyvaert, 2019; Reyff, 2020).
See Footnote 6 in Table 6.
Rock hammering is analyzed as an impulsive noise source. For
purposes of this analysis, it is assumed that the hammer will have a
maximum strike rate of 460 strikes per minute and will operate for a
maximum duration of 15 minutes before needing to reposition or stop to
check progress. Therefore, noise impacts for rock hammering activities
are assessed using the number of blows per 15-minute interval (6,900
blows) and the number of 15-minute intervals anticipated over the
course of the day based on the durations provided in Tables 1, 7, and
8. As with rotary drilling, very little information is available
regarding source levels associated with nearshore rock hammering. In
previous IHAs related to the Shipyard, NMFS relied on preliminary
measurements from the Tappan Zee Bridge replacement project (Reyff,
2018a, 2018b) as well as data from a WSDOT concrete pier demolition
project (Escude, 2012) to inform proxy SLs for rock hammering. However,
a few discrepancies in the preliminary data of the Tappan Zee Bridge
reports have been identified resulting from NMFS' further inspection
into the report's data. Therefore, the SLs reported only from the
Escude (2012) concrete pier demolition project are used as proxy values
for rock hammering activities associated with P-381 (Table 6).
Level B Harassment Zones--Transmission loss (TL) is the decrease in
acoustic intensity as an acoustic pressure wave propagates out from a
source. TL parameters vary with frequency, temperature, sea conditions,
current, source and receiver depth, water depth, water chemistry, and
[[Page 19516]]
bottom composition and topography. The general formula for underwater
TL is:
TL = B * log10 (R1/R2),
Where:
B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. The recommended TL coefficient for most nearshore
environments is the practical spreading value of 15. This value results
in an expected propagation environment that would lie between spherical
and cylindrical spreading loss conditions, which is the most
appropriate assumption for the Navy's activities in the absence of
specific modelling. All Level B harassment isopleths are reported in
Tables 7 and 8 considering RMS SLs.
Level A Harassment Zones--The ensonified area associated with Level
A harassment is more technically challenging to predict due to the need
to account for a duration component. Therefore, NMFS developed an
optional User Spreadsheet tool to accompany the Technical Guidance
(NMFS, 2018a) that can be used to relatively simply predict an isopleth
distance for use in conjunction with marine mammal density or
occurrence to help predict potential takes. We note that because of
some of the assumptions included in the methods underlying this
optional tool, we anticipate that the resulting isopleth estimates are
typically going to be overestimates of some degree, which may result in
an overestimate of potential take by Level A harassment. However, this
optional tool offers the best way to estimate isopleth distances when
more sophisticated modeling methods are not available or practical. For
stationary sources (such as from impact and vibratory pile driving,
drilling, DTH, and rock hammering), the optional User Spreadsheet tool
predicts the distance at which, if a marine mammal remained at that
distance for the duration of the activity, it would be expected to
incur PTS. Inputs used in the User Spreadsheet can be found in Appendix
A of the Navy's application, Appendix A of the Navy's addendum, and the
resulting isopleths are reported in Tables 7 and 8.
Table 7--Calculated Distance and Areas of Level A and Level B Harassment for Impulsive Noise
[DTH, impact pile driving, hydraulic rock hammering]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment \2\ Level B harassment
Total --------------------------------------------------------------
Activity ID Year \1\/activity Purpose Duration, count, production High frequency
size, and or rate days cetaceans (harbor Phocid pinnipeds All species
porpoise)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1............ 2 Hydraulic Rock Shutter Panel 5 hours/day (20 56 5,034.5 m/0.417417 2,261.9 m/0.417417 541.17 m/0.277858
Hammer. Demolition (112 intervals/day at km\2\. km\2\. km\2\.
panels). 15 each).
3............ 2-3 Hydraulic Rock Removal of Granite 2.5 hours/day (10 47 3,171.6 m/0.417417 1,424.9 m/0.417417 541.17 m/0.277858
Hammer. Quay Wall (2,800 intervals/day at km\2\. km\2\. km\2\.
cy). 15 min each).
4............ 2-3 Hydraulic Rock Berth 1 Top of Wall 10 hours/day (40 74 7,991.8 m/0.417417 3,590.5 m/0.417417 541.17 m/0.277858
Hammer. Demolition for intervals/day at km\2\. km\2\. km\2\.
Waler Install (320 15 min each).
lf).
6............ 2 Hydraulic Rock Mechanical Rock 12 hours/day (48 60 9,024.7 m/0.417417 4,054.5 m/0.417417 541.17 m/0.277858
Hammer. Removal (700 cy) intervals/day at km\2\. km\2\. km\2\.
at Berth 11 Basin 15 min each).
Floor.
10........... 2 Hydraulic Rock Mechanical Rock 12 hours/day (48 25 9,024.7 m/0.417417 4,054.5 m/0.417417 541.17 m/0.277858
Hammer. Removal (300 cy) intervals/day at km\2\. km\2\. km\2\.
at Berth 1 Basin 15 min each).
Floor.
21........... 2 Hydraulic Rock Removal of 4 hours/day (16 15 4,388.6 m/0.417417 1,949.2 m/0.417417 541.17 m/0.277858
Hammer. Emergency Repair intervals/day at km\2\. km\2\. km\2\.
Concrete (500 cy) 15 min each).
at Berth 1.
7............ 2 DTH Mono-hammer... Relief Holes at 924 4-6 inch holes 35 178.9 m/0.047675 80.4 m/0.014413 2,512 m/0. 417417
Berth 11 Basin 27 holes/day. km\2\. km\2\. km\2\.
Floor.
11........... 2 DTH Mono-hammer... Dry Dock 1 North 50 9-inch holes 2 25 244.8 m/0.073751 110 m/0.022912 13,594 m/0.417417
entrance Rock holes/day. km\2\. km\2\. km\2\.
Anchors.
22........... 2-3 DTH Mono-hammer. Center Wall 72 9-inch holes 2 36 244.8 m/0.073751 110 m/0.022912 13,594 m/0.417417
Foundation Rock holes/day. km\2\. km\2\. km\2\.
Anchors.
34........... 3-4 DTH Mono-hammer. Dry Dock 1 North 36 9-inch holes 2 18 244.8 m/0.073751 110 m/0.022912 13,594 m/0.417417
Rock Anchors. holes/day. km\2\. km\2\. km\2\.
35........... 4-5 DTH Mono-hammer. Dry Dock 1 West 36 9-inch holes 2 18 244.8 m/0.073751 110 m/0.022912 13,594 m/0. 417417
Rock Anchors. holes/day. km\2\. km\2\. km\2\.
R............ 2 Impact Pile Dry Dock 1 North 48 28-inch Z-shaped 6 1,568.6 m/0.417417 704.7 m/0.364953 2,512 m/0.417417
Driving. Entrance Temporary sheets 8 sheets/ km\2\. km\2\. km\2\.
Cofferdam. day.
5............ 2 Impact Pile Berth 1 Support of 28 28-inch Z-shaped 8 988.2 m/0.403411 444.0 m/0.201158 2,512 m/0.417417
Driving. Excavation. sheets 4 piles/day. km\2\. km\2\. km\2\.
8............ 2 Impact Pile Temporary Cofferdam 14 28-inch Z-shaped 4 988.2 m/0.403411 444.0 m/0.201158 2,512 m/0.417417
Driving. Extension. sheets 4 piles/day. km\2\. km\2\. km\2\.
[[Page 19517]]
12........... 2 Impact Pile Center Wall Tie-in 15 28-inch Z-shaped 4 988.2 m/0.403411 444.0 m/0.201158 2,512 m/0.417417
Driving. to West Closure sheets 4 piles/day. km\2\. km\2\. km\2\.
Wall.
24........... 2-3 Impact Pile Center Wall East 23 28-inch Z-shaped 12 622.5 m/0.334747 279.7 m/0.090757 2,512 m/0.417417
Driving. Tie-in to Existing sheets 2 piles/day. km\2\. km\2\. km\2\.
Wall.
A4........... 2 DTH Cluster Drill. Dry Dock 1 North 18 78-inch shafts 117 84,380.4 m/0.417417 37,909.7 m/0.417417 39,811 m/0.417417
Entrance 10 hours/day 6.5 km\2\. km\2\. km\2\.
