Notice2026-22021
Obayashi-Jay Dee Joint Venture; Cemetery Brook Drain Tunnel Project; Grant of Permanent Variance
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
October 29, 2026
Effective
October 29, 2026
Issuing agencies
Labor DepartmentOccupational Safety and Health Administration
Abstract
In this notice, OSHA grants a permanent variance to Obayashi-- Jay Dee Joint Venture (OJD) related to work in compressed air environments.
Full Text
<html>
<head>
<title>Federal Register, Volume 91 Issue 208 (Thursday, October 29, 2026)</title>
</head>
<body><pre>
[Federal Register Volume 91, Number 208 (Thursday, October 29, 2026)]
[Notices]
[Pages 68173-68183]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-22021]
-----------------------------------------------------------------------
DEPARTMENT OF LABOR
Occupational Safety and Health Administration
[Docket No. OSHA-2026-0001]
Obayashi--Jay Dee Joint Venture; Cemetery Brook Drain Tunnel
Project; Grant of Permanent Variance
AGENCY: Occupational Safety and Health Administration (OSHA), Labor.
ACTION: Notice.
-----------------------------------------------------------------------
SUMMARY: In this notice, OSHA grants a permanent variance to Obayashi--
Jay Dee Joint Venture (OJD) related to work in compressed air
environments.
DATES: The permanent variance specified by this notice becomes
effective on October 29, 2026 and shall remain in effect until the
completion of the Cemetery Brook Drain Tunnel Project or until modified
or revoked by OSHA.
FOR FURTHER INFORMATION CONTACT: Information regarding this notice is
available from the following sources:
Press inquiries: Contact Mr. Frank Meilinger, Director, OSHA Office
of
[[Page 68174]]
Communications, U.S. Department of Labor; telephone: (202) 693-1000
ext. 18477; email: <a href="/cdn-cgi/l/email-protection#1b767e727772757c7e69357d697a75787268295b7f7477357c746d"><span class="__cf_email__" data-cfemail="5b363e323732353c3e29753d293a35383228691b3f3437753c342d">[email protected]</span></a>.
General and technical information: Contact Mr. Kevin Robinson,
Director, Office of Technical Programs and Coordination Activities,
Directorate of Technical Support and Emergency Management, Occupational
Safety and Health Administration, U.S. Department of Labor;
telephone:(202) 693-1000 ext. 11538; email: <a href="/cdn-cgi/l/email-protection#493b262b20273a262767222c3f2027092d2625672e263f"><span class="__cf_email__" data-cfemail="03716c616a6d706c6d2d6866756a6d43676c6f2d646c75">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Copies of this Federal Register notice. Electronic copies of this
Federal Register notice are available at <a href="http://www.regulations.gov">http://www.regulations.gov</a>.
This Federal Register notice, as well as news releases and other
relevant information, also are available at OSHA's web page at <a href="http://www.osha.gov">http://www.osha.gov</a>.
I. Overview
On June 30, 2025, Obayashi--Jay Dee Joint Venture (OJD or the
applicant), submitted under Section 6(d) of the Occupational Safety and
Health Act of 1970 (the Act), 29 U.S.C. 655, and 29 CFR 1905.11
(variances and other relief under Section 6(d)) an application for a
permanent variance from several provisions of the OSHA standard that
regulates work in compressed air, 1926.803 of 1926 Subpart S--
Underground Construction, Caissons, Cofferdams, and Compressed Air, and
an interim order allowing it to proceed while OSHA considers the
request for a permanent variance (OSHA-2026-0001-0002). This notice
addresses OJD's application for a permanent variance and interim order
for construction of the Cemetery Brook Drain Tunnel Project in
Manchester, New Hampshire, only and is not applicable to future OJD
tunneling projects.
Specifically, this notice addresses Obayashi--Jay Dee's application
for a permanent variance and interim order from the provisions of the
standard that: (1) require the use of the decompression values
specified in decompression tables in Appendix A of subpart S (29 CFR
1926.803(f)(1)); and (2) require the use of automated operational
controls and a special decompression chamber (29 CFR
1926.803(g)(1)(iii) and (xvii), respectively).
OSHA reviewed Obayashi--Jay Dee's application for the variance and
interim order and determined that they were appropriately submitted in
compliance with the applicable variance procedures in Section 6(d) of
the Occupational Safety and Health Act of 1970 (OSH Act; 29 U.S.C. 655)
and OSHA's regulations at 29 CFR 1905.11 (Variances and other relief
under section 6(d)), including the requirement that the applicant
inform workers and their representatives of their rights to petition
the Assistant Secretary of Labor for Occupational Safety and Health for
a hearing on the variance application.
OSHA also reviewed the alternative procedures in Obayashi--Jay
Dee's application and preliminarily determined that the applicant's
proposed alternatives, on the whole, subject to the conditions in the
request and imposed by the interim order, provide measures that are as
safe and healthful as those required by the cited OSHA standards. On
May 29, 2026, OSHA published a Federal Register notice announcing
Obayashi--Jay Dee's application for permanent variance, stating the
preliminary determination along with the basis of that determination,
and granting the interim order (91 FR 32095). OSHA requested comments
on each.
OSHA did not receive any comments or other information disputing
the preliminary determination that the alternatives were at least as
safe as OSHA's standard, nor any objections to OSHA granting a
permanent variance. Accordingly, through this notice OSHA grants a
permanent variance, subject to the conditions set out in this document.
A. Background
The information that follows about Obayashi--Jay Dee, its methods,
and the Cemetery Brook Drain Tunnel Project comes from the Obayashi--
Jay Dee variance application.
Obayashi--Jay Dee is a contractor for the Cemetery Brook Drain
Tunnel Project (the project), that works on complex tunnel projects
using innovations in tunnel-excavation methods. The applicant's workers
engage in the construction of tunnels using advanced shielded
mechanical excavation techniques in conjunction with an earth pressure
balanced micro-tunnel boring machine (TBM). Using shielded mechanical
excavation techniques, in conjunction with precast concrete tunnel
liners and backfill grout, TBMs provide methods to achieve the face
pressures required to maintain a stabilized tunnel face through various
geologies and isolate that pressure to the forward section (the working
chamber) of the TBM.
Obayashi--Jay Dee asserts that it bores tunnels using a TBM at
levels below the water table through soft soils consisting of clay,
silt, and sand. TBMs are capable of maintaining pressure at the tunnel
face, and stabilizing existing geological conditions, through the
controlled use of a mechanically driven cutter head, bulkheads within
the shield, ground-treatment foam, and a screw conveyor that moves
excavated material from the working chamber. The forward-most portion
of the TBM is the main chamber, and this chamber is the only
pressurized segment of the TBM.
The main chamber (airlock) is a double compartment chamber (inner
lock and outer lock). The inner lock is the primary work area and the
outer lock is used for personnel transfer only. A door separates the
inner and outer locks, allowing personnel to transfer from one pressure
zone to another. This configuration allows workers to access the main
chamber for compression and decompression, and medical personnel to
access the main chamber if required in an emergency.
Obayashi--Jay Dee Hyperbaric Operations Manual (HOM) for the
Cemetery Brook Drain Project indicates that the maximum pressure to
which it is likely to expose workers during project interventions for
the tunnel drives is 37 pounds per square inch gauge (p.s.i.g.). The
applicant will pressurize the working chamber to the level required to
maintain a stable tunnel face, which for this project Obayashi--Jay Dee
estimates will be up to a pressure not exceeding 37 p.s.i.g., which
does not exceed the maximum pressure specified by the OSHA standard at
29 CFR 1926.803(e)(5).\1\ Obayashi--Jay Dee is not seeking a variance
from this provision of the compressed-air standard.
---------------------------------------------------------------------------
\1\ The decompression tables in Appendix A of subpart S express
the working pressures as pounds per square inch gauge (p.s.i.g.).
