There are those who believe that
concrete water tanks provide the safest
option available for areas that are prone
Concrete tanks need
extensive technical know-
how to build and install
correctly.
water. Another disadvantage of porous
concrete is that the pores provide any
present bacteria purchase on the tank’s
walls. The tank can, however, be sealed
to reduce the likelihood of leaching and
bacteria growth.
Cost is also a consideration, as
concrete storage tanks are expensive to
install and remove, while repair is also
expensive. In contrast, fibreglass and
stainless steel storage tanks are finding
purchase in the global market.
Fibreglass and steel are both
non-porous, which means they won’t
leach chemicals into the water and
provide place for bacteria growth. Both
materials are very resistant to corrosion,
as well as the effects of the freeze/thaw
cycle. Also, both storage tanks come in
single, double, and even triple-walled
constructions, to ensure maximum
protection of the product.
An added benefit is that both
materials are recyclable and can be
reused after their lives as storage tanks
have expired.
Steel-coated tanks and concrete
reservoirs can be used in a broad
spectrum of industry sectors, including
agriculture,
aquaculture,
mining,
and firefighting.
Water Sewage & Effluent September/October 2017
31
Concrete tanks: pros and cons
to fires. These would ideally be in-
ground concrete tanks.
According to Eco Water, a
concrete water tanks supplier in the
US, this water storage method keeps
water cold and dark and ‘have been
proven for over 100 years to be free
from algae, cryptosporidium, and
legionnaires’ disease’.
Concrete rainwater tanks naturally
reduce acidity in rainwater and,
because the temperature is kept lower in
in-ground reservoirs, they are less prone
to bacteria and last much longer than
any other type of water tank. The added
advantage of placing in-ground tanks
is that it maximises land area and even
further improves the cooling of water.
Yet another sector of the population
attests, however, that there are many
issues common to concrete storage
tanks that can compromise the material
stored in the tank, while storage tank
materials like fibreglass and stainless
steel present a superior alternative to
concrete storage.
In colder climates, where concrete
is not a flexible material and is subjected
to the expansion and contraction
caused by freeze/thaw cycles, over
time, the integrity of the concrete can
be weakened, to the point where it will
eventually crack, compromising the
contents, which may leak out.
Concrete is porous and is made with
calcium carbonate; therefore, leaching
can occur. If the water in the tank is
acidic, it will leach the calcium from the
concrete into the water, resulting in hard
technology
water storage, although countries such
as India and Pakistan still favour this
storage method.
An Australian journalist, Bill Brown,
reported of the research carried out
by the Department of Public Health,
Government of Western Australia, that
plastic tanks are also causing copper
poisoning owing to corroding water
pipes attached to the plastic tanks.
What happens is that rainwater
mixes with the drinking water in the open
tanks, and the naturally acidic rainwater
then reacts with the copper pipes, with
the contaminated water passing into the
drinking water taps.
This issue, however, does not
happen with cement tanks as they
leach lime into the water, which serves
to reduce the acidity and corrosion of
pipes. Brown observed that dissolved
copper initiates gastric problems as
well as headaches and liver damage.
Plastic tanks also affect the biological
properties of water where different
microorganisms grow and multiply at
a faster rate compared with clay or
cement tanks. The growth of different
worms is also possible, especially when
contaminated with rainwater.
In most rural areas, however, piped-
in water does not exist, so water tanks
provide the means to get water to
the people.
Prestressed co ncrete storage tanks.