Foundation Support days/shaft.
Piles.
9d........... 2 DTH Cluster Drill. Gantry Crane 16 72-inch shafts 80 67,025.7 m/0.417417 30,112.8 m/0.417417 39,811 m/0.417417
Support Piles. 10 hours/day 5 km\2\. km\2\. km\2\.
days/shaft.
13d.......... 2-3 DTH Cluster Dry Dock 1 North 20 84-inch shafts 70 106,228.6 m/ 47,725.5 m/0.417417 39,811 m/0.417417
Drill. Temporary Work 10 hours/day 3.5 0.417417 km\2\. km\2\. km\2\.
Trestle. days/shaft.
15d.......... 2-3 DTH Cluster Dry Dock 1 North 18 78-inch shafts 135 84,380.4 m/0.417417 37,909.7 m/0.417417 39,811 m/0.417417
Drill. Leveling Piles 10 hours/day 7.5 km\2\. km\2\. km\2\.
(Diving Board days/shaft.
Shafts).
16d.......... 2-3 DTH Cluster Wall Shafts for Dry 20 78-inch shafts 150 84,380.4 m/0.417417 37,909.7 m/0.417417 39,811 m/0.417417
Drill. Dock 1 North. 10 hours/day 7.5 km\2\. km\2\. km\2\.
days/shaft.
17d.......... 2-3 DTH Cluster Foundation Shafts 23 108-inch shafts 196 225,376.2 m/ 101,255.2 m/ 39,811 m/0.417417
Drill. for Dry Dock 1 10 hours/day 8.5 0.417417 km\2\. 0.417417 km\2\. km\2\.
North. days/shaft.
29d.......... 3-4 DTH Cluster Dry Dock 1 West 20 84-inch shafts 70 106,228.6 m/ 47,725.5 m/0.417417 39,811 m/0.417417
Drill. Temporary Work 10 hours/day 3.5 0.417417 km\2\. km\2\. km\2\.
Trestle. days/shaft.
31d.......... 3-4 DTH Cluster Wall Shafts for Dry 22 78-inch shafts 165 84,380.4 m/0.417417 37,909.7 m/0.417417 39,811 m/0.417417
Drill. Dock 1 West. 10 hours/day 7.5 km\2\. km\2\. km\2\.
days/shaft.
32d.......... 3-4 DTH Cluster Foundation Shafts 23 108-inch shafts 196 225,376.2 m/ 101,255.2 m/ 39,811 m/0.417417
Drill. for Dry Dock 1 10 hours/day 8.5 0.417417 km\2\. 0.417417 km\2\. km\2\.
West. days/pile.
33d.......... 3-4 DTH Cluster Dry Dock 1 West 18 78-inch shafts 135 84,380.4 m/0.417417 37,909.7 m/0.417417 39,811 m/0.417417
Drill. Leveling Piles 10 hours/day 7.5 km\2\. km\2\. km\2\.
(Diving Board days/pile.
Shafts).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note, for the purposes of this analysis, the construction years are identified as years 2 through 5; takes for marine mammals during Year 1 of the
Navy's construction activities were authorized in a previously issued IHA (87 FR 19886, April 6, 2022).
\2\ To determine underwater harassment zone size, ensonified areas from the source were clipped along the shoreline using Geographical Information
Systems (GIS).
Table 8--Calculated Distance and Areas of Level A and Level B Harassment for Non-Impulsive Noise
[Rotary drilling and vibratory pile driving/extracting]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment \2\ Level B harassment
Duration, count, Total ----------------------------------------------------------------------------
Activity Year \1\/ Purpose size, and or production High frequency
ID activity rate days cetaceans (harbor Phocid pinnipeds All species
porpoise)
--------------------------------------------------------------------------------------------------------------------------------------------------------
R........ 2 Vibratory Pile Dry Dock 1 North 48 28-inch Z- 6 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Driving. Entrance shaped sheets 8
Temporary sheets/day.
Cofferdam.
2........ 2-3 Vibratory Remove Berth 1 168 25-inch Z- 42 12.2 m/0.000454 km\2\ 5.0 m/0.000078 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Sheet Piles. shaped sheets 4
piles/day.
5........ 2 Vibratory Pile Install Berth 1 28 28-inch Z- 8 12.2 m/0.000454 km\2\ 5.0 m/0.000078 km\2\ 13,594 m/0.417417 km\2\.
Driving. Support of shaped sheets 4
Excavation. piles/day.
8........ 2 Vibratory Pile Install 14 28-inch Z- 4 12.2 m/0.000454 km\2\ 5.0 m/0.000078 km\2\ 13,594 m/0.417417 km\2\.
Driving. Temporary shaped sheets 4
Cofferdam piles/day.
Extension.
12....... 2 Vibratory Pile Center Wall Tie- 15 28-inch Z- 4 12.2 m/0.000454 km\2\ 5.0 m/0.000078 km\2\ 13,594 m/0.417417 km\2\.
Driving. In to Existing shaped sheets 4
West Closure piles/day.
Wall.
18....... 2 Vibratory Berth 11 End 60 28-inch Z- 10 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Wall Temporary shaped sheets 8
Guide Wall. piles/day.
19....... 2 Vibratory Remove Berth 1 28 28-inch Z- 5 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Support of shaped sheets 8
Excavation. piles/day.
20....... 2 Vibratory Remove Berth 1 108 28-inch Z- 18 16.0 m/0.000733 km\2\ 6.6 m/0.000136 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Emergency shaped sheets 6
Repairs. piles/day.
[[Page 19518]]
23....... 2-3 Vibratory Dry Dock 1 North- 16 28-inch Z- 3 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Remove Center shaped sheets 8
Wall Tie-in to piles/day.
West Closure
Wall.
24....... 2-3 Vibratory Center Wall East 23 28-inch Z- 12 7.7 m/0.000185 km\2\ 3.2 m/0.000032 km\2\ 13,594 m/0.417417 km\2\.
Pile Driving. Tie-in to shaped sheets 2
Existing Wall. piles/day.
25....... 2-3 Vibratory Dry Dock 1 West 15 28-inch Z- 3 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Remove Center shaped sheets 8
Wall Tie-in to piles/day.
West Closure
Wall.
26....... 2-3 Vibratory Remove Center 23 28-inch Z- 12 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Wall Tie-in to shaped sheets 8
Existing Wall. piles/day.
27....... 2-3 Vibratory Remove Temporary 96 28-inch Z- 12 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Cofferdam. shaped sheets 8
piles/day.
28....... 2-3 Vibratory Remove Temporary 14 28-inch Z- 2 19.4 m/0.001041 km\2\ 8.0 m/0.0002 km\2\ 13,594 m/0.417417 km\2\.
Extraction. Cofferdam shaped sheets 8
Extension. piles/day.
A1....... 2 Rotary Drill.. Dry Dock 1 North 18 102-inch 18 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Entrance borings 1 hour/
Foundation day 1 casing/
Support Piles-- day.
Install Outer
Casing.
A2....... 2 Rotary Drill.. Dry Dock 1 North 18 102-inch 18 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.41747 km\2\.
Entrance borings 9 hours/
Foundation day 1 socket/
Support Piles-- day.
Pre-Drill
Socket.
A3....... 2 Rotary Drill.. Dry Dock 1 North 18 102-inch 18 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Entrance borings 15
Foundation minutes/casing
Support Piles-- 1 casing/day.
Remove Outer
Casing.
9a....... 2 Rotary Drill.. Gantry Crane 16 102-inch 16 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Support--Instal borings 1 hour/
l Outer Casing. day 1 casing/
day.
9b....... 2 Rotary Drill.. Gantry Crane 16 102-inch 16 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Support--Pre- borings 9 hours/
Drill Socket. day 1 socket/
day.
9c....... 2 Rotary Drill.. Gantry Crane 16 102-inch 16 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Support--Remove borings 15
Outer Casing. minutes/casing
1 casing/day.
13a...... 2-3 Rotary Drill Dry Dock 1 North 20 102-inch 20 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Temporary Work borings 1 hour/
Trestle--Instal day 1 casing/
l Outer Casing. day.
13b...... 2-3 Rotary Drill Dry Dock 1 North 20 102-inch 20 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Temporary Work borings 9 hours/
Trestle--Pre- day 1 socket/
Drill Socket. day.
