Introduction to Water pollution

Indroduction
Water pollution occurs when harmful
substances are released into the water in
large quantities which cause damage to
people, wildlife, or habitat or indirectly into
water bodies without proper treatment to
remove harmful compounds.
 Water pollution is a major problem in the
global context. It has been suggested that it
is the leading worldwide cause of deaths and
diseases, and that it accounts for the deaths
of more than 14,000 people daily.



WATER POLLUTION


Ideal water supply
– Quality.
– Quantity.



Water quality parameter
– Physical.


Suspended solid (SS), color, taste, smell, temp.

– Chemical.


Dissolved substances, alkalinity, hardness,
fluoride, heavy metal, organic compound, nutrient
(nitrogen & phosphorus), pH, biochemical oxygen
demand (BOD), chemical oxygen demand (COD).

– Biology.


Bacteria, virus, protozoa, helminthes.


WATER POLLUTION
Will cause
– Soil contamination.
– Air contamination.
– Food chain contamination.
– Esthetic.
 Lack of clean water supply for
– Domestic demand.
– Industry use.
– Agriculture use.



WATER POLLUTION


Will also cause
– Breeding of diseases vector.
– Spreading of water borne diseases.
– Food poisoning.
– Skin problem.


WATER POLLUTION
80% of diseases in developing countries
are due to water supply contamination.
 4 – 5 million child died every year due to
water supply contamination.
 More than 1 million died after severe
diarrhea.



Pollution Defined
 Any

chemical , biological, or
physical change in water quality
that has a harmful effect on
living organisms or makes water
unsuitable for desired uses.


Types and Sources of Water
Pollution
Infectious Agents

 Oxygen-Demanding
 Inorganic Chemicals
 Organic Chemicals
 Plant Nutrients
 Sediment
 Radioactive
 Thermal
…



Water Pollution
Two major classifications



Point Source



Non-point
Source


Sources of Pollution
Point Sources
-Discharge from a specific
location (pipe, ditch or sewer)
-Easier to identify and regulate
Ex: Factories, Sewage Treatment

Plants, Mines, Thermal Outlets and
Oil Tankers.


Point Sources
 Single

large source
 Can localize it to one spot
– Industrial Plants

- Sewage pipes


Point Source - Example

LUST - Leaky Underground Storage Tanks
 22% of the 1.2 million UST are LUST



Non-Point Sources
-Cannot be traced to a specific
discharge
-Difficult to identify and control
Ex: Golf Courses, Agriculture, …


Non-point

Sources

Diffuse source or many smaller point sources
 Automobiles
 Fertilizer on fields




Sources of Water Pollution

17



Examples of
Polluted Waters


Water Quality Indicators
We will now
take a look at
the water
quality
indicators.


TOTAL DISSOLVED SOLIDS (TDS)
TDS is the measure of the material
dissolved in water.

This measure is related to hardness,
salinity and conductivity.
Hard water has more TDS than soft
water.


Salinity
Salinity refers to the salt
concentration in water, mostly
sodium chloride.
Salinity is historically measured
in parts per thousand (ppt) or
grams per liter.


Salinity
Saltwater can cause problems
when it replaces fresh
groundwater near the coastal
areas.


TOTAL SUSPENDED SOLIDS (TSS)
TSS is the measure of the sediment
suspended in the water.
TSS is related to turbidity.
Water with high TSS usually has high
Total Dissolved Solids (TDS) as well.

Sediment
Erosion causes loose soil
to enter the waterways
Suspended sediment blocks
sunlight to plants and
reduces dissolved oxygen.
As sediments settle, they can
smother bottom (benthic)
organisms.