U.S. CHEMICAL S AF E T Y AN D H A Z AR D INVESTIG AT I O N BO AR D
INVESTIGATION REPORT
METHANOL TANK EXPLOSION AND FIRE
(2 Dead, 1 Critically Injured)
BETHUNE POINT WASTEWATER TREATMENT PLANT
CITY OF DAYTONA BEACH, FLORIDA
JANUARY 11, 2006
KEY ISSUES:
鈥? HAZARD COMMUNICATION
鈥? HOT WORK CONTROL
鈥? PLASTIC PIPE IN FLAMMABLE SERVICE
鈥? FLAME ARRESTER MAINTENANCE
鈥? FLORIDA PUBLIC EMPLOYEE SAFETY PROGRAMS
REPORT NO. 2006-03-I-FL
MARCH 2007
Bethune Point WWTP March 2007
Contents
1.0 INTRODUCTION ...........................................................................................................................8
1.1 Background...................................................................................................................................... 8
1.2 Investigative Process........................................................................................................................ 8
1.3 City of Daytona Beach..................................................................................................................... 8
1.4 Bethune Wastewater Treatment Plant.............................................................................................. 9
1.5 Advanced Wastewater Treatment Process..................................................................................... 10
1.6 Methanol ........................................................................................................................................ 11
1.7 Water Environment Federation...................................................................................................... 11
2.0 INCIDENT DESCRIPTION..........................................................................................................12
2.1 Pre-Incident Events........................................................................................................................ 12
2.2 The Incident ................................................................................................................................... 13
2.3 Emergency Response ..................................................................................................................... 15
3.0 ANALYSIS....................................................................................................................................16
3.1 Chemical Hazard Recognition ....................................................................................................... 16
3.2 Safety and Hazard Review in Job Planning ................................................................................... 19
3.3 Methanol Piping............................................................................................................................. 20
3.3.1 Piping Design.................................................................................................................... 20
3.3.2 Piping Specifications and Standards................................................................................. 22
3.3.3 Piping Failure.................................................................................................................... 23
3.4 Methanol Tank Flame Arrester ...................................................................................................... 26
4.0 REGULATORY ANALYSIS........................................................................................................30
4.1 OSHA Regulations ........................................................................................................................ 30
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4.2 Florida Public Employee Safety .................................................................................................... 32
4.2.1 History .............................................................................................................................. 32
4.2.2 Florida Municipal Safety Program Survey ....................................................................... 33
4.2.3 Florida Public Facility Chemical Incidents....................................................................... 34
4.2.4 Safety Consultation........................................................................................................... 34
5.0 KEY FINDINGS............................................................................................................................35
6.0 ROOT AND CONTRIBUTING CAUSES....................................................................................37
6.1 Root Causes ................................................................................................................................... 37
6.2 Contributing Causes....................................................................................................................... 37
7.0 RECOMMENDATIONS...............................................................................................................38
Governor and Legislature of the State of Florida ....................................................................................... 38
City of Daytona Beach................................................................................................................................ 39
National Fire Protection Association .......................................................................................................... 39
U.S. Department of Labor, Occupational Safety and Health Administration............................................. 39
Water Environment Federation................................................................................................................... 40
Methanol Institute ....................................................................................................................................... 40
Camp Dresser & McKee Inc....................................................................................................................... 41
8.0 REFERENCES ..............................................................................................................................43
APPENDIX A: Root Cause Logic Diagram .............................................................................................. 45
APPENDIX B: Public Employee OSHA Coverage...................................................................................51
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Bethune Point WWTP March 2007
Figures
Figure 1. Bethune Point WWTP. ................................................................................................................. 9
Figure 2. Bethune Point WWTP accident site. .......................................................................................... 13
Figure 3. Bethune Point WWTP safety related training sessions. ............................................................. 18
Figure 4. Aboveground PVC methanol pipes ............................................................................................ 21
Figure 5. Failed 1-inch PVC pipe showing fracture surface ...................................................................... 24
Figure 6. Methanol spray from 1-inch pipe flanges onto the crane cab..................................................... 25
Figure 7. Location of man-lift basket and 4-inch vent pipe....................................................................... 26
Figure 8. Protectoseal model No. 864 flame arrester................................................................................. 27
Figure 9. Flame arrester plate corrosion (outside) ..................................................................................... 28
Figure 10. Flame arrester plate corrosion (inside) ..................................................................................... 28
Tables
Table 1. Bethune Point WWTP safety training classes from 1994-2005................................................... 17
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Bethune Point WWTP March 2007
Acronyms and Abbreviations
ASME American Society of Mechanical Engineers
BNR Biological Nutrient Removal
BOCA Building Officials Code Administrators
CDM Camp Dresser & McKee Inc.
CFR Code of Federal Regulations
CSB U. S. Chemical Safety and Hazard Investigation Board
FAC Florida Administrative Code
HAZCOM Hazard Communication
IRIC Indian River Industrial Contractors
MSDS Material Safety Data Sheet
NACE National Association of Corrosion Engineers
NFPA National Fire Protection Association
NPS Nominal Pipe Size
OJT On-the-Job Training
OSHA Occupational Safety and Health Administration
pH Hydrogen Ion Concentration
PVC Polyvinyl Chloride
SCBA Self Contained Breathing Apparatus
WEF Water Environment Federation
WWTP Wastewater Treatment Plant
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Bethune Point WWTP March 2007
Executive Summary
On January 11, 2006, an explosion and fire occurred at the City of Daytona Beach, Bethune Point
Wastewater Treatment Plant (Bethune Point WWTP) in Daytona Beach, Florida, killing two employees
and severely burning a third.
The Bethune Point WWTP processes wastewater using a treatment that requires the addition of methanol,
a highly flammable liquid. The methanol is stored in an aboveground storage tank.