13c...... 2-3 Rotary Drill Dry Dock 1 North 20 102-inch 20 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Temporary Work borings 15
Trestle--Remove minutes/casing
Outer Casing. 1 casing//day.
14....... 2-3 Rotary Drill Remove Dry Dock 20 84-inch 20 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
1 North borings 15
Temporary Work minutes/casing
Trestle Piles. 1 casing/day.
15a...... 2-3 Rotary Drill Dry Dock 1 North 18 84-inch 18 2.1 m/0.000014 km\2\ 1.3 m/0.000005km\2\ 1,848 m/0.417417 km\2\.
Leveling Piles-- borings 1 hour/
Install Outer day 1 casing/
Casing. day.
15b...... 2-3 Rotary Drill Dry Dock 1 North 18 84-inch 18 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Leveling Piles-- borings 9 hours/
Pre-Drill day 1 socket/
Socket. day.
15c...... 2-3 Rotary Drill Dry Dock 1 North 18 84-inch 18 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Leveling Piles-- borings 15
Remove Outer minutes/casing
Casing. 1 casing/day.
16a...... 2-3 Rotary Drill Dry Dock 1 North 20 102-inch 20 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Wall Shafts-- borings 1 hour/
Install Outer day 1 casing/
Casing. day.
16b...... 2-3 Rotary Drill Dry Dock 1 North 20 102-inch 20 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Wall Shafts-- borings 9 hours/
Pre-Drill day 1 socket/
Socket. day.
16c...... 2-3 Rotary Drill Dry Dock 1 North 20 102-inch 20 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Wall Shafts-- borings 15
Remove Outer minutes/casing
Casing. 1 casing/day.
17a...... 2-3 Rotary Drill Dry Dock 1 North 23 126-inch 23 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Foundation borings 1 hour/
Shafts--Install day 1 casing/
Outer Casing. day.
[[Page 19519]]
17b...... 2-3 Rotary Drill Dry Dock 1 North 23 126-inch 23 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Foundation borings 9 hours/
Shafts Pre- day 1 socket/
Drill Sockets. day.
17c...... 2-3 Rotary Drill Dry Dock 1 North 23 126-inch 23 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Foundation borings 15
Shafts--Remove minutes/casing
Outer Casing. 1 casing/day.
29a...... 3-4 Rotary Drill Dry Dock 1 West 20 102-inch 20 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Temporary Work borings 1 hour/
Trestle--Instal day 1 casing/
l Outer Casing. day.
29b...... 3-4 Rotary Drill Dry Dock 1 West 20 102-inch 20 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Temporary Work borings 9 hours/
Trestle--Pre- day 1 socket/
Drill Socket. day.
29c...... 3-4 Rotary Drill Dry Dock 1 West 20 102-inch 20 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Temporary Work borings 15
Trestle--Remove minutes/casing
Outer Casing. 1 casing/day.
30....... 3-4 Rotary Drill Dry Dock 1 West 20 84-inch 20 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Remove borings 15
Temporary Work minutes/pile 1
Trestle Piles. pile/day.
31a...... 3-4 Rotary Drill Dry Dock 1 West 22 102-inch 22 2.1 m/0.000014 km\2\ 1.3 m/0.000005km\2\ 1,848 m/0.417417 km\2\.
Wall Shafts-- borings 1 hour/
Install Outer day 1 casing/
Casing. day.
31b...... 3-4 Rotary Drill Dry Dock 1 West 22 102-inch 22 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Wall Shafts-- borings 9 hours/
Pre-Drill day 1 socket/
Socket. day.
31c...... 3-4 Rotary Drill Dry Dock 1 West 22 102-inch 22 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Wall Shafts-- borings 15
Remove Outer minutes/casing
Casing. 1 casing/day.
32a...... 3-4 Rotary Drill Dry Dock 1 West 23 126-inch 23 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Foundation borings 1 hour/
Shafts--Install day 1 casing/
Outer Casing. day.
32b...... 3-4 Rotary Drill Dry Dock 1 West 23 126-inch 23 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Foundation borings 9 hours/
Shafts Pre- day 1 socket/
Drill Sockets. day.
32c...... 3-4 Rotary Drill Dry Dock 1 West 23 126-inch 23 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Foundation borings 15
Shafts--Remove minutes/casing
Outer Casing. 1 casing/day.
33a...... 3-4 Rotary Drill Dry Dock 1 North 18 84-inch 18 2.1 m/0.000014 km\2\ 1.3 m/0.000005 km\2\ 1,848 m/0.417417 km\2\.
Leveling Piles-- borings 1 hour/
Install Outer day 1 casing/
Casing. day.
33b...... 3-4 Rotary Drill Dry Dock 1 West 18 84-inch 18 8.9 m/0.000248 km\2\ 5.4 m/0.000091 km\2\ 1,848 m/0.417417 km\2\.
Leveling Piles-- borings 9 hours/
Pre-Drill day 1 socket/
Socket. day.
33c...... 3-4 Rotary Drill Dry Dock 1 North 18 84-inch 18 0.8 m/0.000002 km\2\ 0.5 m/0.000001 km\2\ 1,848 m/0.417417 km\2\.
Leveling Piles-- borings 15
Remove Outer minutes/casing
Casing. 1 casing/day.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note, for the purposes of this analysis, the construction years are identified as years 2 through 5; takes for marine mammals during Year 1 of the
Navy's construction activities were authorized in a previously issued IHA (87 FR 19886, April 6, 2022).
\2\ To determine underwater harassment zone size, ensonified areas from the source were clipped along the shoreline using Geographical Information
Systems (GIS).
The calculated maximum distances corresponding to the underwater
marine mammal harassment zones from impulsive (impact pile driving,
rock hammering, DTH) and non-impulsive (vibratory pile driving, rotary
drilling) noise and the area of the harassment zone within the ROI are
summarized in Tables 7 and 8, respectively. Sound source locations were
chosen to model the greatest possible affected areas; typically, these
locations will be at the riverward end of the super flood basin. The
calculated distances do not take the land masses into consideration,
but the ensonified areas do. Neither consider the reduction that will
be achieved by the required use of a bubble curtain and therefore all
take estimates are considered conservative. Refer to Figures 6-1
through 6-20 of the Navy's application for visual representations of
the calculated maximum distances corresponding to the underwater marine
mammal harassment zones from impulsive (impact pile driving, rock
hammering, DTH) and non-impulsive (vibratory pile driving, rotary
drilling) noise and the corresponding area of the harassment zone
within the ROI.
Calculated distances to Level A harassment and Level B harassment
thresholds are large, especially for DTH and rock hammering activities.
However, in most cases the full distance of sound propagation will not
be reached due to the presence of land masses and anthropogenic
structures that will prevent the noise from reaching nearly the full
extent of the harassment isopleths. Refer to Figure 1-3 in the Navy's
application for the ROI, which illustrates that the land masses
preclude the sound from traveling more than approximately 870 m (3,000
ft) from the source, at most. Areas encompassed within the threshold
(harassment zones) were calculated by using a Geographical Information
System (GIS) to clip the maximum calculated distances to the extent of
the ROI (see Figure 2).
[[Page 19520]]
Concurrent Activities--Simultaneous use of pile drivers, hammers,
and drills could result in increased SPLs and harassment zone sizes
given the proximity of the component sites and the rules of decibel
addition (see Table 9 below). Due to the relatively small size of the
ROI, the use of a single DTH cluster drill or rock hammer will ensonify
the entire ROI to the Level A (PTS Onset) harassment thresholds (refer
to Table 7). Therefore, when this equipment is operated in conjunction
with other noise-generating equipment, there will be no change in the
size of the harassment zone. The entire ROI will remain ensonified to
the Level A harassment thresholds for the duration of the activity and
there will be no Level B harassment zone. However, when DTH cluster
drills or rock hammers are not in use, increased SPLs and harassment
zone sizes within the ROI could result. Due to the substantial amount
of rock hammering and DTH excavation required for the construction of
the multifunctional expansion of Dry Dock 1, the only scenarios
identified in which cluster drills and/or rock hammers will not be in
operation will be at the end of the project (construction years 3 and
4) when two rotary drills or two rotary drills and a DTH mono-hammer
(9-inch) could be used simultaneously (refer to Table 2).