Therefore, throughout this notice, OSHA expresses the p.s.i. value
specified by 29 CFR 1926.803(e)(5) as p.s.i.g., consistent with the
terminology in Appendix A, Table 1 of subpart S.
---------------------------------------------------------------------------
Obayashi--Jay Dee employs specially trained personnel for the
construction of the tunnel. To keep the machinery working effectively,
Obayashi--Jay Dee asserts that these workers must periodically enter
the excavation working chamber of the TBM to perform hyperbaric
interventions during which workers would be exposed to air pressures up
to 37 p.s.i.g, which does not exceed the maximum pressure specified by
the existing OSHA standard at 29 CFR 1926.803(e)(5). These
interventions consist of conducting inspections or maintenance work on
the cutter-head structure and cutting tools of the TBM, such as
changing replaceable cutting tools and disposable wear bars, and, in
rare cases, repairing structural damage to the cutter head. These
interventions are the only time that workers are exposed to compressed
air. Interventions in the excavation working chamber (the pressurized
[[Page 68175]]
portion of the TBM) take place only after halting tunnel excavation and
preparing the machine and crew for an intervention.
During interventions, workers access the working chamber by first
passing through the outer lock. They then pass through a door to enter
the inner lock, which includes the primary decompression area. The
working chamber is designed to accommodate three people, which is the
maximum crew size allowed under the permanent variance. When the crew
is engaged in decompression activities, there is no other work
performed on the working face.
Obayashi--Jay Dee asserts that these innovations in tunnel
excavation have greatly reduced worker exposure to hazards of
pressurized air work because they have eliminated the need to
pressurize the entire tunnel for the project and thereby reduce the
number of workers exposed, as well as the total duration of exposure,
to hyperbaric pressure during tunnel construction. These advances in
technology have substantially modified the methods used by the
construction industry to excavate subaqueous tunnels compared to the
caisson work regulated by the current OSHA compressed-air standard for
construction at 29 CFR 1926.803.
In addition to the reduced exposures resulting from the innovations
in tunnel-excavation methods, Obayashi--Jay Dee asserts that
innovations in hyperbaric medicine and technology improve the safety of
decompression from hyperbaric exposures. These procedures, however,
deviate from the decompression process that OSHA requires for
construction in 29 CFR 1926.803(f)(1) and the decompression tables in
Appendix A of 29 CFR 1926, subpart S. Nevertheless, according to
Obayashi--Jay Dee, their use of decompression protocols incorporating
oxygen is more efficient, effective, and safer for tunnel workers than
compliance with the decompression tables specified by the existing OSHA
standard.
Obayashi--Jay Dee contends that the alternative safety measures
included in the application provide Obayashi--Jay Dee's workers with a
place of employment that is at least as safe as they would be under
OSHA's compressed-air standard for construction. OJD also provided OSHA
a project-specific HOM (OSHA-2026-0001-0003) for the Cemetery Brook
Drain Tunnel Project that requires specialized medical support and
hyperbaric supervision to provide assistance to a team of specially
trained airlock attendants and hyperbaric or compressed-air workers to
support their assertions of equivalency in worker protection.
OSHA included all the above information in the Federal Register
notice announcing Obayashi--Jay Dee's variance application and did not
receive any comments disputing any of that information, including the
safety assertions made by Obayashi--Jay Dee in the variance
application.
II. The Variance Application
Pursuant to the requirements of OSHA's variance regulations (29 CFR
1905.11), the applicant has certified that it notified its affected
workers \2\ of the variance application and request for interim order
by posting, at prominent locations where it normally posts workplace
notices, a summary of the application and information specifying where
the workers can examine a copy of the application. In addition, the
applicant has certified that it informed its workers of their right to
petition the Assistant Secretary of Labor for Occupational Safety and
Health for a hearing on the variance application.
---------------------------------------------------------------------------
\2\ See the definition of ``Affected employee or worker'' in
section VII.C of this Notice.
---------------------------------------------------------------------------
III. OSHA History of Approval of Nearly Identical Variance Requests
OSHA has previously approved several nearly identical variances
involving the same types of tunneling equipment used for similar
projects (tunnel construction variances). OSHA notes that it granted
several subaqueous tunnel construction permanent variances from the
same provisions of OSHA's compressed-air standard (29 CFR
1926.803(e)(5), (f)(1), (g)(1)(iii), and (g)(1)(xvii)) that are the
subject of the present application: (1) Impregilo, Healy, Parsons,
Joint Venture (IHP JV) for the Anacostia River Tunnel in Washington, DC
(80 FR 50652, August 20, 2015); (2) Traylor JV for the Blue Plains
Tunnel in Washington, DC (80 FR 16440, March 27, 2015); (3) Tully/OHL
USA Joint Venture for the New York Economic Development Corporation's
New York Siphon Tunnel project (79 FR 29809, May 23, 2014); (4) Salini-
Impregilo/Healy Joint Venture for the Northeast Boundary Tunnel in
Washington, DC (85 FR 27767, May 11, 2020); (5) McNally/Kiewit SST for
the Shoreline Storage Tunnel in Cleveland, Ohio (88 FR 15080, March 10,
2023); (6) Traylor Shea Joint Venture for the Alexandria RiverRenew
Tunnel Project in Alexandria, Virginia and Washington, DC (88 FR 15090,
March 10, 2023); (7) Traylor-Sundt Joint Venture, for the Integrated
Pipeline Tunnel Project in Dallas, Texas (88 FR 83152, November 28,
2023); (8) Ballard Marine Construction for the Bay Park Conveyance
Tunnel Project in Nassau County, New York (89 FR 8442, February 7,
2024); (9) Ballard Marine Construction for the Lower Olentangy Tunnel
Project in Columbus, Ohio (89 FR 78906, September 26, 2024); and (10)
McNally/ASI Marine for the Southerly Tunnel and Consolidation Project
in Cleveland, Ohio (90 FR 60752, December 29, 2025). OSHA also granted
an interim order to Ballard Marine Construction for the Suffolk County,
New York Outfall Tunnel Project (86 FR 5253, January 19, 2021). The
proposed alternate conditions in this notice are nearly identical to
the alternate conditions of the previous permanent variances.\3\ OSHA
is not aware of any injuries or other safety issues that arose from
work performed under these conditions in accordance with the previous
variances.
---------------------------------------------------------------------------
\3\ The previous tunnel construction variances allowed further
deviation from OSHA standards by permitting employee exposures above
50 p.s.i.g., based on the composition of the soil and the amount of
water that will be above the tunnel for various sections of this
project. The current permanent variance includes substantively the
same safeguards as the variances that OSHA granted previously even
though employees will not be exposed to pressures higher than 37
p.s.i.g.
---------------------------------------------------------------------------
IV. Applicable OSHA Standard and the Relevant Variance
A. Variance From Paragraph (f)(1) of 29 CFR 1926.803, Requirement To
Use OSHA Decompression Tables
OSHA's compressed-air standard for construction requires
decompression in accordance with the decompression tables in Appendix A
of 29 CFR 1926, subpart S (see 29 CFR 1926.803(f)(1)). As an
alternative to the OSHA decompression tables, the applicant proposes to
use newer decompression schedules (the 1992 French Decompression
Tables) that rely on staged decompression and supplement breathing air
used during decompression with air or oxygen (as appropriate).\4\ The
applicant asserts decompression protocols using the 1992 French
Decompression Tables for air or oxygen as specified by the Cemetery
Tunnel Drain Project-specific HOM are safer for tunnel workers than the
decompression protocols specified in
[[Page 68176]]
Appendix A of 29 CFR 1926 Subpart S. Accordingly, the applicant commits
to following the decompression procedures described in that HOM, which
requires Obayashi--Jay Dee to follow the 1992 French Decompression
Tables to decompress compressed air workers (CAWs) after they exit the
hyperbaric conditions in the working chamber.