The U.S. Chemical Safety and Hazard Investigation Board (CSB) determined that maintenance workers
using a cutting torch on a roof above the methanol storage tank accidentally ignited vapors coming from
the tank vent. The flame flashed back into the storage tank, causing an explosion inside the tank that
precipitated multiple methanol piping failures and a large fire that engulfed the tank and workers.
The investigation identified the following root causes:
The City of Daytona Beach
鈥? did not implement adequate controls for hot work at the Bethune Point WWTP, and
鈥? had a hazard communication program that did not effectively communicate the hazards associated
with methanol at the Bethune Point WWTP.
The investigation identified the following contributing causes:
鈥? The City of Daytona Beach has no program to evaluate the safety of non-routine tasks.
鈥? The piping and valves in the methanol system were constructed of polyvinyl chloride in lieu of
steel.
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Bethune Point WWTP March 2007
鈥? An aluminum flame arrester was installed on the methanol tank vent even though methanol
corrodes aluminum.
鈥? The operation and maintenance manual for the Bethune Point WWTP did not include a
requirement to maintain the flame arrester.
This CSB report makes recommendations to the Governor and Legislature of the State of Florida; the City
of Daytona Beach; the U.S. Department of Labor, Occupational Safety and Health Administration; the
National Fire Protection Association; the Water Environment Federation; the Methanol Institute; and
Camp Dresser & McKee Inc.
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Bethune Point WWTP March 2007
1.0 INTRODUCTION
1.1 Background
On January 11, 2006, an explosion and fire occurred at the City of Daytona Beach, Bethune Point WWTP
in Daytona Beach, Florida. Two employees died and one was severely burned after a worker using a
cutting torch accidentally ignited vapors coming from the methanol storage tank vent. An explosion
inside the tank followed, causing the attached piping to fail and release about 3,000 gallons of methanol,
which burned.
1.2 Investigative Process
Investigators from the U.S. Chemical Safety and Hazard Investigation Board (CSB) arrived at the facility
on January 13, 2006. The CSB examined and collected physical evidence from the incident, interviewed
Bethune WWTP employees and others, and reviewed relevant documents. The CSB coordinated its work
with a number of other investigative organizations, including:
鈥? Division of the State Fire Marshal, State of Florida;
鈥? City of Daytona Beach Police Department; and
鈥? City of Daytona Beach Fire Department.
1.3 City of Daytona Beach
The City of Daytona Beach, located on the east coast of central Florida in Volusia County, has about
64,000 residents and is governed by a city commission composed of a mayor and six elected
commissioners. The commission hires a city manager who presents a budget for the commission鈥檚
approval, oversees city operations, and manages about 800 city employees.
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Bethune Point WWTP March 2007
The Bethune Point WWTP is part of the Waste/Water group in the Utilities department, whose director
reports to the city manager.
1.4 Bethune Wastewater Treatment Plant
Eleven city employees operate the Bethune Point WWTP, treating about 13 million gallons per day before
discharging to the Halifax River (Figure 1).
Figure 1. Bethune Point WWTP.
(Picture courtesy of the City of Daytona Beach)
The plant originally used conventional wastewater treatment. This treatment is appropriate for the
wastewater that Bethune Point receives, but is ineffective at removing nitrogen and phosphorus
compounds that promote algae growth.
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Bethune Point WWTP March 2007
In the late 1980s, the State of Florida required wastewater treatment plants to reduce the discharge of
compounds that promote algae growth. The City of Daytona Beach contracted Camp Dresser & McKee
Inc.1 (CDM) in 1989 to redesign the Bethune Point plant to incorporate an advanced wastewater treatment
process to remove nitrogen and phosphorus compounds. CDM鈥檚 scope of work was to specify the
process, develop the conceptual and detailed designs, prepare construction and project specifications, and
oversee construction. The City of Daytona Beach separately contracted Indian River Industrial
Contractors (IRIC) to build the advanced wastewater treatment process. Operation of the new process
started in 1993.
1.5 Advanced Wastewater Treatment Process
Advanced wastewater treatment is a biological nutrient removal (BNR) process where specialized
bacteria, with the addition of an organic nutrient, convert nitrogen compounds into nitrogen gas. The
Bethune Point WWTP uses methanol as the organic nutrient for the bacteria. Chemical metering pumps
continuously fed methanol to the process from a 10,000-gallon carbon steel storage tank.
In 1999, the City of Daytona Beach modified the BNR process to operate without the continuous
methanol feed; however, the facility continued to use the methanol system and 10,000-gallon storage tank
for sporadic methanol addition. As a result, the facility maintained a large inventory of methanol even
though demand was substantially reduced. The methanol storage tank contained between 2,000 and 3,000
gallons when the incident occurred.
1
CDM is a multinational consulting, engineering, and construction firm specializing in water and wastewater
treatment facilities.
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Bethune Point WWTP March 2007
1.6 Methanol
Methanol (commonly known as methyl or wood alcohol) is a Class 1B flammable liquid with a flash
point of 54潞F (12潞C); its explosive limits are 6 to 36.5 volume percent in air. Methanol vapors are heavier
than air with a vapor density (air=1) of 1.1.2
Methanol vapors burn with a colorless flame in daylight, although the presence of other materials can
color the flame. Methanol is a skin and eye irritant and highly toxic when ingested. 3
In addition to wastewater treatment, methanol is used in the manufacture of numerous consumer products
including plastics, paints, adhesives, and fuels.4
The Methanol Institute represents manufacturers of methanol and distributes health, safety, and
environmental information on the use and distribution of methanol.
1.7 Water Environment Federation
The Water Environment Federation (WEF) is a not-for-profit technical and educational organization with
members from the wastewater industry. WEF offers training programs, workshops, and seminars. In
addition, WEF publishes technical manuals and other information for the wastewater industry.
2
Lewis, R., 2000. Sax鈥檚 Dangerous Properties of Industrial Materials (10th Edition).
3
Ibid.
4
Methanol Institute website, 2006, www.methanol.org.
