2. Water TerminologyWater Terminology
Surface waterSurface water: Fresh water found on Earth surface in stream and: Fresh water found on Earth surface in stream and
rivers, lakes, ponds, reservoirs, and wetlandsrivers, lakes, ponds, reservoirs, and wetlands
GroundwaterGroundwater refers to the water below the water table whererefers to the water below the water table where
saturated conditions existsaturated conditions exist
This water originates as surface water seeps into the soil andThis water originates as surface water seeps into the soil and
finds its way to the groundwater aquiferfinds its way to the groundwater aquifer
AquiferAquifer is an underground zone or body of Earth material fromis an underground zone or body of Earth material from
which groundwater can be obtainedwhich groundwater can be obtained
Water BudgetWater Budget is a model that balances the inputs, outputs, andis a model that balances the inputs, outputs, and
storage of water in a systemstorage of water in a system
The various processes of the hydrologic cycle are input & outputThe various processes of the hydrologic cycle are input & output
terms of the water balanceterms of the water balance
TheThe global water budget isglobal water budget is balancedbalanced by the circulationby the circulation systemssystems onon
land, in the atmosphere, and in the oceans that move water fromland, in the atmosphere, and in the oceans that move water from
areas of excess to area of deficitareas of excess to area of deficit
3. Water UseWater Use
Water use can be classified into four broad categories:Water use can be classified into four broad categories: (1)(1)
domestic usedomestic use;; (2)(2) agricultural useagricultural use;; (3)(3) industrial useindustrial use; and; and
(4)(4) in-stream usein-stream use
It is important to remember that some uses of water areIt is important to remember that some uses of water are
consumptiveconsumptive, while others are, while others are nonconsumptivenonconsumptive
Domestic use accounts for aboutDomestic use accounts for about 10%10% of the total waterof the total water
withdrawalswithdrawals
However, in regions experiencing rapid population growthHowever, in regions experiencing rapid population growth
domestic use is expected to increase sharplydomestic use is expected to increase sharply
4. Water UseWater Use
Water use can be classified into four broad categories:Water use can be classified into four broad categories: (1)(1)
domestic usedomestic use;; (2)(2) agricultural useagricultural use;; (3)(3) industrial useindustrial use; and; and
(4)(4) in-stream usein-stream use
It is important to remember that some uses of water areIt is important to remember that some uses of water are
consumptiveconsumptive, while others are, while others are nonconsumptivenonconsumptive
Domestic use accounts for aboutDomestic use accounts for about 10%10% of the total waterof the total water
withdrawalswithdrawals
However, in regions experiencing rapid population growthHowever, in regions experiencing rapid population growth
domestic use is expected to increase sharplydomestic use is expected to increase sharply
5. Water UseWater Use
Agricultural UseAgricultural Use
Irrigation is the majorIrrigation is the major
consumptive use of waterconsumptive use of water
in most parts of the worldin most parts of the world
and it accounts for aboutand it accounts for about
68%68% of the total waterof the total water
withdrawalswithdrawals
Improved agriculturalImproved agricultural
irrigationirrigation could reducecould reduce
withdrawals by betweenwithdrawals by between
20 and 30%20 and 30%
Industrial water useIndustrial water use
accountsaccounts for aboutfor about 22%22%
worldwideworldwide. Since most. Since most
industrial processesindustrial processes
involve heat exchanges,involve heat exchanges,
90% of the water used by90% of the water used by
industry is for cooling andindustry is for cooling and
is returned to the source,is returned to the source,
so only a small amount isso only a small amount is
actually consumedactually consumed
6. Water UseWater Use
In-stream UseIn-stream Use
includes the use ofincludes the use of
rivers for navigation,rivers for navigation,
hydroelectric powerhydroelectric power
generation, fish andgeneration, fish and
wildlife habitats, andwildlife habitats, and
recreationrecreation
Consumptive UseConsumptive Use is anis an off-streamoff-stream
use in which water does not return touse in which water does not return to
the stream or groundwater resourcethe stream or groundwater resource
immediately after useimmediately after use
This water is consumed by plants andThis water is consumed by plants and
animals or in industrial processes andanimals or in industrial processes and