---------------------------------------------------------------------------
\4\ In 1992, the French Ministry of Labour replaced the 1974
French Decompression Tables with the 1992 French Decompression
Tables, which differ from OSHA's decompression tables in Appendix A
by using: (1) staged decompression as opposed to continuous (linear)
decompression; (2) decompression tables based on air or both air and
pure oxygen; and (3) emergency tables when unexpected exposure times
occur (up to 30 minutes above the maximum allowed working time).
---------------------------------------------------------------------------
Depending on the maximum working pressure and exposure times, the
1992 French Decompression Tables provide for air decompression with or
without oxygen. Obayashi--Jay Dee asserts that oxygen decompression has
many benefits, including (1) keeping the partial pressure of nitrogen
in the lungs as low as possible; (2) keeping external pressure as low
as possible to reduce the formation of gas bubbles in the blood; (3)
removing nitrogen from the lungs and arterial blood and increasing the
rate of nitrogen elimination; (4) improving the quality of breathing
during decompression stops so that workers are less tired and to
prevent bone necrosis; (5) reducing decompression time by approximately
33 percent as compared to air decompression; and (6) reducing
inflammation.
In addition, the project-specific HOM requires a physician,
certified in hyperbaric medicine, to manage the medical condition of
CAWs during hyperbaric exposures and decompression. A trained and
experienced airlock attendant is also required to be present during
hyperbaric exposures and decompression. This airlock attendant is to
operate the hyperbaric system to ensure compliance with the specified
decompression table. A hyperbaric supervisor, who is trained in
hyperbaric operations, procedures, and safety, directly oversees all
hyperbaric interventions, and ensures that staff follow the procedures
delineated in the HOM or by the attending physician.
B. Variance From Paragraph (g)(1)(iii) of 29 CFR 1926.803,
Automatically Regulated Continuous Decompression
Obayashi--Jay Dee seeks a permanent variance from the OSHA standard
at 29 CFR 1926.803(g)(1)(iii), which requires automatic controls to
regulate decompression. As noted above, the applicant is conducting the
staged decompression according to the 1992 French Decompression Tables
under the direct control of the trained airlock attendant and under the
oversight of the hyperbaric supervisor.
Breathing air under hyperbaric conditions increases the amount of
nitrogen gas dissolved in a CAW's tissues. The greater the hyperbaric
pressure under these conditions and the more time spent under the
increased pressure, the greater the amount of nitrogen gas is dissolved
in the tissues. When the pressure decreases during decompression,
tissues release the dissolved nitrogen gas into the blood system, which
then carries the nitrogen gas to the lungs for elimination through
exhalation. Releasing hyperbaric pressure too rapidly during
decompression can increase the size of the bubbles formed by nitrogen
gas in the blood system, resulting in decompression illness (DCI),
commonly referred to as ``the bends.'' This description of the etiology
of DCI is consistent with current scientific theory and research on the
issue.
The 1992 French Decompression Tables, proposed for use by the
applicant, provide for stops during worker decompression (i.e., staged
decompression) to control the release of nitrogen gas from tissues into
the blood system. Studies show that staged decompression, in
combination with other features of the 1992 French Decompression Tables
such as the use of oxygen, result in a lower incidence of DCI than the
use of automatically regulated continuous decompression.\5\ In
addition, the applicant asserts that staged decompression administered
in accordance with its HOM is at least as effective as an automatic
controller in regulating the decompression process because the HOM
requires a hyperbaric supervisor who directly supervises all hyperbaric
interventions and ensures that the airlock attendant, who is a
competent person in the manual control of hyperbaric systems, follows
the schedule specified in the decompression tables, including stops.
---------------------------------------------------------------------------
\5\ See, e.g., Dr. Eric Kindwall, EP (1997), Compressed air
tunneling and caisson work decompression procedures: development,
problems, and solutions. Undersea and Hyperbaric Medicine, 24(4),
pp. 337-345. This article reported 60 treated cases of DCI among
4,168 exposures between 19 and 31 p.s.i.g. over a 51-week contract
period, for a DCI incidence of 1.44% for the decompression tables
specified by the OSHA standard. Dr. Kindwall notes that the use of
automatically regulated continuous decompression in the Washington
State safety standards for compressed-air work (from which OSHA
derived its decompression tables) was at the insistence of
contractors and the union, and against the advice of the expert who
calculated the decompression table and recommended using staged
decompression. Dr. Kindwall then states, ``Continuous decompression
is inefficient and wasteful. For example, if the last stage from 4
p.s.i.g. . . . to the surface took 1h, at least half the time is
spent at pressures less than 2 p.s.i.g. . . ., which provides less
and less meaningful bubble suppression . . . .'' In addition, Dr.
Kindwall addresses the continuous-decompression protocol in the OSHA
compressed-air standard for construction, noting that ``[a]side from
the tables for saturation diving to deep depths, no other widely
used or officially approved diving decompression tables use straight
line, continuous decompressions at varying rates. Stage
decompression is usually the rule, since it is simpler to control.''
---------------------------------------------------------------------------
C. Variance From Paragraph (g)(1)(xvii) of 29 CFR 1926.803, Requirement
of Special Decompression Chamber
The OSHA compressed-air standard for construction requires
employers to use a special decompression chamber of sufficient size to
accommodate all CAWs being decompressed at the end of the shift when
total decompression time exceeds 75 minutes (see 29 CFR
1926.803(g)(1)(xvii)). Use of the special decompression chamber enables
CAWs to move about and flex their joints to prevent neuromuscular
problems during decompression.
Space limitations in the TBM do not allow for the installation and
use of an additional special decompression lock or chamber. The
applicant proposes that it be permitted to rely on the airlocks (inner
lock and outer lock) in lieu of adding a separate, special
decompression chamber. Because only a few workers out of the entire
crew are exposed to hyperbaric pressure, the airlocks (which, as noted
earlier, connect directly to the working chamber) are of sufficient
size to accommodate all of the exposed workers during decompression.
The applicant uses the existing airlocks, each of which adequately
accommodates a three-member crew for this purpose, when decompression
lasts up to 75 minutes. When decompression exceeds 75 minutes, the main
chamber permits the crew to stand and extend their extremities. In the
event of an emergency or requirement to conduct decompression outside
of the main chamber, the applicant will have both a medical and shuttle
chamber onsite during tunneling operations, both of which are double
compartment chambers equipped to support hyperbaric medical treatment.
The shuttle chamber supports limited hyperbaric medical treatment while
the medical lock supports full medical treatment. The medical and
shuttle chambers will be on standby during hyperbaric and post-
hyperbaric interventions in the event there is a requirement to treat
personnel suffering with decompression illness. The shuttle chamber
shall be stationed within the tunnel as close as possible to the main
chamber. Workers will have the ability to exit the main chamber (during
decompression stops) and move into the shuttle chamber under the strict
planning and supervision of the hyperbaric supervisor and hyperbaric
physician. The shuttle chamber will
[[Page 68177]]
have the ability to additionally lock onto the on-site medical lock as
needed and as directed by the hyperbaric physician. For hyperbaric
treatment purposes, both the shuttle and medical chambers will enable
CAWs to move about and flex their joints and receive treatment as
required. The applicant asserts that this alternative arrangement is as
effective as a special decompression chamber in that it has sufficient
space for all the CAWs at the end of a shift and enables the CAWs to
move about and flex their joints to prevent neuromuscular problems.
V. Decision
After reviewing the proposed alternatives, OSHA has determined that
the applicant's proposed alternatives, on the whole, subject to the
conditions in the request and imposed by this permanent variance,
provide measures that are as safe and healthful as those required by
the cited OSHA standards addressed in section IV of this notice.