When two noise sources have overlapping sound fields, there is
potential for higher sound levels than for non-overlapping sources
because the isopleth of one sound source encompasses the sound source
of another isopleth. In such instances, the sources are considered
additive and combined using the rules of decibel addition, presented in
Table 9 below (NMFS, 2021d; WSDOT, 2020).
Table 9--Adjustments for Sound Exposure Level Criterion
------------------------------------------------------------------------
Adjustments to
Difference in specifications for
Source types sound level (at Level A harassment
specified meters) RMS/SELss*
calculations
------------------------------------------------------------------------
Non-impulsive, continuous/Non- 0 or 1 dB........ Add 3 dB to the
impulsive, continuous, OR highest sound level
(at specified
meters) AND adjust
number of piles per
day to account for
overlap (space and
time).
2 or 3 dB........ Add 2 dB to the
highest sound level
(at specified
meters) AND adjust
number of piles per
day to account for
overlap (space and
time).
Impulsive source (multiple 4 to 9 dB........ Add 1 dB to the
strikes per second)/Impulsive highest sound level
source (multiple strikes per (at specified
second. meters) AND adjust
number of piles per
day to account for
overlap (space and
time).
10 dB or more.... Add 0 dB to the
highest sound level
(at specified
meters) AND adjust
number of piles per
day to account for
overlap (space and
time).
------------------------------------------------------------------------
* RMS level for vibratory pile driving/rotary hammer and single strike
SEL (SELss) level for DTH/rock hammer.
For simultaneous usage of three or more continuous sound sources,
the three overlapping sources with the highest SLs are identified. Of
the three highest SLs, the lower two are combined using the above
rules, then the combination of the lower two is combined with the
highest of the three. For example, with overlapping isopleths from 24-,
36-, and 42-inch diameter steel pipe piles with sound source levels of
161, 167, and 168 dB RMS respectively, the 24- and 36-inch would be
added together; given that 167-161 = 6 dB, then 1 dB is added to the
highest of the two sound source levels (167 dB), for a combined noise
level of 168 dB. Next, the newly calculated 168 dB is added to the 42-
inch steel pile with sound source levels of 168 dB. Since 168-168 = 0
dB, 3 dB is added to the highest value, or 171 dB in total for the
combination of 24-, 36-, and 42-inch steel pipe piles (NMFS, 2021d). By
using this method, revised proxy SPLs were determined for the use of
two 102-inch diameter rotary drills and the use of two 108-inch rotary
drills and one 9-inch DTH mono-hammer. The revised proxy values are
presented in Table 10 and the resulting harassment zones are summarized
in Table 11 (visually depicted in Figures 6-21 and 6-22 in the Navy's
application).
Table 10--Revised Proxy Values for Simultaneous Use of Non-Impulsive Sources
----------------------------------------------------------------------------------------------------------------
Source A Source B
------------------------------------------------------------------------------------------------- Revised proxy
RMS SPL (dB re RMS SPL (dB re RMS SPL (dB re
Equipment 1 [micro]Pa) Equipment 1 [micro]Pa) 1 [micro]Pa)
----------------------------------------------------------------------------------------------------------------
Rotary Drill.......................... 154 Rotary Drill............ 154 157
Two Rotary Drills..................... 157 DTH Mono-Hammer......... 167 167
----------------------------------------------------------------------------------------------------------------
Table 11--Level A and Level B Harassment Zones Resulting From Concurrent Activities
----------------------------------------------------------------------------------------------------------------
Level A harassment Level B harassment
--------------------------------------------------------------------------
Multiple source scenario High frequency
cetaceans (harbor Phocid pinnipeds All species
porpoise)
----------------------------------------------------------------------------------------------------------------
2 Rotary Drills (9 hrs).............. 23.6 m/0.001514 km\2\.. 9.7 m/0.000294 km\2\... 2,929 m/0.417417 km\2\.
2 Rotary Drills (9 hrs) and 1 DTH 74.2 m/0.012773 km\2\.. 30.5 m/0.002489 km\2\.. 13,594 m/0.417417
Mono-Hammer (5 hrs). km\2\.
----------------------------------------------------------------------------------------------------------------
[[Page 19521]]
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information, that
inform the take calculations. We also describe how the information
provided above is synthesized to produce a quantitative estimate of the
take that is reasonably likely to occur.
Potential exposures to impact and vibratory pile driving, rotary
drilling, DTH, and rock hammering noise for each acoustic threshold
were estimated using marine mammal density estimates (N) from the Navy
Marine Species Density Database (NMSDD; Navy, 2017) or from monitoring
reports from the Berth 11 Waterfront Improvements and P-310
construction projects. Specifically, where monitoring data specific to
the project area were available, they were used, and the NMSDD data
were used when there were no monitoring data available. The take
estimate was determined using the following equation: take estimate = N
* days of activity * area of harassment. A 10 m shutdown zone designed
to prevent animal interactions with equipment was subtracted from the
Level A harassment zone, and the area of the Level A harassment zone
was subtracted from the Level B harassment zone to avoid double
counting of takes during these take calculations. Days of construction
were conservatively based on relatively slow daily production rates.
The pile type, size, and installation method that produce the largest
zone of influence were used to estimate exposure of marine mammals to
noise impacts. In instances where an activity will ensonify the entire
ROI to the Level A harassment threshold, all potential takes are
assumed to be by Level A harassment.
Because some construction activities will occur over more than 1
construction year, the number of takes per year were determined by the
percent duration of each construction activity occurring each year
(calculated by months). For example, if an activity were to occur for 6
months, with 3 months occurring in year 2 and 3 months occurring in
year 3, then 50 percent of the takes were assigned to year 2 and 50
percent to year 3. In instances where only one take was calculated but
activities spanned more than 1 construction year, one take was
authorized for each construction year. Table 12 summarizes the
calculated duration percentages for each activity that were used to
divide take numbers by year.
Table 12--Division of Takes by Construction Year
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total amount and estimated Year 2 \1\ Year 3 \1\ Year 4 \1\ Year 5 \1\
Activity ID dates Activity component % takes % takes % takes % takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
(A1,2,3,4) Center Wall--Install Drill 18 shafts Apr 23 to Aug Install 102-inch diameter 100 0 0 0
Foundation Support Piles. 23. outer casing.
Pre-drill 102-inch outer 100 0 0 0
casing.
Remove 102-inch outer casing. 100 0 0 0
Drill 79-inch diameter shaft. 100 0 0 0
(R) Dry Dock 1 North Entrance--Install Install 48 sheet piles Apr 23 28-inch wide Z-shaped sheets. 100 0 0 0
Temporary Cofferdam. to May 23.
(1) Berth 11--Remove Shutter Panels... Remove 112 panels Apr 23 to Concrete shutter panels...... 100 0 0 0
Apr 23.
(2) Berth 1--Remove Sheet Piles....... Remove 168 sheet piles Apr 23 25-inch-wide Z-shaped........ 80 20 0 0
to Jun 24.
(3) Berth 1--Remove Granite Block Quay 2,800 cy Apr 23 to Jun 24.... Removal of granite blocks.... 80 20 0 0
Wall.
(4) Berth 1--Top of Wall Removal for 320 lf Apr 23 to Jun 24...... Mechanical concrete removal.. 80 20 0 0
Waler Installation.
(5) Berth 1--Install southeast corner Install 28 sheet piles Apr 23 28-inch-wide Z-shaped........ 100 0 0 0
SOE. to Jul 23.
(6) Berth 11--Mechanical Rock Removal 700 cy Apr 23 to Aug 23...... Excavate Bedrock............. 100 0 0 0
at Basin Floor.
(7) Berth 11 Face--Mechanical Rock Drill 924 relief holes Apr 23 4-6 inch diameter holes...... 100 0 0 0
Removal at Basin Floor. to Aug 23.
(8) Temporary Cofferdam Extension..... Install 14 sheet piles Apr 23 28-inch-wide Z-shaped........ 100 0 0 0
to Jun 23.
(9a, b, c, d) Gantry crane Support Drill 16 shafts Apr 23 to Aug Set 102-inch diameter casing. 100 0 0 0
Piles at Berth 1 West. 23. Pre-drill 102-inch rock 100 0 0 0
socket.
