Efficient Mitigation After Flood
Achieved in Record Time
By PAUL E. FRISK, ASCS Ductworks Inc.
0n July 28, 1997, a catastrophic rain as carpet, fiberglass insulation, wood containments were set into place during
storm invaded the skies above surfaces, ceiling tile, etc. This not only this process. Application of the biocide
Colorado State University in Fort Collins, reduced the humidity and amplification not only reduced the number of viable
Colorado. Within five hours, 5.3 inches of biological contaminants, but made biological contaminants, but aided
of rain fell onto the university grounds. the working space for the various greatly in reducing the concentrations of
Later, up to 18 feet of water entered contractors safer and less offensive to dust and fiberglass fibers from
some of the campus buildings. This the olfactory senses. becoming airborne.
combined with a sheet flow caused by
14 inches of rain that fell west (in the Next, determination of what mechanical Because of the raw sewage, visible
foothills) of the campus during the same equipment might be salvageable and mold growth and the threat of other
time frame. This article will focus on one what needed replacement was unknown bacterium, utmost protection
of forty buildings affected by the necessary. We determined that most of of the employees was of the greatest
storm-Morgan Library. Morgan was not the air handlers and ducting were concern. Because the filters and
only the largest building affected, but one salvageable, though the threat of severe fiberglass insulated surfaces were
of the most damaged. biological amplification had to be dealt showing signs of visible mold growth,
with swiftly. Mold counts for the air inside all Ductworks Inc./Rocky Mountain
Water entered the building with such the basement had been tested and Catastrophe employees were protected
force that oak doors were blown off their reported daily. The counts were so with full tyvex suits, half face respirators,
hinges; 2000-pound fans, and extreme we required that all contractors hard hats, rubber surgical and kevlar
500-pound fans were moved off their gloves and safety glasses.
pads to considerable distances. Return
鈥淥nly one product
plenum were crushed and mangled. In addition, during the first two weeks of
Severe damage to the building restoration, both indoor and outdoor air
met the criteria of
surfaces, mechanical and electrical was monitored for airborne biological
equipment resulted from the water levels. Elevated levels of moisture and
all the parties
damage. However, the most detrimental biological contamination were reported.
involved 鈥?
problem appeared to be that the Because of this, we determined that
university stored more than 45,000 removing the fiberglass insulated
Fosters 40-20.鈥?
books in the basement area of Morgan surfaces alone would not be sufficient.
Library. The system required an extra blanket of
protection for operation during the
The library is a 300,000 square foot wear half face respirators and other upcoming lower fall/winter
building with the mechanical equipment personal protective equipment for the temperatures. These long-term
located in the basement area. Problems first three weeks. Much of this was protection measures would reduce the
revolved around the water damage and because the large air handlers (four risk of building occupants from
associated particulate matter (silt, walk-in HVAC units) and associated becoming irritated or ill because of
grass, raw sewage, etc.) and biological ducting were lined with fiberglass. The airborne contaminants.
contamination. The problem university insulated surfaces and other porous
officials were most concerned with, surfaces had become saturated with Elevated moisture/humidity levels,
however, was that classes were moisture and were starting to support temperatures and nutritional
scheduled to start in less than one mold growth. requirements present created a severe
month! threat for biological amplification.
Return and supply plenum were sealed Mitigation of the moisture laden
Ductworks Inc. of Denver, Colorado was off from the basement at the riser surfaces required swift and efficient
called to assess the damage and give transition to reduce biological migration action. Not only were the fiberglass
a price quotation. Upon acceptance of into other sections of the ventilation surfaces of the air handling and
the bid, Ductworks immediately initiated system that were not damaged by the conveyance systems saturated with
the cleaning and repairs to the building. flood (upper floors). All fiberglass water, the fiberglass wrapping for the
Dehumidifying machines were set up insulated surfaces and filters (pleated steam and chill pipes were saturated.
outside the building in numerous pre-filters and bags) were treated with All of this insulation was also removed
locations to try to dry out the building a sanitizing agent (to help reduce the and disposed of.
interior. These machines were number of biological contaminants on
incorporated during the entire the surface). After the fiberglass A decision was made that the air
restoration activity. insulated surfaces were treated, they handler cabinet walls and ducting would
were removed, bagged and disposed be cleaned of all residual debris, wiped
The first act initiated was demolishing of to reduce cross contamination into with Trisodium Phosphate, and treated
all of the porous water laden material the indoor air, isolation cocoon with a long lasting fungicidal coating that
and removal of it from the building, such was approved for the use on the interior
of ventilation systems. Only one product areas were monitored weekly and
since large amounts of dirty water were
met the criteria of all the parties biological counts were never found to
swept into the coil fins. Because the
involved-Fosters 40-20. Several have biological activity or amplification.
fiberglass surfaces within the air handler
remediation consultants and industrial After the first two weeks, swab and air
cabinets had been removed, no
hygienists picked this product over a sampling revealed levels were actually
protective barriers had to be installed
dozen or so products as the best for the declining.
to prevent moisture from penetrating the
project. insulation鈥檚 surface during the power
After the biological results were taken
rinsing.
