FEATURE
37
Water contamination
Alicia Mentz, marketing manager of Agrinet, says: “Wastewater
is a common everyday problem that can end up resulting in
thousands of rands of water damage especially when the
water comes into contact with a material, thereby resulting in
destructive processes such as rotting of wood, growth, rusting
of steel, de-laminating of materials such as plywood, and
many others. It can also be immensely frustrating working on
a jobsite after recent rains. The accumulation of wastewater
can be caused by rain, flooding, burst or leaking pipes, or
simply just groundwater seeping through.”
There are three basic categories of wastewater, based on the
level of contamination.
• Category 1 Water - Refers to a source of water
that does not pose substantial threat to humans and
classified as "clean water". Examples are broken
water supply lines, tub or sink overflows or appliance
malfunctions that involves water supply lines.
• Category 2 Water - Refers to a source of water that
contains a significant degree of chemical, biological
or physical contaminants and causes discomfort or
sickness when consumed or even exposed to. Known
as ‘grey water’. This type carries microorganisms
and nutrients of micro-organisms. Examples are
toilet bowls with urine (no faeces), sump pump
failures, seepage due to hydrostatic failure and water
discharge from dishwashers or washing machines.
• Category 3 Water - Known as ‘black water’ and is
grossly unsanitary. This water contains unsanitary
agents, harmful bacteria and fungi, causing
severe discomfort or sickness. Type 3 category is
contaminated water sources that affect the indoor
environment. This category includes water sources
from sewage, seawater, rising water from rivers or
streams, ground surface water or standing water.
Category 2 Water or Grey Water that is not promptly
removed from the structure and or has remained
stagnant may be re classified as Category 3 Water.
Toilet back flows that originates from beyond the
toilet trap is considered black water contamination
regardless of visible content or colour.
“The removal of wastewater is often challenging; in most
cases the water needs to be pumped out. Depending on
the circumstances, there are two types of pumps that are
used for this application, namely; fuel driven pumps and
electrical submersible drainage pumps. Both these pump
types are generally low pressure, high volume pumps for
the purpose of draining water quickly and each having their
own advantages and disadvantages,” says Mentz.
Fuel driven pumps
As the name implies, these pumps are driven by either
a petrol- or diesel-fuelled engine that in turn rotates the
pump shaft, turning the impellor and pumping water. These
units are installed above the water line and draw the water
with the use of a suction pipe or hose, it is important that
the size of the suction pipe is no smaller than 50mm.
These pumps are mostly used for Category 1 to Category 2
wastewater but upon request, pumps that pump Category
3 wastewater are available.
Advantages of fuel driven pumps
• No power or power cables required
• Easily removeable and stored
• Economically viable
• Cost-effective maintenance when using reputable
brands like Honda or Powermaster
"It can also be
immensely
frustrating
working on
a jobsite
after recent
rains. The
accumulation
of wastewater
can be caused
by rain,
flooding, burst
or leaking
pipes, or
simply just
groundwater
seeping
through.”
August 2020 Volume 26 I Number 06
www.plumbingafrica.co.za