Remove 102-inch casing....... 100 0 0 0
72-inch diameter shafts...... 100 0 0 0
(10) Berth 1--Mechanical Rock Removal 500 cy Apr 23 to Sep 23...... Excavate Bedrock............. 100 0 0 0
at Basin Floor.
(11) Dry Dock 1 North Entrance--Drill Drill 50 rock anchors Apr 23 9-inch diameter holes........ 100 0 0 0
Tremie Tie Downs. to Oct 23.
(12) Center Wall--Install Tie-In to Install 15 sheet piles Apr 23 28-inch wide Z-shaped........ 100 0 0 0
Existing West Closure Wall. to Dec 23.
(13a, b, c, d) Dry Dock 1 North-- Drill 20 shafts May 23 to Nov Set 102-inch diameter casing. 60 40 0 0
Temporary Piles. 24.
Pre-drill 102-inch rock 60 40 0 0
socket.
Remove 102-inch casing....... 60 40 0 0
84-inch diameter shafts...... 60 40 0 0
(14) Dry Dock 1 North--Remove Remove 20 piles May 23 to Nov 84-inch diameter drill piles. 60 40 0 0
Temporary Work Trestle Piles. 24.
(15a, b, c, d) Dry Dock 1 North-- Drill 18 shafts May 23--Nov Set 84-inch casing........... 60 40 0 0
Install Leveling Piles (Diving Board 24. Pre-drill 84-inch rock socket 60 40 0 0
Shafts). Remove 84-inch casing........ 60 40 0 0
78-inch diameter shaft....... 60 40 0 0
(16a, b, c, d) Wall Shafts for Dry Drill 20 shafts Jun 23 to Nov Set 102-inch diameter casing. 60 40 0 0
Dock 1 North. 24. Pre-drill 102-inch rock 60 40 0 0
socket.
Remove 102-inch casing....... 60 40 0 0
Drill 78-inch diameter shaft. 60 40 0 0
(17a, b, c, d) Foundation Shafts for Drill 23 shafts Jun 23 to Nov Set 126-inch diameter Casing. 60 40 0 0
Dry Dock 1 North. 24. Pre-drill 126-inch rock 60 40 0 0
socket.
Remove 126-inch casing....... 60 40 0 0
[[Page 19522]]
Drill 108-inch diameter 60 40 0 0
shafts.
(18) Berth 11 End Wall--Remove Remove 60 sheet piles Jul 23 28-inch wide Z-shaped........ 100 0 0 0
Temporary Guide Wall. to Aug 23.
(19) Remove Berth 1 southeast corner Remove 28 sheet piles Jul 23 28-inch-wide Z-shaped........ 100 0 0 0
SOE. to Sep 23.
(20) Removal of Berth 1 Emergency Remove 216 sheet piles Aug 23 28-inch-wide Z-shaped........ 100 0 0 0
Repair Sheet Piles. to Mar 24.
(21) Removal of Berth 1 Emergency 765 cubic meters (1,000 cy) Mechanical concrete removal.. 100 0 0 0
Repair Tremie Concrete. Aug 23 to Mar 24.
(22) Center wall foundation--Drill in Install 72 rock anchors Aug 9-inch diameter holes........ 80 20 0 0
monolith Tie Downs. 23 to May 24.
(23) Center Wall--Remove tie-in to Remove 16 sheet piles Aug 23 28-inch-wide Z-shaped........ 60 40 0 0
existing west closure wall (Dry Dock to Aug 24.
1 North).
(24) Center wall East--sheet pile tie- Install 23 sheet piles Aug 23 28-inch wide Z-shaped........ 50 50 0 0
in to Existing Wall. to Oct 24.
(25) Remove tie-in to West Closure Remove 15 sheet pile Dec 23 28-inch wide Z-shaped........ 30 70 0 0
Wall (Dry Dock 1 West). to Dec 24.
(26) Remove Center wall East--sheet Remove 23 sheet piles Dec 23 28-inch wide Z-shaped........ 30 70 0 0
pile tie-in to Existing Wall (Dry to Dec 24.
Dock 1 West).
(27) Dry Dock 1 north entrance--Remove Remove 96 sheet piles Jan 24 28-inch wide Z-shaped........ 33 66 0 0
Temporary Cofferdam. to Sep 24.
(28) Remove Temporary Cofferdam Remove 14 sheet piles Jan 24 28-inch wide Z-shaped........ 33 66 0 0
Extension. to Sep 24.
(29a, b, c, d) Dry Dock 1 West-- Drill 20 shafts Apr 24 to Feb Set 102-inch diameter casing. 0 50 50 0
Install Temporary Piles. 26. Pre-drill 102-inch rock 0 50 50 0
socket.
Remove 102-inch casing....... 0 50 50 0
84-inch diameter shafts...... 0 50 50 0
(30) Dry Dock 1 West--Remove Temporary Remove 20 piles Apr 24 to Feb 84-inch diameter piles....... 0 50 50 0
Work Trestle Piles. 26.
(31a, b, c, d) Wall Shafts for Dry Drill 22 shafts Jun 24 to Feb Set 102-inch diameter casing. 0 50 50 0
Dock 1 West. 26. Pre-drill 102-inch rock 0 50 50 0
socket.
Remove 102-inch casing....... 0 50 50 0
78-inch diameter shaft....... 0 50 50 0
(32a, b, c, d) Foundation Shafts for Drill 23 shafts Jun 24 to Feb Set 126-inch casing.......... 0 50 50 0
Dry Dock 1 West. 26. Pre-drill 126-inch rock 0 50 50 0
socket.
Remove 126-inch casing....... 0 50 50 0
Drill 108-inch diameter shaft 0 50 50 0
(33a, b, c, d) Dry Dock 1 West-- Drill 18 shafts Jun 24 to Feb Set 84-inch casing........... 0 50 50 0
Install Leveling Piles (Diving Board 26. Pre-drill 84-inch rock socket 0 50 50 0
Shafts). Remove 84-inch casing........ 0 50 50 0
Drill 78-inch diameter shaft. 0 50 50 0
(34) Dry Dock 1 North--Tie Downs...... Install 36 rock anchors Jul 9-inch diameter holes........ 0 70 30 0
24 to Jul 25.
(35) Dry Dock 1 West--Install Tie Install 36 rock anchors Dec 9-inch diameter hole......... 0 0 30 70
Downs. 25 to Dec 26.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Note, for the purposes of this analysis, the construction years are identified as years 2 through 5; takes for marine mammals during Year 1 of the
Navy's construction activities were authorized in a previously issued IHA (87 FR 19886, April 6, 2022).
We describe how the information provided above is brought together
to produce a quantitative take estimate in the species sections below.
A summary of authorized take is available in Table 16.
Harbor Porpoise
Harbor porpoises are expected to be present in the project area
from April to December. Based on density data from the NMSDD, their
presence is highest in spring, decreases in summer, and slightly
increases in fall. During construction monitoring in the project area,
there were three harbor porpoise observations between April and
December of 2017; two harbor porpoise observations in early August of
2018; and one harbor porpoise observation in 2020 (Cianbro, 2018; Navy,
2019; NAVFAC, 2021). There were no harbor porpoise observations in the
project area in 2021 (NAVFAC, 2022). Given that monitoring data
specific to the project area are available, the more general NMSDD data
were not used to determine species density in the project area.
Instead, the Navy used observation data from the 2017 and 2018
construction monitoring for the Berth 11 Waterfront Improvements
Project and determined that the density of harbor porpoise for the
largest harassment zone was equal to 0.04/km\2\. Estimated take was
calculated with this density estimate multiplied by the harassment zone
multiplied by the days for each activity (see Table 13).
[[Page 19523]]
Table 13--Estimated Take of Harbor Porpoise by Project Activity
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Level A Take by Level A harassment Level B Take by Level B harassment
Total harassment --------------------------------------------- harassment --------------------------------------------
Activity ID Year/activity Purpose Density production zone zone
days (km\2\) Total Year 2 Year 3 Year 4 Year 5 (km\2\) Total Year 2 Year 3 Year 4 Year 5
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A........... 2 Rotary Drill..... Center Wall-- 0.04 18 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Install
Foundation
Support Piles.