enters human tissue or products orenters human tissue or products or
evaporates during use but is notevaporates during use but is not
returned to its sourcereturned to its source
7. Water PollutionWater Pollution
Water PollutionWater Pollution refers to degradation of water qualityrefers to degradation of water quality
Any physical, chemical, or biological change in water qualityAny physical, chemical, or biological change in water quality
that adversely affects living organisms or makes waterthat adversely affects living organisms or makes water
unsuitable for desired use can be considered pollutionunsuitable for desired use can be considered pollution
Water pollutantsWater pollutants include excessive amounts of heavy metals,include excessive amounts of heavy metals,
certain radioactive isotopes, fecal coliform bacteria,certain radioactive isotopes, fecal coliform bacteria,
phosphorus, nitrogen, sodium, and other useful elements,phosphorus, nitrogen, sodium, and other useful elements,
acids, suspended solids and sediment, organic chemicals,acids, suspended solids and sediment, organic chemicals,
oxygen demanding wastes and effluents, as well as certainoxygen demanding wastes and effluents, as well as certain
pathogenic bacteria and virusespathogenic bacteria and viruses
The signs of water pollutionThe signs of water pollution: bad taste, offensive odors from: bad taste, offensive odors from
lakes, rivers, and sea beaches; unchecked growth of aquaticlakes, rivers, and sea beaches; unchecked growth of aquatic
weeds in water bodies; decrease in number of aquatic animals inweeds in water bodies; decrease in number of aquatic animals in
surface water bodies; oil and grease floating on water surfaces;surface water bodies; oil and grease floating on water surfaces;
coloration of water, etc. Outbreak of a waterborne disease is acoloration of water, etc. Outbreak of a waterborne disease is a
particularly visible type of water pollutionparticularly visible type of water pollution
8. Water Pollution SourcesWater Pollution Sources
Natural sourcesNatural sources include poison springs, oil seeps,include poison springs, oil seeps,
sedimentation from erosionsedimentation from erosion
With exploding human population pollution by agricultural,With exploding human population pollution by agricultural,
municipal and industrial sources has become a major concernmunicipal and industrial sources has become a major concern
for the welfare of mankindfor the welfare of mankind
All segments of our societyAll segments of our society (urban, rural, industrial, agricultural,(urban, rural, industrial, agricultural,
military) may contribute to the problem of water pollutionmilitary) may contribute to the problem of water pollution
MostMost of the sources result fromof the sources result from runoffrunoff andand leaksleaks oror seepageseepage ofof
pollutantspollutants
Pollutants are also transported by air and deposited in waterPollutants are also transported by air and deposited in water
bodiesbodies
9. Water Pollution SourcesWater Pollution Sources
Point sourcesPoint sources includeinclude
factories, power plants,factories, power plants,
sewage treatment plants,sewage treatment plants,
underground coal mines,underground coal mines,
oil wells, etcoil wells, etc
Nonpoint sourcesNonpoint sources suchsuch
as runoff are diffused andas runoff are diffused and
intermittent and influencedintermittent and influenced
by many factors such asby many factors such as
land use, climate,land use, climate,
topography, hydrology,topography, hydrology,
vegetation etcvegetation etc
Difficult to monitor andDifficult to monitor and
controlcontrol
Urban nonpoint sourcesUrban nonpoint sources
include urban runoff frominclude urban runoff from
streets or fieldsstreets or fields
Such runoff contains allSuch runoff contains all
sorts of pollutants, fromsorts of pollutants, from
heavy metals to chemicalsheavy metals to chemicals
and sedimentand sediment
Rural sources ofRural sources of
nonpointnonpoint pollution arepollution are
associated withassociated with
agriculture, mining, oragriculture, mining, or
forestryforestry
16. Water PollutionWater Pollution
Arsenic Contamination of GroundwaterArsenic Contamination of Groundwater
has been reported inhas been reported in 20 countries20 countries of theof the
world encompassing all the continents butworld encompassing all the continents but
the extent of groundwater contamination inthe extent of groundwater contamination in
BangladeshBangladesh is by far the most severe as itis by far the most severe as it
covers almostcovers almost 80% of the country80% of the country
61 out of 64 districts61 out of 64 districts, the Southern, South-, the Southern, South-
