1. Water Resources &
Pollution
Gloria Blanco
Wilfredo Amiot

2. Water Resources
Water is a vital resource that sustains life,
moderates climate, shapes the earth’s
surface, and provides habitat for many
organisms.

3. Freshwater
 Less than 1% of global water is
available as freshwater.
 Some sources Include:
 Groundwater- Water which
infiltrates the ground and perco-
lates downward through the soil, gravel, and
porous rock layers until it reaches a non-
permeable rock layer.
 Zone of Aeration- First few levels below the
soil’s surface which traps mostly air instead of
water.
 Zone of Saturation- Deeper subsurface layer
with all porous space filled with water.

4. Freshwater Source: Groundwater
 Water Table- The upper limit of the zone
of saturation.
 Natural/Lateral Recharge- Groundwater
in aquifers are replenished through the
percolation of precipitation OR the
movement of water from rivers and
streams.
 Watershed- Drainage basin;
land surrounding large bodies of
water that contribute to surface
runoff.

5. Depletion
 Populations rely heavily on aquifers to run
properly.
 Overdraft- Withdrawals exceed recharge and
water tables begin to fall.
 Land Subsidence- Overdraft from the the
aquifer can cause the land above the reservoir
collapse.

6. Increasing Supplies
 Desalination- Process which removes
dissolved salts from ocean water or from
brackish seas and lakes.
 Reverse Osmosis- Push saline water through
membranes that separate salt from water.
 Distillation- Evaporating the water and
collecting it as it condenses, leaving the salt
behind.

7. Water Pollution
 Water Pollution: is any chemical,
biological, or physical change in water
quality that has harmful effects on living
organism or uses:

8. Major Categories of water pollutants
 Infectious Agents: such as bacteria,
viruses and protozoa
 Oxygen-Demanding wastes: organic
waste
 Inorganic chemicals: acids, compounds
of toxic metals and salts
 Organic chemicals: oil, gasoline and
pesticides and plastic
 Plant nutrients: nitrates and phosphates
 Sediment: soil and silt
 Radioactive Materials: uranium, radon
 Thermal Pollution: Excessive heat.

9. Water pollution can come from
single or multiple sources.
 Point Sources: discharge pollutants at
specific locations through drain
pipes, ditches, or sewer lines
into the water surface.
Such as factories.
 Nonpoint Sources: are scattered and
diffuse and cannot be traced to any
single site of discharge.
Such as runoff and
precipitation.

10. Human activities can overload lakes with
plant nutrients and kill marine life.
 Eutrophication: the process by which
a body of water becomes enriched in
dissolved nutrients (such as phosphates
and nitrates) that stimulate the growth
of aquatic plant life usually resulting in
the depletion of dissolved oxygen.
 Cultural Eutrophication: is the
process of human activities near urban
or agricultural areas that input excess plant nutrients into
bodies of water.

11. In parts of the world’s oceans are dump sites
for toxic materials and garbage from ships.
 Dredge spoils: The discharge from a
dredge, materials often with toxic metals
and scrape from bottoms of harbor and
rivers to maintain shipping channel.
 Septic Tank: A sewage-disposal tank in
which a continuous flow
of waste material
is decomposed by
anaerobic bacteria.

12. Treatments to reduce water pollution
 Primary sewage treatment: It is a physical
process that uses screens and a grit tank to
remove large floating objects and solids such as
sand and rock.

13. Water Pollution
 Secondary sewage treatment: It is a
biological process in which aerobic
bacteria remove up to 90% of dissolved
and biodegradable, oxygen-demanding
organic wastes.

14.  Advanced or tertiary sewage
treatment: It is a series of specialized
chemical and physical process that remove
specific pollutants left in the water after
primary and secondary treatment.

