| Water
Pollution Factsheet
Water
is polluted when it contains materials
that make it unsuitable for a given
use
The story
so far:
Fresh water is fundamental to the
survival of humans and most other
land-based life forms.
Ninety seven per cent of the earth's
water is the salt water of oceans
and seas. Most of the remaining
3 per cent is in polar ice caps,
glaciers, the atmosphere or underground
and hard to reach. Only 0.4 per
cent is available for use. This
water supply is maintained by water
evaporating from oceans and lakes
and then falling to the earth as
rain in a process called the 'water
cycle'.
However, growing population, increased
economic activity and industrialisation
has resulted in an increased demand
for fresh water. In addition, rapid
urbanisation is changing patterns
of consumption. This has caused
a severe misuse of water resources.
Discharging untreated sewage and
chemical wastes directly into rivers,
lakes and drains has become a traditional
habit. Water bodies can no longer
cope with the increasing pollution
load.
In Pakistan, water is mainly used
for industrial, agricultural and
domestic purposes.
The
following table shows its percentage
consumption for every use.
Purpose Percentage
Agriculture 69%
Industry 23%
Domestic uses 8%
Since most water is being used by
the agricultural sector, irrigation
can cause waterlogging and salinity.
This happens when the water table
rises close to the surface of the
soil. If plants do not use this
water, it evaporates, leaving salts
behind. Even in uncultivated, barren
lands, a water table within 2 meters
of the surface can cause salinity
in the soil. If irrigation water
containing high levels of contaminants
evaporates, it can result in damage
to the soil.
The Punjab province draws its major
share of drinking water from the
natural ground water aquifer. Groundwater
becomes contaminated when chemicals
from surface water seep into soil
and come in contact with the flowing
groundwater. The movement of groundwater
is through open spaces in soil and
rock layers, which is usually very
slow, indicating a very low dilution
of contaminants. According to WHO,
groundwater of Lahore up to 700-ft
deep has been seriously contaminated
and should not be used for human
consumption. In 1989, pollution
was found to a depth of 300-ft,
and to 500-ft in 1992.
Sources
of surface and ground water pollution
•
Municipal Sewage
Municipal sewage is a major source
of pollution. About 2 million wet
tonnes of human excreta are annually
produced in the urban sector of
which around 50% go into water bodies
to pollute them. National Conservation
Strategy (NCS) states that almost
40% of deaths are related to water
borne diseases.
Domestic wastewater collects on
the streets and in low-lying areas.
The situation is further aggravated
by the addition of untreated wastes
from small-scale industries.
In Pakistan, drinking water supply
lines and open sewage drains in
the streets are laid side by side.
As a result, water is frequently
contaminated when pipes erode. Most
main sewers are between 30-50ft
below ground level and are made
of 10ft cement sections linked without
proper safety seals. Poor connections
combined with deteriorating low
quality sewer pipes cause a lot
of leakage. This outflow from sewer
mixes with the water table and the
contamination is carried to deeper
levels. Hence the ground water which
is considered safe becomes adulterated
with everything from PCBs, lead,
cyanides, mercury, solvents, hydrocarbon
compounds, hospital and pharmaceutical
industry waste.
Ravi teems with toxic industrial
effluent and untreated domestic
sewage as soon as it enters Pakistan.
This has made it literally a large
open sewer.
•
Industries
Industrial wastewater contains toxic
chemicals. It is alarming that most
industries have been started without
proper planning and waste treatment
plants. They just dispose of untreated
toxic waste into nearby drains,
canals or rivers. Lahore, Faisalabad,
Karachi, Sialkot contribute major
pollution loads into their water
bodies.
According to an EPD source, 9000
million gallons of wastewater having
20,000 tons of BOD5 loading are
daily discharged into water bodies
from the industrial sector. [Proceedings
of International Symposium by CEWR
in 1993, Paper by M.A. Saleemi].
Automobile service stations are
another major contributor to surface
water pollution. Untreated oil,
grease and dirt find its way into
nearby canals and rivers where it
damages the ecosystem.
•
Landfills & Leaching
Leaching is the process where chemicals
from a material dissolve into water
while it is being filtered through
that material. The resulting mixture
is called leachate consisting of
residues from decomposed organic
matter and metals.
Major contributors to leachate are
municipal solid waste, hospital
waste, chemical fertilisers, pesticides,
stagnant ponds, toxic industrial
waste, and sewage. Rusting cans,
discarded batteries and appliances,
paints, pesticides, cleaning fluids,
newspaper inks, and other chemicals
may also add to the toxic mixture
of leachate.
