Water, Sewage & Effluent November December 2018 | Page 13

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Water Sewage & Effluent November/December 2018
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contamination from ‘faucets’ (which
we call a tap), sink surfaces, and
patients.
This brought me to the realisation
that the sanitary drainage system from
the ‘fixtures’ (WC, bidet, shower, bath,
washbasin, sink, sluice, slop hopper,
floor drains, and grease trap) all
become contaminated and contribute
to — and exacerbate — the problem.
It is vital to note that each of
the above-mentioned fixtures are
connected to the sanitary drain, which
is connected to a sewer network
from the building down to the sewage
treatment plant. All along the building,
the drainage system is connected
to the bathrooms, sluice rooms, slop
hoppers, kitchens, floor drains, grease
traps, mortuary, and all the other
hospital drainage.
This building drainage is connected
to the municipal sewer and this sewer
is connected to the sewage reticulation
and eventually connected to the
sewage treatment works. All along
this sewage network, other buildings
are connected, such as mortuaries,
abattoirs,
butcheries,
factories,
restaurants, and even the undertaker.
innovations
important to note that a SANS standard
is not compulsory unless it has been
specifically promulgated as such.
There is a hospital design document
called R108, but it only states that the
water and drainage must be designed by
‘an experienced engineer’. The design
of a hospital drainage system and water
system requires specialised competence
and experience as well as high-quality
materials, fixtures, equipment, and
systems, since health and safety is a
high priority and the preservation of a
‘clean environment’ is crucial.
It is a startling fact that many
hospitals
are
struggling
with
contamination and the so-called
‘hospital bug’ or ‘super bug’. And this
seems to be pandemic. In a research
report published by the US National
Library of Medicine – National
Institute of Health, titled, Hospital
Drains as Reservoirs of Pseudomonas
aeruginosa: Multiple-Locus Variable-
Number of Tandem Repeats Analysis
Genotypes Recovered from Faucets,
Sink Surfaces and Patients (and,
interestingly, filed under ‘Pathogens’),
the researchers indicate that
they found the above-mentioned
Let’s have a look at the vulnerable
environment that is a hospital,
and some examples of how easily
contamination and pathogens can
spread:
• There are washbasins in the
ICU right next to the bed of an
ill person. If the plumber has
to work on the washbasin and
remove the trap, then all the
air in the pipeline will escape
into the ICU.
• When a nurse or nursing
assistant empties a bedpan
in the sluice room, the
air in the sluice room is
contaminated. The same
happens when a patient or
a visitor uses a toilet. People
complain about ‘bad smells’,
when in essence, bad smells
are germs and it is the
reason someone invented
the so-called ‘toilet friend’
— an extractor to extract
the foul-smelling air directly
from the WC.
• When a cleaner opens a floor
drain outlet to clean it, then
the foul air from the piping
escapes into the kitchen,
perhaps without even being
noticed.
It is essential that the internal and external systems are designed
by one engineer, with one responsibility, and based on one set of
design criteria and assumptions.
Hospitals —
by nature a
contaminated
environment
The building drainage is connected to the municipal sewer, which is connected to the sewage
reticulation and eventually connected to the sewage treatment works. Any drainage system
requires access to allow for maintenance and to remove blockages — and this is by means of
‘inspection eyes’ that are situated on all fittings such as bends, tees, and junctions.
In fact, from any fixture in any building
down to the sewage treatment works,
the only barrier between the user of the
fixture and the total sanitation system,
is a thin layer of water, called a trap.
This trap of water is about 75mm thick.
In any drainage system, there
is a need for access to allow for
maintenance and to remove blockages.
The access is by means of inspection
eyes that are situated on all fittings
such as bends, tees, and junctions on
the above-ground piping, and externally
underground, there are manholes,
inspection chambers, rodding eyes,
and cleaning eyes, placed at a required
distance of at least 25m apart.
In wet areas, such as kitchens and
food preparation areas, floor drains
are required.
Now, when any of the access points
inside the building, including floor
drains, is opened for maintenance or
to unblock a blockage, then the highly