Western, and North-eastern regions of theWestern, and North-eastern regions of the
country are worst affected, threatening livescountry are worst affected, threatening lives
of almostof almost 75 million people75 million people
Levels of arsenic in underground drinkingLevels of arsenic in underground drinking
water is so high so thatwater is so high so that WHO describesWHO describes
arsenic contamination of Bangladesh’sarsenic contamination of Bangladesh’s
water supply aswater supply as “ the largest poisoning of“ the largest poisoning of
population in history”population in history”
17. Waterborne Diseases and Health Effects of Water PollutionWaterborne Diseases and Health Effects of Water Pollution
Each yearEach year several billionseveral billion people particularly in poor countries arepeople particularly in poor countries are
exposedexposed to waterborne diseases whose effects vary in severity fromto waterborne diseases whose effects vary in severity from
upset stomach to deathupset stomach to death
Historically, outbreaks of serious waterborne diseases such asHistorically, outbreaks of serious waterborne diseases such as
diarrhoea, cholera, and typhoid feverdiarrhoea, cholera, and typhoid fever have caused tremendoushave caused tremendous
hardships on society andhardships on society and killed thousandskilled thousands of peopleof people
As much as 80% of all disease and some 25 million deaths each yearAs much as 80% of all disease and some 25 million deaths each year
may be attributable to water contaminationmay be attributable to water contamination
Escherichia coliEscherichia coli, a type of fecal coliform bacteria responsible for, a type of fecal coliform bacteria responsible for
causing humancausing human illness and deathillness and death
Outbreaks result from eatingOutbreaks result from eating contaminated meatcontaminated meat and drinkingand drinking
contaminatedcontaminated juices or waterjuices or water
Water with any fecal coliform bacteria unsuitable for drinkingWater with any fecal coliform bacteria unsuitable for drinking
Human and animal wastes usually create the most serious health-Human and animal wastes usually create the most serious health-
related water pollution problemsrelated water pollution problems
More than 500 typesMore than 500 types of disease-causing bacteria, viruses, andof disease-causing bacteria, viruses, and
parasites can travelparasites can travel from human and animal excrementfrom human and animal excrement through waterthrough water
18.
19. Pollution ControlPollution Control
Two approachesTwo approaches to deal with water pollution problems are:to deal with water pollution problems are:
1.1. Reduce the sourcesReduce the sources
2.2. Treat the water to remove or convert the pollutants toTreat the water to remove or convert the pollutants to
harmless formsharmless forms
Reduction at the source is the most environmentally preferableReduction at the source is the most environmentally preferable
way of dealing with pollutantsway of dealing with pollutants
The second method is used for a variety of pollution problemsThe second method is used for a variety of pollution problems
—include chlorination and filtering of water to remove—include chlorination and filtering of water to remove
contaminants and chemical treatment with material such ascontaminants and chemical treatment with material such as
ozone which oxidizes certain pollutantsozone which oxidizes certain pollutants
Soil conservation methods help protect water qualitySoil conservation methods help protect water quality
Applying precisely determined amounts of fertilizers, irrigationApplying precisely determined amounts of fertilizers, irrigation
water, and pesticideswater, and pesticides
Preserving wetlandsPreserving wetlands
21. Water Conservation & Sustainable UseWater Conservation & Sustainable Use
Water ConservationWater Conservation is the careful use and protection of wateris the careful use and protection of water
resources and involves both the quantity of water used and itsresources and involves both the quantity of water used and its
qualityquality
Conservation is an essential component ofConservation is an essential component of sustainable watersustainable water
useuse
Sustainable Water UseSustainable Water Use may be defined as the use of watermay be defined as the use of water
resources by people that allows our society to develop andresources by people that allows our society to develop and
flourish into an indefinite future without degrading the variousflourish into an indefinite future without degrading the various
components of the hydrologic cycle or the ecological systemscomponents of the hydrologic cycle or the ecological systems
that depend on itthat depend on it