2 Rotary Drill..... Center Wall-- 0.04 18 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Install
Foundation
Support Piles.
2 Rotary Drill..... Center Wall-- 0.04 18 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Install
Foundation
Support Piles.
2 DTH Cluster Drill Center Wall-- 0.04 117 0.417417 2 2 0 0 0 0.417417 0 0 0 0 0
Install
Foundation
Support Piles.
R........... 2 Vibratory Pile Dry Dock 1 North 0.04 6 0.0014041 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Entrance--Install
Temporary
Cofferdam.
2 Impact Pile Dry Dock 1 North 0.04 6 0.417417 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Entrance--Install
Temporary
Cofferdam.
1........... 2 Hydraulic Rock Shutter Panel 0.04 56 0.417417 1 1 0 0 0 0.277858 0 0 0 0 0
Hammer. Demolition (112
panels).
2........... 2-3 Vibratory Remove Berth 1 0.04 42 0.000454 0 0 0 0 0 0.417417 \1\ 2 1 1 0 0
Extraction. Sheet Piles.
3........... 2-3 Hydraulic Rock Removal of Granite 0.04 47 0.417417 \1\ 2 1 1 0 0 0.277858 0 0 0 0 0
Hammer. Quay Wall (2,800
cy).
4........... 2-3 Hydraulic Rock Berth 1 Top of 0.04 74 0.417417 \1\ 2 1 1 0 0 0.277858 0 0 0 0 0
Hammer. Wall Demolition
for Waler Install
(320 lf).
5........... 2 Vibratory Pile Install Berth 1 0.04 8 0.000454 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Support of
Excavation.
2 Impact Pile Berth 1 Support of 0.04 8 0.403411 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Excavation.
6........... 2 Hydraulic Rock Mechanical Rock 0.04 60 0.417417 1 1 0 0 0 0.277858 0 0 0 0 0
Hammer. Removal (700 cy)
at Berth 11 Basin
Floor.
7........... 2 DTH Mono-hammer.. Relief Holes at 0.04 35 0.047675 0 0 0 0 0 0.417417 1 1 0 0 0
Berth 11 Basin
Floor.
8........... 2 Vibratory Pile Install Temporary 0.04 4 0.000454 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Cofferdam
Extension.
2 Impact Pile Temporary 0.04 4 0.403411 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Cofferdam
Extension.
9........... 2 Rotary Drill..... Gantry Crane 0.04 16 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Support--Install
Outer Casing.
2 Rotary Drill..... Gantry Crane 0.04 16 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Support--Pre-
Drill Socket.
2 Rotary Drill..... Gantry Crane 0.04 16 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Support--Remove
Outer Casing.
2 DTH Cluster Drill Gantry Crane 0.04 80 0.417417 1 1 0 0 0 0.417417 0 0 0 0 0
Support Piles.
10.......... 2 Hydraulic Rock Mechanical Rock 0.04 25 0.417417 0 0 0 0 0 0.277858 0 0 0 0 0
Hammer. Removal (300 cy)
at Berth 1 Basin
Floor.
11.......... 2 DTH Mono-hammer.. Dry Dock 1 North 0.04 25 0.073751 0 0 0 0 0 0.417417 0 0 0 0 0
Entrance Rock
Anchors.
12.......... 2 Vibratory Pile Center Wall Tie-In 0.04 4 0.000454 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. to Existing West
Closure Wall.
2 Impact Pile Center Wall Tie-in 0.04 4 0.403411 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. to West Closure
Wall.
13.......... 2-3 Rotary Drill... Dry Dock 1 North 0.04 20 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Temporary Work
Trestle--Install
Outer Casing.
2-3 Rotary Drill... Dry Dock 1 North 0.04 20 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Temporary Work
Trestle--Pre-
Drill Socket.
[[Page 19524]]
2-3 Rotary Drill... Dry Dock 1 North 0.04 20 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Temporary Work
Trestle--Remove
Outer Casing.
2-3 DTH Cluster Dry Dock 1 North 0.04 70 0.417417 \1\ 2 1 1 0 0 0.417417 0 0 0 0 0
Drill. Temporary Work
Trestle.
14.......... 2-3 Rotary Drill... Remove Dry Dock 1 0.04 20 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
North Temporary
Work Trestle
Piles.
15.......... 2-3 Rotary Drill... Dry Dock 1 North 0.04 18 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Leveling Piles--
Install Outer
Casing.
2-3 Rotary Drill... Dry Dock 1 North 0.04 18 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Leveling Piles--
Pre-Drill Socket.
2-3 Rotary Drill... Dry Dock 1 North 0.04 18 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Leveling Piles--
Remove Outer
Casing.
2-3 DTH Cluster Dry Dock 1 North 0.04 135 0.417417 2 1 1 0 0 0.417417 0 0 0 0 0
Drill. Leveling Piles
(Diving Board
Shafts).
16.......... 2-3 Rotary Drill... Dry Dock 1 North 0.04 20 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Wall Shafts--
Install Outer
Casing.
2-3 Rotary Drill... Dry Dock 1 North 0.04 20 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Wall Shafts--Pre-
Drill Socket.
2-3 Rotary Drill... Dry Dock 1 North 0.04 20 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Wall Shafts--
Remove Outer
Casing.
2-3 DTH Cluster Wall Shafts for 0.04 150 0.417417 3 2 1 0 0 0.417417 0 0 0 0 0
Drill. Dry Dock 1 North.
17.......... 2-3 Rotary Drill... Dry Dock 1 North 0.04 23 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Foundation
Shafts--Install
Outer Casing.
2-3 Rotary Drill... Dry Dock 1 North 0.04 23 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Foundation Shafts
Pre-Drill Sockets.
2-3 Rotary Drill... Dry Dock 1 North 0.04 23 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Foundation
Shafts--Remove
Outer Casing.
2-3 DTH Cluster Foundation Shafts 0.04 196 0.417417 3 2 1 0 0 0.417417 0 0 0 0 0
Drill. for Dry Dock 1
North.
18.......... 2 Vibratory Berth 11 End Wall 0.04 10 0.001041 0 0 0 0 0 0.417417 0 0 0 0 0
Extraction. Temporary Guide
Wall.
19.......... 2 Vibratory Remove Berth 1 0.04 5 0.001041 0 0 0 0 0 0.417417 0 0 0 0 0
Extraction. Support of
Excavation.
20.......... 2 Vibratory Remove Berth 1 0.04 18 0.000733 0 0 0 0 0 0.417417 1 1 0 0 0
Extraction. Emergency Repairs.
21.......... 2 Hydraulic Rock Removal of 0.04 15 0.417417 0 0 0 0 0 0.277858 0 0 0 0 0
Hammer. Emergency Repair
Concrete (500 cy)
at Berth 1.
22.......... 2-3 DTH Mono-hammer Center Wall 0.04 36 0.073751 0 0 0 0 0 0.417417 0 0 0 0 0
Foundation Rock
Anchors.
23.......... 2-3 Vibratory Dry Dock 1 North- 0.04 3 0.001041 0 0 0 0 0 0.417417 0 0 0 0 0
Extraction. Remove Center
Wall Tie-in to
West Closure Wall.
24.......... 2-3 Vibratory Pile Center Wall East 0.04 12 0.000185 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Tie-in to
Existing Wall.
2-3 Impact Pile Center Wall East 0.04 12 0.334747 0 0 0 0 0 0.417417 0 0 0 0 0
Driving. Tie-in to
Existing Wall.
25.......... 2-3 Vibratory Dry Dock 1 West 0.04 3 0.001041 0 0 0 0 0 0.417417 0 0 0 0 0
Extraction. Remove Center
Wall Tie-in to
West Closure Wall.
26.......... 2-3 Vibratory Remove Center Wall 0.04 12 0.001041 0 0 0 0 0 0.417417 0 0 0 0 0
Extraction. Tie-in to
Existing Wall.
27.......... 2-3 Vibratory Remove Temporary 0.04 12 0.001041 0 0 0 0 0 0.417417 0 0 0 0 0
Extraction. Cofferdam.
28.......... 2-3 Vibratory Remove Temporary 0.04 2 0.001041 0 0 0 0 0 0.417417 0 0 0 0 0
Extraction. Cofferdam
Extension.