In addition, OSHA has determined that each of the following
alternatives are at least as effective as the specified OSHA
requirements:
A. 29 CFR 1926.803(f)(1)
The applicant has proposed to implement equally effective
alternative measures to the requirement in 29 CFR 1926.803(f)(1) for
compliance with OSHA's decompression tables. The HOM specifies the
procedures and personnel qualifications for performing work safely
during the compression and decompression phases of interventions. The
HOM also specifies the decompression tables the applicant proposes to
use (the 1992 French Decompression Tables). Depending on the maximum
working pressure and exposure times during the interventions, the
tables provide for decompression using air, pure oxygen, or a
combination of air and oxygen. The decompression tables also include
delays or stops for various time intervals at different pressure levels
during the transition to atmospheric pressure (i.e., staged
decompression). In all cases, a physician certified in hyperbaric
medicine will manage the medical condition of CAWs during
decompression. In addition, a trained and experienced airlock
attendant, experienced in recognizing decompression sickness or
illnesses and injuries, will be present. Of key importance, a
hyperbaric supervisor, trained in hyperbaric operations, procedures,
and safety, will directly supervise all hyperbaric operations to ensure
compliance with the procedures delineated in the project-specific HOM
or by the attending physician.
Prior to granting the previous permanent variances to Traylor JV,
IHP JV, Tully/OHL JV, Salini-Impregilo/Healy JV, McNally/Kiewit SST JV,
Traylor Shea JV, McNally/ASI Marine and Ballard Marine Bay Park Tunnel
New York, OSHA conducted a review of the scientific literature and
concluded that the alternative decompression method (i.e., the 1992
French Decompression Tables) Obayashi--Jay Dee proposed would be at
least as safe as the decompression tables specified by OSHA when
applied by trained medical personnel under the conditions imposed by
the permanent variance.
Some of the literature indicates that the alternative decompression
method may be safer, concluding that decompression performed in
accordance with these tables resulted in a lower occurrence of DCI than
decompression conducted in accordance with the decompression tables
specified by the standard. For example, H. L. Andersen studied the
occurrence of DCI at maximum hyperbaric pressures ranging from 4
p.s.i.g. to 43 p.s.i.g. during construction of the Great Belt Tunnel in
Denmark (1992-1996).\6\ This project used the 1992 French Decompression
Tables to decompress the workers during part of the construction.
Andersen observed 6 DCI cases out of 7,220 decompression events and
reported that switching to the 1992 French Decompression tables reduced
the DCI incidence to 0.08% compared to a previous incidence rate of
0.14%. The DCI incidence in the study by H. L. Andersen is
substantially less than the DCI incidence reported for the
decompression tables specified in Appendix A.
---------------------------------------------------------------------------
\6\ Andersen HL (2002). Decompression sickness during
construction of the Great Belt tunnel, Denmark. Undersea and
Hyperbaric Medicine, 29(3), pp. 173-188.
---------------------------------------------------------------------------
OSHA found no studies in which the DCI incidence reported for the
1992 French Decompression Tables were higher than the DCI incidence
reported for the OSHA decompression tables.\7\
---------------------------------------------------------------------------
\7\ Le P[eacute]chon JC, Barre P, Baud JP, Ollivier F (September
1996). Compressed air work--French Tables 1992--operational results.
JCLP Hyperbarie Paris, Centre Medical Subaquatique Interentreprise,
Marseille: Communication a l'EUBS, pp. 1-5 (see Ex. OSHA-2012-0036-
0005).
---------------------------------------------------------------------------
OSHA's experience with the previous ten variances, which all
incorporated nearly identical decompression plans and did not result in
safety issues, also provides evidence that the alternative procedure as
a whole is at least as effective for this type of tunneling project as
compliance with OSHA's decompression tables. The experience of State
Plans \8\ that granted variances (Nevada, Oregon and Washington) \9\ or
promulgated a new standard (California) \10\ for hyperbaric exposures
occurring during similar subaqueous tunnel-construction work provide
additional evidence of the effectiveness of this alternative procedure.
---------------------------------------------------------------------------
\8\ In Section 18 of the OSH Act, Congress expressly provides
that States and U.S. territories may adopt, with Federal approval, a
plan for the development and enforcement of occupational safety and
health standards. OSHA refers to States and territories which have
developed and are operating their own job safety and health programs
as ``States with OSHA-approved State Plans.'' Their programs must be
at least as effective in providing safe and healthful employment and
places of employment as the Federal standards (29 U.S.C. 667).
\9\ These state variances are available in the docket for the
2015 Traylor JV variance: Exs. OSHA-2012-0035-0006 (Nevada), OSHA-
2012-0035-0005 (Oregon), and OSHA-2012-0035-0004 (Washington).
\10\ See California Code of Regulations, Title 8, Subchapter 7,
Group 26, Article 154, available at <a href="http://www.dir.ca.gov/title8/sb7g26a154.html">http://www.dir.ca.gov/title8/sb7g26a154.html</a>.
---------------------------------------------------------------------------
B. 29 CFR 1926.803(g)(1)(iii)
The applicant developed, and proposed to implement, an equally
effective alternative to 29 CFR 1926.803(g)(1)(iii), which requires the
use of automatic controllers that continuously decrease pressure to
achieve decompression in accordance with the tables specified by the
standard. The applicant's alternative includes using the 1992 French
Decompression Tables for guiding staged decompression to achieve lower
occurrences of DCI, using a trained and competent attendant for
implementing appropriate hyperbaric entry and exit procedures, and
providing a competent hyperbaric supervisor and attending physician
certified in hyperbaric medicine to oversee all hyperbaric operations.
In reaching this conclusion, OSHA again notes the experience of
previous nearly identical tunneling variances, the experiences of
States with OSHA-approved State Plans, and a review of the literature
and other information noted earlier.
C. 29 CFR 1926.803(g)(1)(xvii)
The applicant developed, and proposed to implement, an effective
alternative to the use of the special decompression chamber required by
29 CFR 1926.803(g)(1)(xvii). The TBM's airlocks (inner and outer locks)
appear to satisfy all of the conditions of the special decompression
chamber, including that they provide sufficient space for the maximum
crew of three CAWs to stand up and move around, and safely accommodate
decompression
[[Page 68178]]
times up to 360 minutes. Therefore, again noting OSHA's previous
experience with nearly identical variances including the same
alternative, OSHA preliminarily determined that the TBM's airlocks
(inner and outer locks) function as effectively as the special
decompression chamber required by the standard.
Based on a review of available evidence, the experience of State
Plans that granted variances (Nevada, Oregon, and Washington) \11\ or
promulgated a new standard (California) \12\ for hyperbaric exposures
occurring during similar subaqueous tunnel-construction work, and the
information provided in the applicant's variance application, OSHA is
granting the permanent variance.
---------------------------------------------------------------------------
\11\ These state variances are available in the docket: Exs.
OSHA-2012-0035-0006 (Nevada), OSHA-2012-0035-0007 (Oregon), and
OSHA-2012-0035-0008 (Washington).
\12\ See California Code of Regulations, Title 8, Subchapter 7,
Group 26, Article 154, available at <a href="http://www.dir.ca.gov/title8/sb7g26a154.html">http://www.dir.ca.gov/title8/sb7g26a154.html</a>.
---------------------------------------------------------------------------
Pursuant to Section 6(d) of the Occupational Safety and Health Act
of 1970 (29 U.S.C. 655(d)), and based on the record discussed above,
the agency finds that when Obayashi--Jay Dee complies with the
conditions of the following order, the working conditions of the
workers are at least as safe and healthful as if Obayashi--Jay Dee
complied with the working conditions specified by paragraphs (f)(1),
(g)(1)(iii), and (g)(1)(xvii) of 29 CFR 1926.803. Therefore, Obayashi--
Jay Dee must: (1) comply with the conditions listed below under
``Conditions Specified for the Permanent Variance'' for the period
between the date of this notice and completion of the Cemetery Brook
Drain Tunnel Project; (2) comply fully with all other applicable
provisions of 29 CFR part 1926; and (3) provide a copy of this Federal
Register notice to all employees affected by the conditions, including
the affected employees of other employers, using the same means it used
to inform these employees of the application for a permanent variance.