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2.0 Incident Description
2.1 Pre-Incident Events
In 2004 and 2005, several hurricanes damaged the Bethune Point WWTP, including two metal roofs used
to shade two chemical storage areas. Facility personnel removed one of the damaged metal roofs in 2005
without incident. The second metal roof, installed over the methanol storage tank, was about 30 feet
above the ground and more difficult to access. In consultation with the facility superintendent, the lead
mechanic determined that facility personnel could remove the second damaged metal roof using a city-
owned crane and a rented man-lift. The lead mechanic planned the job to remove the metal roof. The
facility superintendent did not review details of the job and possible hazards.
On Monday, January 9, 2006, the lead mechanic and a mechanic prepared to remove the metal roof. They
retrieved the man-lift and crane from other city facilities. The lead mechanic then familiarized himself
with the operation of the man-lift. Workers at the Bethune Point WWTP had previously used the city
crane and were familiar with its operation.
On Tuesday, January 10, 2006, the lead mechanic, the mechanic, and a third worker began removing the
metal roof over the methanol storage tank. Standing in the man-lift, the lead mechanic and mechanic cut
the metal roof into sections with an oxy-acetylene cutting torch and attached the cut sections to the crane
hook. The third worker operated the crane to lower the cut sections to the ground. While cutting the
metal roof, sparks from the torch ignited a grass fire. The crane operator extinguished the grass fire with
a garden hose. In the early afternoon, the workers ran out of oxygen for the cutting torch and stopped
work for the day. The lead mechanic ordered another oxygen cylinder so the job could resume on
Wednesday.
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Bethune Point WWTP March 2007
2.2 The Incident
On Wednesday, January 11, 2006, three workers5 continued the roof removal. About 11:15 a.m., the lead
mechanic and the third worker were cutting the metal roof directly above the methanol tank vent. Sparks,
showering down from the cutting torch, ignited methanol vapors coming from the vent, creating a fireball
on top of the tank. The fire flashed through a flame arrester on the vent, igniting methanol vapors and air
inside the tank, causing a explosion inside the steel tank. Figure 2 is an overview of the accident site
showing the crane, man-lift, and tank after the incident.
Figure 2. Bethune Point WWTP accident site.
(Picture courtesy of the City of Daytona Beach)
5
The workers included the lead mechanic and mechanic who worked on January 9 and 10, 2006 and a new worker
from the facility.
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Bethune Point WWTP March 2007
The explosion inside the methanol storage tank
鈥? rounded the tank鈥檚 flat bottom, permanently deforming the tank and raising the side wall about one
foot;
鈥? ripped the nuts from six bolts used to anchor the tank to a concrete foundation;
鈥? blew the flame arrester off the tank vent pipe;
鈥? blew a level sensor off a 4-inch flange on the tank top;
鈥? separated two 1-inch pipes, valves, and an attached level switch from flanges on the side of the tank;
鈥? separated a 4-inch tank outlet pipe from the tank outlet valve; and
鈥? separated a 4-inch tank fill pipe near the top the tank.
Methanol discharged from the separated pipes ignited and burned, spreading the fire. Methanol also
flowed into the containment around the tank and through a drain to the WWTP where it was diluted and
harmlessly processed.
The lead mechanic and the third worker were in the man-lift basket over the methanol tank when the
ignition occurred. They were likely burned from the initial fireball and burning methanol vapors
discharging from the tank vent under pressure from the explosion. The lead mechanic, fully engulfed in
fire, likely jumped or fell from the man-lift. Emergency responders found his body within the concrete
containment next to the tank.
The third worker stated that he had been partially out of the man-lift basket leaning over the roof when
the fire ignited. On fire, he climbed onto the roof to escape. Co-workers, unable to reach him with a
ladder, told him to jump to an adjacent lower roof and then to the ground. He sustained second- and third-
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Bethune Point WWTP March 2007
degree burns over most of his body, and was hospitalized for 4 months before being released to a medical
rehabilitation facility.
Methanol sprayed from separated pipes onto the crane, burning the crane cab with the mechanic inside.
On fire, he exited the cab and was assisted by co-workers. He died in the hospital the following day.
2.3 Emergency Response
Bethune Point WWTP workers heard the explosion and immediately went to the scene of the fire and
aided the victims. The facility superintendent and a facility operator called 911 to report the incident and
request fire and medical assistance. City Fire Station # 1 dispatched the first unit at 11:18 a.m., which
arrived at Bethune Point WWTP at 11:22 a.m. When the unit arrived, the methanol and an adjacent
empty tank were fully involved in the fire.
Firefighters provided first aid to the two burn victims and set up a fire monitor to provide a continuous
stream of water onto burning insulation on the adjacent tank. Firefighters then evacuated everyone to an
assembly point outside the main gate. The Volusia County Hazardous Materials (HAZMAT) Team also
responded and assumed control of the firefighting effort. Firefighters extinguished the fire later that
afternoon. The HAZMAT Team emergency responders recovered the body of the first victim the
following day.
In addition to the three victims of the fire, 14 people sought medical evaluation. They included nine
firefighters, four Bethune Point WWTP employees, and one police officer. After evaluation, one
firefighter was transported to the hospital, treated, and released. There were no off-site consequences
from this incident.
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3.0 Analysis
The following sections analyze several causes CSB identified (Appendix A) including
鈥? a lack of methanol hazard recognition;
鈥? a lack of safety and hazard review in job planning;
鈥? methanol piping failure; and
鈥? an ineffective flame arrester.
3.1 Chemical Hazard Recognition
Chemical hazard recognition is commonly addressed through a hazard communication (HAZCOM)
program that provides employees with information on chemical hazards and trains them on specific
hazards and the use of available information. OSHA standards6 require HAZCOM programs, however
the City of Daytona Beach is not required to comply with these standards (Section 4.0). Although not
required by regulation, the City of Daytona Beach maintains and makes available written information on
chemical hazards and conducts safety and HAZCOM training.
