Freshwater Frenzy
6th Grade
Created by:
Abby Croucher, Misty Harger & Stephanie Hines
Sponsored by:
Indicators addressed:
6.3.8 Explain that freshwater, limited in supply and uneven in distribution, is essential
for life and also for most industrial processes. Understand that this resource can
be depleted or polluted, making it unavailable or unsuitable for life.
6.3.16 Explain that human activities, such as reducing the amount of forest cover,
increasing the amount and variety of chemicals released into the atmosphere, and
farming intensively, have changed the capacity of the environment to support
some life forms.
Objectives: Students will be able to
 Describe how freshwater is distributed around the world in different forms and
different amounts
 Explain the difference between groundwater and freshwater and the different
forms of each
 Define watershed
 Define acid rain and its sources
 Describe how acid rain affects wildlife
 Explain how different human activities pollute freshwater
Materials Required:
For Engagement activity:
 Where is the Water?
o 9 clear, 1,000 ml containers (enough for groups of students, or as one
demo)
o Graduated cylinder
o Masking tape
o Marker
o Tablespoon
o Medicine dropper or pipette
o Water supply
For Centers:
 Exploring a Watershed model – this can be built beforehand by teacher or as a
student project
o Large plastic tub or storage container, e.g. rectangular under-the-bed
containers
o Aluminum foil or rocks of different sizes for creating watershed
topography
o Paper maiche (flour, water, newspaper, mixing bowl) or clear plastic to
cover entire watershed
o Water supply
o Watering can
o Map of local watershed (optional)
 WebQuest
o Web Quest sheet (attached)
o Access to the Internet
 Surface water & pollution study
o Surface water photos and questions (attached)
 pH Basics
o pH strips or pH meter
o solutions for pH station – use a selection of 5-6 solutions of acids and
bases
 lemon or lime juice--acidic
 any fruit juice—acidic
 soda pop--acidic
 baking soda in water--basic
 table salt in water--should be close to neutral, but may be slightly
basic
 vinegar--acidic
 hand soap--basic
 any soaps/detergents--basic
 tap water--on a public system should be buffered around 7.3; if
from a well could be different (posing a good question to
students!)
 bleach--very basic**may be too hazardous (use your discretion)
 toilet bowl cleaner--very acidic**may be too hazardous (use your
discretion)
o plastic cups for solutions (one/solution)
o Student sheet (attached)
 Design an Aquifer:
o Plastic cups (one/student)
o Gravel (one cup/student)
o Sand (one cup/student)
o Measuring cup
o Water
o Bucket for water waste
o Old newspaper for drying out sand
o Aquifer handout (attached)
 Science Journals
 Acid Rain Effects (to be assembled as a center and explored over the
following week or so)
o Vinegar
o Water
o 50 ml beakers
o Large plastic cups with drainage holes poked in bottom or pots – 3 for
each student or group
o Radish seeds – 9 for each set of pots/cups
o Potting soil
o A sunny spot or grow light
For Elaboration activity:
 Who Polluted the White River? See attached for materials.
Lesson Introduction & Background Information:
Water is a requirement for all life. Over 70% of the human body is water and
over 70% of the earth’s surface is covered by water. The majority of the earth’s water
(97%) is in the oceans; the remainder exists as freshwater. Seawater is unavailable for
wildlife or human use, except in marine species and after desalination, a very costly, thus
generally prohibitive, procedure. Therefore, life depends upon a very small amount of
water.
For humans, freshwater is a requirement in a number of areas. Most of the
world’s freshwater is used for agriculture (70%). Industry takes up 22%, while domestic
use requires the remaining 8%. However, throughout the different countries of the world,
these numbers vary. In low income countries, such as those throughout Africa, Asia,
South and Central America, an average of 87% of the freshwater is used for agriculture,
leaving 8% for industry and 5% for domestic uses. In high income countries, such as
Western Europe and North America, on average only 30% is required for agriculture,
59% for industry and 11% for domestic use.
The proportion of use throughout the world varies because of population,
infrastructure and economics, but also because of the uneven distribution of freshwater.
For example, Algeria, a “water scarce” country, withdraws 142 m^3/capita/year; Niger, a
“water stressed” country, withdraws 46 m^3/capita/year; and Sudan, with no threat to
availability, 597 m^3/capita/year (http://www.worldwater.org/waterData.htm). Algeria
and Sudan are similar in size and population, yet fall in arid-semi-arid and tropical zones,
respectively. Niger is about half the size in land and population and falls in an arid zone
(http://www.countrywatch.com/cw_regions.asp?REGION=1).