Additionally, this order will remain in effect until one of the
following conditions occurs: (1) completion of the Cemetery Brook Drain
Tunnel Project; or (2) OSHA modifies or revokes this final order in
accordance with 29 CFR 1905.13.
VI. Description of the Specified Conditions for the Permanent Variance
The conditions for the variance are set out in the Order at the end
of this document. This section provides additional detail regarding the
conditions in the Order.
Condition A: Scope
The scope of the permanent variance limits coverage to the work
situations specified. Clearly defining the scope of the permanent
variance provides Obayashi--Jay Dee, their employees, potential future
applicants, other stakeholders, the public, and OSHA with necessary
information regarding the work situations in which the permanent
variance applies. To the extent that Obayashi--Jay Dee exceeds the
defined scope of this variance, it will be required to comply with
OSHA's standards. This permanent variance applies only to the
applicant, Obayashi--Jay Dee, and only to the remainder of construction
work on the Cemetery Brook Drain Tunnel Project.
Condition B: List of Abbreviations
Condition B defines abbreviations used in the permanent variance.
OSHA believes that defining these abbreviations serves to clarify and
standardize their usage, thereby enhancing the applicant's and its
employees' understanding of the conditions specified by the permanent
variance.
Condition C: Definitions
The condition defines a series of terms, mostly technical terms,
used in the permanent variance to standardize and clarify their
meaning. OSHA believes that defining these terms serves to enhance the
applicant's and its employees' understanding of the conditions
specified by the permanent variance.
Condition D: Safety and Health Practices
This condition requires the applicant to develop and submit to OSHA
a HOM specific to the Cemetery Brook Drain Tunnel Project at least six
months before using the TBM for tunneling operations. The applicant
must also submit, at least six months before using the TBM, proof that
the TBM's hyperbaric chambers have been designed, fabricated,
inspected, tested, marked, and stamped in accordance with the
requirements of the most recent edition of ASME PVHO-1 (Safety
Standards for Pressure Vessels for Human Occupancy). These requirements
ensure that the applicant develops hyperbaric safety and health
procedures suitable for the project.
The submission of the HOM enables OSHA to determine whether the
safety and health instructions and measures it specifies are
appropriate to the field conditions of the tunnel (including expected
geological conditions), conform to the conditions of the variance, and
adequately protect the safety and health of the CAWs. It also
facilitates OSHA's ability to ensure that the applicant is complying
with these instructions and measures. The requirement for proof of
compliance with ASME PVHO-1 is intended to ensure that the equipment is
structurally sound and capable of performing to protect the safety of
the employees exposed to hyperbaric pressure. The applicant has
submitted the HOM and proof of compliance with the most recent edition
of ASME PVHO-1.
Additionally, the condition includes a series of related hazard
prevention and control requirements and methods (e.g., decompression
tables, job hazard analyses (JHA), operations and inspections
checklists, incident investigation, and recording and notification to
OSHA of recordable hyperbaric injuries and illnesses) designed to
ensure the continued effective functioning of the hyperbaric equipment
and operating system.
Condition E: Communication
This condition requires the applicant to develop and implement an
effective system of information sharing and communication. Effective
information sharing and communication are intended to ensure that
affected workers receive updated information regarding any safety-
related hazards and incidents, and corrective actions taken, prior to
the start of each shift. The condition also requires the applicant to
ensure that reliable means of emergency communications are available
and maintained for affected workers and support personnel during
hyperbaric operations. Availability of such reliable means of
communications enables affected workers and support personnel to
respond quickly and effectively to hazardous conditions or emergencies
that may develop during TBM operations.
Condition F: Worker Qualification and Training
This condition requires the applicant to develop and implement an
effective qualification and training program for affected workers. The
condition specifies the factors that an affected worker must know to
perform safely during hyperbaric operations, including how to enter,
work in, and exit from hyperbaric conditions under both normal and
emergency conditions. Having well-trained and qualified workers
performing hyperbaric intervention work is intended to ensure that they
recognize, and respond appropriately to, hyperbaric safety and
[[Page 68179]]
health hazards. These qualification and training requirements enable
affected workers to cope effectively with emergencies, as well as the
discomfort and physiological effects of hyperbaric exposure, thereby
preventing worker injury, illness, and fatalities.
Paragraph (2)(e) of this condition requires the applicant to
provide affected workers with information they can use to contact the
appropriate healthcare professionals if the workers believe they are
developing hyperbaric-related health effects. This requirement provides
for early intervention and treatment of DCI and other health effects
resulting from hyperbaric exposure, thereby reducing the potential
severity of these effects.
Condition G: Inspections, Tests, and Accident Prevention
Condition G requires the applicant to develop, implement, and
operate a program of frequent and regular inspections of the TBM's
hyperbaric equipment and support systems, and associated work areas.
This condition helps to ensure the safe operation and physical
integrity of the equipment and work areas necessary to conduct
hyperbaric operations. The condition also enhances worker safety by
reducing the risk of hyperbaric-related emergencies.
Paragraph (3) of this condition requires the applicant to document
tests, inspections, corrective actions, and repairs involving the TBM,
and maintain these documents at the jobsite for the duration of the
job. This requirement provides the applicant with information needed to
schedule tests and inspections to ensure the continued safe operation
of the equipment and systems, and to determine that the actions taken
to correct defects in hyperbaric equipment and systems were
appropriate, prior to returning them to service.
Condition H: Compression and Decompression
This condition requires the applicant to consult with the
designated medical advisor regarding special compression or
decompression procedures appropriate for any unacclimated CAW and then
implement the procedures recommended by the medical advisor. This
provision ensures that the applicant consults with the medical advisor,
and involves the medical advisor in the evaluation, development, and
implementation of compression or decompression protocols appropriate
for any CAW requiring acclimation to the hyperbaric conditions
encountered during TBM operations. Accordingly, CAWs requiring
acclimation have an opportunity to acclimate prior to exposure to these
hyperbaric conditions. OSHA believes this condition will prevent or
reduce adverse reactions among CAWs to the effects of compression or
decompression associated with the intervention work they perform in the
TBM.
Condition I: Recordkeeping
Under OSHA's recordkeeping requirements in 29 CFR part 1904
regarding Recording and Reporting Occupational Injuries and Illnesses,
the employer must maintain a record of any recordable injury, illness,
or fatality (as defined by 29 CFR part 1904) resulting from exposure of
an employee to hyperbaric conditions, or any other work condition, by
completing the OSHA Form 301 Incident Report and OSHA Form 300 Log of
Work-Related Injuries and Illnesses. The applicant did not seek a
variance from this standard and therefore Obayashi--Jay Dee must comply
fully with those requirements.
Examples of important information to include on the OSHA Form 301
Injury and Illness Incident Report (along with the corresponding
questions on the form) are:
Q14
<bullet> the task performed;
<bullet> the composition of the gas mixture (e.g., air or oxygen);
<bullet> an estimate of the CAW's workload;
<bullet> the maximum working pressure;
<bullet> temperature in the work and decompression environments;
<bullet> unusual occurrences, if any, during the task or
decompression
Q15
<bullet> time of symptom onset;
<bullet> duration between decompression and onset of symptoms
Q16
<bullet> type and duration of symptoms;
<bullet> a medical summary of the illness or injury
Q17
<bullet> duration of the hyperbaric intervention;
<bullet> possible contributing factors;
<bullet> the number of prior interventions completed by the injured
or ill CAW; and the pressure to which the CAW was exposed during those
interventions.\13\
---------------------------------------------------------------------------
\13\ See 29 CFR 1904 Recording and Reporting Occupational
Injuries and Illnesses (<a href="http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9631">http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9631</a>); recordkeeping
forms and instructions <a href="https://www.osha.gov/recordkeeping/forms">https://www.osha.gov/recordkeeping/forms</a>.