[[Page 19525]]
29.......... 3-4 Rotary Drill... Dry Dock 1 West 0.04 20 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Temporary Work
Trestle--Install
Outer Casing.
3-4 Rotary Drill... Dry Dock 1 West 0.04 20 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Temporary Work
Trestle--Pre-
Drill Socket.
3-4 Rotary Drill... Dry Dock 1 West 0.04 20 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Temporary Work
Trestle--Remove
Outer Casing.
3-4 DTH Cluster Dry Dock 1 West 0.04 70 0.417417 \1\ 2 0 1 1 0 0.417417 0 0 0 0 0
Drill. Temporary Work
Trestle.
30.......... 3-4 Rotary Drill... Dry Dock 1 West 0.04 20 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Remove Temporary
Work Trestle
Piles.
31.......... 3-4 Rotary Drill... Dry Dock 1 West 0.04 22 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Wall Shafts--
Install Outer
Casing.
3-4 Rotary Drill... Dry Dock 1 West 0.04 22 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Wall Shafts--Pre-
Drill Socket.
3-4 Rotary Drill... Dry Dock 1 West 0.04 22 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Wall Shafts--
Remove Outer
Casing.
3-4 DTH Cluster Wall Shafts for 0.04 165 0.417417 3 0 1 2 0 0.417417 0 0 0 0 0
Drill. Dry Dock 1 West.
32.......... 3-4 Rotary Drill... Dry Dock 1 West 0.04 23 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Foundation
Shafts--Install
Outer Casing.
3-4 Rotary Drill... Dry Dock 1 West 0.04 23 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Foundation Shafts
Pre-Drill Sockets.
3-4 Rotary Drill... Dry Dock 1 West 0.04 23 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Foundation
Shafts--Remove
Outer Casing.
3-4 DTH Cluster Foundation Shafts 0.04 196 0.417417 3 0 1 2 0 0.417417 0 0 0 0 0
Drill. for Dry Dock 1
West.
33.......... 3-4 Rotary Drill... Dry Dock 1 North 0.04 18 0.000014 0 0 0 0 0 0.417417 0 0 0 0 0
Leveling Piles--
Install Outer
Casing.
3-4 Rotary Drill... Dry Dock 1 West 0.04 18 0.000248 0 0 0 0 0 0.417417 0 0 0 0 0
Leveling Piles--
Pre-Drill Socket.
3-4 Rotary Drill... Dry Dock 1 North 0.04 18 0.000002 0 0 0 0 0 0.417417 0 0 0 0 0
Leveling Piles--
Remove Outer
Casing.
3-4 DTH Cluster Dry Dock 1 West 0.04 135 0.417417 2 0 1 1 0 0.417417 0 0 0 0 0
Drill. Leveling Piles
(Diving Board
Shafts).
34.......... 3-4 DTH Mono-hammer Dry Dock 1 North 0.04 18 0.073751 0 0 0 0 0 0.417417 0 0 0 0 0
Rock Anchors.
35.......... 4-5 DTH Mono-hammer Dry Dock 1 West 0.04 18 0.073751 0 0 0 0 0 0.417417 0 0 0 0 0
Rock Anchors.
------------------------------------------------------------------------------------------------------------------------------------------
Total..... ................... .................. ......... .......... ........... 29 13 10 6 0 ........... 4 3 \2\ 2 0 0
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Note: for the purposes of this analysis, the construction years are identified as years 2 through 5; takes for marine mammals during Year 1 of the Navy's construction activities were
authorized in a previously issued IHA (87 FR 19886, April 6, 2022).
\1\ In instances where only 1 take was calculated but activities spanned more than 1 construction year, 1 take was requested by the Navy for each construction year.
\2\ 1 take by Level B harassment was added to construction year 3 to account for average group size of harbor porpoises (see https://www.fisheries.noaa.gov/species/harbor-
porpoise#:~:text=The%20harbor%20porpoise%20is%20a,estuaries%2C%20harbors%2C%20and%20fjords).
** No additional takes are expected to result from the simultaneous use of 2 rotary drills and a DTH mono-hammer in construction years 3 and 4 and the simultaneous use of 2 rotary drills in
construction year 4.
[[Page 19526]]
Although no construction activity is currently planned for the
final year of the LOA period (construction year 6), potential schedule
slips may occur as a result of equipment failure, inclement weather, or
other unforeseen events. However, potential takes that could occur
during year 6 as a result of delays to activities scheduled for years
2-5 are accounted for through the analyses for those years, and no
additional take is authorized.
Harbor Seal
Harbor seals may be present year-round in the project vicinity,
with consistent densities throughout the year. Harbor seals are the
most common pinniped in the Piscataqua River near the Shipyard.
Sightings of this species were recorded during monthly surveys
conducted in 2017 and 2018 (NAVFAC Mid-Atlantic, 2018, 2019b) as well
as during Berth 11 and P-310 construction monitoring in 2017, 2018,
2020 and 2021 (Cianbro, 2018; Navy, 2019; NAVFAC, 2021, 2022), and
therefore density estimates from these efforts were considered in the
analysis. Based on observations recorded during the Berth 11 Waterfront
Improvements (199 observations of harbor seals during year 1 and 249
observations of harbor seals during year 2 [448 total] over 322 days)
and P-310 project construction monitoring (721 observations of harbor
seals during year 1 and 451 observations of harbor seals during year 2
[1,172 total] over 349 days), harbor seal density was estimated to be
3.0/km\2\ in the project area (Cianbro, 2018; Navy, 2019; NAVFAC, 2021,
2022).
Takes by Level A harassment were calculated for harbor seals where
the density of animals (3 harbor seals/km\2\) was multiplied by the
harassment zone and the number of days per construction activity. This
method was deemed to be inappropriate by the Navy for calculating takes
by Level B harassment for harbor seals as it produced take numbers that
were lower than the number of harbor seals that has been previously
observed in the Navy's monitoring reports. Therefore, the Navy proposed
(and NMFS concurred) to increase the estimated take by Level B
harassment to more accurately reflect harbor seal observations in the
monitoring reports, by using the value of three harbor seals observed a
day multiplied by the total number of construction days (i.e., 349
days), resulting in 1,047 takes per year by Level B harassment. This
method is consistent with the methodology used to estimate takes by
Level B harassment in IHA issued by NMFS for the first year of P-381
construction activities (87 FR 19866, April 6, 2022).
Additional takes by Level B harassment may occur during the
simultaneous use of two rotary drills and a DTH mono-hammer in
construction years 3 and 4 and the simultaneous use of two rotary
drills in construction year 4. The simultaneous use of 2 rotary drills
will result in 28 additional takes by Level B harassment of harbor
seals. The simultaneous use of 2 rotary drills and a DTH mono-hammer
will result in 22 additional takes by Level B harassment of harbor
seals. Note, the use of cluster drills and rock hammers in construction
years 2 and 3 result in the entire ROI being ensonified to Level A
harassment thresholds; therefore, there will be no change to the size
of the harassment zones from concurrent construction activities during
these years and thus no need to authorize additional takes. To account
for concurrent activities in construction years 3 and 4, the Navy
requested to add additional takes by Level B harassment to the
estimated take numbers (22 harbor seal in construction year 3 and 50
harbor seal in construction year 4). Therefore the Navy requests and
NMFS authorizes 1,047 takes by Level B harassment for harbor seals in
construction year 2, 1,069 takes by Level B harassment for harbor seals
in construction year 3, 1,097 takes by Level B harassment for harbor
seals in construction year 4, and 1,047 takes by Level B takes for
harbor seals in construction year 5 (note the division of takes over
the construction years is summarized in Table 12).
Take by Level A harassment of harbor seals is shown in Table 14
below. Note that where the Level A harassment zone is as large as the
Level B harassment zone and fills the entire potentially ensonified
area, the enumerated takes in the Level A harassment column may be in
the form of Level A harassment and/or Level B harassment, but are
authorized as takes by Level A harassment. The authorized takes by
Level B harassment are not included in Table 14 as they were calculated
by a different method (i.e., by using the value of three harbor seals
observed per day multiplied by the total number of construction days;
i.e., 349 days).