As part of the investigation, the CSB analyzed Bethune Point WWTP employee continuing training
records for safety and HAZCOM for 12 years preceding the incident; Table 1 lists these safety training
topics. Of these, the City offered HAZCOM (also known as Right-to-Know) training only seven times
and not since 2002. OSHA standards require employers to conduct HAZCOM training annually.
6
29 CFR Part 1910, Occupational Safety and Health Standards.
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Bethune Point WWTP March 2007
Table 1. Bethune Point WWTP safety training classes from 1994-2005.
Sessions Last Year
Safety Training Topic
Conducted Conducted
Gas Detector 2 2005
Lockout Tagout 3 2004
Self Contained Breathing Apparatus (SCBA) 11 2003
Fire Extinguisher 1 2003
Confined Space 2 2002
Right-to-Know 鈥? Material Safety Data Sheets
7 2002
(HAZCOM)
Heat Exhaustion - Hot Environment 3 2001
Blood Borne Pathogens 2 2000
Fall Arrester 2 2000
Ultra Violet Lamps 1 2000
Uninterruptible Power Supply 1 2000
Air Pac (SCBA) 6 1999
Process Hazard Analysis Team Meeting 1 1998
Vehicular safety 1 1997
Fire Safety 1 1997
Foot Protection Awareness 1 1997
Entry Retrieval System 1 1996
Back Safety 1 1995
The city used a variety of training resources, including the Daytona Beach Fire Department; private
contractors; equipment suppliers; and city personnel.
The contract for the 1993 plant upgrade that added the methanol system included a requirement for staff
training; however, a detailed record of this training was unavailable. While a training abstract found in
the contract files listed training topics, the CSB could not determine from this abstract if the methanol
storage tank, flame arrester, and methanol hazards were covered. Interviewed employees remembered
some methanol system training in 1993, but none could identify the purpose of the flame arrester or how
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Bethune Point WWTP March 2007
the tank vented. In addition, employees could not remember if any of the HAZCOM (Right-to-Know)
training sessions covered methanol hazards.
Up to calendar year 2000, the City offered an average of five safety-related training sessions at Bethune
Point WWTP each year; however, since 2000 the number of such sessions7 declined steadily (Figure 3).
This decline may have been influenced by the repeal of the Florida public employee safety law (2000)
and the elimination of City of Daytona Beach full-time Safety Position (2004).
10
9
8
Number of safety related training
sessions reported to CSB
7
6
5
4
3
2
1
0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Year
Figure 3. Bethune Point WWTP safety related training sessions.
In summary, the CSB found that the scope, content, and frequency of the HAZCOM training provided to
Bethune Point WWTP employees did not adequately prepare them to deal with the hazards associated
with flammable materials such as methanol.
7
Many of the sessions were less than 1 hour in length.
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Bethune Point WWTP March 2007
3.2 Safety and Hazard Review in Job Planning
The CSB found that the City of Daytona Beach had not implemented a systematic method for identifying
hazards during non-routine work,8 nor did the City have a permit-to-work system. Non-routine tasks can
be among the most hazardous at any facility. The lack of formal written procedures and general
unfamiliarity with the work increase the risk of these tasks. A permit-to-work system is a widely used
technique for evaluating hazards of non-routine work. Had the city used a permit-to-work system or other
work control practice, this incident may have been prevented.
The objective of permit-to-work systems is to ensure that non-routine work is properly planned and
authorized prior to commencing. Generally, a designated individual who is not the planner or executor of
the work signs the permit authorizing the work to proceed. This individual is typically a supervisor,
safety technician, or senior operator.
Permits can be issued to control any type of work, but those that are inherently hazardous are the most
important. Lees (2001) and the Center for Chemical Process Safety (CCPS) (1995) list hazardous
activities, including hot work9, that especially warrant inclusion in a permit system
8
Examples of non-routine work can include repairs, corrective maintenance, troubleshooting, and infrequent tasks.
9
Hot work is defined as any work that may be a source of ignition, including open flames, cutting and welding,
sparking of electrical equipment, grinding, buffing, drilling, chipping, sawing, or other similar operations that
create hot metal sparks or hot surfaces from friction or impact.
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Bethune Point WWTP March 2007
3.3 Methanol Piping
3.3.1 Piping Design
CDM, the methanol system designer, specified10 polyvinyl chloride (PVC) piping, valves, and fittings for
all of the above- and below ground piping in the methanol system.
The aboveground PVC piping (Figure 4) included:
鈥? a 4-inch nominal pipe size (NPS) fill pipe that connected a flange on the top of the tank to a fill
connection near ground level;
鈥? a 4-inch NPS outlet pipe, connected to a valve on a flange near the bottom of the tank that supplied
the methanol pumps;
鈥? two 1-inch NPS pipes and PVC valves that connected a level switch to two flanges near the bottom of
the tank; and
鈥? a 4-inch NPS vent pipe connected to a flange on the top of the tank to the flame arrester. The flame
arrester end of this pipe was threaded.
10
Bethune Point WWTP Facility Upgrade project specifications prepared by CDM, under contract to the City of
Daytona Beach, section 11354, Methanol Feed System.
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Bethune Point WWTP March 2007
Figure 4. Aboveground PVC methanol pipes
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Bethune Point WWTP March 2007
3.3.2 Piping Specifications and Standards
The CDM methanol system specification11 required that 鈥淸t]he entire system shall comply with all
applicable OSHA rules and regulations.鈥? Therefore, OSHA standard 1910.106, 鈥淔lammable and
Combustible Liquids,鈥? would have applied to this installation. This standard requires that all
aboveground piping containing flammable liquids be steel, nodular iron, or malleable iron. The tensile
strength and fracture toughness12 of steel is more than ten times greater than the PVC plastic pipe used for
the methanol system.