---------------------------------------------------------------------------
Condition I adds additional reporting responsibilities, beyond
those already required by the OSHA standard. The applicant is required
to maintain records of specific factors associated with each hyperbaric
intervention. The information gathered and recorded under Condition I,
in concert with the information provided under Condition J (using OSHA
Form 301 Injury and Illness Incident Report to investigate and record
hyperbaric recordable injuries as defined by 29 CFR 1904.4, 1904.7, and
1904.8 -.12), enables the applicant and OSHA to assess the
effectiveness of the permanent variance in preventing DCI and other
hyperbaric-related effects.
Condition J: Notifications
Under the notifications condition, the applicant is required,
within specified periods of time, to notify OSHA of: (1) any recordable
injury, illness, in-patient hospitalization, amputation, loss of an
eye, or fatality that occurs as a result of hyperbaric exposures during
TBM operations; and in-patient hospitalization, amputation, loss of an
eye or fatality that occurs during other operations must also be
reported pursuant to 29 CFR 1910.39(a); (2) provide OSHA a copy of the
hyperbaric exposures incident investigation report (using OSHA Form 301
Injury and Illness Incident Report) of these events within 24 hours of
the incident; (3) include on OSHA Form 301 Injury and Illness Incident
Report information on the hyperbaric conditions associated with the
recordable injury or illness, the root-cause determination, and
preventive and corrective actions identified and implemented; (4)
provide the certification that affected workers were informed of the
incident and the results of the incident investigation; (5) notify
OSHA's Office of Technical Programs and Coordination Activities (OTPCA)
and the Concord, New Hampshire OSHA Area Office within 15 working days
should the applicant need to revise the HOM to accommodate changes in
its compressed-air operations that affect Obayashi--Jay Dee's ability
to comply with the conditions of the permanent variance; and (6)
provide OTPCA and the Concord, New Hampshire OSHA Area Office at the
end of the project, with a report evaluating the effectiveness of the
decompression tables.
It should be noted that the requirement for completing and
submitting the hyperbaric exposure-related (recordable) incident
investigation report (OSHA 301 Injury and Illness Incident Report) is
more restrictive than the current recordkeeping requirement of
completing OSHA Form 301 Injury and
[[Page 68180]]
Illness Incident Report within 7 calendar days of the incident (29 CFR
1904.29(b)(3)). This modified, more stringent incident investigation
and reporting requirement is restricted to intervention-related
hyperbaric (recordable) incidents only. Providing rapid notification to
OSHA is essential because time is a critical element in OSHA's ability
to determine the continued effectiveness of the variance conditions in
preventing hyperbaric incidents, and the applicant's identification and
implementation of appropriate corrective and preventive actions.
Further, these notification requirements also enable the applicant,
its employees, and OSHA to assess the effectiveness of the permanent
variance in providing the requisite level of safety to the applicant's
workers and based on this assessment, whether to revise or revoke the
conditions of the permanent variance. Timely notification permits OSHA
to take whatever action may be necessary and appropriate to prevent
possible further injuries and illnesses. Providing notification to
employees informs them of the precautions taken by the applicant to
prevent similar incidents in the future.
Additionally, this condition requires the applicant to notify OSHA
if it ceases to do business, has a new address or location for the main
office, or transfers the operations covered by the permanent variance
to a successor company. In addition, the condition specifies that the
transfer of the permanent variance to a successor company must be
approved by OSHA. These requirements allow OSHA to communicate
effectively with the applicant regarding the status of the permanent
variance and expedite the agency's administration and enforcement of
the permanent variance. Stipulating that the applicant is required to
have OSHA's approval to transfer a variance to a successor company
provides assurance that the successor company has knowledge of, and
will comply with, the conditions specified by the permanent variance,
thereby ensuring the safety of workers involved in performing the
operations covered by the permanent variance.
VII. Order
As of the effective date of this final order, OSHA is revoking the
interim order granted to the employer on May 29, 2026 (91 FR 32095) and
replacing it with a permanent variance order.
OSHA issues this final order authorizing Obayashi--Jay Dee to
comply with the following conditions instead of complying with the
requirements of 29 CFR 1926.803 (f)(1), (g)(1)(iii), and (g)(1)(xvii).
These conditions are:
A. Scope
The permanent variance applies only when Obayashi--Jay Dee stops
the tunnel-boring work, pressurizes the working chamber, and the CAWs
either enter the working chamber to perform an intervention (i.e.,
inspect, maintain, or repair the mechanical-excavation components), or
exit the working chamber after performing interventions.
The permanent variance applies only to work:
1. That occurs in conjunction with construction of the Cemetery
Brook Drain Tunnel Project, a tunnel constructed using advanced
shielded mechanical-excavation techniques and involving operation of a
TBM;
2. In the TBM's forward section (the working chamber) and
associated hyperbaric chambers used to pressurize and decompress
employees entering and exiting the working chamber; and
3. Performed in compliance with all applicable provisions of 29 CFR
part 1926 except for the requirements specified by 29 CFR 1926.803
(f)(1), (g)(1)(iii), and (g)(1)(xvii).
4. This order will remain in effect until one of the following
conditions occurs: (1) completion of the Cemetery Brook Drain Tunnel
Project; or (2) OSHA modifies or revokes this final order in accordance
with 29 CFR 1905.13.
B. List of Abbreviations
Abbreviations used throughout this permanent variance include the
following:
1. CAW--Compressed-air worker
2. CFR--Code of Federal Regulations
3. DCI--Decompression Illness
4. DMT--Diver Medical Technician
5. TBM--Earth Pressure Balanced Micro-Tunnel Boring Machine
6. HOM--Hyperbaric Operations Manual
7. JHA--Job hazard analysis
8. OJD--Obayashi--Jay Dee Joint Venture
9. OSHA--Occupational Safety and Health Administration
10. OTPCA--Office of Technical Programs and Coordination Activities
C. Definitions
The following definitions apply to this permanent variance,
Obayashi--Jay Dee's project-specific HOM, and all work carried out
under the conditions of this permanent variance.
1. Affected employee or worker--an employee or worker who is
affected by the conditions of this permanent variance, or any one of
his or her authorized representatives. The term ``employee'' has the
meaning defined and used under the Occupational Safety and Health Act
of 1970 (29 U.S.C. 651 et seq.).
2. Airlock--A compartment/chamber with controlled pressure and
parallel sets of doors to permit movement between areas at different
pressures.
3. Atmospheric pressure--the pressure of air at sea level,
generally 14.7 pounds per square inch absolute (p.s.i.a.), 1 atmosphere
absolute, or 0 pounds per square inch gauge (p.s.i.g.).
4. Compressed-air worker--an individual who is specially trained
and medically qualified to perform work in a pressurized environment
while breathing air at pressures not exceeding 37 p.s.i.g.
5. Competent person--an individual who is capable of identifying
existing and predictable hazards in the surroundings or working
conditions that are unsanitary, hazardous, or dangerous to employees,
and who has authorization to take prompt corrective measures to
eliminate them.\14\
---------------------------------------------------------------------------
\14\ Adapted from 29 CFR 1926.32(f).
---------------------------------------------------------------------------
6. Decompression illness--an illness (also called decompression
sickness or ``the bends'') caused by gas bubbles appearing in body
compartments due to a reduction in ambient pressure. Examples of
symptoms of decompression illness include, but are not limited to:
joint pain (also known as the ``bends'' for agonizing pain or the
``niggles'' for slight pain); areas of bone destruction (termed
dysbaric osteonecrosis); skin disorders (such as cutis marmorata, which
causes a pink marbling of the skin, or in people with darker skin
tones, the rash will appear as a marbled or lacy dark brown or purplish
color); spinal cord and brain disorders (such as stroke, paralysis,
paresthesia, and bladder dysfunction); cardiopulmonary disorders, such
as shortness of breath; and arterial gas embolism (gas bubbles in the
arteries that block blood flow).\15\
---------------------------------------------------------------------------
\15\ See Appendix 10 of ``A Guide to the Work in Compressed-Air
Regulations 1996,'' published by the United Kingdom Health and
Safety Executive available from NIOSH at <a href="http://www.cdc.gov/niosh/docket/archive/pdfs/NIOSH-254/compReg1996.pdf">http://www.cdc.gov/niosh/docket/archive/pdfs/NIOSH-254/compReg1996.pdf</a>.
