DNA
What are the environmental
issues associated with the
Three Gorges Dam?
Water Pollution
How can we keep
dinosaur pee clean?
Agenda
1.
DNA
2.
LC – Three Gorges Dam
3.
N – freshwater pollution
4.
V – Sewage treatment plants
5.
A – freshwater GW
6.
L – prelab: oil spills
Homework
• Water taboo cards due 2/24 ; 2/25
(VOCABULARY POSTED ONLINE NOW!)
• Student-Led-Conferences handout due 2/20 ;
2/23
• Bring in supplies for oil spill lab due 2/20 ; 2/23
• Complete Virtual Tour: Hyperion Treatment
Plant 2/20 ; 2/23
Most infamous dam: Three
Gorges Dam in China
• Lit © protocol:
• Discussion facilitators take the lead by introducing their
reading to the group and starting the discussion with a
multi-faceted, open-ended question
• Students share and have a discussion that grows
organically from one conversation point to another
• Once Lit ©s have begun, they will last for 15 minutes
Lit © reflection:
• Thank you for sharing your insights today
• Please reflect on the following questions on a separate
sheet of paper:
• What was an important contribution you made to the discussion
today?
• What was an important idea or explanation expressed by
someone else during the discussion?
• Were you a careful and caring listener who gave speakers
complete attention when they were speaking?
Lit © reflection ?s, larger:
• What was an important contribution you
made to the discussion today?
• What was an important idea or explanation
expressed by someone else during the
discussion?
• Were you a careful and caring listener who
gave speakers complete attention when they
were speaking?
Review:
Water pollution – any change in water
quality that can harm living organisms or
make the water unfit for human uses such
as irrigation and recreation
Water pollution can enter through
point or nonpoint sources
Point sources: drain pipes, sewer lines,
factories, sewage treatment plants,
underground mines, oil tankers
Nonpoint sources: cropland, livestock
feedlots, logged forests, urban streets,
parking lots, lawns, golf courses
Worst water polluters
1. Agricultural activities
2. Industrial facilities
3. Mining
Climate change will make
water pollution even worse
• Some areas will get more precipitation, while others
get less
• Intense downpours can flush more harmful
chemicals, plant nutrients, and microorganisms into
waterways
• Prolonged drought can reduce river flows that
dilute wastes (spread infectious diseases more
rapidly)
Water is polluted by disease-causing
agents, oxygen-demanding wastes, plant
nutrients, organic and inorganic
chemicals, sediment, and excess heat
• Exposure to infectious disease organisms
(pathogens)
• Not having enough water for effective
sanitation
Some sobering facts
• 2010, UN: unsafe water kills more people
than war and all other forms of violence
combined
• WHO: 1 in 7 people do not have access to
clean drinking water
• WHO: 3.2 million people die prematurely
every ear from infectious diseases spread
by contaminated water
More sobering facts
• Diarrhea kills a child under the age of 5
every 18 seconds
• UN estimates that it would cost $23 billion
per year over 8-10 years to bring low-cost
and safe drinking water and sanitation to
those who do not have it
Using tech to solve problems
Using tech to solve problems
Using tech to solve problems
• LifeStraw Water Filter
• 0.2-micron filter physically
removes 99.9999% of all
bacteria, such as
salmonella, cholera and
E.coli; removes 99.9% of all
protozoa, such as giardia
and cryptosporidium
Does your water have pathogens?
• Safe for drinking = 100 mL sample of water
should have no colonies of coliform bacteria
• Safe for swimming = 100 mL sample of water
should have no more than 200 colonies of
coliform bacteria
• Raw sewage can contain millions of colonies
Testing water for pathogens
1. Low Dissolved Oxygen (DO) levels indicate
potentially more bacterial colonies
2. Chemical analysis by looking for specific
chemicals
3. Indicator species
4. Bacteria and yeasts are being engineered to
glow in the presence of specific water
pollutants
Testing water for pathogens
1. Low Dissolved Oxygen (DO) levels indicate
potentially more bacterial colonies
2. Chemical analysis by looking for specific
chemicals
3. Indicator species
4. Bacteria and yeasts are being engineered to
glow in the presence of specific water
pollutants
Pollution of freshwater streams
Flowing streams can recover from a
moderate level of degradable water
pollutants if they are not overloaded and
their flows are not reduced
Natural dilution and biodegradation
processes do not eliminate slowly
degradable and nondegradable pollutants!
Explain the graph
With your elbow partner, read the oxygen
sag curve
Independently, write a 4-sentence
summary of what the curve is depicting
You may use some sentence starters to
help you out:
Sentence stems for Oxygen Sag Curve
• The ____ curve represents the __________,
which is ______ in the _____ zone and then…
• The organisms present in the ____ zone seem
to be ______ tolerant of waste. This is inferred
from __________________.
• The types of organisms ____ the point of waste
is _________ than the organisms _____ the point
of waste.
Explain the graph
With your elbow partner, read the oxygen
sag curve
Independently, write a 4-sentence
summary of what the curve is depicting
You may use some sentence starters to
help you out:
Sewage Treatment Plants
Gallery Walk: Freshwater pollution
• Read and summarize your group’s article
• Create a mini poster with your summary
and highlights
• Everybody writes in their own color
• We will complete a gallery walk towards
the end of class