Table 14--Estimated Take by Level A Harassment of Harbor Seal by Project Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A Take by Level A harassment
Total harassment --------------------------------------------
Activity ID Year/ activity Purpose Density production zone (km
days \2\) Total Year 2 Year 3 Year 4 Year 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
A............................... 2 Rotary Drill.... Center Wall-- 3 18 0.000005 0 0 0 0 0
Install
Foundation
Support Piles.
2 Rotary Drill.... Center Wall-- 3 18 0.000091 0 0 0 0 0
Install
Foundation
Support Piles.
2 Rotary Drill.... Center Wall-- 3 18 0.000001 0 0 0 0 0
Install
Foundation
Support Piles.
2 DTH Cluster Center Wall-- 3 117 0.417417 147 147 0 0 0
Drill. Install
Foundation
Support Piles.
R............................... 2 Vibratory Pile Dry Dock 1 North 3 6 0.0002 0 0 0 0 0
Driving. Entrance--Install
Temporary
Cofferdam.
2 Impact Pile Dry Dock 1 North 3 6 0.364953 7 7 0 0 0
Driving. Entrance--Install
Temporary
Cofferdam.
1............................... 2 Hydraulic Rock Shutter Panel 3 56 0.417417 70 70 0 0 0
Hammer. Demolition (112
panels).
2............................... 2-3 Vibratory Remove Berth 1 3 42 0.000078 0 0 0 0 0
Extraction. Sheet Piles.
3............................... 2-3 Hydraulic Rock Removal of Granite 3 47 0.417417 59 47 12 0 0
Hammer. Quay Wall (2,800
cy).
4............................... 2-3 Hydraulic Rock Berth 1 Top of 3 74 0.417417 93 74 19 0 0
Hammer. Wall Demolition
for Waler Install
(320 lf).
5............................... 2 Vibratory Pile Install Berth 1 3 8 0.000078 0 0 0 0 0
Driving. Support of
Excavation.
2 Impact Pile Berth 1 Support of 3 8 0..201158 5 5 0 0 0
Driving. Excavation.
[[Page 19527]]
6............................... 2 Hydraulic Rock Mechanical Rock 3 60 0.417417 75 75 0 0 0
Hammer. Removal (700 cy)
at Berth 11 Basin
Floor.
7............................... 2 DTH Mono-hammer. Relief Holes at 3 35 0.014413 1 1 0 0 0
Berth 11 Basin
Floor.
8............................... 2 Vibratory Pile Install Temporary 3 4 0.000078 0 0 0 0 0
Driving. Cofferdam
Extension.
2 Impact Pile Temporary 3 4 0.201158 2 2 0 0 0
Driving. Cofferdam
Extension.
9............................... 2 Rotary Drill.... Gantry Crane 3 16 0.000005 0 0 0 0 0
Support--Install
Outer Casing.
2 Rotary Drill.... Gantry Crane 3 16 0.000091 0 0 0 0 0
Support--Pre-
Drill Socket.
2 Rotary Drill.... Gantry Crane 3 16 0.000091 0 0 0 0 0
Support--Remove
Outer Casing.
2 DTH Cluster Gantry Crane 3 80 0.417417 100 100 0 0 0
Drill. Support Piles.
10.............................. 2 Hydraulic Rock Mechanical Rock 3 25 0.417417 31 31 0 0 0
Hammer. Removal (300 cy)
at Berth 1 Basin
Floor.
11.............................. 2 DTH Mono-hammer. Dry Dock 1 North 3 25 0.022912 2 2 0 0 0
Entrance Rock
Anchors.
12.............................. 2 Vibratory Pile Center Wall Tie-In 3 4 0.000078 0 0 0 0 0
Driving. to Existing West
Closure Wall.
2 Impact Pile Center Wall Tie-in 3 4 0.201158 2 2 0 0 0
Driving. to West Closure
Wall.
13.............................. 2-3 Rotary Drill.. Dry Dock 1 North 3 20 0.000005 0 0 0 0 0
Temporary Work
Trestle--Install
Outer Casing.
2-3 Rotary Drill.. Dry Dock 1 North 3 20 0.000091 0 0 0 0 0
Temporary Work
Trestle--Pre-
Drill Socket.
2-3 Rotary Drill.. Dry Dock 1 North 3 20 0.000001 0 0 0 0 0
Temporary Work
Trestle--Remove
Outer Casing.
2-3 DTH Cluster Dry Dock 1 North 3 70 0.417417 88 53 35 0 0
Drill. TemporaryWork
Trestle.
14.............................. 2-3 Rotary Drill.. Remove Dry Dock 1 3 20 0.000002 0 0 0 0 0
North Temporary
Work Trestle
Piles.
15.............................. 2-3 Rotary Drill.. Dry Dock 1 North 3 18 0.000005 0 0 0 0 0
Leveling Piles--
Install Outer
Casing.
2-3 Rotary Drill.. Dry Dock 1 North 3 18 0.000091 0 0 0 0 0
Leveling Piles--
Pre-Drill Socket.
2-3 Rotary Drill.. Dry Dock 1 North 3 18 0.000001 0 0 0 0 0
Leveling Piles--
Remove Outer
Casing.
2-3 DTH Cluster Dry Dock 1 North 3 135 0.417417 169 101 68 0 0
Drill. Leveling Piles
(Diving Board
Shafts).
16.............................. 2-3 Rotary Drill.. Dry Dock 1 North 3 20 0.000005 0 0 0 0 0
Wall Shafts--
Install Outer
Casing.
2-3 Rotary Drill.. Dry Dock 1 North 3 20 0.000091 0 0 0 0 0
Wall Shafts--Pre-
Drill Socket.
2-3 Rotary Drill.. Dry Dock 1 North 3 20 0.000001 0 0 0 0 0
Wall Shafts--
Remove Outer
Casing.
2-3 DTH Cluster Wall Shafts for 3 150 0.417417 188 113 75 0 0
Drill. Dry Dock 1 North.
17.............................. 2-3 Rotary Drill.. Dry Dock 1 North 3 23 0.000005 0 0 0 0 0
Foundation
Shafts--Install
Outer Casing.
2-3 Rotary Drill.. Dry Dock 1 North 3 23 0.000091 0 0 0 0 0
Foundation Shafts
Pre-Drill Sockets.
2-3 Rotary Drill.. Dry Dock 1 North 3 23 0.000001 0 0 0 0 0
Foundation
Shafts--Remove
Outer Casing.
2-3 DTH Cluster Foundation Shafts 3 196 0.417417 245 147 98 0 0
Drill. for Dry Dock 1
North.
18.............................. 2 Vibratory Berth 11 End Wall 3 10 0.0002 0 0 0 0 0
Extraction. Temporary Guide
Wall.
19.............................. 2 Vibratory Remove Berth 1 3 5 0.0002 0 0 0 0 0
Extraction. Support of
Excavation.
20.............................. 2 Vibratory Remove Berth 1 3 18 0.000136 0 0 0 0 0
Extraction. Emergency Repairs.
21.............................. 2 Hydraulic Rock Removal of 3 15 0.417417 19 19 0 0 0
Hammer. Emergency Repair
Concrete (500 cy)
at Berth 1.
22.............................. 2-3 DTH Mono- Center Wall 3 36 0.022912 2 1 1 0 0
hammer. Foundation Rock
Anchors.
23.............................. 2-3 Vibratory Dry Dock 1 North-- 3 3 0.0002 0 0 0 0 0
Extraction. Remove Center
Wall Tie-in to
West Closure Wall.
24.............................. 2-3 Vibratory Pile Center Wall East 3 12 0.000032 0 0 0 0 0
Driving. Tie-in to
Existing Wall.
2-3 Impact Pile Center Wall East 3 12 0.090757 3 2 1 0 0
Driving. Tie-in to
Existing Wall.
25.............................. 2-3 Vibratory Dry Dock 1 West 3 3 0.0002 0 0 0 0 0
Extraction. Remove Center
Wall Tie-in to
West Closure Wall.
26.............................. 2-3 Vibratory Remove Center Wall 3 12 0.0002 0 0 0 0 0
Extraction. Tie-in to
Existing Wall.
27.............................. 2-3 Vibratory Remove Temporary 3 12 0.0002 0 0 0 0 0
Extraction. Cofferdam.
[[Page 19528]]
[…truncated; see source link]Indexed from Federal Register on March 31, 2023.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.