Freshwater is divided into surface water (glaciers, lakes, rivers and streams) and
groundwater (aquifers). Only a small percentage of the total freshwater is readily
available for human use (.03% of the world’s total water amount). Most students are
familiar with surface water, but few are familiar with groundwater.
Groundwater
Water that filters underground from precipitation or from surface water is
groundwater. It moves below ground, downward due to gravity and horizontally, due to
the tilt of the underground geology. It may also eventually seep into bodies of surface
water (lakes, stream and oceans).
Groundwater is held in the pores between rocks and soil particles. The size of the
pores determines how much water is held and how quickly it flows. These pores may be
saturated or unsaturated with water. The top level of saturated pores is the water table.
The water table may fluctuate due to precipitation and groundwater extraction.
http://ga.water.usgs.gov/edu/earthgw.html
The storage mechanisms of groundwater are aquifers. Aquifers are underground
geologic formations that can hold, transmit and yield water. Aquifers are generally made
by confining layers (layers of material, such as clay, that are impermeable to other
substances), by unconfined layers (such as silt, sand or gravel) that filter infiltrating
water, or a combination of both. However, groundwater can become polluted by toxic
substances, such as pesticides, gasoline additives, or other chemicals, that cannot be
filtered by soil or that occur in such great quantities overwhelm the filtering capacity of
soil. In such cases, groundwater is dangerous for human consumption.
Another threat to groundwater is the depletion of aquifers, or groundwater
mining. Humans extract groundwater by wells. Wells drilled into confined aquifers
result in artesian wells because of the high pressure in the pressurized rock. Water can
literally blast out without any aid of a pump.
Groundwater is constantly restored by surface water infiltration or percolation
from precipitation or surface water. However, when groundwater is withdrawn faster
than it is restored, such as the case on a large scale in Texas and Arizona, aquifers
become depleted. This can also happen on a smaller scale to individual homeowners
whose wells “run dry.” The U.S. has a large supply of groundwater, holding 96% of its
freshwater total (http://www.in.gov/idem/enviroed/lessonplans/water.html).
Surface Water
Surface water faces the same pollution risks as groundwater. Many human
activities are having a negative affect on condition of surface waters throughout the
world. Farming, deforestation, industry, vehicles, recreation, and lack of sewage systems
all damage the cleanliness of surface water. While groundwater has the protection of
filtering layers and time, the only protection between surface water and pollution are the
human-created barriers. In many situations, these barriers simply do not exist. When
surface waters become polluted, wildlife cannot be supported. Certain plants and animals
can tolerate higher levels of pollution, but as pollution compounds, no wildlife can be
supported. For example, a cyanide spill in Romania has killed everything, down to the
bacteria, in the Tisza River. Waters through Hungary and Yugoslavia have slowly
become infected, and the polluted waters now threaten Europe’s second largest river, the
Danube (http://news.bbc.co.uk/1/hi/world/europe/642880.stm).
In this lesson your students will be exploring surface water in a watershed model.
A watershed is the land area that drains water to a common body of water (stream, river,
lake or ocean). Watersheds are delineated by ridges and vary in size depending upon the
topography. Watersheds vary in size and smaller watersheds are simply part of another,
larger watershed. For example, the White River watershed is part of the Wabash
watershed, which is part of the Ohio watershed, which is part of the Mississippi
watershed.
Acid Rain
Your students will also explore one form of human-created pollution that affects
water, acid rain. “Acid rain” (acids that fall out of the atmosphere) occurs in wet and dry
forms. The wet form is fog, rain, or snow. The acidic water flows over and through the
ground and affects a variety of plants and animals. The strength of the effects depend on
many factors, including how acidic the water is, the chemistry and ability of the soil to
resist change in pH, as well as the types of fish, trees, and other living things that rely on
the water.
The dry form refers to acidic gases and particles. About half of the acidity in the
atmosphere falls back to earth through dry deposition. The wind blows these acidic
particles and gases onto buildings, cars, homes, and trees. These gases and particles may
also be washed from trees and other surfaces by precipitation, compounding acid to acid
in the acid rain, making the combination more acidic than the falling rain alone.
