Unit D

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Grade 8 Water Systems

• Unit D

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Where does the water we drink come from?
3
Big Ideas of Water Systems

• Water is crucial to life on Earth
• Water systems influence climate and weather
  patterns
• Water is an important resource that needs to be
  managed sustainable
• Chapter 10 Safe Drinking Water
• Chapter 11 Water Quality
• Chapter 12 Water, Weather, and Climate

4
Safe Drinking Water - Introduction

• Why is it often unsafe to drink water directly
  from nature?
• Why cant fresh water just be pumped into our
  homes?
• What do you think must happen in order for water
  to be safe for humans to consume?

5
KEY QUESTION

• Where does water come from?
• Suggestions?

6
Looking Ahead

• We use water in many different ways ever day.
• Water circulates around Earth in the water cycle.
• The skills of analysis can be used to determine
  personal water use and ways to reduce water use.
• Water must be treated before it is safe to drink.
• The skills of technological problem solving can
  be used to design and build a sample water
  filtration device.
• The media report on water-related issues in
  different ways.

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Vocabulary

• Water cycle
• Melting
• Sublimination
• Evaporation
• Condensation
• Deposition
• Freezing
• Runoff
• Groundwater

• Aquifer
• Water table
• Precipitation
• Polar ice sheet
• Icecap
• Glacier
• Water treatment
• Floc
• Sustainability

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10.2 What is Water?

• OBJECTIVE Demonstrate an understanding of the
  characteristics of the earths water systems and
  the influence of water systems on a specific
  region
• Does water always look clean and pure?
• Clean vs. Dirty water sample

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Why do we need water?

• Helps the body transport substances to all the
  tissues and organs
• Needed in order for chemical reactions to take
  place
• Keeps the body cool
• Essential for our health

10
Describing Water

• Most water in nature is not pure
• Some have a different colour or smell to them
• They are usually a mixture of water and other
  substances
• Some substances mixed with water are needed and
  some are dangerous

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The Water Particle

• Made up of HYDROGEN and OXYGEN (H2O)
• These particles are joined together

12
States of Water

• Solid (ice) definite shape water particles
  cannot move freely
• Liquid (water) particles vibrate faster free
  to move around
• Gas (water vapour) particles are very far
  apart have a lot of energy and move quickly in
  all directions
• They all behave differently

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Page 269 - Homework

• Describe a particle of water. What other
  particles make up a particle of water?
• You are given a sample of tap water that is
  clear, yellowish, and odourless. Is this a sample
  of pure water? Explain.
• Choose one of the states of water
• Draw a labeled diagram to show the arrangement of
  water particles in this state.
• Describe the arrangement of water particles in
  this state

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Page 269 - Homework

• Describe a particle of water. What other
  particles make up a particle of water?
• You are given a sample of tap water that is
  clear, yellowish, and odourless. Is this a sample
  of pure water? Explain.
• Choose one of the states of water
• Draw a labeled diagram to show the arrangement of
  water particles in this state.
• Describe the arrangement of water particles in
  this state

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10.3 The Water Cycle

• Water vapour is an invisible gas
• Steam coming off of a boiling kettle is not water
  vapourit is condensed liquid water
• Water vapour that escapes from a kettle is
  invisible, but, outside the kettle, the water
  vapour quickly condenses when it meets the cooler
  air to form a mist that we call steam

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Changes of State

• Handout
• Melting change of state from a solid to a
  liquid solid gains more thermal energy
• Sublimination change of state from a solid to a
  gas without first becoming a liquid solid gains
  thermal energy
• Evaporation change of state from a liquid to a
  gas liquid gains thermal energy
• Condensation change of state from a gas to a
  liquid gas loses thermal energy
• Despoition change of state from a gas to a
  solid gas loses thermal energy
• Freezing change of state from a liquid to a
  solid liquid loses thermal energy

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Changes of state
Increasing thermal energy of particles
SUBLIMINATION
Condensation
Freezing
Melting
Evaporation
SOLID
LIQUID
GAS
DEPOSITION
Decrease thermal energy of particles
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Melting, Evaporation and Sublimination in Nature