• Agriculture
Excessive and uncontrolled use of
chemical fertilisers and pesticides
promotes contaminated agricultural
run off. This not only pollutes
the surface drains but the water
trickling down to lower layers of
soil causes a severe contamination
of the natural aquifer. Over abstraction
of groundwater prompts recharge
from the surface water drains, which
themselves are severely contaminated.
• Water pollution
and humans
The WHO reports that 25-30% of all
hospital admissions are connected
to water borne bacterial and parasitic
conditions, with 60% of infant deaths
caused by water infections.
The long-term effects on human health
of pesticides and other pollutants
include colon and bladder cancer,
miscarriage, birth defects, deformation
of bones, and sterility.
Contamination of fresh water with
radionuclides, which can result
from mining, testing, disposal and
manufacturing of radioactive material,
as well as transportation accidents,
has led to increased incidences
of cancer, developmental abnormalities
and death.
Cesspools of stagnant dirty water,
both in rural and urban areas, account
for a large number of deaths caused
by potentially fatal diseases like
cholera, malaria, dysentery and
typhoid.
Nitrate concentration in water above
45mg/l makes it unfit for drinking
by infants. The nitrates are reduced
in body to nitrites and cause a
serious blood condition called the
"Blue Baby Syndrome".
Higher concentrations of nitrate
causes gastric cancer.
Untreated and highly toxic industrial
sewage is also used for irrigation
near major cities. This can contaminate
crops and consequently affect consumers.
• Water pollution
and the environment
Karachi'suntreated wastewater from
domestic sewage and industrial estates
is discharged into the Layari and
Malir rivers, which fall into the
Arabian Sea. This waste has begun
to pose a serious threat to the
marine environment, as the channel
water is contaminated not only with
bacteria but also with toxic chemicals.
Water pollution also extends a savage
threat to wildlife of Pakistan.
Animals drink water out of polluted
water bodies, ailing ponds, rivers
and streams. This sickens the animals
and some may even die. Oil spills
kill thousands of fish in oceans.
Extreme pollution of river Ravi
has destroyed the once existing
42 species of fish and the bird
life around the river has migrated
to other areas. Survival of small
invertebrates, micro fauna and flora
is also threatened.
What can be
done?
•
Identify industrial units that are
the biggest polluters of river water.
If National Environmental Quality
Standards (NEQS) regarding wastewater
were strictly enforced, these industries
would have to reduce and treat their
waste prior to disposal.
• A regular qualitative and
quantitative monitoring of fresh
water resources
• Construct proper sanitary
landfill sites
• Investigate ground water
quality
• Provide Government help
for waste management by industries
• Throw refuse into garbage
cans. Visitors who throw garbage
into pools, lakes, ponds, and even
along the beaches pollute recreational
sites on a daily basis. This not
only pollutes the water but also
mars the beauty of the site
• Dispose of unwanted paints
or oils carefully. They should not
be thrown into drains or sewers
• Participate in awareness
raising activities. Students can
be a great help in this regard
• Conserve water at home and
at work, rather than wasting it
• Boil or filter drinking
water to eliminate disease-causing
bacteria
• Conducting epidemiological
study in the areas close to contaminated
water bodies will help to assess
the affect of polluted water on
health of the consumers.
WWF's Position
WWF has
focused its attention on the issues
of urban and industrial pollution.
It provides assistance to the industrial
sector in reducing polluted discharges
into air, water and soil.
WWF-Pakistan enhances capacity of
industrial sector so that they can
implement environmental solutions.
In this regard, training workshops
have been organised on the subjects
of industrial waste management and
waste minimisation technology.
To promote environmental awareness
of water pollution issues, a water
pollution monitoring kit (mobile
laboratory) was developed by WWF
and launched in the four provinces
of Pakistan. The kit is easy to
use and is fabricated using cost
effective material. It is capable
of monitoring 14 pollutants.
For more information on Water Pollution,
please visit the following sites:
www.iwpca.org
www.ec.gc.ca
www.soton.ac.uk
www.life.ca
www.eihs.niehs.nih.gov
www.ssr.com
www.webdirectory.com/pollution/water_pollution
www.cities.poly.edu
www.bpinews.com
www.state.nv.us
Compiled and
edited by Environmental Pollution
Unit, WWF- Pakistan
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