Wind is also a function in the affects of acid rain. The acid compounds are blown
to places other than where the compounds were produced, spreading the disturbance.
Acid rain results from the burning of fossil fuels. Coal, natural gas, and oil omit
sulfur dioxide (SO2) (Sox) and nitrogen oxides (NOx) (Nox) when burned. The largest
culprits in Sox and Nox are energy producers and vehicles. Cleaning up the omissions
from power plants and vehicles and relying more on renewable energy (wind, solar and
hydropower), are the best ways to reduce acid rain.
http://www.epa.gov/airmarkets/acidrain/
Acid rain is measured by pH. pH is a logarithmic scale that runs from 1-14,
growing less acidic (more alkaline) as the numbers increase. Pure water has a pH of 7;
rain water has a pH of 5.5 (because of the carbon dioxide dissolved in it); acid rain in the
US runs about 4.3 (http://www.epa.gov/airmarkets/acidrain/). In this activity, your
students will explore the pH of different, common mixtures. They will make a non-toxic
simulation of acid rain and will monitor its affect on plants.
Procedures:
1. Engage your students in Where in the World is the Water? (adapted from Water,
Water, Everywhere?, IDEM)
a. Prepare before class 9 1,000 ml containers (beakers work best). Label
them: ocean, icecaps/glaciers, groundwater, saline lakes, freshwater lakes,
soil moisture, atmosphere & rivers. Label the 9th jar “All the water in the
world” on one side; “Currently useable freshwater” on the other side.
(You can also break students into groups so that each group has their own
set.) Fill up the 9th beaker with 1,000 ml of water.
b. Ask students to guess how the world’s water is divided into each of the
categories. Place those amounts into the containers. Next demonstrate the
true division (or print chart and hand out to individual groups to do):
Source
Amount in ml
Oceans
973
Icecaps/glaciers
21
Groundwater (to 13,000 ft) 6.1
Saline lakes
0.08
Freshwater lakes
0.09
Soil moisture
0.05
Atmosphere
0.01
Rivers
Can’t be measured
http://ga.water.usgs.gov/edu/earthwherewater.html
Percentage of Total
97 (approximate)
2.1
0.6
0.1
0.1
0.005
0.001
0.0001
The original beaker should now be empty.
c. Ask students which of these are currently and realistically useable.
d. Turn jar to reveal “Currently useable freshwater” and put back in it the
groundwater, freshwater lakes, soil moisture, and river water. A total of
0.3% of the world’s water is useable by humans.
e. Discuss with students what we use water for and compare to the amount of
what is available.
2. Exploring freshwater. Before class, prepare several different centers in which
your students can explore different forms of and issues regarding freshwater.
Students need at least 10 minutes for each station.
a. Design an aquifer
b. WebQuest for surface water
c. Exploring a watershed
d. Surface water
e. Learning about pH
f. Acid Rain Effects
g. Journaling
3. Discuss what the students discovered at each of stations. (See Background
Information.) Go through any as a group, as necessary.
4. Continue to explore acid rain. Using the samples from the Acid Rain Effects
Center, watch the affects of acid rain (in the form of vinegar) on seeds and plants.
(Adapted from: http://web.stclair.k12.il.us/splashd/acradexp.htm) This is a good
time to inform your students from the Background Information.
5. Bring together all of the activities in Who Polluted the White River? (Attached)
Assessment Questions:
1. Explain the importance of conserving freshwater, and keeping it free of pollution.
How is it even more important in certain areas?
2. If there was not any freshwater on Earth, how would that affect agriculture and
industries? How would that affect life on Earth, including humans, plants, and
animals?
3. Although about 75% of the earth is covered with water, explain why people
throughout the world are focused on water pollution and conservation as an important
issue.
4. Explain two human activities that have an impact on the whole environment. How do
these activities impact wildlife?
Extensions:
 Model the watershed on your local watershed using topographical maps.
 Use aquatic or terrestrial invertebrates instead of plants to monitor the affects of
pH on wildlife.
 Learn about the factors that affect water quality and participate in a water quality
monitoring. Go to http://www.in.gov/dnr/soilcons/riverwatch/ for more
information.
 Make the pollution of the watershed into a WhoDunit?
Connections:
This lesson could have additional applications in Social Studies – including geography,
economics, and history; chemistry; and made into a creative writing assignment.