Note: Health effects associated with hyperbaric intervention,
but not considered symptoms of DCI, can include: barotrauma (direct
damage to air-containing cavities in the body such as ears, sinuses,
and lungs); nitrogen narcosis (reversible alteration in
consciousness that may occur in hyperbaric environments and is
caused by the anesthetic effect of certain gases at high pressure);
and oxygen toxicity (a central nervous system
[[Page 68181]]
condition resulting from the harmful effects of breathing molecular
---------------------------------------------------------------------------
oxygen (O<INF>2</INF>) at elevated partial pressures).
7. Diver Medical Technician--Member of the dive team who is
experienced in first aid.
8. Earth Pressure Balanced Tunnel Boring Machine--the machinery
used to excavate a tunnel.
9. Hot work--any activity performed in a hazardous location that
may introduce an ignition source into a potentially flammable
atmosphere.\16\
---------------------------------------------------------------------------
\16\ Also see 29 CFR 1926.1202 for examples of hot work.
---------------------------------------------------------------------------
10. Hyperbaric--at a higher pressure than atmospheric pressure.
11. Hyperbaric intervention--a term that describes the process of
stopping the TBM and preparing and executing work under hyperbaric
pressure in the working chamber for the purpose of inspecting,
replacing, or repairing cutting tools and/or the cutterhead structure.
12. Hyperbaric Operations Manual--a detailed, project-specific
health and safety plan developed and implemented by Obayashi--Jay Dee
for working in compressed air during the Cemetery Brook Drain Tunnel
Project.
13. Inner Lock--primary lock of the main chamber, provides access
to the working chamber for performing work on the tunnel face or TBM
repair.
14. Job hazard analysis--an evaluation of tasks or operations to
identify potential hazards and to determine the necessary controls.
15. Main Chamber--The main compartment of the airlock.
16. Medical Advisor--medical professional experienced in the
physical requirements of compressed air work and the treatment of
decompression illness.
17. Medical Lock--A double compartment chamber equipped to support
full hyperbaric medical treatment.
18. Outer Lock--The secondary lock of the main chamber, used for
transferring occupants in and out of the inner lock.
19. Pressure--a force acting on a unit area. Usually expressed as
pounds per square inch (p.s.i.).
20. p.s.i.a.--pounds per square inch absolute, or absolute
pressure, is the sum of the atmospheric pressure and gauge pressure. At
sea-level, atmospheric pressure is approximately 14.7 p.s.i.a. Adding
14.7 to a pressure expressed in units of p.s.i.g. will yield the
absolute pressure, expressed as p.s.i.a.
21. p.s.i.g.--pounds per square inch gauge, a common unit of
pressure; pressure expressed as p.s.i.g. corresponds to pressure
relative to atmospheric pressure. At sea-level, atmospheric pressure is
approximately 14.7 p.s.i.a. Subtracting 14.7 from a pressure expressed
in units of p.s.i.a. yields the gauge pressure, expressed as p.s.i.g.
At sea level the gauge pressure is 0 p.s.i.g.
22. Qualified person--an individual who, by possession of a
recognized degree, certificate, or professional standing, or who, by
extensive knowledge, training, and experience, successfully
demonstrates an ability to solve or resolve problems relating to the
subject matter, the work, or the project.\17\
---------------------------------------------------------------------------
\17\ Adapted from 29 CFR 1926.32(m).
---------------------------------------------------------------------------
23. Shuttle lock--a double compartment chamber equipped to support
limited medical hyperbaric treatment.
24. Working chamber--an enclosed space in the TBM in which CAWs
perform interventions, and which is accessible only through an airlock.
D. Safety and Health Practices
1. Obayashi--Jay Dee must implement the project-specific HOM
submitted to OSHA as part of the application (see OSHA-2026-0001-0003).
The HOM provides the minimum requirements regarding expected safety and
health hazards (including anticipated geological conditions) and
hyperbaric exposures during the tunnel-construction project.
2. Obayashi--Jay Dee must demonstrate that the TBM on the project
is designed, fabricated, inspected, tested, marked, and stamped in
accordance with the most recent requirements of ASME PVHO-1 (Safety
Standards for Pressure Vessels for Human Occupancy) for the TBM's
hyperbaric chambers.
3. Obayashi--Jay Dee must implement the safety and health
instructions included in the manufacturer's operations manuals for the
TBM, and the safety and health instructions provided by the
manufacturer for the operation of decompression equipment.
4. Obayashi--Jay Dee must ensure that there are no exposures to
pressures greater than 37 p.s.i.g.
5. Obayashi--Jay Dee must ensure that air or oxygen is the only
breathing gas in the working chamber.
6. Obayashi--Jay Dee must follow the 1992 French Decompression
Tables for air or oxygen decompression as specified in the HOM;
specifically, the extracted portions of the 1992 French Decompression
tables titled, ``French Regulation Air Standard Tables.''
7. Obayashi--Jay Dee must equip airlocks used by employees with an
air or oxygen delivery system, as specified by the HOM for the project.
Obayashi--Jay Dee is prohibited from storing in the tunnel any oxygen
or other compressed gases used in conjunction with hyperbaric work.
8. Workers performing hot work under hyperbaric conditions must use
flame-retardant personal protective equipment and clothing.
9. In hyperbaric work areas, Obayashi--Jay Dee must maintain an
adequate fire-suppression system approved for hyperbaric work areas.
10. Obayashi--Jay Dee must develop and implement one or more job
hazard analysis (JHA) for work in the hyperbaric work areas, and
review, periodically and as necessary (e.g., after making changes to a
planned intervention that affects its operation), the contents of the
JHAs with affected employees. The JHAs must include all the job
functions that the risk assessment \18\ indicates are essential to
prevent injury or illness.
---------------------------------------------------------------------------
\18\ See ANSI/AIHA Z10-2012, American National Standard for
Occupational Health and Safety Management Systems, for reference.
---------------------------------------------------------------------------
11. Obayashi--Jay Dee must develop a set of checklists to guide
compressed-air work and ensure that employees follow the procedures
required by the permanent variance (including all procedures required
by the HOM approved by OSHA for the project, which this permanent
variance incorporates by reference). The checklists must include all
steps and equipment functions that the risk assessment indicates are
essential to prevent injury or illness during compressed-air work.
12. Obayashi--Jay Dee must ensure that the safety and health
provisions of this project-specific HOM adequately protect the workers
of all contractors and subcontractors involved in hyperbaric operations
for the project to which the HOM applies.\19\
---------------------------------------------------------------------------
\19\ See ANSI/ASSE A10.33-2011, American National Standard for
Construction and Demolition Operations--Safety and Health Program
Requirements for Multi-Employer Projects, for reference.
---------------------------------------------------------------------------
E. Communication
1. Prior to beginning a shift, Obayashi--Jay Dee must implement a
system that informs workers exposed to hyperbaric conditions of any
hazardous occurrences or conditions that might affect their safety,
including hyperbaric incidents, gas releases, equipment failures, earth
or rockslides, cave-ins, flooding, fires, or explosions.
[[Page 68182]]
2. Obayashi--Jay Dee must provide a power-assisted means of
communication among affected workers and support personnel in
hyperbaric conditions where unassisted voice communication is
inadequate.
(a) Obayashi--Jay Dee must use an independent power supply for
powered communication systems, and these systems must operate such that
use or disruption of any one phone or signal location will not disrupt
the operation of the system from any other location.