• Runoff Water from precipitation and melting snow
• Groundwater water that comes through soil and
  cracks in rocks underground springs and wells
• Aquifer a geological formation of loose rock or
  soil that is saturated in groundwater
• Water table loose rock and soil below the
  Earths surface are saturated with water

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Condensation, Freezing, and Deposition in Nature

• Precipitation solid or liquid water that falls
  to Earths surface
• Polar ice sheet sheet of ice covering the North
  or South Poles
• Icecap a large block of ice that permanently
  covers land
• Glacier a river of ice formed from snow moves
  slowly downhill

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Page 273 - Homework

• Look at Figure 2. Where can you find each of the
  three states of water?
• Describe the water cycle. Draw your own labelled
  diagram.
• Briefly describe how solid and liquid water may
  be converted to water vapour.
• Describe how water vapour changes into solid and
  liquid water above Earths surface.
• Does all surface runoff move directly into
  rivers, lakes, and oceans? Explain.

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Page 273 - Homework

• Look at Figure 2. Where can you find each of the
  three states of water?
• Describe the water cycle. Draw your own labelled
  diagram.
• Briefly describe how solid and liquid water may
  be converted to water vapour.
• Describe how water vapour changes into solid and
  liquid water above Earths surface.
• Does all surface runoff move directly into
  rivers, lakes, and oceans? Explain.

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10.5 Making Water Drinkable

• What do you think is involved in the water
  treatment process?
• What are some different methods to make our water
  drinkable?
• In this section, we will be learning about the
  process for treating wastewater or sewage in a
  water treatment plant

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The Water Treatment Process

• Remove large objects from the water the screen
  at the end of the tube blocks large objects from
  entering
• Water enters a large tank where a chemical is
  added (alum) alum make clumps in the water where
  most of the waste goes to (floc)
• Water and floc enter a settling tank floc
  settles to the bottom
• Partially clean water moves through a sand and
  charcoal filter which removes remaining waste
  solids and small pieces water is now clear,
  colourless and odorless
• Water still may contain some bacteria and so
  chlorine and ozone can be added to kill these
  organisms
• The water is ready to use

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Other Treatment Options
Type of Treatment How it works When it is used
Reverse Osmosis
Ultraviolet (UV) Radiation
Water Softening
Boiling
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Page 278 - Homework

• List and describe the six main steps that water
  goes through in the water treatment process.
• Is clear, colourless, and odourless drinking
  water always safe to drink? Explain.
• Describe how the membrane works in the reverse
  osmosis process. Use a labeled diagram in your
  description.
• Why is it important to ensure that treated water
  remains safe to drink when it is stored after
  treatment?
• Describe one way to make stored water safe.

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Page 278 - Homework

• List and describe the six main steps that water
  goes through in the water treatment process.
• Is clear, colourless, and odourless drinking
  water always safe to drink? Explain.
• Describe how the membrane works in the reverse
  osmosis process. Use a labeled diagram in your
  description.
• Why is it important to ensure that treated water
  remains safe to drink when it is stored after
  treatment?
• Describe one way to make stored water safe.

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Chapter 10 Review

• Page 284 and 285
• Review questions 1-12
• Chapter 10 Quiz on _______________

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Chapter 11 Water Quality

• What does polluted water look like?
• Does it always look dirty?
• Some substances and micro-organisms that pollute
  our water are not always visible
• It may look clean but there is sill a possibility
  that it can be dirty

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Chapter 11 Intro Photo

• What is shown in the picture?
• What pollutants can you see in the water?
• How might have these pollutants enter the body of
  water?

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KEY QUESTION

• What substances are in water, and where do they
  comes from?

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Looking Ahead

• Only a tiny fraction of the water on Earth is
  fresh water available for out use.
• Water can contain many ifferent contaminants.
• The skills of scientific inquiry can be used to
  test water quality.
• Water must be used sustainably.
• Wastewater must be treated before being returmed
  to the environment.