Insulation removal from the interiors of and analyzed, the University and other
steel ducting is fairly simple; though decision making entities were
Next, the supply and return fans were
removing the fibers from the glue can impressed beyond the best of
power washed clean and sanitized.
be rather difficult or almost impossible. expectations. At this point they decided
Water damage to the fan motors had
Many years ago, Ductworks Inc. that the same processes, procedures
rendered them inoperable, and all power
developed a method (when removal is and products would be enacted for all
connections had to be cut. Thus, no
the only answer) that removes most of of the other twelve buildings ravished by
protection of the fan motors was
the fibers in a simple, but effective the flood.
required. Because of the extreme
manner. The key for successful moisture, fan shaft bearings became
application of any fungicidal resurfacing The cost of salvaging the soiled and
locked frozen. After cleaning and
agent is a good preparation (profile) of water damaged components of the
sanitizing, new bearings were therefore
the surface and following the ventilation system saved the university
installed and then balanced.
manufacturer 鈥檚 application Post hundreds of thousands of dollars,
By separating various components of
biological sampling by an independent compared to demolishing and replacing
the HVAC system with sheet plastic
party would determine the effectiveness the existing ducting and air handlers.
protective barriers and negative air in
of the product, but also the contractor鈥檚 This could only have been a wise
the spaces, Ductworks Inc. technicians
ability to apply it correctly. decision if the students and library staff
were able to isolate and control cross
had no ill effects when the systems were
contamination. This allowed them to
After the fiberglass insulated surfaces put into operation. Except for easy
mitigate all of the various sections of the
inside the air handler were removed, the access to and from the building,
large HVAC systems during the same
cleaning could begin. All four HVAC thorough, swift, and efficient mitigation
time.
systems (SE-1, SF-2, SF3 and A-1) eliminated what could have been an
utilize a dual duct system with extremely even greater catastrophe--delay of the
Both the cold and hot deck ducting were
large cooling coils. These coils had start of a new school year. Isolation,
internally lined with a fiberglass insulated
become infested with large amounts of efficient removal of the moisture laden
duct liner as was the return ducting. After
leaves, grass, silt, toilet paper and other materials, cleaning, and the application
the liner was cleaned, sanitized and
debris. Before cleaning the coils and of long lasting biostat products solved
removed, all steel ducting interiors were
drain pans, inspection of the drain鈥檚 the biological amplification problem. An
swabbed with Trisodium Phosphate. A
ability to function was performed. Some coat of Fosters 40-20 was applied to even bigger benefit, however, was that
drains were completely clogged with all duct interiors after adequate drying the school鈥檚 ventilation systems would
debris. time. have a preventive solution for problems
that may lie in the future as well.
These drain lines were pumped out and The Fosters 40-20 would prohibit the
flushed free of all debris. The large I tip my hat to the University for having
growth of biological contaminants (in an
particles were easily washed from the the wisdom and courage to take on the
already moist ideal environment) while
coil fins, though removing the silt from task. Teamwork between the various
the rest of the building was being
the coil fins presented another problem. contractors, the University, and
mitigated. In addition, the 40-20 also
After power washing the heating and consultants is what really pulled this
reduced the risk to other project workers
cooling coils, they appeared to be clean, project off with great success. The
from coming in contact with possible
but observation of the coil fins after they University had to take on the task or
pathogens (especially blood borne)
dried showed silt residue. The coils close their doors. Congratulations the
while retrofitting the damaged sections
were then treated with an emulsifying University for immediate reaction to the
of the ventilation system. This is always
coil cleaning agent that required two devastation, for keeping a cool head
of major concern when working in an
applications and a thorough rinsing. amiss the chaos that must have been
environment where biological
Whenever an emulsifying coil cleaning unbelievable, and for their dedication
contaminants and humidity levels are
agent is used, thorough rinsing is and professional management of all the
extreme.
extremely important. When thorough crafts. Commendation to them for their
rinsing has not been achieved and the proactive stance, without which there
As the building became lower in
HVAC unit is brought back into might not have been a Fall semester.
humidity and more surfaces were
operation, the building occupants can cleaned, sanitized and treated with the
become very ill by the caustic fumes. Paul E. Frisk is Vice President/Chief
biostatic coating, air sampling and
Commercial Estimator for Ductworks,
swab samples (taken by a third party)
After the coils were cleaned, all of the Inc. of Wheat Ridge, CO. In business
revealed a tremendous reduction.
associated drain pans were cleaned since 1990, Ductworks specializes in
Though after swab sampling, the levels
and sanitized. All coils were first commercial/industrial building air and
were less than fifty colony units on
hand-surface vacuumed, power surface mitigation.
completed systems. This is quite
washed, then applied with an remarkable when considering that the
emulsifying coil cleaning agent and levels outside the containments and
Reprinted from DucTales Magazine with
thoroughly rinsed. This was the only way treated areas were well above any permission of the North American Duct Cleaners
these coils could have been salvaged standard for human occupancy. These Association and Paul E. Frisk, ASCS
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