OSHA standard 1910.106 does allow materials that soften on fire exposure such as plastics, but only
when 鈥渘ecessary.鈥? CDM stated13 that it specified PVC for its compatibility with methanol and its ability
to withstand the system pressure. The CSB noted that published corrosion data indicate that steel is
compatible with methanol, that steel piping is widely used in flammable liquid systems, and that the
methanol tank specified by CDM was made of steel. From this, the CSB concluded that no necessity to
use PVC pipe existed.
The CDM methanol tank specification14 required that the tank comply with National Fire Protection
Association Standard (NFPA) 30, Flammable and Combustible Liquids Code (1990). NFPA 30 section
3-3.3 requires that all valves connected to storage tanks be steel. Despite this requirement, CDM
11
Bethune Point WWTP Upgrade project specifications (idem).
12
Fracture toughness is a measure of a materials ability to resist brittle failure.
13
In response to an interrogatory in which the CSB asked CDM to describe the necessity for using PVC piping.
14
Bethune WWTP Upgrade project specifications prepared by CDM, under contract to the City of Daytona Beach,
section 13515, Methanol Chemical Storage Tank.
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Bethune Point WWTP March 2007
informed Indian River Industrial Contractor Inc. (IRIC), the facility constructor, that PVC ball valves
could be used.15
Although NFPA 30 and OSHA standard 1910.106 permit plastic materials in aboveground flammable
liquid systems under certain conditions, other widely recognized standards prohibit them. These include
the American Society of Mechanical Engineers (ASME) Process Piping Code, ASME B31.316 and the
Building Officials Code Administrators (BOCA) National Mechanical Code, Seventh Edition.17
3.3.3 Piping Failure
The physical evidence indicates that the PVC piping connected to the methanol tank mechanically failed
in multiple locations from the upward movement of the tank caused by the internal explosion. This
evidence includes:
鈥? The burn pattern on the side of the tank, which most likely occurred when pressure from the internal
explosion forced methanol up an internal pipe and sprayed it out of the separated fill pipe onto the
side of the tank.
鈥? The burn pattern on the ground east of the tank, which most likely occurred when pressure from the
explosion sprayed methanol onto the ground through the failed outlet pipe connected near the bottom
of the tank.
鈥? Two PVC valves and a portion of the connected pipe found in the concrete containment that
surrounded the tank. These valves and their associated PVC pipe and flanges were installed between
15
CDM response to an IRIC request for information dated May 12, 1993.
16
Chapter VII, Nonmetallic Piping and Piping Lined with Nonmetals, paragraph A323.4.2 (a) (1).
17
Article 9, Flammable and Combustible Liquid Storage and Piping Systems, paragraph M-901.5.
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Bethune Point WWTP March 2007
steel flanges on the tank and steel flanges on the level switch. A recovered valve shows the fractured
PVC pipe between the valve and flange (Figure 5).
Figure 5. Failed 1-inch PVC pipe showing fracture surface
鈥? PVC material lodged in the threads of the flame arrester and visible damage to the threads on the end
of the PVC vent pipe.
The two fractured PVC pipes supporting the level switch pointed directly toward the crane cab where the
mechanic was sitting. Methanol discharging under pressure most likely sprayed the cab, ignited and
seriously burned the mechanic inside. Figure 6 shows the burned-out cab aligned with the 1-inch pipe
flanges on the tank.
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Bethune Point WWTP March 2007
Figure 6. Methanol spray from 1-inch pipe flanges onto the crane cab.
The PVC vent pipe was below the man-lift basket. After the flame arrester blew off the vent pipe,
burning methanol vapors under pressure would have likely discharged into the basket where two workers
were standing. Figure 7 shows the location of the basket relative to the vent pipe.
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Bethune Point WWTP March 2007
Figure 7. Location of man-lift basket and 4-inch vent pipe
Had the methanol piping and valves been constructed of steel, the system would most likely have
remained intact. The mechanic in the crane would likely not have been killed, and the other two workers
may have been less severely injured.
3.4 Methanol Tank Flame Arrester
The methanol storage tank vent was equipped with a flame arrester in accordance with NFPA 30. Flame
arresters are devices that stop a flame while allowing gases and vapors to flow freely and work by
channeling gas and/or vapor through narrow gaps between metal plates. The transfer of heat to the plates
extinguishes a flame moving through the gaps. Proper sizing of the gaps and plates is critical to the flame
arrester performance. Any blockage in the gaps or corrosion of the plates can render a flame arrester
ineffective.
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Bethune Point WWTP March 2007
The flame arrester on the methanol storage tank vent pipe was a Protectoseal Model No. 864 (Figure 8).
Because the vent through the flame arrester was always open, the tank discharged methanol vapors when
filled or warmed and took in air when drained or cooled.
Figure 8. Protectoseal Model No. 864 flame arrester
(picture courtesy of Protectoseal)
The flame arrester plates and housing were aluminum. Published corrosion data18 indicates that methanol
corrodes aluminum. The flame arrester was severely corroded on the interior surface, the plates were
clogged with aluminum oxide scale, and plates were broken with portions missing (Figure 9 and Figure
10). Corrosion on the broken plate edges indicates that the broken plate damage most likely occurred
prior to the incident.
18
NACE International, The Corrosion Society (2002). Corrosion Survey Database (COR路SUR). NACE
International.
27
Bethune Point WWTP March 2007
Figure 9. Flame arrester plate corrosion (outside)
Figure 10. Flame arrester plate corrosion (inside)
Correspondence among the construction company (IRIC); the construction manager (CDM); and the City
of Daytona Beach indicated that the need for a flame arrester was identified late in the project. IRIC
proposed three models for purchase, all of which had aluminum plates installed in an aluminum housing.
CDM selected the Protectoseal Model 864 because it was readily available. Although Protectoseal
offered flame arresters made of materials not corroded by methanol, none of these was proposed or
selected.
