5.38.2 SITE EVALUATION
When
operations will take place where the water is suspected or known to
be contaminated, a site assessment must be conducted. This
assessment should include:
·
Any suspected contaminants and potential hazards.
·
Testing of the dive environment: It is not always possible to tell
whether an environment is contaminated either by sight or by smell.
Any diving environment should be approached with caution and when
contamination is suspected, the water tested prior to commencing
operations.
·
Wind: In situations where there may be toxic fumes, the dive station,
compressor, and topside personnel must be situated up-wind from any
source of contamination to the air.
·
Current: Both on the surface and underwater, the diver should
approach any known point-source of contaminant from the up-current side
whenever possible. This will allow the current to carry
contaminants away from the diver.
·
Perimeter: Whenever possible, a perimeter should be established
around the dive station and dive site to keep unprotected persons
away from any possible contamination.
·
Established zones: Zone management should be employed when
applicable to keep unprotected personnel and equipment outside of
the hot zone.
5.38.3 TOPSIDE PERSONNEL PROTECTIVE EQUIPMENT: EPA
SELECTION GUIDELINES
To aid in the selection of complete protective
ensembles, including chemical protective clothing and respirators,
the United States Environmental Protection Agency's (EPA) Office of
Emergency and Remedial Response has designated four levels of
chemical hazards, ranging from extremely dangerous or unknown
(Level A) to situations where only basic work wear (Level D) is the
required protection. The OSHA Standard recommends the use of
these guidelines, which can assist employers in complying with the
protective equipment requirements of the Standard.
The
following is a brief review of the EPA guidelines. These are
explained in greater detail in Appendix B of the OSHA Standard and
Table 1.
·
Level A calls for a vapor-tight suit (total-encapsulating) that is
non-permeable to the chemicals to which a worker will be
exposed. Also necessary is an approved, positive-pressure
self-contained breathing apparatus (SCBA) or a NIOSH-approved,
positive-pressure air-line respirator with escape SCBA having no
less than a five-minute air cylinder. Outer and inner
chemical-resistant gloves and chemical-resistant boots with a steel
toe and shank should also be used.
·
Level B necessitates the same level of respiratory protection and
complete skin coverage. However, protective clothing does not
have to be vapor tight.
·
Level C calls for a full-face piece, or half-mask air-purifying
respirator, and splash garments used with outer and inner chemical
resistant gloves and chemical resistant boots with a steel toe and
shank.
·
Level D calls for basic work wear such as long sleeve coveralls,
hard-soled shoes and face shields or goggles.
a.
Before any diving operation is conducted in contaminated water a
risk assessment is vital. Personal Protective Equipment (PPE) must
be selected based on its known ability to protect workers from the
specific hazards present or suspected. This applies to the diver
and the topside personnel. There are four different
categories of topside PPE from the least protective - Level D - to
total encapsulation - Level A. Requirements for these levels
are set forth in Table 1.
b.
The key variables that must be considered when selecting PPE are:
·
Identification of the hazard(s)
·
Route of potential hazard to employees, i.e., inhalation, skin
absorption, ingestion, and eye or skin contact
·
The performance of PPE materials, seams, visors, and all other
vital components
·
Matching PPE durability of materials such as seam, tear, burst, and
abrasion strength to dive site-specific conditions
·
Matching site environmental conditions to PPE effect on employees
(i.e., heat stress, hypothermia, dehydration, duration of task,
etc.)
·
Equipment selection (PPE). Site specific variables must be
considered and protection geared to the worst case situation if
those variables are not positively identified. The more that
is known about the site, the easier it will be to customize
suitable PPE to ensure protection of the dive team topside members.
TABLE
1
GUIDELINES FOR SELECTION OF PERSONAL PROTECTIVE
EQUIPMENT
(Go to the ADCI web site in the Safety Notices
section for the entire guideline, as well as all tables.)
5.38.4 DIVER-WORN OR CARRIED EQUIPMENT AND
ACCESSORIES
a.
Selection of the diver-worn equipment must be based on the level of
contamination protection required. The following equipment
configurations are only recommendations! Responsibility for
selection of equipment and diving technique must be made by the
persons engaged in the diving activity as identified in the Dive
Plan and/or Job Safety Analysis.
b.
Equipment that supports the diver must also be compatible with the
contaminants that may be encountered.
c.
There are three levels of protection for diver-worn equipment and
accessories, from the most protective - Level One - to the least
protective - Level Three. Requirements for these levels are set
forth in Table 2.