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Vocabulary

• Salinity
• Concentration
• Desalination
• Contaminant
• Fertilizer
• Herbicide
• Pesticide
• Turbid

• Thermal pollution
• Watershed
• Bioremediation
• Sewer system
• Blackwater
• Greywater
• Wastewater
• Stormwater runoff

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11.1 Fresh Water and Salt Water

• Can we drink salt water?
• Large quantities can be deadly
• Kidneys dont have the ability to process a high
  concentration of salt

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Salt Water vs Fresh Water

• Salt Water

• Fresh Water

• Contains a lot of salt
• Swimmers can easily float in the water
• Has a lot of salinity (the amount of salt in the
  water)
• Has a greater density

• The salinity in fresh water is less than 1

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Try This Activity

• Materials
• Small graduated cylinder
• 2 cups or small bowls
• Marker
• Teaspoon
• tap water
• 2 paper labels
• Salt

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Page 291 - Homework

• What percentage of water on Earth is fresh water?
• Describe two special characteristics of salt
  water.
• Why are engineers developing desalination
  technologies?
• Briefly describe a desalination process.
• What can make desalination expensive?
• Name two renewable energy sources that can be
  used in desalination.

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Page 291 - Homework

• What percentage of water on Earth is fresh water?
• Describe two special characteristics of salt
  water.
• Why are engineers developing desalination
  technologies?
• Briefly describe a desalination process.
• What can make desalination expensive?
• Name two renewable energy sources that can be
  used in desalination.

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11.2 Contaminants in Water

• How does water become polluted?
• Where are some specific places where water is
  contaminated?
• Contaminants an unwanted substance in a mixture
• What human activities have an effect on water
  sources?
• Farming, road salting, garbage dumping, burning
  fossil fuels, etc.

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Sources of Chemical Contaminants

• Salt
• Minerals
• Fertilizers
• Herbicides and Pesticides
• Acid Rain
• Other Toxic Chemicals

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Salt

• Can come from road salt, gravel, and sand in the
  winter
• When the snow melts, it carries the salt into
  nearby forests on washes into bodies of water

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Minerals

• Can come from rocks that dissolve into water
• Limestone (example) is a soft rock that
  dissolves in water which adds calcium carbonate
  to the water

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Fertilizers

• Fertilizer a substance used to give nutrients to
  plants, usually to increase crop production
• Fertilizers can be carried during rainfalls to
  streams and lades

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Herbicides and Pesticides

• Herbicides a chemical substance used to kill or
  slow the growth of certain plants, often used to
  kill weeds that compete with crop plants
• Pesticides a chemical substance used to kill
  animal pests, often used to kill insects that
  damage crops
• Ex DDT (kills flies, mosquitoes and potato
  beetles)

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Acid Rain

• Chemicals that are released into the air from
  burning of fossil fuels
• These chemicals reach with water vapour to form
  acid rain

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Other Toxic Chemicals

• Transportation industry
• Garbage dump and sewage
• Ship spills (oil spills)

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Sources of Biological Contaminants

• Manure
• E-coli (damages local water)
• Local water containing parasites
• Animal feces

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Page 295 - Homework

• Name two parts of the water cycle in which
  contaminants can be introduced.
• What are the two main categories of contaminants
  in water?
• Why are they a problem?
• Choose 2 chemical contaminants that could be
  found in a freshwater source. For each one,
• Identify a source of the contaminant
• Describe how the contaminant got into the water
• Briefly describe how a biological contaminant was
  able to get into groundwater wells at Walkerton.

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Page 295 - Homework

• Name two parts of the water cycle in which
  contaminants can be introduced.
• What are the two main categories of contaminants
  in water?
• Why are they a problem?
• Choose 2 chemical contaminants that could be
  found in a freshwater source. For each one,
• Identify a source of the contaminant
• Describe how the contaminant got into the water
• Briefly describe how a biological contaminant was
  able to get into groundwater wells at Walkerton.