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Bethune Point WWTP March 2007
Flame arresters require regular inspection and maintenance (cleaning) to maintain functionality. Dirt and
small particles collecting in the narrow gaps between the flame arrester plates, insects nesting in the
housing, and corrosion can degrade performance. Regular inspection can identify excessive corrosion. In
1993, when the methanol system became operational, both Protectoseal19 and a major methanol
producer20 recommended regular flame arrester maintenance and inspection. However, no requirement
for flame arrester maintenance and inspection was included with the operation and maintenance
instructions CDM provided the City. Interviews indicate that Bethune Point WWTP personnel were
unaware of the need to inspect and maintain the flame arrester.
The CSB concluded that the flame arrester did not prevent the fire outside the tank from igniting the tank
contents. Routine inspections would have detected the corrosion in the flame arrester that occurred over
12 years. The use of an aluminum flame arrester in methanol service, coupled with the lack of inspection
and maintenance, allowed the flame arrester to corrode to the point that it no longer functioned.
19
From literature normally provided by Protectoseal with flame arresters.
20
Based on a DuPont methanol product guide provided by CDM and found in the City of Daytona Beach contract
file for the 1993 upgrades to the Bethune Point WWTP.
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4.0 Regulatory Analysis
4.1 OSHA Regulations
The City of Daytona Beach was not required to comply with or implement OSHA regulations. Had the
city implemented hot work and HAZCOM programs conforming to OSHA safety standards, the hazards
of using a torch in proximity to the methanol tank would likely have been identified and possibly
prevented.
Public employers are not covered by the Occupational Safety and Health Act of 1970 because section 3(5)
of the act defines 鈥渆mployer鈥? as 鈥渁 person engaged in a business affecting commerce that has employees,
but does not include the United States (not including the United States Postal Service) or any State or
political subdivision of a State.鈥?
The Occupational Safety and Health Act includes two opportunities for city, county, and state employers
to provide OSHA coverage: 鈥渟tate plans鈥? and 鈥減ublic employee-only plans.鈥? Section 18 of the Act
authorizes states to establish their own occupational safety and health programs, or 鈥渟tate plans,鈥? and
Section 18(c)(6) requires all states that run their own state plans to establish 鈥渁n effective and
comprehensive occupational safety and health program applicable to all employees of public agencies of
the State and its political subdivisions.鈥? Twenty one states have adopted OSHA state plans. OSHA
regulation 29 CFR 1956.1 allows states that do not have state plans to adopt 鈥減ublic employee-only
plans鈥? to provide OSHA coverage even where no state plan covering private employers is in effect.
Three states have adopted these 鈥減ublic employee plans鈥? Appendix B includes a list of states and their
OSHA coverage.
The federal government establishes staffing and enforcement benchmarks for 鈥渟tate plans鈥? and 鈥減ublic
employee-only plans鈥? to ensure enforcement and standards are 鈥渁t least as effective鈥? as the federal
30
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program. The state programs must also adopt all OSHA standards or issue their own standards that are
鈥渁t least as effective as鈥? OSHA standards. The federal government matches funding for approved 鈥渟tate
plans鈥? and 鈥減ublic employee-only plans.鈥?21
OSHA coverage provides four major benefits to employees:
鈥? Coverage by OSHA standards (or equivalent state standards). Most of these are in 29 CFR 1910
(General Industry) and 1926 (Construction).
鈥? Ability to file a complaint and receive an OSHA inspection without fear of employer retaliation.
鈥? Right to participate in, receive the results of OSHA inspections, and have an opening and closing
conference with the OSHA inspector separate from the employer.
鈥? Ability to request and receive information from the employer on workplace monitoring of chemicals,
noise and radiation levels, and chemical hazards covered by the OSHA HAZCOM standard. The
Occupational Safety and Health Act also gives employees the right to review their employer鈥檚 injury
and illness log and relevant exposure and medical records.
Some of the remaining 26 states without 鈥渟tate plans鈥? and 鈥減ublic employee-only plans鈥? provide safety
and health protection to public employees, although these programs do not receive federal funding and are
not subject to federal OSHA oversight. Florida had such a program until it was eliminated in 2000.
21
Further information about state plans is available at http://www.osha.gov/dcsp/osp/index.html.
31
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4.2 Florida Public Employee Safety
4.2.1 History
The Florida Occupational Safety and Health Act, 22 enacted in 1982, directed the Florida Division of
Safety (a division within the Department of Labor and Employment Security) to assist employers (both
private and public, including cities and counties) to make their workplaces safer and decrease the
frequency and severity of on-the-job injuries. State, city, and county employers were required to comply
with most OSHA regulations and the state had the authority to cite public employers.
The Florida legislature repealed Chapter 442 in 1999.23 Until its repeal, the Florida legislature
appropriated approximately $11 million per year for occupational safety and health programs, which
funded a statewide staff of 146 employees, 21 of whom worked in a consulting program for private small
businesses that received matching funds from the federal government. The remaining 125 staff members
addressed public sector (i.e., state and municipal employers) occupational safety and health compliance.
Following the repeal of Chapter 442, the governor issued an executive order24 addressing public employee
safety and health. State agencies listed in the executive order were directed 鈥渢o voluntarily comply鈥? with
General Industry OSHA standards.25 The executive order recommends that each city and county (as well
as state agencies not specifically covered in the first part of the executive order) 鈥渞eview鈥? existing
policies, practices and procedures concerning workplace safety and implement any policies, practices or
22
Florida Statutes, Chapter 442.20.
23
Chapter 2001-65, House Bill No. 669. The repeal was effective July 1, 2000.
24
Florida Executive Order Number 2000-292 dated September 25, 2000.
25
29 CFR 1910, Subparts C through T and Subpart Z. Construction standards in 29 CFR 1926 are excluded.
32
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procedures made necessary by the repeal of Chapter 442.鈥? 26 The Florida legislature provided no funding
to state agencies, cities or counties to implement the executive order.