DIVER-WORN OR CARRIED EQUIPMENT AND ACCESSORIES
(See ADCI web site Safety Notices section for
this table)
Any actual or suspected breach of a Level One Diving
System is cause for the immediate termination of diving operations.
5.38.5 DECONTAMINATION PROCEDURES
In certain highly contaminated diving situations, the following
procedures may be
applied, but are not necessarily applicable for every job:
a.
The area surrounding the diving control station may be divided into
three (3) zones for proper isolation of contamination. The zone
immediately surrounding the point of water entry/exit is deemed
"high contamination." The zone where divers and gear
progress after initial decontamination is termed "low
contamination." The final zone into which the divers progress
after they have been decontaminated and all diving gear removed is
"clean."
b.
An effective color-coding system may be employed to communicate
clearly the demarcation point of the decontamination area. One
system might be to use red to identify all "high" areas,
yellow for "low" areas, and green for "clean"
areas. If at all feasible, the "clean" zone should be
positioned up-wind of the contaminated zones.
c.
Initial Freshwater Rinse: Spray off bulk of contaminants
using high-pressure, clear freshwater rinse. If effluent does not
require capture, begin hosing diver as he initially exits water to
limit quantity of contaminants transferred to the dive station.
·
Take precautions to direct water flow away from potential points of
leakage of diver's rig such as exhaust valves, seal junctions, etc.
A high-pressure jet of water directed at such potential breach
points may inject contaminants inside of the protective gear and
into contact with the diver. Care should be taken to ensure the
removal of the bulk of contaminants at this stage in order to
afford the greatest efficacy of subsequent decontamination steps.
d. Oversuit: If a reasonable
expectation exists for encountering bulky, adherent contaminants in
the course of a dive, the use of a disposable oversuit is strongly
encouraged. Disposable hazardous material protective suits may be
secured to a diver after he has been outfitted with the entire
diving rig.
·
No effort to make the oversuit water-tight should be attempted.
Such action could complicate the dive by creating air pockets that
could affect buoyancy of the diver. As the diver arrives on the
dive station, the oversuit should be cut away to allow for
decontamination of the diver and equipment. At this time, removal
of dive gear such as harnesses, weight belts, emergency gas supply
(bailout) tanks, etc. should be performed with these items
themselves being properly decontaminated.
e.
Scrub Down: After the diver has been initially rinsed and his
equipment removed, the diver may be scrubbed with a stiff-bristle
synthetic brush and a cleaning solution as applicable. Long-handled
brushes may facilitate the cleaning process. Hand-held brushes may
be employed for detailed cleaning of the dive helmet and the
neck-dam interface.
·
Once the diver has been thoroughly scrubbed with cleaning solution
applied from head to toe, he should be rinsed with fresh water.
Care should be taken to ensure the diver has been cleaned of all
visible contamination, most notably in the area adjacent to the
neck-dam, helmet, and dry suit.
·
The composition of the cleaning solution should be appropriate for
the contaminant to be removed.
f.
Undress Diver: Once the diver has been adequately decontaminated
and moved into the "low contamination" zone, the dive
gear should be removed. First, disconnect the locking mechanism
from the helmet to dry suit and remove the helmet. Then, remove the
dry suit and gloves, and finally, undergarments.
·
If there are no indications that the diving rig has been breached
during the dive, the diver may proceed to the "clean"
zone and if applicable take a post-dive shower.
·
If there are positive indications of dermal exposure to
contaminants, additional decontamination measures may be required.
g.
Clean Equipment: After removal from the diver, all equipment should
undergo secondary decontamination.
h. Capture Effluent: In some circumstances it will be
necessary that all fluids used to rinse, wash, and re-rinse the
diver and equipment must be captured for appropriate hazardous
material disposal. If necessary, the above procedures will need to
be altered to ensure that all decontamination procedures take place
within a water impermeable capturing area.
5.38.6 HAZARD
EVALUATION AND IDENTIFICATION1
a.
When the threat of a chemical hazard is suspected, consider
conducting a historical review of the site. Items such as spill
history, known chemicals present, volume of chemicals, active
discharges, air quality, present and past nature of operations, and
presence of extremely hazardous substances should be examined.
Facility safety officers, plant supervisors, or technicians may
provide useful information.
b.
When planning Contaminated Water Diving Operations, water
temperature needs to be taken into account when determining the
proper equipment to be used.
c.
Check with local, state, or federal water quality agencies for
current advisories on biotoxins, waterborne pathogens, microbial
contamination, fish or shellfish advisories, beach closures, or
storm events, any of which may indicate pollutants to be present.
d.
When hazardous contaminants are suspected, consider
