HEALTH AND SANITATION
37
• The following equipment will be needed:
○ A high-quality digital chlorine meter/
test kit
○ A digital thermometer for measuring
water temperature
○ Anti-vandal tools for removing aerators
and supply stop covers (check with the
appropriate manufacturers)
• Important – Sewer gases, floor drains
and traps: If an overwhelming smell of
sewer gas is detected in the building or
when entering bathrooms that have been
unused for long periods of time, it is likely
that floor traps or fixture traps have run
dry. It may be possible, while very rare
and only in extreme instances, that turning
on exhaust fans under such conditions
could cause an explosion. Play it safe!
If high concentrations of sewer gases
are suspected in the building, evacuate
the building and contact the local fire
department to assess the condition.
• Ensuring that there are no dry traps in the
plumbing system is a critically important
first step. Building sanitary systems harbour
many waterborne microorganisms, and
dry traps and floor drains can provide a
pathway for those pathogens to enter the
building. Go through the building and slowly
pour clean water into floor drains and sinks
to make sure that traps are fully restored.
Remember, sanitary systems have been
implicated in the spread of the coronavirus,
so any dry trap provides a potential pathway
for exposure to the virus and other harmful
microorganisms.
• Know which products are installed in
the building: It will be important to know
which specific plumbing products, fixtures
and fittings are installed in the building
prior to beginning. Look for markings on
plumbing fixtures and fittings that detail
manufacturer and the flush volumes per
flush on toilets and urinals, and the flow
rate. (Flush volumes are typically shown in
close proximity to the manufacturer’s logo,
and faucet flow rates are typically found
embossed on faucet aerators.) Contact
the manufacturer of those products to
seek guidance regarding their specific
flushing recommendations. Always follow
manufacturer instructions. Be careful not
to overlook features such as break rooms,
kitchen sinks, coffee makers, ice machines,
carbonated drink dispensers, dishwashers,
executive bathrooms, hair washing stations
and church baptistries.
• Exhaust fans and water heating systems:
After verifying that all floor drains and
fixture traps have been restored, go
through the building and turn on available
exhaust fans in rooms that have plumbing
fixtures and fixture fittings (toilets, urinals,
showers, faucets). Turn all water heaters
and boilers off and allow the water to start
to cool. If the building has a hot water
circulation system, allow it to continue to
circulate water.
• Potential for sanitary system blockages: It
is possible that solid waste in the sanitary
building drain has dried out and solidified.
This can result in blockages during the
flushing process or after the building
reopens. Never leave a room unattended
while the flushing process is ongoing.
• Tips for reducing splashing and reducing
aerosols: When flushing toilets, always
close the toilet seat lid. If the toilet does
not have a seat lid, utilise a non-porous,
rigid, flat device such as a piece of rigid
plastic that covers the toilet bowl. This
will help reduce aerosols resulting from
flushing the toilet. A plastic trash can lid
may work well for this purpose. Do not
attempt to make the cover airtight, as
some air will be required to get into the
toilet bowl to allow the toilet to flush. Clean
the flat device with a disinfecting cleaner
after each use.
• When flushing urinals, consider covering
the urinal with a plastic trash bag to trap
aerosols if numerous, repetitive flush
activations are required. For sinks and
showers, consider using a plastic trash
bag with a hole cut out at the centre of the
bottom of the bag just large enough to slip
over the showerhead or the faucet outlet and
tape it in place. Make sure that the trash bag
cannot block the fixture drain outlet.
• Flushing times and cycles: Consult a
plumbing professional to determine the
number of flushes and flush times required
to remove the stagnant water from the
water supply lines. This will be based on
plumbing system size and geometry, and
the flush volumes and flow rates of the
installed fixtures and fixture fittings (faucets
and showerheads).
• The flushing process: It is important
to conduct the flushing process in the
sequence detailed herein. This will result
in discharging contaminated hot water
without running it through the entire
plumbing system to the greatest extent
possible, and then getting fresh water to
distal sections of the plumbing system
safely and efficiently.
IAPMO would like to thank the following experts
for their input to these recommendations:
Dr Andrew J. Whelton, Purdue University; Dr
Catlin R. Proctor, Purdue University; Dr William J.
Rhoads, Virginia Tech University, Dr Janet Stout,
Special Pathogens Laboratory. PA
October 2020 Volume 26 I Number 08
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