serious health threat to humans is sewage backflows. In an indoor environment,
water is considered to be the most long-term destructive substance. Since water
supports the growth of microorganisms, it also weakens and dissolves a lot of
various materials as well. Since it flows, water is capable of carrying various
kinds of allergens and pathogens that are hazardous to people.
quick reaction to backups, flooding, spillage, seepage is necessary when a
water emergency occurs. To save valuable property from direct water damage and
microbial growth from destroying your belongings, immediate attention needs to
Waste And Sewage
A very significant threat to human health is sewage.
However, the seriousness of the health threat depends on the content
of the sewage and the degree and extent of penetration into the building
environment. The amount of time the sewage remains in contact with
materials; the quantity of sewage and the porosity of contaminated materials
are the factors that dictate the degree of penetration. The restoration response
may vary in each situation so you should consider at least three examples of
sewage leaking into an indoor environment.
In this situation, the waste is designated in one specific location, is contained,
and does not exert force on the building infrastructure. A limited amount
of time in terms of contact has occurred. Waste that overflows in a
bathroom and is deposited on and confined to a tile floor is an example of
this situation might be. In this situation, there is a limited quantity
of waste, which is isolated and does not touch absorbent materials. Decontamination,
which includes disinfection, cleaning and water extraction, can be effective in
lessening this particular potential health risk.
Waste that originates in the built environment is deposited or flows
beyond the confines of the building’s disposal system. In this case,
there is limited or confined flooding, but water and waste penetrates the
structure and furnishings of the building. For example, flooding
occurs in a men’s room of an office building, water flows under a wall
and into the carpet of an adjacent hallway. In this case, although it
penetrates regions of the environment that have complex surfaces and are
difficult to restore, there is a limited amount of waste that is confined
to a relatively small area of the building. Drying all surfaces that
have been in contact with the sewage is an effective restoration technique
that involves decontamination. Getting rid of the cushion and treating the
two sides of the carpet
thoroughly with a disinfectant are all necessary in terms of stretch-in
carpets, cleaning and lifting the contaminated carpet. Affected
porous wall materials need to be sanitized with a disinfectant and
evaluated for replacement. Comprehensive and aggressive treatment can be
effective due to the confinement of the sewage spill.
Where the waste is widely dispersed and penetrates both the structure and
its furnishings waste that originates in the built environment, along with
other wastes from the primary line of the sewage system, is backed up into
the natural environment. In this situation, because h
umans can be
exposed to pathogenic raw wastes that has penetrated and become contained
by the building and its furnishings there is extensive risk. Homeowners will
have to be evacuated, and restoration should begin immediately if flooding
is from this kind of primary outside sewage system. In this situation, by
using respirators with high-efficiency particulate air (HEPA) cartridges,
rubber boots, gloves, splash goggles, and protective garments restoration
and cleaning professionals should be cared for. To avoid puncture
wounds during the restoration process, extreme care should be taken. Restoration
personnel who have open sores or cuts should not be allowed to work
on this kind of restoration project.
How to Handle Contamination
When a building is contaminated with sewage backing up
from the septic lines, or flooding of a building occurs that involves
sewage or a heavy load or organic matter, as in the case of river
flooding, a serious threat to human health exists. Extensive damage to
materials will occur immediately or in time without appropriate action. Before
the cause of the backup is determined, flooding subsides and the problem
is corrected, a duration of time will have to pass. This allows extensive
contamination and permeation of absorbent (hygroscopic) materials such as concrete,
paper, gypsum and wood to occur. This penetration with organic matter and
water leads to the growth of potentially ailment-causing
(or opportunistic) microorganisms. These kinds of bacterial
organisms may pose a serious health risk to occupants of the building. Organic
matter and water-saturated materials can be used as substrate for growth
of microorganisms such as gram-negative bacteria and toxigenic fungus that
can create substances that are lethal to humans and are hazardous to materials.
To contribute to microbial growth on structural materials and contents, a
large amount of water inside a building will cause high humidity.
Some of the questions to be answered in this situation include the following: What
are the effects of the initial contamination of the building, its
contents, and the health and welfare of its occupants? To thoroughly
clean up the contamination and repair the damage, what is needed?
Should the whole building or just a part of the building be evacuated and
for how long should this last? Can semi-porous materials be sanitized and freed
from contamination, or should they be replaced? What is the
trade-offs of using insufficient measures to remediate the damage?
What are the indicators that help show when the building is safe or not
safe for people to move it? What procedures should be used to test
for these indicators? What is the effect of the sewage damage on
other systems, especially the air changing systems (ACS) and the heating,
ventilating, and air conditioning (HVAC) systems in the build environment?
There are several factors that are related to the remediation of the problem.
Among these are the nature of the contamination, the types of
water-damaged materials (organic or synthetic; porous, semi porous, or
nonporous), the sewagemicroflora (pathogens and allergens), organic matter
load, water volume, and impact of ambient outdoor temperature and humidity
on the indoor environment. Of major concern is the survival of
sewage-borne micro flora (viral, bacterial, fungal, parasitic, and their
potential transmission to
humans. The potential exists for some fungal and bacterial contaminants
to establish an ecological niche and present a health risk from chronic
exposure for some time after the event.
Scope of these Guidelines
The discussions within this paper will address the immediate and longer term
effects of sewage-flooding contamination on the building’s structural
materials and contents; the potential effects on occupants; and the steps
to remove contamination to include flushing with clean water and detergent
solutions, vacuuming, dehumidification, and disinfection. The potential
health threats presented at each stage of remediation will be discussed.
These include the production of bioaerosols during removal of gross
contamination, the long-term effects of residual moisture and organic
matter on the building and occupants, and the colonization and growth of
non-sewage-borne species of microorganisms such as molds and other fungi.
Assessment of Damage and
Danger to Health
The factors that determine the extent of contamination within the building
include the volume and the solids content of the sewage backflow, whether
flooding is isolated to the basement or involves other levels as well, and
how long the contamination has been in place. The assumption must be that
potential pathogens are present in the contamination. Such microbial
contamination includes bacteria, fungi, viruses, and parasites. This
lists the micro flora that may be found in raw, untreated sewage and the
diseases that these organisms have the potential to cause. Also,
hypersensitivity lung disease has been shown to be caused by repeated
flooding of homes with sewer water.
The routes of exposure of the building occupants to these pathogens are
contact, ingestion, and inhalation. An incomplete or inadequate job
of cleaning and disinfection may leave residue that can be a substrate for
disease-causing microorganisms. Occupants may be infected by contacting
contaminated surfaces, with inadvertent transmission from hands to mouth,
or aerosolization of contamination may result in the inhalation of microorganisms
or their products (e.g., endotoxins). Residue and
microbial contaminants also can be tracked by occupants’ feet to other
parts of the building.
Another aspect of health impact is that the conditions caused by sewage
backflow or flooding are conductive to the growth of nonsewage
microorganisms. These conditions include wetness, humidity, and
organic matter. Microorganisms, which exist in various life stages
in both indoor and outdoor environments, would then have the opportunity
for exponential population growth. These species can produce
which are potential sources for disease. For example, mold allergy is a
common source of indoor air symptoms and complaints.
In regard to the susceptibility of building occupants, those individuals whose
immune systems are in some way compromised (i.e., immune and compromised),
or who are otherwise susceptible due to age, medication, or
underlying illness, are considered to be at greater risk of contracting
potentially fatal infections than those individuals who are healthy.