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11.3 Testing Water Quality

• Water quality is an indicator of how good or bad
  the water in a certain system is
• What would you classify as good water?
• What would you classify as bad water?

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When Testing Water

• Look at the turbidity
• Test the temperature
• Find out the acidity of the water (pH)
• Test the salt content (salinity)
• Look for other dissolved substances in the water

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Turbidity

• Turbid not clear containing tiny specks of
  sediment or other solid matter
• Makes the water cloudy
• Clear water is better than turbid water

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Temperature

• Warm water contains less dissolved oxygen than
  cold water
• Thermal pollution increasing the temperature of
  the water (kills the bacteria)

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Acidity

• Water is acidic if it contains chemicals such as
  sulfuric acid or nitric acid
• We can measure the acidity with an indicator that
  has a different colour for every pH level
• Water is acidic if its pH is below 7 basic if
  it is above 7

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Salinity

• You need a conductive apparatus
• Electricity is used

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Other Dissolved Substances

• Chlorine
• Nitrates
• Iron and copper
• Calcium and magnesium

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Page 297 - Homework

• List at least three factors mentioned in this
  section that decrease water quality.
• How can you test a water source to see whether it
  is acidic or not?
• What is thermal pollution? How do nuclear power
  plants contribute to thermal pollution?
• How could each of the following substances enter
  a freshwater source?
• Chlorine - calcium
• Nitrates - acid

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Page 297 - Homework

• List at least three factors mentioned in this
  section that decrease water quality.
• How can you test a water source to see whether it
  is acidic or not?
• What is thermal pollution? How do nuclear power
  plants contribute to thermal pollution?
• How could each of the following substances enter
  a freshwater source?
• Chlorine - calcium
• Nitrates - acid

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11.4 Watersheds

• The highest parts of North America are called the
  continental divides
• The divide the waters on each side, which helps
  the water flow downwards
• 80 of Canadas surface water goes towards the
  Arctic Ocean
• Figure 1

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Watershed

• Watershed an area surrounded by high land and
  drained by a river and its area all the runoff
  in the watershed leaves the watershed at the same
  exit
• Read page 299 and 300

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Page 300 - Homework

• Describe how a continental divide affects the
  direction of water flow over land.
• Name a continental divide, and describe where it
  is.
• Explain the meaning of the term watershed.
• Briefly describe the role of a Conservation
  Authority.
• What is the process called in which organisms are
  used to remove contaminants from the environment?

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Page 300 - Homework

• Describe how a continental divide affects the
  direction of water flow over land.
• Name a continental divide, and describe where it
  is.
• Explain the meaning of the term watershed.
• Briefly describe the role of a Conservation
  Authority.
• What is the process called in which organisms are
  used to remove contaminants from the environment?

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11.7 Wastewater Treatment

• Water goes through 5 stages of treatment
• Preliminary Treatment
• Primary Treatment
• Secondary Treatment
• Final Treatment
• Solids Processing

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Preliminary Treatment

• Wastewater passes through a bar screen which
  removes larger objects
• The wastewater is slowed down and put into a tank
  where it settles
• The sand, gravel and other heavy objects sink
• Water goes onto the next stage

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Primary Treatment

• The wastewater goes into a large settling tank
• Sits for several hours
• Solid particles settle at the bottom of the tank

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Secondary Treatment

• A process that removes organic matter from
  wastewater
• Oxygen is added which helps micro-organisms to
  grow which will eat the bacteria in the water
• Any remaining solids continue to settle on the
  bottom

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Final Treatment

• Wastewater is disinfected to kill harmful
  organisms
• Clean water is released into the lake

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Solids Processing

• The solids that were removed from the water in
  the primary and secondary treatment stages is
  sent to the digester
• After 15 days, bio-solids (wet, soil-like
  material) are sent to the landfill or are
  incinerated

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Types of Water

• Blackwater water that contains feces and urine
  also called sweage
• Greywater water that has been used for cooking,
  laundry, bathing, or similar tasks
• Wastewater water that has been used or
  contaminated by human activity blackwater and
  greywater
• Stormwater runoff water, usually from
  precipitation, that runs off roods, lawns and
  paved areas

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Page 307 - Homework

• Explain in your own words how greywater is
  different from blackwater.
• List two sources of wastewater.
• What is the purpose of the primary stage of
  sewage treatment?
• Explain the difference between a septic system
  and a sewage system.
• Explain the difference between a septic system
  and a sewage system.

