5. Two thirds (2/3) of our
planet is covered by
water.
97.5% of the water is
saltwater.
The majority of freshwater
is beyond our reach,
locked into polar snow
and ice.
6. 66% of the human body
is made up of water.
At just 2% dehydration
your performance
decreases by around
20%.
We should drink at least
1½ litres of water a
day.
8. The number of
people with access
to clean water has
doubled in the last
20 years.
1.1 billion people in
the world still do not
have access to safe
water. This is nearly
20% of the
population.
9. 1. Safe water (Potable Water)
Free from foreign materials including bacterias.
Cleansing to Eyes.
Delicious to taste.
2. Polluted water
Contain harmful substances of all types
(Physical, chemicals)
Including pathogenic organisms.
3. Contaminated water
Contain harmful pathogenic organisms (fecal matter)
10. Sources of Water
1. Rain
2. Surface water
3. Ground water / Sub surface water
24. The hydrologic (Water) cycle is the process, powered by the sun's energy, which
moves water between the oceans, the sky, and the land.
It can be studied by starting at any of the following processes:
evaporation, condensation, precipitation, interception, infiltration, percolation,
transpiration, runoff, and storage.
26. Hazards of polluted water
1. Biological hazards
A. Bacterial: Typhoid, Cholera, Bac: Dysent:
B. Viral: Polio, Hepatitis A & E
C. Protozoal: Amoebiasis, giardiasis
27. D. Helminthic: Round worm, Whip worm,
Hydrated disease
E. Leptospiral : Weil’s Disease
F. Cyclops : Guinea worm
28. 2. Other hazards:
GIT disturbances ( due to Na, Mg & Ca ions)
E.g:- MgSo4, Lead to Diarrhoea
Lead poisoning
Iodine Deficiency
Fluorine Deficiency
Hardness of water
Infant met haemoglobinemia
30. Criteria for water Quality
1. Physical Qualities
2. Chemical Qualities
3. Bacteriological Indicators
4. Radiological standards
31. 1. Physical Qualities
Turbidity : Must be free from turbidity ( < 5 NTU)
Color : Must be free from color
Odor : No odor ( Non objectionable / Acceptable)
Taste : Must be palatable ( Non objectionable / Acceptable)
34. Toxic Inorganic mg/L
Mercury 0.002 mg / L or less
Selenium 0.01 mg / L or less
Lead 0.05 mg / L or less
Magnese 0.05 mg / L or less
cyanide 0.05 mg / L
Free saline & Ammonia: 0.05 mg / L or less
Fluoride 1.4 – 2.4 mg/L
Hydrocarbons 0.01 mg / L or less
Total Hardness: 2mEq /L
Total solids 500 mg / L
35. Nitrites : 3
Zinc (Zn) 5
Nitrates: 45 mg / L or less
Residual chlorine 0.2-0.5 at consumer end
0.5-1.5 at source.
Dissolve O2 Not less than 5 mg / L
O2 absorbed
at 370C in 4 hrs: should not be > 1 mg / L
36. 3. Bacteriological Indicators
1. No sample should contain E. coli in 100 ml of water.
2. No sample should contain > 3 coliform / 100 ml of water.
3. Not > 5% of samples throughout the year should have
coliform in 100 ml.
4. No two consecutive samples should have coliform in 100
ml.