Warm-up 4/7/14
Should this chemical be banned? Why or why not.
1.
2.
3.
4.
5.
6.
7.
It can cause excessive sweating and vomiting.
It is a major component in acid rain.
It can cause severe burns in its gaseous state.
Accidental inhalation can kill you.
It contributes to erosion.
It decreases effectiveness of automobile brakes.
It has been found in tumors in terminal cancer patient.
Water Resources
Where does your drinking water
come from?
I. Earth’s Water Supply
A. Where is Earth’s water?
1. 97.2% - oceans
2. 2.2% - icecaps and glaciers
3. 0.6% - surface or groundwater
B. Earth’s supply of fresh water is continuously
being renewed through the water cycle
1. Definition – the movement of water from the
oceans and freshwater sources to the air and
land and finally back to the oceans
2. Processes:
a. evaporation – from surface water, soil and
organisms
b. condensation – air containing water vapor
cools and forms clouds
c. precipitation – rain, sleet, snow, or hail
i. may run-off into surface water
ii. may infiltrate into groundwater
d. transpiration
Review Questions
1. What percentage of Earth’s water is
available to us as fresh water?
.6%
Now do the Water Cycle Worksheet.
II. Surface Water
A. Running Water
1. Includes rivers and streams
2. May enter through
surface run-off from the
surrounding watershed
(the land area from which
surface run-off drains into
a system of rivers and
streams)
NC River Basins
Journey of a River
B. Standing Water
1. Includes lakes, ponds, wetlands
(ie. swamps and marshes), and
reservoirs
2. Form when run-off gets caught in
low places, or by artificial means
Do Now
1. What percent of freshwater is there in the
world?
2. What percent of freshwater is frozen in
glaciers?
3. What is a watershed?
III. Groundwater
A. Water continues to move downward after it
hits the ground, through permeable layers of
soil and rock, then stops moving when it
reaches an impermeable layer of rock
B. Water table – the level below which the ground
is saturated with water
1. May be high in some areas (ie. near
the sea, or in low-lying forests), and deep
in others (ie. deserts)
2. Depth may change with precipitation,
drought, or overuse of wells
C. Aquifers – layers of rock or sediment that allow
groundwater to pass freely; sources of
groundwater
1. Rate of movement varies with amount of
precipitation, porosity of the rock, and slope of
the aquifer
2. Groundwater may leave the aquifer and
become surface water at the “zone of discharge”,
may pump out on its own (when under pressure)
through an “artesian well”, or may be accessed
by drilling wells
Saturated zone: pore spaces are completely
filled with water.
#5.3 Aim:
What is groundwater?
Agenda
QOD (10)
Lesson: groundwater (15)
Now write the definitions on the back of your picture.
Aquifer: an underground layer of permeable rock
or sediment that contains water.
Water table: The top of the region that is
saturated, or completely filled with water
Impermeable: substance that liquids cannot flow
through
Permeable: substance that liquids can flow
through
Artesian well: a well in which water flows to the
surface naturally because it is under pressure
Well: a hole in the ground that reaches down to
the saturation zone
Zone of Aeration: A region below the Earth's
surface that is marked by the presence of both
water and air in the pores of rocks and soil.
Cone of Depression: The region shaped like an
inverted cone, in which the water-table is drawn
down or depressed in the vicinity of a borehole
from which groundwater is being abstracted by
pumping.
Artesian Well
Review Questions
1. What is a watershed? How does water get
from a watershed to a river?
The land area from which water
drains into rivers and streams.
2. Describe how groundwater forms.
Water moves down through
the ground through permeable
layers of rock until it hits an
impermeable layer.
3. What causes the differences in the depth
of the water table?
Precipitation
Drought
Overuse
4. Name 2 ways that we may
obtain water from an aquifer.
Drilling wells or artesian wells.
IV. Uses of Water
A. Residential use
1. The average person in the U.S. uses about 300 L of
water each day
2. Uses include personal hygiene, cleaning, flushing toilets,
gardening/landscaping, car washing, and recreational
activities
How long can we keep this up?