(b) Obayashi--Jay Dee must test communication systems at the start
of each shift and as necessary thereafter to ensure proper operation.
F. Worker Qualifications and Training
Obayashi--Jay Dee must:
1. Ensure that each affected worker receives effective training on
how to safely enter, work in, exit from, and undertake emergency
evacuation or rescue from, hyperbaric conditions, and document this
training.
2. Provide effective instruction on hyperbaric conditions, before
beginning hyperbaric operations, to each worker who performs work, or
controls the exposure of others, and document this instruction. The
instruction must include:
(a) The physics and physiology of hyperbaric work;
(b) Recognition of pressure-related injuries;
(c) Information on the causes and recognition of the signs and
symptoms associated with decompression illness, and other hyperbaric
intervention-related health effects (e.g., barotrauma, nitrogen
narcosis, and oxygen toxicity);
(d) How to avoid discomfort during compression and decompression;
(e) Information the workers can use to contact the appropriate
healthcare professionals should the workers have concerns that they may
be experiencing adverse health effects from hyperbaric exposure; and
(f) Procedures and requirements applicable to the employee in the
project-specific HOM.
3. Repeat the instruction specified in paragraph (G) of this
condition periodically and as necessary (e.g., after making changes to
its hyperbaric operations).
4. When conducting training for its hyperbaric workers, make this
training available to OSHA personnel and notify the OTPCA at OSHA's
national office and OSHA's Concord, New Hampshire Area Office before
the training takes place.
G. Inspections, Tests, and Accident Prevention
1. Obayashi--Jay Dee must initiate and maintain a program of
frequent and regular inspections of the TBM's hyperbaric equipment and
support systems (such as temperature control, illumination,
ventilation, and fire-prevention and fire-suppression systems), and
hyperbaric work areas, as required under 29 CFR 1926.20(b)(2),
including:
(a) Developing a set of checklists to be used by a competent person
in conducting weekly inspections of hyperbaric equipment and work
areas; and
(b) Ensuring that a competent person conducts daily visual checks
and weekly inspections of the TBM.
2. Obayashi--Jay Dee must remove any equipment that is found to
constitute a safety hazard until Obayashi--Jay Dee corrects the
hazardous condition and has the correction approved by a qualified
person.
3. Obayashi--Jay Dee must maintain records of all tests and
inspections of the TBM, as well as associated corrective actions and
repairs, at the job site for the duration of the tunneling project and
for 90 days after the final project report is submitted to OSHA.
H. Compression and Decompression
Obayashi--Jay Dee must consult with its attending physician
concerning the need for special compression or decompression exposures
appropriate for CAWs not acclimated to hyperbaric exposure.
I. Recordkeeping
In addition to completing OSHA Form 301 Injury and Illness Incident
Report and OSHA Form 300 Log of Work-Related Injuries and Illnesses,
Obayashi--Jay Dee must maintain records of:
1. The date, times (e.g., time compression started, time spent
compressing, time performing intervention, time spent decompressing),
and pressure for each hyperbaric intervention.
2. The names of all supervisors and DMTs involved for each
intervention.
3. The name of each individual worker exposed to hyperbaric
pressure and the decompression protocols and results for each worker.
4. The total number of interventions and the amount of hyperbaric
work time at each pressure.
5. The results of the post-intervention physical assessment of each
CAW for signs and symptoms of decompression illness, barotrauma,
nitrogen narcosis, oxygen toxicity or other health effects associated
with work in compressed air for each hyperbaric intervention.
J. Notifications
1. To assist OSHA in administering the conditions specified herein,
Obayashi--Jay Dee must:
(a) Notify the OTPCA and the Concord, New Hampshire OSHA Area
Office at <a href="http://www.osha.gov/contactus/byoffice">www.osha.gov/contactus/byoffice</a> of any recordable injury,
illness, or fatality (by submitting the completed OSHA Form 301 Injury
and Illness Incident Report) \20\ resulting from exposure of an
employee to hyperbaric conditions, including those that do not require
recompression treatment (e.g., nitrogen narcosis, oxygen toxicity,
barotrauma), but still meet the recordable injury or illness criteria
of 29 CFR 1904. The notification must be made within 8 hours of the
incident or 8 hours after becoming aware of a recordable injury,
illness, or fatality; a copy of the incident investigation (OSHA Form
301 Injuries and Illness Incident Report) must be submitted to OSHA
within 24 hours of the incident or 24 hours after becoming aware of a
recordable injury, illness, or fatality. In addition to the information
required by OSHA Form 301 Injuries and Illness Incident Report, the
incident-investigation report must include a root-cause determination,
and the preventive and corrective actions identified and implemented.
---------------------------------------------------------------------------
\20\ See 29 CFR 1904 (Recording and Reporting Occupational
Injuries and Illnesses) (<a href="http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9631">http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9631</a>); recordkeeping
forms and instructions <a href="https://www.osha.gov/recordkeeping/forms">https://www.osha.gov/recordkeeping/forms</a>.
---------------------------------------------------------------------------
(b) Provide certification to OTPCA and the Concord, New Hampshire
OSHA Area Office within 15 working days of the incident that Obayashi--
Jay Dee informed affected workers of the incident and the results of
the incident investigation (including the root-cause determination and
preventive and corrective actions identified and implemented).
(c) Notify the OTPCA and the Concord, New Hampshire OSHA Area
Office within 15 working days and in writing, of any change in the
compressed-air operations that affects Obayashi--Jay Dee's ability to
comply with the conditions specified herein.
(d) Upon completion of the Cemetery Brook Drain Tunnel Project,
evaluate the effectiveness of the decompression tables used throughout
the project, and provide a written report of this evaluation to the
OTPCA and the
[[Page 68183]]
Concord, New Hampshire OSHA Area Office.
Note: The evaluation report must contain summaries of: (1) The
number, dates, durations, and pressures of the hyperbaric
interventions completed; (2) decompression protocols implemented
(including composition of gas mixtures (air and/or oxygen), and the
results achieved; (3) the total number of interventions and the
number of hyperbaric incidents (decompression illnesses and/or
health effects associated with hyperbaric interventions as recorded
on OSHA Form 301 Injuries and Illness Incident Report and OSHA Form
300 Log of Work-Related Injuries and Illnesses, and relevant medical
diagnoses, and treating physicians' opinions); and (4) root causes
of any hyperbaric incidents, and preventive and corrective actions
identified and implemented.
(e) To assist OSHA in administering the conditions specified
herein, inform the OTPCA and the Concord New Hampshire OSHA Area Office
as soon as possible, but no later than seven (7) days, after it has
knowledge that it will:
(i) Cease doing business;
(ii) Change the location and address of the main office for
managing the tunneling operations specified herein; or
(iii) Transfer the operations specified herein to a successor
company.
(f) Notify all affected employees of this permanent variance by the
same means required to inform them of its application for a permanent
variance.
2. This permanent variance cannot be transferred to a successor
company without OSHA approval.
OSHA hereby grants a permanent variance to Obayashi--Jay Dee Joint
Venture for the completion of the Cemetery Brook Drain Tunnel Project
in Manchester, New Hampshire.
VIII. Authority and Signature
David Keeling, Assistant Secretary of Labor for Occupational Safety
and Health, 200 Constitution Avenue NW, Washington, DC 20210,
authorized the preparation of this notice. Accordingly, the agency is
issuing this notice pursuant to 29 U.S.C. 655(d), Secretary of Labor's
Order No. 7-2025 (90 FR 27878, June 30, 2025), and 29 CFR 1905.11.
Signed at Washington, DC, on October 5, 2026.
David Keeling,
Assistant Secretary of Labor for Occupational Safety and Health.
[FR Doc. 2026-22021 Filed 10-28-26; 8:45 am]
BILLING CODE 4510-26-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on October 29, 2026.
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.