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Chapter 11 Review

• Page 310 and 311
• Questions 1-10, and 13
• Quiz on ______________

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Ch 12 Water, Weather, and Climate

• What do you think of when you hear the word
  water?
• What do you think of when you hear the word
  weather and climate?
• Do changes in climate effect the changes in
  weather?
• Changes in climate do not necessarily cause
  immediate or predictable changes in weather (in
  the spring, the climate in Ontario is getting
  warmer, however, that does not mean that every
  spring day is warmer than the previous day)

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Chapter 12 Introduction

• What is in the picture on page 314?
• What is happening?
• Why do you think this is happening?
• Flooding has happened from the river which causes
  erosion which collapses the road
• What does this scene have to do with weather?
• More water than usual because of unexpected
  weather changes which causes the river to
  overflow and the road to break apart

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Looking Ahead

• The climate of a region and the weather on any
  particular day, are affected by large bodies of
  surface water
• Climate affects waters temperature and changes
  of state on Earth
• Research skills can be used to assess issues
  related to local and global water supply
• Global warming is affecting water systems around
  the world
• The long-term sustainability of water systems
  depends on how well we manage and care for water

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KEY QUESTION

• How do water systems, weather, and climate affect
  each other?

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Vocabulary

• Weather
• Climate
• Heat capacity
• Heat sink

• Convection
• Global warming
• Flood plain

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12.1 Surface Water and Climate

• OVERALL EXPECTATION Demonstrate an understanding
  of the characteristics of Earths water systems
  and the influence of water systems on a specific
  region
• What are factors that affect our climate?
• Distance from the equator
• How close we are to bodies of water
• Altitude (height above sea level)

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Facts

• What is the climate in areas that are higher
  above sea level?
• Coller climates
• Top of mountains are usually cooler
• What is the climate in areas that are close to
  bodies of water?
• Winds and ocean currents effect climate
• What is the climate like in areas close to the
  equator?
• Hotter climate

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What is the climate like where we live?
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What is the difference between weather and
climate?

• CLIMATE is what we expect (seasonal)
• WEATHER is what we get (day to day)
• Temperatures in Air and on Land Activity?

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Weather and Climate

• Weather day-to-day environmental conditions in a
  given place at a given time includes
  temperature, cloud cover, wind speed, and
  precipitation
• Climate an average of weather conditions in an
  area over 30 years

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Causes of Temperature Differences

• How much energy is coming from the sun
• Different seasons

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Heat Capacity

• The Earth supports life because of its heat
  capacity
• Heat capacity a measure of the amount of thermal
  energy needed to increase temperature how much
  thermal energy an object can hold
• the higher the heat capacity of a substance, the
  more thermal energy it can store
• Soil and rock can not store as much heat as
  water they need less thermal energy to heat up
• Gravel or rocks release thermal energy faster
  than water

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Heat Sinks and Climate

• Heat sink matter that absorbs thermal energy but
  does not change state or significantly increase
  in temperature
• Water (energy is always moving around and energy
  goes through the entire body)
• Ocean water never really heats up (it does get
  warm)
• Convection circulating currents heat up the gas
  or liquid from fast or slow moving particles
• Water circulates
• Air circulates

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Page 319 Homework

• What is the difference between weather and
  climate?
• Explain in your own words how the heat capacity
  of water makes any body of water a good heat
  sink.
• Describe how warm water at the surface of a lake
  or ocean mixes with deeper, cooler water.
• Why do areas close to large bodies of water have
  milder climate than inland?