15. Questions:
1. Of the following which constitutes the greatest percent of
use for water withdrawn in the world today
(a). Flushing toilets in residential homes
(b). Drinking water (human consumption)
(c). Smelting of metal in manufacturing
(d). Irrigation for food production
(e). Coolant water for electricity produced by coal
2. Which of the following would least likely reduce the
nutrient loading into the Chesapeake Bay estuary?
(a). Replanting of riparian zones and sea grass beds
(b). Upgrade of current sewage treatment plants
(c). Improvement of manure containment lagoons in feedlots
(d). Government subsidies for cotton crops
(e). Re-introduction of native oyster beds

16. Questions:
3. Which of the following river conditions would yield the
highest dissolved oxygen content?
(a). Fast-moving cold water, large amounts of submerged vegetative
biomass
(b). Slow-moving cool waters, large amounts of emergent vegetative
biomass
(c). Slow-moving warm waters, low amounts of submerged
vegetative biomass
(d). Stagnant, warm water with large clumps of algae
(e). Warm water with little vegetative biomass
4. In coastal areas, withdrawing groundwater to the point
where lateral recharge into the oceans becomes limited
can cause
(a). Hypoxic conditions
(b). Increased vertical recharge
(c). Saltwater intrusion
(d). Change in the zone of aeration
(e). drought

17. 5. The loss of riparian land along a river
would cause which of the following?
I. Increased Flooding
II. Decreased turbidity
III. Increased non-point source pollution
(a). I only
(b). II only
(c). III only
(d). I and III
(e). I, II, and III

18. Questions:
6. The process of human activities near urban or agricultural areas that input
excess plant nutrients into lakes is known as?
(a). artificial fertilization
(b). cultural eutrophication
(c). thermal pollution
(d). lake stratification
(e). synthetic primary production
7. Which of the following is NOT a nonpoint-source pollutant?
(a). sediment loading from erosion
(b). runoff of pesticides from cropland
(c). animal wastes from feedlots
(d). fertilizers runoff from urban lawns
(e). a sewage treatment plant effluent pipe
8. A type of wastewater treatment that includes some form of physical cleaning is
I. primary treatment
II. secondary treatment
III. tertiary treatment
(a). I only
(b). II only
(c). III only
(d). I and III
(e). I, II, III

19. Questions Continued:
9. Which of the following will result in accelerated
eutrophication when introduced into streams, lakes and
bays?
(a). bacteria and viruses
(b). pesticides
(c). herbicides
(d). phosphates
(e). acid wastes and salts
10. The largest source of oil pollution found in the ocean is
from:
(a). urban and industrial runoff from the land
(b). oil tanker accidents transporting oil between port cities
(c). offshore drilling rigs in the Gulf of Mexico
(d). pipeline leaks near coastal areas
(e). the Alaskan pipeline

20. Answers:
1. (d). Irrigation for food production
2. (d). Government subsidies for cotton
crops
3. (a). Fast-moving cool water, large
amounts of submerged vegetative biomass
4. (c). Saltwater intrusion
5. (d). I and III

21. Answers:
6. (b). Cultural eutrophication
7. (e). A sewage treatment plant effluent
pipe
8. (d). I and III
9. (d). Phosphates
10. (a). Urban and industrial runoff from the
land

22. Free Response Question
 The Colorado River runs 1,450 miles from the headwaters
of the Rocky Mountains to the Gulf of California. The river
has many dams, aqueducts, and canals that divert water in
order to supply water for electricity, irrigation, recreation,
and domestic use.
 a) Describe and discuss two environmental problems that
are associated with water diversion.
 b) If there is a shortage of water, choices will have to be
made as to whether water should be diverted to urban
areas, agricultural areas, or natural ecosystems. Make an
argument for diverting water for urban consumption and an
argument for permitting the flow of water to natural areas.
 c) Identify another example (other than the Colorado
River) of a large-scale water-diversion project. Discuss two
environmental problems that have resulted, or might
result, from this project.

23. Part A
 a). Describe and discuss two
environmental problems that
are associated with water diversion.
 Four points: one point can be
earned for each of the first two
appropriate descriptions of
environmental problems of water
diversion (additional descriptions
are not scored); one point can be
earned for a discussion of each of
the environmental problems
previously described.

24. Part B

25. Part C