B. Industrial use
1. About 44% of all fresh water is used by
industry
2. Uses include transporting goods, disposal of
waste, generating power, cooling machinery,
mining and refining natural resources,
manufacturing raw materials, and producing
synthetic materials
C. Agricultural use
1. The single largest user of water in the U.S.
(almost ½ of all freshwater use)
2. Irrigation – the process of bringing water to
an area for use in growing crops
Review Questions
1. Compare your daily residential use of water
to that of a person in a developing country
(like Kenya). What ways do you use water that
they probably do not?
-daily shower
-wash cars
Exit Ticket
1. Make a list of all of the ways that you have
used water yesterday.
Don’t forget to include industrial and agricultural
uses!
Do Now 3-28-13
1. What is the difference between a drill well,
and an artesian well?
2. What percentage of Earth’s water is
available to us as fresh water?
3. Describe how groundwater forms.
V. Water Resource Problems
A. Overdraft
1. Occurs when a body of water is drained faster
than it is filled; may occur in surface water or
groundwater Ex. The Ogallala aquifer is the
largest aquifer in the world and supplies water to
8 midwestern states; the water in this aquifer is
expected to last only 40 more years
Ogallalla Aquifer
2. Other problems with
overdraft–
a. intrusion of salt
water into freshwater
aquifers (coastal
aquifers)
b. subsidence, or
sinking, of bedrock
B. Habitat degradation or destruction
1.Includes water diversion (changing stream
courses), building dams and reservoirs, and
draining wetlands
2. Damages or destroys habitat of aquatic
organisms such as fish, amphibians, and
invertebrates, as well as migratory birds
Extinct woodpecker because of habitat loss
Review Questions
1. What is overdraft? What causes overdraft?
Overdraft occurs when a
body of water is drained
faster than it is
replenished.
2. Why do humans change stream
courses, build dams and reservoirs, and
drain wetlands?
The main reason is to develop the
land.
3. What do humans need to do in order to
solve some of our water resource problems?
Make water conservation a
priority.
VI. Water Treatment
A. Removing Salts
1. The process by
which salts are
removed from the
water is called
desalination
In 2002 there were about 12,500 desalination plants
around the world in 120 countries. They produce
some 14 million m3/day of freshwater, which is less
than 1% of total world consumption.
2. Methods:
a. Distillation – water is heated to boiling so
water evaporated but salt remains; water
vapor is cooled and fresh water collected
b. Reverse Osmosis- salt water is forced
through a strainer that traps the salt and lets
the fresh water pass
Distillation
c. Freezing – salt water is frozen and
separates, forming an ice and brine slush;
ice can be melted to obtain fresh water
B. Water Purification
 Water Purification
1. This process removes harmful chemicals
and microorganisms that make the water
unpotable, or unfit to drink
2. Process:
a. Screening – traps and removes large
debris from water
b. Sedimentation –
i. water passes to large settling tanks where
particles suspended in the water settle to the
bottom as sediment
ii. chemicals called coagulants may be added
to cause the particles to clump together and
aid in settling
c. Filtration – water is passed through a
filtering material such as fine sand to
remove smaller particles
d. Aeration –
•water is exposed to air and sunlight by
allowing it to spray into the air or flow as
a waterfall
•bacteria enter the water and break
down organic matter and oxygen is
mixed in; this process improves the
smell and taste of the water
e. Sterilization – water is exposed to
extreme heat or chemicals such as
chlorine in order to remove harmful
bacteria and microorganisms
B. Water Purification
Review Questions
1. If the ocean was your only source of water,
what process could remove the salt so it
would be drinkable? Describe how this might
be done.
Distillation or reverse
osmosis
2. What does “unpotable” mean?
It means that it is unsafe to
drink.
3. Name the 5 steps of the water
treatment process.
1.Screening
2.Sedimentation
3.Filtration
4.Aeration
5.Sterilization