The Redwoods Group
The Redwoods Group Insurance Program for YMCAs
RISK MANAGEMENT TOPIC
TOPIC: Aquatic Entrapment Guidelines – Pools and Spas
drain to become the sole inlet to the pump and becomes
UPDATE: Since the drafting of this article, the Virginia Graeme Baker
dangerous when there is an inadequate or missing drain cover.
Pool and Spa Safety Act has become federal law. Although the terms of
this law govern, the information below is still a useful reference to steps
that can be taken to address entrapment hazards in conjunction with
the requirements of the law. For more information on the Virginia
Graeme Baker act requirements, see RMT: Virginia Graeme Baker Act
Resources and
The U.S. Consumer Product Safety Commission cites 30 spa and
http://www.poolsafely.gov/state-local-officials/pool-spa-safety-act-requirements/.
hot tub incidents since 1990 in which long hair became entangled
in the drain grates – ten of which resulted in drowning deaths.
The National Spa and Pool Institute and the American National
Standards Institute have drafted a consensus standard to address the
These incidents typically involve females with long, fine hair who
are underwater with their head near a suction inlet. The water flow
risk of entrapment in pools and spas. This standard applies to both new
into the inlet draws the hair into the inlet and the hair becomes
construction and existing facilities.
entangled in and around protrusions and holes of the cover.
The nearly 150 documented entrapment incidents in pools and spas
Entrapment occurs because of the entanglement, not necessarily
over the last 20 years have resulted in 36 deaths. These figures almost
because of strong suction forces. These cases most frequently
certainly understate the problem, however – experts believe that many
occur in spas or hot tubs. Clothing or jewelry may become
cases of entrapment are classified solely as a near drowning or
entangled in loose or inappropriate ladders and similar equipment,
drowning. A majority of the victims of aquatic entrapment are aged five
or they can also be caught in a drain much as hair is and cause
to fourteen.
entrapment. Scenarios involving clothing and jewelry are, however,
relatively rare.
Hair or Mechanical Entrapment /
Entanglement
There are five types of suction
entrapment
Evisceration / Disembowelment
●
body entrapmenta section of the torso becomes entrapped
●
limb entrapmentan arm or leg is caught by or pulled into an open
drainpipe
●
hair entrapment or entanglementhair is pulled into and/or wrapped
around the grate of the drain cover
●
mechanical entrapmentthe bather’s jewelry or clothing gets caught
in the drain or the grate
●
eviscerationthe victim's buttocks come into contact with the pool
suction outlet and he or she is disemboweled
Body Entrapment / Limb Entrapment
These deaths or injuries primarily occur when the body or a limb is held
against the drain by the suction of the circulation pump, but also can
occur if a child gets a hand or foot caught between a ladder and the
pool wall or in some other restricted space. Such incidents primarily
involve children from eight to sixteen years old with the average age
being ten. In some of the cases the child may have been playing with
the open drain, e.g., inserting a hand or foot into the pipe, and then
became trapped by the resulting suction. From 1999 to 2010, 35% of
the reported entrapment cases were due to body entrapment. Many
different design and maintenance circumstances can potentially
produce entrapment conditions in pools and spas. The range of historic
scenarios suggest that this hazard exists whenever two conditions
coexist: 1 – there is an open drain or a flat grating that can be
completely covered by a body part; 2 – there is a plumbing
configuration that allows a suction buildup if the drain is blocked. This
poses a serious problem if the configuration allows a single bottom
The typical disembowelment scenario involves a young child, two
to six years old, who sits on an uncovered drain in a public wading
pool. Young children have access to the bottom drain in wading
pools because of the shallow water. Drains are normally equipped
with anti-vortex covers whose dome-shape prevents sealing of the
pipe opening by the body. However, if the cover or grate is
unfastened, broken, or missing, the potential for an incident exists.
If a child's buttocks cover the drain opening, the resulting suction
force can rupture the rectum and eviscerate the child. A small
change in pressure is sufficient to cause such injury extremely
quickly.
All pools and spas are required by the new standard to employ
the following in order to prevent entrapment:
1. All suction outlet covers/grates (main drain covers) that are fully
submerged shall be listed by a nationally recognized testing
laboratory. Any covers or grates that are built site specific must
be certified by a professional engineer to conform to the same
standards as the nationally recognized covers or grates. The
maximum system flow may not exceed the rating on any single
suction outlet cover/grate.
2. If a safety vacuum release system (SVRS) is used it must be
tested and listed. A venting SVRS device is permitted if it is
between the check valve and the main drains, but is not
permitted between the check valve and the pump. A
non-venting SVRS device is not permitted if your pool
incorporates a check valve.
3. A custom engineered vent system must be designed and
certified by a professional engineer to relieve a vacuum at the
© The Redwoods Group, 2017
Released 8/17/2006 | Revised 1/10/2013
The Redwoods Group
Aquatic Entrapment Guidelines – Pools and Spas — Page 2 of 3
outlet within 3 seconds after the covers are blocked.
■
As an alternative to point 2.a above you may convert the
main drain suction outlet to a return inlet by changing the
plumbing. This will route 100% of the system outlet flow
through the skimmer/overflow system.