Today, no Florida state laws or regulations exist to require municipalities to implement safe work
practices for or communicate chemical hazards to municipal employees.
4.2.2 Florida Municipal Safety Program Survey
The CSB conducted a telephone survey of six Florida cities and three Florida counties to determine the
extent of their voluntary compliance with OSHA standards. As part of the survey, the CSB investigators
interviewed occupational safety and health or loss control managers.
Most entities surveyed reported having policies requiring compliance with OSHA standards. In some
cases, the CSB also spoke with union representatives at the surveyed city or county. Some union
representatives confirmed voluntary compliance with OSHA standards, but others described hazardous
conditions and incidents indicating that OSHA standards and good safety practices are not fully
implemented and that conditions are not evaluated or remedied, despite employee complaints.
Voluntary compliance with OSHA standards does not provide public sector employees with all the rights
conveyed to private sector employees (and covered public sector employees) under the Occupational
Safety and Health Act. Even if the employer conforms with all OSHA General Industry standards,
employees remain without the legal right to receive an OSHA inspection or to review relevant records and
medical and exposure information. Additionally, non-mandatory safety programs are vulnerable to
changes in budgetary priorities.
26
Although mandatory for state agencies, other political subdivisions and the public have no legal obligation to
comply with an executive order issued by the governor.
33
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4.2.3 Florida Public Facility Chemical Incidents
In addition to surveying several Florida cities and counties, the CSB researched27 the frequency and
severity of chemical incidents at Florida public facilities. In addition to the incident at the Bethune
WWTP, the CSB found 33 additional chemical incidents at public facilities in the last five years. The
incidents resulted in 9 injuries, 23 medical evaluations for chemical exposure, and 15 evacuations
involving the facility or surrounding community. All of these incidents involved chemicals that would
normally be included in an OSHA compliant hazard communication program.
4.2.4 Safety Consultation
The University of South Florida administers a voluntary private sector worker safety consultation
program for the State of Florida. Half of the program funding comes from the Florida鈥檚 Workers鈥?
Compensation Trust Fund, the other half as matching funds from the U.S. Department of Labor.28 The
program has a state-wide staff of 17 and offers confidential health and safety compliance consulting to
private small business owners, with the goal of encouraging them to voluntarily improve workplace
safety. Because of restrictions on federal funding, the program is prohibited from offering consultation to
Florida鈥檚 public employers.
27
Media reports, National Response Center reports and the EPA Risk Management Program database.
28
Section 21(d) of the Occupational Safety and Health Act of 1970 authorizes states to enter into a cooperative
agreement with OSHA and receive matching Federal funds for consultation programs.
34
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5.0 Key Findings
1. The City of Daytona Beach has no program, written or otherwise, to control hot work at city
facilities.
2. The CSB found no evidence that workers at the Bethune Point WWTP received any methanol
hazard training in the last 10 years.
3. The City of Daytona Beach does not require work plan reviews to evaluate the safety of non-
routine tasks.
4. OSHA 1910.106 permits the use of plastic piping in flammable liquid piping systems when
necessary but does not define necessary.
5. NFPA 30 permits the use of plastic piping in flammable liquid piping systems under certain
conditions.
6. The methanol tank did not comply with NFPA 30. Valves and their connection to the tank were
PVC instead of steel.
7. The failure of the PVC piping attached to the tank and in the methanol system greatly increased
the consequences of the incident.
8. Flame arrester maintenance requirements were not included in the operation and maintenance
manual for the methanol system.
9. An aluminum flame arrester was installed on the methanol tank; methanol corrodes aluminum.
10. The flame arrester was not inspected or cleaned since its installation in 1993.
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Bethune Point WWTP March 2007
11. The flame arrester was so degraded (gaps between the plates inside the flame arrester were
plugged with dirt and aluminum oxide and portions of the plates were corroded away) that it did
not prevent a flame from entering the tank which greatly increased the consequences of the
incident.
12. No Florida state laws or regulations exist to require municipalities to implement safe work
practices.
13. No Florida state laws or regulations exist to require municipalities to communicate chemical
hazards to municipal employees.
14. Florida municipalities are not covered by OSHA workplace safety standards.
15. No state or federal oversight of public employee safety exists in the State of Florida.
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6.0 Root and Contributing Causes
6.1 Root Causes
The City of Daytona Beach
1. did not implement adequate controls for hot work at the Bethune Point WWTP; and
2. had an ineffective HAZCOM program.
6.2 Contributing Causes
1. The City of Daytona Beach has no systematic program to evaluate the safety of non-routine tasks.
2. The aboveground piping and valves in the methanol system were constructed of PVC in lieu of
steel.
3. An aluminum flame arrester was installed on the methanol tank even though methanol is known
to corrode aluminum.
4. The operation and maintenance manual for the Bethune Point WWTP did not include a
requirement to maintain the flame arrester.
37
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7.0 Recommendations
The CSB makes recommendations based on the findings and conclusions of the investigation.
Recommendations are made to parties that can affect change to prevent future incidents, which may
include the facility where the incident occurred, the parent company, industry organizations responsible
for developing good practice guidelines, regulatory bodies, and/or organizations that have the ability to
broadly communicate lessons learned from the incident, such as trade associations and labor unions.
Governor and Legislature of the State of Florida
2006-03-I-FL-R1
Enact legislation requiring state agencies and each political subdivision (i.e. counties and municipalities)
of Florida to implement policies, practices, procedures, including chemical hazards covering the
workplace health and safety of Florida public employees that are at least as effective as OSHA. Establish
and fund a mechanism to ensure compliance with these standards.
Consider legislation providing coverage of Florida public employees under an occupational safety and
health program in accordance with Section 18(b) of the Occupational Safety and Health Act of 1970, and
Code of Federal Regulations 29 CFR 1956.1.
2006-03-I-FL-R2
Develop and fund a workplace safety and health consultation program for Florida public employees
similar to the private sector program currently administered by the Florida Safety Consultation Program at
the University of South Florida.