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t
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Page 319 Homework

• What is the difference between weather and
  climate?
• Explain in your own words how the heat capacity
  of water makes any body of water a good heat
  sink.
• Describe how warm water at the surface of a lake
  or ocean mixes with deeper, cooler water.
• Why do areas close to large bodies of water have
  milder climate than inland?

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12.2 Glaciers, Polar Ice and Global Warming

• Are greenhouse gases and global warming the same
  thing?
• Nothe greenhouse effect has an effect on global
  warming but they are not the same thing
• What is the greenhouse effect?
• Carbon dioxide and methane are some examples of
  greenhouse gases
• More thermal energy gets trapped in the
  atmosphere

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What do you already know about global warming?
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The Effects of Climate Change

• When climate is cold, there is an ice build up on
  glaciers more ice covers the land
• If there is more precipitation or if more ice
  melts, then the ice coverings start to melt
• Global Warming an increase in the Earths
  average atmospheric temperature

99
What happens in Canada?

• Global warming is lowering the water levels in
  Lake Ontario
• Water is evaporating quickly

100
El Nino

• A large current of warm water that forms in the
  Pacific Ocean
• Warm water current moves north which warms the
  air above
• Warm air moves inland which can increase the
  temperatures in winter
• Less snow and precipitation

101
Storms and Hurricanes

• Warm air currents that develop into hurricanes
• Hurricane winds push ocean water around to create
  storms

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Page 322 - Homework

• The Athabasca Glacier in Western Canada continues
  to shrink every year. What does this suggest
  about the climate in that region? Explain your
  answer.
• In your own words, explain how rising sea levels
  are an indication of global warming.
• Explain what is happening to water levels in the
  Great Lakes.
• What is El Nino? Describe the effects of El Nino
  on Canadian weather.
• Explain how hurricanes form.

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Page 322 - Homework

• The Athabasca Glacier in Western Canada continues
  to shrink every year. What does this suggest
  about the climate in that region? Explain your
  answer.
• In your own words, explain how rising sea levels
  are an indication of global warming.
• Explain what is happening to water levels in the
  Great Lakes.
• What is El Nino? Describe the effects of El Nino
  on Canadian weather.
• Explain how hurricanes form.

105
12.4 Floods and Droughts

• Floods

• Droughts

• Caused by heavy rainfall or rapid snow melt
• Add moisture to dry land, provide nutrients, etc.

• Caused by dry weather conditions where water
  evaporates faster than it is replaced
• Can cause forest fires

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Floods

• Type 1 Rapid snowmelt or heavy rain
• Type 2 Flash floods are the most deadly and
  damaging
• Produced by a sudden storm
• Type 3 Storm surges are floods that occur along
  coastlines when hurricanes come ashore
• Very dangerous
• One came after Hurricane Katrina which killed and
  destroyed many
• Type 4 Ice jam floods usually happen in the
  spring and is from river ice breaking up and
  being jammed into narrow parts of the river

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Preventing Floods

• New homes should not be built on flood plains
  (low area of land alongside a river)
• Using dams to control water

108
Droughts

• Less than 2.5 cm of precipitation annually
  desert
• 6 months or more with no rain or snow season
  drought
• Humans use it to drink and bottle water to sell
  and therefore we lose even more water

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Page 327 - Homework

• How are floods and droughts sometimes good for
  the natural environment?
• Briefly describe two strategies that would reduce
  the chances of homes being damaged by floods.
• Does damming a river make the water source more
  sustainable? Explain your answer.
• What human activities worsen the effects of
  drought?
• How does soil compaction affect the water system?

110
12.6 Water is Life

• A lot of people do not have access to water while
  others over use it
• Worlds first Water Day March 22, 2005

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Page 330 - Homework

• Describe, in your own words, the United Nations
  Millennium Declaration on water rights.
• Explain how buying and selling water conflicts
  with the idea that access to clean water is a
  basic human right.

112
Chapter 12 Summary

• Page 334 and 335
• Questions on page 336 and 337, 1-10

113
Unit D Summary

• Questions on page 340 and 341
• 1-8, 10 and 13
• Unit D test on _____________