■
Replace flat covers smaller than 12” x 12” with
listed/approved covers/grates.
■
Replace damaged and aged covers. In the past 10 years,
31% of entrapment cases involved broken, missing, or
disengaged covers.
■
Fasten covers properly. Covers or grates should not be able
to be removed without the use of tools.
■
Repair or replace damaged sump and fasteners. Enlarge the
sump if necessary to conform to ANSI standard.
4. Skimmers and overflows (gutters) shall be vented to the
atmosphere or incorporate an equalizer line. Any equalizer line
must be protected by an approved cover or grate.
5. Multiple pumps may draw water from a common sump provided
that the total flow from the pumps does not exceed an individual
main drain cover or grate rating. The water velocity in the sump
and connecting piping cannot exceed six feet per second.
Newly constructed pools and spas must utilize one of the
following ways of reducing entrapment potential:
1. Main drains are not required: The surface skimmer or
overflow/gutter system may draw 100% of the system outlet
flow.
2. Gutter/Overflow system: The perimeter/gutter overflow system
draws water through a gravity flow to a remote collector tank
that is not bather accessible.
3. Dual drains: A minimum of 2 listed/approved covers/grates are
provided for each pump in the suction outlet system. These
drains must be at least 3 feet apart measured from the center
or on different planes (wall and floor) and must simultaneously
draw water through a common line. Each suction outlet fitting
must be rated for the maximum system flow.
4. Channel drain system: One or more channel grates are
permitted provided they are 3 inches or greater in width and 31
inches or greater in length and fastened to prevent removal.
5. Custom designed suction outlet fittings: Any custom designs
must be approved by a licensed professional engineer.
6. Gravity fed system: Systems that use gravity flow through one
or more listed/approved covers/grates into a collection tank
must be vented to the atmosphere. If the collector tank is bather
accessible (as in a vanishing edge pool) the collection tank
must meet the entrapment standards of the pool and spa
guidelines or of the wading pool guidelines, depending on water
depth. A modulating float valve allowing direct suction is not
permitted if there is only one bather accessible main drain for
the system.
7. Venturi Debris Removal System: These systems are
acceptable through a single floor mount suction outlet provided
they have a listed/approved cover/grate.
8. Other Means: Any alternative configuration, design, or system
may be used provided the alternative meets the intent of the
standard and is approved by a certified engineer.
Existing pools or spas must meet the following:
1. Any pool that is to be retrofit as new must be in accordance
with any of the options in the Newly constructed pools and spa
section.
2. When a full retrofit is not feasible, the following corrective
actions shall be taken to minimize the risk of entrapment:
3.
■
Establish the maximum system flow through either a direct
measurement test or through calculation. Install higher rated
covers that exceed the determined flow or change to a lower
flow pump.
4. Existing installations with a single main drain that have an
approved cover or grate must add at least one of the following:
5.
■
a gravity flow system
■
additional listed/approved outlet(s)
■
a certified vent system
■
a safety vacuum release system (SVRS)
6. A single main drain or equalizer line is acceptable providing it is
protected by an approved cover or grate and it is plumbed
through a skimmer that is manufactured to permanently prevent
the installation of a balance valve.
7. An installment with multiple approved covers or grates where at
least one is located more than 24” below the normal operating
water level require no corrective action.
8. An installment with multiple listed/approved covers/grates
located 24” or less below the water line (zero-entry or shallow
water pools) shall add at least one of the following:
9.
■
additional listed/approved covers/grates (total of 3 or more)
■
a safety vacuum release system (SVRS)
■
a certified vent system
■
a gravity flow system
Wading pools should meet the following requirement because
their shallow water levels may increase the hazard of suction
evisceration.
The wading pool must have dual main drains with approved covers
or grates and at least one of the following:
●
additional listed/approved covers/grates (total 3 or more)
●
a certified vent system
●
a safety vacuum release system (SVRS)
●
a channel drain system
●
a gutter or 100% overflow system
●
a gravity flow system
The presence of all the necessary construction to reduce the risk
of entrapment does not completely prevent the possibility of
entanglement or other accidents.
© The Redwoods Group, 2017
Released 8/17/2006 | Revised 1/10/2013
The Redwoods Group
Aquatic Entrapment Guidelines – Pools and Spas — Page 3 of 3
●
Children in a pool, spa, or hot tub should be directly
supervised by an adult at all times; they should never be left
alone and they should not be permitted to submerge their
heads in spas or hot tubs without immediate supervision.
●
Children under 6 should not be allowed in spas or hot tubs
except with written direction and authorization from a consulting
physician.
●
Nobody should be in the water without someone else
monitoring their activity: even lifeguards and pool
maintenance personnel must stringently follow this rulesuch
liberties have cost many individuals their lives.
Keep your pools and spas safe…make certain that users are not
exposed to the dangers of entrapment.
Please call us at 800-463-8546 to discuss this or any other risk
management safety tip, or visit our web site at
www.redwoodsgroup.com to learn more about YMCA risk
management issues.
© The Redwoods Group, 2017
Released 8/17/2006 | Revised 1/10/2013