38
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City of Daytona Beach
2006-03-I-FL-R3
Adopt city ordinances to require departments to implement policies, practices, and procedures concerning
safety and health in the workplace for city employees that are at least as effective as relevant OSHA
standards. Emphasize compliance with chemical standards, including hot work procedures (OSHA
Welding, Cutting, and Brazing Standard, Sections 1910.251 and 1910.252) and chemical hazard
communication (OSHA Hazard Communication Standard 29 CFR 1910.1200). Implement procedures to
ensure compliance with these policies, practices and procedures.
2006-03-I-FL-R4
Ensure that flammable liquid storage tanks used throughout the city comply with NFPA 30 and minimum
federal standards in 29 CFR 1910.106, including appropriate piping and flame arresters.
National Fire Protection Association
2006-03-I-FL-R5
Revise NFPA 30 to specifically exclude the use of thermoplastics in aboveground flammable liquid
service.
U.S. Department of Labor, Occupational Safety and Health
Administration
2006-03-I-FL-R6
Revise 29 CFR 1910.106 to specifically exclude the use of thermoplastics in aboveground flammable
liquid service.
39
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Water Environment Federation
2006-03-I-FL-R7
Work with the Methanol Institute to prepare and distribute a technical bulletin containing information on
the safe receipt, storage, use, and dispensing of methanol in wastewater treatment plants. In addition,
include information on basic fire and explosion prevention measures when using bulk methanol (e.g.,
flame arrester maintenance, hot work programs, electrical classification).
2006-03-I-FL-R8
Work with the Methanol Institute to prepare safety training materials for wastewater treatment facilities
that use methanol.
Methanol Institute
2006-03-I-FL-R9
Work with the Water Environment Federation to prepare and distribute a technical bulletin containing
information on the safe receipt, storage, use, and dispensing of methanol in wastewater treatment plants.
In addition, include information on basic fire and explosion prevention measures when using bulk
methanol (e.g., flame arrester maintenance, hot work programs, electrical classification).
2006-03-I-FL-R10
Work with the Water Environment Federation to prepare safety training materials for wastewater
treatment facilities that use methanol.
40
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Camp Dresser & McKee Inc.
2006-03-I-FL-R11
Revise CDM policies and procedures to ensure that appropriate quality control measures are applied so
that designs specify appropriate materials and comply with applicable safety standards. Ensure that
wastewater treatment plant design engineers are aware of the importance of proper material selection as
well as the findings and recommendations of this report.
2006-03-I-FL-R12
Communicate the findings and recommendations of this report to all companies that contracted with
CDM for methanol and other flammable liquid systems that were constructed with aboveground plastic
pipe. Recommend replacing plastic pipe with an appropriate material in accordance with NFPA 30 and
OSHA 1910.106.
2006-03-I-FL-R13
Communicate the findings and recommendations of this report to all companies that contracted with
CDM for flammable liquid systems that included a flame arrester. Emphasize the importance of periodic
maintenance of the flame arrester to ensure its effective performance.
41
Bethune Point WWTP March 2007
By the
U.S. Chemical Safety and Hazard Investigation Board
Carolyn W. Merritt
Chair
John S. Bresland
Member
Gary Visscher
Member
William Wark
Member
William Wright
Member
Date of Board Approval
42
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8.0 References
American Society of Mechanical Engineers (ASME), 1999, Process Piping Code, ASME B31.3.
Center for Chemical Process Safety (CCPS), 1995. Guidelines for Safe Process Operations and
Maintenance, American Institute of Chemical Engineers (AIChE).
Florida, 2006a. Fire Prevention and Control Florida Statutes, Chapter 663.
Florida, 2006b. The Florida Fire Prevention Code, Florida Administrative Code, Chapter 69A-60.
Lees, F. P., 2001. Loss Prevention in the Process Industries, Vol. 3, Butterworth-Heinemann.
National Fire Protection Association (NFPA), 2003a. Fire protection in Wastewater Treatment Plants,
NFPA 820.
NFPA, 2003b. Standard for Fire Prevention During Welding, Cutting and other Hot Work, NFPA 51B.
NFPA, 2003c. Uniform Fire Code, NFPA 1.
NFPA, 2003d. Uniform Fire Code-Florida Edition, NFPA 1.
Occupational Safety and Health Administration (OSHA), 2006. Flammable and combustible liquids, 29
CFR 1910.106, OSHA.
Pegula, S. M., 2004. Fatal Occupational Injuries to Government Workers, 1992 to 2001, Bureau of Labor
Statistics, 2004.
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Appendix A: ROOT CAUSE LOGIC DIAGRAM
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47
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Appendix B: PUBLIC EMPLOYEE OSHA COVERAGE
48
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PUBLIC EMPLOYEE OSHA COVERAGE
State OSHA Coverage
Alabama
Alaska State Plan
Arizona State Plan
Arkansas
California State Plan
Colorado
Connecticut Public Employee Only Plan
Delaware
Florida
Georgia
Hawaii State Plan
Illinois
Indiana State Plan
Iowa State Plan
Kansas
Kentucky State Plan
Louisiana
Maine
Maryland State Plan
Massachusetts
Michigan State Plan
Minnesota State Plan
Mississippi
Missouri
Montana
Nebraska
Nevada State Plan
New Hampshire
New Jersey Public Employee Only Plan
New Mexico State Plan
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State OSHA Coverage
New York Public Employee Only Plan
North Carolina State Plan
North Dakota
Ohio
Oklahoma
Oregon State Plan
Pennsylvania
Puerto Rico State Plan
Rhode Island
South Carolina State Plan
Tennessee State Plan
Texas
Utah State Plan
Vermont State Plan
Virgin Islands Public Employee Only Plan
Virginia State Plan
Washington State Plan
West Virginia
Wisconsin
Wyoming State Plan
50
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